Abstract: An automatic detection system for control of oil spillage into sea waters comprising a plurality of optical fiber cables connected each to a control box and to a plurality of sensors located remotedly in the open sea, and each of the sensors is a part of a closed loop of a light signal, transmitted from the control box and received back by it. Each of the sensors consists of a floating buoy affixed to a permanent location in the open sea, having its center of gravity adjustable and stabilized, so that when it floats, the central part of the sensor rests at sea level. The buoy is provided with a central bore, into which the optical fiber cable's ending is positioned; and a plurality of concentric channels are provided from all sides of the bore, leading sea water from the outer surface of the buoy inwards.

Abstract: The present invention relates to a railing selected among hollow railings, grilles, tubes or the like in which a continuous sensor made of an optical fiber extends, which railing is filled with a suitable filling material, the sensor fiber being connected to outside control and/or alarm units to form a complete circuit. The optical fiber has advantageously a numerical aperture (NA) of 0.08.ltoreq.NA.ltoreq.0.5 preferably the following parameters:Bending loss .alpha.exp(-.beta.r), r-Bending radius .beta..alpha.N.A. (b/a) .gamma. b-cladding radius, a-core radius of the fiber, 0.1.ltoreq..gamma..ltoreq.3.0.The filling material has preferably the form of pellets and is suitably selected among glass, steel, ceramics or sand.The railing preferably comprises a binder selected among soft rubber and plastics, e.g. a polyester. The binder may comprise also a material selected among an irritating material and a dye.The railing may also be a system of railing wherein the sensor extends through all the railings.

Abstract: Procedure for preparing a laminated plate structure having an optical fiber situated therein, in which the optical fiber is situated between two respective laminating agent layers, in turn situated between two glass plates, the optical fiber extending out from the structure at opposite ends thereof. Grooves are cut out of the laminating agent layers around both opposite ends of the fiber extending out form the structure, with tubes being inserted over these respective opposite ends of the fiber and into the grooves, so that the fibers can move freely within these respective tubes. Then, the tubes and adjoining plates are adhered to one another, with appropriate compression being applied to form the final laminated structure.

Abstract: The present invention relates to a wallpaper which comprises an optical fibre which together with an outside control and/or alarm unit forms a closed optical circuit. The wallpaper is a sheet made from a suitable material, e.g. paper, plastic material and textile fabrics. This material may have the adhesive layer on itself. Alternatively, the adhesive is applied before lamination. The invention relates also to a process for the manufacture of the wallpaper.

Abstract: Manufacture of optical fibre preforms. A material such as Si, Ge and B.sub.2 O.sub.3 is evaporated in vacuo into a silica tube and is made to condense therein as a viscous liquid which is then oxidized. The operation may be repeated several times with different materials. In this way the tube is clad from within in such a way that the optical index of refraction increases from the periphery inwards. Upon completion of the cladding the tube is collapsed into a rod which is then used for drawing optical fibres.

Abstract: Manufacture of optical fibre preforms. A material such as Si, Ge and B.sub.2 O.sub.3 is evaporated in vacuo into a silica tube and is made to condense therein as a viscous liquid which is then oxidized. The operation may be repeated several times with different materials. In this way the tube is clad from within in such a way that the optical index of refraction increases from the periphery inwards. Upon completion of the cladding the tube is collapsed into a rod which is then used for drawing optical fibres.

Abstract: A flexible foamed or solid rubber mass is produced on a substrate by ejection. Two pressurized containers are used, one containing an aqueous latex dispersion together with a pressurized inert propellant and the other an aqueous coagulant solution together with a pressurized propellant and the solutions are ejected simultaneously from two vessels so as to converge on the target and impinge thereon at spots distanced from each other by not more than 50 cm.The invention also provides an apparatus for carrying out the method.The invention is applicable whenever it is desired to produce instantaneously a flexible foamed or solid rubber mass on a substrate. One of the important applications of the invention is self-defense and the combatting of riots.