212 résultats pour "gase"

• Georgia (country) - country.

  1917. During the subsequent Soviet period, religious practice was strongly discouraged because the Soviet state was officially atheistic; however, the GeorgianOrthodox Church was allowed to function openly. Orthodox Christianity is the religion of about 58 percent of the Georgian population. Muslims represent about 19 percent of the country’s population, with ethnicAzerbaijanis, Kurds, and Ajars comprising the principal Muslim groups. Ajars are ethnic Georgians who converted to Islam in the 17th...

• Iran - country.

  Zagros mountains. In the more arid central part of the country, wild pistachio and other drought-resistant trees grow in areas that have not been disturbed by humanactivity. Tamarisk and other salt-tolerant bushes grow along the margins of the Dasht-e Kavir. A wide variety of native mammals, reptiles, birds, and insects inhabit Iran. Many species of mammals—including wolves, foxes, bears, mountain goats, red mountainsheep, rabbits, and gerbils—continue to thrive. Others—including Caspian tigers,...

• West Virginia - geography.

  Forests, mostly of hardwood varieties, cover 79 percent of West Virginia. The principal commercial species are the oak, yellow poplar, maple, birch, beech, black walnut,hickory, and gum. Softwoods include pines and hemlock firs. Flowering trees include the wild crab apple, dogwood, hawthorn, and redbud. Among the many floweringbushes and plants are the rhododendron, which is the state flower, the laurel, blueberry, hepatica, wild geranium, and black-eyed Susan. Insects and disease, mostly introd...

• West Virginia - USA History.

  Forests, mostly of hardwood varieties, cover 79 percent of West Virginia. The principal commercial species are the oak, yellow poplar, maple, birch, beech, black walnut,hickory, and gum. Softwoods include pines and hemlock firs. Flowering trees include the wild crab apple, dogwood, hawthorn, and redbud. Among the many floweringbushes and plants are the rhododendron, which is the state flower, the laurel, blueberry, hepatica, wild geranium, and black-eyed Susan. Insects and disease, mostly introd...

• Spain - country.

  B Natural Resources Spain has a number of mineral resources. The largest known deposits are of iron ore, zinc, and lead. Spain also produces significant quantities of copper and mercury.These deposits are mined mainly in Huelva province in southwestern Spain, around Cartagena on the Mediterranean, and at various points along the Bay of Biscay inthe north. Additionally, uranium is mined in the region of Extremadura, near the Portuguese frontier, where pyrites, fluorspar, gypsum, tungsten, and po...

• Canada.

  Six general landform regions are distinguishable in Canada: the Appalachian Region, the Great Lakes and St. Lawrence Lowlands, the Canadian Shield, the Great Plains,the Canadian Cordillera, and the Canadian Arctic Archipelago. B1 Appalachian Region and Great Lakes and St. Lawrence Lowlands Eastern Canada consists of the Appalachian Region and the Great Lakes and St. Lawrence Lowlands. The Appalachian Region embraces Newfoundland Island, NovaScotia, New Brunswick, Prince Edward Island, and the G...

• Canada - country.

  Six general landform regions are distinguishable in Canada: the Appalachian Region, the Great Lakes and St. Lawrence Lowlands, the Canadian Shield, the Great Plains,the Canadian Cordillera, and the Canadian Arctic Archipelago. B1 Appalachian Region and Great Lakes and St. Lawrence Lowlands Eastern Canada consists of the Appalachian Region and the Great Lakes and St. Lawrence Lowlands. The Appalachian Region embraces Newfoundland Island, NovaScotia, New Brunswick, Prince Edward Island, and the G...

• Canada - Canadian History.

  Six general landform regions are distinguishable in Canada: the Appalachian Region, the Great Lakes and St. Lawrence Lowlands, the Canadian Shield, the Great Plains,the Canadian Cordillera, and the Canadian Arctic Archipelago. B1 Appalachian Region and Great Lakes and St. Lawrence Lowlands Eastern Canada consists of the Appalachian Region and the Great Lakes and St. Lawrence Lowlands. The Appalachian Region embraces Newfoundland Island, NovaScotia, New Brunswick, Prince Edward Island, and the G...

