National Library of Energy BETA

Sample records for biosensor-guided synthetic evolution

  1. Design and Optimization of a Biochemical Production Platform with Biosensor-Guided Synthetic Evolution

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    3, 2015 DOE BETO Conversion Review Eric J. Steen, Ph.D. Lygos, Inc. DESIGN & OPTIMIZATION OF A BIOCHEMICAL PRODUCTION PLATFORM WITH BIOSENSOR-GUIDED SYNTHETIC EVOLUTION 2 CELLULOSIC SUGARS MALONYL-COA FATTY ACIDS MALONIC ACID § Malonyl-CoA lies on the carbon superhighway in biology § Pathway is compatible with all available, low-cost feedstocks § Malonyl-CoA is basis of fatty acid production (90%+ yields reported) § Malonic acid is an ideal molecule to produce biologically

  2. Synthetic Biology: Engineering, Evolution and Design (SEED) Conference 2014

    SciTech Connect (OSTI)

    Voigt, Christopher

    2014-07-01

    SEED2014 focused on advances in the science and technology emerging from the field of synthetic biology. We broadly define this as technologies that accelerate the process of genetic engineering. It highlighted new tool development, as well as the application of these tools to diverse problems in biotechnology, including therapeutics, industrial chemicals and fuels, natural products, and agriculture. Systems spanned from in vitro experiments and viruses, through diverse bacteria, to eukaryotes (yeast, mammalian cells, plants).

  3. CX-010216: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Design and Optimization of a Biochemical Production Platform with Biosensor-guided Synthetic Evolution CX(s) Applied: A9, B3.6 Date: 02/28/2013 Location(s): California Offices(s): Golden Field Office

  4. Dartmouth Stellar Evolution Database and the ACS Survey of Galactic Globular Clusters II. Stellar Evolution Tracks, Isochrones, Luminosity Functions, and Synthetic Horizontal-Branch Models

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Dotter, A; Chaboyer, B; Jevremovic, D; Kostov, V; Baron, E; Ferguson, J; Sarajedini, A; Anderson, J

    Web tools are also available at the home page (http://stellar.dartmouth.edu/~models/index.html). These tools allow users to create isochrones and convert them to luminosity functions or create synthetic horizontal branch models.

  5. Synthetic fuels

    SciTech Connect (OSTI)

    Not Available

    1989-01-01

    In January 1982, the Department of Energy guaranteed a loan for the construction and startup of the Great Plains project. On August 1, 1985, the partnership defaulted on the $1.54 billion loan, and DOE acquired control of, and then title to, the project. DOE continued to operate the plant, through the ANG Coal Gasification Company, and sell synthetic fuel. The DOE's ownership and divestiture of the plant is discussed.

  6. synthetic chemistry

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    synthetic chemistry - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Fuel Cycle Defense Waste Management Programs Advanced

  7. Establishment of stable synthetic mutualism without co-evolution between microalgae and bacteria demonstrated by mutual transfer of metabolites (NanoSIMS isotopic imaging) and persistent physical association (Fluorescent in situ hybridization)

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    de-Bashan, Luz E.; Mayali, Xavier; Bebout, Brad M.; Weber, Peter K.; Detweiler, Angela M.; Hernandez, Juan- Pablo; Prufert-Bebout, Leslie; Bashan, Yoav

    2016-03-03

    The demonstration of a mutualistic interaction requires evidence of benefits for both partners as well as stability of the association over multiple generations. A synthetic mutualism between the freshwater microalga Chlorella sorokiniana and the soil-derived plant growth-promoting bacterium (PGPB) Azospirillum brasilense was created when both microorganisms were co-immobilized in alginate beads. Using stable isotope enrichment experiments followed by high-resolution secondary ion mass spectrometry (SIMS) imaging of single cells, we demonstrated transfer of carbon and nitrogen compounds between the two partners. Further, using fluorescent in situ hybridization (FISH), mechanical disruption and scanning electron microscopy, we demonstrated the stability of their physicalmore » association for a period of 10 days after the aggregated cells were released from the beads. The bacteria significantly enhanced the growth of the microalgae while the microalgae supported growth of the bacteria in a medium where it could not otherwise grow. In conclusion, we propose that this microalga-bacterium association is a true synthetic mutualism independent of co-evolution. (155 words).« less

  8. Synthetic and Mechanistic Chemistry

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Synthetic and Mechanistic Chemistry Synthetic and Mechanistic Chemistry Synthetic and mechanistic chemical sciences play an important role in Lab missions dedicated to energy security, emerging challenges, global security, and core weapons missions. Get Expertise Dave Thorn Chemistry Program Manager Email Josh Smith Chemistry Communications Email "Research into alternative forms of energy, of which biofuels is a key component, is one of the major national security imperatives of this

  9. Synthetic and Mechanistic Chemistry

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and Mechanistic Chemistry Security at center of chemical and mechanistic chemistry research at Lab Project Description Los Alamos scientists are using synthetic and mechanistic chemistry to address energy security and other emerging challenges, including global security and core weapons missions. Synthetic chemistry includes work in ligands for catalysts, fission-products separations for isotope delivery, and labeled substrates for reaction mechanisms. Other research addresses materials

  10. Synthetic guide star generation

    DOE Patents [OSTI]

    Payne, Stephen A. (Castro Valley, CA) [Castro Valley, CA; Page, Ralph H. (Castro Valley, CA) [Castro Valley, CA; Ebbers, Christopher A. (Livermore, CA) [Livermore, CA; Beach, Raymond J. (Livermore, CA) [Livermore, CA

    2008-06-10

    A system for assisting in observing a celestial object and providing synthetic guide star generation. A lasing system provides radiation at a frequency at or near 938 nm and radiation at a frequency at or near 1583 nm. The lasing system includes a fiber laser operating between 880 nm and 960 nm and a fiber laser operating between 1524 nm and 1650 nm. A frequency-conversion system mixes the radiation and generates light at a frequency at or near 589 nm. A system directs the light at a frequency at or near 589 nm toward the celestial object and provides synthetic guide star generation.

  11. Synthetic guide star generation

    DOE Patents [OSTI]

    Payne, Stephen A.; Page, Ralph H.; Ebbers, Christopher A.; Beach, Raymond J.

    2004-03-09

    A system for assisting in observing a celestial object and providing synthetic guide star generation. A lasing system provides radiation at a frequency at or near 938 nm and radiation at a frequency at or near 1583 nm. The lasing system includes a fiber laser operating between 880 nm and 960 nm and a fiber laser operating between 1524 nm and 1650 nm. A frequency-conversion system mixes the radiation and generates light at a frequency at or near 589 nm. A system directs the light at a frequency at or near 589 nm toward the celestial object and provides synthetic guide star generation.

  12. Biodegradable synthetic bone composites

    DOE Patents [OSTI]

    Liu, Gao; Zhao, Dacheng; Saiz, Eduardo; Tomsia, Antoni P.

    2013-01-01

    The invention provides for a biodegradable synthetic bone composition comprising a biodegradable hydrogel polymer scaffold comprising a plurality of hydrolytically unstable linkages, and an inorganic component; such as a biodegradable poly(hydroxyethylmethacrylate)/hydroxyapatite (pHEMA/HA) hydrogel composite possessing mineral content approximately that of human bone.

  13. Synthetic and Mechanistic Chemistry publications

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Synthetic and Mechanistic Chemistry » Synthetic and Mechanistic Synthetic and Mechanistic publications Research into alternative forms of energy, especially energy security, is one of the major national security imperatives of this century. Get Expertise Dave Thorn Chemistry Program Manager Email Josh Smith Chemistry Communications Email "Research into alternative forms of energy, of which biofuels is a key component, is one of the major national security imperatives of this century.

  14. SYNTHETIC SLING FAILURE - EVALUATIONS & RECOMMENDATIONS

    SciTech Connect (OSTI)

    MACKEY TC; HENDERSON CS

    2009-10-26

    The information and evaluations provided in this report were compiled to address the recurring problem of synthetic sling failure. As safety is the number one priority in all work aspects, a solution must be devised to prevent accidents from occurring. A total of thirteen cases regarding synthetic sling failure were evaluated in order to determine their causes, effects, and preventative measures. From the collected data, it was found that all cases in which the synthetic sling contacted the edge of its load resulted in sling failure. It is required that adequate synthetic sling protection devices be used to protect slings in any lift where the sling comes in direct contact with the edge or corner of its load. However, there are no consensus codes or standards stating the type, material, or purpose of the type of protective device used to protect the sling from being cut. Numerous industry standards and codes provide vague descriptions on how to protect synthetic slings. Without a clear, concise statement of how to protect synthetic slings, it is common for inadequate materials and sling protection devices to be used in an attempt to meet the intent of these requirements. The use of an inadequate sling protection device is the main cause of synthetic sling failure in all researched cases. Commercial sling protection devices come in many shapes and sizes, and have a variety of names, as well as advertised uses. 'Abrasion pads' and 'wear protectors' are two different names for products with the same intended purpose. There is no distinguishable way to determine the extent of sling protection which these devices will provide, or what specific scenarios they are made for. This creates room for error in a field where error is unacceptable. This report provides a recommended action for hoisting and rigging activities which require synthetic slings to contact a load, as well as recommended changes to industry standards which will benefit overall industry safety.

  15. Differential Optical Synthetic Aperture Radar

    DOE Patents [OSTI]

    Stappaerts, Eddy A. (San Ramon, CA)

    2005-04-12

    A new differential technique for forming optical images using a synthetic aperture is introduced. This differential technique utilizes a single aperture to obtain unique (N) phases that can be processed to produce a synthetic aperture image at points along a trajectory. This is accomplished by dividing the aperture into two equal "subapertures", each having a width that is less than the actual aperture, along the direction of flight. As the platform flies along a given trajectory, a source illuminates objects and the two subapertures are configured to collect return signals. The techniques of the invention is designed to cancel common-mode errors, trajectory deviations from a straight line, and laser phase noise to provide the set of resultant (N) phases that can produce an image having a spatial resolution corresponding to a synthetic aperture.

  16. Synthetic substrates for enzyme analysis

    DOE Patents [OSTI]

    Bissell, E.R.; Mitchell, A.R.; Pearson, K.W.; Smith, R.E.

    1983-06-14

    Synthetic substrates are provided which may be represented as A-D. The A moiety includes an amino acid, polypeptide, or derivative. The D moiety includes 7-amino coumarin derivatives having an electron withdrawing substituent group at the 3 position carbon or fused between the 3 and 4 position carbons. No Drawings

  17. Synthetic substrates for enzyme analysis

    DOE Patents [OSTI]

    Bissell, Eugene R. (Alamo, CA); Mitchell, Alexander R. (Livermore, CA); Pearson, Karen W. (Livermore, CA); Smith, Robert E. (Livermore, CA)

    1983-01-01

    Synthetic substrates are provided which may be represented as A-D. The A moiety thereof includes an amino acid, polypeptide, or derivative thereof. The D moiety thereof includes 7-amino coumarin derivatives having an electron withdrawing substituent group at the 3 position carbon or fused between the 3 and 4 position carbons.

  18. Synthetic LDL as targeted drug delivery vehicle

    DOE Patents [OSTI]

    Forte, Trudy M. (Berkeley, CA); Nikanjam, Mina (Richmond, CA)

    2012-08-28

    The present invention provides a synthetic LDL nanoparticle comprising a lipid moiety and a synthetic chimeric peptide so as to be capable of binding the LDL receptor. The synthetic LDL nanoparticle of the present invention is capable of incorporating and targeting therapeutics to cells expressing the LDL receptor for diseases associated with the expression of the LDL receptor such as central nervous system diseases. The invention further provides methods of using such synthetic LDL nanoparticles.

  19. Synthetic thermoelectric materials comprising phononic crystals

    DOE Patents [OSTI]

    El-Kady, Ihab F; Olsson, Roy H; Hopkins, Patrick; Reinke, Charles; Kim, Bongsang

    2013-08-13

    Synthetic thermoelectric materials comprising phononic crystals can simultaneously have a large Seebeck coefficient, high electrical conductivity, and low thermal conductivity. Such synthetic thermoelectric materials can enable improved thermoelectric devices, such as thermoelectric generators and coolers, with improved performance. Such synthetic thermoelectric materials and devices can be fabricated using techniques that are compatible with standard microelectronics.

  20. Synthetic carbonaceous fuels and feedstocks

    DOE Patents [OSTI]

    Steinberg, Meyer (Huntington Station, NY)

    1980-01-01

    This invention relates to the use of a three compartment electrolytic cell in the production of synthetic carbonaceous fuels and chemical feedstocks such as gasoline, methane and methanol by electrolyzing an aqueous sodium carbonate/bicarbonate solution, obtained from scrubbing atmospheric carbon dioxide with an aqueous sodium hydroxide solution, whereby the hydrogen generated at the cathode and the carbon dioxide liberated in the center compartment are combined thermocatalytically into methanol and gasoline blends. The oxygen generated at the anode is preferably vented into the atmosphere, and the regenerated sodium hydroxide produced at the cathode is reused for scrubbing the CO.sub.2 from the atmosphere.

  1. Synthetic Antimicrobial Oligomers Induce Composition-dependent...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    generated in antimicrobial-membrane interactions is an essential step to elucidating such molecular mechanisms and therefore to the pre dictive design of synthetic AMP analogs. ...

  2. Synthetic Aperture Radar Persistent Scatterer Interferometry...

    Open Energy Info (EERE)

    NA, 2010 DOI Not Provided Check for DOI availability: http:crossref.org Online Internet link for Synthetic Aperture Radar Persistent Scatterer Interferometry (PSInSAR)...

  3. Sandia National Laboratories: Synthetic Aperture Radar (SAR)...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Synthetic Aperture Radar (SAR) Imagery The following is a selection of imagery available for your viewing, sorted by frequency band andor program. (Note: Resolutions are for...

  4. Synthetic Genomics Inc | Open Energy Information

    Open Energy Info (EERE)

    search Name: Synthetic Genomics Inc. Place: La Jolla, California Sector: Hydro, Hydrogen, Renewable Energy Product: California-based company planning to create new types of...

  5. Structural Evolution

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Evolution in the Neutron Rich-Nucleus 14 B Shadi Bedoor Department of Physics Western Michigan University We have studied 14 B employing two complementary reactions: 13 B(d,p)...

  6. Synthetic analogs of bacterial quorum sensors

    DOE Patents [OSTI]

    Iyer, Rashi (Los Alamos, NM); Ganguly, Kumkum (Los Alamos, NM); Silks, Louis A. (Los Alamos, NM)

    2011-12-06

    Bacterial quorum-sensing molecule analogs having the following structures: ##STR00001## and methods of reducing bacterial pathogenicity, comprising providing a biological system comprising pathogenic bacteria which produce natural quorum-sensing molecule; providing a synthetic bacterial quorum-sensing molecule having the above structures and introducing the synthetic quorum-sensing molecule into the biological system comprising pathogenic bacteria. Further is provided a method of targeted delivery of an antibiotic, comprising providing a synthetic quorum-sensing molecule; chemically linking the synthetic quorum-sensing molecule to an antibiotic to produce a quorum-sensing molecule-antibiotic conjugate; and introducing the conjugate into a biological system comprising pathogenic bacteria susceptible to the antibiotic.

  7. Synthetic analogs of bacterial quorum sensors

    DOE Patents [OSTI]

    Iyer, Rashi S.; Ganguly, Kumkum; Silks, Louis A.

    2013-01-08

    Bacterial quorum-sensing molecule analogs having the following structures: ##STR00001## and methods of reducing bacterial pathogenicity, comprising providing a biological system comprising pathogenic bacteria which produce natural quorum-sensing molecule; providing a synthetic bacterial quorum-sensing molecule having the above structures and introducing the synthetic quorum-sensing molecule into the biological system comprising pathogenic bacteria. Further is provided a method of targeted delivery of an antibiotic, comprising providing a synthetic quorum-sensing molecule; chemically linking the synthetic quorum-sensing molecule to an antibiotic to produce a quorum-sensing molecule-antibiotic conjugate; and introducing the conjugate into a biological system comprising pathogenic bacteria susceptible to the antibiotic.

  8. Performance limits for maritime Inverse Synthetic Aperture Radar...

    Office of Scientific and Technical Information (OSTI)

    Performance limits for maritime Inverse Synthetic Aperture Radar (ISAR). Citation Details In-Document Search Title: Performance limits for maritime Inverse Synthetic Aperture Radar...

  9. Synthetic heparin-binding growth factor analogs

    DOE Patents [OSTI]

    Pena, Louis A.; Zamora, Paul; Lin, Xinhua; Glass, John D.

    2007-01-23

    The invention provides synthetic heparin-binding growth factor analogs having at least one peptide chain that binds a heparin-binding growth factor receptor, covalently bound to a hydrophobic linker, which is in turn covalently bound to a non-signaling peptide that includes a heparin-binding domain. The synthetic heparin-binding growth factor analogs are useful as soluble biologics or as surface coatings for medical devices.

  10. Synthetic CO.sub.2 acceptor

    DOE Patents [OSTI]

    Lancet, Michael S. (Pittsburgh, PA); Curran, George P. (Pittsburgh, PA)

    1981-08-18

    A synthetic CO.sub.2 acceptor consisting essentially of at least one compound selected from the group consisting of calcium oxide and calcium carbonate supported in a refractory carrier matrix, the carrier having the general formula Ca.sub.5 (SiO.sub.4).sub.2 CO.sub.3. A method for producing the synthetic CO.sub.2 acceptor is also disclosed.

