Analysis of cavern stability at the West Hackberry SPR site. (open access)

Analysis of cavern stability at the West Hackberry SPR site.

This report presents computational analyses that simulate the structural response of caverns at the Strategic Petroleum Reserve (SPR) West Hackberry site. The cavern field comprises 22 caverns. Five caverns (6, 7, 8, 9, 11) were acquired from industry and have unusual shapes and a history dating back to 1946. The other 17 caverns (101-117) were leached according to SPR standards in the mid-1980s and have tall cylindrical shapes. The history of the caverns and their shapes are simulated in a three-dimensional geomechanics model of the site that predicts deformations, strains, and stresses. Future leaching scenarios corresponding to oil drawdowns using fresh water are also simulated by increasing the volume of the caverns. Cavern pressures are varied in the model to capture operational practices in the field. The results of the finite element model are interpreted to provide information on the current and future status of subsidence, well integrity, and cavern stability. The most significant results in this report are relevant to Cavern 6. The cavern is shaped like a bowl with a large ceiling span and is in close proximity to Cavern 9. The analyses predict tensile stresses at the edge of the ceiling during repressuization of Cavern 6 following …
Date: May 1, 2009
Creator: Ehgartner, Brian L. & Sobolik, Steven Ronald
Object Type: Report
System: The UNT Digital Library
Analysis of Contribution from Edge Radiation to Optical Diffraction Radiation (open access)

Analysis of Contribution from Edge Radiation to Optical Diffraction Radiation

Beam size measurement with near-field optical diffraction radiation (ODR) has been carried out successfully at CEBAF. The ODR station is installed on the Hall-A beam line after eight bending magnets. The ODR images were affected by an unexpected radiation. Some calculations for analyzing the source of the radiation will be presented. Furthermore, two schemes will be proposed to alleviate the contamination.
Date: May 1, 2009
Creator: C. Liu, P. Evtushenko, A. Freyberger, C. Liu, A.H. Lumpkin
Object Type: Article
System: The UNT Digital Library
Analysis of Mesoscale Model Data for Wind Integration (Poster) (open access)

Analysis of Mesoscale Model Data for Wind Integration (Poster)

Supports examination of implications of national 20% wind vision, and provides input to integration and transmission studies for operational impact of large penetrations of wind on the grid.
Date: May 1, 2009
Creator: Schwartz, M.; Elliott, D.; Lew, D.; Corbus, D.; Scott, G.; Haymes, S. et al.
Object Type: Article
System: The UNT Digital Library
Analysis of sheltering and evacuation strategies for an urban nuclear detonation scenario. (open access)

Analysis of sheltering and evacuation strategies for an urban nuclear detonation scenario.

Development of an effective strategy for shelter and evacuation is among the most important planning tasks in preparation for response to a low yield, nuclear detonation in an urban area. This study examines shelter-evacuate policies and effectiveness focusing on a 10 kt scenario in Los Angeles. The goal is to provide technical insights that can support development of urban response plans. Results indicate that extended shelter-in-place can offer the most robust protection when high quality shelter exists. Where less effective shelter is available and the fallout radiation intensity level is high, informed evacuation at the appropriate time can substantially reduce the overall dose to personnel. However, uncertainties in the characteristics of the fallout region and in the exit route can make evacuation a risky strategy. Analyses indicate that only a relatively small fraction of the total urban population may experience significant dose reduction benefits from even a well-informed evacuation plan.
Date: May 1, 2009
Creator: Yoshimura, Ann S. & Brandt, Larry D.
Object Type: Report
System: The UNT Digital Library
Application of Goubau Surface Wave Transmission Line for Improved Bench Testing of Diagnostic Beamline Elements (open access)

Application of Goubau Surface Wave Transmission Line for Improved Bench Testing of Diagnostic Beamline Elements

