Abstract: A process for producing an acyloxynaphthoic acid represented by the general formula ##STR1## wherein R.sub.1 represents a hydrogen atom or an alkyl group, which comprises(a) oxidizing an acylalkylnaphthalene represented by the general formula ##STR2## wherein R.sub.1 is as defined, and R.sub.2 represents a lower alkyl group, with a peroxide, and(b) oxidizing the resulting acyloxyalkylnaphthalene represented by the general formula ##STR3## wherein R.sub.1 and R.sub.2 are as defined above, with molecular oxygen in an organic solvent in the presence of a catalyst comprising a bromine compound and a cobalt compound.

Abstract: Optical cable having a central core with grooves along the outside, the grooves housing tubes containing optical fibers. The grooves are inclined to the core axis and preferably are sinusoidal in that they extend around the core in each direction while extending axially and do not complete a revolution around the core before changing direction. In preferred structures, the tubes contact around a concave base surface of the grooves or contact opposing groove walls. In addition, the tubes provide greater strength if they are in a load transmitting relationship with a metal sheath if there is one. The structure also allows for a different water blocking material to be used within the tubes than outside the tubes and within the grooves so as to satisfy different property requirements.

Abstract: Optical waveguide having a fused silica core and a fluorine doped silica cladding is made by heating a cylinder of silica in fluorine, the cylinder initially having an outer annular particulate or porous region which is dried by the fluorine and into which fluorine diffuses to lower the refractive index of the silica when fused. The cylinder is made by depositing particulate silica onto a mandrel, drying the silica in chlorine, and heating the silica to densify it. Further particulate silica is deposited and is then heated in a fluorine-containing gas to dry, fluorine diffuse, and sinter the porous outer part of the silica. The resulting tubular silica preform is heated to collapse the tubular preform into a rod from which optical waveguide is drawn, the waveguide having a fluorine doped silica cladding.

Abstract: A fiber for lateral beaming of a laser beam, wherein an affected portion in a cavity of an internal organ in a living body is irradiated by the laser beam in a through-endoscopic manner. The fiber for lateral beaming of the laser beam is constructed such that a transparent tubular member is coupled to the forward end portion of a fiber through two coating layers, and an anti-reflection coating layer is formed on a laser beam exiting surface of the transparent tubular member. Owing to the anti-reflection coating layer, this fiber for lateral beaming is free from the harmful leaking beam. Since the transparent tubular member is connected to the fiber through the two coating layes, the fiber can avoid being broken.

Abstract: A tubular porous silica preform is made by depositing particulate silica on a mandrel from which the preform is subsequently removed. A solid cylindrical porous silica preform is made by depositing particulate silica on an end surface of a support body. The porous preforms are then dried and the tubular preform is heated in a fluorine containing atmosphere to introduce a fluorine dopant into the silica. The rod preform is then placed inside the tubular preform and the two preforms are further dried in a chlorine atmosphere to remove residual moisture. The dual preforms are then heated in a zone sintering furnace to consolidate and collapse the porous material of the rod and tubular preforms into a transparent fused silica rod. The composite preform obtained is heated and dielectric optical waveguide drawn from it, the waveguide having a pure silica or doped silica core derived from the rod preform and a fluorine doped silica cladding derived from the tubular preform.

Abstract: Optical waveguide having a fused silica core and a fluorine doped silica cladding is made by heating a cylinder of silica in fluorine, the cylinder initially having an outer annular particulate or porous region which is dried by the fluorine and into which fluorine diffuses to lower the refractive index of the silica when fused. The cylinder is made by depositing particulate silica onto a mandrel, drying the silica in chlorine, and heating the silica to densify it. Further particulate silica is deposited and is then heated in a fluorine-containing gas to dry, fluorine diffuse, and sinter the porous outer part of the silica. The resulting tubular silica preform is heated to cause fusion of the porous silica and to collapse the tubular preform into a rod from which optical waveguide is drawn, the waveguide having a fluorine doped silica cladding. The fluorine drying and diffusion steps produce HF which is extremely corrosive.

