A technique for converting olefinic light hydrocarbons to ether-rich liquid fuels and olefinic gasoline including etherification, olefin upgrading and transhydrogenation operations. The preferred process includes: reacting a fresh hydrocarbon stream containing C.sub.4 + iso-alkene with lower aliphatic alcohol in an etherification zone in contact with an acidic etherification catalyst under etherification conditions whereby an effluent stream containing C5+ tertiary-alkyl ether is produced; separating the etherification effluent stream to provide a first liquid stream comprising C5+ ether and a second stream comprising unreacted alcohol and C4+ hydrocarbons; contacting the second stream with acidic metallosilicate catalyst for conversion of oxygenates and olefins under olefin oligomerization and isomerization conditions at elevated temperature; separating oligomerization effluent to recover an intermediate hydrocarbon stream rich in C.sub.4 + paraffinic hydrocarbon, a light gas stream, and a liquid product stream comprising C.sub.6 + olefinic gasoline; contacting the C.sub.4 + intermediate hydrocarbon stream with lower alkene in the presence of transhydrogenation catalyst whereby C.sub.4 + paraffin is converted to C4+ olefin, including iso-alkene; separating transhydrogenation effluent to recover C4+ olefin containing iso-alkene; and passing at least a portion of iso-alkene to the etherification zone for co-conversion with fresh hydrocarbon and alcohol to produce tertiary-alkyl ether.

This invention relates to processes for converting lower aliphatic alcohol, such as methanol, and olefinic hydrocarbons to high octane liquid fuel. In particular, this invention relates to a system for the production of tertiary-alkyl ethers in the presence of a lower alkanol, such as methanol, combined with the conversion of olefins to gasoline and a transhydrogenation step to convert branched paraffins to branched olefins for recycle.
Technical progress in catalytic olefins upgrading, oxygenate conversion to lower olefins (e.g.- methanol-to-olefins - "MTO"), and the commercial methanol-to-gasoline ("MTG") process have provided important synthetic fuel sources. Also, there has been considerable development of processes synthetic alkyl tertiary-alkyl ethers as octane boosters in place of conventional lead additives in gasoline. The etherification processes for the production of methyl tertiary alkyl ethers, in particular methyl t-butyl ether (MTBE) and t-amyl methyl ether (TAME) have been the focus of considerable research attention to resolve certain limitations in the etherification process with respect to the opportunity to drive the equilibrium dependent etherification reaction to completion by conducting etherification in the presence of excess methanol. It is known that recovering unreacted methanol by conventional separation and extraction techniques imposes severe economic burdens on the etherification process.
Recognizing the common feedstock (e.g. - methanol) for the synthetic production of gasoline as well as the production of methyl tertiary alkyl octane boosting ethers, research workers have endeavored to combine these processes in a manner to provide a synergistically beneficial integrated process.
It is known that isobutylene and other isoalkenes produced by hydrocarbon cracking may be reacted with methanol, ethanol, isopropanol and other lower aliphatic primary and secondary alcohols over an acidic catalyst to provide tertiary ethers. Methanollis considered the most important C.sub.1 -C.sub.4 oxygenate feedstock because of its widespread availability and low cost. Therefore, primary emphasis herein is placed on MTBE and TAME.
In recent years, a major technical challenge presented to the petroleum refining industry has been the requirement to establish alternate processes for manufacturing high octane gasoline in view of the regulated requirement to eliminate lead additives as octane enhancers as well as the development of more efficient, higher compression ratio gasoline engines requiring higher octane fuel. To meet these requirements the industry has developed non-lead octane boosters and has reformulated high octane gasoline to incorporate an increased fraction of aromatics. While these and other approaches will fully meet the technical requirements of regulations requiring elimination of gasoline lead additives and allow the industry to meet the burgeoning market demand for high octane gasoline, the economic impact on the cost of gasoline is significant. Accordingly, workers in the field have intensified their effort to discover new processes to manufacture the gasoline products required by the market place. One important focus of that research is a new process to produce high octane gasolines blended with lower aliphatic alkyl ethers as octane boosters and supplementary fuels. C.sub.5 -C.sub.7 methyl alkyl ethers, especially methyl t-butyl ether (MTBE) and t-amyl methyl ether (TAME) have been found particularly useful for enhancing gasoline octane. Therefore, improvements to the processes related to the production of these ethers are matters of high importance and substantial challenge to research workers in the petroleum refining arts. It is known that isobutylene may be reacted with methanol over an acidic catalyst to provide methyl tertiary butyl ether (MTBE) and iso-amylenes may be reacted with methanol over an acidic catalyst to produce t-amyl methyl ether (TAME). In these etherification processes, a problem of major importance is that methanol is not totally converted and the separation of methanol from the etherification reaction product due to the proclivity of methanol to form a very dilute azeotropic mixture with hydrocarbons and the strong solubility of methanol in both water and hydrocarbons. While it would be beneficial from an equilibrium standpoint to use large excesses of methanol in etherification, subsequent separation problems have limited that process improvement. Due largely to these factors, the cost associated with conventional methanol separation and recycling in the etherification reaction represents approximately 30% of the cost of the total etherification process.
In U.S. Pat. No. 4,684,757 to Avidan et al., the well-known ability of zeolite type catalyst to convert methanol to olefins is utilized by directing unreacted methanol from an etherification reaction to a zeolite catalyzed conversion reaction for conversion to olefin, thereby obviating the need to separate and recycle methanol in the etherification reaction. However, the process incorporates an alkylation step in one embodiment to produce alkylate as well as C.sub.5 + gasoline and C.sub.5 + ethers.
The process for the conversion of methanol to olefins utilized in the Avidan et al. patent is but one in a series of analogous processes based upon the catalytic capabilities of zeolites. It is known that medium pore acid zeolites, such as ZSM-5, can convert methanol to hydrocarbons of higher average molecular weight. Depending on various conditions of space velocity, temperature and pressure methanol, and lower oxygenates in general, can be converted in the presence of zeolite type catalyst to olefins which may then oligomerize to provide gasoline or distillate or may be converted further to produce aromatics.
The feasibility and adaptability of the basic chemistry of zeolite oxygenates conversion to produce useful conversion processes has been the subject of much inventive research activity. Recent developments in zeolite catalyst and hydrocarbon conversion processes have created interest in using oxygenates and olefinic feedstocks for producing C.sub.5 + gasoline, diesel fuel, etc. In addition to the basic work derived from ZSM-5 type zeolite catalyst, a number of discoveries have contributed to the development of a new industrial process. This process has significance as a safe, environmentally acceptable technique for utilizing feedstocks that contain lower olefins, especially C.sub.2 -C.sub.5 alkenes. In U.S. Pat. Nos. 3,960,978 and 4,021,502, Plank, Rosinski and Givens disclose conversion of C.sub.2 -C.sub.5 olefins, alone or in admixture with paraffinic components into higher hydrocarbons over crystalline zeolites having controlled acidity. Reaction conditions of moderate severity favor the conversion of olefins to predominantly gasoline boiling range products with little paraffins conversion. Milder reaction temperatures and high operating pressures can produce distillate range fuels as well from lower olefins. Garwood et al. have also contributed improved processing techniques in U.S. Pat. Nos. 4,150,062, 4,211,640 and 4,227,992. The above identified disclosures are incorporated herein by reference.
A well-known process for the conversion of oxygenates to gasoline is the methanol to gasoline process, known as MTG. The process is described in U.S. Pat. No. 3,931,349 to Kuo, U.S. Pat. No. 4,404,414 to Penick et al. and in the publication by C. D. Chang, Catal. Rev.-Sci. Eng., 25, 1 (1983). These references are incorporated herein in their entirety.
Recognizing the limiting problems of the etherification processes to produce MTBE and TAME and the potential that resides in the general area of the chemistry of oxygenate and olefin conversion with zeolites to resolve those problems, the following objectives of the instant invention have been established: It is an object of the present invention to provide an improved process for the production of high octane gasoline incorporating lower alkyl tertiary-alkyl ethers from isoalkene-rich hydrocarbons, especially MTBE manufacture. It is another object of the present invention to provide an integrated process and reactor system for production of liquid fuels from isoalkene-rich hydrocarbons incorporating etherification with alkanol and olefins conversion and transfer dehydrogenation of paraffins, especially branched C4-C5 isoalkanes.

Iso-olefin etherification, upgrading and paraffin transhydrogenation


A method for fabricating a flat band of parallel, contiguous strands or wires using just a single strand or wire. Wire is wound onto a drum to produce a single-wire helix having a predetermined pitch, after which the same wire is wound in a reverse direction onto the drum to produce a second single-wire helix contiguous with the first one. These two winding steps are repeated until a helix having the desired number of contiguous wires has been formed. Unwinding the multi-wire helix from the drum produces the desired flat band of parallel, contiguous wires.

