Exotic physics: search for doubly-charged higgs bosons decaying to dileptons in p anti-p collisions at s**(1/2) = 1.96 tev (open access)

Exotic physics: search for doubly-charged higgs bosons decaying to dileptons in p anti-p collisions at s**(1/2) = 1.96 tev

The authors present the results of a search for doubly-charged Higgs bosons (H{sup {+-}}{sup {+-}}) decaying to dileptons (ll') using {approx} 240 pb{sup -1} of p{bar p} collision data collected by the CDF II experiment at the Fermilab Tevatron. In the search region, given by same-sign ll' mass m{sub ll'} > 80 GeV/c{sup 2} (100 GeV/c{sup 2} for ee channel), they observe no evidence for H{sup {+-}}{sup {+-}} production. They set limits on {sigma}(p{bar p} {yields} H{sup ++}H{sup --} {yields} l{sup +}l'{sup +}l{sup -}l'{sup -}) as a function of the mass of the H{sup {+-}}{sup {+-}} and the chirality of its couplings. Assuming exclusive same-sign dilepton decays, they derive lower mass limits on H{sub L}{sup {+-}}{sup {+-}} of 133 GeV/c{sup 2}, 136 GeV/c{sup 2}, and 115 GeV/c{sup 2} in the ee, {mu}{mu}, and e{mu} channels, respectively, and a lower mass limit of 113 GeV/c{sup 2} on H{sub R}{sup {+-}}{sup {+-}} in the {mu}{mu} channel, all at the 95% confidence level.
Date: November 15, 2004
Creator: Acosta, D.
Object Type: Report
System: The UNT Digital Library
Spent Fuel Transportation Package Response to the Baltimore Tunnel Fire Scenario (open access)

Spent Fuel Transportation Package Response to the Baltimore Tunnel Fire Scenario

On July 18, 2001, a freight train carrying hazardous (non-nuclear) materials derailed and caught fire while passing through the Howard Street railroad tunnel in downtown Baltimore, Maryland. The United States Nuclear Regulatory Commission (USNRC), one of the agencies responsible for ensuring the safe transportation of radioactive materials in the United States, undertook an investigation of the train derailment and fire to determine the possible regulatory implications of this particular event for the transportation of spent nuclear fuel by railroad. Shortly after the accident occurred, the USNRC met with the National Transportation Safety Board (NTSB, the U.S. agency responsible for determining the cause of transportation accidents), to discuss the details of the accident and the ensuing fire. Following these discussions, the USNRC assembled a team of experts from the National Institute of Standards and Technology (NIST), the Center for Nuclear Waste Regulatory Analyses (CNWRA), and Pacific Northwest National Laboratory (PNNL) to determine the thermal conditions that existed in the Howard Street tunnel fire and analyze the effects of this fire on various spent fuel transportation package designs. The Fire Dynamics Simulator (FDS) code, developed by NIST, was used to determine the thermal environment present in the Howard Street tunnel during the …
Date: November 15, 2006
Creator: Adkins, Harold E.; Cuta, Judith M.; Koeppel, Brian J.; Guzman, Anthony D. & Bajwa, Christopher S.
Object Type: Report
System: The UNT Digital Library
Army Gas-Cooled Reactor Systems Program Quarterly Progress Report: July 1 - September 30, 1963 (open access)

Army Gas-Cooled Reactor Systems Program Quarterly Progress Report: July 1 - September 30, 1963

Report documenting the progress of the Army Gas-Cooled Reactor Systems Program to develop a mobile nuclear power plant for military field operation.
Date: November 15, 1963
Creator: Aerojet-General Corporation
Object Type: Report
System: The UNT Digital Library
Energy distribution in a relativistic DC electron beam (open access)

Energy distribution in a relativistic DC electron beam

None
Date: November 15, 2000
Creator: Alexey Burov, Sergei Nagaitsev and Alexander Shemyakin
Object Type: Report
System: The UNT Digital Library
Targeted discovery of glycoside hydrolases from a switchgrass-adapted compost community (open access)

Targeted discovery of glycoside hydrolases from a switchgrass-adapted compost community

