Degree Discipline

Degree Level

712 Matching Results

Results open in a new window/tab.

A Detailed Chemical Kinetic Reaction Mechanism for n-Alkane Hydrocarbons from n-Octane to n-Hexadecane (open access)

A Detailed Chemical Kinetic Reaction Mechanism for n-Alkane Hydrocarbons from n-Octane to n-Hexadecane

Detailed chemical kinetic reaction mechanisms have been developed to describe the pyrolysis and oxidation of the n-alkanes, including n-octane (n-C{sub 8}H{sub 18}), n-nonane (n-C{sub 9}H{sub 20}), n-decane (n-C{sub 10}H{sub 22}), n-undecane (n-C{sub 11}H{sub 24}), n-dodecane (n-C{sub 12}H{sub 26}), n-tridecane (n-C{sub 13}H{sub 28}), n-tetradecane (n-C{sub 14}H{sub 30}), n-pentadecane (n-C{sub 15}H{sub 32}), and n-hexadecane (n-C{sub 16}H{sub 34}). These mechanisms include both high temperature and low temperature reaction pathways. The mechanisms are based on previous mechanisms for n-heptane, using the same reaction class mechanism construction developed initially for n-heptane. Individual reaction class rules are as simple as possible in order to focus on the parallelism between all of the n-alkane fuels included in the mechanisms, and there is an intent to develop these mechanisms further in the future to incorporate greater levels of accuracy and predictive capability. Several of these areas for improvement are identified and explained in detail. These mechanisms are validated through comparisons between computed and experimental data from as many different sources as possible. In addition, numerical experiments are carried out to examine features of n-alkane combustion in which the detailed mechanisms can be used to compare processes in all of the n-alkane fuels. The mechanisms for all of these …
Date: September 25, 2007
Creator: Westbrook, C K; Pitz, W J; Herbinet, O; Silke, E J & Curran, H J
Object Type: Article
System: The UNT Digital Library
Waste Isolation Pilot Plant Geotechnical Analysis Report for July 2005 - June 2006, Volume 2, Supporting Data (open access)

Waste Isolation Pilot Plant Geotechnical Analysis Report for July 2005 - June 2006, Volume 2, Supporting Data

This report is a compilation of geotechnical data presented as plots for each active instrument installed in the underground at the Waste Isolation Pilot Plant (WIPP) through June 30, 2006. A summary of the geotechnical analyses that were performed using the enclosed data is provided in Volume 1 of the Geotechnical Analysis Report (GAR).
Date: March 25, 2007
Creator: Westinghouse TRU Solutions LLC
Object Type: Report
System: The UNT Digital Library
Thermal Emittance Measurement Design for Diamond Secondary Emission (open access)

Thermal Emittance Measurement Design for Diamond Secondary Emission

Thermal emittance is a very important characteristic of cathodes. A carefully designed method of measuring the thermal emittance of secondary emission from diamond is presented. Comparison of possible schemes is carried out by simulation, and the most accessible and accurate method and values are chosen. Systematic errors can be controlled and maintained at small values, and are carefully evaluated. Aberration and limitations of all equipment are taken into account.
Date: June 25, 2007
Creator: Wu, Q.; Ben-Zvi, Ilan; Burrill, A.; Chang, X.; Kayran, D.; Rao, T. et al.
Object Type: Article
System: The UNT Digital Library
CANCELLED Molecular dynamics simulations of noble gases in liquidwater: Solvati on structure, self-diffusion, and kinetic isotopeeffect (open access)

CANCELLED Molecular dynamics simulations of noble gases in liquidwater: Solvati on structure, self-diffusion, and kinetic isotopeeffect

