Role of Water States on Water Uptake and Proton Transport in Nafion using Molecular Simulations and Bimodal Network (open access)

Role of Water States on Water Uptake and Proton Transport in Nafion using Molecular Simulations and Bimodal Network

Using molecular simulations and a bimodal domain network, the role of water state on Nafion water uptake and water and proton transport is investigated. Although the smaller domains provide moderate transport pathways, their effectiveness remains low due to strong, resistive water molecules/domain surface interactions. The water occupancy of the larger domains yields bulk-like water, and causes the observed transition in the water uptake and significant increases in transport properties.
Date: November 19, 2010
Creator: Michigan, U.; Hwang, Gi Suk; Kaviany, Massoud; Gostick, Jeffrey T.; Kientiz, Brian; Weber, Adam Z. et al.
Object Type: Article
System: The UNT Digital Library
Use of the ARM Measurement of Spectral Zenith Radiance For Better Understanding Of 3D Cloud-Radiation Processes and Aerosol-Cloud Interaction (open access)

Use of the ARM Measurement of Spectral Zenith Radiance For Better Understanding Of 3D Cloud-Radiation Processes and Aerosol-Cloud Interaction

Our proposal focuses on cloud-radiation processes in a general 3D cloud situation, with particular emphasis on cloud optical depth and effective particle size. We also focus on zenith radiance measurements, both active and passive. The proposal has three main parts. Part One exploits the “solar-background” mode of ARM lidars to allow them to retrieve cloud optical depth not just for thin clouds but for all clouds. This also enables the study of aerosol cloud interactions with a single instrument. Part Two exploits the large number of new wavelengths offered by ARM’s zenith-pointing ShortWave Spectrometer (SWS), especially during CLASIC, to develop better retrievals not only of cloud optical depth but also of cloud particle size. We also propose to take advantage of the SWS’ 1 Hz sampling to study the “twilight zone” around clouds where strong aerosol-cloud interactions are taking place. Part Three involves continuing our cloud optical depth and cloud fraction retrieval research with ARM’s 2NFOV instrument by, first, analyzing its data from the AMF-COPS/CLOWD deployment, and second, making our algorithms part of ARM’s operational data processing.
Date: October 19, 2010
Creator: Chiu, D. Jui-Yuan
Object Type: Report
System: The UNT Digital Library
Syntheses, Structure, Magnetism, and Optical Properties of the Ordered Interlanthanide Copper Chalcogenides Ln{sub 2}YbCuQ{sub 5} (Ln = La, Ce, Pr, Nd, Sm; Q = S, Se): Evidence for Unusual Magnetic Ordering in Sm{sub 2}YbCuS{sub 5} (open access)

Syntheses, Structure, Magnetism, and Optical Properties of the Ordered Interlanthanide Copper Chalcogenides Ln{sub 2}YbCuQ{sub 5} (Ln = La, Ce, Pr, Nd, Sm; Q = S, Se): Evidence for Unusual Magnetic Ordering in Sm{sub 2}YbCuS{sub 5}

Ln{sub 2}YbCuQ{sub 5} (Ln = La, Ce, Pr, Nd, Sm; Q = S, Se) have been prepared by direct reaction of the elements in Sb{sub 2}Q{sub 3} (Q = S, Se) fluxes at 900 °C. All compounds have been characterized by single-crystal X-ray diffraction methods and they are isotypic. The structure of Ln{sub 2}YbCuQ{sub 5} consists of one-dimensional {sup 1}{sub {infinity}} [YbCuQ{sub 5}]{sup 6-} ribbons extending along the b axis that are connected by larger Ln{sup 3+} ions. Each ribbon is constructed from two single chains of [YbQ{sub 6}] octahedra with one double chain of [CuQ{sub 5}] trigonal bipyramids in the middle. All three chains connect with each other via edge-sharing. There are two crystallographically unique Ln atoms, one octahedral Yb site, and two disordered Cu positions inside of distorted Q{sub 5} trigonal bipyramids. Both Ln atoms are surrounded by eight Q atoms in bicapped trigonal prisms. The magnetic properties of Ln{sub 2}YbCuQ{sub 5} have been characterized using magnetic susceptibility and heat capacity measurements, while their optical properties have been explored using UV-vis-NIR diffuse reflectance spectroscopy. Cesub 2}YbCuSe{sub 5}, La{sub 2}YbCuS{sub 5}, Ce{sub 2}YbCuS{sub 5}, and Pr{sub 2}YbCuS{sub 5} are Curie-Weiss paramagnets. La{sub 2}YbCuSe{sub 5} and Nd{sub 2}YbCuS{sub 5} show …
Date: November 19, 2010
Creator: Jin, Geng Bang; Choi, Eun Sang; Guertin, Robert P.; Booth, Corwin H. & Albrecht-Schmitt, Thomas E.
Object Type: Article
System: The UNT Digital Library
Improved Space Charge Modeling for Simulation and Design of Photoinjectors (open access)

