A single electron on hole field effect transistor fabricated from a narrow band gap semiconductor. The transistor is such that the valence and conduction bands have sufficiently similar energy levels such that a top region of the valence band at one point (37), e.g. under a gate electrode (34), within the current path of the transistor can be forced to be higher than the bottom region of the conduction band at another point within the transistor, allowing Zener tunelling to occur. The transistor is fabricated from semiconductors with band gaps narrow enough to allow this to occur, for instance InSb and InAISb, CdTe and CDxHg1xe2x88x92xTe.

1. Field of the Invention
This invention relates to an improved structure for a semi-conductor device and methods for using such a device.
2. Discussion of Prior Art
Over the last two decades there has been much interest in semiconductor devices which operate by restricting the motion of current carriers in one or more directions. In such devices the carriers can only occupy a discrete set of energy levels or sub-bands in one or more dimensions. The motion of the carriers is said to be quantised in the direction of confinement.
In heterojunctions, formed by the joining together of two semiconductor compounds of different band gaps, the carriers are confined to a potential or quantum well. A two dimensional electron gas is formed if the carriers are electrons (or a two dimensional hole gas is formed if the majority carriers are holes).
One particular type of semiconductor device which has been fabricated, typically from GaAs, is the single electron transistor which was invented in 1987. In this device the potential well is of such a size that it can hold only a few electrons (typically between 0 and 20). Furthermore, once this number is fixed (by an external contact potential) it does not fluctuate in time by more than one electron.
Such devices are confined to operate at low temperatures (typically less than liquid nitrogen temperatures) due to the physics which allows them to function. The devices rely on the fact that the potential well has a small capacitance, and the energy that it takes for electrons to charge this well is quite large. If the device is cooled to low temperatures the electron thermal energy becomes less than the charging energy. Without a significant source-drain voltage bias the electrons cannot travel through the potential well. This is known as Coulomb blockade.
According to a first aspect of the invention there is provided a field effect single electron transistor fabricated from a narrow band gap semiconductor.
Single Electron Transistors (SET) have the highest charge sensitivity of any man-made device. The SET is suited for applications where it is necessary to measure small fluctuations of charge without disturbing the system under study, or for providing low power transistor action. They also have potential for sensitive detectors of pressure, acceleration and temperature at least. Other detectors may be envisaged.
The transistor of the first aspect of the invention may be referred to as a Zener single electron transistor (Zener SET). Prior art transistors can be referred to as unipolar single electron transistors.
Zener SETs are advantageous because they are potentially simpler to fabricate and control, they may operate at higher temperatures than prior art devices, both n-type and p-type devices may be fabricated, and confinement may be enhanced due to the low effective mass of conduction electrons in p-type devices.
Further advantages of single electron transistors are that they are physically small (e.g. nanoscale) when compared to conventional field effect transistors resulting in a higher packaging density though lower power density.
The transistor preferably contains a heterojunction between layers of a first and a second material. The first material may be InSb or CdxHg1xe2x88x92xTe.
The second material may be InAISb or CdTe or CdxHg1xe2x88x92xTe. The heterojunction may be provided as a single layer of first material adjacent to a single layer of second material. Alternatively, the heterojunction may be provided as a single layer of first material between two layers of second material.
Should the heterojunction be provided as a single layer of first material adjacent to a second material, the second material may be an oxide (i.e. may be an insulator) or may be a semi-conductor. The first material may be considered a narrow band gap semiconductor. In the cases wherein the second material is a semi-conductor it may be considered a wide band gap semi-conductor. Other materials may be suitable for the first and second materials.
The skilled person will realise that should the first material be CdxHg1xe2x88x92xTe the band gap can be tailored to any desired value by adjusting the value of x. As x tends to ≅0.15 the band gap of the material tends to zero. However, x may be chosen to be an optimal value.
Should the second material be CdxHg1xe2x88x92xTe the value of x may be chosen to tend to one (that is CdTe). CdTe is preferred for its electronic properties but may not be achievable in view of other physical considerations: for example crystal growth considerations and lattice mismatch.
There may be provided on a first side of the heterojunction a third material which may be provided as a layer. The third material may function as a first gate electrode. The third material may be a metal. It may be Al or Au, or may be any other suitable conductor. Such a structure is advantageous because the presence of the gate electrode allows the electron/hole gas to be controlled within the heterojunction.
A second gate electrode may be provided on a second side of the heterojunction which is on the opposite side of the heterojunction from the first side. The second gate electrode may be fabricated from a metal. Such a structure in combination with the first gate electrode allows the electron/hole gas to be controlled.
The second gate electrode may be insulated from the materials forming the heterojunction by at least a single layer of insulation. An insulation layer is advantageous in that it modifies the interaction between the second gate electrode and the heterojunction in such a way as to give the desired functionality.
At least one (and preferably two) side gate may be provided. These may help to control the electron/hole gas in the desired manner.
The side gates may be insulated from the materials forming the heterojunction by a layer of insulation.
The side gate may comprise an elongate area along one side of the first or second material above the heterojunction. Preferably when two side gates are provided each forms an area along a side of the first or second material which sides are opposite each other. The areas may be rectangles. Most preferably the two side gates are in the same plane and there exists a gap within that plane between the two areas of side gates. The side gates preferably extend generally parallel to each other.
Preferably, the second gate electrode is provided above and may be insulated from the side gate. Again such a structure allows the electron/ hole gas to be controlled in the desired manner.
The insulation may be silicon dioxide SiO2 or any other suitable insulation material. Indeed, different types of insulation material may be used for different layers of insulation. Or indeed, the layers of insulation separating the materials of the heterojunction and the side gate may be the same as the layers of insulation separating the side gate from the second gate electrode.
Preferably the second gate electrode comprises a primary portion which extends over the gap between the side gates. Such a structure may have a large influence in the electrons in the electron/hole gas.
The second gate electrode may have a first broad region connected to a second broad region via a narrower waist region. The second gate electrode may be a bow tie shape possibly with the central, waist, portion of the bow tie extending over the gap between the side gates.
The skilled person will appreciate that the effect of the side gate electrodes may be thought of as creating a quantum wire wherein electrons or holes are held by an applied electric field in a narrow strip within the electron sheet. The use of electrodes to form the quantum wire may be thought of as soft confinement.
An alternative, or additional, way of forming the quantum wire may be with hard confinement as opposed to through the provision of side gates (soft confinement).
In one embodiment the heterojunction may be provided between a strip of first material and a layer of second material. That is the width of the first material may be much less than the width of the second material. This potentially provides a hard confined quantum wire. The first and second materials may be as described in relation to the embodiments hereinbefore. In particular the first material may be thought of as a narrow band gap semi-conductor and the second material may be thought of as a wide band gap semi-conductor.
The strip of narrow band gap semi-conductor may have a width of substantially 50 nm. However, the strip may have a width substantially in the range 10 nm to 90 nm. More preferably the width of the strip may be substantially in the range 25 nm to 75 nm.
In this embodiment a second gate electrode may be provided overlying the strip of narrow band gap semi-conductor. The second gate electrode may or may not overlie regions of the wide band gap semi-conductor where no narrow band gap semi-conductor is present. Preferably the second gate electrode has the bow tie structure discussed hereinbefore.
Preferably the second gate electrode is separated from the semi-conductor materials by a layer of insulator which may be silicon dioxide.
The narrower waist region of the second gate electrode may have a width of substantially 50 nm. However, the narrower waist region may have a width substantially in the range 10 nm to 90 nm. More preferably the width of the narrower waist region may be substantially in the range 25 nm to 75 nm. The skilled person will appreciate that this may form a region where the second gate electrode overlies the narrow band gap semi-conductor which is substantially square having a side of substantially 50 nm.
In an alternative embodiment the quantum wire may be provided by the V-Groove method for fabricating quantum wires. This may be preferred over the method of providing a thin strip of narrow band gap semi-conductor because the confinement offered may be cleaner.
The transistor may contain a V shaped notch or groove within a substrate layer.
A layer of second material may be provided lining the groove. The layer of second material may also form a V shaped notch or groove. A region of first material may be provided in the V of the notch in the second material.
The notch may be substantially filled with a layer of insulation. However, the notch may be partially filled with insulation such that the first material is covered. The insulation may cover the region of first material. Preferably a second gate electrode is provided on top of the layer of insulation. Preferably the second gate electrode has a bow tie shape having a primary portion as described hereinbefore. The primary portion of the second gate electrode may overlie the region of first material. A plurality of quantum wires may be provided in a single groove. The wires may be stacked one above the other.
In yet another embodiment the transistor may have a layer of second material having a non planar surface upon which a quantum wire has been fabricated.
The substrate may have a surface which is stepped (i.e. has a plurality of steps) due to being cut off axis. That is off-axis to a material lattice plane having atoms aligned to form a smooth surface. The angle of a plane of the stepped surface of the substrate may be adapted to provide a specified distance between steps. The distance may be in the range 0.1 xcexcm to 1 xcexcm. The skilled person will realise the more acute the angle the longer the distance between the steps.
Regions of first material may be provided in regions associated with the steps in the second material. The regions of the first material may be covered with an insulator. The insulator may also cover the surface of the second material where there is no first material provided. It will be appreciated by the skilled person that when fabricating quantum wires by such a method the thin layer of the first material may cover the entire non planar surface of the second material with regions being concentrated in regions associated with the steps.
A second gate electrode may be provided on top of the layer of insulation overlying the regions of first material. The gate may have substantially the dimensions as discussed hereinbefore.
The second gate electrode may overlie a number of regions of first material. The regions of first material may be considered to be quantum wires.
In yet another embodiment the transistor may comprise at least one ridge grown quantum wire. The ridge grown quantum wire may include reverse mesa etched from a substrate. Ridges in-between the reverse mesa may have a layer of second material provided upon a surface. On a surface region of the layer of second material there may be provided a region of first material.
A second gate electrode may be provided overlying the region of first material and the second gate electrode may be separated from the first material be a layer of insulation.
The transistor may be thought of as providing a controllable single potential maxima or minima along a quantum wire. That is providing a quantum dot within a quantum wire.
The various techniques for forming quantum wires are disclosed in the PhD thesis of Matthew John Steer, dated October 1997, entitled xe2x80x9cOptical and Structural Characterisation of III-V Semiconductor Quantum Wires and Quantum Dot Structuresxe2x80x9d from the University of Sheffield. This thesis is incorporated by reference and the skilled person is directed to read this thesis.
At a third and fourth end of the transistor (which are at opposite ends of a plane parallel with the first and second sides) there may be provided a drain and a source electrode. The drain and source electrodes allow a bias voltage to be applied to the electron/hole gas to cause the carriers to flow through the transistor.
Preferably the dimensions of the primary portion of the second gate electrode are such that it is less than substantially 100 nm in width measured along an axis perpendicular to the drain and the source. More preferably less than 75 nm and most preferably less than substantially 50 nm.
The transistor may be fabricated so that the primary charge carriers may be either holes or electrons. That is the device may be fabricated so that it is p-type or n-type. This has the advantage that circuits could potentially be fabricated from a number of transistors according to the invention such that the device would use complementary technology similar to the philosophy behind CMOS technology. As the skilled person will realise this is advantageous in that such devices are low power because they have substantially zero quiescent current.
Should the device be fabricated from p-type samples there is the advantage that there is enhanced quantisation in the confined region.
In use, should the primary charge carrier be electrons, the primary portion of the second gate electrode may cause a single potential barrier when a bias voltage is applied between the first and second gates. (Conversely if the primary charge carriers are holes a single potential well may be caused when a voltage is applied between the first and second gate).
It may be possible to cause an equivalent potential barrier or well within a non-narrow band gap semi-conductor by applying high gate bias potentials. However, the gradient of the potential field would be such that electrons could not be held within the field; any electron within the well or barrier would be able to Zener tunnel out of the region. That is, the wave function would leak out of the well or barrier, due to the steepness of the sides.
With a sufficiently high gate (first gate to second gate) bias voltage unoccupied quantised energy levels will occur in the valence band below the primary portion of the second gate electrode. These energy levels may be occupied by charge carriers tunnelling from the conduction band to the valence band (Zener tunnelling).
Narrow band gap may be defined as a material having a valence band at an appropriate level to complement the conduction band such that electrons can use the valence band to tunnel in the manner described hereinbefore. An alternative or additional definition of narrow band gap may be the use of a material having a band gap of less than substantially 1 eV between the conduction and valence bands. Most preferably a band gap of less than substantially xc2xd eV may exist between the conduction and valence bands.
Should the heterojunction be provided as a layer of first material between two layers of second material, the layers may be arranged such that a permanent strain is caused throughout the layer of first material. This is advantageous because it may shift the energy of heavy holes within the valence band such that electrons tunnelling through the transistor can only utilise light holes. As a result of this it is likely that the performance of an n-type device will be as good as the p-type device due to the low effective mass of the light holes.
According to a second aspect of the invention there is provided a method of holding a charge carrier within a quantum dot created by a pair of gate electrodes across a heterojunction, in which a bias voltage applied across the gate electrodes cause a single potential barrier or well within a sheet of charge near the heterojunction such that one or more charge carriers are confined within the barrier or well.
Preferably the method comprises using narrow band gap semi-conductors to provide the sheet of charge. These may show the necessary physical properties to allow the single maxima or minima of field to be provided, in which a charge carrier can be held within.
A potential barrier would be caused in an n-type device and a potential well would be caused in a p-type device.
The method may comprise cooling the heterojunction, for example to substantially liquid nitrogen temperatures (77K). The method may comprise cooling the heterojunction to below liquid nitrogen temperatures, perhaps to substantially liquid helium temperatures (4K).
As discussed in the introduction such cooling may bring the thermal energy of the charge carriers below the charging energy of the quantum dot.
The method may comprise applying a bias along the heterojunction (between a source and drain electrode) such that charge carriers are caused to flow along the heterojunction when potential caused by the gate electrodes allows.
According to a third aspect of the invention there is provided a method of detection comprising using a charge detector wherein the gate electrodes of a field effect transistor according to the first aspect of the invention are connected to a potential source which is representative of the quantity being detected such that variations in the quantity causes variations in the potential applied to the gate electrodes which, in turn, causes a change in current flowing through the transistor.
An advantage of such a device is that the effect may be used directly to measure small changes in an electric field (perhaps this can be thought of as a sensitive electrometer).
Preferably the change of current caused is on an order substantially equal to the original current flowing through the transistor.
Further possible applications may be the formation of an accelerometer or may be of a pressure sensor. The forces exerted on a Zener SET may be enough to alter the physical dimensions of the potential barrier or well. This may change the energy of a quantised level in the valence band relative to the Fermi energy (the energy levels are a function of geometry as well as a function of applied bias voltage) thus causing a change in the current flow through the device.
The method may have a sensitivity comparable with that of a scanning electron microscope.
According to a fourth aspect of the invention there is provided a single electron transistor which relies on Zener Tunnelling of electrons into the valence band of the semi-conductor material from which it is fabricated, to provide transistor action.
According to a fifth aspect of the invention there if provided a single electron transistor in which the energy levels of heavy holes within the valence band are shifted below the energy levels of light holes.
This has the advantage that only light holes are used as electrons tunnel into the valence band so that it is likely the performance of an n-type device will be as good as the p-type device due to the low effective mass of the light holes.
Preferably the energy level of the energy levels of heavy holes are shifted by applying a permanent strain to a material in which electron confinement occurs.
Preferably the material in which the electron confinement occurs in a narrow band gap semi-conductor, which may be provided between two layers of wide band gap semi-conductor.
The strain may be applied to the narrow band gap semi-conductor by lattice strain caused by interaction with the wide band gap semi-conductor.

