The present invention relates generally to an environmental control unit for use in air handling systems that provides highly effective filtration of noxious gases (such as ammonia). Such a filtration system utilizes novel metal-doped silica-based gels to trap and remove such undesirable gases from an enclosed environment. Such gels exhibit specific porosity requirements and density measurements. Furthermore, in order for proper metal doping to take effect, such gels must be treated while in a wet state. The combination of these particular properties and metal dopant permits highly effective noxious gas filtration such that uptake and breakthrough results are attained, particularly in comparison with prior silica gel filtration products. Methods of using and specific filter apparatuses are also encompassed within this invention.

There is an ever-increasing need for air handling systems that include air filtration systems that can protect an enclosure against noxious airborne vapors and particulates released in the vicinity of the enclosure. Every year there are numerous incidents of noxious vapors contaminating building environments and causing illness and disruptions. There is also a current effort to protect buildings and other significant enclosures against toxic airborne vapors and particulates being released as part of terrorist acts. As a result, new filter design requirements have been promoted by the military to protect from certain toxic gases. Generally speaking, whether in a civilian or military setting, a typical air filtration system that contains only a particulate filter (for example, a cardboard framed fiberglass matt filter) provides no protection at all against toxic vapors. Commercially available electrostatic fiber filters exhibit higher removal efficiencies for smaller particles than standard dust filters, but they have no vapor filtration capability. HEPA ("High-Efficiency Particulate Air") filters are used for high-efficiency filtration of airborne dispersions of ultrafine solid and liquid particulates such as dust and pollen, radioactive particle contaminants, and aerosols. However, where the threat is a gaseous chemical compound or a gaseous particle of extremely small size (i.e., <0.001 microns), the conventional commercially-available HEPA filters cannot intercept and control those types of airborne agents.
The most commonly used filter technology to remove vapors and gases from contaminated air is activated carbon. Such carbon-based gas filtration has been implemented in a wide variety of vapor-phase filtration applications including gas masks and military vehicle and shelter protection. In these applications, activated carbon impregnated with metal salts is used to remove a full range of toxic vapors (such as arsine, Sarin gas, etc.). These toxic gases require a high filtration efficiency typically not needed for most commercial applications. To the contrary, typical commercial filters generally include activated carbon materials on or incorporated within non-woven fabrics (fiber mats, for instance), with coexisting large fixed beds of packed adsorbent particles. Such commercial filters used for air purification generally are used until an easily measurable percentage (e.g., 10%) of the challenge chemical(s) concentration is measured in the effluent. Greater long-term efficiency is desired for gas masks and/or military vehicle applications.
Impregnated, activated carbons are used in applications where required to remove gases that would not otherwise be removed through the use of unimpregnated activated carbons. Such prior art impregnated carbon formulations often contain copper, chromium and silver impregnated on an activated carbon. These adsorbents are effective in removing a large number of toxic materials, such as cyanide-based gases and vapors.
In addition to a number of other inorganic materials, which have been impregnated on activated carbon, various organic impregnates have been found useful in military applications for the removal of cyanogen chloride. Examples of these include triethylenediamine (TEDA) and pyridine-4-carboxylic acid.
Various types of high-efficiency filter systems, both commercial and military types, have been proposed for building protection using copper-silver-zinc-molybdenum-triethylenediamine impregnated carbon for filtering a broad range of toxic chemical vapors and gases. However, such specific carbon-based filters have proven ineffective for other gases, such as, ammonia, ethylene oxide, formaldehyde, and nitrogen oxides. As these gases are quite prominent in industry and can be harmful to humans when present in sufficient amounts (particularly within enclosed spaces), and, to date, other filter devices have proven unsuitable for environmental treatment and/or removal thereof, there exists a definite need for a filter mechanism to remedy these deficiencies, particularly in both high and low relative humidity (RH) environments. Each chemical is affected differently by adsorbed water. For ammonia, it is most difficult (design limiting) to filter at a low relative humidity since adsorbed water actually enhances the ammonia affinity of the target adsorbents. For ethylene oxide the reverse is true since exposure to high humidity is problematic in designing a proper filter system. To date, no filtration system having a relatively small amount of filter medium present has been provided that effectively removes such gases at their design limiting RH for long durations of time at relatively high challenge concentrations (e.g., 1,000 ppm) without eventually eluting through the filter.
It has been realized that silica-based compositions make excellent gas filter media. However, little has been provided within the pertinent prior art that concerns the ability to provide uptake and breakthrough levels by such filter media on a permanent basis and at levels that are acceptable for large-scale usage. Uptake basically is a measure of the ability of the filter medium to capture a certain volume of the subject gas; breakthrough is an indication of the saturation point for the filter medium in terms of capture. Thus, it is highly desirable to find a proper filter medium that exhibits a high uptake (and thus quick capture of large amounts of noxious gases) and long breakthrough times (and thus, coupled with uptake, the ability to not only effectuate quick capture but also extensive lengths of time to reach saturation). The standard filters in use today are limited for noxious gases, such as ammonia, to slow uptake and relatively quick breakthrough times. There is a need to develop a new filter medium that increases uptake and breakthrough, as a result.
The closest art concerning the removal of gases such as ammonia utilizing a potential silica-based compound doped with a metal is taught within WO 00/40324 to Kemira Agro Oy. Such a system, however, is primarily concerned with providing a filter media that permits regeneration of the collected gases, presumably for further utilization, rather than permanent removal from the atmosphere. Such an ability to easily regenerate (i.e., permit release of captured gases) such toxic gases through increases of temperature or changes in pressure unfortunately presents a risk to the subject environment. To the contrary, an advantage of a system as now proposed is to provide effective long-duration breakthrough (thus indicating thorough and effective removal of unwanted gases in substantially their entirety from a subject space over time, as well as thorough and effective uptake of substantially all such gases as indicated by an uptake measurement. The Kemira reference also is concerned specifically with providing a dry mixture of silica and metal (in particular copper I salts, ultimately), which, as noted within the reference, provides the effective uptake and regenerative capacity sought rather than permanent and effective gas (such as ammonia) removal from the subject environment. The details of the inventive filter media are discussed in greater depth below.

Air filtration media comprising metal-doped silicon-based gel materials


The present invention includes a co-polymer film which can be applied over a surface of an article to form a continuous surface that is more biocompatible and has a smoother surface morphology than an untreated article. In general the co-polymer film of the invention can be formed by providing a hydrophobic polymer block, such as polydimethylsiloxane (PDMS) with functional xe2x80x94OH end groups and reacting the xe2x80x94OH ends with a conventional monomer or prepolymer of a film-forming polymer capable of reacting with xe2x80x94OH groups. Such reactions are exemplified, using as reactive PDMS a triblock copolymer of the polylactone-polysiloxane-polylactone (PL-PDMS-PL) type, or silicone polyesters. The xe2x80x94OH groups of the polylactone blocks can react with any of a variety of isocyanates in a suitable solvent to form a polymer having PDMS incorporated with its structure. The film can be applied to the surface of an article by any convenient means of coating the article with the reaction mixture in solvent, and allowing the solvent to evaporate.

