A hydrogen purification system that is used to separate hydrogen gas from a mixed gas source. The hydrogen purification system includes a hydrogen separator. Within the hydrogen separator is a first chamber into which the mixed gas source is fed. A plurality of tubes extend into the first chamber. Each of the plurality of tubes is permeable only to hydrogen. Gap spaces exist within the first chamber in between any of the plurality of tubes that are arranged in adjacent positions. The mixed source gas passes through the gap spaces as it permeates the first chamber. The mixed gas source spreads thinly over the exterior of the tubes within the confines of the gap spaces. Hydrogen from the mixed gas source permeates thru the tube walls and into the interior of the tubes that are in parallel and the hydrogen is collected in a chamber.

1. Field of the Invention
The present invention relates to systems and methods that are used to separate hydrogen from a volume of mixed gas. More particularly, the present invention is related to systems and methods that separate hydrogen from a volume of mixed gas by exposing the mixed gas to a hydrogen permeable material through which only atomic hydrogen can readily pass.
2. Prior Art Description
In industry, there are many applications for the use of purified hydrogen. However, in many common processes that produce hydrogen, the hydrogen gas produced is not pure. Rather, when hydrogen is produced, the resultant gas is often contaminated with water vapor, hydrocarbons and/or other contaminants. In many instances, however, it is desired to have ultra pure hydrogen. In the art, ultra pure hydrogen is commonly considered to be hydrogen having purity levels of at least 99.999%. In order to achieve such purity levels, hydrogen gas must be actively separated from its contaminants.
In the prior art, one of the most common ways to purify contaminated hydrogen gas is to pass the gas through a conduit made of a hydrogen permeable material, such as palladium or a palladium alloy. As the contaminated hydrogen gas passes through the conduit, atomic hydrogen permeates through the walls of the conduit, thereby separating from the contaminants. In such prior art processes, the conduit is kept internally pressurized and is typically heated to at least three hundred degrees Centigrade. Within the conduit, molecular hydrogen disassociates into atomic hydrogen on the surface of the conduit and the conduit absorbs the atomic hydrogen. The atomic hydrogen permeates through the conduit from a high pressure side of the conduit to a low pressure side of the conduit. Once at the low pressure side of the conduit, the atomic hydrogen recombines to form molecular hydrogen. The molecular hydrogen that passes through the walls of the conduit can then be collected for use. Such prior art systems are exemplified by U.S. Pat. No. 5,614,001 to Kosaka et al., entitled Hydrogen Separator, Hydrogen Separating Apparatus And Method For Manufacturing Hydrogen Separator.
The flow rate of hydrogen gas through the walls of a conduit is proportional to the length of the conduit and the thickness of the walls of the conduit. Thus, a highly efficient purification system would have a very long, very thin conduit to maximize flow rate. However, palladium is a very expensive precious metal. Consequently, conduits made of palladium and palladium alloys are very expensive to manufacture. As such, it is desirable to use as little of the palladium as possible in manufacturing a hydrogen gas purification system. Furthermore, conduits made from palladium and palladium alloys typically hold gas under pressure and at high temperatures. Accordingly, the walls of the conduit cannot be made too thin, otherwise the conduit will either rupture or collapse depending upon the pressure gradient present across the wall of the conduit.
A typical prior art hydrogen separator uses coils made from palladium tubing. Coils are used to maximize the surface area of the palladium within a confined space. However, there are many disadvantages associated with the use of coiled tubing. In order for a palladium based hydrogen separator to work, it must be heated to a temperature in excess of 300 degrees Centigrade. As palladium coils are heated to such temperatures, they expand. Furthermore, as hydrogen diffuses through the walls of the palladium coils, the palladium expands significantly. As a palladium coil is repeatedly expanded and contracted, the palladium coil twists. The twisting of the palladium coils fatigues the palladium and causes the palladium to become brittle. Eventually, a palladium coil will crack and the hydrogen separator will cease to work.
Another disadvantage of hydrogen separators that use coiled palladium tubing is that the coils of palladium are very susceptible to vibration damage. The palladium coils within a hydrogen separator act as springs. If the hydrogen separator experiences any vibrations during operation, those vibrations resonate within the palladium coils, causing the palladium coils to move. As the palladium coils resonate and move, the palladium experiences fatigue and becomes brittle. This eventually causes the palladium coils to crack and fail.
Yet another disadvantage of hydrogen separators that use palladium coils is that of contaminant gas back up. If a hydrocarbon rich gas is introduced into a palladium coil, some hydrogen will disassociate from the hydrocarbon and will pass through the wall of the palladium coil. What is left behind in the palladium coil is mostly carbon and oxygen, which forms carbon dioxide and carbon monoxide. The carbon dioxide and carbon monoxide fill the palladium tube. New hydrocarbon gas must therefore diffuse through this contaminant gas before it can reach the surface of the palladium coil. If there is a large back up of contaminant gas, the hydrocarbons may take a very long time to reach a palladium surface. Hydrogen in the supply gas must be able to reach the palladium surface in a timeframe that is short compared to the residence time of gas in the coil. However, the concentration of the non-hydrogen component in the supply gas will increase gradually as more and more hydrogen is removed as the gas stream progresses through the coil. This greatly reduces the efficiency of the hydrogen separator. If the flow in the palladium tubing is increased to flush out contaminant gas, hydrocarbons may flow through the palladium tubing before ever having a chance to lose hydrogen through the palladium. This too greatly reduces the efficiency of the hydrogen separator.
To further complicate matters, conduits made from palladium and palladium alloys may become less efficient over time as the interior walls of the conduits become clogged with contaminants. In order to elongate the life of such conduits, many manufacturers attempt to clean the conduits by reverse pressurizing the conduits. In such a procedure, the exterior of the conduit is exposed to pressurized hydrogen. The hydrogen passes through the conduit wall and into the interior of the conduit. As the hydrogen passes into the interior of the conduit, the hydrogen may remove some of the contaminants that have deposited on the interior wall of the conduit.
Due to the generally cylindrical shape of most prior art hydrogen purification conduits, the conduits are capable of withstanding a fairly high pressure gradient when the interior of the conduit is pressurized higher than the exterior of the conduit. However, when such conduits are cleaned and the external pressure of the conduit is raised higher than the interior pressure, a much lower pressure gradient must be used, otherwise the conduits will implode.
In the prior art, improved conduit designs have been developed that attempt to minimize the amount of palladium used in a conduit, yet increase the strength of the conduit. One such prior art device is shown in U.S. Pat. No. 4,699,637 to Iniotakis, entitled Hydrogen Permeation Membrane. In the Iniotakis patent, a thin layer of palladium is reinforced between two layers of mesh. The laminar structure is then rolled into a conduit. Such a structure uses less palladium. However, the conduit is incapable of holding the same pressure gradient as solid palladium conduits. Accordingly, the increase in efficiency provided by the thinner palladium layer is partially offset by the decreased pressure limits, and thus gas flow rate, that are capable of being processed.
Another prior art approach to limiting the amount of palladium used is to create membranes that are placed over apertures, like a skin on a drum. A pressure gradient is then created on opposite sides of the membrane, thereby causing hydrogen to flow through the membrane. Such prior art systems are exemplified by U.S. Pat. No. 5,734,092 to Wang et al., entitled Planar Palladium Structure. A problem associated with such prior art systems is that the palladium or palladium alloy membrane is typically positioned in a level plane, wherein a pressure gradient exists from one side of the membrane to the other. Since the membrane is flat, it has little structural integrity when trying to resist the forces created by the pressure gradient. Accordingly, in order to prevent the membrane from rupturing, solid perforated substrates are used to reinforce the membrane. The solid perforated substrates, however, are complicated to manufacture, restrict the flow through the membrane, and reduce the efficiency of the overall system.
U.S. Pat. No. 6,152,987 to Ma, entitled Hydrogen Gas-Extraction Module And Method Of Fabrication, discloses a hydrogen separator where a solid layer of hydrogen permeable material is deposited over a porous substrate of dissimilar material. The porous substrate supports the hydrogen permeable material and provides much more support than prior art mesh support systems. However, the porous substrate only allows gas to contact the hydrogen permeable material where a pore gap is exposed to the hydrogen permeable material. This configuration greatly limits the area of hydrogen permeable material actually exposed to gas. Furthermore, due to differences in thermal coefficients and other physical properties, hydrogen permeable material deposited on a substrate of a dissimilar material tends to separate from the substrate. This can cause leakage of contaminated gas through the hydrogen permeable material and the eventual failure of the system.
U.S. Patent Application No. 2003/0190486 to Roa et al, also discloses a hydrogen separator where a solid layer of hydrogen permeable material is deposited over a porous substrate of dissimilar material. In the Roa application, a palladium alloy is deposited over the porous substrate of dissimilar material using a first electroplating process. Copper is then deposited on the palladium in a second electroplating process. The palladium and copper layers are then annealed to produce a palladium alloy in place on the substrate. However, the porous substrate again only allows gas to contact the hydrogen permeable material where a pore gap is exposed to the hydrogen permeable material. This configuration greatly limits the area of hydrogen permeable material actually exposed to gas.
Furthermore, palladium alloy does not bond well to the porous substrate of dissimilar material. This leads to eventual failure. In prior art systems, such as the previously cited Ma patent and the Roa application, where palladium alloy is deposited directly on a porous substrate, another problem is that the substrates have large pore sizes to maximize exposure of the palladium alloy to gas. This requires that thick uneven layers of palladium be deposited over the porous substrate to cover the pores of the substrate. This causes faults in the layer of palladium that tend to fail over time.
Attempts have been made to eliminate these problems by creating a porous structure of a palladium alloy and then coating this porous structure with a solid layer of the same palladium alloy. In U.S. Patent Application Publication No. 2004/0237779 to Ma, entitled Composite Gas Separation Modules Having Intermediate Porous Metal Layers, a porous stainless steel substrate is provided. A porous intermediate layer of palladium alloy is then created by electroplating the palladium alloy directly onto the stainless steel. Finally, a solid layer of palladium alloy is deposited onto the porous intermediate layer.
In such systems, the porous layer of palladium alloy is still deposited directly onto the porous substrate of dissimilar material. The dissimilar materials bond poorly resulting in many eventual detachment flaws. More importantly, the intermediate palladium alloy layer is deposited using electroplating techniques. In electroplating, ions of a metal are drawn through an electroplating solution. Such an electroplating solution contains hydrocarbons. As the ions of palladium alloy are deposited onto the porous stainless steel substrate, the deposited particles of palladium alloy tend to become coated in carbon from the electroplating solution. The carbon coating on the deposited particles of palladium alloy prevent hydrogen from being able to permeate through the palladium alloy. Rather, the carbon acts as a physical barrier between the palladium alloy and the hydrogen. This greatly inhibits the performance of the hydrogen separator.
A need therefore exists in the art of hydrogen purification for a system and method that can handle high flow rates of gas per unit area, and yet uses only a minimal amount of hydrogen permeable material. A need also exists for a hydrogen purification system with a hydrogen permeable layer that is strongly bonded to its supporting substrate and unobstructed by carbon, so that it can more reliably pass hydrogen while withstanding large pressure gradients and repeated temperature cycles over longer periods of time. These needs are met by the present invention as described and claimed below.

