gravity heating
41Autonomous building — An autonomous building is a building designed to be operated independently from infrastructural support services such as the electric power grid, municipal water systems, sewage treatment systems, storm drains, communication services, and in some …
42Petroleum — For other uses, see Petroleum (disambiguation). Proven world oil reserves, 2009 …
43Colonization of Mars — An artist s conception of the colonization of Mars, with a cutaway showing part of the interior The colonization of Mars by humans is the focus of speculation and serious study because the surface conditions and availability of water on Mars make …
44Heat exchanger — An interchangeable plate heat exchanger Tubular heat exchan …
45Heat pipe — A heat pipe is a heat transfer mechanism that can transport large quantities of heat with a very small difference in temperature between the hotter and colder interfaces. Inside a heat pipe, at the hot interface a fluid turns to vapour and the… …
46metallurgy — metallurgic, metallurgical, adj. metallurgically, adv. metallurgist /met l err jist/ or, esp. Brit., /meuh tal euhr jist/, n. /met l err jee/ or, esp. Brit., /meuh tal euhr jee/, n. 1. the technique or science of working or heating metals so as… …
47continental landform — ▪ geology Introduction any conspicuous topographic feature on the largest land areas of the Earth. Familiar examples are mountains (including volcanic (volcanism) cones), plateaus, and valleys. (The term landform also can be applied to… …
48Ganymede (moon) — Ganymede Image of Ganymede s anti Jovian hemisphere taken by the Galileo probe. Lighter surfaces, such as in recent impacts, grooved terrain and the whitish north polar cap at upper right, are enriched in water ice. Discovery …
49Mammatus cloud — Mammatus clouds in San Antonio, Texas, 2009 Appearance The cloud appears to have smooth, round puffs hanging from its underside …
50Glossary of fuel cell terms — The Glossary of fuel cell terms lists the definitions of many terms used within the fuel cell industry. The terms in this glossary may be used by fuel cell industry associations, in education material and fuel cell codes and standards to name but …
