767 résultats pour "higher"

• Air - chemistry.

  lighting systems, fertilizers, and semiconductors (substances used to make the chips in computers, calculators, televisions, microwave ovens, and many other electronicdevices). A Oxygen More than half of the oxygen produced in the United States is used by the steel industry, which injects the gas into basic oxygen furnaces to heat and produce steel(see Iron and Steel Manufacture: Basic Oxygen Process ). Metalworkers also combine oxygen with acetylene to produce high-temperature torch flames th...

• Unemployment.

  set up to monitor the economy and provide advice to the president and Congress. Between 1945 and 1990 nine cyclical swings in unemployment occurred; all weresmaller than the 1930s depression. During this period the unemployment rate was as low as 2.9 percent (1953) and as high as 9.7 percent (1982). Because of cutbacksin the unemployment insurance program and changes in the nature of employment during the 1980s, however, only 37 percent of jobless workers received benefits in1990. Fears that the...

• Carbon - chemistry.

  Graphite is black and slippery and conducts electricity. In graphite, the atoms form planar, or flat, layers. Each layer is made up of rings containing six carbon atoms.The rings are linked to each other in a structure that resembles the hexagonal mesh of chicken wire. Each atom has three sigma bonds (with 120° between any two ofthe bonds) and belongs to three neighboring rings. The fourth electron of each atom becomes part of an extensive pi bond system. Graphite conducts electricity,because th...

• Wireless Communications.

  were large, heavy units. After the invention of the transistor in 1948, radios shrank in size to small handheld radio transceivers. Public two-way radios with severalfrequency options are widely available as well. Usually limited in range to a few miles, these units are great aids for such mobile professionals as construction workers,film crews, event planners, and security personnel. Simpler two-way radios, called walkie-talkies, have been popular children’s toys for years. Most walkie-talkiesb...

• Rock (mineral).

  pressure mineral assemblage. In a sense, the rock is stuck in a state that is characteristic of its earlier high-temperature and high-pressure environment. Thus,metamorphic rocks carry with them information about the history of temperatures and pressures to which they were subjected. The size, shape, and distribution of mineral grains in a rock are called the texture of the rock. Many metamorphic rocks are named for their main texture. Textures giveimportant clues as to how the rock formed. As t...

• L'industrie high tech aux USA

  Synergie entre les universités et les industries informatiques : implantation de plus de 80 parcs de recherche scientifique ou pôles tech­ nologiques (Route 128 à Boston, Silicon Valley en Californie ... ). ® Conséquences Dès 1994, IBM renoue avec les bénéfices (trois milliards de dollars et six milliards de dollars en 1997), Intel retrouve une place de leader mondial dans les semi-conducteurs en 1992 et Microsoft domine toujours le...

• Mount Everest - geography.

  endangered or killed when their tents collapsed or were ripped to shreds by the gales. Hypothermia, the dramatic loss of body heat, is also a major and debilitatingproblem in this region of high winds and low temperatures. Another hazard facing Everest climbers is the famous Khumbu icefall, which is located not far above Base Camp and is caused by the rapid movement of the Khumbuglacier over the steep rock underneath. The movement breaks the ice into sérac (large, pointed masses of ice) cliffs...

• Badminton.

  Once play has started, players tend to hit straight, low-flying shots called drives. When the shuttle remains close to the center of the court, net shots can be a goodoption. Net shots can be hard-hit or delicate. They are aimed at the front area of the opponent’s court, forcing the opponent to play the shot close to the net. If the opponent manages to return a net shot, the return must be hit high to clear the net. This gives the player a chance for a smash—the deadliest attacking stroke inbadm...

• River.

  IV RIVER PATTERNS River patterns, or general shapes, depend on the geologic zone and the climate of the location. There are four river patterns: meandering, braided, anastomosing, andstraight. A meandering pattern follows a winding, turning course. A braided pattern has connected channels that resemble a hair braid. An anastomosing river patterncombines features of the meandering and braided patterns. Some river patterns are simply straight channels. Meandering and braided are the most common...

• River - Geography.

  IV RIVER PATTERNS River patterns, or general shapes, depend on the geologic zone and the climate of the location. There are four river patterns: meandering, braided, anastomosing, andstraight. A meandering pattern follows a winding, turning course. A braided pattern has connected channels that resemble a hair braid. An anastomosing river patterncombines features of the meandering and braided patterns. Some river patterns are simply straight channels. Meandering and braided are the most common...