Development of cellulosic biofuels from non-food crops is currently an area of intense research interest. Tailoring depolymerizing enzymes to particular feedstocks and pretreatment conditions is one promising avenue of research in this area. Here we added a green-waste compost inoculum to switchgrass (Panicum virgatum) and simulated thermophilic composting in a bioreactor to select for a switchgrass-adapted community and to facilitate targeted discovery of glycoside hydrolases. Small-subunit (SSU) rRNA-based community profiles revealed that the microbial community changed dramatically between the initial and switchgrass-adapted compost (SAC) with some bacterial populations being enriched over 20-fold. We obtained 225 Mbp of 454-titanium pyrosequence data from the SAC community and conservatively identified 800 genes encoding glycoside hydrolase domains that were biased toward depolymerizing grass cell wall components. Of these, {approx}10% were putative cellulases mostly belonging to families GH5 and GH9. We synthesized two SAC GH9 genes with codon optimization for heterologous expression in Escherichia coli and observed activity for one on carboxymethyl cellulose. The active GH9 enzyme has a temperature optimum of 50 C and pH range of 5.5 to 8 consistent with the composting conditions applied. We demonstrate that microbial communities adapt to switchgrass decomposition using simulated composting condition and that full-length genes can …
Date: November 15, 2009
Creator: Allgaier, M.; Reddy, A.; Park, J. I.; Ivanova, N.; D'haeseleer, P.; Lowry, S. et al.
Object Type: Article
System: The UNT Digital Library
Antiprotons and the Crystal Ball (open access)

Antiprotons and the Crystal Ball

During the 1998 running of the Crystal Ball experiment, a couple of brief test runs were done with the C6 beamline tuned to produce antiprotons. Specifically, one shift on July 29th produced runs 329-334 with the beam momentum set for 650 MeV/c, run 355 was done on July 31st with a 550 MeV/c beam momentum, and run 926-929 were obtained in a single shift on November 3rd, also with a beam momentum of 550 MeV/c. The beam tune for the November data was greatly superior to that of the July data, however. Therefore, only the November data have been analyzed in detail, and the results of this analysis are presented in this note. Due to the paucity of statistics that were obtained, it was decided not to attempt to publish the results. However, the results are valuable as a tool for planning a possible future program of dedicated measurements of antiproton-proton annihilation into all-neutral final states using the Crystal Ball. The data in fact show that the Crystal Ball with its large angular acceptance and multi-photon capability would be an excellent detector for such an experiment. Only one other such experiment (the Crystal Barrel experiment at CERN/LEAR) has ever been …
Date: November 15, 1999
Creator: Allgower, C. & Peaslee, D.
Object Type: Report
System: The UNT Digital Library
Hadroproduction of charm at Fermilab E769 (open access)

Hadroproduction of charm at Fermilab E769

Experiment E769 at Fermilab obtained charm hadroproduction data during the 1987-88 Fixed Target running period with a 250 GeV hadron beam incident on thin target foils of Be, Al, Cu, and W. From an analysis of 25% of the recorded 400M trigger sample we have explored the Feynman x, p{sub t}{sup 2} and the atomic number dependence of charm quark production using samples of D{sup +} and D{sup 0} mesons. 7 refs., 4 figs.
Date: November 15, 1990
Creator: Alves, G. A.; Anjos, J. C.; de Mello Neto, J. R. T.; de Miranda, J. M.; da Motta, H.; dos Reis, A. C. et al.
Object Type: Article
System: The UNT Digital Library
Preliminary Screening Analysis for the Environmental Risk Evaluation System: Task 2.1.1: Evaluating Effects of Stressors – Fiscal Year 2010 Progress Report: Environmental Effects of Marine and Hydrokinetic Energy (open access)

Preliminary Screening Analysis for the Environmental Risk Evaluation System: Task 2.1.1: Evaluating Effects of Stressors – Fiscal Year 2010 Progress Report: Environmental Effects of Marine and Hydrokinetic Energy

Possible environmental effects of marine and hydrokinetic (MHK) energy development are not well understood, and yet regulatory agencies are required to make decisions in spite of substantial uncertainty about environmental impacts and their long-term effects. An understanding of risk associated with likely interactions between MHK installations and aquatic receptors, including animals, habitats, and ecosystems, can help reduce the level of uncertainty and focus regulatory actions and scientific studies on interactions of most concern. As a first step in developing the Pacific Northwest National Laboratory (PNNL) Environmental Risk Evaluation System (ERES), PNNL scientists conducted a preliminary risk screening analysis on three initial MHK cases - a tidal project in Puget Sound using Open Hydro turbines, a wave project off the coast of Oregon using Ocean Power Technologies point attenuator buoys, and a riverine current project in the Mississippi River using Free Flow turbines. Through an iterative process, the screening analysis revealed that top-tier stressors in all three cases were the effects of the dynamic physical presence of the device (e.g., strike), accidents, and effects of the static physical presence of the device (e.g., habitat alteration). Receptor interactions with these stressors at the four highest tiers of risk were dominated by marine …
Date: November 15, 2010
Creator: Anderson, Richard M.; Copping, Andrea E. & Van Cleve, Frances B.
Object Type: Report
System: The UNT Digital Library
Comparing FRACHEM and TOUGHREACT for reactive transport modelingof brine-rock interactions in enhanced geothermal systems (EGS) (open access)

