133 résultats pour "vari"

• Gottfried von Straßburg: Tristan (Sprache & Litteratur).

  nu gienc ouch Tristan zehantbegrüezen unde beschouwendie liehten sîne vrouwen.und alse er zuo z’ir nider gesazund redeten diz unde dazvon ir beider dingen,er bat im trinken bringen.Nune was dâ nieman inneâne die küniginnewan cleiniu juncvrouwelîn.der einez sprach: „seht, hie stât wînin disem vezzelîne.”nein, ezn was niht mit wîne,doch ez ime gelîch waere.ez was diu wernde swaere,diu endelôse herzenôt,von der si beide lâgen tôt.nu was aber ir daz unrekant.si stuont ûf und gie hin zehant,dâ daz tr...

• bactéries (faune & Flore).

  de Escherichia coli ) et sur la peau. Les bactéries symbiotiques sont également indispensables dans le processus de fixation de l’azote : des espèces comme les Rhizobium forment des nodules sur les racines des légumineuses ou de certains arbres et fixent l’azote atmosphérique sous une forme organique assimilable par les végétaux (ce quipermet à ces derniers de se développer sur des sols pauvres en azote organique). Les bactéries commensales prélèvent leurs nutriments sur des organismes vivants...

• bactéries.

  de Escherichia coli ) et sur la peau. Les bactéries symbiotiques sont également indispensables dans le processus de fixation de l’azote : des espèces comme les Rhizobium forment des nodules sur les racines des légumineuses ou de certains arbres et fixent l’azote atmosphérique sous une forme organique assimilable par les végétaux (ce quipermet à ces derniers de se développer sur des sols pauvres en azote organique). Les bactéries commensales prélèvent leurs nutriments sur des organismes vivants...

• champ magnétique

  By agreement, we call « north magnetic pole » the place where goes out the magnetic field and « south magnetic pole » the place where enters the magnetic field. Scientists found that the magnetic field enters in the north hemisphere and goes out in the south hemisphere. So, the north magnetic pole located in Canada is actually the south magnetic pole. However, because he is situated near the geographic north, we call it North Pole magnetic. Evolution of the Earth's magnetic field : Since the sev...

• BIOSPHÈRE LES BIOMES GÉNÉRALITÉS La surface de la Terre n'est pas uniforme, mais

  2 régions les plus arides de la Terre. Dans les déserts chauds, les températures diurnes dépassent 38 °C et il ne pleut jamais, car les masses d’air en mouvement ont perdu toute la vapeur d’eau qu’elles contenaient. Les savanes sont des prairies tropicales plus ou moins arides, où des arbres poussent parfois çà et là. Ces étendues herbacées plus ou moins arborées caractérisent les régions tropicales et subtropicales où la température est constamment élevée, et où il existe des variations saison...

• unités de mesure1PRÉSENTATIONunités de mesure, grandeurs conventionnelles et abstraites, choisies pour représenter des grandeurs physiques mesurables, telles que la masse, le temps, la longueur.

  En astronomie, on emploie quatre unités spécifiques : l'unité astronomique (149 597 870 km), l'année-lumière (9,461.10 12 km), le rayon équatorial terrestre (6 378,14 km) et le parsec, distance à laquelle une unité astronomique sous-tend un angle de 1'', soit environ 30 857.10 12 m. 4 UNITÉS DE MASSE Dans le système SI, l'unité fondamentale de masse est le kilogramme (kg), adopté en 1889 par la première Conférence générale des poids et mesures. Par définition, le kilogramme est la masse du...

• Mars - astronomie.

  par les Américains en vue de leur retour sur Terre. La capture sur orbite martienne sera d’une extrême complexité car les deux conteneurs, d’une taille inférieure à celled’un ballon de basket, se trouveront sur des orbites aux coordonnées incertaines. D’autres missions identiques sont envisagées par la NASA jusqu’en 2013. Quant au CNES, compte tenu de la puissance disponible sur Ariane 5, il propose d’ajouter un petitmodule de 200 kg à quelques missions commerciales du lanceur. Ces modules prend...

