Catalyzed Water Oxidation by Solar Irradiation of Band-Gap-Narrowed Semiconductors (Part 2. Overview). (open access)

Catalyzed Water Oxidation by Solar Irradiation of Band-Gap-Narrowed Semiconductors (Part 2. Overview).

The objectives of this report are: (1) Investigate the catalysis of water oxidation by cobalt and manganese hydrous oxides immobilized on titania or silica nanoparticles, and dinuclear metal complexes with quinonoid ligands in order to develop a better understanding of the critical water oxidation chemistry, and rationally search for improved catalysts. (2) Optimize the light-harvesting and charge-separation abilities of stable semiconductors including both a focused effort to improve the best existing materials by investigating their structural and electronic properties using a full suite of characterization tools, and a parallel effort to discover and characterize new materials. (3) Combine these elements to examine the function of oxidation catalysts on Band-Gap-Narrowed Semiconductor (BGNSC) surfaces and elucidate the core scientific challenges to the efficient coupling of the materials functions.
Date: March 18, 2008
Creator: Fujita, E.; Khalifah, P.; Lymar, S.; Muckerman, J. T. & Rodriguez, J.
Object Type: Article
System: The UNT Digital Library
TRANSITION STATE FOR THE GAS-PHASE REACTION OF URANIUM HEXAFLUORIDE WITH WATER (open access)

TRANSITION STATE FOR THE GAS-PHASE REACTION OF URANIUM HEXAFLUORIDE WITH WATER

Density Functional Theory and small-core, relativistic pseudopotentials were used to look for symmetric and asymmetric transitions states of the gas-phase hydrolysis reaction of uranium hexafluoride, UF{sub 6}, with water. At the B3LYP/6-31G(d,p)/SDD level, an asymmetric transition state leading to the formation of a uranium hydroxyl fluoride, U(OH)F{sub 5}, and hydrogen fluoride was found with an energy barrier of +77.3 kJ/mol and an enthalpy of reaction of +63.0 kJ/mol (both including zero-point energy corrections). Addition of diffuse functions to all atoms except uranium led to only minor changes in the structure and relative energies of the reacting complex and transition state. However, a significant change in the product complex structure was found, significantly reducing the enthalpy of reaction to +31.9 kJ/mol. Similar structures and values were found for PBE0 and MP2 calculations with this larger basis set, supporting the B3LYP results. No symmetric transition state leading to the direct formation of uranium oxide tetrafluoride, UOF{sub 4}, was found, indicating that the reaction under ambient conditions likely includes several more steps than the mechanisms commonly mentioned. The transition state presented here appears to be the first published transition state for the important gas-phase reaction of UF{sub 6} with water.
Date: March 18, 2008
Creator: Garrison, S & James Becnel, J
Object Type: Article
System: The UNT Digital Library
Cleanup Verification Package for the 118-F-8:4 Fuel Storage Basin West Side Adjacent and Side Slope Soils (open access)

Cleanup Verification Package for the 118-F-8:4 Fuel Storage Basin West Side Adjacent and Side Slope Soils

This cleanup verification package documents completion of remedial action, sampling activities, and compliance with cleanup criteria for the 118-F-8:4 Fuel Storage Basin West Side Adjacent and Side Slope Soils. The rectangular-shaped concrete basin on the south side of the 105-F Reactor building served as an underwater collection, storage, and transfer facility for irradiated fuel elements discharged from the reactor.
Date: March 18, 2008
Creator: Habel, L. D.
Object Type: Report
System: The UNT Digital Library
THE USE OF VAPOR EXTRACTION SYSTEM AND ITS SUBSEQUENT REDUCTION OF WORKER EXPOSURE TO CARBON TETRACHLORIDE DURING RETRIEVAL OF HANFORDS LEGACY WASTE (open access)

THE USE OF VAPOR EXTRACTION SYSTEM AND ITS SUBSEQUENT REDUCTION OF WORKER EXPOSURE TO CARBON TETRACHLORIDE DURING RETRIEVAL OF HANFORDS LEGACY WASTE

