On High Order Finite-Difference Metric Discretizations Satisfying GCL on Moving and Deforming Grids (open access)

On High Order Finite-Difference Metric Discretizations Satisfying GCL on Moving and Deforming Grids

None
Date: May 23, 2013
Creator: Sjogreen, B.; Yee, H. C. & Vinokur, M.
Object Type: Report
System: The UNT Digital Library
Studies of Exclusive Charmless Semileptonic B Decays and Extraction of |V(Ub)| at BaBar (open access)

Studies of Exclusive Charmless Semileptonic B Decays and Extraction of |V(Ub)| at BaBar

None
Date: May 23, 2013
Creator: Taras, Paul & U., /Montreal
Object Type: Article
System: The UNT Digital Library
BACKSCATTER GUAGE DESCRIPTION FOR INSPECTION OF NEUTRON ABSORBER AND UNIFORMITY (open access)

BACKSCATTER GUAGE DESCRIPTION FOR INSPECTION OF NEUTRON ABSORBER AND UNIFORMITY

This paper describes design, calibration, and testing of a dual He-3 detector neutron backscatter gauge for use in the Savannah River Site Mixed Oxide Fuel project. The gauge is demonstrated to measure boron content and uniformity in concrete slabs used in the facility construction.
Date: May 23, 2012
Creator: Dewberry, R.; Gibbs, K. & Couture, A.
Object Type: Article
System: The UNT Digital Library
Changes to MFRSRCLDOD1MIN Datastream (open access)

Changes to MFRSRCLDOD1MIN Datastream

Significant updates were made to the multifilter rotating shadowband radiometer (MFRSR) cloud optical depth (MFRSRCLDOD) value-added product (VAP) in 2011. The original intent of the update was to add quality control (QC) flags and to update the VAP to use the improved retrievals of liquid water path (LWP) from the Microwave Radiometer Retrievals (MWRRET) VAP rather than the statistical retrievals of LWP from the Microwave Radiometer Line of Sight (MWRLOS) datastream. Although this was originally intended to be a straightforward update of the code, it became more complicated due to the following factors: (1) a new developer and translator team were working with the code; (2) numerous small changes had to be made to the code to consistently implement the QC flags; and (3) ARM standards have changed over the years since the code was originally developed.
Date: May 23, 2012
Creator: McFarlane, S. & Shi, Y.
Object Type: Report
System: The UNT Digital Library
Experimental Study of Parametric Dependence of Electron-scale Turbulence in a Spherical Tokamak (open access)

Experimental Study of Parametric Dependence of Electron-scale Turbulence in a Spherical Tokamak

Electron-scale turbulence is predicted to drive anomalous electron thermal transport. However, experimental study of its relation with transport is still in its early stage. On the National Spherical Tokamak eXperiment (NSTX), electron-scale density fluctuations are studied with a novel tangen- tial microwave scattering system with high radial resolution of ±2 cm. Here, we report a study of parametric dependence of electron-scale turbulence in NSTX H-mode plasmas. The dependence on density gradient is studied through the observation of a large density gradient variation in the core induced by an ELM event, where we found the first clear experimental evidence of density gradient stabilization of electron-gyro scale turbulence in a fusion plasma. This observation, cou- pled with linear gyro-kinetic calculations, leads to the identification of the observed instability as toroidal Electron Temperature Gradient (ETG) modes. It is observed that longer wavelength ETG modes, k⊥ρs < 10 (ρs is the ion gyroradius at electron temperature and k⊥ is the wavenumber perpendicular to local equilibrium magnetic field), are most stabilized by density gradient, and the stabilization is accompanied by about a factor of two decrease in electron thermal diffusivity. Comparisons with nonlinear ETG gyrokinetic simulations shows ETG turbulence may be able to explain the …
Date: May 23, 2012
Creator: Ren, Y.; Kaye, S. M.; Mazzucato, E.; Bell, R. E.; Diallo, A.; Domier, C. W. et al.
Object Type: Report
System: The UNT Digital Library
METAL MEDIA FILTERS, AG-1 SECTION FI (open access)

