68 résultats pour "electric"
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Electric Motors and Generators.
the armature. It is often desirable to generate as high a voltage as possible, and rotating armatures are not practical in such applications because of the possibility of sparkingbetween brushes and slip rings and the danger of mechanical failures that might cause short circuits. Alternators are therefore constructed with a stationary armaturewithin which revolves a rotor composed of a number of field magnets. The principle of operation is exactly the same as that of the AC generator described,...
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Pila eléctrica - ciencia y tecnologia.
descritas anteriormente se invierten hasta que los productos químicos vuelven a su condición original. Una batería de plomo y ácido tiene una vida útil de unos cuatro años.Produce unos 2 V por pila. Recientemente, se han desarrollado baterías de plomo para aplicaciones especiales con una vida útil de 50 a 70 años. Otra pila secundaria muy utilizada es la pila alcalina o batería de níquel y hierro, ideada por el inventor estadounidense Thomas Edison en torno a 1900. El principio defuncionamiento...
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Electric Lighting.
successful arc lamp in 1878. Tungsten filaments were substituted for carbon filaments in incandescent lamps in 1907, and gas-filled incandescent lamps were developedin 1913. The fluorescent lamp was introduced in 1938. See also Lamp. For most of the 20th century the incandescent light bulb was widely used for lighting in homes. More energy-efficient and longer-lasting fluorescent lamps were adoptedfor industrial and office use. In 1979 a compact fluorescent bulb that screwed into ordinary lig...
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General Electric
difficulties, provoquees notamment par Ia diminution des commandos publiques spreeleretrait americain du Vietnam et la reduction du programme spatial . de Ia NASA. Sonlaboratoire d'electronique avaitparticiple activement au proJet. Apollo. 5 tine certain reconversion des activities de General Electric s'effectue en favour des centrales nuclealres. Le groups, qui a construct en 1957 la premiere centrale industrielle des Etats-Unis, detient le brevet des disc- tours a eau boulliante (BWR) pour leq...
- General Electric (entreprise).
- Electric Ladyland
- Las pilas eléctricas - (exposé gratuit en espagnol).
- Schneider Electric (entreprise).
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Blues
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INTRODUCTION
Listening to the Blues
Blues music comes in a variety of styles and forms, including acoustic blues, electric blues, rock, and jazz.
recording of “How Many More Years” demonstrate this structure: a. How many more years do I got to let you dog me around?a. How many more years do I got to let you dog me around?b. I just as soon be dead, sleeping six feet in the ground. Each lyric line is typically sung over the first half (first two bars) of a four-bar line. After each lyric line (the “call”), an instrumental response is commonly played, alsoconsisting of approximately two bars. The tension created by the two-bar call-and-res...
- General Electric
- ELECTRIC DREAMS
- Electric Ladyland [The Jimi Hendrix Experience] - analyse de l'oeuvre musicale.
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Proton
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INTRODUCTION
Proton, elementary particle that carries a positive electric charge and, along with the electron and the neutron, is one of the building blocks of all atoms.
Gordon FraserMicrosoft ® Encarta ® 2009. © 1993-2008 Microsoft Corporation. All rights reserved.
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Electricity
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INTRODUCTION
Electricity, one of the basic forms of energy.
electrons in the neutral object are attracted to the positive object. Some of these electrons flow to the side of the neutral object that is nearest to the positive object.This side of the neutral object accumulates electrons and becomes negatively charged. Because electrons leave the far side of the neutral object while its protonsremain stationary, that side becomes positively charged. Since the negatively charged side of the neutral object is closest to the positive object, the attraction bet...
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Electricidad - ciencia y tecnologia.
forma, las varillas adquieren cargas del mismo signo. Si se cuelga una varilla de un hilo de forma que pueda girar y se le acerca laotra, la primera gira alejándose de la segunda, lo que demuestra que las cargas se repelen. Si las dos varillas tuvieran cargas designo opuesto, la primera se acercaría a la segunda, puesto que las cargas de distinto signo se atraen.© Microsoft Corporation. Reservados todos los derechos. El primer fenómeno eléctrico artificial que se observó fue la propiedad que pre...
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Elementary Particles
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INTRODUCTION
Structure of Matter
Modern physics has revealed successively deeper layers of structure in ordinary matter.
The most fundamental particles that make up matter fall into the fermion category. These fermions cannot be split into anything smaller. The particles that carry theforces acting on matter and antimatter are bosons called force carriers. Force carriers are also fundamental particles, so they cannot be split into anything smaller.These bosons carry the four basic forces in the universe: the electromagnetic, the gravitational, the strong (force that holds the nuclei of atoms together), and the wea...
