Abstract: A soundproofing panel having a core sandwiched between a solid wall and a porous wall. The core being connected to the walls and having partitions extending in the thickness direction between the two walls so as to form cells. Each cell containing at least one sound energy dissipating layer constituted by hollow spherical beads having mutually contacting walls that are porous and micro-perforated, and being held in position in the thickness direction between the two walls by nets that are secured to the partitions.

Abstract: A cowl for a turbomachine nozzle, the cowl having a plurality of repeated patterns disposed circumferentially at a trailing edge, each pattern being asymmetrical about a midplane of the pattern containing a longitudinal axis of the cowl, and each pattern having a first portion inclined radially towards the inside of the cowl and a second portion inclined radially towards the outside of the cowl.

Abstract: A soundproofing panel (2) comprises a core (4) sandwiched between a solid wall (6) and a porous wall (8), the core being connected to the walls and comprising partitions (12) extending in the thickness direction between the two walls so as to form cells (10) each cell containing at least one sound energy dissipating layer (14), the dissipating layers (14) being constituted by hollow spherical beads (20) having mutually contacting walls that are porous and micro-perforated, and being held in position in the thickness direction between the two walls (6, 8) by nets (22) that are secured to the partitions.

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 present invention relates to a process and apparatus for the recovery of liquid aluminium by compression of hot dross.The process comprises placing the dross in a die up to a height which depends on the diameter of said die and which is lower at the center than at the periphery of the die, and then applying to the dross a punch which is moved downwardly at a speed which is lower in proportion to a lower level of concentration of liquid aluminium in the dross.The apparatus comprises a cylindrical die (10) provided with an insert member at each of its ends. The die rests on a base (3) which has an annular groove (4) on its upper face; the lower insert member (7) is of a diameter that is at least equal to the inside diameter of the groove and in any case less than the outside diameter and has a continuous upper face of conical shape; the space (16) between the wall surface of said insert member and the internal wall surface of the die is of a constant width and is disposed facing the groove.

Abstract: The present invention relates to a process and apparatus for the recovery of liquid aluminium by compression of hot dross.The process comprises placing the dross in a die up to a height which depends on the diameter of said die and which is lower at the center than at the periphery of the die, and then applying to the dross a punch which is moved downwardly at a speed which is lower in proportion to a lower level of concentration of liquid aluminium in the dross.The apparatus comprises a cylindrical die (10) provided with an insert member at each of its ends. The die rests on a base (3) which has an annular groove (4) on its upper face; the lower insert member (7) is of a diameter that is at least equal to the inside diameter of the groove and in any case less than the outside diameter and has a continuous upper face of conical shape; the space (16) between the wall surface of said insert member and the internal wall surface of the die is of a constant width and is disposed facing the groove.