• Arctic Ocean - Geography.

  formal claim. Russia maintains that the Lomonosov Ridge, a seabed feature that extends from Siberia to Greenland, is part of its continental shelf. With the warming of the Arctic Ocean and the melting of sea ice, the competition for seabed rights has grown more acute as nations contemplate the ability to explorefor and exploit seabed resources, especially oil and natural gas deposits. In 2007 Russia claimed sovereignty over the North Pole, and Canada claimed sovereignty overthe Northwest Passage...

• Arctic - Geography.

  The Arctic is not a frozen desert devoid of life on land or sea, even during the cold, dark winter months. Spring brings a phenomenal resurgence of plant and animal life.Low temperatures are not always the critical element—moisture, the type of soil, and available solar energy are also extremely important. Some animals adapt well toArctic conditions; for instance, a number of species of mammals and birds carry additional insulation, such as fat, in cold months. Arctic summers with extended dayli...

• Respiración - ciencias de la naturaleza.

  ranas, respiran por la piel y por los pulmones. Los insectos respiran a través de tráqueas que tienen una apertura al exterior y se ramifican en el interior del cuerpo entre lostejidos, transportando aire a los órganos y a las estructuras internas. Los reptiles y los mamíferos respiran sólo por los pulmones; no obstante, las aves tienen unos sacosaéreos en el interior del cuerpo y unos espacios de aire en el interior de algunos huesos; y todas estas cavidades internas están conectadas con los pu...

• Afghanistan - country.

  D Climate Most of Afghanistan has a subarctic mountain climate with dry and cold winters, except for the lowlands, which have arid and semiarid climates. In the mountains and afew of the valleys bordering Pakistan, a fringe effect of the Indian monsoon, coming usually from the southeast, brings moist maritime tropical air in summer.Afghanistan has clearly defined seasons: Summers are hot and winters can be bitterly cold. Summer temperatures as high as 49°C (120°F) have been recorded in thenorth...

• Hazardous Wastes.

  A Source Reduction The best way to eliminate hazardous wastes is not to generate them in the first place. For example, improvements have been made in the production of integratedcircuits: The toxic chlorinated hydrocarbons commonly used in the 1970s were replaced in the 1980s by less toxic glycol ethers and in the 1990s by low-toxicity estersand alcohols. B Recycling Recycling is the recovery or reuse of usable materials from waste. About 5 percent of hazardous waste in the United States is re...

• North America - Geography.

  D Climate Although North America has considerable climatic variety, five principal climatic regions can be identified. The northern two-thirds of Canada and Alaska, as well as all ofGreenland, have subarctic and arctic climates, in which long, dark, bitterly cold winters alternate with brief, mild summers. Most of the region, which receives relativelylittle precipitation, is covered with snow and ice during much of the year. A second climatic region is made up of the eastern two-thirds of the U...

• Egypt - country.

  Egypt has a wide variety of mineral deposits, some of which, such as gold and red granite, have been exploited since ancient times. The chief mineral resource ofcontemporary value is petroleum, found mainly in the Red Sea coastal region, at Al ‘Alamayn (El ‘Alamein) on the Mediterranean, and on the Sinai Peninsula. Otherminerals include phosphates, manganese, iron ore, and uranium. Natural gas is also extracted. D Plants and Animals The vegetation of Egypt is confined largely to the Nile Delta,...

• Electric Lighting.

  successful arc lamp in 1878. Tungsten filaments were substituted for carbon filaments in incandescent lamps in 1907, and gas-filled incandescent lamps were developedin 1913. The fluorescent lamp was introduced in 1938. See also Lamp. For most of the 20th century the incandescent light bulb was widely used for lighting in homes. More energy-efficient and longer-lasting fluorescent lamps were adoptedfor industrial and office use. In 1979 a compact fluorescent bulb that screwed into ordinary lig...

• Extinction (biology) - biology.

  III ROLE OF MASS EXTINCTION IN EVOLUTION Historically biologists—most famous among them British naturalist Charles Darwin—assumed that extinction is the natural outcome of competition between newlyevolved, adaptively superior species and their older, more primitive ancestors. These scientists believed that newer, more highly evolved species simply drove less well-adapted species to extinction. That is, historically, extinction was thought to result from evolution. It was also thought that this...