• Respiratory System.

  rapidly, or laughs while swallowing, the swallowing reflex may not work, and food or fluid can enter the larynx. Food, fluid, or other substances in the larynx initiate acough reflex as the body attempts to clear the larynx of the obstruction. If the cough reflex does not work, a person can choke, a life-threatening situation. TheHeimlich maneuver is a technique used to clear a blocked larynx ( see First Aid). A surgical procedure called a tracheotomy is used to bypass the larynx and get air to...

• Uganda - country.

  Uganda’s population is predominantly rural and is concentrated in the south, particularly in the crescent at the edge of Lake Victoria and in the southwest. Almost allUgandans are black Africans. Foreign residents make up less than 4 percent of the population and come mostly from neighboring states. In 2008 Uganda’s population was estimated at 31,367,972. The estimated growth rate of the population in 2008 was 3.6 percent. The birth rate was 48 per 1,000people and the death rate 12 per 1,000. Th...

• 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...

• Baroque Art and ArchitectureIINTRODUCTIONGerman Baroque ArchitectureThe baroque style of architecture flourished in Germany in the 18th century.

  C Early baroque styles Conversion of Saint PaulItalian baroque painter Caravaggio painted scenes of realism and drama, often selecting lofty, religious themes anddepicting them with lower-class characters and settings with dramatic spotlighting. With its unidealized characters andfocus on the horse’s body, his Conversion of Saint Paul seems to record a stable accident, not a miraculous conversion byGod. This work was painted in 1601 and is in the Cerasi Chapel, Santa Maria del Popolo, Rome, It...

• Silicon Valley et la « high tech »

  d'échanger sans cesse leurs poin ts de vue sur leur s di vers travaux. À la fin des années 60, Marcian - Ted -Ho ff crée, avec le micro­ processeur, le comp osant fonda­ mental de l'ordinateur personnel, et sort, en 1971, à la demande d'une entreprise japonaise,

• Black Death.

  disappeared in the West. V DISAPPEARANCE OF PLAGUE Plague became less common in Europe after the 1530s. The last plague in England was in 1665, the last in Western Europe in 1722. Numerous theories have beenoffered to explain the disappearance of plague. It has been argued that black rats, the primary carriers of plague, may have been replaced by larger brown rats that donot carry the infection. A second theory suggests that increased immunity among the rodents that carried the disease or chang...

• Black Death .

  disappeared in the West. V DISAPPEARANCE OF PLAGUE Plague became less common in Europe after the 1530s. The last plague in England was in 1665, the last in Western Europe in 1722. Numerous theories have beenoffered to explain the disappearance of plague. It has been argued that black rats, the primary carriers of plague, may have been replaced by larger brown rats that donot carry the infection. A second theory suggests that increased immunity among the rodents that carried the disease or chang...

• Gabon - country.

  government is engaged in preservation and reforestation programs. The fish catch in 2005 was 43,941 metric tons. C Mining Mining has developed rapidly since Gabon’s independence in 1960. Annual production of extremely high-grade manganese ore, from Moanda in the southeast, was1,090,000 metric tons in 2004. The rich deposits of iron ore located at Mekambo and Bélinga in the northeast have reserves estimated at more than 500 million metrictons. Exploitation of the iron ore has been hampered by th...

• Airplane.

  For example, the Anglo-French Concorde, a commercial supersonic aircraft, was generally limited to over-water routes, or to those over sparsely populated regions ofthe world. This limitation impacted the commercial viability of the Concorde, which ended its regular passenger service in October 2003. Designers today believe theycan help lessen the impact of sonic booms created by supersonic airliners but probably cannot eliminate them. One of the most difficult practical barriers to supersonic fl...

• Moon - astronomy.

  B Volcanic Features Maria, domes, rilles, and a few craters display indisputable characteristics of volcanic origin. Maria are plains of dark-colored rock that cover approximately 40 percent ofthe Moon's visible hemisphere. The maria formed when molten rock erupted onto the surface and solidified between 3.16 billion and 3.96 billion years ago. This rockresembles terrestrial basalt, a volcanic rock type widely distributed on Earth, but the rock that formed the maria has a higher iron content an...

• Republic of Singapore - country.

  Singaporeans of Chinese and Indian ancestry live in small, nuclear families. Housing favors smaller families, as most units consist of small apartments in high-risebuildings. Western clothing is common, and foods reflect the Chinese, Malay, and Indian origins of the people. D Social Issues Since Singapore became an independent state in 1965, government policies have brought orderliness and efficiency to the country. Examples are supplanting slum andsquatter areas with high-rise public housing p...

• Railroads.