The present invention relates to the basic problem that many of the biomedical devices used in contact with live tissue or body fluids are made of materials of synthetic or natural origin which are not biocompatible. Lack of biocompatibility can lead to blood clotting as well as various other manifestations of inflammation and tissue activation.
In addition, microbial infection can establish themselves on device surfaces. Infectious agents such as bacteria that colonize and form biofilms on surfaces can prove exceedingly difficult to eradicate, [Costerton, J. W. et al. (1999) Science 284:1318-1322]. Devices intended for long-term contact such as implanted stents or indwelling catheters can also serve as a surface for host cell adhesion, permitting host cells to become activated, proliferate or to alter normal physiological function and to restrict function or intended use of a device, for example by restricting fluid flow through the device.
An approach used in the prior art to improve biocompatibility has been based on modifying the surface of a device to make it more hydrophobic. On the other hand increased biocompatibility at least in part can be achieved by making a surface more hydrophilic. Although certain types of polymers, such as silicones and siloxanes, are known to possess many attributes of biocompatibility, there are no reliable physical correlates which enable one to predict biocompatibility with any degree of certainty. Generally, hydrophobic surfaces are more biocompatible than hydrophilic surfaces. Zisman""s critical surface tension [Zisman, W. A., (1964) Adv. Chem. Ser. 43] has been used as a parameter to help assess potential biocompatibility. Materials with an optimum critical surface tension are frequently biocompatible, yet there are notable exceptions. For example, polyethylene and polypropylene have critical surface tensions well within the optimum range, but they are not predictably biocompatible. Other factors are also important. Without a clear understanding of the nature of these factors, biocompatibility remains unpredictable.
Because of the attractive structural properties of polyolefins and polyurethanes, various blending and copolymerization techniques have been developed to impart greater biocompatibility. U.S. Pat. No. 4,872,867 discloses modifying a polyurethane with a water soluble polymer and crossing them in situ with a silane-type coupling agent to form a cross-linked and intertwined polysiloxane network. U.S. Pat. No. 4,636,552 discloses a polydimethyl siloxane with polylactone side chains which are said to be useful for imparting biocompatibility when combined with a base polymer, or used to replace plasticizer. U.S. Pat. No. 4,929,510 discloses a diblock copolymer having a more hydrophobic block and a less hydrophobic block. A solution of the diblock copolymer in a solvent which swells the matrix polymer is used to introduce the diblock into an article of matrix polymer. Thereafter, the article is transferred to water, to force orientation of the incorporated diblock copolymer such that the more hydrophobic block is embedded in the matrix and the less hydrophobic block is exposed on the surface of the article. Examples of diblock copolymers included poly (ethyleneoxide-propylene oxide), N-vinyl-pyrrolidone-vinyl acetate and N-vinyl-pyrrolidone-styrene. U.S. Pat. Nos. 4,663,413 and 4,675,361 disclose segmented block copolymers, in particular polysiloxane-polycaprolactone linear block copolymers. The latter were incorporated into base polymer material to modify the surface properties thereof. Although initially blended in bulk into the base polymer, the copolymer migrates to the surface to form an exceptionally thin, possibly a monolayer film which imparts the desired surface characteristic, specifically, biocompatibility.
Triblock copolymers having a polydimethyl siloxane (PDMS) block flanked by polylactone (PL) blocks have been described, Lovinger, A. J. et al. (1993) J. Polymer Sci. Part B. (Polymer Physics) 31:115-123. Such triblock copolymers have been incorporated into bulk formulations, and also applied as surface coatings, to reduce thrombogenicity, as described in U.S. Pat. No. 5,702,823, incorporated herein by reference. PL-PDMS-PL triblock copolymers are commercially available, for example from Thoratec Laboratories, Berkeley, Calif., which provides a series of such polymers designated xe2x80x9cSMAxe2x80x9d in which the siloxane is dimethyl siloxane and the lactone is caprolactone, and also from Th. Goldschmidt AG, Essen Germany, under the name xe2x80x9cTegomerxe2x80x9d (Trademark, Goldschmidt AG). The nominal molecular weights (number average) of the polysiloxane blocks suitable for use herein range from about 1000 to about 5000, while the nominal molecular weights of the caprolactone blocks range from about 1000 to about 10,000. Tsai, C-C. et al (1994) ASAIO Journal 40:M619-M824, reported comparative studies with PL-PDMS-PL blended into polyvinyl chloride and other base polymers or applied as a coating thereon.
Deppisch, R. et al (1998) Nephrol. Dial. Transplant. 13:1354-1359 reported improved thrombogenic properties for films or membrane structures of polyamide-polyvinyl-pyrrolidone, polyamide-polyarylethersulfone-polyvinylpyrrolidone or polyarylether-polyvinylpyrrolidone. Improved thrombogenic properties were attributed to a microdomain surface structure of hydropholic and hydrophilic surface patches.
U.S. Pat. No. 5,589,563 discloses polymers having surface-modifying end groups, for example, polyurethanes having hard segments and soft segments covalently bonded to end groups such as PDMS or aromatic polycarbonates. The surface-modifying end groups tend to concentrate on the polymer surface to increase the surface hydrophobicity.
More recently, it has been recognized that the interactions between biological substances and man-made materials leading to clotting, inflammatory responses and microbial and host cell reactions are more complex processes in which the surface hydrophobicity of the man-made material is but one factor. Interactions between biological materials and foreign substances have been shown to include, at a minimum, molecular interactions with components of the complement system, with the kallikrein-kinin system, with the intrinsic pathway of coagulation initiation, with platelet and with other cellular components of blood including peripheral blood cells, e.g. monocytes and granulocytes.
In addition, microbial growth and host cell activation and/or proliferation on the polymer surface are problems with potentially serious consequences, especially for implanted or indwelling articles such as catheters and stents. The design of materials having improved biocompatibility must take such factors into account.
The invention includes a co-polymer film and method for improving the biocompatibility of any article of synthetic/polymeric, organic or metallic origin intended to contact blood, tissue or body fluids in the course of a medical treatment or procedure. Such articles include, without limitation, tubing, bags, catheters, stents, probes, feeding tubes, drainage lines, vascular grafts, artificial shunts and the like whether intended for long-term or short-term contact with blood, tissue or other body fluid or their plasma or corpuscular and cellular constituents. The co-polymer film of the invention provides reduced thrombogenicity, reduced bacterial growth and adhesion, reduced toxicity to host cells, and infiltration and seeding with inflammatory cells or host cells, when compared to articles or materials in conventional use or without the polymer film described.


A method for the removal and rapid decomposition of halogenated fumigation agents is described. A fumigation agent, such as methyl bromide, contained in the gas stream exiting a fumigation chamber or structure is captured on activated carbon or other retentive substrate and rapidly decomposed using thiosulfate and water. The method provides an inexpensive, safe, and on-site executable way to remove and detoxify methyl bromide from fumigation discharge gases, thereby reducing or eliminating methyl bromide emissions into the atmosphere.

1. Field of the Invention
The present invention relates to methods for removing and decomposing halogenated hydrocarbon fumigation agents such as methyl bromide. More particularly, the invention provides methods using a substrate such as activated carbon to capture methyl bromide from fumigation gas streams and using thiosulfate to detoxify methyl bromide and thereby reduce or eliminate methyl bromide emissions into the atmosphere during commodity and structure fumigation.
2. Description of the Art
Methyl bromide (bromomethane, CH.sub.3 Br, CAS No. 74-83-9) is an important fumigant for treating agricultural commodities and structures. It is the most widely used fumigant for pest control in perishable produces such as, fresh fruits and vegetables, and cut flowers, endurable produces such as, cereal grains, dry fruits and nuts, and timber, and structures such as, mills, aircraft, and ships. Fumigation with methyl bromide is mandatory for import and export of many agricultural products in international trade. The worldwide use of methyl bromide for fumigating commodities and structures reached 1.8.times.10.sup.7 kg in 1992. It is estimated that 80-95% of the applied methyl bromide is emitted into the air as a result of intentional discharge of methyl bromide waste gases at the end of fumigation and leakage during fumigation.
Although methyl bromide is an effective fumigant, there is serious concern about its use because (1) in the air, it is acutely toxic, and (2) emission of methyl bromide during commodity and soil fumigation are reportedly contributing to stratospheric ozone depletion. The use of methyl bromide has thus been proposed to be discontinued in the United States by 2001, and in the other countries at 2010. However, as there are no effective alternatives, retaining methyl bromide for postharvest and structural fumigation is of great economic importance. Extension of methyl bromide usage may be permitted only if its emissions are sufficiently reduced. As commodity or structural fumigations are always carried out in closed environments, recovering unreacted methyl bromide is feasible. The fumigated products absorb little methyl bromide, leaving most of the applied chemical available for recovery.
Methods have been devised to recycle and recover methyl bromide, for example, by adsorption of methyl bromide on a molecular sieve and then desorption with hot gas (see U.S. Pat. No. 5,505,908).
Various methods have been proposed to recover and decompose methyl bromide from waste fumigation gases. These include passing the waste gas over metal catalysts, such as the oxides of iron, manganese, cobalt, and copper, at high temperatures (100-400.degree. C.), and further reacting with sodium or calcium hydroxide to neutralize the produced hydrogen bromide (Japanese Patent No.73,01,297; Japanese Patent No. 77,04,470); bubbling the waste gas through ethanolamine in the presence of sodium or calcium hydroxide, and further separating the reaction products through solvent extraction and ion-exchangers (Japanese Patent No. 74,127,862); and incinerating the waste gas at high temperature (600-1000.degree. C.), and then treating with sodium hydroxide solution to neutralize the produce hydrogen bromide (Japanese Patent No. 74,61,329; Japanese Patent No. 75,159,462; French Patent No. 231,309). Although these methods have proved successful at experimental scales, they have one or more of the following disadvantages: (1) use of high temperatures, which requires a good containment to prevent methyl bromide from leaking; (2) multiple procedures which require the construction of complex systems and lead to high costs; (3) unsafe or toxic end products such as hydrogen bromide or ethanolamine-hydrogen bromide salt and ethanolamine quaternary ammonium bromide; (4) reactive chemicals such as strong bases; and (5) stringent reaction conditions. These deficiencies have prevented the implementation of any one of these methods on any practical scale.
Various methods have been proposed to remove methyl bromide using activated carbon. U.S. Pat. No. 4,018,704 describes desorption of methyl bromide contained on active carbon using vapor (60-130.degree. C.) of an organic solvent that is inert to methyl bromide. Other methods include drawing methyl bromide waste gases from a fumigation room through an adsorption bed of activated carbon, and discharging the `filtered` air directly into the atmosphere. After methyl bromide is adsorbed on carbon, heated, moist nitrogen gas (130-250.degree. C.) (Japanese Patent No. 74,22,683), or hot methanol vapor (80.degree. C.) (German Patent No. 2,550,504), or hot air (280.degree. C.) (Japanese Patent No. 80,64,827 is used to desorb the methyl bromide. The desorbed methyl bromide is further incinerated at high temperatures (600.degree. C.) in a special furnace, and the hydrogen bromide produced from combustion is finally scrubbed in sodium hydroxide solution to neutralize it. Although some of these methods are successful on experimental and small production scales, none of them has found wide application. The lack of application may be attributed to the following disadvantages: (1) the need to precisely control the time and flow rate in order to eliminate any significant breakthrough of methyl bromide through the adsorption bed; (2) the need for multiple steps and stringent conditions to detoxify methyl bromide-loaded carbon, which gives the necessity for constructing complex detoxification facilities to fulfill these steps and performing the detoxification process off site separately from the removal process; (3) the difficulties and cost involved in transporting the toxic carbon with permissions from environmental regulating agencies to a location where a detoxification facility is available; and (4) high time consumption and cost to accomplish detoxification of methyl bromide and to regenerate the activated carbon.
What is needed is an inexpensive, safe, and on-site executable method to remove and detoxify methyl bromide from fumigation discharge gases.

Methods for removing and decomposing methyl bromide from fumigation

The United States of America as represented by the Secretary of Agriculture

The Regents of the University of California


A controller 1 includes a calculation unit 10 that receives the current sensor value A1 of the vehicle and calculates an injection amount based on the current sensor value A1 and a target value of the ammonia adsorption amount of the selective reduction catalyst 105 so that the ammonia adsorption amount approaches the target value, and a prediction unit 20 that receives the current sensor value B1 and calculates a corrected target value by future prediction based on the current sensor value B1. The calculation unit 10 calculates the injection amount based on the corrected target value calculated by the prediction unit 20.