Single charge carrier transistor, method of holding a charge carrier within a quantum dot, and method of detection


A film cassette for an automatic film processor is provided with a cam surface for consistently and accurately guiding a force-transmitting member into and out of engagement with a pocket formed in a sheet element of a self-developing, peel-apart film unit enclosed therein, for the subsequent movement of the sheet element into a developer liquid spread system located in the film processor for engagement with other film unit elements.

1. Field of the Invention
The present invention relates to photographic apparatus for self-developing, peel-apart film, in general, and to a film cassette for an automatic film processor enclosing a plurality of self-developing, peel-apart film unit elements of the type having their leading ends adapted for engagement by a force-transmitting member for movement into or out of the film cassette for subsequent film unit processing, in particular.
2. Description of the Prior Art
Self-developing, peel-apart film units are well known in the field of instant photography. Each film unit comprises a negative or photosensitive sheet for forming a negative image of a subject, an image receiving sheet for forming a positive subject image and a rupturable pod of processing liquid. A positive images is formed by means of a well-known diffusion transfer process after the pod containing the processing liquid is ruptured and its contents spread between the positive and negative film sheets.
Film units of the aforementioned type are typically exposed and processed in portable, multiple-exposure, instant-type photographic cameras or processed in large format film processing equipment. When employed in a camera as many as ten film units are provided in a single lighttight film negative sheet on the other side of a pressure plate located within the film pack. Pull tabs are attached to one or both of the leading ends of the positive and negative sheets. After exposing an outermost negative sheet at a film plane of the camera a first tab attached to the negative sheet is withdrawn from the camera forcing the exposed negative to be turned 180.degree. about the pressure plate and into superposition with the positive sheet. This movement causes a second tab attached to the forward ends of the positive and negative sheets to enter and pass through the bite of a pair of motor driven pressure applying spread rollers to a position exterior of the camera. A combination of the angle at which the first tab is attached and the force applied by a camera operator causes the first tab to detach from the negative sheet at this time.
After the first tab is so detached, the operator pulls the second tab so as to advance the positive and negative sheets between the pair of spread rollers in a superposed relation. At the beginning of the advancement of the positive and negative sheets the spread rollers apply pressure to a pod containing a processing liquid located at the leading ends thereof, thereby rupturing the same, and spreading its contents between the superposed sheets in a thin uniform layer as the sheets are advanced therebetween. A positive image is formed on the positive sheet outside of the camera by a well known diffusion transfer process. After a required interval of time the positive sheet is peeled away from the negative sheet and the negative sheet, along with the second tab attached thereto are discarded. A more detailed description of this particular type of peel-apart film may be found at pages 185-187 of a book entitled, "Camera Technology" by Norman Goldberg published in 1992 by the Academic Press.
The above-described peel-apart film format has several disadvantages, especially if considered for use in certain photographic apparatus. One disadvantage is film cost. In addition to the multiple tabs and the relatively large amounts of leader material required for each film unit, which necessarily increases material costs, economies of scale are limited by the fact that both a positive and negative sheet must be included within a single film cassette in order to take advantage of such economies, which would substantially increase cassette size and thereby make such a cassette unwieldy for use by a camera operator. Another disadvantage is that this type of film format is not susceptible of inclusion in highly automated film processing equipment. Processing a film unit by pulling certain tabs at various times in the film processing cycle is clearly a processing technique that is inherently manual.
In U.S. patent application Ser. No. 936,513 filed Aug. 28, 1992 by Polizzotto et al., and assigned to the assignee of the present application, an improved film format for a self-developing, peel-apart film unit is disclosed that was specifically designed for use in highly automated photographic apparatus utilizing peel-apart film. A film unit 10 incorporating this improved film format is shown in drawing FIGS. 1A and 1B. The film unit comprises both positive and negative sheet elements with each having pockets formed on a surface of a leading end thereof. A force-transmitting member (or members) engage these sheet element pockets and move the so engaged sheet elements, in a mated configuration, into the bite of a pair of spread rollers in a conventional developer liquid spread system of an automatic film processor in order to initiate the film developing process.
A major problem associated with a photographic sheet element transport system of this type is the inability to consistently insert a force-transmitting member into a sheet element pocket and thereby avoid a sheet element misfeed into, for example, the developer liquid spread system. If the force-transmitting member fails to enter a sheet element pocket formed on a surface thereof, sheet element movement into the developer liquid spread system cannot occur. A correlative problem is the inability to consistently withdraw the force-transmitting member from the sheet element pocket without damaging a sheet element surface. If the path of force-transmitting member movement is not controlled while being withdrawn from the sheet element pocket for movement back toward its start or initial position, it may be dragged across and thereby scratch a sheet element surface. The photosensitive layer of the negative sheet element of a self-developing photographic film unit would be particularly susceptible to such force-transmitting member movement damage.

