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LINUS (Fusion Experiment)
The Linus program was an experimental fusion power project developed by the United States Naval Research Laboratory (NRL) starting in 1971. The goal of the project was to produce a controlled fusion reaction by compressing Plasma (physics), plasma inside a metal liner. The basic concept is today known as magnetized target fusion. The reactor design was based on the mechanical compression of a molten metal liner. A chamber would be filled with molten metal and rotated along one axis, creating a cylindrical cavity in the center. A suitable fusion fuel, heated to several thousand degrees to form it into a plasma, is injected into the center of the cavity. The metal is then rapidly collapsed, and due to the conservation of magnetic flux within the metal, the plasma is confined within the resulting collapsing shell and is itself collapsed. The adiabatic process would raise the temperature and density of the trapped plasma to Lawson criterion, fusion conditions. The use of a liquid met ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interchange Instability
The interchange instability, also known as the Kruskal–Schwarzschild instability or flute instability, is a type of plasma instability seen in magnetic fusion energy that is driven by the gradients in the magnetic pressure in areas where the confining magnetic field is curved. The name of the instability refers to the action of the plasma changing position with the magnetic field lines (i.e. an interchange of the lines of force in space) without significant disturbance to the geometry of the external field. The instability causes flute-like structures to appear on the surface of the plasma, hence it is also referred to as the ''flute instability''. The interchange instability is a key issue in the field of fusion energy, where magnetic fields are used to confine a plasma in a volume surrounded by the field. The basic concept was first noted in a 1954 paper by Martin David Kruskal and Martin Schwarzschild, who demonstrated that a situation similar to the Rayleigh–Taylor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Speed Of Sound
The speed of sound is the distance travelled per unit of time by a sound wave as it propagates through an elasticity (solid mechanics), elastic medium. More simply, the speed of sound is how fast vibrations travel. At , the speed of sound in air is about , or in or one mile in . It depends strongly on temperature as well as the medium through which a sound wave is propagating. At , the speed of sound in dry air (sea level 14.7 psi) is about . The speed of sound in an ideal gas depends only on its temperature and composition. The speed has a weak dependence on frequency and pressure in dry air, deviating slightly from ideal behavior. In colloquial speech, ''speed of sound'' refers to the speed of sound waves in Earth's atmosphere, air. However, the speed of sound varies from substance to substance: typically, sound travels most slowly in gases, faster in liquids, and fastest in solids. For example, while sound travels at in air, it travels at in water (almost 4.3 times a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chevrolet Big-block Engine
The Chevrolet big-block engine is a series of Engine displacement, large-displacement, naturally-aspirated, 90°, overhead valve, Gasoline engine, gasoline-powered, V8 engines that was developed and have been produced by the Chevrolet Division of General Motors from the late 1950s until present. They have powered countless General Motors products, not just Chevrolets, and have been used in a variety of cars from other manufacturers as well - from boats to motorhomes to armored vehicles. Chevrolet had introduced its popular Chevrolet small-block engine (first and second generation), small-block V8 in 1955, but needed something larger to power its Chevrolet Kodiak, medium duty trucks and the heavier cars that were on the drawing board. The big-block, which debuted in 1958 at , was built in standard displacements up to , with aftermarket crate engines sold by Chevrolet exceeding . Mark I (W-series) The first version of the "big-block" V8 Chevrolet engine, known as the W-series, was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymer-bonded Explosive
Polymer-bonded explosives, also called PBX or plastic-bonded explosives, are explosive materials in which explosive powder is bound together in a matrix using small quantities (typically 5–10% by weight) of a synthetic polymer. PBXs are normally used for explosive materials that are not easily melted into a casting, or are otherwise difficult to form. PBX was first developed in 1952 at Los Alamos National Laboratory, as RDX embedded in polystyrene with diisooctyl phthalate (DEHP) plasticizer. HMX compositions with teflon-based binders were developed in 1960s and 1970s for gun shells and for Apollo Lunar Surface Experiments Package (ALSEP) seismic experiments, although the latter experiments are usually cited as using hexanitrostilbene (HNS). Potential advantages Polymer-bonded explosives have several potential advantages: * If the polymer matrix is an elastomer (rubbery material), it tends to absorb shocks, making the PBX very insensitive to accidental detonation, and th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centripetal Force
