268 résultats pour "container"

• 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...

• 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...

• Native Americans of Middle and South America.

  A line that snakes across central Mexico near the Tropic of Cancer forms the northern boundary of Mesoamerica; north of this line rainfall sharply declines and theclimate is much drier. The ancient civilizations of Mesoamerica all arose and developed in the area between this line and the Guatemalan highlands far to the south. Richvolcanic soils are found throughout much of the region. A2 People and Languages Mesoamerica was a great melting pot, home to many peoples and interrelated cultures. In...

• Cnidarians - biology.

  small, inconspicuous polyps. Polyps reproduce asexually to form a medusa—saucer-like structures bud off the polyp and swim away as new medusae. C Cubozoa The medusa phase dominates in animals in the Cubozoan class. Cubozoan medusae are commonly called box jellies because they have a cube shape with a singletentacle or group of tentacles hanging from each corner at the mouth end of the animal. The Cubozoan polyp is small and inconspicuous and an entire polyp transformsinto a medusa in a type of...

• Computer Security.

  might deny usage to legitimate users, and they ensure that information received from an outside source is expected and does not contain computer viruses. VII INTRUSION DETECTION SYSTEMS Security software called intrusion detection systems may be used in computers to detect unusual and suspicious activity and, in some cases, stop a variety of harmfulactions by authorized or unauthorized persons. Abuse and misuse of sensitive system and application programs and data such as password, inventory,...

• 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...

• Chicago (city, Illinois) - geography.

  VI EDUCATIONAL AND CULTURAL INSTITUTIONS Chicago has one of the largest public school systems in the United States. The Chicago Board of Education administers the system in a centralized fashion; in recentyears it has been experimenting with local school councils as a means of partial devolution of authority. These councils, established in 1989, have authority in severalareas, including the ability to approve budgets and curriculum. In addition, Chicago has many private schools, including larg...

• Solar System - astronomy.

  dwarf planets according to the IAU because they have rounded shapes from their own gravity but have not cleared their neighborhoods in space of other objects—bothorbit through the Kuiper Belt, a region beyond Neptune containing thousands of small icy bodies. Pluto and Eris are composed of layers of ice around a rocky core.Ceres qualifies as a dwarf planet because it is spherical but is found in the asteroid belt, a zone between the orbits of Mars and Jupiter that contains thousands of smallrocky...

• Native American Languages.

  From Nahuatl, spoken in Middle America, come avocado, cacao, cocoa, chile/chili, chocolate, coyote, tamale , tomato , and many others. Contributions from South American languages include jaguar, cashew, tapioca, and toucan from Tupinambá; alpaca, condor, jerky, llama, puma, and quinine from Quechua; and barbecue, canoe, guava, hammock, hurricane, iguana, maize, papaya, and potato from Maipurean (Arawakan). Native American languages, in turn, have borrowed words from European language...

• Cat. I INTRODUCTION Cat, small, mainly carnivorous animal, Felis silvestris catus, member of

  D Coat Colors The domestic cat's original coat color was probably grayish-brown with darker tabby stripes, a color that provides excellent camouflage in a variety of environments. Allother coat colors and patterns are the result of genetic mutations; for example, solid coat colors such as black and blue are the result of a gene that suppresses tabbystripes; an orange coat is the result of a gene that transforms black pigment to orange; and a solid white coat is the result of a gene that complet...

• Cat - biology.

  D Coat Colors The domestic cat's original coat color was probably grayish-brown with darker tabby stripes, a color that provides excellent camouflage in a variety of environments. Allother coat colors and patterns are the result of genetic mutations; for example, solid coat colors such as black and blue are the result of a gene that suppresses tabbystripes; an orange coat is the result of a gene that transforms black pigment to orange; and a solid white coat is the result of a gene that complet...

• Whale - biology.

  III BEHAVIOR OF WHALES Studies of whales in captivity have taught scientists much about the complex social behavior of whales. Since the late 1980s, advances in the use of satellite trackingsystems have also broadened opportunities for scientists to observe how whales behave in the wild. A Swimming and Diving Whales swim by making powerful up-and-down movements of the tail flukes, which provide thrust. The power comes from body muscles that flex the lower spine upand down in a wavelike motion...

• Telephone.

  digits is dialed. The development of inexpensive and reliable amplification provided by the introduction of the transistor in the 1960s made practical the design of adialing system based on the transmission of relatively low power tones instead of the higher-power dial pulses. Today most telephones have push buttons instead of a rotary dial. Touch-Tone is an optional service, and telephone companies still maintain the ability to receive pulsedialing. Push-button telephones usually have a switch...

• Bolivia - country.

