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Metal Detectors
A metal detector is an instrument that detects the nearby presence of metal. Metal detectors are useful for finding metal objects on the surface, underground, and under water. The unit itself, consist of a control box, and an adjustable shaft, which holds a pickup coil, which can vary in shape and size. If the pickup coil comes near a piece of metal, the control box will register its presence by a changing tone, a flashing light, and or by a needle moving on an indicator. Usually the device gives some indication of distance; the closer the metal is, the higher the tone in the earphone or the higher the needle goes. Another common type are stationary "walk through" metal detectors used at access points in prisons, courthouses, airports and psychiatric hospitals to detect concealed metal weapons on a person's body. The simplest form of a metal detector consists of an oscillator producing an alternating current that passes through a coil producing an alternating magnetic field. I ... [...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-script 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 Old English was originally written in Anglo-Saxon runes, runes, whose equivalent letter was beorc , meaning "birch". Beorc dates to at least the 2nd-century Elder Futhark, which is now thought to have derived from the Old Italic alphabets' either directly or via Latin alphabet, Latin . The Uncial script, uncial and half-uncial introduced by the Gregorian mission, Gregorian and Hiberno-Scottish mission, Irish missions gradually developed into the Insular scripts' . These Old English Latin alphabets supplanted the ear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geophysics
Geophysics () is a subject of natural science concerned with the physical processes and physical properties of the Earth and its surrounding space environment, and the use of quantitative methods for their analysis. The term ''geophysics'' sometimes refers only to solid earth applications: Earth's shape; its gravitational and magnetic fields; its internal structure and composition; its dynamics and their surface expression in plate tectonics, the generation of magmas, volcanism and rock formation. However, modern geophysics organizations and pure scientists use a broader definition that includes the water cycle including snow and ice; fluid dynamics of the oceans and the atmosphere; electricity and magnetism in the ionosphere and magnetosphere and solar-terrestrial physics; and analogous problems associated with the Moon and other planets. Gutenberg, B., 1929, Lehrbuch der Geophysik. Leipzig. Berlin (Gebruder Borntraeger). Runcorn, S.K, (editor-in-chief), 1967, International ... [...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 founded and led the National Fascist Party. He was Prime Minister of Italy from the March on Rome in 1922 until his deposition in 1943, and "Duce" of Italian Fascism from the establishment of the Italian Fasces of Combat in 1919 until his execution in 1945 by Italian partisans. As dictator of Italy and principal founder of fascism, Mussolini inspired and supported the international spread of fascist movements during the inter-war period. Mussolini was originally a socialist politician and a journalist at the ''Avanti!'' newspaper. In 1912, he became a member of the National Directorate of the Italian Socialist Party (PSI), but he was expelled from the PSI for advocating military intervention in World War I, in opposition to the party's stance on neutrality. In 1914, Mussolini founded a new journal, ''Il Popolo d'Italia'', and served in the Royal Italian Army durin ... [...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 a ... [...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 4, 1881 until his death six months latertwo months after he was shot by an assassin. A lawyer and Civil War general, he served nine terms in the United States House of Representatives and is to date the only sitting member of the House to be elected president. Before his candidacy for the White House, he had been elected to the U.S. Senate by the Ohio General Assemblya position he declined when he became president-elect. Garfield was born into poverty in a log cabin and grew up in northeastern Ohio. After graduating from Williams College, he studied law and became an attorney. He was active in the Disciples of Christ denomination. Garfield was elected as a Republican member of the Ohio State Senate in 1859, serving until 1861. He opposed Confederate secession, was a major general in the Union Army during the American Civil War, and fought in the b ... [...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 inventor, scientist and engineer who is credited with patenting the first practical telephone. He also co-founded the American Telephone and Telegraph Company (AT&T) in 1885. 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 Bell being awarded the first 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 groundbreaking work in optical telecommunications, hydrofoils, and aeronautics. Bell also had a strong influence on the National Geographic Society and its ... [...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: sparking 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 was simply electroma ... [...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 some to be a p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metal Detector From World War 1
A metal (from ancient Greek, Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electrical resistivity and conductivity, electricity and thermal conductivity, heat relatively well. Metals are typically ductile (can be drawn into wires) and malleable (they can be hammered into thin sheets). These properties are the result of the ''metallic bond'' between the atoms or molecules of the metal. 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. In physics, a metal is generally regarded as any substance capable of conducting electricity at a temperature of absolute zero. Many elements and compounds that are not normally classified as metals become metallic under high pressures. For example, the nonmetal iodine gradually becomes a metal at a pressure of between 40 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rebar
Rebar (short for reinforcing bar), known when massed as reinforcing steel or reinforcement steel, is a steel bar used as a Tension (physics), tension device in reinforced concrete and reinforced masonry structures to strengthen and aid the concrete under tension. Concrete is strong under Compression (physics), compression, but has weak tensile strength. Rebar significantly increases the tensile strength of the structure. Rebar's surface features a continuous series of ribs, lugs or indentations to promote a better bond with the concrete and reduce the risk of slippage. The most common type of rebar is carbon steel, typically consisting of hot-rolled round bars with deformation patterns embossed into its surface. Steel and concrete have similar coefficient of thermal expansion, coefficients of thermal expansion, so a concrete structural member reinforced with steel will experience minimal differential stress (mechanics), stress as the temperature changes. Other readily available ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Construction Industry
Construction is a general term meaning the art and science to form objects, systems, or organizations,"Construction" def. 1.a. 1.b. and 1.c. ''Oxford English Dictionary'' Second Edition on CD-ROM (v. 4.0) Oxford University Press 2009 and comes from Latin ''constructio'' (from ''com-'' "together" and ''struere'' "to pile up") and Old French ''construction''. To construct is the verb: the act of building, and the noun is construction: how something is built, the nature of its structure. In its most widely used context, construction covers the processes involved in delivering buildings, infrastructure, industrial facilities and associated activities through to the end of their life. It typically starts with planning, financing, and design, and continues until the asset is built and ready for use; construction also covers repairs and maintenance work, any works to expand, extend and improve the asset, and its eventual demolition, dismantling or decommissioning. The construction i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
