Abstract: Siloxane compounds are removed from the atmospheres by silica supporting an organic sulfonic acid compound. The silica with the organic sulfonic acid compound has a specific surface area down to 500 m2/g and up to 750 m2/g and a pore volume down to 0.8 m3/g and up to 1.2 m3/g, both measured by nitrogen gas adsorption method and has a pore diameter down to 4 nm and up to 8 nm, at the peak of differential pore volume measured by nitrogen gas adsorption method. The durability of gas sensing element against siloxanes is improved.

Abstract: A gas detector comprises a gas detection unit and a filter introducing surrounding atmosphere to the gas detection unit. The filter comprises a gas-permeable organic polymer membrane having an acidic group or a basic group.

Abstract: An end mill includes: at a distal end portion side in a rotation axis direction of a tool body, a plurality of cutting edges continuous from a center side to an outer peripheral side in a radial direction and adjacently arranged in a rotation direction of the tool body; gashes formed on front sides in a rotation direction of the respective cutting edges; and chip discharge flutes continuous with the gashes. The gashes are composed of distal end side depressed faces formed along a distal end side axis making an acute angle with the rotation axis and rear side depressed faces formed along a rear side axis making a smaller acute angle with the rotation axis than the distal end side axis. The distal end side depressed faces and the rear side depressed faces are formed to have shapes overlapping with one another.

Abstract: The present invention provides an end mill including: a shaft-shaped end mill main body; a chip discharge groove extending from a leading end to a trailing end in an axial direction of the end mill main body; a bottom blade which is provided at a leading end portion in the axial direction of the end mill main body and has a spherical shape in which a rotation locus around the axis has a center on the axis; and an outer peripheral blade which is provided along the chip discharge groove, and in which a rotation locus around the axis is convex outward. A curvature radius of the rotation locus of the outer peripheral blade is larger than a curvature radius of the rotation locus of the bottom blade. A twist angle of the outer peripheral blade is 20° or more.

Abstract: The present invention provides an end mill including: a shaft-shaped end mill main body; a chip discharge groove extending from a leading end to a trailing end in an axial direction of the end mill main body; a bottom blade which is provided at a leading end portion in the axial direction of the end mill main body and has a spherical shape in which a rotation locus around the axis has a center on the axis; and an outer peripheral blade which is provided along the chip discharge groove, and in which a rotation locus around the axis is convex outward. A curvature radius of the rotation locus of the outer peripheral blade is larger than a curvature radius of the rotation locus of the bottom blade. A twist angle of the outer peripheral blade is 20° or more.