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Using Contingent Valuation to Explore Willingness to Pay forRenewable Energy: A Comparison of Collective and Voluntary PaymentVehicles (open access)
Relationships between walking and percentiles of adiposity inolder and younger men (open access)

Relationships between walking and percentiles of adiposity inolder and younger men

To assess the relationship of weekly walking distance to percentiles of adiposity in elders (age {ge} 75 years), seniors (55 {le} age <75 years), middle-age men (35 {le} age <55 years), and younger men (18 {le} age <35 years old). Cross-sectional analyses of baseline questionnaires from 7,082 male participants of the National Walkers Health Study. The walkers BMIs were inversely and significantly associated with walking distance (kg/m{sup 2} per km/wk) in elders (slope {+-} SE: -0.032 {+-} 0.008), seniors (-0.045 {+-} 0.005), and middle-aged men (-0.037 {+-} 0.007), as were their waist circumferences (-0.091 {+-} 0.025, -0.045 {+-} 0.005, and -0.091 {+-} 0.015 cm per km/wk, respectively), and these slopes remained significant when adjusted statistically for reported weekly servings of meat, fish, fruit, and alcohol. The declines in BMI associated with walking distance were greater at the higher than lower percentiles of the BMI distribution. Specifically, compared to the decline at the 10th BMI percentile, the decline in BMI at the 90th percentile was 5.1-fold greater in elders, 5.9-fold greater in seniors, and 6.7-fold greater in middle-age men. The declines in waist circumference associated with walking distance were also greater among men with broader waistlines. Exercise-induced weight loss (or self-selection) …
Date: June 1, 2005
Creator: Williams, Paul T.
System: The UNT Digital Library
A short model excitation of an asymmetric force free superconducting transmission line magnet (open access)

A short model excitation of an asymmetric force free superconducting transmission line magnet

A short model of asymmetric force free magnet with single beam aperture was tested at Fermilab together with the excitation test of VLHC transmission line magnet. The design concept of asymmetric force free superconducting magnet was verified by the test. The testing reached up to 104 kA current and no indication of force imbalance was observed. Since the model magnet length was only 10cm, A 0.75m model was constructed and tested at KEK with low current to ensure the validity of the design. The cool down and the excitation at KEK were also successful finding very small thermal contraction of the conductor and reasonable field homogeneity.
Date: September 1, 2005
Creator: Wake, M.; Sato, H.; Carcagno, R.; Foster, W.; Hays, S.; Kashikhin, V. et al.
System: The UNT Digital Library
Benchmarking and Self-Assessment in the Wine Industry (open access)

Benchmarking and Self-Assessment in the Wine Industry

Not all industrial facilities have the staff or theopportunity to perform a detailed audit of their operations. The lack ofknowledge of energy efficiency opportunities provides an importantbarrier to improving efficiency. Benchmarking programs in the U.S. andabroad have shown to improve knowledge of the energy performance ofindustrial facilities and buildings and to fuel energy managementpractices. Benchmarking provides a fair way to compare the energyintensity of plants, while accounting for structural differences (e.g.,the mix of products produced, climate conditions) between differentfacilities. In California, the winemaking industry is not only one of theeconomic pillars of the economy; it is also a large energy consumer, witha considerable potential for energy-efficiency improvement. LawrenceBerkeley National Laboratory and Fetzer Vineyards developed the firstbenchmarking tool for the California wine industry called "BEST(Benchmarking and Energy and water Savings Tool) Winery". BEST Wineryenables a winery to compare its energy efficiency to a best practicereference winery. Besides overall performance, the tool enables the userto evaluate the impact of implementing efficiency measures. The toolfacilitates strategic planning of efficiency measures, based on theestimated impact of the measures, their costs and savings. The tool willraise awareness of current energy intensities and offer an efficient wayto evaluate the impact of future efficiency measures.
Date: December 1, 2005
Creator: Galitsky, Christina; Radspieler, Anthony; Worrell, Ernst; Healy,Patrick & Zechiel, Susanne
System: The UNT Digital Library
Double Gap Alfvén Eigenmodes: Revisiting Eigenmodes Interaction with the Alfvén Continuum (open access)