Despite their great importance in low-temperaturegeochemistry, self-diffusion coefficients of noble gas isotopes in liquidwater (D) have been measured only for the major isotopes of helium, neon,krypton and xenon. Data on the self-diffusion coefficients of minor noblegas isotopes are essentially non-existent and so typically are estimatedby a kinetic theory model in which D varies as the inverse square root ofthe isotopic mass (m): D proportional to m-0.5. To examine the validityof the kinetic theory model, we performed molecular dynamics (MD)simulations of the diffusion of noble gases in ambient liquid water withan accurate set of noble gas-water interaction potentials. Our simulationresults agree with available experimental data on the solvation structureand self-diffusion coefficients of the major noble gas isotopes in liquidwater and reveal for the first time that the isotopic mass-dependence ofall noble gas self-diffusion coefficients has the power-law form Dproportional to m-beta with 0<beta<0.2. Thus our results callinto serious question the widespread assumption that the square rootmodel can be applied to estimate the kinetic fractionation of noble gasisotopes caused by diffusion in ambient liquid water.
Date: May 25, 2007
Creator: Bourg, I.C. & Sposito, G.
Object Type: Report
System: The UNT Digital Library
ICD Complex Operations and Maintenance Plan (open access)

ICD Complex Operations and Maintenance Plan

This Operations and Maintenance (O&M) Plan describes how the Idaho National Laboratory (INL) conducts operations, winterization, and startup of the Idaho CERCLA Disposal Facility (ICDF) Complex. The ICDF Complex is the centralized INL facility responsible for the receipt, storage, treatment (as necessary), and disposal of INL Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) remediation waste.
Date: June 25, 2007
Creator: Gibson, P. L.
Object Type: Report
System: The UNT Digital Library
SUPERCONDUCTING MAGNET NEEDS FOR THE ILC. (open access)

SUPERCONDUCTING MAGNET NEEDS FOR THE ILC.

The ILC Reference Design Report was completed early in February 2007. The Magnet Systems Group was formed to translate magnetic field requirements into magnet designs and cost estimates for the Reference Design. As presently configured, the lLC will have more than 13,000 magnetic elements of which more than 2300 will be based on superconducting technology. This paper will describe the major superconducting magnet needs for the ILC as presently determined by the Area Systems Groups, responsible for beam line design, working with the Magnet Systems Group. The superconducting magnet components include Main Linac quadrupoles, Positron Source undulators, Damping Ring wigglers, a complex array of Final Focus superconducting elements in the Beam Delivery System, and large superconducting solenoids in the e{sup +} and e{sup -} Sources, and the Ring to Main Linac lines.
Date: June 25, 2007
Creator: PARKER, B.; TOMPKINS, J. C.; KASHIKHIN, V. I.; PALMER, M. A. & CLARKE, J. A.
Object Type: Article
System: The UNT Digital Library
The energy coupling efficiency of multi-wavelength laser pulses to damage initiating defects in DKDP nonlinear crystals (open access)

The energy coupling efficiency of multi-wavelength laser pulses to damage initiating defects in DKDP nonlinear crystals

The bulk damage performance of potassium dihydrogen phosphate crystals under simultaneous exposure to 1064-, 532-, and 355-nm nanosecond-laser pulses is investigated in order to probe the laser-induced defect reactions leading to damage initiation during frequency conversion. The results provide insight into the mechanisms governing the behavior of the damage initiating defects under exposure to high power laser light. In addition, it is suggested that the damage performance can be directly related to and predicted from the damage behavior of the crystal at each wavelength separately.
Date: September 25, 2007
Creator: DeMange, P; Negres, R A; Rubenchik, A M; Radousky, H B; Feit, M D & Demos, S G
Object Type: Article
System: The UNT Digital Library
Colliding pulse injection experiments in non-collinear geometryfor controlled laser plasma wakefield acceleration of electrons (open access)

Colliding pulse injection experiments in non-collinear geometryfor controlled laser plasma wakefield acceleration of electrons

An optical injection scheme for a laser-plasma basedaccelerator which employs a non-collinear counter-propagating laser beamto push background electrons in the focusing and acceleration phase viaponderomotive beat with the trailing part of the wakefield driver pulseis discussed. Preliminary experiments were performed using a drive beamof a_0 = 2.6 and colliding beam of a_1 = 0.8 both focused on the middleof a 200 mu m slit jet backed with 20 bar, which provided ~; 260 mu mlong gas plume. The enhancement in the total charge by the collidingpulse was observed with sharp dependence on the delay time of thecolliding beam. Enhancement of the neutron yield was also measured, whichsuggests a generation of electrons above 10 MeV.
Date: June 25, 2007
Creator: Toth, Carl B.; Esarey, Eric H.; Geddes, Cameron G.R.; Leemans,Wim P.; Nakamura, Kei; Panasenko, Dmitriy et al.
Object Type: Article
System: The UNT Digital Library
Advanced Simulation and Computing FY08-09 Implementation Plan Volume 2 Revision 0 (open access)

