Detailed Chemical Kinetic Reaction Mechanism for Biodiesel Components Methyl Stearate and Methyl Oleate (open access)

Detailed Chemical Kinetic Reaction Mechanism for Biodiesel Components Methyl Stearate and Methyl Oleate

New chemical kinetic reaction mechanisms are developed for two of the five major components of biodiesel fuel, methyl stearate and methyl oleate. The mechanisms are produced using existing reaction classes and rules for reaction rates, with additional reaction classes to describe other reactions unique to methyl ester species. Mechanism capabilities were examined by computing fuel/air autoignition delay times and comparing the results with more conventional hydrocarbon fuels for which experimental results are available. Additional comparisons were carried out with measured results taken from jet-stirred reactor experiments for rapeseed methyl ester fuels. In both sets of computational tests, methyl oleate was found to be slightly less reactive than methyl stearate, and an explanation of this observation is made showing that the double bond in methyl oleate inhibits certain low temperature chain branching reaction pathways important in methyl stearate. The resulting detailed chemical kinetic reaction mechanism includes more approximately 3500 chemical species and more than 17,000 chemical reactions.
Date: January 22, 2010
Creator: Naik, C; Westbrook, C K; Herbinet, O; Pitz, W J & Mehl, M
Object Type: Article
System: The UNT Digital Library
The Effect of H and He on Irradiation Performance of Fe and Ferritic Alloys (open access)

The Effect of H and He on Irradiation Performance of Fe and Ferritic Alloys

This research program was designed to look at basic radiation damage and effects and mechanical properties in Fe and ferritic alloys. The program scope included a number of materials ranging from pure single crystal Fe to more complex Fe-Cr-C alloys. The range of materials was designed to examine materials response and performance on ideal/model systems and gradually move to more complex systems. The experimental program was coordinated with a modeling effort. The use of pure and model alloys also facilitated the ability to develop and employ atomistic-scale modeling techniques to understand the inherent physics underlying materials performance
Date: January 22, 2010
Creator: Stubbins, James F.
Object Type: Report
System: The UNT Digital Library
EFRT M-12 Issue Resolution: Comparison of Filter Performance at PEP and CUF Scale (open access)

EFRT M-12 Issue Resolution: Comparison of Filter Performance at PEP and CUF Scale

Pacific Northwest National Laboratory (PNNL) has been tasked by Bechtel National Inc. (BNI) on the River Protection Project-Hanford Tank Waste Treatment and Immobilization Plant (RPP-WTP) project to perform research and development activities to resolve technical issues identified for the Pretreatment Facility (PTF). The Pretreatment Engineering Platform (PEP) was designed, constructed, and operated as part of a plan to respond to issue M12, “Undemonstrated Leaching Processes” of the External Flowsheet Review Team (EFRT) issue response plan.(a) The PEP is a 1/4.5-scale test platform designed to simulate the WTP pretreatment caustic leaching, oxidative leaching, ultrafiltration solids concentration, and slurry washing processes. The PEP replicates the WTP leaching processes using prototypic equipment and control strategies. The PEP also includes non-prototypic ancillary equipment to support the core processing.
Date: January 22, 2010
Creator: Daniel, Richard C.; Billing, Justin M.; Bontha, Jagannadha R.; Brown, Christopher F.; Eslinger, Paul W.; Hanson, Brady D. et al.
Object Type: Report
System: The UNT Digital Library
Marine and Hydrokinetic Energy Development Technical Support and General Environmental Studies Report on Outreach to Stakeholders for Fiscal Year 2009 (open access)

Marine and Hydrokinetic Energy Development Technical Support and General Environmental Studies Report on Outreach to Stakeholders for Fiscal Year 2009

Report on activities working with stakeholders in the emerging marine and hydrokinetic energy industry during FY09, for DOE EERE Office of Waterpower.
Date: January 22, 2010
Creator: Copping, Andrea E. & Geerlofs, Simon H.
Object Type: Report
System: The UNT Digital Library
Reference guide to WPP version 2.0 (open access)

