Summary of operations and performance of the Utica aquifer and North Lake Basin Wetlands restoration project in December 2010-November 2011. (open access)

Summary of operations and performance of the Utica aquifer and North Lake Basin Wetlands restoration project in December 2010-November 2011.

None
Date: September 19, 2012
Creator: LaFreniere, L. M.
Object Type: Report
System: The UNT Digital Library
Fiber Lasers X: Technology, Systems and Aplications (open access)

Fiber Lasers X: Technology, Systems and Aplications

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Date: July 19, 2012
Creator: Drachenberg, D
Object Type: Article
System: The UNT Digital Library
Techniques for correcting velocity and density fluctuations of ion beams (open access)

Techniques for correcting velocity and density fluctuations of ion beams

None
Date: June 19, 2012
Creator: Woo, K. M.; Yu, S. S. & Barnard, J. J.
Object Type: Article
System: The UNT Digital Library
Radioactive Waste Conditioning, Immobilisation, And Encapsulation Processes And Technologies: Overview And Advances (Chapter 7) (open access)

Radioactive Waste Conditioning, Immobilisation, And Encapsulation Processes And Technologies: Overview And Advances (Chapter 7)

The main immobilization technologies that are available commercially and have been demonstrated to be viable are cementation, bituminization, and vitrification. Vitrification is currently the most widely used technology for the treatment of high level radioactive wastes (HLW) throughout the world. Most of the nations that have generated HLW are immobilizing in either alkali borosilicate glass or alkali aluminophosphate glass. The exact compositions of nuclear waste glasses are tailored for easy preparation and melting, avoidance of glass-in-glass phase separation, avoidance of uncontrolled crystallization, and acceptable chemical durability, e.g., leach resistance. Glass has also been used to stabilize a variety of low level wastes (LLW) and mixed (radioactive and hazardous) low level wastes (MLLW) from other sources such as fuel rod cladding/decladding processes, chemical separations, radioactive sources, radioactive mill tailings, contaminated soils, medical research applications, and other commercial processes. The sources of radioactive waste generation are captured in other chapters in this book regarding the individual practices in various countries (legacy wastes, currently generated wastes, and future waste generation). Future waste generation is primarily driven by interest in sources of clean energy and this has led to an increased interest in advanced nuclear power production. The development of advanced wasteforms is a …
Date: October 19, 2012
Creator: Jantzen, Carol M.; Lee, William E. & Ojovan, Michael I.
Object Type: Book
System: The UNT Digital Library
The Cornell-SLAC Pixel Array Detector at LCLS (open access)

The Cornell-SLAC Pixel Array Detector at LCLS

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Date: November 19, 2012
Creator: Hart, P.; Boutet, S.; Carini, G.; Dragone, A.; Duda, B.; Freytag, D. et al.
Object Type: Article
System: The UNT Digital Library
Fast Pyrolysis Oil Stabilization: An Integrated Catalytic and Membrane Approach for Improved Bio-oils (open access)

Fast Pyrolysis Oil Stabilization: An Integrated Catalytic and Membrane Approach for Improved Bio-oils

This University of Massachusetts, Amherst project, "Fast Pyrolysis Oil Stabilization: An Integrated Catalytic and Membrane Approach for Improved Bio-oils" started on 1st February 2009 and finished on August 31st 2011. The project consisted following tasks: Task 1.0: Char Removal by Membrane Separation Technology The presence of char particles in the bio-oil causes problems in storage and end-use. Currently there is no well-established technology to remove char particles less than 10 micron in size. This study focused on the application of a liquid-phase microfiltration process to remove char particles from bio-oil down to slightly sub-micron levels. Tubular ceramic membranes of nominal pore sizes 0.5 and 0.8 µm were employed to carry out the microfiltration, which was conducted in the cross-flow mode at temperatures ranging from 38 to 45 C and at three different trans-membrane pressures varying from 1 to 3 bars. The results demonstrated the removal of the major quantity of char particles with a significant reduction in overall ash content of the bio-oil. The results clearly showed that the cake formation mechanism of fouling is predominant in this process. Task 2.0 Acid Removal by Membrane Separation Technology The feasibility of removing small organic acids from the aqueous fraction of fast …
Date: October 19, 2012
Creator: \Huber, George W.; Upadhye, Aniruddha A.; Ford, David M.; Bhatia, Surita R. & Badger, Phillip C.
Object Type: Report
System: The UNT Digital Library
CHARACTERIZATION OF TANK 16H ANNULUS SAMPLES PART II: LEACHING RESULTS (open access)

