A control arrangement (10) comprises a first selectable controller (12) for controlling an action, and a second selectable controller (14) for controlling the action. The arrangement also includes a selector (22) for selecting one of the controllers (12, 14) to control the action. The arrangement (10) further includes a first heat exchanger (16) associated with the first controller (12) to effect a transfer of heat between the first controller (12) and the first heat exchanger (16). The arrangement also includes a second heat exchanger (18) associated with the second controller (14) to effect a transfer of heat between the second controller (14) and the second heat exchanger (18).

Many components in gas turbine engines are required to be cooled in order to avoid overheating. In some cases, for example in the case of power electronic components, cooling is achieved by attaching the components to heat sinks.
In many applications in gas turbine engines, the heat sinks are supplied with a fluid, such as fuel or air, which acts as the low temperature reservoir to absorb the heat.
A problem with this arrangement is that in some conditions of use of the engine, the temperature difference between the fluid and the component to be cooled is not large enough to effect sufficient cooling of the component.

Control arrangement for cooling power electronic components


Method, systems and software are proposed for obtaining for blocks of a first image similar blocks of a second image (the “reference image”). The blocks of the first image are processed sequentially, for each block trying out a number of candidate locations in the second image and evaluating a cost function for each. Each candidate location in the second image is displaced by a respective motion vector from the block of the first image. In a first aspect of the invention the cost function is a function of a predicted motion vector for future blocks of the first image (i.e. blocks of the first image which have not yet been processed). In a second aspect of the invention the motion vectors are given by location values which are not all whole pixel spacings, halves of the pixel spacing, or quarters of the pixel spacing.

Due to the huge size of the raw digital video data (or image sequences) used by present day multimedia applications, compression must be applied to such data so that it can be transmitted and stored. There have been many important video compression standards, including the ISO/IEC MPEG-1, MPEG-2, MPEG-4 standards and the ITU-T H.261, H.263, H.264 standards. The ISO/IEC MPEG-1/2/4 standards are used extensively by the entertainment industry to distribute movies, digital video broadcast including video compact disk or VCD (MPEG-1), digital video disk or digital versatile disk or DVD (MPEG-2), recordable DVD (MPEG-2), digital video broadcast or DVB (MPEG-2), video-on-demand or VOD (MPEG-2), high definition television or HDTV in the US (MPEG-2), etc. The MPEG-4 standard is more advanced than MPEG-2 and can achieve high quality video at lower bit rate, making it very suitable for video streaming over internet, digital wireless network (e.g. 3 G network), multimedia messaging service (MMS standard from 3 GPP), etc. MPEG-4 is accepted into the next generation high definition DVD (HD-DVD) standard and the MMS standard. The ITU-T H.261/3/4 standards are designed for low-delay video phone and video conferencing systems. The early H.261 standard was designed to operate at bit rates of p*64 kbit/s, with p=1, 2, . . . , 31. The later H.263 standard is very successful and is widely used in modern day video conferencing systems, and in video streaming in broadband and in wireless network, including the multimedia messaging service (MMS) in 2.5 G and 3 G networks and beyond. The latest standard, H.264 (also called MPEG-4 Version 10, or MPEG-4 AVC) is currently the state-of-the-art video compression standard. It is so powerful that MPEG decided to jointly develop with ITU-T in the framework of the Joint Video Team (JVT). The new standard is called H.264 in ITU-T and is called MPEG-4 Advance Video Coding (MPEG-4 AVC), or MPEG-4 Version 10. H.264 is used in the HD-DVD standard, Direct Video Broadcast (DVB) standard and probably the MMS standard. Based on H.264, a related standard called the Audio Visual Standard (AVS) is currently under development in China. AVS 1.0 is designed for high definition television (HDTV). AVS-M is designed for mobile applications. H.264 has superior objective and subjective video quality over MPEG-1/2/4 and H.261/3. The basic encoding algorithm of H.264 [1] is similar to H.263 or MPEG-4 except that integer 4=4 discrete cosine transform (DCT) is used instead of the traditional 8=8 DCT and there are additional features include intra prediction mode for I-frames, multiple block sizes and multiple reference frames for motion estimation/compensation, quarter pixel accuracy for motion estimation, in-loop deblocking filter, context adaptive binary arithmetic coding, etc.
Motion Estimation is the core part in most video compression standards such as MPEG-1/2/4 and H.261/3/4, to exploit temporal redundancy, so its performance directly affects the compression efficiency, subjective video quality and coding speed of a video coding system.
In block matching motion estimation (BMME), the most common measure of the distortion between the current block and the reference block in ME is the sum of absolute difference (SAD), for an N×N block, defined as:
      SAD              (              mvx        ,        mvy            )        =            ∑                        m          =          0                ,                  n          =          0                            N        -        1                                                            F            t                                          (                                          x                +                m                            ,                              y                +                n                                      )                          -                              F                          t              -              1                                                      (                                          x                +                m                +                mvx                            ,                              y                +                n                +                mvy                                      )                                    where Ft is the current frame, Ft−1 is the reference frame and (mvx, mvy) represents the current motion vector (MV). For a frame with width=X, height=Y, and block size=N×N, the total number of search points at which the SAD needs to be evaluated in order to find the optimum motion vector in a search range equal to ±W is:
            (              X        N            )                  (              Y        N            )                          (                              2                        W                    +          1                )            2        ,which is equal to 1673100 for X=352, Y=288, N=16 and W=32. This is a huge number that can consume huge computation power in a video encoder. Many fast algorithms [2]-[9] have been proposed to reduce the number of search points in ME, such as Three-Step Search (TSS) [11], 2D log Search [12], New Three-Step Search (NTSS) [3], MVFAST [7], and PMVFAST [2]. MVFAST and PMVFAST significantly outperform the first three algorithms as they perform center-biased ME using a median motion vector predictor as a search center and hence reduce the number of bits for MV encoding by smoothing the motion vector field.
The PMVFAST algorithm (which is a significant improvement on MVFAST and other fast algorithms, and thus was accepted into MPEG standard [10]) initially considers a set of MV predictors, including median, zero, left, top, top-right and previous co-located MV predictor. FIG. 1 illustrates the locations of the locations of the current block, the left block, the top block, the topRight block, the topRightRight block, and the right block (which is a "future block", i.e. a block which is processed after the current block). It computes the SAD cost for each prediction. In later developments, PMVFAST was modified to compute the RD (Rate Distortion) cost [13] instead of the SAD cost using the following cost function:J(m,λmotion)=SAD(s,c(m))+λmotion(R(m−p))  (1)where s is the original video signal and c is the reference video signal, m is the current MV, p is the median MV predictor of the current block, λmotion is a Lagrange multiplier and R(m−p) represents the bits used to encode the motion information. The next step in PMVFAST is to select the MV predictor that has minimum cost, and perform large or small diamond searches based on the value of the minimum cost obtained from the MV predictors.
A separate but important issue in defining current video coding standards, is the use of subpixel motion vectors including half-pixel, quarter-pixel or perhaps even ⅛-pixel motion vectors, which give more accurate description of motion and can give a PSNR gain of about 1 dB over integer-pixel motion estimation. With half-pixel precision, motion vectors can take on uniformly-spaced location values such as 0.0, 0.5, 1.0, 1.5, 2.0, etc. With quarter-pixel precision, motion vectors can take on location values such as 0.00, 0.25, 0.50, 0.75, 1.00, 1.25, 1.50, 1.75, 2.00, etc. With ⅛ pixel precision, motion vectors can take on location values such as 0.000, 0.125, 0.250, 0.375, 0.500, 0.625, 0.750, 0.875, 1.000, 1.125, 1.250, 1.375, 1.500, 1.625, 1.750, 1.875, 2.000, etc.
It is well known that motion vector distribution tends to be center-biased, which means that motion vectors tend to be very close to (0, 0). This is shown in FIG. 6 (a), which shows the motion vector distribution in Foreman sequence using the Full Search (FS) algorithm for (0,0) MV. In addition, as shown in FIG. 6(b), the motion vector distribution is also biased towards the median predictor (medianMV) which is the median of the motion vectors for the left block, top block and topright block shown in FIG. 1. In addition, the motion vector is also biased towards the adjacent motion vectors (leftMV, topMV, topRightMV) in the current frame and the collocated motion vector (preMV) in the previous frame, as shown in FIG. 6(c). It is also biased towards the bottom-right motion vector (preBottomRightMV) in the previous frame, as shown in FIG. 6(d). These can all be considered predictors for the motion vector of the current vector and they can be used in PMVFAST.

Enhanced block-based motion estimation algorithms for video compression

The Hong Kong University of Science and Technology


A thin film magnetic head comprises: lower magnetic layer, insulating layer, upper magnetic layer and a protective layer, in this order, on a substrate, and has an end face exposed to a recording medium running surface. The protective layer is comprised of 20 to 75 mole % of ZrO.sub.2 and 25 to 80 mole % of WO.sub.3 (ZrO.sub.2 being partly replaced by Y.sub.2 O.sub.3, MgO, CaO and/or oxides of rare earth elements), with hardness Hv of 400 to 700 kgf/mm.sup.2 adjustable according to selection of composition and residual not more than 0.35 GPa.

