Abstract: An extracoronal precise attachment comprising a male component, which is to be secured to the natural tooth or implant, and a female component, which is securable thereto and is to be connected to the tooth substitute. The female component has a plastic insert which is formed from a friction member, which encloses a portion of the male component, and a securing member, which connects thereto and is inserted in the female component.To adjust the friction between the male and female components, that is to say to activate the female component, the latter has a bore which traverses therethrough and through the securing member of the plastics insert, a screw being screwable into the bore and having a threaded pin portion and a threadless cylindrical portion, the head of the screw being supported on the female component in such a manner that, when the screw is being rotated in position, a pressure is exerted upon the plastics insert.This arrangement permits the friction to be very easily and accurately adjusted.

Abstract: A method for forming indium antimonide photodiodes by ionic implantation of the S.sub.34.sup.+ isotope of sulphur on a p type indium antimonide substrate. These photodiodes may be readily coupled to an N channel charge transfer device which provides multiplexing of the photodiodes and readout of the charges.

Abstract: The surface of a substrate which includes a plurality of photovoltaic junctions spaced along it is prepared as follows: a first anodic oxide layer is formed to cover the whole surface of the substrate and ensures perfect control of the photovoltaic junctions, a second layer is deposited of metal which is impervious to the radiation to be detected, then through photolithography, only the zones of the second layer that it is desired to render impervious to the radiation to be detected are maintained and the remainder removed; and finally, a layer of dielectric material is deposited to cover the whole surface.

Abstract: A process yielding a glass blank in the form of a rod intended for drawing an optical fiber of the kind of self-focussing fiber i.e. having a radial refractive index gradient, having features (substantially transparency or transmission efficiency) lower than those of the fibers intended for long distance communication but sufficient for middle distance transmission, and which exhibits a lower cost than known processes. In a first stage a phase separation yields a "hard" phase (rich in silicon) and a "soft" phase (poor in silicon and rich in impurities) due to the drawing of a rod from a bath of molten glass through a cooling system having a strong temperature gradient and creating a radial refractive index gradient. In a second stage the soft phase is leached, eliminating the impurities contained in the soft phase but keeping safe the radial gradient. In a third stage a consolidation treatment is a pure annealing treatment rendering the hard phase more homogeneous.