Reducing the Cost of Thermal Energy Storage for Parabolic Trough Solar Power Plants (open access)

Reducing the Cost of Thermal Energy Storage for Parabolic Trough Solar Power Plants

Thermal energy storage systems using phase change materials were evaluated for trough systems that use oil, steam, and high temperature salts as heat transfer fluids. A variety of eutectic salts and metal alloys were considered as phase change materials in a cascaded arrangement. Literature values of specific heat, latent heat, density, and other thermophysical properties were used in initial analyses. Testing laboratories were contracted to measure properties for candidate materials for comparison to the literature and for updating the models. A TRNSYS model from Phase 1 was further developed for optimizing the system, including a novel control algorithm. A concept for increasing the bulk thermal conductivity of the phase change system was developed using expanded metal sheets. Outside companies were contracted to design and cost systems using platecoil heat exchangers immersed in the phase change material. Laboratory evaluations of the one-dimensional and three-dimensional behavior of expanded metal sheets in a low conductivity medium were used to optimize the amount of thermal conductivity enhancement. The thermal energy storage systems were compared to baseline conventional systems. The best phase change system found in this project, which was for the high temperature plant, had a projected cost of $25.2 per kWhth, The best …
Date: June 25, 2013
Creator: Gawlik, Keith
Object Type: Report
System: The UNT Digital Library
Cosmography From Two-Image Lens Systems: Overcoming the Lens Profile Slope Degeneracy (open access)

Cosmography From Two-Image Lens Systems: Overcoming the Lens Profile Slope Degeneracy

None
Date: April 25, 2013
Creator: Suyu, S.H. & /UC, Santa Barbara /KIPAC, Menlo Park
Object Type: Article
System: The UNT Digital Library
New Manufacturing Method for Paper Filler and Fiber Material (open access)

New Manufacturing Method for Paper Filler and Fiber Material

The use of fillers in printing and writing papers has become a prerequisite for competing in a global market to reduce the cost of materials. Use of calcium carbonates (ranging from 18% to 30%) as filler is a common practice in the paper industry but the choices of fillers for each type of papers vary widely according to its use. The market for uncoated digital printing paper is one that continues to introduce exciting growth projections. and it is important to understand the effect that new manufacturing methods of calcium carbonates have on the energy efficiency and paper production. Research conducted under this award showed that the new fiber filler composite material has the potential to increase the paper filler content by up to 5% without losing mechanical properties. Benefits of the technology can be summarized as follows for a 1% filler increase per metric ton of paper produced: (i) production cost savings over $12, (ii) Energy savings of 100,900 btu, (iii) CO{sub 2} emission savings of 33 lbs, and additional savings for wood preparation, pulping, recovery of 203593 btu with a 46lbs of CO{sub 2} emission savings per 1% filler increase. In addition the technology has the potential to …
Date: August 25, 2013
Creator: Doelle, Klaus
Object Type: Report
System: The UNT Digital Library
NEW RESULTS ON THE LASER PRODUCED RELATIVISTIC ELECTRON-POSITRON PAIR PLASMA RESEARCH (open access)

NEW RESULTS ON THE LASER PRODUCED RELATIVISTIC ELECTRON-POSITRON PAIR PLASMA RESEARCH

None
Date: March 25, 2013
Creator: Chen, H
Object Type: Article
System: The UNT Digital Library
Flammability Control In A Nuclear Waste Vitrification System (open access)

Flammability Control In A Nuclear Waste Vitrification System

The Defense Waste Processing Facility at the Savannah River Site processes high-level radioactive waste from the processing of nuclear materials that contains dissolved and precipitated metals and radionuclides. Vitrification of this waste into borosilicate glass for ultimate disposal at a geologic repository involves chemically modifying the waste to make it compatible with the glass melter system. Pretreatment steps include removal of excess aluminum by dissolution and washing, and processing with formic and nitric acids to: 1) adjust the reduction-oxidation (redox) potential in the glass melter to reduce radionuclide volatility and improve melt rate; 2) adjust feed rheology; and 3) reduce by steam stripping the amount of mercury that must be processed in the melter. Elimination of formic acid in pretreatment has been studied to eliminate the production of hydrogen in the pretreatment systems, which requires nuclear grade monitoring equipment. An alternative reductant, glycolic acid, has been studied as a substitute for formic acid. However, in the melter, the potential for greater formation of flammable gases exists with glycolic acid. Melter flammability is difficult to control because flammable mixtures can be formed during surges in offgases that both increase the amount of flammable species and decrease the temperature in the vapor …
Date: July 25, 2013
Creator: Zamecnik, John R.; Choi, Alexander S.; Johnson, Fabienne C.; Miller, Donald H.; Lambert, Daniel P.; Stone, Michael E. et al.
Object Type: Article
System: The UNT Digital Library
Mathematical and Computational Tools for Predictive Simulation of Complex Coupled Systems under Uncertainty (open access)