Double Gap Alfvén Eigenmodes: Revisiting Eigenmodes Interaction with the Alfvén Continuum

A new type of global shear Alfvén Eigenmode is found in tokamak plasmas where the mode localization is in the region intersecting the Alfvén continuum. The eigenmode is formed by the coupling of two solutions from two adjacent gaps (akin to potential wells) in the shear Alfvén continuum. For tokamak plasmas with reversed magnetic shear it is shown that the toroidiciy-induced solution tunnels through the continuum to match the ellipticity-induced Alfvén eigenmode (TAE and EAE, respectively) so that the resulting solution is continuous at the point of resonance with the continuum. The existence of these Double Gap Alfvén Eigenmodes (DGAEs) allows for potentially new ways of coupling edge fields to the plasma core in conditions where the core region is conventionally considered inaccessible. Implications include new approaches to heating and current drive in fusion plasmas as well as its possible use as core diagnostic in burning plasmas.
Date: December 1, 2005
Creator: Gorelenkov, N. N.
System: The UNT Digital Library
Leaching of FGD Byproducts Using a CSTX (open access)

Leaching of FGD Byproducts Using a CSTX

Leaching studies of coal utilization byproducts (CUB) are often performed to determine the compatibility of the material in a particular end-use or disposal environment. Typically, these studies are conducted using either a batch or a fixed-bed column technique. Fixed-bed columns offer the advantage of a continuous flow of effluent that provides elution profiles with changing elution volume and pH. Unfortunately, clogs can form in fixed-bed leaching columns, either because of cementitious properties of the material itself, such as is seen for fluidized bed combustion (FBC) fly ash, or because of precipitate formation, such as can occur when a high-calcium ash is subjected to sulfate-containing leachates. Also, very fine-grained materials, such as gypsum, do not provide sufficient permeability for study in a fixed-bed column. A continuous, stirred-tank extractor (CSTX) is being used as an alternative technique that can provide the elution profile of column leaching but without the low permeability problems. The CSTX has been successfully employed in the leaching of flue gas desulfurization products that would not be sufficiently permeable under traditional column leaching conditions. The results indicate that the leaching behavior depends on a number of factors, including (but not limited to) solubility and neutralization capacity of the mineral …
Date: September 1, 2005
Creator: Kairies, C.L.; Schroeder, K.T. & Cardone, C.R.
System: The UNT Digital Library
Empirical Analysis of the Spot Market Implications ofPrice-Responsive Demand (open access)

Empirical Analysis of the Spot Market Implications ofPrice-Responsive Demand

Regardless of the form of restructuring, deregulatedelectricity industries share one common feature: the absence of anysignificant, rapid demand-side response to the wholesale (or, spotmarket) price. For a variety of reasons, most electricity consumers stillpay an average cost based regulated retail tariff held over from the eraof vertical integration, even as the retailers themselves are oftenforced to purchase electricity at volatile wholesale prices set in openmarkets. This results in considerable price risk for retailers, who aresometimes additionally forbidden by regulators from signing hedgingcontracts. More importantly, because end-users do not perceive real-time(or even hourly or daily) fluctuations in the wholesale price ofelectricity, they have no incentive to adjust their consumptionaccordingly. Consequently, demand for electricity is highly inelastic,which together with the non storability of electricity that requiresmarket clearing over very short time steps spawn many other problemsassociated with electricity markets, such as exercise of market power andprice volatility. Indeed, electricity generation resources can bestretched to the point where system adequacy is threatened. Economictheory suggests that even modest price responsiveness can relieve thestress on generation resources and decrease spot prices. To quantify thiseffect, actual generator bid data from the New York control area is usedto construct supply stacks and intersect them with demand curves …
Date: August 1, 2005
Creator: Siddiqui, Afzal S.; Bartholomew, Emily S. & Marnay, Chris
System: The UNT Digital Library
Effects of Overhangs on the Performance of ElectrochromicWindows (open access)

