States

HWMA/RCRA Closure Plan for the Basin Facility Basin Water Treatment System - Voluntary Consent Order NEW-CPP-016 Action Plan (open access)

HWMA/RCRA Closure Plan for the Basin Facility Basin Water Treatment System - Voluntary Consent Order NEW-CPP-016 Action Plan

This Hazardous Waste Management Act/Resource Conservation and Recovery Act closure plan for the Basin Water Treatment System located in the Basin Facility (CPP-603), Idaho Nuclear Technology and Engineering Center (INTEC), Idaho National Laboratory Site, was developed to meet future milestones established under the Voluntary Consent Order. The system to be closed includes units and associated ancillary equipment included in the Voluntary Consent Order NEW-CPP-016 Action Plan and Voluntary Consent Order SITE-TANK-005 Tank Systems INTEC-077 and INTEC-078 that were determined to have managed hazardous waste. The Basin Water Treatment System will be closed in accordance with the requirements of the Hazardous Waste Management Act/Resource Conservation and Recovery Act, as implemented by the Idaho Administrative Procedures Act 58.01.05.009 and 40 Code of Federal Regulations 265, to achieve "clean closure" of the tank system. This closure plan presents the closure performance standards and methods of achieving those standards for the Basin Water Treatment Systems.
Date: November 7, 2007
Creator: Evans, S. K.
Object Type: Report
System: The UNT Digital Library
Molecular Line Emission from Massive Protostellar Disks: Predictions for ALMA and the EVLA (open access)

Molecular Line Emission from Massive Protostellar Disks: Predictions for ALMA and the EVLA

We compute the molecular line emission of massive protostellar disks by solving the equation of radiative transfer through the cores and disks produced by the recent radiation-hydrodynamic simulations of Krumholz, Klein, & McKee. We find that in several representative lines the disks show brightness temperatures of hundreds of Kelvin over velocity channels {approx} 10 km s{sup -1} wide, extending over regions hundreds of AU in size. We process the computed intensities to model the performance of next-generation radio and submillimeter telescopes. Our calculations show that observations using facilities such as the EVLA and ALMA should be able to detect massive protostellar disks and measure their rotation curves, at least in the nearest massive star-forming regions. They should also detect significant sub-structure and non-axisymmetry in the disks, and in some cases may be able to detect star-disk velocity offsets of a few km s{sup -1}, both of which are the result of strong gravitational instability in massive disks. We use our simulations to explore the strengths and weaknesses of different observational techniques, and we also discuss how observations of massive protostellar disks may be used to distinguish between alternative models of massive star formation.
Date: May 7, 2007
Creator: Krumholz, M R; Klein, R I & McKee, C F
Object Type: Article
System: The UNT Digital Library
SERDP ER-1376 Enhancement of In Situ Bioremediation of Energetic Compounds by Coupled Abiotic/Biotic Processes:Final Report for 2004 - 2006 (open access)

SERDP ER-1376 Enhancement of In Situ Bioremediation of Energetic Compounds by Coupled Abiotic/Biotic Processes:Final Report for 2004 - 2006

This project was initiated by SERDP to quantify processes and determine the effectiveness of abiotic/biotic mineralization of energetics (RDX, HMX, TNT) in aquifer sediments by combinations of biostimulation (carbon, trace nutrient additions) and chemical reduction of sediment to create a reducing environment. Initially it was hypothesized that a balance of chemical reduction of sediment and biostimulation would increase the RDX, HMX, and TNT mineralization rate significantly (by a combination of abiotic and biotic processes) so that this abiotic/biotic treatment may be a more efficient for remediation than biotic treatment alone in some cases. Because both abiotic and biotic processes are involved in energetic mineralization in sediments, it was further hypothesized that consideration for both abiotic reduction and microbial growth was need to optimize the sediment system for the most rapid mineralization rate. Results show that there are separate optimal abiotic/biostimulation aquifer sediment treatments for RDX/HMX and for TNT. Optimal sediment treatment for RDX and HMX (which have chemical similarities and similar degradation pathways) is mainly chemical reduction of sediment, which increased the RDX/HMX mineralization rate 100 to150 times (relative to untreated sediment), with additional carbon or trace nutrient addition, which increased the RDX/HMX mineralization rate an additional 3 to 4 …
Date: August 7, 2007
Creator: Szecsody, James E.; Comfort, Steve; Fredrickson, Herbert L.; Boparai, Hardiljeet K.; Devary, Brooks J.; Thompson, Karen T. et al.
Object Type: Report
System: The UNT Digital Library
EFFECTS OF ONE WEEK TRITIUM EXPOSURE ON EPDM ELASTOMER (open access)

