655 résultats pour "work"

• Thermodynamics I INTRODUCTION Thermodynamics, field of physics that describes and correlates the physical properties of macroscopic systems of matter and energy.

  Carnot EngineThe idealized Carnot engine was envisioned by the French physicist Nicolas Léonard Sadi Carnot, who lived during theearly 19th century. The Carnot engine is theoretically perfect, that is, it converts the maximum amount of energy intomechanical work. Carnot showed that the efficiency of any engine depends on the difference between the highest andlowest temperatures reached during one cycle. The greater the difference, the greater the efficiency. An automobileengine, for example, wou...

• Comenius, John Amos

  enlightenment, peace, international co-operation and prosperity. This should be helped by the spread of education into all layers of society, and to each individual. The outbreak of the Civil War curtailed Comenius' activities in England. He left for Sweden to reform its educational system, hoping at the same time that Sweden's policy and participation in the Thirty Years' War might result in the liberation of the Kingdom of Bohemia from the rule of the Habsburgs and facilitate the repat...

• 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...

• Ant - biology.

  The workers of many ant species carry a stinger within the hind end of the gaster. These ants use the stinger to defend against their enemies. In some species, workerants lack a stinger but use the tip of their gaster to squirt or dab poison at other small animals and when fighting battles with other ants, fending off predators, or killinginsects or other animals that they use as food. III PHYSIOLOGY Ants have a rigid, external skeleton called an exoskeleton that gives the soft, inner body its...

• Richard Wagner I INTRODUCTION Richard Wagner (1813-1883), German composer, conductor, and essayist, one of the most influential cultural figures of the 19th century.

  May 1864 he was summoned to Munich by the 18-year-old King Ludwig II of Bavaria, who settled Wagner's debts, paid him a generous allowance, and provided himwith housing. Wagner was soon joined in his new home by Cosima von Bülow, Liszt’s daughter and the wife of German conductor and pianist Hans von Bülow. Wagnerand Cosima began a relationship that produced three children before the dissolution of the Bülows' marriage in 1870. Mounting hostility toward Wagner by members ofLudwig’s court resulted...

• Homer I INTRODUCTION Homer, the name traditionally assigned to the author of the Iliad and the Odyssey, the two major epics that have survived from Greek antiquity.

  Apollo ), and some have argued that portions of the texts, such as the concluding scenes of the Odyssey, were added by another hand. However, they generally believed that Homer was a poet (or at most, a pair of poets) much like the poets they knew from their own experience. They believed that the Iliad and the Odyssey, although based on traditional materials, were independent, original, and largely fictional. In the last 200 years, however, this view has changed radically, following the emer...

• Homer.

  Apollo ), and some have argued that portions of the texts, such as the concluding scenes of the Odyssey, were added by another hand. However, they generally believed that Homer was a poet (or at most, a pair of poets) much like the poets they knew from their own experience. They believed that the Iliad and the Odyssey, although based on traditional materials, were independent, original, and largely fictional. In the last 200 years, however, this view has changed radically, following the emer...

• Ballet I INTRODUCTION Tchaikovsky's The Nutcracker The Nutcracker is a classic ballet with music by Peter Ilyich Tchaikovsky.

  Joffrey Ballet SchoolTraining for classical ballet dancers must begin when the students are very young. Here, teacher Dorothy Lister workswith her pre-ballet class of six-year-olds at the Joffrey Ballet School. These students are learning the five basic positions ofclassical ballet.Susan Kunklin/Photo Researchers, Inc. Different systems of ballet training have evolved, named after countries (Russia, France) or teachers (Italian dancer Enrico Cecchetti, Danish choreographer AugustBournonville). T...

• Cubism I INTRODUCTION Cubism, movement in modern art, especially in painting, invented by Spanish artist Pablo Picasso and French artist Georges Braque in 1907 and 1908.

  Mont Sainte-Victoire by CézanneFrench artist Paul Cézanne painted Mont Sainte-Victoire, a mountain near his home in Provence in southern France, onmany occasions. Over time, the images he produced became flatter, less realistic, and more abstract. In this late version,painted from 1902 to 1904, patches of color barely indicate the mountain, sky, and foreground, while creating a rhythmicpattern across the painting’s surface. The mountain and sky, both intensely blue, appear almost to merge.Philad...

