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The attenuation in the signal of ground motion intensity plays an important role in the assessment of possible strong groundshaking. A seismic wave loses energy as it propagates through the earth (seismic attenuation). This phenomenon is tied into the dispersion of the seismic energy with the distance. There are two types of dissipated energy:
The SI unit of molar absorption coefficient is the square metre per mole (m 2 /mol), but in practice, quantities are usually expressed in terms of M −1 ⋅cm −1 or L⋅mol −1 ⋅cm −1 (the latter two units are both equal to 0.1 m 2 /mol). In older literature, the cm 2 /mol is sometimes used; 1 M −1 ⋅cm −1 equals 1000 cm 2 /mol.
The main discussion of these abbreviations in the context of drug prescriptions and other medical prescriptions is at List of abbreviations used in medical prescriptions. Some of these abbreviations are best not used, as marked and explained here.
The attenuation coefficient of a volume, denoted μ, is defined as [6] =, where Φ e is the radiant flux;; z is the path length of the beam.; Note that for an attenuation coefficient which does not vary with z, this equation is solved along a line from =0 to as:
The term is based on X-ray notation, where the innermost electron shell is known as the K-shell. Physically, this sudden increase in attenuation is caused by the photoelectric absorption of the photons. For this interaction to occur, the photons must have more energy than the binding energy of the K-shell electrons (K-edge).
Abbreviation Meaning q: each, every (from Latin quaque) : q15: every 15 minutes q6h q6° once every 6 hours q2wk: once every 2 weeks qAc Before every meal (from Latin quaque ante cibum)
In those situations, the most general form of the Beer–Lambert law states that the total attenuation can be obtained by integrating the attenuation coefficient over small slices dz of the beamline: = = (), = = (). These formulations then reduce to the simpler versions when there is only one active species and the attenuation coefficients are ...
The absorption was attributed to a sequence of overtone and combination bands whose intensity decreases at each step, giving rise to an absolute minimum at 418 nm, at which wavelength the attenuation coefficient is about 0.0044 m −1, which is an attenuation length of about 227 meters. These values correspond to pure absorption without ...