Improved Space Charge Modeling for Simulation and Design of Photoinjectors

Photoinjectors in advanced high-energy accelerators reduce beam energy spreads and enhance undulator photon fluxes. Photoinjector design is difficult because of the substantial differences in time and spatial scales. This Phase I program explored an innovative technique, the local Taylor polynomial (LTP) formulation, for improving finite difference analysis of photoinjectors. This included improved weighting techniques, systematic formula for high order interpolation and electric field computation, and improved handling of space charge. The Phase I program demonstrated that the approach was powerful, accurate, and efficient. It handles space charge gradients better than currently available technology.
Date: April 19, 2010
Creator: Robert H. Jackson, Thuc Bui, John Verboncoeur
Object Type: Report
System: The UNT Digital Library
Electrodeposition of U and Pu on Thin C and Ti Substrates (open access)

Electrodeposition of U and Pu on Thin C and Ti Substrates

Physics experiments aimed at deducing key parameters for use in a variety of programs critical to the mission of the National Laboratories require actinide targets placed onto various substrates. The target material quantity and the substrate desired depend upon the type of experiment being designed. The physicist(s) responsible for the experimental campaign will consult with the radiochemistry staff as to the feasibility of producing a desired target/substrate combination. In this report they discuss the production of U and Pu targets on very thin C and Ti substrates. The techniques used, plating cells designed for, tips, and limits is discussed.
Date: May 19, 2010
Creator: Henderson, R. A. & Gostic, J. M.
Object Type: Article
System: The UNT Digital Library
Comparative Gamma Spectroscopy with SrI2(Eu), GYGAG(Ce) and Bi-loaded Plastic Scintillators (open access)

Comparative Gamma Spectroscopy with SrI2(Eu), GYGAG(Ce) and Bi-loaded Plastic Scintillators

We are developing new scintillator materials that offer potential for high resolution gamma ray spectroscopy at low cost. Single crystal SrI{sub 2}(Eu) offers {approx}3% resolution at 662 keV, in sizes of {approx}1 in{sup 3}. We have developed ceramics processing technology allowing us to achieve cubic inch scale transparent ceramic scintillators offering gamma spectroscopy performance superior to NaI(Tl). We fabricated a bismuth-loaded plastic scintillator that demonstrates energy resolution of {approx}8% at 662 keV in small sizes. Gamma ray spectroscopy can be used to identify the presence of weak radioactive sources within natural background. The ability to discriminate close-lying spectral lines is strongly dependent upon the energy resolution of the detector. In addition to excellent energy resolution, large volume detectors are needed to acquire sufficient events, for example, to identify a radioactive anomaly moving past a detector. We have employed a 'directed search' methodology for identifying potential scintillator materials candidates, resulting in the discovery of Europium-doped Strontium Iodide, SrI{sub 2}(Eu), Cerium-doped Gadolinium Garnet, GYGAG(Ce), and Bismuth-loaded Polymers. These scintillators possess very low self-radioactivity, offer energy resolution of 3-8% at 662 keV, and have potential to be grown cost-effectively to sizes similar to the most widely deployed gamma spectroscopy scintillator, Thallium-doped Sodium Iodide, …
Date: November 19, 2010
Creator: Cherepy, N J
Object Type: Article
System: The UNT Digital Library
Complete Calculation of Evaluated Maxwellian-Averaged Cross Sections and Their Uncertainties for S-Process Nucleosynthesis (open access)

Complete Calculation of Evaluated Maxwellian-Averaged Cross Sections and Their Uncertainties for S-Process Nucleosynthesis