• South America - Geography.

  South America is dominated by relatively warm climatic regimes. Spanning nearly the entire continent along the equator is a belt of humid tropical climate that grades tothe north and south into broad zones where the length of the rainy season and the amount of rainfall diminish. These zones have wet summers and dry winters and aresubject to prolonged droughts. Droughts are a particularly serious problem in northeastern Brazil and along the northern coast of Venezuela and Colombia. The areas ofra...

• North Dakota - geography.

  Bismarck, the growing season averages 134 days, as the average date of the last killing frost is May 11 and that of the first killing frost is September 22. The length ofthe growing season drops to about 110 days in the northerly reaches of the state. The long periods of summer sunshine at this latitude, providing as much as 16 hoursof daylight in summer, help crops to mature quickly, thus compensating somewhat for the relatively short growing season. Temperatures in the north are, on the averag...

• North Dakota - USA History.

  Bismarck, the growing season averages 134 days, as the average date of the last killing frost is May 11 and that of the first killing frost is September 22. The length ofthe growing season drops to about 110 days in the northerly reaches of the state. The long periods of summer sunshine at this latitude, providing as much as 16 hoursof daylight in summer, help crops to mature quickly, thus compensating somewhat for the relatively short growing season. Temperatures in the north are, on the averag...

• Calor - ciencia y tecnologia.

  puede corresponder a movimientos rotacionales, vibracionales y traslacionales de las partículas de una sustancia. La temperatura, sin embargo, sólo depende delmovimiento de traslación de las moléculas. En teoría, las moléculas de una sustancia no presentarían actividad traslacional alguna a la temperatura denominada ceroabsoluto. Véase Molécula. 3 ESCALAS DE TEMPERATURA Escalas de temperaturaComparación de las escalas de temperatura Kelvin, Celsius y Fahrenheit.© Microsoft Corporation. Reser...

• Contaminación atmosférica - geografía.

  nitrógeno, y de un 30 a un 40% de las partículas en suspensión emitidos a la atmósfera en Estados Unidos proceden de las centrales eléctricas que queman combustiblesfósiles, las calderas industriales y las calefacciones. Un 80% del monóxido de carbono y un 40% de los óxidos de nitrógeno e hidrocarburos emitidos proceden de lacombustión de la gasolina y el gasóleo en los motores de los coches y camiones. Otras importantes fuentes de contaminación son la siderurgia y las acerías, las fundicionesde...

• Contaminación atmosférica - ciencias de la naturaleza.

  nitrógeno, y de un 30 a un 40% de las partículas en suspensión emitidos a la atmósfera en Estados Unidos proceden de las centrales eléctricas que queman combustiblesfósiles, las calderas industriales y las calefacciones. Un 80% del monóxido de carbono y un 40% de los óxidos de nitrógeno e hidrocarburos emitidos proceden de lacombustión de la gasolina y el gasóleo en los motores de los coches y camiones. Otras importantes fuentes de contaminación son la siderurgia y las acerías, las fundicionesde...

• Volcán - ciencias de la naturaleza.

  Volcán Stromboli, islas EoliasStromboli es una de las islas que constituyen el grupo insular siciliano de las Eolias (también denominadas Lípari), famosa por elvolcán activo que la originó. Su población se concentra en unas pocas aldeas de tamaño reducido.C. Falco/Photo Researchers, Inc. Algunos volcanes son mucho más activos que otros. Se puede decir que algunos se encuentran en estado de erupción permanente, al menos en el presente geológico. ElStromboli, en las islas Lípari cerca de Sicilia,...

• Libya - country.

  junipers and mastic trees are found in the higher elevations. Only a few large mammals are found in Libya. Wildlife includes desert rodents, hyenas, gazelles, and wildcats. Eagles, hawks, and vultures are common. E Environmental Issues Libya has undertaken a number of major irrigation projects intended to ease the country’s water shortage. The most ambitious is the so-called Great Man-Made River(GMMR), a massive 25-year irrigation scheme begun in 1984. The GMMR is a vast water pipeline system d...

