99 résultats pour "length"

• Bhutan - country.

  languages ( see Indo-Iranian Languages) and follow Hinduism. Nepalese people constitute a significant portion of Bhutan’s population. They are the most recent settlers, occupying south central and southwestern Bhutan. TheNepalese are mainly Rai, Gurung, and Limbu ethnic groups from the eastern mountains of Nepal. Nepalese immigration has been banned since 1959, when theBhutanese government feared the minority would become too populous. Nepalese are not permitted to live in the central Middle Hi...

• Observatory - astronomy.

  Ultraviolet radiation, X rays, and gamma rays have shorter wavelengths than visible light has. These types of radiation tell astronomers about the hottest and mostviolent phenomena in the universe. Earth’s atmosphere blocks most of this radiation, so astronomers must send their observatories above the atmosphere aboardballoons, rockets, or satellites. Ultraviolet telescopes are much like visible light telescopes, but X-ray telescopes must have special nested cylindrical mirrors to prevent Xrays...

• Comet - astronomy.

  may exceed the planet Jupiter in size, however. Observations from telescopes on Earth and in space indicate that most of the gases in the coma and tail of a comet are fragmentary molecules, or radicals, of the mostcommon elements in space: hydrogen, carbon, nitrogen, and oxygen. The radicals, for example, of CH, NH, and OH may be broken away from the stable molecules CH 4 (methane), NH 3 (ammonia), and H 2O (water), which may exist as ices or more complex, very cold compounds in the nucleus. Al...

• Africa - history.

  Africa’s other major mountainous regions occur at the northern and southern fringes of the continent. The Atlas Mountains, a system of high ranges, extend for 2,200 km(1,400 mi) across Morocco, Algeria, and Tunisia, roughly parallel to the northern coast. These ranges enclose a number of broad inland basins and plateaus. In the west, theHigh (or Grand) Atlas contains Toubkal (4,165 m/ 13,665 ft), the highest peak of the system. Toward the east, the Atlas consists of two parallel ranges: the Tell...

• Africa.

  The highest elevations in Africa are found in the various ranges of East Africa. After Kilimanjaro, the next highest peaks are Mount Kenya (5,199 m/17,057 ft), north ofKilimanjaro in central Kenya; Margherita Peak (5,109 m/ 16,762 ft) in the Ruwenzori Range on the border between Uganda and the Democratic Republic of the Congo(DRC); Ras Dashen (4,620 m/ 15,157 ft) in the Ethiopian Highlands of northern Ethiopia; Mount Meru (4,565 m/ 14,977 ft), close to Kilimanjaro in Tanzania; and MountElgon (4,...

• From Pride and Prejudice - anthology.

  But why Mr Darcy same so often to the Parsonage, it was more difficult to understand. It could not be for society, as he frequently sat there ten minutes togetherwithout opening his lips; and when he did speak, it seemed the effect of necessity rather than of choice—a sacrifice to propriety, not a pleasure to himself. He seldomappeared really animated. Mrs Collins knew not what to make of him. Colonel Fitzwilliam's occasionally laughing at his stupidity, proved that he was generallydifferent, wh...

• Cell (biology) - biology.

  proteins, or other proteins required by the cell. While relatively simple in construction, prokaryotic cells display extremely complex activity. They have a greater range of biochemical reactions than those found in theirlarger relatives, the eukaryotic cells. The extraordinary biochemical diversity of prokaryotic cells is manifested in the wide-ranging lifestyles of the archaebacteria andthe bacteria, whose habitats include polar ice, deserts, and hydrothermal vents—deep regions of the ocean un...

• Butterflies and Moths - biology.

  The smallest butterflies are certain blues that have wingspans of a mere 0.7 cm (0.25 in). The largest are the female giant birdwings of Papua New Guinea, whichmeasure up to 30 cm (12 in) across. Moths range in size from tiny Microlepidoptera, several groups of small moths with wings no more than 0.16 cm (0.06 in) across, togiant silk moths, such as the atlas moth, which may exceed 30 cm (12 in) in wingspan. IV REPRODUCTION AND LIFE CYCLE Butterflies locate potential mates by sight, identifyin...

• Bicycle.

  narrow as possible to minimize weight and interference with pedaling. F Specialty Bicycles Many other types of bicycles are designed for special purposes. Although not as common as standard single-rider racing, touring, mountain, or recreational bicycles,they nonetheless have significant niches. Recumbent bicycles are bicycles on which the rider sits upright as if in a chair, with legs and feet stretched out in front. Because they support the rider’s lower back,recumbents allow the rider far mo...

• Ice Hockey.