Advanced Simulation and Computing FY08-09 Implementation Plan Volume 2 Revision 0

The Stockpile Stewardship Program (SSP) is a single, highly integrated technical program for maintaining the safety and reliability of the U.S. nuclear stockpile. The SSP uses past nuclear test data along with current and future nonnuclear test data, computational modeling and simulation, and experimental facilities to advance understanding of nuclear weapons. It includes stockpile surveillance, experimental research, development and engineering programs, and an appropriately scaled production capability to support stockpile requirements. This integrated national program requires the continued use of current facilities and programs along with new experimental facilities and computational enhancements to support these programs. The Advanced Simulation and Computing Program (ASC) is a cornerstone of the SSP, providing simulation capabilities and computational resources to support the annual stockpile assessment and certification, to study advanced nuclear-weapons design and manufacturing processes, to analyze accident scenarios and weapons aging, and to provide the tools to enable Stockpile Life Extension Programs (SLEPs) and the resolution of Significant Finding Investigations (SFIs). This requires a balanced resource, including technical staff, hardware, simulation software, and computer science solutions. In its first decade, the ASC strategy focused on demonstrating simulation capabilities of unprecedented scale in three spatial dimensions. In its second decade, ASC is focused on …
Date: April 25, 2007
Creator: McCoy, M; Kusnezov, D; Bikkel, T & Hopson, J
Object Type: Report
System: The UNT Digital Library
THE SUPERCONDUCTION MAGNETS OF THE ILC BEAM DELIVERY SYSTEM. (open access)

THE SUPERCONDUCTION MAGNETS OF THE ILC BEAM DELIVERY SYSTEM.

The ILC Reference Design Report was completed early in February 2007. The Magnet Systems Group was formed to translate magnetic field requirements into magnet designs and cost estimates for the Reference Design. As presently configured, the ILC will have more than 13,000 magnetic elements of which more than 2300 will be based on superconducting technology. This paper will describe the major superconducting magnet needs for the ILC as presently determined by the Area Systems Groups, responsible for beam line design, working with the Magnet Systems Group. The superconducting magnet components include Main Linac quadrupoles, Positron Source undulators, Damping Ring wigglers, a complex array of Final Focus superconducting elements in the Beam Delivery System, and large superconducting solenoids in the e{sup +} and e{sup -} Sources, and the Ring to Main Linac lines.
Date: June 25, 2007
Creator: PARKER,B.; ANEREELA, M.; ESCALLIE, J.; HE, P.; JAIN, A.; MARONE, A. et al.
Object Type: Article
System: The UNT Digital Library
Initial Report on the Development of a Monte Carlo-Markov Chain Joint Inversion Approach for Geothermal Exploration (open access)

Initial Report on the Development of a Monte Carlo-Markov Chain Joint Inversion Approach for Geothermal Exploration

Geothermal exploration and subsequent characterization of potential resources typically employ a variety of geophysical, geologic and geochemical techniques. However, since the data collected by each technique provide information directly on only one or a very limited set of the many physical parameters that characterize a geothermal system, no single method can be used to describe the system in its entirety. Presently, the usual approach to analyzing disparate data streams for geothermal applications is to invert (or forward model) each data set separately and then combine or compare the resulting models, for the most part in a more or less ad hoc manner. However, while each inversion may yield a model that fits the individual data set, the models are usually inconsistent with each other to some degree. This reflects uncertainties arising from the inevitable fact that geophysical and other exploration data in general are to some extent noisy, incomplete, and of limited sensitivity and resolution, and so yield non-unique results. The purpose of the project described here is to integrate the different model constraints provided by disparate geophysical, geological and geochemical data in a rigorous and consistent manner by formal joint inversion. The objective is to improve the fidelity of …
Date: April 25, 2007
Creator: Foxall, W; Ramirez, A; Carlson, S; Dyer, K & Sun, Y
Object Type: Report
System: The UNT Digital Library
Simulations of carbon fiber composite delamination tests (open access)