Comparing FRACHEM and TOUGHREACT for reactive transport modelingof brine-rock interactions in enhanced geothermal systems (EGS)

Coupled modelling of fluid flow and reactive transport ingeothermal systems is challenging because of reservoir conditions such ashigh temperatures, elevated pressures and sometimes high salinities ofthe formation fluids. Thermal hydrological-chemical (THC) codes, such asFRACHEM and TOUGHREACT, have been developed to evaluate the long-termhydrothermal and chemical evolution of exploited reservoirs. In thisstudy, the two codes were applied to model the same geothermal reservoir,to forecast reservoir evolution using respective thermodynamic andkinetic input data. A recent (unreleased) TOUGHREACT version allows theuse of either an extended Debye-Hu?ckel or Pitzer activity model forcalculating activity coefficients, while FRACHEM was designed to use thePitzer formalism. Comparison of models results indicate that differencesin thermodynamic equilibrium constants, activity coefficients andkinetics models can result in significant differences in predictedmineral precipitation behaviour and reservoir-porosity evolution.Differences in the calculation schemes typically produce less differencein model outputs than differences in input thermodynamic and kineticdata, with model results being particularly sensitive to differences inion-interaction parameters for highsalinity systems.
Date: November 15, 2005
Creator: Andre, L.; Spycher, N.; Xu, T.; Pruess, K. & Vuataz, F.-D.
Object Type: Article
System: The UNT Digital Library
A Barrel IFR Instrumented With Limited Streamer Tubes for BABAR Experiment (open access)

A Barrel IFR Instrumented With Limited Streamer Tubes for BABAR Experiment

The new barrel Instrumented Flux Return (IFR) of BABAR detector will be reported here. Limited Streamer Tubes (LSTs) have been chosen to replace the existing RPCs as active elements of the barrel IFR. The layout of the new detector will be discussed: in particular, a cell bigger than the standard one has been used to improve efficiency and reliability. The extruded profile is coated with a resistive layer of graphite having a typical surface resistivity between 0.2 and 0.4 MOhm/square. The tubes are assembled in modules and installed in 12 active layers of each sextant of the IFR detector. R&D studies to choose the final design and Quality Control procedure adopted during the tube production will be briefly discussed. Finally the performances of installed LSTs into 2/3 of IFR after 8 months of operations will be reported.
Date: November 15, 2006
Creator: Andreotti, M.
Object Type: Article
System: The UNT Digital Library
Complex Genetic Disorders and Intellectual Property Rights Final Report (open access)

Complex Genetic Disorders and Intellectual Property Rights Final Report

None
Date: November 15, 2006
Creator: Andrews, Lori, B.
Object Type: Report
System: The UNT Digital Library
Recent Developments in SHERPA (open access)

Recent Developments in SHERPA

Some recent QCD-related developments in the SHERPA event generator are presented. In the past decades, event generators such as PYTHIA [1, 2] and HERWIG [3, 4] have been central for nearly all physics analyses at particle physics experiments at the high-energy frontier. This will also hold true at the LHC, where a large number of interesting signals for new particles or new phenomena (the Higgs boson or any other manifestation of the mechanism behind electro-weak symmetry breaking, supersymmetry, extra dimensions etc.) is hampered by a plethora of severe, sometimes overwhelming backgrounds. Nearly all of them are largely influenced by QCD. Therefore it seems fair to say that the success of the LHC in finding new physics may very well depend on a deep and detailed understanding of old physics, like QCD. Examples for this include, among others, the central-jet veto for the vector boson fusion channel for Higgs production or topologies, where gauge bosons emerge in association with many jets, a background for many search channels. In a reflection on increased needs by the experimental community, aiming at higher precision, incorporation of new physics models and so on, the work horses of old have undergone serious renovation efforts, resulting in …
Date: November 15, 2011
Creator: Archibald, Jennifer; Gleisberg, Tanju; Hoeche, Stefan; Krauss, Frank; Schonherr, Marek; Schumann, Steffen et al.
Object Type: Article
System: The UNT Digital Library
Processing of High Level Waste: Spectroscopic Characterization of Redox Reactions in Supercritical Water - Final Report (open access)

