A differential pressure transducer has a measurement chamber which is divided by a membrane into first and second measurement spaces which can be exposed to first and second pressures whereby differential pressure causes deflection of the membrane from its neutral position. A deflection sensor measures the deflection of the membrane and produces a deflection signal. An electromagnet arrangement produces a magnetic force which compensates for the deflection force which is caused by the differential pressure. The coil current for producing the magnetic compensation force represents a measure of the differential pressure.

This invention relates to an differential pressure transducer which is especially suited for measuring the differential pressure in a severe industrial environment.
A differential pressure transducer is defined as a measurement means for measurement of differential pressure.
Differential pressure transducers are widely used for example in the chemical industry, food industry, aviation industry, in water treatment plants, etc. for purposes of among others flow measurement in flowing media, the control of filters, speed measurement in aircraft or water craft. The necessity of precise measurement of small differential pressures, typically roughly 100 mbar, around a high absolute (conventionally static) pressure of for example 100 bar, has led to development of relatively expensive and complex pressure transducers, since these devices on the one hand must demonstrate their serviceability in the transfer from ambient pressure to high absolute operating pressure and on the other hand must be sensitive enough to be able to measure small differential pressures with the desired accuracy.
WO 96/41141 discloses a pressure transducer in which a measurement membrane of electrically conductive material such as steel divides a measurement chamber into two measurement spaces. The membrane can be exposed to measurement pressures which yield a differential pressure in the two measurement chambers and it is deflected by the differential pressure from its neutral position. In one measurement chamber wall opposite the membrane there is a coil. Relative movements between the coil and membrane are measured via measuring inductance.
In pressure transducers of this type the problem is that, as a result of the elasticity of the measurement membrane, which is linear only in a narrow range, for larger deflections of the measurement membrane there is no longer a linear relationship between the change of the differential pressure and the corresponding change of inductance. Furthermore, there is the danger of inelastic deformations of the membrane which adulterate the measurement results over the long term, for which reason the long term serviceability of the pressure transducer is not ensured. In addition, temperature changes and/or corrosion can significantly change the material properties of the membrane; this can lead to further measurement errors.
DE-A1-31 06 835 describes a differential pressure measurement device which has a measurement chamber which is divided into two measurement spaces by a measurement membrane. The measurement chamber is hermetically sealed against the medium to the outside by means of separation membranes and the differential pressure can be measured in it. To transfer the differential pressure to be measured from the separation membranes to the measurement membrane, the two measurement spaces between the measurement membrane and the respective separation membrane are filled with oil. The measurement membrane in its center has a semiconductor sensor with which the deflection of the measurement membrane from its neutral position is measured. To prevent mechanical overload of the semiconductor sensor there is a compensation device which is coupled via a mechanical connection to the semiconductor sensor and thus the measurement membrane in order to counteract the deflection caused by the differential pressure. In the differential pressure measurement device as claimed in this patent the problem of mechanical overloading of the measurement membrane is reduced.
However, the differential pressure measurement means as claimed in DE-A1-31 06 835, as also otherwise all other known pressure transducers, has a complicated and expensive structure; this makes it unsuited for economical production in large series. At the same time the force of gravity in all known pressure transducers with a measurement membrane represents another error source in that under the influence of gravity the measurement membrane can already be deformed as a result of its inherent weight; this results in an error in pressure measurement which is dependent on the position of the pressure transducer.
The object of this invention is to make available a differential pressure transducer which is structurally simple, which can be economically produced in large series, and which is long-lived and itself enables reliable differential pressure measurements under ambient conditions which are severe with respect to corrosion and temperature.
The differential pressure transducer according to the invention has a measurement chamber which is defined by a housing and which is divided by a membrane device into a first measurement space which can be exposed to a first measurement pressure and a second measurement space which can be exposed to a second measurement pressure. The membrane device comprises at least one measurement membrane, the membrane device being arranged and made such that a deflection force which is engendered by the first measurement pressure and the second measurement pressure causes deflection of the measurement membrane from its neutral position. The pressure transducer furthermore has a deflection sensor means for measuring deflection of the measurement membrane from its neutral position and for producing a deflection signal depending on this deflection. The pressure transducer according to the invention is characterized in that it furthermore has an electromagnet arrangement which comprises magnet means and a microengineering current-carrying coil, and an electrical switching arrangement. The electromagnet arrangement is made to produce a magnetic force which couples the measurement membrane to the housing and the electrical switching device is used to produce a coil current depending on the deflection signal such that the magnetic force acting on the measurement membrane essentially compensates for the deflection force which is caused by the differential pressure and which acts on the measurement membrane. The coil current for producing the magnetic compensation force represents a measure of the differential pressure. The current intensity of the coil current is output as the output quantity of the pressure transducer.
Microengineering is defined as the means and processes which are employed to use and/or produce (preferably in series) extremely small technical devices or equipment. In microengineering the aspect of production, especially series production, is just as important as that of the function of a microengineering device. Microengineering components (for example, the coil of the pressure transducer as in the invention) therefore often have essentially flat, two-dimensional structures. They can be produced by means of methods of planar technology, especially printing processes (for example screen printing in thick film technology, vapor deposition in thin film technology, UV lithography).
In the context of microengineering, the term xe2x80x9csmallxe2x80x9d, at least in mechanical and/or electromechanical devices, means that their main dimensions are in the centimeter or subcentimeter range.
A xe2x80x9cmagnetic forcexe2x80x9d is the force which an electrical conductor or permanent magnet experiences in a magnetic field and xe2x80x9cmagnetic meansxe2x80x9d are means of electrically conductive and/or magnetic material which can experience a magnetic force in a magnetic field.
The differential pressure transducers known to date are not suited for production with methods of planar technology. They have components with structures which are essentially three-dimensional and their production is structurally complex. In the pressure transducer as claimed in DE-A1-31 06 835 this applies especially to the compensation device which comprises an electromagnet with a coil and a permanent magnetic armature, and the two have structurally complex three-dimensional structures. Conversely, the microengineering (and thus flat) coil of the differential pressure transducer according to the invention can be produced with means and methods of microengineering. In this way the possibility of economical, large-series production of the differential pressure transducer as claimed in the invention is established. At the same time, the microengineering structure of the coil yields an outstanding possibility for miniaturization not only of the coil itself, but the entire differential pressure transducer in accordance with the invention. By miniaturizing the pressure transducer the measurement errors which are caused by gravity can be greatly reduced, since the weight of the membrane decreases with the cube of the geometric dimensions. The reduction of the influence of gravity then allows the use of mechanically softer materials for producing the measurement membrane. In this way the choice of materials which can be used to produce the measurement membrane is greatly increased so that some chemically resistant materials can be used which, to date, had not been considered for the measurement membrane of known pressure transducers, because their low mechanical strength under the influence of gravity and/or large differential pressures has/have caused overly large measurement errors.
In the differential pressure transducer as claimed in the invention, the feedback principle is used to measure the differential pressure. The pressure difference to be measured between the two measurement spaces is applied to the membrane device. By means of the differential pressure either directly (i.e. without pressure transfer) or indirectly (i.e. after amplifying or weakening the pressure) a deflection force is produced which causes deflection of the measurement membrane of the membrane device from its neutral position. A deflection sensor measures the deflection of the measurement membrane from its neutral position, produces a deflection signal which corresponds to this deflection, and supplies it to an electrical switching device. The measurement membrane is coupled by magnetic means and an electromagnetic arrangement which comprises a current-conducting coil to the housing of the pressure transducer, i.e there is a magnetic force which is acting directly or indirectly between the measurement membrane and the housing. The switching device is electrically connected to the coil of the electromagnet arrangement and produces a coil current such that the coil interacts by means of magnetic force with the magnetic means such that overall a force is exerted by the housing on the measurement membrane which essentially compensates for the deflection force acting on the measurement membrane in order to cancel the deflection of the measurement membrane from its neutral position. This is, in turn, measured by the deflection sensor (thus the feedback loop is closed). As a measure for the differential pressure the strength of the coil current which is necessary to produce the magnetic compensation force is measured. This in contrast, for example, to the differential pressure transducers of the type described in WO 96/41141 where the deflection of the measurement membrane is used as a measure for the differential pressure. Thus, in the differential pressure transducer according to the invention, large deflections of the measurement membrane are avoided. This yields the advantage that, in the pressure transducer of the invention, the measurement membrane need not meet high demands with respect to its mechanical properties in terms of to elasticity and/or linearity. In particular, it is feasible to produce the measurement membrane of the invention using those materials which are mechanically soft and/or which have a small linear elasticity range but, for example, are especially resistant to corrosion.
The differential pressure transducer according to the invention overall represents an intelligent measurement sensor in which the pressure is measured by active compensation of the deflection of a mechanical structure, by which the measurement result becomes essentially independent of the mechanical properties of the structure.
Preferably the electromagnet arrangement is made for non-contact exertion of force between the housing and the measurement membrane by means of remote magnetic action. This embodiment of the invention enables prompt control of the opposing force which compensates for the compressive force.
The coil can be attached to the housing by gluing, embedding, welding, soldering or in some other suitable way. Preferably the coil is embedded completely in one housing wall which borders the measurement chamber so that the coil top which faces the measurement membrane is essentially coplanar to the surface of this housing wall facing the measurement membrane. This embodiment of the invention is especially advantageous when the pressure transducer is being cleaned.
Advantageously the measurement membrane is located in the measurement chamber which is defined by the housing such that the housing walls ensure effective overload protection against mechanical overloads of the measurement membrane. This is done by the distance which is perpendicular to the plane of the measurement membrane between the measurement membrane and the housing walls which border the measurement chamber being chosen to be as small ask possible. When the measurement membrane is overloaded as a result of the overly large differential pressure then the measurement membrane contacts one housing wall and is supported by it, thus preventing inelastic extension of the measurement membrane.
According to one preferred embodiment of the invention the electromagnet arrangement is made as an integral part of the deflection sensor means, to measure the deflection of the measurement membrane from its neutral position an electrical signal being measured which has been produced in the coil by relative motion between the magnetic means and the coil. In this embodiment of the invention thus the electromagnet arrangement on the one hand has the function of a servo device (or an actuator) for the measurement membrane by its acting via magnetic force on the measurement membrane in order to return it into its neutral position against the compressive force. On the other hand, the electromagnet arrangement also has the function of a deflection sensor means or a sensor for measuring the deflection of the measurement membrane from its neutral potion. Thus the sensor is at the same time also an actuator. In other embodiments of the invention the functions of the servo device and the deflection sensor means however can also be assumed by separate devices. Thus for example a Hall probe can be used to measure the deflection of the measurement membrane.
Advantageously the electromagnet arrangement is made and arranged essentially symmetrical with respect to a plane of symmetry which is defined by the measurement membrane, in order to reduce the formation of the asymmetrical temperature distributions which cause errors in pressure measurement. These asymmetrical temperature distributions are often the cause of errors in pressure measurement by means of differential pressure transducers. With the symmetrical formation of the electromagnet arrangement at the same time position-dependent errors can be actively compensated, which even in the pressure transducer as claimed in the invention are still present as a result of the action of gravity on the measurement membrane when the latter is not positioned vertically.
According to one preferred embodiment of the invention the membrane device comprises simply a single membrane in the form of the measurement membrane, the membrane device being made and the measurement membrane being arranged such that one side of the measurement membrane is directly exposed to the first measurement pressure and the other side of the measurement membrane is directly exposed to the second measurement pressure. This embodiment of the invention enables simple construction of the membrane device with simply one single membrane.
According to another preferred embodiment of the invention the membrane device comprises a first pressure pick-up membrane which can be exposed to the first measurement pressure and which is coupled to transfer force to the measurement membrane. For purposes of conversion of force per unit area (i.e. amplification or reduction of the surface force) the effective (i.e. freely suspended) surface of the first pressure pick-up membrane has a surface size which differs from the effective surface of the measurement membrane. The measurement of comparatively large differential pressures is enabled by this embodiment of the invention. The pressure pick-up membrane can be connected by means of a solid connecting part to the measurement membrane in order to transfer force. The membrane device can furthermore comprise a second pressure pick-up membrane which can be exposed to the second measurement pressure and which is coupled to the measurement membrane in order to transfer force, and for purposes of conversion of force per unit area the effective surface of the second pressure pick-up membrane can have a surface size which is different from the effective surface of the measurement membrane.
Preferably the measurement membrane consists essentially of a mechanically soft material with high resistance to corrosion. Preferably the membrane material is also resistant to other chemical reactions when it comes into contact with chemically reactive media. Possible materials for producing the measurement membrane are polytetrafluorethylene (PTFE, better known under the commercial name of Teflon), ethylene tetrafluorethylene (EFTE), polyethylene cotrifluorethylene (ECTFE), perfluoraloxypolymers (PFA), polyvinylidene fluoride (PVDF), copolymers of tetrafluormethylene/hexafluorpropylene (FEP), other fluorine-containing plastics, polyethylene (PE), stainless steel, polyesters, etc.
The measurement membrane however can also be produced from a conventional membrane material and/or by means of suitable treatment of the surface it can be protected against corrosion and/or other chemical reactions.
In one preferred embodiment of the invention the magnetic means comprise means which are formed essentially from ferromagnetically soft material. With a given coil geometry, coil current, and distance between the coil and the magnetic means thus extremely large magnetic forces can be produced between the housing and the measurement membrane. To produce the magnetic means according to this embodiment of the invention suitable ferromagnetically soft materials are amorphous metals, iron-nickel alloys (for example, as are sold under the commercial name Permalloy), silicon iron, iron, ferrites, silicon-iron-aluminum and others.
Furthermore, it is preferred that the magnetic means comprise permanent magnetic means of ferromagnetically hard material. The group of materials suitable for producing magnetic means according to this embodiment of the invention comprises aluminum-nickel, aluminum-nickel-cobalt, rare earths, neodymium-iron-boron, neodymium-iron-cobalt, hard ferrite magnets and others.
In still another version of the invention the magnetic means comprise means which are produced from electrically conductive material, preferably gold or copper. The magnetic means in this version of the invention generally do not consist of magnetic material, but rather the electrically conductive material acts only in conjunction with an alternating current as an (electro)magnet. The magnetic means can be made for example in the form of a short-circuited flat coil or in the form of a plate of electrically conductive material. In this embodiment of the invention in the coil of the electromagnet arrangement an alternating current is generated which produces a magnetic field which changes over time in the area of the magnetic means. In this way a current is induced in the (electrically conductive) magnetic means so that they act as an electromagnet and experience a force as a result of the magnetic field.
In one preferred embodiment of the invention the switching device for controlling the coil currents in two coils comprises a differential oscillator. In alternative embodiments of the invention the switching device for controlling the current or currents in one or more coils can comprise one or more bridge circuits.
The following detailed description of this invention is used in conjunction with the attached drawings only as an example for better understanding of the invention and should not be interpreted as a limitation of the scope of protection of the patent claims. For one skilled in the art other advantageous embodiments and combinations of features can be easily recognized from the following description in conjunction with the attached drawings and the totality of the patent claims and however still lie within the scope of this invention.


