Abstract: A microwave-frequency power-transmission window assembly includes a microwave-frequency power-transmission window comprising: two tubes each having two parallel oblique planar cross sections, one oblique planar cross section being non-perpendicular to the central axis of the tube and being of constant thickness in the oblique planar cross section; and an optical plate assembled between the two respective ends of the two tubes positioned facing one another; a tubular extension element extending the microwave-frequency power-transmission window; two centring rings that centre the microwave-frequency power-transmission window in the tubular extension element; and an external housing equipped with two transparent portions positioned at the ends of the microwave-frequency power-transmission window tubular extension element.

Abstract: A microwave-frequency power-transmission window assembly includes a microwave-frequency power-transmission window comprising: two tubes each having two parallel oblique planar cross sections, one oblique planar cross section being non-perpendicular to the central axis of the tube and being of constant thickness in the oblique planar cross section; and an optical plate assembled between the two respective ends of the two tubes positioned facing one another; a tubular extension element extending the microwave-frequency power-transmission window; two centring rings that centre the microwave-frequency power-transmission window in the tubular extension element; and an external housing equipped with two transparent portions positioned at the ends of the microwave-frequency power-transmission window tubular extension element.

Abstract: An optically pumped atomic clock includes an optically pumped atomic resonator provided with a vacuum-tight envelope equipped with optical interfaces and comprising, inside the vacuum-tight envelope a resonant cavity, optical mirrors, and caesium traps made of graphite, and outside the vacuum-tight envelope a vacuum pump, a magnetic shield, a magnetic field coil, an RF cable, a caesium oven, and an interface for connection with the caesium oven.

Abstract: An optically pumped atomic clock includes an optically pumped atomic resonator provided with a vacuum-tight envelope equipped with optical interfaces and comprising, inside the vacuum-tight envelope a resonant cavity, optical mirrors, and caesium traps made of graphite, and outside the vacuum-tight envelope a vacuum pump, a magnetic shield, a magnetic field coil, an RF cable, a caesium oven, and an interface for connection with the caesium oven.

Abstract: An RF frequency window comprises a dielectric disc, a main metal skirt brazed all the way around the periphery of the dielectric disc and a surrounding prestressing ring in contact with the main metal skirt around the periphery of the dielectric disc and applying, in the rest state, over the whole of the periphery of the dielectric disc, a radial compressive stress directed towards the center of the dielectric disc, the prestressing ring comprising a set of at least one cooling channel in the longitudinal direction of the prestressing ring.

Abstract: An RF frequency window comprises a dielectric disc, a main metal skirt brazed all the way around the periphery of the dielectric disc and a surrounding prestressing ring in contact with the main metal skirt around the periphery of the dielectric disc and applying, in the rest state, over the whole of the periphery of the dielectric disc, a radial compressive stress directed towards the center of the dielectric disc, the prestressing ring comprising a set of at least one cooling channel in the longitudinal direction of the prestressing ring.

Abstract: A computerized on-board system for controlling a train or rail vehicle is provided. The computerized on-board system includes a train control and monitoring system (TCMS) having a main processor unit (MPU) for controlling the train and electronic control, command and monitoring equipment for providing control data for the train. The computerized on-board system also includes at least one display unit for making the control data of the train provided by the main processor unit (MPU) or by the electronic equipment available and a main data transfer network. The electronic equipment includes at least one additional item of equipment, the at least one additional item of equipment being electronic equipment for automatic train control (ATC) or video surveillance equipment (CCTV). The display unit processes the data and displays data produced by one of the at least one additional items of equipment.

Abstract: A method for producing amines by the hydrogenation of nitrile compounds in the presence of a catalyst, notably a method for producing diamines by the continuous hydrogenation of dinitrile compounds in the presence of a Raney-metal catalyst, includes controlling the molar flow of nitrile compounds and the mass flow of catalyst in a hydrogenation piston reactor in order to minimize the occurrence of impurities and deterioration of the catalyst.

Abstract: Embodiments of the present invention are directed to rendering computer graphics using an augmented direct light model which approximates the effect of indirect light in shadows. More specifically, a shadow illuminator light source is provided for. The shadow illuminator light source is associated with an ordinary, or primary light source and is used to provide illumination in areas which are in shadows with respect to the primary light source. The shadow illuminator provides illumination only to areas which are considered to be in the shadows with respect to the light source the shadow illuminator is associated with. Thus, the shadow illuminator may be used to approximate the effects of indirect light.

Abstract: A method for producing amines by the hydrogenation of nitrile compounds in the presence of a catalyst, notably a method for producing diamines by the continuous hydrogenation of dinitrile compounds in the presence of a Raney-metal catalyst, includes controlling the molar flow of nitrile compounds and the mass flow of catalyst in a hydrogenation piston reactor in order to minimize the occurrence of impurities and deterioration of the catalyst.

