Abstract: The method of preventing adhesion of gypsum foreign matter comprises providing ultrasonic vibration to a member coming into contact with a gypsum slurry containing air bubbles.

Abstract: A process for producing a high-purity silica, which comprises the steps of reacting a crude silica with ammonium fluoride, acid ammonium fluoride or a mixture thereof in an aqueous medium to produce ammonium silicofluoride, separating the ammonium silicofluoride from an unreacted silica and impurities by the means of a solid/liquid separation, and reacting the thus-obtained ammonium silicofluoride with ammonia in an aqueous medium. This process is a low cost process, and enables to control properties of silica.

Abstract: A process for producing a high-purity silica, which comprises the steps of reacting a crude silica with ammonium fluoride, acid ammonium fluoride or a mixture thereof in an aqueous medium to produce ammonium silicofluoride, separating the ammonium silicofluoride from an unreacted silica and impurities by the means of a solid/liquid separation, and reacting the thus-obtained ammonium silicofluoride with ammonia in an aqueous medium. This process is a low cost process, and enables to control properties of silica.

Abstract: Silica particles having an average particle size of 5 to 100 .mu.m, a BET specific surface area of not more than 20 m.sup.2 /g and a pore volume of not more than 0.1 ml/g, each of which has on its surface a plurality of protuberances with a smooth configuration , a diameter at half the protuberance height of the said protuberance being 0.2 to 5.0 .mu.m and a height of the said protuberance being 0.2 to 4.0 .mu.m, and a process for producing the silica particles, which comprises (A) reacting hydrosilicofluoric acid, ammonium silicofluoride or a mixture thereof with ammonia in an aqueous medium to form a silica slurry, (B) separating a silica from the silica slurry, and (C) calcining, after optionally drying, the separated silica at a temperature of not less than 500.degree. C.

Abstract: Pyrazoline derivatives useful as insecticides having the formula ##STR1## wherein X represents a hydrogen atom or a halogen atom; Y represents a halogen atom, a trifluoromethyl group or --A--R'; R represents a C.sub.1-10 alkyl group, a lower alkenyl group or a lower alkynyl group; and A represents an oxygen atom, a sulfur atom, a sulfinyl group or a sulfonyl group and R' represents a halogen-substituted lower alkyl group.

Abstract: Pyrazoline derivatives useful as insecticides having the formula ##STR1## wherein R.sup.1 represents hydrogen atom, a lower alkyl group, (CH.sub.2).sub.n CN group, (CH.sub.2).sub.n OR group, phenyl group or a halogen-substituted phenyl group; R.sup.2 represents hydrogen atom or methyl group; Y represents hydrogen atom or chlorine atom; X represents oxygen atom, sulfur atom, sulfinyl or sulfonyl group; R.sup.3 represents a halogen-substituted lower alkyl group; and n is integer 1 to 3 and R represents a lower alkyl group.

Abstract: Ketone derivatives represented by the general formula (I) ##STR1## where R is --CH.sub.2 R.sup.1 (where R.sup.1 is a hydrogen atom or an alkyl group), a halogen-substituted alkyl group, a cyano-substituted alkyl group, a cyclopropyl group, ##STR2## (where R.sup.2 is a hydrogen atom or an alkyl group and Y is a hydrogen atom or a halogen atom) or ##STR3## (where R.sup.3 is a hydrogen atom, an alkyl group, a phenyl group or a halogen-substituted phenyl group, and Z is a hydrogen atom or a halogen atom), and X is an oxygen atom or a sulfur atom.

Abstract: Pyrazoline derivatives having the formula ##STR1## wherein R.sup.1 represents hydrogen atom, a lower alkyl group, phenyl group or a halogen-substituted phenyl group; R.sup.2 represents hydrogen atom or phenyl group which can have halogen substituents; X represents oxygen or sulfur atom; Y and Z respectively represent hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group, nitro-group, trifluoromethyl group, a lower alkylthio group, an acyl group, nitrile group or a lower alkyl sulfonyl group.