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Self-propelled Particles
Self-propelled particles (SPP), also referred to as self-driven particles, are terms used by physicists to describe autonomous agents, which convert energy from the environment into directed or persistent random walk. Natural systems which have inspired the study and design of these particles include walking, swimming or flying animals. Other biological systems include bacteria, cells, algae and other micro-organisms. Generally, self-propelled particles often refer to artificial systems such as robots or specifically designed particles such as swimming Janus particles, Janus colloids, bimetallic nanorods, nanomotors and walking grains. In the case of directed propulsion, which is driven by a chemical gradient, this is referred to as chemotaxis, observed in biological systems, e.g. bacteria quorum sensing and ant pheromone detection, and in synthetic systems, e.g. enzyme molecule chemotaxis and enzyme powered hard and soft particles. Overview Self-propelled particles interact wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schwarm Wanderheuschrecke
A flight is a small military unit within the larger structure of an air force, Naval aviation, naval air service, or Army aviation, army air corps; and is usually subordinate to a larger Squadron (aviation), squadron. A military aircraft flight is typically composed of four aircraft, though two to six aircraft may also form an aircraft flight; along with their aircrews and ground staff. In some very specific examples, typically involving historic aircraft, a flight may contain as many as twelve aircraft, as is the case with the Battle of Britain Memorial Flight (BBMF) of the British Royal Air Force (RAF). In most usages, two or more flights make up a Squadron (aviation), squadron. Foreign languages equivalents include (French language, French), (Spanish language, Spanish), (Portuguese language, Portuguese), ''lanka'' (Ukrainian language, Ukrainian), (Romanian language, Romanian), (Russian language, Russian), and (German language, German). In the case of a non-flying, or " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grubbs' Catalyst
Grubbs catalysts are a series of transition metal carbene complexes used as catalysts for olefin metathesis. They are named after Robert H. Grubbs, the chemist who supervised their synthesis. Several generations of the catalyst have also been developed. Grubbs catalysts tolerate many functional groups in the alkene substrates, are air-tolerant, and are compatible with a wide range of solvents. For these reasons, Grubbs catalysts have become popular in Organic Chemistry#Organic synthesis, synthetic organic chemistry. Grubbs, together with Richard R. Schrock and Yves Chauvin, won the Nobel Prize in Chemistry in recognition of their contributions to the development of olefin metathesis. First-generation Grubbs catalyst In the 1960s, ruthenium trichloride was found to catalyze olefin metathesis. Processes were commercialized based on these discoveries. These ill-defined but highly active homogeneous catalysts remain in industrial use. The first well-defined ruthenium catalyst was rep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nymph Of Locust - Project Gutenberg EText 16410
A nymph (; ; sometimes spelled nymphe) is a minor female nature deity in ancient Greek folklore. Distinct from other Greek goddesses, nymphs are generally regarded as personifications of nature; they are typically tied to a specific place, landform, or tree, and are usually depicted as maidens. Because of their association with springs, they were often seen as having healing properties; other divine powers of the nymphs included divination and shapeshifting. In spite of their divine nature, they were not immortal. Nymphs are divided into various broad subgroups based on their habitat, such as the Meliae ( ash tree nymphs), the Dryads (oak tree nymphs), the Alseids ( grove nymphs), the Naiads ( spring nymphs), the Nereids (sea nymphs), the Oceanids (ocean nymphs), and the Oreads (mountain nymphs). Other nymphs included the Hesperides (evening nymphs), the Hyades (rain nymphs), and the Pleiades (companions of Artemis). Nymphs featured in classic works of art, literature, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Active Matter
Active matter is matter composed of large numbers of active "agents", each of which consumes energy in order to move or to exert mechanical forces. Such systems are intrinsically out of thermal equilibrium. Unlike thermal systems relaxing towards equilibrium and systems with boundary conditions imposing steady currents, active matter systems break time reversal symmetry because energy is being continually dissipated by the individual constituents. Most examples of active matter are biological in origin and span all the scales of the living, from bacteria and self-organising bio-polymers such as microtubules and actin (both of which are part of the cytoskeleton of living cells), to schools of fish and flocks of birds. However, a great deal of current experimental work is devoted to synthetic systems such as artificial self-propelled particles. Active matter is a relatively new material classification in soft matter: the most extensively studied model, the Vicsek model, dates fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BIO-LGCA
In Computational biology, computational and Mathematical and theoretical biology, mathematical biology, a biological lattice-gas cellular automaton (BIO-LGCA) is a discrete model for moving and interacting biological agents, a type of cellular automaton. The BIO-LGCA is based on the Lattice gas automaton, lattice-gas cellular automaton (LGCA) model used in fluid dynamics. A BIO-LGCA model describes cells and other motile biological agents as point particles moving on a discrete lattice, thereby interacting with nearby particles. Contrary to classic cellular automaton models, particles in BIO-LGCA are defined by their position and velocity. This allows to model and analyze active fluids and collective migration mediated primarily through changes in momentum, rather than density. BIO-LGCA applications include cancer invasion and Cancer, cancer progression. Model definition As are all cellular automaton models, a BIO-LGCA model is defined by a lattice \mathcal, a state space \mathcal, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Self-propulsion
