Chichibu Cement Co., Ltd.

Tokuji Akiba

Keiichi Minegishi

Hiroshi Machida

Giichi Sudoh

Keiichi Katayama

Norio Ogawa

Akihiko Takei

Tadao Kato

Hiroshi Harada

Motoshi Abe

A voltage non-linearity type resistor and a process for the preparation of a voltage non-linearity type resistor wherein pre-sintering is effected at a temperature of no lower than 700.degree. C. with a basic composition including X mole % of ZnO and (100-X) mole % of Fe.sub.2 O.sub.3 (wherein 40.ltoreq.X.ltoreq.60), and sintering is then effected with the resulting pre-sintered body to which at least one of V.sub.2 O.sub.5, Bi.sub.2 O.sub.3, MgO, Al.sub.2 O.sub.3, MoO.sub.3, Sb.sub.2 O.sub.3, SiO.sub.2, NiO, SrO.sub.2 and PbO is further added in a proportion of 0.01-40% by weight.

Process for the preparation of voltage non-linearity type resistors

A material for destroying concrete structures, rock formations and the like comprises a mixture of 20 to 80 parts by weight of coarse-grained quicklime adjusted to a particle size of from 88 to 3000 microns, and 20 to 80 parts by weight of cement. The cement may contain calcium sulfoaluminate as a hydraulic component, and a retardant may be added to the mixture to retard the hydration of the calcium sulfoaluminate. The material is blended with water and then injected into holes formed in the body to be destroyed, the material expanding as it hydrates to crack and fracture the body.

Material for destroying concrete structures

A humidity sensor element comprising a metal oxide semiconductor sintered member having a composition composed of TiO.sub.2 and V.sub.2 O.sub.5, the member being formed with a pair of electrodes. When the element is used at a temperature of less than 400.degree. C., it is possible to detect the humidity as a variation of electric resistance.

Humidity sensor element

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Kumagaya, Japan

Tokuji Akiba