  11. Evolution Securities Ltd formerly Evolution Beeson Gregory |...

    Open Energy Info (EERE)

    7AN Product: Evolution Securities is the investment banking business of Evolution Group plc providing equity research, institutional sales and trading and corporate finance...

  12. New Synthetic Methods for Hypericum Natural Products

    SciTech Connect (OSTI)

    Insik Jeon

    2006-12-12

    Organic chemistry has served as a solid foundation for interdisciplinary research areas, such as molecular biology and medicinal chemistry. An understanding of the biological activities and structural elucidations of natural products can lead to the development of clinically valuable therapeutic options. The advancements of modern synthetic methodologies allow for more elaborate and concise natural product syntheses. The theme of this study centers on the synthesis of natural products with particularly challenging structures and interesting biological activities. The synthetic expertise developed here will be applicable to analog syntheses and to other research problems.

  13. Synthetic heparin-binding factor analogs

    DOE Patents [OSTI]

    Pena, Louis A.; Zamora, Paul O.; Lin, Xinhua; Glass, John D.

    2010-04-20

    The invention provides synthetic heparin-binding growth factor analogs having at least one peptide chain, and preferably two peptide chains branched from a dipeptide branch moiety composed of two trifunctional amino acid residues, which peptide chain or chains bind a heparin-binding growth factor receptor and are covalently bound to a non-signaling peptide that includes a heparin-binding domain, preferably by a linker, which may be a hydrophobic linker. The synthetic heparin-binding growth factor analogs are useful as pharmaceutical agents, soluble biologics or as surface coatings for medical devices.

  14. Cross-linked structure of network evolution

    SciTech Connect (OSTI)

    Bassett, Danielle S.; Wymbs, Nicholas F.; Grafton, Scott T.; Porter, Mason A.; CABDyN Complexity Centre, University of Oxford, Oxford, OX1 1HP ; Mucha, Peter J.; Department of Applied Physical Sciences, University of North Carolina, Chapel Hill, North Carolina 27599

    2014-03-15

    We study the temporal co-variation of network co-evolution via the cross-link structure of networks, for which we take advantage of the formalism of hypergraphs to map cross-link structures back to network nodes. We investigate two sets of temporal network data in detail. In a network of coupled nonlinear oscillators, hyperedges that consist of network edges with temporally co-varying weights uncover the driving co-evolution patterns of edge weight dynamics both within and between oscillator communities. In the human brain, networks that represent temporal changes in brain activity during learning exhibit early co-evolution that then settles down with practice. Subsequent decreases in hyperedge size are consistent with emergence of an autonomous subgraph whose dynamics no longer depends on other parts of the network. Our results on real and synthetic networks give a poignant demonstration of the ability of cross-link structure to uncover unexpected co-evolution attributes in both real and synthetic dynamical systems. This, in turn, illustrates the utility of analyzing cross-links for investigating the structure of temporal networks.

  15. Immobilization of radioiodine in synthetic boracite

    DOE Patents [OSTI]

    Babad, H.; Strachan, D.M.

    1982-09-23

    A nuclear waste storage product is disclosed in which radioiodine is incorporated in a synthetic boracite. The boracite may be prepared by reacting a transition metal iodide with an alkali horate under mild hydrothermal conditions, drying the reaction product, and then hot pressing.

  16. Coal based synthetic fuel technology assessment guides

    SciTech Connect (OSTI)

    Not Available

    1981-09-01

    Seventeen synthetic fuel processes are described in detail and compared on a uniform basis. This work was supported by the Energy Information Administration for the purpose of technology assessment of the processes, their efficiency, the capitalized and operating cost of plants of similar size, possible constraints, possible siting problems, regional effects, pollution control, etc. (LTN)

  17. Newmark-Hall synthetic history development

    SciTech Connect (OSTI)

    Aramayo, G.A.

    1990-11-01

    The methodology used to develop synthetic acceleration time histories with spectral content that envelopes the Newmark-Hall spectra is described. Six acceleration time histories are developed for two conditions of foundation and 3 critical damping factors. The target spectra corresponds to the mediam centered probability level.

  18. Micro/nanofabricated environments for synthetic biology

    SciTech Connect (OSTI)

    Collier, Pat [ORNL; Simpson, Michael L [ORNL

    2011-01-01

    A better understanding of how confinement, crowding and reduced dimensionality modulate reactivity and reaction dynamics will aid in the rational and systematic discovery of functionality in complex biological systems. Artificial micro- and nanofabricated structures have helped elucidate the effects of nanoscale spatial confinement and segregation on biological behavior, particularly when integrated with microfluidics, through precise control in both space and time of diffusible signals and binding interactions. Examples of nanostructured interfaces for synthetic biology include the development of cell-like compartments for encapsulating biochemical reactions, nanostructured environments for fundamental studies of diffusion, molecular transport and biochemical reaction kinetics, and regulation of biomolecular interactions as functions of micro- and nanofabricated topological constraints.

  19. A model for improving microbial biofuel production using a synthetic

    Office of Scientific and Technical Information (OSTI)

    feedback loop (Journal Article) | SciTech Connect A model for improving microbial biofuel production using a synthetic feedback loop Citation Details In-Document Search Title: A model for improving microbial biofuel production using a synthetic feedback loop Cells use feedback to implement a diverse range of regulatory functions. Building synthetic feedback control systems may yield insight into the roles that feedback can play in regulation since it can be introduced independently of native

  20. Vehicle Technologies Office Merit Review 2014: Synthetic Solutions for

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Correcting Voltage Fade in LMR-NMC Cathodes | Department of Energy Synthetic Solutions for Correcting Voltage Fade in LMR-NMC Cathodes Vehicle Technologies Office Merit Review 2014: Synthetic Solutions for Correcting Voltage Fade in LMR-NMC Cathodes Presentation given by Argonne National Laboratory at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about synthetic solutions for correcting voltage fade in LMR-NMC

  1. Synthetic biology and crop engineering | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Synthetic biology and crop engineering Synthetic biology and crop engineering Breakout Session 2: Frontiers and Horizons Session 2-A: Synthetic Biology and the Promise of Biofuels Jonathan Burbaum, Program Director, Department of Energy, Office of Science, ARPA-E PDF icon b13_burbaum_2-a.pdf More Documents & Publications EIS-0481: Final Programmatic Environmental Impact Statement EIS-0481: Draft Programmatic Environmental Impact Statement EIS-0481: Notice of Intent to Prepare a Programmatic

  2. Synthetic magnetoelectric coupling in a nanocomposite multiferroic

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Jain, P.; Wang, Q.; Roldan, M.; Glavic, A.; Lauter, V.; Urban, C.; Bi, Z.; Ahmed, T.; Zhu, J.; Varela, M.; et al

    2015-03-13

    Given the paucity of single phase multiferroic materials (with large ferromagnetic moment), composite systems seem an attractive solution to realize magnetoelectric coupling between ferromagnetic and ferroelectric order parameters. Despite having antiferromagnetic order, BiFeO₃ (BFO) has nevertheless been a key material due to excellent ferroelectric properties at room temperature. We studied a superlattice composed of 8 repetitions of 6 unit cells of La₀.₇Sr₀.₃MnO₃ (LSMO) grown on 5 unit cells of BFO. Significant net uncompensated magnetization in BFO, an insulating superlattice, is demonstrated using polarized neutron reflectometry. Remarkably, the magnetization enables magnetic field to change the dielectric properties of the superlattice, whichmore » we cite as an example of synthetic magnetoelectric coupling. Importantly, controlled creation of magnetic moment in BFO is a much needed path toward design and implementation of integrated oxide devices for next generation magnetoelectric data storage platforms.« less

  3. Inversion of synthetic aperture radar interferograms for sources...

    Open Energy Info (EERE)

    Inversion of synthetic aperture radar interferograms for sources of production-related subsidence at the Dixie Valley geothermal field Jump to: navigation, search OpenEI Reference...

  4. Synthetic Information and Decision Informatics for Complex Systems...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Dynamics & Simulation Science Laboratory SALISHAN 2010 Tackling Big Data: HPC Approaches to Informatics Synthetic Information and Decision Informatics for Complex Socially-Coupled...

  5. New synthetic strategy for porous molecular materials towards gas

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    separation | Center for Gas SeparationsRelevant to Clean Energy Technologies | Blandine Jerome New synthetic strategy for porous molecular materials towards gas separation

  6. A versatile synthetic route for the preparation of titanium metal...

    Office of Scientific and Technical Information (OSTI)

    metal-organic frameworks Citation Details In-Document Search Title: A versatile synthetic route for the preparation of titanium metal-organic frameworks Exploitation of new ...

  7. Environmental data energy technology characterizations: synthetic fuels

    SciTech Connect (OSTI)

    Not Available

    1980-04-01

    Environmental Data Energy Technology Characterizations are publications which are intended to provide policy analysts and technical analysts with basic environmental data associated with key energy technologies. This publication provides documentation on synthetic fuels (coal-derived and oil shale). The transformation of the energy in coal and oil shale into a more useful form is described in this publication in terms of major activity areas in the synthetic fuel cycles, that is, in terms of activities which produce either an energy product or a fuel leading to the production of an energy product in a different form. The activities discussed in this document are coal liquefaction, coal gasification, in-situ gasification, and oil shales. These activities represent both well-documented and advanced activity areas. The former activities are characterized in terms of actual operating data with allowance for future modification where appropriate. Emissions are assumed to conform to environmental standards. The advanced activity areas examined are those like coal liquefaction and in-situ retorting of oil shale. For these areas, data from pilot or demonstration plants were used where available; otherwise, engineering studies provided the data. The organization of the chapters in this volume is designed to support the tabular presentation in the summary volume. Each chapter begins with a brief description of the activity under consideration. The standard characteristics, size, availability, mode of functioning and place in the fuel cycle are presented. Next, major legislative and/or technological factors influencing the commercial operation of the activity are offered. Discussions of resources consumed, residuals produced, and economics follow. To aid in comparing and linking the different activity areas, data for each area are normalized to 10/sup 12/ Btu of energy output from the activity.

  8. Motion Measurement for Synthetic Aperture Radar.

    SciTech Connect (OSTI)

    Doerry, Armin W.

    2015-01-01

    Synthetic Aperture Radar (SAR) measures radar soundings from a set of locations typically along the flight path of a radar platform vehicle. Optimal focusing requires precise knowledge of the sounding source locations in 3 - D space with respect to the target scene. Even data driven focusing techniques (i.e. autofocus) requires some degree of initial fidelity in the measurements of the motion of the radar. These requirements may be quite stringent especially for fine resolution, long ranges, and low velocities. The principal instrument for measuring motion is typically an Inertial Measurement Unit (IMU), but these instruments have inherent limi ted precision and accuracy. The question is %22How good does an IMU need to be for a SAR across its performance space?%22 This report analytically relates IMU specifications to parametric requirements for SAR. - 4 - Acknowledgements Th e preparation of this report is the result of a n unfunded research and development activity . Although this report is an independent effort, it draws heavily from limited - release documentation generated under a CRADA with General Atomics - Aeronautical System, Inc. (GA - ASI), and under the Joint DoD/DOE Munitions Program Memorandum of Understanding. Sandia National Laboratories is a multi - program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of En ergy's National Nuclear Security Administration under contract DE - AC04 - 94AL85000.

  9. Computational optimization of synthetic water channels.

    SciTech Connect (OSTI)

    Rogers, David Michael; Rempe, Susan L. B.

    2012-12-01

    Membranes for liquid and gas separations and ion transport are critical to water purification, osmotic energy generation, fuel cells, batteries, supercapacitors, and catalysis. Often these membranes lack pore uniformity and robustness under operating conditions, which can lead to a decrease in performance. The lack of uniformity means that many pores are non-functional. Traditional membranes overcome these limitations by using thick membrane materials that impede transport and selectivity, which results in decreased performance and increased operating costs. For example, limitations in membrane performance demand high applied pressures to deionize water using reverse osmosis. In contrast, cellular membranes combine high flux and selective transport using membrane-bound protein channels operating at small pressure differences. Pore size and chemistry in the cellular channels is defined uniformly and with sub-nanometer precision through protein folding. The thickness of these cellular membranes is limited to that of the cellular membrane bilayer, about 4 nm thick, which enhances transport. Pores in the cellular membranes are robust under operating conditions in the body. Recent efforts to mimic cellular water channels for efficient water deionization produced a significant advance in membrane function. The novel biomimetic design achieved a 10-fold increase in membrane permeability to water flow compared to commercial membranes and still maintained high salt rejection. Despite this success, there is a lack of understanding about why this membrane performs so well. To address this lack of knowledge, we used highperformance computing to interrogate the structural and chemical environments experienced by water and electrolytes in the newly created biomimetic membranes. We also compared the solvation environments between the biomimetic membrane and cellular water channels. These results will help inform future efforts to optimize and tune the performance of synthetic biomimetic membranes for applications in water purification, energy, and catalysis.

  10. Synthetic muscle experiment will likely return to Earth in March |

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Princeton Plasma Physics Lab Synthetic muscle experiment will likely return to Earth in March By Jeanne Jackson DeVoe October 26, 2015 Tweet Widget Google Plus One Share on Facebook A photo taken by Astronaut Scott Kelly of a sample of the synthetic muscle experiment floating in the International Space Station. (Photo by Scott Kelly, Courtesy of NASA ) A photo taken by Astronaut Scott Kelly of a sample of the synthetic muscle experiment floating in the International Space Station. Gallery: A

  11. Synthetic muscle developed with PPPL scientists' help launches | Princeton

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Plasma Physics Lab muscle developed with PPPL scientists' help launches By Jeanne Jackson DeVoe April 8, 2015 Tweet Widget Google Plus One Share on Facebook Lenore Rasmussen examines a titanium coupon used in her synthetic muscle being treated in an oxygen plasma at PPPL. (Photo by Elle Starkman/PPPL Office of Communications) Lenore Rasmussen examines a titanium coupon used in her synthetic muscle being treated in an oxygen plasma at PPPL. Gallery: Lenore Rasmussen was one of several

  12. Synthetic muscle developed with PPPL scientists' help ready for launch |

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Princeton Plasma Physics Lab Synthetic muscle developed with PPPL scientists' help ready for launch By Jeanne Jackson DeVoe April 8, 2015 Tweet Widget Google Plus One Share on Facebook Gallery: The Dragon spacecraft in orbit. Photo courtesy of NASA) (Photo by Photo courtesy of NASA) The Dragon spacecraft in orbit. Photo courtesy of NASA) The synthetic muscle material before it was packed for transport to the International Space Station. ( Photo courtesy of NASA ) (Photo by Photo courtesy of

  13. Copy of Synthetic Biology of Novel Thermophilic Bacteria for Enhanced

    Office of Scientific and Technical Information (OSTI)

    Production of Ethanol from 5-Carbon Sugars (LDRD %23 105944). (Conference) | SciTech Connect Copy of Synthetic Biology of Novel Thermophilic Bacteria for Enhanced Production of Ethanol from 5-Carbon Sugars (LDRD %23 105944). Citation Details In-Document Search Title: Copy of Synthetic Biology of Novel Thermophilic Bacteria for Enhanced Production of Ethanol from 5-Carbon Sugars (LDRD %23 105944). Abstract not provided. Authors: Reichmuth, David ; Kozina, Carol L. ; Sale, Kenneth L. ;

  14. Designer synthetic media for studying microbial-catalyzed biofuel

    Office of Scientific and Technical Information (OSTI)

    production (Journal Article) | SciTech Connect Designer synthetic media for studying microbial-catalyzed biofuel production Citation Details In-Document Search Title: Designer synthetic media for studying microbial-catalyzed biofuel production Background: The fermentation inhibition of yeast or bacteria by lignocellulose-derived degradation products, during hexose/pentose co-fermentation, is a major bottleneck for cost-effective lignocellulosic biorefineries. To engineer microbial strains

  15. Designer synthetic media for studying microbial-catalyzed biofuel

    Office of Scientific and Technical Information (OSTI)

    production (Journal Article) | SciTech Connect Designer synthetic media for studying microbial-catalyzed biofuel production Citation Details In-Document Search Title: Designer synthetic media for studying microbial-catalyzed biofuel production × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional

  16. Development of a removable conformal coating through the synthetic

    Office of Scientific and Technical Information (OSTI)

    incorporation of Diels-Adler thermally reversible adducts into an epoxy resin. (Conference) | SciTech Connect Conference: Development of a removable conformal coating through the synthetic incorporation of Diels-Adler thermally reversible adducts into an epoxy resin. Citation Details In-Document Search Title: Development of a removable conformal coating through the synthetic incorporation of Diels-Adler thermally reversible adducts into an epoxy resin. An epoxy-based conformal coating with a

  17. A hybrid synthetic pathway for butanol production by a hyperthermophilic

    Office of Scientific and Technical Information (OSTI)

    microbe (Journal Article) | SciTech Connect A hybrid synthetic pathway for butanol production by a hyperthermophilic microbe Citation Details In-Document Search Title: A hybrid synthetic pathway for butanol production by a hyperthermophilic microbe Authors: Keller, Matthew W. ; Lipscomb, Gina L. ; Loder, Andrew J. ; Schut, Gerrit J. ; Kelly, Robert M. ; Adams, Michael W.W. Publication Date: 2015-01-01 OSTI Identifier: 1233934 Grant/Contract Number: AR0000081 Type: Publisher's Accepted

  18. Application of Synthetic Diesel Fuels | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Synthetic Diesel Fuels Application of Synthetic Diesel Fuels 2005 Diesel Engine Emissions Reduction (DEER) Conference Presentations and Posters PDF icon 2005_deer_schaberg.pdf More Documents & Publications Effect of GTL Diesel Fuels on Emissions and Engine Performance The Potential of GTL Diesel to Meet Future Exhaust Emission Limits Performance Characteristics of Coal-to-Liquids (CTL) Diesel in a 50-State Emissions Compliant Passenger Car

  19. Intramolecular hydrogen bonding as a synthetic tool to induce chemical

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    selectivity in acid catalyzed porphyrin synthesis Intramolecular hydrogen bonding as a synthetic tool to induce chemical selectivity in acid catalyzed porphyrin synthesis Authors: Megiatto, J. D., Patterson, D., Sherman, B. D., Moore, T. A., Gust, D., and Moore, A. L. Title: Intramolecular hydrogen bonding as a synthetic tool to induce chemical selectivity in acid catalyzed porphyrin synthesis Source: Chemical Communications Year: 2012 Volume: 48 Pages: 4558-4560 ABSTRACT: A straightforward

  20. Synthetic Biology of Novel Thermophilic Bacteria for Enhanced Production of

    Office of Scientific and Technical Information (OSTI)

    Ethanol from 5-Carbon Sugars (LDRD %23 105944). (Conference) | SciTech Connect Synthetic Biology of Novel Thermophilic Bacteria for Enhanced Production of Ethanol from 5-Carbon Sugars (LDRD %23 105944). Citation Details In-Document Search Title: Synthetic Biology of Novel Thermophilic Bacteria for Enhanced Production of Ethanol from 5-Carbon Sugars (LDRD %23 105944). Abstract not provided. Authors: Sapra, Rajat ; Reichmuth, David ; Kozina, Carol L. ; Sale, Kenneth L. ; Keasling, Jay ; Tang,

  1. Synthetic environment employing a craft for providing user perspective reference

    DOE Patents [OSTI]

    Maples, Creve (Albuquerque, NM); Peterson, Craig A. (Albuquerque, NM)

    1997-10-21

    A multi-dimensional user oriented synthetic environment system allows application programs to be programmed and accessed with input/output device independent, generic functional commands which are a distillation of the actual functions performed by any application program. A shared memory structure allows the translation of device specific commands to device independent, generic functional commands. Complete flexibility of the mapping of synthetic environment data to the user is thereby allowed. Accordingly, synthetic environment data may be provided to the user on parallel user information processing channels allowing the subcognitive mind to act as a filter, eliminating irrelevant information and allowing the processing of increase amounts of data by the user. The user is further provided with a craft surrounding the user within the synthetic environment, which craft, imparts important visual referential an motion parallax cues, enabling the user to better appreciate distances and directions within the synthetic environment. Display of this craft in close proximity to the user's point of perspective may be accomplished without substantially degrading the image resolution of the displayed portions of the synthetic environment.

