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Reduction of pertechnetate by acetohydroxamic acid: Formation of [TcNO(AHA)2(H2O)]+ and implications for the UREX process. (open access)

Reduction of pertechnetate by acetohydroxamic acid: Formation of [TcNO(AHA)2(H2O)]+ and implications for the UREX process.

Reductive nitrosylation and complexation of ammonium pertechnetate by acetohydroxamic acid has been achieved in aqueous nitric and perchloric acid solutions. The kinetics of the reaction depend on the relative concentrations of the reaction components and are accelerated at higher temperatures. The reaction does not occur unless conditions are acidic. Analysis of the x-ray absorption fine structure spectroscopic data is consistent with a pseudo-octahedral geometry with the linear Tc-N-O bond typical of technetium nitrosyl compounds, and electron spin resonance spectroscopy is consistent with a the d{sup 5} Tc(II) nitrosyl complex. The nitrosyl source is generally AHA, but may be augmented by products of reaction with nitric acid. The resulting low-valency trans-aquonitrosyl(diacetohydroxamic)-technetium(II) complex (1) is highly soluble in water, extremely hydrophilic, and is not extracted by tri-n-butylphosphate in a dodecane diluent. Its extraction properties are not pH-dependent; titration studies indicate a single species from pH 4.5 down to -0.6 (calculated). This molecule is resistant to oxidation by H{sub 2}O{sub 2}, even at high pH, and can undergo substitution to form other technetium nitrosyl complexes. The formation of 1 may strongly impact the fate of technetium in the nuclear fuel cycle.
Date: February 26, 2008
Creator: 1Harry Reid Center for Environmental Studies, Nuclear Science and Technology Division, University of Nevada, Las Vegas, Las Vegas, NV, 89154-4006; Gong, Cynthia-May S; Poineau, Frederic; Lukens, Wayne W & Czerwinski, Kenneth R.
Object Type: Article
System: The UNT Digital Library
Frequency Doubling Broadband Light in Multiple Crystals (open access)

Frequency Doubling Broadband Light in Multiple Crystals

The authors compare frequency doubling of broadband light in a single nonlinear crystal with doubling in five crystals with intercrystal temporal walk off compensation, and with doubling in five crystals adjusted for offset phase matching frequencies. Using a plane-wave, dispersive numerical model of frequency doubling they study the bandwidth of the second harmonic and the conversion efficiency as functions of crystal length and fundamental irradiance. For low irradiance the offset phase matching arrangement has lower efficiency than a single crystal of the same total length but gives a broader second harmonic bandwidth. The walk off compensated arrangement gives both higher conversion efficiency and broader bandwidth than a single crystal. At high irradiance, both multicrystal arrangements improve on the single crystal efficiency while maintaining broad bandwidth.
Date: July 26, 2000
Creator: ALFORD,WILLIAM J. & SMITH,ARLEE V.
Object Type: Article
System: The UNT Digital Library
Archaeological Survey Within the Proposed McDermott Development Site (open access)

Archaeological Survey Within the Proposed McDermott Development Site

Archaeological survey results for proposed 33 acre McDermott Development Site in Collin County, Texas.
Date: January 26, 2006
Creator: AR Consultants
Object Type: Text
System: The Portal to Texas History
Middleware for Astronomical Data Analysis Pipelines (open access)

Middleware for Astronomical Data Analysis Pipelines

In this paper the authors describe the approach to research, develop, and evaluate prototype middleware tools and architectures. The developed tools can be used by scientists to compose astronomical data analysis pipelines easily. They use the SuperMacho data pipelines as example applications to test the framework. they describe their experience from scheduling and running these analysis pipelines on massive parallel processing machines. they use MCR a Linux cluster machine with 1152 nodes and Luster parallel file system as the hardware test-bed to test and enhance the scalability of the tools.
Date: January 26, 2005
Creator: Abdulla, G.; Liu, D.; Garlick, J.; Miller, M.; Nikolaev, S.; Cook, K. et al.
Object Type: Article
System: The UNT Digital Library
Simulation of the Future LSST Data Pipelines (open access)

