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Zeaxanthin Radical Cation Formation in Minor Light-Harvesting Complexes of Higher Plant Antenna (open access)

Zeaxanthin Radical Cation Formation in Minor Light-Harvesting Complexes of Higher Plant Antenna

Previous work on intact thylakoid membranes showed that transient formation of a zeaxanthin radical cation was correlated with regulation of photosynthetic light-harvesting via energy-dependent quenching. A molecular mechanism for such quenching was proposed to involve charge transfer within a chlorophyll-zeaxanthin heterodimer. Using near infrared (880-1100 nm) transient absorption spectroscopy, we demonstrate that carotenoid (mainly zeaxanthin) radical cation generation occurs solely in isolated minor light-harvesting complexes that bind zeaxanthin, consistent with the engagement of charge transfer quenching therein. We estimated that less than 0.5percent of the isolated minor complexes undergo charge transfer quenching in vitro, whereas the fraction of minor complexes estimated to be engaged in charge transfer quenching in isolated thylakoids was more than 80 times higher. We conclude that minor complexes which bind zeaxanthin are sites of charge transfer quenching in vivo and that they can assume Non-quenching and Quenching conformations, the equilibrium LHC(N)<--> LHC(Q) of which is modulated by the transthylakoid pH gradient, the PsbS protein, and protein-protein interactions.
Date: January 31, 2008
Creator: Avenson, Thomas H.; Ahn, Tae Kyu; Zigmantas, Donatas; Niyogi, Krishna K.; Li, Zhirong; Ballottari, Matteo et al.
Object Type: Article
System: The UNT Digital Library
IN SITU Device for Real-Time Catalyst Deactivation Measurements (open access)

IN SITU Device for Real-Time Catalyst Deactivation Measurements

SCR catalyst management has become an important operations and maintenance activity for coal-fired utility boilers in the United States. To facilitate this activity, a method to determine Catalyst Activity in situ is being developed. This report describes the methodology and presents the results of a two ozone season demonstration conducted at Alabama Power Company's Gorgas Unit 10 during the 2005 and 2006 ozone seasons. The results showed that the in situ measurements are in good agreement with the laboratory measurements and the technique has some advantages over the traditional laboratory method of determining Catalyst Activity and Reactor Potential. SCR Performance is determined by the overall Reactor Potential (the product of the Catalyst Activity and the available surface area per unit of flue gas). The in situ approach provides a direct measurement of Reactor Potential under actual operating conditions, whereas laboratory measurements of Catalyst Activity need to be coupled with estimates of catalyst pluggage and flue gas flowrate in order to assess Reactor Potential. The project also showed that the in situ activity results can easily be integrated into catalyst management software to aid in making informed catalyst decisions.
Date: March 31, 2008
Creator: Research, Fossil Energy
Object Type: Report
System: The UNT Digital Library
A METHOD FOR ESTIMATING GAS PRESSURE IN 3013 CONTAINERS USING AN ISP DATABASE QUERY (open access)

A METHOD FOR ESTIMATING GAS PRESSURE IN 3013 CONTAINERS USING AN ISP DATABASE QUERY

The U.S. Department of Energy's Integrated Surveillance Program (ISP) is responsible for the storage and surveillance of plutonium-bearing material. During storage, plutonium-bearing material has the potential to generate hydrogen gas from the radiolysis of adsorbed water. The generation of hydrogen gas is a safety concern, especially when a container is breached within a glove box during destructive evaluation. To address this issue, the DOE established a standard (DOE, 2004) that sets the criteria for the stabilization and packaging of material for up to 50 years. The DOE has now packaged most of its excess plutonium for long-term storage in compliance with this standard. As part of this process, it is desirable to know within reasonable certainty the total maximum pressure of hydrogen and other gases within the 3013 container if safety issues and compliance with the DOE standards are to be attained. The principal goal of this investigation is to document the method and query used to estimate total (i.e. hydrogen and other gases) gas pressure within a 3013 container based on the material properties and estimated moisture content contained in the ISP database. Initial attempts to estimate hydrogen gas pressure in 3013 containers was based on G-values (hydrogen gas …
Date: July 31, 2008
Creator: Friday, G; L. G. Peppers, L & D. K. Veirs, D
Object Type: Report
System: The UNT Digital Library
A High Temperature Electrochemical Energy Storage System Based on Sodium Beta-Alumina Solid Electrolyte (Base) (open access)