Effects of Overhangs on the Performance of ElectrochromicWindows

None
Date: December 1, 2005
Creator: Tavil, Aslihan & Lee, Eleanor S.
System: The UNT Digital Library
CO2 Sequestration in Unmineable Coal Seams: Potential Environmental Impacts (open access)

CO2 Sequestration in Unmineable Coal Seams: Potential Environmental Impacts

An initial investigation into the potential environmental impacts of CO2 sequestration in unmineable coal seams has been conducted, focusing on changes in the produced water during enhanced coalbed methane (ECBM) production using a CO2 injection process (CO2-ECBM). Two coals have been used in this study, the medium volatile bituminous Upper Freeport coal (APCS 1) of the Argonne Premium Coal Samples series, and an as-mined Pittsburgh #8 coal, which is a high volatile bituminous coal. Coal samples were reacted with either synthetic produced water or field collected produced water and gaseous carbon dioxide at 40 οC and 50 bar to evaluate the potential for mobilizing toxic metals during CO2-ECBM/sequestration. Microscopic and x-ray diffraction analysis of the post-reaction coal samples clearly show evidence of chemical reaction, and chemical analysis of the produced water shows substantial changes in composition. These results suggest that changes to the produced water chemistry and the potential for mobilizing toxic trace elements from coalbeds are important factors to be considered when evaluating deep, unmineable coal seams for CO2 sequestration.
Date: September 1, 2005
Creator: Hedges, S. W.; Soong, Yee; McCarthy Jones, J. R.; Harrison, D. K.; Irdi, G. A.; Frommell, E. A. et al.
System: The UNT Digital Library
The effect of unheated sections on moisture transport in theemplacement drift (open access)

The effect of unheated sections on moisture transport in theemplacement drift

A thermal-hydrologic-natural-ventilation model is configuredfor simulating temperature, humidity, and condensate distributions in thecoupled domains of the in-drift airspace and the near-field rockmass.Meaningful results are obtained from the model for a practicalapplication in which the beneficial effects of unheated drift sectionsare analyzed. Sensitivity to the axial dispersion coefficient is alsostudied with the model.
Date: September 1, 2005
Creator: Danko, G.; Birkholzer, J. & Barahmi, D.
System: The UNT Digital Library
2005 DOE Hydrogen Program Review PresentationCOST AND PERFORMANCE ENHANCEMENTS FOR A PEM FUEL CELL TURBOCOMPRESSOR (open access)

2005 DOE Hydrogen Program Review PresentationCOST AND PERFORMANCE ENHANCEMENTS FOR A PEM FUEL CELL TURBOCOMPRESSOR

The objectives of the program during the past year was to complete Technical Objectives 2 and 3 and initiate Technical Objective 4 are described. To assist the Department of Energy in the development of a low cost, reliable and high performance air compressor/expander. Technical Objective 1: Perform a turbocompressor systems PEM fuel cell trade study to determine the enhanced turbocompressor approach. Technical Objective 2: Using the results from technical objective 1, an enhanced turbocompressor will be fabricated. The design may be modified to match the flow requirements of a selected fuel cell system developer. Technical Objective 3: Design a cost and performance enhanced compact motor and motor controller. Technical Objective 4: Turbocompressor/motor controller development.
Date: April 1, 2005
Creator: Gee, Mark K.
System: The UNT Digital Library
Large releases from CO2 storage reservoirs: analogs, scenarios,and modeling needs (open access)

Large releases from CO2 storage reservoirs: analogs, scenarios,and modeling needs

