The reductive removal of nitrogen oxides from the exhaust gas from internal combustion engines operated predominantly under lean conditionstakes place in a selective catalytic reduction (SCR) of the nitrogen oxides by means of ammonia or a compound which can be decomposed into ammonia as reducing agent. Conventional SCR catalysts typically have a relatively narrow working temperature window, usually 350° C. to 520° C., in which good nitrogen oxide conversions can be achieved with sufficient selectivity. SCR catalyst formulations whose working window is in the temperature range from 150° C. to 350° C. generally not be used at higher temperatures since they oxidize the ammonia required as reducing 18 agent to nitrogen oxides at above 350° C. To cover the entire exhaust gas temperature range typical of vehicles having been operating internal combustion enginesextending from 200° C. to 600° C., it has therefore mostly been necessary to use complicated exhaust gas systemscontaining a plurality of catalysts having different working temperature ranges. Disclosed is a structured SCR catalyst whose working range extends over a significantly broader temperature window and by means of which complicated exhaust gas units can be considerably simplified, with a saving of components.

The present invention relates to a structured catalyst for the removal of nitrogen oxides from exhaust gases from internal combustion engines operated predominantly at a lean air/fuel ratio by selective catalytic reduction using ammonia or a compound which can be decomposed into ammonia as reducing agent. Such internal combustion engines are diesel engines and directly injected petrol engines. They are referred to collectively as lean-burn engines.
The exhaust gas from lean-burn engines contains not only the usual pollutant gases carbon monoxide CO, hydrocarbons HC and nitrogen oxides NOx but also a relatively high proportion of oxygen of up to 15% by volume. Carbon monoxide and hydrocarbons can easily be made nonpolluting by oxidation. The reduction of the nitrogen oxides to nitrogen is significantly more difficult because of the high oxygen content.
A known method of removing nitrogen oxides from exhaust gases in the presence of oxygen is the process of selective catalytic reduction (SCR process) by means of ammonia which can also be generated in situ from a precursor compound such as urea. In this process, comproportionation of the nitrogen oxides with ammonia takes place with formation of nitrogen over a suitable catalyst, referred to as SCR catalyst for short.
Since internal combustion engines are operated in transient driving cycles in the motor vehicle, the SCR catalyst has to ensure very high nitrogen oxide conversions at good selectivity even under widely varying operating conditions. Both complete and selective nitrogen oxide conversion at low temperatures and selective and complete conversion of high concentrations of nitrogen oxide as occur, for example, during full-load driving in very hot exhaust gas have to be ensured. In addition, the widely varying operating conditions present difficulties in the exact metering of ammonia, which should ideally be introduced in a stoichiometric ratio to the nitrogen oxides to be reduced. As a result, severe demands are made on the robustness of the SCR catalyst, i.e. its ability to reduce nitrogen oxides to nitrogen with high conversions and selectivities over a broad temperature window at highly variable space velocities over the catalyst and a fluctuating supply of reducing agent.
EP 0 385 164 B1 describes all-active catalysts for the selective reduction of nitrogen oxides by means of ammonia, which contain titanium oxide and at least one oxide of tungsten, silicon, boron, aluminum, phosphorus, zirconium, barium, yttrium, lanthanum and cerium together with an additional component selected from the group of oxides of vanadium, niobium, molybdenum, iron and copper.
U.S. Pat. No. 4,961,917 claims catalyst formulations for the reduction of nitrogen oxides by means of ammonia, which contain zeolites having a silica:alumina ratio of at least 10 and a pore structure which is linked in three dimensions by pores having an average kinetic pore diameter of at least 7 Angstrom together with iron and/or copper as promoters. EP 1 495 804 and U.S. Pat. No. 6,914,026 disclose methods of improving the stability of such zeolite-based systems under hydrothermal aging conditions.
The SCR catalyst formulations described in the documents mentioned, which represent the present prior art, all display good nitrogen oxide conversions only above 350° C. In general, the reaction proceeds optimally only in a relatively narrow temperature range. This conversion optimum is typical of SCR catalysts and is due to the mode of operation of the catalysts.
As a result of the optimal stoichiometry of the reaction, the reduction of a 1:1 molar mixture of nitrogen monoxide NO and nitrogen dioxide NO2 with ammonia NH3 proceeds many times as quickly as the reduction of pure nitrogen monoxide NO. The nitrogen oxides NOx present in the exhaust gas from lean-burn engines comprise predominantly NO and have only small proportions of NO2. However, since the oxidation of NO to NO2 has to be promoted kinetically by an oxidation catalyst at temperatures below 300° C., SCR catalysts do not display any significant conversions in the low-temperature range if they do not have a certain oxidizing power. On the other hand, an excessively high oxidizing power at temperatures above 350° C. leads to ammonia being oxidized by the high oxygen content of the exhaust gas from lean-burn engines to form lower-valent nitrogen oxides such as nitrous oxide N2O. This firstly results in loss of the reducing agent required for the SCR reaction and, secondly, NOx in the form of the undesirable secondary emission N2O is formed. This leads overall to a significant limitation of the operating window of low-temperature SCR catalysts to a very narrow temperature range. For example, SCR catalysts containing noble metals display very high NOx conversions in the range from 100 to 250° C., but the temperature range in which the catalyst operates with satisfactory selectivity to nitrogen is generally restricted to from 20 to 50° C.
The conflict in terms of objectives between an oxidizing power which is too high and consequently a lack of selectivity and an oxidizing power which is too low and therefore unsatisfactory lower-temperature activity is the reason why SCR catalysts such as the formulations mentioned in EP 0 385 164 B1 or U.S. Pat. No. 4,961,917 have to be used either in combination with an upstream oxidation catalyst or/and in combination with a further catalyst capable of reducing nitrogen oxides for removing nitrogen oxides from the exhaust gas from lean-burn engines in order to be able to ensure removal of the nitrogen oxides at all operating temperatures which occur during driving operation, which are in the range from 200° C. and 600° C. The supplementary catalyst capable of reducing nitrogen oxides can be a low-temperature SCR catalyst, a nitrogen oxide storage catalyst, an HC-DeNOx catalyst or another suitable, reduction-active catalyst technology or combinations thereof.
For example US 2006/0039843 discloses such a system solution. Paragraph [0062] describes, as advantageous embodiment, a system for purifying exhaust gas, in which a substrate coated with an SCR catalyst is arranged between the reducing agent injector and a catalyst support which is coated with an SCR catalyst and an ammonia decomposition catalyst. The SCR catalyst formulations are, in a preferred embodiment according to this text, selected so that the first catalyst operates optimally at relatively high operating temperatures while the second catalyst is more suitable for use in cooler segments of the exhaust gas system.
DE 103 60 955 A1 describes an exhaust gas purification unit for an internal combustion engine, in which ammonia utilized as reducing agent in the SCR reaction is generated from appropriate exhaust gas constituents over a first (in the flow direction) catalyst when a rich exhaust gas composition is present. The ammonia generated by the first catalyst is stored temporarily on a second (in the flow direction) catalyst in the case of a rich exhaust gas composition. In the case of a lean exhaust gas composition, the nitrogen oxides present in the exhaust gas are reduced using the temporarily stored ammonia. Downstream of the second catalyst, there is a third, noble metal-containing catalyst which comprises at least one of the platinum group metals Pt, Pd or Rh on support materials which are able to store ammonia in the case of a rich exhaust gas composition and liberate ammonia in the case of a lean exhaust gas composition. According to this document, the temperature activity ranges of the standard SCR catalyst used in the second position and the noble metal-containing catalyst complement one another so that the proposed exhaust gas purification unit is able to increase the nitrogen oxide conversion considerably, especially at low temperatures.
Although such system solutions ensure that the nitrogen oxides present in the exhaust gas from the lean-burn engine are largely removed in transient operation of the engine, they have considerable disadvantages. Thus, space has to be provided in the vehicle for installation of all catalysts required. Furthermore, each catalyst generates a measurable exhaust gas counterpressure which leads to reductions in the engine power available for operating the vehicle and thus ultimately to increased fuel consumption. In addition, such system solutions require complicated studies on the vehicle application during the development phase of a vehicle so as to ensure that all catalysts are arranged in an optimal position with regard to conversion and selectivity behavior. Here, the optimal position of the catalysts is critically dependent on the achievable operating temperatures and thus firstly on the distance from the engine and secondly on the heat losses in the exhaust gas unit. Of course, each further component incurs higher costs.
In paragraph [0021] of the abovementioned document DE 103 60 955, it is proposed that, in order to minimize the pressure drop, the third, noble-metal containing catalyst be applied to an outflow-end zone of the second catalyst, with this zone covering from 5 to 50% of the total length L of the second catalyst.
The proposed solution reduces the difficulties caused by the configuration as a system to only a limited extent. Since the third catalyst configured as an outflow-end zone of the second catalyst is a noble metal-containing catalyst and, as a result of its high oxidizing power, displays unsatisfactory selectivity to nitrogen at temperatures above 250° C., high N2O secondary emissions are to be expected above this temperature.

Structured SCR catalyst for the reduction of nitrogen oxides in the exhaust gas from lean-burn engines using ammonia as reducing agent


An imaging device, such as a digital camera, has a mechanism for compensating an image blur caused by hand jiggling and is capable of consecutively shooting, through one operation of a shutter operation section (36), frames of an image in a state where the mechanism (20) is operational and in a state where the mechanism is not operational.

