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boiler

(Encyclopedia)boiler, device for generating steam. It consists of two principal parts: the furnace, which provides heat, usually by burning a fuel, and the boiler proper, a device in which the heat changes water in...

breakfast cereal

(Encyclopedia)breakfast cereal, a food made from grain, commonly eaten in the morning. The oldest type of cereal, known as porridge or gruel, requires cooking in water or milk. The modern breakfast cereals, however...

steering system

(Encyclopedia)steering system, in automobiles, steering wheel, gears, linkages, and other components used to control the direction of a vehicle's motion. Because of friction between the front tires and the road, es...

thyroxine

(Encyclopedia)thyroxine thīrŏkˈsēn [key], substance secreted by the thyroid gland. The hormone thyroxine forms by combining the amino acid tyrosine with iodine. Complexed to a protein, it is stored in the folli...

Uribe Vélez, Álvaro

(Encyclopedia)Uribe Vélez, Álvaro, 1952–, Colombian politician. A lawyer from a wealthy cattle-ranching family, he held a number of government posts before becoming mayor of Medellín in 1982; he was later a Co...

rowing

(Encyclopedia)rowing, the art of propelling a boat by means of oars operated by hand. Boats propelled by oars (e.g., the galley) were used in ancient times for both war and commerce. Rowing is now generally used on...

Caracalla

(Encyclopedia)Caracalla kărəkălˈə [key], 188–217, Roman emperor (211–17); son of Septimius Severus. His real name was Marcus Aurelius Antoninus, and he received his nickname from the caracalla, a Gallic tu...

Chad, Lake

(Encyclopedia)Chad, Lake chăd, chäd [key], N central Africa. It lies mainly in Chad and Cameroon. Some 550 sq mi (1,425 sq km) in area in 2003, the shallow lake has been greatly reduced in size since the 1960s, w...

Castro, Raúl

(Encyclopedia)Castro, Raúl (Raúl Castro Ruz) käsˈtrō [key], 1931–, Cuban revolutionary and government official, younger brother of Fidel Castro. A loyal supporter of his brother and a Communist, Raúl Castr...

menopause

(Encyclopedia)menopause klīmăkˈtərĭk, klīˌmăktĕrˈĭk [key], transitional phase in a woman's life when the ovaries stop releasing eggs, ovarian production of estrogen and other hormones tapers off, and men...