Processing of High Level Waste: Spectroscopic Characterization of Redox Reactions in Supercritical Water - Final Report

Current efforts are focused on the oxidative dissolution of chromium compounds found in Hanford tank waste sludge. Samples of chromium oxides and hydroxides with varying degrees of hydration are being characterized using Raman, FTIR, and XPS spectroscopic techniques. Kinetics of oxidation reactions at subcritical and supercritical temperatures are being followed by Raman spectroscopy using a high temperature stainless steel cell with diamond windows. In these reactions both hydrogen peroxide and nitrate anions are used as the oxidizing species with Cr(III) compounds and organic compounds as reducing agents.
Date: November 15, 2000
Creator: Arrington, C. A., Jr.
Object Type: Report
System: The UNT Digital Library
Fabrication of Yb-123 Tapes (open access)

Fabrication of Yb-123 Tapes

While Bi-2223 tapes have been the workhorses of the superconductor industry, their poor performance in applied magnetic fields restrict their use to below 30 K. Melt-processing of Ag-clad Yb-123 PIT tapes offers a simple and scalable technique for fabricating long-length HTS conductors capable of being used at 77 K. Under reduced oxygen partial pressure, the peritectic temperature of Yb-123 is below the melting point of Ag, and this facilitates the adaptation of melt-texturing methods for fabricating these tapes. The effect of melt-processing temperature on current density was also explored; a temperature of 965 C yielded optimal critical current values. The critical current density achieved at 4.2 K was 20,000 A/cm{sup 2}, corresponding to a critical current of 52 A. Based on the above results, an optimal processing zone for melt-processing of Ag-clad Yb-123 tapes was determined. These results hold promise for melt-processing of Ag-clad Yb-123 tapes as an alternative to Bi-2223 PIT technology.
Date: November 15, 2000
Creator: Athur, S.; Balachandran, U. & Salama, K.
Object Type: Article
System: The UNT Digital Library
Observation of an Excited Charm Baryon Omega^*_C Decaying to Omega^0_C Gamma (open access)

Observation of an Excited Charm Baryon Omega^*_C Decaying to Omega^0_C Gamma

The authors report the first observation of an excited singly-charmed baryon {Omega}*{sub c} (css) in the radiative decay {Omega}{sub c}{sup 0}{gamma}, where the {Omega}{sub c}{sup 0} baryon is reconstructed in the decays to the final states {Omega}{sup -}{pi}{sup +}, {Omega}{sup -} {pi}{sup +}{pi}{sup 0}, {Omega}{sup -}{pi}{sup +}{pi}{sup -}{pi}{sup +}, and {Xi}{sup -} K{sup -} {pi}{sup +}{pi}{sup +}. This analysis is performed using a dataset of 230.7 fb{sup -1} collected by the BABAR detector at the PEP-II asymmetric-energy B Factory at the Stanford Linear Accelerator Center. The mass difference between the {Omega}*{sub c} and the {Omega}{sub c}{sup 0} baryons is measured to be 70.8 {+-} 1.0(stat) {+-} 1.1(syst) MeV/c{sup 2}. They also measure the ratio of inclusive production cross sections of {Omega}*{sub c} and {Omega}{sub c}{sup 0} in e{sup +}e{sup -} annihilation.
Date: November 15, 2006
Creator: Aubert, B.
Object Type: Article
System: The UNT Digital Library
Search for Lepton Flavor Violating Decays $\tau^\pm \to \ell^\pm{\pi^0}, \ell^\pm\eta, \ell^\pm{\eta^\prime}$ (open access)

Search for Lepton Flavor Violating Decays $\tau^\pm \to \ell^\pm{\pi^0}, \ell^\pm\eta, \ell^\pm{\eta^\prime}$

A search for lepton flavor violating decays of the {tau} lepton to a lighter mass lepton and a pseudoscalar meson has been performed using 339 fb{sup -1} of e{sup +}e{sup -} annihilation data collected at a center-of-mass energy near 10.58GeV by the BABAR detector at the SLAC PEP-II storage ring. No evidence of signal has been found, and upper limits on the branching fractions are set at 10{sup -7} level.
Date: November 15, 2006
Creator: Aubert, B.
Object Type: Article
System: The UNT Digital Library
Science and technology of ultrananocrystalline diamond (UNCD) thin films for multifunctional devices. (open access)

Science and technology of ultrananocrystalline diamond (UNCD) thin films for multifunctional devices.

