States

Month

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
Federal Register, Volume 76, Number 99, May 23, 2011, Pages 29633-29988 (open access)

Federal Register, Volume 76, Number 99, May 23, 2011, Pages 29633-29988

Daily publication of the U.S. Office of the Federal Register contains rules and regulations, proposed legislation and rule changes, and other notices, including "Presidential proclamations and Executive Orders, Federal agency documents having general applicability and legal effect, documents required to be published by act of Congress, and other Federal agency documents of public interest" (p. ii). Table of Contents starts on page iii.
Date: May 23, 2011
Creator: United States. Office of the Federal Register.
Object Type: Journal/Magazine/Newsletter
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
Journal of the House of Representatives of Texas: 82nd Legislature, Regular Session, May 23, 2011 (open access)

Journal of the House of Representatives of Texas: 82nd Legislature, Regular Session, May 23, 2011

Proceedings of the House of Representatives of Texas for the 83rd day of the regular session of the 82nd Legislature documenting legislation, reports, discussions, votes, and points-of-order.
Date: May 23, 2011
Creator: Texas. Legislature. House of Representatives.
Object Type: Legislative Document
System: The Portal to Texas History
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
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
The Motor Vehicle Supply Chain: Effects of the Japanese Earthquake and Tsunami (open access)

The Motor Vehicle Supply Chain: Effects of the Japanese Earthquake and Tsunami

This report discusses the effect that the March 2011 Great Tohoku Earthquake and Tsunami in the northeast coast of Japan has on the auto production facilities in the United States. Not long after the earthquake and tsunami the disruptions in Japanese industrial activity, the impact on global supply chains could also be significant. This is especially important in industries such as autos, telecommunications and consumer electronics.
Date: May 23, 2011
Creator: Canis, Bill
Object Type: Report
System: The UNT Digital Library
The Motor Vehicle Supply Chain: Effects of the Japanese Earthquake and Tsunami (open access)

The Motor Vehicle Supply Chain: Effects of the Japanese Earthquake and Tsunami

None
Date: May 23, 2011
Creator: unknown
Object Type: Report
System: The UNT Digital Library
OECD 2-D Core Concrete Interaction (CCI) tests : CCI-2 test plan, Rev. 0 January 31, 2004. (open access)

OECD 2-D Core Concrete Interaction (CCI) tests : CCI-2 test plan, Rev. 0 January 31, 2004.

The Melt Attack and Coolability Experiments (MACE) program addressed the issue of the ability of water to cool and thermally stabilize a molten core-concrete interaction when the reactants are flooded from above. These tests provided data regarding the nature of corium interactions with concrete, the heat transfer rates from the melt to the overlying water pool, and the role of noncondensable gases in the mixing processes that contribute to melt quenching. As a follow-on program to MACE, The Melt Coolability and Concrete Interaction Experiments (MCCI) project is conducting reactor material experiments and associated analysis to achieve the following objectives: (1) resolve the ex-vessel debris coolability issue through a program that focuses on providing both confirmatory evidence and test data for the coolability mechanisms identified in MACE integral effects tests, and (2) address remaining uncertainties related to long-term two-dimensional molten core-concrete interactions under both wet and dry cavity conditions. Achievement of these two program objectives will demonstrate the efficacy of severe accident management guidelines for existing plants, and provide the technical basis for better containment designs for future plants. In terms of satisfying these objectives, the Management Board (MB) approved the conduct of two long-term 2-D Core-Concrete Interaction (CCI) experiments designed …
Date: May 23, 2011
Creator: Farmer, M. T.; Kilsdonk, D. J.; Lomperski, S.; Aeschlimann, R. W. & Basu, S. (Nuclear Engineering Division)
Object Type: Report
System: The UNT Digital Library
OECD MCCI 2-D Core Concrete Interaction (CCI) tests : CCI-2 test data report-thermalhydraulic results, Rev. 0 October 15, 2004. (open access)

OECD MCCI 2-D Core Concrete Interaction (CCI) tests : CCI-2 test data report-thermalhydraulic results, Rev. 0 October 15, 2004.

The Melt Attack and Coolability Experiments (MACE) program addressed the issue of the ability of water to cool and thermally stabilize a molten core-concrete interaction when the reactants are flooded from above. These tests provided data regarding the nature of corium interactions with concrete, the heat transfer rates from the melt to the overlying water pool, and the role of noncondensable gases in the mixing processes that contribute to melt quenching. As a follow-on program to MACE, The Melt Coolability and Concrete Interaction Experiments (MCCI) project is conducting reactor material experiments and associated analysis to achieve the following objectives: (1) resolve the ex-vessel debris coolability issue through a program that focuses on providing both confirmatory evidence and test data for the coolability mechanisms identified in MACE integral effects tests, and (2) address remaining uncertainties related to long-term two-dimensional molten core-concrete interactions under both wet and dry cavity conditions. Achievement of these two program objectives will demonstrate the efficacy of severe accident management guidelines for existing plants, and provide the technical basis for better containment designs for future plants. In terms of satisfying these objectives, the Management Board (MB) approved the conduct of two long-term 2-D Core-Concrete Interaction (CCI) experiments designed …
Date: May 23, 2011
Creator: Farmer, M. T.; Lomperski, S.; Kilsdonk, D. J.; Aeschlimann, R. W. & Basu, S.
Object Type: Report
System: The UNT Digital Library
OECD/MCCI 2-D Core Concrete Interaction (CCI) tests : final report February 28, 2006. (open access)

OECD/MCCI 2-D Core Concrete Interaction (CCI) tests : final report February 28, 2006.

Although extensive research has been conducted over the last several years in the areas of Core-Concrete Interaction (CCI) and debris coolability, two important issues warrant further investigation. The first issue concerns the effectiveness of water in terminating a CCI by flooding the interacting masses from above, thereby quenching the molten core debris and rendering it permanently coolable. This safety issue was investigated in the EPRI-sponsored Melt Attack and Coolability Experiments (MACE) program. The approach was to conduct large scale, integral-type reactor materials experiments with core melt masses ranging up to two metric tons. These experiments provided unique, and for the most part repeatable, indications of heat transfer mechanism(s) that could provide long term debris cooling. However, the results did not demonstrate definitively that a melt would always be completely quenched. This was due to the fact that the crust anchored to the test section sidewalls in every test, which led to melt/crust separation, even at the largest test section lateral span of 1.20 m. This decoupling is not expected for a typical reactor cavity, which has a span of 5-6 m. Even though the crust may mechanically bond to the reactor cavity walls, the weight of the coolant and the …
Date: May 23, 2011
Creator: Farmer, M. T.; Lomperski, S.; Kilsdonk, D. J.; Aeschlimann, R. W. & Basu, S.
Object Type: Report
System: The UNT Digital Library