  E Plants and Animals Because of the wide variations in elevation, plant and animal species of nearly every climatic zone are found in Bolivia. A coarse grass, called ichu, grows on the largelybarren high plateau in the west. Para rubber trees, more than 2,000 species of hardwood trees, and vanilla, sarsaparilla, and saffron plants are common in the tropicalforests of the east. The llama, found chiefly on the Altiplano, is an efficient beast of burden. Alpacas and vicuñas also inhabit the platea...

• 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...

• 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...

• 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...

• Massachusetts - geography.

  mi). Other large artificial lakes include Wachusett Reservoir, East Brimfield Reservoir, and Cobble Mountain Reservoir. Assawompsett Pond, covering about 10 sq km(about 4 sq mi), is the largest natural lake. North Watuppa Pond and Long Pond are other large natural lakes. Lake Chaubunagungamaug, near Webster, is usuallycalled Webster Lake, because the Algonquian name is difficult to pronounce and spell. The full version of the Native American name is said to be the longest place-namein North Amer...

• 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...

• Pacific Ocean - Geography.

  concretions of iron and manganese oxides that sometimes also contain copper, cobalt, and nickel. Programs are under way to examine the feasibility of mining thesedeposits. See also Deep-Sea Exploration. Contributed By:Fred N. SpiessMicrosoft ® Encarta ® 2009. © 1993-2008 Microsoft Corporation. All rights reserved.

• Nova - astronomy.

  When first discovered, the spectrum of a nova shows that the expanding layers of gas that cause the brightening have temperatures of 40,000° to 50,000° C (70,000°to 90,000° F)—about eight times as hot as the surface of the Sun. By the time a nova reaches maximum brightness, the temperature of the material has fallen to about10,000° C (about 20,000° F), or lower. Just after maximum brightness, the escaping cloud of gas cools and expands enough to become transparent. This transparency allows astro...

• Antarctica - geography.

  The geographic South Pole lies near the center of the continent in East Antarctica. This point is where all map lines of longitude converge at the southern end ofEarth’s axis of rotation. Distinct from the geographic south pole is the south magnetic pole, where the lines of force of Earth’s magnetic field emerge vertically,arching upward over the planet to enter Earth again at the north magnetic pole. The south-seeking end of a compass needle points to the south magnetic pole. Thesouth magnetic...

• Miami (Florida) - geography.

  VI EDUCATIONAL AND CULTURAL INSTITUTIONS Colleges and universities in the area include the University of Miami, Florida International University, Barry University, St. Thomas University, and Florida MemorialCollege. Miami-Dade Community College, one of the nation’s largest two-year colleges, has six campuses in the region. Leading museums include the Historical Museumof Southern Florida, the Miami Museum of Science, the Miami Art Museum, the Lowe Art Museum on the campus of the University of M...

• Aksum.

  doctrine that Christ was both divine and human. The Council of Chalcedon condemned Monophysitism in 451, and since that time the Coptic Church has beenindependent of other Christian churches. After the Council of Chalcedon, priests who continued to teach Monophysitism were persecuted in the eastern Roman Empire, and many migrated to Aksum. The influxof priests, along with the support of the royal family, strengthened missionary efforts in Aksum. Many churches and monasteries were founded after 4...

• Animal Courtship and Mating - biology.

  activity. These animals frequently copulate in water, and the penis helps transfer sperm before it is carried away by the currents Ostriches and rheas also contain apenis within the cloaca. Virtually all snakes and lizards display yet another variation of internal fertilization. Located in the tail are two penises, called hemepenes, which are covered by spinesand knobs that help lock it into place during mating. The male uses one hemepene at a time for copulation. Male salamanders secrete large...

• Arab Music I INTRODUCTION Umm Kulthum Egyptian singer Umm Kulthum was revered throughout Egypt, North Africa, and the Near East for her powerful voice and improvisational skill.

  The rhythmic structure of Arab music is similarly complex. Rhythmic patterns have up to 48 beats and typically include several downbeats (called dums ) as well as upbeats (called taks) and silences, or rests. To grasp a rhythmic mode, the listener must hear a relatively long pattern. Moreover, the performers do not simply play the pattern; they elaborate upon and ornament it. Often the pattern is recognizable by the arrangement of downbeats. The Rhythm in Arab Music illustration demonstratesa...

• Psychoanalysis.

  A cornerstone of modern psychoanalytic theory and practice is the concept of anxiety, which institutes appropriate mechanisms of defense against certain dangersituations. These danger situations, as described by Freud, are the fear of abandonment by or the loss of the loved one (the object), the risk of losing the object's love,the danger of retaliation and punishment, and, finally, the hazard of reproach by the superego. Thus, symptom formation, character and impulse disorders, andperversions,...

