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The NOAEL is determined or proposed by qualified personnel, often a pharmacologist or a toxicologist. [citation needed] The NOAEL could be defined as "the highest experimental point that is without adverse effect," meaning that under laboratory conditions, it is the level where there are no side-effects. It either does not provide the effects ...
Characteristic X-rays are emitted when outer-shell electrons fill a vacancy in the inner shell of an atom, releasing X-rays in a pattern that is "characteristic" to each element. Characteristic X-rays were discovered by Charles Glover Barkla in 1909, [ 1 ] who later won the Nobel Prize in Physics for his discovery in 1917.
By contrast, far ultraviolet light, X-rays, gamma-rays, and all particle radiation from radioactive decay are ionizing. Visible and near ultraviolet electromagnetic radiation may induce photochemical reactions , or accelerate radical reactions , such as photochemical aging of varnishes [ 4 ] or the breakdown of flavoring compounds in beer to ...
Threshold dose is a dose of drug barely adequate to produce a biological effect in an animal. In dose-response assessment, the term ‘threshold dose’ is refined into several terminologies, such as NOEL, NOAEL, and LOAEL.
Iodinated contrast contains iodine.It is the main type of radiocontrast used for intravenous administration.Iodine has a particular advantage as a contrast agent for radiography because its innermost electron ("k-shell") binding energy is 33.2 keV, similar to the average energy of x-rays used in diagnostic radiography.
Mass attenuation coefficients of selected elements for X-ray photons with energies up to 250 keV. The mass attenuation coefficient, or mass narrow beam attenuation coefficient of a material is the attenuation coefficient normalized by the density of the material; that is, the attenuation per unit mass (rather than per unit of distance).
Two-dimensional powder diffraction setup for high-energy X-rays. HEX-rays entering from the left are diffracted in forward direction at the sample and registered by a 2D detector such as an image plate. [2] With these advantages, HEX-rays can be applied for a wide range of investigations. An overview, which is far from complete:
The DQE is generally expressed in terms of Fourier-based spatial frequencies as: [10] = = ()where u is the spatial frequency variable in cycles per millimeter, q is the density of incident x-ray quanta in quanta per square millimeter, G is the system gain relating q to the output signal for a linear and offset-corrected detector, T(u) is the system modulation transfer function, and W(u) is the ...