• British Columbia - Geography.

  hemlock, Douglas fir, Sitka spruce, and various cedars, grows rapidly in the mild, wet climate and produces the largest trees in Canada. In the dry lowlands of thesouthern and central interior, ponderosa and lodgepole pines, aspen, and bunchgrass are characteristic. Spruce dominates the Prince George region. Prairie grasses andstands of aspen are found in the northeastern corner of the province. At elevations higher than about 1,800 m (about 6,000 ft), an alpine vegetation of shrubs, mosses,and...

• British Columbia - Canadian History.

  hemlock, Douglas fir, Sitka spruce, and various cedars, grows rapidly in the mild, wet climate and produces the largest trees in Canada. In the dry lowlands of thesouthern and central interior, ponderosa and lodgepole pines, aspen, and bunchgrass are characteristic. Spruce dominates the Prince George region. Prairie grasses andstands of aspen are found in the northeastern corner of the province. At elevations higher than about 1,800 m (about 6,000 ft), an alpine vegetation of shrubs, mosses,and...

• Manhattan Project - U.

  other possible uses of nuclear energy, such as using uranium to operate large power plants or, perhaps, as power sources for ships or submarines. Then Nazi Germanyinvaded Poland on September 1, 1939, and Europe plunged into war. The scientists realized that any plans to build large-scale nuclear power plants would have to waituntil the war was over. Two weeks after the invasion of Poland, Hitler made a radio speech in which he threatened Britain with “a weapon against which there is no defense.”...

• Terrorism.

  exploitation, ethnic discrimination, and religious persecution. Perceived inequities in the distribution of wealth and political power have led some terrorists to attempt tooverthrow democratically elected governments. To achieve a fairer society, they would replace these governments with socialist or communist regimes. Left-wingterrorist groups of the 1960s and 1970s with such aims included Germany’s Baader-Meinhof Gang, Italy’s Red Brigades, and the Weather Underground ( see Weathermen) in the...

• Nunavut - Canadian History.

  The Arctic Lands is a complex geological area that is centered on the Arctic Ocean. It includes coastal plains, plateaus, and mountains. Coastal plains and plateaus arefound in the western Northwest Territories section of the Arctic Lands, such as on Victoria Island, which is mostly a large, flat plateau. In striking contrast to theserelatively gentle landscapes, the eastern Nunavut section of the Arctic Lands is dominated by a jagged chain of ice-covered mountains. The mountains on EllesmereIsl...

• Ontario - Geography.

  governed Ontario’s initial settlement and development. The province’s most important river is the St. Lawrence. Its route was much improved and enlarged by dredgingand canal building in the mid-20th century. This enabled large ocean-going vessels to reach Great Lake ports ( see St. Lawrence Seaway). The Ottawa River was an important early route to the interior for fur traders and timber merchants. The Niagara River, because of its falls, is a great center of hydroelectric power as well as aninte...

• Ontario - Canadian History.

  governed Ontario’s initial settlement and development. The province’s most important river is the St. Lawrence. Its route was much improved and enlarged by dredgingand canal building in the mid-20th century. This enabled large ocean-going vessels to reach Great Lake ports ( see St. Lawrence Seaway). The Ottawa River was an important early route to the interior for fur traders and timber merchants. The Niagara River, because of its falls, is a great center of hydroelectric power as well as aninte...

• Australia - country.

  itself forms most of the border between New South Wales and Victoria. Considerable lengths of the Murray, Darling, and Murrumbidgee rivers are navigable during thewet seasons. The central plains region, also known as the Channel Country, is interlaced by a network of rivers. During the rainy season these rivers flood the low-lying countryside,but in dry months they become merely a series of water holes. The Victoria, Daly, and Roper rivers drain a section of the Northern Territory. In Queensland...

• Australia - Geography.

  itself forms most of the border between New South Wales and Victoria. Considerable lengths of the Murray, Darling, and Murrumbidgee rivers are navigable during thewet seasons. The central plains region, also known as the Channel Country, is interlaced by a network of rivers. During the rainy season these rivers flood the low-lying countryside,but in dry months they become merely a series of water holes. The Victoria, Daly, and Roper rivers drain a section of the Northern Territory. In Queensland...

