Empirical Study of Ne in H-Mode Pedestal in DIII-D (open access)

Empirical Study of Ne in H-Mode Pedestal in DIII-D

There is compelling empirical [1] and theoretical [2] evidence that the global confinement of H-mode discharges increases as the pedestal pressure or temperature increases. Therefore, confidence in the performance of future machines requires an ability to predict the pedestal conditions in those machines. At this time, both the theoretical and empirical understanding of transport in the pedestal are incomplete and are inadequate to predict pedestal conditions in present or future machines. Recent empirical results might be evidence of a fundamental relation between the electron temperature T{sub e} and electron density n{sub e} profiles in the pedestal. A data set from the ASDEX-Upgrade tokamak has shown that {eta}{sub e}, the ratio between the scale lengths of the n{sub e} and T{sub e} profiles, exhibits a value of about 2 throughout the pedestal, despite a large range of the actual density and temperature values [3]. Data from the DIII-D tokamak show that over a wide range of pedestal density, the width of the steep gradient region for the T{sub e} profile is about 1-2 times the corresponding width for the n{sub e} profile, where both widths are measured from the plasma edge [4]. Thus, the barrier in the density might form a …
Date: May 5, 2005
Creator: . Groebner, R. J.; Osborne, T. H.; Fenstermacher, M. E.; Leonard, A. W.; Mahdavi, M. A.; Snyder, P. B. et al.
Object Type: Article
System: The UNT Digital Library
Prediction of Corrosion of Alloys in Mixed-Solvent Environments (open access)

Prediction of Corrosion of Alloys in Mixed-Solvent Environments

Corrosion is much less predictable in organic or mixed-solvent environments than in aqueous process environments. As a result, US chemical companies face greater uncertainty when selecting process equipment materials to manufacture chemical products using organic or mixed solvents than when the process environments are only aqueous. Chemical companies handle this uncertainty by overdesigning the equipment (wasting money and energy), rather than by accepting increased risks of corrosion failure (personnel hazards and environmental releases). Therefore, it is important to develop simulation tools that would help the chemical process industries to understand and predict corrosion and to develop mitigation measures. To create such tools, we have developed models that predict (1) the chemical composition, speciation, phase equilibria, component activities and transport properties of the bulk (aqueous, nonaqueous or mixed) phase that is in contact with the metal; (2) the phase equilibria and component activities of the alloy phase(s) that may be subject to corrosion and (3) the interfacial phenomena that are responsible for corrosion at the metal/solution or passive film/solution interface. During the course of this project, we have completed the following: (1) Development of thermodynamic modules for calculating the activities of alloy components; (2) Development of software that generates stability diagrams …
Date: June 5, 2003
Creator: A. Anderko, P. Wang, R. D. Young, D. P. Riemer, P. McKenzie and M. M. Lencka (OLI Systems Inc.) & Laboratory), S. S. Babu and P. Angelini (Oak Ridge National
Object Type: Report
System: The UNT Digital Library
Systematics of Fission-Product Yields (open access)

Systematics of Fission-Product Yields

None
Date: May 5, 2002
Creator: A.C.Wahl
Object Type: Report
System: The UNT Digital Library
INCONEL 690 CORROSION IN WTP (WASTE TREATMENT PLANT) HLW (HIGH LEVEL WASTE) GLASS MELTS RICH IN ALUMINUM & BISMUTH & CHROMIUM OR ALUMINUM/SODIUM (open access)

INCONEL 690 CORROSION IN WTP (WASTE TREATMENT PLANT) HLW (HIGH LEVEL WASTE) GLASS MELTS RICH IN ALUMINUM & BISMUTH & CHROMIUM OR ALUMINUM/SODIUM

