Abstract: The present invention provides a piping unit that facilitates downsizing of a cooler by decreasing the temperature of fluid to be introduced into the cooler without reducing the cooling effect of a cooler. A piping unit is for introduction of heated fluid into a cooler, the piping unit being formed from synthetic resin and including a heat exchange structure on an inner peripheral surface.

Abstract: A vent duct having an inner fluid flow passage includes a bent portion formed to a duct body portion at which the fluid flow passage is bent, and a protruded portion formed on a downstream side of the bent portion so as to protrude from an inner peripheral surface portion toward an axial center of the fluid flow passage, wherein the protruded portion includes an upstream side end portion formed to be gently continuous to the inner peripheral surface portion of a downstream side portion of the bent portion, a body portion extending from the upstream side end portion toward the downstream side portion along the fluid flow passage, and a downstream side end portion along the fluid flow passage to be continuous to the body, the downstream side end portion of the protruded portion being formed to be perpendicular to the inner peripheral surface portion.

Abstract: A vent duct having an inner fluid flow passage includes a bent portion formed to a duct body portion at which the fluid flow passage is bent, and a protruded portion formed on a downstream side of the bent portion so as to protrude from an inner peripheral surface portion toward an axial center of the fluid flow passage, wherein the protruded portion includes an upstream side end portion formed to be gently continuous to the inner peripheral surface portion of a downstream side portion of the bent portion, a body portion extending from the upstream side end portion toward the downstream side portion along the fluid flow passage, and a downstream side end portion along the fluid flow passage to be continuous to the body, the downstream side end portion of the protruded portion being formed to be perpendicular to the inner peripheral surface portion.

Abstract: Ferromagnetic fine powder for magnetic recording, characterized by comprising platelet like ferrite crystal particles which have such a metallic element composition that the Ba/Fe molar ratio is 1/50 to 1/8 and that the total amount of Ni and Zn is less than 0.5 mole and not less than 0.07 mole per mole of Fe, a crystal phase of magnetoplumbite phase, spinel phase or composite phase thereof and a saturation magnetization of 60 emu/g or more; and a process for producing said ferromagnetic fine powder for magnetic record.

Abstract: A process for producing ferromagnetic fine particles for magnetic recording which comprises preparing a starting material solution containing Ba, Fe and Me (Me representing at least one element selected from the group consisting of Co, Ti, Ni, Mn, Zr, Zn, Ge, Nb and V, the amount of which is 0.2 mol or less per mol of Fe) selected such that the molar ratio of Ba/(Fe+Me) is (1+m)/12 (m being a number of 0.1 to 2), mixing this starting material solution with an alkaline solution to form a coprecipitate-containing alkaline suspension, collecting and using the coprecipitate as precursor, or subjecting the coprecipitate-containing alkaline suspension to a heat treatment at a temperature below 250.degree. C. to form a precursor, and calcining such precursor at 650.degree.-950.degree. C. to produce the hexagonal platelet Ba-ferrite particles. The process is further characterized in that a boron compound is contained in the precursor in an amount of (0.01 to 1) mmol (calculated as B.sub.2 O.sub.

Abstract: A cobalt-containing magnetic iron oxide powder is provided by first coating a magnetic iron oxide base powder with a ferrous compound and then coating it with a cobalt compound. The cobalt-containing magnetic iron oxide powder provided is improved in stability of coercivity under aging and various other magnetic properties, and the magnetic tape produced by using the powder is also appreciably improved in stability of coercivity under aging as well as in various magnetic properties such as squareness, orientability and switching field distribution.

Abstract: A process is provided for coating the particle surfaces of a phosphor-containing magnetic iron oxide powder with a cobalt compound after subjecting said powder to an activation treatment with an aqueous alkaline and/or acidic medium. The cobalt-containing magnetic iron oxide powder obtained according to this process has excellent coercivity and thermal stability, and the magnetic tape produced by using said powder has not only high coercivity but also excellent squareness, orientability and remanent induction.

Abstract: A phosphorus-containing magnetic iron oxide powder is subjected to the activation with an aqueous alkaline medium under pressure and then coated with a cobalt compound or a cobalt compound and other metallic compound(s) to produce a cobalt-containing magnetic iron oxide powder. The magnetic iron oxide powder obtained according to this process finds its best application to the production of magnetic recording media.