Abstract: A plurality of thin flexible sheet ribs are secured to thin flexible sheet stringer members to form a distortable frame structure. One edge of the ribs lie in a curved surface such as a parabolic cylindrical surface. A thin sheet of boron-silicate glass, preferably formed with a second surface mirror, is annealed and then bent at room temperature to abut the edges of the ribs lying in the curved surface and is retained in place by ribs at opposite edges of the sheet. The inherent strength of the glass under stress, when bent, provides structural rigidity to the combined elements.

Abstract: An apparatus for effectively making the supply of material slurry at a high pressure into a high-pressure liquefaction reaction vessel and relief of the pressure of the high-pressure product slurry to permit the discharge of the product slurry as a low-pressure slurry. At least one cylinder having a float therein is used. The material slurry is charged at a low pressure into the cylinder from one end of the latter. Then, the high-pressure product slurry after the reaction is charged from the other end of this cylinder or another cylinder so that the material slurry is pressurized and forcibly supplied to the reaction vessel by the high pressure possessed by the high-pressure product slurry.

Abstract: An n-type TiO.sub.2 semiconductor anode for a water photolysis cell having one or more grooves exhibits increased oxygen evolution and greater photocurrent with minimal photon reflection losses.

Abstract: A nickel cathode has a nickel oxide layer on its surfaces. A plurality of spaced apart grooves are in the nickel oxide layer and extend into the nickel. The cathode can be utilized in a water photolysis apparatus which also includes an N type photocatalytic semiconductor anode. Both the cathode and anode are in an aqueous basic electrolyte solution. The anode and cathode are electrically biased by a solar cell. The biasing potential of the solar cell raises the voltage potential of the cathode and lowers the Fermi level of the anode.