Maltose Biochemistry and Transport in Plant Leaves (open access)

Maltose Biochemistry and Transport in Plant Leaves

Transitory starch builds up in photosynthesizing leaves during the day and is then degraded each night. It has recently been shown through mutant analysis and genetically engineered plants that transitory starch is required for maximal rates of photosynthesis, especially in high carbon dioxide atmospheres. Understanding the pathway by which carbon is exported from chloroplasts at night is limited. Previous work has shown that starch conversion to sucrose at night involves maltose export from chloroplasts. This pathway for carbon export from chloroplasts normally does not occur during the day. The regulation of maltose formation, the transporters that allow export of maltose from the chloroplast, and the cytosolic reactions by which maltose is converted to sucrose remain obscure. Genomic and biochemical approaches are proposed here to address maltose metabolism and transport. The research will cover three areas (1) how are hydrolytic and phosphorylytic starch degradation regulated, (2) how is maltose exported from chloroplasts, and (3) how is maltose converted to sucrose in the cytosol? It is expected that this research will lead to new insights about photosynthesis at high carbon dioxide levels, how carbon is partitioned in plants, and how partitioning can be altered to adapt plants to human needs.
Date: April 25, 2008
Creator: Weber, Andreas P.M.
Object Type: Report
System: The UNT Digital Library
Advanced Simulation and Computing FY08-09 Implementation Plan Volume 2 Revision 0 (open access)

Advanced Simulation and Computing FY08-09 Implementation Plan Volume 2 Revision 0

The Stockpile Stewardship Program (SSP) is a single, highly integrated technical program for maintaining the safety and reliability of the U.S. nuclear stockpile. The SSP uses past nuclear test data along with current and future nonnuclear test data, computational modeling and simulation, and experimental facilities to advance understanding of nuclear weapons. It includes stockpile surveillance, experimental research, development and engineering programs, and an appropriately scaled production capability to support stockpile requirements. This integrated national program requires the continued use of current facilities and programs along with new experimental facilities and computational enhancements to support these programs. The Advanced Simulation and Computing Program (ASC) is a cornerstone of the SSP, providing simulation capabilities and computational resources to support the annual stockpile assessment and certification, to study advanced nuclear-weapons design and manufacturing processes, to analyze accident scenarios and weapons aging, and to provide the tools to enable Stockpile Life Extension Programs (SLEPs) and the resolution of Significant Finding Investigations (SFIs). This requires a balanced resource, including technical staff, hardware, simulation software, and computer science solutions. In its first decade, the ASC strategy focused on demonstrating simulation capabilities of unprecedented scale in three spatial dimensions. In its second decade, ASC is focused on …
Date: April 25, 2007
Creator: McCoy, M; Kusnezov, D; Bikkel, T & Hopson, J
Object Type: Report
System: The UNT Digital Library
Initial Report on the Development of a Monte Carlo-Markov Chain Joint Inversion Approach for Geothermal Exploration (open access)

Initial Report on the Development of a Monte Carlo-Markov Chain Joint Inversion Approach for Geothermal Exploration

Geothermal exploration and subsequent characterization of potential resources typically employ a variety of geophysical, geologic and geochemical techniques. However, since the data collected by each technique provide information directly on only one or a very limited set of the many physical parameters that characterize a geothermal system, no single method can be used to describe the system in its entirety. Presently, the usual approach to analyzing disparate data streams for geothermal applications is to invert (or forward model) each data set separately and then combine or compare the resulting models, for the most part in a more or less ad hoc manner. However, while each inversion may yield a model that fits the individual data set, the models are usually inconsistent with each other to some degree. This reflects uncertainties arising from the inevitable fact that geophysical and other exploration data in general are to some extent noisy, incomplete, and of limited sensitivity and resolution, and so yield non-unique results. The purpose of the project described here is to integrate the different model constraints provided by disparate geophysical, geological and geochemical data in a rigorous and consistent manner by formal joint inversion. The objective is to improve the fidelity of …
Date: April 25, 2007
Creator: Foxall, W; Ramirez, A; Carlson, S; Dyer, K & Sun, Y
Object Type: Report
System: The UNT Digital Library
Protocols for Monitoring Habitat Restoration Projects in the Lower Columbia River and Estuary (open access)