A plow assembly includes a pair of plow wings which are pivotally mounted at opposite ends of a center plow. Each of the plow wings may pivot between a forwardly angled position and an aligned position. The plow assembly may pivot a trailing plow wing in response to the center plow being urged or angled toward that side of the vehicle. The plow wings may be oriented in their forwardly angled position until the center plow is at least substantially urged or pivoted toward its angled position or toward a position between the center position and the angled position. The trailing plow wing may be pivoted or urged to its aligned position in response to the center plow being substantially urged or pivoted toward its angled position or toward a position between its center position and its angled position.

It is known to provide pivotable plow wings at one or both ends of a main plow of a plow assembly for a vehicle. Examples of such plow assemblies are shown in U.S. Pat. Nos. 6,408,549; 6,442,877; and 6,412,199, which are hereby incorporated herein by reference. The plow wings may be adjustable via actuation of corresponding actuators and may be adjustable independently of a position or orientation of the main or center plow. It is also known to provide a plow assembly with plow wings which each move between a forwardly angled position, where the plow wing is angled forwardly from the main plow, and an aligned position, where the plow wing is generally aligned with the main plow. The plow wings may pivot between their positions in response to pivotal movement of the main plow relative to the vehicle. Such a snowplow assembly is disclosed in U.S. Pat. No. 3,477,151, issued to Zanella on Nov. 11, 1969.


A bird feeder designed for overhead positioning is provided having a dispensing component which protectively holds and controllably dispenses particulate bird feed, and a refilling component liftable by an elongated staff and configured to add bird feed to the dispensing component.

1. Field of the Invention
This invention relates to bird feeding devices, and more particularly relates to the re-filling of bird feeding devices intended for overhead installation.
2. Description of the Prior Art
Bird feeding devices, as generally employed on residential properties, are usually positioned at elevated locations above the ground as by way of pendant attachment to a tree or support upon a pole. The feeder device is generally comprised of a housing for protectively holding a quantity of particulate bird feed material, said housing having apertures for dispensing the feed in a reasonably controlled manner, and usually at least one horizontally protruding perch to serve as a roost for birds.
The re-filling of the feeder housing with bird feed often requires the use of a climbing device such as a step stool or ladder to remove the feeder from its elevated position and then replace it reloaded with bird feed. Such procedure involves inconvenience and risk of accident, and further involves the need to own and store a ladder or step stool.
There has been earlier disclosed the use of pulley devices and similar mechanical innovations to facilitate the raising and lowering of bird feeders. However, such devices involve installation challenges and are susceptible to malfunction or deterioration due to weathering factors.
Accordingly, it is an object of the present invention to provide a bird feeder apparatus designed for overhead installation which obviates the need for climbing so as to service the apparatus for the purpose of re-filling it with particulate bird feed material.
It is another object of this invention to provide a bird feeder apparatus as in the foregoing object which is resistant to malfunction, easy to service and amenable to low cost manufacture.
These objects and other objects and advantages of the invention will be apparent from the following description.


