Tupamaro V.tii-po-'ma-roN Member of the National Liberation Move¬ ment, a Uruguayan leftist urban guerrilla organization founded c. 1963 and named for Tupac Amaru II, an 18th-century Peruvian revolutionary. The earliest Tupamaro efforts involved robbing banks and businesses and distributing the goods to the poor, but in the late 1960s they mounted a wave of violence aimed at the authorities. The military government that seized power in 1973 launched an offensive against them, killing some 300 and imprisoning 3,000 others. When democratic rule returned in 1985, the Tupamaros were reorganized as a political party.
tupelo \'tu-p3-,lo\ Any of about seven species of trees that make up the genus Nyssa in the sour gum family (Nyssaceae). Five are found in moist or swampy areas of eastern North America, one in eastern Asia, and one in western Malaysia. They all have horizontal or hanging branches, broad leaves, and male and female flowers on different plants. North American species bear greenish-white flowers and small bluish-black or purple ber¬ ries. The most widespread North American species is the black gum. Tupelo wood, most of which comes from the water tupelo ( N. aquatica), is pale yellow to light brown, fine-textured, and strong. It is used for crates and boxes, flooring, wooden utensils, and veneers.
Tupian \tii-'pe-3n\ languages Family of South American Indian lan¬ guages with at least seven subgroups, spoken or formerly spoken in scat¬ tered areas from the Andes Mountains to the Atlantic Ocean and (with two exceptions) south of the Amazon River to southernmost Brazil and Paraguay. About one half of the 50 attested Tupian languages are extinct. The largest subgroup, Tupi-Guaram, includes the extinct language Tupi- namba, the source for borrowings of many New World flora and fauna terms into Portuguese and hence other European languages. Another lan¬ guage of the subgroup, Guarani, is spoken as a first or second language by more than 90% of Paraguayans, who consider it a token of Paraguayan identity.
Tupolev officially ANTK imeni A.N. Tupoleva formerly OKB- 156 Russian aerospace design bureau that is a major producer of pas¬ senger airliners and military bombers. It originated in 1922 as a group within the U.S.S.R.’s Central Aerohydrodynamics Institute to develop military aircraft. Under Andrei Tupolev, it created the TB-1 (ANT-4) all- metal, cantilever-wing bomber (first flights 1925-26). After several years’ confinement for political reasons, Tupolev was freed, and in 1943 he reestablished his team as the design bureau OKB-156. At the end of World War II, the bureau built the Tu-4 strategic bomber, a copy of the U.S. B-29. In the 1950s it produced the turboprop Tu-95 heavy bomber (NATO, “Bear”), which became a Soviet mainstay, and the first Soviet jetliner, the Tu-104 (first flown 1955). Between the late 1950s and early ’80s, it intro¬ duced new supersonic bombers, including the variable-wing Tu-22M (“Backfire”) and Tu-160 (“Blackjack”), and airliners such as the Tu-114 turboprop, Tu-154 trijet, and Tu-144 supersonic transport. In 1989, in honor of Tupolev (died 1972), the bureau was renamed ANTK imeni A.N. Tupoleva. After the dissolution of the U.S.S.R. in 1991, it became a joint stock company with the Russian government holding a limited financial interest. In the 1990s its projects involved jetliners such as the Tu-204 (in service 1996) and Tu-324.
Tupolev Vtii-pol-yifX, Andrei (Nikolayevich) (b. Nov. 10, 1888, Pustomazovo, Russia—d. Dec. 23, 1972, Moscow) Russian aircraft designer. In 1918 he cofounded the U.S.S.R.’s Central Aerohydrodynam¬ ics Institute, and in 1922 he became head of its design bureau (see Tupolev),
producing airplanes of all-metal construction. Arrested in 1937 on charges of activities against the state, he was assigned to work on the design of military aircraft. Under confinement, he led a team that produced the Tu-2 twin-engine tactical bomber, which was widely used in World War II. Freed during the war, Tupolev and his reestablished design bureau rep¬ licated the U.S. B-29; the resulting Tu-4 became the Soviet Union’s prin¬ cipal strategic bomber until the mid-1950s. After adapting jet propulsion to several piston-engine airframes, Tupolev introduced the swept-wing Tu-16 (NATO, “Badger”) jet bomber (first flown 1952) and its civilian derivative Tu-104 (1955), one of the first jet transports to provide regular passenger service. Tupolev and his son Alexei headed the effort that pro¬ duced the Tu-144 supersonic transport, the first passenger jet to exceed Mach 1 (1969).
Turn \'tu-ra\, Cosimo or Cosme Tura (b. c. 1430, Ferrara—d. 1495, Ferrara) Italian painter. Court painter to the Este family at Ferrara, his early Renaissance style was influenced by Andrea Mantegna and Piero della Francesca. A master of allegory and decorative painting, he was the founder and first significant figure of the school of Ferrara. His work is characterized by a mannered, nervous, and wiry line, carefully rendered detail, and brilliant colour.
TurabI \tu-'ra-be\, Hasan al- (b. 1932, The Sudan) Sudanese Muslim religious scholar and lawyer. After receiving a traditional Muslim educa¬ tion, he studied at the University of London and the Sorbonne in Paris. In the early 1950s he joined the Sudanese branch of the Muslim Brother¬ hood. While teaching law at the University of Khartoum (1957-65), he participated in the 1958 revolution that ended military rule. He later served in the national legislature (1965-67). He supported the 1985 over¬ throw of Gaafar Mohamed el-NiMEiRi. That same year he formed the National Islamic Front (NIF), an incarnation of the Muslim Brotherhood. In 1989 the NIF supported a coup that brought ‘Umar Hasan al-Bashlr to power. He later served as speaker of the National Assembly (1996-98) and was arrested in 2001 during a power struggle with al-Bashlr.
turbidity current Underwater current of abrasive sediments. Such cur¬ rents appear to be relatively short-lived, transient phenomena that occur at great depths. They are thought to be caused by the slumping of sedi¬ ment that has piled up at the top of the continental slope, particularly at the heads of submarine canyons. Slumping of large masses of sediment creates a dense slurry, which then flows down the canyon to spread out over the ocean floor and deposit a layer of sand in deep water. Repeated deposition forms submarine fans, analogous to the alluvial fans found at the mouths of river canyons.
turbine Vtor-bon, 'tor-.blnV Any of various devices that convert the energy in a stream of fluid into mechanical energy by passing the stream through a system of fixed and moving fanlike blades and causing the lat¬ ter to rotate. A turbine looks like a large wheel with many small radiat¬ ing blades around its rim. There are four broad classes of turbine: water (hydraulic), steam, wind, and gas. The most important application of the first three is the generation of electricity; gas turbines are most often used in aircraft.
turbojet Jet engine in which a TURBiNE-driven compressor draws in and compresses air, forcing it into a combustion chamber into which fuel is injected. Ignition causes the gases to expand and to rush first through the turbine and then through a nozzle at the rear. Forward thrust is generated as a reaction to the rearward momentum of the exhaust gases. The tur¬ bofan or fanjet, a modification of the turbojet, came into common use in the 1960s. In the turbofan, some of the incoming air is bypassed around the combustion chamber and is accelerated to the rear by a turbine- operated fan. It moves a much greater mass of air than the simple turbo¬ jet, providing advantages in power and economy. See also ramjet.