Abstract: A system and method for inducing flow of a dense gas through a fluid circuit without the use of a compressor or other pumping means. A heat absorption chamber has an outlet in fluid communication with the inlet of a heat rejection chamber and has an inlet in fluid communication with an outlet from the heat rejection chamber. Thermal energy absorbed by the dense gas in the heat absorption chamber causes the density of the dense gas to decrease sufficiently to cause the dense gas to flow to the heat rejection chamber. After heat energy is subsequently rejected from the heated dense gas, its density increases, and gravitational or radial acceleration forces acting thereupon induce the cooled, dense gas to flow to the heat absorption chamber displacing the dense gas therewithin. The fluid flow system of the present invention may be used for heat transfer or may be applied to processes such as solvent extraction, reduction of particle size, and oxidation of organic materials employing supercritical water.

Abstract: Inexpensive process is provided for the application of substantially uniform metal oxide coatings onto continuous multi-filament refractory fiber tows. The resulting coated refractory fiber tows are useful, for example, for the preparation of refractory fiber composites having excellent physical and mechanical properties. Composites can be prepared employing a ceramic, metal or glass matrix.

Abstract: Refractory filaments in the form of a multifilament tow or fabrics woven therefrom are coated with protective oxide coatings to provide reinforcing materials that are useful in creating refractory composites. The refractory filaments are contacted with a liquid medium which contains a metal oxide or metal oxide precursor so that a substantially continuous coating of metal oxide or metal oxide precursor forms on the surface of each of the filaments. The filaments are then treated to substantially remove residual components of the liquid medium other than the metal oxide or metal oxide precursor. The coated filaments are stabilized, the above steps optionally are repeated to increase the coating thickness, and the coated filaments are heated to convert the metal oxide or metal oxide precursor into substantially continuous, uniform metal oxide coatings on the filaments.