Abstract: A polishing apparatus comprises a polishing tool having a polishing surface, and a holder device (top ring) for holding a semiconductor wafer (a substrate). The polishing apparatus further comprises a color CCD camera for taking a color image of a region on the polishing surface; an image processor for determining whether or not any foreign matter exists on the polishing surface based on a condition of a color in color image data acquired by the color CCD camera; and an apparatus operation control section which in response to determination of the image processing section, stops relative movement between the semiconductor wafer and the polishing surface and separates the top ring and the polishing surface from each other.

Abstract: The invention relates to a method for the production of 2-coumarone or substituted 2-coumarones, whereby cyclohexanone or substituted cyclohexanone is reacted with a carboxyl-containing acylating agent a) to give methyl 2-(2-oxo-cyclohexyl)-2-hydroxyacetate or substituted methyl 2-(2-oxo-cyclohexyl)-2-hydroxyacetates, which are either a1) directly converted to 2-coumarone or substituted 2-coumarones by means of catalytic gas-phase dehydrogenation, or a2) dehydrated by means of azeotropic distillation under basic conditions, or by use of a strong acid, or a strongly acidic ion exchanger to a mixture of methyl 2-oxocyclohexylidenacetate and the enol-lactone of the 2-oxocyclohexylidenacetic acid, or a mixture of substituted methyl 2-oxocyclohexylidenacetate and the enol-lactone of the substituted 2-oxocyclohexylidenacetic acid, which is finally converted in turn by catalytic gas-phase dehydrogenation to 2-coumarone, or substituted 2-coumarones, or b) are directly converted under acidic or basic conditions into a

Abstract: Ferromagnetic granular ultrafine particles consisting essentially of .epsilon.' iron carbide represented by the composition formula:.epsilon.'-Fe.sub.2.2 Chaving an average particle size of about 0.01 to 0.2 .mu.m, and ferromagnetic acicular ultrafine particles consisting essentially of .epsilon.' iron carbide represented by the composition formula:.epsilon.'-Fe.sub.2.2 Chaving a major axis of about 0.05 to 0.5 .mu.m, a minor axis of about 0.01 to 0.06 and an axial ratio of 4 to 20, which have good coercive force and a small magnetic domain.