Film cassette having a force transmitting member motion guiding surface incorporated therein


A self regulated feeder for a footbath for animals may include a hollow container for a source of fluid, an outlet passageway to connect the hollow container with the footbath, an air return passageway to connect the hollow container to ambient air to return air to the hollow container, and a differential valve to restrict the returning air to the hollow container. The fluid may include air, and the fluid may include a liquid having a disinfect agent. The self regulated feeder may include a flush passageway to flush the footbath, and the air return passageway may be connected to a liquid trap container to prevent fluid from the footbath from reaching the hollow container.

In a dairy parlor it is common to have the cows exiting the dairy parlor walk through a foot bath of various sizes. This foot bath would have disinfectant, medication, or other chemical that is dissolved in water. The common prior art procedure is that there would be the area having a small pool which contains the water. The dairyman uses a hose to fill the pool with the water, and then pours the disinfectant chemical liquid and/or powder into the water and mixes these in the pool manually.
Also, there are automatically operated devices that replicate these actions i.e. clean out the bath by flushing with water to completely empty the bath, add water, add chemical.
During the course of the cows moving through the foot bath, a certain amount of manure will commonly collect in the foot bath. After a certain number of cows have passed through the footbath, then the dairyman will empty the footbath.
U.S. Pat. No. 5,774,909 (Stable) discloses a foot bath for the use in the treatment of cattle and other livestock. There is a resilient pad which is covered with a shallow layer of disinfectant fluid. As the cow steps on the pad, the fluid flows around the foot.
U.S. Pat. No. 5,630,379 (Gerk et al.) discloses what is called an "electrically controlled spraying device for cleaning and treating animals". There are rails around an enclosure and discharge nozzles mounted to spray a cleaning fluid or a treatment fluid under the animal, and it states that the device is able to clean the hooves of the animal.
U.S. Pat. No. 5,224,224 (Hintz et al.) discloses a foot bathing fixture that includes a seat supported on a raised pedestal. This is incorporated into a shower enclosure for a person.
U.S. Pat. No. 4,979,536 (Midkiff) discloses a portable a truck tire washing apparatus. There are two longitudinally-spaced tire rotating driveable roller trailer assemblies mounted on a support member and a liquid spraying means for spraying the tires.
U.S. Pat. No. 4,228,554 (Tumminaro) shows a toilet for animals particularly adapted for pets such as dogs and cats. There is a user platform on which the animal stands, and the platform has an upper surface which is gradually inclined down on shallow angle toward a center opening of the toilet. A flushing liquid is provided to flow over the surface to clean the waste material from the upper surface, and a bowl is located beneath the upper platform to receive the waste.
U.S. Pat. No. 2,989,965 (Rod) discloses a "foot wear decontaminating apparatus" for use in the atomic industry. The user steps on a platform immersed in a fluid, and a high frequency agitator washes off the contaminating material.
U.S. Pat. No. 2,956,565 (Anderson) discloses therapeutic equipment for remedial bathing and massaging treatment of feet and legs of animals. There is a container filled with granular solids such as soft, clean sand possibly 104 inches long, 42 inches wide and 18 inches high to contain the granular material. The racing horse, for example, is brought to stand with all feet in the soft wet bed and is permitted to sink to a depth somewhere between the ankle and knee height. Heat that could be applied to alleviate the soreness of the animal.
U.S. Pat. No. 853,533 (Byrd) shows a foot bath intended to be occupied by horses as they drink from the attached water trough. There is a drain to keep the water at the desired depth.
A disadvantage of other manual and automatic systems is that these systems are based on a batch-made approach in which a bath is made, is allowed to deteriorate at an increasing rate, and is replaced after a designated time or number of animals with fresh solution.

Self-regulated liquid dispenser and system for maintaining a liquid level in a container of dispensed liquid


The invention prevents leg chafing, and keeps the garment from riding up in the wearer's crotch area, by disposing weights on the garment. If the garment is an undergarment, then Modal® fabric, a bio-based fiber made by spinning reconstituted cellulose from beech trees, is especially preferred, as it is extremely soft, and wicks away moisture in an effective manner. It is an object of the invention to reduce leg chafing. It is a further object of the invention to teach a method of preventing garments from riding up into the wearer's crotch area.

The increasing number of overweight citizens creates numerous and well known problems in the area of public health, and there are equally numerous public and private programs devoted to addressing the issues that arise from this trend. While some issues are serious and life threatening, there are other issues equally serous but rarely discussed. One of these issue is leg chafing. Chafing is a condition of soreness of the skin that occurs from the skin's repeatedly rubbing against an irritant, such as clothing or other skin. Leg chafing occurs when the skin of the upper thighs rubs together with movement such as walking or running. This can be very painful, and can lead to irritation of the upper thighs resulting in reddened, raw skin or rashes. In some extreme cases the skin can be completely rubbed off, leading to bleeding. The situation is worse on hot days, when the inner thighs perspire and the moisture adds to the discomfort. It also worsens when the upper thighs accumulate greater stores of fat.
Wearing shorts would protect the inner thighs if the fabric of the shorts stayed in place covering the thighs. In many cases, however, the shorts 'ride up', or bunch up into the crotch area with movement, such as walking. This is very uncomfortable and the fabric must be continually pulled back down.
One way to reduce chafing is to wear long pants, but this is uncomfortable for some people, especially on hot days, and can be extremely uncomfortable for very heavy people. Skirts would be more comfortable if a solution to the chafing could be found. Some heavy women also feel that skirts are more flattering than pants. Wearing pants also may not be feasible for professional women who must wear skirts at work.


Approaches for verifying connectivity of signals in a circuit design include generating a configured version of the circuit design based on input parameter values. The configured version specifies connections from source pins of ports of circuit blocks of the configured version to destination pins of ports of circuit blocks. Expected source-destination connections between source pins and destination pins of the ports of the circuit blocks of the configured version are determined from the input parameter values. A connectivity checker that includes HDL code is generated based on the expected source-destination connections. For each of the expected source-destination connections, the HDL code forces a first signal value on a source pin of the expected source-destination connection in the configured version of the circuit design and determines whether or not a second signal value at a destination pin of the expected source-destination connection matches the first signal value.

Some circuit design tools provide developers with the capability to customize generic forms of circuit designs in order to implement circuits that are suitable for each developer's particular application. The generic forms of the circuit designs are sometimes referred to as logic cores or intellectual property (IP) cores. Developers rely on logic cores to reduce development time and costs.
The parameterization available for some logic cores may result in a very large number of possible combinations of signal connections between circuit blocks of the logic core. Verifying that the signal connections are correct is imperative. However, using a functional verification approach to verify correct signal connectivity would consume a large number of simulation resources and involve significant efforts to develop suitable test benches. The number of simulation runs required to check the correct signal connections may be very large in logic cores having a large number of connections to check. For example, in gigabit transceivers that are available in devices from XILINX®, Inc., the transceiver has 52 channels, and each channel has 335 signal pins, 66 quad pins, and 30 pins for helper logic blocks. This results in 22,412 (52*(335+66+30)) pins with a large number of signal connections between those pins to check.