The Hanford Site is a decommissioned nuclear productions complex located in south eastern Washington and is operated by the Department of Energy (DOE). From 1955 to 1973, carbon tetrachloride (CCl{sub 4}), used in mixtures with other organic compounds, was used to recover plutonium from aqueous streams at Z Plant located on the Hanford Site. The aqueous and organic liquid waste that remained at the end of this process was discharged to soil columns in waste cribs located near Z Plant. Included in this waste slurry along with CCl{sub 4} were tributyl phosphate, dibutyl butyl phosphate, and lard oil. (Truex et al., 2001). In the mid 1980's, CCl{sub 4} was found in the unconfined aquifer below the 200 West Area and subsequent ground water monitoring indicated that the plume was widespread and that the concentrations were increasing. It has been estimated that approximately 750,000 kg (826.7 tons) of CCl{sub 4} was discharged to the soil from 1955 to 1973. (Truex et al., 2001). With initial concentration readings of approximately 30,000 parts per million by volume (ppmv) in one well field alone, soil vapor extraction began in 1992 in an effort to remove the CCl{sub 4} from the soil. (Rohay, 1999). Since …
Date: March 18, 2008
Creator: DA, PITTS
Object Type: Article
System: The UNT Digital Library
Properties of Transition Metal Atoms and Ions (open access)

Properties of Transition Metal Atoms and Ions

Accomplishments of this project include: (1) improvement of the accuracy and efficiency of the RCI methodology to permit it to tackle almost all TM properties, and making good progress in extending these gains to the RE. Our improvements have stimulated improvements in the GRASP package, done by Froese Fischer. RCI efficiency gains are estimated to be {approx} 200x since the start of the project - about 10x from hardware improvements (originally DOE funded) and about 20x from software improvements. The net result is that currently the longest runs don't exceed 1 day. (2) identification and removal of systematic errors in several TM properties. To some extent, the PI became a 'court of last resort' for experimenters who wondered why certain theoretical-experimental discrepancies existed. Auxiliary analysis codes were written and successfully used to improve the systematic understanding of correlation effects in TM and RE. This improved efficiency and a priori understanding of what new projects might involve. [Unsurprisingly, there are several cases which the PI was unable to resolve. Work on these is unpublished]. (3) education and training of graduate students and postdocs.
Date: March 18, 2008
Creator: Donald, Beck, R.
Object Type: Report
System: The UNT Digital Library
Catalyzed Water Oxidation by Solar Irradiation of Band-Gap-Narrowed Semiconductors (Part 1. Overview). (open access)

Catalyzed Water Oxidation by Solar Irradiation of Band-Gap-Narrowed Semiconductors (Part 1. Overview).

The objectives of this report are: (1) Investigate the catalysis of water oxidation by cobalt and manganese hydrous oxides immobilized on titania or silica nanoparticles, and dinuclear metal complexes with quinonoid ligands in order to develop a better understanding of the critical water oxidation chemistry, and rationally search for improved catalysts. (2) Optimize the light-harvesting and charge-separation abilities of stable semiconductors including both a focused effort to improve the best existing materials by investigating their structural and electronic properties using a full suite of characterization tools, and a parallel effort to discover and characterize new materials. (3) Combine these elements to examine the function of oxidation catalysts on Band-Gap-Narrowed Semiconductor (BGNSC) surfaces and elucidate the core scientific challenges to the efficient coupling of the materials functions.
Date: March 18, 2008
Creator: Fujita, E.; Khalifah, P.; Lymar, S.; Muckerman, J. T. & Rodgriguez, J.
Object Type: Article
System: The UNT Digital Library
41. DISCOVERY, SEARCH, AND COMMUNICATION OF TEXTUAL KNOWLEDGE RESOURCES IN DISTRIBUTED SYSTEMS a. Discovering and Utilizing Knowledge Sources for Metasearch Knowledge Systems (open access)

41. DISCOVERY, SEARCH, AND COMMUNICATION OF TEXTUAL KNOWLEDGE RESOURCES IN DISTRIBUTED SYSTEMS a. Discovering and Utilizing Knowledge Sources for Metasearch Knowledge Systems

