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Squirmer
The squirmer is a model for a spherical microswimmer swimming in Stokes flow. The squirmer model was introduced by James Lighthill in 1952 and refined and used to model Paramecium by John Blake in 1971. Blake used the squirmer model to describe the flow generated by a carpet of beating short filaments called cilia on the surface of Paramecium. Today, the squirmer is a standard model for the study of self-propelled particles, such as Janus particles, in Stokes flow. Velocity field in particle frame Here we give the flow field of a squirmer in the case of a non-deformable axisymmetric spherical squirmer (radius R). These expressions are given in a spherical coordinate system. u_r(r,\theta)=\frac 2 3 \left(\frac -1\right)B_1P_1(\cos\theta)+\sum_^\left(\frac-\frac\right)B_nP_n(\cos\theta)\;, u_(r,\theta)=\frac 2 3 \left(\frac+1\right)B_1V_1(\cos\theta)+\sum_^\frac 1 2\left(n\frac+(2-n)\frac\right)B_nV_n(\cos\theta)\;. Here B_n are constant coefficients, P_n(\cos\theta) ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stokes Flow
Stokes flow (named after George Gabriel Stokes), also named creeping flow or creeping motion,Kim, S. & Karrila, S. J. (2005) ''Microhydrodynamics: Principles and Selected Applications'', Dover. . is a type of fluid flow where advective inertial forces are small compared with viscous forces. The Reynolds number is low, i.e. \mathrm \ll 1. This is a typical situation in flows where the fluid velocities are very slow, the viscosities are very large, or the length-scales of the flow are very small. Creeping flow was first studied to understand lubrication. In nature this type of flow occurs in the swimming of microorganisms, sperm and the flow of lava. In technology, it occurs in paint, MEMS devices, and in the flow of viscous polymers generally. The equations of motion for Stokes flow, called the Stokes equations, are a linearization of the Navier–Stokes equations, and thus can be solved by a number of well-known methods for linear differential equations. The primary Green' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Lighthill
Sir Michael James Lighthill (23 January 1924 – 17 July 1998) was a British applied mathematician, known for his pioneering work in the field of aeroacoustics and for writing the Lighthill report on artificial intelligence. Biography James Lighthill was born to Ernest Balzar Lichtenberg and Marjorie Holmes: an Alsatian mining engineer who changed his name to Lighthill in 1917, and the daughter of an engineer. The family lived in Paris until 1927, when the father retired and returned to live in England. As a young man, James Lighthill was known as Michael Lighthill. Lighthill was educated at Winchester College, and graduated with a BA from Trinity College, Cambridge in 1943. He specialised in fluid dynamics, and worked at the National Physical Laboratory at Trinity. Between 1946 and 1959 he was Beyer Professor of Applied Mathematics at the University of Manchester. Lighthill then moved from Manchester to become director of the Royal Aircraft Establishment at Farnbor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 motion. 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 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 with each other, which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shaker Pusher
Shaker or Shakers may refer to: Religious groups * Shakers, a historically significant Christian sect * Indian Shakers, a smaller Christian denomination Objects and instruments * Shaker (musical instrument), an indirect struck idiophone * Cocktail shaker, a device used to mix beverages (usually alcoholic) by shaking * Shaker (salt and pepper), condiment dispensers designed to allow diners to distribute grains of edible salt and ground peppercorns * Shaker (laboratory), a device used to stir liquids in chemistry and biology * Shaker (testing device), a vibration device used in endurance testing or modal testing * Shaker scoop, an auto component * Shale shakers, a type of solids control equipment Music * Shaker (musical instrument), an indirect struck idiophone * Shaker (Lil Shaker), a Ghanaian recording artist, songwriter, producer and performer * The Shakers (band) a pseudonym for the band Kingsize Taylor and the Dominoes * Los Shakers, a Uruguayan band * ''Shaker'' (David Joh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shaker Puller
Shaker or Shakers may refer to: Religious groups * Shakers, a historically significant Christian sect * Indian Shakers, a smaller Christian denomination Objects and instruments * Shaker (musical instrument), an indirect struck idiophone * Cocktail shaker, a device used to mix beverages (usually alcoholic) by shaking * Shaker (salt and pepper), condiment dispensers designed to allow diners to distribute grains of edible salt and ground peppercorns * Shaker (laboratory), a device used to stir liquids in chemistry and biology * Shaker (testing device), a vibration device used in endurance testing or modal testing * Shaker scoop, an auto component * Shale shakers, a type of solids control equipment Music * Shaker (musical instrument), an indirect struck idiophone * Shaker (Lil Shaker), a Ghanaian recording artist, songwriter, producer and performer * The Shakers (band) a pseudonym for the band Kingsize Taylor and the Dominoes * Los Shakers, a Uruguayan band * ''Shaker'' (David J ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlamydomonas Reinhardtii
''Chlamydomonas reinhardtii'' is a single-cell green alga about 10 micrometres in diameter that swims with two flagella. It has a cell wall made of hydroxyproline-rich glycoproteins, a large cup-shaped chloroplast, a large pyrenoid, and an eyespot that senses light. ''Chlamydomonas'' species are widely distributed worldwide in soil and fresh water. ''Chlamydomonas reinhardtii'' is an especially well studied biological model organism, partly due to its ease of culturing and the ability to manipulate its genetics. When illuminated, ''C. reinhardtii'' can grow photoautotrophically, but it can also grow in the dark if supplied with organic carbon. Commercially, ''C. reinhardtii'' is of interest for producing biopharmaceuticals and biofuel, as well being a valuable research tool in making hydrogen. History The ''C. reinhardtii'' wild-type laboratory strain c137 (mt+) originates from an isolate collected near Amherst, Massachusetts, in 1945 by Gilbert M. Smith. The species' name h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Faxén's Law
