Measurement of total ion flux in vacuum Arc discharges (open access)

Measurement of total ion flux in vacuum Arc discharges

A vacuum arc ion source was modified allowing us to collections from arc plasma streaming through an anode mesh. The mesh had ageometric transmittance of 60 percent, which was taken into account as acorrection factor. The ion current from twenty-two cathode materials wasmeasured at an arc current of 100 A. The ion current normalized by thearc current was found to depend on the cathode material, with valuesinthe range from 5 percent to 11 percent. The normalized ion current isgenerally greater for light elements than for heavy elements. The ionerosion rates were determined fromvalues of ion currentand ion chargestates, which were previously measured in the same experimental system.The ion erosion rates range from 12-94 mu g/C.
Date: April 12, 2004
Creator: Anders, Andre; Oks, Efim M.; Yushkov, Georgy Yu. & Brown, Ian G.
Object Type: Article
System: The UNT Digital Library
Testing of a Continuous Sampling Mercury CEM at the EPA-Rotary Kiln Incinerator Simulator Facility (open access)

Testing of a Continuous Sampling Mercury CEM at the EPA-Rotary Kiln Incinerator Simulator Facility

This report has been prepared to document the performance of the continuous sampling mercury monitoring system developed by Ames Laboratory for use as a continuous emission monitor (CEM). This work was funded by the U.S. Department of Energy, Office of Environmental Management, Office of Science and Technology, through the Mixed Waste Focus Area. The purpose of the project is to develop instrumentation and methods for spectroscopic field-monitoring applications. During FY01 this included continued development and testing of an echelle spectrometer system for the detection of mercury (Hg) by atomic absorption. Due to the relatively poor limits of detection for Hg by optical emission techniques, the CEM has been designed for the detection of elemental Hg by optical absorption. The sampling system allows continuous introduction of stack gas into the CEM for analysis of elemental and total Hg in the gas stream. A heated pyrolysis tube is used in this system to convert oxidized Hg compounds to elemental Hg prior to analysis for total Hg. The pyrolysis tube is bypassed to measure elemental Hg. The CEM is designed to measure the elemental Hg concentration of the gas sample, measure the total Hg concentration, perform a zero check (analysis of room air), …
Date: April 12, 2002
Creator: Baldwin, D. P.; Bajic, S. J.; Eckels, D. E. & Zamzow, D. S.
Object Type: Report
System: The UNT Digital Library
Upstream Migration of Pacific Lampreys in the John Day River : Behavior, Timing, and Habitat Use : Annual Report 2000. (open access)

Upstream Migration of Pacific Lampreys in the John Day River : Behavior, Timing, and Habitat Use : Annual Report 2000.

Historic accounts and recent observations of Pacific lampreys (Lampetra tridentata) at mainstem Columbia River dams indicate the number of Pacific lampreys migrating upriver has decreased dramatically over the last 60 years. Consequently, state, federal, and tribal governments have recently expressed concern for this species. Little is known about the biological and ecological characteristics of habitats suitable for upstream migrating Pacific lampreys. If rehabilitation efforts are to be done effectively and efficiently, we must gain knowledge of factors limiting survival and reproduction of Pacific lampreys. From data gathered in the first year of this project, we can for the first time, describe the timing, extent, and patterns of movements for Pacific lampreys. We have tested methods and gained information that will allow us to refine our objectives and approach in future work. Knowledge of behavior, timing, and the resulting quantification of habitat use will provide a means to assess the suitability of overwintering and spawning habitats and allow the establishment of goals for recovery projects. Further research is necessary, including multiple years of data collection, tracking of movement patterns through the spawning season, and more rigorously examining habitat use.
Date: April 12, 2001
Creator: Bayer, Jennifer M.; Seelye, James G. & Robinson, T. Craig
Object Type: Report
System: The UNT Digital Library
Vendor Capability for Low Thermal Expansion Mask Substrates for EUV Lithography (open access)