  Each period begins with a face-off at the blue dot at center ice. During the face-off one player from each team lines up at the dot with the stick blade on the ice. After the referee drops the puck, the two players attempt to gain possession of it. Quick hands and strength are essential qualities for players participating in the face-off. Once the puck is dropped, it is in play until an official’s whistle stops it, a goal is scored, or time expires. The team on offense tries to move the puck f...

• Advertising.

  Advertising agencies make money in a variety of ways. When the agency uses the client’s advertising budget to buy time for an ad on the radio or on television or whenit buys space for an ad in a newspaper or magazine, the media outlet allows the agency to keep 15 percent of the cost of the space or the time as a commission. The15 percent commission has become an advertising industry standard and usually accounts for the largest portion of the agency’s income. Agencies also charge clientsfor the...

• Mars (planet) - astronomy.

  The Martian core is probably much like Earth’s, consisting mostly of iron, with a small amount of nickel. If other light elements, particularly sulfur, exist there as well, thecore may be larger than presently thought. From studying Earth’s magnetic field and core, scientists theorize that the motions of the liquid rock in Earth’s core generateits magnetic field. Mars does not have a significant magnetic field, so scientists believe that Mars’s core is probably solid. However, spacecraft data in...

• 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...

• Cosine.

• Sine. Sine, one of the fundamental ratios of trigonometry. A ratio

• Cosecant Cosecant, one of the six fundamental ratios of trigonometry.

• Secant (trigonometry) Secant (trigonometry), one of the fundamental ratios of trigonometry.

• Square (geometry).

• Beetle - biology.

  cut, or crush prey. Beetles that consume nectar from flowers use tubelike mouthparts to suck up nectar like a primitive straw. C Thorax The thorax, the body region behind the head, consists of three segments that provide attachments for the legs and wings. Each segment of the thorax carries a pair oflegs. The middle segment also bears the stiff wing sheaths called elytra, and the hind segment holds the membranous hind wings. D Legs Beetles have six jointed legs, each leg with five parts. The f...

• aircraft, Japanese

• Optics I INTRODUCTION Mirage Mirages appear because differences in air temperature cause light rays from an object to take different paths to a viewer's eye.

  Refraction of Light by DiamondsThe brilliance of diamonds is due to their high refractive index, a measure of how strongly a transparent material bendslight rays. The skill of the gem-cutter lies in angling the facets of the stone so that each light ray entering it is reflectedmany times before it emerges again.Spencer Grant/Photo Researchers, Inc. The amount of light reflected depends on the ratio of the refractive indexes for the two media. The plane of incidence contains the incident ray and...

• Cotangent.

• Congo (river) - Geography.

  region as Portuguese territory, leaving a marble shaft on the riverbank as proof of his discovery. To Europeans the river became known as the Rio de Padrão (Pillar River). The Kongo king welcomed Cam and subsequent Portuguese explorers and established friendly trading relations with the Portuguese. More than 300 yearselapsed before serious exploration of the Congo was undertaken. Francisco José de Lacerda, a Portuguese explorer, reached the copper-rich Katanga region from the east in 1798, as...

• Ship. I INTRODUCTION Ship, vessel that is buoyant in the water and used

  B1 Biremes Experience soon proved that longer ships posed a new set of problems: They were weaker structurally, more difficult to maneuver, and presented a larger target to anyenemy ship with a ram. In the 8th century BC Mediterranean shipbuilders eliminated these problems with the bireme , a war galley built to accommodate two levels, or banks , of oarsmen. Oarsmen on the lower level rowed oars from ports cut into the side of the vessel, while those above rowed from the deck. This arrangemen...

• Tangent (trigonometry).

• Goose - biology.

  Branta comes from a German word meaning “burned” and all of the geese in this genus have black plumage somewhere on their bodies. The brant, a sea goose that also belongs to this genus, is found on both coasts of North America. Brants are darker than barnacle and Canada geese and similar in size to the smallest Canadageese. Like the Canada and barnacle goose, the brant nests in Arctic regions. But unlike them, it winters chiefly on salt water. Instead of the white cheeks of Canadaand barnacle g...

• Victoria (queen) I INTRODUCTION Victoria (queen) (1819-1901), queen of the United Kingdom of Great Britain and Ireland (1837-1901) and empress of India (1876-1901).

  Queen Victoria never truly recovered from Albert’s death in December 1861 at the age of 42. For almost a decade she remained in strict mourning. She rarely set footin London, and she avoided most public occasions, including the state opening of Parliament. She made an exception, however, for the unveiling of statues dedicated toPrince Albert and, after a few years, for attendance at army reviews. Behind the scenes, she continued to correspond with and talk to her ministers, and she took comfort...