• Condorcet, Marie-Jean-Antoine-Nicolas Caritat de

  years he also came under the influence of Euler, Fontaine, the Bernouillis and, above all, of the distinguished mathematician and academician, Jean Le Rond D'Alembert , who became his patron. He was elected Perpetual Secretary of the Academy of Sciences in 1773, and in 1782 became a member of the French Academy. An enthusiastic supporter and theorist of the Revolution, he played an important role in the drafting of the Déclaration des droits in 1789. Suspected later of being a Girondin, he w...

• Richard Wagner.

  which took place in August 1876. Wagner completed his final opera, Parsifal (which he called a 'festival drama of dedication' for the Festspielhaus), in 1882, and it premiered that July. In September Wagner moved to Venice, where in February 1883, after a heated argument with Cosima, he suffered a fatal heart attack. He was buried in Bayreuth. III MUSIC AND THOUGHT In the early 19th century, an opera was structured as a succession of conventional self-contained forms such as aria (a vocal so...

• United Nations.

  and programs to carry out its recommendations. It elects members to serve on certain agencies and programs, and it coordinates those programs through variouscommittees. B Security Council The Security Council is the most powerful body in the UN. It is responsible for maintaining international peace, and for restoring peace when conflicts arise. Its decisionsare binding on all UN members and have the force of international law. The Security Council has the power to define what is a threat to sec...

• Eleanor Roosevelt.

  disliked Washington, D.C., which she found only slightly less provincial than Albany. Moreover, she feared that the role of first lady would be a confining one. “I neverwanted to be a president’s wife,” she privately declared just after the election. At the time of Franklin’s election Eleanor was an independent journalist, making money from a monthly column in Woman's Home Companion and from radio broadcasts, where she regularly spoke out on controversial political issues. She sat on the board...

• Eleanor Roosevelt - USA History.

  disliked Washington, D.C., which she found only slightly less provincial than Albany. Moreover, she feared that the role of first lady would be a confining one. “I neverwanted to be a president’s wife,” she privately declared just after the election. At the time of Franklin’s election Eleanor was an independent journalist, making money from a monthly column in Woman's Home Companion and from radio broadcasts, where she regularly spoke out on controversial political issues. She sat on the board...

• 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...

• Slavery in the United States - U.

  tripled, from about 1.2 million to almost 4 million in 1860. The natural growth of the slave population meant that slavery could survive without new slave imports. Natural population growth also hastened the transition from an African to an African American slave population. By the 1770s, only about 20 percent of slaves in thecolonies were African-born, although the concentration of Africans remained higher in South Carolina and Georgia. After 1808 the proportion of African-born slavesbecame tin...

• Galileo.

  V WORK IN ASTRONOMY During most of his time in Padua, Galileo showed little interest in astronomy, although in 1595 he declared in a letter that he preferred the Copernican theory that Earthrevolves around the Sun to the assumptions of Aristotle and Ptolemy that planets circle a fixed Earth ( see Astronomy: The Copernican Theory ; Ptolemaic System). A Observations with the Telescope In 1609 Galileo heard that a telescope had been invented in Holland. In August of that year he constructed a t...

• Archaeology.

  Prehistoric archaeology is practiced by archaeologists known as prehistorians and deals with ancient cultures that did not have writing of any kind. Prehistory, a term coined by 19th-century French scholars, covers past human life from its origins up to the advent of written records. History—that is, the human past documented insome form of writing—began 5000 years ago in parts of southwestern Asia and as recently as the late 19th century AD in central Africa and parts of the Americas. Becaus...

• 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...

• Frank Lloyd Wright I INTRODUCTION Robie House The Frederick C.

  Hills/DeCaro HouseAmerican architect Frank Lloyd Wright, a pioneer of modern architecture, lived and worked in the Chicago area during thelate 19th and early 20th centuries. He designed many single-family houses, known as prairie houses. The Hills/DeCarohouse in Oak Park, west of Chicago, is one of more than 20 houses Wright designed while living in the town between 1890and 1910.© 2007 Frank Lloyd Wright Foundation / Artists Rights Society (ARS), New York / Photo: Mary Ann Hemphill/Photo Researc...