A High Temperature Electrochemical Energy Storage System Based on Sodium Beta-Alumina Solid Electrolyte (Base)

This report summarizes the work done during the period September 1, 2005 and March 31, 2008. Work was conducted in the following areas: (1) Fabrication of sodium beta{double_prime} alumina solid electrolyte (BASE) using a vapor phase process. (2) Mechanistic studies on the conversion of {alpha}-alumina + zirconia into beta{double_prime}-alumina + zirconia by the vapor phase process. (3) Characterization of BASE by X-ray diffraction, SEM, and conductivity measurements. (4) Design, construction and electrochemical testing of a symmetric cell containing BASE as the electrolyte and NaCl + ZnCl{sub 2} as the electrodes. (5) Design, construction, and electrochemical evaluation of Na/BASE/ZnCl{sub 2} electrochemical cells. (6) Stability studies in ZnCl{sub 2}, SnCl{sub 2}, and SnI{sub 4} (7) Design, assembly and testing of planar stacks. (8) Investigation of the effect of porous surface layers on BASE on cell resistance. The conventional process for the fabrication of sodium ion conducting beta{double_prime}-alumina involves calcination of {alpha}-alumina + Na{sub 2}CO{sub 3} + LiNO{sub 3} at 1250 C, followed by sintering powder compacts in sealed containers (platinum or MgO) at {approx}1600 C. The novel vapor phase process involves first sintering a mixture of {alpha}-alumina + yttria-stabilized zirconia (YSZ) into a dense ceramic followed by exposure to soda vapor at …
Date: March 31, 2008
Creator: Virkar, Anil
Object Type: Report
System: The UNT Digital Library
Oxidation Resistant, Cr Retaining, Electrically Conductive Coatings on Metallic Alloys for SOFC Interconnects (open access)

Oxidation Resistant, Cr Retaining, Electrically Conductive Coatings on Metallic Alloys for SOFC Interconnects

This report describes significant results from an on-going, collaborative effort to enable the use of inexpensive metallic alloys as interconnects in planar solid oxide fuel cells (SOFCs) through the use of advanced coating technologies. Arcomac Surface Engineering, LLC, under the leadership of Dr. Vladimir Gorokhovsky, is investigating filtered-arc and filtered-arc plasma-assisted hybrid coating deposition technologies to promote oxidation resistance, eliminate Cr volatility, and stabilize the electrical conductivity of both standard and specialty steel alloys of interest for SOFC metallic interconnect (IC) applications. Arcomac has successfully developed technologies and processes to deposit coatings with excellent adhesion, which have demonstrated a substantial increase in high temperature oxidation resistance, stabilization of low Area Specific Resistance values and significantly decrease Cr volatility. An extensive matrix of deposition processes, coating compositions and architectures was evaluated. Technical performance of coated and uncoated sample coupons during exposures to SOFC interconnect-relevant conditions is discussed, and promising future directions are considered. Cost analyses have been prepared based on assessment of plasma processing parameters, which demonstrate the feasibility of the proposed surface engineering process for SOFC metallic IC applications.
Date: March 31, 2008
Creator: Gorokhovsky, Vladimir
Object Type: Report
System: The UNT Digital Library
Calendar Year 2007 Program Benefits for ENERGY STAR Labeled Products (open access)