Metal corrosion tests were conducted with four high waste loading non-Fe-limited HLW glass compositions. The results at 1150 C (the WTP nominal melter operating temperature) show corrosion performance for all four glasses that is comparable to that of other typical borosilicate waste glasses, including HLW glass compositions that have been developed for iron-limited WTP streams. Of the four glasses tested, the Bi-limited composition shows the greatest extent of corrosion, which may be related to its higher phosphorus content. Tests at higher suggest that a moderate elevation of the melter operating temperature (up to 1200 C) should not result in any significant increase in Inconel corrosion. However, corrosion rates did increase significantly at yet higher temperatures (1230 C). Very little difference was observed with and without the presence of an electric current density of 6 A/inch{sup 2}, which is the typical upper design limit for Inconel electrodes. The data show a roughly linear relationship between the thickness of the oxide scale on the coupon and the Cr-depletion depth, which is consistent with the chromium depletion providing the material source for scale growth. Analysis of the time dependence of the Cr depletion profiles measured at 1200 C suggests that diffusion of Cr …
Date: November 5, 2009
Creator: AA, KRUGER; Z, FENG; H, GAN & IL, PEGG
Object Type: Report
System: The UNT Digital Library
Infiltration Heat Recovery in Building Walls: Computational Fluid Dynamics Investigations Results (open access)

Infiltration Heat Recovery in Building Walls: Computational Fluid Dynamics Investigations Results

Conventional calculations of heating (and cooling) loads for buildings assume that conduction heat loss (or gain) through walls is independent of air infiltration heat loss (or gain). During passage through the building envelope, infiltrating air substantially exchanges heat wall insulation leading to partial recovery of heat conducted through the wall. The Infiltration Heat Recovery (IHR) factor was introduced to quantify the heat recovery and correct the conventional calculations. In this study, Computational Fluid Dynamics was used to calculate infiltration heat recovery under a range of idealized conditions, specifically to understand factors that influence it, and assess its significance in building heat load calculations. This study shows for the first time the important effect of the external boundary layers on conduction and infiltration heat loads. Results show (under the idealized conditions studied here) that (1) the interior details of the wall encountered in the leakage pa th (i.e., insulated or empty walls) do not greatly influence the IHR, the overall relative location of the cracks (i.e., inlet and outlet locations on the wall) has the largest influence on the IHR magnitude, (2) external boundary layers on the walls substantially contribute to IHR and (3) the relative error in heat load calculations …
Date: August 5, 2002
Creator: Abadie, Marc O.; Finlayson, Elizabeth U. & Gadgil, Ashok J.
Object Type: Report
System: The UNT Digital Library
The Dynamic Response of Thick-Liquid Shielding in Z-IFE Reactors (open access)

The Dynamic Response of Thick-Liquid Shielding in Z-IFE Reactors

A major concern in the design of thick-liquid protected inertial fusion reactors of all types is the dynamic response of the shielding liquid to the pulsed explosions. Induced liquid motion can stress and damage solid chamber structures such as the firstwall. In a z-pinch based inertial fusion (Z-IFE) reactor this issue becomes particularly critical due to the relatively large proposed target yields of several GJ. In this paper we summarize an analysis of the liquid response taking into account ablation of target facing surfaces, pocket venting, and neutron isochoric heating. The impact of varying several reactor parameters is also discussed.
Date: October 5, 2005
Creator: Abbott, R P
Object Type: Article
System: The UNT Digital Library
Electricity: The Road Toward Restructuring (open access)

Electricity: The Road Toward Restructuring

The Public Utility Holding Company Act of 1935 (PUHCA) and the Federal Power Act (FPA) were enacted to eliminate unfair practices and other abuses by electricity and gas holding companies by requiring federal control and regulation of interstate public utility holding companies. Comprehensive energy legislation has passed the House and Senate. The House passed H.R. 6 on April 11, 2003. On July 31, 2003, the Senate suspended debate on S. 14, inserted the text of H.R. 4 (107th Congress) as a substitute, and passed H.R. 6. A conference agreement was reached November 17, 2003, and passed by the House the next day. H.R. 6 includes an electricity title that would, in part, repeal PUHCA, would prospectively repeal the mandatory purchase requirement under PURPA, and would create an electric reliability organization. On June 15, 2004, H.R. 4503, a comprehensive energy policy bill, passed the House.
Date: June 5, 2002
Creator: Abel, Amy & Parker, Larry
Object Type: Report
System: The UNT Digital Library
Neutral Kaon Interferometry in Au+Au collisions at sqrt(s_NN) =200 GeV (open access)

