A method for operating an internal combustion engine. The latter has at least one combustion, one induction pipe, and one throttle valve. From the actual position of the throttle valve, a gas charge of the combustion chamber is defined. To improve the emissions and fuel consumption characteristics of the internal combustion engine, the minimum gas pressure is measured that exists in the induction pipe assigned to the combustion chamber at the end of the intake stroke. From this gas pressure, a value is determined which more closely approximates the actual gas charge of the combustion chamber.

The present invention relates to a method for operating an internal combustion engine having at least one combustion chamber, one induction pipe, and one throttle valve.
In modern internal combustion engines having direct fuel injection and/or having an electronic gas pedal, the quantity of gas to be introduced into the combustion chamber is determined, inter alia, according to the quantity of fuel to be injected into the combustion chamber. This is necessary, inter alia, in order to generate a mixture in the combustion chamber in which combustion-generated emissions and fuel consumption are minimized. In this context, the quantity of gas, or the xe2x80x9cgas charge,xe2x80x9d is defined as a function of the actual position of the throttle valve, because the assumption is made that at a defined throttle position only a certain quantity of gas can reach the combustion chamber.
However, the problem in defining the gas charge of the combustion chamber in this manner is that the throttle valves themselves are manufactured within certain tolerances, so that when different throttle valves are set at the same angle, the result can be differing gas charges in corresponding combustion chambers. The gas charge actually present in the combustion chamber can therefore differ from the gas charge defined by the throttle valve position in ways that are not immediately predictable, which makes the creation of an optimal mixture dependent on the accidental presence of a xe2x80x9cstandard throttle valve.xe2x80x9d
The present invention therefore has the objective of refining a method of the type cited above so that the mixture can always be adjusted with great precision.
This objective is achieved as a result of the fact that the minimum gas pressure is measured that is present in the induction pipe assigned to the combustion chamber at the end of the intake stroke, and that from this a value is determined which better approximates the actual gas charge of the combustion chamber.
The method according to the present invention is based on the following consideration: In an internal combustion engine having one intake valve, the piston at the beginning of the intake stroke is located in the upper dead center and then travels to the lower dead center. In this context, the quantity of gas behind the throttle valve continually expands in volume. This has the consequence that the pressure falls. In the lower dead center, the maximum volume and therefore the minimum pressure is achieved. Shortly thereafter, the intake valve closes. At this point in time, roughly the same pressure exists in the combustion chamber as in the induction pipe. By taking account of the characteristic data of the internal combustion engine, the gas charge in the combustion chamber can be calculated from this minimum pressure. Since this gas charge is calculated from the gas pressure that actually exists in the induction pipe, the leakage through the throttle valve and behind the throttle valve due to manufacturing tolerances is taken into account in the gas charge. This value is therefore more precise and can be used to produce mixtures more precisely. The pressure in the induction pipe is preferably measured by a sensor provided in the induction pipe.
In one very advantageous refinement, a gas charge of the combustion chamber is defined from the actual position of the throttle valve, the defined value is compared with the measured value, and then, if the comparison shows that the difference between the measured and the defined gas charge lies outside of a permissible range, the position of the throttle valve is corrected. Therefore, in this refinement, the gas charge measured from the minimum gas pressure and the gas charge defined by the actual position of the throttle valve are combined with each other. In this context, by determining a permissible range, a range of tolerance created, which makes it unnecessary to resort to control interventions too frequently.
In this context, the correction takes place preferably so that the difference between the measured and the defined gas charge is equal to zero. This means that the gas charge is optimized.
The above-mentioned method is particularly well suited for internal combustion engines that have a plurality of combustion chambers and also is particularly well suited for internal combustion engines in which each combustion chamber or a group of combustion chambers (e.g., a cylinder bank) has assigned to it its own induction pipe and its own throttle valve. For this reason, it is proposed in one refinement that the above-mentioned method be carried out independently for a plurality of combustion chambers having their own induction pipe and especially their own throttle valve. In this way, for each individual combustion chamber or for each group of combustion chambers, a value can be calculated which more closely approximates the actual gas charge of this individual combustion chamber, and the position of the throttle valve. assigned to this combustion chamber can be corrected. In this manner, the emissions and fuel consumption characteristics of the individual cylinders of the internal combustion engine are optimized.
Correcting the position of the throttle valve can take place in varying ways. One possibility is to correct an offset, usually taken into account in calculating the gas charge, and a slope. This offset is a value which makes it possible to take into account the air leakage streams through gaps between the throttle valve and the wall of the induction pipe and through other leakage points between the throttle valve and the combustion chamber. The slope takes into account the multiplicative errors in the throttle valve system. In response to a difference between the value for the gas charge defined by the actual position of the throttle valve and a value calculated on the basis of the minimal gas pressure, it can be assumed that the offset and the slope do not optimally reflect the actual reality. This can be partially compensated for by correcting the offset as proposed in accordance with the present invention. The same applies to the slope. In this context, the correction can take place in a multiplicative manner, meaning a change in the slope, or in an additive manner, meaning a change in the xe2x80x9coffset.xe2x80x9d A correction of the offset and/or the slope is recommended especially in response to generally low pressure levels in the induction pipe, i.e., in an operating state in which the throttle valve is closed relatively far, because in an operating state of this type the aforementioned leakage streams play a relatively large role.
Intervening in the control of the throttle valve position has the advantage over regulating the throttle valve position directly on the basis of the pressure-based gas charge that the optimal gas charge can be achieved more rapidly and without transient effects. Calculating the gas charge on the basis of the throttle valve position makes it possible to react immediately to a change in the driver""s requests. On the other hand, the minimum pressure in one cylinder can only be measured anew after an entire rotation of the camshaft.
At an overall high induction pipe pressure, as is also mentioned in one refinement of the present invention, the regulation of the throttle valve position is influenced. In addition, it is also possible to influence the calculation of a setpoint value of the throttle valve. Both measures make it possible to react quickly to differences between the defined and the measured values.
The precision of the above-mentioned method is even more improved in one refinement which, in calculating the gas charge, takes into account the partial pressure of the internal residual gas.
The present invention also relates to a computer program, which is suited to carrying out the above-mentioned method, if it is executed on a computer. In one preferred refinement of this computer program, it is stored in a storage device, in particular in a flash memory.
Finally, the present invention relates to a control and regulating unit for an internal combustion engine, especially of a motor vehicle, having at least one combustion chamber, one induction pipe, and one throttle valve, the unit defining a gas charge of the combustion chamber from the actual position of the throttle valve. To improve the emissions and fuel consumption behavior of the internal combustion engine, the control and regulating unit is connected to a pressure sensor arranged in the induction pipe, and it determines a value that more closely approximates the actual gas charge from the minimal gas pressure existing in the induction pipe assigned to the combustion chamber at the end of the intake stroke.
Especially preferred is the refinement of the control and regulating unit, in which, if the comparison shows that the calculated gas charge of the combustion chamber does not roughly correspond to the defined gas charge, then a correction signal for the position of the throttle valve is generated.
Finally, a control and regulating unit of this type is particularly advantageous if it is suited for internal combustion engines having a plurality of combustion chambers and a plurality of pressure sensors and throttle valves each assigned to one combustion chamber. This is the case in the refinement in which the control unit is connected to a multiplicity of pressure sensors, each assigned to one combustion chamber, and, in particular, generates a plurality of independent correction signals for the corresponding throttle valves.

Method, a computer program, and a control and regulating unit for operating an internal combustion engine


A lead acid cell having unitized positive and negative electrodes positioned within a container such that the respective edges of the positive electrode are spaced apart from the edges of negative electrode. The electrodes are each made up of at least one plate having a major surface with a composition thereon for imparting a negative or positive polarity. The plates of each electrode have first and second edges in which the second edges are connected to an associated current collector and the first edges of each electrode oppose each other in spaced apart relation.

