Abstract: A method of determining the solid/liquid phase of an aqueous solution, characterized in that it comprises the following steps: a) subjecting said aqueous solution to a beam of photons; b) recording the Raman spectrum of the photons scattered by said solution in the wave number range between 2500 cm?1 to 4000 cm?1; and c) processing said recording in order to deduce therefrom the solid/liquid phase of said aqueous solution.

Abstract: A method of determining the concentration of a salt that may be present in a substance containing at least some water, comprising the following steps: a) recording the Raman spectrum of photons scattered by the substance in the wave number range 2500 cm?1 to 4000 cm?1; b) determining, for a given temperature of the substance, two points of said spectrum corresponding to two specific wave numbers; c) calculating the ratio of two magnitudes representative of said points to obtain a measurement ratio; and d) comparing said measurement ratio to a reference chart representative of the concentration of the salt for various temperatures as a function of the concentration of said salt. The method advantageously requires no taking of samples and may be contactless.

Abstract: The use in an electro-optical modulator of an electro-optical crystal in the form of a solid-solution compound of formula (NH.sub.4).sub.x Rb.sub.1 -.sub.x H.sub.1 -.sub.y D.sub.y SeO.sub.4, x and y being concentration coefficients varying from 0 to 1, (crystals of hydrogenated or deuterated rubidium or ammonium selenates) in order to modify the polarization, the phase or the intensity of an incident light beam, using a small control voltage.

Abstract: The present invention relates to an apparatus for translatory manipulation of an element, such as an axle.Apparatus characterized in that it comprises a displacement device (2) for each direction in space in which the axle (1) is to be manipulated, each displacement device (2) comprising two blades (3) prestressed in opposition, constituted by an alloy which is pseudoelastic or has shape memory, disposed on opposite sides of heating and/or cooling means (4) giving rise to a thermal gradient between the two blades (3) and thus their martensitic transformation causing their deformation.