title: Potential applications of differential permeability membranes in the control of gas composition in closed circuit atmospheres.
abstract: Long hyperbaric exposures of humans, at pressures in excess of 2.5 atmospheres, require that the oxygen concentration of the breathing gas be maintained at levels less than atmospheric air, in order to prevent pulmonary oxygen toxicity. Carbon dioxide produced by humans must be removed from the breathing gas of closed environments. Differential permeability gas separation devices can be used to reduce the concentrations of carbon dioxide and oxygen in recirculating nitrogen/oxygen atmospheres. The application of these devices can eliminate the requirement for nitrogen to dilute oxygen, and reduce, or eliminate, the requirement for carbon dioxide absorbents. The use of differential permeability gas separation devices for the production of nitrogen/oxygen breathing gas mixtures for divers, using air as a source gas, can produce mixtures with unacceptably high levels of carbon dioxide.
authors.affiliation: Undersea Research Foundation, Box 696, North, VA, 23128, USA. morgan@vims.edu
authors.forename: J M
authors.initials: JM
authors.lastname: Wells
mesh_terms: D000389:Air Conditioning / Q000295:instrumentation*; D001273:Atmosphere Exposure Chambers; D001274:Atmospheric Pressure; D002245:Carbon Dioxide / Q000009:adverse effects / Q000737:chemistry / Q000378:metabolism; D004242:Diving; D018504:Ecological Systems, Closed; D006801:Humans; D006931:Hyperbaric Oxygenation; D008021:Life Support Systems / Q000295:instrumentation*; D008567:Membranes, Artificial; D009584:Nitrogen / Q000737:chemistry / Q000378:metabolism; D010100:Oxygen / Q000009:adverse effects / Q000737:chemistry / Q000378:metabolism; D010539:Permeability
chemical_list: D008567:Membranes, Artificial; D002245:Carbon Dioxide; C041364:nitrox; D009584:Nitrogen; D010100:Oxygen