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Overpressure
Overpressure (or blast overpressure) is the pressure caused by a shock wave over and above normal atmospheric pressure. The shock wave may be caused by sonic boom or by explosion An explosion is a rapid expansion in volume of a given amount of matter associated with an extreme outward release of energy, usually with the generation of high temperatures and release of high-pressure gases. Explosions may also be generated ..., and the resulting overpressure receives particular attention when measuring the effects of nuclear weapons or thermobaric bombs. Effects According to an article in the journal '' Toxicological Sciences'', Blast overpressure (BOP), also known as high energy impulse noise, is a damaging outcome of explosive detonations and firing of weapons. Exposure to BOP shock waves alone results in injury predominantly to the hollow organ systems such as auditory, respiratory, and gastrointestinal systems. An EOD suit worn by bomb disposal experts can protect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Effects Of Nuclear Weapon
The effects of a nuclear explosion on its immediate vicinity are typically much more destructive and multifaceted than those caused by conventional explosives. In most cases, the energy released from a nuclear weapon detonated within the lower atmosphere can be approximately divided into four basic categories: *the blast and shock wave: 50% of total energy *thermal radiation: 35% of total energy *ionizing radiation: 5% of total energy (more in a neutron bomb) * residual radiation: 5–10% of total energy with the mass of the explosion. Depending on the design of the weapon and the location in which it is detonated, the energy distributed to any one of these categories may be significantly higher or lower. The physical blast effect is created by the coupling of immense amounts of energy, spanning the electromagnetic spectrum, with the surroundings. The environment of the explosion (e.g. submarine, ground burst, air burst, or exo-atmospheric) determines how much energy is distrib ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sonic Boom
A sonic boom is a sound associated with shock waves created when an object travels through the air faster than the speed of sound. Sonic booms generate enormous amounts of sound energy, sounding similar to an explosion or a thunderclap to the human ear. The crack of a supersonic bullet passing overhead or the crack of a bullwhip are examples of a small sonic boom. Sonic booms due to large supersonic aircraft can be particularly loud and startling, tend to awaken people, and may cause minor damage to some structures. This led to the prohibition of routine supersonic flight overland. Although sonic booms cannot be completely prevented, research suggests that with careful shaping of the vehicle, the nuisance due to sonic booms may be reduced to the point that overland supersonic flight may become a feasible option. A sonic boom does not occur only at the moment an object crosses the sound barrier and neither is it heard in all directions emanating from the supersonic objec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pound Per Square Inch
The pound per square inch (abbreviation: psi) or, more accurately, pound-force per square inch (symbol: lbf/in2), is a unit of measurement of pressure or of stress based on avoirdupois units and used primarily in the United States. It is the pressure resulting from a force with magnitude of one pound-force applied to an area of one square inch. In SI units, 1 psi is approximately . The pound per square inch absolute (psia) is used to make it clear that the pressure is relative to a vacuum rather than the ambient atmospheric pressure. Since atmospheric pressure at sea level is around , this will be added to any pressure reading made in air at sea level. The converse is pound per square inch gauge (psig), indicating that the pressure is relative to atmospheric pressure. For example, a bicycle tire pumped up to 65 psig in a local atmospheric pressure at sea level (14.7 psi) will have a pressure of 79.7 psia (14.7 psi + 65 psi). When gauge pressure is referenced to som ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermobaric Bomb
A thermobaric weapon, also called an aerosol bomb, or a vacuum bomb, is a type of explosive munition that works by dispersing an aerosol cloud of gas, liquid or powdered explosive. The fuel is usually a single compound, rather than a mixture of multiple substances. Many types of thermobaric weapons can be fitted to hand-held launchers, and can also be launched from airplanes. Terminology The term ''thermobaric'' is derived from the Greek words for 'heat' and 'pressure': ''thermobarikos'' (θερμοβαρικός), from ''thermos'' (θερμός) 'hot' + ''baros'' (βάρος) 'weight, pressure' + suffix ''-ikos'' (-ικός) '-ic'. Other terms used for the family of weapons are high-impulse thermobaric weapons, heat and pressure weapons, vacuum bombs, and fuel-air explosives (FAE). Mechanism File:Dust explosion 00.jpg, Experimental setup File:Dust explosion 01.jpg, Finely-ground flour is dispersed File:Dust explosion 02.jpg, Cloud of flour is ignited File:Dust explosion 03. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bomb Suit
A bomb suit, Explosive Ordnance Disposal (EOD) suit or a blast suit is a heavy suit of body armor designed to withstand the pressure generated by a bomb and any fragments the bomb may produce. It is usually worn by trained personnel attempting bomb disposal. In contrast to ballistic body armors, which usually focus on protecting the torso and head, a bomb suit must protect all parts of the body, since the dangers posed by a bomb's explosion affect the entire body. Parts of the bomb suit overlap for maximum protection. The suit protects in several different ways. It deflects or stops projectiles that may come from an exploded device. It also stops or greatly decreases the pressure of the blast wave being transmitted to the person inside of the suit. Most bomb suits, such as the Advanced Bomb Suit, use layers of Kevlar, foam, and plastic to accomplish these functions. In order to maximize protection, bomb suits come with a pair of interchangeable gloves and wrist guard attachmen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shock Wave