This invention relates generally to methods for forming flat bands of parallel, contiguous strands, and, more particularly, to methods for forming such bands using just a single strand.
Flat bands of parallel, contiguous strands are useful for a number of purposes. For example, the strands can be in the form of wire and the band can be used to produce miniature potentiometer spring contacts. The contiguous wires (e.g., 30 in number) of such contacts are joined together at one end, and the free ends form a set of fingers for making electrical contact with a resistance surface. Examples of such miniature spring contacts and methods for making them are described in U.S. Pat. Nos. 3,579,822, 3,733,573, 3,735,079 and 3,755,892, all in the name of Frank L. Dieterich.
In the past, such long multi-strand bands have typically been formed by joining together wires dispensed from a number of separate spools. This technique has not proven to be entirely satisfactory, primarily because the wires are usually very fine (e.g., 0.002 to 0.005 inches in diameter) and wire damage and breakage can frequently occur. The breakage of just a single wire of the 30 being brought together will usually require a costly interruption in the manufacturing process.
It should therefore be appreciated from the foregoing that there is a definite need for an improved method for producing a lengthy band of parallel, contiguous strands or wires, which is not susceptible to frequent manufacturing interruptions. The present invention fulfills this need.

Method for forming a flat band of parallel, contiguous strands


A cooperatively controlled robotic system includes a main robot assembly, and an arm assembly comprising a proximal end and a distal end. The arm assembly is connected to the main robot assembly at the proximal end. The system also includes a tool assembly connected to the arm assembly at the distal end, a first force sensor between the distal end of the arm assembly and the tool assembly, and a second force sensor between the proximal end of the arm assembly and the main robot assembly. The system includes a control system that is configured to determine a force applied at the first force sensor based on a force detected by the second force sensor, and to compare the determined force to a force detected by the first force sensor to detect a failure of at least one of the first and second force sensors.

1. Technical Field
The field of the currently claimed embodiments of this invention relates to surgical robots, and more particularly to cooperatively-controlled surgical robotic systems with redundant force sensing.
2. Discussion of Related Art
The SteadyHand micromanipulation robot, disclosed in U.S. Pat. No. 8,911,429, which is hereby incorporated by reference, is a force-controlled surgical device with a primary force/torque sensor located between the last joint of the robot and the surgical instrument adapter. When the surgeon applies a force on the handle of the instrument attached to the adapter, the forces and torques measured by the force/torque sensor are resolved at the handle and the robot complies with the forces and torques by moving the instrument in a corresponding direction. The reliability of the primary force/torque sensor is critical to meeting the stringent safety and efficiency requirements common in surgical applications.
Force/torque sensors are susceptible to many modes of failure due to accidents, misuse, or hazards in the environment. They can provide incorrect measurements from temperature changes, electrical noise, or permanent mechanical deformations. The SteadyHand robot uses a force/torque sensor as the main human interaction input for controlling the motion of the robot. In the case where the measurements are incorrect, it is possible that the robot will react in an unexpected and possibly unsafe manner. This is especially undesirable in high-risk scenarios such as surgery where any undesirable motion of the surgical instrument held by the robot could cause severe injury and even death of the patient. In addition, a robot operating in vicinity of humans should be able to detect the intentions of the operator, detect collisions between itself and objects in its workspace, and have intuitive robot interaction methods. Accordingly, improved systems and methods are needed for ensuring accurate force sensing in cooperatively-controlled surgical robots.

Cooperatively-controlled surgical robotic system with redundant force sensing


A folding collapsible table including two stands connected in parallel by a folding connecting plate, two L-shaped extension supports respectively inserted into the stands and locked at the desired elevation by a respective lock, and a folding table plate turned about the horizontal top extension rod of one L-shaped extension support, the folding table plate having grooved coupling plates at the bottom detachably forced into engagement with the horizontal top extension rods of the L-shaped extension supports for permitting the folding table plate to be supported on the horizontal top extension rods of the L-shaped extension supports for serving.

The present invention relates to tables, and relates more particularly to a folding collapsible table which can be conveniently adjusted to the desired height when in use, or folded up into a collapsed condition for storage.
When going to the outside for an outdoor activity, it is difficult to find a place for writing or placing things. There are movable furniture specifically designed for use outdoors. However, these movable articles commonly need much storage space. Furthermore, these movable articles cannot be adjusted to the desired height to fit different users.


A method for generating one or more subsurface stress models. The method may include receiving seismic data. A plurality of first geomechanical property models may be generated based at least partially on the seismic data. A second geomechanical property model may be generated based at least partially on the seismic data. The second geomechanical property model may have a lower resolution than the first geomechanical property models. A stress model, a strain model, or a combination thereof may be generated based on the second geomechanical property model. One or more subsurface stress models may be generated based on the stress model, the strain model, or the combination thereof and the first geomechanical property models.

Seismic inversion data may be used as an input in geomechanical simulations to construct 3D geomechanical property models. The geomechanical simulations may employ stochastic seismic inversion to construct the 3D geomechanical property models. The stochastic seismic inversion may generate a plurality of geomechanical property models that are equally probable. Thus, each model may be further analyzed to predict a final result (e.g., a subsurface stress field model).
It may take several weeks to produce a subsurface stress field model using a particular geomechanical property model. Accordingly, it may take several months or longer to produce subsurface stress field models for each of the equally probably geomechanical property models.

Systems and methods for downscaling stress for seismic-driven stochastic geomechanical models


An apparatus for reducing the transmission of vibrations from an engine to a transmission line having two flywheel elements capable of rotation relative to one another, the first element being drivingly connected to the engine and the second element being drivingly connected to the transmission line. The two flywheel elements are connected by a spring mounting and abutments. A first abutment of the spring mounting is frictionally connected with limited rotational capacity to the second flywheel element. The frictional contact between the first abutment and the second flywheel element is smaller than the frictional contact between the second abutment and the first flywheel element.

The present invention relates to an apparatus for reducing the transmission of engine induced vibration to the drive line. Such an apparatus is the subject matter of the commonly owned, earlier filed U.S. application Ser. No. 829,508, filed on Feb. 14, 1986 and now U.S. Pat. No. 4,724,719. The apparatus described in that application has a split flywheel, with the two flywheel elements arranged on the same axis. The flywheels are drivingly connected to one another by a spring mounting. One of the flywheels is connected to the engine, while the other flywheel is connected to the transmission. An abutment of the spring mounting allocated to one of the flywheel elements is arranged on a second abutment that is frictionally connected to this flywheel element. The second abutment is drivingly connected to the flywheel element, without limiting the rotational capacity of the second abutment relative to the flywheel element, while the strength of the frictional connection is greater than the maximum torque of the engine.
The drive system of a motor vehicle can be designed such that the resonant frequency if at all possible lies somewhat below the idling speed of the engine. Consequently, the resonant frequency is excited virtually only when starting the engine. Thus, travel operation is performed in the so-called hypercritical range, so that the frequency of the vibrations occurring in travel operation is generally considerably higher than the resonant frequency. Only relatively low vibrational amplitudes occur between the device or flywheel elements during travel, a transmission of the vibrations from the engine to the drive line or vice versa being prevented by the spring mounting between the flywheel elements. If, when starting the engine, the resonant range of the device or of the flywheel is run through, the device or flywheel elements execute comparatively large displacement movements relative to one another. However, these movements are effectively damped because the forces transmitted by the spring mounting between the device or flywheel elements exceed the strength of the frictional contact, so that the abutment part frictionally connected to a particular device or flywheel element slips relative to that element.
As long as the forces transmitted between the device or flywheel elements by the spring mounting--such as during the travel of a vehicle--are lower than the strength of the frictional contact, the spring mounting cannot exert any damping effect. This is desirable in the case of the relatively small displacement vibrations that occur in the hypercritical range. However, there are situations in which larger relative movements between the device or flywheel elements can occur even outside the resonant frequency of the drive line. This happens, for example, in the load change between coasting and drive of a vehicle. As the forces occurring in such a load change are often less than the strength of the frictional contact, a damping of the vibrations associated with the load change is not readily possible.
It is therefore an object of the invention to design an apparatus of the initially-mentioned type so that relative movements occurring between the device or flywheel elements are already effectively damped when the forces acting between the device and the flywheel elements in these relative movements are weaker than the maximum engine torque, but stronger than a threshold value to be specified. The maximum engine torque is a predetermined maximum rated engine torque for a particular engine.
This and other objects are achieved by a spring mounting with first and second abutments. The first abutment is frictionally connected with limited rotational capacity to the second flywheel element, while the second abutment, which is arranged on the first abutment, is frictionally connected to the first flywheel element. The frictional contact between the first abutment and the second flywheel element is smaller than the frictional contact between the second abutment and the first flywheel element.
The present invention allows one of the abutment parts to yield or break away even with relatively small torques, and consequently damp relative movements between the device or flywheel elements comparatively early. Only when there are very strong torques or extremely high vibration amplitudes of the relative movements between the device or flywheel elements does the other abutment also yield with a corresponding damping effect.
Thus, the invention ensures a progressive damping of the relative movements of the device or flywheel elements, so that the damping increases with increasing relative movements.
According to a preferred embodiment of the invention, the progressivity can be further improved by each abutment part being frictionally connected to one or both flywheel elements via one or more clutches affected by clearance, the clutches having in each case a different clearance so that, when there is correspondingly strong relative movement of the device or flywheel elements, the effects of the clutches come into action successively with corresponding increase of the respective frictional contact between the abutment part and the particular device or flywheel element.
In a further preferred embodiment of the invention, the abutments are annular discs, radially overlapping one another and having, in the overlap region, cut-outs or windows extending in peripheral direction and overlapping one another which accommodate helical compression springs which are arranged in peripheral direction. The face ends of the springs--seen in axial view--each passes through the planes of the disc. The annular discs forming the first abutment are frictionally connected in the region of their inner periphery by means of coupling laminae to the one device or flywheel element, while the annular discs forming the second abutment are frictionally connected in the region of their outer periphery by means of coupling laminae to the other device or flywheel element. This achieves a space-saving and easily assembled design.
At the same time, it is advantageous if the annular discs forming the first abutment in preferred embodiments have on their inner periphery radial projections which interact in the manner of stops, with clearance in peripheral direction, with counter-projections on the one device or flywheel element or a hub part of the same. It is also advantageous if the annular discs forming the second abutment have on their outer periphery corresponding projections which interact in the manner of stops, with clearance in peripheral direction, with counter-projections which are arranged on the other device or flywheel element or a peripheral rim of the same. In this way, the limited mobility of one of the abutment parts with respect to the allocated device or flywheel element can be ensured very simply.
Further objects, features, and advantages of the present invention will become more apparent from the following description when taken with the accompanying drawings, which show for purposes of illustration only, an embodiment constructed in accordance with the present invention.