A non-invasive blood analyzer includes a light source unit for irradiating a portion of a living body, the portion including a blood vessel, and includes an image capturing unit for capturing an image of the irradiated portion. An analyzing unit is included for setting an analysis region in the captured image and analyzing a blood vessel portion in the set analysis region. The image capturing unit captures images of the irradiated portion of the living body a plurality of times and the analyzing unit specifies analysis regions including the same blood vessel portions with respect to the captured images. The analyzing unit determines these regions based upon a position of a feature in sequential images and calculates at least one of blood vessel width, blood component concentration and blood component concentration ratio with respect to the blood vessel portion in each specified analysis region.

1. Field of the Invention
The present invention relates to a non-invasive blood analyzer and provides an apparatus for transcutaneously measuring a size of a blood vessel, a blood component concentration and a blood component concentration ratio in real time with excellent reproducibility without exsanguinating blood.
2. Description of the Related Arts
A method of directly measuring a blood vessel width by using images has been carried out with microcirculation (particularly at blood vessel on retina) as an object (refer to, for example, M. J. DEVANEY et al., "Continuous Measurement of Vascular Diameters via Television Microscopy", ISA TRANSACTION, Vol. 15, No. 1, pp. 73-78, 1976). However, according to the method, a blood vessel of several tens .mu.m is measured as an object and accordingly, the method is not suitable for actual clinical use.
Further, an apparatus for measuring transcutaneously a hemoglobin concentration and a hematocrit has been devised. For example, there has been disclosed an apparatus of irradiating a plurality of wavelengths of light to a human body and measuring hemoglobin in blood from a change in an optical intensity caused by pulsation in "Hemoglobin concentration measuring apparatus" (Japanese Examined Patent Publication No. JP-B-3-71135). Similarly, there has been disclosed a method of calculating a hematocrit in blood by utilizing pulsation or the like in "System and method for non-invasive hematocrit monitoring" (U.S. Pat. No. 5,372,136).
However, these publications pose a problem in accurately calculating an absolute value, since an amount of blood for constituting an object of inspection is not specified. Further, it is anticipated that a difference is caused in measured value depending on a portion of the living body for mounting a sensor which is problematic in view of reproducibility or the like.
Further, although there has been disclosed a method of measuring the above-described items from images of red corpuscles flowing in a capillary in "Apparatus and method for in vivo analysis of RED and WHITE blood cell indices" (U.S. Pat. No. 4,998,533), according to the method, the system is extremely large-scaled.
Also, various non-invasive blood analyzers such as shown below are known. For example, an apparatus in which an image of an inside region of a blood vessel contained in a portion of a living body is captured to analyze the morphology and the number of blood cells from the obtained image (See U.S. Pat. No. 5,598,842 or Japanese Unexamined Patent Publication No. HEI 7(1995)-308312), an apparatus in which images of a blood vessel contained in a portion of a living body are captured by a plural number of times to determine a differential image thereof for detecting a blood cell image (See Japanese Unexamined Patent Publication No. HEI 7(1995)-308311), an apparatus provided with means for searching a blood vessel of a desired size contained in a portion of a living body by mechanically moving a transparent plate positioned in close contact with a skin surface of the living body so as to capture an image of the blood vessel through the transparent plate (See Japanese Unexamined Patent Publication No. HEI 8(1996)-299310), an apparatus in which an image of a blood vessel and a tissue contained in a portion of a living body is captured to calculate an amount of a blood component from an image density distribution distributed across the blood vessel in the captured image (See Published International Patent Application Number WO 97/24066) and the like are known.
Here, if images of a portion of a living body are to be captured time-sequentially by means of such a non-invasive blood analyzer to find a time-sequential change of an analysis value, an image capturing apparatus is separated from the living body after an image of the portion of the living body has been captured and, after several hours or several days, an image of the portion of the living body is captured again. However, since the reproducibility of the blood vessel portion whose images are to be captured is not ensured, it is difficult to obtain an analysis value accurately with respect to the same blood vessel portion.


An air induction system for inducting air into an engine of an automobile is disclosed. The air induction system has an air cleaner and an air inlet tube. The air cleaner is in fluid communication with the engine of the automobile for filtering intake air inducted into the engine. The air inlet tube is made of a first material and is connected at a first end to the air cleaner and open to ambient air at a second end. The inlet tube has a flexible portion that flexes as a result of internal pressure pulsations during the air induction event. The flexing reduces or eliminates acoustic standing waves that have significant pressure fluctuations at the same location in the air induction system as the flexible portion.

Internal combustion engines require an air intake or induction system for capturing, cleaning and directing air into the combustion chambers of the engine. Typically, such air induction systems have an air inlet tube attached to the front structure of a vehicle, for example, the front inner fender or behind the headlamps. The inlet tube has an open end for taking in outside air and an opposite end that is connected to an air filter box containing an air filter. The air filter box cleans the intake air by passing it through the filter. In addition, the air filter box provides broadband attenuation of the noise generated by the pressure differential across the inlet valve during the air induction event. The filtered air is then drawn through the air induction outlet tube, through the intake manifold, and into the engine. The clean air is mixed with fuel and the mixture is combusted in the combustion chambers of the engine.
One problem confronting air induction system designers is the noise created by the engine during the air induction event. The noise signature is defined, in part, by the creation of acoustic standing waves that resonate within the air induction system. Prior art induction system designs have tried to address this problem by changing the dimensions of the ducted system as well as including reactive silencers, porous ducts, tuning holes, expansion chambers, etc., within the air induction system. Another problem confronting prior art air induction systems is the collection of water, snow, heat, and debris into the system. Conventional air induction systems addressed this problem by locating the inlet in an environmentally low-risk area of the vehicle. However, while these prior art air inlet tube designs have addressed some of the issues described above, problems still exist.
Therefore, there is a need for an new and improved air induction system having components that address both the collection of water/snow/heat/debris and the noise problems prevalent in prior art systems. The new and improved air induction system will allow the components to be packaged in environments where prior art components couldn't be packaged.

Air induction system having an environmentally resistant acoustic membrane


A microfabricated fuel heating value monitoring device comprises a microfabricated gas chromatography column in combination with a catalytic microcalorimeter. The microcalorimeter can comprise a reference thermal conductivity sensor to provide diagnostics and surety. Using microfabrication techniques, the device can be manufactured in production quantities at a low per-unit cost. The microfabricated fuel heating value monitoring device enables continuous calorimetric determination of the heating value of natural gas with a 1 minute analysis time and 1.5 minute cycle time using air as a carrier gas. This device has applications in remote natural gas mining stations, pipeline switching and metering stations, turbine generators, and other industrial user sites. For gas pipelines, the device can improve gas quality during transfer and blending, and provide accurate financial accounting. For industrial end users, the device can provide continuous feedback of physical gas properties to improve combustion efficiency during use.

