equilibrium


equilibrium
1. The condition of being evenly balanced; a state of repose between two or more antagonistic forces that exactly counteract each other. 2. In chemistry, a state of apparent repose created by two reactions proceeding in opposite directions at equal speed; in chemical equations, sometimes indicated by two opposing arrows (⇄) instead of the equal sign. SYN: dynamic e.. SEE ALSO: e. constant. [L. aequilibrium, a horizontal position, fr. aequus, equal, + libra, a balance]
- acid-base e. SYN: acid-base balance.
- Donnan e. when a semipermeable membrane or its equivalent ( e.g., a solid ion fexchanger) separates a nondiffusible substance, such as protein, from diffusible substances, the diffusible anions and cations are distributed on the two sides of the membrane so that 1) the products of their concentrations are equal, and 2) the sum of the diffusible and nondiffusible anions on either side of the membrane is equal to the sum of the concentrations of diffusible and nondiffusible cations; the unequal distribution of diffusible ions thus produced creates a potential difference across the membrane (membrane potential). SYN: Gibbs-Donnan e..
- dynamic e. SYN: e. (2).
- genetic e. the condition of a dynamic genetic system in which the several rates of change between all possible pairs of parts are such that the composition is invariant.
- Gibbs-Donnan e. SYN: Donnan e..
- Hardy-Weinberg e. that state in which the genetic structure of the population conforms to the prediction of the Hardy-Weinberg law; it is not a stable e., although for a large mating population it may be approximated. SYN: random mating e..
- nitrogenous e. a condition in which the amount of nitrogen excreted from the body equals that taken in with the food; nutritive e. so far as protein is concerned.
- nutritive e. condition in which there is a perfect balance between intake and excretion of nutritive material, so that there is no increase or loss in weight. SYN: physiologic e..
- physiologic e. SYN: nutritive e..
- radioactive e. a situation (not a true e.) in which a particular atom is being produced by the radioactive breakdown of a precursor while it is itself breaking down, the two breakdowns matching so that after a period of time the ratio of radioactivity of product and precursor is constant with time.
- random mating e. SYN: Hardy-Weinberg e..
- secular e. a type of radioactive e. in which the half-life of the precursor (parent) radioisotope is so much longer than that of the product (daughter) that the radioactivity of the daughter becomes equal to that of the parent with time.
- stable e. e. in which, after every small perturbation, the original state will tend to be restored.
- transient e. a type of radioactive e. in which the half-life of the parent radioisotope is longer than that of the daughter so that the ratio of activities of parent and daughter become constant as they decrease with time.
- unstable e. e. in which the response to a small perturbation will tend to make the perturbation greater ( e.g., a logged feedback process of zero order).

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equi·lib·ri·um .ē-kwə-'lib-rē-əm, .ek-wə- n, pl -ri·ums or -ria -rē-ə
1) a state of balance between opposing forces or actions that is either static (as in a body acted on by forces whose resultant is zero) or dynamic (as in a reversible chemical reaction when the velocities in both directions are equal)
2) a state of intellectual or emotional balance

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equi·li·bri·um (e″kwĭ-libґre-əm) [L. aequus equal + libra balance] 1. a condition in which opposing forces exactly counteract each other; called also balance. 2. postural balance of the body; see sense of equilibrium, under sense.

Medical dictionary. 2011.

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  • Equilibrium — is the condition of a system in which competing influences are balanced and it may refer to:cienceBiology* Equilibrioception, the sense of balance present in humans and animals * Homeostasis, the ability of an open system, especially living… …   Wikipedia

  • Equilibrium — Жанры симфонический блэк метал фолк метал Годы с 2001 Страна …   Википедия

  • Equilibrium — E qui*lib ri*um, n.; pl. E. {Equilibriums}, L. {Equilibria}. [L. aequilibrium, fr. aequilibris in equilibrium, level; aequus equal + libra balance. See {Equal}, and {Librate}.] 1. Equality of weight or force; an equipoise or a state of rest… …   The Collaborative International Dictionary of English

  • Equilibrium — Saltar a navegación, búsqueda Equilibrium Título Equilibrium Ficha técnica Dirección Kurt Wimmer Producción Jan de Bont Lucas Foster Guión …   Wikipedia Español

  • equilibrium — equilibrium, social equilibrium In normative functionalist theory generally, and the work of Talcott Parsons in particular, the commonplace concept of equilibrium (a state of balance in which opposing forces or tendencies neutralize each other)… …   Dictionary of sociology

  • Equilibrium — oder Aequilibrium bezeichnet allgemein, den durch das Zusammenwirken zweier oder mehrerer Kräfte, die sich aufheben, bedingten Zustand der Ruhe, siehe Gleichgewicht (Physik) in der Spieltheorie das Nash Equilibrium oder Nash Gleichgewicht über… …   Deutsch Wikipedia

  • Equilibrium — Equilibrium. См. Равновесие. (Источник: «Металлы и сплавы. Справочник.» Под редакцией Ю.П. Солнцева; НПО Профессионал , НПО Мир и семья ; Санкт Петербург, 2003 г.) …   Словарь металлургических терминов

  • equilibrium — index balance (equality), composure, equipoise, parity, status quo Burton s Legal Thesaurus. William C. Burton. 2006 …   Law dictionary

  • Equilibrium — es una película del director Kurt Wimmer. El film se situa en un futuro después de la tercera guerra mundial, con la humanidad privada de las emociones por efecto del prozium el opio de las masas y del arma más poderosa que el hombre mismo puede… …   Enciclopedia Universal

  • equilibrium — c.1600, from L. aequilibrium, from aequus equal (see EQUAL (Cf. equal)) + libra a balance, scale, plummet (see LIBRA (Cf. Libra)) …   Etymology dictionary

  • equilibrium — equipoise, poise, *balance, tension Analogous words: stableness or stability (see corresponding adjective at LASTING): stabilization, steadying (see corresponding verbs at STABILIZE): counterbalancing or counterbalance, counterpoising or… …   New Dictionary of Synonyms


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