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A University Consortium on Low Temperature Combustion for High Efficiency, Ultra-Low Emission Engines (open access)

A University Consortium on Low Temperature Combustion for High Efficiency, Ultra-Low Emission Engines

The objective of the University consortium was to investigate the fundamental processes that determine the practical boundaries of Low Temperature Combustion (LTC) engines and develop methods to extend those boundaries to improve the fuel economy of these engines, while operating with ultra low emissions. This work involved studies of thermal effects, thermal transients and engine management, internal mixing and stratification, and direct injection strategies for affecting combustion stability. This work also examined spark-assisted Homogenous Charge Compression Ignition (HCCI) and exhaust after-treatment so as to extend the range and maximize the benefit of Homogenous Charge Compression Ignition (HCCI)/ Partially Premixed Compression Ignition (PPCI) operation. In summary the overall goals were:  Investigate the fundamental processes that determine the practical boundaries of Low Temperature Combustion (LTC) engines.  Develop methods to extend LTC boundaries to improve the fuel economy of HCCI engines fueled on gasoline and alternative blends, while operating with ultra low emissions.  Investigate alternate fuels, ignition and after-treatment for LTC and Partially Premixed compression Ignition (PPCI) engines.
Date: December 31, 2009
Creator: Assanis, Dennis N.; Atreya, Arvind; Chen, Jyh-Yuan; Cheng, Wai K.; Dibble, Robert W.; Edwards, Chris et al.
Object Type: Report
System: The UNT Digital Library
Implementation of longitudinal dynamics with barrier RF in BETACOOL and comparison to ESME (open access)

Implementation of longitudinal dynamics with barrier RF in BETACOOL and comparison to ESME

The barrier bucket RF system is successfully used on Recycler storage ring at Fermilab. The special program code ESME was used for numerical simulation of longitudinal phase space manipulations. This program helps optimizing the various regimes of operation in the Recycler and increasing the luminosity in the colliding experiments. Electron and stochastic cooling increases the phase space density in all degrees of freedom. In the case of a small phase space volume the intrabeam scattering introduces coupling between the transverse and longitudinal temperatures of the antiproton beam. For numerical simulations of the cooling processes at the Recycler, a new model of the barrier buckets was implemented in the BETACOOL code. The comparison between ESME and BETACOOL codes for a stationary and moving barrier buckets is presented. This article also includes an application of the barrier bucket numerical model for simulation of the luminosity distribution for RHIC colliding experiments. These simulations take into account the specific longitudinal distribution of the bunch and the vertex size of the detector.
Date: August 31, 2009
Creator: Smirnov, A.; Fedotov, A.; Sidorin, A.; Krestnikov, D.; Bhat, C. & Prost, L.
Object Type: Article
System: The UNT Digital Library
[Conference Registration Form for Daniel C. Graney] (open access)

[Conference Registration Form for Daniel C. Graney]

Registration form filled out by Daniel C. Graney for the Texas Stonewall Democratic Caucus Statewide Conference in Austin, including contact information and workshop selections in Raise Money Without Even Trying, Legal Tips for Political Action Committees, and Making Your Endorsements Matter. Also, there is an envelope addressed to the Texas Stonewall Democratic Caucus at Dallas, Texas from Daniel C. Graney at San Antonio, Texas.
Date: January 31, 2009
Creator: unknown
Object Type: Text
System: The UNT Digital Library
Project Response To ASME Question for Comparison of Pure Oxy-Firing to Diluted Oxy-Firing (open access)

Project Response To ASME Question for Comparison of Pure Oxy-Firing to Diluted Oxy-Firing

