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446 Matching Results
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Utilization of Partially Gasified Coal for Mercury Removal
In this project, General Electric Energy and Environmental Research Corporation (EER) developed a novel mercury (Hg) control technology in which the sorbent for gas-phase Hg removal is produced from coal in a gasification process in-situ at a coal burning plant. The main objective of this project was to obtain technical information necessary for moving the technology from pilot-scale testing to a full-scale demonstration. A pilot-scale gasifier was used to generate sorbents from both bituminous and subbituminous coals. Once the conditions for optimizing sorbent surface area were identified, sorbents with the highest surface area were tested in a pilot-scale combustion tunnel for their effectiveness in removing Hg from coal-based flue gas. It was determined that the highest surface area sorbents generated from the gasifier process ({approx}600 m{sup 2}/g) had about 70%-85% of the reactivity of activated carbon at the same injection rate (lb/ACF), but were effective in removing 70% mercury at injection rates about 50% higher than that of commercially available activated carbon. In addition, mercury removal rates of up to 95% were demonstrated at higher sorbent injection rates. Overall, the results of the pilot-scale tests achieved the program goals, which were to achieve at least 70% Hg removal from baseline …
Date:
September 9, 2008
Creator:
Samuelson, Chris; Maly, Peter & Moyeda, David
Object Type:
Report
System:
The UNT Digital Library
QUANTIFYING UNCERTAINTIES IN GROUND MOTION SIMULATIONS FOR SCENARIO EARTHQUAKES ON THE HAYWARD-RODGERS CREEK FAULT SYSTEM USING THE USGS 3D VELOCITY MODEL AND REALISTIC PSEUDODYNAMIC RUPTURE MODELS
This project seeks to compute ground motions for large (M>6.5) scenario earthquakes on the Hayward Fault using realistic pseudodynamic ruptures, the USGS three-dimensional (3D) velocity model and anelastic finite difference simulations on parallel computers. We will attempt to bound ground motions by performing simulations with suites of stochastic rupture models for a given scenario on a given fault segment. The outcome of this effort will provide the average, spread and range of ground motions that can be expected from likely large earthquake scenarios. The resulting ground motions will be based on first-principles calculations and include the effects of slip heterogeneity, fault geometry and directivity, however, they will be band-limited to relatively low-frequency (< 1 Hz).
Date:
January 9, 2008
Creator:
Rodgers, A & Xie, X
Object Type:
Article
System:
The UNT Digital Library
DEVELOPMENT OF AG-1 SECTION FI ON METAL MEDIA FILTERS - 9061
Development of a metal media standard (FI) for ASME AG-1 (Code on Nuclear Air and Gas Treatment) has been under way for almost ten years. This paper will provide a brief history of the development process of this section and a detailed overview of its current content/status. There have been at least two points when dramatic changes have been made in the scope of the document due to feedback from the full Committee on Nuclear Air and Gas Treatment (CONAGT). Development of the proposed section has required resolving several difficult issues associated with scope; namely, filtering efficiency, operating conditions (media velocity, pressure drop, etc.), qualification testing, and quality control/acceptance testing. A proposed version of Section FI is currently undergoing final revisions prior to being submitted for balloting. The section covers metal media filters of filtering efficiencies ranging from medium (less than 99.97%) to high (99.97% and greater). Two different types of high efficiency filters are addressed; those units intended to be a direct replacement of Section FC fibrous glass HEPA filters and those that will be placed into newly designed systems capable of supporting greater static pressures and differential pressures across the filter elements. Direct replacements of FC HEPA filters …
Date:
December 9, 2008
Creator:
Adamson, D & Charles A. Waggoner, C
Object Type:
Article
System:
The UNT Digital Library
Work Plan: Targeted Investigation to Assess Current Conditions Associated With the Carbon Tetrachloride Plume Downgradient From the Former CCC/Usda Facility at Milford, Nebraska.
The Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) formerly operated a grain storage facility at Milford, Nebraska. In May 2008, the CCC/USDA directed the Environmental Science Division of Argonne National Laboratory, as its technical consultant, to develop a work plan for a targeted investigation at the Milford site. The purpose of the targeted investigation is to assess the current extent and configuration of the carbon tetrachloride plume downgradient from the former CCC/USDA facility and proximal to the banks of the Big Blue River, which borders the area of concern to the east, southeast, and northeast. In 1995, carbon tetrachloride contamination was detected by the Nebraska Department of Health and Human Services in a private drinking water well and a livestock well 1.25 mi south of Milford (Figure 1.1). The Trojan drinking water well is located directly downgradient (approximately 300 ft east) of the former CCC/USDA facility. Low levels of carbon tetrachloride contamination were also found in the Troyer livestock well, approximately 1,200 ft north of the former CCC/USDA facility.
