Sublimation, fractional, defined

The volatile fraction as defined by the various wet oxidation methods and most of the direct injection methods would be that fraction removed by acidification and purging with inert gas at room temperature. In the freeze-drying method of Gordon and Sutcliffe [29] the volatile fraction is that fraction lost by sublimation in vacuo. There have been no actual determinations of these losses, and for the most part Skopintsev s numbers were accepted as valid for all of these methods, largely because they are the only numbers available. 

If re-contamination of the aheady purified fraction can be avoided, step sublimation offers the advantages of purifying several grams of material on the time scale of hours at defined thermal condition. The latter is of particular importance for newly synthesised compounds with unknown sublimation temperatures. 

AT = Ts — (unless otherwise defined) u = air velocity, miles/hr or ft/sec X = mole fraction of water vapor A = molar heat of sublimation, Btu/mole p = density, Ibm/ft d = frost thickness, ft... 

Equation (VI-11), the equation required to compute the number of exchanged deuteriums from the density of the sublimate, is derived as follows. In order to obtain a function of the density, which is directly proportional to the mole fraction, of deuterium, Linderstr0m-Lang introduced the quantity U, which appeared in Eq. (VI-11), and is defined as follows ... 

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