Abstract: A cellular sound insulation structure and associated aircraft, a cell of which is provided with a diaphragm which includes a membrane having at least one orifice passing through a thickness of the membrane, and at least one tube surmounting the orifice and extending from a face of the membrane into one compartment of the cell, the tube comprising a free end, forming an acoustic outlet, which is positioned at a distance (p) from the base cross section of the cell. Also, a method for manufacturing such a cellular sound insulation structure, as well as to a tool for inserting a diaphragm into a cell. Such a cellular structure makes it possible to treat a wider acoustic frequency spectrum, and its acoustic dimensioning as well as its manufacture are simplified.

Abstract: An acoustic panel comprising a cellular structure, such as a honeycomb structure, having cells that open at least onto a first frontal face of the structure. The panel comprises a capsular skin which is fastened to the first frontal face of the cellular structure next to a plurality of cells. The capsular skin including a continuous layer of material, in one piece, forming capsules that extend into the cellular structure. At least one channel is provided at the apex of each capsule for the passage of acoustic waves. Such a panel effectively attenuates the noise of aircraft engines, in particular, the low frequencies. It is extremely easy to manufacture industrially, the capsular skin being able to be obtained by molding with polymerization in situ, the polymerizable material then adhering to the cellular structure while it polymerizes.

Abstract: A method for producing an alveolar soundproofing structure in which a portion of a membrane of a diaphragm including an acoustic outlet is inserted into a hole of a perforated membrane which covers a cell of the alveolar structure, and the diaphragm is pressed into the cell with the perforated membrane becoming deformed and is fixed at that location. It also relates to the alveolar structure. Such a method enables different types of diaphragms to be inserted into different configurations of cells and enables the diaphragm to be fixed therein, in accordance with the sound frequencies to be processed.

Abstract: A method and a facility for filling a high- or medium-voltage gas-insulated electrical apparatus in which the insulating gas comprises a mixture of heptafluoroisobutyronitrile ((CF3)2CFCN) and carbon dioxide. The method and the facility using a mixture of (CF3)2CFCN and CO2 in pressurised liquid form which is heated to a temperature no lower than the critical temperature of the mixture.

Abstract: A method and a facility for filling a high- or medium-voltage gas-insulated electrical apparatus in which the insulating gas comprises a mixture of heptafluoroisobutyronitrile ((CF3)2CFCN) and carbon dioxide. The method and the facility using a mixture of (CF3)2CFCN and CO2 in pressurised liquid form which is heated to a temperature no lower than the critical temperature of the mixture.

Abstract: The present invention relates to medium- or high-voltage equipment having low environmental impact, including a leaktight enclosure in which there are located electrical components covered with a solid dielectric layer of varying thickness and a gaseous medium for providing electrical insulation and/or for extinguishing electric arcs that are likely to occur in said enclosure, and that comprises heptafluoroisobutyronitrile in a mixture with a dilution gas.

Abstract: The present invention provides medium- or high-voltage equipment including a leaktight enclosure in which there are located electrical components and a gas mixture for providing electrical insulation and/or for extinguishing electric arcs that are likely to occur in said enclosure, the gas mixture comprising heptafluoroisobutyronitrile, carbon dioxide, and oxygen in small quantities. Electrical components covered in a solid dielectric layer of varying thickness are located inside said leaktight enclosure of the equipment of the invention.

Abstract: The present invention provides medium- or high-voltage equipment including a leaktight enclosure in which there are located electrical components and a gas mixture for providing electrical insulation and/or for extinguishing electric arcs that are likely to occur in said enclosure, the gas mixture comprising heptafluoroisobutyronitrile, carbon dioxide, and oxygen in small quantities. Electrical components covered in a solid dielectric layer of varying thickness are located inside said leaktight enclosure of the equipment of the invention.

Abstract: The present invention relates to medium- or high-voltage equipment having low environmental impact, including a leaktight enclosure in which there are located electrical components covered with a solid dielectric layer of varying thickness and a gaseous medium for providing electrical insulation and/or for extinguishing electric arcs that are likely to occur in said enclosure, and that comprises heptafluoroisobutyronitrile in a mixture with a dilution gas.

Abstract: This arcing contact element (10, 18) is capable of occupying an initial position in which it is in contact with another arcing contact element (18, 10), as well as a second position, in which it is separated from this other arcing contact element so as to allow interruption of the current. This element consists of carbon fibres embedded in a matrix which includes at least one electrically conducting material linked to graphite.