• Victoria (queen).

  Queen Victoria never truly recovered from Albert’s death in December 1861 at the age of 42. For almost a decade she remained in strict mourning. She rarely set footin London, and she avoided most public occasions, including the state opening of Parliament. She made an exception, however, for the unveiling of statues dedicated toPrince Albert and, after a few years, for attendance at army reviews. Behind the scenes, she continued to correspond with and talk to her ministers, and she took comfort...

• From Bulfinch's Mythology: Theseus - anthology.

  One of the most celebrated of the adventures of Theseus is his expedition against the Amazons. He assailed them before they had recovered from the attack ofHercules, and carried off their queen Antiope. The Amazons in their turn invaded the country of Athens and penetrated into the city itself; and the final battle inwhich Theseus overcame them was fought in the very midst of the city. This battle was one of the favourite subjects of the ancient sculptors, and is commemorated inseveral works of...

• Digestive System.

  The stomach, located in the upper abdomen just below the diaphragm, is a saclike structure with strong, muscular walls. The stomach can expand significantly to storeall the food from a meal for both mechanical and chemical processing. The stomach contracts about three times per minute, churning the food and mixing it with gastricjuice. This fluid, secreted by thousands of gastric glands in the lining of the stomach, consists of water, hydrochloric acid, an enzyme called pepsin, and mucin (the...

• Space Shuttle - astronomy.

  The two SRBs, with their combined thrust of some 26 million newtons (about 5.8 million lb), provide most of the power for the first two minutes of flight. The SRBs takethe space shuttle to an altitude of 45 km (28 mi) and a speed of 4,973 km/h (3,094 mph) before they separate and fall back into the ocean to be retrieved,refurbished, and prepared for another flight. After the boosters fall away, the three main engines continue to provide thrust. These engines are clustered at the rear end of the...

• Marketing.

  Where advertising reaches a mass audience, personal or direct selling focuses on one customer at a time. That kind of individual attention makes direct sellingexpensive, but it also makes it effective. As the costs of personal selling have risen, the utilization of salespeople has changed. Simple transactions are completed byclerks. Salespeople are now used primarily where the products are complex and require detailed explanation, customized application, or careful negotiation over priceand paym...

• Snake (reptile).

  in their heads that conduct sound. They are able to hear low-frequency sounds and to sense vibrations that travel through the ground or water. The majority of snakeshave good eyesight, especially for detecting moving objects, although most burrowing snakes can only distinguish between light and dark. Pit vipers, boas, and pythons have an unusual adaptation for detecting warm-blooded prey and predators. On the heads of these snakes are small pits lined with cellsthat are extremely sensitive to he...

• Genetics - biology.

  construct identical buildings. Just as each contractor would require a full copy of the blueprint to construct a complete building, each new cell needs a complete copy ofan organism’s genetic information to function properly. Organisms use two types of cell division to ensure that DNA is passed down from cell to cell during reproduction. Simple one-celled organisms and other organisms thatreproduce asexually—that is, without the joining of cells from two different organisms—reproduce by a proces...

• African Literature I INTRODUCTION African Literature, oral and written literature produced on the African continent.

  that few scholars of African culture know any African languages, and few Africans know an African language other than their own. The best-known literatures in Africanlanguages include those in Yoruba and Hausa in West Africa; Sotho, Xhosa, and Zulu in southern Africa; and Amharic, Somali, and Swahili in East Africa. In West Africa, Yoruba writing emerged after Bishop Ajayi Crowther, a former slave, developed a script for the language and in 1900 published the first Yorubatranslation of the Bible...

• 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...

• Canadian Literature I INTRODUCTION Canadian Literature, literature of the peoples of Canada.

  William Henry DrummondPoet William Henry Drummond described the lives of French Canadian farmers, loggers, and rural workers in verse thatreflected their mix of French and English speech. He gained recognition in the late 19th and early 20th centuries.Library of Congress In the early 19th century, most Canadian poetry imitated earlier British poetry. Poets Oliver Goldsmith (grandnephew of the Anglo-Irish writer of the same name),Charles Sangster, Charles Mair, and Levi Adams exemplified literary...

• Cancer (medicine).

  unable to repair the DNA damage, p53 instructs the cell to undergo programmed cell death, or apoptosis , putting a stop to runaway cell division before it starts. Programmed cell death is a normal part of cell life and is tightly controlled by many genes, primarily p53. In a cancerous cell, one or more mutations prevent these genes from doing their jobs. When mutated, p53 allows a cell to continue to divide, even with damaged DNA.This can lead to additional mutations in proto-oncogenes or tumor...

