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Thesis. Submitted by J. Lorrain. Theoretical analyses of interphase processes involving vapors and liquids are presented. Monoatomic and reacting vapors were considered in situations such as condensation, evaporation and heat transfer between the vapor and its liquid. These developments are believed to be the most accurate to date in describing such processes. The implications of the presence of diatomic and heavier naolecules in liquid metal vapors in their condensation heat transfer are discussed. It is shown that some assumed detailed mechanisms of condensation of these species can explain the low experimental condensation heat transfer coefficients of liquid metals. Results of an experimental investigation of the condensation mechanism and condensation heat transfer of nitrogen tetroxide vapor are presented. From measurements of temperature profiles in the vapor near the vapor-llquid interface during condensation it was concluded that both major components of the vapor (nitrogen dioxide and nitrogen tetroxide) condense at comparable rates. This mechanism is in qualitative agreement with the experimental condensation heat transfer coefficients, which were found to be 10 to 20% higher than predicted by Nusselt's theory. This is apparentiy the first determination of a detailed condensation mechanism at moderate pressures where traditional methods (e.g., vacuum evaporation techniques) can not …

Thesis. The specific heat was measured from 2.55 to 15.7 deg K, first with no external magnetic field, and then with magnetic fields along the c-axis and a-axis of intensity of 1000, 3000, and 5800 Oe. Two specific heat anomalies were observed: a Schottky anomaly caused by the ground state exchange splitting of the Yb/sup 3+/, and spin reorientation of the Fe sublattice. (DLC)

Using new experimental techniques, the spectra of $gamma$-rays from the capture of neutrons by $sup 181$Ta were measured at the Livermore 100-MeV linac for neutrons from 2 eV to 9 x 10$sup 4$ eV with a (Ge(Li)-NaI) three-crystal spectrometer. Individual primary $gamma$-ray lines were resolved to 1778-keV excitation in $sup 182$Ta. Neutron resonances were resolved to 200-eV neutron energy. Data analysis techniques and codes were developed to extract positions and intensities of resolved transitions from the large data matrices accumulated in this experiment. Techniques were developed to unfold the unresolved $gamma$- ray spectra using the simple response of the three-crystal spectrometer. The resolved transition data were used to place 110 states with spin and parity assignments in the $sup 182$Ta level diagram below 1780-keV excitation. A set of 1240 E1 transition strengths were analyzed to extract 1.38 +- 0.11 degrees of freedom for the most likely chisquared fit to the distribution of widths. The E1 strength function was extracted for E/sub gamma/ = 4 to 6 MeV and compared with previous results. The $gamma$-ray spectra for E/sub gamma/ = 1.5 to 6.1 MeV were unfolded for neutron energy groups between 20 and 9 x 10$sup 4$ eV. Below 5-MeV $gamma$-ray …

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