Simulation of the Future LSST Data Pipelines

In this paper we describe our approach to build a pipeline simulator for the future Large-scale Synoptic Survey Telescope (LSST). The simulated pipeline will be used to research and evaluate software architectures that are efficient and flexible. It will also be used to define the real-time software and hardware requirements needed to support the anticipated LSST data rates. The LSST data pipeline requirements are still being defined, however, previous surveys can provide a good source for data requirements. Our approach is to use the SuperMacho data pipeline as a prototyping tool to identify a framework for building Modular Data-Centric Pipeline (MDCP) architectures. The prototyping is done in a hierarchical fashion to help capture and define the general data attributes (schema) first. We then model other necessary components based on science and performance requirements. We use identified schemas or data attributes as a way to define a data model for LSST.
Date: July 26, 2004
Creator: Abdulla, Ghaleb M.
Object Type: Article
System: The UNT Digital Library
Electric Utility Policy: Comparison of House-Passed H.R. 6 and S.Amdt. 1412, 108th Congress (open access)

Electric Utility Policy: Comparison of House-Passed H.R. 6 and S.Amdt. 1412, 108th Congress

None
Date: August 26, 2003
Creator: Abel, Amy
Object Type: Report
System: The UNT Digital Library
[Letter from Julie Abel to Phillip C. Diebel - January 26, 2001] (open access)

[Letter from Julie Abel to Phillip C. Diebel - January 26, 2001]

A letter to Phillip C. Diebel from Julie Abel regarding a grant check from the Getty Education Institute for the Arts to the North Texas Institute for Educators in the Visual Arts (NTIEVA).
Date: January 26, 2001
Creator: Abel, Julie A.
Object Type: Letter
System: The UNT Digital Library
Final Scientific Report (open access)

Final Scientific Report

Viscosities of water, nitrogen and carbon dioxide have been measured at elevated pressures and temperatures in the diamond-anvil cell. A strong correlation between viscosity and entropy has been confirmed.
Date: June 26, 2009
Creator: Abramson, Evan
Object Type: Report
System: The UNT Digital Library
Thermal Decomposition of Radiation-Damaged Polystyrene (open access)

Thermal Decomposition of Radiation-Damaged Polystyrene

The radiation-damaged polystyrene (given the identification name of 'polycube') was fabricated by mixing high-density polystyrene material ("Dylene Fines # 100") with plutonium and uranium oxides. The polycubes were used in the 1960s for criticality studies during processing of spent nuclear fuel. The polycubes have since been stored for almost 40 years at the Hanford Plutonium Finishing Plant (PFP) after failure of two processes to reclaim the plutonium and uranium oxides from the polystyrene matrix. Thermal decomposition products from this highly cross-linked polystyrene matrix were characterized using Gas Chromatograph/Mass Spectroscopy (GC/MS) system coupled to a horizontal furnace. The decomposition studies were performed in air and helium atmospheres at about 773 K. The volatile and semi-volatile organic products for the radiation-damaged polystyrene were different compared to virgin polystyrene. The differences were in the number of organic species generated and their concentrations. In the inert (i.e., helium) atmosphere, the major volatile organic products identified (in order of decreasing concentrations) were styrene, benzene, toluene, ethylbenzene, xylene, nathphalene, propane, .alpha.-methylbenzene, indene and 1,2,3-trimethylbenzene. But in air, the major volatile organic species identified changed slightly. Concentrations of the organic species in the inert atmosphere were significantly higher than those for the air atmosphere processing. Overall, 38 …
Date: September 26, 2000
Creator: Abrefah, John & Klinger, George S.
Object Type: Report
System: The UNT Digital Library
EARLY ENTRANCE COPRODUCTION PLANT (open access)

