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2005 Laser Diagnostics in Combustion Gordon Conference July 31-August 5, 2005 (open access)

2005 Laser Diagnostics in Combustion Gordon Conference July 31-August 5, 2005

The Gordon Research Conference (GRC) on LASER DIAGNOSTICS IN COMBUSTION was held at Mount Holyoke College from 7/31/2005 thru 8/5/2005. The Conference was well-attended with 121 participants (attendees list attached). The attendees represented the spectrum of endeavor in this field coming from academia, industry, and government laboratories, both U.S. and foreign scientists, senior researchers, young investigators, and students. In designing the formal speakers program, emphasis was placed on current unpublished research and discussion of the future target areas in this field. There was a conscious effort to stimulate lively discussion about the key issues in the field today. Time for formal presentations was limited in the interest of group discussions. In order that more scientists could communicate their most recent results, poster presentation time was scheduled. Attached is a copy of the formal schedule and speaker program and the poster program. In addition to these formal interactions, ''free time'' was scheduled to allow informal discussions. Such discussions are fostering new collaborations and joint efforts in the field. I want to personally thank you for your support of this Conference. As you know, in the interest of promoting the presentation of unpublished and frontier-breaking research, Gordon Research Conferences does not permit …
Date: August 1, 2005
Creator: Allen, Mark G.
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
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
Angular resolution of the Pierre Auger Observatory (open access)

Angular resolution of the Pierre Auger Observatory

We studied the angular resolution of the Pierre Auger Detector using data collected from January 2004 to May 2005. The detector consists of two independent components, the fluorescence detector and the surface detector. Hybrid events, observed simultaneously by both components, have smaller reconstruction uncertainties than the events observed with only one component. The hybrid resolution is extracted from artificial showers generated by laser shots, while the surface detector angular accuracy is then determined from the comparison of the hybrid geometrical fit with the one obtained from the surface detector alone. We used adjacent surface detector stations to cross check our methods. The angular reconstruction accuracy of the surface detector events is given as a function of station multiplicity.
Date: August 1, 2005
Creator: Bonifazi, C.
System: The UNT Digital Library
Anisoplanatism in adaptive optics systems due to pupil aberrations (open access)

Anisoplanatism in adaptive optics systems due to pupil aberrations

Adaptive optics systems typically include an optical relay that simultaneously images the science field to be corrected and also a set of pupil planes conjugate to the deformable mirror of the system. Often, in the optical spaces where DM's are placed, the pupils are aberrated, leading to a displacement and/or distortion of the pupil that varies according to field position--producing a type of anisoplanatism, i.e., a degradation of the AO correction with field angle. The pupil aberration phenomenon is described and expressed in terms of Seidel aberrations. An expression for anisoplanatism as a function of pupil distortion is derived, an example of an off-axis parabola is given, and a convenient method for controlling pupil-aberration-generated anisoplanatism is proposed.
Date: August 1, 2005
Creator: Bauman, B
System: The UNT Digital Library
Aperture calculation of the Pierre Auger Observatory surface detector (open access)

Aperture calculation of the Pierre Auger Observatory surface detector

We determine the instantaneous aperture and integrated exposure of the surface detector of the Pierre Auger Observatory, taking into account the trigger efficiency as a function of the energy, arrival direction (with zenith angle lower than 60 degrees) and nature of the primary cosmic-ray. We make use of the so-called Lateral Trigger Probability function (or LTP) associated with an extensive air shower, which summarizes all the relevant information about the physics of the shower, the water tank Cherenkov detector, and the triggers.
Date: August 1, 2005
Creator: Allard, D.; Allekotte, I.; Armengaud, E.; Aublin, J.; Bertou, Xavier; Chou, A. et al.
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
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
Atomic-Resolution Observations of Semi-Crystalline IntegranularThin Films in Silicon Nitride (open access)

Atomic-Resolution Observations of Semi-Crystalline IntegranularThin Films in Silicon Nitride