  III GAUGES The gauge of track is the distance between the inner edges of the rails at points 1.59 cm (0.626 in) below the top of the heads. In the United States, Canada, theUnited Kingdom, Mexico, Norway, Sweden, and much of continental Europe, the standard gauge is 143.51 cm (56.5 in). Why this measurement became the standard isa matter of speculation. Probably the tradition is inherited from early tramroads built to accommodate wagons with axles 1.5 m (5 ft) long; some of the early edge rail...

• Burundi - country.

  D Way of Life Most Burundians live in self-contained compounds of small round grass huts scattered over the country’s many hills. The rugo , the traditional Tutsi hut, is divided into sections and surrounded by an enclosure and cattle corrals. Families farm scattered plots of land on different soils at different altitudes to minimize crop failure. Thefloors of valleys are avoided due to higher temperatures and tsetse fly infestation. Social roles are largely determined by ethnicity, with the T...

• Pollution.

  One of the greatest challenges caused by air pollution is global warming, an increase in Earth’s temperature due to the buildup of certain atmospheric gases such ascarbon dioxide. With the heavy use of fossil fuels in the 20th century, atmospheric concentrations of carbon dioxide have risen dramatically. Carbon dioxide and othergases, known as greenhouse gases, reduce the escape of heat from the planet without blocking radiation coming from the Sun. Because of this greenhouse effect,average glob...

• Denmark - country.

  forests, which cover just 11.6 percent of the country, include conifers (mainly fir, spruce, larch, and pine), beech, oak, birch, and ash. Several varieties of ferns andmosses common to the northern European mainland are also found. Wild animals are scarce. Natural animal life is limited to deer and small animals such as foxes,squirrels, hares, wild ducks, pheasants, and partridges. Numerous species of freshwater fish live in Denmark’s streams and lakes. F Environmental Issues Considered highly...

• Jupiter (planet) - astronomy.

  Beneath the supercritical fluid zone, the pressure reaches 3 million Earth atmospheres. At this depth, the atoms collide so frequently and violently that the hydrogenatoms are ionized—that is, the negatively charged electrons are stripped away from the positively charged protons of the hydrogen nuclei. This ionization results in asea of electrically charged particles that resembles a liquid metal and gives rise to Jupiter’s magnetic field. This liquid metallic hydrogen zone is 30,000 to 40,000 k...

• Utah - geography.

  Temperatures decrease from the south to the north in the state. In the mountains the average temperature drops about 0.5°C (about 1°F) for every about 300 m(about 1,000 ft) rise in elevation. Average July temperatures range from less than 16°C (60°F) in the mountains to more than 27°C (80°F) in a few locations insouthern Utah. At Salt Lake City average July temperatures range from a low of 18°C (64°F) to a high of 33°C (92°F). There is a great variation between daytime andnighttime temperatures,...

• Utah - USA History.

  Temperatures decrease from the south to the north in the state. In the mountains the average temperature drops about 0.5°C (about 1°F) for every about 300 m(about 1,000 ft) rise in elevation. Average July temperatures range from less than 16°C (60°F) in the mountains to more than 27°C (80°F) in a few locations insouthern Utah. At Salt Lake City average July temperatures range from a low of 18°C (64°F) to a high of 33°C (92°F). There is a great variation between daytime andnighttime temperatures,...

• Slovakia - country.

  The country is divided informally into the three regions of Western Slovakia, Central Slovakia, and Eastern Slovakia, corresponding to administrative divisions that wereabolished in 1989. Most of Slovakia’s 600,000 Hungarians live in the southern parts of Western and Central Slovakia, which served as the cultural center of Hungary forseveral centuries after Hungary proper was invaded by the Ottomans in the 16th century. The Ruthenian and Ukrainian minorities are concentrated in the northernregio...

• Hawaii (state) - geography.

  limestone along the coast. The volcanoes of the Hawaiian Islands are all so-called shield volcanoes, or lava domes. Unlike the volcanoes of Alaska and South America, those of Hawaii were notcreated by very explosive eruptions. Formed mostly by lava flows, they are great rounded mountain masses, rather than steep-sided cones. Mauna Kea, dormant forcenturies, is the highest mountain in the state. It rises to 4,205 m (13,796 ft) above sea level, and its summit is dotted with cinder cones formed by...

• Hawaii (state) - USA History.

  limestone along the coast. The volcanoes of the Hawaiian Islands are all so-called shield volcanoes, or lava domes. Unlike the volcanoes of Alaska and South America, those of Hawaii were notcreated by very explosive eruptions. Formed mostly by lava flows, they are great rounded mountain masses, rather than steep-sided cones. Mauna Kea, dormant forcenturies, is the highest mountain in the state. It rises to 4,205 m (13,796 ft) above sea level, and its summit is dotted with cinder cones formed by...