• Nitrógeno - ciencia y tecnologia.

  eliminación de verrugas. Los bancos de semen utilizan nitrógeno líquido para conservar el material genético. Los laboratorios deinvestigación lo emplean para atrapar materiales volátiles. Frecuentemente, la refrigeración con nitrógeno líquido es el punto departida para alcanzar temperaturas más bajas usando helio líquido.Yoav Levy/Phototake NYC La mayor parte del nitrógeno utilizado en la industria química se obtiene por destilación fraccionada del aire líquido, y se usa para sintetizar amoníaco...

• Water - chemistry.

  flourides in drinking water has been found to reduce tooth decay. See Fluorine. Seawater contains, in addition to concentrated amounts of sodium chloride, or salt, many other soluble compounds, as the impure waters of rivers and streams areconstantly feeding the oceans. At the same time, pure water is continually lost by the process of evaporation, and as a result the proportion of the impurities that givethe oceans their saline character is increased. See Ocean and Oceanography. VII WATER...

• Circulatory System.

  C Additional Functions In addition to oxygen, the circulatory system also transports nutrients derived from digested food to the body. These nutrients enter the bloodstream by passingthrough the walls of the intestine. The nutrients are absorbed through a network of capillaries and veins that drain the intestines, called the hepatic portal circulation.The hepatic portal circulation carries the nutrients to the liver for further metabolic processing. The liver stores a variety of substances, suc...

• Diving (underwater).

  compensator (or control) device (BCD or BC), which the diver wears as a vest. By adding air to the BCD, the diver becomes more buoyant and rises. By releasing air,the diver becomes less buoyant and sinks. With minor adjustments of air, the diver can achieve neutral buoyancy. A third hose attaches to pressure gauges that diversuse to monitor how much air remains in the tank. A fourth hose attaches to a backup breathing device called an alternate air source, or octopus. Divers also wear a belt w...

• Trinidad and Tobago - country.

  III PEOPLE The history of Trinidad and Tobago is reflected in the makeup of its population, among the most ethnically diverse in the Caribbean. Blacks of African ancestry andAsians of Indian ancestry each make up about 40 percent of the population. The remainder is mainly of mixed ancestry, although there are also small groups of peopleof Chinese, European, South American, and Middle Eastern descent. The ethnic diversity of Trinidad and Tobago owes its origins to slavery and its abolition. Afr...

• Kyrgyzstan - country.

  are Bishkek, the capital, located on the Chu River in the far north; and Osh, located in the Fergana Valley. A Ethnic Groups Ethnic Kyrgyz make up about 65 percent of the population of Kyrgyzstan. Uzbeks, who live primarily in the Fergana Valley, constitute about 14 percent of thepopulation. Russians, who live principally in Bishkek and other industrial centers, make up about 13 percent of the population. Other ethnic groups include Hui (ChineseMuslims, also known as Dungans), Ukrainians, Uygur...

• Colombia - country.

  In Bogotá the average high temperature in January is 20°C (68°F), and in July the average high is 19°C (65°F). The highs for the same months in Barranquilla are 32°C(89°F) and 33°C (91°F). Throughout the year, three-month periods of rain and dry weather alternate. Along the Pacific coast precipitation is heavy. At Bogotá the annual rainfall averages about1,060 mm (about 42 in), and in Barranquilla it averages about 800 mm (about 32 in). Dry weather prevails on the slopes of the Cordillera Orient...

• Argentina - country.

  Patagonia lies in the rain shadow of the Andes and so receives little moisture. As a result it is used primarily for grazing sheep, although some crops are grown on smallfarms in irrigated valleys. Several major oil fields also are in Patagonia. At the southern tip of Patagonia is Tierra del Fuego, a large mountainous island shared byArgentina and Chile. B Rivers and Lakes Most of Argentina’s rivers empty into the Atlantic Ocean. Three rivers—the Paraná, Paraguay, and Uruguay—flow generally sou...