The thin intergranular phase in a silicon nitride (Si3N4)ceramic, which has been regarded for decades as having an entirely amorphous morphology, is shown to have a semi-crystalline structure. Using two different but complementary high-resolution electron microscopy methods, the intergranular atomic structure was directly imaged at the atomic level. These high-resolution images show that the atomic arrangement of the dopand element cerium takes very periodic positions not only along the interface between the intergranular phase and the Si3N4 matrix grains, but it arranges in a semi-crystalline structure that spans the entire width of the intergranular phase between two adjacent matrix grains, in principle connecting the two separate matrix grains. The result will have implications on the approach of understanding the materials properties of ceramics, most significantly on the mechanical properties and the associated computational modeling of the atomic structure of the thin intergranular phase in Si3N4 ceramics.
Date: August 1, 2005
Creator: Ziegler, Alexander; Idrobo, Juan C.; Cinibulk, Michael K.; Kisielowski, Christian; Browning, Nigel D. & Ritchie, Robert O.
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
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
Broader Impacts of the International Linear Collider (open access)

Broader Impacts of the International Linear Collider

Large-scale scientific endeavors such as the International Linear Collider Project can have a lasting impact on education and outreach to our society. The ILC will provide a discovery platform for frontier physical science and it will also provide a discovery platform for broader impacts and social science. The importance of Broader Impacts of Science in general and the ILC in particular are described. Additionally, a synopsis of education and outreach activities carried out as an integral part of the Snowmass ILC Workshop is provided.
Date: August 1, 2005
Creator: Bardeen, M.; /Fermilab; Ruchti, R. & /NSF, Wash., D.C. /Notre Dame U.
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
Characterization of an Electroactive Polymer for OverchargeProtection in Secondary Lithium Batteries (open access)

Characterization of an Electroactive Polymer for OverchargeProtection in Secondary Lithium Batteries

This report describes Characterization of an Electroactive Polymer for OverchargeProtection in Secondary Lithium Batteries.
Date: August 1, 2005
Creator: Chen, Guoying; Thomas-Alyea, Karen E.; Newman, John & Richardson,Thomas J.
System: The UNT Digital Library
Cleaning Products and Air Fresheners: Emissions and ResultingConcentrations of Glycol Ethers and Terpenoids (open access)

Cleaning Products and Air Fresheners: Emissions and ResultingConcentrations of Glycol Ethers and Terpenoids

Experiments were conducted to quantify emissions and concentrations of glycol ethers and terpenoids from cleaning product and air freshener use in a 50-m{sup 3} room ventilated at {approx}0.5 h{sup -1}. Five cleaning products were applied full-strength (FS); three were additionally used in dilute solution. FS application of pine-oil cleaner (POC) yielded 1-h concentrations of 10-1300 {micro}g m{sup -3} for individual terpenoids, including {alpha}-terpinene (90-120), d-limonene (1000-1100), terpinolene (900-1300), and {alpha}-terpineol (260-700). One-hour concentrations of 2-butoxyethanol and/or dlimonene were 300-6000 {micro}g m{sup -3} after FS use of other products. During FS application including rinsing with sponge and wiping with towels, fractional emissions (mass volatilized/dispensed) of 2-butoxyethanol and d-limonene were 50-100% with towels retained, {approx}25-50% when towels were removed after cleaning. Lower fractions (2-11%) resulted from dilute use. Fractional emissions of terpenes from FS use of POC were {approx}35-70% with towels retained, 20-50% with towels removed. During floor cleaning with dilute solution of POC, 7-12% of dispensed terpenes were emitted. Terpene alcohols were emitted at lower fractions: 7-30% (FS, towels retained), 2-9% (FS, towels removed), and 2-5% (dilute). During air-freshener use, d-limonene, dihydromyrcenol, linalool, linalyl acetate, and {beta}-citronellol were emitted at 35-180 mg d{sup -1} over three days while air concentrations averaged …
Date: August 1, 2005
Creator: Singer, Brett C.; Destaillat, Hugo; Hodgson, Alfred T. & Nazaroff,William W.
System: The UNT Digital Library
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 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
Detecting gamma-ray bursts with the pierre auger observatory using the single particle technique (open access)

Detecting gamma-ray bursts with the pierre auger observatory using the single particle technique

During the past ten years, gamma-ray Bursts (GRB) have been extensively studied in the keV-MeV energy range but the higher energy emission still remains mysterious. Ground based observatories have the possibility to investigate energy range around one GeV using the ''single particle technique''. The aim of the present study is to investigate the capability of the Pierre Auger Observatory to detect the high energy emission of GRBs with such a technique. According to the detector response to photon showers around one GeV, and making reasonable assumptions about the high energy emission of GRBs, we show that the Pierre Auger Observatory is a competitive instrument for this technique, and that water tanks are very promising detectors for the single particle technique.
Date: August 1, 2005
Creator: Allard, Denis; Parizot, E.; Bertou, Xavier; Beatty, J.; Vernois, M.Du; Nitz, D. et al.
System: The UNT Digital Library
DIRECT DECOMPOSITION OF METHANE TO HYDROGEN ON METAL LOADED ZEOLITE CATALYST (open access)