Patent document 1 describes an exhaust purification system. The exhaust purification system includes an oxidation catalyst, a DPF, and a selective reduction catalyst, which are sequentially provided in an exhaust pipe of an engine. The exhaust purification system further includes an injector to inject urea water between the DPF and the selective reduction catalyst. The selective reduction catalyst selectively reduces NOx in the exhaust gas in an atmosphere in which a reducing agent such as ammonia is present. The injector opens when a drive pulse generated by a controller is applied, and injects the urea water to the upstream side of the selective reduction catalyst. The urea water injected by the injector is thermally decomposed or hydrolyzed by the heat of the exhaust gas. As a result, ammonia is produced as a reducing agent. The produced ammonia is supplied to the selective reduction catalyst.    Patent Document 1: Japanese Unexamined Patent Publication No. 2013-11255

Injection amount calculation device, injection amount control method, and exhaust gas purification device


[Problem]

An electric power steering apparatus that energizes a steering apparatus of a vehicle by using a rotational torque of a motor as an assist torque, applies a driving force of the motor as the assist torque to a steering shaft or a rack shaft by means of a transmission mechanism such as gears or a belt through a reduction mechanism. In order to accurately generate the assist torque (a steering assist torque), a control apparatus for such a conventional electric power steering apparatus performs a feedback control of a motor current. The feedback control adjusts a voltage supplied to the motor so that a difference between a current control value and a detected motor current value becomes small, and the adjustment of the voltage applied to the motor is generally performed by an adjustment of a duty ratio of a PWM (Pulse Width Modulation) control.
Here, a general configuration of an electric power steering apparatus will be described with reference to FIG. 1. As shown in FIG. 1, a column shaft 2 connected to a steering wheel (a handle) 1 is connected to tie rods 6 of steered wheels through reduction gears 3, universal joints 4A and 4B, and a rack and pinion mechanism 5. The column shaft 2 is provided with a torque sensor 10 for detecting the steering torque of the steering wheel 1, and a motor (a brushless DC motor) 20 for assisting the steering force of the steering wheel 1 is connected to the column shaft 2 through the reduction gears 3. Electric power is supplied to a control unit (ECU) 30 for controlling the electric power steering apparatus from a battery 14, and an ignition signal is inputted into the control unit 30 through an ignition key 11. The control unit 30 calculates a steering assist torque command value Tref of an assist command based on a steering torque T detected by the torque sensor 10 and a velocity V detected by a velocity sensor 12, and controls a current I supplied to the motor 20 based on calculated steering assist torque command value Tref. Furthermore, it is also possible to obtain the velocity V from a CAN communication network of the vehicle.
The control unit 30 mainly comprises a CPU, and general functions performed by programs within the CPU (or an MCU or an MPU) are shown in FIG. 2. Furthermore, FIG. 2 shows a case of a vector control system that performs current control by means of a d-axis current command value Id and a q-axis current command value Iq.
In the case of the vector control, a rotation sensor (such as a resolver or a Hall sensor) 21 for detecting a rotational position θ is connected to the motor 20, the rotational position θ from the rotation sensor 21 is inputted into a rotational speed calculating section 22, and a rotational speed ω is calculated. The steering torque T, the velocity V and the rotational speed ω are inputted into a steering assist torque command value calculating section 31, and the steering assist torque command value Tref is calculated. A current command value calculating section 32 calculates the d-axis current command value Id and the q-axis current command value Iq based on the steering assist torque command value Tref, the rotational position θ and the rotational speed ω. The d-axis current command value Id, the q-axis current command value Iq and the rotational position θ are inputted into an each-phase current command value calculating section 33. Each-phase current command values Iaref, Ibref and Icref that are calculated by the each-phase current command value calculating section 33, are inputted into subtracting sections for feedback 34a, 34b and 34c, respectively. Each-phase currents ia, ib and ic of the motor 20 that are detected by current detectors 38a, 38b and 38c, are fed back into the subtracting sections 34a, 34b and 34c. Deviations (Iaref-ia, Ibref-ib and Icref-ic) obtained by the subtracting sections 34a, 34b and 34c, are inputted into a PI control section 35. Voltage command values Varef, Vbref and Vcref that are calculated by the PI control section 35, drive and control the motor 20 via a PWM control section 36 and an inverter 37.
In the above-described electric power steering apparatus, since resistance values of three phases between the brushless DC motor 20 and the control unit 30 (i.e. resistance (R) and inductance (L)) are not identical, and are different respectively, as shown in FIG. 3, there is a problem that maximum amplitude values of currents ia, ib and ic that flow in three phases do not become identical, and torque ripple occurs. That is to say, in the case of FIG. 3, with respect to a peak value of the phase current ib, a gap Pa appears in the phase current ia, and a gap Pc appears in the phase current ic. Furthermore, with respect to variation in each-phase current values of the motor, variation factors of the inverter circuit 37, substrates, wiring resistances and so on within the control unit 30 are conceivable other than variation in characteristic of a stand-alone motor.
From the aspect of improving steering performances, reducing operating noises and vibrations due to such a difference in the peak value of the phase current, is strongly requested.
In order to solve such a problem, for example, in Japanese Patent Application Laid-Open No. 2009-81951 (Patent Document 1), a motor control signal generating section comprises a phase resistance correction calculating section, preliminarily-measured each-phase resistance values Ru, Rv and Rw, and a reference resistance value R are stored in the phase resistance correction calculating section, based on these stored values, correction components εd and εq for canceling out a voltage drop item of a voltage equation that varies depending on a rotational angle of the motor, are calculated, the motor control signal generating section corrects a d-axis voltage command value Vd* and a q-axis voltage command value Vq* that aims to suppress occurrence of the torque ripple due to differences in each-phase resistance values by overlaying these correction components εd and εq on the d-axis voltage command value Vd* and the q-axis voltage command value Vq*.
Furthermore, in Japanese Patent Application Laid-Open No. 2010-130707 (Patent Document 2), a three-phase correction section calculates armature winding resistances Ru, Rv and Rw, or rates of winding resistance Gu, Gv and Gw of three phases based on command currents id* and iq* on the d-axis and the q-axis, and a current value is detected by a current sensor, based on the calculated armature winding resistances Ru, Rv and Rw, or the calculated rates of winding resistance Gu, Gv and Gw, a correction for compensating a deviation from a setup value that is due to variation in winding resistance values of three phases, is performed with respect to each-phase command voltages Vu, Vv and Vw that are obtained by a dq-axes/three-phase converting section, even in the case that each-phase winding resistance values are different due to resistance change caused by variation in manufacturing resistances and an ambient temperature, and so on, a deviation of the command voltage due to that difference is corrected, and the torque ripple is reduced.

Control apparatus for electric power steering apparatus

Abstract: [Problem]

Abstract: An object of the present invention is to provide a control apparatus for an electric power steering apparatus that improves ripple accuracy of a torque, a velocity and so on, does not generate abnormal noises and does not generate an uncomfortable feeling with respect to a steering by compensating each-phase characteristics of a motor and the control apparatus and converting into a desired characteristic, and at the same time conforming each-phase characteristics.

Abstract: [Means for Solving the Problem]

Abstract: The present invention is a control apparatus for an electric power steering apparatus that calculates a steering assist torque command value based on a steering torque generated in a steering shaft and a velocity, calculates each-phase current command values from the steering assist torque command value, and controls a motor that provides a steering mechanism with a steering assist torque based on current control values calculated from the each-phase current command values and each-phase current values of the motor, comprising: arranging filters having a characteristic that compensates each-phase characteristics of the motor and the control apparatus at each pathway, and conforming the each-phase characteristics of the motor and the control apparatus, and at the same time, making the each-phase characteristics of the motor and the control apparatus becoming a desired characteristic.


A human joint rehabilitation apparatus, the apparatus includes a movable platform configured to support a portion of a patient's body including the joint, and a motorized mechanical energy source configured to move at least a portion of the platform to apply motion to the joint, wherein the patient dynamically controls the motorized mechanical energy source to operate the motion of the joint.

Continuous passive motion or manually applied physical therapy to an injured or post operative limb is the primary rehabilitative treatment chosen by most doctors and therapists. Many limb and joint exercising devices are known. Generally, these machines have a motor driven limb support, with the limb support capable of being set to periodically move the limb in a preset range of positions, for a preset length of duration, and at a preset speed. Once these angles, speed, and duration have been chosen, the machine automatically moves the limb from a straightened position back and forth into these pre-chosen positions at the pre-chosen speed for the pre-chosen duration.
Resetting positions and safety cutoffs are available for the user of current machines. However, because all variables are preset and constant, typically, initial therapy cycles of the machine are often too severe and painful, whereas, later therapy cycles are insufficient due to the limbering of the joint and the joint's capability of greater movement as the therapy session progresses. Further, current machines do not allow for total joint isolation, but often require the use of other joints to achieve joint movement (such as hip joint movement in the case of the knee).
Current machines and therapists do not sense the pain of the patient at all and do a limited job of sensing joint stiffness. A machine is needed that will allow total flexibility in the treatment of a joint, including flexion, extension, rotation, duration, and speed, but in doing so, the machine needs to be sensitive to the pain threshold of the patient and the flexibility of the joint being rehabilitated.
Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements.