  2. Evolution Energies | Open Energy Information

    Open Energy Info (EERE)

    Name: Evolution Energies Product: US-based designer and installer of large scale photovoltaic systems. References: Evolution Energies1 This article is a stub. You can help...

  3. Apparatus, systems, and methods for ultrasound synthetic aperature focusing

    DOE Patents [OSTI]

    Schuster, George J.; Crawford, Susan L.; Doctor, Steven R.; Harris, Robert V.

    2005-04-12

    One form of the present invention is a technique for interrogating a sample with ultrasound which includes: generating ultrasonic energy data corresponding to a volume of a sample and performing a synthetic aperture focusing technique on the ultrasonic energy data. The synthetic aperture focusing technique includes: defining a number of hyperbolic surfaces which extend through the volume at different depths and a corresponding number of multiple element accumulation vectors, performing a focused element calculation procedure for a group of vectors which are representative of the interior of a designated aperture, performing another focused element calculation procedure for vectors corresponding to the boundary of the aperture, and providing an image corresponding to features of the sample in accordance with the synthetic aperture focusing technique.

  4. Kapitza problem for the magnetic moments of synthetic antiferromagnetic systems

    SciTech Connect (OSTI)

    Dzhezherya, Yu. I.; Demishev, K. O.; Korenivskii, V. N.

    2012-08-15

    The dynamics of magnetization in synthetic antiferromagnetic systems with the magnetic dipole coupling in a rapidly oscillating field has been examined. It has been revealed that the system can behave similar to the Kapitza pendulum. It has been shown that an alternating magnetic field can be efficiently used to control the magnetic state of a cell of a synthetic antiferromagnet. Analytical relations have been obtained between the parameters of such an antiferromagnet and an external magnetic field at which certain quasistationary states are implemented.

  5. Dual chain synthetic heparin-binding growth factor analogs

    DOE Patents [OSTI]

    Zamora, Paul O.; Pena, Louis A.; Lin, Xinhua

    2009-10-06

    The invention provides synthetic heparin-binding growth factor analogs having two peptide chains each branched from a branch moiety, such as trifunctional amino acid residues, the branch moieties separated by a first linker of from 3 to about 20 backbone atoms, which peptide chains bind a heparin-binding growth factor receptor and are covalently bound to a non-signaling peptide that includes a heparin-binding domain, preferably by a second linker, which may be a hydrophobic second linker. The synthetic heparin-binding growth factor analogs are useful as pharmaceutical agents, soluble biologics or as surface coatings for medical devices.

  6. Dual chain synthetic heparin-binding growth factor analogs

    DOE Patents [OSTI]

    Zamora, Paul O.; Pena, Louis A.; Lin, Xinhua

    2012-04-24

    The invention provides synthetic heparin-binding growth factor analogs having two peptide chains each branched from a branch moiety, such as trifunctional amino acid residues, the branch moieties separated by a first linker of from 3 to about 20 backbone atoms, which peptide chains bind a heparin-binding growth factor receptor and are covalently bound to a non-signaling peptide that includes a heparin-binding domain, preferably by a second linker, which may be a hydrophobic second linker. The synthetic heparin-binding growth factor analogs are useful as pharmaceutical agents, soluble biologics or as surface coatings for medical devices.

  7. Synthetic aperture design for increased SAR image rate

    DOE Patents [OSTI]

    Bielek, Timothy P.; Thompson, Douglas G.; Walker, Bruce C.

    2009-03-03

    High resolution SAR images of a target scene at near video rates can be produced by using overlapped, but nevertheless, full-size synthetic apertures. The SAR images, which respectively correspond to the apertures, can be analyzed in sequence to permit detection of movement in the target scene.

  8. Renewable Energy from Synthetic Biology (LBNL Science at the Theater)

    ScienceCinema (OSTI)

    Keasling, Jay

    2011-04-28

    Jay Keasling, co-leader of Berkeley Lab's Helios Project, is a groundbreaking researcher in the new scientific field of synthetic biology. In Helios, he directs the biology program, incorporating a range of approaches to increasing the efficacy and economy of plants and cellulose-degrading microbes to make solar-based fuels. He is a UC Berkeley professor of Chemical and Bioengineering, and founder of Amyris Biotechnologies, a company that was honored as a Technology Pioneer for 2006 by the World Economic Forum. Keasling has succeeded in using synthetic biology to develop a yeast-based production scheme for precursors of the antimalarial drug artemisinin in work funded by the Bill & Melinda Gates Foundation.

  9. Synthetic aperture integration (SAI) algorithm for SAR imaging

    DOE Patents [OSTI]

    Chambers, David H; Mast, Jeffrey E; Paglieroni, David W; Beer, N. Reginald

    2013-07-09

    A method and system for detecting the presence of subsurface objects within a medium is provided. In some embodiments, the imaging and detection system operates in a multistatic mode to collect radar return signals generated by an array of transceiver antenna pairs that is positioned across the surface and that travels down the surface. The imaging and detection system pre-processes the return signal to suppress certain undesirable effects. The imaging and detection system then generates synthetic aperture radar images from real aperture radar images generated from the pre-processed return signal. The imaging and detection system then post-processes the synthetic aperture radar images to improve detection of subsurface objects. The imaging and detection system identifies peaks in the energy levels of the post-processed image frame, which indicates the presence of a subsurface object.

  10. Synthetic nanotubes lay foundation for new technology: Artificial pores

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    mimic key features of natural pores | Argonne National Laboratory Synthetic nanotubes lay foundation for new technology: Artificial pores mimic key features of natural pores By Tona Kunz * July 17, 2012 Tweet EmailPrint Scientists have overcome key design hurdles to expand the potential uses of nanopores and nanotubes. The creation of smart nanotubes with selective mass transport opens up a wider range of applications for water purification, chemical separation and fighting disease.

  11. Pentavalent Uranium Chemistry - Synthetic Pursuit Of A Rare Oxidation State

    SciTech Connect (OSTI)

    Graves, Christopher R; Kiplinger, Jaqueline L

    2009-01-01

    This feature article presents a comprehensive overview of pentavalent uranium systems in non-aqueous solution with a focus on the various synthetic avenues employed to access this unusual and very important oxidation state. Selected characterization data and theoretical aspects are also included. The purpose is to provide a perspective on this rapidly evolving field and identify new possibilities for future developments in pentavalent uranium chemistry.

  12. Kinetically tuned dimensional augmentation as a versatile synthetic route

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    towards robust metal-organic frameworks | Center for Gas SeparationsRelevant to Clean Energy Technologies | Blandine Jerome Kinetically tuned dimensional augmentation as a versatile synthetic route towards robust metal-organic frameworks Previous Next List Dawei Feng, Kecheng Wang, Zhangwen Wei, Ying-Pin Chen, Cory M. Simon, Ravi K. Arvapally, Richard L. Martin, Mathieu Bosch, Tian-Fu Liu, Stephen Fordham, Daqiang Yuan, Mohammad A. Omary, Maciej Haranczyk, Berend Smit & Hong-Cai Zhou,

  13. Sandia National Laboratories: Pathfinder Airborne ISR and Synthetic

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Aperture Radar (SAR) Systems Pathfinder Airborne ISR Systems What is SAR? Areas of Expertise Images VideoSAR Publications Facebook Twitter YouTube Flickr RSS Pathfinder Airborne ISR Systems Pathfinder Airborne ISR and Synthetic Aperture Radar (SAR) Systems Tactical Eyes for the Warfighter Tactical Eyes for the Warfighter Actionable Intelligence for the Decision Maker Actionable Intelligence for the Decision Maker All Weather, Persistent, Optical Like All Weather, Persistent, Optical Like

  14. CO2 Removal using a Synthetic Analogue of Carbonic Anhydrase

    SciTech Connect (OSTI)

    Harry Cordatos

    2010-09-14

    Project attempts to develop a synthetic analogue for carbonic anhydrase and incorporate it in a membrane for separation of CO2 from coal power plant flue gas. Conference poster presents result of first 9 months of project progress including concept, basic system architecture and membrane properties target, results of molecular modeling for analogue - CO2 interaction, and next steps of testing analogue resistance to flue gas contaminants.

  15. Method and apparatus for removing heat from electronic devices using synthetic jets

    DOE Patents [OSTI]

    Sharma, Rajdeep; Weaver, Stanton Earl; Seeley, Charles Erklin; Arik, Mehmet; Icoz, Tunc; Wolfe Jr, Charles Franklin; Utturkar, Yogen Vishwas

    2015-12-01

    An apparatus for removing heat comprises a heat sink having a cavity, and a synthetic jet stack comprising at least one synthetic jet mounted within the cavity. At least one rod and at least one engaging structure to provide a rigid positioning of the at least one synthetic jet with respect to the at least one rod. The synthetic jet comprises at least one orifice through which a fluid is ejected.

  16. Method and apparatus for removing heat from electronic devices using synthetic jets

    DOE Patents [OSTI]

    Sharma, Rajdeep; Weaver, Stanton Earl; Seeley, Charles Erklin; Arik, Mehmet; Icoz, Tunc; Wolfe, Jr., Charles Franklin; Utturkar, Yogen Vishwas

    2015-11-24

    An apparatus for removing heat comprises a heat sink having a cavity, and a synthetic jet stack comprising at least one synthetic jet mounted within the cavity. At least one rod and at least one engaging structure to provide a rigid positioning of the at least one synthetic jet with respect to the at least one rod. The synthetic jet comprises at least one orifice through which a fluid is ejected.

  17. Method and apparatus for removing heat from electronic devices using synthetic jets

    DOE Patents [OSTI]

    Sharma, Rajdeep; Weaver, Jr., Stanton Earl; Seeley, Charles Erklin; Arik, Mehmet; Icoz, Tunc; Wolfe, Jr., Charles Franklin; Utturkar, Yogen Vishwas

    2014-04-15

    An apparatus for removing heat comprises a heat sink having a cavity, and a synthetic jet stack comprising at least one synthetic jet mounted within the cavity. At least one rod and at least one engaging structure to provide a rigid positioning of the at least one synthetic jet with respect to the at least one rod. The synthetic jet comprises at least one orifice through which a fluid is ejected.

  18. Method for producing and regenerating a synthetic CO.sub.2 acceptor

    DOE Patents [OSTI]

    Lancet, Michael S. (Pittsburgh, PA); Curran, George P. (Pittsburgh, PA); Gorin, Everett (San Rafael, CA)

    1982-01-01

    A method for producing a synthetic CO.sub.2 acceptor by feeding a mixture of finely divided silica and at least one finely divided calcium compound selected from the group consisting of calcium oxide and calcium carbonate to a fluidized bed; operating the fluidized bed at suitable conditions to produce pellets of synthetic CO.sub.2 acceptor and recovering the pellets of synthetic CO.sub.2 acceptor from the fluidized bed. Optionally, spent synthetic CO.sub.2 acceptor can be charged to the fluidized bed to produce regenerated pellets of synthetic CO.sub.2 acceptor.

  19. Method for producing and regenerating a synthetic CO[sub 2] acceptor

    DOE Patents [OSTI]

    Lancet, M. S.; Curran, G. P.; Gorin, E.

    1982-05-18

    A method is described for producing a synthetic CO[sub 2] acceptor by feeding a mixture of finely divided silica and at least one finely divided calcium compound selected from the group consisting of calcium oxide and calcium carbonate to a fluidized bed; operating the fluidized bed at suitable conditions to produce pellets of synthetic CO[sub 2] acceptor and recovering the pellets of synthetic CO[sub 2] acceptor from the fluidized bed. Optionally, spent synthetic CO[sub 2] acceptor can be charged to the fluidized bed to produce regenerated pellets of synthetic CO[sub 2] acceptor. 1 fig.

  20. Apodized RFI filtering of synthetic aperture radar images

    SciTech Connect (OSTI)

    Doerry, Armin Walter

    2014-02-01

    Fine resolution Synthetic Aperture Radar (SAR) systems necessarily require wide bandwidths that often overlap spectrum utilized by other wireless services. These other emitters pose a source of Radio Frequency Interference (RFI) to the SAR echo signals that degrades SAR image quality. Filtering, or excising, the offending spectral contaminants will mitigate the interference, but at a cost of often degrading the SAR image in other ways, notably by raising offensive sidelobe levels. This report proposes borrowing an idea from nonlinear sidelobe apodization techniques to suppress interference without the attendant increase in sidelobe levels. The simple post-processing technique is termed Apodized RFI Filtering (ARF).

  1. Synthetic aperture radar images with composite azimuth resolution

    DOE Patents [OSTI]

    Bielek, Timothy P; Bickel, Douglas L

    2015-03-31

    A synthetic aperture radar (SAR) image is produced by using all phase histories of a set of phase histories to produce a first pixel array having a first azimuth resolution, and using less than all phase histories of the set to produce a second pixel array having a second azimuth resolution that is coarser than the first azimuth resolution. The first and second pixel arrays are combined to produce a third pixel array defining a desired SAR image that shows distinct shadows of moving objects while preserving detail in stationary background clutter.

  2. Phase correction system for automatic focusing of synthetic aperture radar

    DOE Patents [OSTI]

    Eichel, Paul H. (Albuquerque, NM); Ghiglia, Dennis C. (Placitas, NM); Jakowatz, Jr., Charles V. (Albuquerque, NM)

    1990-01-01

    A phase gradient autofocus system for use in synthetic aperture imaging accurately compensates for arbitrary phase errors in each imaged frame by locating highlighted areas and determining the phase disturbance or image spread associated with each of these highlight areas. An estimate of the image spread for each highlighted area in a line in the case of one dimensional processing or in a sector, in the case of two-dimensional processing, is determined. The phase error is determined using phase gradient processing. The phase error is then removed from the uncorrected image and the process is iteratively performed to substantially eliminate phase errors which can degrade the image.

  3. A versatile synthetic route for the preparation of titanium metal-organic

    Office of Scientific and Technical Information (OSTI)

    frameworks (Journal Article) | SciTech Connect A versatile synthetic route for the preparation of titanium metal-organic frameworks Citation Details In-Document Search Title: A versatile synthetic route for the preparation of titanium metal-organic frameworks Exploitation of new titanium metal-organic frameworks (Ti-MOFs) with high crystallinity has been attracting great attention due to their vast application potential in photocatalysis. Herein a versatile synthetic strategy, namely, High

  4. Time-frequency analysis of synthetic aperture radar signals

    SciTech Connect (OSTI)

    Johnston, B.

    1996-08-01

    Synthetic aperture radar (SAR) has become an important tool for remote sensing of the environment. SAR is a set of digital signal processing algorithms that are used to focus the signal returned to the radar because radar systems in themselves cannot produce the high resolution images required in remote sensing applications. To reconstruct an image, several parameters must be estimated and the quality of output image depends on the degree of accuracy of these parameters. In this thesis, we derive the fundamental SAR algorithms and concentrate on the estimation of one of its critical parameters. We show that the common technique for estimating this particular parameter can sometimes lead to erroneous results and reduced quality images. We also employ time-frequency analysis techniques to examine variations in the radar signals caused by platform motion and show how these results can be used to improve output image quality.