Neutral Kaon Interferometry in Au+Au collisions at sqrt(s_NN) =200 GeV

We present the first statistically meaningful results fromtwo-K0s interferometry in heavy-ion collisions. A model that takes theeffect of the strong interaction into account has been used to fit themeasured correlation function. The effects of single and coupled channelwere explored. At the mean transverse mass m_T = 1.07 GeV, we obtain thevalues R = 4.09 +- 0.46 (stat.) +- 0.31 (sys) fm and lambda = 0.92 +-0.23 (stat) +- 0.13 (sys), where R and lambda are the invariant radiusand chaoticity parameters respectively. The results are qualitativelyconsistent with m_T systematics established with pions in a scenariocharacterized by a strong collective flow.
Date: August 5, 2006
Creator: Abelev, B. I.; Adams, J.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D. et al.
Object Type: Article
System: The UNT Digital Library
DEVELOPMENT OF THE H1700 SHIPPING PACKAGE (open access)

DEVELOPMENT OF THE H1700 SHIPPING PACKAGE

The H1700 Package is based on the DOE-EM Certified 9977 Packaging. The H1700 will be certified by the Packaging Certification Division of the National Nuclear Security Administration for the shipment of plutonium by air by the United Stated Military both within the United States and internationally. The H1700 is designed to ship radioactive contents in assemblies of Radioisotope Thermoelectric Generators (RTGs) or arrangements of nested food-pack cans. The RTG containers are designed and tested to remain leaktight during transport, handling, and storage; however, their ability to remain leaktight during transport in the H1700 is not credited. This paper discusses the design and special operation of the H1700.
Date: June 5, 2009
Creator: Abramczyk, G.; Loftin, B. & Mann, P.
Object Type: Article
System: The UNT Digital Library
Variability of Ocean Heat Uptake: Reconciling Observations and Models (open access)

Variability of Ocean Heat Uptake: Reconciling Observations and Models

This study examines the temporal variability of ocean heat uptake in observations and in climate models. Previous work suggests that coupled Atmosphere-Ocean General Circulation Models (A-OGCMs) may have underestimated the observed natural variability of ocean heat content, particularly on decadal and longer timescales. To address this issue, we rely on observed estimates of heat content from the 2004 World Ocean Atlas (WOA-2004) compiled by Levitus et al. (2005). Given information about the distribution of observations in WOA-2004, we evaluate the effects of sparse observational coverage and the infilling that Levitus et al. use to produce the spatially-complete temperature fields required to compute heat content variations. We first show that in ocean basins with limited observational coverage, there are important differences between ocean temperature variability estimated from observed and infilled portions of the basin. We then employ data from control simulations performed with eight different A-OGCMs as a test-bed for studying the effects of sparse, space- and time-varying observational coverage. Subsampling model data with actual observational coverage has a large impact on the inferred temperature variability in the top 300 and 3000 meters of the ocean. This arises from changes in both sampling depth and in the geographical areas sampled. Our …
Date: May 5, 2005
Creator: AchutaRao, K. M.; Santer, B. D.; Gleckler, P. J.; Taylor, K.; Pierce, D.; Barnett, T. et al.
Object Type: Article
System: The UNT Digital Library
Tank Characterization Report for Single Shell Tank (SST) 241-TX-118 (open access)

Tank Characterization Report for Single Shell Tank (SST) 241-TX-118

None
Date: May 5, 2000
Creator: Adams, M. R.
Object Type: Report
System: The UNT Digital Library
Geometric transitions and D-term SUSY breaking (open access)

