Internally replenished gas-containing enclosures are described. Such enclosures include a replenishing gas source internal to the enclosure, wherein the gas source comprises a gas contained within a permeable membrane. Exemplary gas sources include a plurality of bubbles and pouches. Materials useful...http://www.google.es/patents/US7538972?utm_source=gb-gplus-sharePatente US7538972 - Internally replenished enclosure
