661 résultats pour "usées"
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eaux usées (faune & Flore).
4.2 Composition La composition des eaux usées s’analyse par le biais de diverses mesures physiques, chimiques et biologiques. Les analyses les plus fréquentes comportent des mesures dedéchets solides, de la demande biochimique en oxygène mesurée après 5 jours (DBO5), de la demande chimique en oxygène (DCO) et du pH. Les déchets solidescomprennent les solides dissous et en suspension. Les solides dissous sont les matériaux qui passent à travers un papier filtre et les solides en suspension sont...
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Electronic Music
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INTRODUCTION
Electronic Music, music that requires the use of electronic devices to produce or manipulate sound during its composition and performance.
III SYNTHESIZERS AND OTHER ELECTRONIC TECHNOLOGY Moog SynthesizerThe musical synthesizer was invented by American Robert Moog. Soon after Moog introduced an early version in 1964, itbecame known as the “Moog Synthesizer,” and then simply as the “Moog.” Here, Japanese composer Isao Tomita uses aMoog synthesizer in his studio.Huynh Cong/AP/Wide World Photos In the 1950s sound synthesizers were developed, principally in the United States. Synthesizers enabled composers to produce sounds electroni...
- Exposé eaux usées
- Exposé sur les eaux usées
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Golf.
I
INTRODUCTION
Golf, outdoor game in which individual players use specially designed
caddie or caddy. (Caddies, once an integral feature of the game, have now been replaced on many courses by motorized carts and pull carts.) In England the game was made popular by the attention given it by James VI of Scotland, later James I of England, and his son Charles I. In the 18th century the first golf associations were established. They included the Honourable Company of Edinburgh Golfers (founded 1744) in Edinburgh, Scotland;the Saint Andrews Society of Golfers (1754) in Saint Andrew...
- Henri Matisse Henri Matisse (1869-1954), French artist, leader of the fauve group (see Fauvism), regarded as one of the great formative figures in 20th-century art, a master of the use of color and form to convey emotional expression.
- canut, use n.
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Birth Control.
without a prescription and used alone or with a condom, diaphragm, or cervical cap. Spermicides used alone must be inserted deep into the vagina before each act ofintercourse and a woman should not douche for six to eight hours after intercourse. With typical use, spermicides used alone are effective in preventing pregnancyabout 74 percent of the time. They may cause an allergic reaction such as irritation of the vagina or penis. B Intrauterine Device The intrauterine device (IUD) is a small pl...
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Telecommunications.
commonly referred to as wireless communications, use technologies such as cordless telephones, cellular radio telephones, pagers, and satellites. Wirelesscommunications offer increased mobility and flexibility. In the future some experts believe that wireless devices will also offer high-speed Internet access. C Wires and Cables Wires and cables were the original medium for telecommunications and are still the primary means for telephone connections. Wireline transmission evolved fromtelegraph...
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Internet.
usually pays a fixed monthly fee for a dedicated connection. In exchange, the company providing the connection agrees to relay data between the user’s computer andthe Internet. Dial-up is the least expensive access technology, but it is also the least convenient. To use dial-up access, a subscriber must have a telephone modem, a device thatconnects a computer to the telephone system and is capable of converting data into sounds and sounds back into data. The user’s ISP provides software that con...
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Rocket.
the vacuum of space, however, demonstrated that this belief was not true. In fact, rockets produce more thrust in the vacuum of space than on Earth. Air pressure andfriction with the air reduce a rocket’s thrust by about 10 percent on Earth as compared to the rocket’s performance in space. B Thrust and Efficiency Thrust is a measurement of the force of a rocket, or the amount of “push” exerted backward to move a rocket forward. Thrusts vary greatly from rocket to rocket.Engineers measure thrust...
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Rocket - astronomy.
the vacuum of space, however, demonstrated that this belief was not true. In fact, rockets produce more thrust in the vacuum of space than on Earth. Air pressure andfriction with the air reduce a rocket’s thrust by about 10 percent on Earth as compared to the rocket’s performance in space. B Thrust and Efficiency Thrust is a measurement of the force of a rocket, or the amount of “push” exerted backward to move a rocket forward. Thrusts vary greatly from rocket to rocket.Engineers measure thrust...
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World Wide Web.
browser does not display the URL for the user. Instead, to indicate that an item is selectable, the browser changes the color of the item on the screen and keeps theURL associated with the link hidden. When a user clicks on an item that corresponds to a selectable link, the browser consults the hidden information to find theappropriate URL, which the browser then follows to the selected page. Because a link can point to any page in the Web, the links are known as hyperlinks. See also Hypermedia...
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Alcoholism.
Although a consensus is growing among health professionals that alcohol dependence is a disease, society’s attitudes toward individuals with drinking problems remainambivalent and confused. Until the mid-20th century, the typical picture of the alcoholic was of someone without steady employment, unable to sustain familyrelationships and most likely in desperate financial straits. But this stereotype was largely dispelled when highly respected people publicly admitted their alcoholdependence and...
