3232 résultats pour "système"

• électronique de spin.

  La structure décrite ci-dessus est une « vanne de spin » ; elle peut être utilisée comme un détecteur de champ magnétique. Il suffit d’utiliser deux couches magnétiques présentant des comportements différents. La première, appelée « couche dure », est insensible à un champ magnétique externe ; au contraire, la seconde, dite « couche douche », voit son aimantation tourner en fonction de l’intensité du champ magnétique extérieur. Ainsi, en fonction de son orientation, un champ magnétique externe v...

• World War I .

  and troops to Europe from the United States and other overseas sources. In 1914 Britain implemented a sea blockade of Germany to prevent the delivery of importssuch as food and war materials. The same year, Germany began using submarines to disrupt Allied seaborne traffic and prevent supplies from reaching Britain. In 1915Germany instituted a submarine blockade around Britain. From February 1915 to September 1915 and again in 1917, Germany used unrestricted submarine warfare,sinking ships withou...

• California - geography.

  The Basin and Range province is an arid area of mountain ranges, basins, and deserts. In California it is represented primarily by parts of the Great Basin and SonoranDesert sections. Within the Great Basin lies Death Valley, whose lowest elevation, 86 m (282 ft) below sea level, is the lowest point in the Western Hemisphere. TheSonoran Desert section is characterized by numerous flat plains separated by low but rugged ranges. It includes the extensive Mojave, or Mohave, Desert. Also in thisprov...

• California - USA History.

  The Basin and Range province is an arid area of mountain ranges, basins, and deserts. In California it is represented primarily by parts of the Great Basin and SonoranDesert sections. Within the Great Basin lies Death Valley, whose lowest elevation, 86 m (282 ft) below sea level, is the lowest point in the Western Hemisphere. TheSonoran Desert section is characterized by numerous flat plains separated by low but rugged ranges. It includes the extensive Mojave, or Mohave, Desert. Also in thisprov...

• Sewage Disposal.

  greater load on the piping system and the treatment plant. The amount of storm-water drainage to be carried away depends on the amount of rainfall as well as on the runoff or yield of the watershed ( see Drainage). A typical metropolitan area discharges a volume of wastewater equal to about 60 to 80 percent of its total daily water requirements, the rest being used for washingcars and watering lawns, and for manufacturing processes such as food canning and bottling. B Composition The composi...

• James Madison.

  In the spring of 1784 Madison again ran for election to the Virginia assembly, and won. He served nearly three years there, pursuing the same objectives he had foughtfor in Congress. He advocated strengthening the federal government, which was an unpopular position in Virginia, as it was in most of the states. He consistentlysupported measures, at both state and national levels, that would best safeguard the rights of the individual. Madison also continued to oppose any connection betweenchurch...

• James Madison

  In the spring of 1784 Madison again ran for election to the Virginia assembly, and won. He served nearly three years there, pursuing the same objectives he had foughtfor in Congress. He advocated strengthening the federal government, which was an unpopular position in Virginia, as it was in most of the states. He consistentlysupported measures, at both state and national levels, that would best safeguard the rights of the individual. Madison also continued to oppose any connection betweenchurch...

• James Madison - USA History.

  In the spring of 1784 Madison again ran for election to the Virginia assembly, and won. He served nearly three years there, pursuing the same objectives he had foughtfor in Congress. He advocated strengthening the federal government, which was an unpopular position in Virginia, as it was in most of the states. He consistentlysupported measures, at both state and national levels, that would best safeguard the rights of the individual. Madison also continued to oppose any connection betweenchurch...

• Chaos et catastrophe (Sciences & Techniques)

  Takens, à la fin des années 1960. Si on peut définir l'état d'un système par seulement trois paramètres, on peut alors le symboliserpar un point dans un espace à trois dimensions. L'évolution du système est alors représentée par la trajectoire du point sur unecourbe. Considérons deux situations proches, représentées par deux points voisins l'un de l'autre. Quand le système n'est paschaotique, les deux points décrivent deux courbes très proches l'une de l'autre, tout en restant voisins. Dans le c...

• Ireland - country.

