Abstract: An induction heating device for continuously moving metal strip (22) for heat treatment or coating purposes comprises a flattened, spirally wound coil having the turns interlinked by an oblique connection on a small side of the coil, and surrounding the continuously moving metal strip (22). Means (24-26) are provided for suppressing the transverse component of the magnetic field created by the said coil.

Abstract: It concerns a monomer, a polymer obtained from the monomer and a process for obtaining the said polymer. The monomer consists of a polyether containing at least 3 ether units and pyrrole or thiophene units bonded to the ends of the chains of this polyether via, for each of these heterocycic compounds, either their carbon atoms in the 3,3'-positions of their heterocycles or, as regards more particularly the pyrrole groups, via their respective nitrogen atoms, the 2- and 2'-positions of these heterocycles being, however, free of all substitutions or, at the very most, substituted by easily removable groups (protective groups, for example). Application to the purification and recovery of metal ions such as radioactive silver.

Abstract: Aqueous alkaline solid electrolyte comprising a polar polymer matrix which is solid at ambient temperature, and a compound or mixture of basic compounds selected from alkaline metal, alkaline-earth or ammonium hydroxides. Preferably, the matrix is a polyether homopolymer or copolymer of different ethers or polyethers. The invention also concerns electrodes and/or electrochemical generators containing such an alkaline polymer solid electrolyte.

Abstract: A method and a device for measuring compensation balance and imbalance in an electrical supply network having a balancing coil. An auxiliary measurement signal is injected into the network's neutral circuit, changes in the homopolar voltage induced by the auxiliary signal injection are measured, and an impedance measurement is obtained by comparing the changes in the hompolar voltage with the injected auxiliary measurement signal, in terms of both amplitude and phase. A parallel current may advantageously be injected into the neutral circuit at the secondary winding of a homopolar transformer placed in the neutral coil.

Abstract: The method and the device are applicable to the penetrations (2) of a pressurised water nuclear reactor vessel head (1) during operation.The device includes a double circuit for picking off two gas samples (100, 16, 17; 12, 13, 14, 15) and a measurement assembly (18) which regularly compares the content, especially of water vapour, in the two samples picked off. The first sample is taken from the volume of a chamber (7) where the possible leak (10) emerges, and the second in proximity to the head (1) outside the region immediately affected by the leak. The assembly (18) makes it possible to generate (19) an alarm in the event of a leak and to distinguish it from operational alarms.Techniques and means are also provided for determining the flow rate of sweeping in the volume of the chamber (7) and for checking the pick-off and detection systems.

Abstract: Pulse width modulation quasi-resonant voltage inverter including a bridge (2) and an oscillating circuit consisting of an inductance (5) in series with the voltage source (1) and of a capacitor (6) in parallel with the bridge (2), the sampling period was much greater than the resonance period, characterized in that it includes a controlled component operating in blocked/saturated mode (7) in parallel with the capacitor (6) and a voltage sensor (8) parallel with the capacitor (6), the component (7) being controlled by the sensor (8) so as to short-circuit the capacitor (6) when the voltage across the latter's terminals is zero and to enable the transitions of the signal for control of the pulse width modulation regulation.

Abstract: The nacelle (2) and the fork (20) permit rapid interventions by helicopter on bundle-type overhead cables (1). The metal nacelle (2) carrying operators and equipment has on its sides (16) fixing hooks (14). The nacelle (2) can be fixed to overhead cables (1) by fixing bars (7) equipped with notches (8). The fork (20) has gripping ends (22) able to grasp the nacelle (2) beneath hooks (14). It is equipped with pyrotechnic bolts allowing jettisoning to take place if it is urgently necessary to lighten the load of the helicopter. Application to the repair and maintenance of overhead cables of the public power distribution network and in particular to the replacement of coupling sleeves.

Abstract: Method of regulating a voltage inverter operating in quasi-resonance, including an inverter bridge with controlled components (transistors, GTO etc.) operating in turned off-saturated mode, and an oscillating circuit arranged on the DC voltage source side, and consisting of an inductor in series with the DC voltage source, and of a capacitor connected in parallel with the inverter bridge, characterized in that pulse-width modulation regulation is carried out, in which the sampling period is very much greater than and of the order of about ten or more times the resonance period of the oscillating circuit.

Abstract: Catalytic process for controlled oxidation of methane using microwaves, characterized in that it makes use of a catalyst exhibiting in its structure electrical charge defects and geometric deformations enabling it to absorb electromagnetic energy, or microwaves, under the effect of an electromagnetic field.

Abstract: A fire barrier aeration device intended to ensure free exchange of air between two spaces separated by a wall which is equipped therewith and to break the passage of gas through the wall, when fire breaks out in one of the spaces, comprises at least one body (10) made of a refractory material intended to be disposed in an orifice of the wall. The body is passed through by an aeration passage (17) at the end of which, emerging on a face of the body which is turned in the direction from where the fire may come, there is disposed an element (21) made of an intumescent material which in the absence of fire leaves a portion of the cross section of the aeration passage (17) free and which is at least partially surrounded by a flexible material (22) for guiding and confining the inflation of the intumescent material (21) in the aeration passage (17) in order to make the material completely block the passage in the case of fire.

