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Wilson Cloud
A transient condensation cloud, also called a Wilson cloud, is observable surrounding large explosions in humid air. When a nuclear weapon or high explosive is detonated in sufficiently humid air, the "negative phase" of the shock wave causes a rarefaction of the air surrounding the explosion but not of the air contained within it. The rarefied air is temporarily cooled, which causes condensation of some of the water vapor within the rarefied air. When the pressure and temperature return to normal, the Wilson cloud dissipates. Mechanism Since heat does not leave the affected air mass, the change of pressure following a detonation is adiabatic, with an associated change of temperature. In humid air, the drop in temperature in the most rarefied portion of the shock wave can bring the air temperature below its dew point, at which moisture condenses to form a visible cloud of microscopic water droplets. Since the pressure effect of the wave is reduced by its expansion (the same p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crossroads Baker Explosion
Crossroads is a junction where four roads meet. Crossroads, crossroad, cross road(s) or similar may also refer to: Film and television Films * ''Crossroads'' (1928 film), a 1928 Japanese film by Teinosuke Kinugasa * ''Cross Roads'' (film), a 1930 British film by Reginald Fogwell * ''Crossroads'' (1937 film), a Chinese film starring Zhao Dan * ''Crossroads'' (1938 film), a French mystery film directed by Curtis Bernhardt * ''Crossroads'' (1942 film), an American mystery film starring William Powell and Hedy Lamarr * ''The Crossroads'' (1942 film), a French drama film directed by André Berthomieu * ''The Crossroads'' (1951 film), an Italian crime film by Fernando Cerchio * ''The Crossroads'' (1952 film), an Argentine film * ''The Crossroads'' (1960 film), a French-Spanish drama film by Alfonso Balcázar * ''Crossroads'' (1976 film), a short film by Bruce Conner * ''Crossroad'', a 1976 Hong Kong-Taiwanese film by Chin Han * ''Crossroads'' (1986 film), a film starring R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sub-atomic Particle
In physics, a subatomic particle is a particle smaller than an atom. According to the Standard Model of particle physics, a subatomic particle can be either a composite particle, which is composed of other particles (for example, a baryon, like a proton or a neutron, composed of three quarks; or a meson, composed of two quarks), or an elementary particle, which is not composed of other particles (for example, quarks; or electrons, muons, and tau particles, which are called leptons). Particle physics and nuclear physics study these particles and how they interact. Most force-carrying particles like photons or gluons are called bosons and, although they have quanta of energy, do not have rest mass or discrete diameters (other than pure energy wavelength) and are unlike the former particles that have rest mass and cannot overlap or combine which are called fermions. The W and Z bosons, however, are an exception to this rule and have relatively large rest masses at approxima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contrail
Contrails (; short for "condensation trails") or vapour trails are line-shaped clouds produced by aircraft engine exhaust or changes in air pressure, typically at aircraft cruising altitudes several kilometres/miles above the Earth's surface. They are composed primarily of water, in the form of ice crystals. The combination of water vapor in aircraft engine exhaust and the low ambient temperatures at high altitudes causes the trails' formation. Impurities in the engine exhaust from the fuel, including soot and sulfur compounds (0.05% by weight in jet fuel) provide some of the particles that serve as cloud condensation nuclei for water droplet growth in the exhaust. If water droplets form, they can freeze to form ice particles that compose a contrail. Their formation can also be triggered by changes in air pressure in wingtip vortices, or in the air over the entire wing surface. Contrails, and other clouds caused directly by human activity, are called ''homogenitus''. The va ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rope Trick Effect
''Rope trick'' is the term given by American nuclear physicist John Malik to the curious lines and spikes which emanate from the fireball of nuclear explosions under certain conditions, just after detonation. Description The adjacent photograph shows two unusual phenomena: bright spikes projecting from the bottom of the fireball, and the peculiar mottling of the expanding fireball surface. The surface of the fireball, with a temperature over 20,000 Kelvin, emits huge amounts of visible light radiation, more than 100 times the intensity at the Sun's surface. Anything solid in the area absorbs the light and rapidly heats. The "rope tricks" that protrude from the bottom of the fireball are caused by the heating, rapid vaporization and then expansion of guy wires that extend from the shot cab—the housing at the top of the bomb tower that contains the explosive device—to the ground. Malik observed that when the guy wires were painted black, spike formation was enhanced, and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transonic
Transonic (or transsonic) flow is air flowing around an object at a speed that generates regions of both subsonic and Supersonic speed, supersonic airflow around that object. The exact range of speeds depends on the object's critical Mach number, but transonic flow is seen at flight speeds close to the speed of sound (343 m/s at sea level), typically between Mach number, Mach 0.8 and 1.2. The issue of transonic speed (or transonic region) first appeared during World War II. Pilots found as they approached the sound barrier the airflow caused aircraft to become unsteady. Experts found that shock waves can cause large-scale Flow separation, separation downstream, increasing drag, adding asymmetry and unsteadiness to the flow around the vehicle. Research has been done into weakening shock waves in transonic flight through the use of Anti-shock body, anti-shock bodies and supercritical airfoils. Most modern jet engine, jet powered aircraft are engineered to operate at transon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vapor Cone