In recent years, an imaging device (hereinafter, referred to as "digital camera") such as a digital still camera and a digital video camera, which is capable of converting an optical image of an object to an electrical image signal to be outputted therefrom, has rapidly come into widespread use. There has been brought a dramatic improvement in reducing a size and a weight of a digital camera and in increasing magnification of optical zoom, markedly enhancing user-friendliness. As a result, the digital camera has become an imaging device which can be much commonly handled by a general user.
However, if the down sized and light weight digital camera having the zoom of large magnification is used by a person who is not skilled in shooting, hand jiggling is easily caused upon shooting. And if the hand jiggling is caused, shot images cannot be stable, resulting in markedly deteriorated quality of the shot images.
As a digital camera enabling a reduction in quality deterioration, which is caused by the hand jiggling, of shot images, for example, as disclosed in patent documents 1 and 2, many digital cameras carrying mechanisms for compensating influence of the image blur caused by the hand jiggling have been developed and already commercialized.
And a consecutive shooting function, in the digital camera, with which a plurality of frames of an image can be consecutively shot through one shutter operation performed by a shooter has been upgraded. Furthermore, a digital camera having a function, such as an automatic bracket function, of shooting while changing shooting conditions such as an exposure has become popular.    Patent document 1: Japanese Laid-Open Patent Publication No. 2000-13671    Patent document 2: Japanese Laid-Open Patent Publication No. 2001-117129


A headlamp adjuster includes an adjustment gear for axially positioning an output shaft relative to a housing of the adjuster. A driving engagement of the adjustment gear and output shaft runs out at either axial extreme position to which the output shaft can be adjusted, and rotation of the adjustment gear can continue without further movement of the output shaft and without damage to the adjuster or a headlamp assembly in which the adjuster is installed. Biasing assemblies urge the output shaft toward re-engagement with the adjustment gear when the drive direction is reversed.

The direction of light output from headlamps on motor vehicles requires proper aiming, both vertically and horizontally, for safe and optimal performance. Accordingly, adjustment or "aiming" is performed before a vehicle is put into service and may be performed from time to time thereafter if vibration or other conditions or events move the headlamp away from optimal positioning. It is known to provide headlamp assemblies adjustable about both vertical and horizontal axes with adjusters operated by screwdrivers or other implements for lengthening and shortening the adjuster to cause the headlamp assembly to pivot about an axis. Some known adjustment mechanisms include bushings, bosses, O-rings and push nuts that need to be connected to a screw during installation. Although adjusters of this type have proven to be useful, because of the many individual components required, labor for assembly and installation are high. It is preferable to have a pre-assembled adjuster that can be installed quickly and easily in the headlamp assembly and be ready for immediate adjustment.
In some known adjuster configurations, an output shaft is operatively connected to a movable reflector in the headlamp assembly. Linear movement of the adjuster output shaft pivots the reflector to change the direction of light reflected therefrom. In the adjuster, one or several gears can be driven by screwdrivers or other implements for rotating mechanisms in the adjuster and causing linear movement of the output shaft. Problems and difficulties can be encountered if the adjuster is adjusted too far in either direction. If moved axially longer than intended, the headlamp assembly or the adjuster can be damaged, requiring repair or replacement. If withdrawn too far, the output shaft can become disengaged from its driving mechanisms, again causing difficulties and problems which may require replacement or disassembly and repair. When such over adjustment occurs on an assembly line, assembly line output is adversely affected. If over adjustment occurs after the vehicle has been placed in use, access for repairing or replacing the adjustment mechanism can require significant disassembly and cost in time and expense. Placing axial restraints on the movement of the output shaft of the adjuster can eliminate the problem of over adjustment in either direction, but also may result in damage to the drive mechanisms of the adjuster if the restraints are encountered and adjustment attempts continue. Damage may be more likely if powered tools are used for effecting the adjustment.
What is needed is a headlamp adjusted that can tolerate over adjustment in either direction, without damage to the adjuster or to the headlamp assembly in which it is installed, and without becoming disengaged to the extent of being nonfunctional for all purposes.


A frequency divider has an inverting unit and a plurality of switch inverters in series. Each switch inverter comprises two inphase switches and is controlled by a clock. The two inphase switches of each switch inverter are respectively supplied by a first voltage and a second voltage, while any two switch inverters in series are respectively controlled by two inverted clocks. The two inphase switches are selectively turned on and off synchronously.

1. Field of the Invention
The present invention relates to a frequency divider; more particularly, the invention relates to a low-noise frequency divider dividing the high frequency of a clock by 2K.
2. Descriptions of the Related Art
Frequency dividers are widely applied in many fields. For example, in radio frequency (RF) transceivers, a TX RF low band requires a frequency divider to divide the frequency of a clock by four, while a TX RF high band requires a frequency divider divide the frequency of a clock by two. In addition, a RX low band requires a frequency divider to divide the frequency of a clock by four and output four quadrature signals.
Operation frequencies of the TX and RX modes differ by 20 mega Hz (20 MHz), therefore the TX mode is designed to have a lower phase noise at 20 MHz. There are two conventional designs of frequency dividers. One is the dynamic frequency divider, which has a low phase noise, but cannot deal with a high frequency clock. The other frequency divider is a source-coupled-logic (SCL) frequency divider, which can tolerate high frequency clicks, but lacks phase noise integrity.
U.S. Pat. No. 6,130,564 discloses a frequency divider with two inputs and one output. Even though the frequency divider performs a high frequency divider circuit, the frequency divider cannot perform a rail-to-rail swing range; therefore, the frequency divider may function incorrectly due to an indistinguishable signal caused by the non-rail-to-rail swing range.
The paper "A quad-bad GSM-GPRS transmitter with digital auto-calibration" presented in the 2004 JSSC discloses a frequency divider that applies charge sharing principles with the inverter-combined-transmission gate circuitry to achieve frequency dividing. However, due to resistance-like characters of the transmission gate, the charge flowing through the transmission gate cannot flow too quickly. Thus, the frequency divider cannot tolerate high frequency.
As a result, a low-noise frequency divider that divides the high frequency of a clock by 2K is needed in the communication industry.


The current invention relates to the need in the art for a bow sighting device that provides accuracy with the versatility that allows the sighting device to be readily transferred to any bow and fully calibrated using minimal sight in distances. From two sight-in yardages, the current invention extrapolates the remaining yardages on a visible scale essentially filling in the gaps using known mathematical principles of trajectory. Vertically arced displacement of a bow sight used in conjunction with the current invention is capable of performing this desirable function on any bow while allowing the archer to manually select a desired range from full draw.

In the field of archery, target sights have become as important as the bow itself. Conventional bow sights may include a number of sight pins that are manually set by the archer to sight in the arrow. Sighting requires the archer to make repeated releases toward a target located at a predetermined distance while making fine adjustments to the corresponding sight pin. This process is repeated for each desired distance and is known by archers to become cumbersome and time consuming, particularly when sighting multiple bows. Although providing a method for greater accuracy, the presence of multiple sight pins obscures the view of the target and requires the archer to remember the value of each pin while estimating when targets are located between the sighted values.
Efforts have been made to develop archery sights having a single pin capable of vertical adjustments to mimic the theory of multiple sight pins. However, these sights require the same process of fine adjustments for multiple sighting distances repeated for each bow. Like the multiple-pin sights, the archer is required to use two hands to make vertical adjustments to the single sight pin while remembering the scaled setting that applies to each predetermined distance. Therefore, the need for marking each pre-calibrated distance offers little to address the time-expense issue that is much needed in the art.
More recently in the art, moveable-pin sights offer the archer the ability to sight in an arrow using a graduated scale, whereby the vertical positioning of a single sight pin corresponds to a yardage scaled tape prepared by the archer. As known in the art, bow speed impacts the required trajectory necessary to for the bow to travel to the target. Due to this mathematical principle, greater adjustments in the angle of trajectory are required, when attempting to hit a target with a slower bow. The advantage of a real world scale removes the guesswork necessary by the archer; however, each tape used is sighted for a specific bow speed and arrow. As a result the moveable-site cannot be used on multiple bows without creating multiple, removable, scaled tapes.


An X-ray tube generates X-rays. An X-ray detector detects X-rays generated from the X-ray tube and transmitted through an object to be examined. A rotating frame continuously rotates the X-ray tube and the X-ray detector around the object. A reconstruction unit reconstructs a plurality of first volume data sets with different scan times for the same scan area of the object on the basis of an output from the X-ray detector. An image processing unit generates single second volume data set corresponding to a maximum value, an average value, a median value, or minimum value of the plurality of reconstructed first volume data sets in the temporal direction.

1. Field of the Invention
The present invention relates to an X-ray computed tomography apparatus and image processing apparatus which generate a plurality of volume data sets with different scan times for the same scan area of an object to be examined.
2. Description of the Related Art
In an X-ray computed tomography apparatus, a technique called a 4DCT scan is available to generate a plurality of volume data sets with different scan times for the same scan area. Recently, this 4DCT scan can superimpose a blood vessel image and a functional image for a blood flow (perfusion). This superimposition processing is useful for image diagnosis. A blood vessel image concerns a time (e.g., a time near a peak of a TDC) at which a blood vessel is imaged most clearly by CT angiography (CTA). A functional image is calculated on the basis of a plurality of volume data sets. More specifically, a functional image is generated by calculating an index (e.g., a CBP, CBV, or MTT) indicating the blood flow dynamic state of tissue (e.g., brain tissue) for each voxel and assigning pixels pieces of color information corresponding to the calculated index values (see, for example, Jpn. Pat. Appln. KOKAI Publication No. 2003-190148).
When a blood vessel image is to be generated, since different volume data sets to be processed exhibit different blood flow dynamic states, the user needs to designate optimal positions (or ranges) for blood vessel image generation for all the volume data sets. In addition, when blood vessel image data is generated on the basis of the volume data set, of all the volume data sets, which concern a predetermined period of time, the generated blood vessel image does not contain any information about a blood vessel at which a contrast agent has not arrived within the predetermined period of time. This causes a phenomenon in which the blood vessel is not imaged even after the function is restored.
When function analysis based on TDC (e.g., an algorithm such as the deconvolution method) is to be executed on the basis of a plurality of volume data sets with different scan times, since the amount of data to be processed is large, a problem arises in terms of processing time.