Vendor Capability for Low Thermal Expansion Mask Substrates for EUV Lithography

Development of manufacturing infrastructure is required to ensure a commercial source of mask substrates for the timely introduction of EUVL. Improvements to the low thermal expansion materials that compose the substrate have been made, but need to be scaled to production quantities. We have been evaluating three challenging substrate characteristics to determine the state of the infrastructure for the finishing of substrates. First, surface roughness is on track and little risk is associated with achieving the roughness requirement as an independent specification. Second, with new flatness-measuring equipment just coming on line, the vendors are poised for improvement toward the SEMI P37 flatness specification. Third, significant acceleration is needed in the reduction of defect levels on substrates. The lack of high-sensitivity defect metrology at the vendors' sites is limiting progress in developing substrates for EWL.
Date: April 12, 2002
Creator: Blaedel, K L; Taylor, J S; Hector, S D; Yan, P Y; Ramamoorthy, A & Brooker, P D
Object Type: Article
System: The UNT Digital Library
Reaction of Phenyl Radical with O2: Thermodynamic Properties, Important Reaction Paths and Kinetics (open access)

Reaction of Phenyl Radical with O2: Thermodynamic Properties, Important Reaction Paths and Kinetics

The Phenyl + O{sub 2} association results in a chemically activated phenyl-peroxy radical which can dissociate to phenoxy radical + O, undergo intramolecular addition of the peroxy radical to several unsaturated carbon sites or react back to phenyl + O{sub 2}. The intramolecular addition channels further react through several paths to ring opening (unsaturated + carbonyl moieties) as well as cyclopentadieny radical + CO{sub 2}. Enthalpy ({Delta}H{sub f(298)}{sup o}), Entropy (S{sub 298}), and heat capacities Cp(T) for species in the decomposition of the ring are evaluated using density functional and ab initio calculations and by comparisons to vinyl + O{sub 2} data of Mebel et al, and phenyl + O{sub 2} data of Hadad et al. Isodesmic reaction analysis is used to estimate enthalpy values of the intermediates and well depths of the adducts. High Pressure limit kinetic parameters are obtained from the calculation results using canonical Transition State Theory. Quantum RRK analysis is utilized to obtain k(E) and modified strong collision or master equation analysis is used for evaluation of pressure fall-off in this complex bimolecular, chemical activation, reaction system. Uncertainty in key barriers is discussed, resulting variations in important reaction product ratios are illustrated, and changes in these …
Date: April 12, 2001
Creator: Bozzelli, J; Sebbar, N; Pitz, W & Bockhorn, H
Object Type: Article
System: The UNT Digital Library
Large Aperture, High-Efficiency Multilayer Dielectric Reflection Gratings (open access)

Large Aperture, High-Efficiency Multilayer Dielectric Reflection Gratings

The authors have designed and fabricated a 355 x 150 mm multilayer dielectric diffraction grating, 1800 l/mm for 1030 nm light, that exhibits >99% diffraction efficiency and a diffracted wavefront flatness of <0.15 {lambda}. This grating is an enabling component of a 1 ps, high rep-rate machining laser currently in operation at LLNL.
Date: April 12, 2002
Creator: Britten, J A; Bryan, S J; Summers, L J; Nguyen, H T; Shore, B W & Lyngnes, O
Object Type: Article
System: The UNT Digital Library
Benchmark Studies of Induced Radioactivity Produced in LHC Materials, Pt I: Remanent Dose Rates (open access)

Benchmark Studies of Induced Radioactivity Produced in LHC Materials, Pt I: Remanent Dose Rates

Samples of materials which will be used in the LHC machine for shielding and construction components were irradiated in the stray radiation field of the CERN-EU high-energy reference field facility. After irradiation, the specific activities induced in the various samples were analyzed with a high-precision gamma spectrometer at various cooling times, allowing identification of isotopes with a wide range of half-lives. Furthermore, the irradiation experiment was simulated in detail with the FLUKA Monte Carlo code. A comparison of measured and calculated specific activities shows good agreement, supporting the use of FLUKA for estimating the level of induced activity in the LHC.
Date: April 12, 2006
Creator: Brugger, M.; Mayer, S.; Roesler, S.; Ulrici, L.; Khater, H.; Prinz, A. et al.
Object Type: Article
System: The UNT Digital Library
Benchmark Studies of Induced Radioactivity Produced in LHC Materials, Pt II Specific Activities (open access)

Benchmark Studies of Induced Radioactivity Produced in LHC Materials, Pt II Specific Activities

