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Comparing Statewide Economic Impacts of New Generation from Wind, Coal, and Natural Gas in Arizona, Colorado, and Michigan: Preprint (open access)

Comparing Statewide Economic Impacts of New Generation from Wind, Coal, and Natural Gas in Arizona, Colorado, and Michigan: Preprint

With increasing concerns about energy independence, job outsourcing, and risks of global climate change, it is important for policy makers to understand all impacts from their decisions about energy resources. This paper assesses one aspect of the impacts: direct economic effects. The paper compares impacts to states from equivalent new electrical generation from wind, natural gas, and coal. Economic impacts include materials and labor for construction, operations, maintenance, fuel extraction, and fuel transport, as well as project financing, property tax, and landowner revenues. We examine spending on plant construction during construction years, in addition to all other operational expenditures over a 20-year span. Initial results indicate that adding new wind power can be more economically effective than adding new gas or coal power, and that a higher percentage of dollars spent on coal and gas will leave the state. For this report, we interviewed industry representatives and energy experts, in addition to consulting government documents, models, and existing literature. The methodology for this research can be adapted to other contexts for determining economic effects of new power generation in other states and regions.
Date: August 1, 2005
Creator: Tegen, S.
System: The UNT Digital Library
Cost Analysis of a Concentrator Photovoltaic Hydrogen Production System (open access)

Cost Analysis of a Concentrator Photovoltaic Hydrogen Production System

The development of efficient, renewable methods of producing hydrogen are essential for the success of the hydrogen economy. Since the feedstock for electrolysis is water, there are no harmful pollutants emitted during the use of the fuel. Furthermore, it has become evident that concentrator photovoltaic (CPV) systems have a number of unique attributes that could shortcut the development process, and increase the efficiency of hydrogen production to a point where economics will then drive the commercial development to mass scale.
Date: August 1, 2005
Creator: Thompson, Jamal R.; McConnell, Robert D. & Mosleh, Mohsen
System: The UNT Digital Library
The Rare decay K+ ---> pi+ nu anti-nu at the next-to-next-to-leading order in QCD (open access)

The Rare decay K+ ---> pi+ nu anti-nu at the next-to-next-to-leading order in QCD

The authors calculate the complete next-to-next-to-leading order QCD correction of the charm quark contribution to the branching ratio for the rare decay K{sup +} {yields} {pi}{sup +}{nu}{bar {nu}} in the standard model. The inclusion of these {Omicron}({alpha}{sub s}) contributions leads to a significant reduction of the theoretical uncertainty from {+-} 10.1% down to {+-} 2.4% in the relevant parameter P{sub c}, implying the left over scale uncertainties in {Beta}(K{sup +} {yields} {pi}{sup +}{nu}{bar {nu}}) and in the determination of |V{sub td}|, sin 2{beta} and {gamma} from the K {yields} {pi}{nu}{bar {nu}} system to be {+-} 1.3%, {+-} 1.0%, {+-} 0.006 and {+-} 1.2{sup o}, respectively. for the charm quark {ovr MS} mass m{sub c}(m{sub c}) = (1.30 {+-} 0.05) GeV and |V{sub us}| = 0.2248 the next-to-leading order value P{sub c} = 0.37 {+-} 0.06 is modified to P{sub c} = 0.37 {+-} 0.04 at the next-to-next-to-leading order level with the latter error fully dominated by the uncertainty in m{sub c}(m{sub c}). Adding the recently calculated long-distance contributions we find {Beta}(K{sup +} {yields} {pi}{sup +}{nu}{bar {nu}}) = (8.0 {+-} 1.1) x 10{sup -11} with the quoted error almost entirely due to the present uncertainties in m{sub c}(m{sub c}) and the …
Date: August 1, 2005
Creator: Buras, A. J.; Gorbahn, M.; Haisch, U. & Nierste, U.
System: The UNT Digital Library
A Measurement of the K0 charge radius and a CP violating asymmetry together with a search for CP violating e1 direct photon emission in the rare decay K(L) ---> pi+ pi- e+ e- (open access)

A Measurement of the K0 charge radius and a CP violating asymmetry together with a search for CP violating e1 direct photon emission in the rare decay K(L) ---> pi+ pi- e+ e-

