FLUX DISTRIBUTIONS AND LEAKAGE CURRENTS FOR SRE, P-16 (open access)

FLUX DISTRIBUTIONS AND LEAKAGE CURRENTS FOR SRE, P-16

BS>Two-group, two-region criticality calculations were made for 10 and 11 ft diameter tanks. The 10 ft tank required a core radius of 102 cm and the 11 ft tank a core radius of 95 cm for criticality. In the calculations, the fluxes were assumed to go to zero at the edge oi the graphite reflector. The fast group of the two-group calculation was broken down into 3 fast groups. The leakage out of the core and reflector for the 4 energy groups is given. (M.C.G.)
Date: January 29, 1954
Creator: Balent, R.
Object Type: Report
System: The UNT Digital Library
Tested method to minimize plutonium assay discrepancies between laboratories (open access)

Tested method to minimize plutonium assay discrepancies between laboratories

Plutonium assay differences are frequently observed between laboratories exchanging plutonium dioxide powders. These differences are commonly the result of chemical changes and/or nonhomogeneities in sampled materials. The irregularities are often caused by moisture absorption during sampling, packaging, shipment, and storage of the materials. A method is proposed which eliminates the effects of chemical change in samples, particularly moisture absorption, and minimizes sampling error. A nondestructive thermal watts/gram test on every preweighed sampled and total dissolution of these samples for chemical assay are the primary features which make this method effective. Because this method minimizes the error related to exchange material, it is possible to design an interlaboratory exchange program which demonstrates the assay capabiliies of the participants. In an experiment performed to demonstrate the effectiveness of this method, three PuO/sub 2/ batches of varying isotopic composition were synthesized at Mound to be used in the exchange tess. Powder sample aliquots from each batch were weighed directly into their vials under controlled atmospheric conditions. Calorimetric heat measurements were made on each vial to test homogeneity and verify sample weight. Six vials of each batch were chemically assayed at Mound and six at NBL (New Brunswick Laboratory). Both laboratories chose controlled-potential coulometry …
Date: January 29, 1982
Creator: Seiler, R. J.; Goss, R. L.; Rodenburg, W. W. & Rogers, D. R.
Object Type: Report
System: The UNT Digital Library
HEXAFLUORIDES OF MOLYBDENUM, TUNGSTEN AND URANIUM. II. REACTIONS WITH LIQUID AND GASEOUS DINITROGEN TETROXIDE (open access)

HEXAFLUORIDES OF MOLYBDENUM, TUNGSTEN AND URANIUM. II. REACTIONS WITH LIQUID AND GASEOUS DINITROGEN TETROXIDE

Molybdenum and tungsten hexafluorides form the solids nitrosylium pentafluoroxymolybdate(VI) and -tungstate(VI), respectively. Uranium hexafluoride gives nitrosylium hexafluorouranate(V) STANOUF/sub 6/!, the same salt that it forms with nitric oxide. (auth)
Date: January 29, 1962
Creator: Geichman, J. R.; Smith, E. A.; Swaney, L. R. & Ogle, P. R.
Object Type: Report
System: The UNT Digital Library
Theoretical approach for enhanced mass transfer effects in-duct flue gas desulfurization processes (open access)

Theoretical approach for enhanced mass transfer effects in-duct flue gas desulfurization processes