A new method to estimate remanent dose rates, to be used with the Monte Carlo code FLUKA, was benchmarked against measurements from an experiment that was performed at the CERN-EU high-energy reference field facility. An extensive collection of samples of different materials were placed downstream of and laterally to a copper target, intercepting a positively charged mixed hadron beam with a momentum of 120 GeV/c. Emphasis was put on the reduction of uncertainties such as careful monitoring of the irradiation parameters, the use of different instruments to measure dose rates, detailed elemental analyses of the irradiated materials and detailed simulations of the irradiation experiment. Measured and calculated dose rates are in good agreement.
Date: April 12, 2006
Creator: Brugger, M.; Mayer, S.; Roesler, S.; Ulrici, L.; Khater, H.; Prinz, A. et al.
Object Type: Article
System: The UNT Digital Library
Gas phase chemical detection with an integrated chemical analysis system (open access)

Gas phase chemical detection with an integrated chemical analysis system

Microfabrication technology has been applied to the development of a miniature, multi-channel gas phase chemical laboratory that provides fast response, small size, and enhanced versatility and chemical discrimination. Each analysis channel includes a sample preconcentrator followed by a gas chromatographic separator and a chemically selective surface acoustic wave detector array to achieve high sensitivity and selectivity. The performance of the components, individually and collectively, is described.
Date: April 12, 2000
Creator: Casalnuovo, Stephen A.; Frye-Mason, Gregory Charles; Kottenstette, Richard; Heller, Edwin J.; Matzke, Carolyn M.; Lewis, Patrick R. et al.
Object Type: Article
System: The UNT Digital Library
A Contract Based System For Large Data Visualization (open access)

A Contract Based System For Large Data Visualization

VisIt is a richly featured visualization tool that is used to visualize some of the largest simulations ever run. The scale of these simulations requires that optimizations are incorporated into every operation VisIt performs. But the set of applicable optimizations that VisIt can perform is dependent on the types of operations being done. Complicating the issue, VisIt has a plugin capability that allows new, unforeseen components to be added, making it even harder to determine which optimizations can be applied. We introduce the concept of a contract to the standard data flow network design. This contract enables each component of the data flow network to modify the set of optimizations used. In addition, the contract allows for new components to be accommodated gracefully within VisIt's data flow network system.
Date: April 12, 2005
Creator: Childs, H. R.; Brugger, E S; Bonnell, K S; Meredith, J S; Miller, M C; Whitlock, B J et al.
Object Type: Article
System: The UNT Digital Library
Chicago metropolitan area critical infrastructure protection program electric power disruption emergency preparedness drill March 5, 2002 summary and lessons learned. (open access)

Chicago metropolitan area critical infrastructure protection program electric power disruption emergency preparedness drill March 5, 2002 summary and lessons learned.

Since January 2000, the Metropolitan Mayors Caucus, the Chicago Department of Environment, and the U.S. Department of Energy Office of Critical Infrastructure Protection (now part of the Office of Energy Assurance) have been collaborating on the development and implementation of guidelines that municipal governments can use in preparing for electric power disruptions. On March 5, 2002 Commonwealth Edison (ComEd), the electric company serving the Chicago metropolitan area, held a drill to test its emergency preparedness procedures. ComEd invited three communities in the metropolitan area--Buffalo Grove, Oak Brook, Riverside--to participate in the drill as part of their own emergency planning efforts to respond to electric power disruptions. Although ComEd had held joint exercises with the City of Chicago, this was the first time that a cooperative exercise with the suburban communities was conducted. The Infrastructure Assurance Center of Argonne National Laboratory, under the sponsorship of the U.S. Department of Energy's Office of Energy Assurance helped facilitate the drill in the communities. A series of meetings involving ComEd, community controllers (who helped organize the drill but did not participate directly), and Argonne personnel was held to lay out the ground rules for the drill and determine how it would operate. Attachment 1 …
Date: April 12, 2002
Creator: Cirillo, D.
Object Type: Report
System: The UNT Digital Library
Baryon stopping and hadronic spectra in Pb-Pb collisions at 158 GeV/nucleon (open access)