• Sweden - country.

  mi) and is Sweden’s second largest lake, after Vänern. The two lakes, together with several smaller lakes, rivers, and canals, form an internal water route called theGöta Canal. Built in the early 19th century, the Göta Canal extends for about 386 km (about 240 mi) and provides a scenic transportation link between the Baltic Sea,at Stockholm, and the Kattegat. Sweden’s other large lakes in the district include Mälaren, Hjälmaren, and the famously picturesque Siljan. D Climate Although one-seven...

• Nebraska - geography.

  by natural resource districts to limit the rate of pumping for irrigation. C Climate Nebraska has a typical continental climate with wide seasonal variations in temperature. C1 Temperature Winter temperatures below -20°C (0° F) and summer temperatures in the upper 30°s C (lower 100°s F) are common. The average January temperature varies from about -7° C (about 20° F) in the northeast to about -2° C (about 29° F) in the southwest. The average for July, thehottest month, ranges from about 26° C...

• Nebraska - USA History.

  by natural resource districts to limit the rate of pumping for irrigation. C Climate Nebraska has a typical continental climate with wide seasonal variations in temperature. C1 Temperature Winter temperatures below -20°C (0° F) and summer temperatures in the upper 30°s C (lower 100°s F) are common. The average January temperature varies from about -7° C (about 20° F) in the northeast to about -2° C (about 29° F) in the southwest. The average for July, thehottest month, ranges from about 26° C...

• Iowa - geography.

  Okoboji, Lost Island, Silver, and West Swan lakes. In addition, reservoirs have been created by damming several smaller Iowa rivers. There are a number of largereservoirs behind dams on the Mississippi River along the Iowa state line. C Climate Iowa’s climate is characterized by warm, generally moist summers and cold winters. Temperatures vary considerably from season to season and, at times, from day today. However, monthly averages are relatively uniform throughout the state and usually vary...

• Iowa - USA History.

  Okoboji, Lost Island, Silver, and West Swan lakes. In addition, reservoirs have been created by damming several smaller Iowa rivers. There are a number of largereservoirs behind dams on the Mississippi River along the Iowa state line. C Climate Iowa’s climate is characterized by warm, generally moist summers and cold winters. Temperatures vary considerably from season to season and, at times, from day today. However, monthly averages are relatively uniform throughout the state and usually vary...

• Jamaica - country.

  majority, the Church of God, Baptists, Anglicans, Seventh-day Adventists, Pentecostalists, and Roman Catholics predominate. Several well-established Jewish, Muslim,and Hindu communities exist. A number of popular sects, such as Pocomania and Rastafarianism, are a significant and famous feature of the national religious life. C Education School attendance by children between the ages of 6 and 11 is nearly universal, and 84 percent of all 12- to 18-year-olds attend secondary institutions. In 2000...

• Maryland - geography.

  Maryland has no large natural lakes. The largest body of water is a reservoir, Deep Creek Lake, which has a surface area of only 18 sq km (7 sq mi). It lies on theAllegheny Plateau, behind a dam on a tributary of the Youghiogheny River. C Coastline The deeply indented shoreline has a length of 5,134 km (3,190 mi), of which only 50 km (31 miles) fronts on the Atlantic Ocean. The most significant coastal feature isChesapeake Bay. In the bay are many islands and Kent Island is the largest. The sta...

• Maryland - USA History.

  Maryland has no large natural lakes. The largest body of water is a reservoir, Deep Creek Lake, which has a surface area of only 18 sq km (7 sq mi). It lies on theAllegheny Plateau, behind a dam on a tributary of the Youghiogheny River. C Coastline The deeply indented shoreline has a length of 5,134 km (3,190 mi), of which only 50 km (31 miles) fronts on the Atlantic Ocean. The most significant coastal feature isChesapeake Bay. In the bay are many islands and Kent Island is the largest. The sta...

• Mexico City - geography.

  The park houses some of Mexico's most important public buildings, including Chapultepec Castle. Construction of the castle began in 1783. Positioned on the park’shighest elevation, the castle functioned as a fortress during colonial times. It once served as the presidential residence and now houses the National Museum of History,which includes murals by 20th-century Mexican painter Juan O'Gorman. Los Pinos, the official residence and working offices of the president, is also on the grounds, buti...

• Cleveland (Ohio) - geography.