Removal of sulfur dioxide (SO{sub 2}) from the flue gas of coal- burning power plants can be achieved by duct spray drying using calcium hydroxide (Ca(OH){sub 2}) slurries. A primary objective of this research was to discover the aspects of mass transfer into Ca(OH){sub 2} slurries which limit SO{sub 2} absorption. A bench- scale stirred tank reactor with a flat gas/liquid interface was used to simulate SO{sub 2} absorption in a slurry droplet. The absorption rate of SO{sub 2} from gas concentrations of 500 to 5000 ppm was measured at 55{degrees}C in clear solutions and slurries of Ca(OH){sub 2} up to 1.0 M (7 wt percent). Results are reported in terms of the enhancement factor, {O}. This research will allow prediction of conditions where the absorption of SO{sub 2} in Ca(OH){sub 2} slurries can be enhanced by changes to liquid phase constituents (under which SO{sub 2} absorption is controlled by liquid film mass transfer). Experiments in the stirred tank have shown that SO{sub 2} absorption in a 1.0 M Ca(OH){sub 2} slurry was completely dominated by gas film mass transfer with a large excess of Ca(OH){sub 2} but becomes controlled by liquid film resistance at greater than 50 percent Ca(OH){sub …
Date: January 29, 1992
Creator: Jozewicz, W. (Acurex Corp., Research Triangle Park, NC (United States). Environmental Systems Div.) & Rochelle, G.T. (Texas Univ., Austin, TX (United States). Dept. of Chemical Engineering)
Object Type: Report
System: The UNT Digital Library
Experimental studies of the beam-breakup mode on ETA: comparison with theory (open access)

Experimental studies of the beam-breakup mode on ETA: comparison with theory

The beam breakup mode has been observed and measured on ETA. Comparison between the measurements and the results of a computer code indicate that the beam breakup instability will be the most important limitation on current transport thru ATA. ETA Experiments that will enable a more accurate determination of the magnitude of the instability on ATA are discussed.
Date: January 29, 1982
Creator: Caporaso, G.J. & Struve, K.W.
Object Type: Report
System: The UNT Digital Library
Bibliography and author index for electrical discharges in vacuum (1897 to 1980) (open access)

Bibliography and author index for electrical discharges in vacuum (1897 to 1980)

This bibliography covers the field of electrical discharges in vacuum, comprising both electrical breakdown in vacuum and vacuum arcs. A brief review section lists some review papers which would be helpful to the novice in this field. The bulk of the paper consists of bibliographic listings, arranged by year of publication and within each year, alphabetically by first author. An author index refers one to all papers authored or coauthored by a particular person. There are 2450 papers listed through December 1980.
Date: January 29, 1982
Creator: Miller, H. C.
Object Type: Report
System: The UNT Digital Library
Theoretical approach for enhanced mass transfer effects in-duct flue gas desulfurization processes (open access)

Theoretical approach for enhanced mass transfer effects in-duct flue gas desulfurization processes

This report presents the results of fundamental mass transfer testing for in-duct removal of SO{sub 2}. Following this initial part of an experimental program, it became clear that the amount of initial moisture on the sorbent strongly affected the extent of Ca(OH){sub 2} conversion. Novel techniques aimed at increasing sorbent utilization were investigated and are described. Major novel technique investigated and reported on here was the reaction with SO{sub 2} of sorbents with initial free moisture (damp sorbents). The duct injection process using damp solids has the following steps: preparation of sorbent as a slurry, blending of the slurry with dry recycle materials to create damp solids, injection of the solids into the duct, reaction and drying of the solids with flue gas in the duct, collection in particulate control equipment, and finally recycle of dry solids with some bleed to disposal. The moisture content of the solids at each step affects system performance. Various factors favor high moisture whereas others favor low moisture. (VC)
Date: January 29, 1992
Creator: Jozewicz, W. (Acurex Corp., Research Triangle Park, NC (United States). Environmental Systems Div.) & Rochelle, G.T. (Texas Univ., Austin, TX (United States). Dept. of Chemical Engineering)
Object Type: Report
System: The UNT Digital Library
Exploratory study of coal conversion chemistry. Quarterly report No. 2, August 19, 1981-November 18, 1981. [Hydroxydipnenylmethanes, triphenylmethane, diphenylether] (open access)

Exploratory study of coal conversion chemistry. Quarterly report No. 2, August 19, 1981-November 18, 1981. [Hydroxydipnenylmethanes, triphenylmethane, diphenylether]