The natural gas industry and large volume consumers are seeking inexpensive methods for real-time monitoring of natural gas (NG) constituents. Such real-time monitoring is especially needed for pipeline switching and metering stations, turbine generators, and other industrial user sites.
For pipelines, it is important to have information on the composition of NG in the main pipeline and of the blending in at every mixing location. When the fraction of heavier constituents is too high, it becomes unsuitable for certain end users. Heavier constituents may also condense where temperature and pressure drop, such as at meters, valves, and various locations in end-user facilities. Therefore, speciation is necessary to obtain the composition and hydrocarbon dew point of the NG.
It is also desirable by natural gas sellers and buyers to have immediate knowledge of the BTU value for equitable trade (a BTU, or British Thermal Unit, is the amount of heat required to raise the temperature of one pound of liquid water by 1° F. at its maximum density). Gas heating value and flow measurement errors on the order of a percent or less can have significant impacts to the industry in the areas of lost revenues and cash flow, since many pipeline networks possess gas transfer capacities that range from 0.5 to 1 billion cubic feet per day. As natural gas is sold by the BTU (i.e., the heating value), improved analysis will produce more equitable trade between buyers and sellers by reducing unaccounted for gas content. Because instrumentation for accurate natural gas analysis is expensive to purchase, operate and maintain, ubiquitous metering devices provide only volumetric measures of the quantity of natural gas consumed. However, final billing is determined a month or more later when information from lab analysis is used to convert the volumes to BTU heating values. This difference, known as unaccounted for (UFA) gas content, can be reduced by improved sample handling and analysis, producing more timely and accurate billing. A further complication arises during gas transfers between wholesale or commercial entities along the gas supply chain when both gas volume and heating value indices can be used in the transaction. Discrepancies between the two can result in billing errors or lost revenues. Therefore, a gas transfer system based solely on heating value and made possible by a low-cost approach would be beneficial to the natural gas industry.
Further, certain industrial users have a strong interest in knowing the composition of incoming natural gas. Industrial users will benefit through continuous feedback of physical gas properties during consumption, in particular with gas turbine engines used for power and electricity generation. For NG fueled turbines, efficiency of power generation is dependent on fuel properties and the temperature of the combustion cycle. Turbine controls are based on models that indirectly calculate peak combustor temperatures based on estimates of the fuel heating value. Inaccuracies as high as 40° C. limit the ability to operate at the optimum firing temperature. Controllers error on the side of safety to prevent part-life degradation from overfiring the turbines. Even a small increase in operational efficiency of natural gas-fueled power can save large amounts of natural gas per year and significantly reduce related nitrogen oxide emissions.
Finally, a low-cost monitoring device would enable distributed sensing of the natural gas infrastructure, providing greater pipeline security. Improved real-time information on the composition of gas throughout the system would allow early detection of deleterious events such as pipeline leakage or fouling.
The standard method for natural gas BTU analysis uses gas chromatography (GC) to speciate fuel flows, and then infers heating value from this speciation. See ASTM International 2003, "Standard Test Methods for Analysis of Natural Gas by Gas Chromatography," D1945-03. This method is highly accurate, but expensive in terms of equipment, maintenance, operation, and personnel. Samples are often collected into bottles for once-a-month lab analysis, resulting in billing accuracy delays of a month or longer. In addition, standard GCs and detectors require pressurized specialty gases, some of which are flammable. While slightly less expensive field-portable devices are becoming available, detector requirements have not changed. Automated on-line GCs are currently too expensive to widely distribute over the pipeline infrastructure for real-time analysis. Therefore, on-line GCs are only used at large custody transfer stations where accounting delays would become more costly. Under present conditions, the limited number of instrumentation locations within the gas pipeline network results in significant errors in mass balance and cost recovery that directly influence custody transfer operations. A number of research organizations are attempting to perfect inferential techniques using thermal conductivity or speed of sound measurements. Inorganic compounds such as carbon dioxide, carbon monoxide, and nitrogen confound these measurements, so their concentrations must be independently determined. So far, these techniques cannot determine nitrogen concentration without resorting to gas chromatography.
A pellistor is a type of calorimetric combustible gas sensor that detects a change in the temperature of a heated catalytic element when exposed to a mixture of combustible gas and air. Pellistors in the past have not been designed for speed. Most take several minutes to make accurate readings due to their large thermal masses and the thick diffusion-limiting layers of catalyst substrate on the surface of the sensing elements. Recently, much faster micropellistors, or microcalorimeters, have been developed for determining BTU heating values of natural gas and other fuel gas streams. See U.S. Pat. No. 6,786,716 to Gardner et al.; M. Moorman et al., "Microcombustor array and micro-flame ionization detector for hydrocarbon detection," Proc. SPIE 4981, 40 (2003); M. Moorman et al., "Lower Heating Value Sensor for Fuel Monitoring," submitted to IEEE Sensors (2005); and P. N. Bartlett and S. Guerin, "A Micromachined Calorimetric Gas Sensor: an Application of Electrodeposited Nanostructured Palladium for the Detection of Combustible Gases," Anal. Chem. 75, 126 (2003); which are incorporated herein by reference. The microcalorimeter typically comprises a thin catalyst layer deposited on a thin, resistively heated surface. The fuel, premixed with air, catalytically combusts on this surface. The heat of combustion is measured directly from a feedback circuit powering the sensor. This rapid and sensitive sensor provides a direct measurement of the BTU content of the fuel. When combined with a density measurement, the Wobbe Index can be determined, which is an important fuel property used to aid combustion control in systems such as gas turbines. This microcalorimeter provides stand-alone gas monitoring where low precision analysis (+/−5% BTU) is acceptable. However, while simple and inexpensive, this sensor alone does not provide direct information on constituents of the NG stream.
For many users, including gas transfer/mixing stations and electricity generating turbines, accuracy of 0.1% BTU is required. Further, for pipelines and turbines, speciation is necessary to obtain the NG composition and hydrocarbon dew point. Especially where large quantities of NG are consumed (medium-size or larger switching stations, gas-turbine electricity generators), all fuel properties need to be known. In these applications, widespread deployment of advanced monitoring devices is highly desirable. Further, for market acceptance, the monitoring device must be of low cost. Deployment of low-cost devices within the pipeline network would translate to increased revenues for the gas industry by virtue of more detailed information on the heating value of gas within the system at any given time. Industrial end users would benefit by running natural gas fueled turbines closer to design limits, safely maximizing power while maintaining pollution control.

Microfabricated fuel heating value monitoring device


An example heating, ventilation, and air conditioning (HVAC) vent includes a front surface, an RF module, and an antenna coupled to the RF module. The front surface is configured to direct air flowing through the HVAC vent into a room, and includes an antenna opening. The RF module is configured to wirelessly transmit or wirelessly receive a communication signal. A portion of the antenna protrudes through the antenna opening and beyond a plane of the front surface.

In some industries, such as the heating, ventilation, and air conditioning (HVAC) industry, equipment is made of sheet metal or other types of metal that are not compatible with RF communications. One example of this is an HVAC vent, often called a register, which can be made of sheet metal and placed at the end of a metal duct to allow air to enter or leave ductwork. It is advantageous to use metal for HVAC or other vents for a number of reasons, including but not limited to: established industry convention, durability, strength to weight ratio, strength to size ratio, metal-finishing robustness, and ability to maintain finish and color. However, an HVAC vent and ductwork may poorly transmit RF communication signals, making RF communications to and/or from the HVAC vent difficult or impossible.


A membrane electrode assembly may be made using a one-sided catalyst coated membrane (CCM) wherein only one catalyst layer, either the anode or the cathode, is coated directly on the ion-exchange membrane. In particular, a one-sided CCM may be used where it may not be practicable to coat both sides of the ion-exchange membrane with catalyst layers such as when PTFE is added to the anode catalyst layer to render it reversal tolerant.

1. Field of the Invention
The present invention relates to membrane electrode assembly structures for electrochemical fuel cells and more particularly to modifications to improve tolerance to voltage reversals.
2. Description of the Related Art
Fuel cell systems are currently being developed for use as power supplies in numerous applications, such as automobiles and stationary power plants. Such systems offer promise of economically delivering power with environmental and other benefits. To be commercially viable however, fuel cell systems need to exhibit adequate reliability in operation, even when the fuel cells are subjected to conditions outside the preferred operating range.
Fuel cells convert reactants, namely fuel and oxidant, to generate electric power and reaction products. Fuel cells generally employ an electrolyte disposed between two electrodes namely a cathode and an anode. A catalyst typically induces the desired electrochemical reactions at the electrodes. Preferred fuel cell types include polymer electrolyte membrane (PEM) fuel cells that comprise a polymer membrane as electrolyte and operate at relatively low temperatures.
A broad range of reactants can be used in PEM fuel cells. For example, the fuel stream may be substantially pure hydrogen gas, a gaseous hydrogen-containing reformate stream, or methanol in a direct methanol fuel cell. The oxidant can be, for example, substantially pure oxygen or a dilute oxygen stream such as air.
During normal operation of a PEM fuel cell, fuel is electrochemically oxidized at the anode catalyst, typically resulting in the generation of protons, electrons, and possibly other species depending on the fuel employed. The protons are conducted from the reaction sites at which they are generated, through the electrolyte, to electrochemically react with the oxidant at the cathode catalyst. The catalysts are preferably located at the interfaces between each electrode and the adjacent electrolyte.
Polymer electrolyte membrane (PEM) fuel cells employ a membrane electrode assembly (MEA) which comprises an ion-exchange membrane disposed between the two electrodes. Separator plates, or flow field plates for directing the reactants across one surface of each electrode substrate, are disposed on each side of the MEA.
Each electrode contains a catalyst layer, comprising an appropriate catalyst or an admixture of appropriate catalysts, which is located next to the ion-exchange membrane. The catalyst may be a metal black, an alloy, an unsupported or supported metal catalyst. A commonly used catalyst is, for example, platinum supported on carbon. The catalyst layer typically contains ionomer, which may be similar to that used for the ion-exchange membrane (for example, up to 30% by weight Nafion® brand perfluorosulfonic-based ionomer). The catalyst layer may also contain a binder such as polytetrafluoroethylene.
The electrodes may also contain a substrate (typically a porous electrically conductive sheet material) that may be employed for purposes of reactant distribution and/or mechanical support. Optionally, the electrodes may also contain a sublayer (typically containing an electrically conductive particulate material, for example, finely comminuted carbon particles, also known as carbon black) between the catalyst layer and the substrate. A sublayer may be used to modify certain properties of the electrode (for example, interface resistance between the catalyst layer and the substrate).
Electrocatalyst can be incorporated at the electrode/membrane interface in polymer electrolyte fuel cells by applying it as a layer on either an electrode substrate or on the membrane itself. In the former case, electrocatalyst particles are typically mixed with a liquid to form a slurry or ink which is then applied to the electrode substrate. While the slurry preferably wets the substrate surface to a certain extent, the slurry may penetrate into the substrate such that it is no longer catalytically useful since the reaction zone is generally only close to the ion-exchange membrane. Comparatively lower catalyst loadings can thus typically be achieved by coating the ion-exchange membrane with a catalyst layer while still maintaining performance. In addition to waste of catalyst material, a thicker electrocatalyst layer as typically coated on electrode substrates may also lead to increased mass transport losses.
Typical methods of preparing a catalyst coated membrane (CCM) also start with the preparation of a slurry. A slurry typically comprises a carbon-supported catalyst, the polymer matrix/binder and a suitable liquid vehicle such as, for example water, methanol or isopropanol. The slurry is then either directly applied onto the membrane by, for example screen printing, or applied onto a separate carrier or release film from which, after drying, it is subsequently transferred onto the membrane using heat and pressure in a decal process. Alternatively, the CCM may be made by other known methods such as vapor deposition, casting or extrusion.
Efficiency of the MEA in the fuel cell is typically affected by the quality of the contact between the catalyst layer and the ion-exchange membrane. When the quality of such a contact is relatively poor, partial or complete delamination of the MEA may result over time. CCMs typically have a better contact between catalyst layer and ion-exchange membrane as compared with GDEs bonded to an ion-exchange membrane, particularly with low catalyst loadings such as, for example, less than 0.3 mg/cm2 of platinum catalyst. It may be difficult to prepare a suitable GDE with such low catalyst loadings.
However, there may also be indirect costs associated with coating catalyst layers on ion-exchange membranes. Both the catalyst and the ion-exchange membrane are relatively expensive components found in a typical PEM fuel cell, particularly as compared to gas diffusion layers. Errors in coating a catalyst layer on an ion-exchange membrane may result in the entire CCM being rejected.
While CCM techniques typically result in an interface with higher connectivity or contiguity between the catalyst and the ion-exchange membrane and thus better performance in the corresponding fuel cell, improvements are still needed in over-all fuel cell performance and durability.