Apparatus for reducing vehicle drive train vibrations


A gravity water separation system that may be integrated within a well completion. A diverted flowpath is provided for produced hydrocarbons, external to the completion tubing. As produced hydrocarbons travel through the diverted flowpath, they pass through separation stages wherein gravity separation ensues by migration through predefined flow ports which extend from produced oil “separation chamber(s)” into separated “water chamber(s).”

Growing emphasis on increasing the reservoir recovery factor for subsea well operations provides a stimulus for separation of water from produced hydrocarbons. Additionally, onshore wells very often have to cope with significant water breakthrough (70-80%+ of water in oil (WiO)). Fundamentally, water separation provides significant operational efficiency gains.
Water separation provides for reduction of back pressure on the reservoir by reduction of static hydraulic head (i.e., lower specific gravity of produced fluid in the pipeline, which can be significant in deeper waters and deeper reservoirs) and reduced frictional effects in the subsea pipeline. It may operate at a lower relative flowrate than for the combined oil+effluent volume. The reduction of back pressure on the reservoir and the reduced frictional effects in the subsea pipeline provide an opportunity for increasing total reservoir recovery over field life, by reducing field abandonment pressure, and/or deferring the time at which pressure boosting might be considered necessary, where feasible.
Water separation allows for the reduction in size of export flowline(s) for a given scenario. Reduction in size of export flowline(s) can significantly reduce the total installed cost of the pipeline, particularly on subsea developments where pipeline costs are always a predominant cost factor. Water separation also reduces dependence on chemical injection, which is otherwise required for hydrate mitigation. By eliminating dependence on chemical injection, consumables cost over field life may be reduced.
A need exists for a technique that addresses the emphasis on increasing the reservoir recovery factor for subsea well operations by separation of water from produced hydrocarbons. A new technique in necessary to simplify total system installation and to provide available separation capacity at the earliest point in field life without disruption to production. The following technique may solve one or more of these problems.


A flowmeter based on the pressure difference across a flow resistance element which is an array of surfaces generally parallel to the flow direction, which is operated such that over at least part of its range the Reynolds number is larger than the traditional limiting Reynolds number for laminar flow of approximately 2000. Also, the L/D ratio is shorter than in a traditional laminar flow element, so that for at least part of its range its operation is determined by the behavior of boundary layers forming on those surfaces. Such a flow resistance element provides a pressure drop vs. flowrate relationship which over a wide range of flow conditions is less steep than quadratic. This allows a larger flowrate turndown ratio for a given range of differential pressure measurement. The flowmeter may additionally comprise other sensors and a microprocessor.

This invention pertains to the field of measurement of fluid flowrate.
Among the many techniques for measuring flowrate are those which measure a pressure or pressure difference and then determine flowrate by means of a relationship between that measured pressure and flowrate. Pressure measurements can be measurements at a point (such as a pitot tube), measurements along a line (such as a pitot bar or averaging pitot tube), or measurements which involve the entire flow. The last category of the three categories, i.e., measurements which involve the entire flow, is termed obstruction type flowmeters.
Obstruction type flowmeters are themselves conventionally subdivided into the following three types: orifices, venturis, and nozzles, as described in many basic fluid mechanics texts such as xe2x80x9cFluid Mechanicsxe2x80x9d by Frank White. An orifice is a calibrated opening, usually sharp-edged, of smaller open area than the duct in which it is placed. A pressure drop, which is irrecoverable, exists across the orifice and this pressure drop is also the signal which is measured to indicate the flow. A nozzle is similar to an orifice in that the measured pressure signal is the irrecoverable pressure drop, but the nozzle is more smoothly contoured than an orifice and so produces a smaller irrecoverable pressure drop, if all other parameters are comparable. Finally, a venturi also employs a contraction to an area smaller than the duct in which it is placed, but it has a region of smooth contouring both upstream and especially downstream of the minimum area, in order to reduce the irrecoverable pressure drop. The pressure signal from a venturi is taken by placing one pressure tap at the wall of the minimum-area passage and another pressure tap upstream or downstream at the full-area duct, and taking the difference between those two readings. In contrast to the orifice and nozzle, the pressure signal from a venturi is due mainly to the change in static pressure between the faster-moving fluid at the minimum area and the slower-moving fluid elsewhere. A venturi of course has some irrecoverable pressure drop, but the pressure signal from a venturi is larger, often many times larger, than the irrecoverable pressure drop.
All of these obstruction type flowmeters are most commonly used in a range which is termed turbulent flow or, if not fully turbulent, at least transition flow. As described by the Reynolds number (which is defined as density*velocity*characteristic dimension which would be the minimum diameter of the orifice nozzle or venturi, divided by the viscosity of the fluid), this would be a Reynolds number above approximately 10000. In these flowmeters the relationship between the pressure signal (measured pressure difference) and flowrate is generally quadratic or almost quadratic, i.e., deltap=C*flowrate{circumflex over ( )}n where n is approximately 2. In fact, in calibrating or describing obstruction type flowmeters, the governing relation between pressure signal and flow is usually quoted as deltap=C*flowrate{circumflex over ( )}2, and any departure from that perfectly quadratic relationship is absorbed into a secondary dependence of the proportionality constant C on Reynolds number and perhaps other quantities such as area ratio.
In the design and selection of flowmeters, an important consideration is the so-called turndown ratio, which is the ratio between the maximum and minimum flowrates measurable with the device. A flowmeter with a larger turndown ratio is more versatile and useful than a flowmeter with a smaller turndown ratio. Basically, the turndown ratio for obstruction type flowmeters derives from the fact that any pressure measuring technology has its own range limitation which is similar to a turndown ratio, that is, the usable range of maximum to minimum values of pressure which are measurable with a given accuracy. The maximum measurable pressure difference is determined by the structural limitation of the diaphragm or similar element within the pressure transducer. The minimum pressure difference is determined by considerations of signal-to-noise ratio and desired accuracy. Because of the quadratic or nearly quadratic relation between pressure signal and flowrate, an obstruction type flowmeter does not achieve an especially large turndown ratio for a given ratio of measurable pressures. For example, for traditional orifices nozzles and venturis, achieving a turndown ratio of 10 in flow measurement requires measuring pressures ranging by a factor of 100. Achieving a turndown ratio of 100 in flow measurement requires pressure measurements differing by a factor of 10000. With a single pressure transducer, achieving a pressure reading ratio of 100 is marginally possible and achieving a pressure reading ratio of 10,000 is virtually impossible. The resulting small turndown ratio is one of the significant disadvantages of obstruction type flowmeters. It may be possible to use two pressure measuring devices of different range if the more sensitive device can be exposed to some degree of overpressure (pressure larger than its design range for measuring) without being damaged, but the limitations of the quadratic relationship are still clearly evident. A flowrate-pressure relationship with an exponent of less than 2 would be desirable in order to enable a larger turndown ratio in flow measurements.
The flowmeter of the present invention does not necessarily operate in the laminar flow regime. However, for sake of comparison, it is also useful to discuss here the laminar flow regime. A classical result is that pressure drop is linearly proportional to flowrate, for the situation of fully-developed laminar flow. This means that the exponent of the pressure drop vs. flowrate relationship is 1, which would be attractive for a flowmeter in those circumstances in which it can be achieved. The geometries for which this derivation is most commonly presented are circular tubes and parallel plates. The restriction about laminar flow implies a low Reynolds number. The restriction about fully-developed flow implies a long flow passage, with the pressure drop or velocity profile being observed sufficiently far away from the entrance region, or else with the overall length being long compared to the entrance region so that the principal behavior is that of the fully-developed flow. Flowmeters are commercially available using a laminar flow element, which is an array of many tubes or flow passages of constant cross sectional area which are fluid mechanically in parallel with each other. In order to meet the restrictions of laminar and fully-developed flow, laminar flow elements are designed with a substantially large L/D (D being the diameter of an individual flow passageway, or an effective diameter if the geometry is non-circular), and effort is made to stay at a Reynolds number which is well within the laminar range. For example, literature from Meriam Co., Cleveland Ohio, one of the commercial suppliers of laminar flow elements, recommends use of the devices only at Reynolds numbers below 300. The pressure drop in the use of Meriam""s devices is measured across the entire laminar flow element including the entrance region, which is done on the assumption that the overall length of the laminar flow element is much longer than the length of the entrance (developing flow) region. In another design of laminar flowmeter, U.S. Pat. No. 5,511,416 recommends a maximum Reynolds number of 2000 or preferably 1000 and adjusts the number of available flow passages or flow area to maintain laminar flow by staying below that Reynolds number. In U.S. Pat. No. 5,837,903, Weigand, with respect to a traditional laminar flow element having a large L/D and intending to operate at low Reynolds number, notes and curve-fits a nonlinearity but carefully remains within the laminar flow regime as described exactly or with only slight corrections by the Hagen-Poiseuille Law. In general the literature pertaining to this geometry teaches away from using this geometry for flow measurement at any Reynolds number above the strictly laminar range, i.e., a Reynolds number of several hundred or at most one to two thousand, because if the flow is not strictly laminar the relationship of pressure drop vs. flowrate is not as simple as for the case of strictly laminar flow. Also, the literature pertaining to this geometry teaches that the effect of the entrance region must be minimized by making the laminar flow element so long that the entrance region is only a small fraction of the overall length. The problem with complying with these teachings of the literature about laminar flow elements is that for many flows of practical interest, the laminar flow element would have to become quite large. It becomes large in cross-section in order to reduce the velocity to a small enough value to meet the Reynolds number restriction, and it is long in order to meet the requirement for L/D of a passageway. It then would also need a substantial size of transition region to go from a possibly turbulent pipe section to a large enough cross-sectional area to produce low velocity laminar flow, followed by a similar transition back to the original cross-sectional area.
Accordingly, it is an object of the invention to provide a flowmeter based on pressure measurements, such that a larger flowrate turndown ratio is obtainable than is obtained from conventional orifices, nozzles or venturis, for a given pressure measurement ratio.
It is further an object of the invention to accomplish this without the problems of large size which are associated with a conventional laminar flow element. It is further an object of the invention to accomplish this in a way which can be used at larger Reynolds numbers than can conventional laminar flow elements. It is further an object of this invention to develop a geometry of flow obstruction element for which the pressure drop vs. flowrate relationship has an exponent smaller than 2 at Reynolds numbers larger than those traditionally associated with laminar flow.
Finally, it is an object of the invention in one embodiment to combine this invention with a variation of cross-sectional flow area to obtain a still further reduction in the steepness of the relation between the measured pressure quantity and the flowrate.
This invention is the use of a flow geometry resembling a laminar flow element, i.e., an array of surfaces or passages all of which are substantially parallel to each other and to the general flow direction, but this invention is the use of this geometry at Reynolds numbers which can extend substantially higher than the Reynolds number limitation traditionally taught, and without necessarily adhering to the traditionally taught requirement of long L/D. It has been found that for this geometry at Reynolds numbers higher than traditionally taught, the flowrate vs. pressure drop characteristics are repeatable to good accuracy, and the exponent in the pressure drop vs. flowrate relationship undergoes a smooth, gradual transition from 1 to nearly 2. It is further found that the range over which this transition occurs is so wide (several orders of magnitude in Reynolds number) that this phenomenon provides a substantial range of less-than-quadratic relationship, and it is advantageous to operate in this range which in the past has often been avoided. As a result, it is possible to create a flowmeter operating in this regime whose turndown ratio is larger than previously achievable, for a given pressure measurement ratio. In this regime the relationship between pressure drop and flowrate is not linear as would be the case in laminar flow. However, the relationship is consistent and repeatable and is sufficiently gentler than quadratic that it is worthwhile to use this geometry because it improves the achievable turndown ratio compared to existing obstruction type flowmeters. Various geometries are possible to achieve this including flat plates, honeycomb and others described herein. This invention is essentially a fourth major category of obstruction type flowmeter for turbulent flow, in addition to the orifices, nozzles and venturis already in use.
A further embodiment of this invention deals with the placement of the pressure taps at regions of unequal area, which may be acceptable in some applications. In this embodiment the pressure drop across the flow resistance element has the characteristics just described, but the pressure difference measured to indicate flow has a relationship of measured pressure vs. flowrate which is somewhat gentler than the overall pressure drop.

