Abstract: To enable surface treatment of the inside of a part or the like and also simplify grinding work by equipment and a procedure that are simple in comparison with convention A first semi-sintered electrode 31 that is formed in a tapered shape whose distal end portion becomes smaller in diameter toward the distal end portion is attached to an electrode supporting tube 26, is configured to be rotatable by a motor 27, is positioned near a seat portion 8 of a nozzle body 1, and generates electrical discharge by surface modifying electrical discharge machining method between the seat portion 8 and the first semi-sintered electrode 31, whereby a coating that is formed as a result of the material that forms the first semi-sintered electrode 31 being moved and deposited can be formed on the seat portion 8 and grinding treatment of the inside of the nozzle body 1 matching the outer diameter of a nozzle needle 2 as has conventionally been the case can be rendered unnecessary.

Abstract: A pressure detection mechanism for a catalyst of an engine, in which the catalyst includes an upstream NSR catalyst and a downstream DPNR catalyst stored in a catalyst casing, which includes a DPNR front pressure detection pipe connected to a space formed by the NSR catalyst, the DPNR catalyst and the catalyst casing, a DPNR rear pressure detection pipe downstream of the DPNR catalyst connected to a space formed by the DPNR catalyst and the catalyst casing, and a pressure difference transducer connected to the DPNR front pressure detection pipe and the DPNR rear pressure detection pipe.

Abstract: Disclosed are electrolessly plated nickel coatings containing 0.5 to 3.0% by weight of phosphorus and 0.05 to 2.0% by weight of boron, coatings obtained by subjecting to heat treatment electrolessly plated nickel coatings containing 0.5 to 3.0% by weight of phosphorus and 0.05 to 2.0% by weight of boron and machine parts having sliding surfaces wherein at least the sliding surfaces are coated with the coatings. The coatings can be suitably provided on base materials composed of aluminum alloys or the like, show high hardness, high impact strength (high toughness) and improved lubricating characteristics such as sliding characteristics and, in addition, can be formed at a high rate.

Abstract: A cobalt-containing ferromagnetic iron oxide powder of which constituent particles each is an aggregate of cobalt-containing ferromagnetic iron oxide micorparticles and has a spherical shape of 5 to 200 .mu.m in diameter has an angle of repose of 35.degree. or smaller and accordingly excellent flowability, as well as to a process for producing the iron oxide powder, are provided. This ferromagnetic iron oxide powder consisting of spherically shaped particles, are easily dispersed in an organic binder to return to the original state of microparticles, and provide improved magnetic characteristics when used as a material for magnetic recording media such as a magnetic tape and the like.