High flame temperature oxy-combustion and low flame temperature oxy-combustion are the two primary types of oxy-combustion, which is the combustion of fossil fuel with oxygen instead of air. High flame temperature oxy-combustion results in increased radiant energy, but heat flux at the water walls has been demonstrated to be maintained within design parameters. Less fossil fuel is used, so less CO{sub 2} is produced. Latent and sensible heat can be partially recovered from the compressors. CO{sub 2} capture costs are decreased. Evenly distributed heat avoids creating hot spots. The NETL IPR capture system can capture 100% of the CO{sub 2} when operating at steady state. New boiler designs for high flame temperature oxy-combustion can take advantage of the higher flame temperatures. High flame temperature oxy-combustion with IPR capture can be retrofitted on existing plants. High flame temperature oxy-combustion has significantly improved radiant heat transfer compared to low flame temperature oxy-combustion, but heat flux at the water walls can be controlled. High flame temperature oxy-combustion used with the NETL's Integrated Pollutant Removal System can capture 95%-100% of the CO{sub 2} with heat recovery. These technologies create CO{sub 2} capture cost savings, and are applicable to new design and existing design boilers.
Date: August 31, 2009
Creator: Schoenfield, Mark & Ochs, Tom
Object Type: Report
System: The UNT Digital Library
An Integrated Solid-State LED Luminaire for General Lighting (open access)

An Integrated Solid-State LED Luminaire for General Lighting

A strong systems approach to designing and building practical LED-based replacement lamps is lacking. The general method of taking high-performance LEDs and marrying them to standard printed circuit boards, drivers and a heat sink has fallen short of the promise of LED lighting. In this program, a top-down assessment of requirements and a bottom-up reinvention of LED sources, electronics, optics and mechanics have resulted in the highest performance lamp possible. The team, comprised of Color Kinetics, the leaders in LED lighting and Cree, the leaders in LED devices took an approach to reinvent the package, the driver and the overall form and aesthetic of a replacement source. The challenge was to create a new benchmark in LED lighting - the resultant lamp, a PAR38 equivalent, met the light output, color, color quality and efficacy marks set out in the program as well as being dimmable, which is important for market acceptance. The approach combined the use of multiple source die, a chip-on-board approach, a very efficient driver topology, the use of both direct emission and phosphor conversion, and a unique faceted optic to avoid the losses, artifacts and hotspots of lensed approaches. The integral heat sink provided a mechanical base …
Date: March 31, 2009
Creator: Dowling, Kevin; Lys, Fritz Morgan Ihor; Datta, Mike; Keller, Bernd & Yuan, Thomas
Object Type: Report
System: The UNT Digital Library
The Greensheet (Fort Worth, Tex.), Vol. 33, No. 270, Ed. 1 Thursday, December 31, 2009 (open access)

The Greensheet (Fort Worth, Tex.), Vol. 33, No. 270, Ed. 1 Thursday, December 31, 2009

Free weekly newspaper that includes business and classified advertising.
Date: December 31, 2009
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
The Greensheet (Arlington-Grand Prairie, Tex.), Vol. 33, No. 269, Ed. 1 Thursday, December 31, 2009 (open access)

The Greensheet (Arlington-Grand Prairie, Tex.), Vol. 33, No. 269, Ed. 1 Thursday, December 31, 2009

Free weekly newspaper that includes business and classified advertising.
Date: December 31, 2009
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
The Greensheet (Houston, Tex.), Vol. 40, No. 311, Ed. 1 Friday, July 31, 2009 (open access)

The Greensheet (Houston, Tex.), Vol. 40, No. 311, Ed. 1 Friday, July 31, 2009

Free weekly newspaper that includes business and classified advertising.
Date: July 31, 2009
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
The Greensheet (Fort Worth, Tex.), Vol. 33, No. 271, Ed. 1 Thursday, December 31, 2009 (open access)

The Greensheet (Fort Worth, Tex.), Vol. 33, No. 271, Ed. 1 Thursday, December 31, 2009

Free weekly newspaper that includes business and classified advertising.
Date: December 31, 2009
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
Well-to-wheels energy use and greenhouse gas emissions analysis of plug-in hybrid electric vehicles. (open access)

Well-to-wheels energy use and greenhouse gas emissions analysis of plug-in hybrid electric vehicles.