System and method for separating hydrogen gas from a mixed gas source using composite structure tubes


A battery load leveling system for an electrically powered system in which a battery is subject to intermittent high current loading, the system including a first battery, a second battery, and a load coupled to the batteries. The system includes a passive storage device, a unidirectional conducting apparatus coupled in series electrical circuit with the passive storage device and poled to conduct current from the passive storage device to the load, the series electrical circuit coupled in parallel with the battery such that the passive storage device provides current to the load when the battery terminal voltage is less than voltage on the passive storage device, and a battery switching circuit that connects the first and second batteries in either a lower voltage parallel arrangement or a higher voltage series arrangement.

This invention relates generally to electric drive systems and, more particularly, to a battery load leveling system that may be utilized with a hybrid or an electric vehicle.
At least one known vehicle includes batteries, typically lead-acid batteries, to provide electric power for vehicle propulsion. For example, FIG. 1 is a prior art vehicle that includes a conventional alternating current (AC) electric propulsion system 10 that is used in electric propelled and also hybrid-electric vehicles. The electric propulsion system includes at least one energy storage unit such as a lead acid battery 12, and a direct current (DC) contactor 14 to electrically disconnect the energy storage unit 12 from a traction inverter 16 via a DC link 18. Specifically, the battery 12 is connected to a DC link which connects to a frequency controlled inverter such as traction DC-AC inverter 16 for controlling power to an AC motor 20.
In the operation of the vehicle, the battery is often called upon to deliver short bursts of power at high current levels, typically during acceleration of the vehicle or while operating the vehicle up a steep grade, for example. When high current is drawn from conventional batteries, battery terminal voltage drops. Such voltage reduction can interfere with proper operation of the vehicle or reduce efficiency of the switching devices in the power control circuit since the control circuit must also be designed to operate at high efficiency at full battery voltage, i.e., when the vehicle is drawing nominal current in a constant speed mode.
One method for reducing the effect of high current requirements on electric drive system batteries is to use an auxiliary passive energy storage device coupled to the DC link to provide additional power during high current situations. One implementation of this method is shown in the prior art FIG. 2. Specifically, FIG. 2 illustrates an energy storage system 30 that includes a traction battery 32 and an ultracapacitor 34, and a relatively low-cost ultracapacitor electronic interface 36 that allows the ultracapacitor 34 to share power with the traction battery 32 during vehicle acceleration and other high power demands while climbing steep grades.
During operation, when the known vehicle is operated during a lower power cruise condition, a diode 40 allows the ultracapacitor voltage to remain at a slightly higher voltage than the battery voltage. Immediately after the high power acceleration is complete, the required current from the energy storage system substantially decreases and the battery voltage increases to the nominal battery voltage or possibly higher voltages, while the ultracapacitor remains at approximately the voltage immediately after the acceleration. Moreover, when the vehicle is decelerating, a silicon-controlled rectifier 42 is gated and the regenerative energy from the electric motor 44 and associated traction drive 46 initially charges the ultracapacitor 34 until the voltage increases to a point where the diode 40 conducts, at which point both the ultracapacitor 34 and battery 32 are partially recharged. As such, the known energy storage system functions quite well and also provides an efficient and low-cost interface between the ultracapacitor and the traction battery in low speed electric vehicles, including golf cars and small utility vehicles. However, during operation, the amount of energy stored in the ultracapacitor 34 is limited by the square of the voltage difference between the maximum battery voltage plus the voltage drop across the diode 40, and the minimum battery voltage plus the voltage drop across the diode 40.
As a result, known energy storage systems are less effective for providing relatively high power levels over an extended period of time while the vehicle is either accelerating under heavy loads and/or climbing steep grades. Moreover, known energy systems include an electronic interface that may be less effective in matching the ultracapacitor output voltage with the voltage level required for the traction drive with acceptable efficiency and at a reasonable cost.

This patent is subject to a terminal disclaimer.

Energy storage system for electric or hybrid vehicle


A dual harmonization method for a worn head-up display system for making the display of piloting information of an aircraft on a display conform with the outside real world includes a step of acquisition of N measurements {circumflex over (K)}ι of head posture detection by a series of sightings Vi corresponding to images oriented according to orientations Oi of one and the same photograph taken by a camera, secured to and aligned with the attitude inertial device D3, then a step of joint computation of the matrices of relative orientation M01 and M23 as joint solutions of the dual harmonization Ûi=Ĝ·{circumflex over (K)}i·{circumflex over (D)}, i varying from 1 to N, in which Ûι is the transpose of the matrix M(image(i)/0) of relative orientation of the image(i) of rank i relative to the display D0, with M01 and M23 respectively equal to the right and left matrices {circumflex over (D)} and Ĝ. A worn head-up display system is configured to implement the dual harmonization method.

The head-up display devices, whether worn or not, make it possible to display in particular a "symbology" conforming to the outside world, that is to say a set of symbols whose position in front of the eye or the pilot allows for a superimposition with the corresponding elements in the outside real world. It can be for example a speed vector, a target on the ground such as a symbol representing a landing runway, a synthetic representation of the terrain or even a sensor image.
This conformal display requires knowledge of the position and of the attitude of the aircraft and, for head-worn display devices, the attitude of the display relative to a fixed reference linked to the aircraft. These different positions and attitudes are supplied by the avionics systems for those of the aircraft, and by the posture detection device DDP for those of the display.
For example and in particular, the avionics systems for supplying the position and the attitude of an aircraft can be:
a global positioning device of GPS (Global Positioning System) type; and
an inertial reference system IRS based on gyroscopes and accelerometers of MEMS (Microelectromechanical Systems) type or on a laser gyroscope, or an attitude and heading reference system AHRS.
As is known, a harmonization of the head-up display system is performed on installation of a head-up display system, worn or not worn, in the cockpit in order to compute the correction of angles to be made to switch from the display reference frame to the aircraft reference frame, and in order to obtain a conformal head-up display.
To date and as is known, the avionics system for supplying the attitude of the aircraft relative to the Earth, hereinafter called attitude inertial device, is:
rigidly secured to the platform of the aircraft, which requires a lengthy harmonization procedure to align said attitude inertial device on said platform, or
attached to the fiducial device linked to the platform, which also requires a lengthy harmonization procedure to align said fiducial device on the platform of the aircraft.
Many platforms of aircraft such as, for example, helicopters or light aeroplanes are not these days equipped with conventional inertial means for supplying their own attitude relative to the Earth but recently it has become possible to use small inertial equipment items capable of suppling the pilot with this attitude information with relatively correct performance levels. These equipment items can easily be packaged in removable modules that can be "attached by suction", that is to say fixed using a sucker, onto the windshield of the supporting structure of the cockpit. Such inertial equipment items of small size also include a device for supplying the position of the equipment item and therefore of the aircraft.
According to a first drawback, the removable nature of this inertial equipment item with a new fixing configuration each time said inertial equipment item is moved requires the implementation of a procedure for a new humanization of the conformal display system that is accurate and rapid.
According to a second drawback, this inertial equipment item knows the heading of the aircraft with relatively little accuracy in the absence of movement of the platform. Indeed, the presence of a positioning device, of GPS type, incorporated in the equipment of item, and of hybridation algorithms, make it possible to refine the knowledge of the heading during the changes in the movement of the aircraft, but on the ground, before take-off, the value known for the heading is relatively incorrect.
A first technical problem is how to provide a worn head-up display system for making the display of piloting information of an aircraft conform with the outside real world and the method for mutual harmonization of the elements of said head-up display system which make it possible to rapidly and accurately know the relative orientation of the attitude inertial device of the removable inertial equipment item, that can easily be moved, relative to the fixed fiducial element linked to the platform, also constituting the fixed element of the posture detection subsystem DDP.
A second technical problem is how to provide a worn head-up display system and a harmonization method which make it possible to rapidly and accurately know the relative orientation of the attitude inertial device of the removable inertial equipment item, that can easily be moved, relative to the fixed fiducial element linked to the platform, and the relative orientation of the display of the worn head-up display system relative to the mobile tracking element of the posture detection subsystem DDP.
A third technical problem is how to provide a head-up display system for making the display of piloting information of an aircraft conform with the outside real world and a harmonization method which makes it possible to rapidly and accurately know the relative orientation of the attitude inertial device of the removable inertial equipment item, that can easily be moved, relative to the platform of the aircraft.