Using the complete KTeV data set of 5241 candidate K{sub L} {yields} {pi}{sup +}{pi}{sup -}e{sup +}e{sup -} decays (including an estimated background of 204 {+-} 14 events), we have measured the coupling g{sub CR} = 0.163 {+-} 0.014 (stat) {+-} 0.023 (syst) of the CP conserving charge radius process and from it determined a K{sup 0} charge radius of <r{sub K{sup 0}}{sup 2}> = (-0.077 {+-} 0.007(stat) {+-} 0.011(syst))fm{sup 2}. We have also determined a first experimental upper limit of 0.04 (90% CL) for the ratio |g{sub E1}|/|g{sub M1}| of the coupling for the E1 direct photon emission process relative to the coupling for M1 direct photon emission process. We also report the measurement of |g{sub M1}| including its associated vector form factor |{bar g}{sub M1}|1 + a{sub 1}/a{sub 2}/(M{sub p}{sup 2} - M{sub K}{sup 2})+2M{sub K}E{sub {gamma}*} where |{bar g}{sub M1}| = 1.11 {+-} 0.12 (stat) {+-} 0.08 (syst) and a{sub 1}/a{sub 2} = (-0.744 {+-} 0.027 (stat) {+-} 0.032 (syst)) GeV{sup 2}/c{sup 2}. In addition, a measurement of the manifestly CP violating asymmetry of magnitude (13.6 {+-} 1.4 (stat) {+-} 1.5 (syst))% in the CP and T odd angle {phi} between the decay planes of the e{sup +}e{sup …
Date: August 1, 2005
Creator: Abouzaid, E.; Arenton, M.; Barker, A. R.; Bellantoni, L.; Bellavance, A.; Blucher, E. et al.
System: The UNT Digital Library
Reduced shear power spectrum (open access)

Reduced shear power spectrum

Measurements of ellipticities of background galaxies are sensitive to the reduced shear, the cosmic shear divided by (1-{kappa}) where {kappa} is the projected density field. They compute the difference between shear and reduced shear both analytically and with simulations. The difference becomes more important an smaller scales, and will impact cosmological parameter estimation from upcoming experiments. A simple recipe is presented to carry out the required correction.
Date: August 1, 2005
Creator: Dodelson, Scott; /Fermilab /Chicago U., Astron. Astrophys. Ctr. /Northwestern U.; Shapiro, Charles; /Chicago U. /KICP, Chicago; White, Martin J. & /UC, Berkeley, Astron. Dept. /UC, Berkeley
System: The UNT Digital Library
ERCOT's Dynamic Model of Wind Turbine Generators: Preprint (open access)

ERCOT's Dynamic Model of Wind Turbine Generators: Preprint

By the end of 2003, the total installed wind farm capacity in the Electric Reliability Council of Texas (ERCOT) system was approximately 1 gigawatt (GW) and the total in the United States was about 5 GW. As the number of wind turbines installed throughout the United States increases, there is a greater need for dynamic wind turbine generator models that can properly model entire power systems for different types of analysis. This paper describes the ERCOT dynamic models and simulations of a simple network with different types of wind turbine models currently available.
Date: August 1, 2005
Creator: Muljadi, E.; Butterfield, C. P.; Conto, J. & Donoho, K.
System: The UNT Digital Library
The Dependence of galaxy colors on luminosity and environment at z~0.4 (open access)

The Dependence of galaxy colors on luminosity and environment at z~0.4

The authors analyze the B-R{sub c} colors of galaxies as functions of luminosity and local galaxy density using a large photometric redshift catalog based on the Red-Sequence Cluster Survey. They select two samples of galaxies with a magnitude limit of M{sub R{sub e}} < -18.5 and redshift ranges of 0.2 {le} z < 0.4 and 0.4 {le} x < 0.6 containing 10{sup 5} galaxies each. they model the color distributions of subsamples of galaxies and derive the red galaxy fraction and peak colors of red and blue galaxies as functions of galaxy luminosity and environment. The evolution of these relationships over the redshift range of x {approx} 0.5 to z {approx} 0.05 is analyzed in combination with published results from the Sloan Digital Sky Survey. They find that there is a strong evolution in the restframe peak color of bright blue galaxies in that they become redder with decreasing redshift, while the colors of faint blue galaxies remain approximately constant. This effect supports the ''downsizing'' scenario of star formation in galaxies. While the general dependence of the galaxy color distributions on the environment is small, they find that the change of red galaxy fraction with epoch is a function of …
Date: August 1, 2005
Creator: Yee, H. K. C.; /Toronto U., Astron. Dept.; Hsieh, B. C.; /Taiwan, Natl. Central U. /Taipei, Inst. Astron. Astrophys.; Lin, Huan; /Fermilab et al.
System: The UNT Digital Library
Resummation (open access)

