IRON-PHOSPHATE GLASS FOR IMMOBILIZATION OF RADIOACTIVE TECHNETIUM (open access)

IRON-PHOSPHATE GLASS FOR IMMOBILIZATION OF RADIOACTIVE TECHNETIUM

Technetium-99 (Tc-99) can bring a serious environmental threat because of its high fission yield, long half-life, and high solubility and mobility in the ground water. The present work investigated the immobilization of Tc-99 (surrogated by Re) by heat-treating mixtures of an iron-phosphate glass with 1.5 to 6 wt.% KReO{sub 4} at {approx}1000 C. The Re retention in the glass was as high as {approx}1.2 wt. % while the loss of Re by evaporation during melting was {approx}50%. Re was uniformly distributed within the glass. The normalized Re release by the 7-day Product Consistency Test was {approx}0.39 g/m{sup 2}, comparable with that in phosphate-bonded ceramics and borosilicate glasses. These results suggest that iron-phosphate glass can provide a good matrix for immobilizing Tc-99.
Date: March 19, 2012
Creator: AA, KRUGER; PR, HRMA; K, XU; J, CHOI; W, UM & J, HEO
Object Type: Article
System: The UNT Digital Library
Tank 26F-2F Evaporator Study (open access)

Tank 26F-2F Evaporator Study

Tank 26F supernate sample was sent by Savannah River Remediation to Savannah River National Laboratory for evaporation test to help understand the underlying cause of the recent gravity drain line (GDL) pluggage during operation of the 2F Evaporator system. The supernate sample was characterized prior to the evaporation test. The evaporation test involved boiling the supernate in an open beaker until the density of the concentrate (evaporation product) was between 1.4 to 1.5 g/mL. It was followed by filtering and washing of the precipitated solids with deionized water. The concentrate supernate (or concentrate filtrate), the damp unwashed precipitated solids, and the wash filtrates were characterized. All the precipitated solids dissolved during water washing. A semi-quantitative X-ray diffraction (XRD) analysis on the unwashed precipitated solids revealed their composition. All the compounds with the exception of silica (silicon oxide) are known to be readily soluble in water. Hence, their dissolution during water washing is not unexpected. Even though silica is a sparingly water-soluble compound, its dissolution is also not surprising. This stems from its small fraction in the solids as a whole and also its relative freshness. Assuming similar supernate characteristics, flushing the GDL with water (preferably warm) should facilitate dissolution and …
Date: December 19, 2012
Creator: Adu-Wusu, K.
Object Type: Report
System: The UNT Digital Library
The Gray Wolf and the Endangered Species Act (ESA): A Brief Legal History (open access)

The Gray Wolf and the Endangered Species Act (ESA): A Brief Legal History

This report provides a brief history of the laws, regulations, and lawsuits related to the wolf's protected status. Fuller analyses of the concepts discussed in this report can be found in the companion report.
Date: January 19, 2012
Creator: Alexander, Kristina
Object Type: Report
System: The UNT Digital Library
Results of the Excreta Bioassay Quality Control Program for April 1, 2009 through March 31, 2010 (open access)

Results of the Excreta Bioassay Quality Control Program for April 1, 2009 through March 31, 2010

A total of 58 urine samples and 10 fecal samples were submitted during the report period (April 1, 2009 through March 31, 2010) to General Engineering Laboratories, South Carolina by the Hanford Internal Dosimetry Program (IDP) to check the accuracy, precision, and detection levels of their analyses. Urine analyses for Sr, 238Pu, 239Pu, 241Am, 243Am 235U, 238U, elemental uranium and fecal analyses for 241Am, 238Pu and 239Pu were tested this year as well as four tissue samples for 238Pu, 239Pu, 241Am and 241Pu. The number of QC urine samples submitted during the report period represented 1.3% of the total samples submitted. In addition to the samples provided by IDP, GEL was also required to conduct their own QC program, and submit the results of analyses to IDP. About 33% of the analyses processed by GEL during the third year of this contract were quality control samples. GEL tested the performance of 21 radioisotopes, all of which met or exceeded the specifications in the Statement of Work within statistical uncertainty (Table 4).
Date: July 19, 2012
Creator: Antonio, Cheryl L.
Object Type: Report
System: The UNT Digital Library
Results of The Excreta Bioassay Quality Control Program For April 1, 2010 Through March 31, 2011 (open access)

Results of The Excreta Bioassay Quality Control Program For April 1, 2010 Through March 31, 2011