Dual harmonization method and system for a worn head-up display system with a removable attitude inertial device in the cockpit


A method, system and computer program product for detecting sensitive personal information in a storage device. A block delta list containing a list of changed blocks in the storage device is processed. After identifying the changed blocks from the block delta list, a search is performed on those identified changed blocks for sensitive personal information using a character scanning technique. After identifying a changed block deemed to contain sensitive personal information, the changed block is translated from the block level to the file level using a hierarchical reverse mapping technique. By only analyzing the changed blocks to determine if they contain sensitive personal information, a lesser quantity of blocks needs to be processed in order to detect sensitive personal information in the storage device in near real-time. In this manner, sensitive personal information is detected in the storage device using fewer computing resources in a shorter amount of time.

Currently, sensitive personal information (also referred to as personally identifiable information) is detected in a storage device in near real-time via textual processing of the files in a file system for the storage device. Sensitive personal information, as used herein, refers to information (e.g., financial and health information, social security numbers, data about children, geolocation data) that can be used on its own or with other information to identify, contact or locate a single person or to identify an individual in context. A file is technically defined as an ordered set of characters implemented over a block device. A file then is a collection of extents, with each extent corresponding to a contiguous set of blocks, obtained from a block device (also referred to as a logical unit number (LUN)). A block is a contiguous set of bits or bytes that forms an identifiable unit of data. Since sensitive personal information is detected in the storage device in near real-time via textual processing of the files at the file layer, all of the blocks associated with those files are also processed. As a result, a large quantity of blocks are being processed in order to detect sensitive personal information in the storage device in near real-time. The system needs to detect sensitive personal information at the file layer since the end user (or other consumer) is usually only interested in that level of granularity of detection.
Hence, the common approach to detecting sensitive personal information involves detecting sensitive personal information at a file by file level leading to large amounts of data being processed even for small changes within a file, perhaps spanning a single block. By processing a large quantity of blocks, an inordinate amount of computing resources is being utilized to detect sensitive personal information. Furthermore, by processing a large quantity of blocks, it increases the time in detecting sensitive personal information.

Detection of sensitive personal information in a storage device

International Business Machines Corporation


Provided is a method for producing a yeast containing glutamic acid at a high concentration. In the method for culturing a yeast, a yeast in a stationary growth phase is subjected to liquid culture under the conditions that the pH of a liquid medium is 7.5 or higher and lower than 11. After the pH of the liquid medium for the yeast in a stationary growth phase is adjusted to 7.5 or higher and lower than 11, the yeast is further cultured, whereby a yeast with a high glutamic acid content can be produced. In the invention, as the yeast, Saccharomyces cerevisiae or Candida utilis can be used. Therefore, by using the yeast with a high glutamic acid content obtained by the above-said method and the extract obtained by extraction from the yeast, a seasoning composition and a food or drink with a high glutamic acid content can be provided.

There is currently a worldwide demand for a natural and health-oriented non-artificial seasoning with no use of additives, as led by Japan and developed countries including European countries and the U.S. Regarding this demand, although a high-value added extract with enhanced "umami" such as nucleic acid has been developed in the yeast extract industry, development is also progressing for amino acids, such as glutamic acid, which is a representative of "umami" equivalent to nucleic acid.
Glutamic acid has been in widespread use for a long time in the form of sodium glutamate as a chemical seasoning or the like. Recently, preference has been shown for the utilization of a culture or extract or the like, which is obtained by culturing yeast naturally containing glutamic acid, in a food or drink.
For example, PTL (Patent Literature) 1 describes a sweetness improver containing a yeast extract as an active component, wherein the yeast extract contains sodium 5′-inosinate and/or sodium 5′-adenylate, sodium 5′-guanylate, sodium 5′-uridylate and sodium 5′-cytidylate at a concentration of 1% to 15%, respectively, and sodium glutamate at a concentration of 1% to 20%.
PTL 2 describes a method for producing a yeast extract containing at least 3% of intracellular free glutamine-derived glutamic acid relative to the extract solids, which includes a step of digesting a yeast containing 15 mg or more of free glutamine per 1 g of dried biomass.
PTL 3 describes a yeast extract obtained by digestion or decomposition of a yeast, wherein when the yeast extract is allowed to pass through a filter membrane having a diameter of 1 μm and the permeate is subjected to gel filtration, and when peptides in the fractionated effluent are detected by absorption spectrophotometry at 220 nm, a portion of peptides having a molecular weight of 10,000 or higher is 10% or higher based on the total amount of all the detected peptides.
PTL 4 describes a yeast extract with a high glutamic acid content, which contains 13% by weight or more of L-glutamic acid (as a Na salt).
PTL 5 describes a yeast extract wherein the content of free amino acid is 25% by weight or more, and the total content of nucleic acid-based gustatory components is 2% by weight or more.
PTL 6 describes a seasoning composition containing nucleic acid-based gustatory substances, glutamic acids, potassium and lactic acid, sodium lactate or potassium lactate, wherein a molar ratio of nucleic acid-based gustatory substance:glutamic acid is in the range of 1:2 to 40, and a molar ratio of (nucleic acid-based gustatory substances+glutamic acids):potassium:(lactic acid, sodium lactate or potassium lactate) is in the range of 1:5 to 80:10 to 80.
PTL 7 describes a yeast which is resistant to a glutamic acid antagonistic growth inhibitor and accumulates glutamic acid in biomass.
PTL 8 describes a method for producing a yeast extract, which uses Yarrowia lipolytica, a yeast having resistance to Nystatin, a drug which obstructs the structure and function of the cell membrane, and which has a capacity to accumulate 530 mg/L or more of L-glutamic acid in biomass.

Method for producing yeast with high glutamic acid content


A cover (1) for a standard container (2), has a substantially rectangular bottom (3) and a substantially rectangular opening (4) at the top. The cover (1) includes lower rib portions (6) which are disposed in a substantially rectangular configuration with rounded corners which fit into the opening (4) of the container (2) and upper rib portions (8) which are disposed in a rectangular configuration dimensioned almost similar to those of the set of lower rib portions (6). The rib portions (6,8) are separated by gaps (7,9) which allow easy washing, and the gaps (7) of one set of rib portions (6) are not adjacent to the gaps (9) of the other set of rib portions (8). To make it easier to grip the cover (1), a portion of its edge is raised to form a handle (10) adjacent to a rib portion (8) of the upper set. Stacking of containers on covers and stacking of covers one on another is thereby greatly facilitated.

The present invention relates to a cover for a standard container, said container having a substantially rectangular bottom with rounded corners and side walls that are flared upwards, the tops of the side walls delimiting a substantially rectangular opening with rounded corners, said cover being constituted by a plate made of a thermo-plastic material and provided with upper rib portions which project from its upper surface in a rectangular configuration with gaps and with lower rib portions which project from its lower surface in a substantially rectangular configuration to fit into the opening.
Such a cover is described in U.S. Pat. No. 2,695,115. The cover described in said patent is provided with two sets of lower ribs, the first of which fits inside the opening of the container and the second of which fits round the outside of the container. Further, the second set of lower ribs makes it difficult to lift the cover with one hand.
The set of upper ribs on the cover described in the above U.S. patent co-operates with a set of ribs located beneath another container.
Since the containers are flared, is not easy to arrange for the set of upper ribs on a cover to match both the set of ribs on the bottom of a second container and the set of lower ribs of an identical cover. In other words, it is difficult to ensure that a pile of identical covers will stack properly, if the covers are specifically designed for proper stacking of closed containers, and vice versa.
Further, the second set of lower ribs which project further than the first set of lower ribs interferes with proper nested stacking of the covers on one another.


A sheet dispenser including a coherent stack of adhesive-bearing sheets that can be unobtrusively permanently or removably adhered on a page of a book, catalog, brochure, etc. The dispenser has a supple cover layer that is a thin, tear-resistant polymeric film that has opposite retaining peripheral portions extending around the sides of the stack and attached to a backing sheet for the dispenser, and has a pressure-sensitive adhesive layer on one or two attachable peripheral portions of the cover layer by which the dispenser can be adhered to the page.