Calendar Year 2007 Program Benefits for ENERGY STAR Labeled Products

ENERGY STAR is a voluntary energy efficiency-labeling program operated jointly by the United States Department of Energy and the United States Environmental Protection Agency (US EPA). Since the program inception in 1992, ENERGY STAR has become a leading international brand for energy efficient products. ENERGY STAR's central role in the development of regional, national, and international energy programs necessitates an open process whereby its program achievements to date as well as projected future savings are shared with committed stakeholders. Through 2007, the program saved 7.1 Quads of primary energy and avoided 128 MtC equivalent. The forecast shows that the program is expected to save 21.2 Quads of primary energy and avoid 375 MtC equivalent over the period 2008-2015. The sensitivity analysis bounds the best estimate of carbon avoided between 84 MtC and 172 MtC (1993 to 2007) and between 243 MtC and 519 MtC (2008 to 2015).
Date: October 31, 2008
Creator: Sanchez, Marla Christine; Homan, Gregory & Brown, Richard
Object Type: Report
System: The UNT Digital Library
Analyst Tools and Quality Control Software for the ARM Data System (open access)

Analyst Tools and Quality Control Software for the ARM Data System

Mission Research develops analyst tools and automated quality control software in order to assist the Atmospheric Radiation Measurement (ARM) Data Quality Office with their data inspection tasks. We have developed web-based data analysis and visualization tools such as the interactive plotting program NCVweb, various diagnostic plot browsers, and a datastream processing status application. These tools allow even novice ARM researchers to be productive with ARM data with only minimal effort. We also contribute to the ARM Data Quality Office by analyzing ARM data streams, developing new quality control metrics, new diagnostic plots, and integrating this information into DQ HandS - the Data Quality Health and Status web-based explorer. We have developed several ways to detect outliers in ARM data streams and have written software to run in an automated fashion to flag these outliers. We have also embarked on a system to comprehensively generate long time-series plots, frequency distributions, and other relevant statistics for scientific and engineering data in most high-level, publicly available ARM data streams. Furthermore, frequency distributions categorized by month or by season are made available to help define valid data ranges specific to those time domains. These statistics can be used to set limits that when checked, …
Date: July 31, 2008
Creator: Moore, Sean & Hughes, Gary
Object Type: Report
System: The UNT Digital Library
Characterization of EGS Fracture Network Lifecycles (open access)

Characterization of EGS Fracture Network Lifecycles

Geothermal energy is relatively clean, and is an important non-hydrocarbon source of energy. It can potentially reduce our dependence on fossil fuels and contribute to reduction in carbon emissions. High-temperature geothermal areas can be used for electricity generation if they contain permeable reservoirs of hot water or steam that can be extracted. The biggest challenge to achieving the full potential of the nation’s resources of this kind is maintaining and creating the fracture networks required for the circulation, heating, and extraction of hot fluids. The fundamental objective of the present research was to understand how fracture networks are created in hydraulic borehole injection experiments, and how they subsequently evolve. When high-pressure fluids are injected into boreholes in geothermal areas, they flow into hot rock at depth inducing thermal cracking and activating critically stressed pre-existing faults. This causes earthquake activity which, if monitored, can provide information on the locations of the cracks formed, their time-development and the type of cracking underway, e.g., whether shear movement on faults occurred or whether cracks opened up. Ultimately it may be possible to monitor the critical earthquake parameters in near-real-time so the information can be used to guide the hydraulic injection while it is in …
Date: March 31, 2008
Creator: Foulger, Gillian R.
Object Type: Report
System: The UNT Digital Library
Rapid Calibration of High Resolution Geologic Models to Dynamic Data Using Inverse Modeling: Field Application and Validation (open access)

Rapid Calibration of High Resolution Geologic Models to Dynamic Data Using Inverse Modeling: Field Application and Validation