Lead-acid batteries have long been used as a power source for automotive starting, vehicular traction, emergency lighting, powering portable tools and appliances, and standby power. Additionally, these batteries are believed to be useful in improving the economics of power generation via load levelling or peak power shaving (i.e., storage of power generated during off-peak hours to supplement that generated during times of peak demand). However, economic load-levelling storage batteries require large cells of high capacity, a long life in cycling service, high quality assurance and a minimum of maintenance. Also, economic recovery and recycling of the large quantity of raw materials involved is such batteries is highly desirable.
Lead-acid batteries suitable for load-levelling service are normally classified as either "flat-plate" or "tubular." In each case, the battery consists of a number of individual cells, each of which contains one or more positive electrodes and one or more negative electrodes which are immersed in a sulfuric acid electrolyte and electrically insulated from one another by an acid-resistant porous separator. All positive electrodes within a cell are electrically connected in parallel as are all negative electrodes within a cell. The capacity of each cell is controlled by the amount of positive and negative active material in the cell and by the number of electrodes and the length, width, and/or thickness of such electrodes. The rate at which a cell discharges is controlled by the surface area of the electrodes available for reaction and can be changed by varying the number of electrodes and/or the surface area of each electrode within a cell.
One method of increasing the surface area of battery electrodes, disclosed in U.S. patent application No. 315,722 is profiling the paste layer on each side of the electrode. An ideal deep-cycling storage battery is one in which both the amount of positive and negative active materials and the surface area of the positive and negative plates can be maximized within a given cell volume.
Typically, large flat-plate cells and batteries used in deep-cycle service, include positive and negative plates positioned such that each pasted positive plate side surface faces, and is oriented essentially parallel to, a pasted negative plate side surface of equivalent area. For the positive and negative plates, the preferred pastes are comprised of lead oxide, water, sulfuric acid and binder as the positive paste composition and lead oxide, water, sulfuric acid, binder and expander as the negative plate composition. The plates are normally separated from one another by one or more layers of porous electrically insulating materials, typically made from glass fibers and porous polymeric materials. In one such cell construction, described in U.S. Pat. No. 4,447,508, the positive plate is separated from the negative plate by three layers of insulating material, one of which is wrapped around the positive plate, and one layer of insulting retainer material. This type of battery involves both high labor cost and high material costs. Additionally, it is difficult to increase the capacity of flat-plate cycling batteries by increasing the size or number of plates because of plate growth, a prevalent cause of failure in prolonged cycle service.
In large tubular-type cells and batteries used for deep-cycle service, the positive electrodes normally consist of a one-piece cast lead conductor in the form of a series of parallel spines projecting downward from a single connecting strap, porous sleeves which are closed at the bottom and positioned relative to said spines in a manner which results in an annular space between said spine and said sleeve along the entire length of the spine, and loose positive active particulate material which is vibrated into the annular space. The negative electrode is normally of the pasted flat-plate type described above. -t is typically positioned such that a sole pasted surface of the negative electrode faces and is parallel to a sole positive electrode surface of equivalent area, and spaced apart from the outer surface of the positive electrode by a porous polymeric ribbed sheet separator. As in the case of flat-plate cells, tubular-type cells consisting of a plurality of positive electrodes, a plurality of negative electrodes and a plurality of complex separators, are difficult to manufacture and inherently costly.
To overcome some of these problems, it is now possible to process lead-acid battery plate stock in continuous form. It is known that continuous grid casting, as described in U.S. Pat. Nos. 4,349,067 and 4,415,010, and continuous metal expansion, as described in U.S. Pat. No. 3,853,626, can be used to produce continuous lengths of battery grid stock which can be passed directly into a continuous pasting machine, such as that described in U.S. Pat. No. 4,271,586. The stock exiting the continuous paster is normally cut into individual grids, but it may be cured in coil from, as disclosed in pending U.S. patent application No. 315,722 and electrochemically formed prior to being divided into individual plats, as disclosed in pending U.S. patent application No. 361,029.
One cell construction utilizing pasted plate stock in continuous form is described in U.S. Pat. No. 3,862,861. It incorporates a continuous length of positive plate stock and a continuous length of negative plate stock positioned such that the pasted positive plate surface is opposite and parallel to the pasted negative plate surface and separated therefrom by continuous separator material. The cell is produced by coiling the aforesaid three-piece composite to form a "jelly-roll" structure which is then placed in a battery container.
A major problem inherent in both large flat plate batteries and a tubular batteries is stratification of the sulfuric acid electrolyte, i.e., the tendency for the electrolyte to separate into a layer of high specific gravity at the bottom of the cell and a layer of low specific gravity at the top of the cell. The high gravity layer at the bottom of the cell accelerates sulfation of the negative plate which reduces cell capacity, and the low gravity layer at the top of the cell increases the tendency towards corrosion of the positive grid which increases the electrical resistance in the cell and, eventually, results in failure of the plate. Acid stratification becomes more pronounced as the height of the cell increases.
One commonly used method to overcome acid stratification is bubbling air through the electrolyte; however, this is costly. Another commonly used method is overcharging the cell to generate gas which mixes the electrolyte, but this technique increases electrolyte loss and maintenance costs and shortens cell life.
Recombination of the gases generated during charging is also a widely used means of minimizing, or eliminating, electrolyte loss. One method of accomplishing such recombination in absorbed electrolyte cells containing flat vertical plate electrodes is described in U.S. Pat. Nos. 4,401,730 and 4,119,772 and involves the reaction of oxygen gas generated at the positive electrode with excess negative active material which is not covered by electrolyte. A similar approach is described in U.S. Pat. No. 4,425,412, which discloses a cell with improved deep-cycle capability based upon a plurality of horizontally disposed positive plates, a plurality of horizontally disposed negative plates, and free unabsorbed electrolyte, in which all active plate surfaces are submerged in electrolyte except the entire uppermost pasted surface of the top negative plate which is free to take part in the recombination reaction. The benefits obtained from the horizontal disposition of the battery plates described in U.S. Pat. No. 4,425,412, are limited to small cells, because in cells containing large plates, the movement of gas and electrolyte within the cell is restricted. Recombination can also be accomplished by the incorporation of a separate non-lead catalyst, as described in U.S. Pat. No. 3,470,024. Both the incorporation of excess negative active material and the use of separate catalysts, however, lower the cell efficiency.
Another factor which reduces the efficiency of large power cells is the increased electrical resistance resulting from the small size and off-center locations of the plate lugs which connect the battery plate to the external electrical contacts of the cell. As illustratively shown in U.S. Pat. Nos. 4,742,611 and 4,509,253, these plate lugs are situated towards one end of the plate and have a cross-sectional area parallel to the upper border of the plate that is normally less than 15% of the cross-sectional area of the upper border when that border is sectioned along the length of the battery plate. The off-center location and reduced cross-sectional area of the lug increases the length of the current-carrying path and, thus, the internal resistance of the cell.
A 2,000-volt, 10 megawatt lead-acid battery energy storage system has been developed utilizing 8,256 cells arranged in 8 parallel strings, each containing 1,032 cells connected in series. The battery includes provision to supply compressed air to each of the individual cells in order to circulate the electrolyte as a means of avoiding acid stratification. It also includes a 7,500-gallon water storage tank and distribution lines to each cell. In operation, the system requires 14 mandays of labor twice per year to water the cells, and utilizes approximately 2,000 tons of lead which must be recycled at the end of life.
While lead-acid storage batteries are suitable for deep-cycling service requirements, there are many limitations. Accordingly, it is an object of the present invention to provide an improved battery structure which reduces or eliminates many of the problems normally associated with the prior art lead-acid storage batteries.

Lead-acid storage battery and related method of construction


A valve includes a cover that is transparent and configured to allow a valve orientation to be visible through the valve cover. The cover may couple to existing mounting bolts of the valve operator housing such that the cover may be retrofitted onto existing valves. The cover may be sized and shaped to prevent water, or other weather, ingress into the valve operator housing.

The efficient transportation of petroleum products (crude oil, gasoline, chemicals, natural gas) is critical to meeting the world's energy demands. Pipelines, rail cars, tankers, ships, and trucks all work in harmony in the transportation network to deliver energy to consumers. One of the most critical components of this network is the pipeline. North America alone depends on over 185,000 miles of liquid petroleum pipelines, 320,000 miles of gas transmission pipelines, and more than two million miles of gas distribution pipelines.
Pipelines are often located above ground and susceptible to natural weather, such as rain, snow, hail, wind, etc. Maintenance along the pipeline may cause significant lost profits and downtime.


The present description relates to a method for notifying at least one node being used from among a plurality of nodes in a multi-node system including the plurality of nodes and a base station for controlling the plurality of nodes, wherein the method comprises a step in which a terminal determines, from the table preemptively shared with the base station, an index for indicating at least one node to be notified; and a step in which the terminal performs communication with the base station using the determined index.

Recently, the data transmission capacity of a wireless (or radio) communication network has been increasing at a vast rate. This is due to the advent and supply of diverse devices, such as smart phones, tablet PCs, and so on, which require Machine-to-Machine (M2M) communication and a high data transmission capacity. Technologies efficiently using a larger number of frequency bands, such as a carrier aggregation technology, cognitive radio technology, and so on, and technologies for increasing the data capacity within a limited frequency, such as multiple antenna technology, coordinated multiple base station technology (or coordinated multi-point technology), and so on, have recently been highlighted for being capable of meeting with the required high data transmission capacity.
Additionally, the radio (or wireless) network is evolving into a network having greater node density capable of accessing the surroundings of a user. Herein, although a node may refer to an antenna of a group of antennae being spaced apart from a distributed antenna system (DAS) at a predetermined distance, the meaning will not be limited only to this and may, therefore, be used to have a broader meaning. More specifically, a node may correspond to a pico-cell base station (PeNB), a home base station (HeNB), an RRH (remote radio head), an RRU (remote radio unit), a relay, a distributed antenna, a port, and so on.
A wireless (or radio) communication system being equipped with such high-density nodes may demonstrate a greater system performance due to the coordination (or cooperation) between the nodes. More specifically, when each of the nodes has its transmission and reception (or tranception) managed by a single control station, so as to collectively operate as an antenna (or antenna group) of a single cell, a more excellent system performance may be demonstrated as compared to when each node operates as an independent base station (Base Station (BS), Advanced BS (ABS), Node-B (NB), eNode-B (eNB), Access Point (AP), and so on). In this case, a distributed multi-node system may be referred to as a distributed antenna system (DAS).
Therefore, a method for configuring nodes that are being used in a distributed multi-node system, which provides services to a user equipment by using multiple nodes, and a user equipment that operates by using such method is being required.

Method and apparatus for notifying a node in a multi-node system


A pneumatic solenoid valve includes a fluid connector, a magnet coil which extends along a coil axis, a yoke arranged on the magnet coil, and an armature movable relative to the yoke and which extends along an armature axis and which is formed for opening and closing the fluid connector. The armature can assume three different switching positions. In the first switching position, the armature and coil axes are arranged parallel to one another and the armature completely closes off the fluid connector. In the second switching position, the armature is rotated about an axis of rotation, such that the armature axis and the coil axis assume an angle with respect to one another and the armature partially opens the fluid connector. In the third switching position, the armature is in a state axially displaced in relation to the first switching position, such that the fluid connector is completely open.

