Abstract: A thermally operated valve for automatic control of the rate of flow of a fluid coolant for hot gases produced by underground gasification of solid fuel deposits or by in situ combustion in oil wells, incorporating a temperature-sensitive element comprising a metal tube several meters long to be incorporated in a pipe for supplying coolant to the well, and a rod of a metal having a low coefficient of expansion coaxial with the pipe, the upper end of which rod is attached to the upper part of the metal tube and the lower end of which rod is flexibly connected to a valve member by a connecting element having adjustable clearance or play.

Abstract: Radioelectric signals transmitted by a transmission line in the form of a sheathed cable having radiating sections whose length is chosen as a function of the wavelength in order to impart a directivity to their radial radiation or maximize the excitation of the monofilar mode in the downstream direction in relation to the transmitter.