While the purpose of geologic storage in deep salineformations is to trap greenhouse gases underground, the potential existsfor CO2 to escape from the target reservoir, migrate upward alongpermeable pathways, and discharge at the land surface. In this paper, weevaluate the potential for such CO2 discharges based on the analysis ofnatural analogs, where large releases of gas have been observed. We areparticularly interested in circumstances that could generate sudden,possibly self-enhancing release events. The probability for such eventsmay be low, but the circumstances under which they occur and thepotential consequences need to be evaluated in order to designappropriate site-selection and risk-management strategies. Numericalmodeling of hypothetical test cases is suggested to determine criticalconditions for large CO2 releases, to evaluate whether such conditionsmaybe possible at designated storage sites, and, if applicable, toevaluate the potential impacts of such events as well as designappropriate mitigation strategies.
Date: September 1, 2005
Creator: Birkholzer, Jens; Pruess, Karsten; Lewicki, Jennifer; Rutqvist,Jonny; Tsang, Chin-Fu & Karimjee, Anhar
System: The UNT Digital Library
Performance of Ultra-Scale Applications on Leading Vector andScalar HPC Platforms (open access)

Performance of Ultra-Scale Applications on Leading Vector andScalar HPC Platforms

The last decade has witnessed a rapid proliferation of superscalar cache-based microprocessors to build high-end capability and capacity computers primarily because of their generality, scalability, and cost effectiveness. However, the constant degradation of superscalar sustained performance, has become a well-known problem in the scientific computing community. This trend has been widely attributed to the use of superscalar-based commodity components who's architectural designs offer a balance between memory performance, network capability, and execution rate that is poorly matched to the requirements of large-scale numerical computations. The recent development of massively parallel vector systems offers the potential to increase the performance gap for many important classes of algorithms. In this study we examine four diverse scientific applications with the potential to run at ultrascale, from the areas of plasma physics, material science, astrophysics, and magnetic fusion. We compare performance between the vector-based Earth Simulator (ES) and Cray X1, with leading superscalar-based platforms: the IBM Power3/4 and the SGI Altix. Results demonstrate that the ES vector systems achieve excellent performance on our application suite - the highest of any architecture tested to date.
Date: January 1, 2005
Creator: Oliker, Leonid; Canning, Andrew; Carter, Jonathan Carter; Shalf,John; Simon, Horst; Ethier, Stephane et al.
System: The UNT Digital Library
Biomimetic bonelike composites and novel bioactive glasscoatings (open access)

Biomimetic bonelike composites and novel bioactive glasscoatings

Metallic orthopaedic implants have been successfully used for decades but they have serious shortcomings related to their osseointegration and the fact that their mechanical properties do not match those of bone. This paper reviews recent advances in the fabrication of novel coatings to improve implant osseointegration and in the development of a new generation of hybrid organic-inorganic implant materials specifically designed for orthopaedic applications.
Date: June 1, 2005
Creator: Tomsia, A.P.; Saiz, E.; Song, J. & Bertozzi, C.R.
System: The UNT Digital Library
Effective Supergravity from the Weakly Coupled HeteroticString (open access)

Effective Supergravity from the Weakly Coupled HeteroticString

The motivation for Calabi-Yau-like compactifications of the weakly coupled E{sub 8} {circle_times} E{sub 8} heterotic string theory, its particle spectrum and the issue of dilaton stabilization are briefly reviewed. Modular invariant models for hidden sector condensation and supersymmetry breaking are described at the quantum level of the effective field theory. Their phenomenological and cosmological implications, including a possible origin for R-parity, are discussed.
Date: May 1, 2005
Creator: Gaillard, Mary K.
System: The UNT Digital Library
Effect of habitat and foraging height on bat activity in the coastal plain of South Carolina. (open access)

Effect of habitat and foraging height on bat activity in the coastal plain of South Carolina.