In fluid dynamics, Faxén's laws relate a sphere's velocity \mathbf and angular velocity \mathbf to the forces, torque, stresslet and flow it experiences under low Reynolds number (creeping flow) conditions. First law Faxen's first law was introduced in 1922 by Swedish physicist Hilding Faxén, who at the time was active at Uppsala University, and is given byDurlofsky, Louis, John F. Brady, and Georges Bossis. "Dynamic simulation of hydrodynamically interacting particles." Journal of fluid mechanics 180.1 (1987): 21–49 , equations (2.15a, b, c). Note sign change. : \mathbf = 6 \pi \mu a \left \left( 1 + \frac \nabla^2\right) \mathbf' - (\mathbf - \mathbf^\infty) \right where * \mathbf is the force exerted by the fluid on the sphere * \mu is the Newtonian viscosity of the solvent in which the sphere is placed * a is the sphere's radius * \mathbf is the (translational) velocity of the sphere * \mathbf' is the disturbance velocity caused by the other spheres in suspension (not by t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Passive Particle, Particle Frame
Passive may refer to: * Passive voice, a grammatical voice common in many languages, see also Pseudopassive * Passive language, a language from which an interpreter works * Passivity (behavior), the condition of submitting to the influence of one's superior * Passive-aggressive behavior, resistance to following through with expectations in interpersonal or occupational situations * Passive income, income resulting from cash flow received on a regular basis * Passive immunity, the transfer of active humoral immunity * Passive experience, observation lacking recipricol interaction; and wrought with delusion of control. Science and technology * Passivation (chemistry), process of making a material "passive" in relation to another material prior to using the materials together * Passivity (engineering) a property of engineering systems, particularly in analog electronics and control systems * Passive solar building design, which uses (or avoids) sunlight as an energy source without ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Puller Squirmer, Swimmer Frame
Puller may refer to: Fish * Several species in the genus '' Chromis'' * One-spot puller or brown puller, ''Atypichthys latus'' * Reticulated puller, ''Dascyllus reticulatus'' * Spiny-tail puller, ''Acanthochromis polyacanthus'' * White-spot puller, ''Dascyllus trimaculatus'' Tools * Bearing puller * Nail puller * Wire puller or wire stretcher * Puller (dog sport tool) People * Richard Puller (1747–1826), English merchant banker * Sir Christopher Puller (1774 – 26 May 1824), English lawyer; briefly Chief Justice of Bengal; son of Richard * Chesty Puller, a United States Marine Corps officer during World War II and the Korean War, and the most decorated Marine in the history of the Corps * Lewis Puller, son of Chesty Puller, who was maimed during the Vietnam War and took his own life due to complications from his injuries two and a half decades later Other * Puller (computer gaming), a character in an MMORPG whose primary task in a party is to get the initial attenti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutral Squirmer, Swimmer Frame
Neutral or neutrality may refer to: Mathematics and natural science Biology * Neutral organisms, in ecology, those that obey the unified neutral theory of biodiversity Chemistry and physics * Neutralization (chemistry), a chemical reaction in which an acid and a base react quantitatively with each other * Neutral solution, a chemical solution which is neither acidic nor basic * Neutral particle, a particle without electrical charge Mathematics * Neutral element or identity element, in mathematics, a special element with respect to a binary operation, such that if the operation is applied to any element in a set, that element is unchanged * Neutral vector, a multivariate random variable that exhibits a particular type of statistical independence (Dirichlet distribution) Philosophy * Neutrality (philosophy), the absence of declared or intentional bias * Neutrality (psychoanalysis) * Neutral level, the physical or material traces of esthesic and poietic processes identified in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pusher Squirmer, Swimmer Frame
Pusher may refer to: Film and television * ''Pusher'' (film series), a trilogy by the Danish director Nicolas Winding Refn ** ''Pusher'' (1996 film), the first film in the series * ''Pusher'' (2012 film), a British remake of the 1996 film, directed by Luis Prieto * ''The Pusher'' (film), a 1960 American film directed by Gene Milford, based on an Ed McBain novel * "Pusher" (The X-Files), a television episode * Pusher, a fictional type of telepathic character in the 2009 film ''Push'' Music * Pusher (musician), Canadian musician * "The Pusher", a 1968 song by Steppenwolf, written by Hoyt Axton * "Pusher", a song by Nickelback from the album ''Curb'', 1996 * The Pusher (band), a Swedish pop group * ''Pusher'', a 2018 album by Dani M Sports and games * Pusher (tennis), a type of defensive tennis player * Pusher game, a type of medal game * Pusher, a stick used to play underwater hockey * Pusher, a game manufactured by Peri Spiele Transport * Pusher (boat), a vessel designed for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Passive Particle, Lab Frame
Passive may refer to: * Passive voice, a grammatical voice common in many languages, see also Pseudopassive * Passive language, a language from which an interpreter works * Passivity (behavior), the condition of submitting to the influence of one's superior * Passive-aggressive behavior, resistance to following through with expectations in interpersonal or occupational situations * Passive income, income resulting from cash flow received on a regular basis * Passive immunity, the transfer of active humoral immunity * Passive experience, observation lacking recipricol interaction; and wrought with delusion of control. Science and technology * Passivation (chemistry), process of making a material "passive" in relation to another material prior to using the materials together * Passivity (engineering) a property of engineering systems, particularly in analog electronics and control systems * Passive solar building design, which uses (or avoids) sunlight as an energy source without ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