Pneumatic solenoid valves are used for controlling air flows in a multiplicity of technical fields of application. In these solenoid valves, a magnetic force is generated by means of a magnet coil and a switching process of the valve is triggered as a result. One area of application of such solenoid valves is the filling of elastic fluid chambers in an adjustment device for pneumatically adjusting a contour of a seat bearing surface (region of the seat surface or backrest) of a seat in a transportation means, such as for example a motor vehicle seat.
The pressure in the fluid chambers often has to be readjusted. On the one hand, this is necessary since leaks in the pneumatic system can lead to a pressure loss in the fluid chambers. On the other hand, it is necessary for the pressure in the fluid chamber to be continuously adapted or readjusted owing to changing local ambient conditions (temperature and/or pressure changes). Here, conventional pneumatic solenoid valves have the disadvantage that the solenoid valve either completely closes or completely opens the fluid connector. This leads to the fluid connector always being completely opened with each readjustment. The complete opening of the fluid connector results in an abrupt change in pressure in the interior of the solenoid valve, which manifests itself as a loud switching noise in the form of clicking, which is perceived as disturbing.


A system, method, and computer-readable storage medium, of which the method includes receiving an image of a tool including a consumable object from a remote device via a network at a processor, decoding the image to identify the consumable object, using the processor, and determining a degradation characteristic, a consumption, or both for the consumable object by providing the decoded image to a neural network. The degradation characteristic represents a mode of degradation and the consumption represents an amount of degradation.

When tools are used, e.g., in the oilfield, they are subject to degradation through use over time. For example, edges on cutting elements and threads can be worn or damaged through normal use. The tool degradation may not be uniform, however, and the rate at which a tool or parts thereof degrade, as well as the type of degradation, may vary depending on a variety of factors. Such factors can include the type of tool, the material that the tool is used to mill or cut (e.g., for drilling/milling/reaming tools), depth, temperature, pressure, fluid, drilling parameters, torque loads, impact loading, etc. Accordingly, the tools are periodically evaluated for deterioration, and, in response, parts are replaced or repaired as needed.

System for characterizing oilfield tools


A brushless motor with axial air gaps is rotated at speeds higher than that of conventional motors by using magnets adjustable in the radial direction. The axial gap machine includes one or more stators, containing windings that conduct electrical currents, and one or more rotors, with sets of permanent magnets rotating on a shaft adjacent the stators. The magnets are supported by bearings in a magnet carrier on the rotor so that the magnets can move radially under the action of centrifugal force opposed by springs. The radial movement of the magnets reduces the number of lines of flux of the magnets that can interact with those created by the electrical currents flowing in the windings. Reducing the flux interaction allows an increase in the speed capability of the machine. Linear radial guides inside the magnet carrier restrict movement of the magnets in all directions other than the radial direction and stops limit outward and inward movement.

1. Field of the Invention
A permanent magnet electric machine of the axial air gap type that can adjust the axial gap field strength to increase the speed of the machine without increasing power by radially shifting the magnets under the influence of centrifugal force acting against spring resistance.
2. Description of Related Art
Back-emf in the machine is directly proportional to the gap flux density, the length of the conductors and the speed of rotation. As the speed increases, the back-emf continuously rises. At a certain speed, the back-emf will equal the applied voltage. This specific speed is called base speed. The motor cannot be rotated beyond the base speed because the back-emf exceeds applied voltage (which is assumed to be fixed and unalterable). In other words, if there is no mechanism to reduce back-emf, the base speed defines a theoretical limit beyond which the motor cannot rotate.
A conventional permanent magnet motor can provide high torques up to base speed, but cannot usually operate beyond it. Achieving maximum speeds that are a factor of three or five times higher than the base speed is difficult and has presented serious technological problems. Several methods have been developed to operate a permanent magnet motor beyond the base speed. These methods can be broadly grouped into electrical means, mechanical means and centrifugal means. The electrical means manipulate voltage or currents applied to the coils, the mechanical means employ a stator adjusted by an external actuator, while the centrifugal means employ movable rotor magnets that are moved by centrifugal action to alter the gap flux.
Several electrical means of enhancing the speed of permanent magnet machines have been devised. These include increasing the number of phases, deactivating some phase coils as speed increases, shaping the current, weakening the gap flux, boosting the applied voltage, changing the phase between the two, or switching from a wye-mode to a delta mode. U.S. Pat. No. 5,677,605 issued Oct. 14, 1997 to Cambier et al and U.S. Pat. No. 5,739,664 issued Apr. 14, 1998 to Deng et al and U.S. Pat. No. 4,546,293 issued Oct. 8, 1985 to Peterson et al, illustrate some of these approaches. The flux weakening technique uses large currents to suppress the field generated by the permanent magnet, thereby reducing the gap field. Large currents, however, increase temperature and potentially damage the magnets. This technique is applied mostly to sine-wave driven motors where mutual inductance between two phase coils is relatively large and non-negligible. It cannot be readily applied to square-wave driven systems, especially when the mutual inductance between the phase windings is negligible, even though attempts have been made to use it for surface-permanent-magnet machines. The voltage boost technique requires additional dc--dc converters to enhance the voltage applied to the motor windings. This, however, increases the cost of the motor drive and increases its weight while its efficiency of operation is reduced.
Mechanical means of enhancing the speed employ a movable stator to bring it closer to rotor magnets, thereby reducing or increasing the axial air gap. U.S. Pat. No. 2,719,331 issued Oct. 4, 1955 to E. Harris and U.S. Pat. No. 2,784,332 issued Mar. 5, 1957 to W. Kober, and U.S. Pat. No. 2,824,275 issued Feb. 18, 1958 to W. Kober, and U.S. Pat. No. 2,892,144 issued Jun. 23, 1959 to W. Kober, disclose means for flexibly mounting the stator such that the axial air gap can be increased or decreased as the load changes. U.S. Pat. No. 3,250,976 issued May 10, 1966 to E. McEntire and U.S. Pat. No. 5,627,419 issued May 6, 1997 to R. Miller, describe a radial gap machine in which the stator can be moved axially. Such methods require complex external energy sources with the overall efficiency of the motors reduced by the energy consumed by these actuating devices.
Centrifugal means to enhance motor speed do not require external devices or energy sources and hence they are self-actuating. They are preferable since they do not reduce the overall efficiency of the machines. The principal used is that rotary permanent magnets tend to fly radially outward under the action of centrifugal force. They have been proposed only for radial gap machines. U.S. Pat. No. 1,153,076 issued Sep 7, 1915 to J. Heinze discloses a hinged magnet and lever mechanism to move the rotating magnets radially outward thereby opening or increasing the radial air gap. U.S. Pat. No. 5,053,659 issued Oct. 1, 1991 to D. Parker also discloses a device for moving permanent magnets using centrifugal force.
These prior art centrifugal devices that are applied to radial gap machines suffer from several problems, namely opposing attraction forces, frictional losses and excessive flux leakage. The opposing attraction force problem stems from the fact that the centrifugal force must be large enough to overcome large attraction forces that exist between the rotor magnets and the stator in radial gap motors. As a result, a very small portion of the centrifugal force is available to increase motor speed. In addition, in radial gap motors the act of moving the magnets introduces significant flux leakage reducing the effectiveness of the magnets.

Axial gap motor with radially movable magnets to increase speed capablity


Polycarbosilane polymers are prepared from 1,3-butadiene or substituted 1,3-butadiene by reacting the butadiene with a dichlorosilane in the presence of a reducing metal. The polymers contain silicon hydride or other crosslinkable groups in the polymer chain.

Various carbosilane polymers and their preparation are known in the art. For example, unsaturated carbosilane polymers are prepared by the ring-opening polymerization of silacyclopent-3-enes. See, for example, U.S. Pat. Nos. 5,171,810 and 5,169,916. It is also known that carbosilane polymers may be crosslinked by hydrosilation, as disclosed, for example, in U.S. Pat. 5,130,390 to Weber and Liao.
U.S. Pat. No. 4,719,273 to Seyferth et al. discloses preceramic polymers prepared by reacting bimetallic compounds of ethylene or acetylene with methyldichlorosilane.
Fujita et al., Journal of Organometallic Chemistry 113:201 (1976) disclose preparation of magnesium/butadiene addition compounds. The reaction of butadiene magnesium with diorganodichlorosilanes to produce diorganosilacyclopent-3-ene derivatives is disclosed in Richter, Journal of Organometallic Chemistry, 289:45 (1985).