  5. Interpretation of Synthetic Aperture Radar measurements of ocean currents

    SciTech Connect (OSTI)

    Rufenach, C.L.; Shuchman, R.A.; Lyzenga, D.R.

    1983-02-28

    Synthetic Aperture Radar (SAR) experiments hae been performed over the last few years to measure ocean currents inferred from shifts in the Doppler spectral peak. Interpretations of aircraft SAR measurements, when compared with limited surface values, tend to underestimate the currents by about 25%. A theory is developed that modifies the classical Doppler expression showing that the radar measurements are dependent on the radar processor (system) bandwidth and the received signal bandwidth. Measured bandwidths give a correction that increases the inferred current values by about 25%, bringing the measurements into good agreement. This new correction lends credence to the theory and increases the potential for application of SAR systems to future ocean current measurements. SAR measurements should include the determination of processor and signal bandwidths such that this correction can be applied.

  6. Moving receive beam method and apparatus for synthetic aperture radar

    DOE Patents [OSTI]

    Kare, Jordin T. (San Ramon, CA)

    2001-01-01

    A method and apparatus for improving the performance of Synthetic Aperture Radar (SAR) systems by reducing the effect of "edge losses" associated with nonuniform receiver antenna gain. By moving the receiver antenna pattern in synchrony with the apparent motion of the transmitted pulse along the ground, the maximum available receiver antenna gain can be used at all times. Also, the receiver antenna gain for range-ambiguous return signals may be reduced, in some cases, by a large factor. The beam motion can be implemented by real-time adjustment of phase shifters in an electronically-steered phased-array antenna or by electronic switching of feed horns in a reflector antenna system.

  7. Innovative regulatory approach for synthetic-based muds.

    SciTech Connect (OSTI)

    Veil, J. A.

    1998-10-22

    The oil and gas industry has historically used water-based muds (WBMs) and oil-based muds (OBMs) in offshore drilling operations. WBMs are less expensive and are widely used. Both the WBMs and the associated drill cuttings maybe discharged from the platform to the sea provided that U.S. Environmental Protection Agency (EPA) discharge limitations are met. In some wells, however, difficult drilling conditions may force a switch from a WBM to an OBM. Neither the OBM nor the associated drill cuttings may be discharged. The OBM is hauled to shore, where it is processed for reuse, while the associated cuttings are injected in a disposal well at the platform or hauled to shore to a disposal facility. Both of these options are expensive. Synthetic-based muds (SBMs) are drilling fluids that use synthetic organic chemicals as base fluids. SBMs were developed to replace OBMs in difficult drilling situations. SBMs are more expensive than OBMs; however, they have superior environmental properties that may permit the cuttings to be discharged on-site. Like OBMs, SBMs are hauled ashore for processing and reuse after the well is drilled. The existing national effluent limitations guidelines (ELGs) for the offshore industry do not include requirements for SBM-cuttings since SBMs were not commonly in use at the time the ELGs were adopted. In late 1997, EPA announced that it would modify the offshore ELGs to include requirements for discharges of cuttings drilled with SBMs. For the first time in the history of the ELG program, EPA is following an innovative presumptive rulemaking process that will lead to development of draft regulations in one year rather than the 4- to 6-year period usually needed. With direction from the federal government to stakeholders concerning information needs for the regulatory development the industry has established several working groups to collect new scientific information on SBMs. This paper describes the presumptive rulemaking process and summarizes the findings of the work groups to date.

  8. Gas evolution from geopressured brines

    SciTech Connect (OSTI)

    Matthews, C.S.

    1980-06-01

    The process of gas evolution from geopressured brine is examined using as a basis the many past studies of gas evolution from liquids in porous media. A discussion of a number of speculations that have been made concerning gas evolution from geopressured brines is provided. According to one, rapid pressure reduction will cause methane gas to evolve as when one opens a champagne bottle. It has been further speculated that evolved methane gas would migrate up to form an easily producible cap. As a result of detailed analyses, it can be concluded that methane gas evolution from geopressured brines is far too small to ever form a connected gas saturation except very near to the producing well. Thus, no significant gas cap could ever form. Because of the very low solubility of methaned in brine, the process of methane gas evolution is not at all analogous to evolution of carbon dioxide from champagne. A number of other speculations and questions on gas evolution are analyzed, and procedures for completing wells and testing geopressured brine reservoirs are discussed, with the conclusion that presently used procedures will provide adequate data to enable a good evaluation of this resource.

  9. Findings and recommendations of the advisory panel on synthetic fuels. Advisory panel on synthetic fuels. Report for the Committee on Science and Technology, US House of Representatives

    SciTech Connect (OSTI)

    Not Available

    1980-01-01

    In a report to the US House of Representatives Committee on Science and Technology, the Advisory Panel defines the most critical energy problem facing the US: obtaining a sufficient supply of liquid hydrocarbons for transportation fuel and for other applications where substitution would be difficult, costly, and time-consuming. Any substantial contribution from synthetic fuels must involve the use of coal, oil shale, and biomass, with the raw materials coming from as many different regions of the country as possible. The panel makes recommendations regarding (1) the emphasis of the Department of Energy's synthetic-fuel demonstration program, (2) implementation of a synthetic-fuel production program, and (3) mitigation of the environmental and socioeconomic impacts of synthetic-fuel production. The panel specifically maintains that federal assistance to commercial-scale projects should be available on a competitive basis to those organizations willing to take substantial marketing risks.

  10. Microstructural Evolution of EGR Cooler Deposits | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Evolution of EGR Cooler Deposits Microstructural Evolution of EGR Cooler Deposits Characterize the thermo-physical properties of the deposit under different operating conditions on ...

  11. Erratum: Evolution of antiferromagnetic susceptibility under...

    Office of Scientific and Technical Information (OSTI)

    Erratum: Evolution of antiferromagnetic susceptibility under uniaxial pressure in Ba ( Fe ... Citation Details In-Document Search Title: Erratum: Evolution of antiferromagnetic ...

  12. FUNDING OPPORTUNITY ANNOUNCEMENT: SOLAR ENERGY EVOLUTION AND...

    Energy Savers [EERE]

    FUNDING OPPORTUNITY ANNOUNCEMENT: SOLAR ENERGY EVOLUTION AND DIFFUSION STUDIES II - STATE ENERGY STRATEGIES (SEEDSII-SES) FUNDING OPPORTUNITY ANNOUNCEMENT: SOLAR ENERGY EVOLUTION ...

  13. Modeling Solar Energy Technology Evolution breakout session ...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Modeling Solar Energy Technology Evolution breakout session Modeling Solar Energy Technology Evolution breakout session This presentation summarizes the information given on the ...

  14. New light on human evolution

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    New light on human evolution New light on human evolution Scientists recently unearthed 8 million-year-old gorilla fossils from the Chorora Formation in Ethiopia, which indicate the human evolutionary split took place 10 million years ago. February 19, 2016 Human-gorilla divergence may have occurred two million years earlier than thought (Photo : Flickr: Rod Waddington) Human-gorilla divergence may have occurred two million years earlier than thought (Photo : Flickr: Rod Waddington) "Our

  15. ARM - Evolution of the Atmosphere

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ListEvolution of the Atmosphere Outreach Home Room News Publications Traditional Knowledge Kiosks Barrow, Alaska Tropical Western Pacific Site Tours Contacts Students Study Hall About ARM Global Warming FAQ Just for Fun Meet our Friends Cool Sites Teachers Teachers' Toolbox Lesson Plans Evolution of the Atmosphere The earth's atmosphere plays a crucial role in shaping the weather, climate, and life-supporting systems. However, the ocean and atmosphere are the earth's fluid outer layers and are

  16. Photoreactive synthetic regulator of protein function and methods of use thereof

    DOE Patents [OSTI]

    Trauner, Dirk; Isacoff, Ehud Y; Kramer, Richard H; Banghart, Matthew R; Fortin, Doris L; Mourot, Alexandre

    2015-03-31

    The present disclosure provides a photoreactive synthetic regulator of protein function. The present disclosure further provides a light-regulated polypeptide that includes a subject synthetic regulator. Also provided are cells and membranes comprising a subject light-regulated polypeptide. The present disclosure further provides methods of modulating protein function, involving use of light.

  17. Recent Advances on Carbon Nanospheres: Synthetic Routes and Applications

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhang, Pengfei; Qiao, Zhenan; Dai, Sheng

    2015-04-02

    Carbon-based materials are the most popular material types in both fundamental research and industrial applications, partly because of their well-controlled nano-morphologies. In the past two decades, we have witnessed a number of breakthroughs in carbon research: fullerenes, carbon nanotubes, and more recently graphene. Nowadays, carbon nanospheres are attracting more and more attention worldwide due to their excellent performance in various fields: drug delivery, heterogeneous catalysis, encapsulation of support and electrode materials. Actually, spherical carbon is an old material, whereas controlling carbon spheres in the nanometer range is a recent story. In the past 5 years, it has become possible tomore »precisely control the particle size, surface area, pore size, chemical composition, and dispersity of carbon nanospheres. Toward this end, a number of synthetic strategies are emerging, such as hydrothermal carbonization of biomass-based resources, extended Stöber synthesis, and organic–organic self-assembly via different binding methods. In this feature article, we summarize recent routes for carbon nanospheres and briefly touch on their applications to shed light on the potential of this field. Throughout this article, a special emphasis is placed on the possible modulation of spherical structures at the nanoscale, and we wish to inspire many more designs and applications of carbon nanostructures in the near future.« less

  18. Lynx: A High-Resolution Synthetic Aperture Radar

    SciTech Connect (OSTI)

    Doerry, A.W.; Hensley, W.H.; Pace, F.; Stence, J.; Tsunoda, S.I.; Walker, B.C.; Woodring, M.

    1999-03-08

    Lynx is a high resolution, synthetic aperture radar (SAR) that has been designed and built by Sandia National Laboratories in collaboration with General Atomics (GA). Although Lynx may be operated on a wide variety of manned and unmanned platforms, it is primarily intended to be fielded on unmanned aerial vehicles. In particular, it may be operated on the Predator, I-GNAT, or Prowler II platforms manufactured by GA Aeronautical Systems, Inc. The Lynx production weight is less than 120 lb. and has a slant range of 30 km (in 4 mm/hr rain). It has operator selectable resolution and is capable of 0.1 m resolution in spotlight mode and 0.3 m resolution in stripmap mode. In ground moving target indicator mode, the minimum detectable velocity is 6 knots with a minimum target cross-section of 10 dBsm. In coherent change detection mode, Lynx makes registered, complex image comparisons either of 0.1 m resolution (minimum) spotlight images or of 0.3 m resolution (minimum) strip images. The Lynx user interface features a view manager that allows it to pan and zoom like a video camera. Lynx was developed under corporate finding from GA and will be manufactured by GA for both military and commercial applications. The Lynx system architecture will be presented and some of its unique features will be described. Imagery at the finest resolutions in both spotlight and strip modes have been obtained and will also be presented.

  19. Antibody evolution could guide HIV vaccine development

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Antibody evolution could guide HIV vaccine development Antibody evolution could guide HIV vaccine development The antibody studied is called a broadly cross-reactive neutralizing antibody, and details of its generation could provide a blueprint for effective vaccination. April 4, 2013 Co-evolution of virus and antibody - The evolution of the viral protein (green) from 14 weeks through 100 weeks post-transmission is compared to the maturation of the human antibody. Co-evolution of virus and

  20. Phenomenological implementations of TMD evolution

    SciTech Connect (OSTI)

    Boglione, Mariaelena; Gonzalez Hernandez, Jose Osvaldo; Melis, Stefano; Prokudin, Alexey

    2015-03-01

    Although the theoretical set-up of TMD evolution appears to be well established, its phenomenological implementations still require special attention, particularly as far as the interplay between perturbative and non-perturbative contributions is concerned. These issues have been extensively studied in Drell-Yan processes, where they seem to be reasonably under control. Instead, applying the same prescriptions and methodologies to Semi-Inclusive Deep Inelastic (SIDIS) processes is, at present, far from obvious. Some of the controversies related to the applications of TMD Evolution to SIDIS processes will be discussed with practical examples, exploring different kinematical configurations of SIDIS experiments.

  1. Designer synthetic media for studying microbial-catalyzed biofuel production

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Tang, Xiaoyu; da Costa Sousa, Leonardo; Jin, Mingjie; Chundawat, Shishir; Chambliss, Charles; Lau, Ming W; Xiao, Zeyi; Dale, Bruce E; Balan, Venkatesh

    2015-01-01

    Background: The fermentation inhibition of yeast or bacteria by lignocellulose-derived degradation products, during hexose/pentose co-fermentation, is a major bottleneck for cost-effective lignocellulosic biorefineries. To engineer microbial strains for improved performance, it is critical to understand the mechanisms of inhibition that affect fermentative organisms in the presence of major components of a lignocellulosic hydrolysate. The development of a synthetic lignocellulosic hydrolysate (SH) media with a composition similar to the actual biomass hydrolysate will be an important advancement to facilitate these studies. In this work, we characterized the nutrients and plant-derived decomposition products present in AFEX™ pretreated corn stover hydrolysate (ACH). Themore » SH was formulated based on the ACH composition and was further used to evaluate the inhibitory effects of various families of decomposition products during Saccharomyces cerevisiae 424A (LNH-ST) fermentation. Results: The ACH contained high levels of nitrogenous compounds, notably amides, pyrazines, and imidazoles. In contrast, a relatively low content of furans and aromatic and aliphatic acids were found in the ACH. Though most of the families of decomposition products were inhibitory to xylose fermentation, due to their abundance, the nitrogenous compounds showed the most inhibition. From these compounds, amides (products of the ammonolysis reaction) contributed the most to the reduction of the fermentation performance. However, this result is associated to a concentration effect, as the corresponding carboxylic acids (products of hydrolysis) promoted greater inhibition when present at the same molar concentration as the amides. Due to its complexity, the formulated SH did not perfectly match the fermentation profile of the actual hydrolysate, especially the growth curve. However, the SH formulation was effective for studying the inhibitory effect of various compounds on yeast fermentation. Conclusions: The formulation of SHs is an important advancement for future multi-omics studies and for better understanding the mechanisms of fermentation inhibition in lignocellulosic hydrolysates. The SH formulated in this work was instrumental for defining the most important inhibitors in the ACH. Major AFEX decomposition products are less inhibitory to yeast fermentation than the products of dilute acid or steam explosion pretreatments; thus, ACH is readily fermentable by yeast without any detoxification.« less

  2. Designer synthetic media for studying microbial-catalyzed biofuel production

    SciTech Connect (OSTI)

    Tang, Xiaoyu [Biogas Inst. of Ministry of Agriculture, Chengdu (China); da Costa Sousa, Leonardo [Michigan State Univ., East Lansing, MI (United States); Jin, Mingjie [Michigan State Univ., East Lansing, MI (United States); Chundawat, Shishir [Michigan State Univ., East Lansing, MI (United States); State Univ. of New Jersey, Piscataway, NJ (United States); Chambliss, Charles [Baylor Univ., Waco, TX (United States); Lau, Ming W [Michigan State Univ., East Lansing, MI (United States); Xiao, Zeyi [Sichuan Univ., Chengdu (China); Dale, Bruce E [Michigan State Univ., East Lansing, MI (United States); Balan, Venkatesh [Michigan State Univ., East Lansing, MI (United States)

    2015-01-01

    Background: The fermentation inhibition of yeast or bacteria by lignocellulose-derived degradation products, during hexose/pentose co-fermentation, is a major bottleneck for cost-effective lignocellulosic biorefineries. To engineer microbial strains for improved performance, it is critical to understand the mechanisms of inhibition that affect fermentative organisms in the presence of major components of a lignocellulosic hydrolysate. The development of a synthetic lignocellulosic hydrolysate (SH) media with a composition similar to the actual biomass hydrolysate will be an important advancement to facilitate these studies. In this work, we characterized the nutrients and plant-derived decomposition products present in AFEX pretreated corn stover hydrolysate (ACH). The SH was formulated based on the ACH composition and was further used to evaluate the inhibitory effects of various families of decomposition products during Saccharomyces cerevisiae 424A (LNH-ST) fermentation. Results: The ACH contained high levels of nitrogenous compounds, notably amides, pyrazines, and imidazoles. In contrast, a relatively low content of furans and aromatic and aliphatic acids were found in the ACH. Though most of the families of decomposition products were inhibitory to xylose fermentation, due to their abundance, the nitrogenous compounds showed the most inhibition. From these compounds, amides (products of the ammonolysis reaction) contributed the most to the reduction of the fermentation performance. However, this result is associated to a concentration effect, as the corresponding carboxylic acids (products of hydrolysis) promoted greater inhibition when present at the same molar concentration as the amides. Due to its complexity, the formulated SH did not perfectly match the fermentation profile of the actual hydrolysate, especially the growth curve. However, the SH formulation was effective for studying the inhibitory effect of various compounds on yeast fermentation. Conclusions: The formulation of SHs is an important advancement for future multi-omics studies and for better understanding the mechanisms of fermentation inhibition in lignocellulosic hydrolysates. The SH formulated in this work was instrumental for defining the most important inhibitors in the ACH. Major AFEX decomposition products are less inhibitory to yeast fermentation than the products of dilute acid or steam explosion pretreatments; thus, ACH is readily fermentable by yeast without any detoxification.

