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Most US coals contain sulfur concentrations that prevent their being burned without some form of sulfur removal. Current coal-cleaning technology can only remove the fairly reactive pyritic (inorganic) and aliphatic (organic) sulfur. A process which removes the more refractory hetero-aromatic sulfur could substantially increase the amount of coal reserves amenable to chemical cleaning. Sodium metal dispersions convert refractor model compounds into lighter desulfurized products and non-volatile sulfur-rich char. When treated with sodium, coal-derived solids show substantial desulfurization. The same treatment applied to coal-derived liquids, when combined with vacuum distillation of the reaction product, yields a desulfurized light distillate, an increase in absolute amount of distillate, and retention of sulfur in the vacuum residue. The presence of sodium in the residue allows fixation of the residual sulfur as Na/sub 2/SO/sub 4/ upon combustion, eliminating production of SO/sub 2/ in the flue gas. Intimate contacting of sodium salts with high sulfur coal also fixes 97 to 99% of the sulfur as Na/sub 2/SO/sub 4/ upon combustion. This technique takes advantage of the high energy available for carbon-sulfur bond cleavage during combustion and the reaction of SO/sub 2/ to form Na/sub 2/SO/sub 4/ to provide an inexpensive method for complete coal desulfurization.

The condensed polynuclear aromatic clusters of coal are believed to be linked principally by straight-chain aliphatic bridges varying from 0 to 4 carbon atoms in length and the cleavage of these linkages is expected to be an important step in the coal liquefaction process. This study focuses on the means by which Lewis acid catalysts, specifically AlCl/sub 3/ and ZnCl/sub 2/, promote the cleavage of these linkages. To facilitate product identification and interpretation of reaction mechanisms, organic compounds which model the aliphatic bridges were used on substrates. All experiments were performed in a magnetically stirred autoclave under either an H/sub 2/ or N/sub 2/ atmosphere at elevated pressure to determine the role of H/sub 2/. Reaction temperatures ranging from 200 to 350/sup 0/C were used to avoid the complication of pyrolysis reactions. Reaction products were identified with the aid of gas chromatography/mass spectrometry, and quantitative product yields were determined by gas chromatography. Experiments with AlCl/sub 3/ and the substrates containing two phenyl rings linked by 0 to 4 carbon atoms showed that AlCl/sub 3/ catalyzed cleavage of all the aliphatic bridges. ZnCl/sub 2/ was totally inactive in cleaving the alkyl bridges in these compounds. Substitution of a phenyl group by …

Thesis. The optical absorption spectra of Ho/sup 3+/ in the rare earth salt HoF/sub 3/ is studied. Such optical region studies (visible radiation) are easily performed with standard light sources and optical arrangements. Since the energy range of visible light coincides with the excitation energy range for a number of electronic transitions within the rare earth salts, the studies theoretically provide considerable information about rare earth electronic energy levels. Data are compiled for the effects of an applied magnetic field upon the spectra and the effect of sample temperature on the observed absorption spectra. 61 references. (MCW)

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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 modeling of the Ames Laboratory Research Reactor core region and the input required to utilize the Monte Carlo computer code KENO for criticality calculations are described. Reactivity calculations in terms of k- effective were made for various reactor configurations and compared to measurements made on the actual reactor. (16 references) (auth)

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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)

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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 …