Carbosilane polymers prepared from butadiene


A cold plate and an integrated circuit cooling module embodying a cross-hatch coolant flow distribution scheme. Cross hatch flow distribution is achieved by way of two sets of channels which run perpendicular to each other. The first set of channels is formed on a base plate. The second, perpendicular set is includes a set of inlet channels and a set of interleaved outlet channels formed on a distribution plate. In the preferred embodiment, the base and distribution plates are separated by an interposer plate that has nozzles which cause a liquid coolant to impinge, under pressure, on the floor of the base plate.

a. Field of the Invention
This invention relates to liquid cooled semiconductor modules.
b. Related Art
Cooling of integrated circuit chips in large computers is often accomplished placing the chips in a number of liquid cooled modules. FIG. 1 shows a cross-sectional view of a prior art thermal conduction module 10 for providing cooling of the integrated circuit chips 12 contained therein. As is well known, the power consumed in the circuits within the chips 12 generates heat which must be removed. The chips 12 may have different power requirements and different ranges of operating temperatures. Thus, in order to obtain reliable operation of the integrated circuits, the cooling must be of such character as to maintain the temperature of each chip within its required operating range.
The chips 12 are mounted (by way of solder balls 28) on one side of a substrate 14, generally made of ceramic, which has pins 16 extending from the other side thereof. These connecting pins 16 provide for the plugging of the module into a board (not shown) which may carry auxiliary circuits, etc. A housing or cap 18 is attached to the substrate 14 by means of a flange 20 which extends from the periphery of the substrate 14 to the cap 18. The cap 18 is made of a good heat conductive material such as copper or aluminum. The cap has small cylindrical openings 22 located therein, which are arranged in a matrix directly adjacent to the exposed surface of each chip 12.
Each of the openings 22 receives a spring loaded pin piston 24. Each piston 24 has a square header 26 which contacts the chip surface. Heat generated by the chips 12 is carried away by the pistons 24 to the cap 18. A cold plate 30, attached to or designed as an integral part of the cap 18, transfers the heat to a stream of coolant (for example chilled water) which flows from an inlet 32 to an outlet 34. The coolant carries the heat away from the thermal conduction module assembly 10.
As the power consumption of integrated chips has increased, the amount of heat which needs to removed from the chips and the thermal conduction module has increased as well. Since the ability of the thermal conduction module to remove heat from the chips is dependant on the ability of the cold plate to remove heat from the pistons and the TCM cap, a great deal of design effort has been put into developing an efficient cold plate design.
FIG. 2 shows a top-cutaway view of a prior art cold plate 200 having a serpentine coolant flow path 202 between an inlet 203 and an outlet 204. A number of bolt holes 205 are provided for attaching the cold plate to the cap of a thermal conduction module. One limitation of the cold plate of FIG. 2 is that the serpentine coolant flow path is generally serial. Thus, a single stream of coolant carries away heat from the chips as it passes over the pistons on its way from the inlet 203 to the outlet 204. Given such a serial flow path, in order to properly cool chips having higher power dissipations the rate of water flow must substantially be increased.
Increasing the flow rate to accommodate chips with high power dissipations can prove to be a difficult and costly exercise. In order to accomplish an increase of flow rate by a factor of X, the pressure drop between the inlet and the outlet of the TCM must be increased by X squared. Increases in pressure can be costly in several respects. For example, increasing coolant pressure typically requires larger and more expensive compression/cooling units. Further, suitable fittings and coolant supply tubing (typically more expensive) must be provided to accommodate the higher pressures.
Another problem with serial flow paths is that as the length of the path increases the required pressure drop must also be increased in proportional relationship to maintain a given flow rate. Thus, if the substrate to be cooled becomes larger, or the number of rows of integrated circuits on a given sized substrate increases, the longer flow path will cause a proportional increase in the required pressure drop.
FIG. 3 shows an example of another prior art cold plate 300 that uses fins for improved heat transfer. Four fins 302 extend from two opposite walls of the cold plate to form a sinuous path for water flow. Each parallel segment of the path is relatively wide and is further divided into four parallel channels by a three by three parallel line of short fins 304. The gaps between the short fins increase the turbulence in the water flow. The parallel channels provide increased fin area with lower flow resistance. While the embodiment of FIG. 3 is an improvement over that of FIG. 2, the coolant is still forced to flow along an essentially serial path over the pins of the TCM. Further, as the number of fins is increased the pressure drop required to maintain sufficient cooling is increased as well.

Cross-hatch flow distribution and applications thereof

International Business Machines Corporation


A driver circuit for generating a driving signal by pulse-width modulation (PWM) includes a half-bridge circuit formed essentially of a pair of series-connected FETs. When the level of an ultrasonic signal, or of the driving signal, is to be maximized, the individual FETs are switched at a switching frequency matched to the frequency of the driving signal. When the level of the ultrasonic signal, or the driving signal is to be reduced, on the other hand, the individual FETs are switched with specific timing determined based on the frequency of a clock signal of which period is shorter than that of the driving signal.

1. Field of the Invention
The present invention relates to an ultrasonic transmitter for radiating ultrasonic waves, an ultrasonic transceiver for radiating ultrasonic waves and receiving echoes of the radiated ultrasonic waves, and a sounding apparatus including an ultrasonic transceiver for detecting objects using ultrasonic waves.
2. Description of the Related Art
Today, ultrasonic sounding apparatuses, such as scanning sonars, are widely used for detecting underwater objects (targets). A scanning sonar for detecting underwater objects in all surrounding directions has a generally cylindrical transducer. The scanning sonar forms an ultrasonic transmitting beam oriented in all directions around the transducer by activating vibrating elements arranged on a cylindrical surface of the transducer. Also, the scanning sonar forms a receiving beam oriented in a particular horizontal direction using a specific number of vertically arranged sets, or columns, of vibrating elements centered on that horizontal direction. Typically, this receiving beam is rotated around the transducer to detect underwater objects in a full-circle area by successively switching the columns of vibrating elements.
An ultrasonic transceiver of the aforementioned type of scanning sonar usually includes full-bridge circuits, each including four switching devices, for driving individual vibrating elements. Such an ultrasonic transceiver employs a pulse-duration modulation (PDM) control method which uses a signal having the same frequency as frequency (transmitting frequency) fs of an ultrasonic signal as drive signals for driving the switching devices.
FIG. 8 is an equivalent circuit of a full-bridge circuit used in an ultrasonic transceiver, and FIGS. 9A-9C are diagrams showing a driving pulse signal generated by the full-bridge circuit of FIG. 8 and drive signals supplied to individual switching devices Q1-Q4 of the full-bridge circuit.
Referring to FIGS. 8, 9A-9C, designated by GQ1-GQ4 are gates of the switching devices Q1-Q4, respectively, designated by XD is a vibrating element, designated by C1 and C2 are capacitors for isolating direct-current (dc) components, designated by VB is a driving voltage, and designated by VXD is a load voltage across the vibrating element XD.
As shown in FIG. 8, the full-bridge circuit includes a circuit in which a source of the switching device Q1 is connected to the driving voltage VB, a drain of the switching device Q1 is connected to a source of the switching device Q2, and a drain of the switching device Q2 is grounded and a circuit in which a source of the switching device Q3 is connected to the driving voltage VB, a drain of the switching device Q3 is connected to a source of the switching device Q4, and a drain of the switching device Q4 is grounded. In this full-bridge circuit, the drain of the switching device Q1 is connected to one of terminals of the vibrating element XD via the dc-isolating capacitor C1 and the drain of the switching device Q3 is connected to the other terminal of the vibrating element XD via the dc-isolating capacitor C2.
The drive signals having a frequency fs as shown in FIG. 9B are supplied to the switching devices Q1, Q4 and the drive signals having the same frequency fs as shown in FIG. 9C are supplied to the switching devices Q2, Q3, whereby the aforementioned driving pulse signal having the load voltage VXD as shown in FIG. 9A is produced and fed into the vibrating element XD. The driving pulse signal causes the vibrating element XD to oscillate and radiate the ultrasonic signal into a surrounding environment. The amplitude of oscillation (vibration) of the vibrating element XD can be adjusted by varying an on-duty ratio which is the ratio of the sum of ON periods of the driving pulse signal, or the sum of periods when the load voltage VXD is equal to VB or −VB during a given time duration, to the sum of ON and OFF periods during the same time duration. An example of an ultrasonic transmitter employing the aforementioned type of full-bridge circuit is found in Japanese Patent Application No. 2002-343913, for instance.
An ultrasonic transmitter employing the aforementioned type of full-bridge circuit has a problem in that the number of components increases due to the need for four switching devices in each full-bridge circuit and circuit configuration becomes complicated, resulting in an eventual increase in product cost.
One approach to the resolution of the aforementioned problem is to employ a half-bridge circuit including a pair of switching devices Q1, Q2 as shown in FIG. 10 in an ultrasonic transceiver.
FIG. 10 is an equivalent circuit of the half-bridge circuit, and FIGS. 11A-11C are diagrams showing a driving pulse signal generated by the half-bridge circuit of FIG. 10 and drive signals supplied to the individual switching devices Q1, Q2 of the half-bridge circuit.
Referring to FIGS. 10, 11A-11C, designated by GQ1, GQ2 are gates of the switching devices Q1, Q2, respectively, designated by XD is a vibrating element, designated by C is a capacitor, designated by VB is a driving voltage, and designated by VXD is a load voltage across the vibrating element XD.
As shown in FIG. 10, the half-bridge circuit is a circuit in which a source of the switching device Q1 is connected to the driving voltage VB, a drain of the switching device Q1 is connected to a source of the switching device Q2, a drain of the switching device Q2 is grounded, and the drain of the switching device Q1 is connected to one of terminals of the vibrating element XD via the capacitor C.
The drive signals as shown in FIGS. 11A and 11B are supplied to the switching devices Q1 and Q2, respectively, whereby the aforementioned driving pulse signal having the load voltage VXD as shown in FIG. 11A is produced by the PDM control method and fed into the vibrating element XD. The driving pulse signal causes the vibrating element XD to oscillate and radiate the ultrasonic signal to the exterior. The amplitude of oscillation (vibration) of the vibrating element XD is regulated by varying the on-duty ratio as in the full-bridge circuit.
In the aforementioned circuit configuration in which the vibrating element XD is driven by the half-bridge circuit using the PDM control method, however, there occur harmonics as shown in FIGS. 12A-12C, 13A-13C.
FIG. 12A shows the waveform of a driving pulse signal obtained when an ultrasonic signal is produced at maximum output power by using the half-bridge circuit, FIG. 12B is a frequency spectrum of the driving pulse signal observed at the same time, and FIG. 12C is a frequency spectrum of the ultrasonic signal.
FIG. 13A shows the waveform of a driving pulse signal obtained when an ultrasonic signal is produced at output power reduced to a specific level (−20 dB) by using the half-bridge circuit, FIG. 13B is a frequency spectrum of the driving pulse signal observed at the same time, and FIG. 13C is a frequency spectrum of the ultrasonic signal. Shown in FIGS. 12A-12C, 13A-13C are examples in which the frequency fs of the ultrasonic signal is 81 kHz.
When the vibrating element XD is driven at the maximum output power using the half-bridge circuit, there occur harmonics of which frequencies are odd multiples of the frequency fs (i.e., multiples of the transmitting frequency fs by 3, 5, etc.) as shown in FIGS. 12A-12C. The odd-numbered harmonics, which also occur when the full-bridge circuit is used, can be suppressed by inserting a low-pass filter in an output stage connected to the vibrating element XD.
In a case where the output power is reduced by using the half-bridge circuit, there occur harmonics having all integral multiples of the transmitting frequency fs (i.e., multiples of the frequency fs by 2, 3, 4, etc.) as shown in FIGS. 13A-13C. While almost all of these harmonic components can be suppressed by using a low-pass filter, the second harmonic component can only be removed by use of an additional filter having a high Q factor, rendering circuit design extremely difficult. This is because the second harmonic has a frequency component very close to the transmitting frequency fs of the ultrasonic signal. (In the example of FIG. 12C, the frequency fs of the ultrasonic signal is 81 kHz so that the frequency 2 fs of the second harmonic is 162 kHz.) In addition, the levels of the harmonics vary so little compared to the level of the ultrasonic signal that it is necessary to use a filter having a remarkably large attenuation factor. It is extremely difficult to configure a system which satisfies all these requirements. Even if it is at all possible to design such a system, a series of complicated adjustments would be necessary in manufacturing the system, causing an increase in work load.
One approach to the solution of the above problem would be to employ a pulse-width modulation (PWM) control method in the half-bridge circuit instead of the PDM control method. The term "pulse-width modulation", or "PWM", as used in this Specification is a form of pulse-duration modulation, in which the vibrating element XD is driven by a driving pulse signal having a higher frequency fa than the transmitting frequency fs of the ultrasonic signal so that there is output a signal containing multiple pulses having a period Ta within a period Ts of the transmitted ultrasonic signal to pulse-duration-modulate a signal based on the sum of durations of these multiple pulses within the period Ts. When such a driving pulse signal for PDM control operation is supplied to the vibrating element XD, the vibrating element XD resonates at the transmitting frequency fs, and not at the frequency fa of the driving pulse signal, thereby emitting the ultrasonic signal at the transmitting frequency fs. The pulselength of these pulses is determined by comparing a sawtooth-shaped ramp signal having a frequency fc (=fa) higher than the frequency fs of the ultrasonic signal with an analog control signal having the same waveform as the ultrasonic signal, wherein the sawtooth-shaped ramp signal and the analog control signal are synchronized with each other.
When the PDM control method is used with the half-bridge circuit, there occur multiple pulses within the period Ts of the ultrasonic signal even when the output power is reduced. Thus, extremely narrow pulses are not generated within the period Ts so that the half-bridge circuit does not produce such spurious emissions (e.g., the second harmonic) that are difficult to remove.
However, because the frequency fc of the ramp signal and the frequency fa of the driving pulse signal determined by the ramp signal are higher than the frequency fs of the ultrasonic signal, output efficiency decreases as a result of an increase in power loss due to heat generation by the switching devices Q1, Q2 when the half-bridge circuit is operated at the maximum output power.

