Abstract: Catalysts for purification of exhaust gases from internal combustion engines which are a mixture of aluminum oxide, calcium oxide and one or more of the elements platinum, palladium and rhodium, and method for their use.

Abstract: An electromagnet for degaussing a magnetic head and which includes a yoke having a gap and one or more coils wound thereon is characterized by the middle portion of the yoke face, at and adjacent to said gap, being wider than the magnetic tape that passes by the magnetic head, and by the side portions of said yoke face, away from said gap, being narrower than the tape.

Abstract: A tape cassette reel comprises a special clamp which is fitted to a groove of a hub. The clamp comprises an upper rib, a pair of legs extended from the upper rib; a lower rib inserted between the legs and a projected part formed on the lower rib. The projected part is fitted to a cavity formed at the bottom of the groove of the hub. A tape is completely clamped on the hub by the clamp without failure.

Abstract: A tape cassette comprises a cover for covering a wound tape which comprises a polar member mounted on a wall of the cover and a coil spring fitted to the polar member. The polar member has a narrow width slit at the free end and a wide width slit adjacent to the narrow width slit at the side of the fixed end and one end of the coil spring is inserted in to the wide width slit through the narrow width slit and the other end of the coil spring is contacted with a case body.

Abstract: A piezoelectric ceramic composition which comprises the combination of a pyrochlore composite oxide and a base ceramic mixture of PbTiO.sub.3 and PbZrO.sub.3.

Abstract: An electrode for use in electric prevention for corrosion, the electrode comprising a sintered body of a mixture of iron oxide of 90 to 55 mol % in terms of Fe.sub.2 O.sub.3 and a metal oxide of 10 to 45 mol % in terms of MO (M is at least one metal selected from the group consisting of Mn, Ni, Co, Cu and Zn), and a process of electric prevention for corrosion by using said electrode as an anode.

Abstract: A tape cassette including a cylindrical tape guide having a slit in the axial direction and a groove at the end thereof which is fitted to a projection of a pole connected to a half of the case. The cylindrical tape guide can also be provided with a first and second notch formed therein as a substitute for the groove. Moreover, a groove can be formed at each end of the cylindrical tape guide.

Abstract: A video cassette tape reel comprises at least one flange; a ring hub having a groove in parallel to the axis of the hub; a clamp fitted to the groove; and peripheral guides formed in the hub between which the clamp is fitted, whereby a tape clamped on the ring hub is not contacted with the flange in winding the tape.

Abstract: A non-linear resistor comprises a sintered body of a ceramic composition which comprises 99.93 to 50 mole % of zinc oxide as ZnO; 0.01 to 10 mole % of a specific rare earth oxide as R.sub.2 O.sub.3 (R represents lanthanum, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium or lutetium) 0.01 to 10 mole % of an alkaline earth oxide as MO (M represents calcium, strontium or barium) and 0.05 to 30 mole % of cobalt oxide as CoO.

Abstract: A magnetic bulk eraser for erasing a cassette magnetic recording tape. A pair of parallel magnetic disks have alternating magnetic poles around their peripheral surface. The disks are mounted facing each other, and are so aligned that the facing poles are similar, e.g. North faces North, and South faces South. A guide slot through which a cassette magnetic tape may be passed is provided between the magnet disks. A holder having a cassette magnetic tape to be erased moves linearly through the guide slot engaging a rack with pinions. When a handle is rotated manually, the magnetic disks rotate and provide an alternating magnetic flux in the guide slot through which a cassette magnetic tape passes, also driven by the manually operated handle.

Abstract: An attenuator for use in filtering high-frequency waves propagated in a transmission line, comprising ferrite beads having a conductor passed therethrough which are enclosed firmly within a mixture having powder of ferrimagnetic material dispersed in an organic high polymer.

Abstract: A demagnetizer for a magnetic head for a recording/reproducing device. The demagnetizer includes an electromagnet for producing an alternating magnetic field which gradually decreases in intensity. The demagnetizer is mounted in a case formed in the shape of a tape cassette. The electromagnet is resiliently held within the case adjacent to the opening for the magnetic head to be demagnetized. The electromagnet is energized by an oscillating drive circuit, the output of which is controlled by a capacitor.

Abstract: A ceramic dielectric composition is provided including 35 to 93.5% by weight of SrTiO.sub.3, 4 to 40% by weight of Bi.sub.2 O.sub.3, at least 2.5% but less than 60% by weight of TiO.sub.2, and 0.1 to 5.0% by weight, of an alkali metal oxide based on the total amount of SrTiO.sub.3, Bi.sub.2 O.sub.3 and TiO.sub.2. The ceramic dielectric composition has a high dielectric constant and low dielectric loss and exhibits reduced variations of dielectric constant and the dielectric loss with respect to variation of an applied voltage.

Abstract: Electromagnetic wave-absorbing wall comprising ferrimagnetic plates arranged at some intervals in the direction of the electric field of the electromagnetic wave said ferrimagnetic plates being plates of ferrite having the following general formula:MFe.sub.2 O.sub.4wherein M is a bivalent metal such as Mn, Ni, Co, Mg, Cu, Zn and Cd, or plates of a mixture of ferrite powders or carbonyl iron with organic high molecular weight compounds, and said plates having a specified thickness according to the interval.

Abstract: An electronic part comprises a plastic core holder having a sectional ] shape which has an opening part and a stopper in one side and a bottom; and a plurality of drum cores having windings which are arranged in the core holder to contact the flanges of the adjacent drum cores.

Abstract: Coatings (or coat) for preventing reflection of electromagnetic wave on iron structures and coating material for use in forming said coatings, said coatings comprising ferrite powders and iron powders dispersed in organic high molecular weight compounds and said coating material comprising a dispersion of ferrite powders and iron powders contained in a solution of organic high molecular weight compounds dissolved in organic solvents.

Abstract: A magnetic recording medium is prepared by preparing a nitrocellulose-based magnetic composition by kneading a magnetic powder with a mixture of nitrocellulose in a solvent system containing isopropyl alcohol and blending the kneaded mixture with a polyurethane containing unreacted isocyanate groups; coating a substrate with the resulting magnetic composition and allowing the coated substrate to dry. The improvement comprises replacing substantial portions of the isopropyl alcohol from the group consisting of polyurethane resins, polybutadiene resins, butadiene-acrylonitrile copolymers, vinyl chloride-vinyl acetate-vinyl alcohol copolymers, vinyl chloride-vinyl acetate copolymers, vinyl chloride-vinylidene chloride copolymers, vinylidene chloride-acrylonitrile copolymers, vinyl acetate resins, epoxy resins, phenoxy resins, polyvinyl butyral resins, polyvinyl formal resins and polyester resins.

Abstract: Ferromagnetic metal or alloy particles are prepared by reducing ferromagnetic metal ions in the solution with a reducing agent under a magnetic field to obtain a slurry of ferromagnetic metal or alloy particles and adding an oxidizing agent to an aqueous slurry containing the ferromagnetic metal or alloy particles to prevent deterioration of magnetic characteristics.

Abstract: A magnetic recording medium is prepared by depositing magnetic particles of ferromagnetic, acicular iron oxide upon whose surface is adsorbed cobalt hydroxide, on a supporting substrate.

Abstract: A cassette tape winding apparatus comprises a groove formed on an inner circular surface of an annular wheel and a circular elastic member mounted on an outer circumferential surface of a rotary shaft to firmly fit to the groove.