Abstract: The present invention relates to method for heating and/or air conditioning the passenger compartment of an automobile using a reversible cooling loop containing a refrigerant including 2,3,3,30-tetrafluoropropane and at least one compound chosen from among propane, propylene and ethylene. Said method is particularly suitable when the outside temperature is lower than ?20° C. The method is also suitable for hybrid automobiles, which are designed to operate in alternation between a heat engine and an electric engine, as well as for electric vehicles. The present invention also relates to a composition including 2,3,3,3-tetrafluoropropane and at least one compound chosen from among propylene and ethylene, suitable for being used for refrigeration, air conditioning and heating.

Abstract: The present invention relates to compositions which are based on tetrafluoropropene and more particularly relates to compositions comprising 60% to 90% by weight of 2,3,3,3-tetrafluoropropene and 10% to 40% by weight of at least one compound selected from difluoroethane and difluoromethane, which can be used as a heat transfer fluid.

Abstract: The invention relates to a method for the synthesis of short-chain ?-unsaturated fatty acids of general formula CH2?CH—(CH2)n—COOR in which n is an integer between 2 and 11 and R is H or an alkyl radical containing from 1 to 4 carbon atoms, from long-chain monounsaturated fatty acids or esters of formula CH3—(CH2)m—CH?CH—(CH2)p—COOR in which m and p are integers, either identical or different, between 2 and 11, such that the molecule contains at least 10 adjacent carbon atoms in the main chain, said method comprises the first step of submitting the long-chain monounsaturated fatty acid charge to an oxidation by fermentation using a microorganism containing enzymes of oxygenase type, thus leading to the formation of ?,?-diacids, and then a second step of subjecting the product from the first step to a catalytic metsthesis crossed with ethylene for forming two short-chain ?-unsaturated fatty acids having a main chain length relative to that of the starting unsaturated fatty acid or ester of between 0.2 and 0.