Streamline-based assisted and automatic history matching techniques have shown great potential in reconciling high resolution geologic models to production data. However, a major drawback of these approaches has been incompressibility or slight compressibility assumptions that have limited applications to two-phase water-oil displacements only. We propose an approach to history matching three-phase flow using a novel compressible streamline formulation and streamline-derived analytic sensitivities. First, we utilize a generalized streamline model to account for compressible flow by introducing an 'effective density' of total fluids along streamlines. Second, we analytically compute parameter sensitivities that define the relationship between the reservoir properties and the production response, viz. water-cut and gas/oil ratio (GOR). These sensitivities are an integral part of history matching, and streamline models permit efficient computation of these sensitivities through a single flow simulation. We calibrate geologic models to production data by matching the water-cut and gas/oil ratio using our previously proposed generalized travel time inversion (GTTI) technique. For field applications, however, the highly non-monotonic profile of the gas/oil ratio data often presents a challenge to this technique. In this work we present a transformation of the field production data that makes it more amenable to GTTI. Further, we generalize the approach to …
Date: March 31, 2008
Creator: Datta-Gupta, Akhil
Object Type: Report
System: The UNT Digital Library
Isotope Tracer Studies of Diffusion in Sillicates and of Geological Transport Processes Using Actinide Elements (open access)

Isotope Tracer Studies of Diffusion in Sillicates and of Geological Transport Processes Using Actinide Elements

The objectives were directed toward understanding the transport of chemical species in nature, with particular emphasis on aqueous transport in solution, in colloids, and on particles. Major improvements in measuring ultra-low concentrations of rare elements were achieved. We focused on two areas of studies: (1) Field, laboratory, and theoretical studies of the transport and deposition of U, Th isotopes and their daughter products in natural systems; and (2) Study of calcium isotope fractionation effects in marine carbonates and in carbonates precipitated in the laboratory, under controlled temperature, pH, and rates of precipitation. A major study of isotopic fractionation of Ca during calcite growth from solution has been completed and published. It was found that the isotopic shifts widely reported in the literature and attributed to biological processes are in fact due to a small equilibrium fractionation factor that is suppressed by supersaturation of the solution. These effects were demonstrated in the laboratory and with consideration of the solution conditions in natural systems, where [Ca{sup 2+}] >> [CO{sub 3}{sup 2-}] + [HCO{sub 3}{sup -}]. The controlling rate is not the diffusion of Ca, as was earlier proposed, but rather the rate of supply of [CO{sub 3}{sup 2-}] ions to the interface. …
Date: July 31, 2008
Creator: Wasserburg, Gerald J
Object Type: Report
System: The UNT Digital Library
High-Strength / High Alkaline Resistant Fe-Phosphate Glass Fibers as Concrete Reinforcement (open access)

High-Strength / High Alkaline Resistant Fe-Phosphate Glass Fibers as Concrete Reinforcement

Calcium-iron-phosphate glasses were developed whose chemical durabilities in alkaline solutions (pH 13) were comparable or superior to those of commercial alkaline-resistant (AR) silica-based glasses. However, the tensile strength of Ca-Fe-phosphate fibers, after being exposed to alkaline environments, including wet Portland cement pastes, is lower than that of current AR silicate fibers. Another series of Ca-Fe-phosphate glasses were developed with excellent chemical durability in strong acidic solutions (H2SO4, HF), indicating potential applications where silica-based fibers degrade very quickly, including E-glass. The new Ca-Fe-phosphate glasses can be melted and processed 300 to 500°C lower than silica-based glasses. This offers the possibility of manufacturing glass fibers with lower energy costs by 40-60% and the potential to reduce manufacturing waste and lower gas emissions. It was found that Ca-Fe-phosphate melts can be continuously pulled into fibers depending on the slope of the viscosity-temperature curve and with viscosity ~100 poise, using multi-hole Pt/Rh bushings.
Date: March 31, 2008
Creator: Velez, Mariano
Object Type: Report
System: The UNT Digital Library
The Multi-Scale Mass Transfer Processes Controlling Natural Attenuation and Engineered Remediation: An IFC Focused on Hanford’s 300 Area Uranium Plume Quality Assurance Project Plan (open access)

The Multi-Scale Mass Transfer Processes Controlling Natural Attenuation and Engineered Remediation: An IFC Focused on Hanford’s 300 Area Uranium Plume Quality Assurance Project Plan

