Abstract: A noise-absorption structure comprising a frame over which a gastight membrane is tensioned, the outside face of the membrane receiving soundwaves, a gas such as air filling the volume defined by the frame and the membrane, and energy-dissipation means housed in the volume, which means are of the laminar gas-flow type, of the electrostatic type, or of the electromagnetic type, and area adjustable or controllable to modify the acoustic impedance of the structure as a function of the characteristics of the noise to be absorbed. The invention is particularly applicable in the aviation industry.

Abstract: The hearing aid includes n electrodes for being implanted in the cochlea at n different points chosen to allow identification by the brain of multiple frequency bands of a sound spectrum. A microphone receives the sound spectrum and outputs a sound signal. The instantaneous energy in the frequency bands in the sound signal is measured. The electrodes are operated cyclically as a function of the energy measured in the frequency bands and in an order determined in accordance with a time distribution of the energy in the frequency bands.

Abstract: The invention relates to a cartridge for preparing purified nucleic acids obtained from a sample of cells, the cartridge comprises a filter tube disposed inside a dialysis tube, the ends of the tubes are mounted in endpieces that are interconnected by rigid uprights, the endpieces are designed to be connected to a device for injection and delivery of substances such as a sample of cells, reaction substances, and rinsing substances.

Abstract: A method and apparatus for identifying the position of an object that is movable in a determined three-dimensional zone by means of a video camera (20) or the like mounted on the movable object (14), the camera (20) being capable of being swivelled to sight targets (22) disposed around the movable object (14) and to enable the position and the orientation of said object to be determined accurately by triangulation. The invention is particularly applicable to accurately determining the position and the orientation of a sensor or a tool mounted on a robot.

Abstract: A device for linear spraying of a liquid includes a series of tubes (3.sub.1) which supply liquid from a supply pipe (4) to an elongated spray nozzle (7) in the wall of a chamber (1) and a pipe (2) for delivering gas to the chamber to drive the liquid out of the enclosure. An elongate element (5) is provided in the enclosure to receive the liquid from the feed means. The liquid is spread over a convex surface (5.sub.1) of the element and is then carried off by the gas and flows to two elongate slits (8.sub.1,8.sub.2) adjacent to the nozzle (7) and converging towards the latter. The width of these slits varies periodically and interdependently over their length to form two sheets of the liquid/gas mixture which come together at the nozzle (7) to form at its outlet a mist of liquid confined within an angle (.alpha.) from the nozzle.

Abstract: A multiple electrophoresis method and apparatus for migrating and transferring macromolecules in a vessel (10) containing a plurality of parallel elongate electrodes (14), membranes (22) disposed vertically in the vessel between the columns of electrodes (14), and an electrophoresis gel which is inserted in the vessel in liquid form and which is subsequently solidified to perform electrophoresis. When the electrophoresis is completed, the gel is liquefied, dissolved, or decomposed, and the membranes (22) onto which the macromolecules have been transferred are withdrawn from the vessel.

Abstract: A device for providing a rigid mechanical link with frequency cut-off between two structures, the device comprising a rigid tie-rod (14) the ends of which are secured to the two structures (10, 12) and a cylinder and piston assembly (16, 18) in parallel with the tie-rod (14), the two ends of the cylinder (16) being interconnected by a duct (22) which, together with the cylinder (16), is filled with a liquid of very low viscosity, the device providing filtering of a low excitation frequency applied to one of the structures and preventing the transmission of this frequency to other structures.

Abstract: The invention concerns a method of making a gel plate with a microporous membrane by means of a cassette comprising a rectangular frame and a removable bottom plate, means for tensioning a membrane disposed on the frame substantially uniformly, and means for pouring liquid gel into the frame between the tensioned membrane and the removable bottom plate which also carries a comb for forming wells in the gel plate for receiving samples of macromolecules.The invention makes it quick and easy to manufacture gel plates with a microporous membrane for separation and transfer of macromolecules by electrophoresis.

Abstract: A device is intended for receiving one by one from an entry conveyor (2) flat objects moving along in the same plane in a first direction and for displacing them one by one towards an exit conveyor (5) includes reception conveyor (11) including a plurality of receptacles (12) movable over at least a part of their path in a second direction (F1) substantially orthogonal to the the first direction (F2), each receptacle being capable of receiving a flat object bearing in a position which is slightly inclined with respect to vertical, and a stationary station (7) for reception and stopping in a position which is slightly inclined with respect to vertical of the flat objects originating from the entry conveyor.