EARLY ENTRANCE COPRODUCTION PLANT

The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which produces at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals. The objective is to have these products produced by technologies capable of using synthesis gas derived from coal and/or other carbonaceous feedstock. The objective of Phase I is to determine the feasibility and define the concept for the EECP located at a specific site and to develop a Research, Development, and Testing Plan (RD and T) for implementation in Phase II. The objective of Phase II is to implement the RD and T as outlined in the Phase I RD and T Plan to enhance the development and commercial acceptance of coproduction technology that produces high-value products, particularly those that are critical to our domestic fuel and power requirements. The project will resolve critical knowledge and technology gaps on the integration of gasification and downstream processing to coproduce some combination of power, fuels, and chemicals from coal and other feedstocks. The objective of Phase III is to develop an engineering design package and a financing plan for …
Date: October 26, 2000
Creator: Abughazaleh, John S.; Ahmed, Mushtaq; Anand, Ashok; Anderson, John H.; Benham, Charles; Brent, Fred D. et al.
Object Type: Report
System: The UNT Digital Library
Insulated Pressure Vessels for Vehicular Hydrogen Storage: Analysis and Performance Evaluation (open access)

Insulated Pressure Vessels for Vehicular Hydrogen Storage: Analysis and Performance Evaluation

Insulated pressure vessels are cryogenic-capable pressure vessels that can be fueled with liquid hydrogen (LH{sub 2}) or ambient-temperature compressed hydrogen (CH{sub 2}). Insulated pressure vessels offer the advantages of liquid hydrogen tanks (low weight and volume), with reduced disadvantages (fuel flexibility, lower energy requirement for hydrogen liquefaction and reduced evaporative losses). The work described here is directed at verifying that commercially available pressure vessels can be safely used to store liquid hydrogen. The use of commercially available pressure vessels significantly reduces the cost and complexity of the insulated pressure vessel development effort. This paper describes a series of tests that have been done with aluminum-lined, fiber-wrapped vessels to evaluate the damage caused by low temperature operation. All analysis and experiments to date indicate that no significant damage has resulted. Required future tests are described that will prove that no technical barriers exist to the safe use of aluminum-fiber vessels at cryogenic temperatures. Future activities also include a demonstration project in which the insulated pressure vessels will be installed and tested on two vehicles. A draft standard will also be generated for obtaining certification for insulated pressure vessels.
Date: June 26, 2001
Creator: Aceves, S. M.; Martinez-Frias, J.; Garcia-Villazana, O. & Espinosa-Loza, F.
Object Type: Article
System: The UNT Digital Library
Monitoring the Migrations of Wild Snake River Spring/Summer Chinook Salmon Juveniles, 2007-2008 Report of Research. (open access)

Monitoring the Migrations of Wild Snake River Spring/Summer Chinook Salmon Juveniles, 2007-2008 Report of Research.

This report provides results from an ongoing project to monitor the migration behavior and survival of wild juvenile spring/summer Chinook salmon in the Snake River Basin. Data reported is from detections of PIT tagged fish during late summer 2007 through mid-2008. Fish were tagged in summer 2007 by the National Marine Fisheries Service (NMFS) in Idaho and by the Oregon Department of Fish and Wildlife (ODFW) in Oregon. Our analyses include migration behavior and estimated survival of fish at instream PIT-tag monitors and arrival timing and estimated survival to Lower Granite Dam. Principal results from tagging and interrogation during 2007-2008 are listed below: (1) In July and August 2007, we PIT tagged and released 7,390 wild Chinook salmon parr in 12 Idaho streams or sample areas. (2) Overall observed mortality from collection, handling, tagging, and after a 24-hour holding period was 1.4%. (3) Of the 2,524 Chinook salmon parr PIT tagged and released in Valley Creek in summer 2007, 218 (8.6%) were detected at two instream PIT-tag monitoring systems in lower Valley Creek from late summer 2007 to the following spring 2008. Of these, 71.6% were detected in late summer/fall, 11.9% in winter, and 16.5% in spring. Estimated parr-to-smolt survival …
Date: May 26, 2009
Creator: Achord, Stephen; Sandford, Benjamin P. & Hockersmith, Eric E.
Object Type: Report
System: The UNT Digital Library
Supreme Court: Church-State Cases, 2001-2002 Term (open access)