In preparing a thin film magnetic head, upper and lower magnetic layers of sendust or amorphous materials are made on a substrate formed of a wear-resistant material, such as ferrite or sapphire. A coil conductor layer of conductive metals and an insulating layer are formed between these magnetic layers and subjected to repeated etching for patterning to a predetermined contour (pattern). Finally, a protective layer is formed for protecting the magnetic layers against wear caused by the running of the magnetic recording medium. Alumina or SiO.sub.2 have been used as the material for the protective layer.
In the above construction, it is well-known that, when the protective layer is sufficiently harder than the magnetic layers, the magnetic layers undergo premature wear due to sliding contact with the running recording medium. This results in the partially advancing wear (partial abrasion) of the magnetic layers, which leads to a spacing loss.
On the other hand, if the protective layer is too soft, the magnetic head in its entirety tends to undergo premature wear, resulting in a shortened service life and decreased durability. It is therefore preferred for the hardness of the protective layer to be approximately equal to or slightly lower than that of the magnetic layers.
Also, in view of the sliding properties and the resistance to the recording medium and the partially advancing wear, the protective layer needs to be 20 to 40 .mu.m or more in thickness. However, with such a film thickness, the protective layer usually undergoes peeling or cracking due to the cumulative internal stress. For this reason, the internal stress needs to be reduced to a value as low as possible. One effective method of obviating this drawback would be match to the coefficients of thermal expansion of the materials making up the magnetic head. However, it is generally difficult with conventional techniques to effect matching the coefficients of thermal expansion of the magnetic metal materials and the protective layer.
In the Japanese Patent KOKAI Publication No. 62-16218 (1987), a mixture of MgO and SiO.sub.2 is disclosed as a protective layer for effectively suppressing such partially advancing wear. It is also described therein that a moderate hardness Hv of 450 to 850 kgf/mm.sup.2 and a desired coefficient of thermal expansion may be realized by selecting the compositional ratio of MgO to SiO.sub.2 so that the SiO.sub.2 has a concentration of 10 to 70% in the MgO/SiO.sub.2 mixture.


This invention provides a method for increasing the activity of catalysts. The method requires the introduction of the catalyst into nano-structured surfaces. The catalysts are introduced as functional groups in molecules forming a monolayer on a surface. A mixed monolayer of catalyst and inert molecules generates ordered domains of molecules on the surface. The catalyst is confined in regions of 0.5 nm to 3 nm in size and is surrounded by an inert material. The presence of such ordered domains that commensurate in size with the reactants, enhance the performance of the catalyst and increase the rate of the reaction.

Catalysis is a powerful, general phenomenon that allows a reaction to proceed rapidly at a relatively low temperature. A catalyst is a substance that speeds up a reaction without being consumed itself. Catalysts for chemical reactions can be single atoms, atomic clusters, single molecules, organometallic compounds, surfaces, and biomolecules such as ribozymes and proteins. Catalysts operate by providing a lower-energy pathway for the reaction.
In order to provide a lower-energy pathway for a reaction. Successful catalysis depends on controlling the local environment of the reactants such that the molecule is shifted to a more reactive state. In practice, this usually means stressing the molecular bonds, increasing the polarization around the molecule, holding a normally high-energy state stable for a longer time, or in some cases, simply increasing the number of times that a molecule attempts to react.
One important biological catalyst is the enzyme. Enzymes are a class of protein macromolecules that increase the rate of the majority of the biochemical reactions carried out at body temperature. The catalytic activity of the enzymes is reflected in their ability to precisely position molecules and atoms in reactive arrangements.
Surfaces of solid materials are an additional class of important catalysts. Solid surfaces adsorb gaseous reactants and weaken their intramolecular bonds. Weakening the molecular bonds in the reactants, lowers the activation energy needed for the reaction, thus increasing the rate of the reaction.
In order to control the energy of a reactant, the catalyst itself must attain certain morphology. The catalyst morphology can be governed by the orientation of one molecule or by the configuration of two or more neighboring molecules. In a single molecular layer, specific orientation of a molecule with respect to neighboring molecules may be obtained. A single layer of molecules that is adsorbed on a surface is sometimes called a monolayer. Monolayer-forming molecules are usually long-chain hydrocarbon molecules terminated with reactive groups. One end of the molecule is reactive to the solid surface such that when the molecules are introduced to the surface, they bind to it and assemble into a single molecular layer.
When a monolayer is produced with two different molecules, phase segregation can occur, leading to local domains, patches or worm-like phases in the monolayer. When a monolayer is constructed on the surface of a nanoparticle, phase segregation occurs as well. Nanoparticles possess a high radius of curvature and this high curvature leads to the generation of phase segregated domains that can be less than 1 or 2 nm. Thus, molecular domains on monolayer-coated nanoparticles may have molecular scale dimensions.
Enhancing the properties of a monolayer catalyst through variations in monolayer structure, improve the catalysis of desired reactions.

Monolayer-coated surfaces as catalytic platforms for organic reactions


Methods, apparatus, systems and articles of manufacture are disclosed to improve resource utilization for binary tree structures. An example apparatus to improve resource utilization for field programmable gate array (FPGA) resources includes a computation determiner to identify a computation capability value associated with the FPGA resources, a k-ary tree builder to build a first k-ary tree having a number of k-ary nodes equal to the computation capability value, and an FPGA memory controller to initiate collision computation by transferring the first k-ary tree to a first memory of the FPGA resources.

In recent years, autonomous devices have performed collision checking tasks to avoid obstacles when traversing regions of interest. Collision checking tasks check the intersection between two given surfaces or volumes that may be represented by shapes, such as triangles, boxes, etc. The collision checking of the shapes is computationally intensive and to prevent unwanted collision of the autonomous devices with obstacles, processing speed must be sufficient.
The figures are not to scale. In general, the same reference numbers will be used throughout the drawing(s) and accompanying written description to refer to the same or like parts.

Methods, systems, articles of manufacture and apparatus to improve resource utilization for binary tree structures


The invention relates to a luminous element arrangement (A), in particular a luminous element field, comprising a plurality of luminous elements, at least one communication interface (5), in particular a bus and/or radio interface, and a converter unit (2), said converter unit (2) activating and/or deactivating the plurality of luminous elements of the luminous element arrangement (A) in response to a signal received via the communication interface (5) such that in top view onto the luminous element arrangement (A) a machine-readable code, in particular a one-dimensional or two-dimensional, machine-readable code is represented.

Machine-readable codes are known. The most widely known representatives thereof are barcodes (or bar codes, stripe codes, line codes), such as those used on many products. Known formats for such barcodes are EAN, UPC, IAN, JAN and codes from the 2/5 family, as well as codes in accordance with Code 39, Code 93, Codebar, Code 128, etc.
Moreover, "two-dimensional" (2D) barcodes are also known, which correspond, for example, to the code block format of Code 49, PDF417, or other formats in which encoded data can be resolved along two dimensions. Known two-dimensional codes are matrix codes, such as, e.g. Data Matrix codes, MaxiCodes, or the Aztec Code. Especially since 1994, the QR code is also a known representative of the 2D code, because it can encode a large amount of data, and also contains an error correction. It is also advantageous that QR codes can be used without licensing costs.

Luminous element arrangement for the dynamic display of a machine-readable code


Diamino compounds, dinitro compounds, diol compounds and a process for preparing the diamino compounds which are useful as materials of poly-imide compounds for obtaining aligning films having high pretilt angles in liquid crystal display elements are provided.. The diamino compounds are represented by the general formula: ##STR1## wherein R.sub.1 -R.sub.6 are a hydrogen atom or an alkyl group having 1 to 22 carbon atoms, respectively, and R.sub.7 -R.sub.12 are a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, F or Cl respectively.

The present invention relates to new diamino compounds, dinitro compounds, diol compounds and a process for preparing the diamino compounds. More specifically, the present invention relates to diamino compounds, dinitro compounds, diol compounds and a process for preparing the diamino compounds which are useful as materials of polyimide compounds for obtaining aligning films having high pretilt angles in liquid crystal display elements.
The main current of liquid crystal display elements which are used in conventional clocks, watches and electronic calculators is a twist nematic (abbreviated as TN hereinafter) mode having a structure in which molecular alignment of nematic liquid crystals is twisted at an angle of 90.degree. on the surface of a couple of upper and lower electrode substrates. However, this display mode is insufficient to obtain improved display in quality and size because it shows an indistinct contrast and a narrow viewing angle. In recent years, since a liquid crystal display device using super twisted birefringence effect was reported by T. J. Scheffer and J. Nethriug, Appl. Phys. Lett., 45 (10), 1021 (1984), a liquid crystal display element using supertwist nematic (abbreviated as STN hereinafter) mode in which the molecular alignment of nematic liquid crystals is twisted at angles of 180-290 degrees between the upper and lower electrode substrates has been developed, and then large panel liquid crystal elements having sufficient display quality are developing. In aligning films which are used for these elements, it is required to have a certain angle between the substrate surface and the liquid crystal molecules so as to align the liquid crystal molecules and give a quick response time and secure bistability. Further, it is desirable to give a wide pretilt angle along with a wide twist angle. Among these elements, in an element having a relatively narrow twist angle (twisted at 180-200 degrees), surface treatment on the electrode substrates is sufficiently conducted in the similar manner to those employed in conventional TN cells which are equipped with aligning films having surface alignment of pretilt angles (abbreviated as .theta. hereinafter) of five degrees and below. However, in STN modes having twist angles of 200-270 degrees along with better display quality, surface alignment having higher pretilt angles (5.degree..theta.<30.degree.) must be used, and therefore liquid crystal display cells having the aligning films which satisfy these angles are required.
In polyimide aligning films which are currently available for the TN mode, the limit of pretilt angles of display cells produced on a industrial scale is about five degrees.
Japanese Publication of Unexamined Patent Application No. 61-240223 describes a liquid crystal display element which is equipped with liquid crystal aligning films produced from a polyimide resin. The resin has a repeating unit represented by a formula: ##STR2## As materials for the polyimide resin, the only diamine represented by a formula: ##STR3## is exemplified.
However, the polyimide aligning films produced from the above diamino compound have a problem that high pretilt angles are unobtainable as shown in the comparative examples described hereinafter. Furthermore, there are polyimide aligning films having high pretilt angles for the STN mode. Problems of these films are stability and reproducibility of pretilt angles over the whole display surface of a cell substrate. In order to obtain the high pretilt angles definitely, the best method which is currently conducted is thin film formation by vacuum oblique evaporation of SiO and the like.
However, when the films are mass-produced by the vacuum evaporation, it is a costly process in its production unit. As the result, it is desired earnestly to realize the aligning films having high pretilt angles by the surface treatment of rubbing organic films that is the same method as in the conventional surface treatment method which has been employed in the TN mode.
Moreover, a method for synthesizing bisphenol A as a diol compound is disclosed in U.S. Pat. No. 2,468,982. ##STR4##


A multi-bank memory device includes rows and columns of memory cores. Each row includes memory cores from one bank interleaved with memory cores from another bank. Banks in different rows can be simultaneously accessed.