Baryon stopping and hadronic spectra in Pb-Pb collisions at 158 GeV/nucleon

Baryon stopping and particle production in Pb+Pb collisions at 158 GeV/nucleon are studied as a function of the collision centrality using new proton, antiproton, charged kaon and charged pion production data measured with the NA49 experiment at the CERN Super Proton Synchrotron (SPS). Stopping, which is measured by the shift in rapidity of net protons or baryons from the initial beam rapidity, increases in more central collisions. This is expected from a geometrical picture of the collisions. The stopping data are quantitatively compared to models incorporating various mechanisms for stopping. In general, microscopic transport calculations which incorporate current theoretical models of baryon stopping or use phenomenological extrapolations from simpler systems overestimate the dependence of stopping on centrality. Approximately, the yield of produced pions scales with the number of nucleons participating in the collision. A small increase in yield beyond this scaling, accompanied by a small suppression in the yield of the fastest pions, reflects the variation in stopping with centrality. Consistent with the observations from central collisions of light and heavy nuclei at the SPS, the transverse momentum distributions of all particles are observed to become harder with increasing centrality. This effect is most pronounced for the heaviest particles. This …
Date: April 12, 2000
Creator: Cooper, Glenn E.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Plutonium Finishing Plant (PFP) Standby Power System Commercial Grade Item (CGI) Critical Characteristics (open access)

Plutonium Finishing Plant (PFP) Standby Power System Commercial Grade Item (CGI) Critical Characteristics

PFP's Standby Power System consists of the diesel generators, the generator control system, Rm 308 UPS, switchgear batteries, and the electrical equipment used to distribute this power. Due to the nature of the equipment and its use throughout general industry, the majority of the system falls within the CGI definition HNF-PRO-268, ''Control of Purchased Items and Services'' and HNF-PRO-1819, ''PHMC Engineering Requirements'' require that the critical characteristics of CGI-procured equipment be established in an engineering document prior to placing the order. HNF-5043 established these critical characteristics for the Standby Power System. This modification adds several items to the document.
Date: April 12, 2000
Creator: DEHKORDI, N.H.
Object Type: Report
System: The UNT Digital Library
SRAT/SME Vessel (open access)

SRAT/SME Vessel

The Defense Waste Processing Facility (DWPF), at the Savannah River Site (SRS), is processing and immobilizing the radioactive high level waste sludge slurry at SRS into a durable borosilicate glass for final geological disposal. Each time a new batch of radioactive sludge is to be processed by the DWPF, the process flow sheet is to be tested and demonstrated to ensure an acceptable melter feed and glass can be made. These demonstrations are completed in the Shielded Cells Facility in the Savannah River National Laboratory at SRS.
Date: April 12, 2006
Creator: DOBOS, J
Object Type: Report
System: The UNT Digital Library
STRUCTURAL DYNAMICS MODEL VALIDATION: PUSHING THE ENVELOPE (open access)

STRUCTURAL DYNAMICS MODEL VALIDATION: PUSHING THE ENVELOPE

None
Date: April 12, 2002
Creator: DOEBLING, SCOTT W.
Object Type: Article
System: The UNT Digital Library
Accelerator Mass Spectrometry Allows for Cellular Quantification of Doxorubicin at Femtomolar Concentrations (open access)

Accelerator Mass Spectrometry Allows for Cellular Quantification of Doxorubicin at Femtomolar Concentrations

Accelerator mass spectrometry (AMS) is a highly sensitive analytical methodology used to quantify the content of radioisotopes, such as {sup 14}C, in a sample. The primary goals of this work were to demonstrate the utility of AMS in determining cellular [{sup 14}C]doxorubicin (DOX) concentrations and to develop a sensitive assay that is superior to high performance liquid chromatography (HPLC) for the quantification of DOX at the tumor level. In order to validate the superior sensitivity of AMS versus HPLC with fluorescence detection, we performed three studies comparing the cellular accumulation of DOX: one in vitro cell line study, and two in vivo xenograft mouse studies. Using AMS, we quantified cellular DOX content up to 4 hours following in vitro exposure at concentrations ranging from 0.2 pg/ml (345 fM) to 2 {micro}g/ml (3.45 {micro}M) [{sup 14}C]DOX. The results of this study show that, compared to standard fluorescence-based HPLC, the AMS method was over five orders of magnitude more sensitive. Two in vivo studies compared the sensitivity of AMS to HPLC using a nude mouse xenograft model in which breast cancer cells were implanted subcutaneously. After sufficiently large tumors formed, DOX was administered intravenously at two dose levels. Additionally, we tested the …
Date: April 12, 2005
Creator: DeGregorio, M W; Dingley, K H; Wurz, G T; Ubick, E & Turteltaub, K W
Object Type: Article
System: The UNT Digital Library
Gas Transport and Control in Thick-Liquid Inertial Fusion PowerPlants (open access)