Protocols for Monitoring Habitat Restoration Projects in the Lower Columbia River and Estuary

Protocols for monitoring salmon habitat restoration projects are essential for the U.S. Army Corps of Engineers' environmental efforts in the Columbia River estuary. This manual provides state-of-the science data collection and analysis methods for landscape features, water quality, and fish species composition, among others.
Date: April 25, 2008
Creator: Roegner, G. Curtis; Diefenderfer, Heida L.; Borde, Amy B.; Thom, Ronald M.; Dawley, Earl M.; Whiting, Allan H. et al.
Object Type: Report
System: The UNT Digital Library
SEISMIC DESIGN REQUIREMENTS SELECTION METHODOLOGY FOR THE SLUDGE TREATMENT & M-91 SOLID WASTE PROCESSING FACILITIES PROJECTS (open access)

SEISMIC DESIGN REQUIREMENTS SELECTION METHODOLOGY FOR THE SLUDGE TREATMENT & M-91 SOLID WASTE PROCESSING FACILITIES PROJECTS

In complying with direction from the U.S. Department of Energy (DOE), Richland Operations Office (RL) (07-KBC-0055, 'Direction Associated with Implementation of DOE-STD-1189 for the Sludge Treatment Project,' and 08-SED-0063, 'RL Action on the Safety Design Strategy (SDS) for Obtaining Additional Solid Waste Processing Capabilities (M-91 Project) and Use of Draft DOE-STD-I 189-YR'), it has been determined that the seismic design requirements currently in the Project Hanford Management Contract (PHMC) will be modified by DOE-STD-1189, Integration of Safety into the Design Process (March 2007 draft), for these two key PHMC projects. Seismic design requirements for other PHMC facilities and projects will remain unchanged. Considering the current early Critical Decision (CD) phases of both the Sludge Treatment Project (STP) and the Solid Waste Processing Facilities (M-91) Project and a strong intent to avoid potentially costly re-work of both engineering and nuclear safety analyses, this document describes how Fluor Hanford, Inc. (FH) will maintain compliance with the PHMC by considering both the current seismic standards referenced by DOE 0 420.1 B, Facility Safety, and draft DOE-STD-1189 (i.e., ASCE/SEI 43-05, Seismic Design Criteria for Structures, Systems, and Components in Nuclear Facilities, and ANSI!ANS 2.26-2004, Categorization of Nuclear Facility Structures, Systems and Components for Seismic …
Date: April 25, 2008
Creator: GW, RYAN
Object Type: Report
System: The UNT Digital Library
Design and Implementation of a Facility for Discovering New Scintillator Materials (open access)

Design and Implementation of a Facility for Discovering New Scintillator Materials

We describe the design and operation of a high-throughput facility for synthesizing thousands of inorganic crystalline samples per year and evaluating them as potential scintillation detector materials. This facility includes a robotic dispenser, arrays of automated furnaces, a dual-beam X-ray generator for diffractometery and luminescence spectroscopy, a pulsed X-ray generator for time response measurements, computer-controlled sample changers, an optical spectrometer, and a network-accessible database management system that captures all synthesis and measurement data.
Date: April 25, 2008
Creator: Derenzo, Stephen; Derenzo, Stephen E; Boswell, Martin S.; Bourret-Courchesne, Edith; Boutchko, Rostyslav; Budinger, Thomas F. et al.
Object Type: Article
System: The UNT Digital Library
Technical Equivalency Documentation for a Newly Aquired Alpha Spectroscopy System (open access)

Technical Equivalency Documentation for a Newly Aquired Alpha Spectroscopy System