Mathematical and Computational Tools for Predictive Simulation of Complex Coupled Systems under Uncertainty

Methods and algorithms are developed to enable the accurate analysis of problems that exhibit interacting physical processes with uncertainties. These uncertainties can pertain either to each of the physical processes or to the manner in which they depend on each others. These problems are cast within a polynomial chaos framework and their solution then involves either solving a large system of algebraic equations or a high dimensional numerical quadrature. In both cases, the curse of dimensionality is manifested. Procedures are developed for the efficient evaluation of the resulting linear equations that advantage of the block sparse structure of these equations, resulting in a block recursive Schur complement construction. In addition, embedded quadratures are constructed that permit the evaluation of very high-dimensional integrals using low-dimensional quadratures adapted to particular quantities of interest. The low-dimensional integration is carried out in a transformed measure space in which the quantity of interest is low-dimensional. Finally, a procedure is also developed to discover a low-dimensional manifold, embedded in the initial high-dimensional one, in which scalar quantities of interest exist. This approach permits the functional expression of the reduced space in terms of the original space, thus permitting cross-scale sensitivity analysis.
Date: March 25, 2013
Creator: Ghanem, Roger
Object Type: Report
System: The UNT Digital Library
Interim salt disposition program macrobatch 6 tank 21H qualification monosodium titanate and cesium mass transfer tests (open access)

Interim salt disposition program macrobatch 6 tank 21H qualification monosodium titanate and cesium mass transfer tests

Savannah River National Laboratory (SRNL) performed experiments on qualification material for use in the Interim Salt Disposition Program (ISDP) Batch 6 processing. This qualification material was a set of six samples from Tank 21H in October 2012. This sample was used as a real waste demonstration of the Actinide Removal Process (ARP) and the Extraction-Scrub-Strip (ESS) tests process. The Tank 21H sample was contacted with a reduced amount (0.2 g/L) of MST and characterized for strontium and actinide removal at 0 and 8 hour time intervals in this salt batch. {sup 237}Np and {sup 243}Am were both observed to be below detection limits in the source material, and so these results are not reported in this report. The plutonium and uranium samples had decontamination factor (DF) values that were on par or slightly better than we expected from Batch 5. The strontium DF values are slightly lower than expected but still in an acceptable range. The Extraction, Scrub, and Strip (ESS) testing demonstrated cesium removal, stripping and scrubbing within the acceptable range. Overall, the testing indicated that cesium removal is comparable to prior batches at MCU.
Date: February 25, 2013
Creator: Washington, A. L. II; Peters, T. B. & Fink, S. D.
Object Type: Report
System: The UNT Digital Library
241-SY Tank Farm Construction Extent of Condition Review for Tank Integrity (open access)

241-SY Tank Farm Construction Extent of Condition Review for Tank Integrity

This report provides the results of an extent of condition construction history review for tanks 241-SY-101, 241-SY-102, and 241-SY-103. The construction history of the 241-SY tank farm has been reviewed to identify issues similar to those experienced during tank 241-AY-102 construction. Those issues and others impacting integrity are discussed based on information found in available construction records, using tank 241-AY-102 as the comparison benchmark. In the 241-SY tank farm, the third DST farm constructed, refractory quality and stress relief were improved, while similar tank and liner fabrication issues remained.
Date: July 25, 2013
Creator: Barnes, Travis J.; Boomer, Kayle D.; Gunter, Jason R. & Venetz, Theodore J.
Object Type: Report
System: The UNT Digital Library
Modeling of a Slanted-Hole Collimator in a Compact Endocavity Gamma Camera (open access)

