Light attenuation coefficient

How is the decadic molar extinction coefficient, ,(/l), of a given compound defined What is described by the decadic light absorption or light attenuation coefficient,... 

Calculate the diffuse light attenuation coefficients, aD(A), as a function of depth for the three indicated wavelengths. Do the results of these light penetration measurements make sense ... 

Fig. 4 Schematic density-dependent distributions of the light attenuation coefficient (encompassing shaded area), dissolved oxygen 02, hydrogen sulfide H2S, ammonium NH4+, and dissolved manganese Mn2+ in the RNL...

Light attenuation coefficient per unit length at wavelength A... 

Fig. 5.56. iPP, sample between two glass slides, crystallization at 141 °C initiated by shearing pulses [ffzx = 0.06 MPa at slide) with various durations. Kinetics of the crystallization is monitored by a measurement of the light attenuation coefficient /(f)//(0). From Komlield et al. [62]... 

The rate of photolytic transformations in aquatic systems also depends on the intensity and spectral distribution of light in the medium (24). Light intensity decreases exponentially with depth. This fact, known as the Beer-Lambert law, can be stated mathematically as d(Eo)/dZ = -K(Eo), where Eo = photon scalar irradiance (photons/cm2/sec), Z = depth (m), and K = diffuse attenuation coefficient for irradiance (/m). The product of light intensity, chemical absorptivity, and reaction quantum yield, when integrated across the solar spectrum, yields a pseudo-first-order photochemical transformation rate constant. 

The fraction of light (expressed as percent) transmitted a particular distance into the medium is an exponential function of the effective attenuation coefficient, in a manner analogous to Beer s law ... 

The attenuation coefficient, t, represents a combination of light scattering and absorption by gases and... 

Using the published absorption coefficients (cr) as a function of wavelength, one can then apply the Beer-Lambert law to calculate the intensity of light transmitted through such a vertical column to the earth s surface or to an altitude z. The resulting attenuation coefficients for 03 are shown in Fig. 3.15 for an overhead sun. Clearly, 03 is responsible for most of the attenuation of light directly from the sun of A < 310 nm reaching the earth s surface. 

One estimate of the attenuation coefficients for light scattering by particles, f, is also given in Fig. 3.15... 

Why can one not just use the decadic light absorption coefficient, a(A), to describe light attenuation in a given water body How is the diffuse attenuation coefficient, aD(A), related to a(A) ... 

The attenuation of a light beam is given in terms of the extinction coefficient, sometimes called the attenuation coefficient or turbidity, and it is a key measure of the optical behavior of particulate systems. In terms of the separate contributions for particle scattering and absorption,... 

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