EFFECTS OF ONE WEEK TRITIUM EXPOSURE ON EPDM ELASTOMER

This report documents test results for the exposure of four formulations of EPDM (ethylene-propylene diene monomer) elastomer to tritium gas at one atmosphere for approximately one week and characterization of material property changes and changes to the exposure gas during exposure. All EPDM samples were provided by Los Alamos National Laboratory (LANL). Material properties that were characterized include mass, sample dimensions, appearance, flexibility, and dynamic mechanical properties. The glass transition temperature was determined by analysis of the dynamic mechanical property data per ASTM standards. No change of glass transition temperature due to the short tritium gas exposure was observed. Filled and unfilled formulations of Dupont{reg_sign} Nordel{trademark} 1440 had a slightly higher glass transition temperature than filled and unfilled formulations of Uniroyal{reg_sign} Royalene{reg_sign} 580H; filled formulations had the same glass transition as unfilled. The exposed samples appeared the same as before exposure--there was no evidence of discoloration, and no residue on stainless steel spacers contacting the samples during exposure was observed. The exposed samples remained flexible--all formulations passed a break test without failing. The unique properties of polymers make them ideal for certain components in gas handling systems. Specifically, the resiliency of elastomers is ideal for sealing surfaces, for example in …
Date: June 7, 2007
Creator: Clark, E
Object Type: Report
System: The UNT Digital Library
Technical Safety Requirements for the B695 Segment of the Decontamination and Waste Treatment Facility (open access)

Technical Safety Requirements for the B695 Segment of the Decontamination and Waste Treatment Facility

This document contains Technical Safety Requirements (TSRs) for the Radioactive and Hazardous Waste Management (RHWM) Division's B695 Segment of the Decontamination and Waste Treatment Facility (DWTF) at Lawrence Livermore National Laboratory (LLNL). The TSRs constitute requirements regarding the safe operation of the B695 Segment of the DWTF. The TSRs are derived from the Documented Safety Analysis (DSA) for the B695 Segment of the DWTF (LLNL 2004). The analysis presented there determined that the B695 Segment of the DWTF is a low-chemical hazard, Hazard Category 3, nonreactor nuclear facility. The TSRs consist primarily of inventory limits as well as controls to preserve the underlying assumptions in the hazard analyses. Furthermore, appropriate commitments to safety programs are presented in the administrative controls section of the TSRs. The B695 Segment of the DWTF (B695 and the west portion of B696) is a waste treatment and storage facility located in the northeast quadrant of the LLNL main site. The approximate area and boundary of the B695 Segment of the DWTF are shown in the B695 Segment of the DWTF DSA. Activities typically conducted in the B695 Segment of the DWTF include container storage, lab-packing, repacking, overpacking, bulking, sampling, waste transfer, and waste treatment. B695 …
Date: September 7, 2007
Creator: Larson, H L
Object Type: Report
System: The UNT Digital Library
Proton hexality from an anomalous flavor U(1) and neutrino masses--Linking to the string scale (open access)

Proton hexality from an anomalous flavor U(1) and neutrino masses--Linking to the string scale

We devise minimalistic gauged U(1)_X Froggatt-Nielsen models which at low-energy give rise to the recently suggested discrete gauge Z_6 symmetry, proton hexality, thus stabilizing the proton. Assuming three generations of right-handed neutrinos, with the proper choice of X-charges, we obtain viable neutrino masses. Furthermore, we find scenarios such that no X-charged hidden sector superfields are needed, which from a bottom-up perspective allows the calculation of g_string, g_X and G_SM's Kac-Moody levels. The only mass scale apart from M_grav is m_soft.
Date: August 7, 2007
Creator: Murayama, Hitoshi; Dreiner, Herbi K.; Luhn, Christoph; Murayama, Hitoshi & Thormeiere, Marc
Object Type: Article
System: The UNT Digital Library
TreeQ-VISTA: An Interactive Tree Visualization Tool with Functional Annotation Query Capabilities (open access)