Minnesota Mining and Manufacturing Company or 3M (the company to which this application is assigned) has developed a rather low profile dispenser for a stack of paper sheets that is described in co-assigned U.S. Pat. No. 5,158,205 (Bodziak et al.). In FIGS. 1-6 of the Bodziak patent, a dispenser made of folded card stock forms a chamber closely containing a stack (12) of paper sheets. Centrally across the top wall (22) of that dispenser is a slot (30) through which paper sheets can be successively pulled from the stack. Each of the sheets has a narrow band of repositionable pressure-sensitive adhesive (14) coated on one surface adjacent one edge. When the uppermost sheet of the stack is pulled through the slot, flanking slits (24) at each end of the slot allow one of two opposed flap-like portions (28) of the top wall to flex as shown in FIG. 4 while the other flap-like portion places a drag on the next sheet so that the uppermost sheet will peel away from the next sheet.
The pop-up dispenser of the Bodziak patent is being used for coherent stacks of Post-it (TM) brand self-stick repositionable notes that consist of pieces of paper, each having a narrow band of repositionable pressure-sensitive adhesive coated on one surface adjacent one edge. Among a variety of other pop-up dispensers that have been described in the art for use with coherent stacks of Post-it (.TM.) brand self-stick repositionable notes are those disclosed in co-assigned U.S. Pat. Nos. 4,416,392 (Smith), 4,653,666 (Mertens), 5,080,255 (Windorski), 5,165,570 (Windorski et al), 5,167,346 (Bodziak et al) and 5,158,205 (Bodziak et al). FIGS. 1-13 of U.S. Pat. No. 5,165,570 illustrate dispensers having a base surface bearing a pair of foam-backed pressure-sensitive adhesive strips covered with a release liner by which the dispenser can be adhesively anchored to a substrate.
U.S. patent application Ser. No. 08/101,615 filed Aug. 3, 1993, (the content whereof is incorporated herein by reference) describes low profile sheet dispenser subassemblies and low profile sheet dispensers for coherent stacks of Post-it (.TM.) brand self-stick repositionable notes, for coherent stacks of Post-it (.TM.) brand repositionable tape flags described in co-assigned U.S. Pat. No. 4,907,825, and other coherent stacks of adhesive bearing sheets such as those described in U.S. Pat. No. 4,895,746 (Mertens) and U.S. Pat. No. 5,086,946 (Blackwell); which low profile sheet dispenser subassemblies or sheet dispensers are adapted to be adhered to a substrate such as on an inside page of a book, catalog, brochure, personal organizer or the like.


A transfer system is provided for press facilities with several successive press stations. The transfer system has divided cross traverses which, with respect to the transport direction, can be moved from the front and the rear into the tool. Each tool includes two respectively transversely divided traverses. For receiving and depositing the workpieces, the cross traverses are adjusted toward and away from one another. In addition, when the tool is closed, the cross traverse are laterally moved past the tool. As required, they may be changed for this purpose into an overtaking position, which can be carried out, for example, by a swivel drive. The transfer system permits a shortening of the minimum time for which the tools must be open with respect to the transfer system and thus allows an increase of the stroke number of the press.

The present invention relates to a transfer system for multi-station presses and/or press working lines.
In for example, multi-station presses or press working lines, transfer systems have the task of transporting sheet metal parts or other workpieces from one press station to another. A workpiece passes successively through all press stations. The transfer system has the task of moving the opening tool over, i.e. below the top tool lifting off the workpiece, of picking up the workpiece, of moving it into the still open tool of the next press station and of depositing the workpiece there. Before the top tool is placed on the workpiece, the corresponding part of the transfer system must have been moved out of the tool.
During this operation, the gripper devices of the transfer system must cover considerable distances and move relatively large masses. Particularly with large-part presses, vehicle body presses and comparable facilities, very high accelerations and braking decelerations result and cannot easily be infinitely increased when the running speed (stroke number) of the press is to be raised.
EP 0388610 B1 describes a press facility which has a two-axis transfer system. The transfer system has two running rails which extend on both sides of the tools along the entire length of the press facility and on which travelling carriages are disposed. The running rails are connected with lifting devices which move the running rails synchronously up and down in the timing of the hybrid press facility. Two mutually opposite travelling carriages respectively are connected with one another by suction bridges or cross traverses. These are provided with vacuum suction devices so that a workpiece can be taken up and deposited in a controlled manner. By way of a transport linkage, the travelling carriages are connected with a drive to provide them with a longitudinal movement. By superimposing the lifting and lowering movement of the running rails on the longitudinal movement of the travelling carriages, the suction bridges negotiate the desired transfer curve by which the parts are transported.
When the tools close, the suction bridges must stand between the tools. Because of the finite moving and transporting speed of the suction bridges, this means that a maximal number of strokes cannot be exceeded. With smaller press strokes, higher stroke numbers are frequently desirable.
In addition, so-called three-axis transfer systems are known, in which, instead of the running rails, transfer bars are provided. In addition to the lifting and lowering movement, the transfer bars can also carry out a transfer movement in the transport direction and an opening and closing movement laterally with respect to the transport direction. The transfer bars carry blades which can reach laterally under the sheet metal parts.
Transfer systems of this type can carry out, for example, a return stroke when the tools of the individual press stations are closed. In the third axis, the blades held on the transfer bars carry out a lateral escape movement and move laterally past the closed tools. However, the blades grip the workpieces only on the edge. For this type of parts transport, the stability of the workpieces must therefore be sufficiently high. If parts are separated in a press station, i.e., if two sheet metal parts are cut out of a blank which are to be transported, e.g., side-by-side, the parts transport cannot be carried out only by means of the blades which reach into the tools from the sides. This limits the application possibilities of the three-axis transfer system.

Traverse-type three-axis transfer system


An electrical connector includes a split bolt, a fastener component, and a pressure bar. The split bolt includes a base, a first upright member, a second upright member, and a conductor receiving channel defined between the first and second upright members. The fastener component has a top surface, a bottom surface, and an opening receiving the first and second upright members. The pressure bar has a bottom section, a first leg, and a second leg. The pressure bar is movably received in the conductor receiving channel.

Split bolt electrical connectors are typically used to electrically and mechanically connect two conductors, such as a tap conductor and a main conductor. The tap and main conductors are inserted into a channel in the split bolt connector. A nut is threadably connected to the split bolt electrical connector to axially move an insert into engagement with the conductors to secure the conductors in the connector.


A hand held two-way mirror assembly 10 having one or more hidden images 26 mounted behind the back surface of a two-way mirror 20, one of which images can be seen when a light 36 behind the image is lit. The mirror assembly includes a frame 12, 14, 16, there being a cavity 30 behind the mirror 20, which cavity receives the lights 36 and a circuit board 48. A speaker 50 is mounted on the board. One or more digitized voices is stored in a memory chip 54 mounted on the board. Electronic switches 52 and 56 select a lamp 36 to be lit when a manually engageable switch is operated, and also cause one of the digitized voice tracks to be broadcast through the speaker, the particular voice track being associated with the illuminated image, the lights and voices preferably being selected in a predetermined manner to follow a script.

Toy devices embodying two-way mirrors are well known in the prior art where the mirror is mounted in a structure provided with a figure or representation in a cavity behind the mirror, which figure or representation may be illuminated. One such an example is shown in U.S. Pat. No. 4,072,314 to Rosen. The purpose of the Rosen device is to provided a toy where children may see a normally hidden image when the toy is turned on, and which toy may be provided with a plurality or voice tracks one of which is randomly selected by a mechanism within the toy when the toy is turned on. In Rosen a three dimensional figure is disposed behind a two-way mirror, which figure may be illuminated through operation of a suitable switch. The mirror is pivotally mounted on a base. Rosen further discloses a multi-track disk player in the base which commences operation simultaneously with the operation of the light behind the mirror, the disc player randomly playing one of the disc tracks on the disc.
A somewhat similar concept is shown in U.S. Pat. No. 3,798,833 to Campbell which discloses a crystal ball-like object having an image provided therein, which image may be illuminated and seen when the device is turned on, the device also being provided with a multi-track disc player, one of which tracks is played when the toy is turned on.
Another patent which discloses a device behind a mirror is U.S. Pat. No. 2,483,901 to Harris which discloses an advertising device having two separated compartments, each of which may receive a product to be advertised. Each compartment can be individually illuminated to display the product therein. Davis et al U.S. Pat. No. 3,805,432 discloses a display device provided with a continuous belt carrying advertising messages, the belt being disposed behind a two-way mirror. A speaker is also associated with this device.
Other two-way mirror devices are U.S. Pat. Nos. 1,197,736 and 647,139 to Hartford et al and Howe, respectively In Hartford a view behind the mirror is illuminated when a coin is placed in a receptacle. In Howe an image mounted behind the mirror may be seen when the mirror is held up to the light.


An apparatus having a substrate, an LED light source attached to the substrate, an electrical connector attached to the substrate and electrically connected to the LED light source, a potting material on the substrate and covering at least a portion of the electrical connector; and a barrier separating the potting material from the LED light source, the barrier having a height that exceeds the thickness of the potting material on the substrate.

1. Field
The present disclosure relates to light emitting devices, and more particularly, to a light emitting diode source with a protective barrier.
2. Background
A light emitting diode (LED) is a semiconductor material impregnated, or doped, with impurities. These impurities add "electrons" and "holes" to the semiconductor, which can move in the material relatively freely. Depending on the kind of impurity, a doped region of the semiconductor can have predominantly electrons or holes, and is referred to as N-type or P-type semiconductor regions, respectively. In LED applications, the semiconductor includes an N-type semiconductor region and a P-type semiconductor region. A reverse electric field is created at the junction between the two regions, which cause the electrons and holes to move away from the junction to form an active region. When a forward voltage sufficient to overcome the reverse electric field is applied across the P-N junction, electrons and holes are forced into the active region and combine. When electrons combine with holes, they fall to lower energy levels and release energy in the form of light.
LEDs have traditionally been packaged in through-hole or surface mount package configurations. An example of a through-hole package includes an LED encased in a cylindrical or dome shaped lens with anode and cathode leads connected to the LED and extending through the bottom of the lens. These LED packages are often mounted to a circuit board with other LED packages and/or electronic components. For example, an LED driver circuit may be mounted to the circuit board and connected to any number of LED packages to provide an LED light source as an incandescent or fluorescent lamp replacement. As another example, various processing components mounted to the circuit board may be connected to an LED package to provide an indication to an observer of some processing condition or state.
An LED package may be mounted to a circuit board and connected to other LED packages and/or electronic components using various electrical connectors. By way of example, an LED package may be connected to a terminal mounted on the circuit board via an electrical trace and one or more other LED packages and/or electronic components may also be connected to the terminal. As another example, the LED package may be connected to one or more other LED packages and/or electronic components via a wire soldered to a pad connected to the LED package by an electrical trace.
In various lighting applications, such as exterior lighting, refrigeration, damp environment, automotive, trucking, and other harsh environments, a potting material may be applied to the circuit board or light source assembly to protect the electronic components, electrical connectors and electrical traces from moisture intrusion. The potting material, however, is not an optical compound, and therefore, should not obstruct the optical path of the light emitted from the LED. If the optical path is obstructed, a significant reduction in light output and/or a change in color of the emitted light may occur.
As LED packages continue to evolve, it has become increasingly more difficult to apply a potting material to a circuit board without detracting from the optical properties of the LED. The trend in LED packaging has been toward thinner and smaller LED packages. In some cases, such as the so called chip on board (COB) or LED Array approach, the package has been significantly minimized or removed completely, resulting in very small form factor packaging with minimum height. Typical methods of applying potting compounds do not work well with such thin packages with minimal protection of the semiconductor chips, resulting in obstructions of the optical path and loss of light. Accordingly, there is a need in the art for improved methods for applying potting material to such packages or modifications to such packages to enable potting without covering the optical emitting area of the LED, especially as package heights continue to decrease.

