Kubelka

InstmmentaHy, both the hiding power and tinting strength can be determined from the amount of the incident light reflectance of coated white and black substrates. Relationships derived from Kubelka and Munk theory (6) are appHed in actual calculations. 

When both absorption and scattering are present, the Beer-Lambert law must be replaced by the Kubelka-Munk equation employing the absorption and scattering coefficients iC and S, respectively. This gives the redectivity... 

Grayness of a fabric swatch is not directly proportional to its content of black pigment (or artificial sod). A basic formula relating reflectance to the pigment content or concentration can be appHed to the evaluation of detergency test swatches (51,99—101). In simple form, an adaptation of the Kubelka-Munk equation, it states that the quantity (1 — i ) /2R (where R is the fraction of light reflected from the sample) is a linear function of the sod content of the sample. 

Strictly speaking the Kubelka-Munk function is only applicable und ing conditions [67 — 73] ... 

These general requirements also apply to adsorbents laden with s these requirements are not fulfilled to the same extent in thin-layer ( phy. So the Kubelka-Munk function does not apply without qualif... 

The intensity of the emitted fluorescence In is, therefore, directly proportional to the amount of substance applied a This relationship is much simpler than the Kubelka-Munk function and always leads to a linear calibration curve passing through the origin If this is not true then interference is occurring [5]... 

Kubelka, W., Eichhorn-Kaiser, S. Pharm. Acta Helv. 197Q 45, 513-519. 

V. Kubelka, P. Kozak, and M. Stejskal, VSCHT, Prague, Czechoslovakia. 

Ultraviolet-visible (UV-vis) diffuse reflectance spectra of supported WOx samples and standard W compounds were obtained with a Varian (Cary 5E) spectrophotometer using polytetrafluoroethylene as a reference. The Kubelka-Munk function was used to convert reflectance measurements into equivalent absorption spectra [12]. Spectral features of surface WOx species were isolated by subtracting from the W0x-Zr02 spectra that of pure Z1O2 with equivalent tetragonal content. All samples were equilibrated with atmospheric humidity before UV-vis measurements. 

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