Date:
July 9, 2008
Creator:
LaFreniere, L. M.
Object Type:
Report
System:
The UNT Digital Library
Automated Structure Solution with the PHENIX Suite
Significant time and effort are often required to solve and complete a macromolecular crystal structure. The development of automated computational methods for the analysis, solution and completion of crystallographic structures has the potential to produce minimally biased models in a short time without the need for manual intervention. The PHENIX software suite is a highly automated system for macromolecular structure determination that can rapidly arrive at an initial partial model of a structure without significant human intervention, given moderate resolution and good quality data. This achievement has been made possible by the development of new algorithms for structure determination, maximum-likelihood molecular replacement (PHASER), heavy-atom search (HySS), template and pattern-based automated model-building (RESOLVE, TEXTAL), automated macromolecular refinement (phenix.refine), and iterative model-building, density modification and refinement that can operate at moderate resolution (RESOLVE, AutoBuild). These algorithms are based on a highly integrated and comprehensive set of crystallographic libraries that have been built and made available to the community. The algorithms are tightly linked and made easily accessible to users through the PHENIX Wizards and the PHENIX GUI.
Date:
June 9, 2008
Creator:
Zwart, Peter H.; Zwart, Peter H.; Afonine, Pavel; Grosse-Kunstleve, Ralf W.; Hung, Li-Wei; Ioerger, Tom R. et al.
Object Type:
Book
System:
The UNT Digital Library
Acquisition of Single Crystal Growth and Characterization Equipment
Final Report for DOE Grant No. DE-FG02-04ER46178 'Acquisition of Single Crystal Growth and Characterization Equipment'. There is growing concern in the condensed matter community that the need for quality crystal growth and materials preparation laboratories is not being met in the United States. It has been suggested that there are too many researchers performing measurements on too few materials. As a result, many user facilities are not being used optimally. The number of proficient crystal growers is too small. In addition, insufficient attention is being paid to the enterprise of finding new and interesting materials, which is the driving force behind much of condensed matter research and, ultimately, technology. While a detailed assessment of this situation is clearly needed, enough evidence of a problem already exists to compel a general consensus that the situation must be addressed promptly. This final report describes the work carried out during the last four years in our group, in which a state-of-the-art single crystal growth and characterization facility was established for the study of novel oxides and intermetallic compounds of rare earth, actinide and transition metal elements. Research emphasis is on the physics of superconducting (SC), magnetic, heavy fermion (HF), non-Fermi liquid (NFL) and …
Date:
December 9, 2008
Creator:
Maple, M. Brian & Zocco, Diego A.
Object Type:
Report
System:
The UNT Digital Library
Mass Models and Environment of the New Quadruply Lensed Quasar SDSS J1330+1810
We present the discovery of a new quadruply lensed quasar. The lens system, SDSS J1330+1810 at z{sub s} = 1.393, was identified as a lens candidate from the spectroscopic sample of the Sloan Digital Sky Survey. Optical and near-infrared images clearly show four quasar images with a maximum image separation of 1.76 inch, as well as a bright lensing galaxy. We measure a redshift of the lensing galaxy of z{sub 1} = 0.373 from absorption features in the spectrum. We find a foreground group of galaxies at z = 0.31 centred {approx} 120 inch southwest of the lens system. Simple mass models fit the data quite well, including the flux ratios between images, although the lens galaxy appears to be {approx} 1 mag brighter than expected by the Faber-Jackson relation. Our mass modeling suggests that shear from nearby structure is affecting the lens potential.
Date:
September 9, 2008
Creator:
Oguri, Masamune; Inada, Naohisa; Blackburne, Jeffrey A.; Shin, Min-Su; Kayo, Issha; Strauss, Michael A. et al.