Ultrasonic transmitter, ultrasonic transceiver and sounding apparatus


A mountable ball holder comprises a receiving member and a cover. The receiving member has resilient first, second, and third arcuate members that define a ball receiving area. The first, second, and third arcuate members each lie in a separate plane and converge to form a mounting portion. The mounting portion has at least one attachment member for securing an external surface of the mounting portion to a support structure. The cover is secured to an internal surface of the mounting portion such that the cover conceals the at least one attachment member.

Whether at school, at the gym, or at home, the storage and/or display of a ball such as, a basketball, football, exercise ball, or the like, can be a frustrating experience. Keeping the ball securely on a shelf, on the floor, or in any other storage location is virtually impossible, because the ball invariably rolls from its desired position. Not only is a loose ball potentially dangerous, but a loose ball is more susceptible to damage. Additionally, loose balls will cause an area to have a cluttered appearance. Accordingly, there exists a need for a mountable ball holder that can securely hold a ball in a desired location. There further exists a need for a mountable ball holder that is easy to use and assemble.


A method and system for efficient translation of memory addresses in computer systems. The present invention enables address translations between different address spaces to be performed without using the table lookup step typically required in the prior art. Thus, the present invention provides significant improvements in both time and space efficiency over prior art implementations of address translation. In modern computer systems where direct memory access (DMA) operations are used extensively, especially in the emerging field of operating system (OS) bypass technology, the performance improvements afforded by the present invention are particularly critical to the realization of an efficient and high performance system. A method and system for efficiently translating memory addresses in computer systems and the address representation used are described herein.

1. Field of the Invention
The present invention relates to the field of memory management in computer systems. More specifically, the present invention relates to the optimization of memory address translation.
2. Related Art
Memory management is an important facet in the operation of modern computer systems. In particular, efficient memory management is a crucial factor to high performance in today's computer systems. Accordingly, much effort has been expended towards improving the efficiency of memory management, especially with respect to the efficiency of memory-related operations and representations.
One important instance of memory management involves the translation, or mapping, of a memory address from one address space to another address space. An address space delineates a range of memory addresses which a computer system can access under defined circumstances. Typically, multiple address spaces are used in a modern computing environment. For example, when a virtual address is referenced, it is often necessary to identify the physical address corresponding to the virtual address so that the contents at the physical memory location represented by the virtual address can be accessed. In this case, the virtual address of a virtual address space needs to be translated to the underlying physical address of a physical address space.
Generally, software and hardware systems frequently have to translate one synthetic address to a physical address or to another synthetic address. In this context, a synthetic address is a memory address based on an abstract index and an offset. Synthetic addresses within a given synthetic address space share the same abstract index but each has a different offset. Examples of synthetic addresses include virtual addresses and addresses used for remote direct memory access (remote DMA, or RDMA) operations between different computer systems.
In prior art methods for performing address translation or memory mapping, a table-based lookup is generally a required step. For example, a hash table, a page table, or another kind of table is used to store the relationship between a source address and its target address. Whenever an address translation is triggered by an operation requesting access to a source address representing a target address, a table lookup step has to be performed. This step is performed in order to retrieve the target address that corresponds to the source address so that the memory access request can be serviced. Typically, the table lookup step is required every time an address needs to be translated under the prior art.
However, these prior art methods are inefficient because performing a table lookup is expensive both in terms of computational time and space requirement. Under these prior art methods, every address translation requires a table lookup, thus the time and area requirements increase as the number of translations performed becomes larger. Consequently, these prior art methods are far from ideal in systems implementing DMA, where numerous address translations are routinely performed. The inefficiency inherent in these prior art methods is further aggravated in modern computer systems having multiple hosts and with remote DMA implemented, since even more extensive address translations are typical in such an environment. These prior art methods are therefore not well suited to the implementation of modern high speed computer systems.
Thus, there exists a need for a method and system for performing memory address translations with minimal overhead computations, thereby providing improved efficiency and performance enhancement over the prior art in order to meet the ever-increasing performance demand of modern high performance systems.

Method for efficient translation of memory addresses in computer systems


An apparatus for determining in vivo hyperalgesia to thermal stimulation in an unrestrained subject within a predetermined space permitting the selective application of radiant heat to a site of the subject comprises a timer, a movable light source, a light detector and a stopper for the timer, the light source and the detector, the stopper being electrically connected thereto and automatically activated by the light detector upon site withdrawal, and a starter for the timer and the light source and for activating the light detector that is electrically connected thereto. When the light source is aimed at the site and positioned at a distance effective to locally provide radiant heat thereto and the starter is activated, after a latency time period the light beam elicits a spontaneous withdrawal response from the subject that is detected by the detector. The timer, the light source and detector, the stopper and the starter are part of an electrical circuit which is to be connected to a power source prior to use.

