hysteresis


hysteresis
1. Failure of either one of two related phenomena to keep pace with the other; or any situation in which the value of one depends upon whether the other has been increasing or decreasing. 2. The lag of a magnetic effect behind its cause. SYN: magnetic inertia. 3. The temperature differential that exists when a substance, such as reversible hydrocolloid, melts at one temperature and solidifies at another. 4. The basis of a type of cooperativity observed in many enzyme-catalyzed reactions in which the degree of cooperativity is associated with a slow conformational change of the enzyme. Cf.:allosterism, cooperativity. [G. h., a coming later]
- static h. the difference in the value reached by a dependent variable at a particular constant value of the independent variable, depending on whether the latter value had been approached from above or below; e.g., in measuring the pressure volume relations of the lungs, if one completely expires and then inspires to a particular volume and holds it constant, the transpulmonary pressure required to maintain that lung volume is greater than if one had completely inspired and then expired to the same volume and held it constant.

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hys·ter·e·sis .his-tə-'rē-səs n, pl -e·ses -.sēz
1) the lagging of a physical effect on a body behind its cause (as behind changed forces and conditions) <all manometers must be tested for \hysteresis as well as for sensitivity and natural frequency (H. D. Green)>
2 a) the influence of the previous history or treatment of a body on its subsequent response to a given force or changed condition <a study has been made of the phenomenon of rennet \hysteresis, in which the time of coagulation of heated milk is progressively greater with increase in the time interval between heating and addition of rennet (J. S. Fruton)>
b) the changed response of a body that results from this influence

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hys·te·re·sis (his″tə-reґsis) [Gr. hysterēsis a lagging behind] 1. a time lag in the occurrence of two associated phenomena, as between cause and effect. 2. in cardiac pacemaker terminology, the number of pulses per minute below the programmed pacing rate that the heart must drop in order to cause initiation of pacing.

Medical dictionary. 2011.

Look at other dictionaries:

  • Hysteresis — Hystérésis L hystérésis est la propriété d un système qui tend à demeurer dans un certain état quand la cause extérieure qui a produit le changement d état a cessé. Cycle d hystérésis L exemple le plus trivial d hystérésis est celui d un système… …   Wikipédia en Français

  • Hystéresis — Hystérésis L hystérésis est la propriété d un système qui tend à demeurer dans un certain état quand la cause extérieure qui a produit le changement d état a cessé. Cycle d hystérésis L exemple le plus trivial d hystérésis est celui d un système… …   Wikipédia en Français

  • hystérésis — [ isterezis ] n. f. • 1890; angl. hysteresis; du gr. husterein « être en retard » ♦ Phys. Retard de l effet sur la cause dans le comportement des corps soumis à une action physique. Hystérésis électrique, magnétique, thermique, élastique. ●… …   Encyclopédie Universelle

  • hysteresis — [his΄tər ē′sis] n. [ModL < Gr hysterēsis, a deficiency < hysterein, to be behind, come short < hysteros, later, behind < IE * udteros, compar. of base * ud , up > OUT] Physics a lag of effect when the forces acting on a body are… …   English World dictionary

  • hysteresis — 1805, from Gk. hysteresis “a coming short, a deficiency.” …   Etymology dictionary

  • Hysteresis — Hys te*re sis, n. [NL., fr. Gr. ? to be behind, to lag.] (Physics) A lagging or retardation of the effect, when the forces acting upon a body are changed, as if from velocity or internal friction; a temporary resistance to change from a condition …   The Collaborative International Dictionary of English

  • hysteresis — hysteresis. См. гистерезис. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • Hysteresis — (griech., magnetische Trägheit, magnetische Reibung), eine auf der Koerzitivkraft beruhende Erscheinung, die darin besteht, daß das Ansteigen der magnetischen Kraft eines Elektromagnets bei der allmählichen Steigerung des Stromes mit letzterer… …   Meyers Großes Konversations-Lexikon

  • Hysteresis — Hysteresis, s. Elektromagnetismus, Bd. 3, S. 421 …   Lexikon der gesamten Technik

  • hysteresis —  Hysteresis  Гистерезис  Зависимость свойств системы от направления изменений внешних условий. Наблюдается в тех случаях, когда состояние тела определяется внешними условиями не только в данный момент времени, но и в предшествующие моменты.… …   Толковый англо-русский словарь по нанотехнологии. - М.

  • Hysteresis — Not to be confused with Hysteria. Fig. 1. Electric displacement field D of a ferroelectric material as the electric field E is first decreased, then increased. The curves form a hysteresis loop. Hysteresis is the dependence of a system not… …   Wikipedia


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