Abstract: There is provided a solar collector comprising a straight tubular metal heat pipe having an evaporator section and a condenser section. Two elongate metal absorber plates are longitudinally connected to the evaporator section and are bent in an outwardly extending X-shape with respect thereto. The absorber plates are in thermally conductive contact with the evaporator section.

Abstract: There is provided a solar collector comprising a solar heat absorber plate thermally conductively connected to the evaporator section of a metal heat pipe. The absorber plate and the evaporator section are surrounded by an evacuated glass envelope joined to the heat pipe at the open end of the evaporator section by a glass-metal seal. The condenser section of the heat pipe is spaced from the evaporator section and is formed for installation in a heat transport system. A flexible portion joins the respective open ends of the evaporator section and the condenser section, such flexible portion having an outer diameter smaller than the inner diameter of the evaporator section and that of the condenser section. The moment of resistance of this flexible portion is smaller than the moment that can be withstood by the glass-metal seal.

Abstract: A solar collector is made from a straight tubular metal heat pipe having an evaporator section and a condenser section and two elongate flat solar-heat metal absorber plates. A plurality of equally spaced parallel cuts is formed in each plate, with the cuts extending transversely of the longitudinal direction of each plate. The two plates are disposed one on the other with their respective parallel cuts in alignment; and alternate portions between consecutive cuts are deformed in opposite directions to provide alternate oppositely disposed semi-cylindrical portions. The evaporator section of the heat pipe is inserted into the resulting cylindrical space; and the semi-cylindrical portions are mechanically pressed against the evaporator section. The two plates are then bent away from each other into an outwardly extending X-shape.

Abstract: Bonding a metal part having a copper surface to glass, in particular a semiconductor device. A small quantity of Cr.sub.2 O.sub.3 or CuO is added to the glass. The copper is oxidized at a relatively low temperature and relatively low oxygen pressure and thereafter sealing-in is performed in a nonoxidizing atmosphere.