Method and apparatus for identifying a cause for a response time problem for a transaction in a distributed computing system that includes a central server and a plurality of subsystems. Data is stored at each subsystem relating to sub-transactions of transactions performed by the subsystems. When a problem is discovered in connection with the completion of a particular transaction, each subsystem of the plurality of subsystems that was involved in the particular transaction is identified, and both instance data relating to all of the sub-transactions of the particular transaction stored at each identified subsystem and current hourly aggregate data stored at each identified subsystem is forwarded to the central server. Root-Cause Analysis is then performed using the forwarded instance data and aggregate data to identify the particular subsystem that caused the transaction problem.

1. Field of the Invention
The present invention relates generally to the data processing field and, more particularly, to a method and apparatus for identifying the cause for a transaction response time problem in a distributed computing system.
2. Description of the Related Art
Distributed computing is a type of computing in which a plurality of separate computing entities interconnected by a telecommunications network operate concurrently to run a single transaction in a transparent and coherent manner, so that the plurality of entities appear as a single, centralized system. In distributed computing, a central server divides a single transaction into a plurality of work packages which are passed to a plurality of subsystems. Each subsystem performs the particular sub-transaction detailed in the work package passed to it, and when it is finished, the completed work package is passed back to the central server. The central server compiles the completed work packages from the various subsystems and presents the results of the transaction to an end user.
In a distributed computing system, it is important to monitor the operation of each subsystem so that the root cause of any transaction response time problem that may occur can be detected and identified. A current technique for identifying the root cause of a transaction response time problem is to attach an Application Response-time Measurement (ARM) correlator to the transaction so that response time information can be gathered at each subsystem, and then correlated at the central server.
In order to reduce the amount of data that is stored locally at each subsystem to be sent over the network to the central server to be correlated, the data collected on a subsystem for each run of a transaction is aggregated over a one hour period. The locally stored aggregated data is sent to the central server on an hourly basis; and after being sent, the locally stored data is normally discarded at the subsystem. Upon completion of a transaction, if a monitor, located on a monitored server where the transaction originated, determines that the transaction exceeded a response time threshold, it will turn on a flag in the ARM correlator for subsequent runs of the transaction to save the instance data (Second Failure Data Capture) which is also needed to perform a "Root-Cause Analysis". A Root Cause Analysis cannot be performed on aggregate data alone because the granularity of aggregate data is too high and, thus, may hide the problem. The Root-Cause Analysis must instead be performed using both the aggregate data and the instance data of the specific transaction in question. The instance data is compared to an average of the aggregate data to determine the sub-transaction that is operating outside the norm represented in the aggregate data.
There are several drawbacks to current techniques for identifying the root cause of a transaction response time problem in a distributed computing system. For one, an aggregate view of the transaction path may not isolate the subsystem where the problem is occurring if the problem is sporadic in nature. In addition, collecting subsequent instances of a transaction run may or may not identify performance problems having the same root cause. In some cases, for example, a transaction may be initiated by a different user from a different location, or may contain different parameters, all of which can impact the outcome of the transaction. Additionally, today's web server environments are often clustered and load balanced, and, as a result, a transaction may not take the same path on subsequent runs as during the actual failure. If a specific transaction path has a problem, but the transaction takes a different path the next time it is executed, the monitoring product would falsely determine that the problem has corrected itself-when, in fact, the problem will resurface once the transaction takes the original path in the future.
Another drawback to current techniques for identifying the root cause of a transaction response time problem in a distributed computing system is that current techniques rely on the user of the monitoring product to analyze the data of the aggregate transaction and the subsequent instances to identify the source of the problem. The event that is sent to the user does not itself give an indication of the cause of the problem because at the time of the event, it is not known which subsystem caused the overall transaction problem.
There is, accordingly, a need for an improved method and apparatus for identifying the cause for a transaction response time problem in a distributed computing system.

This patent is subject to a terminal disclaimer.

Identification of root cause for a transaction response time problem in a distributed environment

International Business Machines Corporation


Provided is a battery capable of obtaining a superior battery capacity and a superior charge-discharge cycle characteristic under high temperature conditions, and improving a load characteristic. A laminate including a cathode (21) and an anode (22) with a separator (23) in between is spirally wound. The cathode (21) includes a cathode mixture layer which includes a lithium-containing complex oxide including at least one kind selected from the group consisting of Co, Ni, Mn and Fe. The anode (22) includes an anode mixture layer including a tin-containing alloy, a carbon material, and a fatty acid or a metal salt thereof. Thereby, a superior battery capacity and a superior charge-discharge cycle characteristic under high temperature conditions can be obtained. Moreover, when the content of the fatty acid or the metal salt thereof in the anode mixture layer is within a range from 0.1 wt % to 6 wt % inclusive, a load characteristic can be improved.

The present invention relates to a battery comprising a cathode, an anode and an electrolyte in which the anode includes an anode mixture layer including a tin-containing alloy powder.
A large number of small-sized portable electronic devices such as camera/VTR (video tape recorder) combination systems, cellular phones, laptop computers or the like have come into widespread in accordance with recent advances in electronics, and a development for reducing their sizes and weights has proceeded. Accordingly, a development in compact and lightweight batteries having a high energy density, specifically secondary batteries as portable power sources used in the portable electronic devices has proceeded. As such secondary batteries, for example, batteries which use a graphite material using intercalation reaction of lithium ions into graphite layers, or a carbon material using an application of insertion/extraction reaction of lithium ions into/from pores as an anode material have been developed and have been in practical use.
However, in accordance with a recent increase in performance of portable devices, a demand for capacity has been growing, so the batteries are required to have a characteristic in which no decline in capacity occurs in spite of repeated cycles of charge and discharge, that is, an excellent charge-discharge cycle characteristic. Moreover, in accordance with diversification of use conditions of the devices, a demand for batteries exhibiting an excellent capacity at high load has been growing. As a method of obtaining such characteristics, for example, it can be considered that light metal such as lithium metal or the like is used as-is as an anode material. However, in this case, in a charging process, the light metal in dendrite form is likely to be deposited on an anode, and a current density becomes extremely high at a tip of a dendrite, so the charge-discharge cycle characteristic may decline due to the decomposition of an electrolyte or the like, or when the dendrite excessively grows to reach a cathode, an internal short circuit may be induced.
In order to inhibit the deposition of lithium in dendrite form, it is considered that a specific alloy is used as an anode active material, and during charge, lithium deposited on a surface of the anode is alloyed with a base metal of an alloy of the anode active material to be introduced into the alloy. As such an alloy, a lithium-lead (Pb) alloy (for example, refer to Japanese Examined Patent Application Publication No. Hei 3-53743, Hei 5-34787, Hei 7-73044 and Hei 8-138654) or a bismuth (Bi)-tin (Sn)-lead-cadmium (Cd) alloy (for example, refer to Japanese Examined Patent Application Publication No. Hei 4-47431 and Hei 3-64987) have been disclosed. However, lead, bismuth and cadmium are not preferable in the viewpoint of recent environmental protection.
Moreover, although a method using a silicon (Si) alloy which causes very little damage to the environment has been proposed (refer to Japanese Unexamined Patent Application Publication No. Hei 7-302588, Hei 10-199524, Hei 7-326342, Hei 10-255768 and Hei 10-302770), the reaction between the silicon alloy and an organic solvent is so large that the charge-discharge cycle characteristic is poor, so it could not be put to practical use.
Further, a method using tin or a tin-containing alloy has been proposed. As the tin-containing alloy, for example, alloy materials of tin and nickel (Ni) (refer to Japanese Examined Patent Application Publication No. Hei 4-12586, Japanese Unexamined Patent Application Publication No. Hei 10-162823 and Sho 10-308207), alloy materials of lithium, aluminum (Al) and tin (refer to Japanese Unexamined Patent Application Publication No. Sho 61-66369), alloy materials of tin and zinc (Zn) (refer to Japanese Unexamined Patent Application Publication No. Sho 62-145650), materials of a tin alloy containing 1 wt % to 55 wt % of phosphorus (P) (refer to Japanese Unexamined Patent Application Publication No. Hei 8-273602), Cu2NiSn and Mg2Sn (refer to Japanese Unexamined Patent Application Publication No. Hei 10-223221), alloy materials of tin and copper (Cu) (refer to Japanese Unexamined Patent Application Publication No. Sho 10-308207), materials of a mixture of a tin-containing phase which absorbs lithium, and a phase made of manganese (Mn), iron (Fe), cobalt (Co), nickel and copper which does not absorb lithium (refer to Japanese Unexamined Patent Application Publication No. Hei 11-86854) have been disclosed.
However, in the case of a battery using tin or a tin-containing alloy, such a problem that the battery cannot fully satisfy requirements for the capacity, the charge-discharge cycle characteristic and a load characteristic arises.
Moreover, in accordance with diversification of use conditions of the devices, a demand for batteries exhibiting an excellent charge-discharge cycle characteristic under high temperature conditions has been growing. However, such a problem that the conventional batteries cannot obtain sufficient characteristics also arises.
In view of the foregoing, it is an object of the invention to provide a battery capable of obtaining a superior battery capacity and a superior charge-discharge cycle characteristic under high temperature conditions, and improving the load characteristic.


A method and system for controlling a transmission window size, wherein a transmission condition of the transmission path between a transmitting element and a receiving element is checked when at least one of the transmitting and receiving elements moves from a first access network to a second access network. Then, the transmission window size is changed in response to the result of said checking step. Thereby, the transmission window can be decreased actively to thereby accelerate the control procedure and improve resource utilization.

