This project seeks to develop a technique, based on coal surface properties, for highly dispersing catalysts in coal for gasification and to investigate the potential of using potassium carbonate and calcium acetate mixtures as catalysts for coal gasification. The work is focused on the elucidation of coal-catalyst precursor interactions in solution and the variables which control the adsorption and dispersion of coal gasification metal catalysts. In order to optimize coal-metal ion interactions and hence maximize catalyst activity, the study examines the surface electrochemistry of a lignite, a subbituminous, and a bituminous coals and their demineralized and oxidized derivatives prior to loading with the catalytic materials. The surface electrical properties of the coals are investigated with the aid of electrophoresis, while the effects of the surface charge on the adsorption of K{sup +} and Ca{sup 2+} are studied by agitating the coals with aqueous solutions of potassium and calcium. Zeta potential studies show that the surfaces of the lignite are negatively charged between about pH2 to 11, the negative charge density increasing with increase in pH. Highly alkaline media promoted calcium adsorption due to high negative charge on the coal, while calcium uptake was inhibited in strongly acidic solutions.

This report documents the Environmental Transport Section`s (ETS) two-dimensional, sequential gaussian puff transport and dispersion model for emergency response. The sequential puff scheme is described, and the dispersion equations are presented. The advantages of this model over the ETS`s PUFF/PLUME model are discussed. Options are calculating a two-dimensional wind field, interpolation procedures, and the wind field grid are described. The various grid systems for puff transport calculations and dose estimates are also described. A flow diagram for the modules comprising the 2DPUF code and a description of each module is presented.

In 1985 the Southeastern Forest Experiment Station (SEFES) in cooperation with the Department of Energy, the Savannah River Forest Station (SRFS) and the Savannah River Ecology Laboratory (SREL) initiated a research/management program to restore a viable population of red-cockaded woodpeckers (RCW) to the Savannah River Site (SRS). We managed to stabilize the population in the first couple of years through an intensive flying squirrel removal project as well as augmentation of female RCW`s to the SRS population. We are now in the expansion phase of the project. In 1990 we have focused our efforts on: (1) developing a cavity excavation method and excavating cavities in suitable habitat; (2) flying squirrel control; (3) translocation of RCW`s; (4) monitoring clan composition and reproduction; (5) identification of old-growth stands with the potential of providing new nesting habitat to support population expansion; and (6) surveying lands near SRS where RCW`s were thought to exist. This report summarizes activities for FY 1990 and plans for FY 1991.

This overview of research conducted at ORNL in 1991 presents information on the subjects of biology, physics, and the environment. Specific topics include gene mutations in kidney disease, technology assessments in thermonuclear fusion, submarine hunting technology, ozone-safe refrigerants, optical data storage via surface enhanced raman spectroscopy, and waste mitigating microbes. (GHH)

CeCu{sub 4}A{ell} and CeCu{sub 2}Zn{sub 2}A{ell} are heavy fermion systems with extremely enhanced C/T (specific heat divided by temperature) values of 2.3 and 1.8 J/K{sup 2} respectively as T {yields} 0 K. The field dependence of the low temperature specific heat is also extreme; 11 T reduces C of CeCu{sub 4}A{ell} by more than a factor of five, 12.5 T suppresses C of CeCu{sub 2}Zn{sub 2}A{ell} about seven times. Magnetic field caused changes of the specific heat of CeCu{sub 4}A{ell} are consistent with a single ion Kondo model. Magnetic correlations are at least partially responsible for the enhanced low temperature specific heat of CeCu{sub 2}Zn{sub 2}A{ell}.

Current progress on the development of the oxygen sensor is reviewed. During this quarter the sensor seal and heating element was redesigned and prototypes were tested. A combustor experiment will be performed in the next one to two quarters. Related information on lean sensors is also reviewed. Additional testing was done on multilayer sensors pulled from storage. (SM)

Research focused on control of misfit dislocations in strained epitaxial layers of GaAs through prepatterning of the substrate. Patterning and etching trenches into GaAs substrates before epitaxial growth results in nonplanar wafer surface, which makes device fabrication more difficult. Selective ion damaging the substrate prior to growth was investigated. The question of whether the overlayer must or must not be discontinuous was addressed. The third research direction was to extend results from molecular beam epitaxially grown material to organometallic chemical vapor deposition. Effort was increased to study the patterning processes and the damage it introduces into the substrate. The research program was initiated after the discovery that 500-eV dry etching in GaAs damages the substrate much deeper than the ion range.

We have constructed an infrared stopped-flow spectrophotometer and initiated a study of the mechanisms of reactions that involve a change in the oxidation state of organometallic complexes. In this summary we highlight our results on reactions (1) that formally involve exchange of a charged species between two metal carbonyl anions, (2) that involve addition of an electron to, or removal of an electron from organometallic complexes that contain a metal-metal bond, and (3) between coordination complexes and metal carbonyl anions.