Reference guide to WPP version 2.0

WPP is a computer program for simulating seismic wave propagation on parallel machines. WPP solves the governing equations in second order formulation using a node-based finite difference approach. The basic numerical method is described in [9]. WPP implements substantial capabilities for 3-D seismic modeling, with a free surface condition on the top boundary, non-reflecting far-field boundary conditions on the other boundaries, point force and point moment tensor source terms with many predefined time dependencies, fully 3-D heterogeneous material model specification, output of synthetic seismograms in the SAC [4] format, output of GMT [11] scripts for laying out simulation information on a map, and output of 2-D slices of (derived quantites of) the solution field as well as the material model. Version 2.0 of WPP allows the free surface boundary condition to be imposed on a curved topography. For this purpose a curvilinear mesh is used near the free surface, extending into the computational domain down to a user specified level. The elastic wave equations and the free surface boundary conditions are discretized on the curvilinear mesh using the energy conserving technique described in [2]. A curvilinear mesh generator is built into WPP and the curvilinear mesh is automatically generated from …
Date: January 22, 2010
Creator: Petersson, A & Sjogreen, B
Object Type: Report
System: The UNT Digital Library
An Assessment of the Penetrations in the First Wall Required for Plasma Measurments for Control of an Advanced Tokamak Plasma Demo (open access)

An Assessment of the Penetrations in the First Wall Required for Plasma Measurments for Control of an Advanced Tokamak Plasma Demo

A Demonstration tokamak (Demo) is an essential next step toward a magnetic-fusion based reactor. One based on advanced-tokamak (AT) plasmas is especially appealing because of its relative compactness. However, it will require many plasma measurements to provide the necessary signals to feed to ancillary systems to protect the device and control the plasma. This note addresses the question of how much intrusion into the blanket system will be required to allow the measurements needed to provide the information required for plasma control. All diagnostics will require, at least, the same shielding designs as planned for ITER, while having the capability to maintain their calibration through very long pulses. Much work is required to define better the measurement needs and the quantity and quality of the measurements that will have to be made, and how they can be integrated into the other tokamak structures.
Date: February 22, 2010
Creator: Young, Kenneth M.
Object Type: Report
System: The UNT Digital Library
Atmospheric Stability Impacts on Power Curves of Tall Wind Turbines - An Analysis of a West Coast North American Wind Farm (open access)

Atmospheric Stability Impacts on Power Curves of Tall Wind Turbines - An Analysis of a West Coast North American Wind Farm

Tall wind turbines, with hub heights at 80 m or above, can extract large amounts of energy from the atmosphere because they are likely to encounter higher wind speeds, but they face challenges given the complex nature of wind flow and turbulence at these heights in the boundary layer. Depending on whether the boundary layer is stable, neutral, or convective, the mean wind speed, direction, and turbulence properties may vary greatly across the tall turbine swept area (40 to 120 m AGL). This variability can cause tall turbines to produce difference amounts of power during time periods with identical hub height wind speeds. Using meteorological and power generation data from a West Coast North American wind farm over a one-year period, our study synthesizes standard wind park observations, such as wind speed from turbine nacelles and sparse meteorological tower observations, with high-resolution profiles of wind speed and turbulence from a remote sensing platform, to quantify the impact of atmospheric stability on power output. We first compare approaches to defining atmospheric stability. The standard, limited, wind farm operations enable the calculation only of a wind shear exponent ({alpha}) or turbulence intensity (I{sub U}) from cup anemometers, while the presence at this …
Date: February 22, 2010
Creator: Wharton, S & Lundquist, J K
Object Type: Report
System: The UNT Digital Library
CgWind: A high-order accurate simulation tool for wind turbines and wind farms (open access)