DIRECT DECOMPOSITION OF METHANE TO HYDROGEN ON METAL LOADED ZEOLITE CATALYST

The manufacture of hydrogen from natural gas is essential for the production of ultra clean transportation fuels. Not only is hydrogen necessary to upgrade low quality crude oils to high-quality, low sulfur ultra clean transportation fuels, hydrogen could eventually replace gasoline and diesel as the ultra clean transportation fuel of the future. Currently, refinery hydrogen is produced through the steam reforming of natural gas. Although efficient, the process is responsible for a significant portion of refinery CO2 emissions. This project is examining the direct catalytic decomposition of methane as an alternative to steam reforming. The energy required to produce one mole of hydrogen is slightly lower and the process does not require water-gas-shift or pressure-swing adsorption units. The decomposition process does not produce CO2 emissions and the product is not contaminated with CO -- a poison for PEM fuel cells. In this work we examined the direct catalytic decomposition of methane over a metal modified zeolite catalyst and the recovery of catalyst activity by calcination. A favorable production of hydrogen was obtained, when compared with previously reported nickel-zeolite supported catalysts. Reaction temperature had a strong influence on catalyst activity and on the type of carbon deposits. The catalyst utilized at …
Date: August 1, 2005
Creator: Petkovic, Lucia M.; Ginosar, Daniel M.; Burch, Kyle C. & Rollins, Harry W.
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
Early testing of a coarse/fine precision motion control system (open access)

Early testing of a coarse/fine precision motion control system

This abstract presents a brief overview of key components of a motion control stage for accurate nanometer level positioning for scanning specimens over an area measuring 50 mm x 50 mm. The completed system will utilize a short-range, third generation 6 degree-of-freedom fine motion control platform (4 microns, 160 micro-radians) carried by a long-range, two-axis x-y positioning system (50 mm x 50 mm). Motion of the controlled platform relative to a measurement frame will be measured using a heterodyne laser interferometer and capacitance sensing. The final stage will be mounted onto an isolation table in a vacuum chamber, itself on isolation supports mounted to a granite slab on bed rock and isolated from the main floor of the building. This whole system is housed in a temperature-controlled laboratory. It is envisaged that the current system will provide the ability to ''pick and place'' at nanometer levels and be used for long range scanning of specimens (including biological specimens), micro- /macroassembly, lithography and as a coordinate measuring machine (CMM). Furthermore, the system performance will be compared with other comparable systems at international locations such as, National Physical Laboratory (NPL) in the UK, Technical University of Eindhoven (TUE) in the Netherlands, Physikalisch-Technische …
Date: August 1, 2005
Creator: Buice, E. S.; Yang, H.; Smith, S. T.; Hocken, R. J.; Seugling, R. M.; Trumper, D. L. et al.
System: The UNT Digital Library
Education and public outreach of the Pierre Auger Observatory (open access)

Education and public outreach of the Pierre Auger Observatory

The Auger collaboration's broad mission in education, outreach and public relations is coordinated in a separate task. Its goals are to encourage and support a wide range of outreach efforts that link schools and the public with the Auger scientists and the science of cosmic rays, particle physics, and associated technologies. This report focuses on recent activities and future initiatives.
Date: August 1, 2005
Creator: Garcia, B.; /Natl. Tech. U., San Rafael & Snow, G.
System: The UNT Digital Library
Effect of chemical composition and superheat on macrostructure of high Cr white iron castings (open access)

Effect of chemical composition and superheat on macrostructure of high Cr white iron castings

White cast irons are frequently used in applications requiring high wear resistance. High Cr white cast irons have a composite microstructure composed of hard (Fe,Cr)7C3 carbides in a steel matrix. Previous research has indicated that the equiaxed region of these high Cr white iron castings is much more wear resistant under high stress abrasive conditions than the columnar region, when the carbides are oriented perpendicular to the wear surface. In the present study, the effect of both the chemical composition, particularly carbon content, and the pouring superheat of the melt on the macrostructure of high Cr white iron castings is investigated.
Date: August 1, 2005
Creator: Dogan, Omer N.
System: The UNT Digital Library