The following are reported: structural studies (dislocation structure of Ni/Ag interphase boundary, structural complexity in grain boundaries with covalent bonding, relation between microscopic properties of two semiconducting grain boundaries and their orientations, diffraction effects due to double positioning in (111) Au bicrystals, sensitivity of diffraction profiles to grain boundary segregation, solute segregation at grain boundaries in Au, 4-body interatomic potential for Si for defect calculations); boundary migration studies (molecular dynamics study of grain boundary migration without participation of grain boundary dislocations); study of short-circuit diffusion along grain boundaries and its dependence on boundary structure; and thin-film deposition/bonding apparatus for manufacturing high-purity bicrystals.

These studies explored whether phosphoinositide (PI) has a role in plants analogous to its role in animal cells. Although no parallel activity of PI in signal transduction was found in plant cells, activity of inositol phospholipid kinase was found to be modulated by light and by cell wall degrading enzymes. These studies indicate a major role for inositol phospholipids in plant growth and development as membrane effectors but not as a source of second messengers.

Unsupported carbide powders with high specific surface area, namely {alpha}-WC (35 m{sup 2}/g, hexagonal), {beta}-WC{sub 0.61} (100 m{sup 2}/g, cubic face centered) and {beta}-WC{sub 0.5} (15 m{sup 2}/g, hexagonal) have been prepared. The key element in this preparation is the successful removal of surface polymeric carbon by careful gasification to methane by means of dihydrogen. These tungsten carbide powders have been used in catalytic reactions of oxidation of H{sub 2} and hydrogenolysis of alkanes, such as butane, hexane, and neopentane.

This year major advances have been made in 3 areas: high-lying, doubly-excited resonance states in the H{sup -}, interaction of relativistic H{sup -} ions with thin carbon foils, and multiphoton photodetachment. We plan to pursue these studies further.

This report reviews work on the optimization of film synthesized rare earth transition metal permanent magnet systems. Topics include: high coercivity in Sm-Fe-Ti-V, Sm-Fe-V, and two element systems; ThMn{sub 12} type pseudobinary SmFe{sub 12 {minus} X}T{sub X}; and sputter process control for the synthesis of precisely textured RE-TM magnetic films. (JL)

A Co/MgO/SiO{sub 2} Fischer-Tropsch catalyst was operated simultaneously with a Cu/ZnO/Al{sub 2}O{sub 3} water-gas-shift catalyst in a slurry reactor for over 400 hours. The process conditions were held constant at a temperature of 240{degrees}C, a pressure of 0.79 MPa, and a 1.1 H{sub 2}/CO feed of 0.065 Nl/min-g.cat. The Fischer-Tropsch activity remained constant at the level predicted by the operation of the Co/MgO/SiO{sub 2} catalyst alone. The water-gas-shift reaction was near equilibrium. The hydrocarbon product distribution of the combined catalyst system was stable and matched that of the CO/MgO/SiO{sub 2} operating alone under similar conditions. The combined catalyst system exhibited a high selectivity to n-alkanes. Neither catalysts`s operation appeared to have a detrimental effect on that of the other, showing promise for future option.

A spectral element method embodying Large Eddy Simulation based on Re- Normalization Group theory for simulating Sub Grid Scale viscosity was chosen for this work. This method is embodied in a computer code called NEKTON. NEKTON solves the unsteady, 2D or 3D,incompressible Navier Stokes equations by a spectral element method. The code was later extended to include the variable density and multiple reactive species effects at low Mach numbers, and to compute transport of large particles governed by inertia. Transport of small particles is computed by treating them as trace species. Code computations were performed for a number of test conditions typical of flow past a deep tube bank in a boiler. Results indicate qualitatively correct behavior. Predictions of deposition rates and deposit shape evolution also show correct qualitative behavior. These simulations are the first attempts to compute flow field results at realistic flow Reynolds numbers of the order of 10{sup 4}. Code validation was not done; comparison with experiment also could not be made as many phenomenological model parameters, e.g., sticking or erosion probabilities and their dependence on experimental conditions were not known. The predictions however demonstrate the capability to predict fouling from first principles. Further work is needed: …

Ongoing work includes the characterization of coal pyrites, the floatability evaluation of typical US coal samples, the flotation behavior of coal pyrites, the electrochemical measurement of the surface properties of coal pyrites, and the characterization of species produced at pyrite surfaces.

During this past period a computer code was developed to determine the global kinetic linear stability for a 1-D Field-Reversed Configuration (FRC). This report will describe the physical assumptions used to model the plasma, the equations solved by the code, the numerical analysis for certain aspects of the code, and some preliminary results from the code.