The response of a recently acquired Canberra{trademark} Alpha Analyst 'Blue' system (Chamber Number's 173-208) used by the Hazards Control, Radiation Safety Section, WBC/Spectroscopy Team has been studied with respect to an existing Canberra system. The existing Canberra system consists of thirty Alpha Analyst dual chambers Model XXXX comprising a total of sixty detectors (Chambers Number's 101-124 and 137-172). The existing chambers were previously compared to an older system consisting of thirty-six Model 7401 alpha spectrometry chambers (Chamber Number's 1-36) Chambers 101-124 and 137-172 are DOELAP accredited. The older system was previously DOELAP accredited for the routine Alpha Spectroscopy program used in LLNL's in vitro bioassay program. The newly acquired Alpha Analyst system operates on a network with software that controls and performs analysis of the current Alpha Analyst system (Chamber Number's 101-124 and 137-172). This exact same software is used for the current system and the newly acquired system and is DOELAP accredited. This document compares results from the existing Alpha System with the newer Alpha Analyst system.
Date: April 25, 2007
Creator: Hickman, D P; Fisher, S K; Hann, P R & Hume, R
Object Type: Report
System: The UNT Digital Library
Method for high temperature mercury capture from gas streams (open access)

Method for high temperature mercury capture from gas streams

A process to facilitate mercury extraction from high temperature flue/fuel gas via the use of metal sorbents which capture mercury at ambient and high temperatures. The spent sorbents can be regenerated after exposure to mercury. The metal sorbents can be used as pure metals (or combinations of metals) or dispersed on an inert support to increase surface area per gram of metal sorbent. Iridium and ruthenium are effective for mercury removal from flue and smelter gases. Palladium and platinum are effective for mercury removal from fuel gas (syngas). An iridium-platinum alloy is suitable for metal capture in many industrial effluent gas streams including highly corrosive gas streams.
Date: April 25, 2006
Creator: Granite, E. J. & Pennline, H. W.
Object Type: Patent
System: The UNT Digital Library
A Filtering Method For Gravitationally Stratified Flows (open access)

A Filtering Method For Gravitationally Stratified Flows

Gravity waves arise in gravitationally stratified compressible flows at low Mach and Froude numbers. These waves can have a negligible influence on the overall dynamics of the fluid but, for numerical methods where the acoustic waves are treated implicitly, they impose a significant restriction on the time step. A way to alleviate this restriction is to filter out the modes corresponding to the fastest gravity waves so that a larger time step can be used. This paper presents a filtering strategy of the fully compressible equations based on normal mode analysis that is used throughout the simulation to compute the fast dynamics and that is able to damp only fast gravity modes.
Date: April 25, 2005
Creator: Gatti-Bono, Caroline & Colella, Phillip
Object Type: Report
System: The UNT Digital Library
Fundamental Optical Processes in Semiconductors (open access)

Fundamental Optical Processes in Semiconductors

None
Date: April 25, 2008
Creator: Wang, H. & Binder, R.
Object Type: Report
System: The UNT Digital Library
Chemical Bonding and Structural Information of Black Carbon Reference Materials and Individual Carbonaceous Atmospheric Aerosols (open access)

Chemical Bonding and Structural Information of Black Carbon Reference Materials and Individual Carbonaceous Atmospheric Aerosols

The carbon-to-oxygen ratios and graphitic nature of a rangeof black carbon standard reference materials (BC SRMs), high molecularmass humic-like substances (HULIS) and atmospheric particles are examinedusing scanning transmission X-ray microscopy (STXM) coupled with nearedge X-ray absorption fine structure (NEXAFS) spectroscopy. UsingSTXM/NEXAFS, individual particles with diameter>100 nm are studied,thus the diversity of atmospheric particles collected during a variety offield missions is assessed. Applying a semi-quantitative peak fittingmethod to the NEXAFS spectra enables a comparison of BC SRMs and HULIS toparticles originating from anthropogenic combustion and biomass burns,thus allowing determination of the suitability of these materials forrepresenting atmospheric particles. Anthropogenic combustion and biomassburn particles can be distinguished from one another using both chemicalbonding and structural ordering information. While anthropogeniccombustion particles are characterized by a high proportion ofaromatic-C, the presence of benzoquinone and are highly structurallyordered, biomass burn particles exhibit lower structural ordering, asmaller proportion of aromatic-C and contain a much higher proportion ofoxygenated functional groups.
Date: April 25, 2007
Creator: Hopkins, Rebecca J.; Tivanski, Alexei V.; Marten, Bryan D. & Gilles, Mary K.
Object Type: Article
System: The UNT Digital Library
Summary Conclusions for the Pilot in-Situ Chromium Reduction Test at Riverbank Army Ammunitions Plant (open access)