CHARACTERIZATION OF TANK 16H ANNULUS SAMPLES PART II: LEACHING RESULTS

The closure of Tank 16H will require removal of material from the annulus of the tank. Samples from Tank 16H annulus were characterized and tested to provide information to evaluate various alternatives for removing the annulus waste. The analysis found all four annulus samples to be composed mainly of Si, Na, and Al and lesser amounts of other elements. The XRD data indicate quartz (SiO{sub 2}) and sodium aluminum nitrate silicate hydrate (Na{sub 8}(Al{sub 6}Si{sub 6}O{sub 24})(NO{sub 3}){sub 2}.4H{sub 2}O) as the predominant crystalline mineral phases in the samples. The XRD data also indicate the presence of crystalline sodium nitrate (NaNO{sub 3}), sodium nitrite (NaNO{sub 2}), gibbsite (Al(OH){sub 3}), hydrated sodium bicarbonate (Na{sub 3}H(CO{sub 3}){sub 2}.2H{sub 2}O), and muscovite (KAl{sub 2}(AlSi{sub 3}O{sub 10})(OH){sub 2}). Based on the weight of solids remaining at the end of the test, the water leaching test results indicate 20-35% of the solids dissolved after three contacts with an approximately 3:1 volume of water at 45 C. The chemical analysis of the leachates and the XRD results of the remaining solids indicate sodium salts of nitrate, nitrite, sulfate, and possibly carbonate/bicarbonate make up the majority of the dissolved material. The majority of these salts were dissolved …
Date: June 19, 2012
Creator: Hay, M. & Reboul, S.
Object Type: Report
System: The UNT Digital Library
High-Power Microwave Switch Employing Electron Beam Triggering (open access)

High-Power Microwave Switch Employing Electron Beam Triggering

A high-power active microwave pulse compressor is described that modulates the quality factor Q of the energy storage cavity by a new means involving mode conversion controlled by a triggered electron-beam discharge through a switch cavity. The electron beam is emitted from a diamond-coated molybdenum cathode. This report describes the principle of operation, the design of the switch, the configuration used for the test, and the experimental results. The pulse compressor produced output pulses with 140 - “165 MW peak power, power gain of 16 - 20, and pulse duration of 16 - 20 ns at a frequency of 11.43 GHz.
Date: September 19, 2012
Creator: Hirshfield, Jay L.
Object Type: Report
System: The UNT Digital Library
Modeling Ion-Exchange Processing With Spherical Resins For Cesium Removal (open access)

Modeling Ion-Exchange Processing With Spherical Resins For Cesium Removal

The spherical Resorcinol-Formaldehyde and hypothetical spherical SuperLig(r) 644 ion-exchange resins are evaluated for cesium removal from radioactive waste solutions. Modeling results show that spherical SuperLig(r) 644 reduces column cycling by 50% for high-potassium solutions. Spherical Resorcinol Formaldehyde performs equally well for the lowest-potassium wastes. Less cycling reduces nitric acid usage during resin elution and sodium addition during resin regeneration, therefore, significantly decreasing life-cycle operational costs. A model assessment of the mechanism behind ''cesium bleed'' is also conducted. When a resin bed is eluted, a relatively small amount of cesium remains within resin particles. Cesium can bleed into otherwise decontaminated product in the next loading cycle. The bleed mechanism is shown to be fully isotherm-controlled vs. mass transfer controlled. Knowledge of residual post-elution cesium level and resin isotherm can be utilized to predict rate of cesium bleed in a mostly non-loaded column. Overall, this work demonstrates the versatility of the ion-exchange modeling to study the effects of resin characteristics on processing cycles, rates, and cold chemical consumption. This evaluation justifies further development of a spherical form of the SL644 resin.
Date: September 19, 2012
Creator: Hang, T.; Nash, C. A. & Aleman, S. E.
Object Type: Article
System: The UNT Digital Library
WBN-1 Cycle 10 TPBAR Tritium Release, Deduced From Analysis of RCS Data TTP-1-3046-00, Rev 0 (open access)

WBN-1 Cycle 10 TPBAR Tritium Release, Deduced From Analysis of RCS Data TTP-1-3046-00, Rev 0

This document contains the calculation of the TPBAR tritium release from the Mark 9.2 design TPBARs irradiated in WBN cycle 10. The calculation utilizes the generalized cycle analysis methodology given in TTP-1-3045 Rev. 0.
Date: February 19, 2012
Creator: Shaver, Mark W.; Niehus, Mark T. & Love, Edward F.
Object Type: Report
System: The UNT Digital Library
Theory and Gyro-fluid Simulations of Edge-Localized-Modes (open access)