A maintenance system of a hydraulic excavator (11) is provided with a maintenance monitoring device (21), a maintenance management server (12) for managing trouble information and operating information for each working machine, a model information server (13), and a service personnel mobile terminal (14) connected to one another through the Internet (15). When trouble occurs in the hydraulic excavator, the maintenance system (21) transmits trouble information to the maintenance management server (12), and the maintenance management server (12) transmits information on occurrence of trouble to the mobile terminal (14) and displays it on a display unit. This system manages the maintenance manuals and other data for each model in a model information database separate from the maintenance database and correlates the two databases based on the model data.

Conventional fault-diagnosis or troubleshooting of a working machine disposed at a work site has usually been performed by the actions of service personnel trained in troubleshooting heading out to the site, performing work for detaching the outer panels of the working machine, running conduction checks on the various sensors and the like, then diagnosing trouble locations, and causes of trouble based on the results of the inspection and in accordance with the experience and knowledge of the service personnel while referring to a repair manual. Next, the service personnel was asked to repair the troubles as requested by the customer as a result of the troubleshooting. Depending on the content of the trouble, sometimes the service personnel could immediately repair the trouble in the site, but other times he had to make the repair while referring to a more detailed repair manual when his experience was insufficient or the trouble was complicated. Further, sometimes parts had to be replaced to repair the trouble. When a detailed repair manual was required or when the inventory of replacement parts had to be examined, he returned to the office.
According to the troubleshooting based on the "Data Collection Device of Drive Machines" disclosed in Japanese Patent Publication (A) No. 7-30977 (Japanese Patent No. 2767363), a body controller mounted on the body of a working machine is connected with an external controller through a communications line, the two controllers communicate, and a troubleshooting program is executed by the body controller and the external controller collects trouble data and diagnoses the trouble based on the trouble data.
The method of service personnel heading out to the work site in which the working machine is disposed to diagnose trouble is troublesome and poor in the efficiency of the maintenance work. Further, when the trouble cannot be immediately repaired on the site, it becomes necessary to return to the office to obtain information of more detailed repair manuals or information on inventory of replacement parts. This is inconvenient for the service personnel and further reduces the work efficiency. In this case, the customer cannot determine when the trouble will be fixed and cannot draw up a work schedule. Further, there was the problem that an estimate of the costs required for repair of the trouble could not be immediately prepared.
With the troubleshooting method disclosed in Japanese Patent Publication (A) No. 7-30977, the work of troubleshooting is simplified and improvement of the work efficiency is aided. However, this method requires that the service personnel transport the external controller to the site, connect the external controller to the body controller mounted in the working machine, and start up a troubleshooting program. In the sense of the service personnel heading out to the site, this method had the same problem as the above-explained conventional troubleshooting method. Also, in view of repairing the trouble the above-mentioned problems are not solved.
On the other hand, in recent years, the working machines have become more diverse in models and design to meet with customer requests. Specifications differ according to the models, and it becomes necessary to prepare manuals or troubleshooting tools, etc. individually for maintenance or repair of the models. Managing the maintenance manuals etc. becomes troublesome and separate work is required for checking inventories or placing orders for the parts for repairing the trouble by referring to parts lists for the different models. Accordingly, time and trouble are required for the maintenance and repair.
Further, recently, there are rental companies owning large numbers of working machines. Some rental companies manage the working machines and maintain and repair them on their own. Even such rental companies suffer from the above problems in maintenance in the same way as the machinery manufacturers.
An object of the present invention is to solve the above problem and provide a maintenance system for a working machine effective for a user such as a rental company independently managing the machines, in which maintenance manuals, part lists, or other data for different models are managed by a model information database of the machinery manufacturer, constructed separately from the maintenance database managed by the machinery manufacturer or rental company, etc., the two databases are correlated on the basis of the model so as to be able to centralize the maintenance work, reduce the work time for maintenance and diagnosis, raise the work efficiency.

Hitachi Construction Machinery Co., Ltd.


A wafer polishing apparatus is provided with a rotating platen to which a polishing pad is affixed and a polishing head that holds a wafer placed on the polishing pad while pressing the wafer. The polishing head has a membrane that contacts the upper surface of the wafer and applying a pressing force thereto and a support plate that supports the membrane. The membrane has a main surface part facing the bottom surface of the support plate and a side surface part facing the outer peripheral edge surface of the support plate. The vertical tension due to the side surface part of the membrane is larger than the lateral tension due to the main surface part of the membrane.

Silicon wafers are widely used as a substrate material for semiconductor devices. The silicon wafers are manufactured by sequentially applying processes such as outer peripheral grinding, slicing, lapping, etching, double-side polishing, single-side polishing, washing, etc., to a silicon single crystal ingot. Among the above processes, the single-side polishing is a process required in order to remove unevenness or waviness on the wafer surface and thus to enhance flatness, in which mirror-finishing by CMP (Chemical Mechanical Polishing) method is performed.
Typically, in the single-side polishing process for a silicon wafer, a single wafer polishing apparatus (CMP apparatus) is used. The wafer polishing apparatus includes a rotating platen to which a polishing pad is affixed and a polishing head that holds a wafer on the polishing pad while pressing the wafer. The apparatus polishes one side of the wafer by rotating the rotating platen and polishing head while feeding slurry.
In order to enhance uniformity of the polishing amount in a wafer surface by uniformly pressing the entire surface of the wafer, a wafer polishing apparatus using a membrane pressurization type polishing head is used. For example, Patent Document 1 describes a wafer polishing apparatus having a membrane that transmits a pressing force to a wafer on the polishing pad and a tension adjusting means for adjusting tension of the membrane. Further, in order to make the polishing amount in a wafer surface uniform, Patent Document 2 describes a polishing head in which areas having different surface roughnesses are concentrically disposed on a wafer holding surface of a membrane (elastic body film). The areas include a first area formed from the outer periphery of the membrane to a section from 10% to 80% of the radius thereof and having an arithmetic-mean roughness Ra of 5.0 μm to 50.0 μm and a second area formed inside the first area having an arithmetic-mean roughness Ra of less than 5.0 μm. Further, Patent Document 3 describes a membrane for a polishing head having a circular bottom part, a wall part rising from the outer edge of the circular bottom part, an annular part extending from the upper end of the wall part to the central direction of a circle, and a projection part located at the terminal end of the annular part.

Wafer polishing apparatus and polishing head used for same


A tire pressure monitoring system (TPMS) is provided. The TPMS includes: a plurality of sensors which output sensing signals, the plurality of sensors including a printable pressure sensor which senses an air pressure of a tire, and a temperature sensor which senses an air temperature inside the tire; a signal processor which is configured to process the sensing signals output by the plurality of sensors; a wireless power receiver which is configured to receive energy from a power source and output power; and a rechargeable battery which is configured to be charged by the power output by the wireless receiver and supply power to the plurality of sensors to sense the air pressure of the tire and the air temperature inside the tire.

1. Field
Embodiments consistent with the present disclosure relate to a tire pressure monitoring system.
2. Description of the Related Art
Abnormalities in tire pressure may cause a significant vehicle accident, such as a burst of a tire due to abnormal wear or heat generation on both sides of a tire tread, a decrease in handling stability, deterioration of gas mileage, or an occurrence of hydroplaning at a low driving speed. Therefore, monitoring a tire pressure is important in order to secure stability of a vehicle.
A tire pressure monitoring system (TPMS) is a device that informs a driver or another device of a vehicle of air pressures of tires, i.e., tire pressure. The TPMS helps to prevent insufficient tire pressure, or tire damage, from causing an accident and inefficient gas mileage.


A resonator structure is presented comprising a closed loop resonator having a distributed Bragg reflector for confining the light within the guiding core. In one embodiment the light is confined from both the internal and the external sides of the device forming a guiding channel (defect) or just by the external side forming a disk resonator. Although the perfectly circular shape is generally preferred, the resonator could be of any closed loop shape such as an ellipse, etc. Although not mentioned explicitly throughout the text, the Bragg reflectors can of any type of distributed reflector such as, for example, a photonic bandgap crystal where the Bragg reflector is constructed by series of holes in a dielectric material. The resonator structure can be used in various applications, such as optical filters, lasers, modulators, spectrum analyzers, wavelockers, interleave filters, and optical add drop multiplexers.

1. Field of the Invention
This invention relates to resonant optical cavities and more particularly to ring-like cavities used in integrated optical devices.
2. Description of the Prior Art
An optical resonator is an important element, which can be incorporated into many of the components used for optical communication systems such as lasers, filters, routers, switches, etc. Such resonator can be easily realized in integrated optical devices with linear waveguides to form a planar lightwave circuit (PLC). One of the most common roles of the optical resonator is to serve as a wavelength dependent coupler between two (or more) waveguides (input/output (I/O) waveguides). This is schematically illustrated in FIGS. 1A and 1B, wherein a circular resonator serves for coupling between two linear waveguides. The light couples from one (input) linear waveguide into the resonator waveguide and from the resonator to the other (output) linear waveguide. In specific wavelengths, known as the resonance wavelengths of the resonator structure, all the light is eventually transferred from the first linear waveguide to the second linear waveguide. The resonator is typically characterized by following parameters:                Free spectral range (FSR);        Loss per revolution;        Coupling to the waveguides;        Q factor, which can be derived from the three parameters defined above.If the material of which the resonator is made of is "active" (i.e. able to provide optical gain), the resonator could operate as a laser, emitting light in the resonance frequencies of the device.
Ring resonators in planar technology are generally comprise of a closed loop waveguide which is made of a material with a higher refractive index than its surrounding (see for example B. E. Little et al., "Vertically coupled glass microring resonator channel dropping filters", IEEE Photonics Technology Letters vol. 11 no. 2, February 1999, p. 215–217). Here, ns is the refractive index of a substrate, ng, Wg and hg are the refractive index, width and height respectively of the input/output waveguides, nr, Wr and hr are the refractive index, width and height, respectively, of the ring, and n0 is the refractive index of a cladding layer as depicted in FIG. 1C.
Such implementation has several disadvantages. Characteristics such as large FSR and low loss are important for a micro-ring resonator, regardless the specific function it fulfills. However, achieving these characteristics simultaneously is difficult since the demands on the resonator shape conflict. To achieve large FSR resonator, the best design would be a circular ring with high refractive index contrast to achieve tight mode profiles. However, these characteristics would result in high losses which stem from three different mechanisms:                Bend radiation losses;        The smaller the core radius the higher the losses;        Core material absorption and scattering (material loss);        Surface scattering from the roughness of the core walls. These losses increase with the core-clad index contrast.
There is therefore a need in the art to design a resonator structure that provides for large FSR and low loss/rev. The performance of a resonator-based device of any kind significantly depends on the resonator loss. There are two primary mechanisms that induce losses in the resonator, namely material loss and radiation loss. Material loss is an inherent property of the material comprising the resonator, and is an exponential function of the length of the resonator. As for the radiation loss, it arises from the waveguide imperfections such as surface roughness, and from the bend related radiation loss. The surface roughness is similar in effect to the material dependant loss and depends on the waveguide shape and refractive index. The bend related loss also depends on the waveguide shape and refractive index, but also critically depends on the radius of curvature. In order to decrease the radiation losses, what is needed is a resonator with large and smooth curvatures. This, however, would result in a very small FSR, and also would increase overall length of the resonator and increase losses related to the material and surface roughness loss. Hence, the current solutions cannot provide reduction of the loss of a resonator below a certain value.