Present contribution represents a significant improvement of our previous calculation of Maxwellian-averaged cross sections and astrophysical reaction rates. Addition of newly-evaluated neutron reaction libraries, such as ROSFOND and Low-Fidelity Covariance Project, and improvements in data processing techniques allowed us to extend it for entire range of sprocess nuclei, calculate Maxwellian-averaged cross section uncertainties for the first time, and provide additional insights on all currently available neutron-induced reaction data. Nuclear reaction calculations using ENDF libraries and current Java technologies will be discussed and new results will be presented.
Date: July 19, 2010
Creator: Pritychenko, B.
Object Type: Article
System: The UNT Digital Library
Annual report of groundwater monitoring at Centralia, Kansas, in 2009. (open access)

Annual report of groundwater monitoring at Centralia, Kansas, in 2009.

In September 2005, periodic sampling of groundwater was initiated by the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) in the vicinity of a grain storage facility formerly operated by the CCC/USDA at Centralia, Kansas. The sampling at Centralia is being performed on behalf of the CCC/USDA by Argonne National Laboratory, in accord with a monitoring program approved by the Kansas Department of Health and Environment (KDHE). The objective is to monitor levels of carbon tetrachloride contamination identified in the groundwater at Centralia (Argonne 2003, 2004, 2005a). Under the KDHE-approved monitoring plan (Argonne 2005b), the groundwater was sampled twice yearly from September 2005 until September 2007 for analyses for volatile organic compounds (VOCs), as well as measurement of selected geochemical parameters to aid in the evaluation of possible natural contaminant degradation (reductive dechlorination) processes in the subsurface environment. The results from the two-year sampling program demonstrated the presence of carbon tetrachloride contamination at levels exceeding the KDHE Tier 2 risk-based screening level (RBSL) of 5 {micro}g/L for this compound in a localized groundwater plume that has shown little movement. The relative concentrations of chloroform, the primary degradation product of carbon tetrachloride, suggested that some degree of reductive dechlorination …
Date: October 19, 2010
Creator: LaFreniere, L. M.
Object Type: Report
System: The UNT Digital Library
Chromosomal Rainbows detect Oncogenic Rearrangements of Signaling Molecules in Thyroid Tumors (open access)

Chromosomal Rainbows detect Oncogenic Rearrangements of Signaling Molecules in Thyroid Tumors

Altered signal transduction can be considered a hallmark of many solid tumors. In thyroid cancers the receptor tyrosine kinase (rtk) genes NTRK1 (Online Mendelian Inheritance in Man = OMIM *191315, also known as 'TRKA'), RET ('Rearranged during Transfection protooncogene', OMIM *164761) and MET (OMIM *164860) have been reported as activated, rearranged or overexpressed. In many cases, a combination of cytogenetic and molecular techniques allows elucidation of cellular changes that initiate tumor development and progression. While the mechanisms leading to overexpression of the rtk MET gene remain largely unknown, a variety of chromosomal rearrangements of the RET or NTKR1 gene could be demonstrated in thyroid cancer. Abnormal expressions in these tumors seem to follow a similar pattern: the rearrangement translocates the 3'-end of the rtk gene including the entire catalytic domain to an expressed gene leading to a chimeric RNA and protein with kinase activity. Our research was prompted by an increasing number of reports describing translocations involving ret and previously unknown translocation partners. We developed a high resolution technique based on fluorescence in situ hybridization (FISH) to allow rapid screening for cytogenetic rearrangements which complements conventional chromosome banding analysis. Our technique applies simultaneous hybridization of numerous probes labeled with different …
Date: August 19, 2010
Creator: O'Brien, Benjamin; Jossart, Gregg H.; Ito, Yuko; Greulich-Bode, Karin M.; Weier, Jingly F.; Munne, Santiago et al.
Object Type: Report
System: The UNT Digital Library
SUMMARY PLAN FOR BENCH-SCALE REFORMER AND PRODUCT TESTING TREATABILITY STUDIES USING HANFORD TANK WASTE (open access)