Theory and Gyro-fluid Simulations of Edge-Localized-Modes

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Date: September 19, 2012
Creator: Xu, X Q
Object Type: Article
System: The UNT Digital Library
Moisture desorption rates from TATB-formulations: experiments and kinetic models (open access)

Moisture desorption rates from TATB-formulations: experiments and kinetic models

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Date: January 19, 2012
Creator: Glascoe, E. A.; Dinh, L. N.; Small, W. & Overturf, G. E.
Object Type: Article
System: The UNT Digital Library
Task 2—Materials for Advanced Boiler and Oxy-combustion Systems (NETL-US) (open access)

Task 2—Materials for Advanced Boiler and Oxy-combustion Systems (NETL-US)

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Date: April 19, 2012
Creator: Holcomb, Gordon R. & Tylczak, Joseph
Object Type: Article
System: The UNT Digital Library
Task 1—Steam Oxidation (NETL-US) (open access)

Task 1—Steam Oxidation (NETL-US)

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Date: April 19, 2012
Creator: Holcomb, Gordon R. & Tylczak, Joseph
Object Type: Article
System: The UNT Digital Library
Thermal annealing of laser damage precursors on fused silica surfaces (open access)

Thermal annealing of laser damage precursors on fused silica surfaces

Previous studies have identified two significant precursors of laser damage on fused silica surfaces at fluenes below {approx} 35 J/cm{sup 2}, photoactive impurities in the polishing layer and surface fractures. In the present work, isothermal heating is studied as a means of remediating the highly absorptive, defect structure associated with surface fractures. A series of Vickers indentations were applied to silica surfaces at loads between 0.5N and 10N creating fracture networks between {approx} 10{micro}m and {approx} 50{micro}m in diameter. The indentations were characterized prior to and following thermal annealing under various times and temperature conditions using confocal time-resolved photo-luminescence (CTP) imaging, and R/1 optical damage testing with 3ns, 355nm laser pulses. Significant improvements in the damage thresholds, together with corresponding reductions in CTP intensity, were observed at temperatures well below the glass transition temperature (T{sub g}). For example, the damage threshold on 05.N indentations which typically initiates at fluences <8 J/cm{sup 2} could be improved >35 J/cm{sup 2} through the use of a {approx} 750 C thermal treatment. Larger fracture networks required longer or higher temperature treatment to achieve similar results. At an annealing temperature > 1100 C, optical microscopy indicates morphological changes in some of the fracture structure of …
Date: March 19, 2012
Creator: Shen, N.; Miller, P. E.; Bude, J. D.; Laurence, T. A.; Suratwala, T. I.; Steele, W. A. et al.
Object Type: Article
System: The UNT Digital Library
Integrated Detection of Pathogens and Host Biomarkers for Wounds (open access)

Integrated Detection of Pathogens and Host Biomarkers for Wounds

The increasing incidence and complications arising from combat wounds has necessitated a reassessment of methods for effective treatment. Infection, excessive inflammation, and incidence of drug-resistant organisms all contribute toward negative outcomes for afflicted individuals. The organisms and host processes involved in wound progression, however, are incompletely understood. We therefore set out, using our unique technical resources, to construct a profile of combat wounds which did or did not successfully resolve. We employed the Lawrence Livermore Microbial Detection Array and identified a number of nosocomial pathogens present in wound samples. Some of these identities corresponded with bacterial isolates previously cultured, while others were not obtained via standard microbiology. Further, we optimized proteomics protocols for the identification of host biomarkers indicative of various stages in wound progression. In combination with our pathogen data, our biomarker discovery efforts will provide a profile corresponding to wound complications, and will assist significantly in treatment of these complex cases.
Date: March 19, 2012
Creator: Jaing, C
Object Type: Report
System: The UNT Digital Library
Energy Spread Reduction of Electron Beams Produced via Laser Wake (open access)

Energy Spread Reduction of Electron Beams Produced via Laser Wake

Laser wakefield acceleration of electrons holds great promise for producing ultra-compact stages of GeV scale, high quality electron beams for applications such as x-ray free electron lasers and high energy colliders. Ultra-high intensity laser pulses can be self-guided by relativistic plasma waves over tens of vacuum diffraction lengths, to give >1 GeV energy in cm-scale low density plasma using ionization-induced injection to inject charge into the wake at low densities. This thesis describes a series of experiments which investigates the physics of LWFA in the self-guided blowout regime. Beginning with high density gas jet experiments the scaling of the LWFA-produced electron beam energy with plasma electron density is found to be in excellent agreement with both phenomenological theory and with 3-D PIC simulations. It is also determined that self-trapping of background electrons into the wake exhibits a threshold as a function of the electron density, and at the densities required to produce electron beams with energies exceeding 1 GeV a different mechanism is required to trap charge into low density wakes. By introducing small concentrations of high-Z gas to the nominal He background the ionization-induced injection mechanism is enabled. Electron trapping is observed at densities as low as 1.3 x …
Date: March 19, 2012
Creator: Pollock, B.
Object Type: Thesis or Dissertation
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
Evaluation Of The Integrated Solubility Model, A Graded Approach For Predicting Phase Distribution In Hanford Tank Waste (open access)

