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loom

(Encyclopedia)loom, frame or machine used for weaving; there is evidence that the loom has been in use since 4400 b.c. Modern looms are of two types, those with a shuttle (the part that carries the weft through the...

ozone layer

(Encyclopedia)ozone layer or ozonosphere, region of the stratosphere containing relatively high concentrations of ozone, located at altitudes of 12–30 mi (19–48 km) above the earth's surface. Ozone in the ozone...

Ordovician period

(Encyclopedia)Ordovician period ôrdəvĭshˈən [key] [from the Ordovices, ancient tribe of N Wales], second period of the Paleozoic era of geologic time (see Geologic Timescale, tablegeologic timescale, table) fr...

Katharine of Aragón

(Encyclopedia)Katharine of Aragón, 1485–1536, first queen consort of Henry VIII of England; daughter of Ferdinand II of Aragón and Isabella of Castile. In 1501 she was married to Arthur, eldest son of Henry VII...

Air Force, United States Department of the

(Encyclopedia)Air Force, United States Department of the, military department within the U.S. Dept. of Defense (see Defense, United States Department of). The Air Force traces its roots to the founding of the Aeron...

radio-frequency identification

(Encyclopedia)radio-frequency identification (RFID), a technology that uses radio waves to transmit data and uniquely identify an animal, person, or thing. An RFID system typically consists of a tag and a reader. T...

Sea Islands

(Encyclopedia)Sea Islands, chain of more than 100 low islands off the Atlantic coast of S.C., Ga., and N Fla., extending from the Santee River to the St. Johns River. The ocean side of the islands is generally sand...

shoe

(Encyclopedia)shoe, foot covering, usually of leather, consisting of a sole and a portion above the sole called an upper. In prehistoric times skins or hides may have been tied around the foot for protection and wa...

fortification

(Encyclopedia)fortification, system of defense structures for protection from enemy attacks. Fortification developed along two general lines: permanent sites built in peacetime, and emplacements and obstacles hasti...

respiration

(Encyclopedia)CE5 Respiratory system respiration, process by which an organism exchanges gases with its environment. The term now refers to the overall process by which oxygen is abstracted from air and is tran...