Abstract: The present invention relates to yarns, fibres or filaments made of thermoplastics and to their manufacture. It relates more particularly to yarns, fibres or filaments exhibiting good fire resistance properties and to processes for the manufacture of these articles. These yarns or fibres made of polymer are obtained by spinning a polymer comprising an additive possessing flame-retardant properties composed of at least particles of a solid substrate on which a flame-retardant compound is adsorbed.

Abstract: The present invention relates to a new flame-retardant composition based on a flame retardant impregnated on an inorganic oxide of high porosity, to a process for preparing it and to its use for flame retarding materials and especially polymers.

Abstract: The rare earth hydroxides are improvedly prepared by (i) treating a rare earth phosphate mineral, e.g., monazite or xenotime, with an aqueous solution of an alkali metal hydroxide, (ii) separating therefrom rare earth hydroxide solids and a liquid phase essentially consisting of alkali metal phosphate and alkali metal hydroxide, (iii) crystallizing alkali metal phosphate from said liquid phase, (iv) separating the mother liquor of crystallization therefrom which contains said alkali metal hydroxide, (v) adding calcium oxide or hydroxide to the mother liquor thus separated to form a precipitate therein, (vi) separating said formed precipitate, and (vii) recycling the mother liquor of separation to said treatment step (i).

Abstract: The uranium, yttrium, thorium and rare earth values contained in a phosphate rock are essentially totally recovered therefrom by, during the wet-process preparation of phosphoric acid from said phosphate rock, acidulating same in the presence of aluminum and/or iron, and optionally silica, and thence recovering said values from the phosphoric acid thus produced.

Abstract: Additive composition for an acid copper electroplating bath, which bath being well adapted for the copper plating of printed circuits, is comprised of (1) the sodium salt of .omega.-sulfo-n-propyl N,N-diethyldithiocarbamate, (2) polyethylene glycol having an average molecular weight ranging from about 6,000 to 20,000, (3) crystal violet, and (4) sulfuric acid.

Abstract: Device for determining the direction of a plane wave comprising P detectors regularly spaced out on a rectilinear base, a clock whose frequency is 1/.tau. and several channels, each connected with a determined direction. The channel m comprises a device sampling all the m.tau. signals of the detectors whose outputs are connected to an adder followed by m - 1 delay cells in series, the output of the last one being applied to the input of the adder. Each adder supplies a signal depending on the difference between the direction m and the direction of the plane wave. Application is to sonars.