Astrophysical Gyrokinetics: Kinetic and Fluid Turbulent Cascades In Magentized Weakly Collisional Plasmas (open access)

Astrophysical Gyrokinetics: Kinetic and Fluid Turbulent Cascades In Magentized Weakly Collisional Plasmas

This paper presents a theoretical framework for understanding plasma turbulence in astrophysical plasmas. It is motivated by observations of electromagnetic and density fluctuations in the solar wind, interstellar medium and galaxy clusters, as well as by models of particle heating in accretion disks. All of these plasmas and many others have turbulentmotions at weakly collisional and collisionless scales. The paper focuses on turbulence in a strong mean magnetic field. The key assumptions are that the turbulent fluctuations are small compared to the mean field, spatially anisotropic with respect to it and that their frequency is low compared to the ion cyclotron frequency. The turbulence is assumed to be forced at some system-specific outer scale. The energy injected at this scale has to be dissipated into heat, which ultimately cannot be accomplished without collisions. A kinetic cascade develops that brings the energy to collisional scales both in space and velocity. The nature of the kinetic cascade in various scale ranges depends on the physics of plasma fluctuations that exist there. There are four special scales that separate physically distinct regimes: the electron and ion gyroscales, the mean free path and the electron diffusion scale. In each of the scale ranges separated …
Date: April 23, 2009
Creator: A.A. Schekochihin, S.C. Cowley, W. Dorland, G.W. Hammett, G.G. Howes, E. Quataert, and T. Tatsuno
Object Type: Report
System: The UNT Digital Library
Smart Energy Management of Multiple Full Cell Powered Applications (open access)

Smart Energy Management of Multiple Full Cell Powered Applications

In this research project the University of South Alabama research team has been investigating smart energy management and control of multiple fuel cell power sources when subjected to varying demands of electrical and thermal loads together with demands of hydrogen production. This research has focused on finding the optimal schedule of the multiple fuel cell power plants in terms of electric, thermal and hydrogen energy. The optimal schedule is expected to yield the lowest operating cost. Our team is also investigating the possibility of generating hydrogen using photoelectrochemical (PEC) solar cells through finding materials for efficient light harvesting photoanodes. The goal is to develop an efficient and cost effective PEC solar cell system for direct electrolysis of water. In addition, models for hydrogen production, purification, and storage will be developed. The results obtained and the data collected will be then used to develop a smart energy management algorithm whose function is to maximize energy conservation within a managed set of appliances, thereby lowering O/M costs of the Fuel Cell power plant (FCPP), and allowing more hydrogen generation opportunities. The Smart Energy Management and Control (SEMaC) software, developed earlier, controls electrical loads in an individual home to achieve load management objectives …
Date: April 23, 2007
Creator: Alam, MOhammad S.
Object Type: Report
System: The UNT Digital Library
Smart Energy Management of Multiple Full Cell Powered Applications (open access)

Smart Energy Management of Multiple Full Cell Powered Applications

In this research project the University of South Alabama research team has been investigating smart energy management and control of multiple fuel cell power sources when subjected to varying demands of electrical and thermal loads together with demands of hydrogen production. This research has focused on finding the optimal schedule of the multiple fuel cell power plants in terms of electric, thermal and hydrogen energy. The optimal schedule is expected to yield the lowest operating cost. Our team is also investigating the possibility of generating hydrogen using photoelectrochemical (PEC) solar cells through finding materials for efficient light harvesting photoanodes. The goal is to develop an efficient and cost effective PEC solar cell system for direct electrolysis of water. In addition, models for hydrogen production, purification, and storage will be developed. The results obtained and the data collected will be then used to develop a smart energy management algorithm whose function is to maximize energy conservation within a managed set of appliances, thereby lowering O/M costs of the Fuel Cell power plant (FCPP), and allowing more hydrogen generation opportunities. The Smart Energy Management and Control (SEMaC) software, developed earlier, controls electrical loads in an individual home to achieve load management objectives …
Date: April 23, 2007
Creator: Alam, Mohammad S.
Object Type: Report
System: The UNT Digital Library
Time-Dependent Measure of a Nano-Scale Force-Pulse Driven by the Axonemal Dynein Motors in Individual Live Sperm Cells (open access)

