Abstract: The invention relates to a process for the production of citric and osocitric acids by a culture of a diploid Candida Lipolytica yeast in a nutrient medium containing substances which are sources of carbon, nitrogen, and mineral compounds, the medium containing thiamin in a concentration in excess of 200 micrograms per liter.

Abstract: This invention relates to the production of citric and/or isocitric acids. The production of citric and/or isocitric acids is effected by cultivating a citric and/or isocitric acid-producing yeast in a culture medium containing a compound selected from cyanoacetic acid, and organic and inorganic derivatives thereof. Increased yields of citric and isocitric acids are obtained using a process in accordance with the invention, preferably using a yeast of the genus Candida.

Abstract: Process for producing aromatic hydrocarbons, particularly benzene and/or toluene from a feed charge containing saturated and unsaturated hydrocarbons, by catalytic treatment of said charge with hydrogen, fractionation of the resulting product to separate a fraction containing benzene and/or toluene, extractive distillation of at least one aromatic hydrocarbon in a column, by means of an extraction solvent from which said hydrocarbon is subsequently separated, and recycling to the reaction zone of at least one portion of the products recovered at the top of said extractive distillation column and containing essentially C.sub.6 and C.sub.7 saturated hydrocarbons.

Abstract: Process for hydrodealkylating alkylaromatic hydrocarbons using a catalyst comprising at least two metals deposited on a carrier, a first of these two metals being selected either from the group consisting of cobalt, ruthenium, osmium, palladium, rhodium, iridium and platinum or from the group consisting of chromium, molybdenum, tungsten and manganese, and the second of these two metals being selected from zinc, cadmium, gallium, indium, thallium, manganese, copper, silver, gold, yttrium, titanium, niobium, tentalum, chromium, molybdenum, tungsten, rhenium, germanium, tin and lead.

Abstract: Used lubricating oils are first heated to 200.degree.-500.degree. C, optionally with added steam, and then filtered through a membrane such as an ultra-filtration membrane. The latter has preferably a cut range of from 5,000 to 300,000.

Abstract: Process for determining characteristics of the geological formations traversed by a borehole, making use of a sonde by means of which the intensity of the .gamma. rays naturally radiated from the formations is measured, both longitudinal and transversal acoustic waves are transmitted to the formations, their travel time and their attenuation between two receivers placed in contact with the formations are measured and by combination of the so-obtained values a resulting value is elaborated which is representative of one characteristic of the surveyed formations.

Abstract: Receiver of continuous structure adapted to be laid on the ground surface or underground, for seismic prospecting on land, comprising at least one support member for geophones, made of a flexible material having an elongated central portion and two lateral portions defining therewith at least one recess, said geophones being fastened to the central portion of the support member and coupled to the earth therethrough and said lateral portions being provided with longitudinal channels housing conductor cables.

Abstract: A dicarboxylic compound complying with one of the general formulae: ##SPC1##In which R is a divalent radical selected from the aliphatic, alicyclic and aromatic radicals, the aliphatic containing 1-20 carbon atoms and the other containing from 5 to 20 carbon atoms, R.sup.1 is selected from the hydrogen atom and the alkyl and cycloalkyl groups containing from 1 to 10 carbon atoms and R.sup.2 is selected from the alkyl and cycloalkyl groups containing from 1 to 10 carbon atoms, the polyester resins derived therefrom being usable as enamelling composition, particularly for coating metal wires.

Abstract: A sampling circuit connected directly to the distillation column consists of a primary loop formed by a sampling tube which penetrates into the column in a region of expansion and vaporization and is equipped with means for limiting the velocity of the vapor collected therein and for separating the entrained liquid fraction if necessary. The sampling circuit further comprises a condenser and a filter, the condensate being returned to the column by a circulating pump and a withdrawal of condensate being effected by a secondary loop for supplying an analyzing device in parallel.

Abstract: This invention relates to gasoline compositions containing additives which are reaction products of a maleic anhydride of the formula ##EQU1## with a linear polyamine of the formulaH.sub.2 N--(CH.sub.2).sub.n -- NH].sub.m R'in which R.sub.1 and R.sub.2 are selected from the group consisting of a hydrogen atom and a monovalent hydrocarbon radical of 1 - 30 carbon atoms, R' is a monovalent aliphatic hydrocarbon radical having 6 - 30 carbon atoms, n is an integer from 3 to 10 and m is an integer from 1 to 10.