Verification of connectivity of signals in a circuit design


Polyalkenylsuccinic acid derivatives are prepared by reacting oligo- or polyolefins having a number average molecular weight (M.sub.N) of from 500 to 10,000 with maleic acid derivatives I ##STR1## where R and R', independently of one another, are each hydroxyl, lower alkyl or halogen or together are oxygen, at elevated temperatures by a process in which effective amounts of free radical acceptors, such as oxygen, are present in the gas phase and in the liquid phase of the reacting system during the reaction. These polyalkenylsuccinic acid derivatives are suitable, after additional imidation, amidation or esterification, as fuel and lubricant additives.

1. Field of the Invention
The present invention relates to an improved process for the preparation of polyalkenylsuccinic acid derivatives from oligo- and polyolefins and maleic acid derivatives and their use as fuel and lubricant additives. The present invention furthermore relates to fuels for gasoline engines and lubricants which contain these polyalkenylsuccinic acid derivatives, and ashless dispersants which are cocondensation products based on these polyalkenylsuccinic acid derivatives.
Polyisobutenylsuccinimides are widely used as ashless dispersants in the lubricant sector. They are present in an amount of up to 10% by weight in engine oils for gasoline and diesel engines and are intended here to prevent the agglomeration of particles, which is referred to in general as sludge formation. The dispersing effect, ie. in this case the imparting of water repellent properties to the particles, is therefore their most important property. In fuels, such compounds are used for keeping the intake system, in particular the intake valves, clean. In recent years, there has been an increasing tendency to replace the polyisobutene radical by other oligoolefin radicals. The requirements for these oligoolefin radicals are comparable with those for the polyisobutene radical.
The corresponding imides are generally prepared from polyamines and polyisobutenylsuccinic anhydride (PIBSA) by condensation. The preparation of PIBSA depends essentially on the polyisobutene (PIB) quality and is effected purely thermally (ene reaction), generally at from 225.degree. to 245.degree. C., with yields of about 65%. The yields can be increased to 90% by adding halogens. By an addition reaction with chlorine and dehydrohalogenation or allylchlorination, the double bond of the PIB can be activated and the reaction temperatures thus reduced to about 170.degree. C. However, the addition of chlorine leads in all cases to chlorine-containing compounds, and the combustion thereof in the engine generally leads to toxic dioxins in the exhaust gases.
2. Description of Related Art
According to U.S. Pat. No. 4,152,499 (1), with an increase in the vinylidene content in the PIB, ie. with higher content of reactive terminal double bonds, lower temperatures down to about 170.degree. C. can be realised in the ene reaction even without the use of halogen. According to the examples, however, the maleation of PIB is carried out at 200.degree. C. with a monomolar excess of maleic anhydride (MA) in order to obtain the yields required for marketing. Furthermore, such a type of reaction results in the formation of tar and opaque products which increase the acid and saponification number of the reaction products after removal of unconverted MA and thus simulate high yields.
U.S. Pat. No. 5,137,980 (2) discloses that polyisobutenes having a high vinylidene content give good results with low tar formation, preferably at from 220.degree. to 265.degree. C., with an excess of from 0.1 to 0.9 mol of MA and at from 4 to 50 bar. However, no information is given about the PIB conversion and the bismaleation fraction. In some cases, the reactions are carried out in the presence of catalysts, such as aluminum chloride, which are difficult to separate off.
DE-A 43 19 672 (3) discloses a process for the preparation of -polyisobutylsuccinic anhydrides from polyisobutene and maleic anhydride, in which polyisobutene containing at least 50% of terminal double bonds is reacted with excess maleic anhydride at from 140.degree. to 200.degree. C. The polyisobutylsuccinic anhydrides thus prepared can be further reacted with aliphatic polyamines to give the corresponding succinamides or succinimides. This preparation process for polyisobutylsuccinic anhydrides which usually gives a small bismaleation fraction does however also have disadvantages, in particular the unsatisfactory yields.
Since PIBSA having a low bismaleation fraction is desirable for certain industrial applications, it is an object of the present invention to provide a process for the preparation of polyalkenylsuccinic acid derivatives which gives products with little or no bismaleation fraction with simultaneously high conversions and good product quality.

Preparation of polyalkenylsuccinic acid derivatives and their use as fuel and lubricant additives


An aqueous, viscoelastic fluid gelled with a viscoelastic surfactant (VES) may suspend solids such as proppants, gravel, drilling debris, waste solids and the like with an effective amount of a nano-sized additive including, but not necessarily limited to alkaline earth metal oxides, alkaline earth metal hydroxides, alkali metal oxides, alkali metal hydroxides, transition metal oxides, transition metal hydroxides, post-transition metal oxides, and post-transition metal hydroxides. The additives may also reduce the amount of VES required to maintain a given viscosity. These viscoelastic surfactant gelled aqueous fluids may be used as treatment fluids for subterranean hydrocarbon formations, such as in hydraulic fracturing, gravel packing and the like. The magnesium oxide, zinc oxide or other nanometer scale-sized additives are at a scale that may provide unique particle charges that use chemisorption, crosslinking and/or other chemistries to associate the micelles and suspend the solids.

Hydraulic fracturing is a method of using pump rate and hydraulic pressure to fracture or crack a subterranean formation. Once the crack or cracks are made, high permeability proppant, relative to the formation permeability, is pumped into the fracture to prop open the crack. When the applied pump rates and pressures are reduced or removed from the formation, the crack or fracture cannot close or heal completely because the high permeability proppant keeps the crack open. The propped crack or fracture provides a high permeability path connecting the producing wellbore to a larger formation area to enhance the production of hydrocarbons.
The development of suitable fracturing fluids is a complex art because the fluids must simultaneously meet a number of conditions. For example, they must be stable at high temperatures and/or high pump rates and shear rates which may cause the fluids to degrade and prematurely settle out the proppant before the fracturing operation is complete. Various fluids have been developed, but most commercially used fracturing fluids are aqueous based liquids which have either been gelled or foamed. When the fluids are gelled, typically a polymeric gelling agent, such as a solvatable polysaccharide is used, which may or may not be crosslinked. The thickened or gelled fluid helps keep the proppants within the fluid during the fracturing operation.
While polymers have been used in the past as gelling agents in fracturing fluids to carry or suspend solid particles in the brine, such polymers require separate breaker compositions to be injected to reduce the viscosity. Further, the polymers tend to leave a coating on the proppant even after the gelled fluid is broken, which coating may interfere with the functioning of the proppant. Studies have also shown that "fish-eyes" and/or "microgels" present in some polymer gelled carrier fluids will plug pore throats, leading to impaired leakoff and causing formation damage. Conventional polymers are also either cationic or anionic which present the disadvantage of likely damage to the producing formations and the conductivity of propped fractures.
Aqueous fluids gelled with viscoelastic surfactants (VESs) are also known in the art. VES-gelled fluids have been widely used as gravel-packing, frac-packing and fracturing fluids because they exhibit excellent rheological properties and are less damaging to producing formations than crosslinked polymer fluids. VES fluids are also used as acid diverting, water and/or gas control fluids. VES fluids are non-cake-building fluids, and thus leave no potentially damaging polymer cake residue.
It has been discovered that alkaline earth metal oxides, alkaline earth metal hydroxides, transition metal oxides, transition metal hydroxides, and mixtures thereof, and in particular magnesium oxide may serve to inhibit or prevent fluid loss in aqueous fluids gelled with VESs, as described in U.S. patent application Ser. No. 11/755,581 filed May 30, 2007 (U.S. Patent Application Publication No. 2008/0060812 A1), incorporated herein in its entirety by reference. Some of these same materials may also be effective as system stabilizers and performance enhancers for aqueous fluids gelled with VESs, as described in U.S. patent application Ser. No. 11/125,465 (U.S. Patent Application Publication 2005/0252658 A1), also incorporated herein in its entirety by reference.
It would be desirable if a method and/or composition would be devised to suspend solids such as proppants, gravel, drilling debris, etc., even more effectively in viscoelastic surfactant gelled aqueous fluids.

This patent is subject to a terminal disclaimer.

Solids suspension with nanoparticle-associated viscoelastic surfactant micellar fluids


An EUV light source collector erosion mitigation method and apparatus for a collector comprising a multilayered mirror collector comprising a collector outer surface composed of a capping material subject to removal due to a removing interaction with materials created in an EUV light-creating plasma, is disclosed which may comprise including within an EUV plasma source material a replacement material. The replacement material may comprise the same material as the capping material of the multilayered mirror. The replacement material may comprise a material that is essentially transparent to light in a selected band of EUV light, e.g., a spectrum of EUV light generated in a plasma of a plasma source material. The replacement material may comprise a material not susceptible to being etched by an etching material used to remove deposited plasma source material from the collector, e.g., a halogen etchant.

An EUV LPP light source using a plasma source material, e.g., tin as the source element suffers from erosion of the primary collector mirror. This erosion is due to sputtering by energetic plasma source material ions, e.g., tin ions and neutrals created by the LPP. Applicants according to aspects of embodiments of the present invention seek to address this issue.


To provide a polycarbonate resin composition excellent in low-birefringence and strength.

