Abstract: A metal ring made of maraging steel is heated in the presence of a halogen compound gas, so as to eliminate an oxide film from the surface of the metal ring and to form a halogenous compound film. Thereafter, the metal ring is heated under a vacuum or reduced pressure atmosphere to eliminate the halogenous compound film, and then it is maintained under an atmosphere comprising ammonia at a processing temperature ranging between 450° C. and 500° C. for a processing time ranging between 30 and 120 minutes, so as to carry out a nitriding processing. The above nitriding processing comprises the steps of: placing the above metal ring into a heating furnace and raising the temperature inside the heating furnace to the above processing temperature; introducing a first mixed gas consisting of 50% to 90% ammonia byvolume, 0.1% to 0.

Abstract: A mixture of water and glass beads is ejected to a root of a gear which has been cut to form gear teeth. The glass beads are oriented so as to be ejected to the root, and the glass beads and the water impart compressive stresses to the surface of the root and grind the surface of the root.

Abstract: Hydrogen isotope is separated and recovered with remarkable reduction in energy consumption in a compact apparatus using a cold reactor and a hot reactor based on dual temperature process by a combination of a first step of at least one isotope exchange reaction stage comprising contacting mists of a feed liquid cocurrently together with a reacting gas with an isotope exchange reaction catalyst at a low temperature, and a second step of a plurality of stages each comprising a gas-liquid contact of the liquid from the first step with vapor of the liquid and the reacting gas and an isotope exchange reaction between the vapor of the liquid and the reacting gas at a high temperature.

Abstract: An apparatus for isotope exchange reaction is used in an apparatus for removing tritium in heavy water-moderated nuclear reactors or heavy water production plants, and comprises a plurality of mist generators and a plurality of reactor columns, the mist generators and the reactor columns being alternately arranged and connected to one another successively in the alternate order. An ultra-sonic generator is provided each in the mist generators. A hydrophobic catalyst bed and a mist separator are provided each in the reactor columns. Water containing hydrogen isotopes to be removed is led into the mist generators to form mists. Mists of the water are supplied into the reactor columns together with hydrogen gas and isotope exchange reaction is carried out in the hydrophobic catalyst beds.

Abstract: Disclosed is a holder for a roll of sheet material, having a pair of support levers rotatable only in one vertical plane pivotally attached in the forward portions of lateral walls projecting from the opposed ends of a rear wall and normally protruding inwardly toward each other. When said roll of sheet material is pushed upwardly in the holder from below said pair of support levers, said pair of support levers are brought into contact with the corners of the roll and are consequently rotated divergently. They presently ride over the corners of the roll and begin to slide over the lateral sides of the roll. When the forward tips of the support levers reach the open ends of the tubular core at the center of the roll, said pair of support levers return to their horizontal position, with the result that the roll will be set stably in position in the holder.