• Thomas Jefferson I INTRODUCTION Thomas Jefferson (1743-1826), third president of the United States (1801-1809) and author of the Declaration of Independence.

  Jefferson was a poor speaker, but his literary talents made him a highly valued member of committees when resolutions and other public papers were drafted. Heemerged as the recognized author of the patriot cause in Virginia and indeed in the whole of the colonies. Jefferson's first public paper, however, was considered toostiff and formal, and it was rewritten. The paper was a response to the greeting of the new governor, Lord Botetourt, to the General Assembly. Jefferson, who nevertook criticis...

• Thomas Jefferson.

  Jefferson was a poor speaker, but his literary talents made him a highly valued member of committees when resolutions and other public papers were drafted. Heemerged as the recognized author of the patriot cause in Virginia and indeed in the whole of the colonies. Jefferson's first public paper, however, was considered toostiff and formal, and it was rewritten. The paper was a response to the greeting of the new governor, Lord Botetourt, to the General Assembly. Jefferson, who nevertook criticis...

• Thomas Jefferson

  Jefferson was a poor speaker, but his literary talents made him a highly valued member of committees when resolutions and other public papers were drafted. Heemerged as the recognized author of the patriot cause in Virginia and indeed in the whole of the colonies. Jefferson's first public paper, however, was considered toostiff and formal, and it was rewritten. The paper was a response to the greeting of the new governor, Lord Botetourt, to the General Assembly. Jefferson, who nevertook criticis...

• Thomas Jefferson - USA History.

  Jefferson was a poor speaker, but his literary talents made him a highly valued member of committees when resolutions and other public papers were drafted. Heemerged as the recognized author of the patriot cause in Virginia and indeed in the whole of the colonies. Jefferson's first public paper, however, was considered toostiff and formal, and it was rewritten. The paper was a response to the greeting of the new governor, Lord Botetourt, to the General Assembly. Jefferson, who nevertook criticis...

• Confucian philosophy, Chinese

  occupies a pre-eminent place in the history of Chinese philosophy. The core of Confucian thought lies in the teachings of Confucius (551-479 BC) contained in the Analects ( Lunyu ), along with the brilliant and divergent contributions of Mencius (372?-289 BC) and Xunzi ( fl. 298-238 BC), as well as the Daxue (Great Learning) and the Zhongyong (Doctrine of the Mean), originally chapters in the Liji (Book of Rites). Significant and original developments, particularly along a quasi-metaphysica...

• 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...

• Frank Lloyd Wright.

  C Usonian Houses Wright achieved his goal of low-cost, democratic American architecture with his Usonian houses of the 1930s. Usonia was Wright’s term for the United States of North America, with an i added for a pleasing sound. The Usonian house had a simple design, usually with an L-shaped floor plan. This plan separated the noisier living space on one leg of the L from the quieter bedroom space on the other leg. The floor was made of concrete slabs, typically in a square grid of 4 by 4...

• Molecule - chemistry.

  attracted to the negatively charged electrons between them. The electrons belong to the molecule as a whole. However, each hydrogen atom now has a complete outershell of two electrons. The formula H 2 describes a hydrogen molecule, a discrete unit. When a molecule contains just two atoms, such as the hydrogen molecule does, it is called a diatomic molecule. Some atoms can form covalent bonds with more than one other atom and thus create a larger molecule. Atoms form molecules with covalent bo...

• Woodrow Wilson.

  daughters. In 1885 Wilson also accepted a position with the newly opened Bryn Mawr College, a school for women near Philadelphia. Wilson was not particularly patient with womenas intellectual associates and did not enjoy his teaching duties. He was, however, able to pursue his writing. A University Professor In 1888 Wilson left Bryn Mawr for a professorship in history and political economy at Wesleyan University in Connecticut. There, in 1889, he published The State, a lengthy textbook analyz...

