16 résultats pour "steam"
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Steam Engine.
wear caused by this pressure, steam-engine valves are frequently made in a cylindrical form entirely enclosing the piston, so that the pressure is equal all around thevalve and friction is minimized. The development of this type of valve is attributed to the American inventor and manufacturer George Henry Corliss. In other types ofslide valves, the moving portion of the valve is designed so that steam does not press directly on the back of the valve. The linkage between the piston of the engine...
- steamer ou steamship.
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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 the...
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Industrial Revolution
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INTRODUCTION
Industrial Revolution, widespread replacement of manual labor by machines that began in Britain in the 18th century and is still continuing in some parts of the world.
The most important advance in iron production occurred in 1784 when Englishman Henry Cort invented new techniques for rolling raw iron, a finishing process thatshapes iron into the desired size and form. These advances in metalworking were an important part of industrialization. They enabled iron, which was relativelyinexpensive and abundant, to be used in many new ways, such as building heavy machinery. Iron was well suited for heavy machinery because of its strength anddurability. Because of t...
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Industrial Revolution .
The most important advance in iron production occurred in 1784 when Englishman Henry Cort invented new techniques for rolling raw iron, a finishing process thatshapes iron into the desired size and form. These advances in metalworking were an important part of industrialization. They enabled iron, which was relativelyinexpensive and abundant, to be used in many new ways, such as building heavy machinery. Iron was well suited for heavy machinery because of its strength anddurability. Because of t...
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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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Water - chemistry.
flourides in drinking water has been found to reduce tooth decay. See Fluorine. Seawater contains, in addition to concentrated amounts of sodium chloride, or salt, many other soluble compounds, as the impure waters of rivers and streams areconstantly feeding the oceans. At the same time, pure water is continually lost by the process of evaporation, and as a result the proportion of the impurities that givethe oceans their saline character is increased. See Ocean and Oceanography. VII WATER...
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Heat (physics)
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INTRODUCTION
Heat Loss from a House
A thermograph shows the large amount of heat lost through a house's windows during winter.
Theoretically, the molecules of a substance would exhibit no activity at the temperature termed absolute zero. See Molecule. III TEMPERATURE SCALES Five different temperature scales are in use today: the Celsius scale, known also as the Centigrade scale, the Fahrenheit scale, the Kelvin scale, the Rankine scale, andthe international thermodynamic temperature scale ( see Thermometer). The Celsius scale, with a freezing point of 0° C and a boiling point of 100° C, is widely used throughout the...
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Les Index Noires
demi-heure après, à Newhaven, joli village de pêcheurs, situé à un mille de Leith, qui forme le port
d'Édimbourg.
que le rendez-vous donné dans la première lettre eût été contremandé dans la seconde. \24 C'était, à vrai dire, son plus gros souci. En tout cas, si Harry Ford ne se trouvait pas à l'arrivée du train à Callander, James Starr était bien décidé à se rendre seul à la fosse Dochart, et même, s'il le fallait, jusqu'au village d'Aberfoyle. Là, il aurait sans doute des nouvelles de Simon Ford, et il apprendrait en quel lieu résidait actuellement le vieil overman. Cependant, le Prince de Galles continua...
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Railroads.
III GAUGES The gauge of track is the distance between the inner edges of the rails at points 1.59 cm (0.626 in) below the top of the heads. In the United States, Canada, theUnited Kingdom, Mexico, Norway, Sweden, and much of continental Europe, the standard gauge is 143.51 cm (56.5 in). Why this measurement became the standard isa matter of speculation. Probably the tradition is inherited from early tramroads built to accommodate wagons with axles 1.5 m (5 ft) long; some of the early edge rail...
- Auto Racing: Notable Land Speed World Records All cars have gasoline-driven internal-combustion engines unless marked (E) for electric, (S) for steam, (T) for turbine, (J) for jet, or (R) for rocket.
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World Energy Supply.
In the 1990s, oil production by non-OPEC countries remained strong and production by OPEC countries rebounded. The result at the end of the 20th century was aworld oil surplus and prices (when adjusted for inflation) that were lower than in 1972. Experts are uncertain about future oil supplies and prices. Low prices have spurred greater oil consumption, and experts question how long world petroleum reservescan keep pace with increased demand. Many of the world’s leading petroleum geologists beli...
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Michel Strogoff
nuit, et celle-là pourrait bien savoir.
Et il fonctionne toujours jusqu'à Kolyvan? Cela, je l'ignore, mais je puis vous assurer, par exemple, qu'il fonctionne de Kazan à Paris! Vous avez adressé une dépêche... à votre cousine?... Avec enthousiasme. Vous avez donc appris?... Tenez, mon petit père, pour parler comme les Russes, répondit Alcide Jolivet, je suis bon enfant, moi, et je ne veux rien avoir de caché pour vous. Les Tartares, Féofar-Kan à leur tête, ont dépassé Sémipalatinsk et descendent le cours de l'Irtyche. Faites-en...
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Ship.
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INTRODUCTION
Ship, vessel that is buoyant in the water and used
B1 Biremes Experience soon proved that longer ships posed a new set of problems: They were weaker structurally, more difficult to maneuver, and presented a larger target to anyenemy ship with a ram. In the 8th century BC Mediterranean shipbuilders eliminated these problems with the bireme , a war galley built to accommodate two levels, or banks , of oarsmen. Oarsmen on the lower level rowed oars from ports cut into the side of the vessel, while those above rowed from the deck. This arrangemen...
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Automobile.
Electric motors have been used to power automobiles since the late 1800s. Electric power supplied by batteries runs the motor, which rotates a driveshaft, the shaftthat transmits engine power to the axles. Commercial electric car models for specialized purposes were available in the 1980s. General Motors Corporation introduced amass-production all-electric car in the mid-1990s. Automobiles that combine two or more types of engines are called hybrids. A typical hybrid is an electric motor with ba...
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Nuclear Energy
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INTRODUCTION
Gundremmingen Nuclear Power Plant, Germany
The first of three boiling-water nuclear reactors at Germany's Gundremmingen plant began operating in 1966 but was
permanently shut down after being decommissioned in 1983.
such as ¯U is induced by the absorption of a neutron as in producing cesium-140, rubidium-93, three neutrons, and 200 MeV, or 3.2 × 10 -11 J (7.7 × 10 -12 cal). A nuclear fission reaction releases 10 million times as much energy as is released in a typical chemical reaction. See Nuclear Chemistry. III NUCLEAR ENERGY FROM FISSION The two key characteristics of nuclear fission important for the practical release of nuclear energy are both evident in equation (2). First, the energy per fiss...