Geometric transitions and D-term SUSY breaking

We propose a new way of using geometric transitions to study metastable vacua in string theory and certain confining gauge theories. The gauge theories in question are N=2 supersymmetric theories deformed to N=1 by superpotential terms. We first geometrically engineer supersymmetry-breaking vacua by wrapping D5 branes on rigid 2-cycles in noncompact Calabi-Yau geometries, such that the central charges of the branes are misaligned. In a limit of slightly misaligned charges, this has a gauge theory description, where supersymmetry is broken by Fayet-Iliopoulos D-terms. Geometric transitions relate these configurations to dual Calabi-Yaus with fluxes, where H_RR, H_NS and dJ are all nonvanishing. We argue that the dual geometry can be effectively used to study the resulting non-supersymmetric, confining vacua
Date: November 5, 2007
Creator: Aganagic, Mina; Aganagic, Mina & Beem, Christopher
Object Type: Article
System: The UNT Digital Library
Modeling Soil/Radionuclide Removal for Yucca Mountain Biosphere Dose Assessments (open access)

Modeling Soil/Radionuclide Removal for Yucca Mountain Biosphere Dose Assessments

None
Date: December 5, 2000
Creator: Aguilar, R. & Smith, A. J.
Object Type: Article
System: The UNT Digital Library
Progress on the Europium Neutron-Capture Study using DANCE (open access)

Progress on the Europium Neutron-Capture Study using DANCE

The accurate measurement of neutron-capture cross sections of the Eu isotopes is important for many reasons including nuclear astrophysics and nuclear diagnostics. Neutron capture excitation functions of {sup 151,153}Eu targets were measured recently using a 4{pi} {gamma}-ray calorimeter array DANCE located at the Los Alamos Neutron Science Center for E{sub n} = 0.1-100 keV. The progress on the data analysis efforts is given in the present paper. The {gamma}-ray multiplicity distributions for the Eu targets and Be backing are significantly different. The {gamma}-ray multiplicity distribution is found to be the same for different neutron energies for both {sup 151}Eu and {sup 153}Eu. The statistical simulation to model the {gamma}-ray decay cascade is summarized.
Date: September 5, 2006
Creator: Agvaanluvsan, U.; Becker, J. A.; Macri, R. A.; Parker, W.; Wilk, P.; Wu, C. Y. et al.
Object Type: Article
System: The UNT Digital Library
Trade and the Americas (open access)

Trade and the Americas

None
Date: March 5, 2002
Creator: Ahearn, Raymond J.
Object Type: Report
System: The UNT Digital Library
Exploring Prompt Measurement Methods for (n,2n) Cross Sections on Radioactive Targets (open access)

Exploring Prompt Measurement Methods for (n,2n) Cross Sections on Radioactive Targets

This report summarizes a study of possible neutron detection technologies for performing prompt (n,2n) measurements on radioactive targets of the type that could be made at the Rare Isotope Accelerator (RIA). The report recommends conducting further research on high-pressure {sup 3}He gas scintillators as it is the best candidate technology. These detectors meet the requirements of a fast response time (fall times around 5-10 ns), gamma ray suppression, (all gamma rays below about 900 keV can be easily discriminated against), and can be easily configured into a 4{pi} array. The one requirement that these detectors fall short is efficiency, but less than a factor of 10 improvement is needed. The possibility of pulse shape discrimination should also be explored for these detectors as this would help to distinguish gamma rays above 900 keV from neutrons. In addition to R&D work on these detectors, Monte Carlo simulations and target development are also recommended areas of further study.
Date: January 5, 2006
Creator: Ahle, L.
Object Type: Report
System: The UNT Digital Library
San Francisco State University IAC 02-06 Final Report (open access)