Abstract: A magnetic recording material which comprises a film of a polyester and a magnetic layer formed on at least one side of said film, said polyester containing more than 85 mol % of the repeating unit represented by the formula below and having an intrinsic viscosity of 0.3 to 1.4, and said film of said polyester having a refractive index ratio of 0.935 to 0.975 in the thickness direction and a density index of 0.02 to 0.08. ##STR1## (where X is a halogen atom selected from fluorine, chlorine, and bromine, or an alkyl group of carbon number 1 to 3; and l and m are an integer of 1 to 2, p is an integer of 2 to 6, and q is an integer of 2 to 4.)Although the magnetic recording material is extremely thin, it exhibits outstanding running performance and electromagnetic conversion characteristics. It makes it possible to miniaturize the magnetic tape cassette and extend the recording time. It is useful for long-time video tape and portable 8-mm video tape.

Abstract: An optical fiber joint and a method of forming such optical fiber joint being reinforced by a reinforcement material, having a prescribed coefficient of thermal expansion, integrally molded thereon by applying heat so as to obtain a predetermined thermal gradient in the reinforcing material, whereby bends in the optical fiber core wire joints are suppressed and the transmission loss of the optical fiber is reduced.

Abstract: A constant discharge device for a pneumatic conveyor for powdery or granular materials includes a discharge regulator valve disposed in a pressure tank that stores the powdery or granular material and movable toward or away from a discharge nozzle which has an open end through which the material is discharged out of the pressure tank into a conveyor pipe. The discharge regulator valve has an air outlet for ejecting a stream of air toward the discharge nozzle. The amount of the material as discharged into the conveyor pipe can be controlled by adjusting the position of the discharge regulator valve with respect to the discharge nozzle, and also by adjusting the rate of flow of air through the outlet of the discharge regulator valve.

Abstract: Before splicing optical fibers having cladding and core of differing refractive index, the cores are axially aligned. The fiber ends are held apart with the fibers approximately coaxial. The fiber end surfaces are then illuminated and reflected light is monitored. Since reflectivity is a function of refractive index, the position of the core in the reflectivity profile of each surface can be readily identified. The fiber ends can then be manouvered transverse of the fiber axes to bring the fiber core centers into registration with a datum line. The fiber ends are then brought close together for splicing. Previously, fibers having nominally identical outside diameters were aligned simply by pressing them into a common V groove, the optical transmission efficiency then depending on fiber/core concentricity. Alternatively, light was injected into the far end of one fiber, monitored at the far end of the other fiber, and the fibers at their near end manipulated to maximize monitored optical power.

Abstract: Benzenecarboxylic acid ester is produced at a higher reaction rate in a better yield in a shorter time by reacting benzenecarboxylic acid having 8 to 10 carbon atoms or its anhydride with aliphatic alcohol having 7 to 11 carbon atoms in the presence of amorphous aluminum compound as a catalyst and an alkali metal compound as a promoter.

Abstract: For making a preform for production of optical fiber, the preform including fused silica, particulate material is deposited on the inside wall of a glass tube while the tube is reciprocated through a microwave cavity for production of a plasma in the tube. Oxygen and a reactant gas containing silica are passed through the tube. Dopant material can be added to the gas mixture and the concentration of the dopant varied to vary the refractive index. After the deposit of a sufficient thickness of particulate material, it is fused. The material can be caused to fuse on to the inner wall of the tube or to shrink away from the inner wall and removed from the tube. When the material is fused onto the wall of the tube it can then be collapsed, then either drawn to a fiber or placed in a further tube and drawn to a fiber. When the fused material shrinks from the tube wall, then it is collapsed to a solid rod, placed in a tube and then drawn to a fiber.

Abstract: Chloroprene having a little content of acetaldehyde is produced by dehydrochlorination of 3,4-dichlorobutene-1 in the presence of an aqueous solution of an alkali metal hydroxide by treating with an ammonium ion donor during or after the dehydrochlorination or in both the steps.

Abstract: In production of chloroprene by dehydrochlorinating 3,4-dichlorobutene-1 in the presence of an aqueous solution of alkali, the mixture of 3,4-dichlorobutene-1 and the aqueous solution of alkali is heated at 85.degree. to 100.degree. C to evaporate a mixture consisting mainly of the resulting chloroprene, unreacted 3,4-dichlorobutene-1 and water rapidly, the evaporated mixture is taken out from the reaction system without subjecting to a distillation and totally condensed, the condensed reaction mixture is separated into an aqueous phase and an organic phase and then the organic phase is fractionally distilled to separate chloroprene from 3,4-dichlorobutene-1. Prior to subjecting the organic phase to the fractional distillation, if the organic phase is previously subjected to a drying means and the water content in the organic phase is reduced to a proper degree, it is possible to avoid formation of polymer of the resulting chloroprene and corrosion of the distillation column.