Time-Dependent Measure of a Nano-Scale Force-Pulse Driven by the Axonemal Dynein Motors in Individual Live Sperm Cells

Nano-scale mechanical forces generated by motor proteins are crucial to normal cellular and organismal functioning. The ability to measure and exploit such forces would be important to developing motile biomimetic nanodevices powered by biological motors for Nanomedicine. Axonemal dynein motors positioned inside the sperm flagellum drive microtubule sliding giving rise to rhythmic beating of the flagellum. This force-generating action makes it possible for the sperm cell to move through viscous media. Here we report new nano-scale information on how the propulsive force is generated by the sperm flagellum and how this force varies over time. Single cell recordings reveal discrete {approx}50 ms pulses oscillating with amplitude 9.8 {+-} 2.6 nN independent of pulse frequency (3.5-19.5 Hz). The average work carried out by each cell is 4.6 x 10{sup -16} J per pulse, equivalent to the hydrolysis of {approx}5,500 ATP molecules. The mechanochemical coupling at each active dynein head is {approx}2.2 pN/ATP, and {approx}3.9 pN per dynein arm, in agreement with previously published values obtained using different methods.
Date: April 23, 2009
Creator: Allen, M J; Rudd, R E; McElfresh, M W & Balhorn, R
Object Type: Article
System: The UNT Digital Library
FILTER COMPONENT ASSESSMENT--CERAMIC CANDLES-- (open access)

FILTER COMPONENT ASSESSMENT--CERAMIC CANDLES--

Efforts at Siemens Westinghouse Power Corporation (SWPC) have been focused on development of hot gas filter systems as an enabling technology for advanced coal and biomass-based gas turbine power generation applications. SWPC has been actively involved in the development of advanced filter materials and component configuration, has participated in numerous surveillance programs characterizing the material properties and microstructure of field tested filter elements, and has undertaken extended, accelerated filter life testing programs. This report summarizes the results of SWPC's filter component assessment efforts, identifying the performance and stability of porous monolithic, fiber reinforced, and filament wound ceramic hot gas candle filters, potentially for {ge}3 years of viable pressurized fluidized-bed combustion (PFBC) service operating life.
Date: April 23, 2004
Creator: Alvin, M. A.
Object Type: Report
System: The UNT Digital Library
Multi-Channel Auto-Dilution System for Remote Continuous Monitoring of High Soil-CO2 Fluxes (open access)

Multi-Channel Auto-Dilution System for Remote Continuous Monitoring of High Soil-CO2 Fluxes

Geological sequestration has the potential capacity and longevity to significantly decrease the amount of anthropogenic CO2 introduced into the atmosphere by combustion of fossil fuels such as coal. Effective sequestration, however, requires the ability to verify the integrity of the reservoir and ensure that potential leakage rates are kept to a minimum. Moreover, understanding the pathways by which CO2 migrates to the surface is critical to assessing the risks and developing remediation approaches. Field experiments, such as those conducted at the Zero Emissions Research and Technology (ZERT) project test site in Bozeman, Montana, require a flexible CO2 monitoring system that can accurately and continuously measure soil-surface CO2 fluxes for multiple sampling points at concentrations ranging from background levels to several tens of percent. To meet this need, PNNL is developing a multi-port battery-operated system capable of both spatial and temporal monitoring of CO2 at concentrations from ambient to at least 150,000 ppmv. This report describes the system components (sampling chambers, measurement and control system, and power supply) and the results of a field test at the ZERT site during the late summer and fall of 2008. While the system performed well overall during the field test, several improvements to the …
Date: April 23, 2009
Creator: Amonette, James E. & Barr, Jonathan L.
Object Type: Report
System: The UNT Digital Library
DEVELOPMENT OF METALLIC HOT GAS FILTERS (open access)