Simulations of carbon fiber composite delamination tests

Simulations of mode I interlaminar fracture toughness tests of a carbon-reinforced composite material (BMS 8-212) were conducted with LSDYNA. The fracture toughness tests were performed by U.C. Berkeley. The simulations were performed to investigate the validity and practicality of employing decohesive elements to represent interlaminar bond failures that are prevalent in carbon-fiber composite structure penetration events. The simulations employed a decohesive element formulation that was verified on a simple two element model before being employed to perform the full model simulations. Care was required during the simulations to ensure that the explicit time integration of LSDYNA duplicate the near steady-state testing conditions. In general, this study validated the use of employing decohesive elements to represent the interlaminar bond failures seen in carbon-fiber composite structures, but the practicality of employing the elements to represent the bond failures seen in carbon-fiber composite structures during penetration events was not established.
Date: October 25, 2007
Creator: Kay, G
Object Type: Report
System: The UNT Digital Library
RECENT ACTIVITIES OF THE NUCLEAR SMUGGLING INTERNATIONAL TECHNICAL WORKING GROUP TO THWART ILLICIT TRAFFICKING (open access)

RECENT ACTIVITIES OF THE NUCLEAR SMUGGLING INTERNATIONAL TECHNICAL WORKING GROUP TO THWART ILLICIT TRAFFICKING

The Nuclear Smuggling International Technical Working Group (ITWG) is an informal association of nuclear forensic practitioners working in partnership with law enforcement, first responder, and nuclear regulatory professionals that cooperate to deter the illicit trafficking of nuclear materials. The objective of the ITWG is to advance the science of nuclear forensics and to provide a common approach and effective technical solutions to governments who request assistance. the ITWG was chartered in 1996 and since that time 30 nations and organizations have participated in 12 annual meetings and two analytical round-robin trials involving plutonium and highly enriched uranium. A third analytical round-robin as well as several table-top exercises are planned for later in 2007-2008. International interest in the ITWG has grown in over the past five years measured by the number of participants at its annual meetings. This growth has spawned the ITWG Nuclear Forensics Laboratories as a companion technical affiliate focusing exclusively on the scientific aspects of nuclear forensics and nuclear smuggling incident response.
Date: October 25, 2007
Creator: Smith, D K; Biro, T; Chartier, B; Mayer, K; Niemeyer, S & Thompson, P
Object Type: Report
System: The UNT Digital Library
A simple and realistic model of supersymmetry breaking (open access)

A simple and realistic model of supersymmetry breaking

We present a simple and realistic model of supersymmetry breaking. In addition to the minimal supersymmetric standard model, we only introduce a hidden sector gauge group SU(5) and three fields X, F and \bar{F}. Supersymmetry is broken at a local minimum of the potential, and its effects are transmitted to the supersymmetric standard model sector through both standard model gauge loops and local operators suppressed by the cutoff scale, which is taken to be the unification scale. The form of the local operators is controlled by a U(1) symmetry. The generated supersymmetry breaking and mu parameters are comparable in size, and no flavor or CP violating terms arise. The spectrum of the first two generation superparticles is that of minimal gauge mediation with the number of messengers N_mess = 5 and the messenger scale 1011 GeV&lt; M_mess&lt; 1013 GeV. The spectrum of the Higgs bosons and third generation superparticles, however, can deviate from it. The lightest supersymmetric particle is the gravitino with a mass of order (1-10) GeV.
Date: September 25, 2007
Creator: Nomura, Yasunori & Papucci, Michele
Object Type: Article
System: The UNT Digital Library
Advanced Accelerator Applications University Participation Program (open access)