  F Plants and Animals Ireland’s animal life does not differ markedly from that of England or France. Over many centuries of human settlement almost all of Ireland’s natural woodlands werecleared, and indigenous animals such as bear, wolf, wildcat, beaver, wild cattle, and the giant Irish deer (a type of fallow deer) gradually disappeared. However, thehardy and versatile Connemara pony, Ireland’s only native pony breed, has been used by Irish farmers since prehistoric times. The great auk, or gar...

• Supreme Court of the United States.

  The Constitution does not specify formal qualifications for membership on the Supreme Court. From the beginning, though, justices have all been lawyers, and mostpursued legal and political careers before serving on the Court. Many justices served as members of Congress, governors, or members of the Cabinet. One president,William Howard Taft, was later appointed chief justice. Some justices came to the Court from private law practice, and others were appointed from positions as lawprofessors. Man...

• Copernic Nicolas, en polonais Miko?aj Kopernik.

  compatibles avec les Écritures. Il fallut l'invention des lunettes et les découvertes qu'elle entraîna pour convaincre petit à petit la communauté scientifique. Complétez votre recherche en consultant : Les livres astronomie - système de Copernic, page 410, volume 1 Complétez votre recherche en consultant : Les corrélats Aristarque de Samos astronomie Brahe Tycho Galilée (Galileo Galilei, dit en français) héliocentrisme Kepler Johannes Lune - La connaissance de la Lune - L'observati...

• 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,...

• 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...

• télévision - informatique.

  4 CAMÉRA DE TÉLÉVISION La caméra de télévision ressemble à un appareil photographique. Elle est équipée d'une ou de plusieurs lentilles ( voir Optique) et d'un dispositif permettant de concentrer sur une surface photosensible l'image formée. Les surfaces sensibles à la lumière sont des tubes électroniques particuliers, appelés tubes analyseurs, qui transforment les variations de luminosité en variations de charge ou d'intensité électrique. Le premier tube à avoir été utilisé dans les caméras...

• Algeria - country.

  areas to fishing. National parks, including the giant Tassili N’Ajjer National Park in the eastern corner of the country, comprise a large proportion of the protected area. The effects of Algeria’s human population on the fragile landscape have been severe. The greatest ecological threats are deforestation and burning of scrub vegetation,conversion of steppe habitat to arable land, and soil erosion due to overgrazing and poor farming practices. Pollution of Mediterranean coastal waters is pervas...

• L'EDUCATION A LA CITOYENNETE A L'ECOLE : Etude comparative en Allemagne/Angleterre/France

  objectifs poursuivis par les autorités publiques dans le domaine de l'éducation à la citoyenneté.Avec l'élargissement de l'Europe, cette volonté de former des futurs citoyens responsables au sein d'une société deplus en plus multiculturelle se retrouve renforcée aujourd'hui. Il convient de donner aux jeunes une idée de ce quel'on désigne par « citoyenneté responsable » au sein d'une société fondée sur la démocratie. Et par la même de leurinculquer les principes de base d'une attitude civique pos...

• LE SYSTÈME DRAMATIQUE DE RACINE

  le spectateur reste dans l'angoisse, ballotté de la crainte à l'espoir.Action simple et rapide. Un événement initial exige un dénouement urgent de la crise : c'est l'arrivée d'Oreste,ambassadeur des Grecs, qui réclame le fils d'Hector pour le faire mettre à mort. Entre cet événement et ceux de lacatastrophe finale, aucun autre; rien que des passions et des sentiments, passions et sentiments tous orientés parAndromaque, dont l'hésitation entre ses deux devoirs attire ou repousse Pyrrhus...

• 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...

• L es insectes, dont on connaît actuellement 1 250 000 espèces, mais dont le nombre pourrait osciller entre 5 et 25 millions, représentent environ 80 % de l'ensemble du règne animal.

  Le corps des insectes est protégé par un squelette externe (exosquelette), carapace riche en sclérotine, substance azotée rigide et très résistante. Une autre substance azotée, mais aux propriétés élastiques, la chitine, assure la souplesse des articulations. Ce squelette, commun à tous les arthropodes, entraîne l'existence de mues. Chez les insectes, le corps est divisé en trois parties bien distinctes : la tête, le thorax et l'abdomen. Complétez votre recherche en consultant : Les corrélats...