The main function of analgesia is to alleviate pain or suppress its perception in a subject.
Pain can be defined in a variety of ways. One of them establishes pain as the perception by a subject of noxious stimuli which produces a withdrawal reaction by the subject. A variety of methods have long been available for the evaluation of subject's response to pain. In general, these experimental procedures must comply with several criteria in order to be of use. The effect to be measured must be unequivacally related to the pain experimented by the subject. The applied stimulus must produce a reproducible and measurable response, and ideally the response should be a single response. However, rarely do methods comply with the latter requirement.
It is recognized that there are at least two modes of pain known as pricking and burning pain. The sensation of pricking pain is one that reaches a sharp peak and subsides quickly while the one of burning pain has a slower onset, rises gradually, then plateaus but never reaches the same type of peak or intensity observed with pricking pain, and lasts for a longer period of time (Keith E. F., Amer. J. Pharm. 132:212-230 (1960)).
Pain has also been classified in accordance with other criteria (Pfeiffer, C. C. et al, Ann. N. Y. Acad. Sci. 51:21 (1948)) . "Supain" is used to describe superficial pain and is similar to the previously referred to as pricking pain. It can easily be elicited by pricking the skin with a needle. The second type of pain is "deepain" which is of an aching character. An example of this type is a tooth ache. Lastly, another type of pain is "sympain" which is exemplified by migraine headaches and is typically felt in the vessels of the temporal region. This pain is relieved by ganglionic blockade. The levels at which pain may be blocked are the receptors themselves. Many agents which block pain by acting superficially do so at the receptor itself. A second way of acting is that where the agents act at the internuncial pool of the spinal cord by blocking pain or raising the threshold for synaptic transmission. Centrally, the thalamus of the brain may also be involved in suppressing pain, or the cortex of the brain may be obtunded. Some analgesic agents may suppress muscle and joint pain. An example of these agents is salicylic acid which relieves pain from deep structures in muscular joint areas.
In order to study the mechanism of action of the different available drugs as well as novel drugs which are constantly being developed there is a broad background of techniques from which to select. However, all the available techniques have some beneficial and some detrimental characteristics. In general, the techniques can be divided into five groups:
1) Chemical methods PA1 2) Electrical methods PA1 3) Mechanical methods PA1 4) Thermal methods and PA1 5) Pharmacological methods
1) Chemical Methods
In general these methods rely on the application of a chemical compound to the skin of a subject. The simpler methods rely on the immersion of a part of the subject in a chemical which causes irritation to the skin. In another method the chemical irritant is administered subcutaneously. A more sophisticated method is one where a writhing agent is inserted in the peritoneal cavity of an animal and produces a characteristic writhing response which occurs five or more times in a period of 10 minutes immediately following the administration of the chemical (Siegmund et al, Proc. Soc. Exptl. Biol. Med. 95:729 (1957)). In general this type of method shows a lack of specificity in the response of the animals. It is unclear whether it is the irritation produced by the administered chemical or the release of some substance which is responsible for the observed effects.
2) Electrical Methods
The more primitive of these type of methods promote the painful stimulation of the skin to produce pain. In general the end point of this method is not sufficiently specific. A variation of this technique involves the application of an electrical current to the rat's scrotum by means of platinum electrodes. The current is increased until the animal squeals. Yet another electrical method is that where an electric current is applied to the pulp of a tooth (Koll, W. and Reffert, H., Arch. Exptl. Pathol. Pharmakol 190:687 (1938)). A modified version of this technique, and currently utilized, consists of delivering to an inlaid filling in a vital tooth a shock at various levels of intensity to determine the threshold of pain with and without a drug. This method has also been applied to humans. This method has the limitation imposed by the proximity of the filling to the pain receptors. In addition, different animals have different responses to the electrical stimulation of the pulp of the tooth and the responses are not always correlatable. The subject must be thus carefully watched and the electrodes require careful attachment for maintaining good electrical contact throughout the testing.
3) Mechanical Methods
The evaluation of the results of these methods is substantially subjective and does not permit the ready quantification thereof. These methods are therefore only applied in general to the primary screening of pain. Surgical blades adapted in various manners are utilized in the most primitive of these methods to produce a pain reaction. The blade is applied with a graded forceps and the amount of pressure necessary to elicit pain is expressed as the number of steps required in order to produce a squeak in the experimental animal . The pressure exercised by the blades of the forceps has also been measured by placing a dynamometer therebetween or between the handles of the forceps. Artery clamps or clips have also been utilized instead of forceps. In humans, mechanical pressure has been applied over bone structures or by eliciting visceral pain such as in the enteric canal or in the esophagus by introducing and inflating balloons therein. The amount of pressure required to produce pain can be measured by means of a manometer but the subject itself is the one to report the degree of pain. A more modern version of the method is that described by Randall-Selitto (Randall, L. O., and Selitto J. J., Arch. Int. Pharmacodyn CXI (4):409 (1957)). The pain threshold is measured in this method as the amount of pressure in mmHg required to induce a flight reaction (struggle) when applied to the foot of an experimental animal. Air pressure from an air line is admitted through a needle valve to a syringe into a pressure gauge which is connected by a T-tube. The syringe is mounted with a plunger downward, to which is connected a short bullet-shaped wooden peg. The pressure is applied through the wooden tip to the plantar surface of the rat's foot at a specified rate of mm Hg per second. The end point is said to have been reached when the rat starts struggling, as subjectively determined by an observer. The Randall-Selitto method has various drawbacks, including the fact that the mechanical stimuli activate both low and high threshold mechanoreceptive nerves in both cutaneous and non-cutaneous tissue, it requires that the experimental animal be restrained during the testing period, exhibiting therefore only limited behavioral movement and suffering from activation of stress-related physiologic responses such as sympatho-drenomedulary and pituitary-adrenal mediated stress responses, and the high degree of inaccuracy because of the subjective determination by an observer of the end point of the animal's response.
4) Thermal Methods
The simplest form of these methods is the hot plate technique originally described by Woolfe and McDonalds (Woolfe, G. and McDonalds, A. D. J. Pharmacol. Exptl. Therap. 80:300 (1944)). Originally, this method utilized a zinc plate with a lamp placed underneath. In a later modification it uses an electric lamp as the source of heat and a copper plate for the conduction of heat (Eddy, N. B. and Leimbach, D., J. Pharmacol EXPTL. Therap. 107:385 (1953)). The first sign of discomfort is usually expressed as an attempt to sit up and lick the forepaws by the experimental animal. This is taken to be an indication of a threshold under the predetermined conditions. Dancing and jumping about by an undrugged animal is taken as an indication of unbearable pain whereas drugged animals more commonly withdraw the hind paws and keep them close to their abdomen. Although widely used, this technique is also only recommended as a preliminary screening one because all points of contact between the animal and the hot plate are subjected to heat and the end-point is also determined subjectively by an observer. A hot wire technique consists of the application of heat from a wire coiled inside an asbestos plate. The animal's tail is placed in a channel made in the plate (Davis, O. L. et al, Brit. J. Pharmacol 1:255 (1946)). Yet another thermal method utilizing light from a headlamp focused on the tip of the tail of an animal (D'Amour, F. E., and Smith, D. L., J. Pharmacol. EXPTL. Therap. 72:74 (1941)). This method measures the time between the application of the heat and the flick of the tail and has therefore been called the "tail flick" method. With this method it is only possible to detect analgesic effects with large doses of chemical compounds such as aspirin and aminopyrine. However, these large doses only elicit a slight degree of analgesia. In general it is considered that this method is solely satisfactory for the detection of potent analgesics (e.g., opiates such as morphine) but unsatisfactory when applied to medium or weak analgesic agents. A further thermal method utilizes a light bulb focused on the loin of an animal which is protected by a plexiglass shield having a port and a shutter positioned between a lens and the animal. When the shutter is opened the timer starts and when the animal reacts the shutter is closed and the timer stopped (Ercoli, N., and Lewis, M. N., J. Pharmacol. EXPTL. Therap. 84:301 (1945)). This method applies an incident light the strength of which can be varied by means of a rheostat. This method is good for detecting potent analgesic substances but has the drawback that it only applies heat to one point of the body and the end-point is subjectively determined by an observer which operates the shutter and starts the timer. Weaker analgesic compounds such as aspirin show no effect when pain is measured by this method.
5) Pharmacological Methods
Typical representatives of this group are methods which rely on the administration of a substance to produce a rise in the temperature of an experimental animal. The skin temperature or the core temperature may be utilized. Yeast is a good example of a substance which can be used for producing an increase in temperature. The ability of a compound to inhibit this induced rise in temperature has been used as a means for evaluating antipyretic analgesic activity. In fact, the Randall-Selitto method described above (Randall, L. O. and Selitto, J. J., supra) is a combination of a mechanical method for evaluating analgesia and a physiological response method. It combines the administration of yeast as a phlogistic in the plantar surface of one paw of a rat and the use of a pressure device for eliciting a response. The threshold in the foot that has been injected with the yeast suspension drops to less than one half that of the control foot one hour after the injection of yeast.
An exhaustive comparison of the various method's known in the art was made by Taber (Taber, R. I., "Predictive Value of Analgesic Assays in Mice and Rats, in Narcotic Antagonists", edited by Braude et al, Advances in Biochemical Phytopharmacology, vol. 8, Raven Press, New York (1974), p. 191)). The scoring of most of the major techniques according to the methods rating scales are listed in the following table taken from Taber (Taber, R. I., supra) and are meant to provide a summary of the foregoing discussion.
TABLE 1 __________________________________________________________________________ Comparison of analgesic tests by rating scale Thermal Mechanical Chemical Electric Mouse Rat Mouse Rat Mouse Rat Mouse Criteria* hot-plate tail-flick tail-flick paw yeast writhing flick-jump tail-shock __________________________________________________________________________ Sensitivity a 2 4 2 4 4 4 3 b 2 2 1 3 4 3 3 c 2 1 2 1 0 2 1 d 1 2 0 2 2 2 2 Simplicity a 2 2 2 2 2 0 1 b 2 2 2 1 2 0 1 Reproducibility 4 4 4 4 4 1 2 Total Score 15 17 13 17 18 12 13 __________________________________________________________________________ *See Table 2.
The electrical methods, while promising, are of substantially no use because they lack simplicity and reproducibility. The remaining methods, however, score low in terms of sensitivity. General criteria for the scoring of the various methods are listed in Table 2 provided hereinbelow which has also been obtained from Taber (Taber, R. I., supra).
TABLE 2 ______________________________________ Analgesic method criteria rating scale Criteria Score ______________________________________ Sensitivity a. Is it sensitive to 1 for each class 4 (max. score) known analgesics? b. How sensitive is it to Median of drug 4 (max. score) doses in the clinical sensitivity range? No Questionable Yes c. Is it insensitive to 0 1 2 nonanalgesics? d. Is there an established, 0 1 2 clear-cut relationship between intensity and end point? Simplicity a. Does it require tech- 0 1 2 nical expertise? b. Does it require sophis- 0 1 2 ticated instrumenta- tion? Reproducibility How many labora- 0-4 4 tories have success- fully used the tech- nique ______________________________________
In general, the mouse writhing and the Randall-Selitto methods can detect antiinflammatory drugs. However, they do not provide for the automated detection of the end-point signal and are subject to substantial observer bias. On the other hand the rat tail flick method has an automated end-point but is very insensitive to various drugs such as antiinflammatory drugs, it lacks a within animal design and tests a particularly insensitive type of skin such as the one occurring in the tail of an animal. This type of skin is scaly and not very responsive to thermal stimulation.
Thus, despite the advantages of the various thermal stimulation methods (Dubner, R., et al, "Responses of Facial Cuntoneous Thermosensitive and Mechenosensive Afferent Fibers in the Monkey to Noxious Heat Stimulation", Adv. Neurol 4:61-71 (1974)), no good behavioral method exists for the quantitation of thermal nociception of hyperalgesia in a subject such as an animal model. The only method capable of quantitating behavioral responses to cutaneous hyperalgesia has been the Randall-Selitto method described above. This method has the various already indicated drawbacks. In addition, this method does not permit the simultaneous measurement of parameters other than the nociceptive threshold in the experimental animal.
Accordingly, there is still a need for a novel and simple method for the qualitative and/or quantitative in vivo measurement of responses to thermal stimulation in an unrestrained subject which overcomes the drawbacks of the prior art methods. Such method should ideally provide an automated detection of the subject's behavioral end-point, permit the use of unrestrained and unstressed animals, and optionally a within subject control, all of which and in the removal of observer bias and between animal variation while providing a powerful tool for distinguishing between centrally mediated and peripherally mediated responses to thermal stimulation.