Object Type:
Article
System:
The UNT Digital Library
Nucleosynthesis in Early Neutrino Driven Winds
Two recent issues related to nucleosynthesis in early proton-rich neutrino winds are investigated. In the first part we investigate the effect of nuclear physics uncertainties on the synthesis of {sup 92}Mo and {sup 94}Mo. Based on recent experimental results, we find that the proton rich winds of the model investigated here can not be the only source of the solar abundance of {sup 92}Mo and {sup 94}Mo. In the second part we investigate the nucleosynthesis from neutron rich bubbles and show that they do not contribute to the nucleosynthesis integrated over both neutron and proton-rich bubbles and proton-rich winds.
Date:
January 9, 2008
Creator:
Hoffman, R; Fisker, J; Pruet, J; Woosley, S; Janka, H & Buras, R
Object Type:
Article
System:
The UNT Digital Library
FLUID TRANSIENTS IN A PIPELINE WITH ONE END OPEN
Water hammer during multi-phase flow is rather complex, but in some cases an upper limit to the pressure surge magnitude during water hammer can be estimated. In the case considered here, a two mile long pipeline with a single high point was permitted to partially drain. Due to gravitational effects, air bubbles up through the pipe line to its highest point, but the time required for air to reach the top of the pipe is rather long. Consequently, some transients caused by valve operations are affected by air entrapment and some are not. The intent of this research was to investigate the complex interactions between air, water vapor, and liquid during water hammer in a long pipe with one end of the pipe open to atmospheric conditions. To understand the system dynamics, experimental data was obtained from a long pipeline with an open end and also from a short, transparent tube. Transient calculations were performed for valve closures and pump operations as applicable. The limitations of available calculation techniques were considered in detail.
Date:
June 9, 2008
Creator:
Leishear, R
Object Type:
Article
System:
The UNT Digital Library
Pacific Northwest GridWise™ Testbed Demonstration Projects; Part I. Olympic Peninsula Project
This report describes the implementation and results of a field demonstration wherein residential electric water heaters and thermostats, commercial building space conditioning, municipal water pump loads, and several distributed generators were coordinated to manage constrained feeder electrical distribution through the two-way communication of load status and electric price signals. The field demonstration took place in Washington and Oregon and was paid for by the U.S. Department of Energy and several northwest utilities. Price is found to be an effective control signal for managing transmission or distribution congestion. Real-time signals at 5-minute intervals are shown to shift controlled load in time. The behaviors of customers and their responses under fixed, time-of-use, and real-time price contracts are compared. Peak loads are effectively reduced on the experimental feeder. A novel application of portfolio theory is applied to the selection of an optimal mix of customer contract types.
Date:
January 9, 2008
Creator:
Hammerstrom, Donald J.; Ambrosio, Ron; Carlon, Teresa A.; DeSteese, John G.; Horst, Gale R.; Kajfasz, Robert et al.
Object Type:
Report
System:
The UNT Digital Library
2007 Annual Health Physics Report for the HEU Transparency Program
During the 2007 calendar year, Lawrence Livermore National Laboratory (LLNL) provided health physics support for the Highly Enriched Uranium (HEU) Transparency Program for external and internal radiation protection and technical expertise related to BDMS radioactive sources and Russian radiation safety regulatory compliance. For the calendar year 2007, there were 172 person-trips that required dose monitoring of the U.S. monitors. Of the 172 person-trips, 160 person-trips were SMVs and 12 person-trips were Transparency Monitoring Office (TMO) trips. There were 12 monitoring visits by TMO monitors to facilities other than UEIE and 10 to UEIE itself. There were two monitoring visits (source changes) that were back to back with 14 monitors. LLNL's Hazard Control Division laboratories provided the dosimetry services for the HEU Transparency monitors.
Date:
April 9, 2008
Creator:
Radev, R
Object Type:
Report
System:
The UNT Digital Library
New Prospects for High-energy Neutrinos from gamma-ray Bursts
High-energy neutrinos from Gamma-Ray Bursts (GRBs) have been expected since the pre-Swift era. Such signals may be detected by future large neutrino detectors such as IceCube. Recently Swift has shown several novel phenomena. We suggest the new prospects for high-energy neutrino emission in the Swift era. Expected signals, if detected, are useful for revealing of the nature of GRBs.
