Recent studies of nuclear mass models show that it is essential to account for the Coulomb redistribution energy when calculating the nuclear potential energy in the heavy-element region. Results obtained by use of a mass model that includes Coulomb redistribution effects on analyzed. Q values of {alpha} and {beta} decay are calculated. Half-lives for {alpha} decay are estimated by use of the Viola-Seaborg systematics. For EC, {beta}{sup +} decay and {beta}{sup {minus}} decay, half-lives are calculated in a microscopic QRPA model. Calculated single-particle level structures in the heavy-element regions are presented. These indicate possible regions of isomers that would be unusually stable with respect to spontaneous fission and {alpha} decay. Finally, we discuss the implications of earlier extensive work on fission properties of nuclei in this region.

Recent studies of nuclear mass models show that it is essential to account for the Coulomb redistribution energy when calculating the nuclear potential energy in the heavy-element region. Results obtained by use of a mass model that includes Coulomb redistribution effects on analyzed. Q values of {alpha} and {beta} decay are calculated. Half-lives for {alpha} decay are estimated by use of the Viola-Seaborg systematics. For EC, {beta}{sup +} decay and {beta}{sup {minus}} decay, half-lives are calculated in a microscopic QRPA model. Calculated single-particle level structures in the heavy-element regions are presented. These indicate possible regions of isomers that would be unusually stable with respect to spontaneous fission and {alpha} decay. Finally, we discuss the implications of earlier extensive work on fission properties of nuclei in this region.

The objective is to develop and test various integrated solar heating, cooling and domestic hot water systems, and to evaluate their performance. Systems composed of new, as well as previously tested, components are carefully integrated so that effects of new components on system performance can be clearly delineated. The SEAL-DOE program includes six tasks which have received funding for the 1991--92 fifteen-month period. These include: (1) a project employing isothermal operation of air and liquid solar space heating systems; (2) a project to build and test several generic solar water heaters; (3) a project that will evaluate advanced solar domestic hot water components and concepts and integrate them into solar domestic hot water systems; (4) a liquid desiccant cooling system development project; (5) a project that will perform system modeling and analysis work on solid desiccant cooling systems research; and (6) a management task. The objectives and progress in each task are described in this report.

The objective is to develop and test various integrated solar heating, cooling and domestic hot water systems, and to evaluate their performance. Systems composed of new, as well as previously tested, components are carefully integrated so that effects of new components on system performance can be clearly delineated. The SEAL-DOE program includes six tasks which have received funding for the 1991--92 fifteen-month period. These include: (1) a project employing isothermal operation of air and liquid solar space heating systems; (2) a project to build and test several generic solar water heaters; (3) a project that will evaluate advanced solar domestic hot water components and concepts and integrate them into solar domestic hot water systems; (4) a liquid desiccant cooling system development project; (5) a project that will perform system modeling and analysis work on solid desiccant cooling systems research; and (6) a management task. The objectives and progress in each task are described in this report.

The long-range objective of this research program is the development of more efficacious technetium-99m radiopharmaceuticals for use as imaging agents in diagnostic nuclear medicine. We seek to isolate and develop distinct site imaging agents, each of which has properties optimized to provide diagnostic information concerning a given pathological condition. The specific objectives during the period (9/1/89 to 8/31/92) include: (1) Development of strategies for improving yields of specific Tc-diphosphonate complexes with optimum imaging properties; (2) Development of electrodes for rapid in situ electrochemical generation of skeletal imaging agents; (3) Development of electrochemical sensors for {Tc} and Re imaging agents; (4) Characterization of stable {Tc}- and Re-diphosphonate complexes obtainable in high yield by structural studies with techniques such as NMR, EXAFS, and Raman spectroscopy; (5) Development of improved separation techniques for the characterization of diphosphonate skeletal imaging agents; (6) Evaluation of the effect of the biological milieu on {Tc}-diphosphonate complexes; and (7) Electrochemical studies of technetium and rhenium complexes synthesized by Professor Deutsch's research group for heart and brain imaging.

