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Electric Arc
An electric arc (or arc discharge) is an electrical breakdown of a gas that produces a prolonged electrical discharge. The electric current, current through a normally Electrical conductance, nonconductive medium such as air produces a plasma (physics), plasma, which may produce visible light. An arc discharge is initiated either by thermionic emission or by field emission. After initiation, the arc relies on thermionic emission of electrons from the electrodes supporting the arc. An arc discharge is characterized by a lower voltage than a glow discharge. An archaic term is voltaic arc, as used in the phrase "voltaic arc lamp". Techniques for arc suppression can be used to reduce the duration or likelihood of arc formation. In the late 19th century, Arc lamp, electric arc lighting was in wide use for Street light#Arc lamps, public lighting. Some low-pressure electric arcs are used in many applications. For example, fluorescent lamp, fluorescent tubes, mercury, sodium, and met ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Movie Projector
A movie projector (or film projector) is an optics, opto-mechanics, mechanical device for displaying Film, motion picture film by projecting it onto a movie screen, screen. Most of the optical and mechanical elements, except for the illumination and sound devices, are present in movie cameras. Modern movie projectors are specially built video projectors (see also digital cinema). Many projectors are specific to a particular film gauge and not all movie projectors are film projectors since the use of film is required. Predecessors The main precursor to the movie projector was the magic lantern. In its most common setup it had a concave mirror behind a light source to help direct as much light as possible through a painted glass picture slide and a lens, out of the lantern onto a screen. Simple mechanics to have the painted images moving were probably implemented since Christiaan Huygens introduced the apparatus around 1659. Initially, candles and oil lamps were used, but oth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vasily V
Vasili, Vasily, Vasilii or Vasiliy ( Russian: Василий) is a Russian masculine given name of Greek origin and corresponds to '' Basil''. It may refer to: * Vasily I of Moscow Grand Prince from 1389–1425 * Vasily II of Moscow Grand Prince from 1425–1462 *Vasili III of Russia Grand Prince from 1505–1533 * Vasili IV of Russia Tsar from 1606–1610 * Basil Fool for Christ (1469–1557), also known as Saint Basil, or Vasily Blazhenny * Vasily Alekseyev (1942–2011), Soviet weightlifter * Vasily Arkhipov (1926–1998), Soviet Naval officer in the Cuban Missile Crisis * Vasily Boldyrev (1875–1933), Russian general * Vasily Chapayev (1887–1969), Russian Army commander * Vasily Chuikov (1900–1982), Soviet marshal * Vasily Degtyaryov (1880–1949), Russian weapons designer and Major General * Vasily Dzhugashvili (1921–1962), Stalin's son * Vasili Golovachov (born 1948), Russian science fiction author * Vasily Grossman (1905–1964), Soviet writer and journalist * Vasily ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Columbia University Press
Columbia University Press is a university press based in New York City New York, often called New York City (NYC), is the most populous city in the United States, located at the southern tip of New York State on one of the world's largest natural harbors. The city comprises five boroughs, each coextensive w ..., and affiliated with Columbia University. Founded in 1893, it is currently directed by Jennifer Crewe (2014–present) and publishes titles in the humanities and sciences, including the fields of literary and cultural studies, history, social work, sociology, religion, film, and international studies. History Columbia University Press was founded in May 1893. In 1933, the first four volumes of the ''History of the State of New York'' were published. In the early 1940s, the Press' revenues rose, partially thanks to the ''Encyclopedia'' and the government's purchase of 12,500 copies for use by the military. Columbia University Press is notable for publishing r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charcoal
Charcoal is a lightweight black carbon residue produced by strongly heating wood (or other animal and plant materials) in minimal oxygen to remove all water and volatile constituents. In the traditional version of this pyrolysis process, called charcoal burning, often by forming a charcoal kiln, the heat is supplied by burning part of the starting material itself, with a limited supply of oxygen. The material can also be heated in a closed retort. Modern charcoal briquettes used for outdoor cooking may contain many other additives, e.g. coal. The early history of wood charcoal production spans ancient times, rooted in the abundance of wood in various regions. The process typically involves stacking wood billets to form a conical pile, allowing air to enter through openings at the bottom, and igniting the pile gradually. Charcoal burners, skilled professionals tasked with managing the delicate operation, often lived in isolation to tend their wood piles . Throughout histo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Spark
An electric spark is an abrupt electrical discharge that occurs when a sufficiently high electric field creates an Ionization, ionized, Electric current, electrically conductive channel through a normally-insulating medium, often air or other gases or gas mixtures. Michael Faraday described this phenomenon as "the beautiful flash of light attending the discharge of common electricity". The rapid transition from a non-conducting to a conductive state produces a brief emission of light and a sharp crack or snapping sound. A spark is created when the applied electric field exceeds the dielectric strength, dielectric breakdown strength of the intervening medium. For air, the breakdown strength is about 30 kV/cm at sea level. Experimentally, this figure tends to differ depending upon humidity, atmospheric pressure, shape of electrodes (needle and ground-plane, hemispherical etc.) and the corresponding spacing between them and even the type of waveform, whether sinusoidal or cosine-rec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon
Carbon () is a chemical element; it has chemical symbol, symbol C and atomic number 6. It is nonmetallic and tetravalence, tetravalent—meaning that its atoms are able to form up to four covalent bonds due to its valence shell exhibiting 4 electrons. It belongs to group 14 of the periodic table. Carbon makes up about 0.025 percent of Earth's crust. Three Isotopes of carbon, isotopes occur naturally, carbon-12, C and carbon-13, C being stable, while carbon-14, C is a radionuclide, decaying with a half-life of 5,700 years. Carbon is one of the timeline of chemical element discoveries#Pre-modern and early modern discoveries, few elements known since antiquity. Carbon is the 15th abundance of elements in Earth's crust, most abundant element in the Earth's crust, and the abundance of the chemical elements, fourth most abundant element in the universe by mass after hydrogen, helium, and oxygen. Carbon's abundance, its unique diversity of organic compounds, and its unusual abi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Society
The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, recognising excellence in science, supporting outstanding science, providing scientific advice for policy, education and public engagement and fostering international and global co-operation. Founded on 28 November 1660, it was granted a royal charter by Charles II of England, King Charles II and is the oldest continuously existing scientific academy in the world. The society is governed by its Council, which is chaired by the society's president, according to a set of statutes and standing orders. The members of Council and the president are elected from and by its Fellows, the basic members of the society, who are themselves elected by existing Fellows. , there are about 1,700 fellows, allowed to use the postnominal title FRS (Fellow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Natural Philosophy, Chemistry And The Arts
''A Journal of Natural Philosophy, Chemistry, and the Arts'', generally known as ''Nicholson's Journal'', was the first monthly scientific journal in Great Britain. William Nicholson began it in 1797 and was the editor until it merged with another journal in January 1814. Nicholson's journal would accept short papers, written by new or anonymous authors, and decide whether to publish them relatively quickly. These attributes distinguished the new journal from the established scientific journal '' The Philosophical Transactions of the Royal Society''. By one account this less-formal model was so appealing that the next year (1798) a similar startup launched, Alexander Tilloch's ''Philosophical Magazine'',Russell, Colin. Enterprise and electrolysis... ''Chemistry World'', Aug. 2003online and in January 1813, a further rival, Thomas Thomson's ''Annals of Philosophy''. Significant articles * Nicholson and Anthony Carlisle split water into hydrogen and oxygen for the first time i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Nicholson (chemist)
William Nicholson (13 December 175321 May 1815) was an English writer, translator, publisher, scientist, inventor, patent agent and civil engineer. He launched the first monthly scientific journal in Britain, ''Journal of Natural Philosophy, Chemistry, and the Arts'', in 1797, and remained its editor until 1814. In 1800, he and Anthony Carlisle were the first to achieve electrolysis, the splitting of water into hydrogen and oxygen, using a voltaic pile. Nicholson also wrote extensively on natural philosophy and chemistry. Early life Nicholson was educated in Yorkshire, and after leaving school, he made two voyages as a midshipman in the service of the British East India Company. His first voyage was to India and the second voyage was to China on board the ''Gatton,'' (1772-1773). Subsequently, having become acquainted with Josiah Wedgwood in 1775, he moved to Amsterdam, where he made a living for a few years as Wedgwood's agent. On his return to England he was persuaded by T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Humphry Davy
Sir Humphry Davy, 1st Baronet (17 December 177829 May 1829) was a British chemist and inventor who invented the Davy lamp and a very early form of arc lamp. He is also remembered for isolating, by using electricity, several Chemical element, elements for the first time: potassium and sodium in 1807 and calcium, strontium, barium, magnesium and boron the following year, as well as for discovering the elemental nature of chlorine and iodine. Davy also studied the forces involved in these separations, inventing the new field of electrochemistry. Davy is also credited with discovering clathrate hydrates. In 1799, he experimented with nitrous oxide and was astonished at how it made him laugh. He nicknamed it "laughing gas" and wrote about its potential as an Anesthesia, anaesthetic to relieve pain during surgery. Davy was a baronet, President of the Royal Society (PRS), Member of the Royal Irish Academy (MRIA), a founder member and Fellow of the Geological Society of London, and a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lightning NOAA
Lightning is a natural phenomenon consisting of electrostatic discharges occurring through the atmosphere between two electrically charged regions. One or both regions are within the atmosphere, with the second region sometimes occurring on the land, ground. Following the lightning, the regions become partially or wholly electrically neutralized. Lightning involves a near-instantaneous release of energy on a scale averaging between 200 megajoules and 7 gigajoules. The air around the lightning flash rapidly heats to temperatures of about . There is an emission of electromagnetic radiation across a wide range of wavelengths, some visible as a bright flash. Lightning also causes thunder, a sound from the shock wave which develops as heated gases in the vicinity of the discharge experience a sudden increase in pressure. The most common occurrence of a lightning event is known as a thunderstorm, though they can also commonly occur in other types of energetic weather systems, such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