In-air test fixtures for beamline elements typically utilize an X-Y positioning stage, and a wire antenna excited by an RF source. In most cases, the antenna contains a standing wave, and is useful only for coarse alignment measurements in CW mode. A surface-wave (SW) based transmission line permits RF energy to be launched on the wire, travel through the beamline component, and then be absorbed in a load. Since SW transmission lines employ travelling waves, the RF energy can be made to resemble the electron beam, limited only by ohmic losses and dispersion. Although lossy coaxial systems are also a consideration, the diameter of the coax introduces large uncertainties in centroid location. A SW wire is easily constructed out of 200 micron magnet wire, which more accurately approximates the physical profile of the electron beam. Benefits of this test fixture include accurate field mapping, absolute calibration for given beam currents, Z-axis independence, and temporal response measurements of sub-nanosecond pulse structures. Descriptions of the surface wave launching technique, transmission line, and instrumentation are presented, along with measurement data.
Date: May 1, 2009
Creator: John Musson, Keith Cole, Sheldon Rubin
Object Type: Article
System: The UNT Digital Library
Application of the MELCOR code to design basis PWR large dry containment analysis. (open access)

Application of the MELCOR code to design basis PWR large dry containment analysis.

The MELCOR computer code has been developed by Sandia National Laboratories under USNRC sponsorship to provide capability for independently auditing analyses submitted by reactor manufactures and utilities. MELCOR is a fully integrated code (encompassing the reactor coolant system and the containment building) that models the progression of postulated accidents in light water reactor power plants. To assess the adequacy of containment thermal-hydraulic modeling incorporated in the MELCOR code for application to PWR large dry containments, several selected demonstration designs were analyzed. This report documents MELCOR code demonstration calculations performed for postulated design basis accident (DBA) analysis (LOCA and MSLB) inside containment, which are compared to other code results. The key processes when analyzing the containment loads inside PWR large dry containments are (1) expansion and transport of high mass/energy releases, (2) heat and mass transfer to structural passive heat sinks, and (3) containment pressure reduction due to engineered safety features. A code-to-code benchmarking for DBA events showed that MELCOR predictions of maximum containment loads were equivalent to similar predictions using a qualified containment code known as CONTAIN. This equivalency was found to apply for both single- and multi-cell containment models.
Date: May 1, 2009
Creator: Phillips, Jesse; Notafrancesco, Allen (USNRC, Office of Nuclear Regulatory Research, Rockville, MD) & Tills, Jack Lee (Jack Tills & Associates, Inc., Sandia Park, NM)
Object Type: Report
System: The UNT Digital Library
Application of the Reduction of Scale Range in a Lorentz Boosted Frame to the Numerical Simulation of Particle Acceleration Devices (open access)

Application of the Reduction of Scale Range in a Lorentz Boosted Frame to the Numerical Simulation of Particle Acceleration Devices

It has been shown [1] that it may be computationally advantageous to perform computer simulations in a boosted frame for a certain class of systems: particle beams interacting with electron clouds, free electron lasers, and laser-plasma accelerators. However, even if the computer model relies on a covariant set of equations, it was also pointed out that algorithmic difficulties related to discretization errors may have to be overcome in order to take full advantage of the potential speedup [2] . In this paper, we focus on the analysis of the complication of data input and output in a Lorentz boosted frame simulation, and describe the procedures that were implemented in the simulation code Warp[3]. We present our most recent progress in the modeling of laser wakefield acceleration in a boosted frame, and describe briefly the potential benefits of calculating in a boosted frame for the modeling of coherent synchrotron radiation.
Date: May 1, 2009
Creator: Vay, J. L.; Fawley, W. M.; Geddes, C. G. R.; Cormier-Michel, E. & Grote, D. P.
Object Type: Article
System: The UNT Digital Library
Are mixed explicit/implicit solvation models reliable for studying phosphate hydrolysis? A comparative study of continuum, explicit and mixed solvation models. (open access)

Are mixed explicit/implicit solvation models reliable for studying phosphate hydrolysis? A comparative study of continuum, explicit and mixed solvation models.

