Abstract: An object is to change reactor core thermal output. A nuclear reactor includes an annular fuel layer and a heat conductive layer stacked on the fuel layer and extending around a periphery of the fuel layer.

Abstract: An object is to efficiently take heat out of a reactor core while retaining fission products. Included are fuel part provided with a covering part on a surface of a nuclear fuel and a heat conductive part.

Abstract: Provided is a nuclear reactor unit that can reduce a temperature increase in a reactor core at the occurrence of an abnormality with a simple structure. Included are a reactor core having radioactive fuel and causing the radioactive fuel to cause a nuclear reaction and a nuclear reactor vessel housing the reactor core and hermetically sealing the reactor core. The nuclear reactor vessel includes an inner shroud covering the entire periphery of the reactor core and an outer shroud covering the entire periphery of the inner shroud. A first space formed by the outer shroud and the inner shroud is in a vacuum condition. The inner shroud includes a main body and a communicating part placed in part of the main body and communicating the first space to a second space, which is a space inside the inner shroud, when the reactor core reaches a threshold temperature or higher.

Abstract: A fluid machine includes: a shaft portion; a shroud surrounding the shaft portion and including an inside surface that forms a flow path-forming surface defining a flow path with the shaft portion; a first propeller rotatably provided in the flow path; a second propeller rotatably provided on a downstream side of the first propeller in the flow path; and a motor including a rotor that is fixed to an outer circumferential portion of the second propeller and that is accommodated in the shroud, and a stator that surrounds the rotor via a clearance and that is fixed in the shroud. A portion of the flow path-forming surface on a downstream side of the second propeller decreases in diameter toward the downstream side, and the shroud includes an inlet flow path that is open at a portion between the first propeller and the second propeller of the flow path-forming surface.

Abstract: Heat can be stably extracted with easy criticality control. A nuclear reactor includes: a fuel portion being a reactor core having a nuclear fuel body; a shielding portion covering all over outer sides of the fuel portion to shield against radiations generated from the reactor core; and a thermal conduction part that conducts heat generated in the reactor core to exterior of the shield part. The nuclear fuel body contains a fissile material with an enrichment not less than 5% by weight throughout an operation period.

Abstract: An outer surface of a part of an airframe includes a mixed region in which a first color similar to a color applied to an adjacent region and a second color having a lower absorption rate of sunlight than the first color are mixed in a predetermined color distribution pattern. A reflective material that contributes to an increase in a reflection rate of sunlight is added to a part to which at least the first color is applied in the mixed region.

Abstract: A fluid machine includes: a shaft portion; a shroud surrounding the shaft portion and including an inside surface that forms a flow path-forming surface defining a flow path with the shaft portion; a first propeller rotatably provided in the flow path; a second propeller rotatably provided on a downstream side of the first propeller in the flow path; and a motor including a rotor that is fixed to an outer circumferential portion of the second propeller and that is accommodated in the shroud, and a stator that surrounds the rotor via a clearance and that is fixed in the shroud. A portion of the flow path-forming surface on a downstream side of the second propeller decreases in diameter toward the downstream side, and the shroud includes an inlet flow path that is open at a portion between the first propeller and the second propeller of the flow path-forming surface.

Abstract: Ensuring a high output temperature while preventing leakage of radioactive substances, etc. A nuclear reactor includes a fuel unit; a shield unit that covers a circumference of the fuel unit for shielding from radioactive rays; and a heat conductive portion that penetrates the shield unit, is arranged such that the heat conductive portion extends to inside of the fuel unit and outside of the shield unit, and transfers heat of the fuel unit to the outside of the shield unit by solid heat conduction.

Abstract: Temperature of a structural member is maintained at allowable temperature or less by suppressing heat transfer from a high-temperature duct to the structural member. An insertion sheet according to the present invention is inserted between a flange and a partition panel. The flange is provided on a bleed duct and is fastened to the partition panel. The bleed duct penetrates through a partition wall of an aircraft. The insertion sheet includes first parts and a second part. The first parts are disposed near respective shafts of rivets provided at a plurality of positions of the insertion sheet. The second part extends among the first parts. The first parts bear a load of fastening, and the second part has thermal conductivity lower than thermal conductivity of the first parts.

Abstract: Temperature of a structural member is maintained at allowable temperature or less by suppressing heat transfer from a high-temperature duct to the structural member. An insertion sheet according to the present invention is inserted between a flange and a partition panel. The flange is provided on a bleed duct and is fastened to the partition panel. The bleed duct penetrates through a partition wall of an aircraft. The insertion sheet includes first parts and a second part. The first parts are disposed near respective shafts of rivets provided at a plurality of positions of the insertion sheet. The second part extends among the first parts. The first parts bear a load of fastening, and the second part has thermal conductivity lower than thermal conductivity of the first parts.