Methods and systems for generating sulfuric acid are disclosed. In some embodiments, the method includes combusting a sulfur-containing material with a gas including oxygen to produce a first stream of sulfur dioxide, mixing water with the first stream of sulfur dioxide to produce a mixed stream, using an energy, electrolytically converting the mixed stream of sulfur dioxide and water into sulfuric acid and hydrogen, generating a source of energy from the hydrogen, and providing the source of energy as at least a portion of the energy for electrolytically converting the first stream of sulfur dioxide and water into sulfuric acid and hydrogen. In some embodiments, the system includes a first chamber for combusting a sulfur-containing material to produce a first stream of sulfur dioxide, an electrolytic cell for converting the first stream into sulfuric acid and hydrogen, and a fuel cell for generating an energy source from the hydrogen.

Considering the present state and future projections for sulfur consumption, large amounts of excess sulfur, e.g., 80 Mt worldwide in the next twenty years, might be accumulated in many areas of the world. For example, supply of recovered sulfur is already outpacing the demand for sulfur in energy-rich regions such as Alberta, Canada, and west Kazakhstan. Such outpacing of the supply of sulfur relative to the demand for sulfur is expected to occur globally and will cause the need for large scale storage of waste sulfur or sulfur products.
However, stockpiles of elemental sulfur are unsafe. For example, sulfur dust can settle near storage sites and acidify the surrounding soil. Acidification and the metals leached from the soil and transported to other locations can cause significant environmental damage, such as drastic changes in local water and soil pH. In addition, long-term sulfur storage poses significant risk of ignition and sulfur fires, as well as the potential for bacterial degradation and oxidation.
Despite such risks and concerns, suitable solutions to safe, e.g., low solubility in water, noncombustible, and reasonably resistant to bacterial digestion, long-term storage of sulfur are not currently available. For example, one method essentially provides a disposal strategy wherein sour gases, i.e., gas mixtures including substantial amounts of acidic gases like hydrogen sulfide (H2S), sulfur dioxide (SO2), sulfur trioxide (SO3), and carbon dioxide (CO2), are re-injected underground. However, this method poses environmental risks because these sour gases might escape over time and be reintroduced into the environment causing ecological damage. For example, acid gas can react with well plugs that are typically made of concrete and escape over time. Other forms of leakage are possible insofar as reservoirs can develop leaks over time.

This patent is subject to a terminal disclaimer.

Systems and methods for generating sulfuric acid

The Trustees of Columbia University in the City of New York


According to the rubbing method of the present invention, since the support is pressed against the rubbing roller by applying fluid pressure to the backside of the support (web), uniform rubbing can be performed without generating wrinkles on the web. In other words, because the web is pressed by fluid pressure, the web follows the rubbing roller, and the orientation film on the surface of the web can be controlled to the optimal condition upon rubbing treatment without generating wrinkles on the web. With this, defects on the surface caused by poor orientation can be significantly reduced.

1. Field of the Invention
The present invention relates to a rubbing method and a method and an apparatus for producing an optical film, and particularly to a rubbing method suitable for forming a liquid crystal orientation film for uniformly orienting liquid crystal molecules and a method and an apparatus for producing an optical film to which the rubbing method is applied.
2. Description of the Related Art
Recently, demand for optical films is increasing. Typical examples of such optical films include optical compensation films used as retardation films in liquid crystal cells, antireflection films and antiglare films, which have various functions.
Typical methods of producing such optical films include a method which comprises performing rubbing treatment on the surface of a belt-shaped flexible support (hereinafter referred to as a "web"), applying a coating solution to the surface of the web using various coating apparatuses and drying and then curing the same to form a coated film (functional film) of various compositions.
The rubbing treatment is a typical technique for orienting liquid crystal molecules in the production of liquid crystal display devices, and generally an orientation film is formed on the surface of a web and the surface of the orientation film is rubbed in one direction by a rubbing roller.
In such production of optical films, poor orientation due to unstable rubbing treatment conditions, which is one of the causes of decreased yield, has become a problem. Thus, various proposals have been made in order to reduce such poor orientation (see Japanese Patent Application Laid-Open Nos. 8-160431, 8-160430 and 2002-55345).
Japanese Patent Application Laid-Open No. 8-160431 proposes a construction in which a rubbing roller is disposed between two, transfer rollers and a web is transferred while being wound on the rubbing roller, enabling continuous production.
Japanese Patent Application Laid-Open No. 8-160430 proposes a construction in which a long web is wound around a rubbing roller disposed diagonally to the traveling direction of the web and the traveling direction of the web is changed to perform continuous rubbing. It is described that this technique is capable of uniformly rubbing orientation films.
Japanese Patent Application Laid-Open No. 2002-55345 proposes a construction in which hot air at about a phase transition temperature of SmA-SmC is sprayed to the web through a spray nozzle, and it is described that an orientation film can be uniformly rubbed under heating and pressurization.

Rubbing method and method and apparatus for producing optical film


An abnormality detection device for an internal combustion engine capable of performing abnormality detection with accuracy, and an air/fuel ratio control apparatus for an internal combustion engine capable of performing air/fuel ratio control with accuracy. An estimated value of the amount of intake air at a valve closing time at which an intake value is closed, is computed. The in-cylinder air/fuel ratio in a cylinder is computed by using the estimated value. The obtained in-cylinder air/fuel ratio is used as an input air/fuel ratio to identify a parameter in a primary delay element. Determination as to the existence/nonexistence of an abnormality in a pre-catalyst sensor (A/F sensor) is made on the basis of the obtained parameter.

A device for detecting an abnormality in an air/fuel ratio sensor (hereinafter also referred to as a "A/F sensor") by utilizing an output from the A/F sensor, for example, as disclosed in Japanese Patent Laid-Open No. 2005-30358, is known. According to this conventional art, an injection quantity, i.e. an amount of fuel from an injector, is changed by open-loop control and determination as to the existence/nonexistence of an abnormality in the A/F sensor is made by evaluating changes in the output from the A/F sensor resulting from changing the amount of duel injection.
Also, an air/fuel ratio control apparatus for internal combustion engines is known in which an output from an A/F sensor is fed back to an injection quantity, for example, as mentioned in Japanese Patent Laid-Open No. 2004-68602. According to this conventional art, a plant model representing a control system from a fuel injection valve to the A/F sensor is identified at successive times, and feedback control is performed by using the values of parameters identified in this model.    [Patent document 1] Japanese Patent Laid-Open No. 2005-30358    [Patent document 2] Japanese Patent Laid-Open No. 2004-68602    [Patent document 3] Japanese Patent Laid-Open No. 5-180059    [Patent document 4] Japanese Patent Laid-Open No. 8-232727    [Patent document 5] Japanese Patent Laid-Open No. 2006-118429    [Patent document 6] Japanese Patent Laid-Open No. 2003-97334    [Patent document 7] Japanese Patent Laid-Open No. 2004-316457    [Patent document 8] Japanese Patent Laid-Open No. 2004-360591

Abnormality detection device for internal combustion engine and air/fuel ratio control apparatus for internal combustion engine


The present invention provides a method for creating a personalized digital planning file for simulation of dental implant placement. After planning, the digital representation in a plaster model may be used to design and produce dedicated surgical templates to assist the surgeon in transferring the implant plan to a patient during medical intervention.