Summary Conclusions for the Pilot in-Situ Chromium Reduction Test at Riverbank Army Ammunitions Plant

A treatability study was conducted at Riverbank Army Ammunition Plant's (RBAAP) Site 17, to evaluate the effectiveness of a permeable reactive barrier (PRB) for the treatment of hexavalent chromium (Cr{sup 6+}). The chromium contamination at Site 17 is hydrologically isolated and unsuitable for standard extraction and treatment (pump and treat). The majority of the chromium contamination at Site 17 is trapped within the fine grain sediments of a clay/slit zone (45 to 63). The PRB was established above and adjacent to the contaminated zone at Site 17 to reduce the hexavalent chromium as it leaches out of the contaminated clay/silt zone separating the A zone from the A zone. Site 17 and the monitoring network are described in the In-Situ Chromium Reduction Treatability Study Work Plan (CH2MHILL, January 2004). The PRB was created by reducing naturally occurring Fe{sup 3+} to Fe{sup 2+} with the injection of a buffered sodium dithionite solution into subsurface chromium source area. The Cr{sup 6+} leaching out of the contaminated clay/silt zone and migrating through the PRB is reduced by Fe{sup 2+} to Cr{sup 3+} and immobilized (Amonette, et al., 1994). The sodium dithionite will also reduce accessible Cr{sup 6+}, however the long-term reductant is the …
Date: April 25, 2007
Creator: Ridley, M.
Object Type: Report
System: The UNT Digital Library
Localized Electron States Near a Metal-SemiconductorNanocontact (open access)

Localized Electron States Near a Metal-SemiconductorNanocontact

The electronic structure of nanowires in contact withmetallic electrodes of experimentally relevant sizes is calculated byincorporating the electrostatic polarization potential into the atomisticsingle particle Schrodinger equation. We show that the presence of anelectrode produces localized electron/hole states near the electrode, aphenomenon only exhibited in nanostructures and overlooked in the past.This phenomenon will have profound implications on electron transport insuch nanosystems. We calculate several electrode/nanowire geometries,with varying contact depths and nanowire radii. We demonstrate the changein the band gap of up to 0.5 eV in 3 nm diameter CdSe nanowires andcalculate the magnitude of the applied electric field necessary toovercome the localization.
Date: April 25, 2007
Creator: Demchenko, Denis O. & Wang, Lin-Wang
Object Type: Article
System: The UNT Digital Library
A Gridded Electron Gun for a Sheet Beam Klystron (open access)

A Gridded Electron Gun for a Sheet Beam Klystron

This paper describes the development of an electron gun for a sheet beam klystron. Initially intended for accelerator applications, the gun can operate at a higher perveance than one with a cylindrically symmetric beam. Results of 2D and 3D simulations are discussed.
Date: April 25, 2008
Creator: Read, M. E.; Miram, G.; Ives, R. L.; Ivanov, V. & Krasnykh, A.
Object Type: Article
System: The UNT Digital Library
Spin Spectrometer at the ALS and APS (open access)

Spin Spectrometer at the ALS and APS

None
Date: April 25, 2007
Creator: Tobin, J G; Morton, S A; Yu, S W; Komesu, T; Waddill, G D & Boyd, P
Object Type: Article
System: The UNT Digital Library
Electrochemical Hydrogen Sensor for Safety Monitoring (open access)

