68 résultats pour "eléctrica"
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vapeurs, faite d'un trait plus clair, venait de s'effacer.
son linceul, surlequel ledocteur jetasonmanteau. Lecouvercle futalors revissé, labière replacée danslacavité dumur, laplaque remisesurl’orifice qu’ellerecouvrit commeavant. Le docteur interrompit lecourant desalanterne électrique, etl’obscurité redevintprofonde. « Prends cecorps », dit-ilàCap Matifou. Cap Matifou soulevadanssesrobustes braslecorps dujeune homme, commeileût faitde celui d’unenfant ; puis,précédé dudocteur etsuivi dePointe Pescade, ilreprit lacontre-allée, qui conduisait directeme...
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Combustibles fósiles - geografía.
antracita (carbón duro con un contenido muy alto en carbono y muy bajo en humedad). Como la antracita es el carbón más rico en carbono y con menor contenido dehumedad, es el de más alto valor energético. Las zonas carboníferas en España se encuentran localizadas en diferentes regiones. En Asturias, León, Palencia, Burgos, Ciudad Real y Córdoba se extraen hulla y antracita;en La Coruña, Teruel y Barcelona, lignito, y en Zaragoza, Lleida y Girona, antracita y lignito. 2.3 Formación del gas natural...
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Aging - biology.
Different theories have been proposed to explain how SF works. One theory is based on the assumption that aging, and diseases that occur more frequently withadvancing age, are caused by structural damage to cells. This damage accumulates in tiny amounts each time the cell divides, eventually preventing the cell fromcarrying out normal functions. One cause of this damage may be free radicals, which are chemical compounds found in the environment and also generated by normal chemical reactions in...
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Physical Chemistry - chemistry.
by the system in the form of the flow of electrical currents, formation of surfaces and changes in surface tension, changes in volume or pressure, and formation ordisappearance of chemical species. B Chemical Kinetics This field studies the rates of chemical processes as a function of the concentration of the reacting species, of the products of the reaction, of catalysts and inhibitors, ofvarious solvent media, of temperature, and of all other variables that can affect the reaction rate. It is...
- La electricidad - (exposé gratuit en espagnol).
- La energía - (exposé gratuit en espagnol).
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Física - ciencia y tecnologia.
teólogo italiano santo Tomás de Aquino, por ejemplo, trató de demostrar que las obras de Platón y Aristóteles eran compatibles con las Sagradas Escrituras. El filósofoescolástico y científico británico Roger Bacon fue uno de los pocos filósofos que defendió el método experimental como auténtica base del conocimiento científico; tambiéninvestigó en astronomía, química, óptica y diseño de máquinas. 2.3 Siglos XVI y XVII Nicolás CopérnicoEl astrónomo polaco Nicolás Copérnico revolucionó la ciencia...
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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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Douglas Mc Gregor 1906-1964 Théorie des X et des Y
6L’école des relations Humaines 2009 /2010 Partie 4: Analyse critique de l’école des relations humaines………..………...44 Conclusion…………………………………………………………………….….46 Introduction : L’école des relations humaines est apparue dans les années 30 après la crise économique de 1929, cette crise a remis en cause les principes et les théories de l’école classique, étant des théories très simples, l’échec de leur application a engendré la formation de ce second mouvement qui est le mouve...
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Optics
I
INTRODUCTION
Mirage
Mirages appear because differences in air temperature cause light rays from an object to take different paths to a viewer's
eye.
Refraction of Light by DiamondsThe brilliance of diamonds is due to their high refractive index, a measure of how strongly a transparent material bendslight rays. The skill of the gem-cutter lies in angling the facets of the stone so that each light ray entering it is reflectedmany times before it emerges again.Spencer Grant/Photo Researchers, Inc. The amount of light reflected depends on the ratio of the refractive indexes for the two media. The plane of incidence contains the incident ray and...
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Royaume-Uni.
les principales ressources énergétiques de l’Union européenne, avec d’énormes gisements de houille, exploités depuis trois cents ans, le pétrole et le gaz naturel du secteurbritannique de la mer du Nord, au large de l’Écosse et de l’Angleterre. Les gisements de charbon du centre-nord de l’Angleterre, du pays de Galles et de l’Écosse, et les gisements de minerai de fer de la zone des Pennines ont joué un rôleimportant dans le développement industriel du pays. Le charbon et le fer ont déterminé la...
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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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Meteorología - ciencias de la naturaleza.
PluviómetroLas precipitaciones se miden con un pluviómetro como este, que se localiza en Tasmania (Australia) y forma parte de una estaciónmeteorológica.Cape Grim B.A.P.S./Simon Fraser/SciencePhoto Library/Photo Researchers, Inc. Las observaciones hechas a nivel del suelo son más numerosas que las realizadas a altitudes superiores. Incluyen la medición de la presión atmosférica, la temperatura, lahumedad, la dirección y velocidad del viento, la cantidad y altura de las nubes, la visibilidad y la...
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Acid Rain.
the Adirondack Mountains of New York State, a quarter of the lakes and ponds are acidic, and many have lost their brook trout and other fish. In the middleAppalachian Mountains, over 1,300 streams are afflicted. All of Norway’s major rivers have been damaged by acid rain, severely reducing salmon and trout populations. E Plants and Animals The effects of acid rain on wildlife can be far-reaching. If a population of one plant or animal is adversely affected by acid rain, animals that feed on tha...
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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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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...
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Bill Clinton.
When Arkansas governor David Pryor ran for the U.S. Senate in 1978, Clinton ran for governor. He promised to improve the state’s schools and highways and toimprove economic conditions so that more jobs would be created. At that time, the average income of people in Arkansas ranked 49th among the 50 states. Clinton woneasily, receiving 60 percent of the vote against four opponents in the Democratic primary election and 63 percent against the Republican candidate, Lynn Lowe, in thegeneral election...
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Bill Clinton - USA History.
When Arkansas governor David Pryor ran for the U.S. Senate in 1978, Clinton ran for governor. He promised to improve the state’s schools and highways and toimprove economic conditions so that more jobs would be created. At that time, the average income of people in Arkansas ranked 49th among the 50 states. Clinton woneasily, receiving 60 percent of the vote against four opponents in the Democratic primary election and 63 percent against the Republican candidate, Lynn Lowe, in thegeneral election...