Phosphate hydrolysis is ubiquitous in biology. However, despite intensive research on this class of reactions, the precise nature of the reaction mechanism remains controversial. In this work, we have examined the hydrolysis of three homologous phosphate diesters. The solvation free energy was simulated by means of either an implicit solvation model (COSMO), hybrid quantum mechanical / molecular mechanical free energy perturbation (QM/MM-FEP) or a mixed solvation model in which N water molecules were explicitly included in the ab initio description of the reacting system (where N=1-3), with the remainder of the solvent being implicitly modelled as a continuum. Here, both COSMO and QM/MM-FEP reproduce Delta Gobs within an error of about 2kcal/mol. However, we demonstrate that in order to obtain any form of reliable results from a mixed model, it is essential to carefully select the explicit water molecules from short QM/MM runs that act as a model for the true infinite system. Additionally, the mixed models tend to be increasingly inaccurate the more explicit water molecules are placed into the system. Thus, our analysis indicates that this approach provides an unreliable way for modelling phosphate hydrolysis in solution.
Date: May 1, 2009
Creator: Kamerlin, Shina C. L.; Haranczyk, Maciej & Warshel, Arieh
Object Type: Article
System: The UNT Digital Library
Assembly and comparison of available solar hot water system reliability databases and information. (open access)

Assembly and comparison of available solar hot water system reliability databases and information.

Solar hot water (SHW) systems have been installed commercially for over 30 years, yet few quantitative details are known about their reliability. This report describes a comprehensive analysis of all of the known major previous research and data regarding the reliability of SHW systems and components. Some important conclusions emerged. First, based on a detailed inspection of ten-year-old systems in Florida, about half of active systems can be expected to fail within a ten-year period. Second, valves were identified as the probable cause of a majority of active SHW failures. Third, passive integral and thermosiphon SHW systems have much lower failure rates than active ones, probably due to their simple design that employs few mechanical parts. Fourth, it is probable that the existing data about reliability do not reveal the full extent of fielded system failures because most of the data were based on trouble calls. Often an SHW system owner is not aware of a failure because the backup system silently continues to produce hot water. Thus, a repair event may not be generated in a timely manner, if at all. This final report for the project provides all of the pertinent details about this study, including the source …
Date: May 1, 2009
Creator: Menicucci, David F. (Building Specialists, Inc., Albuquerque, NM)
Object Type: Report
System: The UNT Digital Library
Assessment of Historic Trend in Mobility and Energy Use in India Transportation Sector Using Bottom-up Approach (open access)

Assessment of Historic Trend in Mobility and Energy Use in India Transportation Sector Using Bottom-up Approach

Transportation mobility in India has increased significantly in the past decades. From 1970 to 2000, motorized mobility (passenger-km) has risen by 888%, compared with an 88% population growth (Singh,2006). This contributed to many energy and environmental issues, and an energy strategy incorporates efficiency improvement and other measures needs to be designed. Unfortunately, existing energy data do not provide information on driving forces behind energy use and sometime show large inconsistencies. Many previous studies address only a single transportation mode such as passenger road travel; did not include comprehensive data collection or analysis has yet been done, or lack detail on energy demand by each mode and fuel mix. The current study will fill a considerable gap in current efforts, develop a data base on all transport modes including passenger air and water, and freight in order to facilitate the development of energy scenarios and assess significance of technology potential in a global climate change model. An extensive literature review and data collection has been done to establish the database with breakdown of mobility, intensity, distance, and fuel mix of all transportation modes. Energy consumption was estimated and compared with aggregated transport consumption reported in IEA India transportation energy data. Different …
Date: May 1, 2009
Creator: Zhou, Nan & McNeil, Michael A.
Object Type: Report
System: The UNT Digital Library
Atomic Layer Deposition for SRF Cavities (open access)