This report describes work accomplished under two tasks: Task A, mechanisms of donor-solvent coal liquefaction, and Task B, CO/H/sub 2/O conversion systems. Under Task A, we describe additional evidence relating to the question of the mechanism of the iron oxide catalyzed cleavage of hydroxydiphenylmethanes. o-Hydroxydiphenylmethane is relatively more sensitive to catalysis by Fe/sub 3/O/sub 4/, a possible one electron oxidant, and triphenylmethane is relatively more sensitive to catalyzed cleavage by SiO/sub 2//Al/sub 2/O/sub 3/, a strong Bronsted acid catalyst. This provides further evidence that in the former case the reactions of radical cations are important in the cleavage mechanism. Tests with Cr/sub 2/O/sub 3/ show it to be ineffective under our reaction conditions as a catalyst for hydroxydiphenylmethane cleavage. We have also used the decomposition of diphenylether in tetralin, which we have previously shown to occur by a radical displacement reaction, as an indicator of steady state radical concentration in tetralin. The results of these experiments indicate that radical concentrations in tetralin are not significantly increased by spiking the tetralin with 1,2-dihydronaphthalene. This in turn suggests that rapid disproportionation of 1,2-dihydronaphthalene to tetralin and naphthalene takes place by way of a concerted reaction, in addition to a slower radical disproportionation …
Date: January 29, 1982
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Investigation of the 2p3/2-3d5/2 line emission of Au53+ -- Au69+ for diagnosing high energy density plasmas (open access)

Investigation of the 2p3/2-3d5/2 line emission of Au53+ -- Au69+ for diagnosing high energy density plasmas

Measurements of the L-shell emission of highly charged gold ions were made under controlled laboratory conditions using the SuperEBIT electron beam ion trap, allowing detailed spectral observations of lines from ironlike Au{sup 53+} through neonlike Au{sup 69+}. Using atomic data from the Flexible Atomic Code, we have identified strong 3d{sub 5/2} {yields} 2p{sub 3/2} emission features that can be used to diagnose the charge state distribution in high energy density plasmas, such as those found in the laser entrance hole of hot hohlraum radiation sources. We provide collisional-radiative calculations of the average ion charge <Z> as a function of temperature and density, which can be used to relate charge state distributions inferred from 3d{sub 5/2} {yields} 2p{sub 3/2} emission features to plasma conditions, and investigate the effects of plasma density on calculated L-shell Au emission spectra.
Date: January 29, 2008
Creator: Brown, G V; Hansen, S B; Trabert, E; Beiersdorfer, P; Widmann, K; Chen, H et al.
Object Type: Article
System: The UNT Digital Library
Stable Spheromaks with Profile Control (open access)

Stable Spheromaks with Profile Control

A spheromak equilibrium with zero edge current is shown to be stable to both ideal MHD and tearing modes that normally produce Taylor relaxation in gun-injected spheromaks. This stable equilibrium differs from the stable Taylor state in that the current density j falls to zero at the wall. Estimates indicate that this current profile could be sustained by non-inductive current drive at acceptable power levels. Stability is determined using the NIMROD code for linear stability analysis. Non-linear NIMROD calculations with non-inductive current drive could point the way to improved fusion reactors.
Date: January 29, 2008
Creator: Fowler, T K & Jayakumar, R
Object Type: Report
System: The UNT Digital Library
Dalitz Plot Analysis of B- -> D+ pi- pi- (open access)