DEVELOPMENT OF METALLIC HOT GAS FILTERS

Successful development of metallic filters with high temperature oxidation/corrosion resistance for fly ash capture is a key to enabling advanced coal combustion and power generation technologies. Compared to ceramic filters, metallic filters can offer increased resistance to impact and thermal fatigue, greatly improving filter reliability. A beneficial metallic filter structure, composed of a thin-wall (0.5mm) tube with uniform porosity (about 30%), is being developed using a unique spherical powder processing and partial sintering approach, combined with porous sheet rolling and resistance welding. Alloy choices based on modified superalloys, e.g., Ni-16Cr-4.5Al-3Fe (wt.%), are being tested in porous and bulk samples for oxide (typically alumina) scale stability in simulated oxidizing/sulfidizing atmospheres found in PFBC and IGCC systems at temperatures up to 850 C. Recent ''hanging o-ring'' exposure tests in actual combustion systems at a collaborating DOE site (EERC) have been initiated to study the combined corrosive effects from particulate deposits and hot exhaust gases. New studies are exploring the correlation between sintered microstructure, tensile strength, and permeability of porous sheet samples.
Date: April 23, 2003
Creator: Anderson, I. E.; Gleeson, B. & Terpstra, R. L.
Object Type: Article
System: The UNT Digital Library
Coming to Washington, DC? Sources of Information on Temporary Housing (open access)

Coming to Washington, DC? Sources of Information on Temporary Housing

This report will introduce a newcomer to the Washington, DC, metropolitan area to sources of general interest, neighborhoods, housing, and public transportation.
Date: April 23, 2004
Creator: Anderson, J. Michael
Object Type: Report
System: The UNT Digital Library
Novel Optical Detection Schemes for In-Situ Mapping of Volatile Organochlorides in The Vadose Zone (open access)

Novel Optical Detection Schemes for In-Situ Mapping of Volatile Organochlorides in The Vadose Zone

The long-term objective of this research is to develop a system for measuring and identifying a wide rang of volatile organic hydrocarbons, including organochlorides, at ppb levels in-situ in the subsurface (''at-dept'') using a fiber-optic REMPI probe. In this renewal proposal we would also like to expand the range of analytes to include contaminated soil and certain metal pollutants such as Hg and Pb. And, to do this in a ruggedized system that is compatible with existing fiber-optic sensors, Raman and fluorescence probes and image guides. The specific focus of much of the proposed work is to identify and optimize those experimental parameters which effect the in-situ determination of organic molecules using resonance-enhanced multi-photon ionization (REMPI). To accomplish this goal we will systematically investigate the dependence of REMPI on laser wavelength, power and other experimental parameters for a variety of high-priority groundwater and vadose zone contaminants to determine optimal measurement conditions. Emphasis will be placed on visible or fiber-optic compatible wavelengths of excitation so that the high transmission of fiberoptics can be fully utilized. A fiber-optic REMPI system is being designed that is suitable for integration into an existing cone penetrometer system being delivered by LLNL. Fiber-optic probe designs that …
Date: April 23, 2004
Creator: Angel, S. Michael
Object Type: Report
System: The UNT Digital Library
Spin Effects in the Fragmentation of Transversely Polarized and Unpolarized Quarks. (open access)

Spin Effects in the Fragmentation of Transversely Polarized and Unpolarized Quarks.

We study the fragmentation of a transversely polarized quark into a non-collinear (k{perpendicular} {ne} 0) spinless hadron and the fragmentation of an unpolarized quark into a non collinear transversely polarized spin 1/2 baryon. These nonperturbative properties are described by spin and k{perpendicular} dependent fragmentation functions and are revealed in the observation of single spin asymmetries. Recent data on the production of pions in polarized semi-inclusive DIS and long known data on A polarization in unpolarized p-N processes are considered: these new fragmentation functions can describe the experimental results and the single spin effects in the quark fragmentation turn out to be surprisingly large.
Date: April 23, 2001
Creator: Anselmino, M.; Boer, D.; D'Alesio, U. & Murgia, F.
Object Type: Article
System: The UNT Digital Library
L Polarization in Unpolarized Hadron Reactions. (open access)

L Polarization in Unpolarized Hadron Reactions.