Light emitting diode source with protective barrier


In a disk drive using a motor frame, the motor frame is provided with a projection preliminarily formed to protrude on its principal surface. The projection has a slit formed at its base. A printed circuit board is inserted into the slit to be engaged with the projection. The motor frame is provided with a positioning boss fitted into a positioning hole formed in the printed circuit board. The motor frame is further provided with a plurality of board holding portions bent upward on the principal surface to be engaged with end portions of the printed circuit board. Preferably, the positioning boss is formed by coining.

This invention relates to a disk drive for driving a floppy disk or a flexible disk to carry out data recording/reproducing operations.
A disk drive of the type is widely used and mounted in a portable electronic equipment such as a laptop personal computer, a notebook computer, or a notebook word processor. The disk drive comprises a magnetic head for reading/writing data from/to a flexible disk, a carriage assembly supporting the magnetic head, a stepping motor for moving the carriage assembly with respect to the flexible disk, and a drive motor called a spindle motor or a direct drive motor for rotating the flexible disk.
The drive motor is mounted to a main frame of the disk drive by the use of a motor frame. The motor frame has a principal surface, i.e., an upper surface on which a printed circuit board may can be mounted and fixed.
In a structure of fixing the printed circuit board to the motor frame, it is required to prevent the printed circuit board from floating up from the motor frame and to improve the parallelism of the printed circuit board. Furthermore, it is required to improve the accuracy in mounting the printed circuit board to the motor frame.
It is therefore an object of this invention to provide a disk drive in which a printed circuit board is fixed to a motor frame with a high accuracy and a high parallelism.
It is another object of this invention to provide a disk drive in which a printed circuit board is mounted to a motor frame in an improved contact condition without requiring additional post-working steps.
Other objects of the present invention will become clear as the description proceeds.
According to this invention, there is provided a disk drive comprising a motor frame having a principal surface and a printed circuit board placed on the principal surface and having a positioning hole, the motor frame having a projection protruding from said principal surface and having a slit on its side surface, a plurality of board holding portions protruding from the principal surface and engaged with end portions of the printed circuit board, and a positioning boss protruding from the principle surface to be fitted into the positioning hole, the printed circuit board being inserted into the slit to be engaged with the projection.

Disk drive improved in mounting structure of a printed circuit board with respect to a motor frame


An air-conditioning apparatus includes: a first bypass pipe connected to an inlet-side passage of an accumulator through a second expansion device, a second passage of a subcooling heat exchanger for exchanging heat between refrigerant flowing through the second passage of the subcooling heat exchanger and refrigerant flowing through a first passage of the subcooling heat exchanger, and a first opening and closing device; a second bypass pipe branched from the first bypass pipe between the subcooling heat exchanger and the first opening and closing device and connected to an injection port of a compressor through a second opening and closing device; and a third bypass pipe branched from a refrigerant pipe between a heat source-side heat exchanger and a use-side heat exchanger and connected to a refrigerant pipe between an inlet side of the compressor and an outlet side of the accumulator through a third expansion device.

When an air-conditioning apparatus such as a multi-air-conditioning apparatus for a building performs a heating operation under low outside air temperature, a discharge temperature of a compressor is excessively high, and hence a frequency of the compressor cannot be increased, with the result that required heating capacity cannot be exerted. Further, when a refrigerant such as R32 is used, the discharge temperature of the compressor is excessively high even during a cooling operation under low outside air temperature. Therefore, it is necessary to lower the discharge temperature of the compressor so that an amount of heat corresponding to a load is supplied. To lower the discharge temperature of the compressor, known techniques provide a circuit for performing liquid injection to the middle of the compressor from a high-pressure liquid pipe of a refrigeration cycle, or an air-conditioning apparatus capable of controlling the discharge temperature to a set temperature irrespective of an operation state (for example, Patent Literature 1).
Further, known techniques provide an air-conditioning apparatus capable of injecting high-pressure liquid refrigerant of the refrigeration cycle to a suction side of the compressor in both of the cooling operation and the heating operation (for example, Patent Literature 2).
Still further, known techniques provide an air-conditioning apparatus including a subcooling heat exchanger on an outlet side of a condenser, and being configured to control a flow rate of refrigerant to flow through the subcooling heat exchanger, thereby controlling the discharge temperature of the compressor (for example, Patent Literature 3).


Various aspects of the invention provide microelectronic component assemblies, memory modules, computer systems, and methods of assembling microelectronic component assemblies. In one particular implementation, a microelectronic component assembly includes a non-leaded first package, a second package, and a plurality of electrical junctions. The first package has a confronting surface that includes an exposed back surface of a microelectronic component and exposed contact surfaces. The second package has a confronting surface that includes an exposed back surface of a microelectronic component and exposed contact surfaces of a number of leads. Each of the junctions couples one of the contacts to the contact surface of one of the leads. The electrical junctions may also physically support the packages with their respective confronting surfaces juxtaposed with but spaced from one another, defining a peripherally open fluid passage and enhancing thermal performance.

Semiconductor chips or dies are typically encapsulated in a package that protects the chips from the surrounding environment. The packages typically include leads or other connection points that allow the encapsulated chip to be electrically coupled to another microelectronic component. Leaded packages include a semiconductor chip bonded to a lead frame either seated on a die paddle or attached directly to the leads in a leads-over-chip attachment. The contact pads on the semiconductor die are then electrically connected to the chip, e.g., by wire bonding. The connected lead frame and chip may then be encapsulated in a mold compound to form a complete microelectronic component package. In most common applications, the leads extend out from the mold compound, allowing the chip to be electrically accessed. Typically, the leads extend laterally outwardly in a flat array that is part of a lead frame. This lead frame may be trimmed and formed into a desired configuration.
One increasingly popular technique for maximizing device density on a substrate is to stack microelectronic devices on top of one another. Stacking just one device on top of a lower device can effectively double the circuitry within a given footprint; stacking additional devices can further increase the circuit density.
In one approach, multiple microelectronic components are assembled in a single package. FIG. 1 schematically illustrates a thin small outline package (TSOP) 10 that includes an upper microelectronic component 20 and a lower microelectronic component 30. Such a TSOP 10 may be used in a memory module for a microelectronic device, for example. Typically, these microelectronic components 20 and 30 are semiconductor dies. Leads 42 of an upper lead frame 40 may be physically attached to the upper microelectronic component 20 via an adhesive, such as a conventional lead-on-chip tape 22. The inner lengths 44 of some or all of the leads 42 are electrically coupled to the upper microelectronic component 20 by individual wire bonds 24. Similarly, leads 52 of a lower lead frame 50 are physically attached to the lower microelectronic component 30 by an adhesive 32. Wire bonds 34 electrically connect the inner lengths 54 of selected leads 52 to the lower microelectronic component 30. The upper microelectronic component 20 and the lower microelectronic component 30 may be attached in a variety of ways, such as by a die attach adhesive 25.
The microelectronic components 20 and 30 and the inner lengths 44 and 54 of the leads 42 and 52, respectively, may be encapsulated in a mold compound 12. An outer length 46 of each lead 42 of the upper lead frame 40 extends outwardly beyond a periphery 14 of the mold compound 12. Similarly, an outer length 56 of each lead 52 of the lower lead frame 50 extends outwardly beyond the periphery 14 of the mold compound 12. The outer lengths 56 of the lower leads 52 may be shaped for connection to a substrate 60 or another microelectronic component. The TSOP 10 shown in FIG. 1 employs lower leads 52 with generally S-shaped outer lengths, which is commonplace for TSOPs; a wide variety of other shapes are known in the art for use in different applications.
The TSOP 10 shown in FIG. 1, and a number of like devices, has little or no good way to dissipate heat generated by the microelectronic components 20 and 30. Air may flow about the exterior of the mold compound 12. In addition, the exposed outer lengths 46 and 56 of the leads 42 and 52, respectively, can help conduct heat away from the microelectronic components 20 and 30 to the ambient environment of the TSOP 10. However, the microelectronic components 20 and 30 themselves are encapsulated in the mold compound 12 and have little direct thermal communication with the ambient atmosphere. This hampers the ability to cool the microelectronic components 20 and 30, increasing the likelihood of failure of the microelectronic components 20 and 30 over time.
The mold compound 12 of such a TSOP 10 often has a coefficient of thermal expansion (CTE) that differs from the CTE of the leads 42 and 52, wire bonds 24 and 34, and microelectronic components 20 and 30. The changes in temperature inherent in conventional manufacturing processes can warp or otherwise damage the microelectronic components 20 and 30 and/or adversely affect the electrical connections between the microelectronic components 20 and 30 and the lead frames 40 and 50, respectively. If either one of the microelectronic components 20 and 30 or their respective electrical connections is damaged, the entire TSOP 10 is considered defective. As a consequence, either an otherwise acceptable microelectronic component must be discarded with the defective microelectronic component or the microelectronic components 20 and 30 must be separated from one another to remove the defective component. For highly cost-competitive products, such as memory modules, both of these options may prove unduly expensive.