Direct Rambus Dynamic Random Access Memories, hereinafter referred to as DRDRAMs, are very fast, highly pipelined memory devices that are becoming an industry standard in high speed processing systems. DRDRAMs include a considerable amount of internal circuitry that supports the pipelined architecture so as to provide for very high communication bandwidths at the device boundary. DRDRAM sustained data transfer rates exceed 1 GB/s.
DR.DRAMs, like most commercially available memories, include memory cells that are arranged in rows and columns. Unlike many commercially available memories, however, DRDRAMs are multi-bank devices that have memory cells logically arranged into banks that can be independently accessed. This results in multiple banks within each DRDRAM, each including a number of memory cells. Gathering the memory cells into banks, and allowing different banks to undergo separate operations simultaneously, increases the overall data transfer rate of the device.
Each bank is associated with one or more sense amplifiers that function to read data from, and write data to, the memory cells within the bank. The sense amplifiers serve as a data communications bridge between the banks of memory cells and the data buses external to the device. Banks are separately activated, possibly simultaneously, or overlapping in time, prior to a read or write operation. When a bank is activated, it communicates with one or more sense amplifiers. When the read or write operation is complete, the bank is deactivated, and the sense amplifiers are precharged, which readies the sense amplifiers for another operation.
Examples of DRDRAMs are described in: "Rambus Direct RDRAM 128/144-Mbit (256 k×16/18×32 s) Preliminary Information," Document DL0059, V1.11, June 2000; and "Rambus Direct RDRAM 256/288-Mbit (1M×16/18×16d) Preliminary Information," Document DL0105, V1.1, August 2000. The contents of the aforementioned documents are hereby incorporated by reference.
FIG. 1 shows a prior art multi-bank memory device. Memory device 100 includes memory cells arranged in rows and columns. Each column is shown as a vertical strip of memory cells, and each row is shown as a horizontal strip of memory cells. For example, strip 102 is a column that includes memory cells 120, 124, and 128, and strip 104 is a column that includes memory cells 130, 134, and 138. In memory device 100, each column corresponds to a single bank of memory cores. For example, memory cores 120, 124, and 128 of strip 102 are part of Bank 0, and memory cores 130, 134, and 136 of strip 104 are part of Bank 1. As shown in FIG. 1, memory device 100 is arranged into "n" banks labeled Bank 0 through Bank (n−1).
Each bank shares sense amplifiers with at least one other bank. For example, sense amplifiers 140, 142, and 144 are shared between memory cores in Bank 0 and memory cores in Bank 1, and sense amplifiers 146, 148, and 150 are shared between memory cores in Bank 1 and memory cores in Bank 2.
Local row decoders are arranged within the array of memory cores. Each local row decoder provides wordline addressing to memory cores in close proximity. For example, in FIG. 1, each of row decoders 122 and 126 provide row decoding for one or more of the memory cores in strip 102.
Column decoding, in contrast to row decoding, is performed globally. Column decode lines driven by column decoders typically traverse an entire row of memory cores, rather than only memory cores nearby. For example, column decoder 110 drives column decode lines 160 shown schematically in FIG. 1 as an arrow. One or more of column decode lines 160 traverse multiple memory cells of the row to enable sense amplifiers within the row across from the column decoder. For example, a column decode line that enables sense amplifiers 146 to read from memory core 131 in Bank 2 will typically travel over, under, or past memory cores 120 and 130 from Banks 0 and 1, respectively.
In memory devices that allow simultaneous access to multiple banks, such as DRDRAMs, column decode lines that traverse memory cores from multiple banks can be problematic, in part because column decode lines addressed to one bank can cause electrical noise in memory cores of other banks being accessed. If noise is great enough, data errors can result.
FIG. 2 shows a prior art sense amplifier suitable for use in a multi-bank memory. Sense amplifier 200 includes N-sense amplifier 202 and P-sense amplifier 204 coupled between sense nodes 232 and 234, isolation transistors 206A, 206B, 208A, and 208B, column decode transistors 210 and 212, and bank select transistors 216 and 218. Sense nodes 232 and 234 are coupled to input output (I/O) lines 224 and 222 through the column decode and bank select transistors. A column decode signal (Y-GATE) on node 214 is coupled to column decode transistors 210 and 212, and a bank select signal (BANK) on node 220 is coupled to bank select transistors 216 and 218. Other column decode lines 230 driven by the column decoder 110 (FIG. 1) pass nearby sense amplifier 200. Other column decode lines 230 are coupled to other sense amplifiers (not shown) in the same manner that Y-GATE is coupled to sense amplifier 200 on node 214.
The operation of sense amplifier 200 is well known. When data from a memory core either to the left or right of sense amplifier 200 is to be read, the appropriate isolation transistors are turned on by either signal ISOL or ISOR, and the N-sense and P-sense amplifiers are activated using signals NLAT and ACT, respectively. The data value (and its complement) being read appears on sense nodes 232 and 234. When both the column decode signal (Y-GATE) on node 214 and the bank select signal (BANK) on node 220 are asserted, transistors 210, 212, 216, and 218 turn on and couple sense amplifier 200 to I/O lines 222 and 224.
When sense amplifier 200 is used in a multi-bank memory device that allows simultaneous operations among banks, the other column decode lines 230 can be actively changing during the operation of sense amplifier 200, causing noise that can potentially cause a data error. For example, referring now back to FIG. 1, if sense amplifier 140 is sensing data from memory core 120 in bank 0 while a column decode line addressing sense amplifier 146 is changing, a data error in sense amplifier 140 can result. As memory devices become larger, and more banks are added, the problem becomes worse.
For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for alternate multi-bank memory devices.


A system for storing data. The system includes a host for processing the data. The system includes a buffer mechanism for storing data and producing interrupt signals to the host for informing the host there is data in the buffer mechanism for the host to process. The buffer mechanism adapting the production of interrupts based on the speed the host can process data. The host is in contact with the buffer mechanism. A method for serving data. The method includes the steps of storing data in a buffer mechanism. Then there is the step of sending an initial interrupt signal to a host from the buffer mechanism informing the host there is data in the buffer mechanism for the host to process. Next there is the step of transferring data in the buffer mechanism to the host. Then there is the step of processing data from the buffer mechanism with the host. Next there is the step of adapting when a subsequent interrupt signal is sent to the host based on the speed the host can process data. Then there is the step of sending the subsequent interrupt signal to the host from the buffer mechanism when there is data in the buffer mechanism for the host to process.

Data packets arriving from a network are usually placed into a buffer queue to be processed by a host computer. When and how often an interrupt signal needs to be generated to alert the host that there are data packets waiting in the queue is usually a compromise between latency (how long the data must wait in the queue before the host is notified) and performance (how often the host is interrupted--an interrupt can require considerable processing by the host). The existing technique of generating an interrupt for every data packet provides minimum latency but can overwhelm a slow host with a large number of interrupts.
Existing schemes generate an interrupt every packet. The card would generate an interrupt every time an end-of-packet buffer is enqueued to the host. This method provides minimum latency but can generate multiple interrupts per packet. Lots of interrupts can be generated for short packets and a slow host (worst combination).
Other existing methods use a counter or timer to limit the number of interrupts but can have latency problems especially for video or voice data. An interrupt is generated every N packet and M clock ticks from the time the last packet was enqueued. This method attempts to minimize the number of interrupt by generating an interrupt after N packets are enqueued (N is programmable). To minimize latence in case N is large, an interrupt is generated based on a timer. The timer is triggered at the end of a packet. If the timer crosses a M threshold (programmable) without detecting the end of another packet, then an interrupt is generated. Using this scheme requires the programming of two parameters: N and M. It is difficult for the host to determine the optimum value for N and M for different load conditions and variations of the host and card.
The present invention produces interrupt signals based on the speed the host can process data. The interrupt signals are sent at intervals which do not overwhelm the host and significantly effect performance.

Method and apparatus for serving data with adaptable interrupts


A process for vapor phase fluorination of methylene chloride with anhydrous hydrogen fluoride (AHF) in the presence of a coprecipitated chromia-alumina impregnated with zinc salt as catalyst, removing HCl and heavier components by distillation, subjecting HFC-32 rich cut to a further step of fluorination in the presence of a fluorination catalyst.