Abstract: A computerized on-board system for controlling a train or rail vehicle is provided. The computerized on-board system includes a train control and monitoring system (TCMS) having a main processor unit (MPU) for controlling the train and electronic control, command and monitoring equipment for providing control data for the train. The computerized on-board system also includes at least one display unit for making the control data of the train provided by the main processor unit (MPU) or by the electronic equipment available and a main data transfer network. The electronic equipment includes at least one additional item of equipment, the at least one additional item of equipment being electronic equipment for automatic train control (ATC) or video surveillance equipment (CCTV). The display unit processes the data and displays data produced by one of the at least one additional items of equipment.

Abstract: Embodiments of the present invention are directed to rendering computer graphics using an augmented direct light model which approximates the effect of indirect light in shadows. More specifically, a shadow illuminator light source is provided for. The shadow illuminator light source is associated with an ordinary, or primary light source and is used to provide illumination in areas which are in shadows with respect to the primary light source. The shadow illuminator provides illumination only to areas which are considered to be in the shadows with respect to the light source the shadow illuminator is associated with. Thus, the shadow illuminator may be used to approximate the effects of indirect light.

Abstract: The invention relates to microwave windows used for providing a vacuum seal and transmitting the electromagnetic energy output by a high-power microwave tube. The window comprises a dielectric disk and a prestressing ring, placed around the periphery of the disk, exerts, when at rest, a radial compressive stress all around the disk. In practice, the disk is brazed to the inside of a metal skirt, and the prestressing ring is an annular portion of a holder used for rigidly fastening the microwave window to an output of the microwave tube. The annular portion has an increased thickness and bears locally on the skirt around the disk. The disk may be made of alumina, the metal skirt made of copper, and the holder made of stainless steel. The resistance of the window to thermal stresses is considerably improved thereby.

Abstract: The invention relates to microwave windows used for providing a vacuum seal and for transmitting the electromagnetic energy output by a high-power microwave tube.

Abstract: The present invention concerns a process for the preparation of a 2-hydroxybenzoic acid and of a 4-hydroxybenzaldehyde and derivatives thereof from a mixture of two phenolic compounds, one carrying a formyl or hydroxymethyl group in the 2 position, and the other carrying a formyl or hydroxymethyl group in the 4 position. The invention also concerns the preparation of a 4-hydroxybenzaldehyde from said mixture. The invention more particularly concerns the preparation of 3-methoxy-4-hydroxybenzaldehyde and of 3-ethoxy4-hydroxybenzaldehyde, respectively known as “vanillin” and ethylvanillin”.

Abstract: The present invention relates to a process for the hydroxycarbonylation of pentenoic acids. By the process, one or a number of pentenoic acids are hydroxycarbonylated to adipic acid, by carbon monoxide and water, in the presence of a catalyst based on iridium and/or rhodium and of at least one iodinated promoter. The reaction mixture obtained is subjected to a refining operation, after having optionally been concentrated, making it possible to separate at least a part of the catalyst. The catalyst thus separated is recycled to an operation for the hydroxycarbonylation of pentenoic acids, of butadiene, or of butadiene derivatives.

Abstract: A method for preparing carboxylic acids by carbonylating a reagent, particularly an alcohol, in the presence of a rhodium catalyst. According to the method, the liquid phase reaction is carried out in a first zone in the presence of a rhodium catalyst, and the resulting reaction mixture is partially vaporised in a second zone. The vaporised fraction containing the carboxylic acid is later purified and the unvaporised liquid fraction containing the catalyst is recirculated to the first zone. The method is charactracterised in that said unvaporised fraction is contacted with carbon monoxide in such a way that this compound is not returned to the second zone.

Abstract: A fluid-circulation heat exchanger including a porous body, made of thermally conductive material, in contact with at least one portion of a part to be cooled. The fluid flows through this porous body. The porous body has pores which generate directional changes of the fluid. These pores are large enough for the head loss of the fluid to be as small as possible on passage through the porous body. Application, in particular, to electron tubes.

Abstract: The present invention relates to a stack device comprising a stack of gate turnoff thyristors GTO, of freewheel diodes DRL, and of diodes D, for a semiconductor circuit, said stack device including power supply electrical connection terminals +HT and -HT, and an output terminal PM, together with electrical connection terminals Cs and Cc between said diodes Ds and Dc and a protection circuit P, wherein the geometrical organization of the wiring of said electrical connection terminals +HT, PM, and -HT is predetermined so as to enable the disposition of said thyristors GTO and of said freewheel diodes in said stack to be modified in order to obtain different electrical functions for the semiconductor circuit.

Abstract: A method for preparing carboxylic acids including (n+1) carbon atoms, or the related esters, by liquid phase carbonylation of an alcohol including (n) carbon atoms, in the presence of a uniform catalytic system based on at least one iridium compound and at least one halogenated promoter. In particular, the method is characterised in that the content of ester related to said carboxylic acid and alcohol is kept between 15 and 35% in the medium during the reaction, while the halogenated promoter content is kept between 10 and 20%, and the partial carbon monoxide pressure is 40-200 bar. Said method enables both the rate of carbonylation and the acetic acid selectivity to be increased.