Centripetal force (from Latin ''centrum'', "center" and ''petere'', "to seek") is the force that makes a body follow a curved trajectory, path. The direction of the centripetal force is always orthogonality, orthogonal to the motion of the body and towards the fixed point of the instantaneous osculating circle, center of curvature of the path. Isaac Newton coined the term, describing it as "a force by which bodies are drawn or impelled, or in any way tend, towards a point as to a centre". In Newtonian mechanics, gravity provides the centripetal force causing astronomical orbits. One common example involving centripetal force is the case in which a body moves with uniform speed along a circular path. The centripetal force is directed at right angles to the motion and also along the radius towards the centre of the circular path. The mathematical description was derived in 1659 by the Dutch physicist Christiaan Huygens. Formula From the kinematics of curved motion it is known ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conservation Of Angular Momentum
Angular momentum (sometimes called moment of momentum or rotational momentum) is the rotational analog of Momentum, linear momentum. It is an important physical quantity because it is a Conservation law, conserved quantity – the total angular momentum of a closed system remains constant. Angular momentum has both a direction (geometry), direction and a magnitude, and both are conserved. Bicycle and motorcycle dynamics, Bicycles and motorcycles, flying discs, Rifling, rifled bullets, and gyroscopes owe their useful properties to conservation of angular momentum. Conservation of angular momentum is also why hurricanes form spirals and neutron stars have high rotational rates. In general, conservation limits the possible motion of a system, but it does not uniquely determine it. The three-dimensional angular momentum for a point particle is classically represented as a pseudovector , the cross product of the particle's position vector (relative to some origin) and its mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eutectic System
A eutectic system or eutectic mixture ( ) is a type of a homogeneous mixture that has a melting point lower than those of the constituents. The lowest possible melting point over all of the mixing ratios of the constituents is called the ''eutectic temperature''. On a phase diagram, the eutectic temperature is seen as the eutectic point (see plot on the right). Non-eutectic mixture ratios have different melting temperatures for their different constituents, since one component's lattice will melt at a lower temperature than the other's. Conversely, as a non-eutectic mixture cools down, each of its components solidifies into a lattice at a different temperature, until the entire mass is solid. A non-eutectic mixture thus does not have a single melting/freezing point temperature at which it changes phase, but rather a temperature at which it changes between liquid and slush (known as the liquidus) and a lower temperature at which it changes between slush and solid (the solidu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theta Pinch
Theta-pinch, or θ-pinch and sometimes known as a thetatron, is a type of fusion power reactor design. The name refers to the configuration of currents used to confine the plasma (physics), plasma fuel in the reactor, arranged to run around a cylinder in the direction normally denoted as theta in polar coordinate diagrams. The name was chosen to differentiate it from machines based on the pinch effect that arranged their currents running down the centre of the cylinder; these became known as z-pinch machines, referring to the Z-axis in cartesian coordinates. Theta-pinch was developed primarily in the United States, mostly at the Los Alamos National Laboratory (LANL) in a series of machines known as Scylla. In 1958, Scylla I was the first machine to clearly demonstrate thermonuclear fusion reactions of deuterium in a controlled manner. It became one of the major lines of fusion research during the 1960s. General Electric and the Naval Research Laboratory also experimented with the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kopeck
The kopeck or kopek is or was a coin or a currency unit of a number of countries in Eastern Europe closely associated with the economy of Russia. It is usually the smallest denomination within a currency system; 100 kopeks are worth 1 ruble or 1 hryvnia. Originally, the kopeck was the currency unit of Imperial Russia, the Russian Soviet Federative Socialist Republic and then the Soviet Union (as the Soviet ruble). , it is the currency unit of Russia, Belarus and Ukraine. The Russian kopeck is also used in two regions of Georgia (country), Georgia, and the List of states with limited recognition, partially recognised states (including by Russia) of Abkhazia and South Ossetia. Partially recognised Transnistria has its own kopeck. In the past, several other countries influenced by Russia and the Soviet Union had currency units that were also named kopecks. The name of the coin of Azerbaijan comes from the word kopeck – gapik (, Azerbaijani manat, manat). No country's kopeck ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
