Abstract: A segment of an abradable ring seal for a turbomachine, includes: a reinforcing support; a composite fabric including fibers impregnated with polymerized resin, and a track of abradable material. The composite fabric is interposed between the reinforcing support 71 and the track of abradable material and is bonded to the reinforcing support, on the one side, and to the track of abradable material, on the other side. The segment of an abradable ring seal has a resistance to tearing in a direction perpendicular to the interface between the track of abradable material and the composite fabric, on the one hand, and between the composite fabric and the reinforcing support, on the other hand, greater than 5.106 newtons per square meter. A process for the manufacture of such a segment is also described.

Abstract: A molded piece 25 of abradable material for use in the manufacture of a segment of an abradable ring seal for a turbomachine includes a mixture of epoxy resin and crosslinking agent. The piece 25 has a curved shape and dimensions adapted to correspond to a receiver provided for that purpose in the inner surface of a casing of a fan of a turbomachine. A process for the manufacture of such a piece is also described.

Abstract: A segment of an abradable ring seal for a turbomachine, includes: a reinforcing support; a composite fabric including fibres impregnated with polymerised resin, and a track of abradable material. The composite fabric is interposed between the reinforcing support 71 and the track of abradable material and is bonded to the reinforcing support, on the one side, and to the track of abradable material, on the other side. The segment of an abradable ring seal has a resistance to tearing in a direction perpendicular to the interface between the track of abradable material and the composite fabric, on the one hand, and between the composite fabric and the reinforcing support, on the other hand, greater than 5.106 newtons per square meter. A process for the manufacture of such a segment is also described.

Abstract: A molded piece 25 of abradable material for use in the manufacture of a segment of an abradable ring seal for a turbomachine includes a mixture of epoxy resin and crosslinking agent. The piece 25 has a curved shape and dimensions adapted to correspond to a receiver provided for that purpose in the inner surface of a casing of a fan of a turbomachine. A process for the manufacture of such a piece is also described.

Abstract: There is described a process for the separation and purification of the platinum group metals from base metal out of acidic aqueous solutions. For this purpose there is used a substituted thiourea of the formulaR.sub.1 R.sub.2 N--CS--NH--CO--R.sub.3orR.sub.1 R.sub.2 N--CS--NH--COOR.sub.3as the precipitation agent. Preferably there are employed N,N-diaklyl-N'-benzoylthiourea wherein R.sub.1 and R.sub.2 are methyl, n-butyl, or n-hexyl.

Abstract: There is described a process for the separation and purification of the platinum group metals from base metal out of acidic aqueous solutions. For this purpose there is used a substituted thiourea of the formulaR.sub.1 R.sub.2 N--CS--NH--CO--R.sub.3orR.sub.1 R.sub.2 N--CS--NH--COOR.sub.3as the extraction agent. Preferably there are employed N,N-dialkyl-N'-benzoylthiourea wherein R.sub.1 and R.sub.2 are methyl, n-butyl, or n-hexyl.