CgWind: A high-order accurate simulation tool for wind turbines and wind farms

CgWind is a high-fidelity large eddy simulation (LES) tool designed to meet the modeling needs of wind turbine and wind park engineers. This tool combines several advanced computational technologies in order to model accurately the complex and dynamic nature of wind energy applications. The composite grid approach provides high-quality structured grids for the efficient implementation of high-order accurate discretizations of the incompressible Navier-Stokes equations. Composite grids also provide a natural mechanism for modeling bodies in relative motion and complex geometry. Advanced algorithms such as matrix-free multigrid, compact discretizations and approximate factorization will allow CgWind to perform highly resolved calculations efficiently on a wide class of computing resources. Also in development are nonlinear LES subgrid-scale models required to simulate the many interacting scales present in large wind turbine applications. This paper outlines our approach, the current status of CgWind and future development plans.
Date: February 22, 2010
Creator: Chand, K K; Henshaw, W D; Lundquist, K A & Singer, M A
Object Type: Article
System: The UNT Digital Library
Drilling and Production Testing the Methane Hydrate Resource Potential Associated with the Barrow Gas Fields (open access)

Drilling and Production Testing the Methane Hydrate Resource Potential Associated with the Barrow Gas Fields

In November of 2008, the Department of Energy (DOE) and the North Slope Borough (NSB) committed funding to develop a drilling plan to test the presence of hydrates in the producing formation of at least one of the Barrow Gas Fields, and to develop a production surveillance plan to monitor the behavior of hydrates as dissociation occurs. This drilling and surveillance plan was supported by earlier studies in Phase 1 of the project, including hydrate stability zone modeling, material balance modeling, and full-field history-matched reservoir simulation, all of which support the presence of methane hydrate in association with the Barrow Gas Fields. This Phase 2 of the project, conducted over the past twelve months focused on selecting an optimal location for a hydrate test well; design of a logistics, drilling, completion and testing plan; and estimating costs for the activities. As originally proposed, the project was anticipated to benefit from industry activity in northwest Alaska, with opportunities to share equipment, personnel, services and mobilization and demobilization costs with one of the then-active exploration operators. The activity level dropped off, and this benefit evaporated, although plans for drilling of development wells in the BGF's matured, offering significant synergies and cost savings …
Date: February 22, 2010
Creator: McRae, Steve; Walsh, Thomas; Dunn, Michael & Cook, Michael
Object Type: Report
System: The UNT Digital Library
Enhanced Named Entity Extraction via Error-Driven Aggregation (open access)

Enhanced Named Entity Extraction via Error-Driven Aggregation

Despite recent advances in named entity extraction technologies, state-of-the-art extraction tools achieve insufficient accuracy rates for practical use in many operational settings. However, they are not generally prone to the same types of error, suggesting that substantial improvements may be achieved via appropriate combinations of existing tools, provided their behavior can be accurately characterized and quantified. In this paper, we present an inference methodology for the aggregation of named entity extraction technologies that is founded upon a black-box analysis of their respective error processes. This method has been shown to produce statistically significant improvements in extraction relative to standard performance metrics and to mitigate the weak performance of entity extractors operating under suboptimal conditions. Moreover, this approach provides a framework for quantifying uncertainty and has demonstrated the ability to reconstruct the truth when majority voting fails.
Date: February 22, 2010
Creator: Lemmond, T. D.; Perry, N. C.; Guensche, J. W.; Nitao, J. J.; Glaser, R. E.; Kidwell, P. et al.
Object Type: Article
System: The UNT Digital Library
Final Technical Report (open access)

Final Technical Report

The research project focuses on the following topics: a) removal of artifacts in the Doppler spectra from the ARM cloud radars, b) development of the second generation Active Remote Sensing of Cloud Layers (ARSCL) cloud data products, and c) evaluation of ARM cloud property retrievals within the framework of the EarthCARE simulator. We continue to pursue research on areas related to radiative transfer, atmospheric heating rates and related dynamics (topics of interest to the ARM science community at this time) and to contribute on an ad-hoc basis to the science of other ARM-supported principal investigators.
Date: February 22, 2010
Creator: Eugene Clothiaux, Johannes Verlinde, Jerry Harrington
Object Type: Report
System: The UNT Digital Library
Identifying the Proteins that Mediate the Ionizing Radiation Resistance of Deinococcus Radiodurans R1 (open access)

Identifying the Proteins that Mediate the Ionizing Radiation Resistance of Deinococcus Radiodurans R1

