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Metal Detectors
A metal detector is an Electronic instrumentation, instrument that detects the nearby presence of metal. Metal detectors are useful for finding metal objects on the surface, underground, and under water. A metal detector consists of a control box, an adjustable shaft, and a variable-shaped pickup coil. When the coil nears metal, the control box signals its presence with a tone, numerical reading, light, or needle movement. Signal intensity typically increases with proximity and/or metal size/composition. A common type are stationary "walk through" metal detectors used at access points in Prison#Security, prisons, Courthouse#Security, courthouses, Airport security, airports and psychiatric hospitals to detect concealed Weapon, metal weapons on a person's body. The simplest form of a metal detector consists of an Electronic oscillator, oscillator producing an alternating current that passes through a coil producing an alternating magnetic field. If a piece of electrically conductiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
B020311e - PFC Generett And SGT Rutledge Probe In Yard Of House
B, or b, is the second Letter (alphabet), letter of the Latin alphabet, used in the English alphabet, modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''English alphabet#Letter names, bee'' (pronounced ), plural ''bees''. It represents the voiced bilabial stop in many languages, including English. In some other languages, it is used to represent other bilabial consonants. History The Roman derived from the Greek alphabet, Greek capital beta (letter), beta via its Old Italic script, Etruscan and Archaic Greek alphabets#Euboean, Cumaean variants. The Greek letter was an adaptation of the Phoenician alphabet, Phoenician letter bet (letter), bēt . The Ancient Egypt, Egyptian Egyptian hieroglyphs, hieroglyph for the consonant voiced bilabial plosive, /b/ had been an image of a foot (hieroglyph), foot and calf , but bēt (Phoenician for "house") was a modified form of a Proto-Sinaitic script, Proto-Sinait ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Treasure Hunting
Treasure hunting is the physical search for treasure. One of the most popular types of modern day treasure hunters are historic shipwreck salvors. These underwater treasure salvors try to find sunken Shipwreck, shipwrecks and retrieve artifacts with both commercial and archaeological value. In many instances, discovery of a wreck only occurs after searching tens of thousands of square nautical miles, thus making discovery normally impossible for archaeologists. Since the popularization of Metal detector, metal detectors in the 1970s, treasure hunting has also taken the form of beach combing for lost valuables. Beach hunters may search for modern jewelry, pocket change, or shipwreck treasure. Most metal detectors will fall in the $150–$600 price range, but can even cost upwards of several thousand dollars. Metal detecting is generally quite tedious and most enthusiasts go years without finding an actually valuable object. Metal detectors are quite useful to Archaeology, archaeol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caligula
Gaius Caesar Augustus Germanicus (31 August 12 – 24 January 41), also called Gaius and Caligula (), was Roman emperor from AD 37 until his assassination in 41. He was the son of the Roman general Germanicus and Augustus' granddaughter Agrippina the Elder, members of the Julio-Claudian dynasty, first ruling family of the Roman Empire. He was born two years before Tiberius became emperor. Gaius accompanied his father, mother and siblings on campaign in Germania, at little more than four or five years old. He had been named after Gaius Julius Caesar, but his father's soldiers affectionately nicknamed him "Caligula" ('little boot'). Germanicus died in Antioch in 19, and Agrippina returned with her six children to Rome, where she became entangled in a bitter feud with Emperor Tiberius, who was Germanicus' biological uncle and adoptive father. The conflict eventually led to the destruction of her family, with Caligula as the sole male survivor. In 26, Tiberius withdrew from pub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benito Mussolini
Benito Amilcare Andrea Mussolini (29 July 188328 April 1945) was an Italian politician and journalist who, upon assuming office as Prime Minister of Italy, Prime Minister, became the dictator of Fascist Italy from the March on Rome in 1922 until Fall of the Fascist regime in Italy, his overthrow in 1943. He was also of Italian fascism from the establishment of the Italian Fasces of Combat in 1919, until Death of Benito Mussolini, his summary execution in 1945. He founded and led the National Fascist Party (PNF). As a dictator and founder of fascism, Mussolini inspired the List of fascist movements, international spread of fascism during the interwar period. Mussolini was originally a socialist politician and journalist at the Avanti! (newspaper), ''Avanti!'' newspaper. In 1912, he became a member of the National Directorate of the Italian Socialist Party (PSI), but was expelled for advocating military intervention in World War I. In 1914, Mussolini founded a newspaper, ''Il P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gerhard Fischer (inventor)
Gerhard Julius Richard Fischer later Gerhard Julius Richard Fisher, Gerhard R. Fisher (March 18, 1899 – May 2, 1988) was a U.S. entrepreneur of German descent. He contributed to the development and popularity of the hand held metal detector. Biography Fisher was born in 1899 in Landeshut, Silesia, to Richard Hugo Georg Arthur Fischer, an engineer, and his wife Margaretha Julia Fischer née Job. His mother was from Łódź, where the parents also married. Around 1906, the Fischer family moved to Dresden. After studying electrical engineering at the Dresden University, Fischer emigrated to the U.S. In 1931, he founded Fisher Research Laboratory, Inc. in Palo Alto, where he served as president until his retirement in 1967. While working with aircraft radio detection finders environment-dependent changes became apparent. From the interference by metal, he concluded that the device must also be suitable for detecting metal. Fisher shared the idea with Albert Einstein who correctly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Camille Gutton