• Iraq - country.

  The Euphrates begins in Turkey, crosses Syria, and enters Iraq at Abū Kam āl. The flow of the Euphrates into Iraq has been greatly reduced by dams built by Turkeyand Syria. The gradient of the Euphrates above the town of H īt, in west central Iraq, is steep. In the 2,640 km (1,640 mi) from its source in Turkey to H īt, the river fallsfrom 3,000 m (10,000 ft) to a low water elevation of 50 m (170 ft) above sea level, an average drop of 1 m per km (6 ft per mi). In Iraq below H īt the fall is very...

• President of the United States.

  Democrats and Republicans—select delegates to attend their party conventions. Primary voters and caucus participants choose delegates who will support their favoredcandidate at the convention. The party conventions, held in the summer before the November general election, formally nominate the winner of the primaries andcaucuses. Would-be candidates crisscross the states that hold the earliest primaries, especially New Hampshire, which holds the country’s first primary, usually in mid-February....

• La pensée politique de l'antiquité (gréco-romaine)

  Section 2 : L'idéal démocratique Les intellectuels sont anti-démocrates . Ils sont des aristocrates à l'origine . L'idéal démocratique ne se voit que dans les discourspolitiques des hommes politiques . Le plus connu c'est le discours de Péricles . Stratège d'Athènes , plus haut magistrat de la ville, fait d'Athènes une ville purement démocratique . Il engage Athènes dans une guerre contre Sparte , 2 visions de la cité , guerreidéologique (431-404) . Dans ce discours il explique pourquoi la démoc...

• « Chaque personne a un droit égal à un système pleinement adéquat de libertés et de droits de base égaux pour tous, compatible avec un même système pour tous. » John Rawls, Justice et Démocratie, 1990. Commentez cette citation.

  l'arbitraire d'un pouvoir que n'encadre aucun droit. Ces droits, accordes egalement a tous, signifient que les institutions de l'Etat garantissent un certain nombre de possibilites pour l'indi- vidu : liberte de pensee, de reunion, de propriete, de culte, du commerce, etc. Nous savons que l'essentiel de ces droits four- nissent la matiere a la Declaration universelle des droits de l'homme adopt& par l'ONU en 1948. Vous avez dit « droits de l'homme » ?Les droits de l'homme ont une histoire. Il en...

• New Jersey - geography.

  C Soils Broadly defined, all of New Jersey’s soils are podzolic soils; that is, they are acidic and contain fairly high amounts of iron oxides. The soils in northern New Jersey areirregular in quality and contain rock fragments and small stones deposited by the continental glaciers of the last Ice Age. The soils of the inner coastal plain, unaffectedby glaciation, are the richest in the state, while those of the outer coastal plain are generally infertile. The newer soil classification system d...

• New Jersey - USA History.

  C Soils Broadly defined, all of New Jersey’s soils are podzolic soils; that is, they are acidic and contain fairly high amounts of iron oxides. The soils in northern New Jersey areirregular in quality and contain rock fragments and small stones deposited by the continental glaciers of the last Ice Age. The soils of the inner coastal plain, unaffectedby glaciation, are the richest in the state, while those of the outer coastal plain are generally infertile. The newer soil classification system d...

• Finland - country.

  Productive forestland is the most valuable natural resource of Finland. Spruce, pine, and silver birch are the principal trees used to manufacture wood and pulp andpaper products. Finland lacks coal and petroleum resources and is a net importer of energy resources. However, Finland does have significant deposits of peat, which is cut from thenumerous peat bogs that cover much of the north. Peat is an important heat source for homes, and it provides about 7 percent of Finland’s electricity needs....

