Encyclopædia Britannica Australia -

Encyclopedias since 1768

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voltage regulator ... Voskhod

voltage regulator: any electrical or electronic device that maintains the voltage of a power source within acceptable limits. The voltage regulator is needed to keep voltages within the prescribed range that can be tolerated by the electrical equipment using that voltage. Such ...
Voltaire: one of the greatest of all French writers. Although only a few of his works are still read, he continues to be held in worldwide repute as a courageous crusader against tyranny, bigotry, and cruelty. His writing embodies characteristic qualities ...
Volterra: town and episcopal see, Pisa provincia, Toscana (Tuscany) regione, central Italy, northwest of Siena. As the ancient Velathri it was one of the 12 cities of the Etruscan confederation. It supported Rome during the Second Punic War in 205 BC, ...
Volterra, Daniele da: Italian Mannerist painter and sculptor, noted for his finely drawn, highly idealized figures done in the style of Michelangelo.
Volterra, Vito: Italian mathematician who strongly influenced the modern development of calculus.
voltmeter: instrument that measures voltages of either direct or alternating electric current on a scale usually graduated in volts, millivolts (0.001 volt), or kilovolts (1,000 volts). The typical commercial or laboratory standard voltmeter in use today is likely to employ an ...
Volturno River: river, south-central Italy. It rises in the Abruzzese Apennines near Alfedena and flows southeast as far as its junction with the Calore River near Caiazzo. It then turns southwest, past Capua, to enter the Tyrrhenian Sea at Castel Volturno, northwest ...
Voltzia: a genus of fossil cone-bearing plants dating to the Early Triassic epoch (beginning 245 million years ago). It belongs to the family Voltziaceae, order Coniferales (sometimes Voltziales). The genus showed interesting modifications of the seed-cone complex of earlier forms. The ...
Volubilis: North African archaeological site, located near Fes in the Jebel Zerhoun Plain of Morocco. Under the Mauretanian king Juba II in the 1st century BC and the 1st century AD, Volubilis became a flourishing centre of late Hellenistic culture. Annexed ...
volumetric analysis: any method of quantitative chemical analysis in which the amount of a substance is determined by measuring the volume that it occupies or, in broader usage, the volume of a second substance that combines with the first in known proportions, ...
voluntarism: any metaphysical or psychological system that assigns to the will (Latin: voluntas) a more predominant role than that attributed to the intellect. Christian philosophers have sometimes described as voluntarist: the non-Aristotelian thought of St. Augustine because of its emphasis on ...
Volunteers of America: religious social-welfare organization in the United States that offers spiritual and material aid to those in need. It was founded in New York City in 1896 by Ballington and Maud Booth as a result of a schism in the Salvation ...
volute: any marine snail of the family Volutidae (subclass Prosobranchia of the class Gastropoda). Most species have large, colourful shells, typically with an elongated aperture in the first whorl of the shell and a number of deep folds on the inner ...
Volvo Aktiebolaget: major Swedish manufacturer of automobiles and related products. Headquarters are in Goteborg.
volvocid: any rounded, plantlike protozoan of the phytoflagellate order Volvocida. Common in fresh water, volvocids often colour ponds and ditches green. Some are classified by botanists as green algae (Chlorophyta). Typical forms have a central nucleus and usually two to four ...
Volvox: a freshwater, chlorophyll-containing organism that lives in colonies; it is assigned by zoologists to the flagellate protozoan order Volvocida and by botanists to the green algae (Chlorophyta). The oval, hollow colonies, one cell in depth and about the size of ...
volvulus: twisting of a portion of the digestive tract on its mesentery (the fold of membrane that attaches the intestine to the posterior abdominal wall), resulting in intestinal obstruction, severe pain, distension of the involved segment, and interference with circulation to ...
Volyn: oblast (province), northwestern Ukraine. The larger northern part of the oblast consists of the flat, swampy lowland of the Pripet Marshes; reed and grass marshes are very extensive; drier areas are generally forested. In the south are the rolling hills ...
Volyn-Podilsk Upland: plateau extending between the Dniester and upper Bug river valleys in the west and the Dnieper River in the east in western Ukraine. In the north, where it is bordered by an escarpment, the plateau reaches to a line between ...
Volzhsky: city, Volgograd oblast (region), southwestern Russia, on the Volga River. Volzhsky was founded in 1951 to house persons working on the large hydroelectric station on the Volga. On completion of the project in 1961, industry was brought in and the ...
Vom: town, Plateau state, central Nigeria, situated on the Jos Plateau near the source of the Kaduna River, 18 miles (29 km) southwest of Jos town. It is the site of the National Veterinary Research Institute (1924) and of western Africa's ...
vomiting: the forcible ejection of stomach contents from the mouth. Like nausea, vomiting may have a wide range of causes, including motion sickness, the use of certain drugs, intestinal obstruction, disease or disorder of the inner ear, injury to the head, ...
von Gierke's disease: most common of a group of hereditary glycogen-storage diseases. It is inherited as an autosomal-recessive trait. In von Gierke's disease, the body's metabolism of glycogen is blocked by the absence of the enzyme glucose-6-phosphatase, which regulates the release of the ...
von Hugel, Friedrich, Baron Von Hugel: Roman Catholic philosopher and author who was the forerunner of the realist revival in philosophy and the theological study of religious feeling.