MEMS devices are currently fabricated primarily in silicon because of the available surface machining technology. However, Si has poor mechanical and tribological properties, and practical MEMS devices are currently limited primarily to applications involving only bending and flexural motion, such as cantilever accelerometers and vibration sensors, However, because of the poor flexural strength and fracture toughness of Si, and the tendency of Si to adhere to hydrophyllic surfaces, even these simple devices have limited dynamic range. Future MEMS applications that involve significant rolling or sliding contact will require the use of new materials with significantly improved mechanical and tribological properties, and the ability to perform well in harsh environments. Diamond is a superhard material of high mechanical strength, exceptional chemical inertness, and outstanding thermal stability. The brittle fracture strength is 23 times that of Si, and the projected wear life of diamond MEMS moving mechanical assemblies (MEMS-MMAS) is 10,000 times greater than that of Si MMAs. However, as the hardest known material, diamond is notoriously difficult to fabricate. Conventional CVD thin film deposition methods offer an approach to the fabrication of ultra-small diamond structures, but the films have large grain size, high internal stress, poor intergranular adhesion, and very rough …
Date: November 15, 2000
Creator: Auciello, O.; Gruen, D. M.; Krauss, A. R.; Jayatissa, A.; Sumant, A.; Tucek, J. et al.
Object Type: Article
System: The UNT Digital Library
Accurate Time-Linked Data Acqusition System Field Deploymemt and Operational Experience (open access)

Accurate Time-Linked Data Acqusition System Field Deploymemt and Operational Experience

None
Date: November 15, 2000
Creator: BERG,DALE E. & ZAYAS,JOSE R.
Object Type: Article
System: The UNT Digital Library
Calculation of emission from hydrogenic ions in super liquid density plasmas (open access)

Calculation of emission from hydrogenic ions in super liquid density plasmas

Previous calculations of line emission were extended to higher density, lower temperature plasmas, typical of those expected in early ablative compression experiments. Emission from Ne-seeded fuel was analyzed in order to diagnose the density and temperature of the compressed core. The Stark/Doppler broadened emission profile is calculated for the H-like Ne resonance line. The observable lineshape is then obtained by time-averaging over expected density and temperature profiles and by including the effects of radiative transfer.
Date: November 15, 1976
Creator: Bailey, D. S. & Valeo, E. J.
Object Type: Article
System: The UNT Digital Library
The NAS Parallel Benchmarks (open access)

The NAS Parallel Benchmarks

The NAS Parallel Benchmarks (NPB) are a suite of parallel computer performance benchmarks. They were originally developed at the NASA Ames Research Center in 1991 to assess high-end parallel supercomputers. Although they are no longer used as widely as they once were for comparing high-end system performance, they continue to be studied and analyzed a great deal in the high-performance computing community. The acronym 'NAS' originally stood for the Numerical Aeronautical Simulation Program at NASA Ames. The name of this organization was subsequently changed to the Numerical Aerospace Simulation Program, and more recently to the NASA Advanced Supercomputing Center, although the acronym remains 'NAS.' The developers of the original NPB suite were David H. Bailey, Eric Barszcz, John Barton, David Browning, Russell Carter, LeoDagum, Rod Fatoohi, Samuel Fineberg, Paul Frederickson, Thomas Lasinski, Rob Schreiber, Horst Simon, V. Venkatakrishnan and Sisira Weeratunga. The original NAS Parallel Benchmarks consisted of eight individual benchmark problems, each of which focused on some aspect of scientific computing. The principal focus was in computational aerophysics, although most of these benchmarks have much broader relevance, since in a much larger sense they are typical of many real-world scientific computing applications. The NPB suite grew out of the …
Date: November 15, 2009
Creator: Bailey, David H.
Object Type: Report
System: The UNT Digital Library
Identification and Evaluation of Fluvial-Dominated Deltaic Reservoirs. (open access)

Identification and Evaluation of Fluvial-Dominated Deltaic Reservoirs.

