Abstract: A hydrocarbon mixture containing modified polycyclic aromatic compounds or modified PAC having a chemical structure of mean molecular weight ranging between 300 and 10,000, the chemical structure being represented by formula (I): (A)x(PAC)y, wherein x and y are integers corresponding to the numbers of A or PAC units, selected such that x/y is equal to at least 1, preferably ranging between 1 and 50 and wherein A is a unit corresponding to a polymerizable monomer containing between 2 and 60 carbon atoms.

Abstract: The invention concerns a method characterised in that it consists in: determining online at least an ultraviolet spectrum portion of at least one of the compounds present in one or the other of the waste water feeding circuits (7, 13) or of the column (8) waste water output (16); qualitatively and quantitatively determining, by mathematical processing of the measured intensity levels, at least a contaminant present in the samples; on the basis of the results obtained and by comparing with pre-defined setpoint values, in restoring said data in the form of electric signals, which control the waste water supply and the stripping column water vapour flow rates.

Abstract: The invention relates to a method for the continuous determination of the damage to at least one system (7) used for the post-treatment of exhaust gases from an internal combustion engine (2), caused by the lubricating oil, the fuel and/or at least one lubricating oil additive and/or fuel additive used.

Abstract: The invention concerns a device wherein the diffusion chamber (6) comprises, between its upstream end and its downstream end, in the direction of the fluid flow, at least an insert (12) formed by an annular ring having an external diameter identical to the internal diameter of the chamber, said annular ring being arranged perpendicular to the axis of the supply conduit and projecting towards the inside part of the chamber from the side wall(s) thereof, to form a lateral obstacle to the fluid flow, the solid surface of the insert (12) being sufficient to generate in the upstream part of the chamber a pressure higher than that of the downstream part.

Abstract: A method wherein the particles are homogeneously distributed like rain to constitute a horizontal bed of particles on the entire section of the chamber (1). The invention is characterised in that it consists in temporarily modifying at least once the loading conditions, so that the profile of the surface (8) of the bed of particles forms, at least at the periphery thereof, an angle &agr; with the horizontal ranging between 6° and 25°, preferably, between 10° and 20°, and in subsequently restoring the loading conditions to obtain a horizontal bed.

Abstract: A process is provided for the preparation of bitumen-polymer compositions wherein bitumen is mixed at a composition between 100.degree. C. and 230.degree. C. with a block copolymer of styrene and a conjugated diene and a coupling agent containing a sulphur-donor compound for a duration of at least 10 minutes. The coupling agent is comprised of an elementary sulphur vulcanization agent and at least one sulphur-donor vulcanization accelerator from among morpholine disulphide, N,N'-disulphide of caprolactam and thiuram polysulphides.

Abstract: Additive formulation for engine fuels incorporating at least one constituent (A) and at least one constituent (B), constituent(A) consisting of at least one composition incorporating products resulting from the reaction of at least one dicarboxylic compound(D), whose carboxylic functions are separated by at the most eight carbon atoms, with at least one polyoxyalkylene glycol or glycol mono-ether (E) of general formula (I):R.sup.1 --O--(R.sup.2 --O).sub.n --H,in which R.sup.1 represents a hydrocarbon group having 1 to 30 carbon atoms, R.sup.2 represents a divalent hydrocarbon group having 2 to 6 carbon atoms and n is a number from 1 to 60; and constituent (B) consisting of at least one detergent-dispersant product. This formulation preferably also comprises a constituent (C) chosen from within the group formed by mineral or synthetic lubricating oils and polyglycols soluble in the fuel.

Abstract: A process is provided for preparing in aqueous emulsion, a bitumen/polymer binder with a continuous three-dimensional polymeric structure. The process comprises:a) forming a reaction mixture in an emulsion formation zone by feeding to the zone(i) a bitumen-polymer component comprised of a bitumen containing 0.5% to 15%, by weight of the bitumen, of a sulphur-crosslinkable elastomeric polymer, the bitumen/polymer component being in the form of a melt viscosity of not more than 2 Pa.s at the melt temperature,(ii) an aqueous phase containing an effective quantity of an emulsifying system, and(iii) a crosslinking system donating sulphur in a quantity such as to provide 0.

Abstract: Catalyst for hydrorefining hydrocarbon feedstocks including niobium trisulphide, said catalyst is particularly suited for the scission of carbon-nitrogen and carbon-sulphur bonds.

Abstract: The present invention relates to the preparation of antioxidant additives to lubricants and to their use in lubricating compositions. The additives according to the invention have the formula:ArAr'(H)N--(R--X).sub.a --R'Ywhere--Ar and Ar' are identical or different aromatic radicals, R and R', which are identical or different, denote a C.sub.2 -C.sub.18 linear or branched alkylene radical, X denotes an oxygen or sulphur atom or an --NH group, a is an integer between 0 and 5 and Y is chosen from the group consisting of --NR.sub.1 R.sub.2, where R.sub.1 and R.sub.2, which are identical or different, denote a hydrogen atom or a C.sub.1 -C.sub.12 alkyl, alkenyl, cycloalkyl or arylalkyl radical --N.dbd.CH--Ar.sub.1 where Ar.sub.1 is an aryl radical containing at least one phenolic group --NR.sub.1 --CO--Ar.sub.1 and ##STR1## where R.sub.3 denotes a saturated or unsaturated, linear or branched alkyl radical.

