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Operation Outward
Operation Outward was a British campaign of the Second World War that attacked Germany and German-occupied Europe with free-flying balloons. It made use of cheap, simple gas balloon, balloons filled with hydrogen and carrying either a trailing steel wire to damage high voltage Electric power transmission, power lines by producing a short circuit, or incendiary devices to start fires in fields, forests and Heath (habitat), heathland. A total of 99,142 Outward balloons were launched; about half carried incendiaries and half carried trailing wires. Compared to Japan's better-known Fu-Go balloon bomb, fire balloons, Outward balloons were crude. They had to travel a much shorter distance so they flew at a lower altitude , compared with and had only a simple mechanism to regulate altitude by means of dropping ballast or venting lifting gas. This meant the balloons were simple to mass-produce and only cost 35 British shilling coin, shillings each (approximately equivalent to £ in ). Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Ministry
The Air Ministry was a department of the Government of the United Kingdom with the responsibility of managing the affairs of the Royal Air Force and civil aviation that existed from 1918 to 1964. It was under the political authority of the Secretary of State for Air. Organisations before the Air Ministry The Air Committee On 13 April 1912, less than two weeks after the creation of the Royal Flying Corps (which initially consisted of both a naval and a military wing), an Air Committee was established to act as an intermediary between the Admiralty and the War Office in matters relating to aviation. The new Air Committee was composed of representatives of the two war ministries, and although it could make recommendations, it lacked executive authority. The recommendations of the Air Committee had to be ratified by the Admiralty Board and the Imperial General Staff and, in consequence, the Committee was not particularly effective. The increasing separation of army and n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benzene
Benzene is an Organic compound, organic chemical compound with the Chemical formula#Molecular formula, molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar hexagonal Ring (chemistry), ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen atoms, benzene is classed as a hydrocarbon. Benzene is a natural constituent of petroleum and is one of the elementary petrochemicals. Due to the cyclic continuous pi bonds between the carbon atoms, benzene is classed as an aromatic hydrocarbon. Benzene is a colorless and highly Combustibility and flammability, flammable liquid with a sweet smell, and is partially responsible for the aroma of gasoline. It is used primarily as a Precursor (chemistry), precursor to the manufacture of chemicals with more complex structures, such as ethylbenzene and cumene, of which billions of kilograms are produced annually. Although benzene is a major Chemical industry, industrial che ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allotropes Of Phosphorus
Elemental phosphorus can exist in several allotropes, the most common of which are white and red solids. Solid violet and black allotropes are also known. Gaseous phosphorus exists as diphosphorus and atomic phosphorus. White phosphorus White phosphorus, yellow phosphorus or simply tetraphosphorus () exists as molecules of four phosphorus atoms in a tetrahedral structure, joined by six phosphorus—phosphorus single bonds. The free P4 molecule in the gas phase has a P-P bond length of ''r''g = 2.1994(3) Å as was determined by gas electron diffraction. Despite the tetrahedral arrangement the P4 molecules have no significant ring strain and a vapor of P4 molecules is stable. This is due to the nature of bonding in the P4 tetrahedron which can be described by spherical aromaticity or cluster bonding, that is the electrons are highly delocalized. This has been illustrated by calculations of the magnetically induced currents, which sum up to 29 nA/T, much more than in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard Wire Gauge
The British Standard Wire Gauge, often referred to as the Standard Wire Gauge or simply SWG, is a unit used to denote wire gauge (size) as defined by British standard, BS 3737:1964, a standard that has since been withdrawn. It is also known as the Imperial Wire Gauge or British Standard Gauge. Although its use has significantly declined, SWG sizes are still used for measuring the thickness of guitar strings and certain types of electrical wire. In modern applications, wire size is more commonly measured in terms of cross-sectional area, expressed in square millimeters, particularly for electrical installation cables. The current British Standard for metallic materials, including wires and sheets, is BS 6722:1986, which exclusively uses metric measurements. History SWG was fixed by Order of Council August 23, 1883. It was constructed by improving the Birmingham Wire Gauge. It was made a legal standard on 1 March, 1884, by the British Board of Trade. SWG is not to be confused ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slow Match
Slow match, also called match cord, is the slow-burning cord or twine fuse used by early gunpowder musketeers, artillerymen, and soldiers to ignite matchlock muskets, cannons, shells, and petards. Slow matches were most suitable for use around black-powder weapons because a slow match could be roughly handled without going out, and only presented a small glowing tip instead of a large flame that risked igniting nearby gunpowder. Slow match of various types was one of the first kinds of artillery fuse. Slow matches were also used in the drilling and blasting of rock to ignite charges of gunpowder. Design and use The slow match attached to the lock of the matchlock gun was usually a length of hemp or flax cord that had been chemically treated to make it burn slowly and consistently for an extended period. In Japan, however, match cord was made from braiding together strands of bark from the Japanese cypress. The rate of burning was approximately 1 ft (305mm) per ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operation Albino