Researchers at Argonne National Laboratory expanded the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model and incorporated the fuel economy and electricity use of alternative fuel/vehicle systems simulated by the Powertrain System Analysis Toolkit (PSAT) to conduct a well-to-wheels (WTW) analysis of energy use and greenhouse gas (GHG) emissions of plug-in hybrid electric vehicles (PHEVs). The WTW results were separately calculated for the blended charge-depleting (CD) and charge-sustaining (CS) modes of PHEV operation and then combined by using a weighting factor that represented the CD vehicle-miles-traveled (VMT) share. As indicated by PSAT simulations of the CD operation, grid electricity accounted for a share of the vehicle's total energy use, ranging from 6% for a PHEV 10 to 24% for a PHEV 40, based on CD VMT shares of 23% and 63%, respectively. In addition to the PHEV's fuel economy and type of on-board fuel, the marginal electricity generation mix used to charge the vehicle impacted the WTW results, especially GHG emissions. Three North American Electric Reliability Corporation regions (4, 6, and 13) were selected for this analysis, because they encompassed large metropolitan areas (Illinois, New York, and California, respectively) and provided a significant variation of marginal generation …
Date: March 31, 2009
Creator: Elgowainy, A.; Burnham, A.; Wang, M.; Molburg, J.; Rousseau, A. & Systems, Energy
Object Type: Report
System: The UNT Digital Library
Chemical Looping Combustion Kinetics (open access)

Chemical Looping Combustion Kinetics

One of the most promising methods of capturing CO{sub 2} emitted by coal-fired power plants for subsequent sequestration is chemical looping combustion (CLC). A powdered metal oxide such as NiO transfers oxygen directly to a fuel in a fuel reactor at high temperatures with no air present. Heat, water, and CO{sub 2} are released, and after H{sub 2}O condensation the CO{sub 2} (undiluted by N{sub 2}) is ready for sequestration, whereas the nickel metal is ready for reoxidation in the air reactor. In principle, these processes can be repeated endlessly with the original nickel metal/nickel oxide participating in a loop that admits fuel and rejects ash, heat, and water. Our project accumulated kinetic rate data at high temperatures and elevated pressures for the metal oxide reduction step and for the metal reoxidation step. These data will be used in computational modeling of CLC on the laboratory scale and presumably later on the plant scale. The oxygen carrier on which the research at Utah is focused is CuO/Cu{sub 2}O rather than nickel oxide because the copper system lends itself to use with solid fuels in an alternative to CLC called 'chemical looping with oxygen uncoupling' (CLOU).
Date: March 31, 2009
Creator: Eyring, Edward & Konya, Gabor
Object Type: Text
System: The UNT Digital Library
Improvement plans for the RHIC/AGS on-line model environments (open access)

Improvement plans for the RHIC/AGS on-line model environments

The on-line models for Relativistic Ion Collider (RHIC) and the RHIC pre-injectors (the AGS and the AGS Booster) can be thought of as containing our best collective knowledge of these accelerators. As we improve these on-line models we are building the framework to have a sophisticated model-based controls system. Currently the RHIC on-line model is an integral part of the controls system, providing the interface for tune control, chromaticity control, and non-linear chromaticity control. What we discuss in this paper is our vision of the future of the on-line model environment for RHIC and the RHIC preinjectors. Although these on-line models are primarily used as Courant-Snyder parameter calculators using live machine settings, we envision expanding these environments to encompass many other problem domains.
Date: August 31, 2009
Creator: Brown, K. A.; Ahrens, L.; Beebe-Wang, J.; Morris, J.; Nemesure, S.; Robert-Demolaize, G. et al.
Object Type: Article
System: The UNT Digital Library
2008 Photoions, Photoionization & Photodetachment Gordon Research Conference January 27-February 1, 2008 (open access)