• Eye. I INTRODUCTION Eye, light-sensitive organ of vision in animals. The eyes of

  Several structures, not parts of the eyeball, contribute to the protection of the eye. The most important of these are the eyelids, two folds of skin and tissue, upper andlower, that can be closed by means of muscles to form a protective covering over the eyeball against excessive light and mechanical injury. The eyelashes, a fringe ofshort hairs growing on the edge of either eyelid, act as a screen to keep dust particles and insects out of the eyes when the eyelids are partly closed. Inside the...

• Smithsonian Institution.

  F Arthur M. Sackler Gallery The Arthur M. Sackler Gallery houses a permanent collection of art from China, South and Southeast Asia, ancient and Islamic Iran, and Japan. Changing exhibitions ofAsian art are drawn from collections in the United States and abroad. The core of the collection was a gift from American research physician and medical publisherArthur M. Sackler. G Cooper-Hewitt, National Design Museum The Cooper-Hewitt is located in New York City and features examples of historical an...

• Greenhouse Effect.

  addition, humans cut down huge tracts of trees for lumber or to clear land for farming or building. This process, known as deforestation, can both release the carbonstored in trees and significantly reduce the number of trees available to absorb carbon dioxide. As a result of these human activities, carbon dioxide in the atmosphere is accumulating faster than Earth’s natural processes can absorb the gas. By analyzing airbubbles trapped in glacier ice that is many centuries old, scientists have d...

• Acid Rain.

  the Adirondack Mountains of New York State, a quarter of the lakes and ponds are acidic, and many have lost their brook trout and other fish. In the middleAppalachian Mountains, over 1,300 streams are afflicted. All of Norway’s major rivers have been damaged by acid rain, severely reducing salmon and trout populations. E Plants and Animals The effects of acid rain on wildlife can be far-reaching. If a population of one plant or animal is adversely affected by acid rain, animals that feed on tha...

• Wolfgang Amadeus Mozart.

  including the sacred style of church music and the so-called galant (courtly) idiom. The elegant though often superficial galant style dominated much instrumental music of the 1760s and 1770s. Mozart’s mastery often demonstrates itself in an ability to expand and deepen the stylistic possibilities of the time. The manner in which heextended the character and form of the concerto, for instance, owes much to his experience in writing operatic arias. A Musical Expressiveness In the masterful Je...

• Honolulu - geography.

  of Brigham Young University. The state’s largest museum, the Bernice Pauahi Bishop Museum, is located in Honolulu. It contains a large collection of Polynesian archaeological artifacts, as well asmany exhibits on Hawaiian history and culture. The museum also has an extensive entomological collection with more than 13 million specimens. Other importantmuseums include the Honolulu Academy of Arts, known for its extensive collection of Japanese, Chinese, and Korean art; the Contemporary Museum, wit...

• Diabetes Mellitus.

  Once diabetes is diagnosed, treatment consists of controlling the amount of glucose in the blood and preventing complications. Depending on the type of diabetes, thiscan be accomplished through regular physical exercise, a carefully controlled diet, and medication. Individuals with Type 1 diabetes must receive insulin, often two to four times a day, to provide the body with the hormone it does not produce. Insulin cannot be takenorally, because it is destroyed in the digestive system. Consequent...

• Buenos Aires (city) - geography.

  The city has produced or nurtured many of the most prominent Spanish-language writers of the 20th century, including Jorge Luis Borges, Julio Cortázar, and ManuelPuig. Buenos Aires has long been one of the primary centers of Spanish-language publishing and printing, and it is home to major publishing companies. It supports theoldest English-language daily newspaper in Latin America, the Buenos Aires Herald, published since 1876. The arts have a long, rich history in Buenos Aires. This is mani...

• Nuclear Weapons.

  Regardless of the method used to attain a supercritical assembly, the chain reaction proceeds for about a millionth of a second, liberating vast amounts of heat energy.The extremely fast release of a very large amount of energy in a relatively small volume causes the temperature to rise to tens of millions of degrees. The resultingrapid expansion and vaporization of the bomb material causes a powerful explosion. VI PRODUCTION OF FISSILE MATERIAL Much experimentation was necessary to make the p...

• Gardening - biology.

  of synthetic and organic fertilizers, see Organic Farming.) Fertilizers usually are sold in packages, on which the percentage by weight of the macronutrients nitrogen (N), phosphorus (P), and potassium (K) are listed on thelabel—always in the order N-P-K. For example, a fertilizer that is labeled 10-5-3 is 10 percent nitrogen, 5 percent phosphorus, and 3 percent potassium. V PLANTING AND TRANSPLANTING Before planting seeds, gardeners prepare, or till, the soil using a variety of methods. Some...