San Francisco State University IAC 02-06 Final Report

The Industrial Assessment Center (IAC) at San Francisco State University (SFSU) has served the cause of energy efficiency as a whole, and in particular for small and medium-sized manufacturing facilities in northern and central California, within a approximately 150 miles (radial) of San Francisco since 1992. In the current reporting period (September 1, 2002 through November 31, 2006) we have had major accomplishments, which include but are not limited to: - Performing a total of 94 energy efficiency and waste minimization audit days of 87 industrial plants - Recommending and analysis of 809 energy efficiency measures - Training 22 energy engineers, most of whom have joined energy services companies in California. - Disseminating energy efficiency information among local manufacturers - Acting as an information source for energy efficiency for local manufacturers and utilizes - Cooperating with local utilities and California Energy Commission in their energy efficiency projects - Performing various assignments by DOE such as dissemination of information on SEN initiative, conducting workshops on energy efficiency issues, contacting large energy user plants - Establishing a course on “Energy: Resources, Alternatives and Conservation” as a general education course at SFSU - Bringing energy issues to the attention of students in classrooms
Date: March 5, 2007
Creator: Ahmad R. Ganji, Ph.D., P.E., IAC DIrector
Object Type: Report
System: The UNT Digital Library
The role of parallel heat transport in the relation between upstream scrape-off layer widths and target heat flux width in H-mode plasmas of NSTX. (open access)

The role of parallel heat transport in the relation between upstream scrape-off layer widths and target heat flux width in H-mode plasmas of NSTX.

The physics of parallel heat transport was tested in the Scrape-off Layer (SOL) plasma of the National Spherical Torus Experiment (NSTX) [M. Ono, et al., Nucl. Fusion 40, 557 (2000) and S. M. Kaye, et al., Nucl. Fusion 45, S168 (2005)] tokamak by comparing the upstream electron temperature (T{sub e}) and density (n{sub e}) profiles measured by the mid-plane reciprocating probe to the heat flux (q{sub {perpendicular}}) profile at the divertor plate measured by an infrared (IR) camera. It is found that electron conduction explains the near SOL width data reasonably well while the far SOL, which is in the sheath limited regime, requires an ion heat flux profile broader than the electron one to be consistent with the experimental data. The measured plasma parameters indicate that the SOL energy transport should be in the conduction-limited regime for R-R{sub sep} (radial distance from the separatrix location) < 2-3 cm. The SOL energy transport should transition to the sheath-limited regime for R-R{sub sep} > 2-3cm. The T{sub e}, n{sub e}, and q{sub {perpendicular}} profiles are better described by an offset exponential function instead of a simple exponential. The conventional relation between mid plane electron temperature decay length ({lambda}{sub Te}) and target …
Date: January 5, 2009
Creator: Ahn, J W; Boedo, J A; Maingi, R & Soukhanovskii, V A
Object Type: Article
System: The UNT Digital Library
An Integrated Hydrologic Bayesian Multi-Model Combination Framework: Confronting Input, parameter and model structural uncertainty in Hydrologic Prediction (open access)

An Integrated Hydrologic Bayesian Multi-Model Combination Framework: Confronting Input, parameter and model structural uncertainty in Hydrologic Prediction

This paper presents a new technique--Integrated Bayesian Uncertainty Estimator (IBUNE) to account for the major uncertainties of hydrologic rainfall-runoff predictions explicitly. The uncertainties from the input (forcing) data--mainly the precipitation observations and from the model parameters are reduced through a Monte Carlo Markov Chain (MCMC) scheme named Shuffled Complex Evolution Metropolis (SCEM) algorithm which has been extended to include a precipitation error model. Afterwards, the Bayesian Model Averaging (BMA) scheme is employed to further improve the prediction skill and uncertainty estimation using multiple model output. A series of case studies using three rainfall-runoff models to predict the streamflow in the Leaf River basin, Mississippi are used to examine the necessity and usefulness of this technique. The results suggests that ignoring either input forcings error or model structural uncertainty will lead to unrealistic model simulations and their associated uncertainty bounds which does not consistently capture and represent the real-world behavior of the watershed.
Date: May 5, 2006
Creator: Ajami, N. K.; Duan, Q. & Sorooshian, S.
Object Type: Article
System: The UNT Digital Library
Structure of the Lithosphere and Upper Mantle Across the Arabian Peninsula (open access)