The Internet network layer service (Internet Protocol Service) is unreliable. IP does not guarantee datagram delivery, in-order delivery of datagrams, and integrity of the data in the datagrams. In IP services, datagrams can overflow router buffers and never reach their destination, datagrams can arrive out of order, and bits in the datagram can get corrupted.
TCP creates a reliable data transfer service on top of IP's unreliable best-effort service. Many popular application protocols use TCP rather than UDP (User Datagram Protocol) primarily because TCP provides reliable data transfer service.
Retransmission of lost and corrupted data is crucial for providing reliable data transfer. TCP provides reliable data transfer by using positive acknowledgements and timers, wherein data that has been received correctly is acknowledged, and packet data units or segments are retransmitted when they or their corresponding acknowledgements are thought to be lost or corrupted. Moreover, TCP uses pipelining, allowing the sender to have multiple transmitted but yet-to-be-acknowledged segments outstanding at any given time. Pipelining can greatly improve the throughput of a TCP connection when the ratio of the segment size to round trip delay is small. The number of transmitted but unacknowledged segments that a sender can have is determined by TCPs flow control and congestion control mechanisms.
According to TCP congestion control, a TCP connection controls its transmission rate by limiting its number of transmitted but yet-to-be-acknowledged segments. This number of permissible unacknowledged segments is often referred to as TCP window size w. Ideally, TCP connections should be allowed to transmit as fast as possible, i.e. to have as large a number of outstanding unacknowledged packets as possible, as long as segments are not lost (dropped at routers) due to congestion. In very broad terms, a TCP connection starts with a small value of w and then "probes" for the existence of additional unused link bandwidth at the links on its end-to-end path by increasing w. A TCP connection continues to increase w until a segment loss occurs, as detected by a timeout or duplicate acknowledgements. When such a loss occurs, the TCP connection reduces w to a "safe level" and then begins probing again for unused bandwidth by slowly increasing w.
An important measure of the performance of a TCP connection is its throughput, i.e. the rate at which it transmits data from the sender to the receiver. Clearly, the throughput will depend on the value of w. If a TCP sender transmits all w segments back-to-back, it must then wait for one round trip time (RTT) until it receives acknowledgements for these segments, at which point it can send w additional segments. If a connection transmits w segments of a maximum segment size (MSS) by every RTT seconds, then the connections throughput, or transmission rate, is (w×MSS)/RTT bytes per second.
The TCP congestion control mechanism has each side of the connection keep track of two additional variables, the congestion window and a threshold.
Once a TCP connection is established between the two end-systems, the application process at the sender provides bytes to the senders TCP send buffer. TCP grabs portions of size MSS, encapsulates each portion within a TCP segment, and passes the segments to a network layer for transmission across the network. The TCP congestion window regulates the times at which the segments are sent into the network. Initially, the congestion window is equal to one MSS. TCP sends the first segment into the network and waits for an acknowledgement. If this segment is acknowledged before its timer times out, the sender increases the congestion window by one MSS and sends out two MSSs. If these segments are acknowledged before their timeouts, the sender increases the congestion window by one MSS for each of the acknowledged segments, giving a congestion window of four MSS, and sends out four MSSs. This procedure continues as long as the congestion window is below the threshold and the acknowledgements arrive before their corresponding timeouts. During this phase of the congestion control procedure, the congestion window increases exponentially, i.e. the congestion window is initialized to one MSS, after one RTT the window is increased to two segments, after two RTTs the window is increased to four segments, after three RTTs the window is increased to eight segments, etc. This phase of the algorithm is called slow start because it begins with a small congestion window equal to one MSS. The slow start phase ends when the window size exceeds the threshold value. Once the congestion window is larger than the current threshold value, the congestion window grows linearly rather than exponentially. This has the effect of increasing the congestion window by one in each RTT for which an entire windows worth of acknowledgements arrives. This phase of the algorithm is called congestion avoidance.
The congestion avoidance phase continues as long as the acknowledgements arrive before their corresponding timeouts. But the window size and hence the rate at which the TCP sender can send, cannot increase forever. Eventually, the TCP rate will be such that one of the links along the path become saturated, and point loss and a resulting timeout at the sender will occur. When a timeout occurs, the threshold value is set to half a value of the current congestion window, and the congestion window is reset to one MSS. The sender then again grows a congestion window exponentially fast using the slow start procedure until the congestion window hits the threshold.
The congestion window imposes an additional constraint on how much traffic a host can send into a connection. Specifically, the amount of unacknowledged data that a host can have within a TCP connection may not exceed the minimum of the congestion window and an advertised window indicating the number of bytes that a receiver is willing to accept. To achieve this, according to a window pacing method, the receiver sends acknowledgement packets including window advertisement data for informing the transmitter of the capacity of the receiver to handle incoming data. Thus, the receiver can signal to the transmitter a suitable window size (i.e. the advertised window) for flow control purposes. In practice, the advertised window specifies how many additional units of data the receiver is prepared to accept. The transmitter then compares the advertised window to the congestion window and adjusts its congestion window according to the size of the advertised window, unless the congestion window maintained by the transmitter is smaller. In principle, both the congestion window and the advertised window can be used to adjust the transmission rate of the transmitter.
Document U.S. Pat. No. 6,219,713 discloses a method and apparatus for adjusting a TCP sliding window with information about network conditions. An underlying network is enabled to use the receiver's window advertisements carried in the acknowledgement packets for controlling the transmission speed of a TCP source. To achieve this, a specific device or network functionality, i.e. a Feedback Information Converter (FIC) is introduced. The FIC includes a function for receiving accepted packet discarding priority levels carried by received data packets. When the FIC knows the nominal bit rate of the TCP source, it can calculate a TCP transmission window size required to keep the priorities of the data packets just greater than or equal to the accepted priority level. Then, the FIC put this calculated window size to the acknowledgement packet instead of the original receiver's advertised window.
Mobility support for Internet devices is quite important, since mobile computing is getting more widespread. It is expected that the number of mobile computers will increase immensely. Furthermore, there are already first products of cellular phones offering IP services. Cellular devices of the 3rd generation will be packet switched devices instead of circuit switched, therefore IP services on 3rd generation cellular devices will be an integral part in the future.
To support mobile devices, which dynamically change their access points to the Internet, the Internet Engineering Task Force (IETF) currently standardizes a protocol supporting mobile Internet devices, called mobile IP. There are two variations of mobile IP, mobile IPv4, based on IPv4, and mobile IPv6, based IPv6. Further details regarding IPv6 can be gathered from the IETF specification RFC 2460.
Mobile IPv6 enhanced mobility will enable seamless handover between heterogeneous access networks. IP telephony or such services will become seamless even in heterogeneous access environments. However, when handovers occur in such environment, some applications such as Web browse and file transfer which use TCP as transport protocol will become problems or their performance will deteriorate. In particular, TCP is a reliable and robust transport protocol tuned for networks with consistent access media. The "consistent access media" means that the bandwidth and/or data rates of a terminal device (mobile or fixed node) accessing the Internet remains stable or relatively stable. This condition might be challenged in the mobile IPv6 networks. When a mobile node performs a handover from one access medium, e.g. a Wireless Local Area Network (WLAN), to another access medium, e.g. a Wideband Code Division Multiple Access (WCDMA) Network, the bandwidth and/or data rate of the mobile node may dramatically change, e.g. from a few megabytes to tens or hundreds of kilobytes. If the mobile node performs the handover from such a high-speed access network to such a low-speed access network and if the mobile node still keeps its original trends of transmission data rate, it would block the access node or make the access node congested. On the contrary, if the mobile node performs a handover from a low-speed access network to a high-speed access network, the access capacity may be underutilized. In addition, whenever a mobile node performs a handover from a CDMA cell with less/more subscribers (other mobile node) to another CDMA cell with more/less subscribers, its access bandwidth will also be no longer "consistent".

Method, system and device for controlling a transmission window size


A power tool control system connected with a drill press provides a system for determining operational settings for the drill press and/or structural factors of a workpiece to be operated upon by the drill press. For instance, the power tool control system may establish a visual indication of the axis of operation of the drill press upon a workpiece and/or determine the thickness, structural composition, and/or moisture content of a workpiece. The determined axis of operation and/or structural factor is utilized to determine the operational settings of the power tool.

The use of power tools, such as drill presses, is commonplace in numerous locations, from construction work sites to home work shops. These power tool devices are used to perform their functions on a variety of different workpieces, such as wood, metal, plastic, and the like.
When performing boring operations upon a workpiece, various structural factors, such as the thickness of the workpiece, hardness of the workpiece, moisture content of the workpiece, and the like may significantly affect the operation of the drill press. Unfortunately, current drill presses may not provide an effective measure of structural factors, such as the thickness of the workpiece, hardness of the workpiece, moisture content of the workpiece, and the like to be operated upon. This may contribute to the inefficient operation of the drill press which may result in decreased productivity. Further, this may contribute to a reduced life span of useful operation of the drill press due to increased operational stresses being placed upon the tool which may result in increased wearing of the working parts of the tool. Further, some current drill presses may fail to provide an efficient system for reducing the speed of the drill press prior to cutting through the workpiece. This may also contribute to a reduced life span of the drill press.
Therefore, it would be desirable to provide a device, which enables the user of a drill press to determine the operational settings of the drill press based on determined structural factors of a work piece.


A composition for an organic thin film may include a first compound having a linear alkylene oxide moiety and a haloalkyl moiety, and a second compound having conductivity and being capable of controlling a work function.

