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convection

(Encyclopedia)convection, mode of heat transfer in fluids (liquids and gases). Convection depends on the fact that, in general, fluids expand when heated and thus undergo a decrease in density (since a given volume...

coast guard

(Encyclopedia)coast guard, special naval force assigned to seaboard duties. Its primary responsibilities usually consist in suppressing contraband trade and aiding vessels in distress. The British coast guard was e...

unidentified flying object

(Encyclopedia)unidentified flying object or UFO, an object or light reportedly seen in the sky whose appearance, trajectory, and general dynamic and luminescent behavior do not readily suggest a logical, convention...

primrose

(Encyclopedia)primrose, common name for the genus Primula of the Primulaceae, a family of low perennial herbs with species found on all continents, most frequently in north temperate regions. Among the better-known...

horsefly

(Encyclopedia)horsefly, common name for the large hairy flies of the family Tabanidae. Male horseflies feed on pollen and nectar, but the females suck blood as well and are common pests of animals and sometimes of ...

radar

(Encyclopedia)radar, system or technique for detecting the position, movement, and nature of a remote object by means of radio waves reflected from its surface. Although most radar units use microwave frequencies, ...

El Niño–Southern Oscillation

(Encyclopedia)El Niño–Southern Oscillation (ENSO) ĕl nēnˈyō [key], large-scale climatic fluctuation of the tropical Pacific Ocean and the overlying atmosphere. The El Niño [Span.,=the child] is the South Am...

vestments

(Encyclopedia)vestments, garments worn by ecclesiastics in ceremonial functions. The cassock, a close-fitting gown buttoning down the front and reaching to the feet, is not a vestment so much as the daily uniform o...

Lehmann, John

(Encyclopedia)Lehmann, John lāˈmən [key], 1907–89, English poet, editor, and publisher. Educated at Trinity College, Cambridge, he began working at Virginia and Leonard Woolf's Hogarth Press in 1931 and manage...

instrument-landing system

(Encyclopedia)CE5 Instrument-landing system (ILS), the most common instrument-landing approach system, uses two beams to guide an airplane. instrument-landing system (ILS), ground-based radio system designed to...