SUMMARY PLAN FOR BENCH-SCALE REFORMER AND PRODUCT TESTING TREATABILITY STUDIES USING HANFORD TANK WASTE

This paper describes the sample selection, sample preparation, environmental, and regulatory considerations for shipment of Hanford radioactive waste samples for treatability studies of the FBSR process at the Savannah River National Laboratory and the Pacific Northwest National Laboratory. The U.S. Department of Energy (DOE) Hanford tank farms contain approximately 57 million gallons of wastes, most of which originated during the reprocessing of spent nuclear fuel to produce plutonium for defense purposes. DOE intends to pre-treat the tank waste to separate the waste into a high level fraction, that will be vitrified and disposed of in a national repository as high-level waste (HLW), and a low-activity waste (LAW) fraction that will be immobilized for on-site disposal at Hanford. The Hanford Waste Treatment and Immobilization Plant (WTP) is the focal point for the treatment of Hanford tank waste. However, the WTP lacks the capacity to process all of the LAW within the regulatory required timeframe. Consequently, a supplemental LAW immobilization process will be required to immobilize the remainder of the LAW. One promising supplemental technology is Fluidized Bed Steam Reforming (FBSR) to produce a sodium-alumino-silicate (NAS) waste form. The NAS waste form is primarily composed of nepheline (NaAlSiO{sub 4}), sodalite (Nas[AlSiO{sub 4}]{sub …
Date: August 19, 2010
Creator: JB, DUNCAN
Object Type: Report
System: The UNT Digital Library
1-D Van der Waals Foams Heated by Ion Beam Energy Deposition (open access)

1-D Van der Waals Foams Heated by Ion Beam Energy Deposition

One dimensional simulations of various initial average density aluminum foams (modeled as slabs of solid metal separated by low density regions) heated by volumetric energy deposition are conducted with a Lagrangian hydrodynamics code using a van der Waals equation of state (EOS). The resulting behavior is studied to facilitate the design of future warm dense matter (WDM) experiments at LBNL. In the simulations the energy deposition ranges from 10 to 30 kJ/g and from 0.075 to 4.0 ns total pulse length, resulting in temperatures from approximately 1 to 4 eV. We study peak pressures and temperatures in the foams, expansion velocity, and the phase evolution. Five relevant time scales in the problem are identified. Additionally, we present a method for characterizing the level of inhomogeneity in a foam target as it is heated and the time it takes for a foam to homogenize.
Date: March 19, 2010
Creator: Zylstra, A; Barnard, J J & More, R M
Object Type: Article
System: The UNT Digital Library
The degree of 5f electron localization in URu2Si2: electron energy-loss spectroscopy and spin-orbit sum rule analysis (open access)

The degree of 5f electron localization in URu2Si2: electron energy-loss spectroscopy and spin-orbit sum rule analysis

We examine the degree of 5f electron localization in URu{sub 2}Si{sub 2} using spin-orbit sum rule analysis of the U N{sub 4,5} (4d {yields} 5f) edge. When compared to {alpha}-U metal, US, USe, and UTe, which have increasing localization of the 5f states, we find that the 5f states of URu{sub 2}Si{sub 2} are more localized, although not entirely. Spin-orbit analysis shows that intermediate coupling is the correct angular momentum coupling mechanism for URu{sub 2}Si{sub 2} when the 5f electron count is between 2.6 and 2.8. These results have direct ramifications for theoretical assessment of the hidden order state of URu{sub 2}Si{sub 2}, where the degree of localization of the 5f electrons and their contribution to the Fermi surface are critical.
Date: May 19, 2010
Creator: Jeffries, J R; Moore, K T; Butch, N P & Maple, M B
Object Type: Article
System: The UNT Digital Library
Rnnotator: an automated de novo transcriptome assembly pipeline from stranded RNA-Seq reads (open access)

Rnnotator: an automated de novo transcriptome assembly pipeline from stranded RNA-Seq reads

