Abstract: According to one embodiment, provided is an active material including a niobium titanium-containing oxide phase and a carbon coating layer. The niobium titanium-containing oxide phase contains a niobium titanium-containing oxide having a monoclinic structure and Na, and a Na content therein is 0 ppm or more and 100 ppm or less. The carbon coating layer coats at least a part of the niobium titanium-containing oxide phase, and contains 0.001% or more of carboxyl group.

Abstract: In general, according to one embodiment, a recycling method is provided. The method includes dispersing an electrode containing a niobium titanium oxide in water; separating the niobium titanium oxide from the electrode dispersed in the water; and applying a first heat treatment to the separated niobium titanium oxide.

Abstract: A method for bonding oxide ceramics and metals which comprises the steps of depositing, on an oxide ceramic material, a composite insert material consisting of a mixture of at least one oxide selected from the group consisting of Cu.sub.2 O, NiO, SiO.sub.2, FeO, AgO, Al.sub.2 O.sub.3, MoO, TiO.sub.2, ZnO, AuO, Cr.sub.2 O.sub.3, CoO, ZrO.sub.2, TaO, WO.sub.2, NbO, MgO, CaO and Y.sub.2 O.sub.3, and at least one metal selected from the group consisting of Cu, Ni, Si, Fe, Ag, Al, Mo, Ti, Zn, Au, Cr, Co, Zr, Ta, W, Nb and Mg by ion plating or spray coating, subjecting the deposited insert material to thermal reaction-promoting treatment to permit metallurgical bond between the composite insert material and the ceramic material, and bonding a metal member to the surface of the insert material by diffusion welding or brazing.

Abstract: A method for assembling narrow gap members by welding is described. In the method, separate narrow gap members having spaces therein when assembled are provided and a deformation-preventive material consisting of a water-soluble material or a material capable of being disintegrated with water is filled in each space and is formed with a through groove or hole in the filled preventive material. In this state, the separate narrow gap members are subjected to welding, and immersed in water to remove the deformation-preventive material from each space. The through grooves may have a width larger than a leg length of each penetration bead, in which a heat-resistant flux is filled in each groove. The deformation-preventive material may be covered with a heat-resistant ceramic backing member shaped in a specific form or with a heat-resistant particle layer and a copper member shaped in conformity with an intended size and shape of a penetration bead.

Abstract: A T-jointing weld beveling for welding a plate member to a rib-like member having a varying thickness in a T-shaped manner is improved in that a beveling width changes in accordance with the thickness of the rib-like member and the edges of the beveled portion are wave-shaped so as to form intermittent gap space portions between the rib-like member and said edges, whereby uniform penetration beads can be formed, the welding can be achieved with a small electric current over the entire length of the rib-like member, and control of a welding condition can be facilitated.

Abstract: A method for bonding Si.sub.3 N.sub.4 or SiC ceramics with metals which comprises the steps of depositing, on the ceramic material, an insert material consisting of a mixture of at least one metal selected from the group consisting of Ni and Cu and at least one member selected from the group consisting of metal oxides, nitrides and carbides by ion plating or spary coating, subjecting the deposited insert material to thermal reaction treatment to permit metallurgical bond between the insert material and the ceramic material, and bonding a metal member to the surface of the insert material by brazing with a brazing material whose melting point is lower than the insert material or by diffusion welding at a temperature lower than a melting point of the insert material.

Abstract: Being a heat pipe heat exchanger wherein a group of heat pipes are arranged in box form and the central part thereof is partitioned, a high temperature fluid being let to flow into one and a low temperature fluid into the other one, respectively, so that, by the specific properties of the heat pipes, the heat given from the high temperature fluid is transferred to the low temperature fluid through the sealed-in fluid in the heat pipes, a plurality of heat pipes of which those on at least the high temperature fluid passage side are bare pipes are arranged to extend over both passages, and the heat pipes on the high temperature fluid passage side are inserted in finless outer pipes. At least the outer surface of these finless outer pipes is treated for resistance to corrosion. Also, these finless outer pipes and the heat pipes are joined by a heat conductive material, so that heat pipes can be easily demounted, and, therefore, the efficiency of the heat exchanger can be varied as required.

Abstract: During arc welding, optical radiation emitted from an arc is detected by means of a photoelectric device, and an electric detection signal from the photoelectric device is used for controlling the travel of a suction hood along a weld line so that the weld fumes may be exhausted through the suction hood and to insure that the weld metal zone is always covered by the suction hood.

Abstract: A process for the diffusion welding of copper and stainless steel, which comprises sandwiching a thin layer of at least one metal selected from the group consisting of Ni, Ni-base alloys, Cr, Ni-Cr, and Cr-Ni with little gas contents, as an insert metal, between the surfaces of copper and stainless steel to be bonded, and then diffusion welding the sandwich.