Argon — This article pertains to the chemical element. For other uses, see Argon (disambiguation). Argon (pronEng|ˈɑrgɒn) is a chemical element designated by the symbol Ar. Argon has atomic number 18 and is the third element in group 18 of the periodic… … Wikipedia
natural gas — a combustible mixture of gaseous hydrocarbons that accumulates in porous sedimentary rocks, esp. those yielding petroleum, consisting usually of over 80 percent methane together with minor amounts of ethane, propane, butane, nitrogen, and,… … Universalium
dating — I In geology and archaeology, the process of determining an object s or event s place within a chronological scheme. Scientists may use either relative dating, in which items are sequenced on the basis of stratigraphic clues (see stratigraphy) or … Universalium
Mathematics and Physical Sciences — ▪ 2003 Introduction Mathematics Mathematics in 2002 was marked by two discoveries in number theory. The first may have practical implications; the second satisfied a 150 year old curiosity. Computer scientist Manindra Agrawal of the… … Universalium
Gaseous fire suppression — Canisters containing argon gas for use in extinguishing fire in a server room without damaging equipment. Gaseous fire suppression is a term to describe the use of inert gases and chemical agents to extinguish a fire. Also called Clean Agent Fire … Wikipedia
Earth Sciences — ▪ 2009 Introduction Geology and Geochemistry The theme of the 33rd International Geological Congress, which was held in Norway in August 2008, was “Earth System Science: Foundation for Sustainable Development.” It was attended by nearly… … Universalium
steel — steellike, adj. /steel/, n. 1. any of various modified forms of iron, artificially produced, having a carbon content less than that of pig iron and more than that of wrought iron, and having qualities of hardness, elasticity, and strength varying … Universalium
List of characters in Artemis Fowl — This is a list of characters in the Artemis Fowl novel series by Eoin Colfer. Contents: Top · 0–9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z … Wikipedia
Atmosphere of Earth — Air redirects here. For other uses, see Air (disambiguation). Qualities of air redirects here. It is not to be confused with Air quality … Wikipedia
Mars — /mahrz/, n. 1. the ancient Roman god of war and agriculture, identified with the Greek god Ares. 2. Astron. the planet fourth in order from the sun, having a diameter of 4222 miles (6794 km), a mean distance from the sun of 141.6 million miles… … Universalium
welding — Technique for joining metallic parts, usually through the application of heat. Discovered in the 1st millennium AD during attempts to manipulate iron into useful shapes, the technique produced a strong, tough blade. Welding traditionally involved … Universalium