Background: Comprehensive annotation and quantification of transcriptomes are outstanding problems in functional genomics. While high throughput mRNA sequencing (RNA-Seq) has emerged as a powerful tool for addressing these problems, its success is dependent upon the availability and quality of reference genome sequences, thus limiting the organisms to which it can be applied. Results: Here, we describe Rnnotator, an automated software pipeline that generates transcript models by de novo assembly of RNA-Seq data without the need for a reference genome. We have applied the Rnnotator assembly pipeline to two yeast transcriptomes and compared the results to the reference gene catalogs of these organisms. The contigs produced by Rnnotator are highly accurate (95percent) and reconstruct full-length genes for the majority of the existing gene models (54.3percent). Furthermore, our analyses revealed many novel transcribed regions that are absent from well annotated genomes, suggesting Rnnotator serves as a complementary approach to analysis based on a reference genome for comprehensive transcriptomics. Conclusions: These results demonstrate that the Rnnotator pipeline is able to reconstruct full-length transcripts in the absence of a complete reference genome.
Date: November 19, 2010
Creator: Martin, Jeffrey; Bruno, Vincent M.; Fang, Zhide; Meng, Xiandong; Blow, Matthew; Zhang, Tao et al.
Object Type: Article
System: The UNT Digital Library
A Geochemical and Sedimentary Record of High Southern Latitude Holocene Climate Evolution from Lago Fagnano, Tierra del Fuego (open access)

A Geochemical and Sedimentary Record of High Southern Latitude Holocene Climate Evolution from Lago Fagnano, Tierra del Fuego

Situated at the southern margin of the hemispheric westerly wind belt and immediately north of the Antarctic Polar Frontal zone, Tierra del Fuego is well-positioned to monitor coupled changes in the ocean-atmosphere system of the high southern latitudes. Here we describe a Holocene paleoclimate record from sediment cores obtained from Lago Fagnano, a large lake in southern Tierra del Fuego at 55{sup o}S, to investigate past changes in climate related to these two important features of the global climate system. We use an AMS radiocarbon chronology for the last 8,000 years based on pollen concentrates, thereby avoiding contamination from bedrock-derived lignite. Our chronology is consistent with a tephrochronologic age date for deposits from the middle Holocene Volcan Hudson eruption. Combining bulk organic isotopic ({delta}{sup 13}C and {delta}{sup 15}N) and elemental (C and N) parameters with physical sediment properties allow us to better understand sediment provenance and transport mechanisms and to interpret Holocene climate and tectonic change during the last 8,000 years. Co-variability and long-term trends in C/N ratio, carbon accumulation rate, and magnetic susceptibility reflect an overall Holocene increase in the delivery of terrestrial organic and lithogenic material to the deep eastern basin. We attribute this variability to westerly wind-derived …
Date: November 19, 2010
Creator: Moy, C M; Dunbar, R B; Guilderson, T P; Waldmann, N; Mucciarone, D A; Recasens, C et al.
Object Type: Article
System: The UNT Digital Library
Confirmatory Survey of the Defense Logistics Agency, Defense National Stockpile Center New Haven Depot, New Haven, Indiana (open access)

Confirmatory Survey of the Defense Logistics Agency, Defense National Stockpile Center New Haven Depot, New Haven, Indiana

The objectives of the radiological confirmatory survey were to collect adequate radiological data for use in evaluating the radiological condition of NHD land areas, warehouses, and support buildings. The data generated from the confirmatory survey activities were used to evaluate the results of the Final Status Survey Report (FSSR) submitted by Cabrera Services (Cabrera 2009). Cabrera has stated that all radioactive materials have been removed and that remediation of the open land areas and structure surfaces was complete, and that the NHD meets the criteria for unrestricted use.
Date: February 19, 2010
Creator: Harpenau, E. M.
Object Type: Report
System: The UNT Digital Library
Radiation in Particle Simulations (open access)

Radiation in Particle Simulations

Hot dense radiative (HDR) plasmas common to Inertial Confinement Fusion (ICF) and stellar interiors have high temperature (a few hundred eV to tens of keV), high density (tens to hundreds of g/cc) and high pressure (hundreds of megabars to thousands of gigabars). Typically, such plasmas undergo collisional, radiative, atomic and possibly thermonuclear processes. In order to describe HDR plasmas, computational physicists in ICF and astrophysics use atomic-scale microphysical models implemented in various simulation codes. Experimental validation of the models used to describe HDR plasmas are difficult to perform. Direct Numerical Simulation (DNS) of the many-body interactions of plasmas is a promising approach to model validation but, previous work either relies on the collisionless approximation or ignores radiation. We present four methods that attempt a new numerical simulation technique to address a currently unsolved problem: the extension of molecular dynamics to collisional plasmas including emission and absorption of radiation. The first method applies the Lienard-Weichert solution of Maxwell's equations for a classical particle whose motion is assumed to be known. The second method expands the electromagnetic field in normal modes (planewaves in a box with periodic boundary-conditions) and solves the equation for wave amplitudes coupled to the particle motion. The third …
Date: November 19, 2010
Creator: More, R; Graziani, F; Glosli, J & Surh, M
Object Type: Article
System: The UNT Digital Library
Proceedings of Pulsed Magnet Design and Measurement Workshop (open access)

