Abstract: A sensor fiber for the detection of changes of temperature, bending, and/or torsion includes a multicore optical waveguide with a fiber Bragg grating (FBG) structure. One embodiment contains at least two FBG cores and a surrounding cladding. The sensor fiber is characterized by one or more distinction and orientation means which produce a marker zone to assign and label each individual FBG core.

Abstract: Methods for making active laser fibers include the production of an optical fiber with disturbed (or deviated) cylindrical symmetry on the glass surface of the fiber. The methods include a preform containing a central core made of glass. In one embodiment, the preform is circular and surrounded by additional glass rods and an outer glass jacket tube. In a first alternative embodiment, this preform is merged during fiber drawing. In a second alternative embodiment, the preform merged in a process forming a compact glass body with disturbed cylindrical symmetry. This compact preform is drawn into a fiber under conditions maintaining the disturbed cylindrical symmetry.

Abstract: A sensor fiber for the detection of changes of temperature, bending, and/or torsion includes a multicore optical waveguide with a fiber Bragg grating (FBG) structure. One embodiment contains at least two FBG cores and a surrounding cladding. The sensor fiber is characterized by one or more distinction and orientation means which produce a marker zone to assign and label each individual FBG core.

Abstract: Methods for making active laser fibers include the production of an optical fiber with disturbed (or deviated) cylindrical symmetry on the glass surface of the fiber. The methods include a preform containing a central core made of glass. In one embodiment, the preform is circular and surrounded by additional glass rods and an outer glass jacket tube. In a first alternative embodiment, this preform is merged during fiber drawing. In a second alternative embodiment, the preform merged in a process forming a compact glass body with disturbed cylindrical symmetry. This compact preform is drawn into a fiber under conditions maintaining the disturbed cylindrical symmetry.

Abstract: The invention relates to an optical waveguide and a semifinished product for producing an optical waveguide having optimized diffraction properties, comprising a trench structure that has a radius-dependent graded refractive index curve and/or a concentric depressed refractive index profile within a core zone (2) and/or within a cladding zone (4). In one embodiment of the optical waveguide and semifinished product, the structure is formed from a succession of differently doped regions containing dopants that are introduced into a base matrix and lower and/or increase the refractive index.

Abstract: An apparatus is proposed for controlling the coating thickness of an optical fiber (2) passing sequentially, in that order, from a unit (1) for fabricating the fiber (2) through a cooling unit (3), a coating unit (4) and along a device (5) which determines the diameter of the fiber. The apparatus includes a control element (14) for controlling a control device (15, 16) as a function of the measured diameter in such a way that the thickness of the coating corresponds to a target value, wherein the control device (15, 16) is placed before the coating unit (4) when viewed in the transport direction of the fiber (2), and the control device (15,16) adjusts the temperature of the fiber (2). Also described is a method for controlling the coating thickness.

Abstract: A device for applying a coating material to an optical fiber (1) has a coating nozzle (7) arranged in a nozzle holder (3) and a coating chamber (17) located before the coating nozzle (7) in the direction of travel of the optical fiber (1). Beyond that the device has at least one inlet channel (19) which is connected to the coating chamber (17), as well as a number of feed lines (23) for different coating materials. A connection can be established between one of the feed lines (23) and the at least one inlet channel (19), so that a change of coating material can be made in a simple manner, particularly a color change, without costly conversion and cleaning operations.

Abstract: The invention relates to electroluminescent arrangements (layers) containing special styrenes and to their use.

Abstract: In an optical fiber (1) with a coating (8) for the cladding of one or more plastic layers containing the fiber core and a color marking (3) on or in the outer plastic layer, the color marking (3) is covered by a further transparent or translucent layer (4).

Abstract: An improvement in a process for the preparation of a pinacol of the formula ##STR1## wherein R.sup.1 and R.sup.2 are identical or different and represent optionally substituted aliphatic, cycloaliphatic, araliphatic or an aromatic hydrocarbon radical by reducing a ketone of the formula ##STR2## wherein R.sup.1 and R.sup.2 have the abovementioned meanings with a base metal, the improvement comprising carrying out the reduction in the presence of an organic halogen compound and in the presence of a phosphoric acid amide, phosphoric acid ester and/or carboxylic acid amide.