The transverse polarization observed in the inclusive production of {Lambda} hyperons in the high energy collisions of unpolarized hadrons is tackled by considering a new set of spin and {kappa}{perpendicular} dependent quark fragmentation functions. Simple phenomenological expressions for these new ''polarizing fragmentation functions'' are obtained by a fit of the data on {Lambda}'s and {bar {Lambda}}'s produced in p - N processes.
Date: April 23, 2001
Creator: Anselmino, M.; Boer, D.; Dalesio, U. & Murgia, F.
Object Type: Article
System: The UNT Digital Library
SALT FOG TEST OF SAM2X5 COATED STAINLESS STEEL CYLINDER (open access)

SALT FOG TEST OF SAM2X5 COATED STAINLESS STEEL CYLINDER

A salt fog test of an iron-based amorphous metal, SAM2X5, coated Type 316L stainless steel (SS316L) cylinder was made. The cylinder was 30-inch diameter by 88-inch long, and 3/8-inch thick. One end was welded shut with a SS316L end cap before coating. The body of the cylinder and the end cap were both coated. The cylinder was coated with SAM2X5 by the HVOF thermal spray process. The coating thickness was 0.015-inch to 0.019-inch thick. The cylinder was tested in a horizontal position. Also included in the test for reference purposes were five coupons (2-inch x 2-inch x 1/8-inch) of uncoated Type 1018 carbon steel (1018CS). The test used an abbreviated form of GM 9540P. Each cycle was 6 hours in duration and the cylinder and reference samples were exposed to a total of eight cycles. The cylinder was in relatively good condition after the test. Along the body of the cylinder only two pinpoint spot sized signs of rust were seen. The 1018CS reference specimens were extensively rusted.
Date: April 23, 2007
Creator: Aprigliano, L F; Rebak, R B; Choi, J; Lian, T & Day, S D
Object Type: Article
System: The UNT Digital Library
Bilayer Conductive-Oxide Buffer Layer Structures for High-J{sub c} YBa{sub 2}Cu{sub 3}O{sub 7-d} Coated Conductors (open access)

Bilayer Conductive-Oxide Buffer Layer Structures for High-J{sub c} YBa{sub 2}Cu{sub 3}O{sub 7-d} Coated Conductors

Epitaxial, conductive-oxide buffer layers having bilayer configurations have been deposited on biaxially textured nickel substrates (RABiTS) by rf and dc-sputter techniques. The conductive bilayer structures comprise the layer sequences of SrRuO{sub 3}/LaNiO{sub 3}/Ni and SrRuO{sub 3}/Cu/Ni. Systematic property characterizations of the buffer layers showed excellent electrical and structural properties. High-quality epitaxial YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (YBCO) films grown by pulsed-laser deposition on these structures exhibited critical current densities (J{sub c}) as high as 1.3 x 10{sup 6} A/cm{sup 2} at 77 K in self-field.
Date: April 23, 2001
Creator: Aytug, T.
Object Type: Article
System: The UNT Digital Library
Energy Policy: The Continuing Debate (open access)

Energy Policy: The Continuing Debate

On April 11, 2003, the House passed comprehensive energy legislation, H.R. 6 (247-175).Action on comprehensive energy legislation is in progress in the Senate. The Senate Energy and Natural Resources Committee began markup of a comprehensive energy bill on April 7, 2003, agreeing by week’s end to provisions regarding hydrogen, hydroelectric relicensing, nuclear and renewable energy. On April 11, 2003, Chairman Domenici pulled a controversial section on climate change from the bill and indicated it would be addressed later.
Date: April 23, 2003
Creator: Bamberger, Robert L.
Object Type: Report
System: The UNT Digital Library
Strategic Petroleum Reserve (open access)

Strategic Petroleum Reserve

None
Date: April 23, 2003
Creator: Bamberger, Robert L.
Object Type: Report
System: The UNT Digital Library
Astronomy Applications of Adaptive Optics at Lawrence Livermore National Laboratory (open access)

Astronomy Applications of Adaptive Optics at Lawrence Livermore National Laboratory