Abstract: A device for unit distribution of thin stacked objects such as letters which reduces the interval between distributed objects includes a rotating drum for contacting and accelerating a leading object from the stack through a slot, a speed sensor for measuring the instantaneous speed of the leading object as it is ejected by the drum through the slot, and an automation unit for controlling the driving of the next object by the drum as a function of the speed of the leading object.

Abstract: A method and apparatus for determining the color of an object which is transparent, diffusing, and absorbent, by illuminating an area of the object by means of a diffuse light flux that is substantially uniform and isotropic, by picking up the light backscattered by a small fraction of the illuminated area of the object by means of an optical system that comprises achromatic doublets and both infrared and ultraviolet filters, together with a diaphragm, and spectrally analyzing said light by means of interference filters and photodetectors. The invention is particularly suitable for determining the color of teeth in the mouth.

Abstract: A method and apparatus for fabricating a microporous-membrane for gel plate separating and transferring macromolecules by electrophoresis, the apparatus comprising a peripheral frame (10) provided with a removable bottom plate and including means (54, 58, 60, 64) enabling the membrane to be tensioned after it has been placed on the liquid gel as cast onto the bottom plate.

Abstract: Improved method for rapidly sequencing elements constituting a linear or linearized and ordered biological sequence such as a DNA fragment is provided. The method consists of extracting purifying and where appropriate fragmenting and/or amplifying a biological sequence in order to obtain a plurality of identical sequences which are subsequently combined to identify the complete DNA fragment.

Abstract: The invention relates to a method and to apparatus for determining the color of a translucent object such as a tooth by measuring the reflectance of said object at wavelengths corresponding essentially to sensitivity maxima of the human eye to hue and to saturation, by calculating the luminance of white included in the luminance of the object illuminated by a determined standard illuminant, by calculating a saturation percentage for the color of the object as seen by the human eye, and by determining the pigmentations of said color relative to white.

Abstract: The disclosed device allows individual transfer of flat objects from an input conveyor on which the objects move in a same plane according to a given direction into receptacles moving at right angles with respect to the direction. It is comprised of a sequentially driven reception conveyor intended to receive one by one the objects resting in a position slightly inclined with respect to the vertical, and a transfer member moving in synchronism with the conveyor in order to transfer to an injection position towards a receptacle the lower edge of an object resting on the reception conveyor. The device may be used in a postal sorting machine.

Abstract: A cartridge for preparing nucleic acids such as DNA from cells comprises two end rings (14) enabling it to be mounted in sealed manner in a tube (10), two dialysis membranes (16) delimiting a dialysis enclosure (18) between them, a filter (20) for retaining cell nuclei dividing said enclosure (18) into two separate compartments, and means (24) for feeding substances into one of the compartments, means (26) for extracting substances from the other compartments, and means (28, 30) for feeding a dialysis liquid into the tube outside the cartridge, or for causing it to flow therethrough. The invention also provides apparatus, and a method using said cartridge.

Abstract: A method of manufacturing a plate of gel for separating and transferring macromolecules by electrophoresis, the method consisting in fixing the periphery of a microporous membrane (10) to a frame (12) and in casting the liquid gel into the frame while avoiding any solid contact with the free face (24) of the membrane opposite to its face that is to be covered in gel, e.g. by placing the frame (12) on a slab (14), with the membrane (10) being above the frame and the slab, and then casting the gel into the frame (12) beneath the membrane (10).

Abstract: A compressor or turbine type rotary machine for compressing or expanding a dangerous gas, e.g. a gas that is toxic or explosive, comprises a closed enclosure formed outside the stator around a shaft passage receiving the shaft of the rotor, the enclosure being delimited by a bell and being filled with a liquid under pressure, a wet type mechanical seal being disposed between the rotor shaft and the stator, inside the stator. The liquid contained in the enclosure is put under pressure, and a magnetic coupling is provided to link the rotor shaft to an outside shaft. The invention makes it possible to prevent any leakage of dangerous gas from the inside to the outside of the rotary machine.

Abstract: A sequential demultiplexing receiver for a network of sensors (20) using spectrum modulation encoding, the receiver being essentially constituted by an integrated optical circuit comprising a substrate (34) that is birefringent or semiconductive on which there are formed mode couplers or mode converters (38) operating by the electro-optical effect and that are sequentially activated at high frequency to generate optical path length differences matching those of the sensors.

Abstract: An array of sensors quasi-distributed in an optical fiber (10), the sensors being delimited along the fiber by intermode coupling zones which are made by exposing the optical fiber (10) to a laser beam (16) through a mask (18) having periodic spatial transmission tuned to the difference between the propagation constants of the two modes to be coupled.