Dalitz Plot Analysis of B- -> D+ pi- pi-

The author reports on a Dalitz plot analysis of B{sup -} {yields} D{sup +}{pi}{sup -}{pi}{sup -} decays, based on a sample of about 383 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. They find the total branching fraction of the three-body decay: {Beta}(B{sup -} {yields} D{sup +} {pi}{sup -}{pi}{sup -}) = (1.08 {+-} 0.01 {+-} 0.05) x 10{sup -3}. the masses and widths of D*{sub 2}{sup 0} and D*{sub 0}{sup 0}, the 2{sup +} and 0{sup +} c{bar u} P-wave states decaying to D{sup +}{pi}{sup -}, are measured: m{sub D*{sub 2}{sup 0}} = (2460.4 {+-} 1.2 {+-} 1.2 {+-} 1.9) MeV/c{sup 2}, {Lambda}{sub D*{sub 2}{sup 0}} = (41.8 {+-} 2.5 {+-} 2.1 {+-} 2.0) MeV, m{sub D*{sub 0}{sup 0}} = (2297 {+-} 8 {+-} 5 {+-} 19) MeV/c{sup 2} and {Lambda}{sub D*{sub 0}{sup 0}} = (273 {+-} 12 {+-} 17 {+-} 45) MeV. The stated errors reflect the statistical and systematic uncertainties, and the uncertainty related to the assumed composition of signal events and the theoretical model.
Date: January 29, 2009
Creator: Aubert, B.
Object Type: Article
System: The UNT Digital Library
Improved Wood Properties Through Genetic Manipulation: Engineering of Syringyl Lignin in Softwood Species Through Xylem-Specific Expression of Hardwood Syringyl Monolignol Pathway Genes (open access)

Improved Wood Properties Through Genetic Manipulation: Engineering of Syringyl Lignin in Softwood Species Through Xylem-Specific Expression of Hardwood Syringyl Monolignol Pathway Genes

Project Objective: Our long-term goal is to genetically engineer higher value raw materials with desirable wood properties to promote energy efficiency, international competitiveness, and environmental responsiveness of the U.S. forest products industry. The immediate goal of this project was to produce the first higher value softwood raw materials engineered with a wide range of syringyl lignin quantities. Summary: The most important wood property affecting directly the levels of energy, chemical and bleaching requirements for kraft pulp production is lignin. Softwoods contain almost exclusively chemically resistant guaiacyl (G) lignin, whereas hardwoods have more reactive or easily degradable lignins of the guaiacyl (G)-syringyl (S) type. It is also well established that the reactive S lignin component is the key factor that permits much lower effective alkali and temperature, shorter pulping time and less bleaching stages for processing hardwoods than for softwoods. Furthermore, our pulping kinetic study explicitly demonstrated that every increase in one unit of the lignin S/G ratio would roughly double the rate of lignin removal. These are clear evidence that softwoods genetically engineered with S lignin are keys to revolutionizing the energy efficiency and enhancing the environmental performance of this industry. Softwoods and hardwoods share the same genetic mechanisms for …
Date: January 29, 2009
Creator: Joshi, Chandrashekhar P. & Chiang, Vincent L.
Object Type: Report
System: The UNT Digital Library
A Possible Phase Transition in Liquid He3 (open access)

A Possible Phase Transition in Liquid He3

A possible phase transition in liquid He{sup 3} has been investigated theoretically by generalizing the Bardeen, Cooper, and Schrieffer equations for the transition temperature in the manner suggested by Cooper, Mills, and Sessler. The equations are transformed into a form suitable for numerical solution and an expression is given for the transition temperature at which liquid He{sup 3} will change to highly correlated phase. Following a suggestion of Hottelson, it is shown that the phase transition is a consequence of the interaction of particles in relative D-states. The predicted value of the transition temperature depends on the assumed form of the effective single-particle potential and the interaction between He{sup 3} atoms. The most important aspects of the single-particle potential are related to the thermodynamic properties of the liquid just above the transition temperature. Two choices of the two-particle interaction, oonstituent with experiments, yield a second-order transition at a temperature between approximately 0.01 K and 0.1 K. The highly correlated phase should exhibit enhanced fluidity.
Date: January 29, 1960
Creator: Emery, V. J. & Sessler, A. M.
Object Type: Report
System: The UNT Digital Library
Rapid Reagentless Detection of M. tuberculosis H37Ra in Respiratory Effluents (open access)