Polycarbonate resins formed of 2,2-bis(4-hydroxyphenyl)propane (popular name: bisphenol A) have been used in various optical material applications such as substrates of CD or DVD, optical films, optical sheets, a wide variety of lenses, or prisms since they are excellent in transparency, heat resistance, low water-absorption properties, chemical resistance, mechanical characteristics, and dimension stability. However, the resins formed of bisphenol A have large birefringence, and it is difficult to use them in the technical fields requiring low-birefringence.
Therefore, in the technical fields requiring low-birefringence, acrylic resins, noncrystalline polyolefins, or polycarbonate resins having a specific structure have been used. However, acrylic resins suffer from high water-absorption properties, low dimension stability, or low chemical resistance properties; and noncrystalline polyolefins suffer from low impact resistance, low chemical resistance properties or high price. Furthermore, some of molded products formed of acrylic resins or noncrystalline polyolefins don't exhibit sufficient low-birefringence, and therefore, in the technical field requiring lower-birefringence, such resins may not be used.
Examples of the polycarbonate resin having a specific structure include copolymerization-polycarbonate resins derived from 9,9-bis(3-methyl-4-hydroxyphenyl)fluorene and tricyclo[5.2.1.02.6]decanedimethanol (see Patent Document 1). Although injection-molded products formed of the resins are excellent in low-birefringence, they suffer from low impact resistance strength.
Examples of the polycarbonate resin having a specific structure include also copolymerization-polycarbonate resins derived from 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene and a prescribed hydroxy compound (see Patent Document 2); a polycarbonate resin composition containing a copolymerization-polycarbonate resin derived from 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene and a prescribed hydroxy compound and a polycarbonate resin derived from bisphenol A in an amount has been proposed (see Patent Document 3); and the applications thereof have been also proposed (see Patent Document 4). Although these polycarbonate resins have lower birefringence compared with the polycarbonate formed of bisphenol A, they suffer from low strength.
Therefore, low-birefringent polycarbonate resins excellent in strength are required.

Abstract: Disclosed is a polycarbonate resin composition prepared by blending                a polycarbonate resin (A) prepared by forming carbonate bonds in a 95-5% by mole of dihydroxy compound represented by formula (1) and a 5-95% by mole of dihydroxy compound represented by formula (2) with a diester carbonate, and        a polycarbonate resin (B) prepared by forming carbonate bonds in dihydroxy compound represented by formula (3) with a diester carbonate or phosgene        in a 45-85% ratio by weight of (100×(A))/((A)+(B)).

Abstract: (in the formula, R1 and R2 represent a hydrogen atom or methyl respectively.)


Separation of luma and chroma in a video. In an embodiment, values on a current line of the sampled video signal, at ¼-period intervals, are compared with values on a previous line of the sampled video signal, at ¼-period intervals. Values on the current line of the sampled video signal are compared to values on a subsequent line of the sampled video signal. This gives information about the vertical frequency content. Values on the current line are compared with values having the same chroma phase on the same line to provide information about horizontal frequency content. The data of vertical and horizontal frequency logic are used by the decision logic to determine the appropriateness of combing based on these comparisons. If combing is not appropriate, the signal is bandpass filtered instead of combed. The low-pass and combing filters are applied to the original signal, not an interpolated or resampled signal.

1. Field of the Invention
The present invention is related to processing of video signals, and, more particularly, to comb filtering ("combing").
2. Background Art
A composite video signal is the sum of a luminance (brightness) signal and a chrominance (color) signal. These signals are also referred to as luma and chroma signals, respectively. The frequency ranges of the luma and chroma signals are designed to overlap.
A problem created by overlapping the luma and chroma frequency spectra is that it is difficult to separate them completely. Therefore, what is needed is a system and method to separate the luma and chroma signals with minimal effect on the quality of the incoming signal.


A method and system for integrating plural disparate information sources into a single stream of information using middleware. Data received from real-time sources (e.g., stock quotes) is given priority for distribution over non-real-time sources (e.g., news sources). By coordinating between several servers, data can be distributed in a load-balanced fashion which also performs self-healing in the face of server errors.

1. Field of the Invention
The present invention is directed to a method and system for integrating heterogeneous information services, and more particularly to a method and system for assembling heterogeneous information streams with asynchrounous or digital rates of arrival into a single information stream.
2. Discussion of the Background
Real-time delivery of information is an integral part of the decision making process of many brokers and investors. Accordingly, real-time information services spend a considerable amount of money delivering such information to a multitude of subscribers. Generally, such information is distributed over a series of wide-band pipes (e.g., leased lines from the information server). Such a delivery mechanism, however, is contrary to the distributed communication architecture used generally across the Internet. On the Internet, subscribers generally are connected to an Internet Service Provider on a connection shared for multiple purposes (e.g., Web browsing and stock trading).

Information distribution method and system


Method and apparatus for imaging tissue by upstream illumination and downstream dual filtering of the exiting light for separation of ballistic photons rays from stray rays. Dual filtering includes spatial filtering via a pinhole and spatial filtering operated by a fast gate. A processor synchronizes flashes of illumination with the fast gate to command opening for passage of the ballistic photons rays and closure to exclude the stray rays. An image detector downstream of the fast gate collects the ballistic photons rays for processing by the processor and display on a monitor as a shadowgram. Illumination flashes have one or more wavelengths and the image detector is adapted to match the selected wavelengths of the illuminating flashes.

Imaging of the interior of soft tissues of the body, such as the female breast has been approached in the past by all known modalities, including ultra sound, X-ray, CT, MI and IR illumination, primarily for the purpose of detecting cancer.
A commonly used imaging method for breast cancer detection is mammography, which employs imaging by use of X-rays. Although this last method is accepted as the gold standard for breast cancer detection, it is not an optimal approach since it suffers from several well-known drawbacks. These drawbacks include involving the examinee to an unpleasant and uncomfortable procedure, also involving exposure to X-ray radiations. Furthermore, there is need to operate expensive equipment which is not available in the office of a practitioner but only in clinics, and the practitioner is required to deal with results providing only low resolution images.
Another method of detection relates to ultrasound technology, actually inexpensive, does not require exposure to X-rays but unfortunately, offers only unacceptable limited resolution.
It has been proposed in the past that IR imaging of soft tissues could become a good alternative to X-rays mammography, eliminating almost all the drawbacks listed hereinabove.
According to the U.S. Pat. No. 5,803,082 to Stapleton et al., proposes an omnidirectional, multispectral and multimodal sensor/display processor for the screening, examination, detection, and diagnosis of breast cancer using stable vision fusion of various wavelengths of illumination. Furthermore, U.S. Pat. No. 4,649,275 to Nelson et al., provides a method and apparatus for high-resolution breast imaging which uses collimated light of a narrow spectral bandwidth rather than ionizing X-ray radiation.
Despite expectations, none of the above-cited patents have reached recognized use, if use at all.
However, regardless of the potential advantages, no IR device for soft tissue imaging, including mammography, has been developed to the stage of commercial application and professional acceptance, due to this method's low sensitivity which results from the very high degree of light scatter that characterizes the passage of IR beams through bodily tissue.
It is thus desirable to provide a method and apparatus as a superior alternative to current methods for soft tissue imaging as a procedure that is comfortable for the examinee.
It is another object of the present invention to provide an examination procedure, wherein the exposure to X-rays is totally avoided, resulting in high-quality imaging.
It is a further object of the present invention to provide an apparatus configured to implement the method that is relatively small and inexpensive, so as to fit into, and be suitable for use in a practitioner's office.

Method and apparatus for imaging tissues


The present invention provides a system and method for reducing power consumption by shaping the spectrum of a downstream signal. Incremental improvements in power consumption due to spectral shaping produces a noticeable reduction in the aggregate power consumed at a central office in asymmetric digital subscriber line (ADSL) systems.

Signal integrity and system performance in digital subscriber line (DSL) systems is a function of transmission power. In other words, the signal-to-noise ratio (SNR) of a signal generally increases as the transmission power increases, and, conversely, the SNR of the signal decreases as transmission power decreases. While the power consumption at individual customer premises (i.e., upstream power consumption) is relatively small, the aggregate effect of hundreds of DSL ports in a DSL access multiplexer (DSLAM) at a central office (CO) becomes significant (i.e., the downstream power consumption becomes significant).
In the specific context of asymmetric digital subscriber line (ADSL) systems, the power level of a downstream signal to a given receiver location is determined by the ADSL transceiver unit (ATU) of the receiver (i.e., the ATU-R), and not the ATU at the CO (i.e., the ATU-C). Thus, in a conventional bit-loading approach within traditional ADSL systems, the ATU-R controls the transmission power, and the role of the CO is merely to comply with the request of the ATU-R. Since a cutback in power results in a loss of performance, the conventional bit-loading approach results in a sub-optimal use of power because the ATU-R invariably requests more power than needed for signal transmission. In other words, there is little incentive for the ATU-R to request a power cutback since a power cutback would almost always result in a loss of performance. Consequently, the CO consumes more power than necessary because the downstream signal power remains unknown until both the ATU-R and ATU-C enter data mode.
Additionally, during initialization, the entire downstream band is transmitted with a flat power spectrum (i.e., the same energy across the entire power spectrum). Since a flat power spectrum is rarely the optimum power spectrum, the initialization procedure is executed with a sub-optimal use of power. Furthermore, as loop length (i.e., reach between the CO and the customer premises) exceeds a given distance, the SNR decreases to the point where not all bins are used for data transmission. In other words, for long loops, only a portion of the bandwidth is used for data transmission. Thus, a full-bandwidth initialization of signals consumes more power than necessary for those loops that utilize only a portion of the bandwidth.
Due to the sub-optimal power consumption, which exists in ADSL systems as well as other types of signal transmission systems, there is a need in the art for reducing power consumption during signal transmission.