TreeQ-VISTA: An Interactive Tree Visualization Tool with Functional Annotation Query Capabilities

Summary: We describe a general multiplatform exploratorytool called TreeQ-Vista, designed for presenting functional annotationsin a phylogenetic context. Traits, such as phenotypic and genomicproperties, are interactively queried from a relational database with auser-friendly interface which provides a set of tools for users with orwithout SQL knowledge. The query results are projected onto aphylogenetic tree and can be displayed in multiple color groups. A richset of browsing, grouping and query tools are provided to facilitatetrait exploration, comparison and analysis.Availability: The program,detailed tutorial and examples are available online athttp://genome-test.lbl.gov/vista/TreeQVista.
Date: May 7, 2007
Creator: Gu, Shengyin; Anderson, Iain; Kunin, Victor; Cipriano, Michael; Minovitsky, Simon; Weber, Gunther et al.
Object Type: Article
System: The UNT Digital Library
Surveillance of Site A and Plot M - Report for 2006. (open access)

Surveillance of Site A and Plot M - Report for 2006.

The results of the environmental surveillance program conducted at Site A/Plot M in the Palos Forest Preserve area for Calendar Year 2006 are presented. Based on the results of the 1976-1978 radiological characterization of the site, a determination was made that a surveillance program be established. The characterization study determined that very low levels of hydrogen-3 (as tritiated water) had migrated from the burial ground and were present in two nearby hand-pumped picnic wells. The current surveillance program began in 1980 and consists of sample collection and analysis of surface and subsurface water. The results of the analyses are used to (1) monitor the migration pathway of water from the burial ground (PlotM) to the hand pumped picnic wells, (2) establish if buried radionuclides other than hydrogen-3 have migrated, and (3) monitor the presence of radioactive and chemically hazardous materials in the environment of the area. Hydrogen-3 in the Red GateWoods picnic wells was still detected this year, but the average and maximum concentrations were significantly less than found earlier. Hydrogen-3 continues to be detected in a number of wells, boreholes, dolomite holes, and a surface stream. Analyses since 1984 have indicated the presence of low levels of strontium-90 in …
Date: May 7, 2007
Creator: Golchert, N. W. & Oversight, ESH /QA
Object Type: Report
System: The UNT Digital Library
CHARACTERIZATION OF TANK 50 SLURRY FOR SALTSTONE WASTE ACCEPTANCE CRITERIA, APRIL 2007 SAMPLES (open access)

CHARACTERIZATION OF TANK 50 SLURRY FOR SALTSTONE WASTE ACCEPTANCE CRITERIA, APRIL 2007 SAMPLES

This report summarizes the results from the characterization of the second quarter April 2007 sampling of Tank 50H for the Saltstone Waste Acceptance Criteria (WAC). Six one liter samples were taken in polyethylene bottles to analyze for the WAC contaminants and a 200 mL sample was taken in a steel container for analysis of volatile organic compounds. The information from this characterization will be given to Waste Solidification Engineering personnel to qualify the transfer of aqueous waste to the Saltstone Facility. The following conclusions are drawn from the analytical results found in this report: (1) All six of the one liter samples taken in April 2007 from the mixed slurry in Tank 50 have the same compositions within the experimental uncertainty of the analyses. (2) Of the ninety-one process, chemical, and radioactive WAC target or limit contaminants listed in Revision 7 of the 'Waste Acceptance Criteria for Aqueous Waste sent to the Z-Area Saltstone Production Facility', eighty-nine had concentrations that were unequivocally less than the WAC limit or target. (3) The two contaminants whose concentrations could not be shown to be less than their WAC targets were methanol and radioactive Nb-93m. Currently the AD Section of SRNL does not have …
Date: December 7, 2007
Creator: Zeigler, K; Ned Bibler, N & David Diprete, D
Object Type: Report
System: The UNT Digital Library
Interspecific Comparison and annotation of two complete mitochondrial genome sequences from the plant pathogenic fungus Mycosphaerella graminicola (open access)

Interspecific Comparison and annotation of two complete mitochondrial genome sequences from the plant pathogenic fungus Mycosphaerella graminicola