Supreme Court: Church-State Cases, 2001-2002 Term

None
Date: November 26, 2002
Creator: Ackerman, David M.
Object Type: Report
System: The UNT Digital Library
Indulging in the Pleasures of God transcript

Indulging in the Pleasures of God

Lecture given Saturday, June 26, 2004 at Abilene Christian University: "Does the Bible really teach that Christianity is self-denying? Experiencing Christianity as restrictive can drain our souls and weaken spiritual life. There is a better way. Why not indulge in the pleasures of God and enjoy Him forever?"
Date: June 26, 2004
Creator: Adcox, Jimmy
Object Type: Sound
System: The Portal to Texas History
Waste and Solvent Composition Limits for Modular Caustic-Side Solvent Extraction Unit (MCU) (open access)

Waste and Solvent Composition Limits for Modular Caustic-Side Solvent Extraction Unit (MCU)

This study examined waste feed and solvent limits for the Modular Caustic-Side Solvent Extraction Unit (MCU) currently being designed and built at the Savannah River Site (SRS) to remove cesium from highly alkaline radioactive waste. The study involved proposing ranges for 12 waste feed components (i.e., Na{sup +}, K{sup +}, Cs{sup +}, OH{sup -}, NO{sub 3}{sup -}, NO{sub 2}{sup -}, Cl{sup -}, F{sup -}, SO{sub 4}{sup 2-}, PO{sub 4}{sup 3-}, and CO{sub 3}{sup 2-}, and AlO{sub 2}{sup -}) through a compilation of SRS waste data. Statistical design methods were used to generate numerous wastes with varying compositions from the proposed ranges. An Oak Ridge National Laboratory (ORNL) model called SXFIT was used to predict the cesium extraction distribution coefficients (D-values) between the organic (solvent) phase and the aqueous waste phase using the waste component concentrations as inputs. The D-values from the SXFIT model were used as input along with MCU base case process parameters to a SASSE (Spreadsheet Algorithm for Stagewise Solvent Extraction) model to calculate final cesium concentrations for the MCU. The SASSE model was developed at Argonne National Laboratory (ANL). The SXFIT D-value and the waste component concentration data were used to develop a handier alternative model (neural …
Date: May 26, 2005
Creator: Adu-Wusu, Kofi; Waler, Douglas D. & Edwards, Thomas B
Object Type: Report
System: The UNT Digital Library
A New Dynamical Diffraction-Based Technique of the Residual Stress Measurements in Thin Films (open access)

A New Dynamical Diffraction-Based Technique of the Residual Stress Measurements in Thin Films

The recently discovered dynamical diffraction effect ''neutron camel'' was used for the residual stress measurements in a thick Si(111) crystal coated with a 2000 {angstrom} thick Ni film. The observed asymmetry of the back-face rocking curve corresponds to the bending radius of {approx} 19 km and the tension force applied to the Ni film is {approx} 90 N/m. Relative deformation of the Si crystallographic cells in the vicinity of diffractive surfaces is |{partial_derivative}u{sub z}/{partial_derivative}z| {approx} 1.6 x 10{sup -6}.
Date: July 26, 2001
Creator: Agamalian, M.
Object Type: Article
System: The UNT Digital Library
The Eastern Statesman (Wilburton, Okla.), Vol. 81, No. 2, Ed. 1 Monday, August 26, 2002 (open access)

The Eastern Statesman (Wilburton, Okla.), Vol. 81, No. 2, Ed. 1 Monday, August 26, 2002

Biweekly student newspaper from Eastern Oklahoma State College in Wilburton, Oklahoma that includes local, state, and campus news along with advertising.
Date: August 26, 2002
Creator: Agent, Alicia & Cunningham, Terren
Object Type: Newspaper
System: The Gateway to Oklahoma History
Minimal pair word list (open access)

