Abstract: In the hydrogen remaining sensor of the present invention, the hydrogen remaining sensor is arranged in a space in which the hydrogen is absorbed/released by the main hydrogen storage alloy, and is equipped with the vessel-like sensor main body in which the sensor hydrogen storage alloy is filled and through which the hydrogen is moved. Also, the easy-to-deform portion in which the strain is caused easily due to the hydrogen absorption/release of the sensor hydrogen storage alloy is provided to a part of the sensor main body, and the strain gauge for measuring the strain of the easy-to-deform portion is provided. As a result, according to the hydrogen remaining sensor of the present invention can contribute to sense precisely a remaining amount of hydrogen in the main hydrogen storage alloy.

Abstract: In the hydrogen remaining sensor of the present invention, the hydrogen remaining sensor is arranged in a space in which the hydrogen is absorbed/released by the main hydrogen storage alloy, and is equipped with the vessel-like sensor main body in which the sensor hydrogen storage alloy is filled and through which the hydrogen is moved. Also, the easy-to-deform portion in which the strain is caused easily due to the hydrogen absorption/release of the sensor hydrogen storage alloy is provided to a part of the sensor main body, and the strain gauge for measuring the strain of the easy-to-deform portion is provided. As a result, according to the hydrogen remaining sensor of the present invention can contribute to sense precisely a remaining amount of hydrogen in the main hydrogen storage alloy.

Abstract: A heat exchange apparatus comprises a heat exchanging portion being disposed so as to surround the outer peripheral surface of a columnar or cylindrical heat exchange target, wherein the heat exchanging portion comprises therein a hollow space for passing heat medium therethrough and is so flexible as to expand toward at least the inner peripheral side by pressure of the heat medium. Heat medium is fed to the heat exchanging portion by a pump. By introducing the heat medium into the heat exchanging portion, the heat exchanging portion expands toward the inner peripheral side, and an inner surface of the heat exchanging portion close contacts with the outer peripheral surface of the heat exchange target, thereby greatly enhancing the heat transfer efficiency. When using a hydrogen storage/discharge container in which hydrogen storage alloy is accommodated as the heat exchange target, hydrogen storage or discharge can be efficiently carried out.

Abstract: In a heat transfer pipe, annular grooves in a direction inclined at an angle of 45° to 90° with respect to an axis of the pipe are continuously formed at an interval in a longitudinal direction of the pipe. The annular grooves desirably have a groove depth of 0.20 mm or more, and a groove pitch of two to five times larger than the groove depth. Moreover, a ratio W/P of a bottom width W of projections of the grooves to the groove pitch P is desirably 0.1 to 0.9.

Abstract: In a heat transfer pipe, annular grooves in a direction inclined at an angle of 45° to 90° with respect to an axis of the pipe are continuously formed at an interval in a longitudinal direction of the pipe. The annular grooves desirably have a groove depth of 0.20 mm or more, and a groove pitch of two to five times larger than the groove depth. Moreover, a ratio W/P of a bottom width W of projections of the grooves to the groove pitch P is desirably 0.1 to 0.9.

Abstract: The present invention relates to a process for producing sinters, including a steps of mixing a powder material with a binder, injection molding the mixture, and then dewaxing and sintering the resulting injection molded article, wherein the binder comprises at least one of: copolymer, a mixture of copolymer, paraffine wax, carnauba wax, a mixture of the paraffine wax and the carnauba wax, a plasticizer, and a lubricant. According to the present invention, the dewaxing step comprises heating the injection molded article to a temperature of 250.degree.-500.degree. C. in a heating rate of 5.degree.-100.degree. C./hour under the pressure not higher than 1 Torr in order to remove 40%-95 % by weight of the binder components. Further, the temperature elevation in the sintering step is started in a vacuum atmosphere and replacing the atmosphere with an inert gas atmosphere in the process of temperature elevation.