Packaged microelectronic component assemblies


A method to reduce power consumption within a clock gated synchronous circuit, said synchronous circuit comprising at least two successive stages, wherein each stage if activated propagates a data signal cycle by cycle to a succeeding stage, comprising the steps of:                deriving a local clock activation signal from an external clock activation signal, wherein said local clock activation signal changes its value every cycle the external clock activation signal indicates a propagation,        propagating the data signal and the local clock activation signal synchronously cycle by cycle from a particular stage to a succeeding stage whenever a local clock activation signal at the particular stage by derivation from the clock activation signal or by propagation through the synchronous circuit changes its value between two successive cycles, in order to propagate the data signal and the local clock activating signal within the same clock domain through the clock gated synchronous circuit.

In a synchronous circuit within a microprocessor, a clock signal is used to define a time reference for the movement of data within that circuit. Such a synchronous circuit includes multiple register stages in what is commonly referred to as a pipeline.
Modern microprocessors suffer a huge power drawback, where power is a combination of static and dynamic contributions, where the static contribution is approximately proportional to the silicon area of a macro. One approach to reduce dynamic power is to switch off the clock signal of not required register stages within the synchronous circuit. This procedure is also known as clock gating. By clock gating, the power dissipated in the clock mesh is reduced as well as data switching power is reduced. The latter is due to the fact that the outputs of the registers are constant if there is no clock signal.
To maximize the benefit of clock gating clock activation or deactivation is performed in a small grain—in the extreme case on a single cycle basis.
A simple clock gating scheme is known from Li et Al, "Deterministic Clock Gating for Microprocessor Power Reduction"; Proceedings of the 9th International Symposium on High Performance Computer-Architecture, 2003, pp. 113-122, wherein a register to be clock gated is connected with the output of an AND-gate whose first input is fed with the clock signal and whose second input is fed with a clock activation signal. A problem in applying this approach for a pipeline is that for each stage a clock activate signal plus a clock signal is needed that are synchronously fed to AND-gates dedicated to the stages.
A common solution for this problem is to generate local clock signals by local clock buffers (LCB) within the stages and to provide a clock activate signal for the first stage of a pipeline and to propagate this clock activate signal parallel to the data signal through the pipeline. The clock activation signal when propagated from stage to stage activates the LCB of a stage it reaches which LCB activates the particular stage by clocking a data register in order to forward a data signal stored within that data register to the next stage. To propagate the clock activation signal from stage to stage synchronous with the data signal, control registers arranged in parallel to the data registers of the pipeline are used. Since the LCB of a stage that activates the data register belonging to that stage would continue to activate the clock whenever the corresponding clock activation signal stored in the control register of the previous stage is high, the control registers of the stages have to be clocked at least twice. Thereby the first clocking is to latch a clock activation signal into the control register in order to activate the LCB of the data register and the second clocking is to reset the clock activation signal in that control register in order to stop activation of the LCB. Due to this, the clock activation signal cannot be propagated through the pipeline within the same clock domain as the data signal as long as the wider and therefore higher power data registers are clocked only once. According to the state of the art, a second LCB per stage is required that forms the clock domain for the clock activation signal propagation within the pipeline.
State-of-the-art circuitries as the circuitry 1 shown in FIG. 1 use a clock activate signal act to activate a LCB 2 in order to activate a set of data clock signals clck_d for the corresponding cycle. Within the circuitry 1, the data clock signals clck_d are provided by a first LCB 2 per stage. The LCB 2 derives the clock signal clck_d from a primary clock signal clck_p generated by a main clock not shown. The LCB 2 can be activated or deactivated by the clock activation signal act. This clock activate signal act is propagated synchronous with the data through the pipeline 3 as schematically depicted by act_0, act_1 for the clock activation signal at the first stage (act_0) and second stage (act_1). Whereby the clock activate signals act stored in control registers 5, each control register 5 associated with each stage of the pipeline 3 indicates whether valid stage data is in the stage and clocking has to be performed or not. To switch on and off this clock activate signal act any control register 5 storing a clock activate signal act has to be clocked at least twice. Hence, the clock activate signal act cannot be latched with the same registers 4 as the data-signals, since compared to the registers 4, the control registers 5 have to be clocked with at least twice. Due to this, the clock activation signal act is propagated within the control registers 5 associated with the stages of the pipeline 3 but clocked within another clocking domain than the registers 4. In order to propagate the clock activation signal act from stage to stage, a second LCB 6 is required per stage. The LCB 6 forms the second clock domain for the clock activation signal act. The LCB 6 derives the control clock signal clck c from the primary clock signal clck_p generated by the main clock not shown. Thereby the switching activity of the control clock signal clck_c is higher than the one of the data clock signal clck_d. Within the example shown, the clock activity of the LCB 6 is twice as high as clock activity of the LCB 2 in the worst-case. An activation of the second LCB 6 takes place if either an incoming activation signal act_0 or an outgoing activation signal act_1 of the particular stage is high, i.e. has a value of '1'.
A main drawback of the synchronous circuit according to the state of the art is that in each stage of the pipeline, two LCBs are needed, one for the clock domain of the data registers for the data signal and a second one for the clock domain of the control registers. This is disadvantageous because LCBs are highly complex and large circuitries with high silicon area requirements and high active as well as leakage power consumption.

Method to reduce power consumption within a clock gated synchronous circuit and clock gated synchronous circuit


The present invention relates to a compound of the formula ##STR1## and the pharmaceutically acceptable salts thereof wherein W is a tricyclic heterocyclic ring system; which is an .alpha.-1 adrenergic antagonist and is useful in the treatment of BPH; also disclosed are .alpha.-1 antagonist compositions and a method for antagonizing .alpha.-1 receptors and treating BPH.

Adrenergic neurons play a major role in the innervation of heart, blood vessel and smooth muscle tissue. Compounds capable of interacting with adrenoceptor sites within adrenergic nerves can initiate a variety of physiological responses, including vasoconstfiction, vasodilation, and increased or decreased heart rate (chronotropic), contractility (inotropic) and metabolic activity. In the past, various adrenergic compounds have been employed to affect these and other physiological responses. However, many adrenergic compounds do not possess significant selectivity to enable desirable interactions with adrenergic receptor sites. That is, these adrenergic compounds do not demonstrate a high degree of specificity for differing receptor types within adrenergic neurons in order to obtain a desired physiological response separate from other possible, and perhaps less desirable, responses of the system.
Benign prostatic hyperplasia (BPH) is a condition which develops in middle-aged and elderly males and refers to the benign overgrowth of the stromal and epithelial elements of the prostate associated with aging. Symptoms of BPH include increased frequency of urination, nocturia, a weak urine stream and hesitancy or delay in starting the urine flow. Chrome consequences of BPH can include hypertrophy of bladder smooth muscle, a decompensated bladder and an increased incidence of urinary tract infection.
Typically, BPH begins at an age in the mid-fifties and is the most common cause of urinary tract problems of men of this age. BPH is apparently rare in men prior to age 40, but at age 60, approximately 50% of men have histological evidence of BPH. The prevalence of BPH continues to increase with age until, at age 80, approximately 80% of men have pathological evidence of BPH.
Although prostatic hyperplasia is a common finding in older men, the presence of urinary symptoms is the essential feature that distinguishes simple anatomic enlargement of the prostate from prostatism, which is the clinical syndrome whereby the patient experiences significant obstruction of urinary flow. It is not uncommon in older men to have a palpably enlarged prostate without showing the symptoms of prostatism. From the patient's perspective, however, the incidence and progression of urinary symptoms are more important than the mere presence of an enlarged prostate.
The discovery in the 1970's (M. Caine, et al., Brit. J. Urol., 47:193-202 (1975)) of large numbers of alpha-adrenergic receptors in the smooth muscle of the prostatic capsule and bladder neck led to the conclusion that there is both a static and a dynamic component to bladder outlet obstruction associated with BPH. The static component derives from the progressive hyperplasia of the prostate with aging, leading to urethral narrowing which causes symptoms of urinary obstruction. Superimposed on this essentially mechanical problem is the variable degree of smooth muscle contraction controlled by the sympatheic nervous system and which is affected by by factors such as stress, cold and sympathomimetic drugs. It is this dynamic component which explains the often rapid fluctuations in symptoms observed in patients with prostatism.
The currently most effective treatment for BPH is the surgical procedure of transurethral resection of the prostate (TURP) Since it removes the obstructing tissue (C. Chapple, Br. Med. Journal 304:1198-1199 (1992)) it is a treatment which is directed to the static and dynamic components of BPH. However, this surgical treatment is associated with rates of mortality (1%) and adverse event (incontinence 2-4%, infection 5-10%, and impotence 5-10%). A non-invasive alternative treatment would thus be highly desirable.
The incidental clinical observation that urinary incontinence developed in women during antihypertensive treatment with prazosin (T. Thien, K. P. Delacre, F. M. J. Debruyne, R. A. P. Koene, Br. Med. Journal, 622-623 (1978)) and the experimental work of Caine (op cit.) contributed to the recognition of the potential role of selective .alpha.-1 adrenoceptor blockade in diseases of the lower urinary tract. Subsequent studies by several groups have documented the functional role of .alpha.-1 adrenoceptors relative to .alpha.-2 adrenoceptors in the stromal compartment of the prostate, thereby providing a putative molecular basis for the use of specific .alpha.-1 adrenoceptor blockers in the non-surgical management of BPH (C. R. Chapple, M. L. Aubry, S. James, M. Greengrass, G. Burnstock, R. T. Turner-Warwick, Br. J. Urol. 63: 487-496 (1989)). Clinical efficacy of .alpha.-1 antagonists in BPH has been demonstrated with several non-selective .alpha.-1 blockers, including terazosin (Hytrin.TM.), prazosin, and doxazosin. Treatment periods as short as two to four weeks with .alpha.-1 adrenoceptor blockers have shown objective improvements in the mean and maximum urinary flow rates (14-96% ) with subjective improvements in patients' symptom scores (R. A. Janknegt, C. R. Chapple, Eur. Urol. 24: 319-326 (1993)). Longer term studies with terazosin, indoramin, prazosin, and doxazosin have similarly demonstrated significant improvements in urinary flow rates and subjective symptom scores (R. A. Janknegt, op. cit., H. Lepor, G. Knapp-Maloney, J. Urol. 145: 263A (1991), W. Chow, D. Hahn, D. Sandhu, Br. J. Urol. 65: 36-38 (1990) and C. R. Chapple, T. J. Christmas, E. J. G. Milroy, Urol. Int. 45: 47-55 (1990)). However, these agents possess similar dose limiting side effects: hypotension, dizziness, and muscle fatigue. Them thus exists a need for a "uroselective" .alpha.-1 antagonist with reduced side effect liabilities.