Atomic Layer Deposition for SRF Cavities

We have begun using Atomic Layer Deposition (ALD) to synthesize a variety of surface coatings on coupons and cavities as part of an effort to produce rf structures with significantly better performance and yield than those obtained from bulk niobium, The ALD process offers the possibility of conformally coating complex cavity shapes with precise layered structures with tightly constrained morphology and chemical properties. Our program looks both at the metallurgy and superconducting properties of these coatings, and also their performance in working structures. Initial results include: (1) results from ALD coated cavities and coupons, (2) new evidence from point contact tunneling (PCT) showing magnetic oxides can be a significant limitation to high gradient operation, (3) a study of high pressure rinsing damage on niobium samples.
Date: May 1, 2009
Creator: Proslier, Th.; Ha, Y.; Zasadzinski, J.; Ciovati, G.; Kneissel, P.; Reece, C. et al.
Object Type: Article
System: The UNT Digital Library
Atomic Layer Deposition for SRF Cavities (open access)

Atomic Layer Deposition for SRF Cavities

We have begun using Atomic Layer Deposition (ALD) to synthesize a variety of surface coatings on coupons and cavities as part of an effort to produce rf structures with significantly better performance and yield than those obtained from bulk niobium, The ALD process offers the possibility of conformally coating complex cavity shapes with precise layered structures with tightly constrained morphology and chemical properties. Our program looks both at the metallurgy and superconducting properties of these coatings, and also their performance in working structures. Initial results include: 1) evidence from point contact tunneling showing magnetic oxides can be a significant limitation to high gradient operation, 2) experimental results showing the production sharp niobium/oxide interfaces from a high temperature bake of ALD coated Al2O3 on niobium surfaces, 3) results from ALD coated structures.
Date: May 1, 2009
Creator: Norem, J; Pellin, M J; Antoine, C Z; Ciovati, G; Kneisel, P; Reece, C E et al.
Object Type: Article
System: The UNT Digital Library
Audit Report "Department of Energy Efforts to Manage Information Technology Resources in an Energy-Efficient and Environmentally Responsible Manner" (open access)

Audit Report "Department of Energy Efforts to Manage Information Technology Resources in an Energy-Efficient and Environmentally Responsible Manner"

The American Recovery and Reinvestment Act of 2009 emphasizes energy efficiency and conservation as critical to the Nation's economic vitality; its goal of reducing dependence on foreign energy sources; and, related efforts to improve the environment. The Act highlights the significant use of various forms of energy in the Federal sector and promotes efforts to improve the energy efficiency of Federal operations. One specific area of interest is the increasing demand for Federal sector computing resources and the corresponding increase in energy use, with both cost and environmental implications. The U.S. Environmental Protection Agency reported that, without aggressive conservation measures, data center energy consumption alone is expected to double over the next five years. In our report on Management of the Department's Data Centers at Contractor Sites (DOE/IG-0803, October 2008) we concluded that the Department of Energy had not always improved the efficiency of its contractor data centers even when such modifications were possible and practical. Despite its recognized energy conservation leadership role, the Department had not always taken advantage of opportunities to reduce energy consumption associated with its information technology resources. Nor, had it ensured that resources were managed in a way that minimized impact on the environment. In …
Date: May 1, 2009
Creator: unknown
Object Type: Report
System: The UNT Digital Library
An Audit Report on Performance Measures at the Board of Podiatric Medical Examiners (open access)

An Audit Report on Performance Measures at the Board of Podiatric Medical Examiners

Report of the Texas State Auditor's Office related to determining whether the Board of Podiatric Medical Examiners accurately reports key performance measures to the Automated Budget and Evaluation System of Texas (ABEST), and has adequate controls in place over the collection, calculation, and reporting of performance measures.
Date: May 2009
Creator: Texas. Office of the State Auditor.
Object Type: Report
System: The Portal to Texas History
An Audit Report on Performance Measures at the Commission on Fire Protection (open access)