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Radar.
gathers the weak returning radar signals and converts them into an electric current. Because a radar antenna may both transmit and receive signals, the duplexerdetermines whether the antenna is connected to the receiver or the transmitter. The receiver determines whether the signal should be reported and often does furtheranalysis before sending the results to the display. The display conveys the results to the human operator through a visual display or an audible signal. B1 The Antenna The rec...
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Computer Science.
theoretical research is called algorithmic complexity. Computer scientists in this field seek to develop techniques for determining the inherent efficiency of algorithmswith respect to one another. Another area of theoretical research called computability theory seeks to identify the inherent limits of computation. Software engineers use programming languages to communicate algorithms to a computer. Natural languages such as English are ambiguous—meaning that theirgrammatical structure and vocab...
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Fire - chemistry.
were usually natural caves. Eventually people learned to dip branches in pitch to form torches. They created crude lamps by filling a hollowed out piece of stone withmoss soaked in oil or tallow (a substance derived from animal fat). By cooking with fire, prehistoric people made the meat of the animals they killed more palatable and digestible. They learned to preserve meat by smoking it over a fire,vastly decreasing the danger of periodic starvation. Cooking also enabled them to add some for...
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Geology.
terminology. Today the geologic time scale is generally agreed upon and used by scientists around the world, dividing time into eons, eras, periods, and epochs. Everyfew years, the numerical time scale is refined based on new evidence, and geologists publish an update. Geologists use several methods to determine geologic time. These methods include physical stratigraphy, or the placement of events in the order of their occurrence,and biostratigraphy, which uses fossils to determine geologic time...
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Alternative Medicine.
The field of chiropractic was founded by David Daniel Palmer in the 1890s. He believed that joint subluxation, or a partial dislocation, is a causal factor in disease andthat removal of the subluxation by thrusting on the bony projections of the vertebrae restores health. In addition to manipulating and adjusting bone and tissue, particularly in the spinal column, chiropractors use a variety of manual, mechanical, and electrical treatments.Chiropractors are most widely recognized for providing d...
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Computer Memory.
been created, information can be retrieved but not changed. Newer technologies allow ROMs to be semi-permanent—that is, the information can be changed, but ittakes several seconds to make the change. For example, a FLASH memory acts like a ROM because values remain stored in memory, but the values can be changed. C External Memory External memory can generally be classified as either magnetic or optical, or a combination called magneto-optical. A magnetic storage device, such as a computer'shar...
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Observatory - astronomy.
Ultraviolet radiation, X rays, and gamma rays have shorter wavelengths than visible light has. These types of radiation tell astronomers about the hottest and mostviolent phenomena in the universe. Earth’s atmosphere blocks most of this radiation, so astronomers must send their observatories above the atmosphere aboardballoons, rockets, or satellites. Ultraviolet telescopes are much like visible light telescopes, but X-ray telescopes must have special nested cylindrical mirrors to prevent Xrays...
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Computer.
which can activate computer commands in conjunction with voice recognition software. “Tablet” computers are being developed that will allow users to interact with theirscreens using a penlike device. E The Central Processing Unit Information from an input device or from the computer’s memory is communicated via the bus to the central processing unit (CPU), which is the part of the computerthat translates commands and runs programs. The CPU is a microprocessor chip—that is, a single piece of sil...
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Drug Dependence.
these drugs develops rapidly, no withdrawal syndrome is apparent when they are discontinued. Phencyclidine, or PCP, known popularly by such names as “angel dust” and “rocket fuel,” has no medical purpose for humans but is occasionally used by veterinarians asan anesthetic and sedative for animals. It became a common drug of abuse in the late 1970s, and is considered a menace because it can easily be synthesized. Itseffects differ from those of other hallucinogens. LSD, for example, produces deta...
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Astronomy - astronomy.
Telescopes may use either lenses or mirrors to gather visible light, permitting direct observation or photographic recording of distant objects. Those that use lenses arecalled refracting telescopes, since they use the property of refraction, or bending, of light ( see Optics: Reflection and Refraction ). The largest refracting telescope is the 40-in (1-m) telescope at the Yerkes Observatory in Williams Bay, Wisconsin, founded in the late 19th century. Lenses bend different colors of light by d...
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Fishing.
directly to the spool and turns the spool one rotation at a time. C Fishing Lines Fishing lines serve as the link between the angler’s reel and the lure or bait. The most popular line used for sportfishing is monofilament nylon line, which is strong anddurable and has a certain amount of stretch, which helps when an angler sets the hook. The line comes in a variety of strengths, from 2-pound test to more than 100-pound test. (Pound test is the amount of pressure that can be put on a line before...