2008 Photoions, Photoionization & Photodetachment Gordon Research Conference January 27-February 1, 2008

This conference brings together scientists interested in a range of basic phenomena linked to the ejection and scattering of electrons from atoms, molecules, clusters, liquids and solids by absorption of light. Photoionization, a highly sensitive probe of both structure and dynamics, can range from perturbative single-photon processes to strong-field highly non-perturbative interactions. It is responsible for the formation and destruction of molecules in astrophysical and plasma environments and successfully used in advanced analytical techniques. Positive ions, which can be produced and studied most effectively using photoionization, are the major components of all plasmas, vital constituents of flames and important intermediates in many chemical reactions. Negative ions are significant as transient species and, when photodetached, the corresponding neutral species often undergoes remarkable, otherwise non-observable, dynamics. The scope of the meeting spans from novel observations in atomic and molecular physics, such as Coulomb Crystals, highly excited states and cold Rydberg plasmas, to novel energy resolved or ultrafast time-resolved experiments, photoionization in strong laser fields, theoretical method development for electron scattering, photoionization and photodetachment and more complex phenomena such as charge transfer and DNA and protein conductivity, important for biological and analytical applications.
Date: March 31, 2009
Creator: GRay, Klaus Muller-Dethefs Nancy Ryan
Object Type: Article
System: The UNT Digital Library
Dynamic Simulation and Optimization of Nuclear Hydrogen Production Systems (open access)

Dynamic Simulation and Optimization of Nuclear Hydrogen Production Systems

This project is part of a research effort to design a hydrogen plant and its interface with a nuclear reactor. This project developed a dynamic modeling, simulation and optimization environment for nuclear hydrogen production systems. A hybrid discrete/continuous model captures both the continuous dynamics of the nuclear plant, the hydrogen plant, and their interface, along with discrete events such as major upsets. This hybrid model makes us of accurate thermodynamic sub-models for the description of phase and reaction equilibria in the thermochemical reactor. Use of the detailed thermodynamic models will allow researchers to examine the process in detail and have confidence in the accurary of the property package they use.
Date: July 31, 2009
Creator: Barton, Paul I.; Kaximi, Mujid S.; Bollas, Georgios & Munoz, Patricio Ramirez
Object Type: Report
System: The UNT Digital Library
Heterogeneous Reburning By Mixed Fuels (open access)

Heterogeneous Reburning By Mixed Fuels

Recent studies of heterogeneous reburning, i.e., reburning involving a coal-derived char, have elucidated its variables, kinetics and mechanisms that are valuable to the development of a highly efficient reburning process. Young lignite chars contain catalysts that not only reduce NO, but they also reduce HCN that is an important intermediate that recycles to NO in the burnout zone. Gaseous CO scavenges the surface oxides that are formed during NO reduction, regenerating the active sites on the char surface. Based on this mechanistic information, cost-effective mixed fuels containing these multiple features has been designed and tested in a simulated reburning apparatus. Remarkably high reduction of NO and HCN has been observed and it is anticipated that mixed fuel will remove 85% of NO in a three-stage reburning process.
Date: March 31, 2009
Creator: Hall, Anderson
Object Type: Report
System: The UNT Digital Library
Fast Tree: Computing Large Minimum-Evolution Trees with Profiles instead of a Distance Matrix (open access)

Fast Tree: Computing Large Minimum-Evolution Trees with Profiles instead of a Distance Matrix