The mitochondrial genomes of two isolates of the wheat pathogen Mycosphaerella graminicola were sequenced completely and compared to identify polymorphic regions. This organism is of interest because it is phylogenetically distant from other fungi with sequenced mitochondrial genomes and it has shown discordant patterns of nuclear and mitochondrial diversity. The mitochondrial genome of M. graminicola is a circular molecule of approximately 43,960 bp containing the typical genes coding for 14 proteins related to oxidative phosphorylation, one RNA polymerase, two rRNA genes and a set of 27 tRNAs. The mitochondrial DNA of M. graminicola lacks the gene encoding the putative ribosomal protein (rps5-like), commonly found in fungal mitochondrial genomes. Most of the tRNA genes were clustered with a gene order conserved with many other ascomycetes. A sample of thirty-five additional strains representing the known global mt diversity was partially sequenced to measure overall mitochondrial variability within the species. Little variation was found, confirming previous RFLP-based findings of low mitochondrial diversity. The mitochondrial sequence of M. graminicola is the first reported from the family Mycosphaerellaceae or the order Capnodiales. The sequence also provides a tool to better understand the development of fungicide resistance and the conflicting pattern of high nuclear and low …
Date: December 7, 2007
Creator: Millenbaugh, Bonnie A; Pangilinan, Jasmyn L.; Torriani, Stefano F.F.; Goodwin, Stephen B.; Kema, Gert H.J. & McDonald, Bruce A.
Object Type: Article
System: The UNT Digital Library
Verification of Gyrokinetic (delta)f Simulations of Electron Temperature Gradient Turbulence (open access)

Verification of Gyrokinetic (delta)f Simulations of Electron Temperature Gradient Turbulence

The GEM gyrokinetic {delta}f simulation code [Chen, 2003] [Chen, 2007] is shown to reproduce electron temperature gradient turbulence at the benchmark operating point established in previous work [Nevins, 2006]. The electron thermal transport is within 10% of the expected value, while the turbulent fluctuation spectrum is shown to have the expected intensity and two-point correlation function.
Date: May 7, 2007
Creator: Nevins, W. M.; Parker, S. E.; Chen, Y.; Candy, J.; Dimits, A.; Dorland, W. et al.
Object Type: Article
System: The UNT Digital Library
ANALYTICAL METHOD FOR MEASURING TOTAL PROTIUM AND TOTAL DEUTERIUM IN A GAS MIXTURE CONTAINING H2, D2,AND HD VIA GAS CHAROMATOGRAPHY (open access)

ANALYTICAL METHOD FOR MEASURING TOTAL PROTIUM AND TOTAL DEUTERIUM IN A GAS MIXTURE CONTAINING H2, D2,AND HD VIA GAS CHAROMATOGRAPHY

The most common analytical method of identifying and quantifying non-radioactive isotopic species of hydrogen is mass spectrometry. A low mass, high resolution mass spectrometer with adequate sensitivity and stability to identify and quantify hydrogen isotopes in the low ppm range is an expensive, complex instrument. A new analytical technique has been developed that measures both total protium (H) and total deuterium (D) in a gas mixture containing H{sub 2}, D{sub 2}, and HD using an inexpensive micro gas chromatograph (GC) with two molecular sieve columns. One column uses D{sub 2} as the carrier gas and the other uses H{sub 2} as the carrier gas. Laboratory tests have shown that when used in this configuration the GC can measure both total protium and total deuterium each with a detection and quantification limit of less than 20 ppm.
Date: August 7, 2007
Creator: Sessions, H
Object Type: Article
System: The UNT Digital Library
Robustness Studies of Ignition Targets for the National Ignition Facility in Two Dimensions (open access)

Robustness Studies of Ignition Targets for the National Ignition Facility in Two Dimensions

Inertial confinement fusion capsules are critically dependent on the integrity of their hot spots to ignite. At the time of ignition, only a certain fractional perturbation of the nominally spherical hot spot boundary can be tolerated and the capsule still achieve ignition. The degree to which the expected hot spot perturbation in any given capsule design is less than this maximum tolerable perturbation is a measure of the ignition margin or robustness of that design. Moreover, since there will inevitably be uncertainties in the initial character and implosion dynamics of any given capsule, all of which can contribute to the eventual hot spot perturbation, quantifying the robustness of that capsule against a range of parameter variations is an important consideration in the capsule design. Here, the robustness of the 300 eV indirect drive target design for the National Ignition Facility [J. D. Lindl, et al., Phys. Plasmas 11, 339 (2004)] is studied in the parameter space of inner ice roughness, implosion velocity, and capsule scale. A suite of two thousand two-dimensional simulations, run with the radiation hydrodynamics code Lasnex, is used as the data base for the study. For each scale, an ignition region in the two remaining variables is …
Date: November 7, 2007
Creator: Clark, D S; Haan, S W & Salmonson, J D
Object Type: Article
System: The UNT Digital Library
On the Use of Rossi Alpha Critical Assembly Measurements for Validating and Constraining Nuclear Data (open access)

