Abstract: A compressor impeller and a method of manufacturing the compressor impeller. The magnesium alloy compressor impeller as a die-cast part comprises a hub shaft part, a hub disk part having a hub surface extending from the hub shaft part in the radial direction, and a plurality of vane parts disposed on the hub surface. The impeller can be manufactured by a die-cast method in which a magnesium alloy heated to a liquidus temperature or higher is supplied into molds with cavities corresponding to the shape of the impeller for a filling time of 1 sec. or shorter, a pressure of 20 MPa or higher is applied to the magnesium alloy in the cavities, and the pressurized state is maintained for a time of 1 sec. or longer.

Abstract: [Problems]To provide a lost-wax cast impeller for a supercharger having no parting line corresponding part on a hub surface and a blade surface in each space demarcated by pairs of long blades adjacent to each other and having excellent aerodynamic performance. [Means for Solving Problems]This method of manufacturing the impeller comprises a step for forming a lost form pattern formed in the substantially same shape as the impeller for the supercharger, a step for forming a mold by eliminating and removing the lost form pattern after the lost form pattern is coated with a refractory, and a step for pouring a molten metal in the mold for casting.

Abstract: Presulfurizing process and presulfurization promoter for a desulfurization catalyst to be used in a hydrodesulfurization unit of petroleum refinery of high molecular hydrocarbons, in which fresh metal oxide in said desulfurization catalyst is sulfurized with hydrogen sulfide produced from sulfur-containing compounds in a feed stream. In the invention, a compound having mercapto alkylthio group: HS—CmH2m—S— (in which “m” is an integer of 2 to 4) is added as promoter at a proportion of 10 ppm to 0.5% by weight and presulfurization is promoted at 180 to 260° C.

Abstract: Method for improving the yield of lighter components in heat-refining process of petroleum heavy oil, and additive used in the method. The heat-treatment in a heating unit is effected in the presence of at least one compound (I) having at least one mercapto alkylthio group: HS--C.sub.m H.sub.2m --S--, in which "m" is an integer of 2 to 4.

Abstract: The present invention is applied to a device for radiating a light spot onto a predetermined location of a recording medium in order to optically record and/or reproduce information. The drive device may include a mobile body having a light-emitting element, an objective lens, a light-receiving element, and a holder for retaining the light-emitting element, the objective lens, and the light-receiving element. The drive device may also include a connecting device for electrically connecting the light-emitting element and the light-receiving element to an external electrical circuit.

Abstract: Method for reducing deposition of cokes in heat-refining process of petroleum high-molecular hydrocarbons, characterized in that heat-treatment in a heating unit is effected in the presence of at least one compound (I) having at least one mercaprtoalkylthio group:HS--C.sub.m H.sub.2m --S--in which "m" is an integer of 2 to 4.

Abstract: A method for the production of a sulfide group-containing thiol compound which comprises causing alkylene sulfide to react with a thiol compound in the presence of at least one basic catalyst selected from the group consisting of basic ion-exchange resins, quaternary ammonium compounds and alkyl pyridinium compounds, thereby inducing the ring-opening addition of the alkylene sulfide to the thiol compound. Further, a method for the production of a sulfide group-containing mercaptocarboxylic ester which comprises causing an alkylene sulfide to react with a mercaptocarboxylic ester.

Abstract: An object is to provide a method for the production of a sulfide group-containing thiol compound which comprises using a solvent capable of effecting the ring-opening addition reaction of an alkylene sulfide to a thiol compound without inducing the alkylene sulfide to polymerize. A method for the production of a sulfide group-containing thiol compound, which comprises effecting the ring-opening addition reaction of an alkylene sulfide represented by the general formula (1): ##STR1## (wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4, which may be identical or different, stand for a hydrogen atom, an alkyl group of 1 to 10 carbon atoms, or an aromatic group of 6 to 15 carbon atoms) to a thiol compound in a solvent of an amide compound or urea substituent-containing compound.

Abstract: An unsaturated aldehyde expressed by Formula (I) below is hydrated with a solution in the presence of a carboxylic-acid-based resin having of a structure expressed by Formula (II) below: ##STR1## where R represents one of a hydrogen atom and a hydrocarbon group having up to five carbons; ##STR2## where R.sub.1 and R.sub.2 respectively represent a hydrogen atom, hydrocarbon group having up to five carbons, or --(--CH.sub.2 --).sub.p1 --X group, p.sub.1, k.sub.1, and m.sub.1 respectively represent an integer from zero to six, n.sub.1 represents an integer from one to six, Y.sub.1 represents --O--, --S--, or --NR.sub.3 --, R.sub.3 represents a hydrogen atom or hydrocarbon group having up to five carbons, and X represents a carboxylic-acid-based resin main body. Using a heat-resistant catalyst as above makest it possible to increase the reaction rate by heating, and produce hydroxyalkanal at high selectivity and yield out of an industrially advantageous high-concentration unsaturated aldehyde solution.

Abstract: The present invention is applied to a device for driving optical component parts, such as an objective lens, in accordance with displacement of a disk. A mobile body, on which the optical component parts are mounted, is supported by at least two plate springs that are not parallel with the disk, in such a manner that the mobile body can be driven in a focusing direction and a tracking direction. The plate springs can have an electric wiring function so that no wires extend from the mobile body.

Abstract: A blood vessel dilator so thin in outside dameter as the "on the wire" type catheter retaining a sufficiently wide liquid lumen and highly manipulatable at branched parts of blood vessels by a separately turnable guide wire and hence readily inserted even into narrow perpheral blood vessels.

Abstract: There is described a method for treating a paper sheet which bears on one side a printed picture image for illuminated display on a light box, wherein a treating liquid is applied on the non-printed back side of the paper sheet to impregnate liquid paraffin into the sheet to increase its light transmittivity and the sharpness of the picture image.