System and method for reducing power consumption by spectral shaping of signals


A method for establishing a communication session between a first communication client located within a first communication network, and a second communication client, via a signaling server located within a second communication network distinct from the first communication network and connected thereto via a address translation device. The method includes the step of binding a first address and a second address of the first communication client within the address translation device, by having the first communication client transmit registration messages according to the UDP protocol to the communication server. The method further includes saving, at the communication server, an incoming signaling message sent from the second communication client and intended for the first communication client; replying, by the communication server, to the registration message of the first communication client that follows with a reply message requesting that the first communication client send a new registration message using the TCP protocol; and delivering, by the communication server, the incoming signaling message after the new registration message using the TCP protocol has been received from the first communication client.

(1) Field of the Invention
This invention relates to communication networks. More precisely, it pertains to the problem of transmitting signaling messages through address translation devices such as NAT ("Network Address Translation") devices.
(2) Description of Related Art
Current communication networks enable the establishment of communication sessions by means of signaling protocols such as H.323, MGCP (Media Gateway Control Protocol) or SIP (Session Initiation Protocol) and SDP (Session Description Protocol).
This SIP protocol is defined by RFC 3261 published by the IETF (Internet Engineering Task Force), and its dual purpose is:                to allow two parties to be brought into contact,        to enable the negotiation of the characteristics of the session to be established (video bitrate, which encoder (CODEC to use, etc.), via the SDP protocol.
The negotiation of session characteristics is specified by RFC 3264, entitled "SDP offer/answer model").
A calling party that wishes to call another party may send a signaling message ("Invite") to a signaling element, known as a "proxy", containing its personal address, the physical address of its terminal (or, more generally speaking, a client), and the personal address of the party being called. The signal element has means (the "registrar") for matching the personal address of the party being called with the physical address of the corresponding terminal. This matching allows the signaling message to be routed to the party being called.
If that party accepts the call, the party responds with new signaling messages that include the physical address of the terminal or client. In this manner, as both terminals know the physical address of the other party, they may establish an IP (Internet Protocol) connection for transmitting data (voice, video, etc.)
However, a problem arises with address translation devices, known as NAT ("Network Address Translation") or NAPT ("Network Address Port Translation") devices, which are defined in RFC 1631, "The IP Network Address Translator", and in RFC 3022 "Traditional IP Network Address Translator (Traditional NAT)". These devices are designed to interface a first network (typically, a private network) with a second network (such as the public Internet network).
The devices (terminals) of the first network have physical IP addresses whose validity is limited to that first network. When they wish to establish communications with devices located outside that first network, the address translation device assigns them a temporary second address, valid for the second network, and saves the association between the client's first and second addresses.
The NAT address translation device therefore modifies the messages transmitted between the two communication networks on the fly, by:                converting the terminals' first addresses into second addresses, within the IP headers of the outgoing messages, i.e. those being sent from the first network to the public second network, and by        converting the terminals' second addresses into first addresses, within the IP headers of the incoming messages, i.e. those being sent from the second network to the first network.
An address translation device, i.e. a NAT device, therefore possesses a table used to match up the first and second addresses. These match-ups are temporary, and are deleted when the connection or session is terminated. These associations or match-ups are conventionally known as "binding".
A problem therefore arises when SIP/SDP signaling messages (or H.323 or others) traverse address translation devices. This problem is known as "NAT traversal".
Signaling protocols, such as SIP and SDP, are considered application protocols. The SIP/SDP protocol, for example may be transmitted via the TCP or UDP protocol, which themselves are located above IP in the protocol stack. An SIP message is therefore, in reality, a succession of parameters enclosed within a TCP or UDP message, which is itself enclosed within an IP message.
NAT address translation devices only edit the parameters found within the IP layer, leaving the parameters found within the higher-up layers intact.
In other words, the physical addresses contained within the SIP and SDP messages are not edited by the address translation devices, unlike the addresses contained within the IP headers.
As a result, the recipient of the signaling message (the client being called) will only know the first address of the calling client. However, as this address is only meaningful within the first network, no communication session can be established.
As this problem is well known, numerous solutions have been advanced to resolve it. There are two main approaches for resolving this problem: approaches based on the calling client, and approaches based on a server or device of the communication network.
The first category notably includes the STUN ("Simple Traversal of UDP through NATs") mechanism, described in RFC 3489. This mechanism allows a client (or terminal) to know its second address. In this manner, prior to a message being sent to the second communication network (for example, the public network), the calling client transmits a request to a STUN server located within this second network. This network replies with a message containing the address (and port) with which it "sees" the client, i.e. its second address.
The client may then use this second address to indicate, via the SDP protocol, which address it wishes to use[[s]] to receive replies.
However, this solution suffers from a major limitation, because numerous NAT devices are said to be "symmetrical" and bind a second address to a pair of parties. Additionally, the second address assigned to the client by the NAT device may be different for communication with the STUN server and for the session to be established with the other party. In a similar case, communication between the client and the other party cannot be established.
Other proposals, based on the same principle, have been made to improve the situation, such as TURN ("Traversal Using Relay NAT") mechanisms.
However, neither the STUN mechanism nor the TURN mechanism is suitable for the SIP protocol.
Additionally, a new mechanism, ICE ("Interactive Connectivity Establishment") has been proposed to make SIP signaling messages suitable for traversal. It is based on the STUN and TURN mechanisms, by adapting them.
The second category of solutions relies upon a device within the communication network. It should be noted that the earliest solutions implemented a server within the network (for example, a STUN server), but with the client having the initiative. In this second family of solutions, however, the initiative and implementation of NAT traversal solutions are both incumbent on a network device.
For example, a first solution belonging to this family is binding an application gateway to the NAT address translation device. This mechanism is known as ALG, for "Application Layer Gateway" or "Application-Level Gateway", and is defined is paragraph 2.9 of RFC 2663, entitled "IP Network Address Translator (NAT) Terminology and Considerations", published in August 1999.
This gateway (or a NAT device having the same functionalities of such a gateway) has means for understanding the application protocols used by the messages. In particular, it can understand the content of signaling messages, and translate the physical addresses contained within the SDP messages so that the parties may exchange their second addresses, rather than their first addresses, and may thereby establish communication sessions.
One variant of this solution consists of using a session controller, or SBC (for "Session Border Controller"), which will be located along the paths of the signaling messages. This type of product makes it possible to control the transmission of the communication sessions and signaling messages between both networks. More precisely, the SBC may play the role of an SIP "proxy" signaling element, which can control the means of transmitting media (a "media proxy") via a protocol such as Megaco, so that the communication sessions may be suitably established between the parties.
However, another technical problem arises in that the NAT address translation devices do not save the bindings within the first and second addresses after the connection or session is terminated.
The SIP signaling messages may be transported by the TCP (Transmission Control Protocol) or UDP (User Datagram Protocol) protocol. The TCP protocol saves an open connection until an action is taken to terminate the session. Additionally, if an SIP session using TCP is used, the NAT address translation device will save the binding until the TCP connection is terminated.
However, for the UDP protocol, no connection is established. Additionally, the NAT address translation device only saves the binding temporarily, i.e. until a predetermined length of time has expired.
Consequently, the use of the UDP protocol to transport an SIP signal raises significant problems for NAT address translation device traversal.
However, using the TCP protocol also raises problems, in that it requires the various participants to save open connections. In such a case, the server or proxy must keep saved as many open connections as there are SIP terminals, or clients, with which it is communicating.
As each TCP connection represents a significant quantity of contextual data, this is a significant burden for the SIP proxy. The designer of a communication network may also find himself faced with very tangible problems, such as the maximum limit of TCP connections that an operating system such as Linux can handle (65536 simultaneous connections).
Additionally, the majority of SIP architectures are currently based on the UDP transport protocol.
In order to remedy the temporary nature of the bindings between the first and second addresses, signaling messages are periodically transmitted between both parties for the sole purpose of keeping the binding active.
These signaling messages are usually "Register" messages of the SIP protocol, which include an "Expires" header containing the expiration value of the binding. This expiration period may be negotiated between the client and the server or proxy. For example, in the first "Register" message, the client indicates a first value. The server or proxy replies with a "200 Ok" message containing a second value in the "Expires" header. In accordance with the standard, the client must then use this second value as the expiration period: it will then send a "Register" message at regular intervals determined by this second value.
This approach is known as "UDP Hole Punching".
However, the TCP protocol has advantages which make it necessary for certain applications.
For example, when a message is large in size, the UDP protocol breaks it down into smaller datagrams, which may lead to fragmentation problems. The threshold is dependent on the communication network, and is determined by its maximum transmission unit (or MTU). This threshold is 1300 bytes for an Ethernet™ network.
As explained in paragraph 18.1.1. of RFC 3261, the UDP protocol may no longer be used once an SIP message has surpassed a size corresponding to this threshold minus a buffer value of 200 bytes. The TCP protocol (or another protocol enabling congestion control) must be used in such a case.
Consequently, neither the use of the UDP protocol nor of the TCP protocol is satisfactory, and there is a need for a solution that remedies the technical problems raised by both of the known solutions. The purpose of this invention is to propose such a solution.