Electrochemical Hydrogen Sensor for Safety Monitoring

A hydrogen safety sensor is presented which provides high sensitivity and fast response time when operated in air. The target application for the sensor is external deployment near systems using or producing high concentrations of hydrogen. The sensor is composed of a catalytically active metal-oxide sensing electrode and a noble metal reference electrode attached to an yttria-stabilized zirconia (YSZ) electrolyte. The sensing approach is based on the difference in oxidation rate of hydrogen on the different electrode materials. Results will be presented for a sensor using a sensing electrode of tin-doped indium oxide (ITO). Response to H{sub 2}, and cross-sensitivity to hydrocarbon and H{sub 2}O are discussed.
Date: April 25, 2003
Creator: Martin, L. P.; Pham, A. Q. & Glass, R. S.
Object Type: Article
System: The UNT Digital Library
Radiochemical Assays of Irradiated VVER-440 Fuel for Use in Spent Fuel Burnup Credit Activities (open access)

Radiochemical Assays of Irradiated VVER-440 Fuel for Use in Spent Fuel Burnup Credit Activities

The objective of this spent fuel burnup credit work was to study and describe a VVER-440 reactor spent fuel assembly (FA) initial state before irradiation, its operational irradiation history and the resulting radionuclide distribution in the fuel assembly after irradiation. This work includes the following stages: (1) to pick out and select a specific spent (irradiated) FA for examination; (2) to describe the FA initial state before irradiation; (3) to describe the irradiation history, including thermal calculations; (4) to examine the burnup distribution of select radionuclides along the FA height and cross-section; (5) to examine the radionuclide distributions; (6) to determine the Kr-85 release into the plenum; (7) to select and prepare FA rod specimens for destructive examinations; (8) to determine the radionuclide compositions, isotope masses and burnup in the rod specimens; and (9) to analyze, document and process the results. The specific workscope included the destructive assay (DA) of spent fuel assembly rod segments with an {approx}38.5 MWd/KgU burnup from a single VVER-440 fuel assembly from the Novovorenezh reactor in Russia. Based on irradiation history criteria, four rods from the fuel assembly were selected and removed from the assembly for examination. Next, 8 sections were cut from the four …
Date: April 25, 2005
Creator: Jardine, L J
Object Type: Report
System: The UNT Digital Library
Data Package for Groundwater Monitoring Well 299-W15-43 at the 200-ZP-1 Operable Unit (open access)

Data Package for Groundwater Monitoring Well 299-W15-43 at the 200-ZP-1 Operable Unit

One new groundwater monitoring well was constructed at the 200-ZP-1 Operable Unit in November 2002. This document provides the information on drilling and construction of this well. One new groundwater monitoring well was constructed in the 200-ZP-1 Operable Unit in November 2002. The purpose of the well is to monitor carbon tetrachloride concentrations in response to the 200-ZP-1 carbon tetrachloride pump-and-treat operations. The well name is 299-W15-43 and the corresponding well number is C3955. Well 299-W15-43 is located about 8 meters west of the 216-T-25 trench. The location of the well is shown on Figure 1. Well 299-W15-43 was drilled in response to the recommendations of a Data Quality Objectives process that indicated a need for additional monitoring wells in the area (BHI-01576). The new well was constructed to the specifications and requirements described in Washington Administrative Code (WAC) 173-160 and WAC 173-303, the Data Quality Objectives document (BHI-01576), and the description of work for well drilling and construction. This document compiles information on the drilling and construction, geophysical logging, and sediment and groundwater sampling applicable to the installation of well 299-W15-43. The information on drilling and construction, well development, and pump installation is summarized from CP-14265. Appendix A contains …
Date: April 25, 2003
Creator: Horton, Duane G.
Object Type: Report
System: The UNT Digital Library
Electrochemical Studies of Passive Film Stability on Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4 Amorphous Metal in Seawater at 90oCElectrochemical Studies of Passive Film Stability on Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4 Amorphous Metal in Seawater at 9 (open access)

Electrochemical Studies of Passive Film Stability on Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4 Amorphous Metal in Seawater at 90oCElectrochemical Studies of Passive Film Stability on Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4 Amorphous Metal in Seawater at 9