1. Field
Example embodiments provide a composition for an organic thin film, an organic thin film, and an electronic device including the organic thin film.
2. Description of the Related Art
An electronic device, e.g., a solar cell and/or an organic light emitting diode, includes a plurality of thin films, e.g., a conductive thin film, an insulation thin film, and/or a semiconductor thin film.
For example, a solar cell is a photoelectric conversion device to convert solar energy into electrical energy, it absorbs solar energy in an active layer including a p-type semiconductor and a n-type semiconductor, and produces electron-hole pairs (EHP) inside a semiconductor, and the produced electrons and holes are transferred to a n-type semiconductor and a p-type semiconductor, respectively, and collected in electrodes in order to use electrical energy outside.
As another example, an organic light emitting diode is a device to convert electrical energy into light, and includes two electrodes and an active layer, e.g., an emission layer therebetween, wherein an electron injected from one electrode and a hole injected from the other electrode are combined with each other in an active layer, e.g., an emission layer to form excitons, and excitons emit light while releasing energy.
Herein, an electronic device, e.g., a solar cell or an organic light emitting diode, may further include a thin film between the active layer and electrode in order to improve device characteristics.

Composition for organic thin film, organic thin film, and electronic device including the organic thin film


Systems and methods may be provided for alternate pricing. The systems and methods may include receiving first information associated with a first claim transaction, where the first information identifies a first drug, a first quantity of the first drug, and a first price for the first drug, determining a first product classification for the identified first drug, where the first product classification indicates that the identified first drug is a preferred drug, and updating an alternate pricing database with the first price for the first drug. The systems and methods may also include utilizing the alternate database to identify one or more lower-cost alternate drugs that are therapeutic alternatives for a requested drug. Customers may be provided with information regarding the identified lower-cost alternate drugs.

With the increasing cost of prescription drugs, patients have become a very price-sensitive group. Indeed, a patient's out-of-pocket cost for a drug may influence the extent to which a patient fills or refills a prescription or otherwise chooses another lower-cost drug. However, alternate pricing information for comparable drugs is typically not readily known to patients, pharmacists, and/or physicians. Accordingly, there is a need in the industry for systems and methods for capturing and providing alternate pricing for drugs.

Systems and methods for alternate pricing for prescription drugs


A method for forming a semiconductor device includes providing a first integrated circuit having a landing pad and attaching a second integrated circuit to the first integrated circuit using at least one bonding layer. The second integrated circuit has an inter-circuit trace, the inter-circuit trace has an inter-circuit trace opening. The method further includes forming an opening through the second integrated circuit, the opening extending through the inter-circuit trace opening, forming a selective barrier on exposed portions of the inter-circuit trace in the opening, extending the opening through the at least one bonding layer to the landing pad, and filling the opening with a conductive fill material. The selective barrier layer comprises at least one of cobalt or nickel, and the conductive fill material electrically connects the inter-circuit trace and the landing pad.

1. Field of the Invention
This invention relates in general to 3-D integration of circuits and more specifically to a barrier for use in 3-D integration of circuits.
2. Description of the Related Art
Traditionally, 3-D integration of circuits is achieved using face-to-face bonding of wafers, such as acceptor wafers and donor wafers, or dies. Acceptor wafer is typically the bottom wafer and donor wafer is typically the top wafer. Interconnects in the bonded wafers or dies are connected using various techniques, such as stitch vias. Formation of stitch vias, which are typically formed on the backside of a donor wafer, is, however, time consuming and requires additional steps for achieving 3-D integration of wafers or dies. In particular, for example, formation of stitch vias requires two inter-wafer vias having differing lengths that are linked on the backside of the donor wafer.
Additionally, etching of inter-wafer vias can cause several problems for etch processing. For example, etching of such inter-wafer vias in low-K dielectric wafers requires etching through multiple types of dielectric materials, such as silicon nitride, silicon carbon-nitride, silicon-oxide, and SiCOH containing low-K dielectrics. This in turn requires a wide range of etch processes, such as both physical and chemical etch processes. Certain physical and chemical etch processes can redistribute the copper into the dielectric layers. This problem, for example, especially occurs when inter-wafer connects are used as embedded etch masks.
Thus, there is a need for improved 3-D integration of circuits.
Skilled artisans appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve the understanding of the embodiments of the present invention.

Barrier for use in 3-D integration of circuits


The present invention relates to oral compositions having enhanced organoleptic characteristics of fattiness, creaminess, soothing, satisfaction, and full mouthfeel, and comprises acylglycerol compounds having substituents R.sub.1, R.sub.2, and R.sub.3 attached at the positions of the OH.sup.31 groups of a glycerol backbone. The substituents R.sup.1 and R.sub.2 are independently selected from conjugated polyunsaturated fatty acids having from 16 carbon atoms to 22 carbon atoms and R.sub.3 is selected from the group consisting of R.sub.1, OH, PO.sub.3 HR.sub.4, and C.sub.6 -C.sub.12 carboxylic acids, wherein R.sub.4 is selected from the group consisting of OH, choline, inositol, serine, and ethanolamine. The oral compositions of the present invention being substantially free of free conjugated polyunsaturated fatty acids.

The desirability of many consumable compositions, especially in low fat or so-called "light" compositions, by the consumer depends, not only on taste, but also on mouthfeel. While the gustatory or taste notes of the compositions may be, more or less, adequately compensated for, the difficulty in reconstituting or reproducing the feeling of the creamy-type consistency or texture which are precisely imparted by fats within the compositions, still remains to be a problem.
It is known that fat is comprised of a mixture of glycerol esters and that the removal of fat from various consumable compositions can adversely affect the organoleptic characteristics of the compositions. As disclosed in U.S. Pat. No. 5,092,964, issued Mar. 3, 1992, to Conte, Jr., et al., the presence of some mono- and diglycerides in butter fat and the unique triglyceride composition make important contributions to the mouthfeel of butter. Alteration of the concentration of these components in butter fat and the relative proportions thereof yields unacceptable mouthfeel. For example, while the development of low calorie triglycerides for foods having reduced fat content, wherein the triglycerides are tailored to consist of a particular combination of saturated medium chain, saturated long chain, and unsaturated long chain fatty acid residues, such as those disclosed in U.S. Pat. No. 4,832,975, issued May 23, 1989, to Yang, and triglycerides comprising both long, saturated fatty acid residues and short, carboxylic acid residues, such as those disclosed in U.S. Pat. No. 5,552,174, issued Sep. 3, 1996, to Wheeler, et al., may provide some reduction in fat and/or calories, they are still less desirable than conventional compositions.
Other attempts to provide low fat/calorie compositions have shown similar results. For example, U.S. Pat. No. 4,199,608, issued Apr. 22, 1980, to Gilmore, et al., and U.S. Pat. No. 4,284,655, issued Aug. 18, 1981, to Miller, et al., which disclose replacing fat with a partial glycerol ester composition, comprising a mixture of mono-, di-, and triglycerides, in whippable toppings and/or comestible spreads; U.S. Pat. No. 4,414,229, issued Nov., 8, 1983, to Bakal, et al., which discloses adding cellulose fibers to butter substitute spreads; and PCT Application No. WO 9,534,222, published Dec. 21, 1995, to Benzi, et al., which discloses adding the diglyceride fraction of an animal or vegetable fat hydrolysate to the flavoring ingredient of low-fat foods.
Conjugated polyunsaturated fatty acids have been known for some time and each of the different acids possess different characteristics and functional properties. For example, conjugated linoleic acid is known to possess anti-oxidation and browning-prevention properties when added to food/food products, as disclosed by Koizumi, et al., Japanese Kokai Patent Application No. HEI 6-276939, published Oct. 4, 1994; inhibit mold growth, as disclosed by Pariza, et al., U.S. Pat. Nos. 5,017,614, issued May 21, 1991, and 5,208, 356, issued May 4, 1993; and increase the efficiency of feed conversion in an animal into body weight by increasing the ratio of lean to fat body mass, as disclosed by Cook, et al., U.S. Pat. No. 5,428,072, which issued Jun. 27, 1995. It has not been known until the present invention, however, that specific acylglycerol compounds comprising conjugated polyunsaturated acids having from 16 to 22 carbons, including conjugated linoleic acid in particular, when added to various oral compositions, including conventional, reduced fat/calorie, low fat/calorie, and no fat/calorie foods and/or beverages/drinks, dental compositions, over-the-counter and/or prescription pharmaceuticals, and nutraceuticals, which when delivered in the mouth, provide enhanced organoleptic characteristics of fattiness, creaminess, soothing, satisfaction, and full mouthfeel. Therefore, the compositions and methods of the present invention are novel.
As a result of the above described discoveries, the present invention provides at least four distinct advantages over compounds disclosed in the prior art. First, the precise acylglycerol compounds of the present invention can be obtained at high purity either by de novo synthesis or purification from natural sources; second, the compounds of the present invention can be used at levels much lower than would be required of other compounds to obtain similar attributes, and therefore provides oral compositions containing less overall fat content than those compositions comprising butterfat, glycerol esters, or fat hydrolysates; third, formulations containing the preferred identified compounds provide a method for delivering the health benefits associated with conjugated linoleic acid; and fourth, these compounds augment the oxidative stability of the compositions in which they are incorporated.
Therefore, it is an object of the present invention to disclose oral compositions having enhanced mouthfeel comprising specific acylglycerol compounds comprising conjugated polyunsaturated fatty acid residues.
It is a further object of the present invention to disclose a method for enhancing the mouthfeel of oral compositions by the addition, to said compositions, of specific acylglycerol compounds comprising conjugated polyunsaturated fatty acid residues.

Oral compositions having enhanced mouth-feel


A display apparatus with a shield unit which is easily mounted includes: a cathode ray tube for displaying images; a first cover in which the cathode ray tube is assembled; a cathode ray tube bracket fixed to the front case for supporting the cathode ray tube, and having a reeve in the rear, a shield cover installed in the rear of the cathode ray tube bracket for shielding an electric field, and having a coupling unit in the front; a guiding rail for shielding an electric field, and of the shield cover with the reeve formed on the cathode ray tube bracket; and a second cover coupled with the first cover for covering the shield cover.