• Woodrow Wilson

  daughters. In 1885 Wilson also accepted a position with the newly opened Bryn Mawr College, a school for women near Philadelphia. Wilson was not particularly patient with womenas intellectual associates and did not enjoy his teaching duties. He was, however, able to pursue his writing. A University Professor In 1888 Wilson left Bryn Mawr for a professorship in history and political economy at Wesleyan University in Connecticut. There, in 1889, he published The State, a lengthy textbook analyz...

• Leonardo da Vinci.

  Leonardo's stylistic innovations are even more apparent in The Last Supper, in which he represented a traditional theme in an entirely new way. Instead of showing the 12 apostles as individual figures, he grouped them in dynamic compositional units of three, framing the figure of Christ, who is isolated in the center of the picture.Seated before a pale distant landscape seen through a rectangular opening in the wall, Christ—who has just announced that one of those present will betrayhim—repres...

• Mental Retardation.

  For example, measles, chicken pox, and whooping cough may lead to encephalitis and meningitis, which can damage the brain. Physical trauma to the brain can also cause mental retardation. Brain damage may result from accidental blows to the head, near drowning, severe child abuse, andchildhood exposure to such toxins as lead and mercury. Experts believe that poverty and a lack of stimulation during infancy and early childhood can be factors inmental retardation. Children raised in poor environmen...

• Uruguay (country) - country.

  Freedom of religion is guaranteed by the constitution of Uruguay. Three-quarters of the people belong to the Roman Catholic Church. There are also sizable Protestantand Jewish congregations. The official language is Spanish, which in Uruguay has been influenced by Italian vocabulary and pronunciation. C Education Uruguay has one of the highest rates of literacy in Latin America, at 98.2 percent of the adult population. Six years of primary education is compulsory, and Uruguay isone of the few n...

• Respiratory System.

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

• Civil Rights Movement in the United States - U.

  The Great Depression of the 1930s increased black protests against discrimination, especially in Northern cities. Blacks protested the refusal of white-owned businessesin all-black neighborhoods to hire black salespersons. Using the slogan “Don't Buy Where You Can't Work,” these campaigns persuaded blacks to boycott thosebusinesses and revealed a new militancy. During the same years, blacks organized school boycotts in Northern cities to protest discriminatory treatment of blackchildren. The bla...

• Peter Paul Rubens I INTRODUCTION Thetis Dipping Achilles in the Styx The sea nymph Thetis is seen dipping her son Achilles in the River Styx to make him immortal.

  Rubens, Equestrian Portrait of the Duke of LermaIn 1603 Flemish painter Peter Paul Rubens traveled to Spain as part of a diplomatic mission. While there, he received acommission for this portrait of the Duke of Lerma, the powerful prime minister of Spanish king Philip III. The painting nowhangs in the Prado Museum in Madrid, Spain.The Prado Museum, Madrid/Archivo Fotografico Oronoz Shortly thereafter, following the example of many northern European artists of the period, Rubens traveled to Italy...

• Turbine.

  steam turbine has supplanted the reciprocating engine as a prime mover in large electricity-generating plants and is also used as a means of jet propulsion. Steam turbines are used in the generation of nuclear power and in nuclear ship propulsion. They operate with fuel-fired boilers for power generation. In cogenerationapplications requiring both process heat (heat used in an industrial process) and electricity, steam is raised at high pressure in the boiler and extracted from the turbineat th...

• Martin Luther King, Jr.

  disorder that local white officials would be forced to end segregation to restore normal business relations. The strategy did not work in Albany. During months ofprotests, Albany’s police chief jailed hundreds of demonstrators without visible police violence. Eventually the protesters’ energy, and the money to bail out protesters,ran out. The strategy did work, however, in Birmingham, Alabama, when SCLC joined a local protest during the spring of 1963. The protest was led by SCLC member FredShut...

• Martin Luther King, Jr.

  disorder that local white officials would be forced to end segregation to restore normal business relations. The strategy did not work in Albany. During months ofprotests, Albany’s police chief jailed hundreds of demonstrators without visible police violence. Eventually the protesters’ energy, and the money to bail out protesters,ran out. The strategy did work, however, in Birmingham, Alabama, when SCLC joined a local protest during the spring of 1963. The protest was led by SCLC member FredShut...