A total of 76 urine samples and 10 spiked fecal samples were submitted during the report period (April 1, 2010 through March 31, 2011) to GEL Laboratories, LLC in South Carolina by the Hanford Internal Dosimetry Program (IDP) to check the accuracy, precision, and detection levels of their analyses. Urine analyses for 14C, Sr, for 238Pu, 239Pu, 241Am, 243Am, 235U, 238U, 238U-mass and fecal analyses for 241Am, 238Pu and 239Pu were tested this year. The number of QC urine samples submitted during the report period represented 1.1% of the total samples submitted. In addition to the samples provided by IDP, GEL was also required to conduct their own QC program, and submit the results of analyses to IDP. About 31% of the analyses processed by GEL during the first year of contract 112512 were quality control samples. GEL tested the performance of 23 radioisotopes, all of which met or exceeded the specifications in the Statement of Work within statistical uncertainty except the slightly elevated relative bias for 243,244Cm (Table 4).
Date: July 19, 2012
Creator: Antonio, Cheryl L.
Object Type: Report
System: The UNT Digital Library
Tunable Plasmonic Nanogap Resonator (open access)

Tunable Plasmonic Nanogap Resonator

None
Date: June 19, 2012
Creator: BOnd, T.; Bora, M.; Chang, A. & Miles, R.
Object Type: Article
System: The UNT Digital Library
Search for Large Extra Dimensions Based on Observations of Neutron Stars with the Fermi-LAT (open access)

Search for Large Extra Dimensions Based on Observations of Neutron Stars with the Fermi-LAT

Large extra dimensions (LED) have been proposed to account for the apparent weakness of gravitation. These theories also indicate that the postulated massive Kaluza-Klein (KK) gravitons may be produced by nucleon-nucleon bremsstrahlung in the course of core collapse of supernovae. Hannestad and Raffelt have predicted energy spectra of gamma ray emission from the decay of KK gravitons trapped by the gravity of the remnant neutron stars (NS). These and other authors have used EGRET data on NS to obtain stringent limits on LED. Fermi-LAT is observing radio pulsar positions obtained from radio and x-ray catalogs. NS with certain characteristics are unlikely emitter of gamma rays, and emit in radio and perhaps x-rays. This talk will focus on the blind analysis we plan to perform, which has been developed using the 1st 2 months of all sky data and Monte Carlo simulations, to obtain limits on LED based on about 1 year of Fermi-LAT data. Preliminary limits from this analysis using these first 2 months of data will be also be discussed.
Date: September 19, 2012
Creator: Berenji, Bijan & /Stanford U., Appl. Phys. Dept. /SLAC
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Saudi Arabia: Background and U.S. Relations (open access)

Saudi Arabia: Background and U.S. Relations

This report discusses the current state of the kingdom of Saudi Arabia, its current relationship with the United States, and future initiatives to further develop U.S.-Saudi relations.
Date: June 19, 2012
Creator: Blanchard, Christopher M.
Object Type: Report
System: The UNT Digital Library
Gap Workshop Report (open access)

Gap Workshop Report

None
Date: March 19, 2012
Creator: Blink, J. A. & Budnitz, R J
Object Type: Report
System: The UNT Digital Library
Unauthorized Alien Students: Issues and “DREAM Act” Legislation (open access)

Unauthorized Alien Students: Issues and “DREAM Act” Legislation

This report looks at the background and history of recent "DREAM Act"s, which address the status of unauthorized alien students. It pays special attention to the June 15, 2012 announcement that come individuals who were brought into the U.S. as children and meet other requirements would be eligible for deferred action for two years.
Date: June 19, 2012
Creator: Bruno, Andorra
Object Type: Report
System: The UNT Digital Library
Constitutional Analysis of Suspicionless Drug Testing Requirements for the Receipt of Governmental Benefits (open access)

Constitutional Analysis of Suspicionless Drug Testing Requirements for the Receipt of Governmental Benefits

This report gives an overview of the issues related to federal or state laws that condition the initial or ongoing receipt of governmental benefits on passing drug tests. These regulations are vulnerable to constitutional challenge, most often due to issues of personal privacy and Fourth Amendment protections against "unreasonable searches."
Date: January 19, 2012
Creator: Carpenter, David H.
Object Type: Report
System: The UNT Digital Library
Spurious Shear in Weak Lensing with LSST (open access)