The purpose of the project is to conduct research at an Integrated Field-Scale Research Challenge Site in the Hanford Site 300 Area, CERCLA OU 300-FF-5 (Figure 1), to investigate multi-scale mass transfer processes associated with a subsurface uranium plume impacting both the vadose zone and groundwater. The project will investigate a series of science questions posed for research related to the effect of spatial heterogeneities, the importance of scale, coupled interactions between biogeochemical, hydrologic, and mass transfer processes, and measurements/approaches needed to characterize a mass-transfer dominated system. The research will be conducted by evaluating three (3) different hypotheses focused on multi-scale mass transfer processes in the vadose zone and groundwater, their influence on field-scale U(VI) biogeochemistry and transport, and their implications to natural systems and remediation. The project also includes goals to 1) provide relevant materials and field experimental opportunities for other ERSD researchers and 2) generate a lasting, accessible, and high-quality field experimental database that can be used by the scientific community for testing and validation of new conceptual and numerical models of subsurface reactive transport.
Date: January 31, 2008
Creator: Fix, N. J.
Object Type: Report
System: The UNT Digital Library
Hydrogen Separation Membranes - Annual Report for FY 2007. (open access)

Hydrogen Separation Membranes - Annual Report for FY 2007.

The objective of this work is to develop dense ceramic membranes for separating hydrogen from other gaseous components in a nongalvanic mode, i.e., without using an external power supply or electrical circuitry.
Date: January 31, 2008
Creator: Chen, L.; Dorris, S. E.; Emerson, J. E.; Lee, T. H.; Park, C. Y.; Picciolo, J. J. et al.
Object Type: Report
System: The UNT Digital Library
ACRF Instrumentation Status: New, Current, and Future - January 2008 (open access)

ACRF Instrumentation Status: New, Current, and Future - January 2008

The purpose of this report is to provide status of the ingest software used to process instrument data for the Atmospheric Radiation Measurement Program Climate Research Facility (ACRF). The report is divided into 4 sections: (1) for news about ingests currently under development, (2) for current production ingests, (3) for future ingest development plans, and (4) for information on retired ingests. Please note that datastreams beginning in “xxx” indicate cases where ingests run at multiple ACRF sites, which results in a datastream(s) for each location.
Date: January 31, 2008
Creator: Koontz, A. S.; Choudhury, S.; Ermold, B. D. & Gaustad, K. L.
Object Type: Report
System: The UNT Digital Library
The Effect of Terrorism on Public Confidence : An Exploratory Study. (open access)

The Effect of Terrorism on Public Confidence : An Exploratory Study.

A primary goal of terrorism is to instill a sense of fear and vulnerability in a population and to erode confidence in government and law enforcement agencies to protect citizens against future attacks. In recognition of its importance, the Department of Homeland Security includes public confidence as one of the metrics it uses to assess the consequences of terrorist attacks. Hence, several factors--including a detailed understanding of the variations in public confidence among individuals, by type of terrorist event, and as a function of time--are critical to developing this metric. In this exploratory study, a questionnaire was designed, tested, and administered to small groups of individuals to measure public confidence in the ability of federal, state, and local governments and their public safety agencies to prevent acts of terrorism. Data were collected from the groups before and after they watched mock television news broadcasts portraying a smallpox attack, a series of suicide bomber attacks, a refinery bombing, and cyber intrusions on financial institutions that resulted in identity theft and financial losses. Our findings include the following: (a) the subjects can be classified into at least three distinct groups on the basis of their baseline outlook--optimistic, pessimistic, and unaffected; (b) the …
Date: October 31, 2008
Creator: Berry, M. S.; Baldwin, T. E.; Samsa, M. E.; Ramaprasad, A. & Sciences, Decision and Information
Object Type: Report
System: The UNT Digital Library
PointCloudExplore 2: Visual exploration of 3D gene expression (open access)