Proceedings of Pulsed Magnet Design and Measurement Workshop

The goals of the Workshop are to assess the design of pulsed system at the NSLS-II and establish mitigation strategies for critical issues during development. The focus of the Workshop is on resolving questions related to the set-up of the pulsed magnet laboratory, on measuring the pulsed magnet's current waveforms and fields, and on achieving tight tolerances on the magnet's alignment and field quality.
Date: January 19, 2010
Creator: Shaftan, T.; Heese, R. & Ozaki,S.
Object Type: Report
System: The UNT Digital Library
Measurements of the Ion Species of Cathodic Arc Plasma in an Axial Magnetic Field (open access)

Measurements of the Ion Species of Cathodic Arc Plasma in an Axial Magnetic Field

Metal and gas ion species and their charge state distributions were measured for pulsed copper cathodic arcs in argon background gas in the presence of an axial magnetic field. It was found that changing the cathode position relative to anode and ion extraction system as well as increasing the gas pressure did not much affect the arc burning voltage and the related power dissipation. However, the burning voltage and power dissipation greatly increased as the magnetic field strength was increased. The fraction of metal ions and the mean ion charge state were reduced as the discharge length was increased. The observations can be explained by the combination of charge exchange collisions and electron impact ionization. They confirm that previously published data on characteristic material-dependent charge state distributions (e.g., Anders and Yushkov, J. Appl. Phys., Vol. 91, pp. 4824-4832, 2002) are not universal but valid for high vacuum conditions and the specifics of the applied magnetic fields.
Date: October 19, 2010
Creator: Oks, Efim & Anders, Andre
Object Type: Article
System: The UNT Digital Library
Simulations for experimental study of warm dense matter and inertial fusion energy applications on NDCX-II (open access)

Simulations for experimental study of warm dense matter and inertial fusion energy applications on NDCX-II

The Neutralized Drift Compression Experiment II (NDCX II) is an induction accelerator planned for initial commissioning in 2012. The final design calls for a {approx}3 MeV, {approx}30 A Li{sup +} ion beam, delivered in a bunch with characteristic pulse duration of 1 ns, and transverse dimension of order 1 mm. The purpose of NDCX II is to carry out experimental studies of material in the warm dense matter regime, and ion beam/hydrodynamic coupling experiments relevant to heavy ion based inertial fusion energy. In preparation for this new machine, we have carried out hydrodynamic simulations of ion-beam-heated, metallic solid targets, connecting quantities related to observables, such as brightness temperature and expansion velocity at the critical frequency, with the simulated fluid density, temperature, and velocity. We examine how these quantities depend on two commonly used equations of state.
Date: March 19, 2010
Creator: Barnard, J. J.; Armijo, J.; Bieniosek, F. M.; Friedman, A.; Hay, M. J.; Henestroza, E. et al.
Object Type: Article
System: The UNT Digital Library
Detailed methodology of geospatial fire behavior analyses for the Savannah River Site. (open access)

Detailed methodology of geospatial fire behavior analyses for the Savannah River Site.

Three data sources were utilized to compare and contrast fire behavior modeling outputs (Table 1) from FlamMap for the Savannah River Site (SRS) in South Carolina.
Date: November 19, 2010
Creator: Hollingsworth, LaWen & Kurth, Laurie
Object Type: Report
System: The UNT Digital Library
Final Report LDRD 04-ERD-019 Development of absolute spectroscopic diagnostics for non-LTE plasmas (open access)

Final Report LDRD 04-ERD-019 Development of absolute spectroscopic diagnostics for non-LTE plasmas

