Abstract: A process for producing chromenes intended for the preparation of thermosetting resins, includes converting an aromatic propargyl ether of general formula (I) into a chromene by homogeneous catalysis with copper salts in anisole at a temperature between 100 and 170° C. Moreover, a process for preparing a material made of thermoset resin, includes successively a) carrying out the above process; b) polymerizing the reaction product obtained in a) so as to obtain the material made of thermoset resin; c) recovering the material made of thermoset resin obtained in b).

Abstract: A fuel supply circuit for an aeronautical cryogenic turbomachine including: at least one cryogenic reservoir containing a liquid fuel topped with a boil-off gas and including a high-pressure liquid pump to supply at least one main propulsion device of the turbomachine with liquid fuel, an auxiliary turbomachine including an electric generator, a gas compressor to supply the auxiliary turbomachine with gaseous fuel, and a buffer gas reservoir connecting the gas compressor to the cryogenic reservoir to reinject gas into the cryogenic reservoir in order to maintain the pressure in the cryogenic reservoir above a predefined value, the electric generator supplying the high-pressure liquid pump and the gas compressor.

Abstract: A method of extruding a material including a binder and one or more energetic fillers and using an installation including an extruder including a sheath having at least one extrusion screw present therein, the extruder having at least one acoustic sensor fastened on the sheath, and a monitor system suitable for detecting an anomaly as a function of the acoustic signal picked up by the acoustic sensor, the monitor system being configured to measure variations in the amplitude of the acoustic signal picked up by the acoustic sensor, the method including an extrusion step for extruding the material through the extruder during which the acoustic signal picked up by the sensor is analyzed by the monitor system, and a detection step for detecting variation in the composition of the extruded material from variation in the amplitude of the acoustic signal.

Abstract: A system for positioning at least one satellite in working orbit, characterized in that the system for positioning satellites in working orbit comprises: a first attachment device configured to attach a first satellite to the system for positioning satellites in working orbit; a main propulsion device with solid propulsion comprising a plurality of parallel solid-propellant cartridges; a secondary propulsion device which is re-ignitable; at least one position sensor configured to measure the position of said system; a monitoring unit connected to said at least one position sensor and which is configured to control a firing of the cartridges of the main propulsion device to move said system from a transfer orbit to a working orbit of the first satellite, said monitoring unit being further configured to control an opening of the first attachment device to separate said system from the first satellite.

Abstract: The invention relates to a method for assembling a first metal part with a second part made of an organic matrix composite material, the first part having a first connecting portion and the second part having a second connecting portion, the method comprising the steps of: causing the first connecting portion and the second connecting portion to overlap, a through-hole of the second connecting portion opening onto the first connecting portion, forming a protective layer on the side wall of the through-hole, forming a seal between the protective layer and the first connecting portion, and forming, by additive manufacturing using cold gas spray deposition of metal powder, a fastening element which extends into the through-hole, is fastened to the first connecting portion and encloses the second connecting portion.

Abstract: The invention relates to a cut-off device comprising: a conductive element and a movable piston, the piston being able to move between a first position in which the current passes in the conductive element and a second position in which the current is cut off, the piston being configured to break the conductive element when moving from its first position to its second position, the piston being positioned in a receiving cavity of a receiving element when said piston is in its second position, characterized in that the receiving element further comprises at least one additional cavity separate from the receiving cavity and linked to said receiving cavity by at least one channel, said at least one channel being open when the conductive element is broken by the piston.

Abstract: The invention relates to a piece comprising a first metal part and a second part made of an organic matrix composite material, in which the first part has a first connecting portion and the second part has a second connecting portion, the second connecting portion having at least one blind hole, the second connecting portion being totally or partially sandwiched between the first connecting portion and a metal fastening element, the fastening element being fastened to the first part on a portion other than the first connecting portion and extending into the at least one blind hole, whereby the first part and the second part are fastened to one another.

Abstract: Piece comprising a first metal part and a second part in organic matrix composite material, wherein the first part has a first connecting portion and the second part has a second connecting portion, the second connecting portion having at least one through-hole, the second connecting portion being totally or partially sandwiched between the first connecting portion and a metal fastening element, the fastening element being fastened on the first part both onto the first connecting portion via the through-hole of the second connecting portion and onto a portion other than the first connecting portion, whereby the first part and the second part are fastened to each other.

Abstract: Cryogenic turbopump feed line, comprising a main channel able to transport a cryogenic fluid, a plurality of secondary channels parallel to and disposed around the main channel in which the plurality of secondary channels are disposed on the periphery of an external perimeter of the main channel.

Abstract: The invention relates to an antenna comprising a radiative antenna element able to emit a signal in at least two disjoint frequency bands and a waveguide covered by the radiative antenna element, comprising two nested resonant cavities, each single-mode or mostly single-mode in a separate frequency band.