Abstract: The plasma torch (10; 11, 12, 14) comprises an electrical power supply (20) with an arc circuit (21) and a coil circuit (22) which are mounted in series and with means (30) for controlling the level of the current flowing in the coil (22) consisting, inter alia, mounted in parallel with this coil (14), of a chopper consisting of a battery of capacitors (31) and of at least one electronic power switch (32) which may be placed distant from the coil. The electronic switch is preferably of the thyristor diode (321, 322) type, with a resonant turn-off circuit (31, 323).A variant of this chopper uses at least one electronic switch of the GTO thyristor type, controllable in triggering and in switching off, or at least one conventional thyristor equipped with an auxiliary extinction circuit.Application to high-power torches, for industrial, for example metallurgical, use.

Abstract: Device for the recovery of a molten core of a nuclear reactor essentially constituted by partitions (4) for subdividing a volume located below the core into narrow empty volumes (5), into which the molten material will slowly flow, and cooling channels (6) for solidifying said material. The vaporization of the coolant advantageously brings about its automatic replenishment under the effect of the hydrostatic pressure of a raised source.

Abstract: Apparatus for measuring axial bending or tensile stresses on a rod (1).A ring (10) carries at least one sensor or transducer (15). A ring (11), parallel to the ring (10), serves as a magnetic target. The rings are formed by two substantially semicircular, dismantlable halves. The measurement consists of estimating the width of the gap (12) between the rings (10 and 11). The sensors (15) can be of the magnetic reluctance type.Application to the measurement of stresses in sliding rods of certain safety taps, cocks or valves.

Abstract: The present invention relates to a plate heat exchanger consisting of a stack of plates (21) clamped against each other in a sealed manner with a sealing joint being intercalated so as to create fluid flow channels between these plates, each plate comprising four holes forming with the holes of the other plates four manifolds (26,27), namely two inlet manifolds and two outlet manifolds, the ends of these manifolds being connected, on one side of the stack, to inlet or outlet pipework (28,29), so as to create two distinct fluid circuits, the joints enabling the channels to communicate with one or the other of the said fluid flow circuits, characterised in that at least one of the two inlet manifolds (26) is provided with a peripheral filtering cartridge (33), the mesh size of which is less than or equal to the distance between two contiguous plates (21), and is connected, at its opposite end to the inlet pipework (28), to the corresponding outlet pipework (29) by a pipe (31) controlled by a valve (32).

Abstract: The invention permits the replacement of a used section of an overhead cable (1) by a new section without depositing said cable on the ground. A nacelle or pod mainly includes a drum (20) onto which is wound the new section to be deposited and on which will be wound the old section to be replaced. The nacelle also includes guide pulleys (14, 16) for the cable (1). The nacelle is suspended on a helicopter by means of a rope, an upper beam (32) and optionally via pyrotechnic means (46) and ball and socket joints (38). It can be completed by jaws (44) for fixing to the cable (1). The invention has application to electric power distribution and transporting cables and to cable railway cables.

Abstract: The black powder to be treated is injected into the bottom portion of a heated dense fluidized bed, said bed having effective depth enabling the carbon the particles of silica to be oxidized into carbon dioxide as the particles go through the dense fluidized bed while being entrained by the fluidization air. The whitened powder is then recovered by filtering the gases leaving said dense fluidized bed. The invention is particularly applicable to the cosmetics industry for producing make-up that uses silica powder.

Abstract: The nacelle (2) permits the rapid replacement of a coupling sleeve (38) between two portions of an overhead cable (1) without depositing said cable on the ground. The nacelle (2) is a metal structure carrying operators and tools. It is suspended on a helicopter, which positions it against the overhead cable (1) and maintains it throughout the change operation for the sleeve (38). By using a force take-up jack (40) at the ends of the sleeve (38), it is possible to replace said sleeve (38) or carry out other operations with respect to this point of the cable (1). The nacelle (2) has pyrotechnic jettisoning or release means. Application to the replacement of sleeves on overhead cables.

Abstract: The present invention provides nacelles or cars (10) and a catwalk or platform (30) which make it possible to instantaneously place one or more operators (2) on overhead cables (1) for carrying out different work activities. Each nacelle (10) is a preferably latticed, metallic structure having pivoting walls (8) for extending the field of action of each operator. Each nacelle has means (5) for attaching to the cables (1). The catwalk (30) can be opened out and is located at the ends of each of the nacelles (10). The present invention is particularly adapted for used in the maintenance and arrangement of electric cables.

Abstract: A process for measuring a physical quantity with a random and pulse-like character, or which is transformable into pulse form is made of a measuring chain, which supplies a result relative to the quantity. An iterative mathematical simulation is carried out taking into account the random variable character of the measured phenomenon by distinguishing the behavior of the single, double, triple, etc. events in the electronic processor of the chain optimized for this purpose. During the simulation, a determination takes place of an approximate result relative to the quantity, and the simulation result is compared with the measured result. The present invention has particular utility in the measurement of the volume activity of nuclides or radioelements present in a circulating fluid, although other utilities are contemplated.

Abstract: A shell structure for constituting the airflow shaft of a water-cooling tower comprises an upright frame support by ground foundations. The frame consists of a grid having at least three intersecting sets of bars, one of the sets comprising horizontal bars connected as to constitute circumferential girdles vertically distributed along the frame while the other two sets comprises bars which are at opposed angles with said horizontal bars, for defining a grid whose elemental pattern is an equilateral triangle. The bars are connected by nodes each receiving bars of all said sets. A veil defining a substantially continuous airflow stack is located within said frame and maintained in tension by connectons to the nodes of the frame. The frame may have a constant cross-section while the veil has a cross-section which varies along the vertical axis of the structure.