• 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...

• Conservation.

  cancers, Hodgkin’s disease and leukemia. Unfortunately, human activities have greatly reduced biodiversity around the world. The 20th century encompasses one of the greatest waves of extinction, orelimination of species, to occur on the planet. The greatest threat to biodiversity is loss of habitat as humans develop land for agriculture, grazing livestock, industry,and habitation. The most drastic damage has occurred in the tropical rain forests, which cover less than seven percent of the Earth’...

• 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...

• Cat Family - biology.

  cats have coats that are mainly brown, yellow, or gray, often with white underbellies. The cubs of many species of cats have spotted coats, which helps hide them ingrass and underbrush from predators. Adult cats that have mainly spotted patterns in their fur include cheetahs, leopards, clouded leopards, jaguars, ocelots, margays, Geoffroy’s cat, and servals. Singlecolor coats are found in lions, pumas, and jaguarundis. Some individuals among leopards and jaguars, and more rarely in other species...

• Panama Canal - Geography.

  The size of ships using the Panama Canal has steadily increased. About 27 percent of the vessels that use the canal are built to the maximum dimensions that can passthrough it (a category called “Panamax”). This has prompted further widening of Gaillard Cut, so that the larger Panamax vessels may transit safely. However, some ofthe world’s commercial and military ships are too large for the canal. Since the 1940s, new U.S. battleships and aircraft carriers have been built exceeding the canal’sdi...

• Soil. I INTRODUCTION Soil, the loose material that covers the land surfaces of

  an exchange between plants and the atmosphere, as oxygen diffuses into the soil and is used by roots for respiration. In turn, the resulting carbon dioxide diffusesthrough pore spaces and returns to the atmosphere. This exchange is most efficient in soils with a high degree of porosity. For farmers, gardeners, landscapers, andothers with a professional interest in soil health, the process of aeration—making holes in the soil surface to permit the exchange of air—is a crucial activity. Theburrowi...

• Asia - geography.

  the Himalayas, the world’s highest mountain system. The Pacific Ocean plate drifted westward, scraping along the Eurasian plate and slipping under its coastal edge. This created the islands of Japan, Taiwan, the Kurils, theRyūky ūs, and the Philippines. Southeast Asia lies at the intersection of the Eurasian, Pacific Ocean, and Indian Ocean plates. Over time the contact between these platescreated the mountain ranges of mainland Southeast Asia. The continued slow movement of the plates causes fr...

• Asia - history.

  the Himalayas, the world’s highest mountain system. The Pacific Ocean plate drifted westward, scraping along the Eurasian plate and slipping under its coastal edge. This created the islands of Japan, Taiwan, the Kurils, theRyūky ūs, and the Philippines. Southeast Asia lies at the intersection of the Eurasian, Pacific Ocean, and Indian Ocean plates. Over time the contact between these platescreated the mountain ranges of mainland Southeast Asia. The continued slow movement of the plates causes fr...

• Chinese Literature I INTRODUCTION Chinese Literature, writings of the Chinese people, with a continuous history of more than 3,000 years.

  (Huang) River basin region in the north. The verses are in lines of four characters (or syllables) and use rhyme and alliteration (repetition of the initial letter). Confuciusquoted them in his works. Because he described them as “without depraved thoughts,” all the verses in the Shi jing have been treated as moral allegories. (4) The Li ji (Book of Ritual ) contains detailed discussions of the principles of conduct at court and in private ceremonies. Although the Han dynasty and later ruler...

• Chinese Literature I INTRODUCTION Chinese Literature, writings of the Chinese people, with a continuous history of more than 3,000 years.

  (Huang) River basin region in the north. The verses are in lines of four characters (or syllables) and use rhyme and alliteration (repetition of the initial letter). Confuciusquoted them in his works. Because he described them as “without depraved thoughts,” all the verses in the Shi jing have been treated as moral allegories. (4) The Li ji (Book of Ritual ) contains detailed discussions of the principles of conduct at court and in private ceremonies. Although the Han dynasty and later ruler...

• Arithmetic I INTRODUCTION Arithmetic, branch of mathematics that arises from counting, the most basic mathematical operation.

  Subtract the units: 6 - 3 = 3. Then subtract the tens column: 6 – 2 = 4. The results of these two single-digit subtractions, written side by side, provide the answer: Subtraction is a bit more complicated if we need to subtract a larger digit from a smaller one. For example, when subtracting 47 from 92, the units value (7) of 47 isgreater than the units value (2) of 92. We can handle this situation using a procedure called borrowing, which is like carrying in reverse. Ten units can be borrowe...