Abstract: In a process for producing an iron oxide having magnetite as a main component by heating to reduce a powder of an oxide or a hydrated iron oxide comprising an iron oxide as a main component in an atmosphere for reduction, an improvement characterized in that said atmosphere for reduction is formed by passing an industrial liquefied nitrogen gas.

Abstract: A magnetic recording tape comprising a polyethylene terephthalate substrate and a magnetic material-containing layer closely adhered onto the substrate, which tape exhibits a reduced envelope variation. The polyethylene terephthalate substrate satisfies the formula:0.051H.sub.1 -0.59A+0.14 .DELTA.n+0.0015 (H.sub.2 -66.67).sup.2 +50.92.ltoreq.20wherein A is the average particle size of the polyethylene terephthalate crystals as determined from the half height width by X-ray diffractometry, and H.sub.1 is the average number of projections present in a unit area of 1 mm.sup.2 on the surface of the substrate, which projections have a height falling within the range of from 0.27 to 0.53 micron, H.sub.2 is the average number of projections similar to H.sub.1 above but having a height falling within the range of from 0.54 to 0.80 micron, rather than 0.27 to 0.53 micron, and .DELTA.n is the birefringence of the substrate.

Abstract: A tape pad for a tape cassette for continuously contacting a magnetic tape under pressure in a casing wherein the tape pad has a fitting hollow in which a supporting member non-rotatably mounted on the casing is inserted to support the tape pad.

Abstract: A magnetic recording medium having more than 550 Oersted of a coercive force, less than 1.8 of a ratio of a coercive force at -196.degree. C. to a coercive force at 25.degree. C., less than 1.0 wt. % of a content of Fe.sup.2+ is prepared by incorporating a magnetic powder obtained by dispersing acicular .gamma.-Fe.sub.2 O.sub.3 in an aqueous solution of a cobalt salt and reducing it with a reducing agent to deposit a cobalt compound on the acicular .gamma.-Fe.sub.2 O.sub.3.

Abstract: An alarm for indicating a lack of liquid in an ultrasonic nebulizer is disclosed. The alarm is responsive to a level sensing device in the nebulizer used to terminate oscillation in response to a low liquid level situation.

Abstract: Both solid magnetic coat layers formed on a substrate of a magnetic recording medium by coating a magnetic varnish are simultaneously smoothed by passing the magnetic recording medium between one or more pairs of rigid rotary rolls which press both magnetic coat layers during their rotation.

Abstract: An ultrasonic transducer including a thin piezo-electric substrate and an interdigital electrode radiating ultrasonic wave beams with excellent focusing characteristics into a liquid medium in contact with the substrate by applying AC voltages to the electrode.

Abstract: The epitaxial growth of boron-phosphorous semiconductors can be accomplished by chemically reacting the gas materials diborane and phosphorous trichloride. The preferable temperature of the substrate in 880.degree. C.-1,110.degree. C. and the preferable ratio of the phosphorous trichloride to diborane in mol is 2-200. Use is made of a composite substrate.

Abstract: The tape cassette comprises a guide rib extending upward from a lower casing to form a supporting surface for the entire width of the magnetic tape and a guide rib extending downward from an upper casing along the rear surface of the guide rib of the lower casing to provide a support for the guide rib of the lower casing.

Abstract: A magnetic recording medium comprises a substrate coated with a magnetic layer wherein a magnetic powder is orientated in a binder and a polyoxyethylenesorbitane higher fatty acid ester surfactant.

Abstract: An improved magnetic tape cassette and separation sheet therefor. The separation sheet, positioned between an inner wall and the tape reels of a cassette, is formed with at least one dome-like protrusion. A plurality of such protrusions are preferably utilized spaced throughout the sheet, each of a diameter R and height H sized to provide an R/H ratio of between about 100 and 10. The separation sheet may be formed with a protrusion shaped to fit into a window in an inner case wall, the window-fitting protrusion extending from a side of said separation sheet opposite from that containing said dome-like protrusions.