Flowmeter based on pressure drop across parallel geometry using boundary layer flow including Reynolds numbers above the laminar range


Provided is a single inductor multiple output (SIMO) direct current-to-direct current (DC/DC) converter that may perform DC/DC conversion by transferring, to output nodes, input current that is input and thereby stored in a single inductor. An output selection unit of the SIMO DC/DC converter may select, from output nodes, a first output node to be supplied with current from a driving unit, and provide output voltage of the first output node and reference voltage of the first output node to a hysteresis comparison unit. The hysteresis comparison unit may control on-time and/or inductor peak current by determining whether the output voltage of the first output node is higher than the reference voltage of the first output node by at least a first threshold, and whether the output voltage of the first output voltage is lower than the reference voltage of the first output voltage by at least a second threshold.

1. Field of the Invention
The present invention relates to a direct current-to-direct current (DC/DC) converter, and more particularly, to a DC/DC converter that may supply current supplied through a single inductor through a plurality of output nodes, and a controlling method thereof.
2. Description of the Related Art
Current portable electronic devices may need both long battery lifespan and multi-functions. Due to the above need, a single inductor multiple output (SIMO) direct current-to-direct current (DC/DC) converter may be further popular in a power management system of a portable electronic device.
Unlike an existing converter structure that includes the same number of inductors as the number of outputs in order to generate multiple output voltage, a SIMO DC/DC converter may be configured to include only a single inductor that is supplied with current and thus, may have great advantages in aspects of a circuit area and cost.
Many portable electronic devices, for example, smart phones may be employed for a variety of applications such as a digital signal processing (DSP) operation, an audio and video play, a wireless communication, and the like. Each of the applications may use different magnitude or range of power supply. The SIMO DC/DC converter may be a solution that may satisfy such need.
In addition, when a graphical apparatus operates for video application, relatively great power may be consumed. Therefore, some apparatuses such as a communication apparatus may be in a sleep mode. In this case, power required for each output may continuously vary depending on a device operation. In response thereto, the SIMO DC/DC converter may be used.
As a conventional art that has embodied such SIMO DC/DC converter, disclosed is "Single-inductor multiple-output switching converters with time-multiplexing control in discontinuous conduction mode," prepared by D. Ma et al., on IEEE J. Solid-State Circuits, vol. 38, no. 1, pp. 89-100, in January of 2003.
In the conventional SIMO DC/DC converter, since the number of amplifiers increases in correspondence to the number of outputs and accordingly, compensation circuits need to be used, a circuit area and complexity may significantly increase according to an increase in the number of outputs.
In the conventional SIMO DC/DC converter, since amplifiers and compensation circuits are used, a circuit area and power consumption may increase. Accordingly, the efficiency may be degraded. In particular, a very considerate design may be required to guarantee the stability of circuit.
Accordingly, there is a desire for a highly efficient SIMO DC/DC converter that may cope with various power requirements in response to a request of output nodes and may also provide long battery lifespan while maintaining a circuit area and complexity to be small.

Single inductor multiple output (SIMO) direct current-to-direct current (DC/DC) converter and control method thereof

Korea University Research and Business Foundation


A device includes a resistor string that includes a plurality resistors with voltage taps disposed therebetween. The device may select one particular voltage tap of the plurality of voltage taps based on received gray level data for a pixel of a display. The device also includes a first amplifier that may be coupled to a first terminal end of the resistor string. The device additionally includes a second amplifier that may be coupled to a second terminal end of the resistor string, wherein the plurality of voltage taps may each supply a tap voltage derived from a voltage between the first amplifier and the second amplifier, wherein any tap amplifier of the device coupled to a voltage tap of the plurality of voltage taps provides a reference voltage thereto.

This disclosure relates to electronic displays and, more particularly, to techniques to implement digital to analog converters in an electronic display.
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present techniques, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
Many electronic devices include an electronic display that displays visual representations based on received image data. More specifically, the image data may include a voltage that indicates desired luminance (e.g., brightness) of a display pixel. For example, in an organic light emitting diode (OLED) display, the image data (e.g., pixel voltage data) may be input to and amplified by one or more amplifiers of a source driver circuit. The amplified pixel voltage may then be supplied to the gate of a switching device (e.g., a thin film transistor) in a display pixel. Based on magnitude of the supplied voltage, the switching device may control magnitude of supply current flowing into a light-emitting component (e.g., OLED) of the display pixel.
Display refresh rates continue to increase to allow for improved device performance. Likewise, display bit depths (e.g., the number of bits used to indicate the color of a single pixel) also has been increasing. At the same time, ever increasing demands on electronic devices have increased the relative importance of power consumption of electronic components in a device. Given these trends, designs of existing display circuitry may be revisited.


