- 1. The degree of firmness of a solid, as determined by its resistance to deformation, scratching, or abrasion. SEE ALSO: h. scale, number. 2. The relative penetrating power of a beam of x-rays, used both within the diagnostic range of energy and in radiation therapy; expressed in terms of half-value layer.- indentation h. a number related to the size of the impression made by an indenter (or tool) of specific size and shape under a known load.
* * *hard·ness (hahrdґnis) 1. a quality of water produced by soluble salts of calcium and magnesium or other substances which form an insoluble curd with soap and thus interfere with its cleansing power. 2. the quality of firmness produced by cohesion of the particles composing a substance, as evidenced by its inflexibility or resistance to indentation, distortion, or scratching. See also hardness number, under number. 3. the quality of x-rays that determines their penetrating power; hardness depends on wavelength: the shorter the wavelength, the harder the rays and the greater their penetrating power. 4. the degree of refraction of the residual gas in a glass tube: the higher the vacuum, the shorter the wavelength of the resulting x-rays.
Medical dictionary. 2011.
См. также в других словарях:
Hardness — Hard ness, n. [AS. heardness.] 1. The quality or state of being hard, literally or figuratively. [1913 Webster] The habit of authority also had given his manners some peremptory hardness. Sir W. Scott. [1913 Webster] 2. (Min.) The cohesion of the … The Collaborative International Dictionary of English
Hardness — Hardness. См. Твердость. (Источник: «Металлы и сплавы. Справочник.» Под редакцией Ю.П. Солнцева; НПО Профессионал , НПО Мир и семья ; Санкт Петербург, 2003 г.) … Словарь металлургических терминов
hardness — index brutality, congealment Burton s Legal Thesaurus. William C. Burton. 2006 … Law dictionary
hardness — (n.) O.E. heardnysse; see HARD (Cf. hard) + NESS (Cf. ness). Meaning difficulty of action or accomplishment is late 14c … Etymology dictionary
hardness — [härd′nis] n. 1. the state or quality of being hard (in various senses) 2. the relative capacity of a substance for scratching another or for being scratched or indented by another … English World dictionary
Hardness — This article is about mechanical properties of materials. For other uses, see Hard. Hardness is the measure of how resistant solid matter is to various kinds of permanent shape change when a force is applied. Macroscopic hardness is generally… … Wikipedia
hardness — /hahrd nis/, n. 1. the state or quality of being hard: the hardness of ice. 2. a relative degree or extent of this quality: wood of a desirable hardness. 3. that quality in water that is imparted by the presence of dissolved salts, esp. calcium… … Universalium
Hardness — (Roget s Thesaurus) < N PARAG:Hardness >N GRP: N 1 Sgm: N 1 hardness hardness &c. >Adj. Sgm: N 1 rigidity rigidity Sgm: N 1 renitence renitence renitency Sgm: N 1 inflexibility inflexibility temper callosity … English dictionary for students
hardness — a measure of the hardness of a metal or mineral. Hardness is a property easy to appreciate but difficult to quantify and measure. The Mohs hardness scale is used in geology to give a rough estimate of hardness by testing which minerals are… … Dictionary of units of measurement
hardness — The toughness of the surface of a metal. See brinell hardness indentation hardness rockwell hardness shore hardness … Dictionary of automotive terms