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Genetic Engineering.
Pseudomonas fluorescens bacterium. The genetically altered Pseudomonas fluorescens bacterium produces light in proportion to the amount of its activity in breaking down the naphthalene, thus providing a way to monitor the efficiency of the process ( see Bioremediation). A3 Medicine In 1982 the United States Food and Drug Administration (FDA) approved for the first time the medical use of a recombinant DNA protein, the hormone insulin, whichhad been cloned in large quantities by inserting th...
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Amphibian (animal) - biology.
strong enough to kill potential predators. C Hearing, Vision, and Vocalizations Amphibians rely on their senses to find food and evade predators. Amphibians lack external ears but have well-developed internal ears. Hearing is most acute in frogs,which typically have a middle ear cavity for transferring sound vibrations from the eardrum, or tympanum, to the inner ear. Frogs and toads also use their keen hearingin communicating with one another. Using a true voice box, or larynx, and a large, exp...
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Dentistry.
Together with dentists, dental hygienists and dental assistants make up the team that provides dental care to patients. Hygienists record patient medical histories, suchas blood pressure and pulse. They clean teeth, apply sealants and fluoride treatments, teach patients sound oral hygiene practices, and often assist with X rays. Manyhygienists receive a two-year associate degree, while others may choose to enroll in a four-year program at a university or in a master’s degree program. There are25...
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Laser.
their atoms into laser light. Consequently, they are the most powerful continuous wave (CW) lasers—that is, lasers that emit light continuously rather than in pulses. C Liquid Lasers The most common liquid laser media are inorganic dyes contained in glass vessels. They are pumped by intense flash lamps in a pulse mode or by a separate gas laserin the continuous wave mode. Some dye lasers are tunable, meaning that the color of the laser light they emit can be adjusted with the help of a prism lo...
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Soccer.
Two assistants, known as linesmen or referees’ assistants, aid the referee. Their primary job is to alert the referee when balls go out of the playing area and to assist inmaking offsides calls (see Rules section below). The assistants carry flags, which they wave when the ball leaves the playing area or use to point to the spot where a foul was committed. V EQUIPMENT Soccer is played with a round leather ball. It is between 68 and 71 cm (27 and 28 in) in circumference and weighs between 396...
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Snake (reptile).
in their heads that conduct sound. They are able to hear low-frequency sounds and to sense vibrations that travel through the ground or water. The majority of snakeshave good eyesight, especially for detecting moving objects, although most burrowing snakes can only distinguish between light and dark. Pit vipers, boas, and pythons have an unusual adaptation for detecting warm-blooded prey and predators. On the heads of these snakes are small pits lined with cellsthat are extremely sensitive to he...
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Beetle - biology.
cut, or crush prey. Beetles that consume nectar from flowers use tubelike mouthparts to suck up nectar like a primitive straw. C Thorax The thorax, the body region behind the head, consists of three segments that provide attachments for the legs and wings. Each segment of the thorax carries a pair oflegs. The middle segment also bears the stiff wing sheaths called elytra, and the hind segment holds the membranous hind wings. D Legs Beetles have six jointed legs, each leg with five parts. The f...
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Fossil Fuels.
water molecules. This crystalline solid is known as gas hydrate. Because technology for the commercial extraction of gas hydrates has not yet been developed, this typeof fossil fuel is not included in most world energy resource estimates. However, in February 2007 the U.S. Department of Energy completed the drilling of a well toretrieve core samples of gas hydrates found in the Prudhoe Bay region of Alaska’s North Slope. By identifying the nature of these gas hydrates, the Energy Departmenthoped...
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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...
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Wireless Communications.
were large, heavy units. After the invention of the transistor in 1948, radios shrank in size to small handheld radio transceivers. Public two-way radios with severalfrequency options are widely available as well. Usually limited in range to a few miles, these units are great aids for such mobile professionals as construction workers,film crews, event planners, and security personnel. Simpler two-way radios, called walkie-talkies, have been popular children’s toys for years. Most walkie-talkiesb...
- ABSTRUS, -USE, adjectif.
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Hydrogen - chemistry.
Hydrogen gas does not usually react with other chemicals at room temperature. That is, it does not split into two hydrogen atoms to combine with other chemicals. Thebond between the hydrogen atoms is very strong and can only be broken with a large amount of energy. However, when heated with a flame or a spark, hydrogen gaswill react violently with oxygen in the air to produce water in the following reaction: 2H2 + O 2 → 2H 2O This chemical equation shows that two hydrogen molecules (H 2) and o...
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Hardware (computer).
Magnetic tape drives use magnetic tape similar to the tape used in VCR cassettes. Tape drives have a very slow read/write time, but have a very high capacity; in fact,their capacity is second only to hard disk drives. Tape drives are mainly used to back up data. Compact disc drives store information on pits burned into the surface of a disc of reflective material ( see CD-ROM). CD-ROMs can store up to 737 megabytes (MB) of data. A Compact Disc-Recordable (CD-R) or Compact Disc-ReWritable (CD-RW)...