A cable splicing closure includes a base having ports for the entry of cables to be spliced, and a tubular cover for sliding axially over a peripheral surface of the base. The surface is formed with a groove which tapers towards the end from which the cover is applied and which carries an O-ring seal that is engaged by the cover and which rolls along the tapering surface of the groove as the cover is slid onto the base. The O-ring seal is rolled substantially more than 50 percent, but less than 100 percent, of its peripheral length when it is rolled into its final sealed position. Thus, the O-ring will exert a force in a direction urging the tubular cover more firmly onto the base.

This invention relates to a cable splice closure, particularly for communications cables (including optical fibre cables).
Typically a closure for cable splices comprises a base having ports for the entry of the cables, and a tubular cover which is closed at one end and arranged to fit at its other end around the periphery of the base, the cover when fitted enclosing splices which have been made between the cables. It is necessary to form a seal between the base and the end of the cover and typically a clamping arrangement is used.


A signal processing apparatus includes: a control section; a signal processing section connected with a plurality of signal processing elements and configured to perform signal processing for enhancing or attenuating an input signal in a specific frequency band; and a crossfade signal section including a crossfade signal processing element capable of replacing at least one of the signal processing elements, wherein the control section is configured to control any one of the signal processing elements among the plurality of signal processing elements, and the crossfade signal processing element, to crossfade to the crossfade signal processing element having the signal processing element as a new characteristic, to perform processing for replacing any one of the signal processing elements by the crossfade signal processing element, and to perform the processing on remaining signal processing elements of the plurality of signal processing elements in the signal processing section.

The present disclosure relates to a signal processing technique for performing crossfade processing on a plurality of input signals to output a selected signal. More particularly, the present disclosure relates to a signal processing technique for performing crossfade processing on a plurality of signals whose signal characteristic has been changed using a plurality of signal processing elements.
Related techniques have been disclosed in Japanese Unexamined Patent Application Publication Nos. 2009-302784 and 06-141236.
The disclosures described in the above patent documents relate to techniques for performing crossfade processing on signals.
In an signal processing apparatus in which a signal characteristic is changed by a combination of a plurality of signal processing elements, if a characteristic is changed in a state of inputting one input signal (for example, an audio signal) without a break of the signal, it becomes necessary to perform crossfade processing using a crossfader.

Signal processing apparatus and signal processing method


A method for stabilizing electrodes against dissolution and/or hydrolysis including use of cosolvents in liquid electrolyte batteries for three purposes: the extension of the calendar and cycle life time of electrodes that are partially soluble in liquid electrolytes, the purpose of limiting the rate of electrolysis of water into hydrogen and oxygen as a side reaction during battery operation, and for the purpose of cost reduction.

The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also be inventions.
A wide variety of battery technologies have been developed for portable and stationary applications, including lead acid, lithium-ion, nickel/metal hydride, sodium sulfur, and flow batteries, among others. (See Reference Number 1, below.) Not one of these technologies is commonly used for applications related to the stabilization and reliability of the electric grid do to exorbitantly high cost, poor cycle and calendar lifetime, and low energy efficiency during rapid cycling. However, the development of lower cost, longer lived batteries is likely needed for the grid to remain reliable in spite of the ever-increasing deployment of extremely volatile solar and wind power.
Existing battery electrode materials cannot survive for enough deep discharge cycles for the batteries containing them to be worth their price for most applications related to the electric grid. (See Reference Number 1, below.) Similarly, the batteries found in electric and hybrid electric vehicles are long lived only in the case of careful partial discharge cycling that results in heavy, large, expensive battery systems. The performance of most existing battery electrode materials during fast cycling is limited by poor kinetics for ion transport or by complicated, multi-phase operational mechanisms.
The use of Prussian Blue analogues, which are a subset of a more general class of transition metal cyanide coordination compounds (TMCCCs) of the general chemical formula AxPy[R(CN)6]z.nH2O (A=alkali cation, P and R=transition metal cations, 0≦x≦2, 0≦y≦4, 0≦z≦1, 0≦n), has been previously demonstrated as electrodes in aqueous electrolyte batteries. (See Reference Numbers 1-7.) TMCCC electrodes have longer deep discharge cycle life and higher rate capability than other intercalation mechanism electrodes, and they enjoy their highest performance in aqueous electrolytes. TMCCC cathodes rely on the electrochemical activity of iron in Fe(CN)6 complexes at high potentials. TMCCC anodes, on the other hand, contain electrochemically active, carbon-coordinated manganese or chromium.
The development of a symmetric battery in which both the anode and the cathode are each a TMCCC is desirable because TMCCCs have longer cycle life and can operate at higher charge/discharge rates than other electrode systems. If one TMCCC electrode were to be paired with a different kind of electrode, it is likely that the full battery would not last as long, or provide the same high-rate abilities as a symmetric cell containing a TMCCC anode and a TMCCC cathode.
TMCCC cathodes are well understood, and the operation of a TMCCC cathode for over 40,000 deep discharge cycles has been previously demonstrated. (See Reference Number 2.) These cathodes typically operate at about 0.9 to 1.1 V vs. the standard hydrogen electrode (SHE). (See Reference Number 8.) One challenge for the development of practical batteries using TMCCC cathodes is their trace solubility in aqueous electrolytes. Their partial dissolution into the battery electrolyte can result in a decrease in battery charge capacity due to mass loss from the electrodes and a decrease in efficiency due to side reactions with the cathode's dissolution products.
The development of a TMCCC anode has proven much more challenging than that of TMCCC cathodes because these materials typically have reaction potentials either near 0 V or below −0.5 V vs. SHE, but not in the range between −0.5 V and 0 V that is most desirable in aqueous electrolytes, and because they operate only in a narrow pH range without rapid hydrolysis to manganese dioxide phases. (See Reference Numbers 8-9.) As the useful electrochemical stability window of aqueous electrolytes at approximately neutral pH (pH=5-8) extends from about −0.4 V to 1 V vs. SHE, an anode reaction potential of 0 V results in a cell voltage lower than the maximum that is possible without decomposition of water. But, in the case of an anode reaction potential below −0.5 V vs. SHE, the charge efficiency of the anode can be poor due to rapid hydrolysis of water to hydrogen gas. Finally, if the Mn(CN)6 groups in the TMCCC anode hydrolyze, the capacity of the electrode is rapidly lost.
What is needed is a system and method for stabilizing TMCCC electrodes against dissolution and/or hydrolysis.

Cosolvent electrolytes for electrochemical devices


The present invention facilitates cluster formation within a communications network by utilizing network topology information to designate network nodes that are crucial for relaying traffic as cluster head nodes, while remaining network nodes are designated as member nodes. A beacon packet transmission rate of a network node or the interval between successive beacon packet transmissions by that node is adjusted by the present invention to facilitate cluster formation independent of network size and varying initial start times of network nodes. In addition, the present invention utilizes the above described cluster formation technique to form a three tier architecture for transmission or flooding of routing information from head node databases throughout the network. The cluster formation technique is applied to cluster head nodes to form an additional network tier of super nodes that distribute routing information, while cluster head nodes route network data traffic. The databases of cluster head nodes are examined subsequent to flooding of head node database information by super nodes, where data missing from a head node database is requested from a corresponding super node, thereby eliminating transmissions of acknowledgment messages.

