density


density
1. The compactness of a substance; the ratio of mass to unit volume, usually expressed as g/cm3 (kg/m3 in the SI system). 2. The quantity of electricity on a given surface or in a given time per unit of volume. 3. In radiological physics, the opacity to light of an exposed radiographic or photographic film; the darker the film, the greater the measured d.. 4. In clinical radiology, a less exposed area on a film, corresponding to a region of greater x-ray attenuation (radiopacity) in the subject; the more light transmitted by the film, the greater the d. of the subject; this is not actually the opposite of the prior definition, since one concerns film d. and the other subject d.. [L. densitas, fr. densus, thick]
- bone d. quantitative measurement of the mineral content of bone, used as an indicator of the structural strength of the bone and as a screen for osteoporosis
- buoyant d. the d. that allows a substance to float in some standard fluid.
- count d. SYN: photon d..
- flux d. 1. SYN: flux (4). 2. either particle flux d., the particle fluence rate, or energy flux d., the energy fluence rate of intensity. Cf.:fluence.
- incidence d. the person-time incidence rate.
- optic d. (OD) SYN: absorbance.
- photon d. the number of counted events recorded in scintigraphy per square centimeter or per square inch of imaged area. SYN: count d..
- spin d. the number of nuclear dipoles per unit volume.
- vapor d. the mass per unit volume of a vapor; since the vapor d. changes with temperature and pressure, it is commonly expressed as a specific gravity, i.e., the weight of the vapor divided by the weight of an equal volume of a reference gas ( e.g., oxygen or hydrogen) at the same temperature and pressure.

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den·si·ty 'den(t)-sət-ē, -stē n, pl -ties
1) the quantity per unit volume, unit area, or unit length: as
a) the mass of a substance per unit volume
b) the distribution of a quantity (as mass, electricity, or energy) per unit usu. of space
c) the average number of individuals or units per space unit <a population \density of 500 per square mile>
2 a) the degree of opacity of a translucent medium
b) ABSORBANCE

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den·si·ty (denґsĭ-te) [L. densus dense] 1. the quality of being compact or dense. 2. quantity per unit space, e.g., the mass of matter per unit volume. Symbol ρ or d>. 3. the degree of darkening of exposed and processed photographic or x-ray film, expressed as the logarithm of the opacity of a given area of the film.

Medical dictionary. 2011.

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  • Density 21.5 — is a piece of music for solo flute written by Edgard Varèse in 1936 and revised in 1946. The piece was composed at the request of Georges Barrère for the premiere of his platinum flute, the density of platinum being close to 21.5 grammes per… …   Wikipedia

  • Density — 21.5 ist eine Komposition für Querflöte solo von Edgar Varèse. Das Stück gilt als richtungsweisende Komposition des 20. Jahrhunderts innerhalb des vergleichsweise schmalen Repertoires für Flöte solo. Der aus Paris stammende Komponist Edgar Varèse …   Deutsch Wikipedia

  • Density 21.5 — ist eine Komposition für Querflöte solo von Edgar Varèse. Das Stück gilt als richtungsweisende Komposition des 20. Jahrhunderts innerhalb des vergleichsweise schmalen Repertoires für Flöte solo. Der aus Paris stammende Komponist Edgar Varèse,… …   Deutsch Wikipedia

  • Density — Den si*ty (d[e^]n s[i^]*t[y^]), n. [L. densitas; cf. F. densit[ e].] 1. The quality of being dense, close, or thick; compactness; opposed to {rarity}. [1913 Webster] 2. (Physics) The ratio of mass, or quantity of matter, to bulk or volume, esp.… …   The Collaborative International Dictionary of English

  • density — [den′sə tē] n. pl. densities [Fr densité < L densitas] 1. the quality or condition of being dense; specif., a) thickness; compactness b) stupidity c) Photog. degree of opacity of a negative 2. quantity or number per unit, as of area …   English World dictionary

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

  • density — I noun closeness, compactness, concentration, concretion, intransparency, opacity, opaqueness, palpability, solidity, thickness II index mass (weight), opacity Burton s Legal Thesaurus. William C. Burton …   Law dictionary

  • density — c.1600, from Fr. densité (16c.), from O.Fr. dempsité (13c.), from L. densitas thickness, from densus thick, dense (see DENSE (Cf. dense)) …   Etymology dictionary

  • density — [n] bulk, mass body, closeness, compactness, concretion, consistency, crowdedness, denseness, frequency, heaviness, impenetrability, massiveness, quantity, solidity, substantiality, thickness, tightness; concept 722 Ant. openness, sparsity,… …   New thesaurus

  • density — ► NOUN (pl. densities) 1) the degree of compactness of a substance; mass per unit volume. 2) the quantity of people or things in a given area or space …   English terms dictionary

  • Density — This article is about mass density. For other uses, see Density (disambiguation). The mass density or density of a material is defined as its mass per unit volume. The symbol most often used for density is ρ (the Greek letter rho). In some cases… …   Wikipedia