Abstract: Metal catalyst particles are deposited on carbon nanotubes by preparing a silane solution of a metal catalyst salt, e.g. platinum or ruthenium chloride, immersing an electrically conducting substrate carrying nanotubes in the silane solution to yield a composite structure of substrate, nanotubes and catalyst, and reducing the composite structure to yield a composite of substrate, carbon nanotubes and metallic catalyst particles.

Abstract: A venturi section or cone for a lightweight firearm such as a recoilles gun which is subjected to high transient pressures and temperatures on firing is formed from a resin impregnated multi-filament fiber material. The material in the form of an elongated tow is wound on a mandrel, cured, and then removed from the mandrel for subsequent operations such as machining or assembly. During manufacture, a hot gas erosion preventing layer is first formed on the mandrel and a plurality of layers of two are helically wound thereon at a helix angle selected to provide adequate axial and hoop strengths for resisting axial thrust and hoop loads produced on firing. Lightweight recoilless guns using such venturi cones are lighter and cheaper to fabricate than conventional guns and will fire more rounds before excessive erosion causes them to be unusable.