Hitachi, Ltd.

Takeo Yamazaki

Tadahiko Miyoshi

Ken Takahashi

Kunihiro Maeda

Shingo Shirakawa

Satoru Ogihara

Takaaki Suzuki

Shigehisa Motowaki

Shigeru Tanaka

Yukio Takeda

Seiichi Yamada

Atsuko Soeta

Kie Nakamura

Masatoshi Nakazawa

Tetsuo Kosugi

Choushiro Kitazawa

Moritaka Shoji

Shinichi Owada

Jun Ozawa

Yoko Wakui

Kazuya Ooishi

Katsuji Shindo

Takahide Matsuo

Tetuo Kosugi

Yoshitaka Yagihashi

Moritaka Syouji

Shinichi Oowada

Tadashi Kitami

Siniti Oowada

A superconducting oxide wire and a method of manufacturing the same are disclosed. The wire comprises a pipe made of a metal and a superconducting oxide material filling the interior of the pipe and comprising superconducting oxide grains which are bonded to each other and which have a perovskite crystal structure having a C face and a C axis. The superconducting oxide grains contain more than 50 vol % of plate-shaped grains of which the length in the direction of the C face is greater than the length in the direction of the C axis. The C faces of most the plate-shaped grains are arranged to be directed toward longitudinal axis of the pipe.

Superconducting wire and method of manufacturing the same

A ceramic resistor includes zinc oxide as a main component, and as essential components, aluminum oxide 3.0-40 mol %, magnesium oxide 2.0-40 mol %, silicon oxide 0.1-10 mol %, and at least one kind of compound 0.005-0.5 mol %, selected from a group consisting of calcium oxide, strontium oxide and barium oxide, and has a positive temperature coefficient of resistance. A neutral grounding resistor and a gas circuit breaker, each using the above-mentioned ceramic resistors, are disclosed.

Ceramic resistor, production method thereof, neutral grounding resistor

A substation includes standard arresters installed near a bushing of a power transmission line entrance and at a connecting bus of a transformer and one or more high voltage arresters having a discharge voltage 10 to 30% higher than a standard arrester. Each high voltage arrester uses zinc oxide elements and is disposed on a line side of a line entrance breaker and/or near an open end of a double main bus in the substation.

Substation with surge arresters

A mixture of calcinated metallic oxides are mixed with ZnO and SiO.sub.2, granulated, compacted and then sintered to form a nonlinear resistor. After sintering, the formed ZnO resistor elements are heat treated, preferably in a two-step heat treating process.

Method of fabricating non-linear resistor

A composite sintered oxide resistor comprising crystal grains of zinc oxide and crystal grains of a zinc oxide compound of other metal or semi-metal element than zinc, and a grain boundary layer having an electric resistance equal to or lower than that of the crystal grains of zinc oxide between the individual crystal grains and which has a very large withstanding capacity against switch surge, a small non-linear coefficient of voltage in the voltage-current characteristics, a positive, smaller resistance-temperature coefficient, and a small percent change in resistivity after heat treatment at 500.degree. C. in the atmosphere.

Oxide resistor

A composite sintered oxide resistor comprising crystal grains of zinc oxide and crystal grains of a zinc oxide compound of other metal or semi-metal element than zinc, and a grain boundary layer having an electric resistance equal to or lower than that of the crystal grains and which of zinc oxide between the individual crystal grains has a very large withstanding capacity against switch surge, a small non-linear coefficient of voltage in the voltage-current characteristics, a positive, smaller resistance-temperature coefficient, and a small percent change in resistivity after heat treatment at 500.degree. C. in the atmosphere.

A paste composed of Li.sub.2 CO.sub.3, SiO.sub.2, Sb.sub.2 O.sub.3 and Bi.sub.2 O.sub.3 is coated and baked on a side surface of a sintered ZnO based nonlinear voltage dependent resistor body to form a high resistance side surface for improving a impulse current withstand of the resistor. The amount of the paste constituent is 1.about.2.5 mol % for Li.sub.2 CO.sub.3, 72.+-.5 mol % for SiO.sub.2, 20.+-.3 mol % for Sb.sub.2 O.sub.3 and 8.+-.2 mol % for Bi.sub.2 O.sub.3.

