Abstract: An effective abrasive composition is provided for polishing a plastic article, particularly a plastic lens, to give a mirror surface thereto. This abrasive composition comprises water, an aluminous abrasive and at least one polishing accelerator selected from the group consisting of aluminum oxalate and aluminum lactate, optionally with at least one sedimentation preventing agent selected from the group consisting of crystalline cellulose and colloidal alumnia.

Abstract: An abrasive composition particularly suitable for polishing an aluminum-based substrate for a magnetic recording disc, the composition comprising: an alumineous abrasive, preferably in an amount of 3 to 25% by weight; a polishing accelerator of gluconic and/or lactic acid, preferably in an amount of 0.1 to 3% by weight; optionally with sodium gluconate and/or sodium lactate in an amount of 0.1 to 3% by weight; colloidal alumina, preferably in an amount of 0.1 to 5% by weight; and water, the composition typically having a pH of 3 to 5.

Abstract: A general-purpose internal combustion engine comprises an engine unit, a recoil starter, a fuel tank disposed on the engine unit, a main air cleaner disposed on the engine unit and coupled with a precleaner, and a muffler disposed on the engine unit. The main air cleaner and the muffler are disposed laterally of the fuel tank in parallel relation to each other, the main air cleaner being located closely to the recoil starter, and the muffler being disposed remotely from the recoil starter. The precleaner has an air inlet member disposed remotely from the muffler and positioned without projecting out of a plane containing a side of the main air cleaner which is remote from the muffler. The precleaner has an air outlet and the main air cleaner has a case with an air inlet defined in a side thereof and a substantially cylindrical filter housed centrally in the case coaxially with the vertical axis thereof.

Abstract: A process and apparatus for controlling the decompression of an internal combustion engine for driving compressors, electric generators, and the like, the process including the steps of starting the engine with the decompression control engaged and the engine decompressed, partially activating the control when the engine reaches a first predetermined speed so that, as the speed is increased, the engine operates compressed, when the engine reaches normal operating speed, fully activating the control and, when the engine speed is decreased to a second predetermined speed below said normal operating speed but above said first predetermined speed, the control is reactivated for decompression operation of the engine until the engine stops.

Abstract: A catalyst for steam reforming of hydrocarbons comprises porous aluminum oxide and nickel oxide, characterized in that the porous aluminum oxide in which the pore volume given by the pores of the pore diameter ranging from 60 to 120 A is not less than 0.35 ml./g. and the pore volume given by the pores of the pore diameter of more than 120 A is not less than 0.1 ml./g. and the purity determined upon ignition dryness is not less than 98% by weight is impregnated with nickel in an amount ranging from 10 to 30% by weight, as converted to nickel oxide basis, based on the total amount by weight of the catalyst.

Abstract: A lubricating oil detector for an internal combustion engine, the detector including a lubricating oil reservoir adapted to be disposed in a chamber of the engine wherein pressure pulsations are produced by reciprocating movement of a piston. An oil level detecting pipe extends to the exterior of a crank case of the engine, the pipe having an end opening at a lowest allowable oil level in the reservoir. A pressure detecting actuator is provided and is adapted to be mounted on the case and connected through a connecting tube to the detecting pipe. When the oil level is below the lowest allowable level, the pressure pulsations in the case are directed to the pressure detecting actuator, which is then actuated to stop the operation of the engine, or to operate an alarm.

Abstract: A catalyst comprising 10 to 30 wt.% of nickel as nickel oxide, 20 to 60 wt.% of calcium as calcium oxide, 10 to 70 wt.% of aluminum as aluminum oxide and containing less than 1 wt.% of silicon dioxide. The catalyst is prepared by using: as the starting material for the nickel component, fine particles of nickel oxide obtained by heating a nickel compound which is decomposed to nickel oxide by heating at a temperature in the range of 400.degree. to 800.degree. C in the presence of oxygen; as the starting material for the calcium component, calcium oxide per se or a calcium compound which is decomposed to calcium oxide by heating and; as the starting material for the aluminum component, alumina cement of a high purity. The catalyst is prepared by mixing and kneading the starting materials with water, molding the same, then keeping the catalyst composition under a highly humid atmosphere at a temperature in the range of 5.degree. to 35.degree.

Abstract: A particulate composition composed of a core of active material and a protective sheath having communicating micro pores to permit access of reactants to the active materials is described as well as a method for preparing same.

Abstract: A sintered catalyst article is prepared by:molding into a shaped article and aging (I) eitherA. a refractory powder of calcium aluminate substantially free of silicon dioxide, alone, orB. a homogenous mixture of1. said refractory powder and2. at least one member selected from the group consisting of aluminum oxide, calcium oxide, beryllium oxide, magnesium oxide, strontium oxide and a compound which is converted by heating to one of said oxides;(II) sintering said molded and aged article at a temperature above 1150.degree.C;the thus sintered catalyst article containing 10 to 60 wt. percent of calcium oxide, 30 to 90 wt. percent of aluminum oxide, 0 to 30 wt. percent of at least one oxide selected from the group consisting of beryllium oxide, magnesium oxide and strontium oxide, and less than 0.2 wt. percent of silicon dioxide.