Abstract: A single photon avalanche diode (SPAD) includes a PN junction in a semiconductor well doped with a first type of dopant. The PN junction is formed between a first region doped with the first type of dopant and a second region doped with a second type of dopant opposite to the first type of dopant. The first doped region is shaped so as to incorporate local variations in concentration of dopants that are configured, in response to a voltage between the second doped region and the semiconductor well that is greater than or equal to a level of a breakdown voltage of the PN junction, to generate a monotonic variation in the electrostatic potential between the first doped region and the semiconductor well.

Abstract: Polymer compounds resulting from the condensation of polyacrylic acids having a molecular weight comprised between 10,000 and 2,000,000 and alkylamines containing at least 12 carbon atoms in their chain. These products constitute paraffin deposit inhibitors and pour point depressants for crude petroleum oils.

Abstract: The present invention provides grafted ethylene copolymers usable more especially as additives for inhibiting the depositions in crude oils.Said copolymer being formed of ethylene and at least one monomer with ethylenic unsaturation, chosen from vinyl esters of C.sub.2 to C.sub.18 monocarboxylic acids, the alkyl esters in the C.sub.1 to C.sub.12 range of unsaturated monocarboxylic acids from the C.sub.3 to C.sub.12 range and the .alpha., .beta.-unsaturated dicarboxylic compounds, on which are fixed the grafts of a homo or copolymer of an .alpha., .beta.-unsaturated monocarboxylic acid ester with at least one alkanol of a chain length equal to or greater than C.sub.12 and at least 20% of which is of a chain length equal to or greater than C.sub.22. Such copolymers may be used more especially as additives for inhibiting the deposition of paraffins and for improving the flow properties of the crude oils.