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Space Force, United States

(Encyclopedia)Space Force, United States (USSF), military force that forms a separate service within the U.S. Dept. of the Air Force, est. Dec. 20, 2019, by act of Congress. The head of the Space Force is the Chief...

polymerase chain reaction

(Encyclopedia)polymerase chain reaction pŏlˈĭmərāsˌ [key] (PCR), laboratory process in which a particular DNA segment from a mixture of DNA chains is rapidly replicated, producing a large, readily analyzed sa...

tungsten

(Encyclopedia)tungsten tŭngˈstən [key] [Swed.,=heavy stone], metallic chemical element; symbol W; at. no. 74; at. wt. 183.84; m.p. about 3,410℃; b.p. 5,660℃; sp. gr. 19.3 at 20℃; valence +2, +3, +4, +5, or...

aspartic acid

(Encyclopedia)CE5 aspartic acid əspärˈtĭk [key], organic compound, one of the 20 amino acids commonly found in animal proteins. Only the l-stereoisomer participates in the biosynthesis of proteins. Its acidi...

anhydride

(Encyclopedia)anhydride ănhīˈdrīd, –drĭd [key] [Gr.,=without water], chemical compound formed by removing water, H2O, from another compound; the anhydride can also react with water to form the original compo...

shoring

(Encyclopedia)shoring, placing of props or braces, called shores, against or beneath a structure for support. Shoring is often used to stabilize a building when it is to undergo structural modification or repair. C...

borer

(Encyclopedia)borer, name applied to various animals that are injurious because of their ability to penetrate plant or animal tissues. Among insects, some borers are beetles, e.g., the flatheaded apple-tree borer, ...

albumin

(Encyclopedia)albumin ălbyo͞oˈmən [key] [Lat.,=white of egg], member of a class of water-soluble, heat-coagulating proteins. Albumins are widely distributed in plant and animal tissues, e.g., ovalbumin of egg, ...

fonio

(Encyclopedia)fonio, annual plant, genus Digitaria, of the grass family (Poaceoe). Native to Senegal, it is a type of millet grown as a staple grain throughout the Sahel region of West Africa, where it has been cul...

polyethylene

(Encyclopedia)polyethylene pŏlˌēĕthˈəlēn [key], widely used plastic. It is a polymer of ethylene, CH2=CH2, having the formula (–CH2–CH2–)n, and is produced at high pressures and temperatures in the pre...