Intensity of absorbed light

Plotting the eoneentration (Ca) versus time t gives a straight line, where Cao is the intereept and k is the slope. The veloeity eonstant k may inelude arbitrary eonstants resulting from various limiting faetors sueh as diffusion eonstants and a fixed intensity of absorbed light. 

The experimental findings of the optical density in the absorption region of the C=0 group (1770 cm-1 at a layer thickness of h = 0.87 x 10 4 cm), of the molar extinction coefficients of irradiated and non-irradiated copolymer films, and of the intensities of absorbed light (= 405 nm) made it possible to determine the quantum efficiency of C=0 group consumption using the known equation... 

The simplest geometry to measure fluorescence of transparent samples is instrumentation of excitation at 90°. In this case, it can be considered that the intensity of absorbed light (7abs) is equal to the intensity of incident light (I0) minus the intensity of transmitted light (/,rans).The transmitted light is expressed by Lambert-Beer Law ... 

Expressions formally quite similar to eqns. (28) and (29) were derived for (sensitized) photoinitiated polymerization [6]. The initiator concentration, [I], is replaced by the intensity of absorbed light (/)... 

In some investigations of photochemical systems, the intensity of absorbed light is not measured, for one reason or another. The data are then reported as relative quantum yields. Such data should never be labeled as ... 

Fluorescence intensities F), which are related to quantum yields through the intensity of absorbed light ()abs)j Eq. 60,... 

The rate of photochemical initiation is given by the product of the intensity of absorbed light (in moles of light quanta per liter and second) and the primary quantum yield. A good survey on different photoinitiators and their photodecomposition by UV light was given by Gruber (55). 

Figure IX-F-21. Plot of the quantum yield of CO formed in the 435.8 nm photodecomposition of biacetyl (Sheats and Noyes (1955) as a function of absorbed light intensity (fj). Data determined at 28°C (open circles) show a linear increase with D, while those at 75°C and the higher intensities of absorbed light are relatively unchanged with D.

For photoinitiations the rate of initiation is Ri = 204, where 0 is the quantum efficiency for initiation and 4 is the intensity of absorbed light. At low levels of absorbance ... 

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