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Thermobaric Explosive
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] |
USS McNulty (DDE-581) Sunk As Target With FAE 1972
USS ''McNulty'' (DE-581) was a Rudderow class destroyer escort, ''Rudderow''-class destroyer escort in the United States Navy during World War II. Namesake John Thomas McNulty was born on 23 April 1897 at Philadelphia, Pennsylvania. He enlisted in the Navy on 14 August 1917 for World War I service, until discharged 7 August 1919. He reenlisted 15 July 1920 for the period to 10 July 1924, and after his third enlistment, 29 July 1924, served continuously until his death. Commissioned Ensign (rank), Ensign on 3 November 1941, he was promoted to Lieutenant (junior grade) on 15 June 1942. He was killed in action on the during the Battle of Savo Island on 9 August 1942. History ''McNulty'' was laid down 17 November 1943 by Bethlehem-Hingham Shipyard, Inc., Hingham, Massachusetts; launched 8 January 1944; sponsored by Mrs. Helen K. McNulty; and commissioned 31 March 1944. After shakedown off Bermuda, ''McNulty'' trained along the east coast until leaving Chesapeake Bay on escort d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blast Front
In fluid dynamics, a blast wave is the increased pressure and flow resulting from the deposition of a large amount of energy in a small, very localised volume. The flow field can be approximated as a lead shock wave, followed by a similar subsonic flow field. In simpler terms, a blast wave is an area of pressure expanding supersonically outward from an explosive core. It has a leading shock front of compressed gases. The blast wave is followed by a blast wind of negative gauge pressure, which sucks items back in towards the center. The blast wave is harmful especially to objects very close to the center or at a location of constructive interference. High explosives that detonate generate blast waves. Sources High-order explosives (HE) are more powerful than low-order explosives (LE). HE detonate to produce a defining supersonic over-pressurization shock wave. Sources of HE include trinitrotoluene (TNT), C-4, Semtex, nitroglycerin, and ammonium nitrate fuel oil (ANFO). LE deflagra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deflagration
Deflagration (Lat: ''de + flagrare'', 'to burn down') is subsonic combustion in which a pre-mixed flame propagates through an explosive or a mixture of fuel and oxidizer. Deflagrations in high and low explosives or fuel–oxidizer mixtures may transition to a detonation depending upon confinement and other factors. Most fires found in daily life are diffusion flames. Deflagrations with flame speeds in the range of 1 m/s differ from detonations which propagate supersonically with detonation velocities in the range of km/s. Applications Deflagrations are often used in engineering applications when the force of the expanding gas is used to move an object such as a projectile down a barrel, or a piston in an internal combustion engine. Deflagration systems and products can also be used in mining, demolition and stone quarrying via gas pressure blasting as a beneficial alternative to high explosives. Terminology of explosive safety When studying or discussing explosive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pneumothorax
A pneumothorax is collection of air in the pleural space between the lung and the chest wall. Symptoms typically include sudden onset of sharp, one-sided chest pain and dyspnea, shortness of breath. In a minority of cases, a one-way valve is formed by an area of damaged Tissue (biology), tissue, and the amount of air in the space between chest wall and lungs increases; this is called a tension pneumothorax. This can cause a steadily worsening Hypoxia (medical), oxygen shortage and hypotension, low blood pressure. This leads to a type of shock called obstructive shock, which can be fatal unless reversed. Very rarely, both lungs may be affected by a pneumothorax. It is often called a "collapsed lung", although that term may also refer to atelectasis. A primary spontaneous pneumothorax is one that occurs without an apparent cause and in the absence of significant lung disease. A secondary spontaneous pneumothorax occurs in the presence of existing lung disease. Smoking increases ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Longitudinal Wave
Longitudinal waves are waves which oscillate in the direction which is parallel to the direction in which the wave travels and displacement of the medium is in the same (or opposite) direction of the wave propagation. Mechanical longitudinal waves are also called ''compressional'' or compression waves, because they produce compression and rarefaction when travelling through a medium, and pressure waves, because they produce increases and decreases in pressure. A wave along the length of a stretched Slinky toy, where the distance between coils increases and decreases, is a good visualization. Real-world examples include sound waves (vibrations in pressure, a particle of displacement, and particle velocity propagated in an elastic medium) and seismic P waves (created by earthquakes and explosions). The other main type of wave is the transverse wave, in which the displacements of the medium are at right angles to the direction of propagation. Transverse waves, for instance, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Defense Intelligence Agency
The Defense Intelligence Agency (DIA) is an intelligence agency and combat support agency of the United States Department of Defense (DoD) specializing in military intelligence. A component of the Department of Defense and the United States Intelligence Community, Intelligence Community (IC), DIA informs national civilian and Military budget of the United States, defense policymakers about the military intentions and capabilities of foreign governments and non-state actors. It also provides intelligence assistance, integration and coordination across uniformed United States Intelligence Community#Members, military service intelligence components, which remain structurally separate from DIA. The agency's role encompasses the collection and analysis of military-related foreign political, economic, industrial, geographic, and National Center for Medical Intelligence, medical and health intelligence. DIA produces approximately one-quarter of all intelligence content that goes into t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Rights Watch