Astronomical applications of adaptive optics at Lawrence Livermore National Laboratory (LLNL) has a history that extends from 1984. The program started with the Lick Observatory Adaptive Optics system and has progressed through the years to lever-larger telescopes: Keck, and now the proposed CELT (California Extremely Large Telescope) 30m telescope. LLNL AO continues to be at the forefront of AO development and science.
Date: April 23, 2003
Creator: Bauman, B J & Gavel, D T
Object Type: Article
System: The UNT Digital Library
UXO Engineering Design. Technical Specification and ConceptualDesign (open access)

UXO Engineering Design. Technical Specification and ConceptualDesign

The design and fabrication of the UXO detector has numerous challenges and is an important component to the success of this study. This section describes the overall engineering approach, as well as some of the technical details that brought us to the present design. In general, an array of sensor coils is measuring the signal generated by the UXO object in response to a stimulation provided by the driver coil. The information related to the location, shape and properties of the object is derived from the analysis of the measured data. Each sensor coil is instrumented with a waveform digitizer operating at a nominal digitization rate of 100 kSamples per second. The sensor coils record both the large transient pulse of the driver coil and the UXO object response pulse. The latter is smaller in amplitude and must be extracted from the large transient signal. The resolution required is 16 bits over a dynamic range of at least 140 dB. The useful signal bandwidth of the application extends from DC to 40 kHz. The low distortion of each component is crucial in order to maintain an excellent linearity over the full dynamic range and to minimize the calibration procedure. The …
Date: April 23, 2005
Creator: Beche, J-F.; Doolittle, L.; Greer, J.; Lafever, R.; Radding, Z.; Ratti, A. et al.
Object Type: Report
System: The UNT Digital Library
Horse Slaughter Prevention Bills and Issues (open access)

Horse Slaughter Prevention Bills and Issues

Report on the practice of horse slaughter for meat consumption, and whether the practice should be banned in future bills.
Date: April 23, 2007
Creator: Becker, Geoffrey S.
Object Type: Report
System: The UNT Digital Library
FISCHER-TROPSCH FUELS PRODUCTION AND DEMONSTRATION PROJECT (open access)

FISCHER-TROPSCH FUELS PRODUCTION AND DEMONSTRATION PROJECT

This project has two primary purposes: (1) Build a small-footprint (SFP) fuel production plant to prove the feasibility of this relatively transportable technology on an intermediate scale (i.e. between laboratory-bench and commercial capacity) and produce as much as 150,000 gallons of hydrogen-saturated Fischer-Tropsch (FT) diesel fuel; and (2) Use the virtually sulfur-free fuel produced to demonstrate (over a period of at least six months) that it can not only be used in existing diesel engines, but that it also can enable significantly increased effectiveness and life of the next-generation exhaust-after-treatment emission control systems that are currently under development and that will be required for future diesel engines. Furthermore, a well-to-wheels economic analysis will be performed to characterize the overall costs and benefits that would be associated with the actual commercial production, distribution and use of such FT diesel fuel made by the process under consideration, from the currently underutilized (or entirely un-used) energy resources targeted, primarily natural gas that is stranded, sub-quality, off-shore, etc. During the first year of the project, which is the subject of this report, there have been two significant areas of progress: (1) Most of the preparatory work required to build the SFP fuel-production plant has …
Date: April 23, 2003
Creator: Bergin, Stephen P.
Object Type: Report
System: The UNT Digital Library
Numerical Models of Waste Glass Models Part I Lumped Parameter Modeling of DWPF (open access)

Numerical Models of Waste Glass Models Part I Lumped Parameter Modeling of DWPF

Defense Waste Processing Facility melter production data from three waste batches were analyzed using a lumped parameter approach which separates effects of melter feed, heater temperature, and power on melt rate under various modes of operation. A detailed distribution of power inputs and heat consumption pathways, as provided by the lumped parameter model, evaluated possible causes of melt rate reduction and other operational data. Theoretical aspects of the steady state analysis, as well as transient analysis, are presented.The lumped model complements the more detailed multi-dimensional computational models by providing boundary conditions for such models, and is the only practical way of predicting transients.
Date: April 23, 2003
Creator: Bickford, D.F.
Object Type: Article
System: The UNT Digital Library
Numerical Models of Waste Glass Models Part II Computational Modeling of DWPF (open access)