  3. Synthetic Coal Slag Infiltration into Varying Refractory Materials

    SciTech Connect (OSTI)

    Kaneko, Tetsuya K.; Thomas, Hugh; Bennett, James P.; Sridhar, Seetharaman

    2012-10-01

    The infiltrations of synthetic coal slag into 99%Al{sub 2}O{sub 3}, 85%Al{sub 2}O{sub 3}15%SiO{sub 2}, and 90%Cr{sub 2}O{sub 3}10%Al{sub 2}O{sub 3} refractories with a temperature gradient induced along the penetration direction were compared to one another. The infiltrating slag was synthesized with a composition that is representative of an average of the ash contents from U S coal feedstock. Experiments were conducted with a hot-face temperature of 1450C in a CO/CO{sub 2} atmosphere. Minimal penetration was observed in the 90%Cr{sub 2}O{sub 3}10%Al{sub 2}O{sub 3} material because interactions between the refractory and the slag produced a protective layer of FeCr{sub 2}O{sub 4}, which impeded slag flow into the bulk of the refractory. After 5 h, the 99%Al{sub 2}O{sub 3} sample exhibited an average penetration of 12.7 mm whereas the 85%Al{sub 2}O{sub 3}15%SiO{sub 2} sample showed 3.8 mm. Slag infiltrated into the 99%Al{sub 2}O{sub 3} and 85%Al{sub 2}O{sub 3}15%SiO{sub 2} refractory systems by dissolving the respective refractories' matrix materials, which consist of fine Al{sub 2}O{sub 3} particles and an amorphous alumino-silicate phase. Due to enrichment in SiO{sub 2}, a network-former, infiltration into the 85%Al{sub 2}O{sub 3}15%SiO{sub 2} system yielded a higher viscosity slag and hence, a shallower penetration depth. The results suggest that slag infiltration can be limited by interactions with the refractory through the formation of either a solid layer that physically impedes fluid flow or a more viscous slag that retards infiltration.

  4. Perpendicular magnetic tunnel junctions with double barrier and single or synthetic antiferromagnetic storage layer

    SciTech Connect (OSTI)

    Cuchet, La; Rodmacq, Bernard; Auffret, Stphane; Sousa, Ricardo C.; Prejbeanu, Ioan L.; Dieny, Bernard

    2015-06-21

    The magnetic properties of double tunnel junctions with perpendicular anisotropy were investigated. Two synthetic antiferromagnetic references are used, while the middle storage magnetic layer can be either a single ferromagnetic or a synthetic antiferromagnetic FeCoB-based layer, with a critical thickness as large as 3.0?nm. Among the different achievable magnetic configurations in zero field, those with either antiparallel references, and single ferromagnetic storage layer, or parallel references, and synthetic antiferromagnetic storage layer, are of particular interest since they allow increasing the efficiency of spin transfer torque writing and the thermal stability of the stored information as compared to single tunnel junctions. The latter configuration can be preferred when stray fields would favour a parallel orientation of the reference layers. In this case, the synthetic antiferromagnetic storage layer is also less sensitive to residual stray fields.

  5. Structural framework, stratigraphy, and evolution of Brazilian marginal basins

    SciTech Connect (OSTI)

    Ojeda, H.A.O.

    1982-06-01

    The structural framework of the Brazilian continental margin is basically composed of eight structural types: antithetic tilted step-fault blocks, synthetic untilted step-fault blocks, structural inversion axes, hinges with compensation grabens, homoclinal structures, growth faults with rollovers, diapirs, and igneous structures. The antithetic tilted and synthetic untilted step-fault blocks are considered as synchronous, complementary structural systems, separated by an inversion axis. Two evaporitic cycles (Paripueira and Ibura) were differentiated in the Sergipe-Alagoas type basin and tentatively correlated to the evaporitic section of other Brazilian marginal basis. Four phases are considered in the evolution of the Brazilian marginal basins: pre-rift, rift, transitional, and drift. During the pre-rift phase (Late Jurassic-Early Cretaceous), continental sediments were deposited in peripheral intracratonic basins. In the rift phase (Early Cretaceous), the breakup of the continental crust of the Gondwana continent gave rise to a central graben and rift valleys where lacustrine sediments were deposited. The transitional phase (Aptian) developed under relative tectonic stability, when evaporitic and clastic lacustrine sequences were being deposited. In the drift phase (Albian to Holocene), a regionl homoclinal structure developed, consisting of two distinct sedimentary sequences, a lower clastic-carbonate and an upper clastic. From the Albian to the Holocene Epoch, structures associated to plastic displacement of salt or shale developed in many Brazilian marginal basins. Two phases of major igneous activity occurred: one in the Early Cretaceous associated with the rift phase of the Gondwana continent, and the other in the Tertiary during the migration phase of the South American and African plates.

  6. System and method for forming synthetic protein crystals to determine the conformational structure by crystallography

    DOE Patents [OSTI]

    Craig, G.D.; Glass, R.; Rupp, B.

    1997-01-28

    A method is disclosed for forming synthetic crystals of proteins in a carrier fluid by use of the dipole moments of protein macromolecules that self-align in the Helmholtz layer adjacent to an electrode. The voltage gradients of such layers easily exceed 10{sup 6}V/m. The synthetic protein crystals are subjected to x-ray crystallography to determine the conformational structure of the protein involved. 2 figs.

  7. System and method for forming synthetic protein crystals to determine the conformational structure by crystallography

    DOE Patents [OSTI]

    Craig, George D.; Glass, Robert; Rupp, Bernhard

    1997-01-01

    A method for forming synthetic crystals of proteins in a carrier fluid by use of the dipole moments of protein macromolecules that self-align in the Helmholtz layer adjacent to an electrode. The voltage gradients of such layers easily exceed 10.sup.6 V/m. The synthetic protein crystals are subjected to x-ray crystallography to determine the conformational structure of the protein involved.

  8. Lighting system with thermal management system having point contact synthetic jets

    DOE Patents [OSTI]

    Arik, Mehmet; Weaver, Stanton Earl; Kuenzler, Glenn Howard; Wolfe, Jr., Charles Franklin; Sharma, Rajdeep

    2013-12-10

    Lighting system having unique configurations are provided. For instance, the lighting system may include a light source, a thermal management system and driver electronics, each contained within a housing structure. The light source is configured to provide illumination visible through an opening in the housing structure. The thermal management system includes a plurality of synthetic jets. The synthetic jets are arranged within the lighting system such that they are secured at contact points.

  9. Process for gasification using a synthetic CO.sub.2 acceptor

    DOE Patents [OSTI]

    Lancet, Michael S. (Pittsburgh, PA); Curran, George P. (Pittsburgh, PA)

    1980-01-01

    A gasification process is disclosed using a synthetic CO.sub.2 acceptor consisting essentially of at least one compound selected from the group consisting of calcium oxide and calcium carbonate supported in a refractory carrier matrix, the carrier having the general formula Ca.sub.5 (SiO.sub.4).sub.2 CO.sub.3. A method for producing the synthetic CO.sub.2 acceptor is also disclosed.

  10. Synthetic Design Microorganisms for Lignin Fuels and Chemicals Presentation for BETO 2015 Project Peer Review

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Synthetic Design Microorganisms for Lignin Fuels and Chemicals 3/26/2015 Synthetic Biology Joshua S. Yuan Associate Professor and Director Texas A&M University This presentation does contain proprietary information 1 Project Goal: Design of Microorganisms for Lignin Fuel * The proposed research aims to address one of the most challenging issues in biofuel production: the utilization of lignin for fungible fuels. * Project Outcome: A viable biological platform for conversion of lignin into

  11. Interactions of Jet Fuels with Nitrile O-Rings: Petroleum-Derived versus Synthetic Fuels

    SciTech Connect (OSTI)

    Gormley, R.J.; Link, D.D.; Baltrus, J.P.; Zandhuis, P.H.

    2008-01-01

    A transition from petroleum-derived jet fuels to blends with Fischer-Tropsch (F-T) fuels, and ultimately fully synthetic hydro-isomerized F-T fuels has raised concern about the fate of plasticizers in nitrile-butadiene rubber o-rings that are contacted by the fuels as this transition occurs. The partitioning of plasticizers and fuel molecules between nitrile o-rings and petroleum-derived, synthetic, and additized-synthetic jet fuels has been measured. Thermal desorption of o-rings soaked in the various jet fuels followed by gas chromatographic analysis with a mass spectrometric detector showed many of the plasticizer and stabilizer compounds were removed from the o-rings regardless of the contact fuel. Fuel molecules were observed to migrate into the o-rings for the petroleum-derived fuel as did both the fuel and additive for a synthetic F-T jet fuel additized with benzyl alcohol, but less for the unadditized synthetic fuel. The specific compounds or classes of compounds involved in the partitioning were identified and a semiquantitative comparison of relative partitioning of the compounds of interest was made. The results provide another step forward in improving the confidence level of using additized, fuIly synthetic jet fuel in the place of petroleum-derived fueL

  12. Interactions of Jet Fuels with Nitrile O-Rings: Petroleum-Derived versus Synthetic Fuels

    SciTech Connect (OSTI)

    Gormley, R.J.; Link, D.D.; Baltrus, J.P.; Zandhuis, P.H.

    2009-01-01

    A transition from petroleum-derived jet fuels to blends with Fischer-Tropsch (F-T) fuels, and ultimately fully synthetic hydro-isomerized F-T fuels has raised concern about the fate of plasticizers in nitrile-butadiene rubber a-rings that are contacted by the fuels as this transition occurs. The partitioning of plasticizers and fuel molecules between nitrile a-rings and petroleum-derived, synthetic, and additized-synthetic jet fuels has been measured. Thermal desorption of o-rings soaked in the various jet fuels followed by gas chromatographic analysis with a mass spectrometric detector showed many of the plasticizer and stabilizer compounds were removed from the o-rings regardless of the contact fuel. Fuel molecules were observed to migrate into the o-rings for the petroleum-derived fuel as did both the fuel and additive for a synthetic F-T jet fuel additized with benzyl alcohol, but less for the unadditized synthetic fuel. The specific compounds or classes of compounds involved in the partitioning were identified and a semiquantitative comparison of relative partitioning of the compounds of interest was made. The results provide another step forward in improving the confidence level of using additized, fully synthetic jet fuel in the place of petroleum-derived fuel.

  13. Procedure for matching synfuel users with potential suppliers. Appendix B. Proposed and ongoing synthetic fuel production projects

    SciTech Connect (OSTI)

    1981-08-07

    To assist the Department of Energy, Office of Fuels Conversion (OFC), in implementing the synthetic fuel exemption under the Powerplant and Industrial Fuel Use Act (FUA) of 1978, Resource Consulting Group, Inc. (RCG), has developed a procedure for matching prospective users and producers of synthetic fuel. The matching procedure, which involves a hierarchical screening process, is designed to assist OFC in: locating a supplier for a firm that wishes to obtain a synthetic fuel exemption; determining whether the fuel supplier proposed by a petitioner is technically and economically capable of meeting the petitioner's needs; and assisting the Synthetic Fuels Corporation or a synthetic fuel supplier in evaluating potential markets for synthetic fuel production. A data base is provided in this appendix on proposed and ongoing synthetic fuel production projects to be used in applying the screening procedure. The data base encompasses a total of 212 projects in the seven production technologies.

  14. Fracture Evolution Following a Hydraulic Stimulation within an...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Evolution Following a Hydraulic Stimulation within an EGS Reservoir Fracture Evolution Following a Hydraulic Stimulation within an EGS Reservoir Fracture Evolution Following a ...

  15. Evolution of twisted magnetic fields

    SciTech Connect (OSTI)

    Zweibel, E.G.; Boozer, A.H.

    1985-02-01

    The magnetic field of the solar corona evolves quasistatically in response to slowly changing photospheric boundary conditions. The magnetic topology is preserved by the low resistivity of the solar atmosphere. We show that a magnetic flux coordinate system simplifies the problem of calculating field evolution with invariant topology. As an example, we calculate the equilibrium of a thin magnetic flux tube with small twist per unit length.

  16. Co-Evolution of Biofuels

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Evolution of Biofuels - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Fuel Cycle Defense Waste Management Programs Advanced

  17. A bio-synthetic interface for discovery of viral entry mechanisms.

    SciTech Connect (OSTI)

    Gutzler, Mike; Maar, Dianna; Negrete, Oscar; Hayden, Carl C.; Sasaki, Darryl Yoshio; Stachowiak, Jeanne C.; Wang, Julia

    2010-09-01

    Understanding and defending against pathogenic viruses is an important public health and biodefense challenge. The focus of our LDRD project has been to uncover the mechanisms enveloped viruses use to identify and invade host cells. We have constructed interfaces between viral particles and synthetic lipid bilayers. This approach provides a minimal setting for investigating the initial events of host-virus interaction - (i) recognition of, and (ii) entry into the host via membrane fusion. This understanding could enable rational design of therapeutics that block viral entry as well as future construction of synthetic, non-proliferating sensors that detect live virus in the environment. We have observed fusion between synthetic lipid vesicles and Vesicular Stomatitis virus particles, and we have observed interactions between Nipah virus-like particles and supported lipid bilayers and giant unilamellar vesicles.

  18. Simulation of Heterogeneous Atom Probe Tip Shapes Evolution during Field Evaporation Using a Level Set Method and Different Evaporation Models

    SciTech Connect (OSTI)

    Xu, Zhijie; Li, Dongsheng; Xu, Wei; Devaraj, Arun; Colby, Robert J.; Thevuthasan, Suntharampillai; Geiser, B. P.; Larson, David J.

    2015-04-01

    In atom probe tomography (APT), accurate reconstruction of the spatial positions of field evaporated ions from measured detector patterns depends upon a correct understanding of the dynamic tip shape evolution and evaporation laws of component atoms. Artifacts in APT reconstructions of heterogeneous materials can be attributed to the assumption of homogeneous evaporation of all the elements in the material in addition to the assumption of a steady state hemispherical dynamic tip shape evolution. A level set method based specimen shape evolution model is developed in this study to simulate the evaporation of synthetic layered-structured APT tips. The simulation results of the shape evolution by the level set model qualitatively agree with the finite element method and the literature data using the finite difference method. The asymmetric evolving shape predicted by the level set model demonstrates the complex evaporation behavior of heterogeneous tip and the interface curvature can potentially lead to the artifacts in the APT reconstruction of such materials. Compared with other APT simulation methods, the new method provides smoother interface representation with the aid of the intrinsic sub-grid accuracy. Two evaporation models (linear and exponential evaporation laws) are implemented in the level set simulations and the effect of evaporation laws on the tip shape evolution is also presented.

  19. Emissions from Buses with DDC 6V92 Engines Using Synthetic Diesel Fuel

    SciTech Connect (OSTI)

    Paul Norton; Keith Vertin; Nigel N. Clark; Donald W. Lyons; Mridul Gautam; Stephen Goguen; James Eberhardt

    1999-05-03

    Synthetic diesel fuel can be made from a variety of feedstocks, including coal, natural gas and biomass. Synthetic diesel fuels can have very low sulfur and aromatic content, and excellent autoignition characteristics. Moreover, synthetic diesel fuels may also economically competitive with California diesel fuel if .roduced in large volumes. Previous engine laboratory and field tests using a heavy-duty chassis dynamometer indicate that synthetic diesel fuel made using the Fischer-Tropsch (F-T) catalytic conversion process is a promising alternative fuel, because it can be used in unmodified diesel engines, and can reduce exhaust emissions substantially. The objective of this study was a preliminary assessment of the emissions from older model transit operated on Mossgas synthetic diesel fuel. The study compared emissions from transit buses operating on Federal no. 2 Diesel fuel, Mossgas synthetic diesel (MGSD), and a 50/50 blend of the two fuels. The buses were equipped with unmodified Detroit Diesel 6V92 2-stroke diesel engines. Six 40-foot buses were tested. Three of the buses had recently rebuilt engines and were equipped with an oxidation catalytic converter. Vehicle emissions measurements were performed using West Virginia University's unique transportable chassis dynamometer. The emissions were measured over the Central Business District (CBD) driving cycle. The buses performed well on both neat and blended MGSD fuel. Three buses without catalytic converters were tested. Compared to their emissions when operating on Federal no. 2 diesel fuel, these buses emitted an average of 5% lower oxides of nitrogen (NOx) and 20% lower particulate matter (PM) when operating on neat MGSD fuel. Catalyst equipped buses emitted an average of 8% lower NOx and 31% lower PM when operating on MGSD than when operating on Federal no. 2 diesel fuel.

  20. Synthetic peptides that cause F-actin bundling and block actin depolymerization

    DOE Patents [OSTI]

    Sederoff, Heike; Huber, Steven C; Larabell, Carolyn A

    2011-10-18

    Synthetic peptides derived from sucrose synthase, and having homology to actin and actin-related proteins, sharing a common motif, useful for causing acting bundling and preventing actin depolymerization. Peptides exhibiting the common motif are described, as well as specific synthetic peptides which caused bundled actin and inhibit actin depolymerization. These peptides can be useful for treating a subject suffering from a disease characterized by cells having neoplastic growth, for anti-cancer therapeutics, delivered to subjects solely, or concomitantly or sequentially with other known cancer therapeutics. These peptides can also be used for stabilizing microfilaments in living cells and inhibiting growth of cells.