PointCloudExplore 2: Visual exploration of 3D gene expression

To better understand how developmental regulatory networks are defined inthe genome sequence, the Berkeley Drosophila Transcription Network Project (BDNTP)has developed a suite of methods to describe 3D gene expression data, i.e.,the output of the network at cellular resolution for multiple time points. To allow researchersto explore these novel data sets we have developed PointCloudXplore (PCX).In PCX we have linked physical and information visualization views via the concept ofbrushing (cell selection). For each view dedicated operations for performing selectionof cells are available. In PCX, all cell selections are stored in a central managementsystem. Cells selected in one view can in this way be highlighted in any view allowingfurther cell subset properties to be determined. Complex cell queries can be definedby combining different cell selections using logical operations such as AND, OR, andNOT. Here we are going to provide an overview of PointCloudXplore 2 (PCX2), thelatest publicly available version of PCX. PCX2 has shown to be an effective tool forvisual exploration of 3D gene expression data. We discuss (i) all views available inPCX2, (ii) different strategies to perform cell selection, (iii) the basic architecture ofPCX2., and (iv) illustrate the usefulness of PCX2 using selected examples.
Date: March 31, 2008
Creator: International Research Training Group Visualization of Large and Unstructured Data Sets, University of Kaiserslautern, Germany; Institute for Data Analysis and Visualization, University of California, Davis, CA; Computational Research Division, Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA; Genomics Division, LBNL; Computer Science Department, University of California, Irvine, CA; Computer Science Division,University of California, Berkeley, CA et al.
Object Type: Report
System: The UNT Digital Library
Expanding Conventional Seismic Stratigrphy into the Multicomponent Seismic Domain (open access)

Expanding Conventional Seismic Stratigrphy into the Multicomponent Seismic Domain

Multicomponent seismic data are composed of three independent vector-based seismic wave modes. These wave modes are, compressional mode (P), and shear modes SV and SH. The three modes are generated using three orthogonal source-displacement vectors and then recorded using three orthogonal vector sensors. The components travel through the earth at differing velocities and directions. The velocities of SH and SV as they travel through the subsurface differ by only a few percent, but the velocities of SV and SH (Vs) are appreciably lower than the P-wave velocity (Vp). The velocity ratio Vp/Vs varies by an order of magnitude in the earth from a value of 15 to 1.5 depending on the degree of sedimentary lithification. The data used in this study were acquired by nine-component (9C) vertical seismic profile (VSP), using three orthogonal vector sources. The 9C vertical seismic profile is capable of generating P-wave mode and the fundamental S-wave mode (SH-SH and SV-SV) directly at the source station and permits the basic components of elastic wavefield (P, SH-SH and SV-SV) to be separated from one another for the purposes of imaging. Analysis and interpretations of data from the study area show that incident full-elastic seismic wavefield is capable of …
Date: August 31, 2008
Creator: Aluka, Innocent J.
Object Type: Report
System: The UNT Digital Library
Reliable and Repeatable Characterization of Optical Streak Cameras (open access)

Reliable and Repeatable Characterization of Optical Streak Cameras

Optical streak cameras are used as primary diagnostics for a wide range of physics and laser experiments at facilities such as the National Ignition Facility (NIF). To meet the strict accuracy requirements needed for these experiments, the systematic nonlinearities of the streak cameras (attributed to nonlinearities in the optical and electrical components that make up the streak camera system) must be characterized. In some cases the characterization information is used as a guide to help determine how experiment data should be taken. In other cases, the characterization data are applied to the raw data images to correct for the nonlinearities. In order to characterize an optical streak camera, a specific set of data is collected, where the response to defined inputs are recorded. A set of analysis software routines has been developed to extract information such as spatial resolution, dynamic range, and temporal resolution from this data set. The routines are highly automated, requiring very little user input and thus provide very reliable and repeatable results that are not subject to interpretation. An emphasis on quality control has been placed on these routines due to the high importance of the camera characterization information.
Date: October 31, 2008
Creator: Michael Charest Jr., Peter Torres III, Christopher Silbernagel, and Daniel Kalantar
Object Type: Article
System: The UNT Digital Library
Energy Efficiency Improvement Opportunities for the Cement Industry (open access)