When grown in the absence of light, the det1 mutants of Arabidopsis thaliana develop characteristics of light-grown plants by morphological, cellular, and molecular criteria. Further, in light-grown plants, mutations in the DET1 gene affect cell-type-specific expression of light-regulated genes and the chloroplast developmental program. Here we show that the addition of exogenously added cytokinins (either 2-isopentenyl adenine, kinetin, or benzyladenine) to the growth medium of dark-germinated wild-type seedlings results in seedlings that resemble det1 mutants, instead of having the normal etiolated morphology. Like det1 mutants, these dark-grown seedlings now contain chloroplasts and have high levels of expression of genes that are normally ``light``-regulated. These results suggest an important role for cytokinins during greening of Arabidopsis, and may implicate cytokinin levels or an increased sensitivity to cytokinins as explanations for some of the observed phenotypes of det1 mutants.

The purpose of this project is to elucidate the way in which the synthesis of ethanol and related fermentation products are regulated in the facultative anaerobe Escherichia coli. We are also investigating the control of other genes required for anaerobic growth. We have isolated both structural and regulatory mutations affecting the expression of alcohol dehydrogenase, the enzyme responsible for the final step in alcohol synthesis. Some of these regulatory mutations also affect other anaerobically induced genes. The adh gene has been cloned and sequenced. The ADH protein is one of the largest highly expressed proteins in E. coli and requires approximately 2700bp of DNA for its coding sequence. We have also isolated mutations affecting the fermentative lactate dehydrogenase and have recently cloned the ldh gene. In consequence it is now possible to construct E. coli strains defective in the production of any one or more of their normal fermentation products (i.e. formate, acetate, lactate, ethanol and succinate). The factors affecting ratio of fermentation products are being investigated by in vivo NMR spectroscopy.

A three-stage thin-film detector for the identification of heavy ion fragments was investigated in beam at HHIRF. An experiment on Eu-152 for the purposes of calibrating a four-crystal Germanium polarimeter was performed. The instrument was then used in an experiment to establish polarities for the low-lying transitions in {sup 82}Sr. The spectral fitting code ROBFIT was applied to the data analysis and shown to perform well on the extraction of weak peaks in high background situations.

XANES and EXAFS measurements were made on a CuO/Al{sub 2}O{sub 3} sample which went through a complete reaction cycle with flue gases, followed by comparison with pure CuO. In the modeling studies, of the possible bridging type adsorption configurations for the SO{sub 2} molecule on CuO/Al{sub 2}O{sub 3}, the only one yielding SO{sub 2} adsorption of possible practical interest is that for the SO{sub 2} molecule bridging a Cu and an Al atom with the molecule bent away from the surface; the bonding energy is 1.66 eV.

XANES spectra are given for a number of model sulfur-containing compounds. The XANES and EXAFS spectra and structures of the inorganic standards (CuSO{sub 4}, FeS{sub 2}, FeS, CuS) are discussed. Calculations were made on SO{sub 2} adsorption on CuO/Al{sub 2}O{sub 3} surface; results show that the SO{sub 2} is adsorbed on the surface via O-Cu bonding, probably in the form of a ``bridge`` with the two oxygen atoms of SO{sub 2}sitting at two surface metal atoms. It is probably better to have low-temperature adsorption in reusable adsorbents because of the lower bonding energy of the O-Cu bonding. The possibility of adsorption at the edge or corner of the material is considered.

RHEED (reflection high energy electron diffraction) was carried out on Cu(110) at 153 to 973 K. Specular spot profiles show decreased scattering intensity around 550 K. RHEED patterns show disappearance of Kikuchi lines above 800 K. LEED indicate anharmonicities on Cu(110) surface at high temperatures. Results suggest that anharmonic effects precede onset of a rough surface at about 800 K. Three possible models were investigated for the clean surface for copper oxide dispersed on alumina; one was selected to use in going on to treat SO{sub 2} sorption. The Gauss-88 technique was used on Cray YMP to initiate cluster calculations for treating adsorption of the SO{sub 2} molecule. Of the possibilities for how SO{sub 2} adsorbs on CuO/Al{sub 2}O{sub 3} surface, sulfur-to-metal bonding was first considered, with the SO{sub 2} molecule on top of the Cu atom; this first configuration was found not to be energetically favorable for adsorption. 4 figs.

We performed XANES and EXAFS measurements at the sulfur K-edge for FeS, CuS and two coals, Powhatan {number_sign}5 and Blacksville {number_sign}2. We have used the measurements of the two standards in discussing the spectra of the spectra of the two coals as described below. We have continued our investigation for the possible bonding configurations of the SO{sub 2} molecule on CuO/Al{sub 2}O{sub 3}. In distinction to sulfur-to-metal (S-M) on-top bonding, we find that oxygen-to-metal (O-M) on-top bonding does provide a possible adsorption configuration of interest. We want next to investigate bridging type adsorption configurations. Before doing this, it is necessary to further examine the detailed behavior of the model for the clean CuO/Al{sub 2}O{sub 3} surface.