States

{sup 17}O NMR Investigation of Oxidative Degradation in Polymers Under Gamma-Irradiation (open access)

{sup 17}O NMR Investigation of Oxidative Degradation in Polymers Under Gamma-Irradiation

The {gamma}-irradiated-oxidation of pentacontane (C{sub 50}H{sub 102}) and the polymer polyisoprene was investigated as a function of oxidation level using {sup 17}O nuclear magnetic resonance (NMR) spectroscopy. It is demonstrated that by using {sup 17}O labeled O{sub 2} gas during the {gamma}-irradiation process, details about the oxidative degradation mechanisms can be directly obtained from the analysis of the {sup 17}O NMR spectra. Production of carboxylic acids is the primary oxygen-containing functionality during the oxidation of pentacontane, while ethers and alcohols are the dominant oxidation product observed for polyisoprene. The formation of ester species during the oxidation process is very minor for both materials, with water also being produced in significant amounts during the radiolytic oxidation of polyisoprene. The ability to focus on the oxidative component of the degradation process using {sup 17}O NMR spectroscopy demonstrates the selectivity of this technique over more conventional approaches.
Date: March 8, 2000
Creator: Alam, Todd M.; Celina, Mathias C.; Assink, Roger A.; Clough, Roger Lee & Gillen, Kenneth T.
Object Type: Article
System: The UNT Digital Library
The United States and Europe: Possible Options for U.S. Policy (open access)

The United States and Europe: Possible Options for U.S. Policy

None
Date: March 8, 2005
Creator: Archick, Kristin
Object Type: Report
System: The UNT Digital Library
X-ray absorption study of the electronic structure of Mn-doped amorphous Si (open access)

X-ray absorption study of the electronic structure of Mn-doped amorphous Si

The electronic structure of Mn in amorphous Si (a-Mn{sub x}Si{sub 1?x}) is studied by X-ray absorption spectroscopy at the Mn L{sub 3,2} edges for x = 0.005-0.18. Except the x = 0.005 sample, which shows a slight signature of Mn{sup 2+} atomic multiplets associated with a local Mn moment, all samples have broad and featureless L{sub 3,2} absorption peaks, corresponding to an itinerant state for all 3d electrons. The broad X-ray absorption spectra exclude the possibility of a localized 3d moment and explain the unexpectedly quenched Mn moment in this magnetically-doped amorphous semiconductor. Such a fully delocalized d state of Mn dopant in Si has not been previously suggested.
Date: March 8, 2008
Creator: Arenholz, Elke; Zeng, Li; Huegel, A.; Helgren, E.; Hellman, F.; Piamonteze, C. et al.
Object Type: Article
System: The UNT Digital Library

Status of the Yucca Mountain Project, License Application, and Repository Design Update

None
Date: March 8, 2005
Creator: Artur, W. John, III
Object Type: Presentation
System: The UNT Digital Library
Quantifying Stratospheric Ozone in the Upper Troposphere Using in situ Measurements of HCl (open access)

Quantifying Stratospheric Ozone in the Upper Troposphere Using in situ Measurements of HCl

A chemical ionization mass spectrometry (CIMS) technique has been developed for precise in situ measurements of hydrochloric acid (HCl) from a high-altitude aircraft. In measurements at subtropical latitudes, minimum HCl values found in the upper troposphere (UT) are often near or below the 0.005-ppbv detection limit of the measurements, indicating that background HCl values are much lower than a global mean estimate. However, significant abundances of HCl were observed in many UT air parcels as a result of stratosphere-to-troposphere transport events. A method for diagnosing the amount of stratospheric ozone in these UT parcels was developed using the compact linear correlation of HCl with ozone found throughout the lower stratosphere (LS). Expanded use of this method will lead to improved quantification of cross-tropopause transport events and validation of global chemical transport models.
Date: March 8, 2004
Creator: Atherton, C. S.; Bergmann, D. J.; Marcy, T. P.; Fahey, D. W.; Gao, R. S.; Popp, P. J. et al.
Object Type: Article
System: The UNT Digital Library
Atmospheric Radiation Measurement Program Facilities Newsletter, February 2001. (open access)

Atmospheric Radiation Measurement Program Facilities Newsletter, February 2001.