1. Technical Field
The present invention pertains to communication systems. In particular, the present invention pertains to a wireless communication system utilizing network topology information to form clusters for data transmission by a minimal quantity of hops and without regard to initial start times of network nodes. In addition, the present invention pertains to a wireless communication system employing cluster formation to form a multiple tier network architecture and facilitate transmission of node link status messages with reduced protocol overhead traffic.
2. Discussion of Related Art
Generally, certain wireless networks, such as a cellular network, commonly utilize a relay station to forward a message from a mobile cellular unit to a desired destination. The relay station is typically a fixed base station where each mobile unit transmits an outgoing message directly to the base station (e.g., the base station is generally within one hop from the mobile units) for forwarding through a public telephone network to the desired destination. Ad hoc wireless networks (e.g., dynamic wireless networks without any routing infrastructure) are typically employed for military and personal communication applications. These types of networks do not include fixed base stations, but rather employ nodes that each dynamically determine a relay type network node to route traffic. Thus, the ad hoc network node is provided with a difficult task of determining a routing path for data transmission. Since several hops are typically required to facilitate communications, the cellular scheme described above is insufficient for ad hoc networks.
The related art has attempted to overcome the aforementioned problem by providing flat and hierarchical network architectures for data routing. In particular, the flat architecture basically includes a single tier of network nodes in communication with each other. The flat architecture performs adequately with small scale networks, however, overhead traffic increases rapidly and exceeds network capacity in response to increasing network size. The hierarchal architecture basically arranges a network into plural tiers or hierarchical levels. The first tier typically includes clusters or cells each including a plurality of communication nodes or cluster members. One node within each cluster is designated as the cluster head and has full connectivity to corresponding member nodes. The second tier includes a backbone network formed of the cluster head nodes to enable communications between different clusters (e.g., for data transmitted over greater distances). Thus, the first network tier represents each network node, while the second network tier represents cluster head nodes. In operation, a network member node initially transmits a message to its corresponding cluster head node which subsequently forwards the message through the backbone network (e.g., through plural hops of cluster head nodes) to a destination cluster head node associated with a destination member node. Since full connectivity exists between each cluster head node and its corresponding member nodes, the destination cluster head node transmits the message to the corresponding destination member node. This type of architecture is typically employed in communication networks for military applications.
The formation of clusters and designation of cluster head nodes is generally performed dynamically within the exemplary hierarchical network, while the network employs a routing protocol to facilitate communications within the network. The routing protocol is preferably a link-state type of protocol that is implemented on the backbone network (e.g., by the cluster head nodes). The cluster head nodes each include a database that has information enabling the cluster head nodes to determine appropriate paths for routing messages. In particular, each head node constructs a routing table to determine a successive link to transmit a message from that node toward a destination head node. This is accomplished by transmitting or flooding routing information from each head node database among cluster head nodes to synchronize those databases. In order to ensure receipt of database information, a receiving head node transmits an acknowledgment message to a source head node transmitting the database information. If an acknowledgment message is not received within a predetermined time interval, the database information is re-transmitted to the network head nodes that have not acknowledged receipt of the database information. In addition, each network node (e.g., cluster head and member nodes) periodically broadcasts a beacon type or node status packet in accordance with the routing protocol. This packet basically advertises the presence of a node within the network, and is typically utilized by cluster head nodes for "keep alive" and neighbor discovery purposes.
In order to facilitate internet routing or routing between the hierarchical and other external networks (e.g., the Internet), a modified version of the conventional Open Shortest Path First (OSPF) Protocol may be employed. The OSPF protocol is basically a routing protocol employed for Internet Protocol (IP) type networks, while the modified protocol or Radio Open Shortest Path First (ROSPF) protocol is similar to OSPF, but is adapted for use with radio or wireless networks. For examples of implementation of the OSPF Protocol, reference is made to RFC 1583, Moy, "OSPF Version 2," March 1994, the disclosure of which is incorporated herein by reference in its entirety.
Routing is accomplished in the OSPF protocol by each network node having a routing database containing information related to network topology (e.g., links between network nodes). The routing database is utilized by each node to determine a path for transmitting a message to a destination site. The routing databases are updated by exchanging Link-State Advertisement (LSA) packets between neighboring nodes. These packets generally include information related to current links of network nodes and are typically transferred periodically and/or in the event of a modification to the network topology. The OSPF protocol designates a particular router to flood LSA packets to neighbors in broadcast type networks, while LSA packets are transmitted via point-to-point within non-broadcast type networks. The ROSPF protocol employed by the hierarchical network described above is similar to the OSPF protocol and exchanges LSA type packets between neighbors (e.g., cluster head and member nodes) to synchronize routing databases as described above.
The hierarchical architecture may provide significant reduction in routing overhead traffic in relation to the flat architecture depending upon the quantity of cluster head nodes employed. Accordingly, the related art provides several clustering techniques to arrange a network into a hierarchical architecture. Initially, a cluster head node may be utilized to replace the functionality of a cellular network base station and basically serves as a pseudo base station for data traffic within a corresponding cluster. A technique of the related art for cluster head designation and subsequent cluster formation includes determining clusters based on identifiers (e.g., identification codes or numbers) of network nodes. This technique basically designates a network node having a lowest (e.g., or greatest) node identifier as a cluster head. The related art has expanded this technique to utilize a node identifier or a degree of node connectivity to designate a cluster head node, and has further modified the technique to employ interconnected non-overlapping clusters to cover an entire network.
In addition, clustering techniques have been employed for military communication applications and provide a basis for routing protocols. One such technique determines cluster head nodes in accordance with initial random start times of network nodes. Basically, each network node may initiate power or start up at various times, thereby providing a generally random node initiation sequence. A network node is designated as a cluster head node in response to node initiation and determining the absence of neighboring nodes. Thus, nodes having early initiation times tend to be designated as cluster head nodes by this technique. The routing protocol commonly designates cluster head nodes and forms clusters based on network node identifiers (e.g., lowest node identifier is designated as a head node) and certain designation rules.
The clustering techniques of the related art suffer from several disadvantages. In particular, the above clustering techniques generally utilize simple criteria to dynamically designate a cluster head without employing network topology information. In particular, the techniques typically designate a cluster head node based on lowest or greatest node identifier. However, this may result in no direct links between cluster head nodes, thereby requiring additional gateway type nodes (e.g., nodes having communications with two cluster head nodes) to facilitate communication between clusters and increasing the quantity of hops required for communication. The approach according to node random start times may designate a significant quantity of nodes as cluster head nodes, where the designations are typically not optimal selections for a network configuration. Further, this cluster formation technique depends upon the particular sequence of node initiation, thereby enabling particular initiation sequences to facilitate a formation failure. Moreover, the above clustering techniques complicate determination of an appropriate interval between node status packet transmissions. When the interval is set to a value below an acceptable range, large scale networks may become congested. Conversely, if the interval is set to a value above an acceptable range, an extensive time interval is required to complete cluster formation. In addition, the above clustering techniques typically require the initial start times of network nodes to be spaced apart a sufficient interval in order to avoid network failure as the quantity of nodes within the network increases.
With respect to the network architectures for data routing, the flat architecture performs adequately for small scale networks, but as network size increases, the flat network rapidly becomes congested since overhead traffic increases exponentially with network size. The hierarchical architecture reduces overhead traffic relative to the flat network architecture, however, this reduction is insufficient when the network employs on the order of several hundred nodes, thereby limiting application of the routing protocol. Although reliability of flooding node database information throughout a network is enhanced by transmission of acknowledgment messages, these messages increase overhead traffic, thereby degrading network performance.
The present invention overcomes the aforementioned problems by utilizing network topology information to identify network nodes crucial for relaying traffic. The identified nodes are designated as cluster head nodes, while remaining nodes are designated as member nodes. Since cluster head nodes basically serve as relay nodes, the present invention removes the need for gateway type nodes. In other words, the present invention designates a minimum quantity of network nodes as cluster head nodes to achieve connectivity among the nodes. Since the present invention employs a deterministic approach, cluster formation remains substantially the same independently of the initial start-up sequence of network nodes. Further, the designation of cluster head nodes by the present invention is optimal since the designated nodes are crucial for relaying network traffic. Moreover, since the quantity of cluster head nodes that may facilitate communications depends upon the interval between node status packet transmissions, the present invention adaptively adjusts that interval to subsequently facilitate cluster formation independent of network size and varying start times of network nodes.
In addition, the present invention employs a cluster formation technique to form a three tier hierarchical network in order to apply the routing protocol to large scale networks. The cluster formation technique is applied to the cluster head nodes or backbone network to form third tier clusters. Nodes within the third tier distribute routing information from head node databases to reduce overhead traffic, while head nodes within the second tier are utilized for data routing. Further, the present invention reduces overhead traffic by eliminating transmission of acknowledgment messages in response to receipt of the database information. Basically, the present invention examines head node databases and requests third tier nodes to supply missing information. Thus, the present invention only sends request messages in response to receipt of the database information and discovering missing data within head node databases, thereby significantly reducing overhead traffic.

Method and apparatus for communication network cluster formation and transmission of node link status messages with reduced protocol overhead traffic


An apparatus for imaging features of an object constructed from a material that includes a first element in the presence of features constructed from a material that includes a second element. The apparatus utilizes a filtered x-ray spectrum to image the object. The filtered x-ray spectrum is generated from a polychromatic x-ray source having energies below a maximum energy. The maximum energy is greater than a dominant absorption edge of the first element. The filter includes a filter element having a dominant absorption edge greater than or equal to a dominant absorption edge of the second element. The filter removes x-rays that would otherwise be absorbed by the second element, thereby improving the relative contrast of images based on x-ray absorption of the first element.

