Abstract: An element of a mixing apparatus having no moving parts. The element includes a hollow cylindrical body provided on an inner surface thereof with projecting plates for disturbing a flow of fluids within the hollow cylindrical body. The hollow cylindrical body is provided on one end thereof with a plurality of projections disposed at regular angular intervals. The hollow cylindrical body is provided on the other end thereof with a plurality of indents disposed at the same regular angular intervals as the projections. Each of the projections of one element is engageable with each of the indents of another element.

Abstract: An immunoassay method using magnetic particles comprising a core and a coating layer on the surface thereof, The core comprises an organic polymer and the coating layer comprises an iron oxide type ferrite coating layer. An antigen or an antibody is bound onto the surface of the coating layer and the particle has a particle size of 0.2 to 3 .mu.m.

Abstract: There is disclosed a method for forming a ferrite coatings on a substrate, which comprises:(a) bringing a substrate into contact with water or an aqueous solution, and(b) adding a ferrous ion solution, an oxidizer solution and a pH controller so that pH and an oxidation-reduction potential may be included within the range specified by A (6, -440 mV), B (6, -130 mV), C (11, -430 mV) and D (11, -740 mV) in a pH - oxidation-reduction potential graph.

Abstract: Disclosed is a method of forming a ferrite film on particulate and/or fibrous substrate by adding an oxidizer solution and a ferrous ion solution to a deoxidized solution containing particulate and/or fibrous substrates to form a thin ferrite film on the particulate and/or fibrous substrates, wherein an addition amount of the ferrous ion solution is controlled such that an oxidation-reduction potential of the deoxidized solution keeps approximately a center point between the oxidation side and the reduction side, when a pH value of the dioxidized solution is adjusted to a constant value between pH 6 and 10.

Abstract: Disclosed is a method for forming a ferrite film comprising, flowing downward or spraying an aqueous oxidizing agent solution on a substrate in a deoxidized atmosphere and simultaneously supplying an aqueous deoxidized solution containing at least ferrous ions, to effect a ferrite crystallization reaction on the substrate. This ferrite film is used for magnetic recording media, photomagnetic recording media, magnetic heads, etc.

Abstract: The present invention is intended to provide a carrier to be used as a two-component developer, wherein a nuclide particle surface has a magnetic plated layer composed of an iron oxide. The carrier according to the present invention is to be used in the electrophotographic method, electrostatic recording method, and electrostatic printing method, and also provides an excellent developer which is lightweight and has a long service life.