Monthly newsletter discussing news and activities related to the Atmospheric Radiation Measurement Program, articles about weather and atmospheric phenomena, and other related topics.
Date: March 8, 2001
Creator: Atmospheric Radiation Measurement Program (U.S.)
Object Type: Journal/Magazine/Newsletter
System: The UNT Digital Library
Effect of Workbench Shielding on Nagasaki Factory Workers' Dose (open access)

Effect of Workbench Shielding on Nagasaki Factory Workers' Dose

None
Date: March 8, 2001
Creator: Azmy, Y.Y.
Object Type: Report
System: The UNT Digital Library
Improvements in bis(cyclopentadienyl)magnesium purity as determined with gas chromatography-mass spectroscopy (open access)

Improvements in bis(cyclopentadienyl)magnesium purity as determined with gas chromatography-mass spectroscopy

Bis(cyclopentadienyl)magnesium (MgCp2) is used commonly as a source for doping nitride materials with magnesium. Increased oxygen incorporation known to accompany the use of MgCp2 makes the purity of this precursor an important consideration in nitride CVD. Gas chromatography-mass spectroscopy (GCMS) methods have now been developed for the identification of volatile impurities in MgCp2. Diethylether, an oxygen containing organic compound (CH{sub 3}CH{sub 2}OCH{sub 2}CH{sub 3}), and additional organic impurities were found in the MgCp2 supplied by three manufacturers. Subsequent refinements in the synthetic processes by these companies have resulted in the availability of MgCp2 free of ether and other organic impurities as determined by GCMS.
Date: March 8, 2000
Creator: BARTRAM,MICHAEL E.
Object Type: Article
System: The UNT Digital Library
CDF Run I B physics results (open access)

CDF Run I B physics results

The CDF Run I B physics program has been very successful, making numerous measurements over a wide variety of B physics topics. Measurements have included masses and lifetimes; discovery of the B{sub c}; B{sub s} {r_arrow} J/{psi}{phi} polarization; B{sup 0} {leftrightarrow} {bar B}{sup 0} mixing; sin (2{beta}); and rare decay limits. Recent results include a search for {Lambda}{sub b} {r_arrow} {Lambda}{gamma} and a study of B{sup 0} {r_arrow} J/{psi}K(*){sup 0} {pi}{sup +}{pi}{sup {minus}} decays. The tools and experience developed during Run I are quite valuable as CDF enters Run II.
Date: March 8, 2001
Creator: Bailey, S.
Object Type: Article
System: The UNT Digital Library
Abandoned Mine Land Fund Reauthorization: Selected Issues (open access)

Abandoned Mine Land Fund Reauthorization: Selected Issues

This report provides a summary of the structure of the Abandon Mine Land (AML) program, distribution of funds, and discusses major proposals considered in the 108th Congress.
Date: March 8, 2005
Creator: Bamberger, Robert L.
Object Type: Report
System: The UNT Digital Library
Hot isostatic pressing of ceramic waste from spent nuclear fuel. (open access)

Hot isostatic pressing of ceramic waste from spent nuclear fuel.

Argonne National Laboratory has developed a process to immobilize waste salt containing fission products, uranium, and transuranic elements as chlorides in a glass-bonded ceramic waste form. This salt was generated in the electrorefining operation used in electrometallurgical treatment of spent Experimental Breeder Reactor-II fuel. The ceramic waste process culminated with a hot isostatic pressing operation. This paper reviews the installation and operation of a hot isostatic press in a radioactive environment. Processing conditions for the hot isostatic press are presented for non-irradiated material and irradiated material. Sufficient testing was performed to demonstrate that a hot isostatic press could be used as the final step of the processing of ceramic waste for the electrometallurgical spent fuel treatment process.
Date: March 8, 2002
Creator: Bateman, Kenneth J.; Rigg, Richard H. & Wiest, James D.
Object Type: Article
System: The UNT Digital Library
Imaging System for the Automated Determination of Microscopical Properties in Hardened Portland Concrete (open access)