The present invention relates to x-ray imaging, and more particularly, to x-ray imaging techniques that can distinguish different elemental substances within the object being imaged.
In x-ray transmission imaging, illumination is projected through an object and the imaging signal results from a subtractive process, i.e. what is imaged is the far field of the illuminations minus any signal that was absorbed, reflected or scattered. In many industries x-ray inspection is being used routinely for inspection of products in the manufacturing environments. Many of these applications require that a particular material be examined in the inspection process in spite of the presence of other materials that also absorb x-rays. For example, surface mounted integrated circuits are examined during manufacture to determine the distribution of solder on the assembly, which in turn, is related to the reliability of the assembly. In such systems, Cu traces, Si chips, and Fe in transformers all conspire to obscure, or xe2x80x98shadowxe2x80x99 the solder joints. Similar problems exist today in the use of x-ray imaging in the food processing industry for foreign object identification, the molding and casting industry for real-time mold-fill visualization, the transportation industry for contraband detection, etc. Hence, techniques that provide some specificity to distinguish between the various overlaid features are needed. In the following discussion, xe2x80x9cspecificityxe2x80x9d is defined as the ability to enhance the contrast of one material with respect to the contrast of an interfering material.
One example where specificity has been accomplished is in the medical use of dual energy imaging to measure bone density and/or body fat. By exploiting the fact that bone absorbs x-rays to higher energies, two images are taken using different accelerating voltages in the x-ray tube. Simple algebra is used to combine these images in a manner that accentuates the less or more absorbing x-rays and provide a xe2x80x98bone imagexe2x80x99 or a xe2x80x98fat imagexe2x80x99. However, this technique requires that two images with exact registration must be taken; hence, any motion of the object (patient) shows up as an inaccuracy. Since it takes several seconds to reset the tube energy, these registration artifacts are difficult to eliminate. In principle, two x-ray sources can be used to take the images, but this increases the system cost and requires periodic calibration to register the two sources.
In principle, the desired specificity can be provided by using a single energy source with a detector that has the ability to detect the energies of the x-rays that reach the detector. For example, U.S. Pat. No. 5,943,388 describes a discrete detector for use with a broad energy range polychromatic illumination source. In this approach, active pixels are created by discrete detectors coupled to a multi-channel analyzer that detects each x-ray photon arriving at each pixel. The photons are counted in bins corresponding to a pre-defined set of energy windows. Each energy window corresponds to a different image. By correctly choosing energy windows that are specifically affected by particular materials, significant improvements in specificity can be achieved. Unfortunately, the cost of the detectors for such a scheme significantly increases the cost of the imaging systems.
All of the previously discussed approaches rely on either imaging using two separately produced spectra with differing energy distributions, which requires the complexity of multiple sources or the delays of energy varying in real-time or energy discrimination in the pixelated detector, with the attendant electronic complexity and cost.
Additionally, there are a number of rastering schemes (similar to the operation of a scanning electron microscope) for building up a material-specific image using a well-defined x-ray spot and a single detector in which the image is reproduced pixel by pixel. Unfortunately, the throughput of such schemes is severely limited by two factors. First, it is difficult to focus x-rays (particularly at industrially relevant energies). A small spot must generally be created by collimation, which substantially reduces the flux of x-rays available for imaging. While this problem can be remedied by using a synchrotron to generate a collimated beam of x-rays, such accelerators are too expensive for routine imaging on production lines and the like. This renders these schemes only useful for failure analysis and scientific studies, as opposed to real-time quality control testing. Second, even if sufficient flux is obtained, the object must be moved for each pixel, requiring milliseconds per pixel to move and settle. Hence, these schemes are impractical if large images are needed.
Broadly, it is the object of the present invention to provide an improved apparatus and method for generating x-ray images having improved elemental specificity.
It is a further object of the present invention to provide an imaging instrument and method that is better suited to production line screening and the like.
These and other objects of the present invention will become apparent to those skilled in the art from the following detailed description of the invention and the accompanying drawings.
The present invention is an apparatus for imaging features of an object constructed from a material that includes a first element in the presence of features constructed from a material that includes a second element. The apparatus utilizes a filtered x-ray spectrum to image the object with the aid of an x-ray detector. The filtered x-ray spectrum is generated from a polychromatic x-ray source having a maximum energy that is determined by the absorption spectrum of the first element. The filter includes a filter element having a dominant absorption edge greater than or equal to the dominant absorption edge of the second element and less than the maximum energy. The filter removes x-rays that would otherwise be absorbed by the second element thereby improving the direct interpretation of contrast of images based on x-ray absorption of the first element.

Elementally specific x-ray imaging apparatus and method


This invention is a method to speed up and prevent inconsistent rates of reaction in the reduction of volume of polystyrene foam products by the application of a liquid and vapors of a terpine or isoprenoid compound where a heat activation within 90 days of the use provides maximum reactivity. In one embodiment the process is localized by the addition of heaters in the processing vessels or tanks to insure active agent form of d-limonene reduction agent.

Polystyrene foams have become popular because they are relatively rigid, they are very light, and they are good insulators. As a result of these properties the foamed polystyrene container has a great proportion of the packaging, the food container and the beverage container markets, a total of billions of pounds a year of polystyrene foam in all.
There are problems with the foamed polystyrene product. The lightweight property that makes it so useful is also a major problem. The fine cells of the foam do not easily compact and the product takes large volumes in areas such as landfills and is so fluffy and light it is hard to recycle. As cups break up they tend to float and blow in a most annoying manner and can be a real source of visual pollution. Also, being a synthetic resin, there is little natural degradation of the base polymer so the foam particles stay around for a long time.
The landfill volume and the durability problems have resulted in major unfavorable publicity for the polystyrene foam product industry. While there is more plastic in many paper cups than in a foam beverage cup, the foam cup is very visible and has become a focal point of the debate on recycling. There have been bans on use of polystyrene food containers within towns due to the load placed on landfills, boycotts and picketing of users by concerned citizens and environmentalists, and substitutions of other materials. The uses and advantages of foam continue but there is a growing movement to require recycling of foam products as well as other plastic materials. A need exists to make polystyrene foam either landfill volume compatible with other types of trash or to find an effective way to recycle it.
In the case of polystyrene foam products, recycling is not easy. In one well documented case, McDonalds in Rochester, NY pledged to recycle from three outlets located in that city. The polystyrene is segregated in separate containers on the floor of the food service area by customers and the bags of foam product from those containers are removed when full and stored. At regular intervals the foam filled bags are trucked to the nearest recycler in Springfield, MA. The truck which is a standard 45 foot trailer and tractor normally would hold up to 40,000 pounds and the cost of the trip, approximately $1500 would amount to a net cost of under 4 cents per pound. The lightweight foam is not a normal material and in the bagged foam a typical load is only 1000 pounds which increases the cost to $1.50 per pound for shipping. For a material that sells as virgin resin pellets in the $0.50 to 0.60 per pound range, the shipment costs alone are nearly three times the maximum value of the recycle. There is a pressing need for volume reduction of foams to make shipping effective.
The problem with recycle does not stop at the shipment costs since a very high volume of material that weighs little must still be reprocessed. The lightweight foam must be reduced in some manner. As noted above it is a good insulator so thermal softening of the foam to compact it requires long times and during these extended low level heatings the resin may be degraded. Compaction by normal means is totally ineffective due to the multiplicity of cells that must be broken. Several methods have been developed such as the poly puff where material is compacted by shear heating against the sides of a drum as a rapidly rotating rotor mixes and stirs the material and use of crammers and enlarged feed section extruders. None of these methods are very effective in reducing foam volume and there is a need for an effective way to introduce foam materials to an extruder or other reprocessing machine.
Once in a typical extruder the normal screw would compact resin by a ratio of under 3 to 1. This compaction is due to a change in the depth of the root of the screw and in addition in some screws it would also be due to a change in the pitch of the screw. As noted before the foam can be reduced thirtyfold before the foam is completely broken down. A screw with flight depth to accomplish a 30:1 volume reduction would not have enough strength to turn due to the extreme depth needed in the root at the feed area and the very narrow outlet end would overshear the polymer and overheat or degrade it. There is a need for a foam volume reduction method to allow use of more normal plastic recycle and processing equipment. At present extra compaction steps and very expensive and specialized equipment is required to recycle polystyrene.
One aproach to the recycling is to use chemicals to reduce the foams. The basic problem is that the chemicals that are obvious are very toxic to the environment and they are often banned by SARA or similar environmental legislation. One chemical series, pinene and terpenes such as d-limonene to reduce the foam volume. This approach is interesting but it fails in some cases. There is an inconsistent activity in collapsing foams that has not previously been noticed. There is a need for such a process but that process must be rapid and effective to have commercial value.
In general all of these problems at present make the recycling of polystyrene foam non-economic and as a result it will not become a commercially viable concept until the shipment and extrusion of polystyrene foams can be reduced in cost. It will also be needed to improve the methods of converting the foams back into pellets or products for further use of the recycled polystyrene.

Reduction in polystyrene with activated agent


Proposed is a device for detecting a chemical/physical phenomenon, in which, via a novel scheme, charges are accumulated in a charge accumulation region. An amount of charges thus accumulated reflects the potential of a sensing region and the potential corresponds to an external environment (chemical phenomenon or physical phenomenon) to be detected. A charge accumulation region 5 includes a first potential well region FD1 that is continuous with a sensing region 3, the boundary potential of the charges held in the first potential well region FD1 being made equal to the potential of the sensing region 3, whereby the potential of the sensing region 3 is made to be reflected in the amount of charges held in the first potential well region FD1.

As a chemical/physical phenomenon detecting device, a pH sensor disclosed in Patent Document 1 is known.
In a conventional chemical/physical phenomenon detection device, charges existing in a sensing region are transferred to a charge accumulation region and accumulated therein, the charges thus accumulated are measured to identify chemical phenomenon or physical phenomenon to be detected.
By surrounding the sensing region with a weir of a predetermined potential, a potential difference between the potential of the weir (e.g. TG region) and the potential of the sensing region is proportional to the amount of charges that can be present in the sensing region. Since the potential of the sensing region changes according to the change in the chemical phenomenon or the physical phenomenon (external environment) to be detected, the change in the external environment is reflected in the potential difference between the potential of the sensing region and the potential of the weir. The sensing region can hold an amount of charges corresponding to the environment exists. Charges in the sensing region are transferred to the charge accumulation region by changing the potential of the TG region that is a part of the weir.