On the Use of Rossi Alpha Critical Assembly Measurements for Validating and Constraining Nuclear Data

Critical assemblies are exquisitely sensitive to details of the microscopic nuclear reactions that govern neutron multiplication. For this reason experimental studies of critical assemblies represent a cornerstone in the process of validating nuclear data. Several different characteristics of a critical system can be measured. The most commonly considered is the so-called effective k eigenvalue, k{sub eff}. Another well-measured property of these systems is {alpha}{sub 0}, the inverse e-folding time of the neutron population in the absence of {beta}-delayed neutrons. Through Monte Carlo calculations and appear to perturbation theory they show that for fast critical systems {alpha}{sub 0} and k{sub eff} can be viewed as lying on a single straight line for any reasonable assumptions about the underlying nuclear data. This means that the two quantities provide the same constraint on nuclear data. In principle, {alpha}{sub 0} could be associated with a very small uncertainty, and this would make the measurements for neutron multiplication rates more useful than k{sub eff} for constraining nuclear data. In practice, though, uncertainties in k{sub eff} and {alpha}{sub 0} are dominated by uncertainties in the representation of the critical system, and not by pure measurement errors for these quantities. This, together with the linear relation between …
Date: March 7, 2007
Creator: Pruet, J & Sleaford, B
Object Type: Report
System: The UNT Digital Library
Predictive three dimensional modeling of Stimulated Brillouin Scattering in ignition-scale experiments (open access)

Predictive three dimensional modeling of Stimulated Brillouin Scattering in ignition-scale experiments

The first three-dimensional (3D) simulations of a high power 0.351 {micro}m laser beam propagating through a high temperature hohlraum plasma are reported. We show that 3D linear kinetic modeling of Stimulated Brillouin scattering reproduces quantitatively the experimental measurements, provided it is coupled to detailed hydrodynamics simulation and a realistic description of the laser beam from its millimeter-size envelop down to the micron scale speckles. These simulations accurately predict the strong reduction of SBS measured when polarization smoothing is used.
Date: November 7, 2007
Creator: Divol, L; Berger, R; Meezan, N; Froula, D H; Dixit, S; Suter, L et al.
Object Type: Article
System: The UNT Digital Library
Demonstrating fractal scaling of residence time distributions on the catchment scale using a fully-coupled, variably-saturated groundwater and land surface model and a Lagrangian particle tracking approach (open access)

Demonstrating fractal scaling of residence time distributions on the catchment scale using a fully-coupled, variably-saturated groundwater and land surface model and a Lagrangian particle tracking approach

The influence of the vadose zone, land surface processes, and macrodispersion on scaling behavior of residence time distributions (RTDs) is studied using a fully coupled watershed model in conjunction with a Lagrangian, particle-tracking approach. Numerical experiments are used to simulate groundwater flow paths from recharge locations along the hillslope to the streambed. These experiments are designed to isolate the influences of topography, vadose zone/land surface processes, and macrodispersion on subsurface RTDs of tagged parcels of water. The results of these simulations agree with previous observations that RTDs exhibit fractal behavior, which can be identified from the power spectra. For cases incorporating residence times that are influenced by vadose zone/land surface processes, increasing macrodispersion increases the slope of the power spectra. In general the opposite effect is demonstrated if the vadose zone/land surface processes are neglected. The concept of the spectral slope being a measure of stationarity is raised and discussed.
Date: November 7, 2007
Creator: Kollet, S J & Maxwell, R M
Object Type: Article
System: The UNT Digital Library
The Zeta Potential of Surface-Functionalized Metallic Nanorod Particles in Aqueous Solution (open access)

The Zeta Potential of Surface-Functionalized Metallic Nanorod Particles in Aqueous Solution