This invention relates to a process for the preparation of difluoromethane (HFC-32) by vapor phase fluorination of methylene chloride with anhydrous hydrogen fluoride (AHF) using a coprecipitated chromia-alumina impregnated with a zinc salt as catalyst and purification of difluoromethane thus obtained, after removal of HCl and heavier components for enhancing the forward reaction of HCFC-31 to HFC-32, is passed over the fluorination catalyst in a second reactor to reduce the concentration of chlorofluoromethane (HCFC-31) by converting to pure HFC-32.
Hydrochlorofluorocarbons and Chlorofluorocarbons are used, extensively, as foam blowing agents, refrigerants, cleaning solvents and propellants for aerosol sprays. However, in the recent years there has been increasing international concern that chlorofluorocarbons may be damaging the earth""s protective ozone layer, which helps in containing the UV rays coming to earth. To this effect an international legislation has been put in place to ensure that their manufacture/use is phased out, completely. Extensive research work is being done to take care of the said concern and efforts are on to find suitable replacement(s) for chlorofluorocarbons. One such replacement could be fluorocarbons which do not contain chlorine, but which contain hydrogen.
The hydrofluorocarbon difluoromethane (HFC-32) is of interest as a substitute by itself or in the form of a blend with other hydrofluoroalkanes like 1,1,1,2-tetrafluoroethane (HFC-134a) and pentafluoraethane (HFC-125) for substituting ozone depleting HCFC""s like chlorodifluoromethane (R-22) and R-502 in refrigeration, air-conditioning and other applications.
It is known in the art that the catalytic vapor phase fluorination of haloalkanes containing at least one halogen atom selected from chlorine or bromine in the molecule with hydrogen fluoride results in the formation of fluorine rich haloalkanes. In the early stages aluminium fluoride and chromium fluoride were found suitable as catalysts for vapour phase fluorination of haloalkanes.
One of the earliest patent, U.S. Pat. No. 2,744,148, disclosed a metal halide of elements selected from nickel, chromium, cobalt, copper or palladium carried on aluminium fluoride as catalyst for fluorination of methylene chloride. However, the yield of HFC-32 was only 15%. The use of an oxygenated chromium trifluoride disclosed in U.S. Pat. No. 2,745,886 gave an yield of 35.7%.
The fluorination of methylene chloride to give HFC-32 involves two reaction steps. The first step is the exchange of one chlorine in dichloromethane by fluorine to give chrofluoromethane (HCFC-31). In the second step HCFC-31 is further fluorinated to give HFC-32. Both the steps referred above are reversible. All subsequent efforts were directed to the development of the fluorination catalyst that gave high conversion of methylene chloride with high selectivity of HFC-32.
UK patent GB 1307224 teaches the preparation of a chromium oxide catalyst for use in fluorination reaction. The examples carried out with methylene chloride and HF at 320xc2x0 C. gave a conversion of 51.7% and selectivity of 63.8% for HFC-32. The U.S. Pat. Nos. 6,337,299 and 6,300,531 reports use of chromium oxide as a fluorination catalyst for methylene chloride conversion to HFC-32. A conversion of 62% and selectivity of 80% for HFC-32 was reported. The U.S. Pat. No. 5,569,795 utilising chromia based, U.S. Pat. No. 5,900,514 utilising bulk chromia, U.S. Pat. No. 6,242,659 utilising chromium oxide with nickel and U.S. Pat. No. 5,763,704 utilising co-precipitated chromium oxide and Zinc as fluorination catalyst for the conversion of methylene chloride to HFC-32 is known. The highest conversion and selectivity of 99% and 93%, respectively were reported in U.S. Pat. No. 5,763,704 using Zn/Cr2O3 catalyst. However this was achieved only when the mole ratio of HF to methylene chloride was as high as 27.
The U.S. Pat. No. 5,710,353 reports the use of alumina or compounds of the element selected from Ti, V, Zr, Ge, Sn, Mo and Pb on alumina for the preparation of fluorination catalyst. This patent reports a very low conversion of 16.4% and a selectivity of 46.3% for HFC-32 using alumina alone. But the co-precipitated TiO2/Al2O3 gave a conversion of 75.7% and selectivity of 82% at a high mole ratio of HF to methylene chloride of about 17.
EP Patent 0128510 reports the use of aluminium chloride or alumina or mixed halide of chromia and alumina or mixed oxides of chromia and alumina or ferric chloride on carbon to generate catalysts for the fluorination of methylene chloride to HFC-32. The highest conversion of methylene chloride reported was 93% with 82% selectivity for HFC-32.
U.S. Pat. Nos. 5,155,082 and 5,763,708 report the use of a mixed oxide catalyst comprising CrO3/Al2O3 for the fluorination of methylene chloride to give HFC-32. The conversion and selectivity obtained was 82% and 89% in U.S. Pat. No. 5,763,708. EP 0805136 discloses a fluorination catalyst prepared by chromium and nickel compounds on aluminium fluoride for the fluorination of methylene chloride to HFC-32 to obtain a 61% conversion of methylene chloride and selectivity of 96% for HFC-32.
A serious problem with the production of difluoromethane by the fluorination of dichloromethane is that a substantial amount of a highly toxic intermediate, chlorofluoromethane (HCFC 31), is produced as an impurity.
To address this impurity, the conventional distillation process is of little help despite the difference in relative volatility between HCFC-31 (b.p. xe2x88x929.1 degree. C.) and HCFC-32 (b.p.: xe2x88x9251.7 degree C.) to bring down HCFC-31 below permissible limits.
European patent application EP 0508 630 describes a process for the contact of HFC-32 with an activated carbon to lower the HCFC-31 impurity in HFC-32. However, in the process, the selectivity is not very high and difluoromethane is adsorbed in the same proportions as HCFC-31, which in turn takes away the useful product as well as exhausts the capacity of the adsorbent at a faster rate than desired.
The use of molecular sieves for the purification of fluorohydrocarbons is known in the art. The purification treatments are usually performed at around ambient temperature. A process has been described in U.S. Pat. No. 5,608,129, to remove the traces of HCFC-31 present in HFC-32 by passing over a 13xc3x97molecular sieve at a temperature of at least 60 degree C.
An article by Rao, J. M. et al [See J. M. Rao et al Journal of Fluorine Chemistry 95 (1999) 177-180] teaches a process for preparing a catalyst based on co-precipitated chromia-alumina doped with zinc and/or magnesium involving the steps of co-precipitating chromia and alumina, washing and drying, shaping and impregnation of zinc chloride. The article also explains the occurrence of dismutation reaction in catalytical vapor phase halogen exchange reaction, which was attributed to the presence of strong acid centres in the catalyst. PCT application no. WO 01/74483 also mentions coprecipitated catalyst promoted with zinc.
The main object of the present invention is to provide a process for the preparation of difluoromethane and minimize the quantity of HCFC-31 in the product stream.
The coprecipitated chromia-alumina with zinc salt catalyst, when employed for the fluorination of methylene chloride, exhibited higher conversion and higher selectivity for HFC-32 under specific process conditions and also minimising formation of side products like methyl chloride and chloroform. The invention also embodies the reduction in the relative percentage of strong acid sites in the catalyst in order to achieve high selectivity.
The present invention relates to a process for the preparation of difluoromethane (HFC-32) by vapor phase fluorination of methylene chloride with anhydrous hydrogen fluoride (AHF) in the presence of a coprecipitated chromia-alumina impregnated with zinc salt as catalyst at a temperature ranging from 225-375xc2x0 C., preferably 250 to 350xc2x0 C., more preferably 260-325xc2x0 C. and contact time not exceeding 20 seconds, preferably between 4 to 10 seconds, removing HCl and heavier components by distillation, subjecting HFC 32 rich cut to a further step of fluorination in presence of fluorination catalyst to convert chlorofluroromethane (HCFC-31), an intermediate formed along with HFC-32, to HFC-32 thereby reducing the concentration of HCFC 31 in HFC-32 rich cut to obtain pure HFC-32.
In another embodiment of the invention the molar ratio of methylene chloride anhydrous hydrogen fluoride is in the range of 1:2.1 to 1:15, preferably in the range of 1:2.5 to 1:6.
Further, according to the present invention, the intermediate HCFC-31 present as an impurity in HFC-32, coming out of the reaction section and after HCl and heavier components removal is converted to HFC-32 by passing over fluorination catalyst in the second reactor to fluorinate HCFC-31 to HFC-32.
In another embodiment of the invention the highly toxic HCFC-31 is converted into the desired HFC-32 therein minimising the interaction of HCFC-31 with the environment substantially.
In another embodiment the heavier components comprising HCFC-31, unreacted methylene chloride and HF obtained after distillation of effluent stream coming out of the reactor is recycled back to the original feed.
The present invention is to provide a process for the preparation of difluoromethane and minimize the quantity of HCFC-31 in the product stream. Further, this product stream is distilled to obtain an HFC-32 rich stream which contains HCFC-31 and HF This stream is passed in the second reactor over a fluorination catalyst to get pure HFC-32.
The catalyst comprising a co-precipitated chromia alumina impregnated with a zinc salt, when employed for the fluorination of methylene chloride exhibited higher conversion and higher selectivity for HFC-32 and also minimising formation of side products like methyl chloride and chloroform. The said catalyst is used to convert the HCFC-31 present in the product stream to HFC-32.
The present invention relates to a process for the reaction of methylene chloride with anhydrous HF in the presence of said catalyst which provides higher conversion of methylene chloride with high selectivity for HFC-32 and also convert HCFC-31 present in the product stream to HFC-32.
The basic factors that influence the conversion of methylene chloride and selectivity for HFC-32 are:
Reaction temperatures
Mole ratio of methylehe chloride to AHF
The contact time for reaction
The characteristics of the precatalyst
The activation of precatalyst with HF.
The co-precipitated chromia alumina catalyst contain chromium-aluminium in the atomic ratio 1:1 to 1:10 and the amount of zinc compound used for impregnation of co-precipitated Chromia/Alumina catalyst ranges from 3-11% by weight. The catalyst should be X-ray amorphous and should contain the alumina in gamma phase and the chromia as chromium oxide trihydrate. The oxidation state of Cr should preferably be Cr (III) and the wt. % of Cr (VI) should be in the range 0-2% of the total chromium present in the said catalyst.
The fluorination reaction is carried out at a temperature in the range of 225-375xc2x0 C. The reaction temperature should preferably be in the range 250-350xc2x0 C. and more preferably between 260-325xc2x0 C.
The fluorination of methylene chloride with AHF using the co-precipitated chromia-alumina with zinc salt as catalyst to give HFC-32 could be carried out at pressures in the range from sub-atmospheric to superatmospheric pressures. The fluorination using the catalyst under the above mentioned temperature conditions is carried out at superatmospheric pressures.
The stoichiometric ratios for the fluorination of methylene chloride with HF is 1:2. However, excess of HF contributes to higher conversions and also extends the life of the said catalyst. The present invention uses excess of AHF and the mol. ratio of methylene chloride to AHF is in the range of 1:2.1 to 1:15, preferably, in the range 1:2.5 to 1:6.
The contact time for the fluorination of methylene chloride using AHF and the coprocitated chromia alumina with zinc salt as catalyst is in the range 3-20 seconds, preferably, in the range of 4-10 seconds.
The catalytic activity in the halogen exchange has been attributed to the Lewis acid centers. In the case of chromia based catalyst the activity was attributed to the number of reversibly oxidizable sites in the precatalyst. In the alumina based catalyst the formation of AlF3 in the beta and gamma phase during activation is critical to the catalytical activity. The activation of precatalyst is carried out under controlled conditions preventing the formation of alpha aluminium fluoride and the amorphous nature of the catalyst is maintained.
The catalyst was calcined and further activated by treating sequentially with N2 at 400xc2x0 C. for 24 hours followed by fluorination in the temperature range 150xc2x0 to 400xc2x0 C. till the exit stream of HF contains less that 1% of moisture.
The production of HFC-32 is carried out by reacting methylene chloride and HF in the presence of a co-precipitated chromia-alumina promoted with zinc salt. The effluent stream coming out of the fluorination reactor comprising of HFC-32, HCl, HCFC-31, unreacted methylene chloride and HF is sent to a second reactor. The separation and purification of HFC-32 is done in a phased manner using a series of distillations/condensations.
In another embodiment of the invention HFC-32 is purified by reacting HCFC-31, an intermediate and present as an impurity, with HF in the presence of the said catalyst. The present invention utilises the principle of enhancing the forward reaction by selectively removing one of the products formed, which in the present invention is HCl.
The present invention embodies the advantages of converting the highly toxic HCFC-31 into the desired HFC-32 therein minimising the interaction of HCFC-31 with the environment substantially.
A more complete appreciation of the invention and the attendant advantages thereof will be more clearly understood by reference to the accompanying drawings, which are for illustrative purposes, hence the same should not be construed to restrict the scope of the invention.