Gene families are growing rapidly, but standard methods for inferring phylogenies do not scale to alignments with over 10,000 sequences. We present FastTree, a method for constructing large phylogenies and for estimating their reliability. Instead of storing a distance matrix, FastTree stores sequence profiles of internal nodes in the tree. FastTree uses these profiles to implement neighbor-joining and uses heuristics to quickly identify candidate joins. FastTree then uses nearest-neighbor interchanges to reduce the length of the tree. For an alignment with N sequences, L sites, and a different characters, a distance matrix requires O(N^2) space and O(N^2 L) time, but FastTree requires just O( NLa + N sqrt(N) ) memory and O( N sqrt(N) log(N) L a ) time. To estimate the tree's reliability, FastTree uses local bootstrapping, which gives another 100-fold speedup over a distance matrix. For example, FastTree computed a tree and support values for 158,022 distinct 16S ribosomal RNAs in 17 hours and 2.4 gigabytes of memory. Just computing pairwise Jukes-Cantor distances and storing them, without inferring a tree or bootstrapping, would require 17 hours and 50 gigabytes of memory. In simulations, FastTree was slightly more accurate than neighbor joining, BIONJ, or FastME; on genuine alignments, FastTree's …
Date: July 31, 2009
Creator: N. Price, Morgan; S. Dehal, Paramvir & P. Arkin, Adam
Object Type: Article
System: The UNT Digital Library
Exact Lattice Supersymmetry (open access)

Exact Lattice Supersymmetry

We provide an introduction to recent lattice formulations of supersymmetric theories which are invariant under one or more real supersymmetries at nonzero lattice spacing. These include the especially interesting case of N = 4 SYM in four dimensions. We discuss approaches based both on twisted supersymmetry and orbifold-deconstruction techniques and show their equivalence in the case of gauge theories. The presence of an exact supersymmetry reduces and in some cases eliminates the need for fine tuning to achieve a continuum limit invariant under the full supersymmetry of the target theory. We discuss open problems.
Date: March 31, 2009
Creator: Catterall, Simon; Kaplan, David B. & Unsal, Mithat
Object Type: Article
System: The UNT Digital Library
Demonstration Assessment of Light-Emitting Diode (LED) Roadway Lighting at the I-35W Bridge, Minneapolis, MN (open access)

Demonstration Assessment of Light-Emitting Diode (LED) Roadway Lighting at the I-35W Bridge, Minneapolis, MN

This report describes the process and results of a demonstration of solid-state lighting (SSL) technology conducted in 2009 at the recently reconstructed I-35W bridge in Minneapolis, MN. The project was supported under the U.S. Department of Energy (DOE) Solid-State Lighting GATEWAY Technology Demonstration Program. Other participants in the demonstration project included the Minnesota Department of Transportation (Mn/DOT), Federal Highways Administration (FHWA), and BetaLED™ (a division of Ruud Lighting). Pacific Northwest National Laboratory (PNNL) conducted the measurements and analysis of the results. DOE has implemented a three-year evaluation of the LED luminaires in this installation in order to develop new longitudinal field data on LED performance in a challenging, real-world environment. This document provides information through the initial phase of the I-35W bridge project, up to and including the opening of the bridge to the public and the initial feedback received on the LED lighting installation from bridge users. Initial findings of the evaluation are favorable, with minimum energy savings level of 13% for the LED installation relative to the simulated base case using 250W high-pressure sodium (HPS) fixtures. The LEDs had an average illuminance level of 0.91 foot candles compared to 1.29 fc for the HPS lamps. The LED luminaires …
Date: August 31, 2009
Creator: Kinzey, Bruce R. & Myer, Michael
Object Type: Report
System: The UNT Digital Library
Target Diagnostic Operations Summary August 28-29, 2009 (open access)

Target Diagnostic Operations Summary August 28-29, 2009

This campaign will validate the capability of fielding cryogenic hohlraums by demonstrating that the radiation temperature is not affected by contamination and ice buildup.
Date: August 31, 2009
Creator: Larson, D W
Object Type: Report
System: The UNT Digital Library
High-Efficiency Thin-Film-Coated Semiconductor Neutron Detectors for Active Dosimetry Monitors (open access)

High-Efficiency Thin-Film-Coated Semiconductor Neutron Detectors for Active Dosimetry Monitors