A comparison of bat activity levels in the Coastal Plain of South Carolina among 5 habitat types: forested riparian areas, clearcuts, young pine plantations, mature pine plantations and pine savannas, using time expansion radio-microphones and integrated detectors to simultaneously monitor bat activity at three heights in each habitat type.
Date: July 1, 2005
Creator: Menzel, Jennifer, M.; Menzel, Michael A.; Kilgo, John C.; Ford, W. Mark; Edwards, John W. & McCracken, Gary F.
System: The UNT Digital Library
Can Deployment of Renewable Energy and Energy Efficiency PutDownward Pressure on Natural Gas Prices (open access)

Can Deployment of Renewable Energy and Energy Efficiency PutDownward Pressure on Natural Gas Prices

High and volatile natural gas prices have increasingly led to calls for investments in renewable energy and energy efficiency. One line of argument is that deployment of these resources may lead to reductions in the demand for and price of natural gas. Many recent U.S.-based modeling studies have demonstrated that this effect could provide significant consumer savings. In this article we evaluate these studies, and benchmark their findings against economic theory, other modeling results, and a limited empirical literature. We find that many uncertainties remain regarding the absolute magnitude of this effect, and that the reduction in natural gas prices may not represent an increase in aggregate economic wealth. Nonetheless, we conclude that many of the studies of the impact of renewable energy and energy efficiency on natural gas prices appear to have represented this effect within reason, given current knowledge. These studies specifically suggest that a 1% reduction in U.S. natural gas demand could lead to long-term average wellhead price reductions of 0.8% to 2%, and that each megawatt-hour of renewable energy and energy efficiency may benefit natural gas consumers to the tune of at least $7.5 to $20.
Date: June 1, 2005
Creator: Wiser, Ryan & Bolinger, Mark
System: The UNT Digital Library
Essential Grid Workflow Monitoring Elements (open access)

Essential Grid Workflow Monitoring Elements

Troubleshooting Grid workflows is difficult. A typicalworkflow involves a large number of components networks, middleware,hosts, etc. that can fail. Even when monitoring data from all thesecomponents is accessible, it is hard to tell whether failures andanomalies in these components are related toa given workflow. For theGrid to be truly usable, much of this uncertainty must be elim- inated.We propose two new Grid monitoring elements, Grid workflow identifiersand consistent component lifecycle events, that will make Gridtroubleshooting easier, and thus make Grids more usable, by simplifyingthe correlation of Grid monitoring data with a particular Gridworkflow.
Date: July 1, 2005
Creator: Gunter, Daniel K.; Jackson, Keith R.; Konerding, David E.; Lee,Jason R. & Tierney, Brian L.
System: The UNT Digital Library
Continual Non-Condensable Gas Removal Testing -- Performance and Lessons Learned (open access)

Continual Non-Condensable Gas Removal Testing -- Performance and Lessons Learned

The operating experience and plant benefit analysis of a membrane-based continuous non-condensable gas (NCG) removal system is discussed. Results from testing at the Mammoth Pacific (Ormat) geothermal plant provide the basis for the benefit analysis.
Date: September 1, 2005
Creator: Mohr, Charles & Mines, Greg
System: The UNT Digital Library
Mechanical Analysis of the Nb3Sn Dipole Magnet HD1 (open access)

Mechanical Analysis of the Nb3Sn Dipole Magnet HD1

The Superconducting Magnet Group at Lawrence Berkeley National Laboratory (LBNL) has recently fabricated and tested HD1, a Nb3Sn dipole magnet. The magnet reached a 16 T field, and exhibited training quenches in the end regions and in the straight section. After the test, HD1 was disassembled and inspected, and a detailed 3D finite element mechanical analysis was done to investigate for possible quench triggers. The study led to minor modifications to mechanical structure and assembly procedure, which were verified in a second test (HD1b). This paper presents the results of the mechanical analysis, including strain gauge measurements and coil visual inspection. The adjustments implemented in the magnet structure are reported and their effect on magnet training discussed.
Date: June 1, 2005
Creator: Ferracin, Paolo; Bartlett, Scott E.; Caspi, Shlomo; Dietderich, Daniel R.; Gourlay, Steve A.; Hannaford, Charles R. et al.
System: The UNT Digital Library
PCC2005 Sample (open access)

