Abstract: Sand blasting nozzle, particularly for the decontamination of radioactive members by means of a jet formed from a mixture of water and abrasive particles.It comprises an intake device able to produce a flat water jet, having an aperture angle .alpha. in the plane of the jet, within a vacuum chamber, a discharge member having in planes perpendicular to the flat jet, two divergent side walls substantially of aperture .alpha. and, on either side of the flat jet, two convergent walls forming an angle .beta., said discharge member forming an integral part of the vacuum chamber, and the angle .beta. being defined in such a way that within the chamber is produced an adequate vacuum to ensure that the flat jet entrains the abrasive particles introduced by a pipe carrying a mixture of gas and abrasive particles.

Abstract: A process is disclosed for the densification of a porous structure. The structure is immersed in a liquid hydrocarbon and is heated by induction so as to form, by decomposition of the hydrocarbon, carbon or pyrolytic graphite which can be deposited in the pores or cavities of the structure. The process may be used for the densification of fabrics or felts for use in pads in disc brakes.