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Analyse
Introduction Through this company analysis, different aspects of DTE Energy Company will be cover in a financial viewpoint. I will firstly give a brief description of DTE Energy Company, after that analyze the industry in which it operates, describe its major market, analyze its financial statement with a spread sheet for the financial analysis, and finally I will determine if I will invest in this company or not. Company, Industr...
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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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Atom - chemistry.
Atoms have several properties that help distinguish one type of atom from another and determine how atoms change under certain conditions. A Atomic Number Each element has a unique number of protons in its atoms. This number is called the atomic number (abbreviated Z). Because atoms are normally electrically neutral,the atomic number also specifies how many electrons an atom will have. The number of electrons, in turn, determines many of the chemical and physical properties ofthe atom. The ligh...
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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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Chemistry - chemistry.
parts of oxygen by weight, which is a ratio of about 1 to 8, regardless of whether the water came from the Mississippi River or the ice of Antarctica. In other words, acompound has a definite, invariable composition, always containing the same elements in the same proportions by weight; this is the law of definite proportions. Many elements combine in more than one ratio, giving different compounds. In addition to forming water, hydrogen and oxygen also form hydrogen peroxide.Hydrogen peroxide h...
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Atom
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INTRODUCTION
Water Molecule
A water molecule consists of an oxygen atom and two hydrogen atoms, which are attached at an angle of 105°.
spontaneously break apart and change, or decay, into other atoms. Unlike electrons, which are fundamental particles, protons and neutrons are made up of other, smaller particles called quarks. Physicists know of six different quarks.Neutrons and protons are made up of up quarks and down quarks —two of the six different kinds of quarks. The fanciful names of quarks have nothing to do with their properties; the names are simply labels to distinguish one quark from another. Quarks are unique amo...
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Physics
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INTRODUCTION
Physics, major science, dealing with the fundamental constituents of the universe, the forces they exert on one another, and the results produced by these forces.
Starting about 1665, at the age of 23, Newton enunciated the principles of mechanics, formulated the law of universal gravitation, separated white light into colors,proposed a theory for the propagation of light, and invented differential and integral calculus. Newton's contributions covered an enormous range of naturalphenomena: He was thus able to show that not only Kepler's laws of planetary motion but also Galileo's discoveries of falling bodies follow a combination of his ownsecond law of m...
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Light - astronomy.
Each different frequency or wavelength of visible light causes our eye to see a slightly different color. The longest wavelength we can see is deep red at about 700 nm.The shortest wavelength humans can detect is deep blue or violet at about 400 nm. Most light sources do not radiate monochromatic light. What we call white light,such as light from the Sun, is a mixture of all the colors in the visible spectrum, with some represented more strongly than others. Human eyes respond best to greenlight...
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Quark
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INTRODUCTION
Quark, smallest known building block of matter.
Constituents of MatterMatter is composed of tiny particles called quarks. Quarks come in six varieties: up (u), down (d), charm (c), strange (s),top (t), and bottom (b). Quarks also have antimatter counterparts called antiquarks (designated by a line over the lettersymbol). Quarks combine to form larger particles called baryons, and quarks and antiquarks combine to form mesons.Protons and neutrons, particles that form the nuclei of atoms, are examples of baryons. Positive and negative kaons aree...
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Teléfono - ciencia y tecnologia.
quedan compactados y producen un aumento de la corriente que circula por el transmisor. Dado que el transmisor de carbono no resultaba práctico a la hora de convertir energía eléctrica en presión sonora, los teléfonos fueron evolucionando hacia receptoresseparados de los transmisores. Esta disposición permite colocar el transmisor cerca de los labios para recoger el máximo de energía sonora, y el receptor en el auricular, locual elimina los molestos ruidos de fondo. En estos teléfonos, el recept...
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Thomas Edison.
While Edison was working on the electric light, he made a scientific discovery that would become important to future generations. Edison noticed that particles of carbonfrom the filament blackened the insides of his light bulbs. This effect was caused by the emission of electrons from the filament, although Edison made the discoverybefore he and other scientists knew the electron existed. Not until 1897 did British physicist J. J. Thomson prove that the blackening observed by Edison was caused b...
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Thomas Edison - USA History.
While Edison was working on the electric light, he made a scientific discovery that would become important to future generations. Edison noticed that particles of carbonfrom the filament blackened the insides of his light bulbs. This effect was caused by the emission of electrons from the filament, although Edison made the discoverybefore he and other scientists knew the electron existed. Not until 1897 did British physicist J. J. Thomson prove that the blackening observed by Edison was caused b...