An iron-based amorphous metal, Fe{sub 49.7}Cr{sub 17.7}Mn{sub 1.9}Mo{sub 7.4}W{sub 1.6}B{sub 15.2}C{sub 3.8}Si{sub 2.4} (SAM2X5), with very good corrosion resistance was developed. This material was prepared as a melt-spun ribbon, as well as gas atomized powder and a thermal-spray coating. During electrochemical testing in several environments, including seawater at 90 C, the passive film stability was found to be comparable to that of high-performance nickel-based alloys, and superior to that of stainless steels, based on electrochemical measurements of the passive film breakdown potential and general corrosion rates. This material also performed very well in standard salt fog tests. Chromium (Cr), molybdenum (Mo) and tungsten (W) provided corrosion resistance, and boron (B) enabled glass formation. The high boron content of this particular amorphous metal made it an effective neutron absorber, and suitable for criticality control applications. This material and its parent alloy maintained corrosion resistance up to the glass transition temperature, and remained in the amorphous state during exposure to relatively high neutron doses.
Date: April 25, 2007
Creator: Farmer, J C; Haslam, J; Day, S D; Lian, T; Saw, C K; Hailey, P D et al.
Object Type: Report
System: The UNT Digital Library
Screening Analysis for EPACT-Covered Commercial HVAC and Water-Heating Equipment (open access)

Screening Analysis for EPACT-Covered Commercial HVAC and Water-Heating Equipment

The Energy Policy and Conservation Act (EPCA) as amended by the Energy Policy Act of 1992 (EPACT) establishes that the U.S. Department of Energy (DOE) regulate efficiency levels of certain categories of commercial heating, cooling, and water-heating equip-ment. EPACT establishes the initial minimum efficiency levels for products falling under these categories, based on ASHRAE/IES Standard 90.1-1989 requirements. EPCA states that, if ASHRAE amends Standard 90.1-1989 efficiency levels, then DOE must establish an amended uniform national manufacturing standard at the minimum level specified in the amended Standard 90.1 and that it can establish higher efficiency levels if they would result in significant additional energy savings. Standard 90.1-1999 increases minimum efficiency levels for some of the equipment categories covered by EPCA 92. DOE conducted a screening analysis to determine the energy-savings potential for EPACT-covered products meet and exceeding these levels. This paper describes the methodology, data assumptions, and results of the analysis.
Date: April 25, 2000
Creator: Somasundaram, Sriram; Armstrong, Peter R.; Belzer, David B.; Gaines, Suzanne C.; Hadley, Donald L.; Katipumula, S. et al.
Object Type: Report
System: The UNT Digital Library
Precious Metal Recovery from Fuel Cell MEA's (open access)

Precious Metal Recovery from Fuel Cell MEA's

In 2003, Engelhard Corporation received a DOE award to develop a cost-effective, environmentally friendly approach to recover Pt from fuel cell membrane electrode assemblies (MEA’s). The most important precious metal used in fuel cells is platinum, but ruthenium is also added to the anode electrocatalyst if CO is present in the hydrogen stream. As part of the project, a large number of measurements of Pt and Ru need to be made. A low-cost approach to measuring Pt is using the industry standard spectrophotometric measurement of Pt complexed with stannous chloride. The interference of Ru can be eliminated by reading the Pt absorbance at 450 nm. Spectrophotometric methods for measuring Ru, while reported in the literature, are not as robust. This paper will discuss the options for measuring Pt and Ru using the method of UV-VIS spectrophotometry
Date: April 25, 2004
Creator: Shore, Lawrence
Object Type: Article
System: The UNT Digital Library
The eukaryotic translation elongation factor eEF1A2 induces neoplastic properties and mediates tumorigenic effects of ZNF217 in precursor cells of human ovarian carcinomas (open access)

The eukaryotic translation elongation factor eEF1A2 induces neoplastic properties and mediates tumorigenic effects of ZNF217 in precursor cells of human ovarian carcinomas