Resummation

We review the work discussed and developed under the topic ''Resummation'' at Working Group 2 ''Multijet final states and energy flow'', of the HERALHC Workshop. We emphasize the role played by HERA observables in the development of resummation tools via, for instance, the discovery and resummation of non-global logarithms. We describe the event-shapes subsequently developed for hadron colliders and present resummed predictions for the same using the automated resummation program CAESAR. We also point to ongoing studies at HERA which can be of benefit for future measurements at hadron colliders such as the LHC, specifically dijet E{sub t} and angular spectra and the transverse momentum of the Breit current hemisphere.
Date: August 1, 2005
Creator: Banfi, A.; Corcella, G.; Dasgupta, M.; Delenda, Y.; Salam, G. P. & Zanderighi, G.
System: The UNT Digital Library
The hybrid performance of the Pierre Auger Observatory (open access)

The hybrid performance of the Pierre Auger Observatory

The Pierre Auger Observatory detects ultra-high energy cosmic rays by implementing two complementary air-shower techniques. The combination of a large ground array and fluorescence detectors, known as the hybrid concept, means that a rich variety of measurements can be made on a single shower, providing much improved information over what is possible with either detector alone. In this paper the hybrid reconstruction approach and its performance are described.
Date: August 1, 2005
Creator: Mostafa, Miguel, A.
System: The UNT Digital Library
Performance of the fluorescence detectors of the pierre auger observatory (open access)

Performance of the fluorescence detectors of the pierre auger observatory

Fluorescence detectors of the Pierre Auger Observatory have been operating in a stable manner since January 2004. After a brief review of the physical characteristics of the detectors, the associated atmospheric monitoring, the calibration infrastructure and the detector aperture, we will describe the steps required for the reconstruction of fluorescence event data, with emphasis on the shower profile parameters and primary energy.
Date: August 1, 2005
Creator: Bellido, Jose A.
System: The UNT Digital Library
Analysis of stops with small stop-neutralino mass difference at a LC (open access)

Analysis of stops with small stop-neutralino mass difference at a LC

A compelling framework to explain dark matter and electroweak baryogenesis is supersymmetry with light scalar top quarks (stops) and a small mass difference between the stop and the lightest neutralino. In this work, the stop detection capability at the ILC for small mass differences between the stop and the neutralino is studied. The analysis is based on a fast and realistic detector simulation. Significant sensitivity for mass differences down to 5 GeV is obtained. It is discussed how the relevant parameters of the scalar tops can be extracted and used to compute the dark matter density in the universe.
Date: August 1, 2005
Creator: Milstene, C.; Carena, Marcela S.; Freitas, A.; Finch, A.; Sopczak, A. & Kluge, Hannelies
System: The UNT Digital Library
Calibration of the surface array of the Pierre Auger Observatory (open access)

Calibration of the surface array of the Pierre Auger Observatory

The ground array of the Pierre Auger Observatory consists of 1600 water Cherenkov detectors, deployed over 3000 km{sup 2}. The remoteness and large number of detectors required a simple, automatic remote calibration procedure. The primary physics calibration is based on the average charge deposited by a vertical and central throughgoing muon, determined with good precision at the detector via a novel rate-based technique and later with higher precision via charge histograms. This value is named the vertical-equivalent muon (VEM). The VEM and the other parameters needed to maintain this calibration over the full energy range and to assess the quality of the detector are measured every minute. This allows an accurate determination of the energy deposited in each detector when an atmospheric cosmic ray shower occurs.
Date: August 1, 2005
Creator: Aglietta, M.; Allison, P. S.; Arneodo, F.; Barnhill, D.; Bauleo, P.; Beatty, J. J. et al.
System: The UNT Digital Library
Assessing the Potential of a Mechanical Continuously Variable Transmission for Wind Turbines (open access)