Gas Transport and Control in Thick-Liquid Inertial Fusion PowerPlants

None
Date: April 12, 2006
Creator: Debonnel, Christophe Sylvain
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Two Rounds of Whole Genome Duplication in the Ancestral Vertebrate (open access)

Two Rounds of Whole Genome Duplication in the Ancestral Vertebrate

The hypothesis that the relatively large and complex vertebrate genome was created by two ancient, whole genome duplications has been hotly debated, but remains unresolved. We reconstructed the evolutionary relationships of all gene families from the complete gene sets of a tunicate, fish, mouse, and human, then determined when each gene duplicated relative to the evolutionary tree of the organisms. We confirmed the results of earlier studies that there remains little signal of these events in numbers of duplicated genes, gene tree topology, or the number of genes per multigene family. However, when we plotted the genomic map positions of only the subset of paralogous genes that were duplicated prior to the fish-tetrapod split, their global physical organization provides unmistakable evidence of two distinct genome duplication events early in vertebrate evolution indicated by clear patterns of 4-way paralogous regions covering a large part of the human genome. Our results highlight the potential for these large-scale genomic events to have driven the evolutionary success of the vertebrate lineage.
Date: April 12, 2005
Creator: Dehal, Paramvir & Boore, Jeffrey L.
Object Type: Article
System: The UNT Digital Library
Hose Instability and Wake Generation By An Intense Electron Beam in a Self-Ionized Gas (open access)

Hose Instability and Wake Generation By An Intense Electron Beam in a Self-Ionized Gas

The propagation of an intense relativistic electron beam through a gas that is self-ionized by the beam's space charge and wakefields is examined analytically and with 3D particle-in-cell simulations. Instability arises from the coupling between a beam and the offset plasma channel it creates when it is perturbed. The traditional electron hose instability in a preformed plasma is replaced with this slower growth instability depending on the radius of the ionization channel compared to the electron blowout radius. A new regime for hose stable plasma wakefield acceleration is suggested.
Date: April 12, 2006
Creator: Deng, S.; Barnes, C. D.; Clayton, C. E.; O'Connell, C.; Decker, F. J.; Fonseca, R. A. et al.
Object Type: Article
System: The UNT Digital Library
CASK/MSC/WP PREPARATION SYSTEM DESCRIPTION DOCUMENT (open access)

CASK/MSC/WP PREPARATION SYSTEM DESCRIPTION DOCUMENT

The purpose of this system description document (SDD) is to establish requirements that drive the design of the Cask/MSC/WP preparation system and their bases to allow the design effort to proceed to license application. This SDD is a living document that will be revised at strategic points as the design matures over time. This SDD identifies the requirements and describes the system design, as they exist at this time, with emphasis on those attributes of the design provided to meet the requirements. This SDD has been developed to be an engineering tool for design control. Accordingly, the primary audience and users are design engineers. This type of SDD both leads and trails the design process. It leads the design process with regard to the flow down of upper tier requirements onto the system. Knowledge of these requirements is essential in performing the design process. This SDD trails the design with regard to the description of the system. The description provided in the SDD is a reflection of the results of the design process to date. This SDD addresses the ''Project Requirements Document'' (PRD) (Canori and Leitner 2003 [DIRS 166275]) requirements. Additional PRD requirements may be cited, as applicable, to drive …
Date: April 12, 2005
Creator: Drummond, S.
Object Type: Report
System: The UNT Digital Library
Assessing condition of turbine engine ceramic components through NDE technology. (open access)

Assessing condition of turbine engine ceramic components through NDE technology.

Thermal barrier coatings (TBCs) and environmental barrier coatings (EBCs) are under development for hot-gas path components to allow higher gas-firing temperatures in advanced (high-efficiency, low-emission) gas turbines. Increasing dependence on the reliability of TBC and EBC components has driven the need for nondestructive evaluation (NDE) methods to assess the condition, or ''health status,'' of these coatings. NDE methods based on elastic optical scatter and thermal imaging have been applied to TBC-coated test specimens that were thermally cycled and to EBC-coated SiC/SiC components that were run in 4.5 MW(e) field-test turbines. One primary interest is to develop NDE methods that can predict a prespall condition. Resulting data suggest a correlation between laser scatter data and thermal cycles for TBC-coated specimens, and thermal imaging results have demonstrated prespall detection for an EBC-coated SiC/SiC combustor liner.
Date: April 12, 2002
Creator: Ellingson, W.A.; Sun, J.G.; Deemer, C.; Erdman, S. & Prested, C.
Object Type: Article
System: The UNT Digital Library
Energy Systems and Population Health (open access)