Nonlinear voltage dependent resistor and method for manufacturing thereof

A nonlinear resistor comprising a sintered body containing zinc oxide as a major component and at least bismuth oxide and boron oxide and electrodes formed thereon, said sintered body having a higher .gamma.-form bismuth oxide phase concentration in upper and/or lower surface layers of the sintered body than in the inner portion of the sintered body, has stabilized properties against long-time voltage application. When the sintered body is further modified by making the .gamma.-form bismuth oxide phase concentration in the periphery portions of the upper and/or lower surface layers lower than that in the inner portions of the upper and/or lower surface layers, the resulting nonlinear resistor shows a higher long-duration current impulse withstand capability.

Nonlinear resistor and process for producing the same

A sintered product composed chiefly of zinc oxide. A paste composed of a glass powder, an organic binder and tin oxide having a catalytic activity for promoting the combustion of organic binder, is coated on the side surfaces of the sintered product. The paste coated on the sintered product is baked to remove by burning the organic binder in the paste. Then, electrodes are attached to the main surfaces of the sintered product to complete a non-linear resistor.

Potentially non-linear resistor and process for producing the same

Disclosed is a voltage non-linear resistor comprising a sintered body composed mainly of zinc oxide, said sintered body including confronting main faces and a face side face connecting the main faces to each other, which has the side face coated with a coating glass layer containing barium oxide. The coating glass layer comprises 40 to 85% by weight of lead oxide, 3 to 25% by weight of boron oxide. 1.5 to 25% by weight of silicon oxide and 0.2 to 15% by weight of barium oxide. The barium oxide acts as a catalyst and exerts a function of completely burning an organic binder at a temperature lower than about 400.degree. C. where the reaction between the organic binder and zinc oxide is not substantially advanced.

Voltage non-linear resistor

Disclosed is a non-linear resistor of a sintered ZnO ceramics, which has a glass coating having a baking temperature higher than 850.degree. C. but a temperature lower than the sintering temperature of the sintered ZnO ceramics, and has a composition:

Non-linear resistor and process for producing same

Oxygen sensor ceramic of solid electrolyte of zirconia-yttria system comprises aggregates of cubic zirconia grains having an average grain size of 2-10 .mu.m and monoclinic zirconia grains having an average grain size of 0.2-1 .mu.m, the appregates of the cubic zirconia grains being in contact with one another, and the monoclinic zirconia grains being distributed as aggregates in clearances among the aggregates of the cubic zirconia grains, and has a high thermal shock resistance, a high mechanical strength and a resistivity equal to that of the ceramic consisting only of cubic zirconia grains. The oxygen sensor ceramic is prepared by mixing zirconia powder having a grain size of 0.1-0.5 .mu.m with 4-8% by mole of yttria powder having an average grain size of 0.5-5 .mu.m, on the basis of total mixture, and molding and firing the mixture at 1,400.degree.-1,550.degree. C.

Oxygen sensor ceramic and process for preparing the same

An alkyl compound of zinc is reacted with alkyl compounds or alkoxyl compounds of boron and silicon in the presence of oxygen, thereby to deposit on a substrate zinc borosilicate glass film through a chemical vapor deposition process. The outlet nozzle of a raw material supply conduit for introducing the raw material compounds into a reaction zone is opened in the direction substantially in parallel with a surface of the substrate on which the glass film is to be deposited so that raw materials may be well mixed at the reaction zone. The glass film thus produced has a uniform thickness and a homogeneous composition of the constituents over an area at least of 40 mm extending from the nozzle and is suited for use as protection films for semiconductor devices and dielectric layer for a thin film capacitor on an industrial base.

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Hitachi, Japan

Takeo Yamazaki