Advanced Accelerator Applications University Participation Program

Our research tasks span the range of technology areas for transmutation, gas-cooled reactor technology, and high temperature heat exchangers, including separation of actinides from spent nuclear fuel, methods of fuel fabrication, reactor-accelerator coupled experiments, corrosion of materials exposed to lead-bismuth eutectic, and special nuclear materials protection and accountability.
Date: July 25, 2007
Creator: Chen, Y. & Hechanova, A.
Object Type: Report
System: The UNT Digital Library
Insertion Devices R and Ds for NSLS-II (open access)

Insertion Devices R and Ds for NSLS-II

NSLS-II is a medium energy storage ring of 3GeV electron beam energy with sub-nm.rad horizontal emittance and top-off capability at 500mA. Damping wigglers will be used not only to reduce the beam emittance but also for broadband sources for users. Cryo-Permanent Magnet Undulators (CPMUs) are considered for hard X-ray linear device, and permanent magnet based Elliptically Polarized Undulators (EPUs) are for polarization control. Rigorous R&amp;D plans have been established to pursue the performance enhancement of the above devices as well as building new types of insertion devices such as high temperature superconducting wiggler/undulators. This paper describes the details of these activities and discuss technical issues.
Date: June 25, 2007
Creator: Tanabe, T.; Harder, D. A.; Rakowsky, G.; Shaftan, T. & Skaritka, J.
Object Type: Article
System: The UNT Digital Library
Ab initio Molecular Dynamics Simulations of Water Under Static and Shock Compressed Conditions (open access)

Ab initio Molecular Dynamics Simulations of Water Under Static and Shock Compressed Conditions

We report herein a series of ab initio simulations of water under both static and shocked conditions. We have calculated the coherent x-ray scattering intensity of several phases of water under high pressure, using ab initio Density Functional Theory (DFT). We provide new atomic scattering form factors for water at extreme conditions, which take into account frequently neglected changes in ionic charge and electron delocalization. We have also simulated liquid water undergoing shock loading of velocities from 5-11 km/s using the Multi-Scale Shock Technique (MSST). We show that Density Functional Theory (DFT) molecular dynamics results compare extremely well to experiments on the water shock Hugoniot.
Date: July 25, 2007
Creator: Goldman, N; Fried, L E; Mundy, C J; Kuo, I W; Curioni, A & Reed, E
Object Type: Article
System: The UNT Digital Library
Error Estimates Derived from the Data for Least-Squares Spline Fitting (open access)

Error Estimates Derived from the Data for Least-Squares Spline Fitting

The use of least-squares fitting by cubic splines for the purpose of noise reduction in measured data is studied. Splines with variable mesh size are considered. The error, the difference between the input signal and its estimate, is divided into two sources: the R-error, which depends only on the noise and increases with decreasing mesh size, and the Ferror, which depends only on the signal and decreases with decreasing mesh size. The estimation of both errors as a function of time is demonstrated. The R-error estimation requires knowledge of the statistics of the noise and uses well-known methods. The primary contribution of the paper is a method for estimating the F-error that requires no prior knowledge of the signal except that it has four derivatives. It is calculated from the difference between two different spline fits to the data and is illustrated with Monte Carlo simulations and with an example.
Date: June 25, 2007
Creator: Blair, Jerome
Object Type: Article
System: The UNT Digital Library
Technical Equivalency Documentation for a Newly Aquired Alpha Spectroscopy System (open access)

Technical Equivalency Documentation for a Newly Aquired Alpha Spectroscopy System

The response of a recently acquired Canberra{trademark} Alpha Analyst 'Blue' system (Chamber Number's 173-208) used by the Hazards Control, Radiation Safety Section, WBC/Spectroscopy Team has been studied with respect to an existing Canberra system. The existing Canberra system consists of thirty Alpha Analyst dual chambers Model XXXX comprising a total of sixty detectors (Chambers Number's 101-124 and 137-172). The existing chambers were previously compared to an older system consisting of thirty-six Model 7401 alpha spectrometry chambers (Chamber Number's 1-36) Chambers 101-124 and 137-172 are DOELAP accredited. The older system was previously DOELAP accredited for the routine Alpha Spectroscopy program used in LLNL's in vitro bioassay program. The newly acquired Alpha Analyst system operates on a network with software that controls and performs analysis of the current Alpha Analyst system (Chamber Number's 101-124 and 137-172). This exact same software is used for the current system and the newly acquired system and is DOELAP accredited. This document compares results from the existing Alpha System with the newer Alpha Analyst system.
Date: April 25, 2007
Creator: Hickman, D P; Fisher, S K; Hann, P R & Hume, R
Object Type: Report
System: The UNT Digital Library
State Response Plan (open access)

State Response Plan

None
Date: September 25, 2007
Creator: Hullinger, P
Object Type: Report
System: The UNT Digital Library
High Performance Ebis for Rhic. (open access)

High Performance Ebis for Rhic.