Abstract: Toluene and poly-methyl benzene hydrocarbons are reacted in the presence of an improved catalyst containing a group VIII noble metal. The catalyst is obtained by admixing a catalyst carrier with a Group VIII noble metal or compound thereof and with a hydrocarbyl aluminum halide. Sulfur may be present. The yield and selectivity are substantially improved as compared to conventional catalysts.

Abstract: Organic compounds of the formula:[(H.sub.3.sub.-n X.sub.n)C - CO.sub.2 M (CO).sub.m (R).sub.p (L).sub.q ].sub.rin which X is a halogen atom, at least one X being fluorine, M is molybdenum or tungsten, R is a hydride ion or a hydrocarbon group, L is a Lewis base and m, n, p, q and r are integers, are manufactured from fluoracetic esters and molybdenum or tungsten carbonyl compounds. They are useful as catalysts for polymerizing or co-polymerizing unsaturated compounds such as butadiene.

Abstract: Process for manufacturing a supported catalyst whose active phase contains mainly molybdenum and iron by impregnating a carrier with an aqueous solution of alkanolamine and a complex of the active phase elements, drying and thereafter roasting the impregnated carrier.

Abstract: A SO.sub.2 containing gas, for example a stack gas, is purified according to a multi-step process, which comprises washing said gas with an aqueous ammonia solution, treating the resulting solution with hydrochloric acid, whereby SO.sub.2 and an aqueous ammonium chloride solution are obtained and separated. The ammonium chloride solution is then reacted with magnesium oxide to recovery ammonia and the resulting magnesium chloride is cracked to produce hydrochloric acid and magnesium oxide, the ammonia, hydrochloric acid and magnesium oxide being recycled to the process.

Abstract: Cyanocarboxylate polymers and copolymers are prepared by reacting a polymer or copolymer of conjugated diolefin with a cyanocarboxylate compound of the formula: ##EQU1## where R and R' are hydrogen atoms or alkyl, cycloalkyl, aryl or acyl groups of 1-12 carbon atoms, or R is a COOR' group or halogen.The resulting polymers or copolymers are useful as finishing agents or additives for unsaturated elastomers.

Abstract: The invention concerns new aromatic polyamine compositions useful as hardening agents containing a major proportion of polyamines of the formula: ##EQU1## IN WHICH Ar and Ar' are divalent aromatic radicals having from 1 to 6 rings, R.sub.1 is a divalent hydrocarbon radical or a radical (R.sub.4 -O).sub.m R.sub.4, R.sub.4 being an alkylene and m an integer from 1 to 100.

Abstract: Process for manufacturing citric acid by aerobic culture of yeast strains in a medium containing at least one n-paraffin, comprising adding to the culture medium, after the phase of exponential growth thereof, a nitrogenous heterocyclic organic compound selected from .alpha.-picolinic acid, 2,6-dipicolinic acid, quinaldic acid, bi-pyridine, orthophenanthroline, 8-hydroxyquinoline and 5-hydroxyquinoxaline, at a concentration from 0.5 to 10 g/liter, and controlling the pH value of said medium during said growth phase by addition of sodium or potassium carbonate.

Abstract: Process for purifying industrial gases containing hydrogen sulfide and for simultaneously producing elemental sulfur, comprising contacting said gases with an aqueous solution of sodium hydroxide and/or sodium carbonate, thereby forming a sodium sulfide solution, contacting said solution with an aqueous solution of ammonium hydrogen carbonate or with a gaseous mixture of CO.sub.2 and NH.sub.3 so as to precipitate sodium hydrogen carbonate, decomposing the latter to CO.sub.2 and neutral sodium carbonate which is recycled, heating the resulting liquid phase to produce NH.sub.3 and H.sub.2 S and producing sulfur by reacting the H.sub.2 S with sulfurous anhydride.

Abstract: Process for selectively producing paraxylene comprising reacting toluene with methanol, dimethylether or vinyl chloride and at least one polymethylbenzene having 4 to 6 methyl groups or a condensed polymethylaromatic compound or a complex containing the same, in the presence, as catalyst, of a zeolite whose pore diameter is at least 7.5 A.

Abstract: Method for determining the shape of an underground cavity and the location of the interface between two media contained therein by making use of a sonic sonde comprising performing, for each position of the sonde, a series of measurements of the time interval between the transmission of an ultrasonic wave from the sonde and the reception of the corresponding echo after reflection on the wall of the cavity, the selection from said measurements of one of those indicating substantially identical time intervals so as to eliminate the false echos and the determination of the average value of the propagation time of said selected echo for each different location of the sonde and for each direction of the transmitted waves.