An electric motor is an electrical machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a wire winding to generate force in the form of rotation of a shaft. Electric motors can be powered by direct current sources, such as from batteries, motor vehicles or rectifiers, or by alternating current sources, such as a power grid, inverters or electrical generators. An electric generator is mechanically identical to an electric motor, but operates in the reverse direction, converting mechanical energy into electrical energy. Electric motors may be classified by considerations such as power source type, internal construction and type of motion output. In addition to AC versus DC types, motors may be brushed or brushless, may be of various phase, may be either air-cooled or liquid-cooled. General-purpose motors with standard dimensions and characteristics provide convenient mechanical power for industrial use.
The largest electric motors are used for ship propulsion, pipeline compression and pumped-storage applications with ratings reaching 100 megawatts. Electric motors are found in industrial fans and pumps, machine tools, household appliances, power tools and disk drives. Small motors may be found in electric watches. In certain applications, such as in regenerative braking with traction motors, electric motors can be used in reverse as generators to recover energy that might otherwise be lost as heat and friction. Electric motors produce linear or rotary force intended to propel some external mechanism, such as a fan or an elevator. An electric motor is designed for continuous rotation, or for linear movement over a significant distance compared to its size. Magnetic solenoids produce significant mechanical force, but over an operating distance comparable to their size. Transducers such as loudspeakers and microphones convert between electrical current and mechanical force to reproduce signals such as speech.
When compared with common internal combustion engines, electric motors are lightweight, physically smaller, provide more power output, are mechanically simpler and cheaper to build, while providing instant and consistent torque at any speed, with more responsiveness, higher overall efficiency and lower heat generation. However, electric motors are not as convenient or common as ICEs in mobile applications as they require a large and expensive battery, while ICEs require a small fuel tank; the first electric motors were simple electrostatic devices described in experiments by Scottish monk Andrew Gordon and American experimenter Benjamin Franklin in the 1740s. The theoretical principle behind them, Coulomb's law, was discovered but not published, by Henry Cavendish in 1771; this law was discovered independently by Charles-Augustin de Coulomb in 1785, who published it so that it is now known with his name. The invention of the electrochemical battery by Alessandro Volta in 1799 made possible the production of persistent electric currents.
After the discovery of the interaction between such a current and a magnetic field, namely the electromagnetic interaction by Hans Christian Ørsted in 1820 much progress was soon made. It only took a few weeks for André-Marie Ampère to develop the first formulation of the electromagnetic interaction and present the Ampère's force law, that described the production of mechanical force by the interaction of an electric current and a magnetic field; the first demonstration of the effect with a rotary motion was given by Michael Faraday in 1821. A free-hanging wire was dipped into a pool of mercury; when a current was passed through the wire, the wire rotated around the magnet, showing that the current gave rise to a close circular magnetic field around the wire. This motor is demonstrated in physics experiments, substituting brine for mercury. Barlow's wheel was an early refinement to this Faraday demonstration, although these and similar homopolar motors remained unsuited to practical application until late in the century.
In 1827, Hungarian physicist Ányos Jedlik started experimenting with electromagnetic coils. After Jedlik solved the technical problems of continuous rotation with the invention of the commutator, he called his early devices "electromagnetic self-rotors". Although they were used only for teaching, in 1828 Jedlik demonstrated the first device to contain the three main components of practical DC motors: the stator and commutator; the device employed no permanent magnets, as the magnetic fields of both the stationary and revolving components were produced by the currents flowing through their windings. The first commutator DC electric motor capable of turning machinery was invented by British scientist William Sturgeon in 1832. Following Sturgeon's work, a commutator-type direct-current electric motor was built by American inventor Thomas Davenport, which he patented in 1837; the motors ran at up to 600 revolutions per minute, powered machine tools and a printing press. Due to the high cost of primary battery power, the motors were commercially unsuccessful and bankrupted Davenport.
Several inventors followed Sturgeon in the development of DC motors, but all encountered the same battery cost issues. As no electricity distribution system was available at the time, no practical commercial market emerged for these motors. After many other more or less successful attempts with weak rotating and reciprocating apparatus Prussian Moritz von Jacobi created the first real rotating electric motor in May 1834, it developed remarkable mechanical output power. His motor set a world record, which Jacobi improv
Nicolaas Adrianus Rupke is a Dutch historian of science, who began his academic career as a marine geologist. He studied biology and geology at the university of Groningen and geology and the history of science at Princeton and Oxford. Early in his studies, Rupke was a Christian and proponent of Flood geology, but came to reject this position; when in 1977 he was elected to a Wolfson College, Oxford research position in the history of science, Rupke made this subject his full-time occupation. A series of similar international research posts followed, until in 1993 he took up a professorship at Göttingen University to teach the history of science and medicine. In 2009, Rupke was awarded a Lower Saxony research chair. In 2012, he took up an endowed professorship at Washington and Lee University in Lexington, Virginia, USA. Rupke is known for his studies of late-modern biology and science & religion. With an interest in the biographical approach, he restored to their contemporary prominence several nineteenth-century scientists, most important among them Richard Owen who well before the appearance of The Origin of Species developed a naturalistic theory of evolution, albeit a non-Darwinian one.
Studies of Alexander von Humboldt came next, in which Rupke developed what he terms the metabiographical approach by exploring how a famous life – in this case Humboldt's – may be multiply retold and reconstructed as part of different belief systems and memory cultures. Rupke is a fellow of Germany's National Academy of Sciences Leopoldina and of the Göttingen Academy of Sciences. Distinctive Properties of Turbiditic and Hemipelagic Mud Layers. Washington, DC: Smithsonian Institution Press, 1974; the Great Chain of History: William Buckland and the English School of Geology. Oxford: Clarendon Press, 1983. Vivisection in Historical Perspective. London, Croom Helm, 1987. Science and the Public Good. London: Macmillan, 1988. Medical Geography in Historical Perspective. London: Wellcome Trust Centre for the History of Medicine, 2000. Richard Owen: Biology without Darwin Chicago and London: University of Chicago Press, 2009. Alexander von Humboldt: A Metabiography. Chicago and London: University of Chicago Press, 2008.
Eminent Lives in Twentieth-Century Religion. Frankurt a. M.: Lang, 2009. Albrecht von Haller im Göttingen der Aufklärung. Göttingen: Wallstein, 2009. Academic homepage. Faculty listing, Göttingen University
This is a list of anime industry companies involved in the production or distribution of anime. Animation International AnimEigo Aniplex of America AT&T / WarnerMedia Crunchyroll Warner Bros. Television Williams Street Discotek Media Disney Hulu Eleven Arts GKIDS Konami Cross Media NY. Miramax Manga Entertainment Media Blasters Netflix NIS America Ponycan USA Right Stuf Inc. Saban Brands Sentai Filmworks Shout! Factory Sony Sony Pictures Television International/Sony Pictures Home Entertainment Funimation Viz Media Editorial Ivrea JBC Animatsu Entertainment Anime Limited Dynit Kazé Manga Entertainment UK MVM Films Universum Film GmbH StudioCanal UK Universal Pictures Madman Entertainment Siren Visual ADV Films AN Entertainment Bandai Entertainment Bandai Visual USA Beez Entertainment Central Park Media US Manga Corps Family Home Entertainment in the 1990s acquired by Lions Gate Entertainment in 2003) Frontier Enterprises Geneon Entertainment. Go Fish Pictures Illumitoon Entertainment Kadokawa Pictures USA NuTech Digital Saban Entertainment Streamline Pictures Synch-Point U.
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