Abstract: A process for the selective extraction of arsenic from acid solutions containing other metals comprising treating the solutions with polyhydroxybenzene derivatives in organic diluent; mono- and di- alkyl derivatives containing at least four alkyl carbon atoms of pyrocatechol and pyrogallic acid are particularly contemplated for use in the removal of arsenic from strongly acid copper-containing electrolyte solutions.

Abstract: A process for rutile flotation from rutile ores associated with iron containing components, in which process an alcoholic solution is employed of N-benzoyl-N-phenylhydroxylamine as a flotation collector of rutile. This process is especially suitable for rutile separation by flotation from rutile-hematite ores, with the use of said selective collector at pH values between 1 and 2.5.

Abstract: Process for coating a conductive substrate used as the anode in an electrochemical cell, in which a direct electric current is passed from a cathode to the said anode through an electrolytic liquid containing a phenolic monomer in order to form a polymeric film of phenolic resin on the substrate.The electrolyte includes from 10 to 200 g/l of allylphenol or a mixture of such with other phenols, and from 5 to 200 g/l of an aliphatic amine, in solution in a mixture of water and alcohol. The polymeric film is deposited by using an electric current of a density not greater than 50 mA/cm.sup.2 of substrate, and the polymeric film so deposited is heated to a temperature of from 100.degree. to 200.degree. C. in order to induce the hardening of the said resin.

Abstract: A process by which transformations of linear polyamides are performed at temperatures below the melting and decomposition temperatures of pure polyamides, wherein anionic polymerization of dry lactams with 4 to 12 carbon atoms is performed in the presence of one or more lithium halides, in amounts ranging from 1 to 10% in weight of the polymer.

Abstract: A photocoagulator is described incorporating a selected light source. The selected light source is a waveguide laser of the type using an active liquid comprising a dye in solution.The laser is so constructed that a cell containing the active liquid and a reservoir, rigid with the cell, for replenishing the liquid in the cell, form a single unit which can be readily removed from the remainder of the laser. An optical pumping source which forms part of the remainder of the laser is arranged to set up a heat gradient in the cell which tends to collimate the stimulated emission in the cell thus avoiding the need for accurate alignment of the reflectors at opposite ends of the cell.

Abstract: The device comprises a housing 16, having an annular chamber 18, the outer walls whereof are connected with conduits 10 and 12 to feed the liquids to be mixed; and the inner walls whereof with radial, conical conduits 24 and 26 which are perpendicular to the first mentioned conduits and which lead into a central chamber 28. Said central chamber 28 communicates by assymetric conduits 48, 50 with observation cell 40.

Abstract: A combustible composition for generating aerosols for the control and modification of weather conditions consisting of a readily oxidizable substance selected from the group consisting of aluminum, magnesium, alkali-metals and alkaline earth metals; an oxidizing agent selected from the groups consisting of:(a) sulphur and sulphur yielding compounds; and(b) organic and inorganic nitrates, alkali-metal and ammonium chlorates and perchlorates;The molar ratio of the oxidizable substance to the oxidizing agent being between 1.5:1 and 3.