Date:
January 9, 2008
Creator:
Murase, K.; /Kyoto U., Yukawa Inst., Kyoto; Nagataki, S. & /KIPAC, Menlo Park
Object Type:
Article
System:
The UNT Digital Library
Soft X-Ray Magnetic Imaging of Focused Ion Beam Lithographically Patterned Fe Thin Films
We illustrate the potential of modifying the magnetic behavior and structural properties of ferromagnetic thin films using focused ion beam 'direct-write' lithography. Patterns inspired by the split-ring resonators often used as components in meta-materials were defined upon 15 nm Fe films using a 30 keV Ga{sup +} focused ion beam at a dose of 2 x 10{sup 16} ions cm{sup -2}. Structural, chemical and magnetic changes to the Fe were studied using transmission soft X-ray microscopy at the ALS, Berkeley CA. X-ray absorption spectra showed a 23% reduction in the thickness of the film in the Ga irradiated areas, but no change to the chemical environment of Fe was evident. X-ray images of the magnetic reversal process show domain wall pinning around the implanted areas, resulting in an overall increase in the coercivity of the film. Transmission electron microscopy showed significant grain growth in the implanted regions.
Date:
November 9, 2008
Creator:
Cook, Paul J.; Shen, Tichan H.; Grundy, PhilJ.; Im, Mi Young; Fischer, Peter; Morton, Simon A. et al.
Object Type:
Article
System:
The UNT Digital Library
A Kinetic Modeling study on the Oxidation of Primary Reference Fuel?Toluene Mixtures Including Cross Reactions between Aromatics and Aliphatics
A detailed chemical kinetic model for the mixtures of Primary Reference Fuel (PRF: n-heptane and iso-octane) and toluene has been proposed. This model is divided into three parts; a PRF mechanism [T. Ogura et al., Energy & Fuels 21 (2007) 3233-3239], toluene sub-mechanism and cross reactions between PRF and toluene. Toluene sub-mechanism includes the low temperature kinetics relevant to engine conditions. A chemical kinetic mechanism proposed by Pitz et al. [Proc. the 2nd Joint Meeting of the U.S. Combust. Institute (2001)] was used as a starting model and modified by updating rate coefficients. Theoretical estimations of rate coefficients were performed for toluene and benzyl radical reactions important at low temperatures. Cross-reactions between alkane, alkene, and aromatics were also included in order to account for the acceleration by the addition of toluene into iso-octane recently found in the shock tube study of the ignition delay [Y. Sakai et al, SAE 2007-01-4014 (2007)]. Validations of the model were performed with existing shock tube and flow tube data. The model well predicts the ignition characteristics of toluene and PRF/Toluene mixtures under the wide range of temperatures (500-1700 K) and pressures (2-50 atm). It is found that reactions of benzyl radical with oxygen molecule …
Date:
January 9, 2008
Creator:
Sakai, Y.; Miyoshi, A.; Koshi, M. & Pitz, W. J.
Object Type:
Article
System:
The UNT Digital Library
Technology Review of Nondestructive Methods for Examination of Water Intrusion Areas on Hanford’s Double-Shell Waste Tanks
Under a contract with CH2M Hill Hanford Group, Inc., PNNL has performed a review of the NDE technology and methods for examination of the concrete dome structure of Hanford’s double-shell tanks. The objective was to provide a matrix of methodologies that could be evaluated based on applicability, ease of deployment, and results that could provide information that could be used in the ongoing structural analysis of the tank dome. PNNL performed a technology evaluation with the objective of providing a critical literature review for all applicable technologies based on constraints provided by CH2M HILL. These constraints were not mandatory, but were desired. These constraints included performing the evaluation without removing any soil from the top of the tank, or if necessary, requesting that the hole diameter needed to gain access to evaluate the top of the tank structure to be no greater than approximately 12-in. in diameter. PNNL did not address the details of statistical sampling requirements as they depend on an unspecified risk tolerance. PNNL considered these during the technology evaluation and have reported the results in the remainder of this document. Many of the basic approaches to concrete inspection that were reviewed in previous efforts are still in …
Date:
May 9, 2008
Creator:
Watkins, Michael L. & Pardini, Allan F.