Imaging System for the Automated Determination of Microscopical Properties in Hardened Portland Concrete

During this CRADA, Honeywell FM and T and MoDOT personnel designed a unique scanning system (including both hardware and software) that can be used to perform an automated scan and evaluation of a concrete sample. The specific goals of the CRADA were: (1) Develop a combined system integration, image acquisition, and image analysis approach to mimic the manual scanning and evaluation process. Produce a prototype system which can: (a) automate the scanning process to improve its speed and efficiency; (b) reduce operator fatigue; and (c) improve the consistency of the evaluation process. (2) Capture and preserve the baseline knowledge used by the MoDOT experts in performing the evaluation process. At the present time, the evaluation expertise resides in two MoDOT personnel. Automation of the evaluation process will allow that knowledge to be captured, preserved, and used for training purposes. (3) Develop an approach for the image analysis which is flexible and extensible in order to accommodate the inevitable pathologies that arise in the evaluation process. Such pathologies include features such as cracks and fissures, voids filled with paste or debris, and multiple, overlapping voids. FM and T personnel used image processing, pattern recognition, and system integration skills developed for other …
Date: March 8, 2000
Creator: Baumgart, C.W.; Cave, S.P. & Linder, K.E.
Object Type: Report
System: The UNT Digital Library
Development of a low-power, low-cost front end electronics module for large scale distributed neutrino detectors (open access)

Development of a low-power, low-cost front end electronics module for large scale distributed neutrino detectors

A number of concepts have been presented for distributed neutrino detectors formed of large numbers of autonomous detectors. Examples include the Antarctic Ross Ice Shelf Antenna Neutrino Array (ARIANNA) [Barwick 2006], as well as proposed radio extensions to the IceCube detector at South Pole Station such as AURA and IceRay. [Besson 2008]. We have focused on key enabling technical developments required by this class of experiments. The radio Cherenkov signal, generated by the Askaryan mechanism [Askaryan 1962, 1965], is impulsive and coherent up to above 1 GHz. In the frequency domain, the impulsive character of the emission results in simultaneous increase of the power detected in multiple frequency bands. This multiband triggering approach has proven fruitful, especially as anthropogenic interference often results from narrowband communications signals. A typical distributed experiment of this type consists of a station responsible for the readout of a cluster of antennas either near the surface of the ice or deployed in boreholes. Each antenna is instrumented with a broadband low-noise amplifier, followed by an array of filters to facilitate multi-band coincidence trigger schemes at the antenna level. The power in each band is detected at the output of each band filter, using either square-law diode …
Date: March 8, 2008
Creator: Beatty, James J. & Kass, Richard D.
Object Type: Report
System: The UNT Digital Library
Regulation of Plant-Based Pharmaceuticals (open access)

Regulation of Plant-Based Pharmaceuticals

None
Date: March 8, 2005
Creator: Becker, Geoffrey S. & Vogt, Donna U.
Object Type: Report
System: The UNT Digital Library
Soft Radiative Strength in Warm Nuclei (open access)

Soft Radiative Strength in Warm Nuclei

Unresolved transitions in the nuclear {gamma}-ray cascade produced in the decay of excited nuclei are best described by statistical concepts: a continuous radiative strength function (RSF) and level density yield mean values of transition matrix elements. Data on the soft (E{sub {gamma}} < 3-4 MeV) RSF for transitions between warm states (i.e. states several MeV above the yrast line) have, however, remained elusive.
Date: March 8, 2004
Creator: Becker, J. A.; Bernstein, L. A.; Garrett, P. E.; Nelson, R. O.; Schiller, A.; Voinov, A. et al.
Object Type: Article
System: The UNT Digital Library
Defect diffusion during annealing of low-energy ion-implanted silicon (open access)