Tricyclic substituted hexahydrobenz [e]isoindole alpha-1 adrenergic antagonists


An optical fiber feedthrough for an optical submerged repeater for use in an optical fiber submarine cable, in which a metal film is coated on the outer peripheral surface of an optical fiber to be introduced into the repeater, and in which a thermoplastic material, such as polyethylene or the like, is filled between the inner wall of a hole made in an end face plate of a pressure resisting container of the repeater and the metal film.

1. Field of the Invention
This invention relates to a feedthrough of an optical submerged repeater used in a long-distance, optical-fiber submarine cable system in the field of optical communication employing a low-loss optical fiber.
2. Description of the Prior Art
An optical submerged repeater is laid in the sea at a depth of several thousand meters and exposed to a water pressure of several hundred atmospheric pressures; therefore, optical and electronic circuits of the optical submerged repeater are housed in a pressure resisting container made of a material of high durability against seawater, for example, stainless steel or beryllium copper. The optical and electronic circuits in the pressure resisting container and an optical-fiber submarine cable are interconnected via a feedthrough attached to an end face plate of the pressure resisting container to serve as an introducing part for an optical fiber and a power feeding conductor. The pressure in the pressure resisting container is usually 0 to 1 atmospheric pressures in terms of gauge pressure and a pressure difference between the inside and outside of the pressure resisting container is very large. Accordingly, the feedthrough is required to have a construction which withstands a high pressure while retaining a high degree of airtightness.


A fuel injection control system generates control pulses which open the fuel injection valves of the engine. The pulse duration is proportional to the injected fuel quantity and can be altered in dependence on air temperature by a circuit which includes a temperature-sensitive resistor. The voltage at this resistor controls a transistor which supplies a supplementary charging current for a timing capacitor.

The invention relates to an apparatus for adapting the fuel quantity supplied by a fuel injection system to prevailing air temperatures. The fuel injection system supplies control information on the basis of engine rpm and air flow rate in the form of injection valve opening pulses whose duration determines the fuel quantity supplied to the engine.
It is a well known fact that the density of the air increases with decreasing temperature and this fact results in a greater air quantity admitted to the combustion chambers of the engine. Since, normally, the fuel-air ratio of the engine is attempted to be held constant, for example corresponding to the stoichiometric ratio or some other predetermined ratio, a correction is required if the fuel injection system cannot itself make the required adjustments for a changing air temperature.
In order to maintain a desired fuel-air ratio when the air temperature drops or, in the most general case, to make any arbitrary correction, a special correction is required which changes the fuel injection duration, and in the normal case, lengthens it.

Apparatus for adapting engine fuel supply to ambient air temperature


A method includes: growing a lattice of alternating sheets of tensile strained silicon and relaxed silicon-germanium on a substrate; isolating a first portion of the lattice from a second portion of the lattice; forming source regions and drain regions on each of the first portion of the lattice and the second portion of the lattice; forming a first gate opening in the first portion of the lattice and a second gate opening in the second portion of the lattice; selectively removing the sheets of relaxed silicon-germanium from under the second gate opening in the second portion of the lattice; selectively removing portions of the sheets of tensile strained silicon from under the first gate opening in the first portion of the lattice; and increasing a germanium content in the relaxed silicon-germanium layers under the first gate opening in the first portion of the lattice.

The exemplary embodiments described herein relate generally to semiconductor devices and methods for the fabrication thereof and, more specifically, to semiconductor devices having strained PFET and NFET nanosheet structures on the same substrate and methods for forming such structures.
A complementary metal oxide semiconductor device (CMOS) uses pairs of p-type and n-type metal oxide semiconductor field effect transistors (MOSFETs) arranged on silicon or silicon-on-insulator (SOI) substrates. A MOSFET, which is used for amplifying or switching electronic signals for logic functions, has source and drain regions connected by a channel. The source region is a terminal through which current in the form of majority charge carriers enters the channel, and the drain region is a terminal through which current in the form of majority charge carriers leaves the channel. In a p-type MOSFET (hereinafter "PFET"), the majority charge carriers are holes that flow through the channel, and in an n-type MOSFET (hereinafter "NFET"), the majority charge carriers are electrons that flow through the channel. The channel may be defined by an element such as one or more fins, one or more nanowires, or one or more sheets. Such fins, nanowires, or sheets include silicon. One or more gates are positioned over or around the channel to control the flow of current between the source and drain regions.
In devices that employ multiple gates or which use gate-all-around (GAA) technology, the devices benefit from electrostatics and immunity to short channel effects. However, the electron mobility in such multi-gate or GAA devices may be degraded by low-mobility sidewalls and other scattering mechanisms. As a result, strain engineering may be used to improve device performance.
Devices in which GAA nanosheets are employed are attractive candidates for 5 nanometer (nm) technology and beyond due to their excellent electrostatics. In such devices, however, increasing both electron and hole mobility for a CMOS structure may be challenging with regard to suspending nanosheet structures.

Dual strained nanosheet CMOS and methods for fabricating


A pulsed light communication device has a plurality of indicator light emitting diodes emitting diodes emitting at least one of a plurality of wavelengths of colored light to correspond to a designated color assigned to a security level for a network. A continuous uninterrupted modulated pulsed light emitting diode light signal may be generated having a sensitivity threshold detection level exceeding minimal parameters of a photodetector.

In the past Wi-Fi Internet security within a building has been problematic, especially within public areas. A facility or business has been faced with many difficult choices particularly when accommodating customer or employee convenience and security concerns related to networks, secure information and/or data as stored on servers. Frequently a company or facility has needed to balance individual needs to access a Wi-Fi networks or servers and security to confidential and/or proprietary information. The present invention provides a unique and convenient method to improve security within a facility with respect to a number of types of networks and Internet access within public, semi-private and/or private areas.
In the past, communication and/or data transfer as embedded within pulsed light emitting diode (LED) light transmissions, and reception of pulsed LED light carrier signals has not been optimized when LED lights have been modulated through a power off state during a transmission cycle. The known modulation techniques actuate the LED's between an on transmission status through an off non-transmission status which in turn causes the memory or the memory cache for the information or data transmission to become exhausted or saturated, slowing the communication rate for the transmission of information and/or data embedded within the pulsed LED light carrier signals. The present invention provides a novel modulation system which maximizes the speed of information and data transmission as embedded within pulsed LED light carrier signals, which in turn reduces memory cache exhaustion or saturation.

Network security and variable pulse wave form with continuous communication

Federal Law Enforcement Development Services, Inc.


Pharmaceutical and nutritional compositions are disclosed containing, in association with a suitable diluent or carrier, at least 10% by weight of a cholesterol fatty acid ester where the fatty acid is gamma-linolenic acid, dihomo-gamma-linolenic acid, adrenic acid, the 22:5 n-6 acid, stearidonic acid, the 20:4 n-3 acid, eicosapentaenoic acid, docosahexaenoic acid, the 22:5 n-3 acid or columbinic acid. Novel cholesterol columbinic acid esters are described.