Device for detecting chemical/physical phenomenon

NATIONAL UNIVERSITY CORPORATION TOYOHASHI UNIVERSITY OF TECHNOLOGY


A method of processing signals may include identifying a plurality of critical elements of a parameter vector based on one or more predefined criteria, wherein the parameter vector represents a relationship between the input signal vector and the output signal vector; identifying a reduced parameter update vector having a plurality of elements, wherein the elements are selected according to a criterion related to the relationship between the input signal vector and the output signal vector; updating the plurality of critical elements of the parameter vector using the reduced parameter update vector to generate an updated parameter vector, wherein the reduced parameter update vector has less elements than the parameter vector; and processing one or more signals associated with the input signal vector using the updated parameter vector.

Many conventional wireless devices perform both wireless transmission and reception and therefore contain both transmitter and receiver components (i.e. transceivers). Transceiver designs may include such transmitter and receiver components arranged in close proximity another, and there often may exist a level of indirect or shared coupling between the components. As a result, many transceiver designs may be susceptible to leakage between the transmitter and receiver chains.
Leakage may be especially prevalent in single or shared antenna systems, where the transmitter and receiver chains may both be coupled to duplexing circuitry. Accordingly, leakage from the transmitter chain to the receiver chain may result in self-interference, where a signal intended for transmission is imposed onto a received signal.
As the transmitted signal is known at the transceiver, it may be possible to model the path between the transmitter and receiver chains in order to cancel out the leakage signal from the signal at the receiver.

This patent is subject to a terminal disclaimer.

Transceiver device and method of processing signals


The invention relates to a benzoic acid salt of methyl(2R,3R)-2-{3-[amino(imino)methyl]benzyl}-3-{[4-(1-oxidopyridin-4-yl)benzoyl]amino}butanoate, and to a benzoic acid salt of methyl(2R,3R)-2-{3-[amino(imino)methyl]benzyl}-3-{[4-(1-oxidopyridin-4-yl)benzoyl]amino}butanoate which is in a crystalline form or in at least partially crystalline form, as well as a process for the preparation of the same, methods of using such salt to treat subjects suffering from conditions which can be ameliorated by the administration of an inhibitor of Factor Xa.

Methyl(2R,3R)-2-{3-[amino(imino)methyl]benzyl}-3-{[4-(1-oxidopyridin-4-yl)benzoyl]amino}butanoate, (CAS number 193153-04-7) has the International Nonproprietary Name Otamixaban and shows the structure illustrated in Formula II:

Methyl(2R,3R)-2-{3-[amino(imino)methyl]benzyl}-3-{[4-(1-oxidopyridin-4-yl)benzoyl]amino}butanoate use in the preparation of a medicament for treating a patient suffering from, or subject to, conditions which can be ameliorated by the administration of an inhibitor of Factor Xa has been disclosed in WO97/24118.
Factor Xa is the penultimate enzyme in the coagulation cascade. Factor Xa (fXa) is a critical serine protease situated at the confluence of the intrinsic and extrinsic pathways of the blood coagulation cascade. FXa catalyses the conversion of prothrombin to thrombin via the prothrombinase complex. Its singular role in thrombin generation, coupled with its potentiating effects on clot formation render it an attractive target for therapeutic intervention.
Both free factor Xa and factor Xa assembled in the prothrombinase complex (Factor Xa, Factor Va, calcium and phospholipid) are inhibited by Otamixaban. Factor Xa inhibition is obtained by direct complex formation between the inhibitor and the enzyme and is therefore independent of the plasma co-factor antithrombin Ill. Effective factor Xa inhibition is achieved by administering the compound either by continuous intravenous infusion, bolus intravenous administration or any other parenteral route such that it achieves the desired effect of preventing the factor Xa induced formation of thrombin from prothrombin. In vivo experiments have demonstrated that Otamixaban is highly efficacious in rodent, canine and porcine models of thrombosis. In addition, recent clinical findings indicate that Otamixaban is efficacious, safe and well tolerated in humans and therefore has considerable potential for the treatment of acute coronary syndrome (K. R. Guertin and Yong-Mi Choi; 2007; Current Medicinal Chemistry, Vol. 14, No. 23; p. 2471-2481). Clinical findings in a dose-ranging clinical trial indicate that Otamixaban reduced prothrombin fragments 1+2 significantly more than unfractionated heparin at the highest dose regimen (Cohen et al., Circulation, Vol. 115, No. 20, May 2007, pages 2642-2651), but said clinical findings do not show data in comparison of age or renal impairment. Further clinical trials demonstrated that Otamixaban induces dose-dependent, rapid direct factor Xa inhibition in patients with stable coronary artery disease who are taking their usual comedication, some of whom have mild renal impairment (Hinder et al., Clinical Pharmacology and Therapeutics, Vol. 80, No. 6, 2006, pages 691-702).
A crystalline form of methyl(2R,3R)-2-{3-[amino(imino)methyl]benzyl}-3-{[4-(1-oxidopyridin-4-yl)benzoyl]amino}butanoate hydrochloride, 2-butanol hemisolvate is disclosed in U.S. Pat. No. 7,034,160. The crystalline form of (methyl(2R,3R)-2-{3-[amino(imino)methyl]benzyl}-3-{[4-(1-oxidopyridin-4-yl)benzoyl]amino}butanoate hydrochloride, 2-butanol hemisolvate contains 2-butanol as a solvate which is not favourable for use in solid pharmaceutical compositions and is a hygroscopic compound.
Hygroscopicity is the ability of a substance to attract and hold water molecules from the surrounding environment through either absorption or adsorption with the adsorbing or absorbing material becoming physically 'changed,' somewhat, increase in volume, stickiness, or other physical characteristic changes of the material as water molecules become 'suspended' between the material's molecules in the process. Therefore hygroscopic compounds are generally very unfavorable for use in solid pharmaceutical compositions.
It is an object of the present invention to find a salt of methyl(2R,3R)-2-{3-[amino(imino)methyl]benzyl}-3-{[4-(1-oxidopyridin-4-yl)benzoyl]amino}butanoate with reduced absorption or adsorption of water molecules from the surrounding environment. It has been found that a benzoic acid salt of methyl(2R,3R)-2-{3-[amino(imino)methyl]benzyl}-3-{[4-(1-oxidopyridin-4-yl)benzoyl]amino}butanoate has favorable reduced absorption or adsorption of water molecules from the surrounding environment.


A magneto-optical data reading member includes a transparent disk substrate, and land-shaped areas formed on the disk substrate in a spiral manner so as to be parallel with each other, and groove-shaped areas formed to be stepped with respect to the land-shaped areas, wherein each of the land-shaped and groove-shaped areas has, in a surface region thereof, a first magnetic film for reading data having a predetermined Curie temperature and a predetermined magnetic coercive force, and a second magnetic film for reading data, formed on the first magnetic film, having a Curie temperature higher than the predetermined Curie temperature and a magnetic coercive force higher than the predetermined magnetic coercive force, and having a plurality of memory pits in series according to the information data to be recorded.

1. Field of the Invention
The present invention relates to a photomagnetic data memorizing apparatus, e.g., a photomagnetic data memorizing disk apparatus capable of performing high-density data write.
2. Description of the Related Art
Conventionally, to write data on a photomagnetic disk, a laser beam is radiated on a magnetic film while a magnetic field is applied to the magnetic film, so that part of the film the temperature of which is increased to a predetermined value (Curie temperature) or more and which has thus lost its coercive force is magnetized, thereby forming a memory pit. To read data, a low-temperature laser beam necessary for data read is spot-radiated, and light reflected by the disk surface is read.
However, the size of a memory pit which can be read is limited by a detecting limit determined by a laser wavelength and a numerical aperture of a lens.
A photomagnetic disk in which the magnetic film has a two-layered structure is experimentally manufactured. One of the two layers is used as a mask to cover pits other than one memory pit from which data is to be read, so that data can be read from memory pits formed at a smaller pitch than the spot diameter of the read beam. In this case, the write wavelength is a short wavelength of less than half the conventional detection limit, and the resolution is increased to twice or more.
According to this technique, a temperature difference is present within a beam spot (Gaussian distribution) formed by beam radiation during reading, and pit reading is enabled only from a high-temperature area within the beam spot. Therefore, the same effect as that obtained when the read beam spot area (diameter) is decreased can be obtained accordingly, and high-density data write can be realized by using the optical system of an existing photomagnetic disk apparatus.
However, although high-density data write can be realized by using the existing laser optical system, no attempt has been so far made to put this idea in practical use, and associated techniques for further increasing the data write density are not sufficient.

Disk having data memorizing portion including land-shaped and groove-shaped areas, and writing/reading apparatus for the same


An analog switch having a low capacitance is achieved. Potentials of input/output terminals of the analog switch and a well potential and a gate potential of an NMOS switching device are operated in synchronization via level shift buffers, thereby cancelling parasitic capacitances present between these elements.

Japanese Patent Application Laid-Open Publication No. H06-169247 (Patent Document 1) discloses an example of a circuit in which a PMOS and an NMOS are connected in parallel as a switching device, which mainly aims to reduce a conducting resistance by controlling a well potential.
Japanese Patent Application Laid-Open Publication No. 2002-135099 (Patent Document 2) discloses an example of a circuit in which a PMOS and an NMOS are connected in parallel as a switching device and a gate potential and a well potential are controlled, and which mainly aims to prevent a current inflow when applying a high voltage upon turning off the power.