Method of making a membrane electrode assembly for electrochemical fuel cells


A system for virtual reality (VR) motion control includes a multi-dimensional motion platform and a thrust universal spherical plain bearing. The VR motion control method includes: setting parameters; calibrating a device; obtaining parameters; receiving a head-mounted display device tracking packet and/or an action control packet; determining whether a real-time angle difference is greater than a set dead zone angle; and calculating a difference between a current angle of a head-mounted display device and a current status of the multi-dimensional motion platform, and feeding the difference into an action control system of the multi-dimensional motion platform, to eliminate the difference. The multi-dimensional motion platform uses single-point bearing or single-point lifting bearing and lever traction-type transmission, thereby realizing functions of swinging and rotating in all directions. The thrust universal spherical plain bearing integrates a common thrust universal spherical plain bearing with a plane thrust bearing.

A motion platform is an apparatus capable of simulating a motion status of a manned device, for example, simulating a car, a ship, an aircraft and so on. There have been a number of device solutions on the current market.
A transmission technology of an existing apparatus is using a combined mechanism of linear motors and using one motor to control a one-dimensional telescopic motion, thereby forming a multi-degree of freedom motion of the platform. According to the transmission technology, power of a transmission structure is used to bear weight on the platform and lift up the platform to perform a motion.
In an existing three-degree of freedom motion platform, three points are used to support the platform, a support bar can perform a linear motion, and controlled motions in three dimensions: a front-back dimension, a right-left dimension and an up-down dimension can be realized by controlling coordinated motions among three support bars, and motion simulation can be realized in combination with a visual effect.
The three-degree of freedom motion platform has been widely used in various fields such as movie theaters, games and amusement parks.
Main defects of the three-degree of freedom motion platform are as follows.
1. The platform has large size and heavy weight, thereby being inconvenient to transport, mount and maintain.
2. The platform needs to be equipped with devices such as a large-sized seat, which causes a relatively high overall height and a relatively large occupied area.
3. Motions in a front-back axis and a left-right axis are mainly realized, up-down amplitude is very small, and the platform cannot implement a rotation function.
4. A need for an additional high-power drive results in relatively high mechanical noise.
At present, there already has a six-degree of freedom platform that can implement finer motion control and a small amount of axial rotation. However, all six-degree of freedom motion platforms at the present stage are large and bulky devices having high costs in all aspects, which goes against personal use or personalized customization and restricts multi-field popularization of a motion simulation device.
At present, VR motion platforms are all obtained by modifying according to 4d/5d and other theater seat technologies. In a main structure, three electric cylinders, double electric cylinders, or six electric cylinders are used as a motion platform drive, where a six-electric cylinder drive has high cost, thereby being relatively rare. During use, coordinate records of an electric cylinder that are recorded in advance are read by using special software, so as to control a motion of the electric cylinder and realize motion control of a plurality of degrees of freedom. Being an electric cylinder supporting structure, except a six-electric cylinder platform that can perform rotation with relatively small amplitude (not greater than 30 degrees), all three- or double-electric cylinder structures cannot perform a rotary motion. In addition, electric cylinders in the solution are responsible for bearing, resulting in large overall weight, a problem that overall power needs to reach kilowatts to ensure normal work, and relatively high requirements for the environment.
Especially for a scenario requiring fixed lifting or lifting and moving under a rail, an existing six-degree of freedom platform cannot meet the requirement at all. Therefore, it is urgent to provide a motion platform with a lifting structure.
If weight of all objects on the multi-dimensional motion platform needs to be borne by one structure, a special thrust universal spherical plain bearing is required to share gravity with other structures, so as to achieve functions of swinging and rotating in all directions.

VR motion control method, multi-dimensional motion platform and thrust universal spherical plain bearing

XI'AN KISSFUTURE NETWORK TECHNOLOGY CO., LTD


Embodiments of the present invention provide a method for sending an electronic mail receipt and a mobile terminal. In the method, a first mobile terminal obtains an electronic mail sent by a second mobile terminal. A header of the electronic mail contains indication information about whether it is required to send a receipt for the electronic mail. When the first mobile terminal determines according to the indication information that it is required to send a receipt, the first mobile terminal obtains a phone number of the second mobile terminal from the electronic mail and sends a short message with preset content to the phone number of the second mobile terminal.

A receipt of an electronic mail (Email) is used to confirm whether the electronic mail has been delivered to an intended recipient or whether the electronic mail has been read by the intended recipient.
In the prior art, an electronic mail receipt is usually sent as an electronic mail message to notify a sender. For instance, for a mobile phone user, it is increasingly popular to use applications of a mobile phone to receive electronic mails. If a sender of an electronic mail requires an electronic mail receipt from an intended recipient of the electronic mail, for the mobile phone user, frequently sending electronic mail receipts consumes network traffic of the mobile phone user.

Method for sending electronic mail receipt and mobile terminal


The present invention provides a method for implementing diversity for a dual-mode communication unit in a communication system. The communication system includes a first transceiver utilizing a first air interface and a second transceiver utilizing a second air interface distinct from the first air interface. The system also includes a controller that includes a selector function. The dual-mode communication unit transmits a first copy of bearer data to the first transceiver utilizing the first air interface. The dual-mode communication unit transmits a second copy of the bearer data to the second transceiver utilizing the second air interface. The first transceiver and the second transceiver sending the copy of the bearer data to the controller. The first transceiver and the second transceiver also send a quality metric to the controller. The controller selects a preferred copy of the bearer data based at least in part upon the quality metrics.

Cellular communication systems are well known. As cellular communication systems evolve, communication systems with dissimilar air-interfaces likewise evolve. For example, one communication system which has evolved from the well known IS-95A system is a communication system commonly referred to as CDMA 2000. In the CDMA 2000 communication system, layer 2 and above messaging/signaling can be compatible with the IS-95A communication; however, the air-interface is different between the communication systems. The differences between the air-interface include, inter alia, channel bandwidth, type of modulation, channel structures, power control and coding gain on the physical link. Such differences between the air-interfaces of these communication systems presents problems when a dual-mode communication unit compatible with both communication requires a handoff between diverse communication systems.
Thus, a need exists for a method and apparatus which overcomes the deficiencies of the prior art.

Method and apparatus for implementing diversity for a dual-mode communication unit


A fluid flow testing apparatus for measuring the pour profile of a container has a rotatable container carrier and an assembly for rotating the container between a first position allowing fluid to be retained within the container and a second position causing fluid to be poured from the container. Sensors for sensing the weight of the container as liquid is poured from the container are provided in order to determine the pour profile of the container. A controller receives input signals from the sensors in order to record the weight of the container over time as liquid is poured from the container as the container is rotated. The change of weight of the container over time establishes a pour profile for the container.

A general object of the present disclosure, in accordance with one aspect of the disclosure, is to provide a method and system to characterize the flow of liquid from a container, for example, to establish the attributes of the pour profile of the container.
The present disclosure embodies a number of aspects that can be implemented separately from or in combination with each other.
A container test system in accordance with one aspect of the disclosure includes a test chamber including rotatable container carrier, and an assembly for rotating the container between upright and inverted positions. The system also includes sensors to measure the change of the weight of the container as fluid is poured from the container. The system further includes a collection assembly for gathering the liquid that flows from the inverted or partially inverted container. Lastly, the system further includes data collection capability to gather and process sensor data in real-time while the system also includes sensors to monitor any external conditions that may affect the test so that the data may be adjusted to compensate for such external conditions.
In accordance with another aspect of the disclosure, there is provided a method of determining the pour profile of a container. The method includes positioning the container on a rotatable container carrier, and rotating the container between an upright and an inverted position. The method further includes reading load cells to measure the change in weight of the container during rotation while the fluid contents are poured from the inside of the container, and reading an accelerometer to monitor and detect any outside environmental interference that may influence the results of the test, and adjusting the test results for such outside interference.