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Electronics.
electronic circuits. The resistors are made from carbon mixtures, metal films, or resistance wire and have two connecting wires attached. Variable resistors, with anadjustable sliding contact arm, are often used to control volume on radios and television sets. E Capacitors Capacitors consist of two metal plates that are separated by an insulating material ( see Capacitor). If a battery is connected to both plates, an electric charge will flow for a short time and accumulate on each plate. If th...
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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...
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Country Music
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INTRODUCTION
Willie Nelson
Country singer and musician Willie Nelson gained national popularity during the 1970s for a string of country hits,
including the 1978 hits "Mammas Don't Let Your Babies Grow Up to Be Cowboys" and "Georgia On My Mind.
Singer and mandolin player Bill Monroe is known as the father of bluegrass music. A virtuoso mandolin player, Monroe combined traditional folk ballads and gospel songswith string-band music played at very fast tempos. Monroe, with his band The Blue Grass Boys, performed from the mid-1920s until Monroe’s death in 1996. Otherwell-known bluegrass performers include banjo player Earl Scruggs, who played with Monroe during the 1940s; the Osborne Brothers, a duo from Kentucky known forits work during...
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Motores y generadores eléctricos - ciencia y tecnologia.
velocidad de los motores de corriente continua puede controlarse mediante la variación de la corriente del campo. 4 GENERADORES DE CORRIENTE ALTERNA (ALTERNADORES) Como se decía antes, un generador simple sin conmutador producirá una corriente eléctrica que cambia de sentido a medida que gira la armadura. Este tipo de corrientealterna es ventajosa para la transmisión de potencia eléctrica, por lo que la mayoría de los generadores eléctricos son de este tipo. En su forma más simple, un generador...
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Televisión - ciencia y tecnologia.
3.1 Iconoscopio Al igual que el tubo tomavistas, el iconoscopio presenta varios inconvenientes. Uno de los mayores es que exige una iluminación enorme del sujeto para producir una señalútil. Si se están utilizando las cámaras de televisión dentro de un estudio bajo condiciones controladas de luz, este inconveniente no es importante, pero el iconoscopio nose puede utilizar para televisar acontecimientos en condiciones adversas de luz. 3.2 Orticón de imágenes Figura 2: tubo orticón imagenLos tub...
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Chemical Analysis - chemistry.
inorganic reactions than by organic functional group chemistry. VII SPECTROSCOPIC TECHNIQUES Spectroscopy, or the study of the interactions of electromagnetic radiation with matter, is the largest and most nearly accurate class of instrumental methods used inchemical analysis and indeed in all of chemistry ( see Spectroscopy; Spectrum). The electromagnetic radiation (emr) spectrum is divided into the following wavelength regions: X ray, ultraviolet, visible, infrared, microwave, and radiowave....
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Rock Music
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INTRODUCTION
Carlos Santana
Mexican-born guitarist Carlos Santana became a superstar in the late 1960s with a string of hits and an appearance at the
famous Woodstock rock festival in 1969.
point (a single pitch sustained through a progression of chords), and the parallel movement of chords, derived from a technique on the electric guitar known as bar-chording. Many elements of African American music have been a continuing source of influence on rock music. These characteristics include riffs (repeated patterns), backbeats (emphasizing the second and fourth beats of each measure; see Musical Rhythm: Pulse and Meter ), call-and-response patterns, blue notes (the use of certain...
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Light
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INTRODUCTION
Light, form of energy visible to the human eye that is radiated by moving charged particles.
simulates the action of a moving charge upon the electric field. It creates a wave that travels along the rope in a direction that is perpendicular to the initial up anddown movement. Because electromagnetic waves are transverse—that is, the vibration that creates them is perpendicular to the direction in which they travel, they are similar to waveson a rope or waves traveling on the surface of water. Unlike these waves, however, which require a rope or water, light does not need a medium, or su...
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Telephone.
digits is dialed. The development of inexpensive and reliable amplification provided by the introduction of the transistor in the 1960s made practical the design of adialing system based on the transmission of relatively low power tones instead of the higher-power dial pulses. Today most telephones have push buttons instead of a rotary dial. Touch-Tone is an optional service, and telephone companies still maintain the ability to receive pulsedialing. Push-button telephones usually have a switch...
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First Aid.
