Abstract: A lubricating oil composition having an improved viscosity index is manufactured by admixing lubricating oil in major proportion with a butadiene polymer in minor proportion, said polybutadiene having a molecular weight of at least 20,000 and a microstructure of from 65 to 85 % ##EQU1## units, from 2 to 35 % of -- CH.sub.2 --CH.sub.2 --CH.sub.2 --CH.sub.2 -- units and from 0 to 25 % of -- CH.sub.2 --CH = CH--CH.sub.2 -- units.

Abstract: Catalytic oxidation of hydrogen sulfide to sulfur in homogeneous liquid phase, by means of molecular oxygen, in an organic solvent whose water content is lower than 60% by volume, said liquid phase comprising a solvent selected from amides, phosphoramides, sulfoxides, nitriles and ethers, said oxidation being conducted in the presence of at least one catalyst selected from the two following categories:A. a chelate of a transition metal selected from the group of metals consisting of iron, manganese, copper and cobalt, the chelate being selected from the group consisting of dialkyldithiocarbamates, alkylxanthates, dithiolates, 8-hydroxyquinolinates and salicylaldimines,B. a salt of said transition metal of the formula MX.sub.m in which M is the transition metal, X is an anion selected from the group consisting of Cl.sup.-, Br.sup.-, ClO.sub.4.sup.-, NO.sub.3.sup.- and SCN.sup.- and m is 2 or 3.

Abstract: The liquid phase dimerization of diolefins is effected by maintaining the diolefins in solution in an inert solvent in contact with a catalyst which is the reaction product of a transition metal carbonyl and a compound which is a transition metal halide or pseudo halide coordinated with groups capable of furnishing three electrons. The dimerization of butadiene to vinyl-4-cyclohexene and cyclooctadiene and the dimerization of C.sub.4 cracked fractions into vinyl-4-cyclohexene are preferred reactions.

Abstract: The method comprises the steps of heating a sample of sediments, determining a group of two parameters S.sub.1 and S.sub.2 which represent, respectively, the amounts of at least one hydrocarbon compound and of at least one oxygen-containing compound formed by heating the organic material contained in the sediment, and evaluating from the determination of this group of parameters the capacity of the sediments to constitute a good mother rock (i.e. source) for hydrocarbons.

Abstract: Ketones are converted by hydrogenation to the corresponding secondary alcohols, in the presence of a soluble catalyst which is obtained by contacting a metal compound, for example a cobalt, nickel or iron salt, with a reducing agent, preferably a trialkylaluminum compound, the reaction being carried out with added metal alcoholate, preferably an alkali metal alcoholate.