A vapor cone (also known as a Mach diamond, shock collar, or shock egg) is a visible cloud of condensed water that can sometimes form around an object moving at high speed through moist air, such as an aircraft flying at transonic speeds. When the localized air pressure around the object drops, so does the air temperature. If the temperature drops below the saturation temperature, a cloud forms. In the case of aircraft, the cloud is caused by expansion fans decreasing the air pressure, density, and temperature below the dew point. Then pressure, density, and temperature suddenly increase across the stern shock wave associated with a return to subsonic flow behind the aircraft. Since the local Mach number is not uniform over the aircraft, parts of the aircraft may be supersonic while others remain subsonic—a flight regime called transonic flight. In addition to making the shock waves themselves visible, water condensation can also occur in the trough between two crests of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lift (force)
When a fluid flows around an object, the fluid exerts a force on the object. Lift is the Euclidean_vector#Decomposition_or_resolution, component of this force that is perpendicular to the oncoming flow direction. It contrasts with the drag (physics), drag force, which is the component of the force parallel to the flow direction. Lift conventionally acts in an upward direction in order to counter the force of gravity, but it is defined to act perpendicular to the flow and therefore can act in any direction. If the surrounding fluid is air, the force is called an aerodynamic force. In water or any other liquid, it is called a Fluid dynamics, hydrodynamic force. Dynamic lift is distinguished from other kinds of lift in fluids. Aerostatics, Aerostatic lift or buoyancy, in which an internal fluid is lighter than the surrounding fluid, does not require movement and is used by balloons, blimps, dirigibles, boats, and submarines. Planing (boat), Planing lift, in which only the lower po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2020 Beirut Explosion
On 4 August 2020, a major explosion occurred in Beirut, Lebanon, triggered by the ignition of 2,750 tonnes of ammonium nitrate. The chemical, confiscated in 2014 from the cargo ship and stored at the Port of Beirut without adequate safety measures for six years, detonated after a fire broke out in a nearby warehouse. The explosion resulted in at least 218 fatalities, 7,000 injuries, and approximately 300,000 displaced individuals, alongside property damage estimated at US$15 billion. The blast released energy comparable to 1.1 TNT equivalent, kilotons of TNT, ranking it among the Largest artificial non-nuclear explosions#Largest accidental artificial non-nuclear explosions by magnitude, most powerful non-nuclear explosions ever recorded and the largest single detonation of ammonium nitrate. The explosion generated a Earthquake, seismic event measuring 3.3 in magnitude, as reported by the United States Geological Survey. Its effects were felt in Lebanon and neighboring regions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operation Sailor Hat
Operation Sailor Hat was a series of explosives effects tests, conducted by the United States Navy Bureau of Ships under the sponsorship of the Defense Atomic Support Agency. The tests consisted of two underwater explosions at San Clemente Island, California in 1964 and three surface explosions at Kahoolawe, Kahoolawe, Hawaii in 1965. They were non-nuclear tests employing large quantities of conventional explosives (trinitrotoluene, TNT and HBX) to determine the effects of a nuclear weapon blast on naval vessels, and the first major test of this kind since Operation Crossroads in July 1946. Each "Sailor Hat" test at Kahoolawe, Kahoolawe consisted of a dome-stacked charge of TNT high explosive detonated on the shore close to the ships under test. Since a TNT detonation releases energy more slowly than a nuclear explosion, the blast effect at close range was designed to be equivalent to a nuclear weapon at greater distance. The main ship used for testing was the former Cleveland- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TNT Detonation On Kaho'olawe Island During Operation Sailor Hat, Shot Bravo, 1965
Troponin T (shortened TnT or TropT) is a part of the troponin complex, which are proteins integral to the contraction of skeletal and heart muscles. They are expressed in skeletal and cardiac myocytes. Troponin T binds to tropomyosin and helps position it on actin, and together with the rest of the troponin complex, modulates contraction of striated muscle. The cardiac subtype of troponin T is especially useful in the laboratory diagnosis of heart attack because it is released into the blood-stream when damage to heart muscle occurs. It was discovered by the German physician Hugo A. Katus at the University of Heidelberg, who also developed the troponin T assay. Subtypes * Slow skeletal troponin T1, TNNT1 (19q13.4, ) * Cardiac troponin T2, TNNT2 (1q32, ) * Fast skeletal troponin T3, TNNT3 (11p15.5, ) Reference values The 99th percentile cutoff for cardiac troponin T (cTnT) is 0.01 ng/mL. The reference range for the high sensitivity troponin T is a normal 52 ng/L. Backgroun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermal Radiation
Thermal radiation is electromagnetic radiation emitted by the thermal motion of particles in matter. All matter with a temperature greater than absolute zero emits thermal radiation. The emission of energy arises from a combination of electronic, molecular, and lattice oscillations in a material. Kinetic energy is converted to electromagnetism due to charge-acceleration or dipole oscillation. At room temperature, most of the emission is in the infrared (IR) spectrum, though above around 525 °C (977 °F) enough of it becomes visible for the matter to visibly glow. This visible glow is called incandescence. Thermal radiation is one of the fundamental mechanisms of heat transfer, along with conduction and convection. The primary method by which the Sun transfers heat to the Earth is thermal radiation. This energy is partially absorbed and scattered in the atmosphere, the latter process being the reason why the sky is visibly blue. Much of the Sun's radiation tra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