Fatty acids of specific types are of considerable interest both for the maintenance of healthy tissue and in the treatment of various diseases. Some fatty acids are of interest in themselves, some because they give rise to particular metabolites such as prostaglandins or other oxygenated derivatives, and some for both reasons. Among them are the essential fatty acids (EFAs) not made by the body and therefore constituting essential nutrients. Among the EFAs of particular interest for both reasons are gamma-linolenic acid (GLA), dihomogammalinolenic acid (DGLA) and eicosapentaenoic acid (EPA). DGLA is an important component of cell membranes and is also the precursor of prostaglandin E.sub.1 (PGE.sub.1); PGE.sub.1 has many desirable effects being an antithrombotic, anti-inflammatory, vasodilator, immunomodulating and cholesterol lowering agent. GLA is an immediate precursor of DGLA and is rapidly converted to DGLA within the body. EPA is also a component of cell membranes and is a precursor of PGE.sub.3 which has actions similar to those of PGE.sub.1. A further fatty acid which is of particular interest as a component of cell membranes is docosahexaenoic acid (DHA).
The conversation pathways of the main series of EFAs in the body are as follows:
TABLE 1 ______________________________________ n-6 n-3 ______________________________________ 18:2 delta-9,12 18:3 delta-9,12,15 (linoleic acid) (alpha-linolenic acid) .vertline. delta-6 desaturase .dwnarw. 18:3 delta-6,9,12 18:4 delta-6,9,12,15 (gamma-linolenic acid) (stearidonic acid) .vertline. elongation .dwnarw. 20:3 delta-8,11,14 20:4 delta-8,11,14,17 (dihomo-gamma-linolenic acid) .vertline. delta-5 desaturase .dwnarw. 20:4 delta-5,8,11,14 20:5 delta-5,8,11,14,17 (arachidonic acid) (`eicosapentaenoic acid`) .vertline. elongation .dwnarw. 22:4 delta-7,10,13,16 22:5 delta-7,10,13,16,19 (adrenic acid) .vertline. delta-5 desaturase .dwnarw. 22:5 delta-4,7,10,13,16 22:6 delta-4,7,10,13,16,19 (`docosahexaenoic acid`) ______________________________________
The above pathways are not normally reversible nor, in man, are n-3 and n-6 series acids inter-convertible.
The acids, which in nature are of the all-cis configuration, are systematically named as derivatives of the corresponding octadecanoic, eicosanoic or docosanoic acids, eg. delta-9,12-octadecadienoic acid or delta-4,7,10,13,16,19-docosahexaenoic acid, but numerical designations such as, correspondingly, 18:2 n-6 or 22:6 n-3 are convenient. Initials, for example, EPA for the 20:5 n-3 acid (eicosapentaenoic acid) or DHA for the 22:6 n-3 acid(docosahexaenoic acid), are also used but do not serve when n-3 and n-6 acids of the same chain length and degree of unsaturation exist as for example with the 22:5 acids. Trivial names in more or less common use in the n-6 series are as shown. Of the n-3 series only 18:3 n-3 has a commonly used trivial name, alpha-linolenic acid, though the name stearidonic acid is coming into use for the 18:4 n-3 acid and the names eicosapentaenoic acid and docosahexanenoic acid as such are also used. The alpha isomer of linolenic acid was characterised earlier than gamma-linolenic acid and reference in the literature simply to linolenic acid, especially in the earlier literature, is to the alpha-acid.

Compositions containing esters of unsaturated fatty acids


An aquarium system is provided for displaying marine life. The aquarium includes a reservoir for receiving water therein, the water in the reservoir defines a reservoir water level. A tank is positioned above the reservoir also for receiving water therein. The water in the tank defines a tank water level such that the reservoir water level is below the tank water level. A fish display tube provides a habitat for the marine life and has first and second ends communicating with the water in the tank. A return tube includes a first end coupled to and communicating with the fish display tube, and a second end communicating with the reservoir such that a syphon on the second end of the return tube draws water from the tank, through the fish display tube and the return tube, into the reservoir. Means are provided for pumping water from the reservoir into the tank to prevent the overflow of water in the reservoir.

The present invention relates generally to an aquarium system, and in particular, to an aquarium system which utilizes a syphon to circulate water through a tube which provides a habitat for marine life therein.
Prior art aquariums generally are limited to a single display tank positioned on an aquarium stand or the like. While various sizes and shapes of aquarium tanks have been previously constructed, large tanks are difficult and expensive to manufacture. In addition, recirculating the water in large aquariums requires the additional expenses of enhanced equipment and of increased electrical usage.
Therefore, It is a primary object and feature of the present invention to provide a visually aesthetic aquarium system for large vertical surfaces, such as walls and the like.
It is a further object and feature of the present invention to provide an aquarium system which is simple to assemble and easy to maintain.
It is still another object and feature of the present invention to provide an aquarium system which may be operated &n a cost efficient manner.
An aquarium system is provided for marine life. The aquarium includes a reservoir for receiving water therein. The water in the reservoir defines a reservoir water level. A tank is positioned above the reservoir also for receiving water therein. The water in the tank defines a tank water level such that the reservoir water level is below the tank water level.
The aquarium system further includes a fish display tube having first and second inlet ends. Each inlet end of the fish display tube communicates with the water in the tank. A return tube has a first end which is coupled to the fish display tube so as to allow water in the fish display tube two pass into the return tube. A second end of the return tube communicates with the reservoir such that a syphon on the second end of the return tube draws water from the tank, through the fish display tube and the return tube, into the reservoir. Means are provided for pumping water from the reservoir into the tank in order to prevent the overflow of water in the reservoir.
A fish inlet structure is positioned between the first and second inlet ends of the fish display tube. The inlet allows for introduction of the fish into the fish display tube. A screen is positioned over each end of the fish display tube in order to prevent fish in the display tube from exiting the display tube through the first or the second inlet end of the fish display tube and entering the tank. A screen is also positioned over a first end of the return tube in order to prevent the fish from exiting the fish display tube through the return tube.


The embodiments disclose a method and apparatus for performing DL MU-MIMO transmission in a radio communication network enabling MU-MIMO. The method comprises: pairing a UE with one or more other UEs for DL MU-MIMO transmission in the radio communication network; scheduling through a control channel at least one real layer and at least one virtual layer to the UE, wherein each of the at least one virtual layer is a real layer scheduled for at least one of the one or more other UEs; and performing DL transmission to the UE and the one or more other UEs on a transport channel, wherein only the at least one real layer is used for DL transmission to the UE, and each of the at least one virtual layer is used for DL transmission to at least one of the one or more other UEs.

In a system enabling MIMO techniques like long-term evolution (LTE) system, MIMO techniques contribute to improve frequency efficiency and network capacity in the 3rd Generation Partnership Project (3GPP). For instance, in transmission mode (TM) 3, TM4 and TM8 of Rel-9, two layer transmissions are scheduled for a single user as single user MIMO (SU-MIMO). Alternatively, two or more user equipments (UEs) can be paired together to share the same time-frequency resources as MU-MIMO. MU-MIMO exploits further the spatial separation and diversity, and higher frequency efficiency than SU-MIMO is expected, which however may not be the case in practice.
Due to the limitation of UE's antenna and processing capability, a typical scenario of MU-MIMO is to schedule each of paired UEs with partial layers. The remained layers are disabled as dummy for other paired UEs. Taking single-layer DL MU-MIMO as example, there are two layers available for two UEs. Usually, only one layer is scheduled for each of paired UEs as shown in FIG. 1.
In conventional MU-MIMO, since the paired UEs are not well separated from each other, each UE suffers strong inter-layer interference from other paired UEs. Usually, opposing to SU-MIMO where joint detection (e.g. minimum mean square estimation (MMSE) or interference rejection combining (IRC) receiver) is used, the interference from a paired UE in MU-MIMO is simply taken as noise without doing joint detection (JD) as done in SU-MIMO, which results in throughput degradation as observed in field test.
In order to improve the MU-MIMO performance, several solutions have been proposed as below:
1) Pair UEs that have Good Spatial Separation
The problem is that spatial separation in DL is difficult to be estimated by eNodeB (eNB). And the pairing rate will be degraded in order to obtain good multiple-user separation. So the performance gain is limited by existing interference and low pairing rate.
2) Design Null Beamforming Weight
The weights for paired UEs can be designed carefully to null the interference. However, the weights are calculated based on the uplink (UL) channel estimation. Due to the channel estimation inaccuracy and non-ideal channel reciprocity, it's difficult to separate well such DL inter-layer interference by eNB.
On the other hand, when null beamforming weight is used, the power of desired signal is degraded compared with that of maximum ratio combining (MRC) and grid of beam (GOB) weights. Furthermore, the computation complexity for of nulling space processing is another challenge for eNB.
3) Do Blind IRC at UE Side
Some advanced UEs have the capability to do blind IRC to mitigate the unknown interference. However, it can not resolve the inter-layer interference well in DL MU-MIMO, among other reasons, blind IRC is not supported by all UEs in any cases. Receiver algorithm is a UE-specific behavior, which is not mandatory by 3GPP. IRC might not be supported or enabled by all UE vendors in any cases, due to the complicated processing, various scenarios and etc. Thus, it can not assume IRC working well at UE side when doing DL MU-MIMO.
4) Do Blind Detection on Presence of Interfering Layers
As specified in 3GPP and descried in the patent application No. US20100285810, the UE-specific reference signal for port7, port8 and port v+6 is independent on UE-specific radio network temporary identifier (RNTI) and length of Physical Resource Block (PRB) allocated. This allows UE to detect blindly if other layers are being co-scheduled for other UEs, and do channel estimation for MMSE or IRC accordingly. It requires UE to do blind detection on presence of interference on each PRB by searching all possible reference sequences. It introduces extra complexity for UE. Furthermore, this kind of blind detection is not robust enough, with possibility of either false alarm or missing, due to the non-perfect orthogonality of reference sequence. In addition, in common reference signal (CRS) based transmission mode (e.g. TM4), the blind detection on presence of interfering layers is infeasible.

Method and apparatus for performing downlink MU-MIMO transmission