Assessing the Potential of a Mechanical Continuously Variable Transmission for Wind Turbines

This paper provides an update to a previous report that summarizes the results of a cooperative research and development agreement (CRADA) between the National Renewable Energy Laboratory (NREL) and Fallbrook Technologies, Inc. (Fallbrook). The purpose of the CRADA is to assess the usefulness of a continuously variable transmission (CVT) for wind turbine applications.
Date: August 1, 2005
Creator: Cotrell, J.
System: The UNT Digital Library
GaInNAs Junctions for Next-Generation Concentrators: Progress and Prospects (open access)

GaInNAs Junctions for Next-Generation Concentrators: Progress and Prospects

We discuss progress in the development of GaInNAs junctions for application in next-generation multijunction concentrator cells. A significant development is the demonstration of near-100% internal quantum efficiencies in junctions grown by molecular-beam epitaxy. Testing at high currents validates the compatibility of these devices with concentrator operation. The efficiencies of several next-generation multijunction structures incorporating these state-of-the-art GaInNAs junctions are projected.
Date: August 1, 2005
Creator: Friedman, D. J.; Ptak, A. J.; Kurtz, S. R.; Geisz, J. F. & Kiehl, J.
System: The UNT Digital Library
Applying EVM principles to Tevatron Beam Position Monitor Project (open access)

Applying EVM principles to Tevatron Beam Position Monitor Project

At Fermi National Accelerator Laboratory (Fermilab), the Tevatron high energy particle collider must meet the increasing scientific demand of higher beam luminosity. To achieve this higher luminosity goal, U. S. Department of Energy (DOE) sponsored a major upgrade of capabilities of Fermilab's accelerator complex that spans five years and costs over fifty million dollars. Tevatron Beam Position Monitor (BPM) system upgrade is a part of this project, generally called RunII upgrade project. Since the purpose of the Tevatron collider is to detect the smashing of proton and anti-protons orbiting the circular accelerator in opposite directions, capability to detect positions of both protons and antiprotons at a high resolution level is a desirable functionality of the monitoring system. The original system was installed during early 1980s, along with the original construction of the Tevatron. However, electronic technology available in 1980s did not allow for the detection of significantly smaller resolution of antiprotons. The objective of the upgrade project is to replace the existing BPM system with a new system utilizing capabilities of modern electronics enhanced by a front-end software driven by a real-time operating software. The new BPM system is designed to detect both protons and antiprotons with increased resolution of …
Date: August 1, 2005
Creator: Banerjee, Bakul
System: The UNT Digital Library
Outdoor Testing of GaInP2/GaAs Tandem Cells with Top Cell Thickness Varied (open access)

Outdoor Testing of GaInP2/GaAs Tandem Cells with Top Cell Thickness Varied

In this study, we measure the performance of GaInP2/GaAs tandem cells under direct beam sunlight outdoors in order to quantify their sensitivity to both spectral variation and GaInP2 top-cell thickness. A set of cells with five different top-cell thicknesses was mounted on a two-axis tracker with the incident sunlight collimated to exclude all except the direct beam. Current-voltage (I-V) curves were taken throughout the course of several days, along with measurements of the direct solar spectrum. Our two major conclusions are: (1) GaInP2/GaAs tandem cells designed for either the ASTM G-173 direct (G-173D) spectrum or the "air mass 1.5 global" (AM1.5G) spectrum perform the best, and (2) cells can be characterized indoors and modeled using outdoor spectra with the same result. These results are equally valid for GaInP2/GaAs/Ge triple-junction cells.
Date: August 1, 2005
Creator: McMahon, W. E.; Emergy, K. E.; Friedman, D. J.; Ottoson, L.; Young, M. S.; Ward, J. S. et al.
System: The UNT Digital Library
Negative hydrogen ion sources for accelerators (open access)