Fluid flow testing for comparing container pour profiles


A network environment includes a wireless access point providing access to a corresponding network. One or more mobile communication devices communicate with the wireless access point to access the network. In response to receiving a request from a mobile communication device to establish the wireless communication link, the wireless access point conveys communications between the mobile communication device and a remote server to authenticate the mobile communication device. During authentication, the wireless access point receives a policy assigned to the mobile communication device. The policy specifies how to route subsequent received data traffic from the mobile communication device. Subsequent to authentication, the wireless access point routes the subsequent data traffic received from the mobile communication device in accordance with the received policy.

Conventional computer devices typically have the ability to identify a presence of WiFi™ access points. For example, according to current technology, to learn of one or more access points in a region, a computer device can transmit a wireless query signal (e.g., a probe request). In response to the wireless query signal, any of one or more active WiFi™ network access points in the region will respond with information indicating their identities (a.k.a., SSIDs). In certain instances, a respective SSID is a human-readable network name assigned to a respective network. Accordingly, via the response information from the access points, the operator of the computer can identify which, if any, WiFi™ networks are available for use in the region.
After identifying available WiFi™ networks, the computer device can initiate display of the identities of the different WiFi™ networks on a display screen. In such an instance, the user of the computer can manually select from a listing of the available WiFi™ networks (SSIDs) to connect. According to conventional techniques, since each SSID (network name) corresponds to a different available for network, the respective user is able to connect to any of multiple networks depending upon the chosen SSID (network name).
If the WiFi™ access point is an open WiFi™ network, the user will not need to provide a password to be granted access to the Internet through the selected WiFi™ access point. Alternatively, in certain instances, such as in secured WiFi™ networks, the user may be required to provide appropriate credentials (such as username, password, etc.) to use the wireless access point if restrictions have been imposed on use of the wireless access point.
If used, a downside of open networks is that illegitimate users (a.k.a., hackers) can potentially eavesdrop on respective wireless communications between a computer device and a respective WiFi™ access point. Via eavesdropping, an illegitimate user may be able to learn of a respective network address associated with the computer device. Using the network address, the illegitimate user may be able to control use of the communication link or steal data. Thus, unsecured wireless communications (such as WiFi™ communications) are undesirable.
To alleviate and/or prevent hacking of wireless communications, several wireless communication protocols have been established for use in WiFi™ applications to provide more secured wireless communications. For example, the EAP (Extensible Authentication Protocol) is a desired protocol for use in wireless network applications. The EAP protocol expands on authentication methods used by the Point-to-Point Protocol (PPP), a protocol often used when connecting a computer to the Internet.
In general, to communicate in accordance with EAP, assume that a user requests to establish a connection with a respective wireless access point. The wireless access point requests that the user (or corresponding mobile communication device) of the communication device provide identification information. The wireless access point forwards the identification information received from the user to an authentication server. The authentication server challenges the user of the communication device to provide proof of the validity of the provided identification information. The wireless access point receives and forwards authentication information (such as password, etc.) received from the user to the authentication server. If the authentication information is correct for the corresponding identity of the communication device, the authentication server notifies the wireless access point to allow the user of the communication device access to the Internet through the wireless access point.

Communication management and policy-based data routing


In an exposure control method and apparatus, pulsed illumination light from an excimer laser light source is reduced by an energy rough modulator before illuminating a reticle. The reticle and a wafer are moved or scanned relative to a projection optical system to sequentially transfer a pattern image of the reticle to individual shot areas on a wafer. An integrator sensor indirectly monitors the amount of exposure on the wafer, and an energy monitor monitors the energy of pulsed illumination light inside the excimer laser light source. Based on the result of measurement by the integrator sensor and the correlation between the result of measurement by the integrator sensor and the result of measurement by the energy monitor, the emission power of the excimer laser light source is finely modulated at a high speed without employing an energy fine modulator that finely modulates the transmittance by a mechanical drive and without causing an energy loss along the optical path of illumination light.

