Abstract: The present invention relates to a fractionating and observation cel of a liquid analysis device comprising a rotor, a central distribution cup or container for said liquid, and an assembly of cells on the periphery of the rotor, wherein the cells and the duct are formed by welding of two plastic pieces comprising said rotor, the liquid feed and gas evacuation duct is provided by the space existing between the two plastic pieces welded to each other by two welding seams along the edges of each duct, the opposite faces of the said pieces that constitute the duct with the said seams being left rough from molding.

Abstract: A new surface-active agent of the formula: ##STR1## wherein R and R' are hydrocarbon groups, M being a cation it is particularly suitable for the production of micro-emulsions in the presence of aqueous saline solutions.One important application thereof is in the assisted recovery of crude oil.

Abstract: In a process for desulphurizing gases containing SO.sub.2 and SO.sub.3 by absorption of the sulphur containing compounds by means of absorbents based on alumina free of alkaline substances, activated alumina or alumina carrying salts or oxides of at least one element selected from the groups IB, IIB, IVB, VB, VIB, VIIB, VIII of the Periodic Classification, the absorption takes place at temperatures comprised between 100.degree. and 400.degree. C., and the absorbent loaded with said compounds in the form of sulphates is heated with a gas containing a reducing gas, especially H.sub.2 S, to a temperature of 250.degree. C. to 450.degree. C., while the elementary sulphur thus formed is separated from said absorbent, whereafter the latter is re-used in a subsequent absorption operation.

Abstract: Process for dispersing molten sulphur in a hydrocarbon material, such as asphalt, tar and more particularly bitumen. The dispersion is effected in such a way as to produce an emulsion of sulphur in very fine particles, with dimensions not exceeding 10 microns, in the hydrocarbon material. A turbine with a gap or clearance of about 0.1 to 2.25 mm. is very useful for this purpose. The emulsions obtained are particularly suitable for road surfaces.