Minimal pair word list

This is a word list of Manipuri written in the roman alphabet with accompanying English glosses. There are several minimal pairs from varying semantic domains.
Date: February 26, 2004
Creator: Aguilar, Amanda G.
Object Type: Text
System: The UNT Digital Library
European Trade Retaliation: The FSC-ETI Case (open access)

European Trade Retaliation: The FSC-ETI Case

None
Date: July 26, 2006
Creator: Aheam, Raymond J.
Object Type: Report
System: The UNT Digital Library
The Global Economic Downturn and Protectionism (open access)

The Global Economic Downturn and Protectionism

This report develops three scenarios to approximate different dimensions of the relationship between the global economic downturn and protectionism. The scenarios are not predictions, but descriptions of how and why pressures for protection could be manifested and transmitted under different circumstances and assumptions.
Date: August 26, 2009
Creator: Ahearn, Raymond J.
Object Type: Report
System: The UNT Digital Library
Morocco-U.S. Free Trade Agreement (open access)

Morocco-U.S. Free Trade Agreement

The United States and Morocco reached agreement on March 2, 2004, to create a free trade agreement (FTA). The FTA is intended to strengthen bilateral ties, boost trade and investment flows, and bolster Morocco’s position as a moderate Arab state. More than 95% of bilateral trade in consumer and industrial products will become duty-free upon entry into force of the agreement. The Senate approved implementing legislation (S. 2677) on July 2, 2004, by a vote of 85-13 and the House approved identical legislation (H.R. 4842) on July 22, 2004, by a vote of 323-99. The next day, the Senate passed House approved H.R. 4842 without amendment by unanimous consent. The legislation was signed by President Bush into law (P.L.108-302) on August 3, 2004. While the FTA was initially scheduled to be implemented on January 1, 2005, it is now expected to go into effect on July 1, 2005.
Date: May 26, 2005
Creator: Ahearn, Raymond J.
Object Type: Report
System: The UNT Digital Library
Trade Conflict and the U.S.-European Union Economic Relationship (open access)

Trade Conflict and the U.S.-European Union Economic Relationship

The United States and the European Union (EU) share a huge, dynamic, and mutually beneficial economic partnership. Not only is the U.S.-EU trade and investment relationship the largest in the world, but it is also arguably the most important. Agreement between the two partners in the past has been critical to making the world trading system more open and efficient.
Date: July 26, 2006
Creator: Ahearn, Raymond J.
Object Type: Report
System: The UNT Digital Library
U.S.-European Union Trade Relations: Issues and Policy Challenges (open access)

U.S.-European Union Trade Relations: Issues and Policy Challenges

None
Date: January 26, 2006
Creator: Ahearn, Raymond J.
Object Type: Report
System: The UNT Digital Library
High-Level Waste Melter Review (open access)

High-Level Waste Melter Review

The U.S. Department of Energy (DOE) is faced with a massive cleanup task in resolving the legacy of environmental problems from years of manufacturing nuclear weapons. One of the major activities within this task is the treatment and disposal of the extremely large amount of high-level radioactive (HLW) waste stored at the Hanford Site in Richland, Washington. The current planning for the method of choice for accomplishing this task is to vitrify (glassify) this waste for disposal in a geologic repository. This paper describes the results of the DOE-chartered independent review of alternatives for solidification of Hanford HLW that could achieve major cost reductions with reasonable long-term risks, including recommendations on a path forward for advanced melter and waste form material research and development. The potential for improved cost performance was considered to depend largely on increased waste loading (fewer high-level waste canisters for disposal), higher throughput, or decreased vitrification facility size.
Date: February 26, 2002
Creator: Ahearne, J.; Gentilucci, J.; Pye, L. D.; Weber, T.; Woolley, F.; Machara, N. P. et al.
Object Type: Article
System: The UNT Digital Library