Method for address translation device traversal for SIP signaling messages through temporary use of the TCP transport protocol


An interactive method comprises: obtaining a first spatial position of the first terminal device relative to a marker; determining a first display position of a first virtual object in virtual space according to the first spatial position; receiving interaction data sent from a second terminal device, wherein the interaction data includes model data of a second virtual object and a second spatial position of the second virtual object relative to a marker; determining a second display position of the second virtual object in virtual space according to the first spatial position and the second spatial position; generating the first virtual object according to the first display position, and the second virtual object according to the data of the second virtual object and the second display position; and displaying the first virtual object and the second virtual object.

With the advancement of technology, Augmented Reality (AR) technology has gradually become a research hotspot at home and abroad. Augmented reality is a technology that increases users' perception to the real world through information provided by computer systems, it superimposes computer-generated content objects, such as virtual objects, scenes, or system prompt information into real scenes, and thereby enhances or modifies the perception to the real world environment or to data representing the real world environment.

Interactive method and augmented reality system

GUANGDONG VIRTUAL REALITY TECHNOLOGY CO., LTD.


An electronic camera includes: an image capturing unit that captures a subject image; an image compression unit that executes a specific type of compression processing on image data obtained by the image capturing unit; and a decision-making unit that makes a decision as to whether or not a camera-shake has occurred based upon first compressed image data resulting from the compression processing executed by the image compression unit on first image data obtained by capturing an image following a photographing instruction and second compressed image data resulting from the compression processing executed by the image compression unit on second image data captured prior to the photographing instruction.

1. Field of the Invention
The present invention relates to a camera that detects the occurrence of camera-shake.
2. Description of the Related Art
There is a camera known in the related art that detects camera-shake during a photographing operation and displays a warning (see Japanese Laid Open Patent Publication No. H5-150308). In the camera disclosed in Japanese Laid Open Patent Publication No. H5-150308, a subject image for autofocusing is obtained before and after the film is exposed and a camera-shake is determined to have occurred if the degree to which the two images are offset from each other exceeds an allowable extent. The image obtained prior to the film exposure is a focused image, whereas the post film exposure image is an image taken immediately after the shutter closes.


An automobile windshield covered with a transparent electrically conducting layer, on which some hollowed spaces are provided in the form of slots. The length of these slots is a function of the wavelength of the microwave radiation. The microwave radiation, as used for transmission of information in portable telephone sets or remote surveillance systems of toll roads, for example, is absorbed by the conducting layer to again be retransmitted by the slots which act as antennas. In this manner, vehicle windshields which are provided with an electrically conducting layer which reflects the infrared can allow microwave radiation to pass through.

1. Field of the Invention
The invention pertains to a windshield that includes a transparent electrically conducting layer, the windshield comprising at least one part of an enclosure within which an antenna for receiving or transmitting microwave radiation is located. The windshield can be an automobile windshield covered by a layer which reflects infrared radiation.
2. Description of the Related Art
Windshields which are provided with an electrically conducting layer with low impedance are used as insulating windshields and/or as electrically heated windshields in the construction industry as well as in the automobile industry. With respect to automobiles, this type of windshield, combined with a casing made of metal, comprises a Faraday cage which isolates the interior of the vehicle from electromagnetic fields: in the construction industry, the use of windows covered by an electrically conducting layer also allows one to electrically isolate rooms when equipping the other walls in an adequate manner. This kind of insulation can also guarantee the protection of sensitive installations such as control consoles against disturbances caused by powerful radio transmitters or radar equipment.
Such electrical insulation, which can be extended to windshields, prevents transmission of electromagnetic radiation in the microwave range. It follows that one cannot use a portable telephone in a vehicle equipped with this type of window. This presents considerable problems if one wishes to install vehicle research and positioning systems, remote control, identification and remote toll devices, or if the transmitter or receiver is located with the antenna inside the vehicle.

Automobile windshield including an electrically conducting layer


The present invention provides a method for stabilizing the crystal structure of a silicon substrate after an ion implantation process including the step of exposing the substrate to a temperature not higher than 200.degree. C. for a time period of not less than 10 seconds, and preferably to a temperature between about 100.degree. C. and about 200.degree. C. for a time period of between about 10 seconds and about 10,000 seconds.

Ion implantation method has been used for placing impurity, or doping, ions in a semiconductor material such as in a silicon substrate at precisely controlled depths and with accurate control of dopant ion concentration. One of the major benefits of the method is its capability to precisely place ions at preselected locations and at predetermined dosage. It is a very reproducible process that enables a high level of dopant uniformity. For instance, a typical variation of less than 1% can be obtained across a wafer.
An ion implanter operates by providing an ion source wherein collisions of electrons and neutral atoms result in a large number of various ions being produced. The ions required for doping are then selected out by an analyzing magnet and sent through an acceleration tube. The accelerated ions are then bombarded directly onto the portion of a silicon wafer where doping is required. The bombardment of the ion beam is usually conducted by scanning the beam or by rotating the wafer in order to achieve uniformity. A heavy layer of silicon dioxide or a heavy coating of a positive photoresist image is used as the implantation mask. The depth of the dopant ions implanted can be determined by the energy possessed by the dopant ions, which is normally adjustable by changing the acceleration chamber voltage. The dosage level of the implantation, i.e., the number of dopant ions that enters into the wafer, is determined by monitoring the number of ions passing through a detector. As a result, a precise control of the junction depth planted in a silicon substrate can be achieved by adjusting the implantation energy, while a precise control of the dopant concentration can be achieved by adjusting the dosage level.
When a silicon substrate is implanted, a high energy ion beam enters a perfect crystal structure below the wafer surface to knock atoms out of the crystal lattice and changes the top layer of a few thousand angstroms thickness to an amorphous structure. The physical change from a crystalline structure to an amorphous structure radically changes the electrical properties of the silicon material and causing damages to an otherwise perfect crystal structure. Generally, the higher the implantation dosage used, the higher the degree of damage is made to the crystal lattice of the silicon material. While the surface layer of the crystal lattice in the silicon is temporarily damaged by the implanted ions, the silicon atoms in the lattice including those which are knocked out of the lattice sites have certain degree of self-repairing capability. This self-repairing capability is normally triggered by thermal energy and the tendency that a crystal structure normally resumes its original condition after a disturbance in its structure has occurred.
An important aspect in the application of the ion implantation technology is the capability of measuring the degree of implantation in the silicon material. In other words, the capability of measuring the disturbance or damage made by the impurity or dopant ions to the perfect crystal structure of silicon. One of the methods capable of measuring the degree of implantation is a TP-400 XP system made by the Therma-Wave Company. The system is utilized for determining the degree of damage in the crystal lattice of a silicon wafer after an ion implantation process. The system is used in semiconductor fabrication processes to first determine the degree of damage in a crystal structure, and then using such data to determine the various implantation parameters such as the implantation energy, the type of impurity ions to be implanted, and the dosage of the ions implanted. An optimal implantation process can then be carried out by using these selected processing parameters based on the test result obtained from a TP-400 XP system. After such an optimum implantation process is determined, the processing parameters can be used for volume. production of a semiconductor device from silicon wafers.
A schematic diagram of the TP-400 XP system 10 is shown in FIG. 1. An argon ion pump laser 12 having an intensity modulation of 1 MHz emits a laser beam 14 through a beam splitter 16 and a condenser lens 18 to irradiate on a silicon wafer 22. The laser beam 14 is condensed into a focused beam 26 having a width of approximately 1 micron at the point in contact with the top surface 24 of the silicon wafer 22. The plasma generated by the argon ion pump laser reacts with the silicon crystal structure damaged by the ion implantation process in the surface layer of the wafer and then reflects from the surface 24. The reflected wave 32 is detected by another helium neon probe laser 28. Assuming the intensity of the incident wave 14 is R and the intensity change in the reflected wave 32 is .DELTA.R, then detector 34 detects a thermal wave (TW) signal which represents .DELTA.R/R. A second beam splitter is used in the path of the detector 34.
FIG. 2 shows a graph illustrating the dependency of the thermal wave signal on the implantation dosage for an ion implantation process utilizing boron as the dopant. Data was obtained by a TP-400 XP system after an ion implantation process was conducted on a silicon wafer by using boron as dopant at an implantation energy of 100 KeV. As shown in FIG. 2, the higher the implantation dosage used, the larger the damage made to the silicon crystal. This is indicated by the increased thermal wave signal. The thermal wave measurement conducted on an implanted silicon wafer surface therefore provides a convenient method for indicating the damage inflicted in a crystal structure after an ion implantation process is conducted on the silicon wafer.
A problem incurred in making thermal wave measurements on an implanted silicon surface is the instability of the data obtained immediately after the wafer is implanted. The phenomenon is attributed to the fact that after ions are implanted into a silicon substrate, even though the crystal lattice in the surface layer is damaged by the implanted ions, the displaced atoms in the crystal lattice have the tendency and capability of self-repairing and thus attempt to repair the damaged structure and to return to its original undamaged state. The self-repairing process is reflected in thermal wave measurements made by the TP-400 XP system by the ever-changing thermal wave. As a result, the degree of damage to the crystal lattice cannot be determined reliably by the thermal wave data. Consequently, the processing parameters for the implantation process cannot be reliably determined and that a fabrication process for volume production of the semiconductor device from a silicon wafer can not be carried out.
It is therefore an object of the present invention to provide a method for stabilizing the crystal structure in a silicon substrate after an ion implantation process that does not have the drawbacks or shortcomings of conventional methods.
It is another object of the present invention to provide a method for stabilizing the crystal structure of a silicon substrate after an ion implantation process by exposing the substrate to a heat treatment temperature that is sufficiently low such that a complete recovery of the crystal structure can not take place.
It is a further object of the present invention to provide a method for stabilizing the crystal structure of a silicon substrate after an ion implantation process by exposing the substrate to a heat treatment temperature not higher than 200.degree. C. such that the damaged crystal structure does not completely recover.
It is still another object of the present invention to provide a method for stabilizing the crystal structure of a silicon substrate after an ion implantation process by exposing the substrate to a heat treatment temperature that is sufficiently low such that only a self-repairing process of the damaged crystal lattice can take place to stabilize the structure.
It is yet another object of the present invention to provide a method for stabilizing the crystal structure of a silicon substrate after an ion implantation process wherein the substrate is exposed to a heat treatment temperature not higher than 200.degree. C. for a time period not less than 10 seconds.
It is another further object of the present invention to provide a method for stabilizing the crystal structure of a silicon substrate after an ion implantation process wherein the substrate is exposed to a temperature that is sufficiently low such that the self-repairing process of the crystal lattice can be saturated while the lattice remains in an implanted state.