METAL MEDIA FILTERS, AG-1 SECTION FI

One application of metal media filters is in various nuclear air cleaning processes including applications for protecting workers, the public and the environment from hazardous and radioactive particles. To support this application the development of the ASME AG-1 FI Standard on Metal Media has been under way for more than ten years. Development of the proposed section has required resolving several difficult issues associated with operating conditions (media velocity, pressure drop, etc.), qualification testing, and quality acceptance testing. Performance characteristics of metal media are dramatically different than the glass fiber media with respect to parameters like differential pressures, operating temperatures, media strength, etc. These differences make existing data for a glass fiber media inadequate for qualifying a metal media filter for AG-1. In the past much work has been conducted on metal media filters at facilities such as Lawrence Livermore National Laboratory (LLNL) and Savannah River National Laboratory (SRNL) to qualify the media as High Efficiency Particulate Air (HEPA) Filters. Particle retention testing has been conducted at Oak Ridge Filter Test Facility and at Air Techniques International (ATI) to prove that the metal media meets or exceeds the 99.97% particle retention required for a HEPA Filter. Even with his testing, …
Date: May 23, 2012
Creator: Adamson, D.
Object Type: Article
System: The UNT Digital Library
SECAD-- a Schema-based Environment for Configuring, Analyzing and Documenting Integrated Fusion Simulations. Final report (open access)

SECAD-- a Schema-based Environment for Configuring, Analyzing and Documenting Integrated Fusion Simulations. Final report

SECAD is a project that developed a GUI for running integrated fusion simulations as implemented in FACETS and SWIM SciDAC projects. Using the GUI users can submit simulations locally and remotely and visualize the simulation results.
Date: May 23, 2012
Creator: Shasharina, Svetlana
Object Type: Report
System: The UNT Digital Library
Uranium Enrichment Standards of the Y-12 Nuclear Detection and Sensor Testing Center (open access)

Uranium Enrichment Standards of the Y-12 Nuclear Detection and Sensor Testing Center

The Y-12 National Security Complex has recently fabricated and characterized a new series of metallic uranium standards for use in the Nuclear Detection and Sensor Testing Center (NDSTC). Ten uranium metal disks with enrichments varying from 0.2 to 93.2% {sup 235}U were designed to provide researchers access to a wide variety of measurement scenarios in a single testing venue. Special care was taken in the selection of the enrichments in order to closely bracket the definitions of reactor fuel at 4% {sup 235}U and that of highly enriched uranium (HEU) at 20% {sup 235}U. Each standard is well characterized using analytical chemistry as well as a series of gamma-ray spectrometry measurements. Gamma-ray spectra of these standards are being archived in a reference library for use by customers of the NDSTC. A software database tool has been created that allows for easier access and comparison of various spectra. Information provided through the database includes: raw count data (including background spectra), regions of interest (ROIs), and full width half maximum calculations. Input is being sought from the user community on future needs including enhancements to the spectral database and additional Uranium standards, shielding configurations and detector types. A related presentation are planned …
Date: May 23, 2012
Creator: Cantrell, J.
Object Type: Article
System: The UNT Digital Library
Ab Initio Many-Body Calculation of the 7Be(p,g)8B Radiative Capture (open access)

Ab Initio Many-Body Calculation of the 7Be(p,g)8B Radiative Capture

None
Date: May 23, 2011
Creator: Navratil, P; Roth, R & Quaglioni, S
Object Type: Article
System: The UNT Digital Library
Characterization of Fish Passage Conditions through a Francis Turbine and Regulating Outlet at Cougar Dam, Oregon, Using Sensor Fish, 2009–2010 (open access)

Characterization of Fish Passage Conditions through a Francis Turbine and Regulating Outlet at Cougar Dam, Oregon, Using Sensor Fish, 2009–2010