Process for the production of difluoromethane


A head (10) of a trigger dispensing device (1) for liquids includes a pre-compression valve (104) disposed in the upper region of the head. The valve (104) has an obturator wall (106) that cooperates with a mouth wall (102) to prevent the passage of liquid. The mouth wall (102) includes a sealing section (102a) with which the obturator wall (106) is sealingly engaged to slide during a pre-compression step of the liquid.

This invention covers a manual trigger-dispensing device for liquids, for example for the hygiene of the home, the deodorization of rooms, the treatment of fabrics before ironing, and the like.
Trigger devices are very widespread, as can be seen on supermarket shelves, especially for their ease of use and functionality. Every year many hundreds of millions of pieces are produced.
Among the numerous types, devices provided with pre-compression valve that allows dispensing the liquid only when the pressure in the pressure chamber is greater than a predefined pressure threshold are particularly popular.
See, for example, document WO 98/11995 or document BS2013A000114 in the name of the Applicant.
This allows obtaining numerous advantages, such as a more uniform jet, a longer range, an accentuated vaporisation and still others.
However, to obtain very high pre-compressions, in order to enhance the above advantages, it is necessary to provide special pre-compression valves.

Dispensing head with pre-compression valve for a trigger dispenser device


A laser projection display device 1 includes a laser light source driving unit 4 setting a current which drives a laser light source according to an image signal, a light sensor 10 detecting a light amount of the laser light generated by the laser light source 5, and a light emission control unit 22 emitting light by supplying a standard image signal and a current setting signal to the laser light source driving unit and setting the laser light source driving unit such that the light amount detected by the light sensor becomes a target value. The light emission control unit supplies the current setting signal to the laser light source driving unit such that light emission is performed a plurality of times with a predetermined current difference, in a fly-back period in one frame of the image signal.

(1) Field of the Invention
The present invention relates to a laser projection display device which performs scanning exiting light from a semiconductor laser or the like with a two-dimensional scanning mirror and performs an image display.
(2) Description of the Related Art
Recently, a laser projection display device using a two-dimensional scanning mirror such as a micro electro mechanical systems (MEMS) mirror and a semiconductor laser light source has spread. At this time, technologies as described below have been proposed in order to stabilize the brightness (the luminance) of a video to be display.
For example, in JP 2006-343397 A, a configuration is disclosed in which light emission intensity of laser light is adjusted corresponding to a change in a raster scanning rate in a horizontal direction at the time of performing raster scanning with respect to the laser light by using a biaxial MEMS resonant mirror. In addition, in JP 2012-155020 A, a configuration is disclosed in which a light amount of laser light exiting from a light source is detected by a standard input current value stored in a storage unit in an invalid scanning range out of a valid scanning range which is valid for forming an image, and in a case where the detected light amount is shifted from a standard light amount value stored in the storage unit by greater than or equal to a predetermined value, a video output current value from which the standard light amount value can be obtained, is searched, and a γ table is changed on the basis of a searching result.


A silencer for a vehicle exhaust assembly is described. The silencer comprises an outer wall, a porous exhaust pipe which defines an inner wall and a sound absorbent fibrous material located between the inner and the outer wall. The sound absorbent fibrous material is substantially unidirectional and parallel with the direction of gas flow through the porous exhaust pipe. The fibre is enclosed in a silencer cartridge. A method of producing such a cartridge is also described.

The silencer of a vehicle exhaust assembly may comprise an outer wall and porous exhaust pipe which defines an inner wall of an annular cavity. Typically, the cavity is randomly packed with sound absorbent material, for example, a glass fibre or basalt fibre material is positioned around the perforated pipe so as to fill the void between the pipe and the outer wall of the silencer and absorb sound waves which pass thereinto.
Since sound absorbent material in the form of glass fibre and basalt fibre is unpleasant to handle, suppliers of such fibrous materials supply the material to vehicle exhaust manufacturers in a suitably shaped and sized pack which is then inserted into the cavity of the silencer. Although the inner wall of the silencers are typically circular in cross section, the outer wall may be circular or oval and, increasingly, the oval outer wall is becoming more common. Numerous attempts have been made to improve the acoustic performance of silencers and it is one of the objects of the present invention to provide a silencer with a silencer cartridge with an improved acoustic performance.
A further problem with silencers of this type is that they are continuously subjected to directional gas flow which tends, over the course of time, to pack down the sound absorbent material or blow it out of the silencer altogether. Furthermore, the sound absorbent material is constantly vibrated so that the silencer material loosens over time and any structure present in the material collapses. The vibrational forces together with the uni-directional flow of gas through the silencer cause rapid degradation of the sound absorbent material leading to the necessity for its eventual replacement. It is a further object of the present invention to overcome these problems.
A still further problem with existing silencers, is that they are typically random packed with sound absorbent material. The random packing process tends to lead to a relatively wide variation in packing densities leading to difficulties in re-producibility and quality control in the final silencer product.
It is a still further object of the present invention to overcome this problem.
U.S. Pat. No. 5,670,756 discloses a silencer with the sound absorbing material wound directly around the outside of the inner sleeve with two or more turns so that the thickness of wound sound absorbing material around the inner sleeve is greater than the dimension of the gap between the inner sleeve and the outer sleeve to give an interference fit between the sound absorbing material and the inner and outer sleeves. The sound absorbing material with the inner sleeve is press fitted into the outer sleeve. The sound absorbing material is prevented from being blown out by exhaust gas flowing through the inside of the inner sleeve so that the silencer is improved in durability. This is provided by the press-fitting of the sound absorbent material which prevents vibration of the sound absorbing material during use. In addition, some stability in density is achieved by this technique compared with random packed silencers. However, although the vibrational problem is reduced, no attempt is made to solve the problem of the long term effect of uni-directional gas flow on the sound absorbing material.
U.S. Pat. No. 5,718,045 describes a similar technique where a sound absorbing material is formed of a heat-resistant fibre layer which is wound around an outer peripheral surface of the porous inner pipe with a binder inter-posed therebetween, and an outer peripheral surface of the heat-resistant fibre layer is press-fitted to an inner peripheral surface of the outer pipe with a predetermined interference. However, again, no attempt is made to address the problem of silencer degradation due to uni-directional gas flow.


A method and system to control an engine brake of a vehicle is provided. The vehicle is provided with a combustion engine having cylinders, an exhaust pressure governor (EPG) regulating the air flow out of the cylinders, an intake air throttle valve (ITV) regulating the air flow into the cylinders, pressure sensing means for sensing a pressure downstream of the cylinders, wherein an engine braking torque can be regulated in two different engine braking modes (a, b), ⋅a first engine braking mode (a), in which the air flow through the EPG is regulated by a closed loop control using the pressure downstream of the cylinders and the ITV is regulated in a feed forward control dependent of the engine speed and a demanded brake torque; ⋅a second engine braking mode (b), in which the EPG is regulated in a feed forward control dependent of the engine speed and the demanded brake torque, and the ITV regulates the braking torque by a closed loop control using the pressure downstream of the cylinders.