Structure of the Lithosphere and Upper Mantle Across the Arabian Peninsula

Analysis of modern broadband (BB) waveform data allows for the inference of seismic velocity structure of the crust and upper mantle using a variety of techniques. This presentation will report inferences of seismic structure of the Arabian Plate using BB data from various networks. Most data were recorded by the Saudi Arabian National Digital Seismic Network (SANDSN) which consists of 38 (26 BB, 11 SP) stations, mostly located on the Arabian Shield. Additional data were taken from the 1995-7 Saudi Arabian IRIS-PASSCAL Deployment (9 BB stations) and other stations across the Peninsula. Crustal structure, inferred from teleseismic P-wave receiver functions, reveals thicker crust in the Arabian Platform (40-45 km) and the interior of the Arabian Shield (35-40 km) and thinner crust along the Red Sea coast. Lithospheric thickness inferred from teleseismic S-wave receiver functions reveals very thin lithosphere (40-80 km) along the Red Sea coast which thickens rapidly toward the interior of the Arabian Shield (100-120 km). We also observe a step of 20-40 km in lithospheric thickness across the Shield-Platform boundary. Seismic velocity structure of the upper mantle inferred from teleseismic P- and S-wave travel time tomography reveals large differences between the Shield and Platform, with the Shield being …
Date: January 5, 2007
Creator: Al-Amri, A. & Rodgers, A.
Object Type: Article
System: The UNT Digital Library
Seeing the Nature of the Accelerating Physics: It's a SNAP (open access)

Seeing the Nature of the Accelerating Physics: It's a SNAP

For true insight into the nature of dark energy, measurements of the precision and accuracy of the Supernova/Acceleration Probe (SNAP) are required. Precursor or scaled-down experiments are unavoidably limited, even for distinguishing the cosmological constant. They can pave the way for, but should not delay, SNAP by developing calibration, refinement, and systematics control (and they will also provide important, exciting astrophysics).
Date: August 5, 2005
Creator: Albert, J.; Aldering, G.; Allam, S.; Althouse, W.; Amanullah, R.; Annis, J. et al.
Object Type: Report
System: The UNT Digital Library
Sample Proficiency Test exercise (open access)

Sample Proficiency Test exercise

The current format of the OPCW proficiency tests has multiple sets of 2 samples sent to an analysis laboratory. In each sample set, one is identified as a sample, the other as a blank. This method of conducting proficiency tests differs from how an OPCW designated laboratory would receive authentic samples (a set of three containers, each not identified, consisting of the authentic sample, a control sample, and a blank sample). This exercise was designed to test the reporting if the proficiency tests were to be conducted. As such, this is not an official OPCW proficiency test, and the attached report is one method by which LLNL might report their analyses under a more realistic testing scheme. Therefore, the title on the report ''Report of the Umpteenth Official OPCW Proficiency Test'' is meaningless, and provides a bit of whimsy for the analyses and readers of the report.
Date: February 5, 2006
Creator: Alcaraz, A.; Gregg, H. & Koester, C.
Object Type: Report
System: The UNT Digital Library
FACT (Version 2.0) - Subsurface Flow and Contaminant Transport Documentation and User's Guide (open access)

FACT (Version 2.0) - Subsurface Flow and Contaminant Transport Documentation and User's Guide

This report documents a finite element code designed to model subsurface flow and contaminant transport, named FACT. FACT is a transient three-dimensional, finite element code designed to simulate isothermal groundwater flow, moisture movement, and solute transport in variably saturated and fully saturated subsurface porous media.
Date: May 5, 2000
Creator: Aleman, S. E.
Object Type: Report
System: The UNT Digital Library
The SPARX Project: R & D Activity Towards X-Rays FEL Sources (open access)

The SPARX Project: R & D Activity Towards X-Rays FEL Sources

SPARX is an evolutionary project proposed by a collaboration among ENEA-INFN-CNR-Universita di Roma Tor Vergata aiming at the construction of a FELSASE X-ray source in the Tor Vergata Campus. The first phase of the SPARX project, funded by Government Agencies, will be focused on R&D activity on critical components and techniques for future X-ray facilities as described in this paper.
Date: August 5, 2005
Creator: Alesini, D.; Bellaveglia, M.; Bertolucci, S.; Biagini, M. E.; Boni, R.; Boscolo, M. et al.
Object Type: Article
System: The UNT Digital Library