1. Technical Field
The present invention relates to a display apparatus with improved mounting of a shield unit for shielding an electric field with a rail coupling means.
2. Related Art
The assembly of display apparatus can be very complex, time consuming and inconvenient. This is due to the fact that, typically, such display apparatus include numerous components, such as a front cover, cathode ray tube (CRT), CRT bracket, shield cover, and rear cover, as well as a main circuit board and a board frame which are associated with each other and which underly the CRT bracket and shield cover.
In assembling these numerous components, various sets of screws are typically used to interconnect the various components. However, during the assembly process, it is necessary for the assembler to manipulate the various components in order to correctly align the screw holes for the purpose of facilitating insertion of the screws to interconnect components. During this process, the various components can inadvertently impact on the underlying main circuit board, thus raising the possibility of damage to the circuit board elements and components.
Therefore, there is a need for an improved display apparatus so that assembly is more convenient and there is no possibility of damage to the electrical components of the display apparatus.

Display apparatus with shield unit easily mounted


A high efficiency, high output, compact ignition coil particularly suited for use in capacitive discharge, multiple pulsing ignition systems, with about ten turns of primary (1) wire (Np) and about five hundred fifty turns of secondary (2) wire (Ns) for an input voltage Vp of approximately 350 volts and a peak output voltage Vs of 30 kV, the core and windings of the coil featuring separate and different primary (31) and secondary (41) core halves structured on the basis of herein developed coil open and closed circuit criteria such that the core half (31) containing the primary winding has a large center post (32) of cross-sectional area Ap with a narrow slot of width W1 around the post (32) for winding the primary wire (1) to provide essentially the total required coil leakage inductance Lpe of about 50 uH for an input capacitance of about 5 uF and spark discharge frequency fcc of about 10 kHz, and the secondary core (41) structured to have a center post (42) of cross-sectional area As about half that of Ap to provide a much larger winding width W2 than W1 to efficiently support the many layered larger coil secondary winding (2) for a same overall outer core diameter D of the coil comprising a pot core or "E" type core structure.

The present invention relates to ignition coils for ignition systems for igniting air-fuel mixtures, and particularly for use in systems using capacitors for storing higher levels of ignition energy, i.e. high energy capacitive discharge ignition systems, and for delivering the energy in the form of a rapidly pulsing (multi-strike) sequence of spark pulses.
Considerable research has been conducted on ignition systems for internal combustion engines for improving their capability to ignite air-fuel mixtures. More specifically, during the past few decades, there has been work done on improving the ability of ignition systems to ignite air-fuel mixtures with poor ignition characteristics, especially of the inherently cleaner and more efficiently burning leans air-fuel mixtures.
Much of the prior art work on so called high energy ignition has focussed on alternative approaches other than coil design for delivering high ignition energy. Little attention has been given to improving the actual coil design, particularly in view of the recent development of the high efficiency, voltage doubling, low turns ratio coil principle disclosed in U.S. Pat. No. 4,677,960 referred to hereinafter as the Voltage Doubling Coil principle, or Doubling principle for short.
Prior art work on spark ignition, including ignition coils, are numerous, and for example, are summarized in Edward F. Obert's book, "Internal Combustion Engines and Air Pollution", pp. 532 to 566, Spark-Ignition Engines, Intext Educational Publishers, 1973. The work reported by Obert, and the work published since then, including the coil design presented in the above patent, are based on well established principles of designing coils by either winding the primary and secondary windings essentially concentrically, or on different arms of a closed magnetic core for high leakage inductance. Included are various ways of performing the winding, especially the much longer secondary winding, and these are well known to one skilled in the art.

High efficiency, high output, compact CD ignition coil


A method for transmitting virtual path failure information in an asynchronous transfer mode network the method includes performing search against a table storing virtual paths being used for generating failure indicative cells for respective ones of the virtual paths when failure of a transmission line is detected. The generated failure indicative cells are transmitted to all of the other apparatuses connected in downstream signal transmitting directions through the virtual path sequentially for a number of predetermined times, and subsequently, intermittently with an interval of a given period of time. When failure is removed, a normal cell is immediately transmitted.

The present invention relates to a method and apparatus for transmitting failure information of a virtual path in an ATM network for all of repeaters and receivers connected downstream of signal transmission direction, which repeaters and receivers will be hereafter referred to in general as "downstream device".
In the transmission networks, when failure is detected at the multiplexed level, a signal, so called an AIS (alarm indication signal) is transmitted to downstream devices of multiplexed paths, so as to prevent failure from propagating. For example, as discussed in Teranishi and Kitamura "Design of Digital Network Transmission Installation", page 32, Electrical Communication Association, 1984, AIS is transmitted by making all multiplexed paths marked.
However, in ATM (Asynchronous Transfer Mode), since a virtual path which corresponds to the multiplexed path, is identified by the header of a cell, AIS has to be transferred in a form of the cell, as discussed in Ohta, Hadama and Satoh "Operation and Maintenance Information in ATM-based transport Networks", 1989 National Conference in Autumn of the Institute of Electronics, Information and Communication Engineers, B-261. The cell used for transferring the maintenance signals, such as AIS, is called as "OAM (operation and maintenance) cell".
When AIS is transferred with the OAM cell, the transfer frequency of OAM cells has to be set optimally. In general, the bandwidth which is assigned to the virtual path has a wide range such as from tens k b/s to tens M b/s. In particular, when the assigned bandwidth is narrow, there is a possibility that the bandwidth of the OAM cells could increase beyond the assigned bandwidth. When the AIS transferring OAM cells is transmitted with a velocity which is beyond the nominal capacity of the assigned virtual path, since the virtual path assigned for the AIS is multiplexed with other virtual paths in the downstream devices, the bandwidths of the other virtual paths are disturbed by the OAM cells. This possibly causes an increase in cell loss ratio.
For instance, as shown in FIG. 1, assuming that a virtual path A having an average capacity of 0.1 Mb/s and a virtual path B having an average capacity of 1.5 Mb/s are accommodated in input lines C and D, each having 1.6 Mb/s capacity, and that the virtual paths A and B are multiplexed in an output line of 1.6 Mb/s capacity. In an ATM multiplexer, a cell buffer is used to store the cells, when the sum of the instantaneous cell rates becomes higher than the output line capacity for a short time.
In FIG. 1, if the average rate of the OAM cells for the virtual path A from the input line C becomes higher than 0.1 Mb/s for a period longer than the short time mentioned above, the cells of the virtual path B will be discarded, because a total input cell rate higher than 1.6 Mb/s makes the cell buffer full. As a result, cell loss ratio at other virtual path becomes higher. On the other hand, when the transfer frequency of the AIS transferring OAM cell is set to be too low, delay in detection of AIS may be caused due to overlooking of the OAM cell in the downstream devices in the virtual path upon occurrence of failure.

Method and apparatus for transmission of failure information of virtual path in ATM network


A syringe assembly has a syringe body adapted to be filled with an injectable liquid and having an annular neck defining an axis and having an axially outwardly open outlet. The neck is adapted to carry a needle. An elastomeric plug engaged axially inward with the neck closes the outlet and a holding ring is fixed to the neck below the plug. A retaining sleeve around the neck is fixed to the holding ring and a cup-shaped safety cap is fixed to the plug and has an end edge confronting the retaining sleeve and spaced axially therefrom. Frangible formations extend from the cap edge to the sleeve.