Evaluation Of The Integrated Solubility Model, A Graded Approach For Predicting Phase Distribution In Hanford Tank Waste

The mission of the DOE River Protection Project (RPP) is to store, retrieve, treat and dispose of Hanford's tank waste. Waste is retrieved from the underground tanks and delivered to the Waste Treatment and Immobilization Plant (WTP). Waste is processed through a pretreatment facility where it is separated into low activity waste (LAW), which is primarily liquid, and high level waste (HLW), which is primarily solid. The LAW and HLW are sent to two different vitrification facilities and glass canisters are then disposed of onsite (for LAW) or shipped off-site (for HLW). The RPP mission is modeled by the Hanford Tank Waste Operations Simulator (HTWOS), a dynamic flowsheet simulator and mass balance model that is used for mission analysis and strategic planning. The integrated solubility model (ISM) was developed to improve the chemistry basis in HTWOS and better predict the outcome of the RPP mission. The ISM uses a graded approach to focus on the components that have the greatest impact to the mission while building the infrastructure for continued future improvement and expansion. Components in the ISM are grouped depending upon their relative solubility and impact to the RPP mission. The solubility of each group of components is characterized …
Date: October 19, 2012
Creator: Pierson, Kayla L.; Belsher, Jeremy D. & Seniow, Kendra R.
Object Type: Article
System: The UNT Digital Library
Corrosion-resistant, high-reflectance Mg/SiC multilayer coatings for solar physics in the 25-80 nm wavelength region (open access)

Corrosion-resistant, high-reflectance Mg/SiC multilayer coatings for solar physics in the 25-80 nm wavelength region

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Date: August 19, 2012
Creator: Soufli, R & Al, E T
Object Type: Article
System: The UNT Digital Library
MODELING GAS TRANSPORT AND REACTIONS IN POLYDIMETHYSILOXANE (open access)

MODELING GAS TRANSPORT AND REACTIONS IN POLYDIMETHYSILOXANE

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Date: July 19, 2012
Creator: Lu, C; Sun, Y; Harley, S J & Glascoe, E A
Object Type: Article
System: The UNT Digital Library
Final Work Plan: ISCR Pilot Test at Montgomery City, Missouri. (open access)

Final Work Plan: ISCR Pilot Test at Montgomery City, Missouri.

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Date: November 19, 2012
Creator: LaFreniere, L. M.
Object Type: Report
System: The UNT Digital Library
Interim Report on the Optimization and Feasibility Studies for the Neutron Detection without Helium-3 Project (open access)

Interim Report on the Optimization and Feasibility Studies for the Neutron Detection without Helium-3 Project

This report provides the status and results of the first year's effort in modeling and simulation to investigate alternatives to helium-3 for neutron detection in safeguards applications.
Date: March 19, 2012
Creator: Ely, James H.
Object Type: Report
System: The UNT Digital Library
Characteristics of Short Wavelength Compressional Alfven Eigenmodes (open access)

Characteristics of Short Wavelength Compressional Alfven Eigenmodes

Most Alfvenic activity in the frequency range between Toroidal Alfven Eigenmodes and roughly one half of the ion cyclotron frequency on NSTX [M. Ono, et al., Nucl. Fusion 40 (2000) 557], that is, approximately 0.3 MHz up to ≈ 1.2 MHz, are modes propagating counter to the neutral beam ions. These have been modeled as Compressional and Global Alfven Eigenmodes (CAE and GAE) and are excited through a Doppler-shifted cyclotron resonance with the beam ions. There is also a class of co-propagating modes at higher frequency than the counter-propagating CAE and GAE. These modes have been identified as CAE, and are seen mostly in the company of a low frequency, n=1 kink-like mode. In this paper we present measurements of the spectrum of these high frequency CAE (hfCAE), and their mode structure. We compare those measurements to a simple model of CAE and present evidence of a curious non-linear coupling of the hfCAE and the low frequency kink-like mode.
Date: December 19, 2012
Creator: Fredrickson, E. D.; Podesta, M.; Bortolon, A.; Crocker, N. A.; Gerhardt, S. P.; Bell, R. E. et al.
Object Type: Report
System: The UNT Digital Library