Spurious Shear in Weak Lensing with LSST

The complete 10-year survey from the Large Synoptic Survey Telescope (LSST) will image {approx} 20,000 square degrees of sky in six filter bands every few nights, bringing the final survey depth to r {approx} 27.5, with over 4 billion well measured galaxies. To take full advantage of this unprecedented statistical power, the systematic errors associated with weak lensing measurements need to be controlled to a level similar to the statistical errors. This work is the first attempt to quantitatively estimate the absolute level and statistical properties of the systematic errors on weak lensing shear measurements due to the most important physical effects in the LSST system via high fidelity ray-tracing simulations. We identify and isolate the different sources of algorithm-independent, additive systematic errors on shear measurements for LSST and predict their impact on the final cosmic shear measurements using conventional weak lensing analysis techniques. We find that the main source of the errors comes from an inability to adequately characterise the atmospheric point spread function (PSF) due to its high frequency spatial variation on angular scales smaller than {approx} 10{prime} in the single short exposures, which propagates into a spurious shear correlation function at the 10{sup -4}-10{sup -3} level on …
Date: September 19, 2012
Creator: Chang, C.; Kahn, S.M.; Jernigan, J.G.; Peterson, J.R.; AlSayyad, Y.; Ahmad, Z. et al.
Object Type: Article
System: The UNT Digital Library
Atmospheric PSF Interpolation for Weak Lensing in Short Exposure Imaging Data (open access)

Atmospheric PSF Interpolation for Weak Lensing in Short Exposure Imaging Data

A main science goal for the Large Synoptic Survey Telescope (LSST) is to measure the cosmic shear signal from weak lensing to extreme accuracy. One difficulty, however, is that with the short exposure time ({approx_equal}15 seconds) proposed, the spatial variation of the Point Spread Function (PSF) shapes may be dominated by the atmosphere, in addition to optics errors. While optics errors mainly cause the PSF to vary on angular scales similar or larger than a single CCD sensor, the atmosphere generates stochastic structures on a wide range of angular scales. It thus becomes a challenge to infer the multi-scale, complex atmospheric PSF patterns by interpolating the sparsely sampled stars in the field. In this paper we present a new method, psfent, for interpolating the PSF shape parameters, based on reconstructing underlying shape parameter maps with a multi-scale maximum entropy algorithm. We demonstrate, using images from the LSST Photon Simulator, the performance of our approach relative to a 5th-order polynomial fit (representing the current standard) and a simple boxcar smoothing technique. Quantitatively, psfent predicts more accurate PSF models in all scenarios and the residual PSF errors are spatially less correlated. This improvement in PSF interpolation leads to a factor of 3.5 …
Date: September 19, 2012
Creator: Chang, C.; Marshall, P.J.; Jernigan, J.G.; Peterson, J.R.; Kahn, S.M.; Gull, S.F. et al.
Object Type: Article
System: The UNT Digital Library
Heavy-ion-induced modification of structural and mechanical properties of carbon-nanotube aerogels (open access)

Heavy-ion-induced modification of structural and mechanical properties of carbon-nanotube aerogels

None
Date: November 19, 2012
Creator: Charnvanichborikarn, S; Shin, S J; Worsley, M A & Kucheyev, S O
Object Type: Article
System: The UNT Digital Library
ARM Standards Policy Committee Report (open access)

ARM Standards Policy Committee Report

Data and metadata standards promote the consistent recording of information and are necessary to ensure the stability and high quality of Atmospheric Radiation Measurement (ARM) Climate Research Facility data products for scientific users. Standards also enable automated routines to be developed to examine data, which leads to more efficient operations and assessment of data quality. Although ARM Infrastructure agrees on the utility of data and metadata standards, there is significant confusion over the existing standards and the process for allowing the release of new data products with exceptions to the standards. The ARM Standards Policy Committee was initiated in March 2012 to develop a set of policies and best practices for ARM data and metadata standards.
Date: September 19, 2012
Creator: Cialella, A; Jensen, M; Koontz, A; McFarlane, S; McCoy, R; Monroe, J et al.
Object Type: Report
System: The UNT Digital Library
A Radiating Shock Evaluated Using Implicit Monte Carlo Diffusion (open access)

A Radiating Shock Evaluated Using Implicit Monte Carlo Diffusion

None
Date: July 19, 2012
Creator: Cleveland, M. & Gentile, N. A.
Object Type: Article
System: The UNT Digital Library
Nutrition Labeling of Restaurant Menus (open access)