The present invention relates to a medical syringe. More particularly this invention concerns a prefilled syringe body ready for installation of a needle and use, and to a method of assembling such a syringe.
A syringe assembly has as described in commonly owned U.S. Pat. No. 5,785,691 a syringe body adapted to be filled with an injectable liquid and having an annular neck defining an axis and forming an axially outwardly open outlet adapted to hold a needle insert that blocks the outlet. The insert is formed with an axially through going passage so that a needle can be inserted axially through the passage of the insert into the body. A retaining collar engaged around the neck holds the insert in the outlet and a plug engaged in the passage fits over the retaining collar. A retaining sleeve fixed around the collar at the neck holds the collar on the neck and has an annular and axially outwardly directed end edge. A cup-shaped safety cap bearing axially inward on the plug has an annular and axially inwardly directed end edge confronting the retaining-sleeve edge and spaced axially therefrom by a gap which is bridged by a plurality of angularly spaced frangible webs unitarily formed with the sleeve and with the cap and extending from the cap edge to the sleeve edge.
The individual parts forming the cap subassembly, that is the insert and the cap, are made on different machines and must be mounted seriatim on the syringe body. Since this final assembly must be done after the syringe body is sterilized and filled, the parts forming the cap subassembly must also be sterile. Since these parts are made by different machines and at different locations, this entails a multipart sterilizing operation in the final clean room where the syringes are capped and prepared for transit.
It is therefore an object of the present invention to provide an improved syringe assembly.
Another object is the provision of such an improved syringe assembly which overcomes the above-given disadvantages, that is which is easier to assemble with the syringe body under sterile conditions.
A further object is to provide an improved method of assemblying a syringe.
A syringe assembly has according to the invention a syringe body adapted to be filled with an injectable liquid and having an annular neck defining an axis and having an axially outwardly open outlet. The neck is adapted to carry a needle. An elastomeric plug engaged axially inward with the neck closes the outlet and a holding ring is fixed to the neck below the plug. A retaining sleeve around the neck is fixed to the holding ring and a cup-shaped safety cap is fixed to the plug and has an end edge confronting the retaining sleeve and spaced axially therefrom. Frangible formations extend from the cap edge to the sleeve.
With the system of this invention the individual parts of the cap subassembly can be manufacture and put together in advance. Thus at the final assembly stage the cap subassembly is put onto the normally prefilled syringe body in a single operation made possible by the use of the holding ring. While the cap is made of a relatively hard and brittle material and similarly the syringe body is made of glass or a hard plastic, the holding ring is somewhat softer so that, even though the plug and holding ring are in the hard cap, they can be fitted over the hard syringe body while assembled together. The saving on steps in assembly is substantial, since the entire cap subassembly can be sterilized at the same time.
The safety cap according to the invention is formed with a pair of radially inwardly projecting ribs engaging the plug. They hold the plug solidly in place while still leaving space for sterilizing liquid or gas to flow through the cap subassembly.
The safety cap itself is formed with an internal annular shoulder and the plug has an enlarged portion engaged over the shoulder to fix the plug permanently in the cap once it is pushed into place. In addition the safety cap is formed with at least one radially throughgoing aperture that gives the end user the ability to see if the plug is properly in place before cracking off the cap. The ribs are normally provided 90xc2x0 offset from the windows so they cause the plug to bulge out the windows, further increasing the hold of the plug in the cap.
The retaining sleeve is formed with a radially inwardly open groove in which the holding ring is fitted. In another system the retaining sleeve is formed with an axially outwardly directed shoulder and the holding ring engages over the shoulder. In both situations the holding ring must be damaged or destroyed to separate it from the retaining sleeve once installed therein.
The holding ring itself according to the invention has an outwardly projecting and axially centered collar formed with an internal luer thread. Thus once the cap is broken off the retaining sleeve and removed along with the plug, a needle subassembly including an externally threaded luer-type base can be screwed right into the collar of the holding ring.
The retaining sleeve in accordance with the invention has a sleeve edge axially confronting and juxtaposed at a gap with the cap end edge. The formations include a plurality of frangible webs unitary with and extending axially between the edges. In addition a plurality of angularly spaced spacer blocks formed on one of the edges alternate with the webs and project at least partially across the gap toward the other edge. The webs are angularly equispaced about the axis and taper toward the retaining sleeve. Thus the axially inwardly effective force applied to the cap to force the holding ring over the neck will be transmitted by the blocks to the retaining sleeve while the frangible webs deform slightly elastically. The cap will not separate from the retaining sleeve unless it is tipped, twisted, or pulled axially out relative to it.
The neck is formed with an outwardly open seat receiving the holding ring. As a result the holding ring will be slightly elastically deformed as it is fitted over the neck, but the axial force to do this will be transmitted by the blocks from the cap to the sleeve carrying the holding ring. Any other force will cause the frangible webs to break well before the holding ring would pull of the neck, so the system is highly tamper proof. Any attempt to open and reclose the syringe would be evident.
The method according to the invention basically comprises the steps of supporting the holding ring on a support element, then fitting the plug over the support element adjacent the holding ring thereon and fitting the cap, formations, and sleeve over the holding ring and plug so that the plug seats and fixes itself in the cap and the holding ring seats and fixes itself in the sleeve. This action forms an integral assembly of the ring, plug, cap, formations, and sleeve which is then sterilized and fitted as one piece over the neck of the body until the ring locks in place thereon with the plug blocking the outlet. Of course according to the invention the ring, plug, cap, formations, and sleeve are fitted together under sterile conditions.
Once sterilized, the assembled ring, plug, cap, formations, and sleeve are encased in a hermetic envelope. This envelope is transported another clean room and there them to the syringe body. Production is therefore greatly rationalized and simplified with the sterile cap assemblies being produced in advance at another location and enclosed in respective hermetic envelopes. In another clean room at the fillers site the packages are opened and the sterile cap assemblies are fitted to the normally prefilled syringe bodies.

Arzneimittel GmbH Apotheker Vetter and Co. Ravensburg


In a method for the depolymerization and reprocessing of material which consists of polyamide 6 waste and/or oligomer-containing polyamide 6 waste and/or oligomer-containing lactam residues and/or oligomer-containing lactam by hydrolysis in a pressure reactor with the addition of water, the material is melted and the melt is conducted continuously at predetermined temperature through the pressure reactor the inside pressure of which is controlled by the dosaged feeding of water or steam.

The present invention relates to a method for the production of polyamide 6 from polyamide waste and to an apparatus for the carrying out of this method.
In the production and processing of polyamide 6 pellets, polyamide 6 waste is produced which is to be further processed in order to improve the economy of the material.
Thus, polyamide 6 waste, if necessary comminuted, is melted down in an extruder and converted into a pelletizable strand. This process is frequently employed for the production of injection-molded pellets since the demands made on these pellets with respect to uniform molecular weight distribution and viscosity are not as great as on pellets which are to be worked into polyamide filament or film.
Furthermore, it is known to depolymerize polyamide waste down to the initial raw material, caprolactam. This method has the disadvantage that it is very detrimental to the environment and very expensive since phosphoric acid is used for the depolymerization and the lactam recovered must be repeatedly distilled to obtain a lactam of high purity. Furthermore, residues remain which must be disposed of.
From East German Patent 264,119, a method for the partial depolymerization of high-molecular polyamide 6 to caprolactam is known in which the caprolactam used as solvent and depolymerization agent is itself simultaneously polymerized, there being obtained therefrom a copolymer having a uniform, ordinary molecular weight distribution. Laboratory experiments have shown that while caprolactam is a good solvent for polyamide 6, it does not act as a depolymerization agent, which is also not possible from a standpoint of the chemism of the course of the polymerization. Only a solution mixture of high-molecular polyamide and lactam is produced. With a product temperature of about 270.degree. C., a polyaddition reaction takes place, i.e. lactam adds onto the non-depolymerized, highly viscous polyamide molecules insofar as the latter are capable of reaction at all. In addition to this, high-molecular polyamide particles which are strongly crosslinked beyond the normal extent, so-called gel particles, are present in the resultant polymer; they are produced upon the cooling of the polyamide waste in the atmosphere of the air, cannot be broken down by the method described in East German Patent 264,119, and thus accumulate in the polyamide.

Method and apparatus for the production of polyamide 6 from polymide waste


Processing a communication is disclosed. A first request to establish communication is received at a redirection node from a requesting communication participant. A destination communication participant associated with the request is determined. A communication session in which the requesting communication participant, the redirection node, and the destination communication participant are participants is established, including sending to equipment associated with the destination communication participant a second request to establish communication. A communication session processing feature not provided with respect to the communication session by a telecommunication service provider associated with a service provider network used to establish and provide the communication session is made available to at least one of the requesting communication participant and the destination communication participant.

Telecommunication processing has been traditionally limited to processing features offered by telecommunications providers. Features such as call forwarding usually require a service agreement with the telecommunications provider to utilize call processing systems maintained by the telecommunications provider. Since telecommunications processing requires the use of communication devices and/or infrastructure beyond the control of the user entity, it is difficult for the user entity to implement new call processing features and/or configure or modify existing services and call processing features. Attempts have been made to implement private telecommunications systems, e.g. PBX (Private Branch Exchange) systems, but they typically lack the ability to extend processing capabilities beyond physically local areas. Also, many desirable processing features have not been available in previous systems. Therefore, there exists a need to enable new ways for telecommunications user entities to implement and control telecommunications processing.

Enhanced services provided using communication redirection and processing


Techniques for reducing resonance in contact fingers of a connector are described herein. An example of a device in accordance with the present techniques includes an add-in-card that includes a circuit board and an edge contact finger disposed on an outer surface of the circuit board. The add-in-card also includes a resonator disposed in an internal layer of the circuit board and coupled to the edge contact finger, wherein the resonator reduces a resonance in the edge contact finger.

Computer systems include a number of components and elements. Often the components are coupled via a bus or interconnect. Previously, input/output (I/O) devices were coupled together through a conventional multi-drop parallel bus architecture referred to as Peripheral Component Interconnect (PCI). More recently, a new generation of an I/O bus referred to as PCI-Express (PCIe) has been used to facilitate faster interconnection between devices utilizing a serial physical-layer communication protocol.
As devices and components become more complex and undertake heavier workloads, performance and power management have become increasing concerns. Part of the performance rests in the transfer speeds at the physical layer. The current PCI Express connector, which operates at 2.5, 5, and 8 GT/s to support Gen 1, 2, and 3 data links, respectively, may not be capable of supporting the 16 GT/s data rate that Gen 4, the future generation of PCIe seeks to achieve. Even with shorter channels, an investment in lower-loss board materials, and improved control of other channel elements, the connector could pose a barrier to Gen 4 implementation.
One data rate limitation is a pronounced resonance in the connector interface that manifests at roughly 8 GHz. This resonance causes frequency notches in the channel differential insertion loss, and corresponding peaks in return loss and lane-to-lane crosstalk that limit its use in a 16 GT/s channel. Several manufacturers produce PCIe connectors, so slight differences in this phenomenon may exist among them. It is understood that this general effect is present in many currently available products, since their basic geometry must conform to the PCIe Card Electromechanical Specification. Due to industry inertia and desire to maintain backward compatibility, it would be difficult to adopt a new high performance connector to supplant the current PCIe connector form factor. A backplane connector, for example, would preclude backward compatibility with current PCIe cards. Consequently, a method of suppressing the resonances in the current form factor is sought to improve data transmission at 16 GT/s.
Currently, with few exceptions, PCIe connector pins and add-in-card (AIC) terminal fingers are manufactured using identical geometry, even though some pins are assigned to high speed differential data lanes, some to lower speed clock lanes, and others to sideband signals, power, and ground. The ground pins adjacent to signals are physically no different from the signal pins, for example. For many pin positions the routing of the designated ground networks contributes to resonances by introducing unwanted reflections. Moreover, the resonance potentially causes crosstalk (e.g. inducement of current on an unintended conductor due to the electromagnetic field generated by driving current/signal on an intended conductor).