Abstract: This invention provides a measure that makes it possible to prevent more effectively, in comparison with the prior art, the invasion of germs from the gap between a dental prosthesis and the gingiva when the dental prosthesis is used in an oral cavity as well as the infection and inflammation associated therewith. There is a dental prosthesis or a component thereof, characterized in that: the dental prosthesis or the component thereof has hydroxyapatite fine particles on a surface of the dental prosthesis or the component thereof; the hydroxyapatite fine particles are sintered bodies; and the hydroxyapatite fine particles have a mean particle size of 10 to 1,000 nm.

Abstract: This invention provides a measure that makes it possible to prevent more effectively, in comparison with the prior art, the invasion of germs from the gap between a dental prosthesis and the gingiva when the dental prosthesis is used in an oral cavity as well as the infection and inflammation associated therewith. There is a dental prosthesis or a component thereof, characterized in that: the dental prosthesis or the component thereof has hydroxyapatite fine particles on a surface of the dental prosthesis or the component thereof; the hydroxyapatite fine particles are sintered bodies; and the hydroxyapatite fine particles have a mean particle size of 10 to 1,000 nm.

Abstract: This invention provides a measure that makes it possible to prevent more effectively, in comparison with the prior art, the invasion of germs from the gap between a dental prosthesis and the gingiva when the dental prosthesis is used in an oral cavity as well as the infection and inflammation associated therewith. There is a dental prosthesis or a component thereof, characterized in that: the dental prosthesis or the component thereof has hydroxyapatite fine particles on a surface of the dental prosthesis or the component thereof; the hydroxyapatite fine particles are sintered bodies; and the hydroxyapatite fine particles have a mean particle size of 10 to 1,000 nm.

Abstract: A shippable in-assembly bolt having a head portion, a threaded portion containing threads and a gripper portion, wherein the gripper portion preferably comprises a grooved structure and an o-ring. The o-ring is intended to sit between the inner wall of a clearance hole in an assembly/subassembly and the grooved structure of the gripper portion. When the o-ring is in position between the inner wall of the clearance hole and the grooved structure of the gripper portion, the o-ring is in both compression and tension and acts to retain the bolt in the assembly during shipping operations. The invention can be used with any type of mechanical fastener, such as bolts, screws, pins, rivets, etc.

Abstract: Toxic metabolic products (e.g., ammonia) in water can be decomposed effectively by a close contact of ammonia with oxygen on the large surface area of plastic substrates in the biofilter tank according to the aquarium of the invention. In the conventional method, toxic metabolic products such as ammonia have been oxidized by blowing air into the water or zeolite and activated carbons have been used to absorb unwanted products but which absorbents are required to be replaced or cleaned frequently to remove clogged materials. In contrast, the plastic substrates in the aquarium of the invention does not require such frequent replacement or cleaning. The rearing tank is connected with the biofilter tank and the algae culture tank via the sump, which functions as a buffer to prevent any adversary effect on the aquatic environmental factors in the reading tank. The sump contains a large volume of water, which also serves to minimize a sudden change in culture conditions.

Abstract: A nail remover according to the present invention includes a tool head having a guide bore extending linearly through the head in a longitudinal direction, a push-rod slidably mounted in the guide bore of the head between a retracted position at which a free end of the push-rod is located in the guide bore and an extended position at which the free end of the push-rod protrudes from the guide bore, a driving device for advancing the push-rod from the retracted position to the extended position, and an actuator for activating the driving device. At least a portion of the peripheral wall defining an outlet of the guide bore is tapered toward an outboard edge of the wall so as to make it easy to introduce a nail into the guide bore. In operation, the guide bore receives the portion of a nail protruding from a plate such as a piece of plywood.

Abstract: A welding accessory which includes an arc shield having outer and inner peripheral surfaces such that a weld can be formed within the inner peripheral surface as the arc shield shields the weld form external air during forming of the weld. The arc shield includes a ceramic material having not less than 40 weight % of boron nitride. The arc shield may be formed of a composite of boron nitride and silicon nitride, a composite of boron nitride and alumina nitride, a composite of boron nitride, aluminum and silicon nitride, or a composite of boron nitride and zirconia.

Abstract: An arc stud welding machine having an arc shield mount section for retaining a generally semicylindrical arc shield segment. The arc shield mount section has a semicylindrical inner clamp member for abutment against an inner surface of said arc shield segment, two quarter cylinder outer clamp members for abutment against an outer surface of said arc shield segment, and pressure screws for applying pressure in the direction of said arc shield segment to said outer clamp members at approximately the middle of the periphery thereof.

Abstract: A concrete revetment is provided which is arcuate in horizontal cross section, and has end portions which are interconnected by a cordal member. The cordal member is adapted to be prestressed by a tension rod to place the cordal member in compressive stress and the arcuate portion of the revetment in tensile stress. The revetment is held in place by anchor means embedded in back-fill on the convex side of the arcuate revetment. A plurality of revetments may be arranged and interlocked horizontally and vertically to form a revetment wall.

Abstract: A joint for reinforcing bars includes a joint main body having a pair of substantially parallel side walls and at least one curved wall which connects together the end edges of both side walls, together and a wedge inserted into wedge bores which are respectively provided in the side walls in such a manner so as to be aligned with each other. The end portion of each of the reinforcing bars which are to be connected together are set in such a manner so as to contact the inside of the curved wall, and the wedge is press-fitted into the wedge bores. Thus the end portion of each reinforcing bar is clamped and thereby rigidly secured between the wedge and the curved wall. The curved portion is formed so as to have a substantially V-shaped inner wall surface including a pair of slanting surfaces. Thus, the end portion of each of the reinforcing bars which is pressed by the wedge is pressed against the pair of slanting surfaces and allowed to bite into the area defined therebetween.