Human Rights Watch (HRW) is an international non-governmental organization that conducts research and advocacy on human rights. Headquartered in New York City, the group investigates and reports on issues including War crime, war crimes, crimes against humanity, Child labour, child labor, torture, human trafficking, and Women's rights, women's and LGBTQ rights. It pressures governments, policymakers, companies, and individual abusers to respect human rights, and frequently works on behalf of refugees, children, migrants, and political prisoners. The organization was founded in 1978 as Helsinki Watch, whose purpose was to monitor the Soviet Union's compliance with the 1975 Helsinki Accords. Its separate global divisions merged into Human Rights Watch in 1988. The group publishes annual reports on about 100 countries with the goal of providing an overview of the worldwide state of human rights. In 1997, HRW shared the Nobel Peace Prize as a founding member of the International C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antipersonnel
An anti-personnel weapon is a weapon primarily used to maim or kill infantry and other personnel not behind armor, as opposed to attacking structures or vehicles, or hunting game. The development of defensive fortification and combat vehicles gave rise to weapons designed specifically to attack them, and thus a need to distinguish between those systems and ones intended to attack people. For instance, an anti-personnel landmine will explode into small and sharp splinters that tear flesh but have little effect on metal surfaces, while anti-tank mines have considerably different design, using much more explosive power to effect damage to armored fighting vehicles, or use explosively formed penetrators to punch through armor plating. Many modern weapons systems can be employed in different roles. For example, a tank's main gun can fire armor-piercing ammunition in the anti-tank role, high-explosive ammunition in the anti-structure role and fragmentation shells in the anti-personn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atmospheric Oxygen
Atmospheric chemistry is a branch of atmospheric science that studies the chemistry of the Earth's atmosphere and that of other planets. This multidisciplinary approach of research draws on environmental chemistry, physics, meteorology, computer modeling, oceanography, geology and volcanology, climatology and other disciplines to understand both natural and human-induced changes in atmospheric composition. Key areas of research include the behavior of trace gasses, the formation of pollutants, and the role of aerosols and greenhouse gasses. Through a combination of observations, laboratory experiments, and computer modeling, atmospheric chemists investigate the causes and consequences of atmospheric changes. Atmospheric composition The composition and chemistry of the Earth's atmosphere is important for several reasons, but primarily because of the interactions between the atmosphere and living organisms. Natural processes such as volcano emissions, lightning and bombardmen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rarefaction
Rarefaction is the reduction of an item's density, the opposite of compression. Like compression, which can travel in waves (sound waves, for instance), rarefaction waves also exist in nature. A common rarefaction wave is the area of low relative pressure following a shock wave (see picture). Rarefaction waves expand with time (much like sea waves spread out as they reach a beach); in most cases rarefaction waves keep the same overall profile ('shape') at all times throughout the wave's movement: it is a ''self-similar expansion''. Each part of the wave travels at the local speed of sound, in the local medium. This expansion behaviour contrasts with that of pressure increases, which gets narrower with time until they steepen into shock waves. Physical examples A natural example of rarefaction occurs in the layers of Earth's atmosphere. Because the atmosphere has mass, most atmospheric matter is nearer to the Earth due to the Earth's gravitation In physics, gravity ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flammability Limit
Flammability limits or explosive limits are the ranges of fuel concentrations in relation to oxygen from the air. Combustion can range in violence from deflagration through detonation. Limits vary with temperature and pressure, but are normally expressed in terms of volume percentage at 25 °C and atmospheric pressure. These limits are relevant both in producing and optimising explosion or combustion, as in an engine, or to preventing it, as in uncontrolled explosions of build-ups of combustible gas or dust. Attaining the best combustible or explosive mixture of a fuel and air (the stoichiometric proportion) is important in internal combustion engines such as gasoline or diesel engines. The standard reference work is still that elaborated by Michael George Zabetakis, a fire safety engineering specialist, using an apparatus developed by the United States Bureau of Mines. Violence of combustion Combustion can vary in degree of violence. A deflagration is a propagation of a c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nano-thermite
Nano-thermite or super-thermite is a metastable intermolecular composite (MIC) characterized by a particle size of its main constituents, a metal fuel and oxidizer, under 100 nanometers. This allows for high and customizable reaction rates. Nano-thermites contain an oxidizer and a reducing agent, which are intimately mixed on the nanometer scale. MICs, including nano-thermitic materials, are a type of reactive materials investigated for military use, as well as for general applications involving propellants, explosives, and pyrotechnics. What distinguishes MICs from traditional thermites is that the oxidizer and a reducing agent, normally iron oxide and aluminium, are in the form of extremely fine powders (nanoparticles). This dramatically increases the reactivity relative to micrometre-sized powder thermite. As the mass transport mechanisms that slow down the burning rates of traditional thermites are not so important at these scales, the reaction proceeds much more quickly. Po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