• Turkey - country.

  has a general elevation of 900 to 1,500 m (3,000 to 5,000 ft) above sea level. The eastern highlands region is the most mountainous and rugged portion of Turkey; Mount Ararat (Ağrı Da ğı) is the highest peak in the country at 5,165 m (16,945ft). Many Christians and Jews believe it to be the same Mount Ararat mentioned in the Bible as the place where Noah’s ark came to rest. The eastern highlands are thesource for both the Tigris (Dicle) and Euphrates (Fir āt)—two of southwestern Asia’s principal...

• Europe .

  D Vegetation Although much of Europe, particularly the west, was originally covered by forest, the vegetation has been transformed by human habitation and the clearing of land.Only in the most northerly mountains and in parts of north central European Russia has the forest cover been relatively unaffected by human activity. On the otherhand, a considerable amount of Europe is covered by woodland that has been planted or has reoccupied cleared lands. The largest vegetation zone in Europe, cuttin...

• Europe - Geography.

  D Vegetation Although much of Europe, particularly the west, was originally covered by forest, the vegetation has been transformed by human habitation and the clearing of land.Only in the most northerly mountains and in parts of north central European Russia has the forest cover been relatively unaffected by human activity. On the otherhand, a considerable amount of Europe is covered by woodland that has been planted or has reoccupied cleared lands. The largest vegetation zone in Europe, cuttin...

• Italy - country.

  C Natural Resources Italy is poor in natural resources. Much of the land is unsuitable for agriculture because of mountainous terrain or unfavorable climate. Italy, moreover, lacks substantialdeposits of basic natural resources such as coal, iron, and petroleum. Natural gas is the country’s most important mineral resource. Other deposits include feldspar andpumice. Many of Italy’s mineral deposits on the islands of Sicily and Sardinia had been heavily depleted by the early 1990s. Italy is rich...

• Vers 1871-1872 IMPRESSIONNISME PORTRAIT France Edgar DEGAS LORENZO PAGANS ET AUGUSTE DE GAS Dans les années 1870, Degas est fasciné...

  Vers 1871-1872 IMPRESSIONNISME PORTRAIT France Edgar DEGAS LORENZO PAGANS ET AUGUSTE DE GAS Dans les années 1870, Degas est fasciné par les musiciens. Il croque plusieurs d'entre eux, dont le ténor espagnol Lorenzo Pagans en pleine représentation dans le salon de son père, Auguste. Degas attachait une grande importance senti­ mentale à ce portrait de Pagans et de son père, Auguste. Il fit un jour comprendre à son ami Paul Poujaud que c'était un de ses ta­ bleaux préférés, ovec un Delacroix...

• Frank Zappa - Musik.

  1969 Burnt Weeny Sandwich Theme from Burnt Weeny SandwichHoliday in Berlin, Full BlownLittle House I Used to Live in 1970 Weasels Ripped My Flesh Prelude to The Afternoon of ASexually Aroused Gas MaskEric Dolphy Memorial BarbecueMy Guitar Wants To Kill Your MamaOrange County Lumber Truck 1970 Chunga's Revenge Transylvania BoogieRoad LadiesTwenty Small CigarsNancy & Mary MusicChunga's RevengeSharleena 1971 Fillmore East: June 1971 Little House I Used To Live InMud SharkWhat Kind of Girl Do You Th...

• Evolución - ciencias de la naturaleza.

  Los pulmones de los organismos que respiran aire y la vejiga natatoria de casi todos los peces actuales han evolucionado a partir delos sacos aéreos dobles de los primitivos peces óseos. En éstos, igual que la vejiga natatoria en los actuales, los sacos aéreos seinflaban y desinflaban para determinar la profundidad a la que nadaba el pez. En otros grupos de peces se transformaron enpulmones primitivos, provistos de abundantes repliegues para maximizar la absorción de oxígeno en un medio pobre en...

• Microprocessor.

  thin layer of oxide about 75 angstroms deep (an angstrom is one ten-billionth of a meter). Nearly every layer that is deposited on the wafer must be patterned accurately into the shape of the transistors and other electronic elements. Usually this is done in aprocess known as photolithography, which is analogous to transforming the wafer into a piece of photographic film and projecting a picture of the circuit on it. A coatingon the surface of the wafer, called the photoresist or resist, changes...