Surgical planning for dental implant placement traditionally uses medical imaging modalities to verify the quantity and quality of a jawbone. Multi-planar reformatted CT (computed tomography) has become one of the most comprehensive and accurate aids for implant treatment planning. CT offers means to visualise the oral anatomy of a patient in a number of differently oriented slices of a volumetric scan and to graphically superimpose on the images representations of commercial implants of varying length, diameter and brand (for example, SimPlant™ provided by Materialise, Leuven, Belgium).
According to the current state of the art a patient is sent to a radiologist for a CT scan. The result of the scan is a stack of 2D slices forming a three-dimensional volumetric "data set" which can then be used as input for a dental planning program. Typically, such a program imports the data set provided by a radiology site without altering any information. Using image-processing techniques such as, for example, image segmentation, three-dimensional models of the bone may be derived from the data set. In the planning environment, the practitioner subsequently defines a curve that follows the arch of the jaw. Several cross-sections can be chosen perpendicular to both the panoramic curve and the axial slices. Typically, implant receptor sites may be chosen in these cross-sections. The practitioner can modify the positions and inclinations of each implant as needed in any of the views, including the 3D view. Fine tuning is performed by shifting and tilting of the implant representations or by changing their dimensions. Each individual implant position can be evaluated in terms of the volume of available bone and its quality. The latter is interpretable in CT images by means of the number of Hounsfield units attributed to each of the voxels, i.e. volumetric building blocks of the CT images.
Disadvantages of using CT for dental implant planning are the additional costs related to scanning and the fact that significant irradiation of the patient is required in order to obtain the volumetric data. Moreover CT or CT-like scanning equipment, such as e.g. cone-beam scanners, is costly and has yet to be widely used in the dental market. Scanning equipment is therefore not always readily available.
To overcome these disadvantages methods for simulating dental implant placement without resorting to volumetric image data such as CT, cone-beam scans, MRI scans, have been proposed.
U.S. Pat. No. 6,319,006 describes a method for producing a drill assistance device for a tooth implant in which an X-ray image is correlated with a three-dimensional image of optically measured visible parts of a patient's remaining dentition. The method comprises taking an X-ray picture of the jaw and the compilation of corresponding measured data record, a three-dimensional, optical measurement of the visible surfaces of the jaw and of the teeth and the compilation of a corresponding measured data record. The measured data records from the X-ray picture and the measured data records from the three-dimensional, optical image are correlated with each other. Based on the information that is available, the type and position of the implant relative to the adjacent teeth is planned and a drill template is produced which is attached to the neighbouring teeth, thus making the exact drilling of an implant pilot hole possible.
However, a disadvantage of this way of working is the lack of three-dimensional information about the shape of the jawbone. While the X-ray image provides information about the bone in a projected image, it does not provide insights about the level of the bone in cross section along the dental arch. As an example, FIG. 1 shows two exemplary cross-sections of a jawbone, which on a frontal X-ray image would both be visualized identically. However the bone in both sections is very different as can be seen from FIG. 1.
In WO 2004/064660 a method for dental registration is provided. The method comprises rigidly coupling a base element to a maxillofacial area, inserting an object comprising at least one of a tool and a tool guide into a mouth in the maxillofacial area, and determining a position of the object relative to the rigid element without a reference element outside the mouth. According to embodiments, the method may comprise combining two non-volumetric images of at least part of the maxillofacial area. The non-volumetric images can be obtained by X-ray, optical scan data or direct bone surface measurements. The method may comprise acquiring the first non-volumetric image including at least a part of the base element, identifying at least one registration mark of the rigid element and registering the image to the second non-volumetric image, thereby registering the registration mark to the area.
The method described in WO 2004/064660 is tedious and not so practically convenient because a foreign object, i.e. the base element, needs to be introduced into the mouth and rigidly coupled to the jaw. The object furthermore needs to be present in the mouth during the imaging. Moreover, the technique does not take into account the fact that X-ray images inherently are inaccurate in the lateral direction, as disclosed in the book "Implants and Restorative Dentistry", Chapter 11—Imaging in oral implantology, page 178. A registration according to the described technique would not compensate for these inaccuracies.

Method for creating a personalized digital planning file for simulation of dental implant placement


An apparatus including a main body member configured as a hand to receive a glove thereon to maintain the glove in a stretched and shaped configuration to prevent drying and shrinking of the glove. The main body includes a matrix of openings therethrough permitting air circulation throughout, as well as a loop formed on a lowermost end of the body to enhance directing of the body interiorly of an associated glove. The palm includes a recess to permit an individual to manually grasp a glove in directing the glove over the body. Modifications of the instant invention include the main body formed of a woven, porous mesh permitting air circulation therethrough, with the mesh formed with an interior fabric liner to receive and subsequently direct preservation oils into a glove mounted on the body. Furthermore, a central core sponge may be utilized to provide a reservoir of oil to be directed through the cloth liner and the mesh body into an associated glove. The mesh body is malleable to permit the fingers to be manipulated to enable stretching of a glove mounted on the body.

1. Field of the Invention
The field of invention relates to glove support apparatus, and more particularly pertains to a new and improved glove support apparatus wherein the same permits air circulation and directing of oils and emollients onto a glove mounted on the apparatus.
2. Description of the Prior Art
The use of glove support apparatus is known in the prior art. Heretofore, however, glove support apparatus has been of expansive and unnecessarily complicated construction to mount gloves thereon to preserve their geometric configuration and prevent shrinking during storage. Examples of the prior art include U.S. Pat. No. 4,565,287 to Rede, et al., wherein a rigid form is mounted interiorly of a glove with a separate thumb portion, wherein each form includes a hollow cavity, and wherein each form is receivable within a pouch formed with an oil impregnated liner to receive the glove forms therewithin.
U.S. Pat. No. 2,524,285 to Chezum illustrates the use of a glove form formed with openings therethrough to permit draining of dirt and debris from the glove subsequent to a washing, wherein the form is provided with a hook to suspend the form during a drying procedure subsequent to a washing of the glove.
U.S. Pat. No. 2,035,094 to Plicki is illustrative of a glove form of a rigid construction formed with a removable thumb to mount a glove thereon.
U.S. Pat. No. 3,409,142 to Mechaneck illustrates a stand for drying gloves, wherein the stand is of a generally rigid construction to enable drying of the glove subsequent to washing thereof, or merely a convenient support of gloves.
U.S. Pat. No. 4,697,724 to Pitcher illustrates a glove form, wherein the digital ends of the fingers and thumb of the glove form are enlarged to save materials in the construction of the organization.
As such, it may be appreciated that there is a continuing need for a new and improved glove support apparatus wherein the same addresses both the problems of ease of use in insertion within an associated glove, as well as effectiveness in the geometric protection of the glove's configuration and for directing preservatives into the glove during support thereon.


High-T.sub.c superconductor quantum interference devices (SQUIDs) for noise-free, accurate measurements of defects and flaws in metal shapes and forms by measuring changes in the secondary magnetic field intensity around any point which is excited by a primary excitation current or by measuring changes in the impedance of the exciting coils. These measured changes are correlated to defects and flaws present in the metal.

Superconductivity was originally discovered by the Dutch scientist Heike Onnes in 1911 while he was studying the electrical properties of mercury at very low temperatures. In more recent times, Ogg (1946) studied superconductivity in ammonia solutions and proposed that superconductivity arose in these quenched metal-ammonia solutions because of mobile electron pairs. About 1973, it was determined that certain niobium metal alloys exhibited superconductivity when cooled to liquid helium (4.degree. K.) temperatures. Later results in the 1970's raised this temperature as high as 23.degree. K. (-250.degree. C.). Until recently, it was believed that superconductivity above this temperature was not possible. This belief was based on the theoretical work of Bardeen, Cooper and Schieffer (BCS theory-1946) which predicted such a limit. In December 1986, Bednorz and Muller announced the discovery (G. Bednorz and A. Mller, Z. Phys., B64 189 (1986)) of a new ceramic superconducting compound based on lanthanum, barium, and copper oxides, whose critical temperature for superconductivity was close to 35.degree. K. By the following month, the critical temperature, Tc, for the onset of superconductivity was raised to nearly 80.degree. K. by C. W. Chu and coworkers (M. K. Wu, J. R. Ashburn, C. J. Tang, P. H. Hor, R. L. Meng, L. Gao, Z. J. Huang, Y. Q. Wang and C. W. Chu, Phys. Rev. Lett. 58 908 (1987)). This was achieved by changing the composition to yttrium barium copper oxide, approximated by the formula: Y.sub.1.0 Ba.sub.1.8 Cu.sub.3.0 O.sub.6.3. Since then, a number of families of superconducting ceramic oxides have been investigated, including:
Bismuth Strontium Calcium Copper Oxide: PA0 Thallium Calcium (Barium) Copper Oxide:
Bi.sub.2 Sr.sub.3-x Ca.sub.x Cu.sub.2 O 8+y2 PA1 T.sub.c =114.degree. K. PA1 Tl Ba.sub.2 Ca Cu.sub.2 O.sub.7 PA1 Tl Ba.sub.2 Ca.sub.2 Cu.sub.3 O.sub.9 PA1 Tl Ba.sub.2 Ca.sub.3 Cu.sub.4 O.sub.11 PA1 Tl Ba.sub.2 Ca.sub.4 Cu.sub.5 O.sub.13 PA1 Tc=120.degree. K. PA1 BaO--K.sub.2 O--Bi.sub.2 O.sub.3 PA1 Tc=30 K. PA1 (a) positioning a high-critical-temperature superconductive quantum interference device having a pair of insulated junctions in a superconductor loop in flux-sensing relationship to a location adjoining said body; PA1 (b) relatively displacing said body and said location; PA1 (c) while said body and said location are relatively displaced, exciting said body with a modulated alternating current and detecting with said device flux irregularities representing flaws in said body; and PA1 (d) establishing locations of said flaws by the relative positions of said location and said body upon the detection of said flux irregularities.
There have been some scattered reports of superconductivity above 162 K., For instance, R. G. Kulkarui has reported superconducting oxides having an approximate composition 0.5 CaO. 0.5 ZnO. Fe.sub.2 O.sub.4, with critical temperatures in this range. Ogushi also reported superconductivity at room temperature in yet ill-defined niobium strontium lanthanum oxides. While these reports have yet to be confirmed independently by other researchers, it is reasonable to expect that superconductors with critical temperatures near to room temperature will soon be obtained.
Niobium-based superconducting alloy wires have long been used for detecting small changes in magnetic field strength. In the prior art, the non-destructive evaluation of defects in metals employs an eddy current technique wherein the impedance change of the primary exciting coil is measured and correlated to the presence of defects and flaws within the metal sample. The method is cumbersome and must be carried out at liquid helium temperatures (.about.4 K.), which is expensive. In this method of nondestructive evaluation, currents are caused to flow in a test specimen by placing it within, or in close proximity to, the primary magnetic field of a probe coil (or array of coils). In turn, these induced currents generate a secondary magnetic field, which, by Lenz's law, opposes the primary magnetic field, thus affecting the impedance of the probe or exciting coil. By using Green's function technique and the Born Approximation, one can demonstrate that the impedance of a single turn coil, which surrounds a conducting non-magnetic cylinder containing a flaw and/or defect, will depend on the size of said flaw, its conductivity, and its depth.
The change of impedance, DZ, due to the flaw is proportional to the change of conductivity D.sigma.=.sigma.-.sigma..sub.o and the square of the flaw length. The flaw depth affects the impedance change differently, depending upon the ratio of flaw position r', to the skin depth. In certain situations, some aspects of the geometry of the flaw can be determined by measuring the probe coil impedance as the probe coil is scanned across the surface containing the flaw.
I have determined that the use of superconductor quantum interference devices to measure flaws and defects in metals produces results much superior to any known heretofore, especially when said devices are used in conjunction with modulated high frequency exciting currents. This is accomplished through exciting coils placed around the metal plate, or wrapped around a cylinder. The arrangement of the SQUIDs includes an alternating bias current, and flux modulation in a locked flux-loop design. This mode of operation ensures minimum noise of voltages produced by the superconductor quantum interference devices, which may result because of critical current fluctuations in the non-identical junctions of the superconducting interference devices, and also because of fluctuations in junction resistances. I have further established that my new and novel methods for non-destructive detection of flaws in metals can be applied to both non-magnetic and ferric-magnetic materials, in contrast to the prior art. I have further determined that the technique of the instant invention is very sensitive, compared to those of the prior art.