Operation or Operations may refer to: Arts, entertainment and media * ''Operation'' (game), a battery-operated board game that challenges dexterity * Operation (music), a term used in musical set theory * ''Operations'' (magazine), Multi-Man Publishing's house organ for articles and discussion about its wargaming products * ''The Operation'' (film), a 1973 British television film * ''The Operation'' (1990), a crime, drama, TV movie starring Joe Penny, Lisa Hartman, and Jason Beghe * The Operation M.D., formerly The Operation, a Canadian garage rock band * "Operation", a song by Relient K from '' The Creepy EP'', 2001 Television Episodes * "The Operation", ''Sky Dancers'' episode 27 (1996) * "The Operation", ''The Golden Girls'' season 1, episode 18 (1986) * "The Operation", ''You're Only Young Twice'' (1997) series 2, episode 8 (1978) Shows * ''The Operation'' (1992–1998), a reality television series from TLC Business * Manufacturing operations, operation of a f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Talc
Talc, or talcum, is a clay mineral composed of hydrated magnesium silicate, with the chemical formula . Talc in powdered form, often combined with corn starch, is used as baby powder. This mineral is used as a thickening agent and lubricant. It is an ingredient in ceramics, paints, and roofing material. It is a main ingredient in many cosmetics. It occurs as foliated to fibrous masses, and in an exceptionally rare crystal form. It has a perfect basal cleavage and an uneven flat fracture, and it is foliated with a two-dimensional platy form. The Mohs scale of mineral hardness, based on scratch hardness comparison, defines value 1 as the hardness of talc, the softest mineral. When scraped on a streak plate, talc produces a white streak, though this indicator is of little importance, because most silicate minerals produce a white streak. Talc is translucent to opaque, with colors ranging from whitish grey to green with a vitreous and pearly luster. Talc is not soluble i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fire Lookout
A fire lookout (sometimes also called a fire watcher) is a person assigned the duty to look for fire from atop a building known as a fire lookout tower. These towers are used in remote areas, normally on mountain tops with high elevation and a good view of the surrounding terrain, to spot smoke caused by a wildfire. Once a possible fire is spotted, "Smoke Reports", or "Lookout Shots" are relayed to the local Emergency Communications Center (ECC), often by radio or phone. A fire lookout can use a device known as an Osborne Fire Finder to obtain the radial in degrees off the tower, and the estimated distance from the tower to the fire. Part of the lookout's duties include taking weather readings and reporting the findings to the Emergency Communications Center throughout the day. Often several lookouts will overlap in coverage areas and each will “cross” the same smoke, allowing the ECC to use triangulation from the radials to achieve an accurate location of the fire. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petersen Coil
Petersen is a common Danish patronymic surname, meaning ''"son of Peter"''. There are other spellings. Petersen may refer to: People In arts and entertainment * Adolf Dahm-Petersen, Norwegian voice specialist * Anja Petersen, German operatic soprano and university lecturer * Anker Eli Petersen, Faroese writer and artist * Ann Petersen, Belgian actress * Chris Petersen (born 1963), American child actor * Devon Petersen (born 1986), South African darts player * Elmer Petersen, American artist * Gustaf Munch-Petersen, Danish writer and painter * Joel Petersen, bass guitarist * John Hahn-Petersen, Danish actor * Josef Petersen, Danish novelist * Patrick Petersen, American actor * Paul Petersen, American movie actor, singer, novelist, and activist * Robert E. Petersen, publisher, auto museum founder * Robert Storm Petersen, Danish cartoonist, writer, animator, illustrator, painter and humorist * Sandy Petersen, American game designer * Uwe Fahrenkrog-Petersen, German mus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circuit Breaker
A circuit breaker is an electrical safety device designed to protect an Electrical network, electrical circuit from damage caused by current in excess of that which the equipment can safely carry (overcurrent). Its basic function is to interrupt current flow to protect equipment and to prevent fire. Unlike a fuse (electrical), fuse, which operates once and then must be replaced, a circuit breaker can be reset (either manually or automatically) to resume normal operation. Circuit breakers are commonly installed in distribution boards. Apart from its safety purpose, a circuit breaker is also often used as a main switch to manually disconnect ("rack out") and connect ("rack in") electrical power to a whole electrical sub-network. Circuit breakers are made in varying current ratings, from devices that protect low-current circuits or individual household appliances, to switchgear designed to protect high voltage, high-voltage circuits feeding an entire city. Any device which pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Three-phase Electric Power
Three-phase electric power (abbreviated 3ϕ) is a common type of alternating current (AC) used in electricity generation, transmission, and distribution. It is a type of polyphase system employing three wires (or four including an optional neutral return wire) and is the most common method used by electrical grids worldwide to transfer power. Three-phase electrical power was developed in the 1880s by several people. In three-phase power, the voltage on each wire is 120 degrees phase shifted relative to each of the other wires. Because it is an AC system, it allows the voltages to be easily stepped up using transformers to high voltage for transmission and back down for distribution, giving high efficiency. A three-wire three-phase circuit is usually more economical than an equivalent two-wire single-phase circuit at the same line-to-ground voltage because it uses less conductor material to transmit a given amount of electrical power. Three-phase power is mainly used dire ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