The long-range objective of this research program is the development of more efficacious technetium-99m radiopharmaceuticals for use as imaging agents in diagnostic nuclear medicine. We seek to isolate and develop distinct site imaging agents, each of which has properties optimized to provide diagnostic information concerning a given pathological condition. The specific objectives during the period (9/1/89 to 8/31/92) include: (1) Development of strategies for improving yields of specific Tc-diphosphonate complexes with optimum imaging properties; (2) Development of electrodes for rapid in situ electrochemical generation of skeletal imaging agents; (3) Development of electrochemical sensors for {Tc} and Re imaging agents; (4) Characterization of stable {Tc}- and Re-diphosphonate complexes obtainable in high yield by structural studies with techniques such as NMR, EXAFS, and Raman spectroscopy; (5) Development of improved separation techniques for the characterization of diphosphonate skeletal imaging agents; (6) Evaluation of the effect of the biological milieu on {Tc}-diphosphonate complexes; and (7) Electrochemical studies of technetium and rhenium complexes synthesized by Professor Deutsch`s research group for heart and brain imaging.

Glass frit will be a major raw material for the operation of the Defense Waste Processing Facility. The frit will be controlled by certificate of conformance and a confirmatory analysis by a commercial laboratory. The following effort provides additional quantitative information on the variability of frit analyses at two commercial laboratories.

Glass frit will be a major raw material for the operation of the Defense Waste Processing Facility. The frit will be controlled by certificate of conformance and a confirmatory analysis by a commercial laboratory. The following effort provides additional quantitative information on the variability of frit analyses at two commercial laboratories.

Results from modeling of transformation toughening in brittle materials using a discrete micromechanical model are presented. The material is represented as a two-dimensional triangular array of nodes connected by elastic springs. Microstructural effects are included by varying the spring parameters for the bulk, grain boundaries, and transforming particles. Using the width of the damage zone and the effective compliance (after the initial creation of the damage zone) as measures of fracture toughness, we find that there is a strong dependence of toughness on the amount, size, and shape of the transforming particles, with the maximum toughness achieved with the higher amounts of the larger particles.

Results from modeling of transformation toughening in brittle materials using a discrete micromechanical model are presented. The material is represented as a two-dimensional triangular array of nodes connected by elastic springs. Microstructural effects are included by varying the spring parameters for the bulk, grain boundaries, and transforming particles. Using the width of the damage zone and the effective compliance (after the initial creation of the damage zone) as measures of fracture toughness, we find that there is a strong dependence of toughness on the amount, size, and shape of the transforming particles, with the maximum toughness achieved with the higher amounts of the larger particles.

I have investigated the effect of scattering in the rock overburden on the position and direction of atmospheric muons as observed at the Soudan 2 detector relative to the surface. The dominant contributions to the fluctuations in those observables arise from multiple Coulomb scattering and delta ray production. The contribution of the other energy loss mechanisms, bremsstrahlung, pair production and nuclear interactions, is small, with slowly increasing importance at very large deviations from the means of the distributions.

I have investigated the effect of scattering in the rock overburden on the position and direction of atmospheric muons as observed at the Soudan 2 detector relative to the surface. The dominant contributions to the fluctuations in those observables arise from multiple Coulomb scattering and delta ray production. The contribution of the other energy loss mechanisms, bremsstrahlung, pair production and nuclear interactions, is small, with slowly increasing importance at very large deviations from the means of the distributions.

Spall, the tensile failure of near-surface layers, which is observed above contained explosions, has been identified as a possible secondary seismic source contributing to teleseismic and regional signals. The relative importance of this secondary source can be constrained if the motion field in the spall zone is characterized. Spall zone motions from nuclear explosions detonated above the water table at Pahute Mesa are analyzed to develop these models. Acceleration, velocity, displacement, and dwell time measurements are made from gauges placed directly above the explosion, most often at the free surface. Decay of peak motions are strongly affected by the free surface with little change in amplitude out to a free surface range of 100 m/kt{sup l/3} followed by rapid decay beyond. Free surface interactions are assessed with first-order elastic spherical wave calculations that match observed peak velocity decays. These results indicate that the spall zone motions may be strongly affected by the scaled depth of burial of the explosion. Spall zone velocities, displacements and dwell times are compared for consistency with a gravitational model. The data is in agreement with the functional form of theoretical models although observed displacements may be as much as a factor of two to four …

Weekly newsletter discussing natural resources, parks, hunting and fishing, and other information related to the outdoors in Texas.