Numerical Models of Waste Glass Models Part II Computational Modeling of DWPF

Computational fluid-dynamics numerical models are developed for joule-heated slurry fed waste glass melters, such as the Defense Waste Processing Facility Melter. An important feature of the analyses is the simulation of the cold cap region with its thermally resistant foamy layer. Using a simplified model which describes the foam void fraction as a function of temperature, based on laboratory sample testing, characteristic features of the cold cap are simulated. Two- and three-dimensional models are presented.
Date: April 23, 2003
Creator: Bickford, D.F.
Object Type: Article
System: The UNT Digital Library
Development of Inorganic Membranes for Hydrogen Separation (open access)

Development of Inorganic Membranes for Hydrogen Separation

This paper presents information and data relative to recent advances in the development at Oak Ridge National Laboratory of porous inorganic membranes for high-temperature hydrogen separation. The Inorganic Membrane Technology Laboratory, which was formerly an organizational element of Bechtel Jacobs Company, LLC, was formally transferred to Oak Ridge National Laboratory on August 1, 2002, as a result of agreements reached between Bechtel Jacobs Company, the management and integration contractor at the East Tennessee Technology Park (formerly the Oak Ridge Gaseous Diffusion Plant or Oak Ridge K-25 Site); UT-Battelle, the management and operating contractor of Oak Ridge National Laboratory; and the U.S. Department of Energy (DOE) Oak Ridge Operations Office. Research emphasis during the last year has been directed toward the development of high-permeance (high-flux) and high-separation-factor metal-supported membranes. Performance data for these membranes are presented and are compared with performance data for membranes previously produced under this program and for membranes produced by other researchers. New insights into diffusion mechanisms are included in the discussion. Fifteen products, many of which are the results of research sponsored by the DOE Fossil Energy Advanced Research Materials Program, have been declared unclassified and have been approved for commercial production.
Date: April 23, 2003
Creator: Bischoff, Brian L. & Judkins, Roddie R.
Object Type: Article
System: The UNT Digital Library
Gamma-ray multiplicity measurement of the spontaneous fission decay of 252Cf in a segmented HPGe/BGO detector array (open access)

Gamma-ray multiplicity measurement of the spontaneous fission decay of 252Cf in a segmented HPGe/BGO detector array

Coincident {gamma} rays from a {sup 252}Cf source were measured using an array of six segmented high-purity germanium (HPGe) Clover detectors each enclosed by 16 bismuth-germanate (BGO) detectors. The detectors were arranged in a cubic pattern around a 1 {micro}Ci {sup 252}Cf source to cover a large solid angle for {gamma}-ray measurement with a reasonable reconstruction of the multiplicity. Neutron multiplicity was determined in certain cases by identifying the prompt {gamma} rays from individual fission fragment pairs. Multiplicity distributions from previous experiments and theoretical models were convolved with the response function of the array and compared to the present results. These results suggest a {gamma}-ray multiplicity spectrum broader than previous measurements and models, and provide no evidence of correlation with neutron multiplicity.
Date: April 23, 2008
Creator: Bleuel, D L; Bernstein, L A; Burke, J T; Gibelin, J; Heffner, M D; Mintz, J et al.
Object Type: Article
System: The UNT Digital Library
Landscape predictions from cosmological vacuum selection (open access)

Landscape predictions from cosmological vacuum selection

In Bousso-Polchinski models with hundreds of fluxes, we compute the effects of cosmological dynamics on the probability distribution of landscape vacua. Starting from generic initial conditions, we find that most fluxes are dynamically driven into a different and much narrower range of values than expected from landscape statistics alone. Hence, cosmological evolution will access only a tiny fraction of the vacua with small cosmological constant. This leads to a host of sharp predictions. Unlike other approaches to eternal inflation, the holographic measure employed here does not lead to staggering, an excessive spread of probabilities that would doom the string landscape as a solution to the cosmological constant problem.
Date: April 23, 2007
Creator: Bousso, Raphael; Bousso, Raphael & Yang, Sheng
Object Type: Article
System: The UNT Digital Library