The present invention relates to a method and apparatus for controlling the amount of exposure of a photosensitive substrate in an exposure apparatus used in a lithography process for producing, for example, semiconductor devices, liquid crystal display devices, image pickup devices (such as charge coupled devices), or thin-film magnetic heads. The invention is suitable for use in full wafer exposure apparatus and, more particularly, for use in exposure control in a scanning projection exposure apparatus of, for example, a scan-and-step type.
The production of semiconductor devices and the like conventionally employs a projection exposure apparatus to project and transfer the pattern of a reticle onto each shot area on a wafer (or a glass plate) coated with a photoresist. As a basic function, the projection exposure apparatus controls the total amount of exposure (total exposure energy) of each point in each shot area on a wafer within an appropriate amount range.
For the exposure control of conventional full wafer projection exposure apparatus, such as steppers, cut-off control is normally performed whether the exposure light source employed is a continuous light source such as an extra-high pressure mercury lamp, or a pulsed laser light source such as an excimer laser light source. In the cut-off control, a portion of the light for exposure of a wafer coated with a photosensitive material is branched and directed to an integrator sensor formed of a photoelectric detector, whereby the amount of exposure of the wafer is indirectly detected. The light emission is continued until the total of exposure amounts detected by the integrator sensor exceeds a predetermined level (critical level) corresponding to a total amount of exposure (hereinafter, referred to as xe2x80x9cset amount of exposurexe2x80x9d) that is required for the photosensitive material used (in the case of continuous light, a shutter is closed when the critical level is exceeded).
In the case of exposure using a pulsed laser light source as an exposure light source, a desired precision reproducibility in exposure control can be achieved by using at least a certain number of laser light pulses for exposure (hereinafter, the xe2x80x9ccertain numberxe2x80x9d will be referred to as xe2x80x9cminimum exposure pulse numberxe2x80x9d) because energy varies from one laser light pulse to another. In the case of a highly sensitive resist for which the set amount of exposure is small, the exposure to at least the minimum exposure pulse number of laser light pulses may become impossible if laser light from the pulsed laser source is directly used for exposure. Therefore, if the set amount of exposure is small, the pulsed laser light must be reduced in intensity by, for example, a light reducing device disposed in the optical path, so that at least the minimum exposure pulse number of laser light pulses can be employed for exposure.
To enable transfer of a pattern of an increased area to a wafer with a high precision without imposing severe requirements on the projection optical system, a step-and-scan projection exposure apparatus has recently been developed that synchronously scans or moves a reticle and a wafer relative to the projection optical system while projecting the images of portions of the pattern of the reticle onto the wafer using the projection optical system, so as to sequentially transfer portions of the pattern of the reticle onto individual shot areas on the wafer by exposure. In such a scanning exposure type apparatus, exposure control regarding a point on a wafer is impossible, and the aforementioned cut-off control cannot be applied. Therefore, for exposure control in scanning exposure type exposure apparatus, the conventional art normally employs a method (open exposure control method) that controls the amount of exposure simply by totalling the light quantity of each illumination pulse, or a method (every pulse exposure amount control method) that controls the energy of every illumination light pulse by measuring the total amount of exposure of an area on a wafer in real time, the area included in a slit-like illumination field (exposed area) extending in the scanning direction, and calculating a target energy value of the next illumination light pulse based on the total amount of exposure.
The former control method requires fine adjustment of pulse energy to satisfy the following equation (1) wherein the number of exposure pulses is an integer in order to achieve a desired linearity in the exposure control:
(set amount of exposure)=(number of pulses)xc3x97(average energy per pulse)xe2x80x83xe2x80x83(1)
In equation (1), the average energy per pulse is a value measured by an integrator sensor immediately before exposure. The latter control method requires fine adjustment of the pulse energy at every emission of a pulse.
A conventional pulsed laser light source used in connection with either of the control methods contains an energy monitor formed by a photoelectric detector, and performs feedback control of the laser electric power source so that the detection result by the energy monitor conforms to an output energy value (central energy value) provided by an external device in order to constantly output light pulses of the same amount of energy. More specifically, the central energy value inputted to the pulsed laser light source is fixed, and the fine modulation of energy of a light pulse is performed using an energy fine modulator.
FIG. 8(a) illustrates a conventional energy fine modulator of a double grating type. In this fine modulator, a stationary grating 41 having light transmitting portions and blocking portions formed at a predetermined pitch and another grating 42 movable in the direction of the grating pitch are arranged one over the other in the optical path of a laser beam LB emitted in a pulsed manner. By shifting the positions of the gratings 41, 42 relative to each other, the laser beam transmittance can be finely modulated. FIG. 8(b) illustrates another conventional energy fine modulator in which two glass plates 43, 44 each coated with anti-reflection coating on both sides are arranged in the optical path of a laser beam LB, with the glass plates symmetrically inclined at a variable inclination angle xcex8. Exploiting a property of the glass plates 43, 44 that the transmittance varies depending on the incident angle of the laser beam LB, the fine modulator finely adjusts the overall laser beam transmittance by controlling the inclination angle xcex8.
The conventional energy fine modulators as shown in FIGS. 8(a) and 8(b), however, have drawbacks in that since a mechanical drive is employed for the adjustment of transmittance, high-speed adjustment of transmittance is difficult. Moreover, since neither of the fine modulators is able to achieve a maximum transmittance of 100%, an energy loss results even in an initial maximum transmittance state, thus adversely affecting device efficiency in utilizing the pulsed light.
The double grating type energy fine modulator as shown in FIG. 8(a) has another drawback in that even though the fine modulator is disposed at the light source-side of a fly eye lens provided as an optical integrator, the overlapping effect of the fly eye lens becomes small if the aperture of the illumination diaphragm is small, so that the grating pattern slightly remains as an illumination non-uniformity in an image. A small aperture of the illumination diaphragm means that a so-called a value, that is, a coherence factor, is small.
Accordingly, it is an object of the present invention to provide an exposure control method capable of finely modulating the energy of illumination light and therefore the amount of exposure of a photosensitive substrate at a high speed without inserting a mechanically-driven energy fine modulator for finely modulating the transmittance (light reduction rate) in the optical path of illumination light, and without causing an energy loss along the optical path of illumination light.
It is another object of the present invention to provide an exposure control apparatus capable of employing the exposure control method of the invention.
According to an aspect of the present invention, there is provided an exposure control method for controlling an amount of exposure of a photosensitive substrate to illumination light in an exposure apparatus that illuminates a mask having a pattern with illumination light emitted from an exposure light source and thereby exposes a photosensitive substrate to the illumination light through the mask to transfer the pattern of the mask to the substrate. In the method, the emitting power of the exposure light source is finely modulated within a predetermined range to control the amount of exposure of the photosensitive substrate. By directly controlling the emitting power of the exposure light source, the method of the invention finely modulates the energy of illumination light without employing mechanical drive and without causing an energy loss along the optical path of the illumination light.
If a pulsed laser light source, such as an excimer laser light source, is used as the exposure light source, the range of energy fine modulation required in order to obtain an integer number of exposure light pulses for each point on the photosensitive substrate is at most plus or minus several percent. Therefore, if an excimer laser light source is used, it becomes possible to make the central energy (emission power) of each pulse from the light source variable within the range required for an integer number of exposure light pulses.
It is preferred that the illuminance of the illumination light in each shot area on the photosensitive substrate be monitored during sequential exposures of a plurality of shot areas, and that the emission power of the exposure light source be finely modulated in accordance with a monitoring deviation result from a target value for exposure of the next shot area on the photosensitive substrate. Thereby, the emission power setting of the exposure light source can be updated, for example, during a shift from one shot area to another.
According to another aspect of the present invention, there is provided an exposure control method for controlling an exposure amount of a photosensitive substrate to illumination light in an exposure apparatus that illuminates a mask having a pattern with illumination light emitted from an exposure light source and thereby exposes a photosensitive substrate to the illumination light through the mask to transfer the pattern of the mask to the substrate. The method includes determining a table of correlation between an illuminance of the illumination light occurring inside or immediately out of the exposure light source and an illuminance of the illumination light occurring on the photosensitive substrate, and controlling the amount of exposure of the photosensitive substrate to the illumination light on the basis of the table of correlation.
According to this method, the illuminance of the illumination light at the exposure light source is detected by, for example, an energy monitor disposed in the exposure light source, and the illuminance of the illumination light on the photosensitive substrate is detected by, for example, an energy monitor of the exposure apparatus. The table of correlation between the outputs from the two energy monitors is determined and stored as a control table. The amount of exposure of the photosensitive substrate is controlled by, for example, fine modulation of the exposure light source emission power. This fine modulation is based on the output from the energy monitor of the exposure apparatus, not the output from the energy monitor of the exposure light source. More specifically, an output of the energy monitor in the exposure light source is determined from the output of the energy monitor of the exposure apparatus and the table of correlation, and the thus-determined output of the energy monitor in the exposure light source is used as a reference for finely modulating the emission power of the exposure light source. Thereby, the exposure control linearity (that is, linearly between target amount of exposure and actual amount of exposure) can be obtained on the basis of the output of the energy monitor of the exposure apparatus.
It is preferred to determine the table of correlation when dummy light emission from the exposure light source is performed without exposing the photosensitive substrate.
It is also preferred to update the table of correlation if a change is expected in the correlation between the illuminance of the illumination light occurring inside or immediately out of the exposure light source and the illuminance of the illumination light occurring on the photosensitive substrate.
Since the correlation between the outputs of the two energy monitors is expected to fluctuate over time, an exposure apparatus-side energy monitor-based exposure control linearity that is stable for a long time can be achieved by sampling data for preparation of a correlation table to update the correlation table if there is a likelihood that the deviation from the correlation will exceed a predetermined amount, i.e., a likelihood that the error of the correlation table will exceed an allowable amount.
In addition, if the exposure light source is a pulsed laser light source, there exists a requirement for a desired exposure reproducibility (reproducibility of the amount of exposure for each area on the photosensitive substrate in the case of scanning exposure), i.e., a minimum number of pulses required (minimum exposure pulse number Nmin). To meet this requirement, the light intensity is reduced by, for example, an energy rough modulator disposed in the optical path, depending on the relationship between the set amount of exposure and the energy per pulse, so that the exposure will be completed by using at least Nmin number of exposure pulses. The range of pulse energy incident on the energy monitor in the exposure light source is narrow, whereas the range of pulse energy incident on the exposure apparatus-side energy monitor is wide. The difference therebetween is, for example, at least 100 fold if an excimer laser light source is employed. Since the correlation between the two energy monitors changes depending on the transmittance in the energy rough modulator, it is preferred to sample data for a correlation table, as well as for an energy determination, prior to exposure while the energy rough modulator is in operation, and to prepare a correlation table based on the sampled data for updating the correlation table. By performing this process, the exposure control linearity based on the exposure apparatus-side energy monitor can be achieved for any set amount of exposure.
If the exposure light source is a pulsed emission type light source in either of the two exposure control methods, it is preferred that the exposure light source pre-emit a number of pulses necessary for stabilization of the emission power of the exposure light source when the light source emission power setting is changed. In a scanning type exposure apparatus, pre-emission (dummy emission) of light may be performed while the illumination field aperture is closed, for example, during the period of acceleration of a stage system, i.e., the preparation time for the scanning exposure operation, or the stabilizing time.
According to still another aspect of the present invention, there is provided an exposure control apparatus for controlling an amount of exposure of a photosensitive substrate to illumination light in an exposure apparatus that illuminates a mask having a pattern with illumination light emitted from an exposure light source and thereby exposes a photosensitive substrate to the illumination light through the mask to transfer the pattern of the mask to the substrate. The apparatus includes a light source modulation unit that finely modulates an emission power of the exposure light source within a predetermined range, a first energy monitor for detecting an illuminance of the illumination light occurring inside or immediately out of the exposure light source, a second energy monitor for detecting an illuminance of the illumination light on the photosensitive substrate, and a controller for controlling the light source modulation unit on the basis of the detection results of the first and second energy monitors. This exposure control apparatus is able to employ either of the exposure control methods.


An attachable two-chamber breast prosthesis includes two volumes of silicone materials that have different degrees of softness. The prosthesis includes three pieces of polyurethane film (a front film, a middle film, and a rear film) that form a front chamber and rear chamber. The periphery of the front chamber is smaller than the periphery of the rear chamber. The rear chamber, which contains the firmer silicone material, extends to the peripheral edge of the prosthesis. The front chamber, which contains the softer silicone material, does not extend all the way to the peripheral edge along the upper region of the prosthesis. By increasing the thickness of the rear chamber along a boomerang-shaped region defined by the peripheries of the front and rear chambers, the firmer silicone material in the rear chamber provides the prosthesis with proper support and reduces the tendency of the prosthesis to pull away from the skin along the top edge of the prosthesis.