Fish passage conditions through a Francis turbine and a regulating outlet (RO) at Cougar Dam on the south fork of the McKenzie River in Oregon were evaluated by Pacific Northwest National Laboratory for the U.S. Army Corps of Engineers, Portland District, using Sensor Fish devices. The objective of the study was to describe and compare passage exposure conditions, identifying potential fish injury regions encountered during passage via specific routes. The RO investigation was performed in December 2009 and the turbine evaluation in January 2010, concurrent with HI-Z balloon-tag studies by Normandeau Associates, Inc. Sensor Fish data were analyzed to estimate 1) exposure conditions, particularly exposure to severe collision, strike, and shear events by passage route sub-regions; 2) differences in passage conditions between passage routes; and 3) relationships to live-fish injury and mortality data estimates. Comparison of the three passage routes evaluated at Cougar Dam indicates that the RO passage route through the 3.7-ft gate opening was relatively the safest route for fish passage under the operating conditions tested; turbine passage was the most deleterious. These observations were supported also by the survival and malady estimates obtained from live-fish testing. Injury rates were highest for turbine passage. Compared to mainstem Columbia …
Date: May 23, 2011
Creator: Duncan, Joanne P.
Object Type: Report
System: The UNT Digital Library
Combined Ideal and Kinetic Effects on Reversed Shear Alfven Eigenmodes (open access)

Combined Ideal and Kinetic Effects on Reversed Shear Alfven Eigenmodes

A theory of Reversed Shear Alfven Eigenmodes (RSAEs) is developed for reversed magnetic field shear plasmas when the safety factor minimum, qmin, is at or above a rational value. The modes we study are known sometimes as either the bottom of the frequency sweep or the down sweeping RSAEs. We show that the ideal MHD theory is not compatible with the eigenmode solution in the reversed shear plasma with qmin above integer values. Corrected by special analytic FLR condition MHD dispersion of these modes nevertheless can be developed. Large radial scale part of the analytic RSAE solution can be obtained from ideal MHD and expressed in terms of the Legendre functions. The kinetic equation with FLR effects for the eigenmode is solved numerically and agrees with the analytic solutions. Properties of RSAEs and their potential implications for plasma diagnostics are discussed.
Date: May 23, 2011
Creator: N.N. Gorelenkov, G.J. Kramer, and R. Nazikian
Object Type: Report
System: The UNT Digital Library
Comment on Li pellet Conditioning in TFTR (open access)

Comment on Li pellet Conditioning in TFTR

Li pellet conditioning in TFTR results in a reduction of the edge electron density which allows increased neutral beam penetration, central heating, and fueling. Consequently the temperature profiles became more peaked with higher central Ti, Te, and neutron emission rates.
Date: May 23, 2011
Creator: Budny, R.V.
Object Type: Report
System: The UNT Digital Library
Computational fluid dynamics analyses of lateral heat conduction, coolant azimuthal mixing and heat transfer predictions in a BR2 fuel assembly geometry. (open access)

Computational fluid dynamics analyses of lateral heat conduction, coolant azimuthal mixing and heat transfer predictions in a BR2 fuel assembly geometry.

To support the analyses related to the conversion of the BR2 core from highly-enriched (HEU) to low-enriched (LEU) fuel, the thermal-hydraulics codes PLTEMP and RELAP-3D are used to evaluate the safety margins during steady-state operation (PLTEMP), as well as after a loss-of-flow, loss-of-pressure, or a loss of coolant event (RELAP). In the 1-D PLTEMP and RELAP simulations, conduction in the azimuthal and axial directions is not accounted. The very good thermal conductivity of the cladding and the fuel meat and significant temperature gradients in the lateral directions (axial and azimuthal directions) could lead to a heat flux distribution that is significantly different than the power distribution. To evaluate the significance of the lateral heat conduction, 3-D computational fluid dynamics (CFD) simulations, using the CFD code STAR-CD, were performed. Safety margin calculations are typically performed for a hot stripe, i.e., an azimuthal region of the fuel plates/coolant channel containing the power peak. In a RELAP model, for example, a channel between two plates could be divided into a number of RELAP channels (stripes) in the azimuthal direction. In a PLTEMP model, the effect of azimuthal power peaking could be taken into account by using engineering factors. However, if the thermal mixing …
Date: May 23, 2011
Creator: Tzanos, C. P. & Dionne, B. (Nuclear Engineering Division)
Object Type: Report
System: The UNT Digital Library
Considerations for Contractile Electroactive Materials and Actuators (open access)