Abstract: A process for separating an aromatic hydrocarbon of the general formula ##STR1## wherein R represents an alkyl group having 1 to 3 carbon atoms andn is 0, 1, 2, or 3 (and wherein the groups R, when n is 2 or 3 can be the same or different),From a mixture comprising said compound and one or more aliphatic hydrocarbon, cycloaliphatic hydrocarbon, alcohol, ether, ketone or a carboxylic acid ester which comprises contacting said mixture with a polyurethane membrane.

Abstract: Unsaturated polyester resins which are suitable for the production of cross-linked polyesters which are with difficulty to saponify contain, in part at least, radicals of 2-alkyl-1.3-propane diols as the alcohol component.

Abstract: The invention relates to a resin composition that is curable by ultra-violet light, which composition comprises(a) 10 to 99.7 percent by weight of a polyester that contains .alpha., .beta.-ethylenically unsaturated dicarboxylic acid radicals and .beta.,.gamma.-ethylenically unsaturated ether groupings, and(b) 0.3 to 10 percent by weight of a photoinitiator.

Abstract: Certain new monosilyl ethers have virtually no effect on the storage stability of unsaturated polyester resins at temperatures up to 70.degree. C, but at higher temperatures effect rapid curing to give polymers which are substantially monomer-free.

Abstract: A coating composition comprising as binder a reaction product of a polyepoxide with more than one 1,2-epoxide group per molecule, wherein its epoxide groups have been reactedA. with 0.01 to 0.5 NH-equivalents, based on one epoxide equivalent, of ammonia or of an aliphatic or cycloaliphatic primary or secondary amine or of an amino carboxylic acid or of a mixture of the aforementioned nitrogen compounds; and subsequentlyB. with 0.40 to 0.90 carboxyl equivalents, based on one epoxide equivalent, of acrylic acid or methacrylic acid or of a mixture of acrylic amd methacrylic acid; and finallyC. with 0.09 to 0.50 carboxyl equivalents, based on one epoxide group, of a saturated aliphatic, a cycloaliphatic or an aromatic carboxylic acid, so that at least 80% of the epoxide groups originally present have been reacted through these three component stages.

Abstract: A chalking-resistant titanium dioxide pigment is produced by mixing the pigment with a vinyl polymer, in form of an aqueous latex, applying the polymer to the pigment in quantities of about 0.1 to 30% by weight based on the final pigment and the mixture containing at least about 30% of water by weight. The polymer is then coagulated, the aqueous phase separated and the pigment-plus-polymer dried. Due to some apparent complexing, the polymer cannot be quantitatively dissolved away from the pigment. The pigment produces chalking-resistant lacquers, paints and coating compositions.

Abstract: Acrylic acid esters of polyhydric alcohols can be stabilized by the addition of allyl compounds.

Abstract: Stabilized acrylic acid esters of polyhydric alcohols which contain as stabilizers polymerisation inhibitors including small amounts of compounds of the styrene type show a non-reduced polymerisation reactivity.

Abstract: The invention relates to dyestuff preparations which containA. dyestuffs which are insoluble in tetrachloroethylene,B. dispersing agents of the formulaR.sup.1 [--NHCO--(O--CHR.sup.2 --CHR.sup.3).sub.X --(O--CHR.sup.4 --CHR.sup.5).sub.y --R.sup.6 --].sub.nwhereinR.sup.1 denotes a hydrocarbon radical such as remains after removing n isocyanate groups from a corresponding isocyanate,n is a number from 1 to 6R.sup.2 - r.sup.5 denote hydrogen, alkyl, phenyl or chloromethyl,X represents the number 0 - 100 andY represents the number 0 to 50 andR.sup.6 denotes O--aryl, O--aralkyl, O--alkaryl, O--CO--alkyl, O--CO--aryl, NH--CO--alkyl, NH--SO.sub.2 --alkyl or O--alkyl andC. optionally, organic solvents of low volatility. The preparations are extremely suitable for the dyeing textile materials from organic, water-immiscible solvents.

Abstract: An air-drying coating composition comprising a reaction product of a polyepoxide with more than one 1,2-epoxide group per molecule, at least 60% of whose epoxide groups have been reactedA. with 0.01 to 0.6 SH-equivalents, based on one epoxide equivalent of hydrogen sulphide, an aliphatic or cycloaliphatic, aromatic or araliphatic dithiol or polythiol or with a mixture thereof, and subsequentlyB. with 0.99 to 0.4 carboxyl equivalents, based on one epoxide equivalent, of acrylic or methacrylic acid or of a mixture thereof.