attenuation coefficient


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attenuation coefficient

A measure of the attenuation of energy waves or particles caused by absorption of energy as they pass through a particular medium (e.g., air, tissue, lead).

attenuation coefficient

The calculated remainder of the x-ray beam that is received by the detectors in a computed tomography (CT) unit. This value is used to determine the CT (Hounsfield) number.
See also: coefficient
References in periodicals archive ?
The effective attenuation coefficient was then estimated according to
Sanjeevaiah, "A method to determine the y ray attenuation coefficients," Nuclear Instruments and Methods, vol.
Figures 1, 2, 3, 4, 5, 6, 7, and 8 show the variation of the Stoneley waves and attenuation coefficient value with respect to gravity field g and rotation Q, respectively, has oscillatory behavior in the whole range of gravity g and rotation for C-T theory, L-S theory, G-L theory, and G-N theory.
The present study has been undertaken to obtain information on the total mass attenuation coefficient ([[mu].sub.t]) values and atomic, molecular, and electronic effective cross sections for nonessential amino acids.
Each pixel of the tomographic image has a characteristic TU value, which is proportional to the linear attenuation coefficient of the media.
* Attenuation coefficient ([alpha]) of ethyl acetate at 27 [degrees]C (Expt.) = 0.69 nep/cm
The jet-head shape resistance coefficient [C.sub.xliq] is a function of the type of liquid and pressure inside it, the jet-head form resistance coefficient [C.sub.x] is the one used in Eq (1) (usually the one used for air under normal pressure) and attenuation coefficient [xi] is calculated from Eq (1).
The attenuation coefficient, [alpha], is obtained from the best-fit equation.
Therefore, aerosol or Mie scattering dominates the total attenuation coefficient [8].
The mass energy absorption and attenuation coefficients are obtained from the computations of Hubell, 1982 and ICRU, 1994.
The MODIS standard algorithm for the diffuse attenuation coefficient of seawater at 490 nm, [K.sub.d](490), has been developed using the ratio of water-leaving radiances at 490 and 555 nm (Austin & Petzold 1981; Mueller 2000).