Abstract: The invention relates to a method which comprises emitting ultrasound into a liquid mixture containing first and second reagents in separate phases initially separated by a liquid precursor-gas barrier, the ultrasound having a high enough energy level to vaporise the precursor gas, such as to contact the reagents and thus to activate a chemical reaction therebetween.

Abstract: Method for rheological characterization of a viscoelastic medium, comprising the following steps: (a) an excitation step during which a vibratory excitation is generated in the viscoelastic medium leading to a deformation of the medium, (b) a deformation measurement step during which the deformation of the medium caused by the excitation is observed, (c) and a characterization step during which at least one non-zero power parameter y is determined such that a rheological parameter of the medium x is equal to x (f)=a+b.fy, where f is the frequency, a is a real number and b a non-zero scale parameter. It is thus possible to obtain mapping of the power parameter y.

Abstract: The invention relates to a method of determining impulse responses from a medium (2) in relation to the transmission of waves between different points (T1-TN). The inventive method consists in: transmitting waves in the medium by generating, at each point j, signals ei(t) each comprising n elementary signals with respective frequencies which are spaced apart in pairs by an interval ?f and which are different from the frequencies of the elementary signals corresponding to the other points; receiving signals rj(t) at points j after the transmission of the aforementioned waves in the medium; and calculating each impulse response hij(t) from a correlation signal between signal ei(t) transmitted at point i and signal rj(t) received at point j.

Abstract: The invention relates to a method of determining impulse responses from a medium (2) in relation to the transmission of waves between different points (T1-TN). The inventive method consists in: transmitting waves in the medium by generating, at each point j, signals ei(t) each comprising n elementary signals with respective frequencies which are spaced apart in pairs by an interval ?f and which are different from the frequencies of the elementary signals corresponding to the other points; receiving signals rj(t) at points j after the transmission of the aforementioned waves in the medium; and calculating each impulse response hij(t) from a correlation signal between signal ei(t) transmitted at point i and signal rj(t) received at point j.