  1. MineSeis -- A MATLAB{reg_sign} GUI program to calculate synthetic

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    seismograms from a linear, multi-shot blast source model (Technical Report) | SciTech Connect MineSeis -- A MATLAB{reg_sign} GUI program to calculate synthetic seismograms from a linear, multi-shot blast source model Citation Details In-Document Search Title: MineSeis -- A MATLAB{reg_sign} GUI program to calculate synthetic seismograms from a linear, multi-shot blast source model × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of

  2. A Versatile Synthetic Route for the Preparation of Titanium Metal-Organic

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Frameworks | Center for Gas SeparationsRelevant to Clean Energy Technologies | Blandine Jerome A Versatile Synthetic Route for the Preparation of Titanium Metal-Organic Frameworks Previous Next List Zou, Lanfang; Feng, Dawei; Liu, Tian-Fu; Chen, Ying-Pin; Yuan, Shuai; Wang, Kecheng; Wang, Xuan; Fordham, Stephen; and Zhou, Hong-Cai. A Versatile Synthetic Route for the Preparation of Titanium Metal-Organic Frameworks. Chem. Sci., 7, 1063-1069 (2016). DOI: 10.1039/c5sc03620h

  3. March 15 PSERC Webinar: Synthetic Power Grid Models: What are They. How

    Energy Savers [EERE]

    They're Made, and Why They Matter | Department of Energy March 15 PSERC Webinar: Synthetic Power Grid Models: What are They. How They're Made, and Why They Matter March 15 PSERC Webinar: Synthetic Power Grid Models: What are They. How They're Made, and Why They Matter March 3, 2016 - 11:10am Addthis The DOE-funded Power Systems Engineering Research Center (PSERC) is offering a free public webinar that will address the problems with obtaining data from power grid models, and the inadequacies

  4. TWO-DIMENSIONAL CELLULAR AUTOMATON MODEL FOR THE EVOLUTION OF ACTIVE REGION CORONAL PLASMAS

    SciTech Connect (OSTI)

    Lpez Fuentes, Marcelo; Klimchuk, James A.

    2015-02-01

    We study a two-dimensional cellular automaton (CA) model for the evolution of coronal loop plasmas. The model is based on the idea that coronal loops are made of elementary magnetic strands that are tangled and stressed by the displacement of their footpoints by photospheric motions. The magnetic stress accumulated between neighbor strands is released in sudden reconnection events or nanoflares that heat the plasma. We combine the CA model with the Enthalpy Based Thermal Evolution of Loops model to compute the response of the plasma to the heating events. Using the known response of the X-Ray Telescope on board Hinode, we also obtain synthetic data. The model obeys easy-to-understand scaling laws relating the output (nanoflare energy, temperature, density, intensity) to the input parameters (field strength, strand length, critical misalignment angle). The nanoflares have a power-law distribution with a universal slope of 2.5, independent of the input parameters. The repetition frequency of nanoflares, expressed in terms of the plasma cooling time, increases with strand length. We discuss the implications of our results for the problem of heating and evolution of active region coronal plasmas.

  5. Basics of Polar-Format algorithm for processing Synthetic Aperture Radar images.

    SciTech Connect (OSTI)

    Doerry, Armin Walter

    2012-05-01

    The purpose of this report is to provide a background to Synthetic Aperture Radar (SAR) image formation using the Polar Format (PFA) processing algorithm. This is meant to be an aid to those tasked to implement real-time image formation using the Polar Format processing algorithm.

  6. Monoclonal antibodies to synthetic pyrethroids and method for detecting the same

    DOE Patents [OSTI]

    Stanker, Larry H. (Livermore, CA); Vanderlaan, Martin (Danville, CA); Watkins, Bruce E. (Livermore, CA); Van Emon, Jeanette M. (Henderson, NV); Bigbee, Carolyn L. (Livermore, CA)

    1992-01-01

    Methods are described for making specific monoclonal antibodies which may be used in a sensitive immunoassay for detection of synthetic pyrethroids in foods and environmental samples. Appropriate sample preparation and enzyme amplification of the immunoassay for this widely-used class of pesticides permits detection at low levels in laboratory and field tested samples.

  7. Monoclonal antibodies to synthetic pyrethroids and method for detecting the same

    DOE Patents [OSTI]

    Stanker, L.H.; Vanderlaan, M.; Watkins, B.E.; Van Emon, J.M.; Bigbee, C.L.

    1992-04-28

    Methods are described for making specific monoclonal antibodies which may be used in a sensitive immunoassay for detection of synthetic pyrethroids in foods and environmental samples. Appropriate sample preparation and enzyme amplification of the immunoassay for this widely-used class of pesticides permits detection at low levels in laboratory and field tested samples. 6 figs.

  8. Angular correlations and high energy evolution

    SciTech Connect (OSTI)

    Kovner, Alex; Lublinsky, Michael

    2011-11-01

    We address the question of to what extent JIMWLK evolution is capable of taking into account angular correlations in a high energy hadronic wave function. Our conclusion is that angular (and indeed other) correlations in the wave function cannot be reliably calculated without taking into account Pomeron loops in the evolution. As an example we study numerically the energy evolution of angular correlations between dipole scattering amplitudes in the framework of the large N{sub c} approximation to JIMWLK evolution (the 'projectile dipole model'). Target correlations are introduced via averaging over an (isotropic) ensemble of anisotropic initial conditions. We find that correlations disappear very quickly with rapidity even inside the saturation radius. This is in accordance with our physical picture of JIMWLK evolution. The actual correlations inside the saturation radius in the target QCD wave function, on the other hand, should remain sizable at any rapidity.

  9. Helicity evolution at small-x

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kovchegov, Yuri V.; Pitonyak, Daniel; Sievert, Matthew D.

    2016-01-13

    We construct small-x evolution equations which can be used to calculate quark and anti-quark helicity TMDs and PDFs, along with the g1 structure function. These evolution equations resum powers of αs ln2(1/x) in the polarization-dependent evolution along with the powers of αs ln(1/x) in the unpolarized evolution which includes saturation efects. The equations are written in an operator form in terms of polarization-dependent Wilson line-like operators. While the equations do not close in general, they become closed and self-contained systems of non-linear equations in the large-Nc and large-Nc & Nf limits. As a cross-check, in the ladder approximation, our equationsmore » map onto the same ladder limit of the infrared evolution equations for g1 structure function derived previously by Bartels, Ermolaev and Ryskin.« less

  10. Evolution of gluon TMD at low and moderate x

    SciTech Connect (OSTI)

    Tarasov, Andrey; Balitsky, Ian

    2015-03-01

    We study how the rapidity evolution of gluon transverse momentum dependent distribution changes from nonlinear evolution at small x << 1 to linear double-logarithmic evolution at moderate x ~ 1.

  11. Rapidity evolution of gluon TMD from low to moderate x

    SciTech Connect (OSTI)

    Balitsky, Ian; Tarasov, A.

    2015-10-05

    In this article, we study how the rapidity evolution of gluon transverse momentum dependent distribution changes from nonlinear evolution at small $x \\ll 1$ to linear evolution at moderate $x \\sim 1$.

  12. Rapidity evolution of gluon TMD from low to moderate x

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Balitsky, Ian; Tarasov, A.

    2015-10-05

    In this article, we study how the rapidity evolution of gluon transverse momentum dependent distribution changes from nonlinear evolution at smallmore » $$x \\ll 1$$ to linear evolution at moderate $$x \\sim 1$$.« less

  13. FILAMENTARY STAR FORMATION: OBSERVING THE EVOLUTION TOWARD FLATTENED ENVELOPES

    SciTech Connect (OSTI)

    Lee, Katherine; Looney, Leslie; Johnstone, Doug; Tobin, John E-mail: lwl@illinois.edu E-mail: jtobin@nrao.edu

    2012-12-20

    Filamentary structures are ubiquitous from large-scale molecular clouds (a few parsecs) to small-scale circumstellar envelopes around Class 0 sources ({approx}1000 AU to {approx}0.1 pc). In particular, recent observations with the Herschel Space Observatory emphasize the importance of large-scale filaments (a few parsecs) and star formation. The small-scale flattened envelopes around Class 0 sources are reminiscent of the large-scale filaments. We propose an observationally derived scenario for filamentary star formation that describes the evolution of filaments as part of the process for formation of cores and circumstellar envelopes. If such a scenario is correct, small-scale filamentary structures (0.1 pc in length) with higher densities embedded in starless cores should exist, although to date almost all the interferometers have failed to observe such structures. We perform synthetic observations of filaments at the prestellar stage by modeling the known Class 0 flattened envelope in L1157 using both the Combined Array for Research in Millimeter-wave Astronomy (CARMA) and the Atacama Large Millimeter/Submillimeter Array (ALMA). We show that with reasonable estimates for the column density through the flattened envelope, the CARMA D array at 3 mm wavelengths is not able to detect such filamentary structure, so previous studies would not have detected them. However, the substructures may be detected with the CARMA D+E array at 3 mm and the CARMA E array at 1 mm as a result of more appropriate resolution and sensitivity. ALMA is also capable of detecting the substructures and showing the structures in detail compared to the CARMA results with its unprecedented sensitivity. Such detection will confirm the new proposed paradigm of non-spherical star formation.

  14. U.S. Natural Gas Supplemental Gas - Synthetic Natural Gas (Million Cubic

    Annual Energy Outlook [U.S. Energy Information Administration (EIA)]

    Feet) Synthetic Natural Gas (Million Cubic Feet) U.S. Natural Gas Supplemental Gas - Synthetic Natural Gas (Million Cubic Feet) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5 Year-6 Year-7 Year-8 Year-9 1980's 123,543 128,003 103,025 95,634 78,632 91,074 81,951 67,017 62,021 67,190 1990's 64,073 62,131 69,229 70,051 67,693 65,335 58,637 55,809 57,387 55,938 2000's 51,958 53,693 55,786 55,794 49,976 53,921 56,971 53,788 53,090 55,934 2010's 57,279 53,745 55,032 48,375 51,127 - = No Data

  15. Method for forming a layer of synthetic corrosion products on tubing surfaces

    DOE Patents [OSTI]

    Lane, Michael H. (Clifton Park, NY); Salamon, Eugene J. M. (Clifton Park, NY)

    1996-01-01

    A method is provided for forming a synthetic corrosion product layer on tube surfaces. The method utilizes two dissimilar materials with different coefficients of thermal expansion. An object tube and sacrificial tube are positioned one inside the other such that an annular region is created between the two tubes' surfaces. A slurry of synthetic corrosion products is injected into this annular region and the assembly is heat treated. This heat causes the tubes to expand, the inner tube with the higher coefficient of expansion expanding more than the outer tube, thereby creating internal pressures which consolidate the corrosion products and adhere the corrosion products to the tubing surfaces. The sacrificial tube may then be removed by conventional chemical etching or mechanical methods.

  16. Synthetic Fuel

    ScienceCinema (OSTI)

    Idaho National Laboratory - Steve Herring, Jim O'Brien, Carl Stoots

    2010-01-08

    Two global energy priorities today are finding environmentally friendly alternatives to fossil fuels, and reducing greenhouse gass Two global energy priorities today are finding environmentally friendly alternatives to fossil fuels, and reducing greenhous

  17. Electrode Materials for Rechargeable Lithium-Ion Batteries: A New Synthetic

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Approach | Argonne National Laboratory Electrode Materials for Rechargeable Lithium-Ion Batteries: A New Synthetic Approach Technology available for licensing: New high-energy cathode materials for use in rechargeable lithium-ion cells and batteries synthesized by using a novel alternative approach Lowers battery pack cost. Layered cathode material contains low-cost manganese, which operates at high rate and high voltage and results in a high-energy-density battery with improved stability.

  18. Synthetic Biology for Tailored Enzyme Cocktails Presentation for BETO 2015 Project Peer Review

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    March 2015 SynTec Synthetic Biology for Tailored Enzyme Cocktails DOE Bioenergy Technologies Office (BETO) 2015 Project Peer Review Biochemical Conversion Sarah Teter Novozymes, Inc This presentation does not contain any proprietary, confidential, or otherwise restricted information NOVOZYMES PRESENTATION 26 Mar 2015 2 ACCELERATE INNOVATION IN ENZYME DISCOVERY REDUCE COSTS FOR PRODUCING CELLULOSIC SUGARS  Deliver a screening platform which can be used to reduce discovery time required for

  19. Synthetic Metabolic Pathways for Bioconversion of Lignin Derivatives to Biofuels Presentation for BETO Project Peer Review

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Synthetic Metabolic Pathways for Bioconversion of Lignin Derivatives to Biofuels WBS: 2.3.2.104 March 25, 2015 Technology Area Review: Biochemical Conversion Principal Investigator: Adam M. Guss Organization: Oak Ridge National Laboratory 2 Goal Statement * Goal: Develop microbial biocatalysts to convert lignin-rich streams into value-added products * Relevance: Adding value to the lignin fraction of plant biomass will improve the economics of biorefineries to enable a bioeconomy Fuels +

  20. Constraining Cosmic Evolution of Type Ia Supernovae (Journal...

    Office of Scientific and Technical Information (OSTI)

    Constraining Cosmic Evolution of Type Ia Supernovae Citation Details In-Document Search Title: Constraining Cosmic Evolution of Type Ia Supernovae We present the first large-scale...

  1. Constraining Cosmic Evolution of Type Ia Supernovae (Journal...

    Office of Scientific and Technical Information (OSTI)

    Constraining Cosmic Evolution of Type Ia Supernovae Citation Details In-Document Search Title: Constraining Cosmic Evolution of Type Ia Supernovae You are accessing a document...

  2. Temperature evolution of electromotive force from Pt on yttrium...

    Office of Scientific and Technical Information (OSTI)

    Temperature evolution of electromotive force from Pt on yttrium-iron-garnet under ferromagnetic resonance Citation Details In-Document Search Title: Temperature evolution of ...

  3. THE REDSHIFT EVOLUTION OF THE RELATION BETWEEN STELLAR MASS,...

    Office of Scientific and Technical Information (OSTI)

    REDSHIFT EVOLUTION OF THE RELATION BETWEEN STELLAR MASS, STAR FORMATION RATE, AND GAS METALLICITY OF GALAXIES Citation Details In-Document Search Title: THE REDSHIFT EVOLUTION OF ...

  4. Evolution of silicic magma chambers and their relationship to...

    Office of Scientific and Technical Information (OSTI)

    Conference: Evolution of silicic magma chambers and their relationship to basaltic volcanism Citation Details In-Document Search Title: Evolution of silicic magma chambers and ...

  5. Structure Evolution and Pulverization of Tin Nanoparticles during...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Structure Evolution and Pulverization of Tin Nanoparticles during Lithiation-Delithiation Cycling. Citation Details In-Document Search Title: Structure Evolution ...

  6. Big Data Projects on Solar Technology Evolution and Diffusion...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Soft Costs Big Data Projects on Solar Technology Evolution and Diffusion: Kickoff Meeting Big Data Projects on Solar Technology Evolution and Diffusion: Kickoff Meeting Graphic ...

  7. Intergranular Strain Evolution near Fatigue Crack Tips in Polycrystall...

    Office of Scientific and Technical Information (OSTI)

    Intergranular Strain Evolution near Fatigue Crack Tips in Polycrystalline Metals Citation Details In-Document Search Title: Intergranular Strain Evolution near Fatigue Crack Tips ...

  8. Detection and characterization of multi-filament evolution during...

    Office of Scientific and Technical Information (OSTI)

    of multi-filament evolution during resistive switching. Citation Details In-Document Search Title: Detection and characterization of multi-filament evolution during resistive ...

  9. HyDIVE (Hydrogen Dynamic Infrastructure and Vehicle Evolution...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    HyDIVE (Hydrogen Dynamic Infrastructure and Vehicle Evolution) Model Analysis HyDIVE (Hydrogen Dynamic Infrastructure and Vehicle Evolution) Model Analysis Presentation by NREL's ...

  10. Centrality evolution of the charged-particle pseudorapidity density...

    Office of Scientific and Technical Information (OSTI)

    Centrality evolution of the charged-particle pseudorapidity density over a broad ... Citation Details In-Document Search Title: Centrality evolution of the charged-particle ...

  11. On the Lack of Evolution in Galaxy Star Formation Efficiency...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: On the Lack of Evolution in Galaxy Star Formation Efficiency Citation Details In-Document Search Title: On the Lack of Evolution in Galaxy Star Formation...

  12. Synthetic fuels and the environment: an environmental and regulatory impacts analysis

    SciTech Connect (OSTI)

    1980-06-01

    Since July 1979 when DOE/EV-0044 report Environmental Analysis of Synthetic Liquid fuels was published the synthetic fuels program proposals of the Administration have undergone significant modifications. The program year for which the development goal of 1.5 million barrels per day is to be reached has been changed from 1990 to 1995. The program plan is now proposed to have two stages to ensure, among other things, better environmental protection: an initial stage emphasizing applied research and development (R and D), including environmental research, followed by a second stage that would accelerate deployment of those synthetic fuel technologies then judged most ready for rapid deployment and economic operation within the environmental protection requirements. These program changes have significantly expanded the scope of technologies to be considered in this environmental analysis and have increased the likelihood that accelerated environmental R and D efforts will be successful in solving principal environmental and worker safety concerns for most technologies prior to the initiation of the second stage of the accelerated deployment plan. Information is presented under the following section headings: summary; study description; the technologies and their environmental concerns (including, coal liquefaction and gasification, oil shale production, biomass and urban waste conversion); regulatory and institutional analyses; and environmental impacts analysis (including air and water quaility analyses, impacts of carbon dioxide and acid rain, water availability, solid and hazardous wastes, coal mining environmental impacts, transportation issues, community growth and change, and regional impacts). Additional information is presented in seventeen appendixes. (JGB)

  13. Erratum: Evolution of antiferromagnetic susceptibility under...

    Office of Scientific and Technical Information (OSTI)

    susceptibility under uniaxial pressure inBa(Fe1-xCox)2As2Phys. Rev. B89, 214404 (2014) Citation Details In-Document Search Title: Erratum: Evolution of antiferromagnetic...

