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sphagnum

(Encyclopedia)sphagnum sfăgˈnəm [key] or peat moss, any species of the large and widely distributed genus Sphagnum, economically the most valuable moss. Sphagnums, the principal constituent of peat, typically gr...

Perrin, Jean Baptiste

(Encyclopedia)Perrin, Jean Baptiste zhäN bätēstˈ pĕrăNˈ [key], 1870–1942, French physicist. From 1910 to 1940 he was professor at the Univ. of Paris, and in 1941 he came to the United States. Perrin specia...

petrology

(Encyclopedia)petrology, branch of geology specifically concerned with the origin, composition, structure, and properties of rocks, primarily igneous and metamorphic, and secondarily sedimentary. It includes petrog...

ziggurat

(Encyclopedia)CE5 Ziggurat ziggurat zĭgˈo͝orăt [key], form of temple common to the Sumerians, Babylonians and Assyrians. The earliest examples date from the end of the 3d millenium b.c., the latest from the...

cellophane

(Encyclopedia)cellophane, thin, transparent sheet or tube of regenerated cellulose. Cellophane is used in packaging and as a membrane for dialysis. It is sometimes dyed and can be moisture-proofed by a thin coating...

Bohr, Aage Niels

(Encyclopedia)Bohr, Aage Niels ägə nēls bōr [key], 1922–2009, Danish physicist, Ph.D. Univ. of Copenhagen, 1954. He worked with his father Niels Bohr (who won the Nobel Prize in Physics in 1922) in the 1940s ...

abbey

(Encyclopedia)abbey, monastic house, especially among Benedictines and Cistercians, consisting of not less than 12 monks or nuns ruled by an abbot or abbess. Many abbeys were originally self-supporting. In the Bene...

titanium

(Encyclopedia)titanium tītāˈnēəm, tĭ– [key] [from Titan], metallic chemical element; symbol Ti; at. no. 22; at. wt. 47.867; m.p. 1,675℃; b.p. 3,260℃; sp. gr. 4.54 at 20℃; valence +2, +3, or +4. Titani...

Chernobyl

(Encyclopedia)Chernobyl chĭrnōˈbyēl [key], Ukr. Chornobyl, abandoned city, N Ukraine, near the Belarus border, on the Pripyat River. Ten miles (16 km) to the north, in the town of Pripyat, is the Chernobyl nucl...

coast protection

(Encyclopedia)coast protection, methods used to protect coastal lands from erosion. Beaches can exist only where a delicate dynamic equilibrium exists between the amount of sand supplied to the beach and the inevit...