Modeling of a Slanted-Hole Collimator in a Compact Endocavity Gamma Camera

N/A
Date: August 25, 2013
Creator: Cui, Y.; Karmuda, M.; Lall, T.; Ionson, J.; Camarda, G.; Hossain, A. et al.
Object Type: Article
System: The UNT Digital Library
Results for the Independent Sampling and Analysis of Used Oil Drums at the Impact Services Facility in Oak Ridge, TN (open access)

Results for the Independent Sampling and Analysis of Used Oil Drums at the Impact Services Facility in Oak Ridge, TN

The U.S. Department of Energy (DOE) requested that Oak Ridge Associated Universities (ORAU), via the Oak Ridge Institute for Science and Education (ORISE) contract, perform independent sampling and analysis of used oils contained within eight 55 gallon drums stored at the former IMPACT Services facility, located at the East Tennessee Technology Park in Oak Ridge, Tennessee. These drums were originally delivered by LATA Sharp Remediation Services (LSRS) to IMPACT Services on January 11, 2011 as part of the Bldg. K-33 demolition project, and the drums plus contents should have been processed as non-hazardous non-radiological waste by IMPACT Services. LSRS received a certificate of destruction on August 29, 2012 (LSRS 2012a). However, IMPACT Services declared bankruptcy and abandoned the site later in 2012, and eight of the original eleven K-33 drums are currently stored at the facility. The content of these drums is the subject of this investigation. The original drum contents were sampled by LSRS in 2010 and analyzed for gross alpha, gross beta, and polychlorinated biphenyls (PCBs), using both compositing and grab sampling techniques. The objective of this 2013 sample and analysis effort was to duplicate, to the extent possible, the 2010 sampling and analysis event to support final …
Date: April 25, 2013
Creator: unknown
Object Type: Report
System: The UNT Digital Library
TP76 -MicroCT Scatter Evaluation (open access)

TP76 -MicroCT Scatter Evaluation

None
Date: January 25, 2013
Creator: Champley, K
Object Type: Report
System: The UNT Digital Library
INDEPENDENT CONFIRMATORY SURVEY SUMMARY AND RESULTS FOR THE FORD NUCLEAR REACTOR, ANN ARBOR, MICHIGAN (open access)

INDEPENDENT CONFIRMATORY SURVEY SUMMARY AND RESULTS FOR THE FORD NUCLEAR REACTOR, ANN ARBOR, MICHIGAN

At the NRC�s request, ORAU conducted confirmatory surveys of the FNR during the period of December 4 through 6, 2012. The survey activities included visual inspections and measurement and sampling activities. Confirmatory activities also included the review and assessment of UM�s project documentation and methodologies. Surface scans identified elevated activity in two areas. The first area was on a wall outside of Room 3103 and the second area was in the southwest section on the first floor. The first area was remediated to background levels. However, the second area was due to gamma shine from a neighboring source storage area. A retrospective analysis of UM�s FSS data shows that for the SUs investigated by the ORAU survey team, UM met the survey requirements set forth in the FSSP. The total mean surface activity values were directly compared with the mean total surface activity reported by UM. Mean surface activity values determined by UM were within two standard deviations of the mean determined by ORAU. Additionally, all surface activity values were less than the corresponding gross beta DCGLW. Laboratory analysis of the soil showed that COC concentrations were less than the respective DCGLW values. For the inter-lab comparison, the DER was …
Date: July 25, 2013
Creator: Altic, Nick A.
Object Type: Report
System: The UNT Digital Library
DWPF simulant CPC studies for SB8 (open access)

DWPF simulant CPC studies for SB8

The Savannah River National Laboratory (SRNL) accepted a technical task request (TTR) from Waste Solidification Engineering to perform simulant tests to support the qualification of Sludge Batch 8 (SB8) and to develop the flowsheet for SB8 in the Defense Waste Processing Facility (DWPF). These efforts pertained to the DWPF Chemical Process Cell (CPC). Separate studies were conducted for frit development and glass properties (including REDOX). The SRNL CPC effort had two primary phases divided by the decision to drop Tank 12 from the SB8 constituents. This report focuses on the second phase with SB8 compositions that do not contain the Tank 12 piece. A separate report will document the initial phase of SB8 testing that included Tank 12. The second phase of SB8 studies consisted of two sets of CPC studies. The first study involved CPC testing of an SB8 simulant for Tank 51 to support the CPC demonstration of the washed Tank 51 qualification sample in the SRNL Shielded Cells facility. SB8-Tank 51 was a high iron-low aluminum waste with fairly high mercury and moderate noble metal concentrations. Tank 51 was ultimately washed to about 1.5 M sodium which is the highest wash endpoint since SB3-Tank 51. This study …
Date: June 25, 2013
Creator: Koopman, D. C. & Zamecnik, J. R.
Object Type: Report
System: The UNT Digital Library
Numerical Studies of Collective Phenomena in Two-Dimensional Electron and Cold Atom Systems (open access)