Advanced Natural Language Processing Tools for Web Information Retrieval, Content Analysis, and Synthesis. The goal of this SBIR was to implement and evaluate several advanced Natural Language Processing (NLP) tools and techniques to enhance the precision and relevance of search results by analyzing and augmenting search queries and by helping to organize the search output obtained from heterogeneous databases and web pages containing textual information of interest to DOE and the scientific-technical user communities in general. The SBIR investigated 1) the incorporation of spelling checkers in search applications, 2) identification of significant phrases and concepts using a combination of linguistic and statistical techniques, and 3) enhancement of the query interface and search retrieval results through the use of semantic resources, such as thesauri. A search program with a flexible query interface was developed to search reference databases with the objective of enhancing search results from web queries or queries of specialized search systems such as DOE's Information Bridge. The DOE ETDE/INIS Joint Thesaurus was processed to create a searchable database. Term frequencies and term co-occurrences were used to enhance the web information retrieval by providing algorithmically-derived objective criteria to organize relevant documents into clusters containing significant terms. A thesaurus provides …
Date: March 18, 2008
Creator: Zamora, Antonio
Object Type: Report
System: The UNT Digital Library
Ecology of Juvenile Salmonids in Shallow Tidal Freshwater Habitats in the Vicinity of the Sandy River Delta, Lower Columbia River, 2007 (open access)

Ecology of Juvenile Salmonids in Shallow Tidal Freshwater Habitats in the Vicinity of the Sandy River Delta, Lower Columbia River, 2007

This document is the first annual report for the study titled “Ecology of Juvenile Salmonids in Shallow Tidal Freshwater Habitats in the Vicinity of the Sandy River Delta in the Lower Columbia River.” Hereafter, we refer to this research as the Tidal Freshwater Monitoring (TFM) Study. The study is part of the research, monitoring, and evaluation effort developed by the Action Agencies (Bonneville Power Administration, U.S. Army Corps of Engineers, U.S. Bureau of Reclamation) in response to obligations arising from the Endangered Species Act as a result of operation of the Federal Columbia River Power System (FCRPS). The project is performed under the auspices of the Northwest Power and Conservation Council’s Columbia Basin Fish and Wildlife Program.
Date: March 18, 2008
Creator: Sobocinski, Kathryn L.; Johnson, Gary E.; Sather, Nichole K.; Storch, Adam; Jones, Tucker A.; Mallette, Christine et al.
Object Type: Report
System: The UNT Digital Library
Remaining Sites Verification Package for the 100-F-26:15 Miscellaneous Pipelines Associated with the 132-F-6, 1608-F Waste Water Pumping Station, Waste Site Reclassification Form 2007-031 (open access)

Remaining Sites Verification Package for the 100-F-26:15 Miscellaneous Pipelines Associated with the 132-F-6, 1608-F Waste Water Pumping Station, Waste Site Reclassification Form 2007-031

The 100-F-26:15 waste site consisted of the remnant portions of underground process effluent and floor drain pipelines that originated at the 105-F Reactor. In accordance with this evaluation, the verification sampling results support a reclassification of this site to Interim Closed Out. The results of verification sampling show that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River.
Date: March 18, 2008
Creator: Dittmer, L. M.
Object Type: Report
System: The UNT Digital Library
Pulse Length Control in an X-Ray FEL by Using Wakefields (open access)

Pulse Length Control in an X-Ray FEL by Using Wakefields

For the users of the high-brightness radiation sources of free-electron lasers it is desirable to reduce the FEL pulse length to 10 fs and below for time-resolved pump and probe experiments. Although it can be achieved by conventional compression methods for the electron beam or the chirped FEL pulse, the technical realization is demanding. In this presentation we study the impact of longitudinal wakefields in the undulator and how their properties can be used to reduced the amplifying part of the bunch to the desired length. Methods of actively controlling the wakefields are presented.
Date: March 18, 2008
Creator: Reiche, S.; Pellegrini, Claudio; Emma, P. & /SLAC, /UCLA
Object Type: Article
System: The UNT Digital Library
Injection Related Background due to the Transverse Feedback (open access)

