Temperature dependence power absorption coefficient

The curves of Fig. 120 show the variation of the absorption coefficient at 2400 A with time for polycaproamide fiber, oxidized in air at various temperatures. For small oxygen pressures, the dependence of the rate of the oxidation of polycaprolactam on the oxygen pressure to the power 0.75 is expressed by a straight line (Fig. 121). This permits us to derive an empirical equation for the dependence of the rate of absorption of oxygen on the pressure [30] ... 

The difficulty in applying this formula lies in the determination of the value of the coefficient Ku- The latter depends on the geometry of the radiating body, the temperatures Ti and T2, and the directional characteristics of the radiating surfaces, as well as their spectral emittance, absorptance, and reflectance (i.e., their color ). Obviously, the heat flux depends to a major extent on the empirical coefficient K, which at best can be given only approximately even when the geometry is known and the surface properties are deflned. Heat radiation increases sharply with temperature because the absolute temperature in the formula appears to the fourth power. 

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