Object Type:
Report
System:
The UNT Digital Library
Renewable Portfolio Standards in the United States - A Status Report with Data Through 2007
Renewables portfolio standards (RPS) have proliferated at the state level in the United States since the late 1990s. In combination with Federal tax incentives, state RPS requirements have emerged as one of the most important drivers of renewable energy capacity additions. The focus of most RPS activity in the U.S. has been within the states. Nonetheless, the U.S. House of Representatives and Senate have, at different times, each passed versions of a Federal RPS; a Federal RPS, however, has not yet been signed into law. The design of an RPS can and does vary, but at its heart an RPS simply requires retail electricity suppliers (also called load-serving entities, or LSEs) to procure a certain minimum quantity of eligible renewable energy. An RPS establishes numeric targets for renewable energy supply, applies those targets to retail electricity suppliers, and seeks to encourage competition among renewable developers to meet the targets in a least-cost fashion. RPS purchase obligations generally increase over time, and retail suppliers typically must demonstrate compliance on an annual basis. Mandatory RPS policies are backed by various types of compliance enforcement mechanisms, and many--but not all--such policies include the trading of renewable energy certificates (RECs). Renewables portfolio standards are …
Date:
April 9, 2008
Creator:
Wiser, Ryan; Wiser, Ryan; Barbose, Galen; Bird, Lori; Churchill, Susannah; Deyette, Jeff et al.
Object Type:
Report
System:
The UNT Digital Library
Vacuum Systems Consensus Guideline for Department of Energy Accelerator Laboratories
Vacuum vessels, including evacuated chambers and insulated jacketed dewars, can pose a potential hazard to equipment and personnel from collapse, rupture due to back-fill pressurization, or implosion due to vacuum window failure. It is therefore important to design and operate vacuum systems in accordance with applicable and sound engineering principles. 10 CFR 851 defines requirements for pressure systems that also apply to vacuum vessels subject to back-fill pressurization. Such vacuum vessels are potentially subject to the requirements of the American Society of Mechanical Engineers (ASME) Pressure Vessel Code Section VIII (hereafter referred to as the 'Code'). However, the scope of the Code excludes vessels with internal or external operating pressure that do not exceed 15 pounds per square inch gauge (psig). Therefore, the requirements of the Code do not apply to vacuum systems provided that adequate pressure relief assures that the maximum internal pressure within the vacuum vessel is limited to less than 15 psig from all credible pressure sources, including failure scenarios. Vacuum vessels that cannot be protected from pressurization exceeding 15 psig are subject to the requirements of the Code. 10 CFR 851, Appendix A, Part 4, Pressure Safety, Section C addresses vacuum system requirements for such cases …
Date:
September 9, 2008
Creator:
Casey,R.; Haas, E.; Hseuh, H. C.; Kane, S.; Lessard, E.; Sharma, S. et al.
Object Type:
Report
System:
The UNT Digital Library
Greensheet (Houston, Tex.), Vol. 39, No. 374, Ed. 1 Tuesday, September 9, 2008
Free weekly newspaper that includes business and classified advertising.
Date:
September 9, 2008
Creator:
unknown
Object Type:
Newspaper
System:
The Portal to Texas History
Greensheet (Houston, Tex.), Vol. 39, No. 166, Ed. 1 Friday, May 9, 2008
Free weekly newspaper that includes business and classified advertising.
Date:
May 9, 2008
Creator:
unknown
Object Type:
Newspaper
System:
The Portal to Texas History
Greensheet (Houston, Tex.), Vol. 39, No. 529, Ed. 1 Tuesday, December 9, 2008
Free weekly newspaper that includes business and classified advertising.
Date:
December 9, 2008
Creator:
unknown
Object Type:
Newspaper
System:
The Portal to Texas History
Greensheet (Houston, Tex.), Vol. 39, No. 270, Ed. 1 Wednesday, July 9, 2008
Free weekly newspaper that includes business and classified advertising.
Date:
July 9, 2008
Creator:
unknown
Object Type:
Newspaper
System:
The Portal to Texas History
Greensheet (Houston, Tex.), Vol. 39, No. 114, Ed. 1 Wednesday, April 9, 2008
Free weekly newspaper that includes business and classified advertising.
Date:
April 9, 2008
Creator:
unknown
Object Type:
Newspaper
System:
The Portal to Texas History
Greensheet (Houston, Tex.), Vol. 39, No. 429, Ed. 1 Thursday, October 9, 2008
Free weekly newspaper that includes business and classified advertising.
Date:
October 9, 2008
Creator:
unknown
Object Type:
Newspaper
System:
The Portal to Texas History
Greensheet (Houston, Tex.), Vol. 39, No. 373, Ed. 1 Tuesday, September 9, 2008
Free weekly newspaper that includes business and classified advertising.
Date:
September 9, 2008
Creator:
unknown
Object Type:
Newspaper
System:
The Portal to Texas History