The repository program has established quality assurance requirements which are to be applied to activities and items which affect compliance with the Waste Acceptance Preliminary Specifications (WAPS). In this report, the aspects of the melter which are significant to meeting the WAPS are identified. Based on the Waste Form Compliance Plans (WCP), the melter plays a significant role in satisfying specification 1.3 (Product Consistency) by ensuring that feed material is sufficiently vitrified before the glass is poured into the canister. Aspects of the melter system important for meeting the WAPS are: administrative controls and process instrumentation which will be used to assure that glass pouring is not initiated at melt temperatures < 950{degrees}C; and composition and rate of degradation of the glass contact refractory.

The repository program has established quality assurance requirements which are to be applied to activities and items which affect compliance with the Waste Acceptance Preliminary Specifications (WAPS). In this report, the aspects of the melter which are significant to meeting the WAPS are identified. Based on the Waste Form Compliance Plans (WCP), the melter plays a significant role in satisfying specification 1.3 (Product Consistency) by ensuring that feed material is sufficiently vitrified before the glass is poured into the canister. Aspects of the melter system important for meeting the WAPS are: administrative controls and process instrumentation which will be used to assure that glass pouring is not initiated at melt temperatures < 950[degrees]C; and composition and rate of degradation of the glass contact refractory.

Periodic bulletin analyzing issues related to Texas legislation. This issue focuses on property values.

This project is divided into method experimental measurements, theoretical development, and geochemical applications. We have completed experimental volumetric measurements on aqueous solutions of CO{sub 2} H{sub 2}S, CH{sub 4}, NH{sub 3} and B(OH){sub 3} at 25 to 432{degree}C and 280 and 350 bar. A vibrating tube densitometer that allows density measurements near bubble point and also measures the bubble pressure was developed and used to measure densities and bubble pressures of aqueous Co{sub 2}. Heat capacity measurements should be completed by the end of the grant period. Simulations of models for methane in water at temperatures to 1000{degrees}C are in progress. In order to facilitate these free energy calculations the possible errors associated with the calculations have been explored in two papers (Wood, 1991; Wood et al., 1991) and methods of controlling and estimating these errors have been developed. Applications of the new data to geochemical processes is now possible. Efforts have focussed on extracting equilibrium constants for carbonic acid dissociation at supercritical condition from published experiments on mineral equilibria in H{sub 2}0-CO{sub 2} fluids (Boehlke and Shock, 1990; and in prep.). As a result, estimates of pKa for carbonic acid are now available at temperatures from 300 to 750{degrees}C …

This project is divided into method experimental measurements, theoretical development, and geochemical applications. We have completed experimental volumetric measurements on aqueous solutions of CO{sub 2} H{sub 2}S, CH{sub 4}, NH{sub 3} and B(OH){sub 3} at 25 to 432{degree}C and 280 and 350 bar. A vibrating tube densitometer that allows density measurements near bubble point and also measures the bubble pressure was developed and used to measure densities and bubble pressures of aqueous Co{sub 2}. Heat capacity measurements should be completed by the end of the grant period. Simulations of models for methane in water at temperatures to 1000{degrees}C are in progress. In order to facilitate these free energy calculations the possible errors associated with the calculations have been explored in two papers (Wood, 1991; Wood et al., 1991) and methods of controlling and estimating these errors have been developed. Applications of the new data to geochemical processes is now possible. Efforts have focussed on extracting equilibrium constants for carbonic acid dissociation at supercritical condition from published experiments on mineral equilibria in H{sub 2}0-CO{sub 2} fluids (Boehlke and Shock, 1990; and in prep.). As a result, estimates of pKa for carbonic acid are now available at temperatures from 300 to 750{degrees}C …