Rapid Reagentless Detection of M. tuberculosis H37Ra in Respiratory Effluents

Two similar mycobacteria, Mycobacteria tuberculosis H37Ra and Mycobacteria smegmatis are rapidly detected and identified within samples containing a complex background of respiratory effluents using Single Particle Aerosol Mass Spectrometry (SPAMS). M. tuberculosis H37Ra (TBa), an avirulent strain, is used as a surrogate for virulent tuberculosis (TBv); M. smegmatis (MSm) is utilized as a near neighbor confounder for TBa. Bovine lung surfactant and human exhaled breath condensate are used as first-order surrogates for infected human lung expirations from patients with pulmonary tuberculosis. This simulated background sputum is mixed with TBa or MSm and nebulized to produce conglomerate aerosol particles, single particles that contain a bacterium embedded within a background respiratory matrix. Mass spectra of single conglomerate particles exhibit ions associated with both respiratory effluents and mycobacteria. Spectral features distinguishing TBa from MSm in pure and conglomerate particles are shown. SPAMS pattern matching alarm algorithms are able to distinguish TBa containing particles from background matrix and MSm for >50% of the test particles, which is sufficient to enable a high probability of detection and a low false alarm rate if an adequate number of such particles are present. These results indicate the potential usefulness of SPAMS for rapid, reagentless tuberculosis screening.
Date: January 29, 2008
Creator: Adams, K L; Steele, P T; Bogan, M J; Sadler, N M; Martin, S; Martin, A N et al.
Object Type: Article
System: The UNT Digital Library
Improved Biorefinery for the Production of Ethanol, Chemicals, Animal Feed and Biomaterials From Sugar Cane (open access)

Improved Biorefinery for the Production of Ethanol, Chemicals, Animal Feed and Biomaterials From Sugar Cane

The Audubon Sugar Institute (ASI) of Louisiana State University’s Agricultural Center (LSU AgCenter) and MBI International (MBI) sought to develop technologies that will lead to the development of a sugar-cane biorefinery, capable of supplying fuel ethanol from bagasse. Technology development focused on the conversion of bagasse, cane-leaf matter (CLM) and molasses into high value-added products that included ethanol, specialty chemicals, biomaterials and animal feed; i.e. a sugar cane-based biorefinery. The key to lignocellulosic biomass utilization is an economically feasible method (pretreatment) for separating the cellulose and the hemicellulose from the physical protection provided by lignin. An effective pretreatment disrupts physical barriers, cellulose crystallinity, and the association of lignin and hemicellulose with cellulose so that hydrolytic enzymes can access the biomass macrostructure (Teymouri et al. 2004, Laureano-Perez, 2005). We chose to focus on alkaline pretreatment methods for, and in particular, the Ammonia Fiber Expansion (AFEX) process owned by MBI. During the first two years of this program a laboratory process was established for the pretreatment of bagasse and CLM using the AFEX process. There was significant improvement of both rate and yield of glucose and xylose upon enzymatic hydrolysis of AFEX-treated bagasse and CLM compared with untreated material. Because of reactor …
Date: January 29, 2009
Creator: Day, Donal F.
Object Type: Report
System: The UNT Digital Library
Subaru Weak Lensing Measurements of Four Strong Lensing Clusters: Are Lensing Clusters Over-Concentrated? (open access)

Subaru Weak Lensing Measurements of Four Strong Lensing Clusters: Are Lensing Clusters Over-Concentrated?