Camille Gutton (30 August 1872 – 19 August 1963) was a French physicist who specialized in radioelectricity. He was responsible for various theoretical and practical advances. He followed some false leads such as research into the hypothetical N rays, which did not in fact exist, and attempts to explain anomalies in laboratory measurements of radio waves in ionized gases, which he thought might be due to positive ions exerting a quasi-elastic force on electrons. His work on very high frequency radio waves helped with the development of radar. He received various honours for his work, and in 1947 was a candidate for the Nobel Prize in Physics. Life Camille Antoine Marie Guttton was born in Nancy on 30 August 1872. His father was an advocate at the Court of Appeal, and his maternal grandfather was Professor of Chemistry at the Nancy Faculty of Sciences. Camille Gutton was the oldest of five children in a close-knit family. His brother Henry Gutton( fr) (1874–1963) became ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Garfield
James Abram Garfield (November 19, 1831 – September 19, 1881) was the 20th president of the United States, serving from March 1881 until Assassination of James A. Garfield, his death in September that year after being shot two months earlier. A preacher, lawyer, and American Civil War, Civil War general, Garfield served nine terms in the United States House of Representatives and is the only sitting member of the House to be elected president. Before his candidacy for the presidency, he had been elected to the U.S. Senate by the Ohio General Assemblya position he declined when he became President-elect of the United States, president-elect. Garfield was born into poverty in a log cabin and grew up in Northeast Ohio, northeastern Ohio. After graduating from Williams College in 1856, he studied law and became an attorney. He was a preacher in the Stone–Campbell Movement and president of the Western Reserve Eclectic Institute, affiliated with the Christian Church (Discipl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alexander Graham Bell
Alexander Graham Bell (; born Alexander Bell; March 3, 1847 – August 2, 1922) was a Scottish-born Canadian Americans, Canadian-American inventor, scientist, and engineer who is credited with patenting the first practical telephone. He also co-founded the AT&T Corporation, American Telephone and Telegraph Company (AT&T) in 1885. Alexander Melville Bell, Bell's father, grandfather, and brother had all been associated with work on elocution and speech, and both his mother and wife were deaf, profoundly influencing Bell's life's work. His research on hearing and speech further led him to experiment with hearing devices, which eventually culminated in his being awarded the first United States patent law, U.S. patent for the telephone, on March 7, 1876. Bell considered his invention an intrusion on his real work as a scientist and refused to have a telephone in his study. Many other inventions marked Bell's later life, including ground-breaking work in Free-space optical commun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
David Edward Hughes
David Edward Hughes (16 May 1830 – 22 January 1900), was a British-American inventor, practical experimenter, and professor of music known for his work on the printing telegraph and the microphone. He is generally considered to have been born in London but his family moved around that time so he may have been born in Corwen, Wales. His family moved to the U.S. while he was a child and he became a professor of music in Kentucky. In 1855 he patented a printing telegraph. He moved back to London in 1857 and further pursued experimentation and invention, coming up with an improved carbon microphone in 1878. In 1879 he identified what seemed to be a new phenomenon during his experiments: electric sparks generated in one device could be heard in a separate portable microphone apparatus he had set up. It was most probably radio transmissions but this was nine years before electromagnetic radiation was a proven concept and Hughes was convinced by others that his discovery wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heinrich Wilhelm Dove
Heinrich Wilhelm Dove (6 October 1803 – 4 April 1879) was a Prussian physicist and meteorologist. Early years Dove was born in Liegnitz in the Kingdom of Prussia. Dove studied history, philosophy, and the natural sciences at the University of Breslau from 1821 until 1824. In 1824, he continued his education at the University of Berlin, finishing in 1826. In 1826, he became a '' Privatdozent'' and in 1828 a Professor extraordinarius at the University of Königsberg. In 1829, he moved to Berlin and taught at the Friedrich Wilhelm Gymnasium. In 1845, he became a '' Professor ordinarius'' at the Friedrich-Wilhelms-Universität in Berlin, where he was elected rector in 1858–1859, and again in 1871–1872. In 1849, he also became the director of the Prussian Meteorological Institute. During his career he published more than 300 papers, some of which delved into experimental physics. He also had an important influence over the science of meteorology, and was considered by s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metal Detector From World War 1
A metal () is a material that, when polished or fractured, shows a lustrous appearance, and conducts electricity and heat In thermodynamics, heat is energy in transfer between a thermodynamic system and its surroundings by such mechanisms as thermal conduction, electromagnetic radiation, and friction, which are microscopic in nature, involving sub-atomic, ato ... relatively well. These properties are all associated with having electrons available at the Fermi level, as against nonmetallic materials which do not. Metals are typically ductile (can be drawn into a wire) and malleable (can be shaped via hammering or pressing). A metal may be a chemical element such as iron; an alloy such as stainless steel; or a molecular compound such as polythiazyl, polymeric sulfur nitride. The general science of metals is called metallurgy, a subtopic of materials science; aspects of the electronic and thermal properties are also within the scope of condensed matter physics and soli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calibration
In measurement technology and metrology, calibration is the comparison of measurement values delivered by a device under test with those of a calibration standard of known accuracy. Such a standard could be another measurement device of known accuracy, a device generating the quantity to be measured such as a voltage, a sound tone, or a physical artifact, such as a meter ruler. The outcome of the comparison can result in one of the following: * no significant error being noted on the device under test * a significant error being noted but no adjustment made * an adjustment made to correct the error to an acceptable level Strictly speaking, the term "calibration" means just the act of comparison and does not include any subsequent adjustment. The calibration standard is normally traceable to a national or international standard held by a metrology body. BIPM Definition The formal definition of calibration by the International Bureau of Weights and Measures (BIPM) is the foll ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