Negative hydrogen ion sources for accelerators

A variety of H{sup -} ion sources are in use at accelerator laboratories around the world. A list of these ion sources includes surface plasma sources with magnetron, Penning and surface converter geometries as well as magnetic-multipole volume sources with and without cesium. Just as varied is the means of igniting and maintaining magnetically confined plasmas. Hot and cold cathodes, radio frequency, and microwave power are all in use, as well as electron tandem source ignition. The extraction systems of accelerator H{sup -} ion sources are highly specialized utilizing magnetic and electric fields in their low energy beam transport systems to produce direct current, as well as pulsed and/or chopped beams with a variety of time structures. Within this paper, specific ion sources utilized at accelerator laboratories shall be reviewed along with the physics of surface and volume H{sup -} production in regard to source emittance. Current research trends including aperture modeling, thermal modeling, surface conditioning, and laser diagnostics will also be discussed.
Date: August 1, 2005
Creator: Moehs, D. P.; Peters, J. & Sherman, J.
System: The UNT Digital Library
The First dark microhalos (open access)

The First dark microhalos

Earth-mass dark matter halos are likely to have been the first bound structures to form in the Universe. Whether such objects have survived to the present day in galaxies depends on, among other factors, the rate of encounters with normal stars. In this letter, we estimate the amount of tidal heating and mass loss in microhalos as a result of stellar encounters. We find that while microhalos are only mildly heated in dwarf galaxies of low stellar density, and they should have been completely destroyed in bulge or M32-like regions of high stellar density. In disk galaxies, such as the Milky Way, the disruption rate depends strongly on the orbital parameters of the microhalo; while stochastic radial orbits in triaxial Galactic potential are destroyed first, systems on non-planar retrograde orbits with large pericenters survive the longest. Since many microhalos lose a significant fraction of their material to unbound tidal streams, the final dark matter distribution in the solar neighborhood is better described as a superposition of microstreams rather than as a set of discrete spherical clumps in an otherwise homogeneous medium. Different morphologies of microhalos have implications for direct and indirect dark matter detection experiments.
Date: August 1, 2005
Creator: Zhao, HongSheng; Observ., /St. Andrews U. /Beijing; Taylor, James E.; /Caltech; Silk, Joseph; U., /Oxford et al.
System: The UNT Digital Library
Looking to the future: A Fermilab viewpoint (open access)

Looking to the future: A Fermilab viewpoint

This is a short paper summarizing a presentation of the evolution of the Fermilab program for the next five to ten years. Emphasis is given to the Fermilab accelerator complex, but external collaboration is emphasized.
Date: August 1, 2005
Creator: Montgomery, H. E.
System: The UNT Digital Library
DOE High Performance Concentrator PV Project (open access)

DOE High Performance Concentrator PV Project

Much in demand are next-generation photovoltaic (PV) technologies that can be used economically to make a large-scale impact on world electricity production. The U.S. Department of Energy (DOE) initiated the High-Performance Photovoltaic (HiPerf PV) Project to substantially increase the viability of PV for cost-competitive applications so that PV can contribute significantly to both our energy supply and environment. To accomplish such results, the National Center for Photovoltaics (NCPV) directs in-house and subcontracted research in high-performance polycrystalline thin-film and multijunction concentrator devices with the goal of enabling progress of high-efficiency technologies toward commercial-prototype products. We will describe the details of the subcontractor and in-house progress in exploring and accelerating pathways of III-V multijunction concentrator solar cells and systems toward their long-term goals. By 2020, we anticipate that this project will have demonstrated 33% system efficiency and a system price of $1.00/Wp for concentrator PV systems using III-V multijunction solar cells with efficiencies over 41%.
Date: August 1, 2005
Creator: McConnell, R. & Symko-Davies, M.
System: The UNT Digital Library
Bandgap Engineering in High-Efficiency Multijunction Concentrator Cells (open access)