The present invention relates to the field of engine brakes of a vehicle. Especially for a vehicle provided with a combustion engine having cylinders with cylinder valves an exhaust pressure governor (EPG) regulating the air flow out of the cylinders and an intake air throttle valve (ITV) regulating the air flow into the cylinders.
Engine brakes which comprise a compression brake and an exhaust pressure governor (EPG) are known. The compression brake closes the cylinders valves, such that the air therein is compressed, whereby a brake torque is created. Normally, the compression brake is controlled by an on/off valve.
The EPG controls the pressure downstream of the cylinders, wherein a closing of the EPG usually leads to a higher exhaust manifold pressure, thereby a higher engine brake torque. The EPG is usually controlled with a closed-loop control with the exhaust pressure as feedback signal.
The total engine brake torque is a combination of the brake torque contribution from the compression brake and the EPG.
The inputs to a controller of the compression brake are the demanded exhaust pressure and the actual exhaust pressure. The output from the controller of the compression brake is a control signal that controls the movement of the EPG. During engine braking, the exhaust pressure is proportional to the engine brake torque and is therefore used to indirectly control the engine brake torque.
For some engines, especially turbo compound engines, and at some engine speeds, it is not possible to control the brake torque contribution from the compression brake between a zero brake torque contribution from the compression brake when it is deactivated and the maximum brake torque contribution from the compression brake that can be achieved with the compression brake activated. Due to the fact that the compression brake is activated by an ON/Off valve, continuous control of engine brake torque is not possible between the maximum torque that can be reached with only the EPG and the torque that is reached with the compression brake only.
Hence, during some conditions, the engine brake torque regulation cannot be regulated indefinitely or in small discrete steps, instead just in an on/off mode, due to the on/off regulation of the compression brake.
There is thus a need for an improved regulation of a vehicles engine brake, which removes the above mentioned disadvantage.
It is desirable to provide an inventive method to control an engine brake of a vehicle, wherein said method facilitates better control possibilities of the engine brake.
The inventive method to control an engine brake of a vehicle is adapted for a vehicle provided with a combustion engine having;
cylinders allowing a compression braking therewith,
an exhaust pressure governor (EPG) regulating the air flow out of the cylinders,
an intake air throttle valve (ITV) regulating the air flow into the cylinders, and
pressure sensing means for sensing a pressure downstream of the cylinders.
The engine brake of said vehicle is adapted to be regulated in two different engine brake modes;
a first engine brake mode, in which the air flow through the EPG is regulated by a closed loop control using said pressure downstream of the cylinders and the ITV is regulated in a feed forward control dependent of the engine speed and a demanded brake torque, and
a second engine brake mode, in which the EPG is regulated in a feed forward control dependent of the engine speed (S) and the demanded brake torque (T), and the ITV regulates the braking torque by a closed loop control using said pressure downstream of the cylinders.
When the ITV is regulated such that the intake air mass flow in the cylinders of the engine is decreased, the braking torque contribution from the compression brake is decreased. An infinite or discrete regulation of the compression brake can thereby be achieved.
Because both the engine brake modes regulates the braking torque with a closed loop control against the pressure downstream of the cylinders a smooth transition between the two different engine brake modes is facilitated.
In the first regulation mode, the EPG is regulated dependent of the sensed pressure downstream of the cylinders, wherein the ITV is regulated in a feed forward control dependent of the engine speed and a demanded brake torque. The position of the ITV is recalled from a two-dimensional map or a list having the engine speed and the demanded brake torque as input signals. The map or list is preferably predetermined and stored in the engine brake controller.
In the second regulation mode, the EPG is regulated in a feed forward control dependent of the engine speed and demanded brake torque. The ITV regulates the braking torque in direct dependency of the sensed pressure downstream of the cylinders. The position of the EPG is recalled from a two-dimensional map or a list having the engine speed and the demanded brake torque as input signals. As before, the map or list is preferably predetermined and stored in the engine brake controller. The second regulation mode is used if the EPG is already completely open and less torque/exhaust pressure is requested, wherein this regulation has to be done with the ITV, whereby the engine brake can be more exact regulated over a greater torque span.
A determination of which of the first and the second engine braking mode that should be used is dependent on a demanded braking torque and an actual engine speed, thereby can always the optimal braking torque regulation be used for all situations of operation of the engine.
It is preferred that the sensing means for sensing a pressure downstream of the cylinders, senses the exhaust manifold pressure from the cylinders. Existing pressure sensors for sensing the exhaust manifold pressure from the cylinders can thereby be used without any additional cost.
It is preferred that the second braking mode is used when a demanded brake torque is below a brake torque threshold value, or an actual engine speed is above an engine speed threshold value. At high engine speeds, an activation of the compression brake gives very high braking torque, where by limit values of the engine can be exceeded, i.e. exhaust temperature, pressure differences over exhaust valves, etc, by controlling the engine brake in the second mode this can be avoided, in that the brake torque is reduced using the ITV.
The second brake mode is also preferred at lower engine speeds and a low brake torque demands.
It is further preferred that said first brake mode is used when a demanded engine brake torque is above an engine brake torque threshold value and an actual engine speed is below an engine speed threshold value. The highest brake torque is achieved when both the EPG and the compression brake is controlled to deliver a maximum brake torque.
It is further preferred that a switching from said second braking mode to said first braking mode is done, when the demanded braking torque increases above an engine braking torque threshold value and the engine speed is below an engine speed threshold value.
It is further preferred that a switching from said first braking mode to said second braking mode is done, when the demanded braking torque is decreasing below an engine torque threshold value, or when the actual engine speed increases above an engine speed threshold value, or when the EPG is completely open and the demanded exhaust manifold pressure is lower than an actual exhaust manifold pressure, or when an EPG actuator failure occurs. An optimal regulation of the braking torque is thereby achieved for all operation conditions of the engine.
It is further preferred that said engine is equipped with a charge air cooler bypass valve (CAC-valve), whereby during engine braking said CAC-valve can be controlled to increase or decrease said exhaust manifold pressure. The CAC-valve can be regulated in the same exact manner, and is suitable to regulate against the pressure downstream of the cylinders, e.g. the exhaust manifold pressure. Thereby can an engine brake controller choose to regulate the air mass flow into the cylinders with either the CAC-valve or the ITV. The temperature of the exhaust gas can thereby be regulated, which is important in order to achieve high enough temperatures for the exhaust gas after treatment system.
It is further preferred that said engine torque threshold value comprises a first and a second engine torque threshold value, wherein said first engine torque threshold value is lower than said second engine torque threshold value, and said engine speed threshold value comprises a first and a second engine speed threshold value, wherein said first engine speed threshold value is lower than said second engine speed threshold value, wherein said first threshold values are used when the reference value increases and the second threshold value are used when the reference value decreases. By using a hysteresis function as described above, unnecessary switching between the two modes of regulation are avoided in the bounder areas.
It is further preferred that said first engine torque threshold value is dependent of the engine speed.
The invention also relates to an engine brake system for a vehicle, where a control unit is arranged to perform said method steps.

Method and engine brake system to control an engine brake of a vehicle


A method of combining digital image data from two different images in a printer enables improved precision of alignment of the image data. The method includes copying a word of first image data into a memory buffer, shifting a word of image data by a predetermined bit offset, overwriting a portion of the first image data with shifted bits from the second word of image data, and copying the shifted word of image data into the memory buffer. The printer forms a line of a printed image using the first and second image data in the memory buffer.

A wide range of printers produce printed documents from digital image data. In some instances, the digital image data represent one or more printed pages and the printer reproduces the printed pages during a print job. Some printers are also configured to merge two or more digital images together to produce a printed page that includes portions of each of the digital images. For example, in a merge operation, the printer merges an overlay digital image over a background digital image to form a single printed page with the overlay digital image merged with the background. The printer merges the image data for both the background image and the digital image to form a composite merged image prior to printing the final document. Document processing systems enable an operator to select two or more digital images and to arrange the digital images on a page in a wide range of configurations.
While existing printers can produce printed output from a combination of multiple digital images, limitations in the processing of the digital data can limit the options for how multiple digital images can be combined in a printed document. For example, many printers form images on a line-by-line basis based on a series of linear sets of binary data, which are commonly denoted as raster image data. A printer that combines two different digital images forms the raster image data with portions of both images that are arranged in the appropriate locations along the line. Existing printers can have limited resolution in positioning an overlay image on a background image in the raster line. For example, one existing printer aligns digital data only at addresses in the raster image line that are evenly divisible by sixteen bits. The digital image data can only be moved by a number of pixels corresponding to the sixteen-bit increment, resulting in a limited number of options for aligning two digital images together during a merge operation. Consequently, improvements to the manipulation of digital data in a printer to form combined printed images with improved alignment precision would be beneficial.

System and method for merged image alignment in raster image data


A camera device by which a still picture photographed without data transfer to a personal computer can be viewed on the personal computer. The camera apparatus includes an optical system, an imaging device 21 for converting light signals of the object from the optical system into electrical signals, an A/D converter 22 for converting the electrical signals from the imaging device 21 into digital picture data, a data compression unit 28a for compressing the picture data from the A/D converter 22 in a pre-set style based on a software program, and a data conversion unit 28, 31, 32 for converting compressed data from the data compression unit 28a into data of a pre-set style that permits recording on a recording floppy disc.