• langue et langage - Langues et Linguistique.

  grandes différences entre elles sur le plan des systèmes phoniques comme sur celui des structures grammaticales. 5. 1 Classification par la forme Les langues peuvent être classées selon la forme de leur grammaire. Au début du XIX e siècle, les linguistes se sont efforcés de regrouper les langues selon quatre catégories morphologiques ou typologiques qui sont liées à la façon dont les mots sont formés. Il s'agit des catégories dites « isolantes », « agglutinantes », « flexionnelles » et « inco...

• Hungary - country.

  Northern Hungary lacks sufficient water, especially between July and October, when precipitation levels are typically low. Canals irrigate the Great Hungarian Plain,which is subject to drought. Because of the country’s mainly flat terrain, only limited water resources can be harnessed for hydroelectric power. F Environmental Issues Rapid industrialization in Hungary following World War II contributed significantly to a number of major environmental problems, including air, water, and soil pollu...

• Uruguay (1998-1999): Nouveau système électoral La vie politique du pays aura été marquée, pendant l'année 1999, par trois scrutins nationaux,...

  Uruguay (1998-1999): Nouveau système électoral La vie politique du pays aura été marquée, pendant l'année 1999, par trois scrutins nationaux, auxquels devaient s'ajouter les élections municipales fixées à mai 2000. Ce calendrier a résulté de la modification de la Constitution approuvée par référendum en décembre 1996. La réforme portait uniquement sur le système électoral: l'ancienne élection nationale unique organisée tous les cinq ans, où l'ensemble des postes électoraux à tous niveaux étaien...

• Constitution of the United States.

  chief executive should have the power to veto legislation, should be elected by Congress or the people, should be eligible to run for reelection, and should command thearmed forces. Some delegates even hoped for a limited monarchy. Not until September 8, more than three months after the convention started, did the final shape ofthe presidency emerge: a single leader, elected to a four-year term and eligible for reelection, with authority to veto bills enacted by Congress. The president was alsog...

• Constitution of the United States - U.

  chief executive should have the power to veto legislation, should be elected by Congress or the people, should be eligible to run for reelection, and should command thearmed forces. Some delegates even hoped for a limited monarchy. Not until September 8, more than three months after the convention started, did the final shape ofthe presidency emerge: a single leader, elected to a four-year term and eligible for reelection, with authority to veto bills enacted by Congress. The president was alsog...

• Cours complet d'histoire africaine

  CHAPITRE I : L’IMPERIALISME EUROPEEN EN AFRIQUE Leçon1 : Les causes de l’impérialisme européen en Afrique (2H) OG1 : Comprendre la situation politique de l’Europe au XIX ème siècle OG2 : Comprendre la situation économique de l’Europe au XIX OG3 : Analyser les causes de l’expansion européenne au XIX ème ème siècle siècle Introduction Au début du XIXe siècle, l’Afrique commence à susciter l’intérêt des européens après l’abolition de l’esclavage. Quelles sont les rais...

• Sir Frederick William Herschel

  pour son travail et sa persévérance . Il avait sui vi, parmi les étoiles, les mouvements d'un petit astre de couleur verte, derrière l' orbite de la planète Saturne . Il pensa d'abord qu'il s'agis sait d'une comète, mais il semblait que l'orbite observée res­ semblait trop à une orbite circulaire pour être confondue avec une comète. Herschel sentit qu 'il avait découvert une nouvelle planète, pour la pre­ mière fois depuis l'antiquité. I...

• Diving (underwater).

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

• Autism.

  may also repeat body movements, such as spinning, rocking, or flapping hands. When upset or excited, they may also harm themselves by skin-biting or head-banging. They may also show significant aggression toward other people or inanimateobjects, or may have episodes of extreme anger or frustration. D Associated Symptoms Some children with autism show other symptoms that do not contribute to the diagnosis of autism itself. Sensory sensitivity is quite common, especially to some textures, sounds,...

• Secrète, souvent repliée sur elle-même, la Chine depuis des siècles fascine et inquiète l'Occident.

