Abstract: The behavior in the cold of crude oil or petroleum distillates may be improved by incorporation of polymeric substances such as a hydrogenated polybutadiene or a hydrogenated copolymer of butadiene with at least one conjugated aliphatic diolefin of 5-8 carbon atoms. The additive is active at concentrations of from 10 to 1,000 grams per m.sup.3 of oil.

Abstract: A device for coupling several data processing units to a central memory, the processing units being each provided with means for exchanging data with peripheral devices and with computing means, the device includes management means for controlling the sequential execution of orders issued from the memory, according to a hierarchical classification of the lists of tasks for the exchange processes and the computing process and further includes devices for commutation upon control of decoding means of a signal produced by the processing units, in accordance with the value of a binary digit associated to a task of a fresh list of actuatable tasks established in a non-hierarchical system.

Abstract: This fuel cell comprises circuits for collecting electrolyte leaks in the fuel and comburent chambers, said circuits being connected to the inlet orifice of the electrolyte pump.The electrolyte tank is located above the electrolyte pump and adjustment means provide for a pressure drop in the electrolyte flow between the tank and the pump inlet.

Abstract: Pressure sensor comprising a rigid tubular element housing an elongated support member, solid or fixed with the sensitive element in the vicinity of one of its end portions, said support element being made of a deformable material and comprising an enlargement shifted or extended with respect to said end portions and in contact with the internal surface of the tubular element.

Abstract: A new type of gripping shoe for traction devices of the caterpillar type, comprising a deformable element of composite structure. The deformable element comprises a body member which is mechanically resistant, deformable and of low elasticity. This body member is provided with a large internal recess housing a sole member of a highly deformable, elastic and substantially incompressible material.

Abstract: The invention relates to a flexible elongated member provided with a reinforcing armouring formed by profiled rods. The convolutions of said reinforcing armouring are wound in such a manner that the moment of inertia of the cross section of the profiled rods is maximum with respect to an axis perpendicular to a radial direction of the elongated member.

Abstract: In a first step, a chromatographic column is calibrated by passing separately through the column each constituent substance of the mixture to be analyzed and by recording at the exit the pulse response of said substance. In a second step, the mixture is passed through the columm and the total pulse response corresponding to the mixture is recorded. In a third step, the concentration of each substance is determined from the total pulse response corresponding to the mixture and the specific pulse responses of each substance.

Abstract: Gels containing molybdenum and iron and optionally other metals, are useful in the production of catalysts or as optical filters. They are produced by conducting essentially a solid - solid reaction between a compound of molybdenum, e.g. ammonium molybdate, and a ferric compound, e.g., ferric nirate, thereby obtaining the same ratio of molybdenum and ferric contents in the gels, as used in the starting materials. Furthermore, the resultant gels are highly homogeneous, and when used as catalysts, the yields of the process are up to plus 99%.

Abstract: New catalyst containing a carrier, platinum, iridium, manganese and optionally halogen. This catalyst is useful for reforming and dehydrogenation of hydrocarbons.

Abstract: Automatic regulation system for a distillation unit including a charging vessel, provided with heating means, surmounted by a distillation column overtopped by a condenser, a withdrawing system and recovery tanks, said system comprising an intermediate tank between the withdrawing system and the recovery tanks, means for controlling the liquid level in said intermediate tank and the discharge of liquid therefrom into the recovery tanks, valve means for applying at will a reduced pressure or the atmospheric pressure to the distillation unit and the intermediate tank and means for changing the recovery tanks in synchronization with the actuation of said valve means.

Abstract: An electrode E.sub.1 having the design function of an ion source is placed in a gas stream and emits by corona discharge effect ions which are collected on two electrodes E.sub.2 and E.sub.3. These electrodes consist of grids placed at right angles to the direction of the gas stream on each side of the electrode E.sub.1 at approximately equal distances from this latter. The device comprises electronic means for amplifying the currents collected at the electrodes E.sub.2 and E.sub.3 as well as for calculating the difference and the sum of the currents collected at the electrodes after amplification.

Abstract: Adjustment and control of a product fraction stream and especially gas oil are effected by a control unit after processing information supplied by an analyzer which takes a direct measurement of the temperature of filtrability of the stream and by detectors which deliver signals representing the flow rate of the gas oil withdrawn, the rate of withdrawn of the next higher product stream, the flow rate of the crude petroleum being processed, the flow rate of the stripping vapor and of the next lower product stream, and the slope of the distillation curve of the crude petroleum in the gas oil zone.

Abstract: Device for generating acoustic waves in a fluid medium by implosion, comprising a main cylinder, a main piston slidably mounted thereinto, said piston having a hollow cylindrical portion housing another cylinder solid with the main one and, through the bottom of which passes the hollow rod of another piston, actuated by hydraulic means and which drives in translation the main piston. By means of an annular valve, solid with the main piston, and further hydraulic means, the main piston may be locked in a position of spaced relationship with respect to the main cylinder and abruptly unlocked, thereby generating an implosion.

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: 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 method of preparing a yeast enriched in L-lysine and capable of excreting an organic acid, such as citric acid, and possibly also isocitric and glutamic acids, when cultivated on a hydrocarbon-containing medium comprises subjecting a yeast of the species Candida lipolytica to the action of a mutagenic agent, such as a chemical agent or radiation, cultivating the thus-treated yeast in a culture medium containing a lysine analogue, preferably that to which the original yeast is most sensitive, in a concentration which is about 50 to 100 times greater than that to which the cells of the original yeast are most sensitive, and cultivating the resultant mutated resistant yeast on a medium containing at least one hydrocarbon such as a C.sub.10 -C.sub.20 normal paraffin as well as conventional nutrients, the cultivation preferably being effected in an agitated aerated medium at a pH of 3 to 6 and a temperature of 25.degree. to 30.degree. C..