This document is provided as a Quarterly Technical Progress Report for the program entitled `Identification and Evaluation of Fluvial- Dominated Deltaic (Class I Oil) Reservoirs in Oklahoma`, covering the reporting period of July 1 - September 30, 1997. Work is progressing as expected for the project. The Tonkawa Play workshop was completed as scheduled on July 9, 1997 in Norman Oklahoma. It was attended by 101 people of whom about 55 were operators. The Bartlesville workshop is scheduled for October and November 1997, in three different sites including Tulsa, Bartlesville, and Norman, Oklahoma. The FDD computer facility is fully operational. During this quarter, there were 10 industry individuals who used the computer facility. This project is serving an extremely valuable role in the technology transfer activities for the Oklahoma petroleum industry, with very positive industry feedback.
Date: November 15, 1997
Creator: Baken, Mary K. & Andrews, Richard
Object Type: Report
System: The UNT Digital Library
Practical superconductor development for electric power applications. (open access)

Practical superconductor development for electric power applications.

None
Date: November 15, 2000
Creator: Balachandran, U.
Object Type: Report
System: The UNT Digital Library
Facility Effluent Monitoring Plan for Pacific Northwest National Laboratory Balance-of-Plant Facilities (open access)

Facility Effluent Monitoring Plan for Pacific Northwest National Laboratory Balance-of-Plant Facilities

The Pacific Northwest National Laboratory (PNNL) operates a number of Research & Development (R&D) facilities for the U.S. Department of Energy (DOE) on the Hanford Site. Facility effluent monitoring plans (FEMPs) have been developed to document the facility effluent monitoring portion of the Environmental Monitoring Plan (DOE 2000) for the Hanford Site. Three of PNNL’s R&D facilities, the 325, 331, and 3720 Buildings, are considered major emission points for radionuclide air sampling, and individual FEMPs were developed for these facilities in the past. In addition, a balance-of-plant (BOP) FEMP was developed for all other DOE-owned, PNNL-operated facilities at the Hanford Site. Recent changes, including shutdown of buildings and transition of PNNL facilities to the Office of Science, have resulted in retiring the 3720 FEMP and combining the 331 FEMP into the BOP FEMP. This version of the BOP FEMP addresses all DOE-owned, PNNL-operated facilities at the Hanford Site, excepting the Radiochemical Processing Laboratory, which has its own FEMP because of the unique nature of the building and operations. Activities in the BOP facilities range from administrative to laboratory and pilot-scale R&D. R&D activities include both radioactive and chemical waste characterization, fluid dynamics research, mechanical property testing, dosimetry research, and molecular …
Date: November 15, 2004
Creator: Ballinger, Marcel Y. & Gervais, Todd L.
Object Type: Report
System: The UNT Digital Library
Coupled Biogeochemical Processes Governing the Stability of Bacteriogenic Uraninite and Release of U(VI) in Heterogeneous Media: Molecular to Meter Scales (open access)

Coupled Biogeochemical Processes Governing the Stability of Bacteriogenic Uraninite and Release of U(VI) in Heterogeneous Media: Molecular to Meter Scales

In-situ reductive biotransformation of subsurface U(VI) to U(IV) (as ?UO2?) has been proposed as a bioremediation method to immobilize uranium at contaminated DOE sites. The chemical stability of bacteriogenic ?UO2? is the seminal issue governing its success as an in-situ waste form in the subsurface. The structure and properties of chemically synthesized UO2+x have been investigated in great detail. It has been found to exhibit complex structural disorder, with nonstoichiometry being common, hence the designation ?UO2+x?, where 0 < x < 0.25. Little is known about the structures and properties of the important bacteriogenic analogs, which are believed to occur as nanoparticles in the environment. Chemically synthesized UO2+x exhibits an open fluorite structure and is known to accommodate significant doping of divalent cations. The extent to which bacteriogenic UO2+x incorporates common ground water cations (e.g., Ca2+) has not been investigated, and little is known about nonstoichiometry and structure defects in the bacteriogenic material. Particle size, nonstoichiometry, and doping may significantly alter the reactivity, and hence stability, of bacteriogenic UO2+x in the subsurface. The presence of associated sulfide minerals, and solid phase oxidants such as bacteriogenic Mn oxides may also affect the longevity of bacteriogenic UO2 in the subsurface.
Date: November 15, 2006
Creator: Bargar, John R.
Object Type: Report
System: The UNT Digital Library