This project sought to further our understanding of non-Local Thermodynamic Equilibrium (NLTE) processes by providing benchmark data to validate computational models. This has been a difficult regime to study in the laboratory, where experimental scales produce strong gradients while interpretation requires well-characterized uniform plasmas. It has also been a difficult regime to simulate, as evidenced by the large discrepancies in predictions of NLTE spectra for fixed plasma properties. Not surprisingly, discrepancies between data and calculations of recombining laser-produced plasmas have been in evidence since the 1980's. The goal here was to obtain data of sufficient accuracy to help resolve these discrepancies and enable better modeling of the NLTE processes that are integral to high-energy density experiments. Advances in target fabrication, diagnostic development and simulation capabilities provided the foundations for this project. Uniform plasmas were to be achieved by using aerogel foams of low enough density ({approx}mg/cm{sup 3}) and thickness ({approx}mm) to be volumetrically heated by a laser. The foams were doped with Ti to provide K- and L-shell emission and recombination spectra during the experiments. A new absolutely calibrated transmission grating spectrometer provided absolute temporal measurements at 18 frequencies, in addition to a CCD image of the time-integrated spectrum. Finally, …
Date: April 19, 2010
Creator: Scott, H. A.
Object Type: Report
System: The UNT Digital Library
2009 Argonne National Laboratory Annual Illness and Injury Surveillance Report (open access)

2009 Argonne National Laboratory Annual Illness and Injury Surveillance Report

The U.S. Department of Energy’s (DOE) commitment to assuring the health and safety of its workers includes the conduct of epidemiologic surveillance activities that provide an early warning system for health problems among workers. The Illness and Injury Surveillance Program monitors illnesses and health conditions that result in an absence of workdays, occupational injuries and illnesses, and disabilities and deaths among current workers.
Date: August 19, 2010
Creator: United States. Department of Energy. Office of Illness and Injury Prevention Programs.
Object Type: Report
System: The UNT Digital Library
Two-stage Framework for a Topology-Based Projection and Visualization of Classified Document Collections (open access)

Two-stage Framework for a Topology-Based Projection and Visualization of Classified Document Collections

During the last decades, electronic textual information has become the world's largest and most important information source available. People have added a variety of daily newspapers, books, scientific and governmental publications, blogs and private messages to this wellspring of endless information and knowledge. Since neither the existing nor the new information can be read in its entirety, computers are used to extract and visualize meaningful or interesting topics and documents from this huge information clutter. In this paper, we extend, improve and combine existing individual approaches into an overall framework that supports topological analysis of high dimensional document point clouds given by the well-known tf-idf document-term weighting method. We show that traditional distance-based approaches fail in very high dimensional spaces, and we describe an improved two-stage method for topology-based projections from the original high dimensional information space to both two dimensional (2-D) and three dimensional (3-D) visualizations. To show the accuracy and usability of this framework, we compare it to methods introduced recently and apply it to complex document and patent collections.
Date: July 19, 2010
Creator: Oesterling, Patrick; Scheuermann, Gerik; Teresniak, Sven; Heyer, Gerhard; Koch, Steffen; Ertl, Thomas et al.
Object Type: Article
System: The UNT Digital Library
NEXT GENERATION MELTER OPTIONEERING STUDY - INTERIM REPORT (open access)

NEXT GENERATION MELTER OPTIONEERING STUDY - INTERIM REPORT

The next generation melter (NOM) development program includes a down selection process to aid in determining the recommended vitrification technology to implement into the WTP at the first melter change-out which is scheduled for 2025. This optioneering study presents a structured value engineering process to establish and assess evaluation criteria that will be incorporated into the down selection process. This process establishes an evaluation framework that will be used progressively throughout the NGM program, and as such this interim report will be updated on a regular basis. The workshop objectives were achieved. In particular: (1) Consensus was reached with stakeholders and technology providers represented at the workshop regarding the need for a decision making process and the application of the D{sub 2}0 process to NGM option evaluation. (2) A framework was established for applying the decision making process to technology development and evaluation between 2010 and 2013. (3) The criteria for the initial evaluation in 2011 were refined and agreed with stakeholders and technology providers. (4) The technology providers have the guidance required to produce data/information to support the next phase of the evaluation process. In some cases it may be necessary to reflect the data/information requirements and overall approach …
Date: October 19, 2010
Creator: MF, GRAY; RB, CALMUS; G, RAMSEY; J, LOMAX & H, ALLEN
Object Type: Report
System: The UNT Digital Library