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Helicopter.
naturally flaps down so as to increase lift. Flapping allows the differences in lift caused by uneven rotor tip speed to cancel out, producing a stable ride. Many helicoptersuse mechanical hinges with lubricated bearings, but some use flexible straps made of a composite material in order to reduce the required maintenance. Helicopters require different amounts of lift and thrust at different times during flight, because the aerodynamic forces acting on them change during hovering andacceleration...
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Television.
A charge-coupled device (CCD) can be much smaller than a camera tube and is much more durable. As a result, cameras with CCDs are more compact and portablethan those using a camera tube. The image they create is less vulnerable to distortion and is therefore clearer. In a CCD, the light from a scene strikes an array ofphotodiodes arranged on a silicon chip. Photodiodes are devices that conduct electricity when they are struck by light; they send this electricity to tiny capacitors. Thecapacitors...
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Submarine.
B Propulsion Modern submarines use either diesel-electric or nuclear power to drive the sub's propeller and to provide internal electric power. Diesel-electric power emerged as themost efficient propulsion system for submarines in the early 20th century, following unsuccessful attempts to use steam or gasoline power. While on the surface, thesubmarine uses a diesel engine to drive the propeller and generate electricity. When submerged, a battery-driven electrical motor takes over for propulsion...
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Classification - biology.
species based on the fewest number of shared changes that have occurred from generation to generation. IV HISTORY OF CLASSIFICATION SYSTEMS Classification is one of the oldest sciences, but despite its age it is still a vigorous field full of new discoveries and methods. Much like other fields of science, greatthinkers have shaped the course of classification. One of the earliest classification schemes was established by Greek philosopher Aristotle, who lived in the 300s BC. Aristotle believe...
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Football.
C Special Teams Each team has players who enter the game during special plays such as kickoffs, field goals, punts, and returns. The kicker kicks off at the beginning of a game or half,and after his team has scored. The kicker also scores points for the offensive team by kicking the ball through the goalpost’s vertical posts, also known as the uprights;these scores are called field goals. When the offensive team must surrender the ball to the opponents, a punter comes in to kick the ball downfi...
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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...
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Air - chemistry.
lighting systems, fertilizers, and semiconductors (substances used to make the chips in computers, calculators, televisions, microwave ovens, and many other electronicdevices). A Oxygen More than half of the oxygen produced in the United States is used by the steel industry, which injects the gas into basic oxygen furnaces to heat and produce steel(see Iron and Steel Manufacture: Basic Oxygen Process ). Metalworkers also combine oxygen with acetylene to produce high-temperature torch flames th...
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Police.
body. In larger agencies, executive officers may be selected through a civil service or merit system, after moving through the ranks from patrol officer to sergeant,lieutenant, captain, and (in still larger agencies) deputy or assistant chief. At the county level, the head of the agency usually holds the title sheriff. The sheriff is almost always elected and has the power to appoint deputies. Sheriffs'departments often provide law enforcement services for unincorporated areas of counties and ar...
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Photosynthesis - biology.
P680 in Photosystem II is now electron deficient because it has donated electrons to P700 in Photosystem I. P680 electrons are replenished by the water that has beenabsorbed by the plant roots and transported to the chloroplasts in the leaves. The movement of electrons in Photosystems I and II and the action of an enzyme split thewater into oxygen, hydrogen ions, and electrons. The electrons from water flow to Photosystem II, replacing the electrons lost by P680. Some of the hydrogen ions maybe...
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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...
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Animation
I
INTRODUCTION
Finding Nemo
A clown fish named Marlin, left, and his friend Dory search for Marlin's son in the computer-animated feature film Finding
Nemo (2003).
Animator at WorkAnimators use computers for every part of the animation process, from creating a storyboard (a scene-by-sceneillustration of the plot) to imitating camera movement. This animator is creating a scene for the motion picture Antz(1998).C. Lepetit/Liaison Agency If an animator is basing the animation project on drawings, one of the most common animation techniques, he or she will first create a series of rough sketches thatoften will be filmed in a pencil test (simple line drawings...
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Western Music
I
INTRODUCTION
Bizet's Carmen
Georges Bizet's Carmen, first performed in Paris in 1875, was a milestone in the history of French opera.
church ceremonies during the period from the 5th to the 7th century. Roman chant became known as Gregorian chant after Pope Gregory I, the Great, who may havecomposed some of the melodies and who actively encouraged an orderly, ritualized use of music by the church. Because Gregory and later popes preferred Gregorianchant to the varieties that had developed elsewhere in Europe, Gregorian chant eventually superseded most of the others. Gregorian and other chant styles arepreserved in many manuscr...