Abstract:
A signalling packet for a communication system has a reference signal to support time and frequency synchronization. The reference signal is modulated so that it varies with time according to a predetermined modulation law. The variation is with respect to both the I and Q channels. Because of the variation with time, receivers can synchronize in frequency and in time with a base station in a simplified manner. Doppler shift can be determined and compensated.
Abstract:
Several emitter stations (MS1-MS4) are allowed to transmit call set-up packets in random access channels and user information packets in traffic channels to a receiver station (BST) which is provided with an array of N sensors (A.sub.l -A.sub.N) and with a receiver (RM) adapted to simultaneously acquire N-1 packets from the emitting stations and to derive therefrom N-1 distinct array output signals (X.sub.1 -X.sub.N-1). During a random access channel (RACH) channel, the identity of the emitting station (MS) as well as the direction of arrival (.theta.) and the power (.sigma.) of its signal are stored in a parameter data base (PDB) together with its weigh vector (W) calculated (WVG) therewith and a traffic channel (TCH) channel allocated (CHC) thereto. During either a RACH or a TCH channel, the weight vectors of a emitting station are provided by the data base and are applied to multipliers (M.sub.1 -M.sub.N-1) which produce the N-1 array output signals. In case of interference between emitting stations using a same TCH channel, another TCH channel is allocated to one of the interfering stations and the weight vectors are updated. The stations also send tracking packets in the RACH channel to update their parameters and accordingly the weight vectors in the data base. The present radio telecommunication system is particularly suitable, e.g., for the pan-European "Global System for Mobile communications" GSM wherein the emitter stations are mobile stations and for similar systems elsewhere.
Abstract:
Diffusion media for use in PEM fuel cells are provided with silicone coatings. The media are made of a porous electroconductive substrate, a first hydrophobic fluorocarbon polymer coating adhered to the substrate, and a second coating comprising a hydrophobic silicone polymer adhered to the substrate. The substrate is preferably a carbon fiber paper, the hydrophobic fluorocarbon polymer is PTFE or similar polymer, and the silicone is moisture curable.
Abstract:
A battery cell assembly includes a battery cell including active material configured to generate power from an electrochemical reaction. A pouch formed from insulating material envelopes the battery cell. The battery cell assembly further includes a cooling element having an internal portion and an external portion. The internal portion is disposed within the pouch and is in thermal communication with the battery cell. The external portion is disposed outside of the pouch. The cooling element is configured to transfer heat generated during the electrochemical reaction away from the battery cell.
Abstract:
A battery cell assembly includes a main body configured to generate power from an electrochemical reaction. The main body has a first end and a second end, a first side and a second side, and a first major surface and a second major surface. A pair of electrical tabs extends outwardly at the first end of the main body. An insulating element is disposed adjacent the first major surface of the main body. A cooling element is disposed adjacent the second major surface of the main body. The cooling element includes at least one cooling passage. The at least one cooling passage is in heat exchange relationship with the main body and configured to transfer heat generated during the electrochemical reaction away from the main body.
Abstract:
A level shifter includes an output stage transistor and a level controller. The level controller receives a selection signal and provides a reference voltage at a gate terminal of the output stage transistor based on the selection signal. The output stage transistor, on being enabled by the reference voltage, provides a first level shifted output based on a first output reference voltage.
Abstract:
An electrical connector having a pair of spaced apart contact portions and a substantially helical resilient portion extending therebetween. The electrical connector for use in a compact space, the electrical connector being flexible and inexpensive, and well suited for use in a vehicle fuel cell electrical system is disclosed.
Abstract:
A microCHP unit including at least one pump (20) and/or fan for circulating a cooling fluid or air through the microCHP unit in normal operation. The microCHP unit comprises an electric power source (32) that is independent from the mains power supply. It also comprises a voltage converter (42) or inverter (44) or both connected between the independent power source (32) and the cooling pump(s) (20) and/or fan(s) (28) of the microCHP unit for converting a supply voltage from the independent electric power source (32) to a different voltage for operating the pump(s) (20) and/or fan(s) (28). A controller (34) is provided to cause the cooling pump(s) 20 and/or fan(s) (28) to operate in the absence of mains power. A charging device (48) is provided to recharge the independent power source (32) when the mains power supply is available.
Abstract:
The invention entitled “A Microwave Induced One Pot Process for The Preparation of Arylethenes” provides a method for the preparation of commercially important 2- or 4-hydroxy substituted arylethenes like styrenes or stilbenes in one pot utilizing cheaper substrates in the form of 2- or 4-hydroxy substituted cinnamic acids and their derivatives as well as reagents in the form of base such as sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium bicarbonate, sodium carbonate, potassium bicarbonate, potassium carbonate, ammonium acetate, imidazole, methylimidazole and the combination thereof, with or without solvent such as dimethylformamide, dimethylsulfoxide, ethylene glycol, diethylene glycol, acetonitrile, acetone, methyl imidazoles, ionic liquid, water and the like. The reaction time vary from 1 min-12 hrs and yield of the products from 49-76% depending upon the base, acid, substrate source of heating monomode or multimode microwave or conventional. It is important to mention that the presence of 2- or 4-hydroxy substitution at phenyl ring of cinnamic acids and their derivatives is essential requirements towards formation of corresponding arylethenes in one step.
Abstract translation:题为“A Microwave Induced One Pot Process for the Preparation of Arylehenes”的发明提供了一种在一个罐中制备商业上重要的2-或4-羟基取代的芳香醚如苯乙烯或二苯乙烯的方法,其使用2-或 4-羟基取代的肉桂酸及其衍生物以及碱的形式的试剂如氢氧化钠,氢氧化钾,氢氧化锂,碳酸氢钠,碳酸钠,碳酸氢钾,碳酸钾,乙酸铵,咪唑,甲基咪唑及其组合 有或没有溶剂如二甲基甲酰胺,二甲基亚砜,乙二醇,二甘醇,乙腈,丙酮,甲基咪唑,离子液体,水等。 反应时间从1分钟-12小时变化,产物的产率从49-76%变化,这取决于加热单模或多模微波或常规的碱,酸,底物来源。 重要的是提到在肉桂酸及其衍生物的苯环上存在2-或4-羟基取代是在一个步骤中形成相应的芳酰基的必要条件。
Abstract:
A roll-forming machine for forming smooth curves in profiled panel sections. The roll forming machine has opposed pinch pass rollers having a roller profile generally corresponding to said profiled panel and a pair of cantilever rollers downstream of said pinch pass rollers. The cantilever rollers have axes of rotation that are offset relative to one another in the direction of travel of the profiled panel through the machine and having a roller profile also generally corresponding to the profiled panel. At least one sweep roller is positioned downstream of the cantilever rollers for bending said panel in a longitudinal direction as said panel passes past said sweep roller. The sweep roller also has a roller profile generally corresponding to the profiled panel. The at least one sweep roller can be positioned to the degree of bend of the smooth curve formed in said profiled panel by the machine.