efflorescence

efflorescence
/ef'leuh res"euhns/, n.
1. the state or a period of flowering.
2. an example or result of growth and development: These works are the efflorescence of his genius.
3. Chem.
a. the act or process of efflorescing.
b. the resulting powdery substance or incrustation.
4. Pathol. a rash or eruption of the skin.
[1620-30; < F < ML efflorescentia. See EFFLORESCE, -ENCE]

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      spontaneous loss of water by a hydrated salt, which occurs when the aqueous vapor pressure of the hydrate is greater than the partial pressure of the water vapour in the air. For example, because the vapour pressures of washing soda (Na2CO3·10H2O) and Glauber's salt (Na2SO4·10H2O) normally exceed that of the water vapour in the atmosphere, these salts effloresce (i.e., lose all or part of their water of hydration), and their surfaces assume a powdery appearance. Hydrated cupric sulfate, or blue vitriol (CuSO4·5H2O), the aqueous vapour pressure of which is lower, undergoes efflorescence only if the air in contact with it is relatively dry. See also deliquescence.

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Universalium. 2010.

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  • efflorescence — [ eflɔresɑ̃s ] n. f. • v. 1562 « surface, croûte »; formation sav. d apr. le lat. class. efflorescere « fleurir » 1 ♦ (1755) Chim. Perte d eau d un cristal par hydratation. Cristaux qui deviennent pulvérulents par efflorescence au contact de l… …   Encyclopédie Universelle

  • Efflorescence — Ef flo*res cence, n. [F. efflorescence.] 1. (Bot.) Flowering, or state of flowering; the blooming of flowers; blowth. [1913 Webster] 2. (Med.) A redness of the skin; eruption, as in rash, measles, smallpox, scarlatina, etc. [1913 Webster] 3.… …   The Collaborative International Dictionary of English

  • efflorescence — EFFLORESCENCE. s. f. Changement qui arrive à une substance minérale, lorsqu elle est chargée de parties salines qui se montrent à sa surface, et y forment un enduit semblable à de la moisissure. On dit, Il y a des Pyrites qui effleurissent, ou… …   Dictionnaire de l'Académie Française 1798

  • efflorescence — 1620s, from Fr. efflorescence, from L. efflorescentem (nom. efflorescens), prp. of efflorescere (see EFFLORESCE (Cf. effloresce)) …   Etymology dictionary

  • efflorescence — [ef΄fləres′əns] n. [Fr < L efflorescens, prp. of efflorescere: see EFFLORESCE] 1. a flowering; blooming 2. the time of flowering 3. the peak or fulfillment, as of a career 4. Chem. a) the changing of certain crystalline compounds to a whitish… …   English World dictionary

  • Efflorescence — Effloresce redirects here, for the album by Oceansize, see Effloresce (album). Efflorescence, in chemistry, is the loss of water (or a solvent) of crystallization from a hydrated or solvated salt to the atmosphere on exposure to air.Examples# A 5 …   Wikipedia

  • EFFLORESCENCE — n. f. T. de Botanique Commencement de la floraison. Fig., Il était alors dans la première efflorescence de son talent. Il se dit aussi, en termes de Médecine, pour désigner une Légère boursouflure de la peau. Il s’emploie spécialement en termes… …   Dictionnaire de l'Academie Francaise, 8eme edition (1935)

  • efflorescence — noun Date: 1626 1. a. the action or process of developing and unfolding as if coming into flower ; blossoming < periods of…intellectual and artistic efflorescence Julian Huxley > b. an instance of such development c. fullness of manifestation ;… …   New Collegiate Dictionary

  • EFFLORESCENCE — s. f. T. de Chimie et de Minéralogie. Changement qui arrive à une substance minérale, quand, exposée à l air, elle se recouvre d une matière pulvérulente. Il y a des pyrites qui tombent en efflorescence.   En Médec., Avoir des efflorescences sur… …   Dictionnaire de l'Academie Francaise, 7eme edition (1835)

  • efflorescence — (èf flo rè ssan s ) s. f. 1°   Terme de botanique. L acte par lequel la floraison commence ; le premier moment où elle a lieu.    Poussière fine et céracée qui se trouve sur certains fruits. 2°   Terme de chimie. Conversion d une substance solide …   Dictionnaire de la Langue Française d'Émile Littré

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