Numerical Studies of Collective Phenomena in Two-Dimensional Electron and Cold Atom Systems

Numerical calculations were carried out to investigate a number of outstanding questions in both two-dimensional electron and cold atom systems. These projects aimed to increase our understanding of the properties of and prospects for non-Abelian states in quantum Hall matter.
Date: July 25, 2013
Creator: Rezayi, Edward
Object Type: Report
System: The UNT Digital Library
Dissecting the Gravitational Lens B1608 656. I. Lens Potential Reconstruction (open access)

Dissecting the Gravitational Lens B1608 656. I. Lens Potential Reconstruction

None
Date: April 25, 2013
Creator: Suyu, S. H.; Marshall, P. J.; Blandford, R. D.; Fassnacht, C. D.; Koopmans, L. V. E.; McKean, J. P. et al.
Object Type: Article
System: The UNT Digital Library
Unveiling the Nature of the Unidentified Gamma-ray Sources V: Analysis of the Radio Candidates with the Kernel Density Estimation (open access)

Unveiling the Nature of the Unidentified Gamma-ray Sources V: Analysis of the Radio Candidates with the Kernel Density Estimation

None
Date: September 25, 2013
Creator: Massaro, F.; D'Abrusco, R.; Paggi, A.; Masetti, N.; Giroletti, M.; Tosti, G. et al.
Object Type: Article
System: The UNT Digital Library
Development of Parallel Computing Framework to Enhance Radiation Transport Code Capabilities for Rare Isotope Beam Facility Design (open access)

Development of Parallel Computing Framework to Enhance Radiation Transport Code Capabilities for Rare Isotope Beam Facility Design

A parallel computing framework has been developed to use with general-purpose radiation transport codes. The framework was implemented as a C++ module that uses MPI for message passing. It is intended to be used with older radiation transport codes implemented in Fortran77, Fortran 90 or C. The module is significantly independent of radiation transport codes it can be used with, and is connected to the codes by means of a number of interface functions. The framework was developed and tested in conjunction with the MARS15 code. It is possible to use it with other codes such as PHITS, FLUKA and MCNP after certain adjustments. Besides the parallel computing functionality, the framework offers a checkpoint facility that allows restarting calculations with a saved checkpoint file. The checkpoint facility can be used in single process calculations as well as in the parallel regime. The framework corrects some of the known problems with the scheduling and load balancing found in the original implementations of the parallel computing functionality in MARS15 and PHITS. The framework can be used efficiently on homogeneous systems and networks of workstations, where the interference from the other users is possible.
Date: September 25, 2013
Creator: Kostin, Mikhail; Mokhov, Nikolai & Niita, Koji
Object Type: Report
System: The UNT Digital Library
Post-growth Annealing of CdZnTe crystals: an analysis of defect-structures and opto-electronic properties (open access)

Post-growth Annealing of CdZnTe crystals: an analysis of defect-structures and opto-electronic properties

N/A
Date: August 25, 2013
Creator: Yang, G.; Bolotnikov, A. E.; Fochuk, P. M.; Camarda, G. S.; Hossain, A.; Roy, U. et al.
Object Type: Article
System: The UNT Digital Library
DWPF Simulant CPC Studies For SB8 (open access)