Apparatus for determining in vivo response to thermal stimulation in an unrestrained subject

The United States of America as represented by the Secretary of the Department of Health and Human Services


The present disclosure provides an edge processing method for a display panel and a display panel having a device for processing an edge. The method includes: determining an irregular edge of the display panel and determining all edge pixels the irregular edge passes through; dividing all the edge pixels into n sets of edge pixels, where n≥2; and inputting frame image information to the display panel, wherein at least one set of the n sets of edge pixels is configured to display a frame image in at least one display frame, and is configured not to display the frame image in at least another display frame.

With the development of display technologies, a requirement of the consumer on the screen occupancy ratio of the display device is getting higher and higher. A display panel having a conventional shape can no longer satisfy the consumer's requirements. In order to increase the screen occupancy ratio, the display panel is rounded to be closer to an edge of the display device, or a groove or a hole is provided in the display panel to place components such as a camera, a light sensor, and a telephone receiver. This leads to a lot of special-shaped edges (i.e., irregular edges) on the display panels. Since sub-pixels are separately arranged, the sub-pixels may form a ladder-like zigzag edge at a special-shaped edge. One existing method is to weaken effects of the zigzag edge by reducing brightness of the sub-pixels at the special-shaped edge. However, this method requires a change of the panel design or occupies a large amount of driving chip resources, thereby resulting in an increase in power consumption. Moreover, the effect of improving the edge zigzag may be limited.

Edge processing method for display panel having irregular edge and display panel

XIAMEN TIANMA MICRO-ELECTRONICS CO., LTD.


The present application discloses a mobile terminal with a built-in anamorphic lens, the mobile terminal is provided with a widescreen anamorphic lens which comprises a cylindrical lens group and a spherical lens group, the cylindrical lens group at least comprises a group of cylindrical negative optical power lenses and a group of cylindrical positive optical power lenses. A widescreen anamorphic lens is arranged in the mobile terminal. The optical characteristics of the cylindrical lens in the widescreen anamorphic lens are utilized to “compress” the incident light entering horizontally while keeping the incident light entering vertically unchanged, so the widescreen anamorphic lens may compress a widescreen image into a standard image area. After the compressed picture taken by the widescreen anamorphic lens is deformed and corrected by the image correction module, widescreen images and videos may be obtained, meeting the needs of users for widescreen shooting by the mobile terminal.

More and more built-in cameras are applied to mobile phones. The mainstream flagship mobile phones on the market have built-in wide-angle cameras, ultra-wide-angle cameras, telephoto cameras, and macro cameras. With the development of future technology and demand, it is undoubtedly a necessity to use mobile phones to take widescreen pictures and videos conveniently and fast, which is impossible for the existing software and hardware on a mobile phone.

Mobile terminal with a built-in anamorphic lens


Disclosed is a manufacturing method of a rigid organic light-emitting diode (OLED) display panel and a display panel. The method comprises steps of providing a first substrate having a first glass substrate and a flexible film; coating an organic compound on the first glass substrate; providing a second substrate; packaging the display area; and cutting and stripping a part of the first glass substrate at the non-display area of the packaged display panel, thereby improving the screen accounting of the display area in the rigid OLED display panel.

An organic light-emitting diode (OLED) display, also known as an organic electroluminescent display, is an emerging display device possessing advantages of simple manufacturing process, low cost, low power consumption, high brightness, wide operating temperature range, thin volume, fast response times, and easy to implement color display and large screen display, easy to implement matching integrated circuit driver, easy to implement flexible display and so on, and thus has broad application prospects.
There are two types of the OLED, including a rigid organic light-emitting diode (rigid OLED) and a flexible organic light-emitting diode (flexible OLED), which differ greatly in the manufacturing process and flow. Specifically, the rigid OLED prepared by using glass as a substrate is more mature and stable in the technique; however, the rigid OLED also has certain shortcomings compared with the flexible OLED, such as a product with a thicker thickness and the terminal area is a glass substrate where the pad bending cannot be performed so that the non-display area of the mobile phone is too large to affect the screen-to-body ratio of the mobile phone in the follow-up process of the mobile phone assembling.
In current narrow frame design, even if the width of the frame is reduced, it is difficult for the frame of the liquid crystal display to be reduced due to the size limitation of the peripheral circuit. At the same time, in order to reduce the size of the frame, the peripheral circuit which is reduced to the limit is easy to affect the charging effect and the circuit yield.

Manufacturing method of a rigid organic light-emitting diode (OLED) display panel and a display panel

Wuhan China Star Optoelectronics Semiconductor Display Technology Co., Ltd.


There is disclosed a system and method for recovering a recurring data segment synchronization pattern in the presence of an arbitrary phase rotation of a pilot carrier by detecting and compensating for the amount of the phase rotation. The system comprises a first synchronization pattern detector capable of receiving a real component of a complex signal and detecting a data segment synchronization pattern on the real component, and a second synchronization pattern detector capable of receiving an imaginary component of a complex signal and detecting a data segment synchronization pattern on the imaginary component. There is also disclosed a method for compensating a pilot carrier phase rotation comprising the steps of determining the angle of pilot carrier phase rotation present in a complex signal and rotating the pilot carrier signal through the same angle in the opposite direction. Methods are also disclosed for compensating signal gain in a complex signal in which pilot carrier phase rotation has occurred.

The present invention is directed, in general, to the reception of high definition television signals and, more specifically, to a system and method for recovering a recurring data segment synchronization pattern in the presence of an arbitrary phase rotation of the pilot carrier by detecting and compensating for the amount of the phase rotation.
The Advanced Television Systems Committee (ATSC) standard for digital high definition television (HDTV) transmission uses a signal that is modulated as an eight (8) level vestigial sideband (VSB) symbol stream with a rate of 10.76 MHz. The ATSC standard defines a data segment as a length of data having eight hundred thirty two (832) symbols. Each data segment begins with a fixed pattern comprising the four symbols xe2x80x9c1001xe2x80x9d. The fixed pattern of xe2x80x9c1001xe2x80x9d indicates the start of a new data segment. The xe2x80x9c1001xe2x80x9d symbols are the first four symbols of the 832 symbols in the data segment.
In the demodulation process, the fixed pattern xe2x80x9c1001xe2x80x9d is used by the receiver to determine the positional alignment of the data segment. Locating (or xe2x80x9crecoveringxe2x80x9d) the positional alignment of the data segment is essential for data frame synchronization and for facilitating symbol timing recovery. Consequently, reliable and robust detection of the recurring four symbol xe2x80x9c1001xe2x80x9d pattern is essential to the operation of any receiver that receives signals that are broadcast according to the ATSC standard.
The baseband signal to be demodulated includes a pilot carrier located exactly at DC on the frequency spectrum. Under normal conditions, the pilot carrier is at the same phase angle (or very near the same phase angle) as the remainder of the signal spectrum. Under these normal conditions, any of a number of well known techniques may be used to recover the data segment synchronization pattern.
If, however, the channel introduces severe phase distortion over the signal spectrum so that the pilot carrier is at a very different phase angle from the remainder of the signal spectrum, then the recovery of the data segment synchronization pattern using standard methods will become much more difficult or even impossible. Severe phase distortions can arise, for example, in a channel where there is a very strong multipath with a very short delay on the order of one symbol period or less.
Under normal conditions in a terrestrial data transmission system, a conventional channel equalizer is used to compensate for channel distortion and multipath. Under conditions of severe phase distortion, a complex channel equalizer operated in a xe2x80x9cblindxe2x80x9d adaptation mode can be used to compensate for channel effects before the data segment synchronization recovery is performed. Although the length of the complex channel equalizer is not very long (on the order of ten (10) to twenty (20) data taps), the complex channel equalizer nevertheless constitutes a substantial hardware component of a demodulator system.
Because a complex channel equalizer performs a two-dimensional complex equalization (as opposed to a conventional equalizer that performs real, or one-dimensional, equalization), a complex channel equalizer can become susceptible to instability in the presence of certain nonlinearities in a complex input signal. Under such conditions, recovery of a data segment synchronization pattern using a complex channel equalizer can be very difficult or even impossible.
There is therefore a need in the art for an improved system and method of recovering a recurring data segment synchronization pattern in the presence of an arbitrary phase rotation of a pilot carrier in an ATSC broadcast signal. There is also a need in the art for an improved system and method that can recover a recurring data segment synchronization pattern without using a complex channel equalizer. There is also a need in the art for an improved system and method that can compensate a baseband signal for an arbitrary phase rotation of a pilot carrier.
To address the above-discussed deficiencies of the prior art, it is a primary object of the present invention to provide an improved system and method of recovering a recurring data segment synchronization pattern in the presence of an arbitrary phase rotation of a pilot carrier in a terrestrial HDTV broadcast signal encoded according to the ATSC standard.
Under specified channel conditions, the present invention allows the data segment synchronization pattern to be detected before the signal is compensated for the phase rotation of the pilot carrier. The present invention compensates for the phase rotation of the pilot carrier prior to the channel equalization and subsequent forward error correction of the signal.
The present invention comprises a first synchronization pattern detector for detecting a data segment synchronization pattern on the real component of the signal and a second synchronization pattern detector for detecting a data segment synchronization pattern on the imaginary component of the signal. This arrangement permits the present invention to detect the data segment synchronization pattern on a signal whose pilot carrier has been rotated by an arbitrary phase angle.
The present invention also comprises circuitry for compensating for the phase rotation of the pilot carrier. The present invention also comprises circuitry for compensating for distortions in signal gain that may occur when pilot carrier experiences phase rotation.
It is a primary object of the present invention to provide an improved system and method for recovering a recurring data segment synchronization pattern in the presence of an arbitrary phase rotation of a pilot carrier.
It is an additional object of the present invention to provide an improved system and method that can recover a recurring data segment synchronization pattern without using a complex channel equalizer.
It is another object of the present invention to provide an improved system and method for compensating for an arbitrary phase rotation of a pilot carrier.
It is still another object of the present invention to provide an improved system and method for compensating for signal gain in a signal in which pilot carrier phase rotation has occurred.
It is yet another object of the present invention to provide an improved feedforward system and method for compensating for pilot carrier phase rotation and signal gain.
It is also another object of the present invention to provide an improved feedback system and method for compensating for pilot carrier phase rotation and signal gain.
The foregoing has outlined rather broadly the features and technical advantages of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features and advantages of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they may readily use the conception and the specific embodiment disclosed as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the invention in its broadest form.
Before undertaking the DETAILED DESCRIPTION, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: the terms xe2x80x9cincludexe2x80x9d and xe2x80x9ccomprise,xe2x80x9d as well as derivatives thereof, mean inclusion without limitation; the term xe2x80x9cor,xe2x80x9d is inclusive, meaning and/or; the phrases xe2x80x9cassociated withxe2x80x9d and xe2x80x9cassociated therewith,xe2x80x9d as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like; and the term xe2x80x9ccontrollerxe2x80x9d means any device, system or part thereof that controls at least one operation, such a device may be implemented in hardware, firmware or software, or some combination of at least two of the same. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. Definitions for certain words and phrases are provided throughout this patent document, those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases.