Superconductive quantum interference device for the non-destructive evaluation of metals


Provided in the present invention is an application for PRDX2 and/or PRDX6 in the preparation of a pharmaceutical composition to treat or prevent damage, aging or diseases resulting from an increase in reactive oxygen species (ROS).

When using oxygen, cells produce free radicals, e.g., reactive oxygen species (ROS) and reactive nitrogen species (RNS). In our bodies, each cell produces 2.5×1011 ROS molecules per day, and human body can produce 40×1021 ROS per day. ROS not only provides and delivers life-sustaining energy, but also helps human body to eliminate bacteria and pathogens, toxins and "junks". ROS also serve as an initiator and adjuster for various metabolisms and signal channels inside our bodies such as JNK/SAPK, P38MAPK, IKK/NF-KB, P13K, Akt, CD40/CD40L, PKC, etc, activates and regulates various transcription factors (e.g. AP-1, Nrf2, NF-KB, p53, ATF-1, HIF, HSP, SIFT-1, MST/FOXO, etc.), influences in vivo transcription and expression of various genes and participates in inflammation, immunization, reproduction, development, metabolism, cell growth, proliferation, cell regeneration, repair, and other modulations in important life processes. ROS enhances and maintains metabolism in cell, tissue and body, thereby maintaining and ensuring normal life activities.
Free radicals in human body are generated in two aspects. Firstly, they are generated from the various metabolic reactions in human body. Secondly, they arise from the exogenous free radical generated from splitting of covalent bonds resulted from high temperature, radiation, photolysis, chemical substances in the environment, such as smoking, drinking alcohol, pollution, drugs, diseases etc.
We have, inside our bodies, a dynamic antioxidant system involving, e.g. superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), which can timely and rapidly remove the excessive ROS inside the body. Under normal physiological conditions, the oxidative-antioxidant system inside our bodies maintains a homeostasis, thereby ensuring normal oxidative stress reactions and preventing ROS from damaging human bodies. Only when ROS is excessively generated and expression of antioxidant enzymes is in shortage, the balance between oxidation and antioxidation is lost and ROS is unable to be cleared timely, and cumulates in the body, thereby resulting in cellular and tissue damages (i.e., oxidative stress) and risk of human health.
ROS can directly or indirectly oxidize or damage DNA, proteins and lipids. ROS can induce gene mutation, denaturation of proteins and peroxidation of lipids, which are considered as major risk factors leading to human aging and various significant diseases, such as infertility, cataract, cancers, cardiovascular diseases, senile dementia/neurodegenerative diseases (such as Alzheimer's disease, Parkinson's disease), diabetes, inflammations (such as osteoarthritis, rheumatoid arthritis, bronchitis, etc.), infections, myocardial ischemia-reperfusion injuries, organ transplantations, atherosclerosis, etc.
Nowadays there are many "drugs for antioxidation". However, there are few drugs that are genuinely effective in regulating oxidation-antioxidation balance.

Application of PRDX2 and/or PRDX6 in improving sperm quality or treating male infertility

Yantai Ju Jie Bioengineering Limited Company


A method for protecting at least one section of a program executed by a microcontroller, included before execution of the section, decrementing or incrementing at least one first counter and storing its state in a non-volatile memory of the microcontroller; in case of the detection of an attack attempt by the microcontroller, activating a flag in the microcontroller RAM; and at the end of the execution of the program section, checking the flag state.

1. Field of the Invention
The present invention generally relates to the protection of information contained in an integrated circuit, for example, in a smart card or the like, with or without contact. The present invention more specifically relates to the protection of critical information contained in an integrated circuit of a smart card or the like against attacks aimed at preventing the card from being disabled after a fraud attempt detection.
2. Discussion of the Related Art
FIGS. 1A and 2A very schematically show an example of a smart card system 10 (FIG. 1A) with contacts, of the type to which the present invention applies. Card 10 supports an integrated circuit chip 20 capable of communicating with a terminal 30 (FIG. 2A) via contacts 21. When card 10 (FIG. 2A) is introduced in a slot 31 of the terminal, contacts 21 of card 10 enter in electric relation with other contacts 32 of terminal 30 to communicate with a computer system 33 thereof.
FIGS. 1B and 2B very schematically show an example of a contactless electronic card or label 10′ (FIG. 1B) of the type to which the present invention applies. In this case, integrated circuit chip 20 supported by electronic label 10′ is connected to an antenna 21′ forming the inductive element of a resonant circuit of the transponder thus formed. This antenna 21′ is intended to communicate by close magnetic coupling with an antenna 31′ of a terminal 30′ when label 10′ (FIG. 2B) is in the electric field radiated by antenna 31′. Antenna 31′ is connected to a computer system 33 of terminal 30′. Electromagnetic transponder 10′ may be brought to a smart card, the antenna being then generally formed of a planar conductive winding supported by the card. It may also be a dual smart card combining the communication functions with and without contact.
FIG. 3 very schematically shows in the form of blocks elements of an integrated circuit chip 20 of the type to which the present invention applies equipping, for example, a smart card with or without contacts.
Integrated circuit 20 forms a microcontroller comprising a central processing unit 22 (CPU) communicating via a bus 23 with different memories, among which at least a memory 24 (ROM), for example, a read-only memory or a FLASH memory, for storing programs to be executed, a RAM 25 used in the execution of programs, and a non-volatile rewritable memory 26 (NVM) (for example, an EEPROM). Chip 20 also comprises input/output ports (I/O COM) 27 towards the outside. These input/output ports are connected either to contacts (for example, contacts 21 of a smart card—FIG. 1A), or to a contactless transmit element (for example, antenna 21′ of an electromagnetic transponder—FIG. 1B).
FIGS. 4A and 4B very schematically illustrates the operation of a program having at least one portion processing critical information (for example, one or several secret keys or cryptography algorithms) undergoing an attack attempt by a hacker aiming at obtaining all or part of the critical information.
After a reset of the circuit microprocessor (20, FIG. 3) of the concerned smart card, different processings are implemented by its central unit according to applications. It is assumed that in the development of its main program (FIG. 5A), a so-called critical section 1 (CRITSECT) processing critical data (for example, key, secret code, or algorithm) to be protected, that is, that must be prevented from coming out from the integrated circuit in which they are to be found, intervenes. This amounts to avoiding the data output through the input/output interface (27, FIG. 3) with or without contact of the integrated circuit when a disturbance is detected.
It is assumed that, in the development of critical section 1, an attack ATT coming from a person attempting to fraud by discovering the card's secret occurs. Such an attack may take different forms. For example, the case in point may be to introduce a disturbance into the component to cause an instruction jump in the development of the critical section and thus obtain the data. The case in point may also be to disturb the execution of the critical section by luminous excitation or to introduce a drift in the component clock. Since the hacker does not, in principle, have access to the program executed by the actual component, such attacks generally cause a physical disturbance on the component.
Conventionally, the protected integrated circuit chips are capable of detecting a hacking attempt within a critical section. This detection (ATTDET) of an attack may take different forms. For example, it is known to detect in hardware fashion a drift in the component clock, the occurrence of a significant luminous excitation or of an electric disturbance on the integrated circuit. In software fashion, the execution of the critical section may be protected by a periodic checking of the software code based on an authentication key stored in a memory of the integrated circuit. Such a calculation is generally called a signature calculation to check the proper execution of the software code in uninterrupted fashion. In the case of an interrupt, the signal is not checked, which enables detection.
Traditionally, after detection of an attack on an integrated circuit chip, the data output from the card must be prevented. To achieve this, the program for processing the disturbance detection generates a card blocking action (REACT). This action generally translates as the writing or the deleting of one or several bits in a rewritable non-volatile memory (26, FIG. 3), for example, of EEPROM or FLASH type. The object of this action is to disable any subsequent operation of the chip to prevent the hacker from repeating his attack. Indeed, an attack must be repeated several times on a same component to enable discovering the secret of an integrated circuit. This repetition and the analysis of the results provided after the interrupts are generally statistically processed based on assumptions made by the pirate to discover the circuit's secret.
A problem which arises is that this action (REACT) generally translates as a strong electric signature of the component (higher power consumption of the integrated circuit), which enables the hacker to detect the attempt to write into the non-volatile memory during the critical section. Such a detectable signature enables the hacker to abruptly interrupt the provision thereto of any signal enabling it to carry on its software execution. The hacker then prevents the card blocking, which enables him to repeat his attack such as illustrated in FIG. 4A. He repeats the attack, possibly by modifying one or several parameters, until one of these attacks succeeds in not being detected and data are then provided by the circuit.
FIG. 4B illustrates, in the form of a very simplified timing diagram, such a reaction of a person attempting fraud after an attempt to block the integrated circuit.
Whatever the action taken by the card, this action will take some time before reaching the blocking. The example of FIG. 4B illustrates the duration of a command, for example, for writing into an EEPROM, starting at a time t0 (START REACT) to end in principle at a time t1 (END).
A hacker, knowing that his attacks are likely to be detected by the smart card, watches over the electric signature of the card to detect a significant variation in the execution of a critical section (SIGN DETECT). For example, this detection occurs at a time t2 before the end of the execution of the control by the card. After this detection, the person attempting to fraud almost immediately stops (time t3, STOP) any operation of the card to prevent the blocking from being complete.
Of course, such actions are in practice automatically performed by a tool programmed for this purpose, which enables fast reaction. In the case of a smart card with contacts, this amounts to abruptly interrupting all contacts between card 10 (FIG. 1A) and its reader 30 (FIG. 2A) to deprive it from any power supply and clock signal. In the case of a contactless card 10′ (FIG. 1B), this amounts to an immediate suppression of any radio-frequency transmitted by reader 30′ (FIG. 2B) depriving the card from power supply and clock.
The present invention will be described hereafter in relation with an example of application to smart cards with contacts. It should however be noted that it more generally applies not only to contactless smart cards but also to any electronic element containing a microcontroller integrating one or several memories likely to contain information which are desired to be protected against piracy attempts by repetition of attacks and actions aiming at preventing the blocking of the integrated circuit by detection of an electric signature thereof.