The primary objectives of this proposal was to define the subset of proteins required for the ionizing radiation (IR) resistance of Deinococcus radiodurans R1, characterize the activities of those proteins, and apply what was learned to problems of interest to the Department of Energy.
Date: February 22, 2010
Creator: Battista, John R
Object Type: Report
System: The UNT Digital Library
Lead-Cooled Fast Reactor (LFR) Design: Safety, Neutronics, Thermal Hydraulics, Structural Mechanics, Fuel, Core, and Plant Design (open access)

Lead-Cooled Fast Reactor (LFR) Design: Safety, Neutronics, Thermal Hydraulics, Structural Mechanics, Fuel, Core, and Plant Design

Fifth chapter from "A Compendium of Reactor Technology" discussing the history and design of lead-cooled fast reactors in nine sections: Lead-cooled Fast Reactor (LFR) Development, Design Criteria and General Specifications, Neutronics, Lead Properties, Compatibility of Structural Materials with Lead, Core, Reactor System, Decay Heat Removal System, and Nuclear Island.
Date: February 22, 2010
Creator: Smith, Craig; Cinotti, L.; Artoli, C. & Grasso, G.
Object Type: Book Chapter
System: The UNT Digital Library
Mixer-Ejector Wind Turbine: Breakthrough High Efficiency Shrouded Wind Turbine (open access)

Mixer-Ejector Wind Turbine: Breakthrough High Efficiency Shrouded Wind Turbine

Broad Funding Opportunity Announcement Project: FloDesign Wind Turbine’s innovative wind turbine, inspired by the design of jet engines, could deliver 300% more power than existing wind turbines of the same rotor diameter by extracting more energy over a larger area. FloDesign Wind Turbine’s unique shrouded design expands the wind capture area, and the mixing vortex downstream allows more energy to flow through the rotor without stalling the turbine. The unique rotor and shrouded design also provide significant opportunity for mass production and simplified assembly, enabling mid-scale turbines (approximately 100 kW) to produce power at a cost that is comparable to larger-scale conventional turbines.
Date: February 22, 2010
Creator: unknown
Object Type: Text
System: The UNT Digital Library
Non-Universality of Transverse Momentum Dependent Parton Distributions at Small-x (open access)

Non-Universality of Transverse Momentum Dependent Parton Distributions at Small-x

We study the universality of the transverse momentum dependent parton distributions at small-x, by comparing the initial/final state interaction effects in dijet-correlation in pA collisions with that in deep inelastic lepton nucleus scattering. We demonstrate the non-universality by an explicit calculation in a particular model where the multiple gauge boson exchange contributions are summed up to all orders. We furthercomment on the implications of our results on the theoretical interpretation of di-hadron correlation in dA collisions in terms of the saturation phenomena in deep inelastic lepton nucleus scattering.
Date: February 22, 2010
Creator: Xiao, Bowen & Yuan, Feng
Object Type: Article
System: The UNT Digital Library
Radiochemistry diagnostics for the National Ignition Facility (open access)

Radiochemistry diagnostics for the National Ignition Facility

Radiochemistry-based techniques will be an important complement to x-ray implosion diagnostics. Simulations demonstrate the value of alpha-induced or deuteron-induced reactions as a direct measurement of static mix contamination in DT-filled ignition capsules. In this proceedings we examine to what extent neutron-induced reactions might be highly correlated with the energetically down-scattered neutron fraction which is, in turn, related to the critical quantity of fuel areal density, {rho}R. Although alpha and deuteron reactions are highly suppressed in HT/D-filled capsules, neutron-induced reactions produce robust abundances and 2% measurements of the relevant radiological ratios is achievable. We conclude that radiochemical data are strongly correlated with the down-scattered fraction and fuel areal density. Unknown physics, primarily uncertainties in the direct T-T fusion neutron cross section and, to a lesser extent, various radiochemical production cross sections are important but calibration shots can be used to reduce these errors. The primary advantage of radiochemistry remains - it is the only technique that samples down-scattered neutrons from the entire capsule during the burn. In particular radiochemistry correlated with other diagnostics can be used to minimize experimental uncertainties and thus maximize gain.
Date: February 22, 2010
Creator: Hoffman, R. D.; Cerjan, C. J.; Shaughnessy, D. A.; Moody, K. J.; Nelson, S. L.; Bernstein, L. A. et al.
Object Type: Article
System: The UNT Digital Library
Bacillus anthracis genome organization in light of whole transcriptome sequencing (open access)