Energy Systems and Population Health

It is well-documented that energy and energy systems have a central role in social and economic development and human welfare at all scales, from household and community to regional and national (41). Among its various welfare effects, energy is closely linked with people s health. Some of the effects of energy on health and welfare are direct. With abundant energy, more food or more frequent meals can be prepared; food can be refrigerated, increasing the types of food items that are consumed and reducing food contamination; water pumps can provide more water and eliminate the need for water storage leading to contamination or increased exposure to disease vectors such as mosquitoes or snails; water can be disinfected by boiling or using other technologies such as radiation. Other effects of energy on public health are mediated through more proximal determinants of health and disease. Abundant energy can lead to increased irrigation, agricultural productivity, and access to food and nutrition; access to energy can also increase small-scale income generation such as processing of agricultural commodities (e.g., producing refined oil from oil seeds, roasting coffee, drying and preserving fruits and meats) and production of crafts; ability to control lighting and heating allows education …
Date: April 12, 2004
Creator: Ezzati, Majid; Bailis, Rob; Kammen, Daniel M.; Holloway, Tracey; Price, Lynn; Cifuentes, Luis A. et al.
Object Type: Article
System: The UNT Digital Library
Formation of Well-defined Nanocolumns by Ion Tracking Lithography (open access)

Formation of Well-defined Nanocolumns by Ion Tracking Lithography

Low dimensional systems on the nanometer scale afford a wealth of interesting possibilities including highly anisotropic behavior and quantum effects. Nanocolumns permit electrical and mechanical contact, yet benefit from two confined dimensions. This confinement leads to new optical, mechanical, electrical, chemical, and magnetic properties. We construct nanocolumn arrays with precise definition and independent control of diameter, length, orientation, areal density and composition so that geometry can be directly correlated to the quantum physical property of interest. The precision and control are products of the fabrication technique that we use. The process starts with an ion of sufficient energy to ''track'' a dielectric such as a film applied uniformly onto a substrate. The energy loss of the ion alters chemical bonding in the dielectric along the ion's straight trajectory. A suitable etchant quickly dissolves the latent tracks leaving high aspect ratio holes of small diameter ({approx}10nm) penetrating a film as thick as several microns. These small holes are interesting and useful in their own right and can be made to any desired size by continuing the etching process. Moreover, they serve as molds for electrochemical filling. After this electro-deposition, the mold material can be removed leaving the columns firmly attached to …
Date: April 12, 2003
Creator: Felter, T E; Musket, R G; Macaulay, J; Contolini, R J & Searson, P C
Object Type: Article
System: The UNT Digital Library
Calcite Precipitation and Trace Metal Partitioning in Groundwater and the Vadose Zone: Remediation of Strontium-90 and Other Divalent Metals and Radionuclides in Arid Western Environments (open access)

Calcite Precipitation and Trace Metal Partitioning in Groundwater and the Vadose Zone: Remediation of Strontium-90 and Other Divalent Metals and Radionuclides in Arid Western Environments

In situ remediation is an emerging technology that will play an important role in DOE's environmental restoration program, and is an area where enhancement in fundamental understanding will lead to significantly improved cleanup tools. In situ remediation technologies have inherent advantages because they do not require the costly removal, transport, and disposal of contamination. In addition, these technologies minimize worker exposure because contaminated materials are not brought to the surface. Finally, these technologies will minimize the generation of secondary waste streams with their associated treatment and disposal. A particularly promising in situ remediation technology is bioremediation. For inorganic contaminants such as radionuclides and metals, in situ bioremediation can be used to alter the mobility or reduce the toxicity of radionuclides and metals by changing the valence state of the radionuclides and metals, degrading or producing complexing ligands, or facilitating partitioning on to or off of solid phases. The purpose of the research presented here was to explore microbially facilitated partitioning of metal and radionuclides by their co-precipitation with calcium carbonate. Although this approach is a very attractive cleanup alternative, its practical implementation requires improved scientific understanding of the geochemical and biological mechanisms involved, particularly with respect to rates and mechanisms …
Date: April 12, 2003
Creator: Ferris, F. Grant
Object Type: Report
System: The UNT Digital Library