1. Field of the Invention
This invention relates to a camera device and, more particularly, to a camera device for digitizing a picture of an object for recording as still picture data.
2. Related Art
Recently, as personal computers are coming into widespread use, digital camera devices, configured for digitizing and recording pictures, are stirring up notice as picture recording devices. As the digital camera devices, there are known such devices in which a pre-set number of object are digitized and recorded in a pre-set recording medium such as a flash memory as still-picture data so that the still pictures can be subsequently outputted to a monitor of the personal computer. The digital camera device usually has the function as a picture reproducing device of displaying a picture recorded on a pre-set recording medium from a picture display unit, such as a LCD panel, provided on the back side of the device. In addition, the digital camera device occasionally has the function of editing picture data such as erasing a recorded picture corresponding to an unneeded picture or an unsatisfactory picture.
In a conventional digital camera device, a flash memory enclosed in a main body portion or a telescopically movable card-type flash memory is used as a recording medium for picture data.
However, in the conventional digital camera device, since these memories are expensive in terms of costs per photographed picture and hence is not suitable as storage medium, it is necessary to transfer the photographed still picture data to a hard disc or a floppy disc in the personal computer for copying after photographing, this data transfer representing a time-and labor-consuming operation. In the conventional digital camera device, these memories are costly such that the user cannot own a number of such memories, so that the number of pictures that can be photographed cannot be increased as desired, while the chance of photographing outdoors is restricted since the user cannot carry the personal computers outdoors.
It is therefore an object of the present invention to provide a camera device whereby a still picture photographed without data transfer to a personal computer can be viewed on the personal computer.
The present invention provides a camera apparatus includes an optical system, an imaging device for converting light signals of the object from the optical system into electrical signals, an A/D converter for converting the electrical signals from the imaging device into digital picture data, data compression means for compressing the picture data from the A/D converter in a pre-set style based on a software program, and data conversion means for converting compressed data from the data compression means into data of a pre-set style that permits recording on a recording floppy disc.
With the present camera apparatus, the light signals of the object from the optical system are converted by the imaging device, A/D converter, data compression means and data convertion means into pre-set data that permits recording on a floppy disc.
Since the light signals of the object from the optical system are converted by the imaging device, A/D converter, data compression means and data conversion means into pre-set data and subsequently recorded on the floppy disc, the photographed still picture can be easily seen on a personal computer on loading the floppy disc carrying recorded still picture of the object on the floppy disc drive of the personal computer. This eliminates the necessity of transferring the photographed still picture data to a hard disc or a floppy disc of the personal computer after photographing to dispense with the time-consuming data transfer operation.

Camera apparatus and method for associating digital picture files with thumbnail images


A pump includes a cylinder and a plunger. The cylinder defines an outlet-side passage therein. The plunger is reciprocably received within the cylinder. An inner peripheral surface of the cylinder and an end surface of the plunger define a pump chamber. The outlet-side passage is communicated with the pump chamber. When the plunger reciprocates within the cylinder, fluid inside the pump chamber is pressurized such that fluid is discharged to an exterior through the outlet-side passage. The inner peripheral surface includes a spherical surface part that surrounds the pump chamber. The spherical surface part is defined by a curved surface having a predetermined curvature such that the pump chamber defines a spherical space. The spherical surface part is provided with an opening of the outlet-side passage, which has a circular shape when observed from a spherical center of the pump chamber.

1. Field of the Invention
The present invention relates to a pump that suctions and discharges fluid.
2. Description of Related Art
A fuel injection apparatus, which injects fuel to a compression ignition internal combustion engine, has a supply pump that compresses fuel and supplies the compressed fuel to a common rail. The supply pump has a hollow-cylindrical compression space (hereinafter, referred as a pump chamber) formed by an inner peripheral surface of a cylinder and an end surface (top portion) of a plunger. When the plunger reciprocates within the cylinder to pressurize fuel in the pump chamber, high pressure fuel is discharged toward the common rail through a discharge passage (for example, JP-A-S64-73166). For example, the discharge passage has an opening that is formed at an inner peripheral surface of the cylinder, which surface surrounds the pump chamber.
In the conventional supply pump, when fuel within the pump chamber is compressed, fuel pressure disadvantageously causes localized stress concentration generated around the opening formed at the inner peripheral surface of the cylinder.
Generation of the stress concentration at the opening formed at the inner peripheral surface of the cylinder will be described with reference to FIGS. 7A and 7B. FIG. 7A is a cross-sectional view of a part of a cylinder of the conventional supply pump, and FIG. 7B is a partial development for developing the vicinity of the opening of the cylinder inner peripheral surface in a circumferential direction along the inner peripheral surface of the cylinder of the conventional supply pump. It should be noted that multiple arrows in FIG. 7B indicate directions of tensile stress generated when fuel within the pump chamber is compressed.
The conventional supply pump, as shown in FIG. 7B, has an opening 130b. For example, the opening 130b has an oval shape and is formed at a cylinder inner peripheral surface 130a of a cylinder 130, which surface surrounds a pump chamber 150. The cylinder inner peripheral surface 130a intersects or is connected with an inner peripheral surface of a discharge passage 130c at the opening 130b as shown in FIG. 7A. When fuel in a pump chamber 150 is pressurized, fuel pressure expands the cylinder inner peripheral surface 130a, which surrounds the pump chamber 150, in a radially outward direction of the cylinder 130. Further, the discharge passage 130c is also expanded in a radially outward direction of the discharge passage 130c. As a result, an outline of the opening 130b formed at the cylinder inner peripheral surface 130a deforms from an oval shape (solid line in FIG. 7B) into a more circular shape (alternate long and short dash line in FIG. 7B).
In the above, tensile stress is applied to the cylinder inner peripheral surface 130a in a circumferential direction of the cylinder 130 along the cylinder inner peripheral surface 130a. Also, tensile stress is applied to the vicinity of the opening 130b, which has the oval shape, and which is formed at the cylinder inner peripheral surface 130a, in the circumferential direction of the discharge passage 130c along the opening 130b.
In the above, tensile stress applied to the vicinity of the opening 130b is large at positions X (indicated by dashed line) and is small at positions Y (indicated by dashed line), and thereby distribution of tensile stress applied to the vicinity of the opening 130b is ununiform. As a result, localized stress concentration is more likely to be generated at the opening 130b of the cylinder inner peripheral surface 130a. Thus, repetition of suctioning and discharging fuel during the operation of the pump may cause fluctuation of stress at the vicinity of the opening 130b, and thereby fatigue failure may be caused disadvantageously. Subsequently, the cylinder may be broken.


An integrated air separation and power generation process produces an O2-enriched gas stream and an N2-enriched gas stream in an air separation unit. The O2-enriched gas stream is introduced with fuel and steam to a combustor, producing flue gas. At least a portion of the flue gas and steam stream exiting the combustor is used to generate power. The N2-enriched gas stream is heated and power is generated from the heated N2-enriched gas stream.

