A pulse tube refrigeration system (21) wherein the pulse tube working gas is cooled to a defined first stage temperature and is brought to a defined second stage temperature by operation of a regenerator (33) and pulse tube (34), which are in flow communic...

Oxygen and hydrogen transport membranes fabricated by plasma spray deposition of a micro-crack-free coating on a substrate. Also disclosed is a multi-layer composite comprising a dense or porous substrate coated with a coating provided by supersonic plasma...