  14. Modeling Solar Energy Technology Evolution breakout session

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Technology Evolution  What is a question we could ask about technology evolution, which when answered could yield deep insight into how to spur innovation? Introductory question CI -KNOW 2 1) Collaboration: How do we create an environment that fosters collaboration? 2) Incentives: What are the incentive structures for innovation? How do we incent individual innovators? (ties directly to creating an environment conducive to collaboration) 3) Feedback: What types of feedback do we need to

  15. Part Mining for Synthetic Biology (2013 DOE JGI Genomics of Energy and Environment 8th Annual User Meeting)

    SciTech Connect (OSTI)

    Voigt, Chris [MIT

    2013-03-01

    Chris Voigt from MIT delivers the opening keynote on "Part Mining for Synthetic Biology" at the 8th Annual Genomics of Energy & Environment Meeting on March 26, 2013 in Walnut Creek, Calif.

  16. Synthetic Biology and the U.S. Biotechnology Regulatory System: Challenges and Options

    SciTech Connect (OSTI)

    Carter, Sarah R.; Rodemeyer, Michael; Garfinkel, Michele S.; Friedman, Robert M

    2014-05-01

    Synthetic Biology and the U.S. Biotechnology Regulatory System: Challenges and Options Sarah R. Carter, Ph.D., J. Craig Venter Institute; Michael Rodemeyer, J.D., University of Virginia; Michele S. Garfinkel, Ph.D., EMBO; Robert M. Friedman, Ph.D., J. Craig Venter Institute In recent years, a range of genetic engineering techniques referred to as synthetic biology has significantly expanded the tool kit available to scientists and engineers, providing them with far greater capabilities to engineer organisms than previous techniques allowed. The field of synthetic biology includes the relatively new ability to synthesize long pieces of DNA from chemicals, as well as improved methods for genetic manipulation and design of genetic pathways to achieve more precise control of biological systems. These advances will help usher in a new generation of genetically engineered microbes, plants, and animals. The JCVI Policy Center team, along with researchers at the University of Virginia and EMBO, examined how well the current U.S. regulatory system for genetically engineered products will handle the near-term introduction of organisms engineered using synthetic biology. In particular, the focus was on those organisms intended to be used or grown directly in the environment, outside of a contained facility. The study concludes that the U.S. regulatory agencies have adequate legal authority to address most, but not all, potential environmental, health and safety concerns posed by these organisms. Such near-term products are likely to represent incremental changes rather than a marked departure from previous genetically engineered organisms. However, the study also identified two key challenges for the regulatory system, which are detailed in the report. First, USDAs authority over genetically engineered plants depends on the use of an older engineering technique that is no longer necessary for many applications. The shift to synthetic biology and other newer genetic engineering techniques will leave many engineered plants without any pre-market regulatory review. Second, the number and diversity of engineered microbes for commercial use will increase in the near future, challenging EPAs resources, expertise, and perhaps authority to regulate them. For each of these challenges, the report sets out a series of options, including an analysis of the advantages and disadvantages of each option from a variety of perspectives, for policy makers to consider. Policy responses will depend on the trade-offs chosen among competing considerations. This report, funded by the Department of Energy with additional funds from the Alfred P. Sloan Foundation, is the result of a two-year process that included interviews, commissioned background papers, discussions, and two workshops that sought input from a wide range of experts, including U.S. federal agency regulators, legal and science policy experts, representatives from the biotechnology industry, and non-governmental organizations. This cross-section of views informed this report, but the conclusions are solely those of the authors. An Executive Summary, full Report, and background papers are available at: http://www.jcvi.org/cms/research/projects/synthetic-biology-and-the-us-biotechnology-regulatory-system/overview/

  17. Mapping the evolution of scientific ideas

    SciTech Connect (OSTI)

    Roberts, David; Herrera, Mark; Gulbahce, Natali

    2009-01-01

    Despite the apparent conceptual boundaries of scientific fields, a formal description for their evolution is lacking. Here we describe a novel approach to study the dynamics and evolution of scientific fields using a network-based analysis. We build an idea network consisting of American Physical Society PACS numbers as nodes representing scientific concepts. Two PACS numbers are linked if there exist publications that reference them simultaneously. We locate scientific fields using Cfinder, an overlapping community finding algorithm, and describe the time evolution of these fields using a community evolution method over the course of 1985-2006. The communities we identify map to known scientific fields, and their age strongly depends on t.heir size, impact and activity. Our analysis further suggests that communities that redefine themselves by merging and creating new groups of ideas tend to have more fitness as measured by the impact per paper, and hence communities with a higher fitness tend to be short-lived. The described approach to quantify the evolution of ideas may be relevant in making predictions about the future of science and how to guide its development.

  18. Fracture Evolution Following a Hydraulic Stimulation within an EGS

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Reservoir | Department of Energy Evolution Following a Hydraulic Stimulation within an EGS Reservoir Fracture Evolution Following a Hydraulic Stimulation within an EGS Reservoir Fracture Evolution Following a Hydraulic Stimulation within an EGS Reservoir presentation at the April 2013 peer review meeting held in Denver, Colorado. PDF icon flow_evolution_peer2013.pdf More Documents & Publications Fracture Evolution Following a Hydraulic Stimulation within an EGS Reservoir Advancing

  19. Using dynamic interferometric synthetic aperature radar (InSAR) to image fast-moving surface waves

    DOE Patents [OSTI]

    Vincent, Paul

    2005-06-28

    A new differential technique and system for imaging dynamic (fast moving) surface waves using Dynamic Interferometric Synthetic Aperture Radar (InSAR) is introduced. This differential technique and system can sample the fast-moving surface displacement waves from a plurality of moving platform positions in either a repeat-pass single-antenna or a single-pass mode having a single-antenna dual-phase receiver or having dual physically separate antennas, and reconstruct a plurality of phase differentials from a plurality of platform positions to produce a series of desired interferometric images of the fast moving waves.

  20. Electrode Materials for Rechargeable Li-ion Batteries: a New Synthetic

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Approach (ANL-IN-10-031) - Energy Innovation Portal Vehicles and Fuels Vehicles and Fuels Energy Storage Energy Storage Find More Like This Return to Search Electrode Materials for Rechargeable Li-ion Batteries: a New Synthetic Approach (ANL-IN-10-031) Argonne National Laboratory Contact ANL About This Technology <p> This figure shows the high-rate performance of the new class of cathode materials featuring bi-layered structures.&nbsp; The highest current rate of 1500

  1. Relative performance of rotary and piston engines on synthetic coal-derived gasoline

    SciTech Connect (OSTI)

    Kappos, C.; Rajan, S.

    1989-01-01

    The paper compares the overall power and emissions features and in-cylinder combustion characteristics of a two-rotor Wankel engine and those of a four-cylinder piston engine, with particular reference to thermal efficiency, oxides of nitrogen, unburnt hydrocarbons, exhaust temperature, ignition delay and combustion interval. The study provides insight into the similarities and differences in the mechanisms of pollutant formation and combustion characteristics of rotary and piston engines, while operating on a synthetic coal-derived gasoline. In particular, the shorter ignition delay and longer combustion interval of the rotary engine indicates its suitability for use with lower quality fuels.

  2. Correction of motion measurement errors beyond the range resolution of a synthetic aperture radar

    DOE Patents [OSTI]

    Doerry, Armin W. (Albuquerque, NM); Heard, Freddie E. (Albuquerque, NM); Cordaro, J. Thomas (Albuquerque, NM)

    2008-06-24

    Motion measurement errors that extend beyond the range resolution of a synthetic aperture radar (SAR) can be corrected by effectively decreasing the range resolution of the SAR in order to permit measurement of the error. Range profiles can be compared across the slow-time dimension of the input data in order to estimate the error. Once the error has been determined, appropriate frequency and phase correction can be applied to the uncompressed input data, after which range and azimuth compression can be performed to produce a desired SAR image.

  3. Numerical analysis of thermally assisted spin-transfer torque magnetization reversal in synthetic ferrimagnetic free layers

    SciTech Connect (OSTI)

    Shen, J.; Shi, M.; Tanaka, T. Matsuyama, K.

    2015-05-07

    The spin transfer torque magnetization reversal of synthetic ferrimagnetic free layers under pulsed temperature rise was numerically studied by solving the LandauLifshitzGilbert equation, taking into account the stochastic random fields, the temperature dependence of magnetic parameters, and the spin torque terms. The anti-parallel magnetization configuration was retained at the elevated temperature, due to interlayer dipole coupling. A significant thermal assistance effect, resulting in a 40% reduction in the switching current, was demonstrated during a nanosecond pulsed temperature rise up to 77% of the Curie temperature.

  4. Cloud radar Doppler spectra in drizzling stratiform clouds: 2. Observations and microphysical modeling of drizzle evolution

    SciTech Connect (OSTI)

    Kollias, P.; Luke, E.; Szyrmer, W.; Rmillard, J.

    2011-07-02

    In part I, the influence of cloud microphysics and dynamics on the shape of cloud radar Doppler spectra in warm stratiform clouds was discussed. The traditional analysis of radar Doppler moments was extended to include skewness and kurtosis as additional descriptors of the Doppler spectrum. Here, a short climatology of observed Doppler spectra moments as a function of the radar reflectivity at continental and maritime ARM sites is presented. The evolution of the Doppler spectra moments is consistent with the onset and growth of drizzle particles and can be used to assist modeling studies of drizzle onset and growth. Time-height radar observations are used to exhibit the coherency of the Doppler spectra shape parameters and demonstrate their potential to improve the interpretation and use of radar observations. In addition, a simplified microphysical approach to modeling the vertical evolution of the drizzle particle size distribution in warm stratiform clouds is described and used to analyze the observations. The formation rate of embryonic drizzle droplets due to the autoconversion process is not calculated explicitly; however, accretion and evaporation processes are explicitly modeled. The microphysical model is used as input to a radar Doppler spectrum forward model, and synthetic radar Doppler spectra moments are generated. Three areas of interest are studied in detail: early drizzle growth near the cloud top, growth by accretion of the well-developed drizzle, and drizzle depletion below the cloud base due to evaporation. The modeling results are in good agreement with the continental and maritime observations. This demonstrates that steady state one-dimensional explicit microphysical models coupled with a forward model and comprehensive radar Doppler spectra observations offer a powerful method to explore the vertical evolution of the drizzle particle size distribution.

  5. Evolution of the spectral index after inflation

    SciTech Connect (OSTI)

    Asgari, A.A.; Abbassi, A.H. E-mail: ahabbasi@modares.ac.ir

    2014-09-01

    In this article we investigate the time evolution of the adiabatic (curvature) and isocurvature (entropy) spectral indices after inflation era for all cosmological scales with two different initial conditions. For this purpose, we first extract an explicit equation for the time evolution of the comoving curvature perturbation (which may be known as the generalized Mukhanov-Sasaki equation). It would be cleared that the evolution of adiabatic spectral index severely depends on the initial conditions moreover, as expected it is constant only for the super-Hubble scales and adiabatic initial conditions. Additionally, the adiabatic spectral index after recombination approaches a constant value for the isocurvature perturbations. Finally, we re-investigate the Sachs-Wolfe effect and show that the fudge factor  1/3 in the adiabatic ordinary Sachs-Wolfe formula must be replaced by 0.4.

  6. Evolution of entanglement under echo dynamics

    SciTech Connect (OSTI)

    Prosen, Tomaz; Znidaric, Marko [Physics Department, FMF, University of Ljubljana, Ljubljana (Slovenia); Seligman, Thomas H. [Centro de Ciencias Fisicas, University of Mexico (UNAM), Cuernavaca (Mexico)

    2003-04-01

    Echo dynamics and fidelity are often used to discuss stability in quantum-information processing and quantum chaos. Yet fidelity yields no information about entanglement, the characteristic property of quantum mechanics. We study the evolution of entanglement in echo dynamics. We find qualitatively different behavior between integrable and chaotic systems on one hand and between random and coherent initial states for integrable systems on the other. For the latter the evolution of entanglement is given by a classical time scale. Analytic results are illustrated numerically in a Jaynes-Cummings model.

  7. Erratum: Evolution of antiferromagnetic susceptibility under uniaxial

    Office of Scientific and Technical Information (OSTI)

    pressure in Ba ( Fe 1 - x Co x ) 2 As 2 [Phys. Rev. B 89 , 214404 (2014)] (Journal Article) | SciTech Connect Erratum: Evolution of antiferromagnetic susceptibility under uniaxial pressure in Ba ( Fe 1 - x Co x ) 2 As 2 [Phys. Rev. B 89 , 214404 (2014)] Citation Details In-Document Search Title: Erratum: Evolution of antiferromagnetic susceptibility under uniaxial pressure in Ba ( Fe 1 - x Co x ) 2 As 2 [Phys. Rev. B 89 , 214404 (2014)] Authors: Dhital, Chetan ; Hogan, Tom ; Yamani, Z. ;

  8. Transformation and Crystallization Energetics of Synthetic and Biogenic Amorphous Calcium Carbonate

    SciTech Connect (OSTI)

    Radha, A. V.; Forbes, Tori Z.; Killian, Christopher E.; Gilbert, P.U.P.A; Navrotsky, Alexandra

    2010-01-01

    Amorphous calcium carbonate (ACC) is a metastable phase often observed during low temperature inorganic synthesis and biomineralization. ACC transforms with aging or heating into a less hydrated form, and with time crystallizes to calcite or aragonite. The energetics of transformation and crystallization of synthetic and biogenic (extracted from California purple sea urchin larval spicules, Strongylocentrotus purpuratus) ACC were studied using isothermal acid solution calorimetry and differential scanning calorimetry. Transformation and crystallization of ACC can follow an energetically downhill sequence: more metastable hydrated ACC ? less metastable hydrated ACC?anhydrous ACC ~ biogenic anhydrous ACC?vaterite ? aragonite ? calcite. In a given reaction sequence, not all these phases need to occur. The transformations involve a series of ordering, dehydration, and crystallization processes, each lowering the enthalpy (and free energy) of the system, with crystallization of the dehydrated amorphous material lowering the enthalpy the most. ACC is much more metastable with respect to calcite than the crystalline polymorphs vaterite or aragonite. The anhydrous ACC is less metastable than the hydrated, implying that the structural reorganization during dehydration is exothermic and irreversible. Dehydrated synthetic and anhydrous biogenic ACC are similar in enthalpy. The transformation sequence observed in biomineralization could be mainly energetically driven; the first phase deposited is hydrated ACC, which then converts to anhydrous ACC, and finally crystallizes to calcite. The initial formation of ACC may be a first step in the precipitation of calcite under a wide variety of conditions, including geological CO? sequestration.

  9. Analysis of Natural Graphite, Synthetic Graphite, and Thermosetting Resin Candidates for Use in Fuel Compact Matrix

    SciTech Connect (OSTI)

    Trammell, Michael P; Pappano, Peter J

    2011-09-01

    The AGR-1 and AGR-2 compacting process involved overcoating TRISO particles and compacting them in a steel die. The overcoating step is the process of applying matrix to the OPyC layer of TRISO particles in a rotating drum in order to build up an overcoat layer of desired thickness. The matrix used in overcoating is a mixture of natural graphite, synthetic graphite, and thermosetting resin in the ratio, by weight, of 64:16:20. A wet mixing process was used for AGR-1 and AGR-2, in that the graphites and resin were mixed in the presence of ethyl alcohol. The goal of the wet mixing process was to 'resinate' the graphite particles, or coat each individual graphite particle with a thin layer of resin. This matrix production process was similar to the German, Chinese, Japanese, and South African methods, which also use various amount of solvent during mixing. See Appendix 1 for information on these countries matrix production techniques. The resin used for AGR-1 and AGR-2 was provided by Hexion, specifically Hexion grade Durite SC1008. Durite SC1008 is a solvated (liquid) resole phenolic resin. A resole resin does not typically have a hardening agent added. The major constituent of SC1008 is phenol, with minor amounts of formaldehyde. Durite SC1008 is high viscosity, so additional ethyl alcohol was added during matrix production in order to reduce its viscosity and enhance graphite particle resination. The current compacting scale up plan departs from a wet mixing process. The matrix production method specified in the scale up plan is a co-grinding jet mill process where powdered phenolic resin and graphite are all fed into a jet mill at the same time. Because of the change in matrix production style, SC1008 cannot be used in the jet milling process because it is a liquid. The jet milling/mixing process requires that a suite of solid or powdered resins be investigated. The synthetic graphite used in AGR-1 and AGR-2 was provided by SGL Carbon, grade KRB2000. KRB2000 is a graphitized petroleum coke. The availability of KRB2000 is perhaps in question, so a replacement synthetic graphite may need to be identified. This report presents data on potential replacements for KRB2000.

  10. Gas-to-liquids synthetic fuels for use in fuel cells : reformability, energy density, and infrastructure compatibility.

    SciTech Connect (OSTI)

    Ahmed, S.; Kopasz, J. P.; Russell, B. J.; Tomlinson, H. L.

    1999-09-08

    The fuel cell has many potential applications, from power sources for electric hybrid vehicles to small power plants for commercial buildings. The choice of fuel will be critical to the pace of its commercialization. This paper reviews the various liquid fuels being considered as an alternative to direct hydrogen gas for the fuel cell application, presents calculations of the hydrogen and carbon dioxide yields from autothermal reforming of candidate liquid fuels, and reports the product gas composition measured from the autothermal reforming of a synthetic fuel in a micro-reactor. The hydrogen yield for a synthetic paraffin fuel produced by a cobalt-based Fischer-Tropsch process was found to be similar to that of retail gasoline. The advantages of the synthetic fuel are that it contains no contaminants that would poison the fuel cell catalyst, is relatively benign to the environment, and could be transported in the existing fuel distribution system.