In physics, a shock wave (also spelled shockwave), or shock, is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a medium, but is characterized by an abrupt, nearly discontinuous, change in pressure, temperature, and density of the medium. For the purpose of comparison, in supersonic speed, supersonic flows, additional increased expansion may be achieved through an expansion fan, also known as a Prandtl–Meyer expansion fan. The accompanying expansion wave may approach and eventually collide and recombine with the shock wave, creating a process of destructive interference. The sonic boom associated with the passage of a supersonic aircraft is a type of sound wave produced by Wave interference, constructive interference. Unlike solitons (another kind of nonlinear wave), the energy and speed of a shock wave alone dissipates relatively quickly with distan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atmospheric Pressure
Atmospheric pressure, also known as air pressure or barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1,013.25 millibars, 760 mm Hg, 29.9212 inchesHg, or 14.696 psi.International Civil Aviation Organization. ''Manual of the ICAO Standard Atmosphere'', Doc 7488-CD, Third Edition, 1993. . The atm unit is roughly equivalent to the mean sea-level atmospheric pressure on Earth; that is, the Earth's atmospheric pressure at sea level is approximately 1 atm. In most circumstances, atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point. As elevation increases, there is less overlying atmospheric mass, so atmospheric pressure decreases with increasing elevation. Because the atmosphere is thin relative to the Earth's radius—especially the dense atmospheric layer at low altitu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Explosion
An explosion is a rapid expansion in volume of a given amount of matter associated with an extreme outward release of energy, usually with the generation of high temperatures and release of high-pressure gases. Explosions may also be generated by a slower expansion that would normally not be forceful, but is not allowed to expand, so that when whatever is containing the expansion is broken by the pressure that builds as the matter inside tries to expand, the matter expands forcefully. An example of this is a Volcano, volcanic eruption created by the expansion of magma in a magma chamber as it rises to the surface. Supersonic explosions created by high explosives are known as detonations and travel through shock waves. wikt:subsonic, Subsonic explosions are created by low explosives through a slower combustion process known as deflagration. Causes For an explosion to occur, there must be a rapid, forceful expansion of matter. There are numerous ways this can happen, both natura ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toxicological Sciences
''Toxicological Sciences'' is a monthly peer-reviewed scientific journal which covers all aspects of research on toxicology. It is published by Oxford University Press on behalf of the Society of Toxicology. It was established in 1981 as ''Fundamental and Applied Toxicology'' and obtained its current name in 1998. The current editor-in-chief is Jeffrey M. Peters, a professor of molecular toxicology and carcinogenesis at The Pennsylvania State University, and the Managing Editor is Virginia F. Hawkins. The editorial staff also includes Associate Editors in subject areas and an editorial board of topic experts. While its ISO 4 abbreviation is ''Toxicol. Sci.'' it is commonly referred to as ''ToxSci''. Abstracting and indexing The journal is abstracted and indexed in Biological Abstracts, BIOSIS, CAB International, Chemical Abstracts Service, Current Contents, EMBASE, Health & Safety Science Abstracts, Science Citation Index, and Toxicology Abstracts. According to the ''Jou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bomb Disposal
Bomb disposal is an explosives engineering profession using the process by which hazardous explosive devices are disabled or otherwise rendered safe. ''Bomb disposal'' is an all-encompassing term to describe the separate, but interrelated functions in the military fields of explosive ordnance disposal (EOD) and improvised explosive device disposal (IEDD), and the Public security, public safety roles of public safety bomb disposal (PSBD) and the bomb squad. History The first professional civilian bomb squad was established by Colonel Sir Vivian Dering Majendie a Major (rank), Major at the time in the Royal Artillery, Majendie investigated an explosion on 2 October 1874 in the Regent's Canal, when the barge 'Tilbury', carrying six barrels of petroleum and five tons of gunpowder, blew up, killing the crew and destroying Macclesfield Bridge and cages at nearby London Zoo. In 1875, he framed the Explosives Act 1875, Explosives Act, the first modern legislation for explosives contro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bar (unit)
The bar is a metric unit of pressure defined as 100,000 Pa (100 kPa), though not part of the International System of Units (SI). A pressure of 1 bar is slightly less than the current average atmospheric pressure on Earth at sea level (approximately 1.013 bar). By the barometric formula, 1 bar is roughly the atmospheric pressure on Earth at an altitude of 111 metres at 15 °C. The bar and the millibar were introduced by the Norwegian meteorologist Vilhelm Bjerknes, who was a founder of the modern practice of weather forecasting, with the bar defined as one megadyne per square centimetre. The SI brochure, despite previously mentioning the bar, now omits any mention of it.. The bar has been legally recognised in countries of the European Union since 2004. British Standard BS 350:2004 ''Conversion Factors for Units''. The US National Institute of Standards and Technology (NIST) deprecates its use except for "limited use in meteorology" and lists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Defense Technical Information Center
The Defense Technical Information Center (DTIC, ) is the repository for research and engineering information for the United States Department of Defense (DoD). DTIC's services are available to DoD personnel, federal government personnel, federal contractors and selected academic institutions. The general public can access unclassified information through its public website. History The DTIC traces its history to the June 1945 formation of the Air Documents Research Center (ADRC), a joint effort of the US Army Air Force, US Navy and Royal Air Force to build a single collection of captured German aeronautical research, based in London. The ADRC was initially tasked with the sorting of the document collection into three broad groups; documents that would assist the war in the Pacific theater, documents of immediate intelligence interest to the United States or British forces and documents of interest for future research. With the ending of the war in 1945, the ADRC moved to Wrig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