We derive radial mass profiles of four strong lensing selected clusters which show prominent giant arcs (Abell 1703, SDSS J1446+3032, SDSS J1531+3414, and SDSS J2111-0115), by combining detailed strong lens modeling with weak lensing shear measured from deep Subaru Suprime-cam images. Weak lensing signals are detected at high significance for all four clusters, whose redshifts range from z = 0.28 to 0.64. We demonstrate that adding strong lensing information with known arc redshifts significantly improves constraints on the mass density profile, compared to those obtained from weak lensing alone. While the mass profiles are well fitted by the universal form predicted in N-body simulations of the {Lambda}-dominated cold dark matter model, all four clusters appear to be slightly more centrally concentrated (the concentration parameters c{sub vir} {approx} 8) than theoretical predictions, even after accounting for the bias toward higher concentrations inherent in lensing selected samples. Our results are consistent with previous studies which similarly detected a concentration excess, and increases the total number of clusters studied with the combined strong and weak lensing technique to ten. Combining our sample with previous work, we find that clusters with larger Einstein radii are more anomalously concentrated. We also present a detailed model …
Date: January 29, 2009
Creator: Oguri, Masamune; Hennawi, Joseph F.; Gladders, Michael D.; Dahle, Haakon; Natarajan, Priyamvada; Dalal, Neal et al.
Object Type: Article
System: The UNT Digital Library
RP-5 Renewable Energy Efficiency Project (open access)

RP-5 Renewable Energy Efficiency Project

This is the sixth quarterly technical report for the RP-5 Renewable Energy Efficiency Project. The report summarizes the work progress, effort and activities that took place during the period from October 1, 2003 through December 31, 2003. The report has been prepared in accordance with the Department of Energy (DOE) Guidelines. In coordination with the DOE, IEUA has revised the original Cooperative Agreement to reflect the actual and current project scope of work. The original Agreement statement of work (SOW) included conceptual and preliminary equipment and systems, which were further evaluated for feasibility and suitability for the project. As a result, some of the equipment was taken out of the project scope. In response to questions from the DOE, IEUA has submitted a summary report on the Organic Rankine Cycle (ORC) secondary power generation units for availability and suitability for this project and associated safety concerns pointed out by the DOE. IEUA has awarded the consulting engineering contract to Parsons Water and Infrastructure, Inc. to provide the project's design and construction services. The project's pre-design kickoff meeting was held at IEUA's headquarters on December 11, 2003. IEUA has submitted a proposal for a grant offered by California Energy Commission (CEC) …
Date: January 29, 2004
Creator: Clifton, Neil; Whitman, Eliza Jane & Zughbi, Jamal A.
Object Type: Report
System: The UNT Digital Library
Correlations between Optical, Chemical and Physical Properties of Biomass Burn Aerosols (open access)

Correlations between Optical, Chemical and Physical Properties of Biomass Burn Aerosols

Aerosols generated from burning different plant fuels were characterized to determine relationships between chemical, optical and physical properties. Single scattering albedo ({omega}) and Angstrom absorption coefficients ({alpha}{sub ap}) were measured using a photoacoustic technique combined with a reciprocal nephelometer. Carbon-to-oxygen atomic ratios, sp{sup 2} hybridization, elemental composition and morphology of individual particles were measured using scanning transmission X-ray microscopy coupled with near-edge X-ray absorption fine structure spectroscopy (STXM/NEXAFS) and scanning electron microscopy with energy dispersion of X-rays (SEM/EDX). Particles were grouped into three categories based on sp2 hybridization and chemical composition. Measured {omega} (0.4-1.0 at 405 nm) and {alpha}{sub ap} (1.0-3.5) values displayed a fuel dependence. The category with sp{sup 2} hybridization >80% had values of {omega} (<0.5) and {alpha}{sub ap} ({approx}1.25) characteristic of light absorbing soot. Other categories with lower sp2 hybridization (20 to 60%) exhibited higher {omega} (>0.8) and {alpha}{sub ap} (1.0 to 3.5) values, indicating increased absorption spectral selectivity.
Date: January 29, 2008
Creator: Hopkins, Rebecca J.; Lewis, K.; Desyaterik, Yury; Wang, Z.; Tivanski, Alexei V.; Arnott, W. P. et al.
Object Type: Article
System: The UNT Digital Library
Pressure gradient passivation of carbonaceous material normally susceptible to spontaneous combustion (open access)