Considerations for Contractile Electroactive Materials and Actuators

Ras Labs produces contractile electroactive polymer (EAP) based materials and actuators that bend, swell, ripple, and contract (new development) with low electric input. In addition, Ras Labs produces EAP materials that quickly contract and expand, repeatedly, by reversing the polarity of the electric input, which can be cycled. This phenomenon was explored using molecular modeling, followed by experimentation. Applied voltage step functions were also investigated. High voltage steps followed by low voltage steps produced a larger contraction followed by a smaller contraction. Actuator control by simply adjusting the electric input is extremely useful for biomimetic applications. Muscles are able to partially contract. If muscles could only completely contract, nobody could hold an egg, for example, without breaking it. A combination of high and low voltage step functions could produce gross motor function and fine manipulation within the same actuator unit. Plasma treated electrodes with various geometries were investigated as a means of providing for more durable actuation.
Date: May 23, 2011
Creator: Lenore Rasmussen, David Schramm, Paul Rasmussen, Kevin Mullaly, Ras Labs, LLC, Intelligent Materials for Prosthetics & Automation, Lewis D. Meixler, Daniel Pearlman and Alice Kirk
Object Type: Article
System: The UNT Digital Library

Economic Development from Gigawatt-Scale Wind Deployment in Wyoming

This presentation provides an overview of economic development in Wyoming from gigawatt-scale wind development and includes a discussion of project context, definitions and caveats, a deployment scenario, modeling inputs, results, and conclusions.
Date: May 23, 2011
Creator: Lantz, E.
Object Type: Presentation
System: The UNT Digital Library
Ekpyrosis and inflationary dynamics in heavy ion collisions: the role of quantum fluctuations (open access)

Ekpyrosis and inflationary dynamics in heavy ion collisions: the role of quantum fluctuations

We summarize recent significant progress in the development of a first-principles formalism to describe the formation and evolution of matter in very high energy heavy ion collisions. The key role of quantum fluctuations both before and after a collision is emphasized. Systematic computations are now feasible to address early time isotropization, flow, parton energy loss and the Chiral Magnetic Effect.
Date: May 23, 2011
Creator: Dusling, K.; Venugopalan, R. & Gelis, F.
Object Type: Article
System: The UNT Digital Library
Estimation of Steady-State and Transcient Power Distributions for the RELAP Analyses of the 1963 Loss-Of-Flow and Loss-Of-Pressure Tests at br2. (open access)

Estimation of Steady-State and Transcient Power Distributions for the RELAP Analyses of the 1963 Loss-Of-Flow and Loss-Of-Pressure Tests at br2.

To support the safety analyses required for the conversion of the Belgian Reactor 2 (BR2) from highly-enriched uranium (HEU) to low-enriched uranium (LEU) fuel, the simulation of a number of loss-of-flow tests, with or without loss of pressure, has been undertaken. These tests were performed at BR2 in 1963 and used instrumented fuel assemblies (FAs) with thermocouples (TC) imbedded in the cladding as well as probes to measure the FAs power on the basis of their coolant temperature rise. The availability of experimental data for these tests offers an opportunity to better establish the credibility of the RELAP5-3D model and methodology used in the conversion analysis. In order to support the HEU to LEU conversion safety analyses of the BR2 reactor, RELAP simulations of a number of loss-of-flow/loss-of-pressure tests have been undertaken. Preliminary analyses showed that the conservative power distributions used historically in the BR2 RELAP model resulted in a significant overestimation of the peak cladding temperature during the transient. Therefore, it was concluded that better estimates of the steady-state and decay power distributions were needed to accurately predict the cladding temperatures measured during the tests and establish the credibility of the RELAP model and methodology. The new approach ('best …
Date: May 23, 2011
Creator: Dionne, B. & Tzanos, C. P. (Nuclear Engineering Division)
Object Type: Report
System: The UNT Digital Library
Facilitating Energy Savings through Enhanced Usability of Thermostats (open access)