Bacillus anthracis genome organization in light of whole transcriptome sequencing

Emerging knowledge of whole prokaryotic transcriptomes could validate a number of theoretical concepts introduced in the early days of genomics. What are the rules connecting gene expression levels with sequence determinants such as quantitative scores of promoters and terminators? Are translation efficiency measures, e.g. codon adaptation index and RBS score related to gene expression? We used the whole transcriptome shotgun sequencing of a bacterial pathogen Bacillus anthracis to assess correlation of gene expression level with promoter, terminator and RBS scores, codon adaptation index, as well as with a new measure of gene translational efficiency, average translation speed. We compared computational predictions of operon topologies with the transcript borders inferred from RNA-Seq reads. Transcriptome mapping may also improve existing gene annotation. Upon assessment of accuracy of current annotation of protein-coding genes in the B. anthracis genome we have shown that the transcriptome data indicate existence of more than a hundred genes missing in the annotation though predicted by an ab initio gene finder. Interestingly, we observed that many pseudogenes possess not only a sequence with detectable coding potential but also promoters that maintain transcriptional activity.
Date: March 22, 2010
Creator: Martin, Jeffrey; Zhu, Wenhan; Passalacqua, Karla D.; Bergman, Nicholas & Borodovsky, Mark
Object Type: Article
System: The UNT Digital Library
Building Energy Information Systems: User Case Studies (open access)

Building Energy Information Systems: User Case Studies

Measured energy performance data are essential to national efforts to improve building efficiency, as evidenced in recent benchmarking mandates, and in a growing body of work that indicates the value of permanent monitoring and energy information feedback. This paper presents case studies of energy information systems (EIS) at four enterprises and university campuses, focusing on the attained energy savings, and successes and challenges in technology use and integration. EIS are broadly defined as performance monitoring software, data acquisition hardware, and communication systems to store, analyze and display building energy information. Case investigations showed that the most common energy savings and instances of waste concerned scheduling errors, measurement and verification, and inefficient operations. Data quality is critical to effective EIS use, and is most challenging at the subsystem or component level, and with non-electric energy sources. Sophisticated prediction algorithms may not be well understood but can be applied quite effectively, and sites with custom benchmark models or metrics are more likely to perform analyses external to the EIS. Finally, resources and staffing were identified as a universal challenge, indicating a need to identify additional models of EIS use that extend beyond exclusive in-house use, to analysis services.
Date: March 22, 2010
Creator: Granderson, Jessica; Piette, Mary Ann & Ghatikar, Girish
Object Type: Article
System: The UNT Digital Library
BWR Assembly Optimization for Minor Actinide Recycling (open access)

BWR Assembly Optimization for Minor Actinide Recycling

The Primary objective of the proposed project is to apply and extend the latest advancements in LWR fuel management optimization to the design of advanced boiling water reactor (BWR) fuel assemblies specifically for the recycling of minor actinides (MAs).
Date: March 22, 2010
Creator: Maldonado, G. Ivan; Christenson, John M.; Renier, J.P.; Marcille, T.F. & Casal, J.
Object Type: Report
System: The UNT Digital Library
Energy Efficiency Services Sector: Workforce Size and Expectations for Growth (open access)