• pont (structure).

  toiture, et cette idée sera reprise et déclinée au XIXe siècle aux États-Unis. En 1502, Léonard de Vinci conçoit le projet d’un pont qui doit être construit à Istanbul : un pont en arc en maçonnerie d’une seule travée de 240 m. Des projets moins ambitieux sont menés à terme au cours de ce siècle, tels que le pont Notre-Dame (1512) — qui sera détruit et remplacé en 1853 — et le Pont-Neuf (1578-1604) à Paris, le Rialto (1588-1591) à Venise, le pont Santa Trinità (1566-1569) à Florence, œuvre de...

• pont (structure) - architecture.

  toiture, et cette idée sera reprise et déclinée au XIXe siècle aux États-Unis. En 1502, Léonard de Vinci conçoit le projet d’un pont qui doit être construit à Istanbul : un pont en arc en maçonnerie d’une seule travée de 240 m. Des projets moins ambitieux sont menés à terme au cours de ce siècle, tels que le pont Notre-Dame (1512) — qui sera détruit et remplacé en 1853 — et le Pont-Neuf (1578-1604) à Paris, le Rialto (1588-1591) à Venise, le pont Santa Trinità (1566-1569) à Florence, œuvre de...

• Weather.

  hours, and the snow can be much deeper in places where the wind piles it up in drifts. Extraordinarily deep snows sometimes accumulate on the upwind side ofmountain slopes during severe winter storms or on the downwind shores of large lakes during outbreaks of polar air. VI WIND Wind is the horizontal movement of air. It is named for the direction from which it comes—for example, a north wind comes from the north. In most places near theground, the wind speed averages from 8 to 24 km/h (from 5...

• Tree - biology.

  The major parts of a tree are its roots, trunk, leaves, flowers, and seeds. These components play vital roles in a tree’s growth, development, and reproduction. A Roots Trees are held in place by anchoring organs called roots. In addition to anchoring the tree, roots also absorb water and minerals through tiny structures called roothairs. From the roots the water and mineral nutrients are carried upward through the wood cells to the leaves. Although the internal structure of most kinds of roots...

• 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...

• Tiger - biology.

  have a simple digestive system designed to process meat so that the nutrients can be readily absorbed into the bloodstream. With the exception of white tigers, which have blue eyes, all tigers have yellow eyes. Tigers mainly use vision to find prey. Although tigers see about as well as humansduring the day, their large eye openings gather more light than do human eyes, making tiger night vision far superior to that of humans. In addition, a special structurein the tiger’s eye, called the tapetu...

• Ghana - country.

  times of depressed cacao prices, Ghana has significantly increased exports of timber to generate needed revenue. In 1988 Ghana initiated a conservation plan called the Forest Resource Management Project. In 1989 Ghana restricted the export of 18 tree species, and in 1994 thecountry banned the export of raw logs. About 4.8 percent (1997) of the country’s land is officially protected, but illegal logging threatens Ghana’s remaining forests. Deforestation, overgrazing, and periodic drought have led...

• Insect - biology.

  they almost always have six legs. In some insects, such as beetles, the legs are practically identical, but in other insects each pair is a slightly different shape. Still otherinsects have specialized leg structures. Examples are praying mantises, which have grasping and stabbing forelegs armed with lethal spines, and grasshoppers andfleas, which have large, muscular hind legs that catapult them into the air. Mole crickets’ front legs are modified for digging, and backswimmers have hind legs de...

• Bird. I INTRODUCTION Bird, animal with feathers and wings. Birds are the only

  B Physical Adaptations for Flight The internal body parts of all birds, including flightless ones, reflect the evolution of birds as flying creatures. Birds have lightweight skeletons in which many of themajor bones are hollow. A unique feature of birds is the furculum, or wishbone, which is comparable to the collarbones of humans, although in birds the left and rightportions are fused together. The furculum absorbs the shock of wing motion and acts as a spring to help birds breathe while they...

• Bird - biology.

  B Physical Adaptations for Flight The internal body parts of all birds, including flightless ones, reflect the evolution of birds as flying creatures. Birds have lightweight skeletons in which many of themajor bones are hollow. A unique feature of birds is the furculum, or wishbone, which is comparable to the collarbones of humans, although in birds the left and rightportions are fused together. The furculum absorbs the shock of wing motion and acts as a spring to help birds breathe while they...