Energy Efficiency Improvement Opportunities for the Cement Industry

This report provides information on the energy savings, costs, and carbon dioxide emissions reductions associated with implementation of a number of technologies and measures applicable to the cement industry. The technologies and measures include both state-of-the-art measures that are currently in use in cement enterprises worldwide as well as advanced measures that are either only in limited use or are near commercialization. This report focuses mainly on retrofit measures using commercially available technologies, but many of these technologies are applicable for new plants as well. Where possible, for each technology or measure, costs and energy savings per tonne of cement produced are estimated and then carbon dioxide emissions reductions are calculated based on the fuels used at the process step to which the technology or measure is applied. The analysis of cement kiln energy-efficiency opportunities is divided into technologies and measures that are applicable to the different stages of production and various kiln types used in China: raw materials (and fuel) preparation; clinker making (applicable to all kilns, rotary kilns only, vertical shaft kilns only); and finish grinding; as well as plant wide measures and product and feedstock changes that will reduce energy consumption for clinker making. Table 1 lists …
Date: January 31, 2008
Creator: Price, Lynn; Worrell, Ernst; Galitsky, Christina & Price, Lynn
Object Type: Report
System: The UNT Digital Library
Workforce Development Advisory Team Mission, Goals, and Objectives (open access)

Workforce Development Advisory Team Mission, Goals, and Objectives

This report documents the creation of a mission, goals, and objectives for the New Mexico Workforce Development Advisory Team as part of the National Security Preparedness Project (NSPP), being performed by the Arrowhead Center of New Mexico State University under a DOE/NNSA grant. The goal of workforce development under the NSPP grant is to assess workforce needs in national security and implement strategies to develop the appropriate workforce. To achieve this goal, it will be necessary to involve the workforce development advisory team in determining the current status of the national security workforce and the educational efforts to train such a workforce. Strategies will be developed and implemented to address gaps and to make progress towards a strong, well-trained workforce available for current and future national security employers.
Date: March 31, 2008
Creator: unknown
Object Type: Text
System: The UNT Digital Library
Cladding Embrittlement During Postulated Loss-Of-Coolant Accidents. (open access)

Cladding Embrittlement During Postulated Loss-Of-Coolant Accidents.

The effect of fuel burnup on the embrittlement of various cladding alloys was examined with laboratory tests conducted under conditions relevant to loss-of-coolant accidents (LOCAs). The cladding materials tested were Zircaloy-4, Zircaloy-2, ZIRLO, M5, and E110. Tests were performed with specimens sectioned from as-fabricated cladding, from prehydrided (surrogate for high-burnup) cladding, and from high-burnup fuel rods which had been irradiated in commercial reactors. The tests were designed to determine for each cladding material the ductile-to-brittle transition as a function of steam oxidation temperature, weight gain due to oxidation, hydrogen content, pre-transient cladding thickness, and pre-transient corrosion-layer thickness. For short, defueled cladding specimens oxidized at 1000-1200 C, ring compression tests were performed to determine post-quench ductility at {le} 135 C. The effect of breakaway oxidation on embrittlement was also examined for short specimens oxidized at 800-1000 C. Among other findings, embrittlement was found to be sensitive to fabrication processes--especially surface finish--but insensitive to alloy constituents for these dilute zirconium alloys used as cladding materials. It was also demonstrated that burnup effects on embrittlement are largely due to hydrogen that is absorbed in the cladding during normal operation. Some tests were also performed with longer, fueled-and-pressurized cladding segments subjected to LOCA-relevant heating …
Date: July 31, 2008
Creator: Billone, M.; Yan, Y.; Burtseva, T. & Daum, R.
Object Type: Report
System: The UNT Digital Library
An experimental study of the impact of location on the effectiveness of recruitment clusters for Red-cockaded Woodpeckers at the Savannah River Site. (open access)

An experimental study of the impact of location on the effectiveness of recruitment clusters for Red-cockaded Woodpeckers at the Savannah River Site.