To develop a compact high-detection-efficiency neutron dosimeter capable of discerning between thermal and fast neutron doses in real time.
Date: December 31, 2009
Creator: Dunn, William L. & McGregor, Douglas
Object Type: Report
System: The UNT Digital Library
Caustic Recycle from Hanford Tank Waste Using Large Area NaSICON Structures (LANS) (open access)

Caustic Recycle from Hanford Tank Waste Using Large Area NaSICON Structures (LANS)

This report presents the results of a 5-day test of an electrochemical bench-scale apparatus using a proprietary (NAS-GY) material formulation of a (Na) Super Ion Conductor (NaSICON) membrane in a Large Area NaSICON Structures (LANS) configuration. The primary objectives of this work were to assess system performance, membrane seal integrity, and material degradation while removing Na from Group 5 and 6 tank waste from the Hanford Site.
Date: March 31, 2009
Creator: Fountain, Matthew S.; Sevigny, Gary J.; Balagopal, S. & Bhavaraju, S.
Object Type: Report
System: The UNT Digital Library
Microbial Fermentation of Abundant Biopolymers: Cellulose and Chitin (open access)

Microbial Fermentation of Abundant Biopolymers: Cellulose and Chitin

Our research has dealt with seven major areas of investigation: i) characterization of cellulolytic members of microbial consortia, with special attention recently given to Clostridium phytofermentans, a bacterium that decomposes cellulose and produces uncommonly large amounts of ethanol, ii) investigations of the chitinase system of Cellulomonas uda; including the purification and characterization of ChiA, the major component of this enzyme system, iii) molecular cloning, sequence and structural analysis of the gene that encodes ChiA in C. uda, iv) biofilm formation by C. uda on nutritive surfaces, v) investigations of the effects of humic substances on cellulose degradation by anaerobic cellulolytic microbes, vi) studies of nitrogen metabolism in cellulolytic anaerobes, and vii) understanding the molecular architecture of the multicomplex cellulase-xylanase system of Clostridium papyrosolvens. Also, progress toward completing the research of more recent projects is briefly summarized. Major accomplishments include: 1. Characterization of Clostridium phytofermentans, a cellulose-fermenting, ethanol-producing bacterium from forest soil. The characterization of a new cellulolytic species isolated from a cellulose-decomposing microbial consortium from forest soil was completed. This bacterium is remarkable for the high concentrations of ethanol produced during cellulose fermentation, typically more than twice the concentration produced by other species of cellulolytic clostridia. 2. Examination of the …
Date: October 31, 2009
Creator: Leschine, Susan
Object Type: Report
System: The UNT Digital Library
Relating D0-anti-D0 Mixing and D0 -> l l- with New Physics (open access)

Relating D0-anti-D0 Mixing and D0 -> l l- with New Physics

We point out how, in certain models of New Physics, the same combination of couplings occurs in the amplitudes for both D{sup 0}-{bar D}{sup 0} mixing and the rare decays D{sup 0} {yields} {ell}{sup +}{ell}{sup -}. If the New Physics dominates and is responsible for the observed mixing, then a very simple correlation exists between the magnitudes of each; in fact the rates for the decay D{sup 0} {yields} {ell}{sup +}{ell}{sup -} are completely fixed by the mixing. Observation of D{sup 0} {yields} {ell}{sup +}{ell}{sup -} in excess of the Standard Model prediction could identify New Physics contributions to D{sup 0}-{bar D}{sup 0} mixing.
Date: March 31, 2009
Creator: Golowich, Eugene; Hewett, JoAnne; Pakvasa, Sandip & Petrov, Alexey A.
Object Type: Article
System: The UNT Digital Library
The Hazard Review Board as an ISMS Key Process (open access)

The Hazard Review Board as an ISMS Key Process

None
Date: July 31, 2009
Creator: McEahern, P. M.
Object Type: Article
System: The UNT Digital Library