Defect diffusion during annealing of low-energy ion-implanted silicon

We present a new approach for investigating the kinetics of defect migration during annealing of low-energy, ion-implanted silicon, employing a combination of computer simulations and atomic-resolution tunneling microscopy. Using atomically-clean Si(111)-7x7 as a sink for bulk point defects created by 5 keV Xe and Ar irradiation, we observe distinct, temperature-dependent surface arrival rates for vacancies and interstitials. A combination of simulation tools provides a detailed description of the processes that underly the observed temperature-dependence of defect segregation, and the predictions of the simulations agree closely with the experimental observations.
Date: March 8, 2000
Creator: Bedrossian, P J; Caturla, M-J & Diaz de la Rubia, T
Object Type: Article
System: The UNT Digital Library
Environmental Solutions, A Summary of Contributions for CY04: Battelle Contributions to the Waste Treatment Plant (open access)

Environmental Solutions, A Summary of Contributions for CY04: Battelle Contributions to the Waste Treatment Plant

In support of the Waste Treatment Plant (WTP), Battelle conducted tests on mixing specific wastes within the plant, removing troublesome materials from the waste before treatment, and determining if the final waste forms met the established criteria. In addition, several Battelle experts filled full-time positions in WTP's Research and Testing and Process and Operations departments.
Date: March 8, 2005
Creator: Beeman, Gordon H.
Object Type: Report
System: The UNT Digital Library
Web technology to support work processes in energy policy research - A case study with energy efficiency standards (open access)

Web technology to support work processes in energy policy research - A case study with energy efficiency standards

This paper focuses on a process to design and build a web-based system to assist staff in day-to-day management and contemporaneous documentation of their work. Other groups that want to use web technology to support their work could apply the approach presented here, but the design itself pertains to a particular set of issues in a unique context. Each user must apply the approach to identify their objectives and design a site to meet them. The main question that the Energy Efficiency Standards Group addressed was: ''How can we facilitate documentation of interim results and final products while conducting a complex, interdependent set of analyses by multiple authors under time pressures for delivering a final product?'' The approach to address this question includes categorization of the components of the work, discussions with staff, development of infrastructure support for documentation, implementation of the documentation process and integration with the workflow, and follow- up with staff. The search for a solution raised a number of issues such as the need for a thorough understanding of the work, consensus building by inclusion of key staff, and deliverable scheduling to allow for contemporaneous documentation. Documentation results vary among the product analyses, from extensive internal …
Date: March 8, 2002
Creator: Benenson, Peter; McMahon, James E. & Brown, Stephen R.
Object Type: Article
System: The UNT Digital Library
Development of a Real-Time Radiological Area Monitoring Network for Emergency Response at Lawrence Livermore National Laboratory (open access)

Development of a Real-Time Radiological Area Monitoring Network for Emergency Response at Lawrence Livermore National Laboratory

A real-time radiological sensor network for emergency response was developed and deployed at the Lawrence Livermore National Laboratory (LLNL). The Real-Time Radiological Area Monitoring (RTRAM) network is comprised of 16 Geiger-Mueller (GM) sensors positioned on the LLNL Livermore site perimeter to continuously monitor for a radiological condition resulting from a terrorist threat to site security and the health and safety of LLNL personnel. The RTRAM network sensor locations coincide with wind sector directions to provide thorough coverage of the one square mile site. These low-power sensors are supported by a central command center (CCC) and transmit measurement data back to the CCC computer through the LLNL telecommunications infrastructure. Alarm conditions are identified by comparing current data to predetermined threshold parameters and are validated by comparison with plausible dispersion modeling scenarios and prevailing meteorological conditions. Emergency response personnel are notified of alarm conditions by automatic radio and computer based notifications. A secure intranet provides emergency response personnel with current condition assessment data that enable them to direct field response efforts remotely. The RTRAM network has proven to be a reliable system since initial deployment in August 2001 and maintains stability during inclement weather conditions.
Date: March 8, 2004
Creator: Bertoldo, N; Hunter, S; Fertig, R; Laguna, G & MacQueen, D
Object Type: Article
System: The UNT Digital Library
Recent plant studies using Victoria 2.0 (open access)

