Gray maximum determination

It is quite apparent from Fig. 8-63 that solar radiation which arrives at the surface of the earth does not behave like the radiation from an ideal gray body, while outside the atmosphere the distribution of energy follows more of an ideal pattern. To determine an equivalent blackbody temperature for the solar radiation, we might employ the wavelength at which the maximum in the spectrum occurs (about 0.5 /im, according to Fig. 8-63) and Wien s displacement law [Eq. (8-13)]. This estimate gives... 

Recentty Tremaine and Gray (97) used the peak maximum elution method to determine adsorption isotherms ctf cellulose surfaces. In this method (98), the adsorption isotherm is obtained from the variation of the peak maximum retention volume with the solute sample size injected. Approximately 25 peaks are recorded for one such determination. Surface areas, heats and entropies of adsorption were computed from the experimental adsorption isotherms and the results were discussed... 

It is important to point out that for a flat surface (a = oo, d = constant) Eq.(16) reduces to Eq.(12), the original Gray s equation. Moreover, for a fixed molecule size, d, increases as the pore size, a, decreases, and reaches a maximum when the radius of the adsorbate becomes equal to the pore radius (hypothetical case). Equation (16) is thus a more general equation than Eq.(12), and permits the dispersion component of the surface free energy for porous and non- porous materials to be determined. 

Figure lU Determination of the position of the maximum of gray level intensity for a region of interest. 

Figure IX-D-3. Experimental determinations of the quantum yields of acetone photodecomposition (01 4- 0ii) as a function of wavelength for photolyses in air at 760Torr and 298 K. The dashed gray curves define an envelope that describes the range of possible values. Values from the two dashed curves were used in estimating the possible range of photolysis constants shown in figure IX-D-6. Authors of the current study recommend use of the values given by the short-dashed line. The maximum values are also given in table IX-D-2.

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