  Himalaya Huang He Mandchourie Mongolie-Intérieure Shaanxi Shandong Shanxi Sichuan Tian Shan Tibet Xinjiang (région autonome ouïgoure du) Yangzi Jiang Les livres Chine - karst à tourelles, au Yunnan, page 1059, volume 2 Chine - Huang He (Le fleuve Jaune), page 1062, volume 2 Les aspects humains La population du pays, qui est composée à 92 % de Chinois Hans, et, pour les 8 % restants, de cinquante-quatre peuples, appelés minorités nationales, est très inégalement répartie. La côt...

• Les prisons

  LES ÉVASIONS En 2001, 1es �WIS#Ms ont atteint le nombre de 54, impliquant 75 détenus. Trente et une ont abouti et concernaient 38 détenus. De plus en plus specta­ culaires, les évasions font la une de la presse. Pourtan� la sécurité est une préoccupation constante dans les prisons. Au quotidien, chaque geste des surveillants est pesé : de l'examen rapide par l'œilleton avant d'ouvrir la porte des cellules jusqu'aux fouilles quotidiennes par palpat...

• Abolitionist Movement.

  The American Revolution (1775-1783) and the French Revolution (1789-1799), widely seen as revolutions by citizens against oppressive rulers, transformed thisEnlightenment assertion into a call for universal liberty and freedom. The successful slave revolt that began in the French colony of Saint-Domingue in 1791 was part of this revolutionary age. Led by François Dominique ToussaintLouverture, black rebels overthrew the colonial government, ended slavery in the colony, and in 1804 established th...

• Abolitionist Movement - U.

  The American Revolution (1775-1783) and the French Revolution (1789-1799), widely seen as revolutions by citizens against oppressive rulers, transformed thisEnlightenment assertion into a call for universal liberty and freedom. The successful slave revolt that began in the French colony of Saint-Domingue in 1791 was part of this revolutionary age. Led by François Dominique ToussaintLouverture, black rebels overthrew the colonial government, ended slavery in the colony, and in 1804 established th...

• Stock Exchange.

  A Example of a Trade In an example of a trade, an investor wanting to buy 200 shares—also known as two round lots, of 100 shares each—of IBM stock will telephone or e-mail the order to abrokerage firm. This communication is normally made to an individual called a stockbroker. The investor might desire to buy the shares at the market, or current, price.On the other hand, the investor may choose to pay no more than a set amount per share. The brokerage firm then contacts one of its floor brokers...

• Cyprus - country.

  40,000 cubic meters (1.4 million cubic feet) of salt water into fresh water per day, opened at Dhekelia in 1997, and a second larger plant opened at Larnaca in 2001. III PEOPLE OF CYPRUS The combined population of the Greek and Turkish sectors (2008 estimate) is 792,604. The overall population density is 86 persons per sq km (222 per sq mi). About69 percent of the island’s inhabitants live in urban areas. Greek-speaking Cypriots make up approximately 85 percent of the population. About 12 perc...

• Libya - country.

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

• Madrid - geography.

  stores and offices on the first one or two levels. While many people rent their apartments, most own them and participate in cooperatives that maintain the building.Because living spaces are small by American standards, madrileños do most of their socializing in the streets, bars, restaurants, and parks of their neighborhoods. Onlya few very wealthy areas north of the city have single family houses with gardens and yards similar to those in American suburbs. Many of the newest neighborhoodsare c...

• 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...

• 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...

• Les sciences construisent-elles leur objet ?

  Transition : L'impossibilité d'invoquer un verdict absolu en matière scientifique et les multiples remises en cause des théories scientifiques réfutent-elles le réalisme scientifique ? La science considérée comme un outil. 2. a) L'histoire des sciences tend à infirmer le réalisme. Si l'on prend par exemple les systèmes astronomiques, nousconstatons que le système astronomique de Ptolémée, qui plaçait la Terre au centre de l'univers, était dans sesprévisions quasiment aussi efficace que celui...

• Criminal Law.

  for rehabilitative treatment for the offender. On the other hand, the goals of punishment may at times conflict. The retributive and deterrence theories call for theinfliction of unpleasant experiences upon the criminal, including harsh prison treatment; but the prison environment may not be conducive to, or may even defeat,rehabilitation. No one theory of punishment addresses all the goals of criminal law. A combination of theories and goals plays a part in the thinking of the legislators who e...