SUMITOMO OSAKA CEMENT CO., LTD.

An optical waveguide device that can efficiently remove a high-order mode light beam and that is also easily manufactured even in a case where a width or a height of an optical waveguide is small is provided. An optical waveguide device includes a substrate 1 on which a rib type optical waveguide 10 is formed, and a slab waveguide SW disposed close to the rib type optical waveguide 10 , in which roughness of at least a part (SF 1 ) of an upper surface of the slab waveguide SW is larger than roughness (SF 0 ) of a surface of a top portion of the rib type optical waveguide.

In an optical waveguide device having a plurality of intersections between a convex optical waveguide and a signal electrode, the occurrence of disturbance modulation at the intersections is effectively reduced, thereby achieving good operating characteristics. The optical waveguide device includes an optical waveguide composed of a protruding portion extending on the substrate, and a signal electrode formed on the substrate and controlling a light wave propagating through the optical waveguide. The optical waveguide includes a Mach-Zehnder optical waveguide including two parallel waveguides having a curved portions, the signal electrode includes two signal lines intersecting the two parallel waveguides at the curved portions and transmitting a differential signal, and each of the two signal lines is configured such that the intersection lengths on the two parallel waveguides are the same as each other.

An object of the present invention is to provide an optical waveguide device that reduces noise light input into a light-receiving element. An optical waveguide device includes a substrate 1 on which an optical waveguide 2 is formed, the optical waveguide 2 including a main waveguide 2 and a branched waveguide 5 branching from a part of the main waveguide, a diffraction grating GT disposed in an end portion of the branched waveguide 5 , a light-receiving element PD disposed on the substrate for receiving a light wave diffracted by the diffraction grating, and a metal film MET 1 disposed on the substrate to surround the diffraction grating.

Provided are a bipolar membrane electrodialyzer where a current efficiency is high such that deposition of scale in a cation exchange membrane caused by divalent cations is suppressed, and a method for operating the same. The method is a method for operating a bipolar membrane electrodialyzer to produce an acid and an alkali from brine using a bipolar membrane electrodialyzer including a bipolar membrane, a cation exchange membrane and an anion exchange membrane, the method including: performing electrodialysis while adjusting an acid solution and/or an alkali solution to contain a salt to be decomposed.

A combustion method using a fuel combustion device, a cement manufacturing method, and a cement calcination facility including a fuel combustion device, in which while the amount of a fossil fuel used as a fuel supplied to a fuel combustion device provided in various facilities such as a cement calcination facility is reduced, the radiation heat transfer amounts of various burners are maintained, whereby the amount of heat transferred to a heating target such as a powder raw material of cement clinker is maintained to maintain a state suitable for calcination, the amount of carbon dioxide emitted from the various facilities is reduced, and the various facilities can be operated at a low cost, and a fuel combustion device including a fuel supply mechanism having a mechanism that supplies a flammable powder, a mechanism that supplies a fuel gas, and a mechanism that supplies a non-flammable powder are used.

A method for producing ammonium nitrate includes a nitrogen dioxide recovery step of bringing nitrogen dioxide in a cement exhaust gas into contact with water to obtain an NOx-containing solution, a reduction reaction step of producing ammonia by bringing a reducing catalyst into contact with the NOx-containing solution, an ammonia recovery step of vaporizing the ammonia with a waste heat gas, a solid-liquid separation step of separating a residue after the ammonia recovery into iron hydroxide and an unused residue of NOx, a neutralization step of bringing the separated nitrate/nitrite nitrogen-containing solution and the NOx-containing solution into contact with the ammonia vaporized and recovered to prepare ammonium nitrate, and a catalyst production step in which magnetite used in the reduction reaction step is obtained by reacting iron sulfate with a sodium hydroxide aqueous solution and separating the mixture into solid and liquid, the sodium sulfate aqueous solution in the solid-liquid separation is separated into sodium hydroxide and sulfuric acid by electrodialysis, and the sodium hydroxide is used in a circulatory manner for preparing the magnetite, where the nitrogen dioxide in the cement exhaust gas is treated simply and efficiently while reducing environmental burden.

Provided are a method for recycling and effectively using a waste emitted from a cement production process, in which calcium carbonate produced using a waste from a cement production process and hydrochloric acid produced in the process are effectively used for preparation of a vinyl chloride resin or the like, and a system that is useful for implementing the method. A method for reusing and recycling a waste generated from a cement production process, includes: electrodialyzing an aqueous solution containing potassium chloride to produce aqueous hydrochloric acid and an aqueous solution containing potassium hydroxide, the aqueous solution containing potassium chloride being obtained by washing chlorine bypass dust generated from a cement production step; adding a part of the aqueous hydrochloric acid to a calcium-containing waste to produce an aqueous solution containing a calcium ion; adjusting a pH of the aqueous solution containing a calcium ion and separating impurities; bringing carbon dioxide emitted from a cement production step into contact with the aqueous solution containing potassium hydroxide obtained through the electrodialysis to produce an aqueous solution containing potassium carbonate; and producing calcium carbonate and an aqueous solution containing potassium chloride using the aqueous solution containing a calcium ion having passed through the separation step and the potassium carbonate, in which a part of the aqueous hydrochloric acid obtained through the electrodialysis and the produced calcium carbonate are used for preparing a vinyl chloride resin or the like.

The present invention also addresses the problem of providing a dispersion liquid, a composition and a cosmetic each containing the dimethylpolysiloxane-coated metal oxide particles. The present invention also addresses the problem of providing a method for producing the dimethylpolysiloxane-coated metal oxide particles. The present invention relates to: polysiloxane-coated metal oxide particles, in which the surfaces of metal oxide particles are coated with dimethylpolysiloxane, and which have a hydroxyl group detection ratio of 10% or less; and a method for producing polysiloxane-coated metal oxide particles, the method comprising a surface treatment step for mixing metal oxide particles with dimethylpolysiloxane having a kinematic viscosity of 500 mm 2 /s to 4000 mm 2 /s inclusive at 25° C., without using a solvent, to coat the surfaces of the metal oxide particles with the dimethylpolysiloxane and a step for subjecting the dimethylpolysiloxane-coated metal oxide particles to a heat treatment at 250° C. to 380° C. inclusive.

An optical waveguide device including: an optical waveguide composed of a protruding portion extending on a substrate; a signal electrode that is formed on the substrate and controls light waves propagating through the optical waveguide, in which the optical waveguide includes a Mach-Zehnder optical waveguide including two parallel waveguides having curved portions, the signal electrode includes two signal lines for transmitting a differential signal, respectively intersecting the two parallel waveguides at the curved portions, and in an intersection region, which is a region on the substrate where the two signal lines and the two parallel waveguides intersect, at least one of the two signal lines has a signal propagation velocity faster than in a portion other than the intersection region or one of the two signal lines has a signal propagation velocity faster than an other signal line.

Mechanical strength of a lens that optically couples an optical waveguide and an optical fiber provided on a substrate is improved. A lens unit that optically couples an optical waveguide provided on a substrate and an optical fiber has a lens portion and a holding portion that holds the lens portion, and the holding portion has a thick portion, along one side surface that is not a surface through which an optical axis passes, in which a thickness measured in a direction of the optical axis is larger than a thickness of an other portion of the holding portion.