Nutrition Labeling of Restaurant Menus

Report that provides a brief overview of the Food and Drug Administration's (FDA) authority to regulate nutrition labeling, modifications to these authorities under the Affordable Care Act (ACA), and a discussion of selected aspects of the proposed rule. Concerns regarding the proposed rule raised by industry, Congress, and the public are also discussed.
Date: November 19, 2012
Creator: Corby-Edwards, Amalia K.
Object Type: Report
System: The UNT Digital Library
Recent developments in the production of carbon micro-ribbons for CNI polarimeters at BNL (open access)

Recent developments in the production of carbon micro-ribbons for CNI polarimeters at BNL

N/A
Date: August 19, 2012
Creator: D., Steski; Sukhanova, L. & Zelenski, A.
Object Type: Article
System: The UNT Digital Library
Low Dose Radiation Cancer Risks: Epidemiological and Toxicological Models (open access)

Low Dose Radiation Cancer Risks: Epidemiological and Toxicological Models

The basic purpose of this one year research grant was to extend the two stage clonal expansion model (TSCE) of carcinogenesis to exposures other than the usual single acute exposure. The two-stage clonal expansion model of carcinogenesis incorporates the biological process of carcinogenesis, which involves two mutations and the clonal proliferation of the intermediate cells, in a stochastic, mathematical way. The current TSCE model serves a general purpose of acute exposure models but requires numerical computation of both the survival and hazard functions. The primary objective of this research project was to develop the analytical expressions for the survival function and the hazard function of the occurrence of the first cancer cell for acute, continuous and multiple exposure cases within the framework of the piece-wise constant parameter two-stage clonal expansion model of carcinogenesis. For acute exposure and multiple exposures of acute series, it is either only allowed to have the first mutation rate vary with the dose, or to have all the parameters be dose dependent; for multiple exposures of continuous exposures, all the parameters are allowed to vary with the dose. With these analytical functions, it becomes easy to evaluate the risks of cancer and allows one to deal …
Date: April 19, 2012
Creator: David G. Hoel, PhD
Object Type: Report
System: The UNT Digital Library
Child Protection Act of 2012: A Brief Legal Analysis (open access)

Child Protection Act of 2012: A Brief Legal Analysis

This report discusses several categories such as: (I) Legislative History, (II) Penalty for Possession of Child Pornography, (III) Harassment of Child Victim or Witnesses etc.
Date: December 19, 2012
Creator: Doyle, Charles
Object Type: Report
System: The UNT Digital Library
Fiber Lasers X: Technology, Systems and Aplications (open access)

Fiber Lasers X: Technology, Systems and Aplications

None
Date: July 19, 2012
Creator: Drachenberg, D
Object Type: Article
System: The UNT Digital Library
Concept Development for Astrophysically Relevant Turbulence on NIF (open access)

Concept Development for Astrophysically Relevant Turbulence on NIF

None
Date: December 19, 2012
Creator: Drake, R P
Object Type: Report
System: The UNT Digital Library
Generating Periodic Terahertz Structures in a Relativistic Electron Beam through Frequency Down-Conversion of Optical Lasers (open access)

Generating Periodic Terahertz Structures in a Relativistic Electron Beam through Frequency Down-Conversion of Optical Lasers

We report generation of density modulation at terahertz (THz) frequencies in a relativistic electron beam through laser modulation of the beam longitudinal phase space. We show that by modulating the energy distribution of the beam with two lasers, density modulation at the difference frequency of the two lasers can be generated after the beam passes through a chicane. In this experiment, density modulation around 10 THz was generated by down-converting the frequencies of an 800 nm laser and a 1550 nm laser. The central frequency of the density modulation can be tuned by varying the laser wavelengths, beam energy chirp, or momentum compaction of the chicane. This technique can be applied to accelerator-based light sources for generation of coherent THz radiation and marks a significant advance toward tunable narrow-band THz sources.
Date: July 19, 2012
Creator: Dunning, Michael
Object Type: Article
System: The UNT Digital Library
Saltstone 3QCY12 TCLP Results (open access)

Saltstone 3QCY12 TCLP Results

A Saltstone waste form was prepared in the Savannah River National Laboratory (SRNL) from a Tank 50H sample and Z-Area premix material for the third quarter of calendar year 2012 (3QCY12). After a 34 day cure, samples of the saltstone were collected, and the waste form was shown to meet the South Carolina Hazardous Waste Management Regulations (SCHWMR) R.61-79.261.24 and R.61-79.268.48(a) requirements for a nonhazardous waste form with respect to RCRA metals and underlying hazardous constituents. These analyses met all quality assurance specifications of USEPA SW-846.
Date: December 19, 2012
Creator: Eibling, R. E.
Object Type: Report
System: The UNT Digital Library