Ovarian epithelial carcinomas (OEC) frequently exhibit amplifications at the 20q13 locus which is the site of several oncogenes, including the eukaryotic elongation factor EEF1A2 and the transcription factor ZNF217. We reported previously that overexpressed ZNF217 induces neoplastic characteristics in precursor cells of OEC. Unexpectedly, ZNF217, which is a transcriptional repressor, enhanced expression of eEF1A2. In this study, array comparative genomic hybridization, single nucleotide polymorphism and Affymetrix analysis of ZNF217-overexpressing cell lines confirmed consistently increased expression of eEF1A2 but not of other oncogenes, and revealed early changes in EEF1A2 gene copy numbers and increased expression at crisis during immortalization. We defined the influence of eEF1A2 overexpression on immortalized ovarian surface epithelial cells, and investigated interrelationships between effects of ZNF217 and eEF1A2 on cellular phenotypes. Lentivirally induced eEF1A2 overexpression caused delayed crisis, apoptosis resistance and increases in serum-independence, saturation densities, and anchorage independence. siRNA to eEF1A2 reversed apoptosis resistance and reduced anchorage independence in eEF1A2-overexpressing lines. Remarkably, siRNA to eEF1A2 was equally efficient in inhibiting both anchorage independence and resistance to apoptosis conferred by ZNF217 overexpression. Our data define neoplastic properties that are caused by eEF1A2 in nontumorigenic ovarian cancer precursor cells, and suggest that eEF1A2 plays a role in mediating ZNF217-induced …
Date: April 25, 2008
Creator: Sun, Yu; Wong, Nicholas; Guan, Yinghui; Salamanca, Clara M.; Cheng, Jung Chien; Lee, Jonathan M. et al.
Object Type: Article
System: The UNT Digital Library
Critical Chemical-Mechanical Couplings that Define Permeability Modifications in Pressure-Sensitive Rock Fractures (open access)

Critical Chemical-Mechanical Couplings that Define Permeability Modifications in Pressure-Sensitive Rock Fractures

This work examined and quantified processes controlling changes in the transport characteristics of natural fractures, subjected to coupled thermal-mechanical-chemical (TMC) effects. Specifically, it examined the effects of mineral dissolution and precipitation mediated by mechanical effects, using laboratory through-flow experiments concurrently imaged by X-ray CT. These were conducted on natural and artificial fractures in cores using water as the permeant. Fluid and mineral mass balances are recorded and are correlated with in-sample saturation, porosity and fracture aperture maps, acquired in real-time by X-ray CT-imaging at a maximum spatial resolution of 15-50 microns per pixel. Post-test, the samples were resin-impregnated, thin-sectioned, and examined by microscopy to define the characteristics of dissolution and precipitation. The test-concurrent X-ray imaging, mass balances, and measurements of permeability, together with the post-test microscopy, were used to define dissolution/precipitation processes, and to constrain process-based models. These models define and quantify key processes of pressure solution, free-face dissolution, and shear-dilation, and the influence of temperature, stress level, and chemistry on the rate of dissolution, its distribution in space and time, and its influence on the mechanical and transport properties of the fracture.
Date: April 25, 2007
Creator: Elsworth, Derek; Grader, Abraham & Brantley, Susan
Object Type: Report
System: The UNT Digital Library
High Energy Neutrino Flash From Far-UV/X-Ray Flares of Gamma-Ray Bursts (open access)

High Energy Neutrino Flash From Far-UV/X-Ray Flares of Gamma-Ray Bursts

The recent observations of bright optical and X-ray flares by the Swift satellite suggest these are produced by the late activities of the central engine. We study the neutrino emission from far-UV/X-ray flares under the late internal shock model. Since the efficiency of pion production in the highest energy is higher than that of the prompt bursts, such neutrino flashes from flares can give comparable or larger contributions to a diffuse very high energy neutrino background if the total energy input into flares is comparable to the radiated energy of the prompt bursts. These signals are very important because they have possibility to probe the nature of flares (baryonic or magnetic, the photon field, the magnetic field, and so on).
Date: April 25, 2006
Creator: Murase, Kohta; /Kyoto U., Yukawa Inst., Kyoto; Nagataki, Shigehiro & /Kyoto U., Yukawa Inst., Kyoto /KIPAC, Menlo Park
Object Type: Report
System: The UNT Digital Library