Bandgap Engineering in High-Efficiency Multijunction Concentrator Cells

This paper discusses semiconductor device research paths under investigation with the aim of reaching the milestone efficiency of 40%. A cost analysis shows that achieving very high cell efficiencies is crucial for the realization of cost-effective photovoltaics, because of the strongly leveraging effect of efficiency on module packaging and balance-of systems costs. Lattice-matched (LM) GaInP/ GaInAs/ Ge 3-junction cells have achieved the highest independently confirmed efficiency at 175 suns, 25?C, of 37.3% under the standard AM1.5D, low-AOD terrestrial spectrum. Lattice-mismatched, or metamorphic (MM), materials offer still higher potential efficiencies, if the crystal quality can be maintained. Theoretical efficiencies well over 50% are possible for a MM GaInP/ 1.17-eV GaInAs/ Ge 3-junction cell limited by radiative recombination at 500 suns. The bandgap - open circuit voltage offset, (Eg/q) - Voc, is used as a valuable theoretical and experimental tool to characterize multijunction cells with subcell bandgaps ranging from 0.7 to 2.1 eV. Experimental results are presented for prototype 6-junction cells employing an active {approx}1.1-eV dilute nitride GaInNAs subcell, with active-area efficiency greater than 23% and over 5.3 V open-circuit voltage under the 1-sun AM0 space spectrum. Such cell designs have theoretical efficiencies under the terrestrial spectrum at 500 suns concentration exceeding …
Date: August 1, 2005
Creator: King, R. R.; Sherif, R. A.; Kinsey, G. S.; Kurtz, S.; Fetzer, C. M.; Edmondson, K. M. et al.
System: The UNT Digital Library
Impact of Coherent Turbulence on Wind Turbine Aeroelastic Response and Its Simulation: Preprint (open access)

Impact of Coherent Turbulence on Wind Turbine Aeroelastic Response and Its Simulation: Preprint

In this paper, we present a brief overview of our recent research results regarding the impact of organized or coherent inflow turbulence on the dynamic response of operating wind turbines. Previous field experimentation has demonstrated that the greatest structural fatigue damage tends to occur during the nighttime hours from coherent turbulence that develops in the stable, nocturnal atmospheric boundary layer. We have found that under such conditions, intense vertical wind shear and temperature gradients create resonant flow fields that are capable of imparting short-period loading and vibrational energy as wind turbine rotor blades pass through regions of organized or coherent turbulence. This energy is subsequently propagated throughout the remainder of the structure, where it is often locally dissipated. We also briefly discuss our recent progress in developing a numerical simulation that includes such coherent inflow conditions that can be used to excite wind turbine design codes.
Date: August 1, 2005
Creator: Kelley, N. D.; Jonkman, B. J.; Scott, G. N.; Bialasiewicz, J. T. & Redmond, L. S.
System: The UNT Digital Library
Analyzing the scalar top co-annihilation region at the ILC (open access)

Analyzing the scalar top co-annihilation region at the ILC

The Minimal Supersymmetric Standard Model opens the possibility of electroweak baryogenesis provided that the light scalar top quark (stop) is lighter than the top quark. In addition, the lightest neutralino is an ideal candidate to explain the existence of dark matter. For a light stop with mass close to the lightest neutralino, the stop-neutralino co-annihilation mechanism becomes efficient, thus rendering the predicted dark matter density compatible with observations. Such a stop may however remain elusive at hadron colliders. Here it is shown that a future linear collider provides a unique opportunity to detect and study the light stop. The production of stops with small stop-neutralino mass differences is studied in a detailed experimental analysis with a realistic detector simulation including a CCD vertex detector for flavor tagging. Furthermore, the linear collider, by precision measurements of superpartner masses and mixing angles, also allows to determine the dark matter relic density with an accuracy comparable to recent astrophysical observations.
Date: August 1, 2005
Creator: Carena, M.; /Fermilab; Finch, A.; U., /Lancaster; Freitas, A.; Milstene, C. et al.
System: The UNT Digital Library
Balancing Performance, Noise, Cost, and Aesthetics in the Southwest Windpower "Storm" Wind Turbine: Preprint (open access)

Balancing Performance, Noise, Cost, and Aesthetics in the Southwest Windpower "Storm" Wind Turbine: Preprint

This paper describes the design, fabrication, and testing of an 1800-watt innovative small wind turbine and discusses the importance of idiosyncratic aerodynamic and aeroacoustic airfoil characteristics for clean airfoils at low Reynolds numbers.
Date: August 1, 2005
Creator: Migliore, P.; Green, J.; Calley, D. & Lonjaret, J.
System: The UNT Digital Library