Experimental determinations of the longitudinal dispersion coefficient and the Peclet number were made for three binary gas systems. The experimental technique involved measuring the dispersion of a step function input to a column packed with glass beads. The diffusional model was employed to obtain the differential equation describing longitudinal dispersion in a packed column. This equation was solved with suitable boundary conditions, and the solution was used in the analysis of the experimental dispersion data. The experimental results show a variation in the Peclet number from 0.1 to 0.6, and in the eddy dispersion coefficient from 0.03 to 1.0 cm/sup 2//sec for the Reynolds number range from 0.03 to 1.0. (auth)

By means of the Mandelstam representation, expressions are obtained for the two-pion-exchange contributions to the higher partial waves of N-N scattering. A set of ten invariant amplitudes is selected, of which each member obeys the Mandelstam representation. Dispersion relations are written for the amplitudes in which the discontinuities are absorptive parts for N-bar-N scattering. By means of the unitarity condition the absorptive parts are expressed as a partial- wave expansion in terms of the pi pi - NN partialwave amplitudes of Frazer and Fulco, except for the contributions of the pole in the pi -N system which are treated exactly in order to ensure better convergence of the partial-wave expansion. The N-N transition amplitudes in the angular-momentum representation are expressed in terms of the invariant amplitudes. (auth)

A mass-spectrometric investigation was performed on sulfur vapor in equilibrium with the condensed phase at 120 to 210 gas-cooled C. It was found that, in this temperature range, equilibrium sulfur vapor contains appreciable quantities of S/sub 8/, S/sub 7/, S/sub 6/, and S/sub 5/ only. The sulfur vapor emanated as a small well-collimated molecular beam from a specially constructed source into an ionization chamber which was designed to exclude from analysis any sulfur vapor that had impinged on the walls or the hot electron filament. Essential identical ionization potentials were determined for S/sub 8/ , S/sub 7/, S/sub 6/, and S/sub 5/ of 9.8 0.4 ev. The heat of vaporizati on of S/sub 7/ was calculated to be approximately 2.5 kcal greater than that of S/ sub 8/. Upper limits for S/sub 8/ and S/sub 7/ composition in S vapor at 120 gas- cooled C were determined to be 86% and 14%, respectively. It is proposed thst S/sub 8/ is the vaporizing species, that S/sub 7/, S/sub 6/, and S/sub 5/ result from dissociation of S/sub 8/. and that all four molecules have a ring configuration. (auth)

S>Studies of the separation process known as zone melting were enclosed in 5 to 10 mm glass tubes and pulled through a stationary heater, which generated a liquid zone. The separation increased as the zone travel rate decreased, as the size of the tube increased, and as the difference in liquid density between the belk solid and the freezing interface increased. It was also found that, for vertical tubes, the separation was much greater when the fluid of lower density Between the buld zone and the freezing interface) was on the bottom the When it was on the top. Insertion of an axial thbe or rod of metal or glass into the zone also increased the separation. A correlation was developed which enables estimation of the separation for various - sithations in zone melting, Equations and principles were developed which enable estimation of the thermal requirements for zone melting and a theoretical study of pure diffusional mass transfer in some melting was also made. A general expression for concentration profiles was derived for materials with a constant distribution coefficient and a method for the rapid estimation of these concentration profiles was developed, Numerical results for eutectic-forming systems were obtained, and …

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