IV SEVERE BLEEDING The presence of blood over a considerable area of a person’s body does not always indicate severe bleeding. The blood may ooze from multiple small wounds or besmeared, giving the appearance of more blood than is actually present. The rate at which blood is lost from a wound depends on the size and kind of blood vesselruptured. Bright red, spurting blood indicates injury to an artery while welling or steadily flowing, dark red blood indicates injury to a vein. Welling or spur...
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Inorganic Chemistry - chemistry.
two electrically charged plates (positively charged top plate and negatively charged bottom plate). By measuring the difference in how fast these electron-laden oildrops fell when the metal plates were charged and uncharged, Millikan was able to calculate the total charge on each oil drop. Because each measurement was a wholenumber multiple of -1.60 × 10 -19 coulombs, Millikan concluded this was the charge carried by a single electron. Using Thomson’s electron charge-to-mass ratio, Millikan then...
- 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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Magnetism
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INTRODUCTION
Magnetism, an aspect of electromagnetism, one of the fundamental forces of nature.
the French physicist Paul Langevin produced a theory regarding the temperature dependence of the magnetic properties of paramagnets (discussed below), which wasbased on the atomic structure of matter. This theory is an early example of the description of large-scale properties in terms of the properties of electrons and atoms.Langevin's theory was subsequently expanded by the French physicist Pierre Ernst Weiss, who postulated the existence of an internal, “molecular” magnetic field inmaterials...
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Electron
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INTRODUCTION
Models of the Atom
Once scientists discovered the electron, they set out to explain how electrons behave in atoms.
Electron Density and Orbital ShapesAtomic orbitals are mathematical descriptions of where the electrons in an atom (or molecule) are most likely to be found.These descriptions are obtained by solving an equation known as the Schrödinger equation, which expresses ourknowledge of the atomic world. As the angular momentum and energy of an electron increases, it tends to reside indifferently shaped orbitals. The orbitals corresponding to the three lowest energy states are s, p, and d, respectively....
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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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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...
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Radioactivity
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INTRODUCTION
Marie Curie
Working with her husband, Pierre Curie, French physicist Marie Curie discovered the radioactive elements polonium and
radium in 1898.
Rutherford when he allowed an alpha-emitting substance to decay near an evacuated thin-glass vessel. The alpha particles were able to penetrate the glass and werethen trapped in the vessel, and within a few days the presence of elemental helium was demonstrated by use of a spectroscope. Beta particles were subsequentlyshown to be electrons, and gamma rays to consist of electromagnetic radiation of the same nature as X rays but of considerably greater energy. A The Nuclear Hypothesis Rutherford...
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Radio.
signal, such as a musical note. This form of modulation, AM, is used in many radiotelephony services including standard radiobroadcasts. AM is also employed for carriercurrent telephony, in which the modulated carrier is transmitted by wire, and in the transmission of still pictures by wire or radio. See Broadcasting, Radio and Television. In FM the frequency of the carrier wave is varied within a fixed range at a rate corresponding to the frequency of a sound signal. This form of modulation, p...
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Internal-Combustion Engine.
any Otto-cycle engine and in actual engines today is slightly more than 40 percent. Diesels are, in general, slow-speed engines with crankshaft speeds of 100 to 750revolutions per minute (rpm) as compared to 2500 to 5000 rpm for typical Otto-cycle engines. Some types of diesel, however, have speeds up to 2000 rpm. Becausediesels use compression ratios of 14 or more to 1, they are generally more heavily built than Otto-cycle engines, but this disadvantage is counterbalanced by theirgreater effici...
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Popular Music
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INTRODUCTION
Satchmo Sings "Back O' Town Blues"
One of the founders of instrumental jazz music, American Louis Armstrong, known as Satchmo, also profoundly influenced
vocal jazz and popular song.
disseminating popular music until the 1920s remained printed sheet music. By the late 19th century, the music-publishing business was centralized in New York City,particularly in an area of lower Manhattan called Tin Pan Alley. “After the Ball” (1892) by Charles K. Harris, the first popular song to sell 1 million copies—in this case, ofsheet music—inspired rapid growth in the music-publishing industry. Composers were hired to rapidly produce popular songs by the dozens, and the techniques ofFost...
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Westinghouse
en 1974 ce departement. En mama temps, le groupe a Ate restructure en trots divisions principales Want le statut de sociehis opOrationnelles :produits pour l'industrie, dispositifs d'energie etsystemes publics (incluant les activites interessant la defense). A cote de cam trois sockftes est maintenue Ia finale Westinghouse Broadcasting, qui gel:we cinq stations de television et sent stations de radio aux Etats-Unis. 5 Westinghouse. dont lesiege a Ate transfers de Pittsburgh A New York, est le Wa...