An Electron Beam Ion Source (EBIS), capable of producing high charge states and high beam currents of any heavy ion species in short pulses, is ideally suited for injection into a synchrotron. An EBIS-based, high current, heavy ion preinjector is now being built at Brookhaven to provide increased capabilities for the Relativistic Heavy Ion Collider (RHIC), and the NASA Space Radiation Laboratory (NSRL). Benefits of the new preinjector include the ability to produce ions of any species, fast switching between species to serve the simultaneous needs of multiple programs, and lower operating and maintenance costs. A state-of-the-art EBIS, operating with an electron beam current of up to 10 A, and producing multi-milliamperes of high charge state heavy ions, has been developed at Brookhaven, and has been operating very successfully on a test bench for several years. The present performance of this high-current EBIS is presented, along with details of the design of the scaled-up EBIS for RHIC, and the status of its construction. Other aspects of the project, including design and construction of the heavy ion RFQ, Linac, and matching beamlines, are also mentioned.
Date: June 25, 2007
Creator: Alessi, J.; Beebe, E.; Gould, O.; Kponou, A.; Lockey, R.; Pikin, A. et al.
Object Type: Article
System: The UNT Digital Library
Interactive, Internet Delivery of Visualization via Structured,Prerendered multiresolution Imagery (open access)

Interactive, Internet Delivery of Visualization via Structured,Prerendered multiresolution Imagery

One of the fundamental problems in remote visualization --where I/O and data intensive visualization activities take place at acentrally located supercomputer center and resulting imagery is deliveredto a remotely located user -- is reduced interactivity resulting from thecombination of high network latency and relatively low network bandwidth.This research project has produced a novel approach for latency-tolerantdelivery of visualization and rendering results where client-side framerate display performance is independent of source dataset size, imagesize, visualization technique or rendering complexity. As such, it is asuitable solution for remote visualization image delivery for anyvisualization or rendering application that can generate image frames inan ordered fashion. This new capability is suitable for use in addressingmany of ASCR s remote visualization needs, particularly deployment atopen computing facilities to provide remote visualization capabilities toteams of scientific researchers.
Date: October 25, 2007
Creator: Bethel, E. Wes; Yoon, Ilmi & Chen, Jerry
Object Type: Report
System: The UNT Digital Library
Fundamentals of Energy Transport in Nanofluids (open access)

Fundamentals of Energy Transport in Nanofluids

We performed computational simulations and theoretical analysis to investigate the underlying origins of large thermal conductivity enhancements observed in nanofluids (colloidal suspensions of solid nanoparticles and/or nanofibers in thermal fluids) and to identify strategies towards tailoring nanofluids for better thermal performance.
Date: February 25, 2007
Creator: Keblinski, Pawel
Object Type: Report
System: The UNT Digital Library
100 Area D4 Project Building Completion Report May 2006 - June 2007 (open access)

100 Area D4 Project Building Completion Report May 2006 - June 2007

This report documents the decontamination and decommissioning (D&D) and the demolition of the 153-N, 1515-N, 1516-N, 1517-N, 1518-N, 1519-N, 1331-N, 1332-N, and 181-NC facilities in the 100 Area of the Hanford Site. The D&D and demolition of these facilities included characterization, engineering, removal of hazardous and radiologically contaminated materials, equipment removal, utility disconnection, deactivation, decontamination, demolition of the structure, and removal of the remaining slabs.
Date: July 25, 2007
Creator: Ison, E. G.
Object Type: Report
System: The UNT Digital Library