  Cleveland Children’s Museum. Also located in University Circle is Severance Hall, the home of the world-acclaimed Cleveland Orchestra. Nearby is the Cleveland PlayHouse, with three large, restored theaters and one of the largest non-profit professional theaters in the country. Downtown is Playhouse Square Center, with fourrecently restored theaters, home to the Cleveland Opera and the Great Lakes Theater Festival. On the waterfront is the Rock and Roll Hall of Fame and Museum,opened in 1995 and...

• Excerpt from Bleak House - anthology.

  patience, courage, hope; so overthrows the brain and breaks the heart; that there is not an honourable man among its practitioners who would not give—who does notoften give—the warning, 'Suffer any wrong that can be done you, rather than come here!' Who happen to be in the Lord Chancellor's court this murky afternoon besides the Lord Chancellor, the counsel in the cause, two or three counsel who are never inany cause, and the well of solicitors before mentioned? There is the registrar below...

• Elementary Particles I INTRODUCTION Structure of Matter Modern physics has revealed successively deeper layers of structure in ordinary matter.

  The most fundamental particles that make up matter fall into the fermion category. These fermions cannot be split into anything smaller. The particles that carry theforces acting on matter and antimatter are bosons called force carriers. Force carriers are also fundamental particles, so they cannot be split into anything smaller.These bosons carry the four basic forces in the universe: the electromagnetic, the gravitational, the strong (force that holds the nuclei of atoms together), and the wea...

• Mississippi - geography.

  The climate of Mississippi is characterized by long, hot, and humid summers and generally mild winters. The higher lands in the northeast are usually cooler than otherareas of the state. D1 Temperature Average January temperatures range from about 6° C (about 42° F) in northeastern Mississippi to about 12° C (about 54° F) along the Gulf Coast. No part of the stateis entirely free from freezing temperatures, but prolonged periods of extreme cold rarely occur. Temperatures more than 15° C (30° F)...

• Mississippi - USA History.

  The climate of Mississippi is characterized by long, hot, and humid summers and generally mild winters. The higher lands in the northeast are usually cooler than otherareas of the state. D1 Temperature Average January temperatures range from about 6° C (about 42° F) in northeastern Mississippi to about 12° C (about 54° F) along the Gulf Coast. No part of the stateis entirely free from freezing temperatures, but prolonged periods of extreme cold rarely occur. Temperatures more than 15° C (30° F)...

• Uzbekistan - country.

  E Environmental Issues The evaporation of the Aral Sea is one of the worst ecological disasters in the world. The Aral has shrunk so much that it now holds only about one-fifth the volume ofwater it held in 1960. The shrinkage is due to irrigation withdrawals from the Amu Darya and Syr Darya, a practice that began on a massive scale in the early 1960s aspart of the Soviet Union’s ill-conceived drive to increase cotton yields in Central Asia. Growing cotton in the naturally arid and saline soil...

• Illinois - geography.

  the state before joining the Mississippi River at Grafton. The Illinois has been deepened and straightened and forms part of the Illinois Waterway. The watershed between rivers that flow into the Mississippi river system and rivers that flow into the Great Lakes is low and in many places is not easily discernible. Inwhat is now the Chicago area, explorers had little difficulty portaging, or carrying, their canoes over the low watershed between the Des Plaines River, which flows intothe Illinois,...

• Illinois - USA History.

  the state before joining the Mississippi River at Grafton. The Illinois has been deepened and straightened and forms part of the Illinois Waterway. The watershed between rivers that flow into the Mississippi river system and rivers that flow into the Great Lakes is low and in many places is not easily discernible. Inwhat is now the Chicago area, explorers had little difficulty portaging, or carrying, their canoes over the low watershed between the Des Plaines River, which flows intothe Illinois,...

• Missouri - geography.

  Saint Francois Mountains, at the eastern end of the crest of the dome. Only in these mountains have the sedimentary rocks been sufficiently eroded away so that theunderlying igneous rocks are exposed. They form the rounded, knoblike peaks of an old mountain range. The peaks project, in isolation or in clusters, between 230 and300 m (750 and 1,000 ft) above the surrounding sedimentary basins. One of these knobs, Taum Sauk Mountain, reaches 540 m (1,772 ft) above sea level and is thehighest point...

• Missouri - USA History.

  Saint Francois Mountains, at the eastern end of the crest of the dome. Only in these mountains have the sedimentary rocks been sufficiently eroded away so that theunderlying igneous rocks are exposed. They form the rounded, knoblike peaks of an old mountain range. The peaks project, in isolation or in clusters, between 230 and300 m (750 and 1,000 ft) above the surrounding sedimentary basins. One of these knobs, Taum Sauk Mountain, reaches 540 m (1,772 ft) above sea level and is thehighest point...