5/14/01 Paul Simms is holding a unit from the vapor filtration system invented by Frank Rickey and himself for the purpose of separating water from the dissolved solids therein. The vapor filtration technique was patented by Purdue University, and was the key development allowing the analysis of trace elements in drinking water by particle-induced x-ray emission. This capability led to a multi-year contract with the US EPA which supported the Van de Graaff laboratory for years.