Metallic nanoparticles suspended in aqueous solutions, and functionalized with chemical and biological surface coatings, are important elements in basic and applied nanoscience research. Many applications require an understanding of the electrokinetic or colloidal properties of such particles. In this paper we describe the results of experiments to measure the zeta potential of metallic nanorod particles in aqueous saline solutions, including the effects of pH, ionic strength, metallic composition, and surface functionalization state. Particle substrates tested include gold, silver, and palladium monometallic particles as well as gold/silver bimetallic particles. Surface functionalization conditions included 11-mercaptoundecanoic acid (MUA), mercaptoethanol (ME), and mercaptoethanesulfonic acid (MESA) self-assembled monolayers (SAMs), as well as MUA layers subsequently derivatized with proteins. Zeta potential data for typical charge-stabilized polystyrene particles are also presented for comparison. Experimental data are compared with theory. The results of these studies are useful in predicting and controlling the aggregation, adhesion, and transport of functionalized metallic nanoparticles within microfluidic devices and other systems.
Date: May 7, 2007
Creator: Dougherty, G M; Rose, K A; Tok, J B; Pannu, S S; Chuang, F S; Sha, M Y et al.
Object Type: Article
System: The UNT Digital Library
Fast Electron Generation in Cones with Ultra-Intense Laser Pulses (open access)

Fast Electron Generation in Cones with Ultra-Intense Laser Pulses

Experimental results from copper cones irradiated with ultra-intense laser light are presented. Spatial images and total yields of Cu K{sub {alpha}} fluorescence were measured as a function of the laser focusing properties. The fluorescence emission extends into the cone approximately 300 {micro}m from the cone tip and cannot be explained by ray tracing including cone wall absorption. In addition the total fluorescence yield from cones is an order of magnitude higher than for equivalent mass foil targets. Indications are that the physics of the laser cone interaction is dominated by preplasma created from the long duration, low energy pre-pulse from the laser.
Date: December 7, 2007
Creator: Mackinnon, A.; VanWoerkom, L.; Akli, K.; Bartal, T.; Beg, F.; Chawla, S. et al.
Object Type: Article
System: The UNT Digital Library
Flow of mantle fluids through the ductile lower crust: Heliumisotope trends (open access)

Flow of mantle fluids through the ductile lower crust: Heliumisotope trends

Heat and mass are injected into the shallow crust when mantle fluids are able to flow through the ductile lower crust. Minimum 3He/4He ratios in surface fluids from the northern Basin and Range province, western North America increase systematically from low, crustal values in the east to high, mantle values in the west, a regional trend that correlates with the rates of active crustal deformation. The highest ratios occur where the extension and shear strain rates are greatest. The correspondence of helium isotope ratios and active trans-tensional deformation indicates a deformation enhanced permeability and that mantle fluids can penetrate the ductile lithosphere in regions even where there is no significant magmatism. Superimposed on the regional trend are local, high-{sup 3}He/{sup 4}He anomalies signifying hidden magmatic activity and/or deep fluid production with locally enhanced permeability, identifying zones with high resource potential, particularly for geothermal energy development.
Date: October 7, 2007
Creator: Kennedy, B. Mack & van Soest, Matthijs C.
Object Type: Article
System: The UNT Digital Library
Revised─Confirmatory Survey Report for Portions of the Auxiliary Building Structural Surfaces and Turbine Building Embedded Piping, Rancho Seco Nuclear Generating Station, Herald, California (open access)

Revised─Confirmatory Survey Report for Portions of the Auxiliary Building Structural Surfaces and Turbine Building Embedded Piping, Rancho Seco Nuclear Generating Station, Herald, California

During the period of October 15 and 18, 2007, ORISE performed confirmatory radiological survey activities which included beta and gamma structural surface scans and beta activity direct measurements within the Auxiliary Building, beta or gamma scans within Turbine Building embedded piping, beta activity determinations within Turbine Building Drain 3-1-27, and gamma scans and the collection of a soil sample from the clay soils adjacent to the Lower Mixing Box.
Date: December 7, 2007
Creator: Adams, W. C.
Object Type: Report
System: The UNT Digital Library
A Study of the Dielectric Properties of Dry and Saturated Green River Oil Shale (open access)