Facilitating Energy Savings through Enhanced Usability of Thermostats

Residential thermostats play a key role in controlling heating and cooling systems. Occupants often find the controls of programmable thermostats confusing, sometimes leading to higher heating consumption than when the buildings are controlled manually. A high degree of usability is vital to a programmable thermostat's effectiveness because, unlike a more efficient heating system, occupants must engage in specific actions after installation to obtain energy savings. We developed a procedure for measuring the usability of thermostats and tested this methodology with 31 subjects on five thermostats. The procedure requires first identifying representative tasks associated with the device and then testing the subjects ability to accomplish those tasks. The procedure was able to demonstrate the subjects wide ability to accomplish tasks and the influence of a device's usability on success rates. A metric based on the time to accomplish the tasks and the fraction of subjects actually completing the tasks captured the key aspects of each thermostat's usability. The procedure was recently adopted by the Energy Star Program for its thermostat specification. The approach appears suitable for quantifying usability of controls in other products, such as heat pump water heaters and commercial lighting.
Date: May 23, 2011
Creator: Meier, Alan; Aragon, Cecilia; Peffer, Therese; Perry, Daniel & Pritoni, Marco
Object Type: Article
System: The UNT Digital Library
A Greenhouse-Gas Information System - Monitoring and Validating Emissions Reporting and Mitigation - Chapter 2: Requirements Framework (open access)

A Greenhouse-Gas Information System - Monitoring and Validating Emissions Reporting and Mitigation - Chapter 2: Requirements Framework

None
Date: May 23, 2011
Creator: Stolaroff, J K
Object Type: Report
System: The UNT Digital Library
HEAT TRANSFER ANALYSIS FOR ION-EXCHANGE COLUMN SYSTEM (open access)

HEAT TRANSFER ANALYSIS FOR ION-EXCHANGE COLUMN SYSTEM

Models have been developed to simulate the thermal characteristics of Crystalline Silicotitanate (CST) ion exchange media fully loaded with radioactive cesium in a column configuration and distributed within a waste storage tank. This work was conducted to support the Small Column Ion Exchange (SCIX) program which is focused on processing dissolved, high-sodium salt waste for the removal of specific radionuclides (including Cs-137, Sr-90, and actinides) within a High Level Waste (HLW) storage tank at the Savannah River Site. The SCIX design includes CST columns inserted and supported in the tank top risers for cesium removal. Temperature distributions and maximum temperatures across the column were calculated with a focus on process upset conditions. A two-dimensional computational modeling approach for the in-column ion-exchange domain was taken to include conservative, bounding estimates for key parameters such that the results would provide the maximum centerline temperatures achievable under the design configurations using a feed composition known to promote high cesium loading on CST. The current full-scale design for the CST column includes one central cooling pipe and four outer cooling tubes. Most calculations assumed that the fluid within the column was stagnant (i.e. no buoyancy-induced flow) for a conservative estimate. A primary objective of …
Date: May 23, 2011
Creator: Lee, S. & King, W.
Object Type: Article
System: The UNT Digital Library
Hidden magnetic configuration in epitaxial La1-rSrzMnO3 films (open access)