An Audit Report on Performance Measures at the Commission on Fire Protection

Report of the Texas State Auditor's Office related to determining whether the Commission on Fire Protection accurately reported selected key performance measures to ABEST and had adequate control systems over the collection, calculation, and reporting of the Commission's key performance measures.
Date: May 2009
Creator: Texas. Office of the State Auditor.
Object Type: Report
System: The Portal to Texas History
An Audit Report on Performance Measures at the School for the Deaf (open access)

An Audit Report on Performance Measures at the School for the Deaf

Report of the Texas State Auditor's Office related to determining whether the School for the Deaf (School) accurately reports selected key performance measures to the Automated Budget and Evaluation System of Texas (ABEST) and has adequate control systems in place over the collecting, calculating, and reporting of selected key performance measures.
Date: May 2009
Creator: Texas. Office of the State Auditor.
Object Type: Report
System: The Portal to Texas History
Autothermal Reforming of Renewable Fuels (open access)

Autothermal Reforming of Renewable Fuels

The conversion of biomass into energy and chemicals is a major research and technology challenge of this century, comparable to petroleum processing in the last century. Recently we have successfully transformed both volatile liquids and nonvolatile liquids and solids into syngas with no carbon formation in autothermal catalytic reactors with residence times of ~10 milliseconds. In the proposed research program we explore the mechanisms of these processes and their extensions to other biomass sources and applications by examining different feeds, catalysts, flow conditions, and steam addition to maximize production of either syngas or chemicals. We will systematically study the catalytic partial oxidation in millisecond autothermal reactors of solid biomass and the liquid products formed by pyrolysis of solid biomass. We will examine alcohols, polyols, esters, solid carbohydrates, and lignocellulose to try to maximize formation of either hydrogen and syngas or olefins and oxygenated chemicals. We will explore molecules and mixtures of practical interest as well as surrogate molecules that contain the functional groups of biofuels but are simpler to analyze and interpret. We will examine spatial profiles within the catalyst and transient and periodic operation of these reactors at pressures up to 10 atm to obtain data from which to …
Date: May 1, 2009
Creator: Schmidt, Lanny D
Object Type: Report
System: The UNT Digital Library
B Lifetimes and Mixing (open access)

B Lifetimes and Mixing

The Tevatron experiments, CDF and D0, have produced a wealth of new B-physics results since the start of Run II in 2001. We've observed new B-hadrons, seen new effects, and increased many-fold the precision with which we know the properties of b-quark systems. In these proceedings, we will discuss two of the most fruitful areas in the Tevatron B-physics program: lifetimes and mixing. We'll examine the experimental issues driving these analyses, present a summary of the latest results, and discuss prospects for the future.
Date: May 1, 2009
Creator: Evans, Harold G.
Object Type: Article
System: The UNT Digital Library
Basic Electropolishing Process Research and Development in Support of Improved Reliable Performance SRF Cavities for the Future Accelerator (open access)

Basic Electropolishing Process Research and Development in Support of Improved Reliable Performance SRF Cavities for the Future Accelerator

Future accelerators require unprecedented cavity performance, which is strongly influenced by interior surface nanosmoothness. Electropolishing is the technique of choice to be developed for high-field superconducting radiofrequency cavities. Electrochemical impedance spectroscopy (EIS) and related techniques point to the electropolishing mechanism of Nb in a sulfuric and hydrofluoric acid electrolyte of controlled by a compact surface salt film under F- diffusion-limited mass transport control. These and other findings are currently guiding a systematic characterization to form the basis for cavity process optimization, such as flowrate, electrolyte composition and temperature. This integrated analysis is expected to provide optimum EP parameter sets for a controlled, reproducible and uniform surface leveling for Nb SRF cavities.
Date: May 1, 2009
Creator: H. Tian, C.E. Reece,M.J. Kelley
Object Type: Article
System: The UNT Digital Library
Benchmark of Different Electromagnetic Codes for the High Frequency Calculation (open access)