Abstract: The system (S) to separate at least two mechanical elements (E1, E2), comprises a holding device comprising a connecting screw integral with a mechanical element (E1) and held by a nut segmented in portions (4n) arranged between the connecting screw and an outer envelope integral with the other mechanical element (E2), the system (S) comprising a force generator generating a thrust force (F) in a longitudinal direction (X-X) and comprising an energy accumulator comprising a sealed chamber with a colloid of a porous matrix and liquid, the chamber deforming in the longitudinal direction (X-X) to adapt to the change from a compressed to a decompressed state in order to generate the force (F), and an activatable actuating element to, either apply a predetermined pressure to the chamber to keep the colloid in the compressed state, or not apply the predetermined pressure to allow the change in state of the colloid.

Abstract: A process for manufacturing chromenes which are intended for the preparation of thermosetting resins, includes transforming an aromatic propargyl ether of general formula (I) into a chromene by flash vacuum thermolysis, at a temperature of between 300 and 600° C., at a pressure of between 4 and 10,000 Pa. It also concerns a process for preparing a material made of thermoset resin, including successively: a) implementation of the above process; b) polymerization of the reaction product obtained in a) so as to obtain the material made of thermoset resin; c) recovery of the material made of thermoset resin obtained in b).

Abstract: A rotor for a turbomachine includes a disc and a plurality of blades fixed to the disc. Each blade of the plurality of blades is fixed to the disc via a lattice structure configured so that a tensile force applied to the lattice structure induces a change in the angle of incidence of the blade. The blades and the lattice structures are configured so that: (i) when the rotor is stationary, the distribution of the angles of incidence of the blades around the disc is aperiodic, and (ii) when the rotor is rotating at a predetermined rotational speed, the angles of incidence of the blades are identical.

Abstract: The invention concerns a device (1) for neutralizing a chemical or biological weapon (2), characterized in that it comprises: a sealed enclosure (3) which delimits an internal volume (31) and is movable between a retracted position and an extended position; a pyrotechnic neutralizing charge (4) which is disposed inside the enclosure (3); a decontaminating agent (5) which is disposed inside the enclosure (3) and surrounds the pyrotechnic neutralizing charge (4); a mitigating agent (6) which is disposed in the enclosure (3) and covers the decontaminating agent (5).

Abstract: A process for the sigmatropic rearrangement of the compound of formula in which R3 is an NO2 group and R4 is either a hydrogen or an NO2 group, includes heat treating the compound by microwave.

Abstract: Nozzle of a spacecraft engine, comprising a nozzle body extending along a main direction, from a proximal end secured to the engine of the spacecraft, and a free distal end, said nozzle body having a plurality of stiffeners extending from an outer surface of the nozzle body, radially with respect to the main direction, said nozzle comprising a thermal insulation system, comprising at least one strip of insulating material disposed so as to surround the outer surface of the nozzle body over at least part of the height of said nozzle body-, said thermal insulation system comprising a plurality of holding elements, each holding element being positioned so as to surround said strips of insulating material, and being disposed between two stiffeners of the nozzle body.

Abstract: A multi-epoxidized biphenyl compound has the formula (I) below wherein R, R1, R2 and R3 are as defined in the description, as well as mixtures of at least two of the compounds. These multi-epoxidized biphenyl compounds are fully suitable as main constituents of thermosetting epoxy resins, i.e. as polyepoxides precursors. They are beneficial substitutes for bisphenol A diglycidyl ether.

Abstract: The invention relates to a device and a method for the connection and linear separation of two elements, such as the two stages of a spacecraft, consisting in using a tube containing a pyrogenic-type material and a glue arranged around the tube, particularly in contact with the elements. The pyrotechnic triggering of the pyrogenic material causes heating and the melting or carbonisation of the glue and the separation of the two elements.

Abstract: A patch antenna intended to equip a spacecraft, the antenna comprising a dielectric substrate, a radiating antenna element present on the dielectric substrate, the radiating antenna element having a center of symmetry and an area devoid of material, the center of symmetry being present in the area devoid of material, and a protective layer covering the radiating antenna element.

Abstract: A pyrotechnic cut-off device includes: a pyrotechnic igniter, a conductive portion and a movable piston, the piston being able to be displaced in a cavity along a direction of displacement following the actuation of the pyrotechnic igniter between a first position of passage of the current in the conductive portion and a second position of cut-off of the current, wherein the piston defines a first sealing portion having a narrowing of section along the direction of displacement, and the cavity has a wall defining a second sealing portion which extends on either side of the conductive portion and which has a narrowing of section along the direction of displacement, the first sealing portion being in contact with the second sealing portion along a contact surface extending on either side of the conductive portion when the piston is in the second position.