Self-propulsion is the autonomous displacement of nano-, micro- and macroscopic natural and artificial objects, containing their own means of motion. Self-propulsion is driven mainly by interfacial phenomena. Various mechanisms of self-propelling have been introduced and investigated, which exploited phoretic effects, gradient surfaces, breaking the wetting symmetry of a droplet on a surface, the Leidenfrost effect The Leidenfrost effect or film boiling is a physical phenomenon in which a liquid, close to a solid surface of another body that is significantly hotter than the liquid's boiling point, produces an insulating vapor layer that keeps the liquid fr ..., the self-generated hydrodynamic and chemical fields originating from the geometrical confinements, and soluto- and thermo-capillary Marangoni flows. Self-propelled system demonstrate a potential as micro-fluidics devices and micro-mixers. Self-propelled liquid marbles have been demonstrated. See also * Self propelle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Active Brownian Particle
An active Brownian particle (ABP) is a model of self-propelled motion in a dissipative environment. It is a nonequilibrium generalization of a Brownian particle. The self-propulsion results from a force that acts on the particle's center of mass and points in the direction of an intrinsic body axis (the particle orientation). It is common to treat particles as spheres, though other shapes (such as rods) have also been studied. Both the center of mass and the direction of the propulsive force are subjected to white noise, which contributes a diffusive component to the overall dynamics. In its simplest version, the dynamics is overdamped and the propulsive force has constant magnitude, so that the magnitude of the velocity is likewise constant (speed-up to terminal velocity is instantaneous). The term ''active Brownian particle'' usually refers to this simple model and its straightforward extensions, though some authors have used it for more general self-propelled particle model ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physica A '', an international scientific journal for experimental and theoretical physics
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Physica may refer to: * Physics (Aristotle) * ''Physica'', a twelfth-century medical text by Hildegard of Bingen * ''Physica'' (journal), a Dutch scientific journal :* ''Physica A'' :* ''Physica B'' ;* ''Physica C'' :* ''Physica D'' :* ''Physica E'' * ''Physica Scripta ''Physica Scripta'' is an international scientific journal for experimental and theoretical physics. It was established in 1970 as the successor of ''Arkiv för Fysik'' and published by the Royal Swedish Academy of Sciences (KVA). Since 2006, it ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Craig Reynolds (computer Graphics)
Craig W. Reynolds (born March 15, 1953), is an artificial life and computer graphics expert, who created the Boids artificial life simulation in 1986. Reynolds worked on the film ''Tron'' (1982) as a scene programmer, and on ''Batman Returns'' (1992) as part of the video image crew. Reynolds won the 1998 Academy Scientific and Technical Award The Scientific and Technical Awards are three different Honorary Awards that are given by the Academy of Motion Picture Arts and Sciences (AMPAS) during the annual Academy Awards season. The Awards have been presented since the 4th Academy Awards ... in recognition of "his pioneering contributions to the development of three-dimensional computer animation for motion picture production." In 2023 at the ALIFE conference he won the life time achievent award of thInternational society for Artificial Life(ISAL). He is the author of the '' OpenSteer'' library. References External linksCraig Reynolds' home page [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boids
Boids is an artificial life program, developed by Craig Reynolds in 1986, which simulates the flocking behaviour of birds, and related group motion. His paper on this topic was published in 1987 in the proceedings of the ACM SIGGRAPH conference. The name "boid" corresponds to a shortened version of "bird-oid object", which refers to a bird-like object, as well as referencing the stereotypical New York pronunciation of 'bird' as . Reynolds' boid model is one example of a larger general concept, for which many other variations have been developed since. The closely related work of Ichiro Aoki is noteworthy because it was published in 1982 — five years ''before'' Reynolds' boids paper. Model details Like most artificial life simulations, Boids is an example of emergent behavior; that is, the complexity of Boids arises from the interaction of individual agents (the boids, in this case) adhering to a set of simple rules. The rules applied in the simplest Boids world are as f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tamás Vicsek
Tamás Vicsek (, born 10 May 1948, Budapest) is a Hungarian scientist with research interests in numerical studies of dense liquids, percolation theory, Monte Carlo simulation of cluster models, aggregation phenomena, fractal growth, pattern formation (computer and laboratory experiments), collective phenomena in biological systems ( flocking, oscillations, crowds), molecular motors, cell locomotion in vitro. He held the position of professor of physics at the Eötvös Loránd University, Budapest, Hungary, and was visiting scientists in various academia. at the website He is the namesake of the [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Collective Motion
Collective motion is defined as the spontaneous emergence of ordered movement in a system consisting of many self-propelled agents. It can be observed in everyday life, for example in flocks of birds, schools of fish, herds of animals and also in crowds and car traffic. It also appears at the microscopic level: in colonies of bacteria, motility assays and artificial self-propelled particles. The scientific community is trying to understand the universality of this phenomenon. In particular it is intensively investigated in statistical physics and in the field of active matter. Experiments on animals, biological and synthesized self-propelled particles, simulations and theories are conducted in parallel to study these phenomena. One of the most famous models that describes such behavior is the Vicsek model introduced by Tamás Vicsek et al. in 1995. Collective behavior of Self-propelled particles Source: Just like biological systems in nature, self-propelled particles also resp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