Method for stabilizing a silicon structure after ion implantation


A device, system and method for enhancing the functionality and efficiency of a chemical and/or enzymatic debriding agent with a physical debriding mechanism. The debriding agent alone and the physical mechanism alone are each capable of at least some debriding activity separately, without being used in the combination. In combination, however, they are more effective, such that the debriding efficacy is increased for the combination. Preferably, the physical debriding mechanism comprises an ultrasound source.

Skin provides an important barrier against infectious agents such as bacteria, viruses, parasites and the like, as well as dangerous or toxic materials, and the dangerous effects of mechanical trauma, damage by ultraviolet light and the like. Damaged skin, however, may not only fail to provide such a barrier, but may itself become infected or otherwise prevent the body from heating the damaged area naturally. For certain types of injuries, such as burns or chronic wounds, for example, where the damaged tissue may be dead, it must be removed in order for the injury to heal and prevent future complications.
Therefore, for these types of injuries, a process known as "debriding" the damaged skin has been developed. The goal of the debriding process is to remove the damaged skin, with minimal or no damage to the healthy surrounding skin and also the layers of tissue below the damaged skin. The damaged skin may itself actually include dead tissue, which as used herein, includes diseased tissue, necrotic tissue and eschar. Eschar is tissue that has been damaged, burned (from thermal, chemical or electrical burn causes, for example) or from ischemia (pressure sores, diabetes or peripheral vascular disease ulcers, for example). Without debridement, bacterial infection of the dead tissue and even sepsis may occur, leading to sloughing of the damaged tissue, often with the initially undamaged tissue becoming compromised by the infection of the dead tissue. This process may lead to death of the patient. If the patient survives and recovers, the delayed healing of the damaged tissue area may cause the development of granulation tissue that eventually forms disfiguring scar tissue, which lacks flexibility as well as other physiological functions and cosmesis (appearance), which are features of healthy skin.
The eschar related complications are so important that the earliest debridement is the standard of care of any necrotic skin area. The debriding process is currently performed with physical or mechanical removal (excision) of the dead tissue, which is clearly disadvantageous because of the potential for damage to healthy tissue, both surrounding the dead tissue and also present below this tissue. For example, for surgical debridement with special knives called dermatomes, it is estimated that up to 30–50% of healthy tissue may be sacrificed during the debriding procedure. The mechanical—surgical debridement process requires a certain level of surgical skills that may not always be available. Mechanical debridement is also painful, requiring local or systemic analgesia. Therefore, the background art has focused on non-mechanical debriding processes, and also mechanical or physical processes which may be more precisely focused in order to avoid damage to healthy tissue.
For example, H. J. Klasen in "A review on the non-operative effect of necrotic tissue from burn wounds", Burns 26 (2000), 207–222, reviews non-surgical treatment of burn wounds, and describes enzymatic and chemical debriding agents, such as proteolytic enzymes and enzymes of plant origins. The review concludes that although enzymatic debridement would appear to be a useful and attractive form of treatment, it unfortunately suffers from highly variable results.
PCT Application No. WO 98/53850 also teaches the use of chemical debriding agents such as enzymes for the treatment of burned skin. However, such chemical debriding agents alone may not prove sufficiently effective for all burn or other eschar situations.
With regard to physical mechanisms for debridement, the background art includes teachings on the use of ultrasound for such debridement. For example, S. F. Schoenbach et al., in Plastic and Reconstructive Surgery, July 1980, 66(1), pp. 34–37, describe experiments performed on rats for reducing the bacterial count of infected full-thickness burn wounds by ultrasonic treatment.
PCT Application No. WO 98/32379 describes an ultrasound system for treatment of neoplastic or precancerous skin tissue. The ultrasound generating element is coupled to a container holding a liquid medium capable of transmitting ultrasound waves, which is preferably a degassed solution such as water. The solution may also contain substances that are activated by ultrasound to release free radicals. However, the use of an independently therapeutic or active solution is not taught or suggested by this reference.
Other uses of ultrasound for skin treatment have been described in French Patent Application No. 2,762,791, which discloses a probe for the simultaneous application of ultrasound and electrical current to the skin; U.S. Pat. No. 4,372,296, which describes a method of treating acne with ultrasound; and U.S. Pat. No. 5,656,015 describes an ultrasonic therapeutic system for the treatment of soft tissue. Again, these references are not focused on the removal of dead tissue.

System for enhanced chemical debridement


An installation for sorting containers, in particular medicine bottles, including a star wheel having a multiplicity of pockets. The pockets each accommodate a container, and therefore the container can be transported by virtue of the star wheel being rotated. The installation includes a first and a second exit, wherein the containers can be fed either to the first exit or to the second exit by retracting and extending of a first diverter and a second diverter, which are located opposite one another on a transporting path. The first and the second diverters are designed to be capable of extending and retracting with respect to a base region of the transporting path.

When filling containers, in particular bottles, it is known in practice that individual, defective containers are fed to a so-called bad product outlet. Thus, the different manufacturing steps are for example monitored during the filling. If a manufacturing step is defective or a container has been damaged, it is sorted out to a bad product outlet. The bad product outlet can, however, also be used to set aside containers as reserve samples or test samples.
The filling of containers with a medical liquid, which for example is used as an infusion solution, as enteral or parenteral nutrition or as a medicine, is subject to high safety precautions. The occurrence of incorrect sorting during the sorting process must be ruled out using system technology, for example whereby it is not the container to be sorted out, but rather another container that is fed to the bad product outlet and said container is sorted out instead of the defective container.
The publication DE 27 046 14 C2 shows a sorting apparatus, which comprises two star wheels. The containers can be selectively fed to a first or a second movement path using pistons connected to a piston and thus sorted.
A piston can thereby only be extended in each case when the other piston is retracted.
In the case of a filling system, in which the containers are moved exactly one position further for each production step, this is usually not a problem since there is enough time to switch over.
In particular, filling systems, by means of which a large number of containers should be filled, do however comprise a plurality of filling stations operating in parallel. Thus, in the case of each cycle, i.e., each time the containers are moved further, a plurality of containers are moved. In order to achieve a high throughput, the speeds at which the containers are moved in a system of this type are high.
This leads to the sorting system described above and known from the prior art not being fast enough at least during one cycle to carry out a switch from good product to bad product outlet. Each of the pistons must be extended virtually over the entire width of the movement path. The star wheel is, however, moving so fast that the piston is not retracted in time before the next container reaches the piston.
For this purpose, it is alternatively known from practice to hold the containers with vacuum plates in the star wheel. When a vacuum is applied, the container remains on a movement path which is determined by the rotation of the star wheel. In contrast, if the vacuum is switched off, containers are ejected to an open wall due to the centripetal force and thus directed to another movement path. Thus, sorting can be carried out by switching the vacuum plates. Sorting systems of this type are also suitable for high speeds since the vacuum plates can be switched independently of one another.
A pneumatic sorting system of this type is, however, both complicated to manufacture and expensive to operate. It has also been found that a pneumatic sorting system of this type with vacuum plates is prone to errors. Thus, it happens time and again that individual containers are ejected from the guides of the transport and sorting system during the sorting. This requires a shutdown of the system which leads to costly production stoppages. In particular when toxic liquids are filled, there is also still a safety risk if the ejected container breaks.

Installation and method for sorting containers