Pressure gradient passivation of carbonaceous material normally susceptible to spontaneous combustion

This invention is a process for the passivation or deactivation with respect to oxygen of a carbonaceous material by the exposure of the carbonaceous material to an oxygenated gas in which the oxygenated gas pressure is increased from a first pressure to a second pressure and then the pressure is changed to a third pressure. Preferably a cyclic process which comprises exposing the carbonaceous material to the gas at low pressure and increasing the pressure to a second higher pressure and then returning the pressure to a lower pressure is used. The cycle is repeated at least twice wherein the higher pressure may be increased after a selected number of cycles.
Date: January 29, 2002
Creator: Ochs, Thomas L.; Sands, William D.; Schroeder, Karl; Summers, Cathy A. & Utz, Bruce R.
Object Type: Patent
System: The UNT Digital Library
Total Dissolved Gas Effects on Incubating Chum Salmon Below Bonneville Dam (open access)

Total Dissolved Gas Effects on Incubating Chum Salmon Below Bonneville Dam

At the request of the U.S. Army Corps of Engineers (USACE; Portland District), Pacific Northwest National Laboratory (PNNL) undertook a project in 2006 to look further into issues of total dissolved gas (TDG) supersaturation in the lower Columbia River downstream of Bonneville Dam. In FY 2008, the third year of the project, PNNL conducted field monitoring and laboratory toxicity testing to both verify results from 2007 and answer some additional questions about how salmonid sac fry respond to elevated TDG in the field and the laboratory. For FY 2008, three objectives were 1) to repeat the 2006-2007 field effort to collect empirical data on TDG from the Ives Island and Multnomah Falls study sites; 2) to repeat the static laboratory toxicity tests on hatchery chum salmon fry to verify 2007 results and to expose wild chum salmon fry to incremental increases in TDG, above those of the static test, until external symptoms of gas bubble disease were clearly present; and 3) to assess physiological responses to TDG levels in wild chum salmon sac fry incubating below Bonneville Dam during spill operations. This report summarizes the tasks conducted and results obtained in pursuit of the three objectives. Chapter 1 discusses the …
Date: January 29, 2009
Creator: Arntzen, Evan V.; Hand, Kristine D.; Carter, Kathleen M.; Geist, David R.; Murray, Katherine J.; Dawley, Earl M. et al.
Object Type: Report
System: The UNT Digital Library
QUALIFICATION OF A RADIOACTIVE HIGH ALUMINUM GLASS FOR PROCESSINGIN THE DEFENSE WASTE PROCESSING FACILITY AT THE SAVANNAH RIVER SITE (open access)

QUALIFICATION OF A RADIOACTIVE HIGH ALUMINUM GLASS FOR PROCESSINGIN THE DEFENSE WASTE PROCESSING FACILITY AT THE SAVANNAH RIVER SITE

At the Savannah River Site (SRS) the Defense Waste Processing Facility (DWPF) has been immobilizing SRS's radioactive high level waste (HLW) sludge into a borosilicate glass for approximately eleven years. Currently the DWPF is immobilizing HLW sludge in Sludge Batch 4 (SB4). Each sludge batch is nominally two million liters of HLW and produces nominally five hundred stainless steel canisters 0.6 meters in diameter and 3 meters tall filled with the borosilicate glass. In SB4 and earlier sludge batches, the Al concentration has always been rather low, (less than 9.5 weight percent based on total dried solids). It is expected that in the future the Al concentrations will increase due to the changing composition of the HLW. Higher Al concentrations could introduce problems because of its known effect on the viscosity of glass melts and increase the possibility of the precipitation of nepheline in the final glass and decrease its durability. In 2006 Savannah River National Laboratory (SRNL) used DWPF processes to immobilize a radioactive HLW slurry containing 14 weight percent Al to ensure that this waste is viable for future DWPF processing. This paper presents results of the characterization of the high Al glass prepared in that demonstration. At …
Date: January 29, 2008
Creator: Bibler, N; John Pareizs, J; Tommy Edwards,T; Charles02 Coleman, C & Charles Crawford, C
Object Type: Article
System: The UNT Digital Library
In Silico Modeling of Geobacter Species. (open access)

In Silico Modeling of Geobacter Species.