• 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...

• Saskatchewan (province) - Geography.

  The length of the frost-free season varies within the province. In the southwest, particularly in the valley lands along the South Saskatchewan River, the frost-freeperiod ranges from 150 to 160 days. Regina enjoys about 123 frost-free days, and Saskatoon has about 111. The far north has only from 85 to 95 frost-free days. One important characteristic of Saskatchewan’s climate is the great variability in temperature and precipitation from year to year, which is often critical for agriculture.The...

• Saskatchewan (province) - Canadian History.

  The length of the frost-free season varies within the province. In the southwest, particularly in the valley lands along the South Saskatchewan River, the frost-freeperiod ranges from 150 to 160 days. Regina enjoys about 123 frost-free days, and Saskatoon has about 111. The far north has only from 85 to 95 frost-free days. One important characteristic of Saskatchewan’s climate is the great variability in temperature and precipitation from year to year, which is often critical for agriculture.The...

• Heart.

  situation. A Cardiac Cycle Although the right and left halves of the heart are separate, they both contract in unison, producing a single heartbeat. The sequence of events from the beginning ofone heartbeat to the beginning of the next is called the cardiac cycle. The cardiac cycle has two phases: diastole, when the heart’s chambers are relaxed, and systole,when the chambers contract to move blood. During the systolic phase, the atria contract first, followed by contraction of the ventricles. T...

• Star (astronomy) - astronomy.

  absorbing the missing colors of light. For example, the set of dark lines made by hydrogen includes a dark red line, the set of dark lines made by sodium includes a pairof dark yellow lines, and the set of dark lines made by iron includes lines of nearly every color. Each element in the gaseous outer layer of a star produces its ownparticular pattern of dark spectrum lines, depending on the temperature and pressure of the gas. Astronomers have observed spectrum lines, or spectra, for hundredsof...

• Ohio - geography.

  conflict with modified Gulf air and causing frontal or cyclonic storms. Gulf air is dominant in summer. In fall, polar air passing over Lake Erie is modified, delaying thekilling frost along the adjacent shoreline. C1 Temperatures The mean annual temperatures for the state range from 9° C (48° F) in the northeast to 13° C (55° F) in the south. Average January temperatures range from -4° C(24° F) in the west to 2° C (35° F) in the south. July averages are 24° C (76° F) in the south and 23° C (73...

• Ohio - USA History.

  conflict with modified Gulf air and causing frontal or cyclonic storms. Gulf air is dominant in summer. In fall, polar air passing over Lake Erie is modified, delaying thekilling frost along the adjacent shoreline. C1 Temperatures The mean annual temperatures for the state range from 9° C (48° F) in the northeast to 13° C (55° F) in the south. Average January temperatures range from -4° C(24° F) in the west to 2° C (35° F) in the south. July averages are 24° C (76° F) in the south and 23° C (73...

• Hinduism.

  they do not share any basic terms. B Sanātana Dharma Evidence from inscriptions indicates that Hindus had begun to use the word dharma for their religion by the 7th century. After other religions of Indian origin also began to use this term, Hindus then adopted the expression san ātana dharma to distinguish their dharma from others. The word san ātana, meaning immemorial as well as eternal, emphasized the unbroken continuity of the Hindu tradition in contrast to the other dharmas . The Bu...

• Comparative Anatomy.

  In comparing two species, anatomists have to be careful to differentiate between homologous structures, which are ones that have evolved from a shared ancestor, andanalogous structures, which have developed from different origins. Homologous structures are built on the same underlying plan. A human arm, a bat’s wing, and awhale’s flipper look quite different from the outside, but the bones inside reveal that these limbs all have the same basic structure. Analogous structures, by contrast,often l...

• 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...

• la division du travail

• Florida - USA History.

  accidentally introduced into the region in the 1880s, and it spread with alarming rapidity throughout the upper reaches of the river. The plant is very difficult toeradicate, and it has also clogged the channels of other Florida rivers. To increase drainage of the Everglades, which drain naturally to Florida Bay and the Gulf ofMexico, a number of drainage channels and canals have been built across southern Florida. Among the rivers flowing from the peninsula to the Gulf of Mexico are the Suwanne...

• 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...