System and method of synchronization recovery in the presence of pilot carrier phase rotation for an ATSC-HDTV receiver


An image processing apparatus includes an image acquisition unit, a region specifying unit, and a partial-image recognition unit. The image acquisition unit acquires first image data representing a first image and second image data representing a second image that is an image acquired by performing additional recording on the first image. The region specifying unit specifies a region, where additional recording is performed with respect to the first image, of the second image in accordance with the first image data and the second image data acquired by the image acquisition unit. The partial-image recognition unit recognizes a partial image recorded in the region specified by the region specifying unit.

(i) Technical Field
The present invention relates to an image processing apparatus, an image processing method, and a non-transitory computer readable medium.
(ii) Related Art
There are many cases where people fill in and submit printed paper sheets (business forms, questionnaires, and the like) by hand. For example, people fill in documents or various questionnaires to be submitted to government and municipal offices and the like. There is a demand that people on the collection side of filled-in paper sheets want handwritten characters, and characters and numbers selected using marks such as a circle in these paper sheets to be automatically read and collected.

Image processing apparatus recognizing a partial image recorded in a specified region, and corresponding image processing method, and non-transitory computer readable medium


Embodiments of the present disclosure include methods, systems, and vehicles for disabling a function of one or more mobile devices within a passenger cabin of a vehicle. A method of disabling a function of one or more mobile devices within a passenger cabin of a vehicle according to the present disclosure includes determining a number of occupants within the passenger cabin based on one or more occupant sensor output signals output by one or more occupant sensors. A disable message is sent to disable a function of the one or more mobile devices in the passenger cabin when the number of occupants present in the passenger cabin is determined to be one. A disable message is sent to disable a function of only the one or more mobile devices associated with a driver of the vehicle when the number of occupants present in the passenger cabin is determined to be greater than one.

Oftentimes, vehicle users introduce mobile devices (e.g., mobile phones, smartphones, personal digital assistants, dedicated mobile media players, mobile personal computers, laptop computers, etc.) into the passenger cabin of a vehicle when entering the vehicle. It may be desirable to disable functionality of a mobile device within a passenger cabin in some situations, such as to disable the ability of the driver to text message while driving.
Accordingly, a need exists for methods, systems, and vehicles for disabling one or more functions of a mobile device while the mobile device is present within a passenger cabin of a vehicle.

Methods, systems, and vehicles for disabling a function of one or more mobile devices within a passenger cabin of a vehicle

Toyota Motor Engineering & Manufacturing North America, Inc.


A pharmaceutical composition is provided for the treatment of systemic infections as well as colonic diseases. The composition comprises a therapeutically effective amount of rifaximin and a therapeutically effective amount of at least one alkaloid or derivative thereof. Methods and kits are also provided.

One of the major obstacles to the development of highly potent pharmaceutical formulations is the poor water solubility of many drugs. Approximately 40% of potential drugs that are identified by pharmaceutical companies are poorly soluble in water, which greatly hinders their clinical use. Low water solubility limits the bioavailability and absorption of these agents.
Rifaximin is a semisynthetic antibiotic belonging to the rifamycin class of antimicrobial drugs exhibiting in vitro activity against Gram-positive, Gram-negative and anaerobic bacteria. Rifaximin acts by inhibiting bacterial ribonucleic acid (RNA) synthesis. Rifaximin is chemically named as [(2S,16Z,18E,20S,21S,22R,23R,24R,25S,26S,27S,28E)-5,6,21,23,25-pentahydroxy-27-methoxy-2,4,11,16,20,22,24,26-octamethyl-2,7 (epoxypentadeca-[1,11,13]trienimino)benzofuro[4,5-e]pyrido[1,2-a]-benzimidazole 1,15(2H)-dione,25-acetate]. Rifaximin has the following chemical formula.

Rifaximin is commercially available under the trade name XIFAXAN®, as a 200 mg and 550 mg film coated oral tablets in USA and as XIFAXANTA® 200 mg, TARGAXAN® 550 mg in UK.
In USA, Rifaximin has been indicated for the treatment of traveler's diarrhea not caused by Escherichia coli, a micro-organism which is not able to penetrate into GI mucosa and therefore remains in contact with gastrointestinal fluids, hepatic encephalopathy and Irritable Bowel Syndrome with Diarrhea.
In UK, Rifaximin 200 mg has been indicated for the treatment of travelers' diarrhea and 550 mg has been indicated for the reduction in recurrence of episodes of overt hepatic encephalopathy in patients ≥18 years of age.
Rifaximin is also approved for the treatment of pathologies whose etiology is in part or totally due to intestinal acute and chronic infections sustained by Gram-positive and Gram-negative bacteria, with diarrhea syndromes, altered intestinal microbial flora, summer diarrhea-like episodes, traveler's diarrhea and enterocolitis, pre- and post-surgery prophylaxis of the infective complications in gastro intestinal surgery; and hyperammonemia therapy as coadjutant.
Rifaximin is a poorly water-soluble and minimally absorbed (<0.4%) drug with in vitro activity against enteric Gram-negative bacteria including enteric pathogens. [Gerard L et al., Rifaximin, a non-absorbable rifamycin antibiotic for use in nonsystemic gastrointestinal infections. Expert Review of Anti-infective therapy, 3(2), 201-211, (2005)].
It has also been reported that rifaximin is characterized by negligible systemic absorption, due to its chemical and physical characteristics [Descombe J J et al., Pharmacokinetic study of rifaximin after oral administration in healthy volunteers. International Journal of Clinical Pharmacology Research, 14 (2), 51-56, (1994)].
Rifaximin has been described to be endowed with an antibacterial activity similar to the activity of rifampin [Venturini A. P. and Marchi E., Chemiotherapia, 5 (4), 257-256, (1986)]. However, its mechanism of action differs from rifampin in that it is not absorbed through the systemic route after oral administration [Venturini A. P., Chemotherapy, 29, 1-3, (1983) and Cellai L. et al., Chemiotherapia, 3, (6), 373-377, (1984)] due to the zwitterionic nature of the compound, which cannot be absorbed by the gastrointestinal tract [Marchi E. et al., Journal of Medicinal Chemistry, 28, 960-963, (1985)].
Hence in addition to poor water solubility, rifaximin has no systemic absorption, which poses a challenge to alleviate systemic infections as well as to formulate suitable compositions of rifaximin.
Although several strategies and formulations such as complexing rifaximin with cyclodextrins, rifaximin nanoparticles have been employed in the prior art to overcome the limitations of solubility and poor systemic absorption, there still remains a need to improve the systemic absorption of rifaximin and enable it for the treatment of systemic infections, particularly Clostridium difficile infection, infections caused by Gram-positive and Gram-negative bacteria as well as for the treatment of colonic diseases.

Pharmaceutical compositions comprising rifaximin