The present invention relates to an integrated air separation and power generation process. More specifically, the present invention relates to a process for separating at least oxygen and nitrogen from air and integrating the use of oxygen and nitrogen into a process for efficiently generating electrical power.
Cogeneration involves using a single fuel source to simultaneously produce, in the same facility, thermal energy, usually in the form of steam, and electric energy. Since the Public Utility Regulatory Policy Act of 1978, owners of cogeneration facilities have been given a financial incentive to sell excess electrical power to utility companies, while utilities are encouraged to purchase that electrical power. Consequently, there has been a continuing effort to improve the energy efficiency of cogeneration plants, particularly in the United States. Moreover, the rising and volatile costs of natural gas have increased the economic incentive for many cogeneration plants to use other fuel sources, such as coal, for example.
Many cogeneration processes use an integrated, high-efficiency combined cycle to increase efficiency. Typically, a combined cycle is a steam turbine (i.e., Rankine-cycle) thermodynamically coupled with a gas turbine (i.e., Brayton-cycle). Steam and gas turbine combined cycle systems are often used where natural gas is the fuel source because natural gas tends to have a lower concentration of impurities that can cause hot corrosion, fouling and rapid deterioration in the gas turbine parts, particularly gas turbine blade surfaces. Therefore, historically, use of high-efficiency steam/gas combined cycle systems has been discouraged where coal is used as a fuel source due to the various impurities in coal that can cause gas turbine corrosion. Consequently, when using a steam/gas combined cycle in a coal combustion cogeneration process, it is important to limit the gas turbine""s exposure to flue gas impurities and temperatures significantly exceeding the maximum admissible value. The maximum admissible temperature for a gas turbine is primarily dictated by the gas turbine""s materials of construction and its other operating conditions and is typically in a range of from about 1000xc2x0 C. to about 1450xc2x0 C. Limiting exposure to flue gas impurities and higher temperatures will help forestall significant corrosion problems with the gas turbine and, thereby, keep equipment maintenance costs down.
U.S. Pat. No. 4,116,005 by Willyoung proposes using a fluidized combustor bed containing sulfur-sorbing particles that are fluidized by a gas turbine""s air exhaust, at about atmospheric pressure, which also provides an O2 source for the coal""s combustion. However, Willyoung""s proposed system fails to further enhance the inherent efficiency of using a steam/gas combined cycle in a cogeneration process. Also, Willyoung""s modification of the combustion chamber with a fluidized bed requires significant expense and upkeep for limiting gas turbine corrosion.
Another factor challenging many coal fired cogeneration processes are gaseous emissions into the atmosphere, particularly nitrogen oxides (NOx), such as nitrogen oxide (NO), nitrogen dioxide (NO2) and nitrous oxide (N2O), sulfur oxides (SOx), such as sulfur dioxide (SO2) and sulfur trioxide (SO3), and carbon dioxide (CO2). Some global warming proponents relate excess N2O and CO2 emissions to climatological change. Also, NOx emissons, such as NO or NO2, in sufficient concentration, can be toxic to health and the environment. Additionally, SOx emissions, in sufficient concentration, can contribute to the production of xe2x80x9cacid rain,xe2x80x9d which can have a detrimental effect on various plant and aquatic life. Thus, it is possible that many or all of these gases could become more stringently regulated, at least in certain market-developed countries or regions, such the United States, Canada, Japan and Europe. Consequently, this prospect of increasing regulatory stringency for some or all gaseous emissions that are typically coal combustion by-products has made coal-fueled cogeneration processes less attractive from an operational cost standpoint.
For instance, various countries, including, among others, France, Germany, the United Kingdom, Australia, the United States, Canada and Japan have agreed to seek internal approval and adoption, within their respective jurisdictions, of the Kyoto Protocol. The Kyoto Protocol ensued from the United Nations Framework Convention on Climate Change, held in December, 1997 at Kyoto, Japan. Under the Kyoto Protocol each participant agreed in principle to xe2x80x9cimplement and/or further elaborate policies and measures in accordance with its national circumstancesxe2x80x9d to, among other things, enhance energy efficiency and protect reservoirs of certain atmospheric gases not controlled by the Montreal Protocol (e.g., CO2).
Generally, under the Kyoto Protocol the participating countries agreed to limit emissions of greenhouse gases specified under the Protocol, including CO2, methane (CH4), N2O, hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulfur hexafluoride (SF6), as well as work towards reducing the overall emissions of these gases by at least 5 percent below 1990 levels in the target period of 2008 to 2012. To date, no legislative amendments to the U.S. Clean Air Act Amendments of 1990 (CAAA) have been passed that would require facilities operating in the U.S. to comply with the Kyoto Protocol greenhouse gas emissions target. Nonetheless, the 1996-2000 U.S. administration has made a policy decision to promote voluntary compliance with the Kyoto Protocol. Accordingly, companies operating in the U.S. that have significant CO2 emissions have been encouraged to voluntarily work towards the Kyoto Protocol""s target level for the greenhouse gases specified. Also, if good progress towards the Protocol""s goals is not shown, it is possible that some further amendments to the CAAA could flow from the Kyoto Protocol. CAAA amendments conforming with the Kyoto Protocol could also be motivated if models are developed to more definitively measure and predict the extent of global climate changes based on current and projected gaseous emissions. Thus, limiting the gaseous emissions, particularly from coal-fueled power generation plants, while maintaining an energy efficient power generation process is becoming a more important commercial objective.
For example, U.S. Pat. No. 5,937,652 by Abdelmalek proposes to produce energy more efficiently and reduce CO2 emissions from a combined coal gasification and synthesis gas (i.e., a carbon monoxide (CO) and hydrogen gas (H2) mixture) combustion process. The coal gasification step is conducted under an oxygen (O2) free atmosphere, while using CO2 and steam as oxidants for the coal fuel. The heat from the coal/CO2 gasification reaction is used to produce steam for driving a steam turbine/generator that produces electricity. Also, Abdelmalek separates CO2 from sulfur dioxide (SO2) and other gases discharged from a boiler using a cyclone separator system disclosed in U.S. Pat. Nos. 5,403,569 and 5,321,946.
Abdelmalek indicates that the process has a higher efficiency because the gasification reaction is run without O2, while the separated CO2, which is recycled back to the gasification chamber for reacting with coal, produces a nitrogen (N2) free synthesis gas, namely a CO and H2 mixture. This CO/H2 mixture is then combusted with O2 to generate heat. According to Abdelmalek, the gross heat value of his combined coal gasification, where little to no O2 is present, and synthesis gas combustion process, where CO and H2 are reacted with O2 to produce the principle heat, is 20% greater versus conventional coal combustion processes, where coal is burned using O2 as a principle oxidant. Abdelmalek also contends that his process reduces CO2 emissions by 20%. Moreover, Abdelmalek teaches that the combustion reaction chemistry, particularly where coal is a fuel source (e.g., coal+O2), makes conventional combustion type reactions inherently limited in the extent to which they can be made any more efficient, even in the context of a cogeneration process. Consequently, Abdelmalek fails to disclose how to improve the efficiency of a cogeneration process primarily using direct combustion of a fuel, such as coal, and/or reduce CO2 emissions to the atmosphere, as well as other gaseous emissions, such as nitrous oxide (NO), nitrous oxide (N2O) and nitrogen dioxide (NO2), (collectively called NOx) and/or sulfur dioxide (SO2) and sulfur trioxide (SO3) (collectively called SOx).
Another example of producing CO2 and energy from the same process and fuel source is disclosed in U.S. Pat. No. 6,047,547 by Heaf. Heaf proposes a portable integrated cogeneration system that produces electric power, steam and liquid CO2 and other products necessary for producing and filling bottled or canned beverage products. Specifically, Heaf proposes using a combustion engine generator (CEG) to produce electric power and a combustion powered water boiler to produce steam. A CO2 recovery unit connected with the CEG and water boiler receives exhaust gases from the CEG and water boiler for separating and recovering CO2 from the exhaust gases and a compressor is used to liquefy the recovered CO2. Heaf suggests that his cogeneration system can produce large quantities of CO2 from one and preferably both the CEG and the combustion powered water boiler. But, with respect to operating efficiency, Heaf only suggests that his integrated cogeneration system xe2x80x9cis efficient and saves costs when incorporated into a beverage production facility.xe2x80x9d But Heaf fails to quantify the efficiency of his proposed cogeneration process. Moreover, Heaf fails to disclose any means or methods for improving operating efficiency in combustion powered boiler systems used outside the context of a beverage production and bottling facility.
U.S. Pat. No. 5,067,837 by Rathbone et al is directed to an air separation process in combination with a chemical process. A nitrogen stream produced in the air separation unit is pressurized to at least 5 atmospheres and heated via heat exchange with a hot fluid produced in the chemical process. The heated nitrogen is then expanded in an expansion turbine to produce work. The nitrogen exiting the turbine is: (a) used to heat the oxygen or fuel in a heat exchanger; (b) vented to the atmosphere; or (c) used to raise steam in a steam generator. However, Rathbone suggests using O2 in a partial oxidation type reaction where purified natural gas is reacted with O2 to form a synthesis gas with a desired CO content (i.e., a gasification process). Also, Rathbone suggests using N2 heated only with a hot synthesis gas produced from a gasification process, rather than a combustion process that oxidizes the fuel more completely to produce a flue gas primarily comprising CO2 and, where natural gas is the fuel, CO2 and water vapor, among other reaction products. Moreover, Rathbone fails to disclose any means or methods for improving operating efficiency in combustion powered boiler systems used outside the context of a natural gas gasification process.
U.S. Pat. No. 5,709,077 (Jan. 20, 1998), U.S. Pat. No. 5,715,673 (Feb. 10, 1998), U.S. Pat. No. 5,956,937 (Sep. 28, 1999) and U.S. Pat. No. 5,970,702 (Oct. 26, 1999), all by Beichel and assigned to Clean Energy Systems, Inc. (Sacramento, Calif.), describe a power generation system in which high pressure fuel and high pressure O2 are burned in a gas generator to generate high temperature gas. The combustion temperature is controlled by cooling water injected into a gas mixing chamber in the gas generator. The high pressure, high temperature steam/CO2 mixture from the gas generator is passed through a series of three turbines with inter-turbine reheaters between the turbines. The gas is condensed and water is recycled to the gas generator.
U.S. Pat. No. 5,680,764 (Oct. 28, 1997) by Viteri, also assigned to Clean Energy Systems, Inc., describes a power generation system where pressurized fuel and O2 are fed to a gas generator to achieve complete combustion and maximum temperature hot gases (6,500xc2x0 R (6,040xc2x0 F., 3,300xc2x0 C.). The hot gases are diluted with water to reduce the temperature to 2,000xc2x0 R (1,540xc2x0 F., 840xc2x0 C.). When hydrogen is used as a fuel, the drive gas is steam and when a light hydrocarbon is used, the drive gas is steam and CO2. The hot gas is expanded in a turbine for powering a vehicle and then condensed into water to complete the Rankine cycle. About 75% of the water is recirculated to the gas generator. In one embodiment, the Rankine cycle is replaced with Otto and Diesel thermal cycles to eliminate the need for a condenser and recirculating water system. Depending on the fuel used, low temperature steam (hydrogen fuel) or steam/CO2 (hydrocarbon fuel) gases are recirculated as the working fluid in the Otto and Diesel embodiment.
U.S. Pat. No. 6,170,264 (Jan. 9, 2001), also by Viteri and assigned to Clean Energy Systems, Inc., describes the same process as U.S. Pat. No. 5,680,764 and further suggests using an air separation plant. Enriched O2 is used in a combustion device and enriched N2 is vented to the atmosphere. In one embodiment, CO2 is sequestered into deep underground or undersea locations.
Typically, the overall energy producing efficiency of most coal-fired cogeneration processes is in a range from about 25% to about 35%. Consequently, there is a need for an integrated cogeneration process for producing electrical power and thermal energy with improved efficiency. Preferably, the total efficiency of an improved cogeneration process would be greater than about 40% and, more preferably, greater than about 50%.
Also, the more energy efficient cogeneration process should have a method for reducing corrosion effects on gas turbines used in steam turbine/gas turbine combined cycle, while being adaptable to incorporating, as desired, a system for reducing and/or eliminating various gaseous emissions, such as CO2, NOx and/or SOx, to the atmosphere.
According to the invention, there is provided an integrated air separation and power generation process, comprising the steps of:
(a) introducing an O2/N2 source to an air separation unit;
(b) separating the O2/N2 source into at least an O2-enriched gaseous stream and an N2-enriched gaseous stream;
(c) introducing at least a portion of the O2-enriched gaseous stream, having a pressure of at least about 3 bars (300 kPa), and fuel to a combustor to produce a combustion mixture;
(d) burning the combustion mixture to produce at least a flue gas;
(e) injecting steam into the combustor, before, during and/or after the combustion mixture burning step, to produce a modified combustion mixture of at least steam and flue gas;
(f) generating power by introducing the modified combustion mixture exiting the combustor into a first power generating means;
(g) heating at least a portion of the N2-enriched gaseous stream, having a pressure of at least 3 bars (300 kPa); and
(h) generating power by introducing the heated N2-enriched gaseous stream into a second power generating means.

Integrated air separation and power generation process