von Neumann, John: Hungarian American mathematician, who made important contributions in quantum physics, logic, meteorology, and computer science. His theory of games had a significant influence upon economics.
von Willebrand's disease: inherited hemorrhagic disorder characterized by a prolonged bleeding time and a deficiency of antihemophilic factor (factor VIII), which is an important blood clotting agent. This disorder is due to deficiencies in von Willebrand factor (vWF), a molecule that facilitates platelet ...
Vonck, Jean-Francois: Belgian lawyer who led the democratic faction, the Vonckists, in the Belgian revolt against Austrian rule in 1789.
Vondel, Joost van den: Dutch poet and dramatist who produced some of the greatest works of Dutch literature.
Vonnegut, Kurt, Jr.: American novelist noted for his pessimistic and satirical novels that use fantasy and science fiction to highlight the horrors and ironies of 20th-century civilization.
Vonones I: king of Parthia (reigned AD 7/8-11).
Voortrekker: (Afrikaans: "Pioneer," or "Leading Migrant"), any of the Afrikaners who left the British Cape Colony in southern Africa to make the Great Trek (q.v.) into the interior from 1835 to the early 1840s.
Vorarlberg: Bundesland (federal state), far western Austria. It is bounded on the north by Bavaria (Germany) and Lake Constance (Bodensee), on the west by Switzerland (across the Rhine River) and Liechtenstein, on the south by Switzerland, and on the east (over ...
Vordingborg: city, Storstroms amtskommune (county), southern Zealand (Sjaelland), Denmark, on Masned Sound. Founded in the 12th century around its castle, which was built by Valdemar I as a defense against the Wends, the town of Vordingborg became a ...
Vorkuta: city, Komi republic, northwestern Russia, on the Vorkuta River. Coal mining began in the area in 1932, but the industry and city did not grow significantly until World War II. Initially the coal exploitation used penal labour. The area subsequently ...
Vorobyev, Arkady: Soviet weight lifter who won two Olympic gold medals and was the first Soviet light-heavyweight lifter to win the world championship.
Voronezh: city and administrative centre of Voronezh oblast (province), western Russia. It lies along the right bank of the Voronezh River above its confluence with the Don. The city was founded in 1586 as a fortress, later forming part of the ...
Voronezh: oblast (province), western Russia. The oblast has an area of 20,250 square miles (52,400 square km) and lies in the basin of the middle Don River, which bisects it north-south. The northeastern part of the oblast consists of the level ...
Vorontsov, Mikhail Illarionovich: Russian statesman who played a major role, particularly in foreign affairs, during the reign (1741-62) of Empress Elizabeth.
Vorontsov, Mikhail Semyonovich, Prince: Russian military and government official who was an outstanding imperial administrator.
Voroshilov, Kliment Yefremovich: military and political leader of the Soviet Union who served as head of state after the death of his close friend and collaborator Joseph Stalin.
Vorosmarty, Mihaly: poet and dramatist who helped make the literature of Hungary truly Hungarian during the era (1825-49) of social reforms. By ridding Hungarian literature of overwhelming classical and German influence, he made it national not only in language but in spirit.
Vorschule: (German: "preparatory school"), a type of private elementary school that developed in Prussia and other north German states in the mid-19th century to prepare upper-class children for secondary schools. Theoretically, any Prussian boy who had completed the Volksschule (a free, ...
Vorskla River, Battle of the: (Aug. 12, 1399), major victory of the Golden Horde (the westernmost division of the Mongol empire, which had suzerainty over the Russian lands) over the Lithuanian ruler Vytautas, which ended his attempt to extend his control over all southern Russia.
Vorster, John: right-wing Nationalist politician, prime minister of the Republic of South Africa (1966-78), who was elected president in 1978 but was forced to resign the following year because of a political scandal.
vorsud: among the Finno-Ugric Udmurt (Votyak) people, a family spirit, literally "luck protector"; the term also designates a birchbark container kept in the family shrine, or kuala, as a receptacle for offerings and possibly an image of the protector. The vorsud ...
Vorticella: genus of the ciliate protozoan order Peritrichida, a bell-shaped or cylindrical organism with a conspicuous ring of cilia (hairlike processes) on the oral end and a contractile unbranched stalk on the aboral end; cilia usually are not found between the ...
Vortigern: also spelled Wyrtgeorn king of the Britons at the time of the arrival of the Saxons under Hengist and Horsa in the 5th century. Though the subject of many legends, he may probably be safely regarded as an actual historical ...
vortograph: the first completely abstract kind of photograph, it is composed of kaleidoscopic repetitions of forms achieved by photographing objects through a triangular arrangement of three mirrors. Alvin Langdon Coburn, a member of the Photo-Secession group and a pioneer in nonobjective ...
Vortsjarv: lake (jarv) in south-central Estonia, with an area of about 110 square miles (280 square km). Vortsjarv forms part of the 124-mile (200-km) course of the Ema River (German: Embach; Lithuanian: Emajogi), which enters the lake from the south and ...
Vosges: massif extending west of the Rhine River Valley in the Haut-Rhin, Bas-Rhin, and Vosges departements of eastern France. Of ancient rocks, the dome-shaped mountains rise to their greatest heights north of Belfort Gap and then spread westward for more than ...
Voskhod: any of a second series of manned Soviet spacecraft. Following the triumph of the Vostok (q.v.) launchings that had put the first human in space, the Soviets developed the first spacecraft capable of carrying more than one crew member. On ...