surface enrichment
1Depletion gilding — is a method for producing a layer of nearly pure gold on an object made of gold alloy by removing the other metals from its surface. It is sometimes referred to as a surface enrichment process.[1] Contents 1 Process 2 Variations 3 …
2African architecture — Introduction the architecture of native Africa, particularly of sub Saharan Africa. In areas where Islam and Christianity linked Africa to the rest of the world in precolonial times, architecture predominates among the visual arts. Included …
3Iran and weapons of mass destruction — This article is about Iran and weapons of mass destruction. For Iran s nuclear power program, see Nuclear program of Iran. Weapons of mass destruction …
4United States — a republic in the N Western Hemisphere comprising 48 conterminous states, the District of Columbia, and Alaska in North America, and Hawaii in the N Pacific. 267,954,767; conterminous United States, 3,022,387 sq. mi. (7,827,982 sq. km); with… …
5Sediment Profile Imagery — (SPI) is an underwater technique for photographing the interface between the seabed and the overlying water. The technique is used to measure or estimate biological, chemical, and physical processes occurring in the first few centimetres of… …
6nuclear reactor — Physics. reactor (def. 4). Also called nuclear pile. [1940 45] * * * Device that can initiate and control a self sustaining series of nuclear fission reactions. Neutrons released in one fission reaction may strike other heavy nuclei, causing them …
7nuclear weapon — an explosive device whose destructive potential derives from the release of energy that accompanies the splitting or combining of atomic nuclei. [1945 50] * * * or atomic weapon or thermonuclear weapon Bomb or other warhead that derives its force …
8mineral deposit — Introduction aggregate of a mineral in an unusually high concentration. About half of the known chemical elements (chemical element) possess some metallic (metal) properties. The term metal, however, is reserved for those chemical… …
9Chemical biology — is a scientific discipline spanning the fields of chemistry and biology that involves the application of chemical techniques and tools, often compounds produced through synthetic chemistry, to the study and manipulation of biological systems.… …
10Iran — /i ran , i rahn , uy ran /, n. a republic in SW Asia. 67,540,002; ab. 635,000 sq. mi. (1,644,650 sq. km). Cap.: Teheran. Formerly (until 1935), Persia. * * * Iran Introduction Iran Background: Known as Persia until 1935, Iran became an Islamic… …