An experimental study of the impact of location on the effectiveness of recruitment clusters for Red-Cockaded Woodpeckers at the Savannah River Site.
Date: May 31, 2008
Creator: Walters, Jeffrey, R.; Johnston, Peter, A.; Crowder, Larry, B. & Priddy, Jeffrey, A.
Object Type: Report
System: The UNT Digital Library
Streamlined Approach for Environmental Restoration Plan for Corrective Action Unit 134: Aboveground Storage Tanks, Nevada Test Site, Nevada (open access)

Streamlined Approach for Environmental Restoration Plan for Corrective Action Unit 134: Aboveground Storage Tanks, Nevada Test Site, Nevada

This Streamlined Approach for Environmental Restoration (SAFER) Plan identifies the activities required for the closure of Corrective Action Unit (CAU) 134, Aboveground Storage Tanks. CAU 134 is currently listed in Appendix III of the Federal Facility Agreement and Consent Order (FFACO) (FFACO, 1996; as amended February 2008) and consists of four Corrective Action Sites (CASs) located in Areas 3, 15, and 29 of the Nevada Test Site (NTS) (Figure 1): (1) CAS 03-01-03, Aboveground Storage Tank; (2) CAS 03-01-04, Tank; (3) CAS 15-01-05, Aboveground Storage Tank; and (4) CAS 29-01-01, Hydrocarbon Stain. CAS 03-01-03 consists of a mud tank that is located at the intersection of the 3-07 and the 3-12 Roads in Area 3 of the NTS. The tank and its contents are uncontaminated and will be dispositioned in accordance with applicable federal, state, and local regulations. This CAS will be closed by taking no further action. CAS 03-01-04 consists of a potable water tank that is located at the Core Complex in Area 3 of the NTS. The tank will be closed by taking no further action. CAS 15-01-05 consists of an aboveground storage tank (AST) and associated impacted soil, if any. This CAS is located on a …
Date: May 31, 2008
Creator: National Security Technologies, LLC
Object Type: Report
System: The UNT Digital Library
Characterization of Fine Particulate Matter (PM) and Secondary PM Precursor Gases in Mexico City (open access)

Characterization of Fine Particulate Matter (PM) and Secondary PM Precursor Gases in Mexico City

This project was one of three collaborating grants designed to understand the atmospheric chemistry and aerosol particle microphysics impacting air quality in the Mexico City Metropolitan Area (MCMA) and its urban plume. The overall effort, titled MCMA- 2006, focused on: 1) the primary emissions of fine particles and precursor gases leading to photochemical production of atmospheric oxidants and secondary aerosol particles and 2) the measurement and analysis of secondary oxidants and secondary fine particular matter (PM) production, with particular emphasis on secondary organic aerosol (SOA). MCAM-2006 pursued it goals through three main activities: 1) performance and publication of detailed analyses of extensive MCMA trace gas and fine PM measurements made by the collaborating groups and others during earlier MCMA field campaigns in 2002 and 2003; 2) deployment and utilization of extensive real-time trace gas and fine PM instrumentation at urban and downwind MCMA sites in support of the MAX-Mex/MILAGRO field measurements in March, 2006; and, 3) analyses of the 2006 MCMA data sets leading to further publications that are based on new data as well as insights from analysis and publication of the 2002/2003 field data. Thirteen archival publications were coauthored with other MCMA-2003 participants. Documented findings included a significantly …
Date: March 31, 2008
Creator: Zavala, Dr. Charles E. Kolb Dr. Douglas R. Worsnop Dr. Manjula R. Canagaratna Dr. Scott C. Herndon Dr. John T. Jayne Dr. W. Berk Knighton Dr. Timothy B. Onasch Dr. Ezra C. Wood Dr. Miguel
Object Type: Report
System: The UNT Digital Library