Injection Related Background due to the Transverse Feedback

The background in the BaBar detector is especially high during injection, when most components are actually having reduced voltages. The situation is worse for the beam in High Energy Ring (HER) when the LER beam is present. It was found that the transverse feedback system plays an important role when stacking more charge on top of existing bunches. Lowering the feedback gain helped and it was realized later that the best scenario would be to gate off the feedback for only the one bunch, which got additional charge injected into it. The explanation is that the blown-up, but centered, original HER bunch plus the small injected off-axis bunch (each with half the charge) would stay in the ring if not touched, but the feedback system sees half the offset and wants to correct it, therefore disturbing and scraping the blown-up part.
Date: March 18, 2008
Creator: Decker, F. J.; Akre, R.; Fisher, A.; Iverson, R. & Weaver, M.
Object Type: Article
System: The UNT Digital Library
Formation of Nanopore-Arrays by Plasma-based Thin FilmDeposition (open access)

Formation of Nanopore-Arrays by Plasma-based Thin FilmDeposition

The ability to fabricate membranes with arrays of apertures only a few nanometers in diameter are important to many fields of research, including ion beam lithography, DNA sequencing, single ion implantations, and single molecule studies. Because even the state-of-the-art lithography tools are limited in their ability to produce nanoscale features, alternative methods of fabricating single pores of nanometer scale have been developed, using ion-beam sculpting and focused-ion-beam assisted deposition. However, these methods cannot simultaneously produce multiple holes of nanometer dimension. Here we report a means of forming arrays of nanopores simultaneously on a thin, solid-state membrane using plasma-based thin-film deposition. By depositing layers of metallic thin films, the aperture sizes of pores in a pre-fabricated membrane can be reduced from a couple of micrometers down to tens of nanometers and even smaller. The technique offers a way to reduce the sizes of aperture of any shape in a variety of substrate materials, both conducting and insulating. Such arrays of nanopores can serve as membrane channels for DNA sequencing, as masks in ion-beam imprinters, for the fabrication of quantum dots, and in other applications.
Date: March 18, 2005
Creator: Ji, Qing; Chen, Y.; Jiang, Ximan; Ji, Lili & Leung, K. N.
Object Type: Report
System: The UNT Digital Library
Structure and Phase Transformations in Pu Alloys (open access)

Structure and Phase Transformations in Pu Alloys

None
Date: March 18, 2008
Creator: Schwartz, A. J.; Massalski, T. B.; Cynn, H.; Evans, W. J.; Farber, D. L.; Wall, M. A. et al.
Object Type: Article
System: The UNT Digital Library
Parris Island Wastewater Treatment Plant SCADA Upgrades Final Report (open access)

Parris Island Wastewater Treatment Plant SCADA Upgrades Final Report

Marine Corp Recruit Depot (MCRD), Parris Island, SC, home of the Easter Recruiting Region Marine Corp Boot Camp, found itself in a situation common to Department of Defense (DOD) facilities. It had to deal with several different types of installed energy-related control systems that could not talk to each other. This situation was being exacerbated by the installation of a new and/or unique type of control system for every new building being constructed or older facility that was being upgraded. The Wastewater Treatment Facility (WWTF) and lift station controls were badly in need of a thorough inspection and a new Supervisory Control and Data Acquisition (SCADA) system upgrade to meet environmental, safety, manpower, and maintenance concerns. A project was recently completed to implement such a wastewater treatment SCADA upgrade, which is compatible with other upgrades to the energy monitoring and control systems for Parris Island buildings and the Pacific Northwest National Laboratory (PNNL) Decision Support for Operations and Maintenance (DSOM) system installed at the Central Energy Plant (CEP). This project included design, specification, procurement, installation, and testing an upgraded SCADA alarm, process monitoring, and display system; and training WWTF operators in its operation. The ultimate goal of this and the …
Date: March 18, 2004
Creator: Meador, Richard J. & Hatley, Darrel D.
Object Type: Report
System: The UNT Digital Library
Thermally induced dephasing in periodically poled KTiOPO4 nonlinear crystals (open access)

Thermally induced dephasing in periodically poled KTiOPO4 nonlinear crystals

Experimental data that exhibits a continuous-wave, second-harmonic intensity threshold (15 kW/cm{sup 2}) that causes two-photon nonlinear absorption which leads to time-dependent photochromic damage in periodically poled KTiOPO{sub 4} is presented and verified through a thermal dephasing model.
Date: March 18, 2004
Creator: Dawson, J W; Pennington, D M; Jovanovic, I; Liao, Z M; Payne, S A; Drobshoff, A D et al.
Object Type: Article
System: The UNT Digital Library
Comment on"Air Emissions Due to Wind and Solar Power" and Supporting Information (open access)