Abstract: A magnetic recording medium made by coating a base with a magnetic coating material which is a dispersion of magnetic particles in a binder of synthetic resins using a polyfunctional aromatic isocyanate as a curing agent, characterized by the addition of a sorbitan stearate type surface active agent which has a sorbitol derivative in the hydrophilic group. The present magnetic recording medium has superior mechanical properties, especially a superior running quality as well as superior electromagnetic properties.

Abstract: A filter operable in a microwave frequency band comprises a conductive closed housing having a bottom wall, an upper wall and side walls between said bottom wall and the upper wall, a plurality of resonators fixed on a straight line on the bottom wall inside of the housing, one end of each resonator being grounded to the bottom wall and the other end of each resonator being free standing, each resonator having at least an elongated center conductor and a dielectric body covering the center conductor at least partially in the longitudinal direction of the center conductor, a pair of connectors mounted at the opposite ends at the side walls for coupling the filter with an external circuit, a pair of loops each connected to the inner conductor of said connector and one end of the loops being grounded to the bottom wall, a pair of confronting conductive disks being provided between the free standing end of each center conductor of a resonator and the upper wall to provide the capacitance between said free standin

Abstract: A concentrated constant type delay device can be assembled in simple steps and has simple and stable structure. The delay device comprises a composite capacitor which comprises a common electrode placed on one surface of a dielectric and a plurality of separated electrodes placed on the other surface of the dielectric and the separated electrodes being respectively connected to each joint of coils connected between an input terminal and an output terminal.

Abstract: A novel ceramic composition exhibiting a solid solution structure of Pb(Fe.sub.1/2 Nb.sub.1/2)O.sub.3 -Pb(Mg.sub.1/3 Nb.sub.2/3)O.sub.3 -Pb(Mg.sub.1/2 W.sub.1/2)O.sub.3, can be sintered at a low sintering temperature; have a high insulation resistance; have a relatively high dielectric constant in the high dielectric type ceramic dielectrics, and; have a low dielectric loss.A particular amount of the additives, i.e., Pb-(Mn.sub.2/3 W.sub.1/3)O.sub.3, Pb(Mb.sub.1/2 W.sub.1/2)O.sub.3 Pb(Mn.sub.1/2 Nb.sub.2/3)O.sub.3, MnO, Pb(Mn.sub.1/3 Ta.sub.2/3)O.sub.3, Li.sub.2 O, Cr.sub.2 O.sub.3 and CeO.sub.2, is added into the composition mentioned above.

Abstract: A magnetic coating material for magnetic recording media is produced by dispersing a magnetic coating material containing from 0.1 to 2.0% of an abrasive and from 0.05 to 1.0% of a betaine type ampholytic antistatic agent, both on the basis of the amount of a magnetic powder, in a dispersion mill using steel balls. The abrasive has a hardness of not lower than 6 on Mohs' scale.

Abstract: A magnetic recording medium, consisting of a base coated with a magnetic coating material, contains finely divided particles of at least either nickel or copper uniformly dispersed in the magnetic coating, in the form of primary particles obtained by pulverization of the skeletal structure of a mother salt or of an aggregated structure. In a method of manufacturing the medium, an antistatic additive, prepared by pulverizing and dispersing at least either Ni powder or Cu powder which retains the skeletal structure of a mother salt or having an aggregated structure, in the presence of a polymeric material, is mixed in the magnetic coating material.

Abstract: A ferrite powder type magnetic toner used in an electrophotography. It comprises a resinous component and a ferrite having a spinel structure comprising components of iron oxide at a ratio of 99.9 to 51 mole % as Fe.sub.2 O.sub.3 and at least one metal oxide selected from the group consisting of manganese oxide, nickel oxide, cobalt oxide, magnesium oxide, copper oxide, zinc oxide and cadmium oxide at a ratio of 0.1 to 49 mole % as MO wherein M represents Ni, Co, Mg, Cu, Zn or Cd.