PCC2005 Sample

Considered herein is a process concept that integrates fly ash amendment of brine produced as a result of oil and gas extraction with subsequent sequestration of carbon dioxide in the resulting alkaline solution. The CO2 solubility-trapping capacity of the alkaline mixture is substantially greater than that of the acidic raw brine. In addition to pH adjustment, addition of CaO-rich combustion byproduct augments the concentration of Ca++ cations initially present in the brine to increase solution capacity for mineral trapping of CO2. One- and two-stage approaches for implementation of this treatment process were considered. Batch reactions were conducted with several Class C fly ashes and one flue gas desulfurization (FGD) byproduct. Preliminary results verify the potential to substantially enhance CO2 sequestration capacity and increase mineral sequestration of absorbed CO2, primarily as CaCO3. Feasibility of the described CO2 sequestration treatment concept was, therefore, successfully demonstrated.
Date: September 1, 2005
Creator: unknown
System: The UNT Digital Library
Development of Damp-Heat Resistant Self-Primed EVA and Non-EVA Encapsulant Formulations at NREL (open access)

Development of Damp-Heat Resistant Self-Primed EVA and Non-EVA Encapsulant Formulations at NREL

Self-primed ethylene-vinyl acetate (EVA) and non-EVA (PMG) encapsulant formulations were developed that have greater resistance to damp heat exposure at 85 deg C and 85% relative humidity (RH) (in terms of adhesion strength to glass substrates) than a commonly used commercial EVA product. The self-primed EVA formulations were developed on the basis of high-performing glass priming formulations that have previously proven to significantly enhance the adhesion strength of unprimed and primed EVA films on glass substrates during damp heat exposure. The PMG encapsulant formulations were based on an ethylene-methylacrylate copolymer containing glycidyl methacrylate.
Date: November 1, 2005
Creator: Pern, F. J. & Jorgensen, G. J.
System: The UNT Digital Library
III-V Growth on Silicon Toward a Multijunction Cell (open access)

III-V Growth on Silicon Toward a Multijunction Cell

A III-V on Si multijunction solar cell promises high efficiency at relatively low cost. The challenges to epitaxial growth of high-quality III-Vs on Si, though, are extensive. Lattice-matched (LM) dilute-nitride GaNPAs solar cells have been grown on Si, but their performance is limited by defects related to the nitrogen. Advances in the growth of lattice-mismatched (LMM) materials make more traditional III-Vs, such as GaInP and GaAsP, very attractive for use in multijunction solar cells on silicon.
Date: November 1, 2005
Creator: Geisz, J.; Olson, J.; McMahon, W.; Friedman, D.; Kibbler, A.; Kramer, C. et al.
System: The UNT Digital Library
American Material Culture: Investigating a World War II Trash Dump (open access)

American Material Culture: Investigating a World War II Trash Dump

The Idaho National Laboratory: An Historical Trash Trove Historians and archaeologists love trash, the older the better. Sometimes these researchers find their passion in unexpected places. In this presentation, the treasures found in a large historic dump that lies relatively untouched in the middle of the Idaho National Laboratory (INL) will be described. The U.S. military used the central portion of the INL as one of only six naval proving grounds during World War II. They dumped trash in dry irrigation canals during and after their wartime activities and shortly before the federal government designated this arid and desolate place as the nation’s nuclear reactor testing station in 1949. When read critically and combined with memories and photographs, the 60-year old trash provides a glimpse into 1940s’ culture and the everyday lives of ordinary people who lived and worked during this time on Idaho’s desert. Thanks to priceless stories, hours of research, and the ability to read the language of historic artifacts, the dump was turned from just another trash heap into a treasure trove of 1940s memorabilia. Such studies of American material culture serve to fire our imaginations, enrich our understanding of past practices, and humanize history. Historical archaeology …
Date: October 1, 2005
Creator: Braun, Julie
System: The UNT Digital Library