Comment on"Air Emissions Due to Wind and Solar Power" and Supporting Information

Katzenstein and Apt investigate the important question of pollution emission reduction benefits from variable generation resources such as wind and solar. Their methodology, which couples an individual variable generator to a dedicated gas plant to produce a flat block of power is, however, inappropriate. For CO{sub 2}, the authors conclude that variable generators 'achieve {approx} 80% of the emission reductions expected if the power fluctuations caused no additional emissions.' They find even lower NO{sub x} emission reduction benefits with steam-injected gas turbines and a 2-4 times net increase in NO{sub x} emissions for systems with dry NO{sub x} control unless the ratio of energy from natural gas to variable plants is greater than 2:1. A more appropriate methodology, however, would find a significantly lower degradation of the emissions benefit than suggested by Katzenstein and Apt. As has been known for many years, models of large power system operations must take into account variable demand and the unit commitment and economic dispatch functions that are practiced every day by system operators. It is also well-known that every change in wind or solar power output does not need to be countered by an equal and opposite change in a dispatchable resource. The …
Date: March 18, 2009
Creator: Mills, Andrew D.; Wiser, Ryan H.; Milligan, Michael & O'Malley, Mark
Object Type: Article
System: The UNT Digital Library
Cooperative Agreement with DOE/OIT on Energy Efficiency and Best Practices - Final Report (open access)

Cooperative Agreement with DOE/OIT on Energy Efficiency and Best Practices - Final Report

This Cooperative Agreement was focuse on the development and dissemination of technologies, best-practices, energy-efficiency assessment programs, etc., that could support industry's drive to become more competitive in a rapidly chaning and highly competitive global marketplace. The Agreement covered a rane of collaborative activities between AIChE and DOE/ITP's various Industries of the Future ("IOF") Teams such as: 1. Help with technology evaluation adn support by providing industry experts to: a) Review solicitation proposals b) Review technology portfolios as deeped appropriate by DOE/ITP c) Market IOF Best Practices through outreach and technical assistance at the plant-level adn via meetings with operations staff. 2) Help establish various programs with industry, academia and National Laboratories to develop tools, methodologies and benchmarks that entities served by IOF would find valuable in establishing goals for improving energy consumption in specific processes. 3) Support IOF with Technology Vision 2020 programs.
Date: March 18, 2009
Creator: Rogers, Joseph E.
Object Type: Report
System: The UNT Digital Library
Systematics of Coupling Flows in AdS Backgrounds (open access)

Systematics of Coupling Flows in AdS Backgrounds

We give an effective field theory derivation, based on the running of Planck brane gauge correlators, of the large logarithms that arise in the predictions for low energy gauge couplings in compactified AdS}_5 backgrounds, including the one-loop effects of bulk scalars, fermions, and gauge bosons. In contrast to the case of charged scalars coupled to Abelian gauge fields that has been considered previously in the literature, the one-loop corrections are not dominated by a single 4D Kaluza-Klein mode. Nevertheless, in the case of gauge field loops, the amplitudes can be reorganized into a leading logarithmic contribution that is identical to the running in 4D non-Abelian gauge theory, and a term which is not logarithmically enhanced and is analogous to a two-loop effect in 4D. In a warped GUT model broken by the Higgs mechanism in the bulk,we show that the matching scale that appears in the large logarithms induced by the non-Abelian gauge fields is m_{XY}^2/k where m_{XY} is the bulk mass of the XY bosons and k is the AdS curvature. This is in contrast to the UV scale in the logarithmic contributions of scalars, which is simply the bulk mass m. Our results are summarized in a set …
Date: March 18, 2003
Creator: Goldberger, Walter D. & Rothstein, Ira Z.
Object Type: Article
System: The UNT Digital Library
MASS MEASUREMENT UNCERTAINTY FOR PLUTONIUM ALIQUOTS ASSAYED BY CONTROLLED-POTENTIAL COULOMETRY (open access)