Recent plant studies using Victoria 2.0

VICTORIA 2.0 is a mechanistic computer code designed to analyze fission product behavior within the reactor coolant system (RCS) during a severe nuclear reactor accident. It provides detailed predictions of the release of radioactive and nonradioactive materials from the reactor core and transport and deposition of these materials within the RCS and secondary circuits. These predictions account for the chemical and aerosol processes that affect radionuclide behavior. VICTORIA 2.0 was released in early 1999; a new version VICTORIA 2.1, is now under development. The largest improvements in VICTORIA 2.1 are connected with the thermochemical database, which is being revised and expanded following the recommendations of a peer review. Three risk-significant severe accident sequences have recently been investigated using the VICTORIA 2.0 code. The focus here is on how various chemistry options affect the predictions. Additionally, the VICTORIA predictions are compared with ones made using the MELCOR code. The three sequences are a station blackout in a GE BWR and steam generator tube rupture (SGTR) and pump-seal LOCA sequences in a 3-loop Westinghouse PWR. These sequences cover a range of system pressures, from fully depressurized to full system pressure. The chief results of this study are the fission product fractions that …
Date: March 8, 2000
Creator: Bixler, Nathan E. & Gasser, Ronald D.
Object Type: Article
System: The UNT Digital Library
Coupled THM Simulations of the Drift Scale Test at Yucca Mountain (open access)

Coupled THM Simulations of the Drift Scale Test at Yucca Mountain

This paper presents a coupled thermal-hydrological-mechanical (THM) analysis of the Drift Scale Test (DST) conducted at Yucca Mountain, Nevada. The DST is a large-scale, long-term thermal test designed to investigate coupled thermal-mechanical-hydrological-chemical behavior in a fractured, welded tuff rock mass in support of nuclear waste isolation efforts. The model used for this analysis utilizes temperature distributions predicted by a thermal-hydrological code as input to a distinct element thermal mechanical code. This paper presents a brief discussion of the test and the coupled model, followed by comparison of predicted and measured displacements. Results show that the model predicts the trend and magnitude of the displacements observed in a cross section monitored in the test through four years of heating. Maximum principal stress levels of 60 MPa are predicted in the crown and floor of the heated drift (HD) after 4 years of heating. Comparison of predicted and observed displacements shows that the model closely predicts vertical displacement above the HD and provides a good estimate of horizontal displacement perpendicular to the HD. These results indicate that a thermal expansion coefficient of 9e-6/{Lambda}C is generally appropriate for the rockmass forming this test. Normal displacements on joints in the cross section examined here …
Date: March 8, 2002
Creator: Blair, S. C.; Carlson, S. R.; Lee, K. & Wagoner, J. L.
Object Type: Article
System: The UNT Digital Library
India-U.S. Relations (open access)

India-U.S. Relations

This report discusses the context of India - U.S relations, and its bilateral issues.
Date: March 8, 2002
Creator: Blood, Peter R
Object Type: Report
System: The UNT Digital Library
Arts and Humanities: Background on Funding (open access)

Arts and Humanities: Background on Funding

This report includes a brief description regarding funding for the arts and humanities as a perennial issue in Congress. Although arts funding represents less than 1% of the Bush Administration’s FY2006 total estimated budget authority, Congress continues to address the concern of whether federal funding is crucial to sustain arts institutions.
Date: March 8, 2005
Creator: Boren, Susan
Object Type: Report
System: The UNT Digital Library
Recommendations on Fuel Parameters for Standard Technical Specifications for Spent Fuel Storage Casks (open access)

Recommendations on Fuel Parameters for Standard Technical Specifications for Spent Fuel Storage Casks

The U.S. Nuclear Regulatory Commission (NRC) is currently reviewing the technical specifications for spent fuel storage casks in an effort to develop standard technical specifications (STS) that define the allowable spent nuclear fuel (SNF) contents. One of the objectives of the review is to minimize the level of detail in the STS that define the acceptable fuel types. To support this initiative, this study has been performed to identify potential fuel specification parameters needed for criticality safety and radiation shielding analysis and rank their importance relative to a potential compromise of the margin of safety.
Date: March 8, 2001
Creator: Bowman, S. M.
Object Type: Report
System: The UNT Digital Library