The propagation of a laser beam through atmospheric turbulence can, under many circumstances, be compensated to near diffraction limited levels, by use of an adaptive optics system. In the ideal case, a beacon light source is generated at the aimpoint. This light traverses through the turbulent path back to the aperture. The distribution of phase perturbations in the aperture plane is sensed, and the reverse of this phase is applied to the outgoing beam. When the turbulent path is long (i.e. a few hundred kilometers), and the effective wind speed is high (such as in the case when the laser is based on a plane, with airspeeds around 200 m/s), the performance of the adaptive optics system can be significantly degraded due to the time delay from when the beacon samples the turbulence, until the beam propagates through the turbulence. This effect has not been treated in the past, because for astronomical applications, the time delays due to the round trip of light are too short (tens of microseconds) to cause problems. This paper presents an analysis of the anisoplanatic effect of the round trip time of light. A formulation of the phase variance has been constructed for this effect. …

The propagation of a laser beam through atmospheric turbulence can, under many circumstances, be compensated to near diffraction limited levels, by use of an adaptive optics system. In the ideal case, a beacon light source is generated at the aimpoint. This light traverses through the turbulent path back to the aperture. The distribution of phase perturbations in the aperture plane is sensed, and the reverse of this phase is applied to the outgoing beam. When the turbulent path is long (i.e. a few hundred kilometers), and the effective wind speed is high (such as in the case when the laser is based on a plane, with airspeeds around 200 m/s), the performance of the adaptive optics system can be significantly degraded due to the time delay from when the beacon samples the turbulence, until the beam propagates through the turbulence. This effect has not been treated in the past, because for astronomical applications, the time delays due to the round trip of light are too short (tens of microseconds) to cause problems. This paper presents an analysis of the anisoplanatic effect of the round trip time of light. A formulation of the phase variance has been constructed for this effect. …

The high temperature alkali corrosion kinetics of SiC have been systematically investigated from 950 to 1100[degrees]C at 0.63 vol % alkali vapor concentration. The corrosion rate in the presence of alkaliis approximately 10[sup 4] to 10[sup 5] times faster than the oxidation rate of SiC in air. The activation energy associated with the alkali corrosion is 406 kJ/mol, indicating a highly temperature-dependent reaction rate. The rate-controlling step of the overall reaction is likely to be the dissolution of silica in the sodium silicate liquid, based on the oxygen diffusivity data.

The high temperature alkali corrosion kinetics of SiC have been systematically investigated from 950 to 1100{degrees}C at 0.63 vol % alkali vapor concentration. The corrosion rate in the presence of alkaliis approximately 10{sup 4} to 10{sup 5} times faster than the oxidation rate of SiC in air. The activation energy associated with the alkali corrosion is 406 kJ/mol, indicating a highly temperature-dependent reaction rate. The rate-controlling step of the overall reaction is likely to be the dissolution of silica in the sodium silicate liquid, based on the oxygen diffusivity data.

Efficiencies of interstitial absorption during pulsed ND:YAG laser welding of vanadium were compared for nitrogen, oxygen, hydrogen, and water vapor. Influence of interstitial levels on the embrittlement of vanadium laser welds was also measured. For 1000 ppM contaminant levels in the weld atmosphere, weld hydrogen content increased 9 ppM, nitrogen content increased 190 ppM, and oxygen content increased from 500 ppM relative to baseplate levels. Welds in ultrahigh-purity argon atmospheres contained 3 ppM hydrogen, 40 ppM nitrogen, and 250 ppM oxygen. Longitudinal all-weld tensile specimens and notched-plate specimens were used to measure weld metal tensile properties at [minus]55C. All of the laser weld notch-strength ratios exceeded unity and weld metal tensile strengths all exceeded the baseplate values. For 1000 ppM atmosphere contaminant levels, the only significant decrease in ductility, as measured by reduction-in-area at fracture was for the weld atmosphere containing oxygen. Weld atmospheres containing 1% nitrogen also reduced the weld ductility, and resulted in the onset of cleavage fracture.