It is an unfortunate fact that many women contract breast cancer and must have the affected breast removed. After removal of one or both breasts, most mastectomy patients in today's society seek a prosthetic replacement to feel whole, and present a normal appearance beneath clothing. Another goal of breast prostheses is to reduce stress on the spine by maintaining the body's natural balance. Early fabric prostheses were never very satisfactory, and surgically implanted prostheses are expensive and involve health risks. Therefore, external silicone breast prostheses have become extremely popular with mastectomy patients.
The first external silicone breast prostheses included a single volume of a two-component cross-linked silicone material contained within a cavity formed by two pieces of polyurethane film. The silicone material is cured in a mold that determines the shape of the prosthesis. Such prostheses were designed to be worn inside a brassiere. An example of such a prosthesis and a mold are described in U.S. Pat. Nos. 4,172,298 and 4,247,351 to Rechenberg.
Eventually, prosthesis designers determined that certain advantages could be obtained by forming a prosthesis from two volumes of silicone materials that have different degrees of softness. Such prostheses include three pieces of polyurethane film, which are welded together along a common peripheral edge to form front and rear chambers. In some products, the firmer silicone material is in the front chamber. In others, the firmer silicone material is in the rear chamber.
U.S. Pat. No. 4,950,291 to Mulligan describes a two-chamber prosthesis in which the front chamber is relatively thin. The silicone material in the larger rear chamber, which is placed next to the chest wall, is softer than that in the front chamber. The softer silicone material conforms to the shape of the chest wall and moves with the body, thereby providing a natural appearance. The softer silicone material helps redistribute the weight of the prosthesis across and against the chest wall and away from the brassiere shoulder strap, which reduces stress on the shoulder. The firmer silicone material in the front chamber supports the soft rear chamber, prevents the prosthesis from collapsing, and gives shape to the product.
As mentioned above, other two-chamber prostheses place the firmer silicone material in the rear chamber. An example of a two-chamber prosthesis of this type is sold by the assignee of the present invention under the trademark "DELTA PERSONALLY." In this prosthesis, the rear chamber, which contains the firmer silicone material, is relatively thin. The larger front chamber contains the softer silicone material. This configuration is advantageous because the firmer rear chamber simulates the pectoralis chest muscles while the softer front chamber moves like a natural breast. This prosthesis provides a significant natural drape with softness to fill and mold to a brassiere cup completely and naturally. The overall softness of the prosthesis helps the prosthesis mold to the chest wall and helps redistribute the weight of the prosthesis across and against the chest wall and away from the brassiere shoulder strap.
Subsequent developments led to the introduction of attachable prostheses, which could be attached to the skin of the wearer. Like the earlier silicone prostheses, the attachable products included a single volume of a two-component cross-linked silicone material contained within a cavity formed by two pieces of polyurethane film. The prosthesis is held in place on the wearer's chest by a skin support or fastening slab, which has a skin-friendly adhesive on one side and an attachment members on the other side. The prosthesis is attached to the skin support by complementary attachment members. U.S. Pat. No. 5,071,433 to Naestoft et al. and U.S. Pat. No. 5,352,307 to Wild describe attachable prostheses that employ hook-and-loop fasteners, where the hook material is on the prosthesis and the loop material forms one side of the skin support.
Although it may appear to be a simple matter to combine the attachment members of the Naestoft patent with the two-chamber prostheses described above, the simple combination of these features leads to unsatisfactory results. In the case of the soft back two-chamber prosthesis, the back chamber is too soft to support the weight of the prosthesis. In the case of the soft front two-chamber prosthesis, the soft front tends to droop under the weight of the prosthesis and cause the top portion of the prosthesis to pull away from the wearer' skin. Although this may be remedied to some degree by moving the attachment members up along the top edge of the prosthesis, this results in positioning of the skin support that is unacceptable for two reasons. First, the skin support must be positioned so close to the edge of prosthesis that it may be visible around the edges of the prosthesis. Second, this configuration tends to suspend most of the weight of the prosthesis from the top of the skin support, which tends to peel the skin support away from the wearer's skin.
Therefore, there is a need in the art for an attachable, two-chamber prosthesis. An attachable two-chamber prosthesis should provide an acceptable fit and transition to the wearer's chest. Furthermore, an attachable two-chamber prostheses must allow the skin support to be adequately concealed beneath the prostheses and minimize the tendency to peel the skin support away from the wearer's skin.

Attachable two-chamber breast prosthesis


Injection noise and silence are detected in an input speech signal and an external amplifier is switched on or off based on the detected injection noise or silence. The input speech signal is digitized and a first copy of the digitized signal is preemphasized. After the input speech signal is preemphasized, a predetermined number of Mel-frequency cepstral coefficients (MFCCs) and difference cepstra are calculated for each window of the speech signal. A measure of signal energy and a measure of the rate of change of the signal energy is computed. A second copy of the digitized input speech signal is processed using amplitude summation or by differencing a center-clipped signal. The measures of signal energy, rate of change of the signal energy, the Mel coefficients, difference cepstra, and either the amplitude summation value or the differenced value are combined to form an observation vector. Hidden Markov Model (HMM) based decoding is used on the observation vector to detect the occurrence of injection noise or silence. A gain switch on an external speech amplifier is turned on after an occurrence of injection noise and remains on for the duration of speech and the amplifier is turned off when an occurrence of silence is detected.

1. Field of the Invention
The present invention relates generally to the field of esophageal speech, and more particularly, to a method for enhancing the clarity of esophageal speech.
2. Description of Related Art
Persons who have had laryngectomies (that is, a surgical removal of the larnyx, most often for treatment of laryngeal cancer) have several options for the restoration of speech, none of which have proven to be completely satisfactory. One relatively successful method, esophageal speech, requires speakers to insufflate, or inject air into the esophagus, thereby replacing the vibration that is normally created by the vocal cords within the larynx, with the vibration of the esophagus. This method is discussed in the article "Similarities Between Glossopharyngeal Breathing And Injection Methods of Air Intake for Esophageal Speech," Weinberg, B. & Bosna, J. F., J. Speech Hear Disord, 35:25-32, 1970, herein incorporated by reference. Esophageal speech is frequently accompanied by an undesired audible injection noise, sometimes referred to as an "injection gulp" or "clunk" which sounds similar to a belch. Not only is this sound unpleasant, but the undesirable effect of the injection gulp is magnified because esophageal speakers generally have low vocal intensity. In addition, for some speakers the injection noise can be mistaken for a speech segment which further diminshes the intelligibility of the speakers voice. A further discussion of these effects may be found in the article "A Comparative Acoustic Study of Normal, Esophageal, and Tracheoespphageal Speech Production, " Robbins, J., Fisher, H. B., Blom, E. C., and Singer, M. I., J. Speech Hear Res, 49:202-210, 1984, herein incorporated by reference.
Considerable work has been undertaken to enhance certain aspects of esophageal speech. Examples of these techniques are discussed in "Replacing Tracheoesophageal Voicing Sources Using LPC Synthesis, " Qi, Y., J. Acoust. Soc. Am., 88:1228-1235, and in "Enhancement of Female Esophageal and Tracheoesophageal Speech," Qi, Y., Weinberg, B. and Bi, N., J. Acoust. Soc. Am., 98:2461-2465, both herein incorporated by reference. Although considerable work has been done in improving esophageal speech, the problem of eliminating injection noise has not been successfully addressed. In addition, there is no device that both eliminates the injection noise, and enhances the voice quality of esphageal speakers.

Enhancement of esophageal speech by injection noise rejection

Technology Research Association of Medical Welfare Apparatus


A method may include receiving registration information from a first user equipment (UE) device and identifying a first multicast service associated with the first UE device. The method may also include transmitting, to the first UE device, a first file associated with the first multicast service and determining a number of UE devices associated with the first multicast service that have provided registration information. The method may further include determining whether a threshold associated with the number of UE devices that have provided registration information has been reached and initiating a broadcast of content associated with the first multicast service, in response to determining that the threshold has been reached.

Multicast communications are used to transmit data to multiple endpoints simultaneously. Currently, multicast communications are delivered to endpoints via a mechanism in which a user device subscribes to a multicast service discovery channel (SDCH). The SDCH is a dedicated channel that periodically transmits a service announcement (SA) file which includes a list of all future broadcasts. The user device monitors the SDCH and identifies multicast information pertaining to the user device.
With the increased use of multicast services, the SA file may become very large. As a result, an endpoint user device may take a significant amount of time to parse through the SA file to obtain information regarding the multicast service relevant to the particular endpoint user device. In addition, with the advent of new technologies, such as autonomous driving, the conventional multicast mechanism using a single SA file may be unable to meet certain requirements associated with multicast communications, such as low latency requirements.

This patent is subject to a terminal disclaimer.

Systems and methods for subscription based multicast service discovery


In an intake system for an engine that includes plural throttle bodies 2 to 4 having throttle valves for changing an intake passage area, the plural throttle bodies 2 to 4 include manually driven side throttle bodies 2 to 4, which have manually driven side throttle valves 2b to 4b that are opened and closed by a throttle operation of a rider, and an electrically driven side throttle body 5, which has an electrically driven side throttle valve 5b that is opened and closed by an electric motor 11, and the intake system includes a valve opening control means 15 that controls an opening of the electrically driven side throttle valve 5b such that a specific output characteristic corresponding to an operating state of an engine is obtained.

1. Technical Field
The present invention relates to an intake system preferably applied to, for example, a multiple cylinder engine for a motorcycle.
2. Background Art
For example, a multiple cylinder engine mounted on a motorcycle includes an intake system of a multi-throttle type having one throttle body for each cylinder. As the intake system of this type, a manual intake system, in which a throttle grip and throttle valves are coupled mechanically by a throttle cable and all the throttle valves are opened and closed mechanically by a throttle grip rotating operation of a rider, is generally used.
On the other hand, recently, there has also been proposed an electric intake system in which an electric motor is coupled to throttle valves via a link mechanism or the like. A throttle grip rotating operation of a rider is detected and all the throttle valves are opened and closed by the electric motor according to this detected rotating operation.
Incidentally, in both the manual type and the electric type, the conventional intake system is constituted so as to control all the throttle valves to open and close uniformly in response to a throttle grip rotating operation of a rider. Therefore, for example, when the rider closes the throttle grip suddenly, all the throttle valves also close suddenly, whereby strong engine brake acts.
However, there is a demand that, depending upon a running state, for example at the time of approaching a corner or at the time of rising from the corner, for example, it is desired to make the engine brake slightly weak even in the case in which the throttle grip is closed suddenly or it is desired to make the rising of a torque slightly gentle even in the case the throttle grip is opened suddenly. In the conventional system, such a demand is coped with by a throttle grip rotating operation of a rider. However, this results in a problem requiring of an excessively high level driving operation from the rider.
The present invention has been devised in view of the conventional situation, and it is an advantage of the present invention to provide an intake system for an engine that can obtain an output characteristic corresponding to a running state without requiring a very high level driving operation from the rider.