Abstract: This invention provides cationic emulsions of bituminous binders of the bitumen/polymer type, formed by a dispersion of an organic phase of the binder in an aqueous phase containing a cationic nitrogenous emulsifier and a mineral or organic acid, the acid being in appropriate quantity so that the pH of the aqueous phase is comprised between 3 and 9. The aqueous phase also contains an agent consisting of at least one water-soluble sequestering salt of polyfunctional nitrogenized carboxylic acid, particularly a salt of alkaline metal or of amine of mono- and di (hydroxy-2 ethyl) glycine and optionally a water-soluble thickening agent. To obtain the emulsions, which are usable for road applications, the emulsifying agent, the sequestering agent and optionally the thickening agent may be used in the form of a premixture containing the agents and called cationic emulsifying system.

Abstract: Polymer with a number average molecular weight of 400 to 20,000 having amino-substituted groups in its molecule and resulting from the reaction of at least one compound having a secondary amine function with 1 to 60 carbon atoms on an unsaturated polyester resulting from the condensation of an unsaturated, aliphatic dicarboxylic compound having at least one alpha ethylene unsaturation of one of the carboxylic groups on at least one epoxidized compound having 2 to 62 carbon atoms chosen from among epoxyalkenes, ethers, epoxyalcohol esters and epoxyacid esters. Middle distillate composition having a distillation range of 150.degree. to 450.degree. C. and incorporating a minor proportion, preferably 0.001 to 2% by weight, of at least one of the aforementioned polymers.

Abstract: This invention relates to a hydrorefining catalyst containing ruthenium sulphide and cobalt and/or nickel sulphide on a refractory oxides support. These catalysts are only very slightly inhibited by polyaromatic compounds or hydrogen sulphide.

Abstract: A bituminous binder emulsion is provided and is formed from a dispersion of an organic phase consisting of a bituminous binder in an aqueous phase incorporating an emulsifying system made up of one or more emulsifying agents, a water-soluble thickener and optionally, a pH regulating agent. The thickener which may be used to control the viscosity of the emulsion incorporates at least 40% scleroglucan by weight. The emulsion obtained may be used for road building applications, water-proofing in civil engineering or construction works, or for industrial purposes.

Abstract: Polynitrogen compound having two terminal cycles of the imide type, its preparation by conventional organic chemistry methods and its use as an additive for engine fuel. This compound complies with the general formula (I): ##STR1## in which R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are as set forth in the specification.

Abstract: Catalyst for hydrorefining hydrocarbon feedstocks consisting of niobium trisulphide, bulk or deposited on an inert support.This catalyst is particularly efficient for the reactions of scission of carbon-nitrogen and carbon-sulphur bonds.

Abstract: The invention relates to a process for isomerizing normal paraffins, particularly C.sub.5 -C.sub.6, in the presence of at least one catalyst based on an omega zeolite having a molar ratio SiO.sub.2 /Al.sub.2 O.sub.3 ranging from 6.5 to 80, a content by weight of sodium lower than 0.2%, crystalline parameters "a" and "c" respectively smaller than or equal to 1.814 nm and 0.760 nm, a capacity of adsorption of nitrogen, measured at 77K under a partial pressure of 0.19, higher than about 8% by weight, the catalyst also comprising at least one metal from group VIII of the periodic table of elements, preferably platinum or/and palladium.

Abstract: Device for adjusting the geometry of a vehicle wheel (14) consisting of a hub-holder (40) designed to accommodate the wheel (14) during rotation, the hub-holder (40) being fixed to the vehicle by means of at least one suspension element (18, 38) which is free to pivot in relation to the vehicle. According to said invention, the suspension element (18, 38) is fixed to the vehicle by means of at least one eccentric (32) which can be rotated in order to vary the angle between the suspension element (18, 38) and the vehicle.

Abstract: A suspension-correcting device for a motorcycle having at least one wheel-axle supporting arm pivoted on its chassis, the arm also supporting at least one disk-brake caliper, through which passes a brake disk fixed to a wheel mounted rotatably on the axle, and suspension parts and shock-absorbers connecting the arm to the chassis, wherein the brake caliper mounted on the supporting arm is capable of rotating relative to the supporting arm within limits allowed by a mechanical connection which connects the caliper to an upper reaction portion of the motorcycle chassis, the assembly being used for limiting the foward dive of the motorcycle during braking.

Abstract: Method for synthesizing greases by adding at least one co-surfactant to the mixture of the thickener in the oil. The addition is made at the initial stage of the formation of a three-dimensional filamentary network of the grease at a temperature between the waxy transition temperature and the melting point of the thickener. The process permits good control of the mechanical behaviour of the greases.