MASS MEASUREMENT UNCERTAINTY FOR PLUTONIUM ALIQUOTS ASSAYED BY CONTROLLED-POTENTIAL COULOMETRY

Minimizing plutonium measurement uncertainty is essential to nuclear material control and international safeguards. In 2005, the International Organization for Standardization (ISO) published ISO 12183 'Controlled-potential coulometric assay of plutonium', 2nd edition. ISO 12183:2005 recommends a target of {+-}0.01% for the mass of original sample in the aliquot because it is a critical assay variable. Mass measurements in radiological containment were evaluated and uncertainties estimated. The uncertainty estimate for the mass measurement also includes uncertainty in correcting for buoyancy effects from air acting as a fluid and from decreased pressure of heated air from the specific heat of the plutonium isotopes.
Date: March 18, 2009
Creator: Holland, M. & Cordaro, J.
Object Type: Article
System: The UNT Digital Library
Final Report - Independent Confirmatory Survey Summary and Results for the Hematite Decommissioning Project (open access)

Final Report - Independent Confirmatory Survey Summary and Results for the Hematite Decommissioning Project

The objectives of the confirmatory surveys were to provide independent contractor field data reviews and to generate independent radiological data for use by the NRC in evaluating the adequacy and accuracy of the licensee’s procedures and survey results.
Date: March 18, 2009
Creator: Bailey, E.N.
Object Type: Report
System: The UNT Digital Library
QCD THERMODYNAMICS WITH ALMOST REALISTIC QUARK MASSES. (open access)

QCD THERMODYNAMICS WITH ALMOST REALISTIC QUARK MASSES.

None
Date: March 18, 2006
Creator: SCHMIDT, C.
Object Type: Article
System: The UNT Digital Library
Studies of nondegenerate, quasi-phase-matched optical parametric amplification (open access)

Studies of nondegenerate, quasi-phase-matched optical parametric amplification

We have performed extensive numerical studies of quasi-phase-matched optical parametric amplification with the aim to improve its nondegenerate spectral bandwidth. Our multi-section fan-out design calculations indicate a 35-fold increase in spectral bandwidth.
Date: March 18, 2004
Creator: Lawrence Livermore National Laboratory
Object Type: Article
System: The UNT Digital Library
Report on Analyses of WAC Samples of Evaporator Overheads - 2004 (open access)

Report on Analyses of WAC Samples of Evaporator Overheads - 2004

In November and December of 2004, the Tank Farm submitted annual samples from 2F, 2H and 3H Evaporator Overhead streams for characterization to verify compliance with the new Effluent Treatment Facility (ETF) Waste Acceptance Criteria (WAC) and to look for organic species. With the exception of slightly high ammonia in the 2F evaporator overheads and high radiation control guide number for the 3H and 2F evaporator overhead samples, all the overheads samples were found to be in compliance with the Effluent Treatment Facility WAC. The ammonium concentration in the 2F-evaporator overhead, at 33 mg/L, was above the ETF waste water collection tank (WWCT) limits of 28 mg/L. The RCG Number for the 3H and 2F evaporator samples at, respectively, 1.38E-02 and 8.24E-03 were higher than the WWCT limit of 7.69E-03. The analytical detection limits for americium-241 and radium-226 in the evaporator samples were not consistently met because of low WWCT detection limits and insufficient evaporator samples.
Date: March 18, 2005
Creator: Oji, L
Object Type: Report
System: The UNT Digital Library
Nanoscience Research for Energy Needs. Report of the National Nanotechnology Initiative Grand Challenge Workshop, March 16-18, 2004 (open access)

Nanoscience Research for Energy Needs. Report of the National Nanotechnology Initiative Grand Challenge Workshop, March 16-18, 2004

This document is the report of a workshop held under NSET auspices in March 2004 aimed at identifying and articulating the relationship of nanoscale science and technology to the Nation's energy future.
Date: March 18, 2004
Creator: Alivisatos, P.; Cummings, P.; De Yoreo, J.; Fichthorn, K.; Gates, B.; Hwang, R. et al.
Object Type: Report
System: The UNT Digital Library