Hidden magnetic configuration in epitaxial La1-rSrzMnO3 films

We present an unreported magnetic configuration in epitaxial La{sub 1-x}Sr{sub x}MnO{sub 3} (x {approx} 0.3) (LSMO) films grown on strontium titanate (STO). X-ray magnetic circular dichroism indicates that the remanent magnetic state of thick LSMO films is opposite to the direction of applied magnetic field. Spectroscopic and scattering measurements reveal that the average Mn valence varies from mixed Mn{sup 3+}/Mn{sup 4+} to an enriched Mn{sup 3+} region near the STO interface, resulting in a compressive lattice along a, b-axis and a possible electronic reconstruction in the Mn e{sub g} orbital (d{sub 3z{sup 2}-r{sup 2}}). This reconstruction may provide a mechanism for coupling the Mn{sup 3+} moments antiferromagnetically along the surface normal direction, and in turn may lead to the observed reversed magnetic configuration.
Date: May 23, 2011
Creator: Kao, Chi-Chang
Object Type: Article
System: The UNT Digital Library
Laboratory Evaluation of LED T8 Replacement Lamp Products (open access)

Laboratory Evaluation of LED T8 Replacement Lamp Products

A report on a lab setting analysis involving LED lamps intended to directly replace T8 fluorescent lamps (4') showing light output, power, and economic comparisons with other fluorescent options.
Date: May 23, 2011
Creator: Richman, Eric E.; Kinzey, Bruce R. & Miller, Naomi J.
Object Type: Report
System: The UNT Digital Library
Lithium Wall Conditioning And Surface Dust Detection On NSTX (open access)

Lithium Wall Conditioning And Surface Dust Detection On NSTX

Lithium evaporation onto NSTX plasma facing components (PFC) has resulted in improved energy confinement, and reductions in the number and amplitude of edge-localized modes (ELMs) up to the point of complete ELM suppression. The associated PFC surface chemistry has been investigated with a novel plasma material interface probe connected to an in-vacuo surface analysis station. Analysis has demonstrated that binding of D atoms to the polycrystalline graphite material of the PFCs is fundamentally changed by lithium - in particular deuterium atoms become weakly bonded near lithium atoms themselves bound to either oxygen or the carbon from the underlying material. Surface dust inside NSTX has been detected in real-time using a highly sensitive electrostatic dust detector. In a separate experiment, electrostatic removal of dust via three concentric spiral-shaped electrodes covered by a dielectric and driven by a high voltage 3-phase waveform was evaluated for potential application to fusion reactors
Date: May 23, 2011
Creator: Skinner, C. H.; Bell, M. G.; Friesen, F. Q. L.; Heim, B.; Jaworski, M. A.; Kugel, H. et al.
Object Type: Article
System: The UNT Digital Library
A Model for Tow Impregnation and Consolidation for Partially Impregnated Thermoset Prepregs (open access)

A Model for Tow Impregnation and Consolidation for Partially Impregnated Thermoset Prepregs

The formation and transport of voids in composite materials remains a key research area in composite manufacturing science. Knowledge of how voids, resin, and fiber reinforcement propagate throughout a composite material continuum from green state to cured state during an automated tape layup process is key to minimizing defects induced by void-initiated stress concentrations under applied loads for a wide variety of composite applications. This paper focuses on modeling resin flow in a deforming fiber tow during an automated process of partially impregnated thermoset prepreg composite material tapes. In this work, a tow unit cell based model has been presented that determines the consolidation and impregnation of a thermoset prepreg tape under an input pressure profile. A parametric study has been performed to characterize the behavior of varying tow speed and compaction forces on the degree of consolidation. Results indicate that increased tow consolidation is achieved with slower tow speeds and higher compaction forces although the relationship is not linear. The overall modeling of this project is motivated to address optimization of the 'green state' composite properties and processing parameters to reduce or eliminate 'cured state' defects, such as porosity and de-lamination. This work is partially funded by the Department …
Date: May 23, 2011
Creator: Jr, John J. Gangloff; Sinha, Shatil & Advani, Suresh G.
Object Type: Article
System: The UNT Digital Library