DWPF Simulant CPC Studies For SB8

Prior to processing a Sludge Batch (SB) in the Defense Waste Processing Facility (DWPF), flowsheet studies using simulants are performed. Typically, the flowsheet studies are conducted based on projected composition(s). The results from the flowsheet testing are used to 1) guide decisions during sludge batch preparation, 2) serve as a preliminary evaluation of potential processing issues, and 3) provide a basis to support the Shielded Cells qualification runs performed at the Savannah River National Laboratory (SRNL). SB8 was initially projected to be a combination of the Tank 40 heel (Sludge Batch 7b), Tank 13, Tank 12, and the Tank 51 heel. In order to accelerate preparation of SB8, the decision was made to delay the oxalate-rich material from Tank 12 to a future sludge batch. SB8 simulant studies without Tank 12 were reported in a separate report.1 The data presented in this report will be useful when processing future sludge batches containing Tank 12. The wash endpoint target for SB8 was set at a significantly higher sodium concentration to allow acceptable glass compositions at the targeted waste loading. Four non-coupled tests were conducted using simulant representing Tank 40 at 110-146% of the Koopman Minimum Acid requirement. Hydrogen was generated during …
Date: September 25, 2013
Creator: Newell, J. D.
Object Type: Report
System: The UNT Digital Library
Size Distribution and Oxide Thickness of Uranium Micro-Spheres (open access)

Size Distribution and Oxide Thickness of Uranium Micro-Spheres

None
Date: July 25, 2013
Creator: Siekhaus, W J & Teslich, N E
Object Type: Report
System: The UNT Digital Library
TP75-MicroCT Test Bed Data Acquisition for Multi-Energy Zeff and Rho-e Decomposition Analysis (open access)

TP75-MicroCT Test Bed Data Acquisition for Multi-Energy Zeff and Rho-e Decomposition Analysis

None
Date: January 25, 2013
Creator: Brown, W. D. & Smith, J. A.
Object Type: Report
System: The UNT Digital Library
The Radiative Properties of Small Clouds: Multi-Scale Observations and Modeling (open access)

The Radiative Properties of Small Clouds: Multi-Scale Observations and Modeling

Warm, liquid clouds and their representation in climate models continue to represent one of the most significant unknowns in climate sensitivity and climate change. Our project combines ARM observations, LES modeling, and satellite imagery to characterize shallow clouds and the role of aerosol in modifying their radiative effects.
Date: September 25, 2013
Creator: Feingold, Graham & McComiskey, Allison
Object Type: Report
System: The UNT Digital Library
Strategies for Voltage Control and Transient Stability Assessment (open access)

Strategies for Voltage Control and Transient Stability Assessment

As wind generation grows, its influence on power system performance will becoming increasingly noticeable. Wind generation di#11;ffers from traditional forms of generation in numerous ways though, motivating the need to reconsider the usual approaches to power system assessment and performance enhancement. The project has investigated the impact of wind generation on transient stability and voltage control, identifying and addressing issues at three distinct levels of the power system: 1) at the device level, the physical characteristics of wind turbine generators (WTGs) are quite unlike those of synchronous machines, 2) at the wind-farm level, the provision of reactive support is achieved through coordination of numerous dissimilar devices, rather than straightforward generator control, and 3) from a systems perspective, the location of wind-farms on the sub-transmission network, coupled with the variability inherent in their power output, can cause complex voltage control issues. The project has sought to develop a thorough understanding of the dynamic behaviour of type-3 WTGs, and in particular the WECC generic model. The behaviour of such models is governed by interactions between the continuous dynamics of state variables and discrete events associated with limits. It was shown that these interactions can be quite complex, and may lead to switching …
Date: September 25, 2013
Creator: Hiskens, Ian A.
Object Type: Report
System: The UNT Digital Library
2013 METALS IN BIOLOGY GORDON RESEARCH CONFERENCE, JANUARY 20-25, 2013 (open access)

2013 METALS IN BIOLOGY GORDON RESEARCH CONFERENCE, JANUARY 20-25, 2013

Typical topics for lectures and posters include: biochemical and biophysical characterization of new metal containing proteins, enzymes, nucleic acids, factors, and chelators from all forms of life; synthesis, detailed characterization, and reaction chemistry of biomimetic compounds; novel crystal and solution structures of biological molecules and synthetic metal-chelates; discussions of the roles that metals play in medicine, maintenance of the environment, and biogeochemical processes; metal homeostasis; application of theory and computations to the structure and mechanism of metal-containing biological systems; and novel applications of spectroscopy to metals in biological systems.
Date: January 25, 2013
Creator: Rosenzweig, Amy
Object Type: Article
System: The UNT Digital Library