Abstract: According to one embodiment, a magnesium-recycling hydrogen generation system includes: a by-product acquisition unit that separates a by-product from a post-reaction solution, which is a solution after reacting with a hydrogen generation material containing a hydrogen-containing magnesium compound that generates hydrogen via a reaction with the solution, to acquire the by-product including more than one type of oxygen-containing magnesium compound that contains oxygen produced by the reaction, a raw material production unit that reacts the by-product with a halogen-containing substance containing halogen and other atoms than the halogen to produce a raw material containing magnesium halide, a hydrogen generation material production unit that reduces the raw material with plasma containing hydrogen to produce the hydrogen generation material, and a hydrogen generator that reacts the hydrogen generation material with the solution to generate hydrogen.

Abstract: According to one embodiment, a magnesium-recycling hydrogen generation system includes: a by-product acquisition unit that separates a by-product from a post-reaction solution, which is a solution after reacting with a hydrogen generation material containing a hydrogen-containing magnesium compound that generates hydrogen via a reaction with the solution, to acquire the by-product including more than one type of oxygen-containing magnesium compound that contains oxygen produced by the reaction, a raw material production unit that reacts the by-product with a halogen-containing substance containing halogen and other atoms than the halogen to produce a raw material containing magnesium halide, a hydrogen generation material production unit that reduces the raw material with plasma containing hydrogen to produce the hydrogen generation material, and a hydrogen generator that reacts the hydrogen generation material with the solution to generate hydrogen.

Abstract: A projector 1 has a first casing 1A (including a first part 2 and a second part 3) and a second casing 1B (including a third part 4). The second casing 1B is moved between an enlarging position where the second casing 1B is protruded from the first casing 1A and a reducing position where the second casing 1B is retracted into the first casing 1A. As the second casing 1B moves to the enlarging position, the distance between the exhaust ports 45 and the exhaust fan 9 increases, so that the wind noise is restricted. As the second casing 1B moves to the reducing position, the exhaust ports 45 are concealed in the first casing 1A, so that the entry of the dust or the like into the projector 1 is prevented.

Abstract: A projector 1 has a first casing 1A (including a first part 2 and a second part 3) and a second casing 1B (including a third part 4). The second casing 1B is moved between an enlarging position where the second casing 1B is protruded from the first casing 1A and a reducing position where the second casing 1B is retracted into the first casing 1A. As the second casing 1B moves to the enlarging position, the distance between the exhaust ports 45 and the exhaust fan 9 increases, so that the wind noise is restricted. As the second casing 1B moves to the reducing position, the exhaust ports 45 are concealed in the first casing 1A, so that the entry of the dust or the like into the projector 1 is prevented.