Absorption volume

Because the losses tend to be excessive in volume absorption gratings, volume holograms are realized in most cases using index (phase) gratings. 

Consider continuous radiation with specific intensity I incident normally on a uniform slab with a source function 5 = Bv(Tex) unit volume per unit solid angle to the volume absorption coefficient Kp and is equal to the Planck function Bv of an excitation temperature Tcx obtained by force-fitting the ratio of upper to lower state atomic level populations to the Boltzmann formula, Eq. (3.4). For the interstellar medium at optical and UV wavelengths, effectively S = 0. 

Flux measurements (Schafer et al. 1974). The collection rate (Vc, nl/min) can be measured by the constant bore collection pipette by timed collections. Radioactive tracers can be added to the lumen or bath fluid. For instance, radioactively labelled inulin can be added to the perfusate (Inp) and can be used to measure volume absorption DV = perfusion rate (Vj-Vc). Unidirectional fluxes, bath to lumen and lumen to bath, for any given substance can be quantified, and permeabilities (Px) can be determined ... 

Intravenous None (directly Into the circulation) potentially immediate effects Emergency use or large volumes Absorption is bypassed Increased risk of adverse effects inject solutions slowly Not suitable for most lipid solutions or insoluble substances... 

Figure 5. The oscillator strength per unit volume (absorption cross section) plotted as a function of cluster size. R is the cluster radius and % is the Bohr radius of the exciton.

It may be mentioned here that the actual mass absorption is smaller than (22) because Q is smaller in the sphere than is its average value in the cell. For a similar reason, the ratio of surface and volume absorptions is somewhat larger in the lower Doppler region than (25). 

According to theory the volume absorption should vary as the square root of the average scattering cross section, per uranium atom, of the material in the sphere. Values of this cross section, its square root, and meas-... 

The ratio 385/500 is just the ratio of the volume absorption in metal and oxide. We have thus assumed that the difference in volume absorptions in metal and oxide is entirely attributable to a decrease in size of the resonance absorption region, the widths and depths of the resonance lines remaning unchanged. 

The final assumption, (6), is that of radiative equilibrium. Here, we assume that the volume absorption rate of IR radiation ial) is equal to the volume rate of emission iactB In). This was discussed in Section IV in terms of the net heating rate H, which is zero in radiative equilibrium (RE). This assumption requires that radiation alone heats or cools the atmosphere. It ignores the important process of convection, which we will include later. 

Figure 4 shows the spatial dependence of absorptions in the fuel rod, where absorption per unit volume is plotted against the square of the radius. The well-known distinction between surface- and volume-absorption shows clearly. 

On the other hand, the relative radiant power reduction a generated by volume absorption liable to Beer s law can be written as ... 

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