Abstract: A sailboat having a triangular frame formed of three beams forming the sides of that frame and three pontoons or hulls disposed at the vertices of the triangle and extending outward from one side of the plane of the triangle. A mast extends outward from the other side of the plane and is connected to the vertices by cables to form a tetrahedral-type space frame which is structurally sound and easily dismantled.

Abstract: A solar cell with improved energy conversion characteristics is formed from ordinary Czochralski or other types of silicon crystals that are sliced parallel to the growth axis or pulling direction. The slices are heat treated at a sufficiently high temperature and for a sufficiently long period of time to activate oxygen donor states in the slices. The heat treatment is of sufficient duration that at periodic maxima of oxygen concentration in the crystal it produces n-type regions where a background p-type dopant is overcompensated. Each n-type region thus formed is adjacent to a p-type region with a p-n junction therebetween. Collector contacts are applied at the faces of the slices to permit collection of carriers.