This project employed a combination of in silico modeling and physiological studies to begin the construction of models that could predict the activity of Geobacter species under different environmental conditions. A major accomplishment of the project was the development of the first genome-based models of organisms known environmental relevance. This included the modeling of two Geobacter species and two species of Pelobacter. Construction of these models required increased sophistication in the annotation of the original draft genomes as well as collection of physiological data on growth yields, cell composition, and metabolic reactions. Biochemical studies were conducted to determine whether proposed enzymatic reactions were in fact expressed. During this process we developed an Automodel Pipeline process to accelerate future model development of other environmentally relevant organisms by using bioinformatics techniques to leverage predicted protein sequences and the Genomatica database containing a collection of well-curated metabolic models. The Automodel Pipeline was also used for iterative updating of the primary Geobacter model of G. sulfurreducens to expand metabolic functions or to add alternative pathways. Although each iteration of the model does not lead to another publication, it is an invaluable resource for hypothesis development and evaluation of experimental data. In order to develop …
Date: January 29, 2008
Creator: Lovley, Derek, R.
Object Type: Report
System: The UNT Digital Library
Observation of B Meson Decays to omegaK* and Improved Measurements for omegarho and omegaf0 (open access)

Observation of B Meson Decays to omegaK* and Improved Measurements for omegarho and omegaf0

We present measurements of B meson decays to the final states {omega}K*, {omega}{rho}, and {omega}f{sub 0}, where K* indicates a spin 0, 1, or 2 strange meson. The data sample corresponds to 465 x 10{sup 6} B{bar B} pairs collected with the BABAR detector at the PEP-II e{sup +}e{sup -} collider at SLAC. B meson decays involving vector-scalar, vector-vector, and vector-tensor final states are analyzed; the latter two shed new light on the polarization of these final states. We measure the branching fractions for nine of these decays; five are observed for the first time. For most decays we also measure the charge asymmetry and, where relevant, the longitudinal polarization f{sub L}.
Date: January 29, 2009
Creator: Aubert, B.
Object Type: Article
System: The UNT Digital Library
Parametric Model for Astrophysical Proton-Proton Interactions and Applications (open access)

Parametric Model for Astrophysical Proton-Proton Interactions and Applications

Observations of gamma-rays have been made from celestial sources such as active galaxies, gamma-ray bursts and supernova remnants as well as the Galactic ridge. The study of gamma rays can provide information about production mechanisms and cosmic-ray acceleration. In the high-energy regime, one of the dominant mechanisms for gamma-ray production is the decay of neutral pions produced in interactions of ultra-relativistic cosmic-ray nuclei and interstellar matter. Presented here is a parametric model for calculations of inclusive cross sections and transverse momentum distributions for secondary particles--gamma rays, e{sup {+-}}, {nu}{sub e}, {bar {nu}}{sub e}, {nu}{sub {mu}} and {bar {nu}}{sub {mu}}--produced in proton-proton interactions. This parametric model is derived on the proton-proton interaction model proposed by Kamae et al.; it includes the diffraction dissociation process, Feynman-scaling violation and the logarithmically rising inelastic proton-proton cross section. To improve fidelity to experimental data for lower energies, two baryon resonance excitation processes were added; one representing the {Delta}(1232) and the other multiple resonances with masses around 1600 MeV/c{sup 2}. The model predicts the power-law spectral index for all secondary particle to be about 0.05 lower in absolute value than that of the incident proton and their inclusive cross sections to be larger than those predicted …
Date: January 29, 2008
Creator: Karlsson, Niklas
Object Type: Thesis or Dissertation
System: The UNT Digital Library