air-breathing power unit
51Positive airway pressure — A typical CPAP machine houses the air pump in a case lined with sound absorbing material for quieter operation. A hose carries the pressurized air to a face mask or nasal pillow …
52Diving regulator — and Octopus Other names Demand valve Uses Reduces pressurized breathing gas to ambient pressure and delivers it to the diver Inventor Manuel Théodore Guillaumet (1838), Benoît Rouquayrol (1860) …
53Mir — This article is about the Soviet/Russian space station. For other uses, see Mir (disambiguation). Mir …
54France — /frans, frahns/; Fr. /frddahonns/, n. 1. Anatole /ann nann tawl /, (Jacques Anatole Thibault), 1844 1924, French novelist and essayist: Nobel prize 1921. 2. a republic in W Europe. 58,470,421; 212,736 sq. mi. (550,985 sq. km). Cap.: Paris. 3.… …
55List of Doctor Who universe creatures and aliens — This is a list of fictional creatures and aliens from the universe of the long running BBC science fiction television series Doctor Who, including Torchwood, The Sarah Jane Adventures and K 9. It covers alien races and other fictional creatures,… …
56International Space Station — ISS redirects here. For other uses, see ISS (disambiguation). International Space Station …
57Oxygen toxicity — Classification and external resources In 1942–43 the UK Government carried out extensive testing for oxygen toxicity in divers. The chamber is pressurised with air to 3.7  …
58Diving watch — Omega Seamaster model 2220.80, with a water resistance of 300 m (1,000 ft). The second crown (at 10 o clock) is a helium release valve. A diving watch is a watch designed for underwater diving that features, as a minimum, a water… …
59Nitrous oxide — N2O redirects here. For other uses, see N2O (disambiguation). Laughing gas redirects here. For other uses, see Laughing gas (disambiguation). Not to be confused with nitric oxide (formula NO) or nitrogen dioxide (formula NO2). For other uses, see …
60international relations — a branch of political science dealing with the relations between nations. [1970 75] * * * Study of the relations of states with each other and with international organizations and certain subnational entities (e.g., bureaucracies and political… …