A Study of the Dielectric Properties of Dry and Saturated Green River Oil Shale

We measured dielectric permittivity of dry and fluid-saturated Green River oil shale samples over a frequency range of 1 MHz to 1.8 GHz. Dry sample measurements were carried out between room temperature and 146 C, saturated sample measurements were carried out at room temperature. Samples obtained from the Green River formation of Wyoming and from the Anvil Points Mine in Colorado were cored both parallel and perpendicular to layering. The samples, which all had organic richness in the range of 10-45 gal/ton, showed small variations between samples and a relatively small level of anisotropy of the dielectric properties when dry. The real and imaginary part of the relative dielectric permittivity of dry rock was nearly constant over the frequency range observed, with low values for the imaginary part (loss factor). Saturation with de-ionized water and brine greatly increased the values of the real and imaginary parts of the relative permittivity, especially at the lower frequencies. Temperature effects were relatively small, with initial increases in permittivity to about 60 C, followed by slight decreases in permittivity that diminished as temperature increased. Implications of these observations for the in situ electromagnetic, or radio frequency (RF) heating of oil shale to produce oil …
Date: February 7, 2007
Creator: Sweeney, J.; Roberts, J. & Harben, P.
Object Type: Article
System: The UNT Digital Library
Extension of the operating parameters of the two stage light gas gun to velocities below 2 km/sec (open access)

Extension of the operating parameters of the two stage light gas gun to velocities below 2 km/sec

None
Date: September 7, 2007
Creator: Thoe, R S
Object Type: Article
System: The UNT Digital Library
NMR structure of the N-terminal domain of the replication initiator protein DnaA (open access)

NMR structure of the N-terminal domain of the replication initiator protein DnaA

DnaA is an essential component in the initiation of bacterial chromosomal replication. DnaA binds to a series of 9 base pair repeats leading to oligomerization, recruitment of the DnaBC helicase, and the assembly of the replication fork machinery. The structure of the N-terminal domain (residues 1-100) of DnaA from Mycoplasma genitalium was determined by NMR spectroscopy. The backbone r.m.s.d. for the first 86 residues was 0.6 +/- 0.2 Angstrom based on 742 NOE, 50 hydrogen bond, 46 backbone angle, and 88 residual dipolar coupling restraints. Ultracentrifugation studies revealed that the domain is monomeric in solution. Features on the protein surface include a hydrophobic cleft flanked by several negative residues on one side, and positive residues on the other. A negatively charged ridge is present on the opposite face of the protein. These surfaces may be important sites of interaction with other proteins involved in the replication process. Together, the structure and NMR assignments should facilitate the design of new experiments to probe the protein-protein interactions essential for the initiation of DNA replication.
Date: August 7, 2007
Creator: Wemmer, David E.; Lowery, Thomas J.; Pelton, Jeffrey G.; Chandonia, John-Marc; Kim, Rosalind; Yokota, Hisao et al.
Object Type: Article
System: The UNT Digital Library
Simple Model Representations of Transport in a Complex Fracture and Their Effects on Long-Term Predictions (open access)

Simple Model Representations of Transport in a Complex Fracture and Their Effects on Long-Term Predictions

A complex fracture model for fluid flow and tracer transport was previously developed that incorporates many of the important physical effects of a realistic fracture, including advection through a heterogeneous fracture plane, partitioning of flow into multiple subfractures in the third dimension, and diffusion and sorption into fracture-filling gouge, small altered rock matrix blocks within the fracture zone, and the unaltered semi-infinite rock matrix on both sides of the fracture zone (Tsang and Doughty, 2003). It is common, however, to represent the complex fracture by much simpler models consisting of a single fracture, with a uniform or heterogeneous transmissivity distribution over its plane and bounded on both sides by a homogeneous semi-infinite matrix. Simple-model properties are often inferred from the analysis of short-term (one to a few days) site characterization (SC) tracer-test data. The question addressed in this paper is: How reliable is the temporal upscaling of these simplified models? Are they adequate are for long-term calculations that cover thousands of years? In this study, a particle-tracking approach is used to calculate tracer-test breakthrough curves (BTCs) in a complex fracture model, incorporating all the features described above, for both a short-term SC tracer test and a 10,000-year calculation. The results …
Date: November 7, 2007
Creator: Doughty, Christine; Tsang, Chin-Fu; Doughty, Christine & Uchida, Masahiro
Object Type: Article
System: The UNT Digital Library