• Adolf Hitler I INTRODUCTION Adolf Hitler (1889-1945), German political and military leader and one of the 20th century's most powerful dictators.

  A Economic Collapse At the end of World War I, the Allies (those countries who had fought against Germany) had demanded that Germany pay reparations—that is, payments for wardamages. The government refused to pay all that was demanded by the Allies. When Germany failed to pay enough, France and Belgium occupied the coal mines in theRuhr industrial area in west central Germany in January 1923. In protest, the German government halted all reparation payments and called for passive resistance by a...

• Adolf Hitler.

  A Economic Collapse At the end of World War I, the Allies (those countries who had fought against Germany) had demanded that Germany pay reparations—that is, payments for wardamages. The government refused to pay all that was demanded by the Allies. When Germany failed to pay enough, France and Belgium occupied the coal mines in theRuhr industrial area in west central Germany in January 1923. In protest, the German government halted all reparation payments and called for passive resistance by a...

• Adolf Hitler .

  A Economic Collapse At the end of World War I, the Allies (those countries who had fought against Germany) had demanded that Germany pay reparations—that is, payments for wardamages. The government refused to pay all that was demanded by the Allies. When Germany failed to pay enough, France and Belgium occupied the coal mines in theRuhr industrial area in west central Germany in January 1923. In protest, the German government halted all reparation payments and called for passive resistance by a...

• 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...

• 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...

• Early sunday morning analyse

  The use of swastikas in his master pieces created a big polemic in Sweden forcing the Prime Minister to remove two of Bengtsson’s paintings. Indeed, because of the European Union Foreign secretaries meeting taking place on September the 4 th and 5 th 2009, Swedish authorities decided to remove these paintings judged “sensitive”. Therefore, Early Sunday Morning (1970) (whose I m going to talk about later) and Hat and Cap Fa...

• Berkeley, George

  during the years 1707-8. Since their first publication in 1871 (but more particularly since it was established that they had at some stage been bound together in the wrong order, thus giving a distorted picture of the development of Berkeley's thought) these have proved an invaluable resource for scholars seeking to understand the evolution of his thinking during this crucial period. The major fruits of that thinking were An Essay towards a New Theory of Vision (1709), A Treatise concernin...

• Art and morality

  have a strong emotional effect, but which make it difficult for us to decide, on account of their complexity, howthey influence our outlook and thus our conduct. This lies at the centre of the long-lasting debate about the effectof tragedy (see Tragedy ). It seems strange that we should be unable to decide whether tragedies of great power, such as Oedipus the King , exalt, devastate, bewilder, affirm or question basic values, and so on. Yet all these positions are held and argued about with...

• Artist's intention

  3 Art and experience Argument (2) rightly assumes that the critic's task is to understand the work itself, and that for a claim about the artist (for example, one concerning the artist's intentions) to be relevant to criticism, theclaim must potentially make a difference to the way we experience the work. But this only tells us that the critic'sinterest in the artist should be for the sake of understanding the work and not vice versa. (An analogy: to inquirewhether someone's hand gesture was in...

• Artistic expression

  various types of neural network. Although classical and connectionist AI are often described as utterly distinctparadigms, research in both these approaches commenced because of this paper. Early connectionist work wasfurther encouraged by McCulloch and Pitts in a paper of 1947. They pointed out that the brain is a parallel-processing device, not a sequential one. Moreover, it can function acceptably even when some cells misfire or die,or when the input signal is 'noisy'. The perf...

• Expressionism I INTRODUCTION Auguste Rodin Regarded as the foremost sculptor of the 19th and 20th centuries, French artist Auguste Rodin captured both dynamic movement and inner psychological states.

  Improvisation 28 (second version)Improvisation 28 (second version) was painted by Russian artist Wassily Kandinsky in 1912. Kandinsky used energeticcolor and form to express the spiritual content of his work. He was also a musician and saw a connection between thevisual arts and music, which he attempted to convey in paintings such as this one.© 2008 Artists Rights Society (ARS), New York / ADAGP, Paris./Bridgeman Art Library, London/New York A new phase of German expressionism called Die Neue...