Methods and systems for detecting a three-dimensional position of a scintillation event converting a radiation into a light. For example, a system includes a crystal array including a plurality of crystal elements arranged at least along a first direction and a second direction, the plurality of crystal elements extending along a third direction between a first end and a second end, the plurality of crystal elements being configured to receive the radiation entered from the second end; wherein: the plurality of crystal elements is arranged into a plurality of crystal pairs; each of the plurality of crystal pairs optically coupled to one light bridge at the first end extending and bridging light along the first direction; each of the plurality of crystal pairs is optically coupled for the light in the second direction with at least a neighboring crystal pair only through two light tunnels.

PET is usually an imaging technique that produces a three-dimensional image of functional processes in an object or a portion thereof to monitor in vivo biologically active molecules labeled by radioactive tracers. The tracer may undergo positron emission decay and emit a positron. The positron may annihilate with an electron, generating a pair of annihilation photons (e.g., gamma photons) that move in approximately opposite directions. The annihilation photons may be absorbed by a plurality of crystal elements (e.g., arranged in the form of one or more rings) that create bursts of optical photons (e.g., visible light photons) that, in turn, may be detected by photodetectors. Then the three-dimensional image of the object may be generated based on coincident photon detections. Because pairs of detected annihilation photons may travel along nearly straight lines (referred to as lines of response (LOR)), the tracer location may be determined by identifying LORs.
In conventional systems, a PET scanner exhibits a progressive reduction in spatial resolution with increased distance away from the center of its field of view (FOV). This resolution loss is at least partly caused by an uncertainty in assigning an LOR to a detected coincident event. The uncertainty of LOR assignment may be relatively smaller for a pair of detector modules located near the scanner's central axis (i.e., an axis along an axial direction of the scanner passing through the center of the FOV) than that located far from the central axis. Also, the uncertainty of LOR assignment may be relatively smaller for a pair of detector modules located closer to each other along the axial direction of the scanner than a pair of detector modules located far away from each other. For example, as illustrated in FIG. 2a, a pair of detector modules 201 and 202 is located nearer to the scanner's center axis than a pair of detector modules 203 and 204. As illustrated in FIG. 2b, the distance between the detector modules 201 and 202 along the axial direction of the scanner is smaller than that between a pair of detector modules 202 and 205. The dotted lines A and B define a range of possible LORs assigned to the detector modules 201 and 202, C and D define a range of possible LORs assigned to the detector modules 203 and 204, and E and F define a range of possible LORs assigned to the detector modules 202 and 205. The difference Δr1 between A and B is smaller than the difference Δr2 between C and D, suggesting a relative smaller resolution loss in detector modules 201 and 202 than detector modules 203 and 204. Similarly, the difference Δr1 is smaller than the difference Δr3 between E and F, suggesting a relative smaller resolution loss in detector modules 201 and 202 than detector modules 202 and 205.
Thus, in order to improve imaging resolution, it is desirable to determine the position or depth of photon gamma interactions occurred within a PET detector. PET imaging systems that provide depth of interaction (DOI) information can assign LORs to coincident events more accurately, thereby resulting in a more uniform resolution throughout the FOV. A plurality of techniques for extracting DOI information from a PET detector has been proposed. A possible way is to optically couple photon-sensors to both ends of a crystal element of a PET detector. For example, as illustrated in FIG. 3a, a photon-sensor 301a and a photon-sensor 301b are optically coupled to two ends of a crystal element 302, respectively. The DOI information of a photon gamma interaction (e.g., a photon gamma interaction 1) within the crystal element 302 may be determined based on the ratio of output energies from the photon-sensors 301a and 301b.
Another exemplary way employs a photon-sensor array coupled to a monolithic crystal. For example, as illustrated in FIG. 3b, a photon-sensor array 303 including a plurality of photon-sensors 301c is optically coupled to a crystal element 304. The DOI information of photon gamma interaction (e.g., a photon gamma interaction 2 or 3) may be determined based on a distribution of outputs of the photon-sensors 301c. For example, when a photon gamma interaction excites one or more photons that are detected by more photon-sensors 301c, it may occur at a position farther away from the photon-sensor array 303.
Yet another exemplary way is based on multilayer crystals optically coupled with a photon-sensor array, and to determine the DOI information based on the characteristics of signals detected by the photon-sensor array. For example, as shown in FIG. 3c, a PET detector includes a first crystal layer 305, a second crystal layer 306, and a photon-sensor array 307 optically coupled to the second crystal layer 306. The properties of the crystals in different layers may be different. The above mentioned techniques may be applied in DOI determination, however, most of them rely on additional detector electronics, thereby requiring considerably more complicated hardware and possibly introducing other issues. Therefore, it is desirable to provide devices, systems, and methods for determining DOI in PET systems efficiently and accurately.

Devices, systems and methods for determining depth of interaction in Positron Emission Tomography detectors

Shanghai United Imaging Intelligence Co., Ltd.


A neural network is used to obtain more robust performance in determining prosodic markers on the basis of linguistic categories.

1. Field of the Invention
The present invention relates to a method for determining prosodic markers and a device for implementing the method.
2. Description of the Related Art
In the conditioning of unknown text for speech synthesis in a TTS system ("text to speech" systems) or text/speech conversion systems, an essential step is the conditioning and structuring of the text for the subsequent generation of the prosody. In order to generate prosodic parameters for speech synthesis systems, a two-stage approach is followed. In this case, firstly prosodic markers are generated in the first stage, which markers are then converted into physical parameters in the second stage.
In particular, phrase boundaries and word accents (pitch-accent) may serve as prosodic markers. Phrases are understood to be groupings of words which are generally spoken together within a text, that is to say without intervening pauses in speaking. Pauses in speaking are present only at the respective ends of the phrases, the phrase boundaries. Inserting such pauses at the phrase boundaries of the synthesized speech significantly increases the comprehensibility and naturalness thereof.
In stage 1 of such a two-stage approach, both the stable prediction or determination of phrase boundaries and that of accents pose problems.
A publication entitled "A hierarchical stochastic model for automatic prediction of prosodic boundary location" by M. Ostendorf and N. Veilleux in computational linguistics, 1994, disclosed a method in which "Classification and Regression Trees" (CART) are used for determining phrase boundaries. The initialization of such a method requires a high degree of expert knowledge. In the case of this method, the complexity rises more than proportionally with the accuracy sought.
At the Eurospeech 1997 conference, a method was published entitled "Assigning phase breaks from part-of-speech sequences" by Alan W. Black and Paul Taylor, in which method the phrase boundaries are determined using a "Hidden Markov Model" (HMM). Obtaining a good prediction accuracy for a phrase boundary requires a training text with considerable scope. These training texts are expensive to create, since this necessitates expert knowledge.

Method and device for determining prosodic markers by neural autoassociators


The invention relates to a semiconductor device with a semiconductor chip, on which a terminal contact formed in one piece, a patterned metallization layer, contacting the terminal contact, and a connecting layer are successively arranged, the patterned metallization layer and the patterned connecting layer forming an electrically conducting contact layer.

