Abstract: Process for the reduction of breakdown risks with respect to the solid dielectric insulant of transmission cables and lines operating under high voltages. The insulant normally separates the conductors of a multi-conductor line or the central conductor and the outer metal envelope of a coaxial line. Small amounts of metal particles with dimensions below 1 micron are added to the dielectric insulant mass.

Abstract: Process for the reduction of breakdown risks with respect to the solid dielectric insulant of transmission cables and lines operating under high voltages. The insulant normally separates the conductors of a multi-conductor line or the central conductor and the outer metal envelope of a coaxial line. Small amounts of metal particles with dimensions below 1 micron are added to the dielectric insulant mass.

Abstract: A method of verifying that a given insulative element conforms with a reference insulative element, comprising the steps of: emitting a primary beam of electrons impinging on the given insulative element, receiving a secondary beam of electrons returned by the given insulative element in response to emission of the primary beam of electrons, and comparing a curve as a function of time of the electrical current of the secondary beam received with a curve as a function of time of a reference electrical current to establish whether or not the given insulative element conforms to a reference insulative element.

Abstract: Process and apparatus for the characterization of an insulator (5) at breakdown with the aid of an electron microscope (1), in which the electron flow rate of the beam (3) is adjusted as a function of in particular backscattered, lost, secondary or absorbed electrons. An automatic controller (9) sensitive to certain sensors (10,12) is provided for this purpose. The electron flow rate is proportional to the voltage to be simulated in the insulator.

Abstract: Process for the preparation of ceramic materials for parts having friction surfaces subject to friction and free from auto/self-adhesion under stress or during aging. A precursor of the ceramic undergoes successive operations of pressing, sintering, polishing the surface obtained, cleaning the solid gangue resulting from the polishing, roasting in the presence of oxygen, and a doping treatment for increasing the dielectric susceptibility and homogeneity of the ceramic material adjacent the friction surfaces and to increase the mobility of the charges.

Abstract: Process for the preparation of ceramic materials for parts having friction surfaces subject to friction and free from auto/self-adhesion under stress or during aging. A precursor of the ceramic undergoes successive operations of pressing, sintering, polishing the surface obtained, cleaning the solid gangue resulting from the polishing, roasting in the presence of oxygen, and a treatment aimed at increasing the dielectric susceptibility and homogeneity of the ceramic material adjacent the friction surfaces and to increase the mobility of charges.

Abstract: A process of elementary and chemical analysis of samples by spectrum analysis of secondary electrons emitted by the sample when it is subjected to a beam of monoenergetic primary electrons concentrated on its surface is characterized in that the intensity of a beam of monoenergetic primary electrons E.sub.p emitted by an electron gun is modulated according to a sinusoidal law at a frequency .omega., in that the secondary electrons of energy E emitted by the sample are collected, in that the intensity of the collected beam is detected by generating an electric detection signal proportional to the intensity, in that the intensity of the component of the frequency .omega. of the detection signal which provides the number of secondary electrons corresponding to the said energy is measured, and, in that the value of the collection energy E is modified in order to scan the energy spectrum comprised between the values E.sub.1 and E.sub.

Abstract: An electroemissive component having variable emissivity is made up of a conductive substrate on which at least one continuous thin film of a solid organometallic compound has been formed by electrochemical deposition and of a conductive deposit constituted by at least one thin film and deposited on said organometallic film, the substrate and the conductive deposit being electrically connected respectively to the two poles of a variable-voltage source which controls the emissivity.The component is particularly well suited to the fabrication of electronic or optoelectronic devices such as electron tubes, luminescent cells, display panels, thin television screens, and brightness amplifiers.