Energy Efficiency Services Sector: Workforce Size and Expectations for Growth

The energy efficiency services sector (EESS) is poised to become an increasingly important part of the U.S. economy. Climate change and energy supply concerns, volatile and increasing energy prices, and a desire for greater energy independence have led many state and national leaders to support an increasingly prominent role for energy efficiency in U.S. energy policy. The national economic recession has also helped to boost the visibility of energy efficiency, as part of a strategy to support economic recovery. We expect investment in energy efficiency to increase dramatically both in the near-term and through 2020 and beyond. This increase will come both from public support, such as the American Recovery and Reinvestment Act (ARRA) and significant increases in utility ratepayer funds directed toward efficiency, and also from increased private spending due to codes and standards, increasing energy prices, and voluntary standards for industry. Given the growing attention on energy efficiency, there is a concern among policy makers, program administrators, and others that there is an insufficiently trained workforce in place to meet the energy efficiency goals being put in place by local, state, and federal policy. To understand the likelihood of a potential workforce gap and appropriate response strategies, one …
Date: March 22, 2010
Creator: Goldman, Charles; Fuller, Merrian C.; Stuart, Elizabeth; Peters, Jane S.; McRae, Marjorie; Albers, Nathaniel et al.
Object Type: Report
System: The UNT Digital Library
Nebular mixing constrained by the Stardust samples (open access)

Nebular mixing constrained by the Stardust samples

Using X-ray microprobe analysis of samples from comet Wild 2 returned by the Stardust mission, we determine that the crystalline Fe-bearing silicate fraction in this Jupiter-family comet is greater than 0.5. Assuming this mixture is a composite of crystalline inner solar system material and amorphous cold molecular cloud material, we deduce that more than half of Wild 2 has been processed in the inner solar system. Several models exist that explain the presence of crystalline materials in comets. We explore some of these models in light of our results.
Date: March 22, 2010
Creator: OGLIORE, R. C.; WESTPHAL, A. J.; GAINSFORTH, Z.; BUTTERWORTH, A. L.; FAKRA, S. C. & Marcus, Matthew A.
Object Type: Article
System: The UNT Digital Library
Plasticity at High Pressures and Strain Rates Using Oblique-Impact Isentropic-Compression Experiments (open access)

Plasticity at High Pressures and Strain Rates Using Oblique-Impact Isentropic-Compression Experiments

None
Date: March 22, 2010
Creator: Florando, Jeff N.; Jiao, Tong; Grunschel, Stephen E.; Clifton, Rodney J.; Lassila, David H.; Ferranti, Louis, Jr. et al.
Object Type: Report
System: The UNT Digital Library
A Proposal for User-defined Reductions in OpenMP (open access)

A Proposal for User-defined Reductions in OpenMP

Reductions are commonly used in parallel programs to produce a global result from partial results computed in parallel. Currently, OpenMP only supports reductions for primitive data types and a limited set of base language operators. This is a significant limitation for those applications that employ user-defined data types (e. g., objects). Implementing manual reduction algorithms makes software development more complex and error-prone. Additionally, an OpenMP runtime system cannot optimize a manual reduction algorithm in ways typically applied to reductions on primitive types. In this paper, we propose new mechanisms to allow the use of most pre-existing binary functions on user-defined data types as User-Defined Reduction (UDR) operators. Our measurements show that our UDR prototype implementation provides consistently good performance across a range of thread counts without increasing general runtime overheads.
Date: March 22, 2010
Creator: Duran, A; Ferrer, R; Klemm, M; de Supinski, B R & Ayguade, E
Object Type: Article
System: The UNT Digital Library
Thin Silicon MEMS Contact-Stress Sensor (open access)

Thin Silicon MEMS Contact-Stress Sensor

This thin, MEMS contact-stress (CS) sensor continuously and accurately measures time-varying, solid interface loads in embedded systems over tens of thousands of load cycles. Unlike all other interface load sensors, the CS sensor is extremely thin (< 150 {micro}m), provides accurate, high-speed measurements, and exhibits good stability over time with no loss of calibration with load cycling. The silicon CS sensor, 5 mm{sup 2} and 65 {micro}m thick, has piezoresistive traces doped within a load-sensitive diaphragm. The novel package utilizes several layers of flexible polyimide to mechanically and electrically isolate the sensor from the environment, transmit normal applied loads to the diaphragm, and maintain uniform thickness. The CS sensors have a highly linear output in the load range tested (0-2.4 MPa) with an average accuracy of {+-} 1.5%.
Date: March 22, 2010
Creator: Kotovsky, J; Tooker, A & Horsley, D
Object Type: Article
System: The UNT Digital Library