Benchmark of Different Electromagnetic Codes for the High Frequency Calculation

In this paper, we present benchmarking results for highclass 3D electromagnetic (EM) codes in designing RF cavities today. These codes include Omega3P [1], VORPAL [2], CST Microwave Studio [3], Ansoft HFSS [4], and ANSYS [5]. Two spherical cavities are selected as the benchmark models. We have compared not only the accuracy of resonant frequencies, but also that of surface EM fields, which are critical for superconducting RF cavities. By removing degenerated modes, we calculate all the resonant modes up to 10 GHz with similar mesh densities, so that the geometry approximation and field interpolation error related to the wavelength can be observed.
Date: May 1, 2009
Creator: Kai Tian, Haipeng Wang, Frank Marhauser, Guangfeng Cheng, Chuandong Zhou
Object Type: Article
System: The UNT Digital Library
Benchmarking Multipacting Simulations in VORPAL (open access)

Benchmarking Multipacting Simulations in VORPAL

We will present the results of benchmarking simulations run to test the ability of VORPAL to model multipacting processes in Superconducting Radio Frequency structures. VORPAL is an electromagnetic (FDTD) particle-in-cell simulation code originally developed for applications in plasma and beam physics. The addition of conformal boundaries and algorithms for secondary electron emission allow VORPAL to be applied to multipacting processes. We start with simulations of multipacting between parallel plates where there are well understood theoretical predictions for the frequency bands where multipacting is expected to occur. We reproduce the predicted multipacting bands and demonstrate departures from the theoretical predictions when a more sophisticated model of secondary emission is used. Simulations of existing cavity structures developed at Jefferson National Laboratories will also be presented where we compare results from VORPAL to experimental data.
Date: May 1, 2009
Creator: C. Nieter, C. Roark, P. Stoltz, K. Tian
Object Type: Article
System: The UNT Digital Library
Best Practices for the Security of Radioactive Materials (open access)

Best Practices for the Security of Radioactive Materials

This work is funded under a grant provided by the US Department of Health and Human Services, Centers for Disease Control. The Department of Health and Mental Hygiene (DOHMH) awarded a contract to Brookhaven National Laboratory (BNL) to develop best practices guidance for Office of Radiological Health (ORH) licensees to increase on-site security to deter and prevent theft of radioactive materials (RAM). The purpose of this document is to describe best practices available to manage the security of radioactive materials in medical centers, hospitals, and research facilities. There are thousands of such facilities in the United States, and recent studies suggest that these materials may be vulnerable to theft or sabotage. Their malevolent use in a radiological-dispersion device (RDD), viz., a dirty bomb, can have severe environmental- and economic- impacts, the associated area denial, and potentially large cleanup costs, as well as other effects on the licensees and the public. These issues are important to all Nuclear Regulatory Commission and Agreement State licensees, and to the general public. This document outlines approaches for the licensees possessing these materials to undertake security audits to identify vulnerabilities in how these materials are stored or used, and to describe best practices to upgrade …
Date: May 1, 2009
Creator: Coulter, D. T. & Musolino, S.
Object Type: Report
System: The UNT Digital Library

Biodiesel Utilization: Update on Recent Analytical Techniques

To understand and increase the use of biodiesel, analytical methods need to be shared and compared to ensure that accurate data are gathered on this complex fuel.
Date: May 1, 2009
Creator: Alleman, T. L.; Fouts, L.; Luecke, J.; Thornton, M. & McAlpin, C.
Object Type: Presentation
System: The UNT Digital Library
Biomass Compositional Analysis Method Variability (Poster) (open access)

Biomass Compositional Analysis Method Variability (Poster)

Poster presented at the 31st Symposium on Biotechnology for Fuels and Chemicals, May 2009, San Francisco.
Date: May 1, 2009
Creator: Templeton, D. W.; Scarlata, C. J.; Sluiter, J. & Wolfrum, E.
Object Type: Article
System: The UNT Digital Library