Flip-chip technologies are used in particular whenever the space required for the redistribution routing of the semiconductor chip is to be optimized. In this case, generally a number of terminal contacts arranged on one side of the semiconductor chip are connected in an electrically conducting manner to a carrier.
The carrier may be formed for example as a metallic chip carrier and as such be a component part of the semiconductor device.
However, it is similarly possible for the carrier to be formed as a printed circuit board, for example as a PCB substrate, on which one or more semiconductor devices are mounted in a flip-chip arrangement. In this case, the substrate is not a component part of the semiconductor device. On arrangement of this type, provided by International Rectifier of El Segunda, Calif., 90245, USA, under the trade name "DirectFET", includes a semiconductor device which has on one side solderable metallizations, which are soldered over their entire surface area to corresponding metallizations of a printed circuit board.
FIG. 1 illustrates a portion of a semiconductor device according to the prior art with a terminal contact 10 formed in one piece. The semiconductor chip 1 represented is shown by way of example as a MOSFET.
The semiconductor chip 1 includes a heavily n-doped drain zone 11, on which a lightly n-doped drift zone 14 is arranged. Embedded in the drift zone 14 are a number of p-doped body zones 15, in which highly n-doped source zones 16 are in turn embedded. The body zones 15 and the source zones 16 are arranged on the side of the drift zone 14 that is facing away from the drain zone 11. A gate electrode 12 is arranged such that it is insulated from the semiconductor zones 14, 15, 16 by an insulating layer 17. A metallization 10, formed in one piece, contacts the various source zones 16 and forms their terminal contact 10. The terminal contact 10 is substantially of a flat form and insulated from the gate electrode 12. The gate electrode 12 is in this case configured in such a way that there are clearances for the terminal contact 10 to the source zones 16.
A reduced representation of the semiconductor chip 1 according to FIG. 1 is schematically represented in FIG. 2. The semiconductor chip 1 has on its front side 19 terminal contacts 10, 13 formed over its full surface area and in one piece. The terminal contact 10 corresponds to the terminal contact 10 already known from FIG. 1 and is connected in an electrically conducting manner and over its full surface area to the source zones 16 represented there. A further terminal contact 13 represents the gate terminal of the semiconductor chip 1, which is connected in an electrically conducting manner to the gate electrode 12 represented in FIG. 1. The connection of such a semiconductor chip 1 to a substrate usually takes place by means of a solder layer applied to the terminal contact 10 over its full surface area.
An arrangement of this type has the disadvantage that the considerable heat loss produced in particular in the case of power semiconductor devices in the semiconductor chip is transferred via the solderable metallization areas to the solder layer and the printed circuit board. As a result, the temperature of the solder can rise above its melting point, which may lead to impairment of the soldered connection concerned.
Instances of damage to the printed circuit board can similarly occur if its temperature reaches excessively high values. For example, FR4, a material typically used for printed circuit boards of this type, with four copper layers, has a permissible maximum temperature of about 110° C. Although alternative materials with a higher permissible maximum temperature are available, they are very expensive.
Instead of the soldered connection mentioned, it is also possible in principle to use a bonded connection, for example of gold or aluminum. However, bonded connections of this type also have relatively low permissible maximum temperatures of approximately 150° C. in the case of gold and approximately 175° C. in the case of aluminum as bonding materials.


A coated electrically conductive substrate has particular utility where there are multiple closely spaced leads and tin whiskers constitute a potential short circuit. This electrically conductive substrate has a plurality of leads separated by a distance capable of bridging by a tin whisker, a silver or silver-base alloy layer coating at least one surface of at least one of the plurality of leads, and a fine grain tin or tin-base alloy layer directly coating said silver layer. An alternative coated electrically conductive substrate has utility where debris from fretting wear may increase electrical resistivity. This electrically conductive substrate has a barrier layer deposited on the substrate that is effective to inhibit diffusion of the substrate into a subsequently deposited layers, which include a sacrificial layer deposited on the barrier layer that is effective to form intermetallic compounds with tin, and a low resistivity oxide metal layer deposited on the sacrificial layer.

(1) Field of the Invention
This invention relates to systems and methods for coating electrically conductive substrates, and more particularly to multi-layer systems and methods for coating electrically conductive substrates.
(2) Description of the Related Art
Throughout this patent application, the word "base" to qualify an alloy means that the alloy contains at least 50%, by weight, of the qualified element, for example, "copper-base" means more than 50%, by weight, of copper. Copper and copper-base alloys (hereinafter generally referred to as "copper") are commonly used in electrical and electronic industries for connectors, electrical harnesses, printed circuit boards, ball grid arrays, leadframes, multichip modules, and the like. While copper provides excellent electrical conductivity, it is known to easily oxidize and tarnish when exposed to elevated temperatures, moisture, or chemicals. Oxidation and tarnishing of copper generally result in high electrical contact resistance, thereby reducing performance of electrical devices. In addition, oxidation and tarnishing of copper reduce the wettability of solder, and generally makes soldering problematic.
One method to reduce oxidation and tarnishing of copper is to apply a tin or tin-base alloy coating (hereinafter generally referred to as "tin") onto a copper substrate. The tin coating acts as a barrier to prevent or reduce oxidation, and thereby maintain the electrical performance of the substrate. However, there are many problems associated with using tin as a coating layer on a conductive substrate. Rapidly at elevated temperatures, and more gradually at room temperature (nominally 25° C.), the tin coating interdiffuses with the copper substrate to form copper-tin intermetallic compounds (IMC's). These IMC's reduce the thickness of the tin coating layer and cause an increase in contact resistance and degradation of solderability.
Exemplary thermal excursions include 250° C. for a few seconds during wire bonding or encapsulation in a polymer, 300° C. for a few seconds during reflow and 150° C. for from 8 to 168 hours for a controlled reduction of tin thickness to reduce friction.
One approach taken to reduce the effect of IMC formation and maintain a low contact resistance is to use a thicker tin coating; however, this approach not only increases the cost of the parts but also causes some functional problems. Where the tin coating is used on an electrical connector, a thicker coating of soft tin increases friction leading to an increased insertion force, making plugging and unplugging the connector physically difficult. For electronic devices, a thicker tin or tin alloy coating is also undesirable since the trend is to make electronic devices thinner and smaller. Moreover, where the tin coating is used on leads of an electronic device, a thick tin coating can cause problems in the coplanarity and fine line definition of the leads.
Another approach taken to reduce the effect of IMC formation is to use a transition barrier layer between the copper substrate and the tin coating to inhibit the growth of IMC. For example, U.S. Pat. No. 4,441,118 reports low IMC growth rates using a copper-nickel alloy substrate with 15-30% nickel.
In another example, a publication by P. J. Kay and C. A. Mackay, in Transactions of the Institute of Metal Finishing, Volume 51, 1979, at page 169, discusses the use of various metals as transition barrier layers. In one example, this publication describes a silver barrier layer having a thickness of 1 micrometer. However, this example was shown to be undesirable because the silver transition barrier layer resulted in no substantial reduction in the diffusion rate between copper and tin. U.S. Pat. No. 4,756,467 to Schatzberg discloses a solderable connector having a copper substrate, a thin layer of silver, a silver-tin alloy layer and an outermost tin layer. The silver-tin alloy layer is formed by a diffusion anneal. Japanese Patent Number 2670348 (publication number 02-301573) to Furukawa Electric Co. Ltd. discloses a copper substrate coated with a barrier layer that is nickel or cobalt, followed by silver layer followed by a melt-solidified layer of tin or tin alloy.
Commonly owned U.S. patent application Ser. No. 10/930,316, that was filed on Aug. 31, 2004 as a continuation of U.S. patent application Ser. No. 09/657,794 discloses a thin anti-tarnish layer disposed between a copper substrate and a tin coating layer. Among the metals disclosed as anti-tarnish layers are zinc, chromium, indium, phosphorous, manganese, boron, thallium, calcium, silver, gold, platinum, palladium and combinations and alloys thereof.
Other barrier layers are disclosed in commonly owned U.S. Pat. No. 5,780,172, to Fister et al., and commonly owned U.S. Pat. No. 5,916,695 to Fister et al. U.S. Pat. Nos. 4,756,467 and 5,916,695 as well as U.S. patent application Ser. No. 10/930,316 are incorporated by reference in their entireties herein.
Another problem associated with the use of tin as a coating layer for a conductive substrate is that tin is susceptible to fretting corrosion. Fretting corrosion is the oxidation of contact surfaces that results from relative motion (fretting) between two mating contact surfaces. The oxidation caused by fretting can result in an unacceptable increase in contact resistance. Certain metals, such as silver, are known to have excellent resistance to fretting corrosion. However, silver tends to tarnish in the atmosphere due to the presence of sulfur dioxide, which causes silver sulfide to form on the surface of the silver. The tarnish is aesthetically unacceptable and could degrade the functional properties of the electrical contact.
Yet another problem associated with the use of a tin coating layer, as well as other coating layers such as zinc, indium, antimony, or cadmium, on a conductive substrate is that tin is susceptible to whiskering. Whiskering occurs as the tin ages and stresses in the tin or at the tin/IMC interface begin to build. Whiskering also occurs due to internal stress resulting from the plating process. To relax the stress, single crystals of tin nucleate from the surfaces like whiskers. Each whisker continues to grow until the internal stresses subside. Whiskering can cause many different problems, including shorting of adjacent electrical contact surfaces. Alloying the tin coating with a small amount of lead (Pb) is a common means of reducing whisker growth. However, because of health and environmental reasons, many industries are striving to reduce or eliminate the use of lead.
Thus, there is a need to develop a coating system that would be able to maintain a low contact resistance and good solderability after fretting and thermal exposure, combined with one or all of the additional attributes of lower coefficient of friction, and reduced whisker growth.

Fretting and whisker resistant coating system and method

Abstract: An alternative coated electrically conductive substrate has particular utility where debris from fretting wear may oxidize and increase electrical resistivity, such an in a connector assembly. This electrically conductive substrate has a barrier layer deposited on the substrate that is effective to inhibit diffusion of constituents the substrate into a plurality of subsequently deposited layers. The subsequently deposited layers include a sacrificial layer deposited on the barrier layer that is effective to form intermetallic compounds with tin, a low resistivity oxide metal layer deposited on said sacrificial layer, and an outermost layer of tin or a tin-base alloy directly deposited on the low resistivity oxide metal layer.

Abstract: In this alternative embodiment, the barrier layer is preferably nickel or a nickel-base alloy and the low resisitivity oxide metal layer is preferably silver or a silver-base alloy.

Abstract: When heated, the coated substrate of this second embodiment forms a unique structure having a copper or copper-base alloy substrate, an intervening layer formed from a mixture or metals including copper and tin, and an outermost layer which is a mixture of a copper-tin intermetallic containing phase and a silver-rich phase. It is believed that this silver-rich phase is particularly beneficial to reduce an increase in resistivity due to oxidation of fretting wear debris.