• Colorado - geography.

  Although the rivers of Colorado are navigable only by small boats, they are important as a source of irrigation water for use in Colorado and adjoining states. However,the water level of the rivers fluctuates seasonally and from year to year. The level is generally low in winter and high in spring and summer, during the runoff of meltedsnow from the mountains. Colorado has no large lakes of natural origin, but there are numerous small lakes in the mountains. The largest bodies of water in Colora...

• Colorado - USA History.

  Although the rivers of Colorado are navigable only by small boats, they are important as a source of irrigation water for use in Colorado and adjoining states. However,the water level of the rivers fluctuates seasonally and from year to year. The level is generally low in winter and high in spring and summer, during the runoff of meltedsnow from the mountains. Colorado has no large lakes of natural origin, but there are numerous small lakes in the mountains. The largest bodies of water in Colora...

• Medicine.

  C Other Health Professionals Medicine is not restricted to physicians. A wide variety of health care practitioners work in this exciting field. By far the largest professional group is nurses. Registerednurses help physicians during examinations, treatment, and surgery. They observe, evaluate, and record patients’ symptoms, administer medications, and provideother care ( see Nursing). Nurse practitioners perform basic duties once reserved for physicians, such as diagnosing and treating common i...

• Idaho - geography.

  Idaho-Montana state line in the southern part of the Bitterroot Mountains. Consequently, nearly all the rivers in the state drain toward the Pacific. Most of Idaho lieswithin the drainage basin of the Columbia River system. The Snake River, which is the chief river in southern and central Idaho, follows a crescent-shaped course forabout 790 km (about 490 mi) across southern Idaho. It then swings northward along the Idaho state line and joins the Columbia River in Washington. Major tributariesof...

• Idaho - USA History.

  Idaho-Montana state line in the southern part of the Bitterroot Mountains. Consequently, nearly all the rivers in the state drain toward the Pacific. Most of Idaho lieswithin the drainage basin of the Columbia River system. The Snake River, which is the chief river in southern and central Idaho, follows a crescent-shaped course forabout 790 km (about 490 mi) across southern Idaho. It then swings northward along the Idaho state line and joins the Columbia River in Washington. Major tributariesof...

• Kansas - geography.

  at the adjoining cities of Kansas City, Kansas, and Kansas City, Missouri. Its chief headstreams are the Republican and Smoky Hill rivers, which join to form the KansasRiver at Junction City. Each of the headstreams has numerous tributaries. The Kansas River proper is only 270 km (170 mi) long, but the Smoky Hill River has a lengthof 870 km (540 mi), and the Republican River has a length of 720 km (450 mi). The main tributary flowing into the Kansas River is the Big Blue River. The Arkansas Rive...

• Kansas - USA History.

  at the adjoining cities of Kansas City, Kansas, and Kansas City, Missouri. Its chief headstreams are the Republican and Smoky Hill rivers, which join to form the KansasRiver at Junction City. Each of the headstreams has numerous tributaries. The Kansas River proper is only 270 km (170 mi) long, but the Smoky Hill River has a lengthof 870 km (540 mi), and the Republican River has a length of 720 km (450 mi). The main tributary flowing into the Kansas River is the Big Blue River. The Arkansas Rive...

• Puerto Rico - geography.

  the length of the day remains fairly constant throughout the year. San Juan has a mean July temperature of 28°C (83°F) and a mean January temperature of 25°C (77°F). The average temperature of the seawater surrounding theisland is 27°C (81°F), with little variation during the course of the year. The entire island is cooled by the trade winds from the northeast. This air also contains much water vapor. As the air is forced to rise over the mountains, it becomescooler and the water vapor condenses...

• Cuba - country.

  Only two land mammals, the hutia, or cane rat, and the solenodon, a rare insectivore that resembles a rat, are known to be indigenous. The island has numerous batsand nearly 300 kinds of birds, including vultures, wild turkeys, quail, finches, gulls, macaws, parakeets, and hummingbirds. The bee hummingbird of Cuba is thesmallest bird in the world. Among the few reptiles are tortoises, caimans, the Cuban crocodile, and a species of boa that can attain a length of 3.7 m (12 ft). More than700 speci...

• United Kingdom - country.

  B Natural Regions and Topography The island of Great Britain can be divided into two major natural regions—the highland zone and the lowland zone. The highland zone is an area of high hills andmountains in the north and west. The lowland zone in the south and east consists mostly of rolling plains. The zones are divided by an imaginary line running throughEngland from the River Exe on the southwest coast to the mouth of the River Tees on the northeast coast. The lowland zone has a milder climat...