  11. Cytotoxicity of synthetic cannabinoids on primary neuronal cells of the forebrain: the involvement of cannabinoid CB{sub 1} receptors and apoptotic cell death

    SciTech Connect (OSTI)

    Tomiyama, Ken-ichi; Funada, Masahiko

    2014-01-01

    The abuse of herbal products containing synthetic cannabinoids has become an issue of public concern. The purpose of this paper was to evaluate the acute cytotoxicity of synthetic cannabinoids on mouse brain neuronal cells. Cytotoxicity induced by synthetic cannabinoid (CP-55,940, CP-47,497, CP-47,497-C8, HU-210, JWH-018, JWH-210, AM-2201, and MAM-2201) was examined using forebrain neuronal cultures. These synthetic cannabinoids induced cytotoxicity in the forebrain cultures in a concentration-dependent manner. The cytotoxicity was suppressed by preincubation with the selective CB{sub 1} receptor antagonist AM251, but not with the selective CB{sub 2} receptor antagonist AM630. Furthermore, annexin-V-positive cells were found among the treated forebrain cells. Synthetic cannabinoid treatment induced the activation of caspase-3, and preincubation with a caspase-3 inhibitor significantly suppressed the cytotoxicity. These synthetic cannabinoids induced apoptosis through a caspase-3-dependent mechanism in the forebrain cultures. Our results indicate that the cytotoxicity of synthetic cannabinoids towards primary neuronal cells is mediated by the CB{sub 1} receptor, but not by the CB{sub 2} receptor, and further suggest that caspase cascades may play an important role in the apoptosis induced by these synthetic cannabinoids. In conclusion, excessive synthetic cannabinoid abuse may present a serious acute health concern due to neuronal damage or deficits in the brain. - Highlights: Synthetic cannabinoids (classical cannabinoids, non-classical cannabinoids, and aminoalkylindole derivatives) induce cytotoxicity in mouse forebrain cultures. Synthetic cannabinoid-induced cytotoxicity towards forebrain cultures is mediated by the CB{sub 1} receptor, but not by the CB{sub 2} receptor, and involves caspase-dependent apoptosis. A high concentration of synthetic cannabinoids may be toxic to neuronal cells that express CB{sub 1} receptors.

  12. Evolution of twist-3 multiparton correlation functions relevant...

    Office of Scientific and Technical Information (OSTI)

    We calculate evolution kernels relevant to the gluonic pole contributions to the asymmetry at the order of alphasub s. We find that all evolution kernels are infrared safe as ...

  13. Environmentally based siting assessment for synthetic-liquid-fuels facilities. Final report

    SciTech Connect (OSTI)

    1980-01-01

    A detailed assessment of the major environmental constraints to siting a synthetic fuels industry and the results of that assessment are used to determine on a regional basis the potential for development of such an industry with minimal environmental conflicts. Secondly, the ability to mitigate some of the constraining impacts through alternative institutional arrangements, especially in areas that are judged to have a low development potential is also assessed. Limitations of the study are delineated, but specifically, the study is limited geographically to well-defined boundaries that include the prime coal and oil shale resource areas. The critical factors used in developing the framework are air quality, water availability, socioeconomic capacity, ecological sensitivity, environmental health, and the management of Federally owned lands. (MCW)

  14. Metabolic engineering of microorganisms for biofuels production: from bugs to synthetic biology to fuels

    SciTech Connect (OSTI)

    Kuk Lee, Sung; Chou, Howard; Ham, Timothy S.; Soon Lee, Taek; Keasling, Jay D.

    2009-12-02

    The ability to generate microorganisms that can produce biofuels similar to petroleum-based transportation fuels would allow the use of existing engines and infrastructure and would save an enormous amount of capital required for replacing the current infrastructure to accommodate biofuels that have properties significantly different from petroleum-based fuels. Several groups have demonstrated the feasibility of manipulating microbes to produce molecules similar to petroleum-derived products, albeit at relatively low productivity (e.g. maximum butanol production is around 20 g/L). For cost-effective production of biofuels, the fuel-producing hosts and pathways must be engineered and optimized. Advances in metabolic engineering and synthetic biology will provide new tools for metabolic engineers to better understand how to rewire the cell in order to create the desired phenotypes for the production of economically viable biofuels.

  15. Synthetic and Thermodynamic Investigations of Ancillary Ligand Influence on Catalytic Organometallic Systems. Final Report

    SciTech Connect (OSTI)

    Nolan, Steven

    2003-03-20

    During the grant period we have been involved in synthesizing and experimentally determining solution enthalpy values associated with partially fluorinated ligands. This has lead to the publication of manuscripts dealing with synthetic, calorimetric and catalytic behavior of partially fluorinated ligands. The collaboration with Los Alamos researchers has lead to the publication of catalytic results in sc CO{sub 2} which have proven very interesting. Furthermore, we have also examined ligands that behave as phosphine mimics. The N-heterocyclic carbenes have been explored as alternatives for tertiary phosphines and have resulted in the design and construction of efficient palladium and nickel system capable of performing C-C and C-N cross coupling reactions. The initial studies in this areas were made possible by exploratory work conducted under the DOE/EPSCoR grant.

  16. Vulnerability reduction study. Coal and synthetics (Section III a). Technical Appendix

    SciTech Connect (OSTI)

    Not Available

    1980-08-01

    This Appendix supports and explains key statements made in the chapter on Coal and Synthetics. The reader will find information and documentation on points that lend themselves to quantification. Evidence is presented that coal supply will not be constrained by production or transportation factors through the 1980s. Any program to increase the direct use of coal in the industrial sector must take into account a number of identifiable difficulties. A deployment schedule for 10 oil shale projects has been developed by the Office of Technology Assessment. This schedule, if adhered to, would result in an initial deployment of an oil shale industry of 400,000 bpd oil equivalent by 1990. In addition, the Appendix provides descriptions of those major elements of Federal legislation that bear directly on coal, notably portions of the Powerplant and Industrial Fuel Use Act of 1978, the Energy Tax Act of 1978, the Energy Security Act of 1980, and the Clean Air Act.

  17. Synthetic Catalysts for CO2 Storage: Catalytic Improvement of Solvent Capture Systems

    SciTech Connect (OSTI)

    None

    2010-08-15

    IMPACCT Project: LLNL is designing a process to pull CO2 out of the exhaust gas of coal-fired power plants so it can be transported, stored, or utilized elsewhere. Human lungs rely on an enzyme known as carbonic anhydrase to help separate CO2 from our blood and tissue as part of the normal breathing process. LLNL is designing a synthetic catalyst with the same function as this enzyme. The catalyst can be used to quickly capture CO2 from coal exhaust, just as the natural enzyme does in our lungs. LLNL is also developing a method of encapsulating chemical solvents in permeable microspheres that will greatly increase the speed of binding of CO2. The goal of the project is an industry-ready chemical vehicle that can withstand the harsh environments found in exhaust gas and enable new, simple process designs requiring less capital investment.

  18. X-ray Moiré deflectometry using synthetic reference images

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Stutman, Dan; Valdivia, Maria Pia; Finkenthal, Michael

    2015-06-25

    Moiré fringe deflectometry with grating interferometers is a technique that enables refraction-based x-ray imaging using a single exposure of an object. To obtain the refraction image, the method requires a reference fringe pattern (without the object). Our study shows that, in order to avoid artifacts, the reference pattern must be exactly matched in phase with the object fringe pattern. In experiments, however, it is difficult to produce a perfectly matched reference pattern due to unavoidable interferometer drifts. We present a simple method to obtain matched reference patterns using a phase-scan procedure to generate synthetic Moiré images. As a result, themore » method will enable deflectometric diagnostics of transient phenomena such as laser-produced plasmas and could improve the sensitivity and accuracy of medical phase-contrast imaging.« less

  19. Synthetic fuel aromaticity and staged combustion. First quarterly technical progress report, September 23-December 31, 1980

    SciTech Connect (OSTI)

    Levy, Arthur; Longanbach, James R.; Chan, Lisa K.

    1981-01-28

    Synthetic liquid fuels, otherwise referred to as synfuels or coal-derived liquids, are probably best characterized from a combustion-environmental point of view as low in hydrogen, low in sulfur, high in nitrogen, and high in aromatics. As a consequence two of the more critical problems in synfuel combustion are NO/sub x/ formation and soot formation (and polycyclic organic matter). This program is directed to these two issues. At first hand the solutions to burning synfuels high in aromatics and fuel-bound nitrogen are diametrically opposed, i.e., high temperature and excess air keep soot levels down, low temperatures and vitiated air keep nitrogen oxide levels down. Staged combustion however offers a logical solution to the above. This program separates and analyzes the synfuel combustion problem via its component parts and then puts them together again phenomenologically via the stage combustion process.

  20. Synthetic graph generation for data-intensive HPC benchmarking: Scalability, analysis and real-world application

    SciTech Connect (OSTI)

    Powers, Sarah S.; Lothian, Joshua

    2014-12-01

    The benchmarking effort within the Extreme Scale Systems Center at Oak Ridge National Laboratory seeks to provide High Performance Computing benchmarks and test suites of interest to the DoD sponsor. The work described in this report is a part of the effort focusing on graph generation. A previously developed benchmark, SystemBurn, allows the emulation of a broad spectrum of application behavior profiles within a single framework. To complement this effort, similar capabilities are desired for graph-centric problems. This report described the in-depth analysis of the generated synthetic graphs' properties at a variety of scales using different generator implementations and examines their applicability to replicating real world datasets.

  1. US Synthetic Corp (TRL 4 Component)- The Development of Open, Water Lubricated Polycrystalline Diamond Thrust Bearings for use in Marine Hydrokinetic (MHK) Energy Machines

    Broader source: Energy.gov [DOE]

    US Synthetic Corp (TRL 4 Component) - The Development of Open, Water Lubricated Polycrystalline Diamond Thrust Bearings for use in Marine Hydrokinetic (MHK) Energy Machines

  2. Project Profile: Helios: Understanding Solar Evolution through Text

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Analytics | Department of Energy Helios: Understanding Solar Evolution through Text Analytics Project Profile: Helios: Understanding Solar Evolution through Text Analytics Logo of SRI International. SRI International, under the Solar Energy Evolution and Diffusion Studies (SEEDS) program, is developing a new system for large-scale text analytics, called Helios, to isolate and map recurring patterns of technology evolution through the inspection of thousands of published technical documents.

  3. Lab works on new model for HIV transmission and evolution

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    works on new model for HIV transmission and evolution Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:Mar. 2016 all issues All Issues » submit Lab works on new model for HIV transmission and evolution Mutates at different rates in different populations February 1, 2014 Lab works on new model for HIV transmission and evolution Lab works on new model for HIV transmission and evolution Contacts Community Programs Office Director Kurt

  4. FUNDING OPPORTUNITY ANNOUNCEMENT: SOLAR ENERGY EVOLUTION AND DIFFUSION

    Energy Savers [EERE]

    STUDIES II - STATE ENERGY STRATEGIES (SEEDSII-SES) | Department of Energy FUNDING OPPORTUNITY ANNOUNCEMENT: SOLAR ENERGY EVOLUTION AND DIFFUSION STUDIES II - STATE ENERGY STRATEGIES (SEEDSII-SES) FUNDING OPPORTUNITY ANNOUNCEMENT: SOLAR ENERGY EVOLUTION AND DIFFUSION STUDIES II - STATE ENERGY STRATEGIES (SEEDSII-SES) FUNDING OPPORTUNITY ANNOUNCEMENT: SOLAR ENERGY EVOLUTION AND DIFFUSION STUDIES II - STATE ENERGY STRATEGIES (SEEDSII-SES) FUNDING OPPORTUNITY ANNOUNCEMENT: SOLAR ENERGY EVOLUTION

  5. THERMAL AND CHEMICAL EVOLUTION OF COLLAPSING FILAMENTS

    SciTech Connect (OSTI)

    Gray, William J.; Scannapieco, Evan

    2013-05-10

    Intergalactic filaments form the foundation of the cosmic web that connect galaxies together, and provide an important reservoir of gas for galaxy growth and accretion. Here we present very high resolution two-dimensional simulations of the thermal and chemical evolution of such filaments, making use of a 32 species chemistry network that tracks the evolution of key molecules formed from hydrogen, oxygen, and carbon. We study the evolution of filaments over a wide range of parameters including the initial density, initial temperature, strength of the dissociating UV background, and metallicity. In low-redshift, Z Almost-Equal-To 0.1 Z{sub Sun} filaments, the evolution is determined completely by the initial cooling time. If this is sufficiently short, the center of the filament always collapses to form a dense, cold core containing a substantial fraction of molecules. In high-redshift, Z = 10{sup -3} Z{sub Sun} filaments, the collapse proceeds much more slowly. This is mostly due to the lower initial temperatures, which lead to a much more modest increase in density before the atomic cooling limit is reached, making subsequent molecular cooling much less efficient. Finally, we study how the gravitational potential from a nearby dwarf galaxy affects the collapse of the filament and compare this to NGC 5253, a nearby starbursting dwarf galaxy thought to be fueled by the accretion of filament gas. In contrast to our fiducial case, a substantial density peak forms at the center of the potential. This peak evolves faster than the rest of the filament due to the increased rate at which chemical species form and cooling occurs. We find that we achieve similar accretion rates as NGC 5253 but our two-dimensional simulations do not recover the formation of the giant molecular clouds that are seen in radio observations.

  6. On some operations suggested by genome evolution

    SciTech Connect (OSTI)

    Dassow, J.; Mitrana, V.

    1996-12-31

    Three operations involved in the genome evolution namely, inversion, transposition and duplication, are considered as operations on strings and languages. We show that, for any pair of these operations, there is a language family which is closed under one of the operations and not closed under the second one; however, under some mild conditions the closure of a language family under one of the operations implies that it also closed with respect to another one. 15 refs.

  7. Evaluation of and Suggested Improvements to the WSM6 Microphysics in WRF- ARW Using Synthetic and Observed GOES-13 Imagery

    SciTech Connect (OSTI)

    Grasso, Lewis; Lindsey, Daniel T.; Lim, Kyo-Sun; Clark, Adam; Bikos, Dan; Dembek, Scott R.

    2014-10-01

    Synthetic satellite imagery can be employed to evaluate simulated cloud fields. Past studies have revealed that the Weather Research and Forecasting (WRF) WRF Single-Moment 6-class (WSM6) microphysics in WRF-ARW produces less upper level ice clouds within synthetic images compared to observations. Synthetic Geostationary Operational Environmental Satellite (GOES)-13 imagery at 10.7 ?m of simulated cloud fields from the 4 km National Severe Storms Laboratory (NSSL) WRF-ARW is compared to observed GOES-13 imagery. Histograms suggest that too few points contain upper level simulated ice clouds. In particular, side-by-side examples are shown of synthetic and observed convective anvils. Such images illustrate the lack of anvil cloud associated with convection produced by the NSSL WRF-ARW. A vertical profile of simulated hydrometeors suggests that too much cloud water mass may be converted into graupel mass, effectively reducing the main source of ice mass in a simulated anvil. Further, excessive accretion of ice by snow removes ice from an anvil by precipitation settling. Idealized sensitivity tests reveal that a 50% reduction of the conversion of cloud water mass to graupel and a 50% reduction of the accretion rate of ice by snow results in a significant increase in anvil ice of a simulated storm. Such results provide guidance as to which conversions could be reformulated, in a more physical manner, to increase simulated ice mass in the upper troposphere.

  8. TH-A-BRF-03: Evaluation of Synthetic CTs Generated Using MR-SIM Data

    SciTech Connect (OSTI)

    Kim, J; Glide-Hurst, C; Doemer, A; Wen, N; Chett, I

    2014-06-15

    Purpose: To describe and evaluate a novel algorithm for generating synthetic CT images from MR-SIM data for dose calculations in MR-only treatment planning. Methods: A voxel-based weighted summation method was implemented to generate synthetic CT (synCT) images. MR data were acquired using Philips 1.0T Panorama high-field open MR-SIM. Retrospective patient data from seven prostate patients and one brain patient (three lesions) enrolled in an IRB-approved study were used. 3D T1-weighted fast field echo and 3D T2-weighted turbo spin echo sequences were utilized for all patients. A 3D balanced turbo field echo sequence using spectral presaturation with inversion recovery was acquired for prostate patients, but 3D ultra-short echo time (UTE)-DIXON was instead acquired for the brain patient to amplify bone signal for semi-automatic bone segmentation. Weight optimization was performed using a training subset of patients. HU value differences between planning CT and synCTs were analyzed using mean absolute error (MAE). Original patient CT-based treatment plans were mapped onto synCTs, dose was recalculated using original leaf motion and MU values, and DRRs were generated. Dosevolume metrics and gamma analysis were used for dosimetric evaluation. Results: Average whole-body MAE of synCTs across all patients was 75+12 HU. In prostate cancer patients, average HU difference between planning and synCTs was 0.9±1.0% for soft tissue structures and 4.3±2.5% for bony structures. DRRs were generated from synCTs and qualitatively showed good geometric agreement with planning CT-generated DRRs. D99, mean dose, and maximum dose to CTV calculated using the synCT remained within 1.2% of planning CT-based dose calculations. All gamma analysis evaluated at 2%/2mm dose difference/distance to agreement) pass rates were greater than 95% with an average of 99.9±0.1% for prostate patients and 98.4±2.2% for three brain lesions. Conclusion: SynCTs were generated with clinically acceptable accuracy comparable to planning CTs, enabling dose computations for MR-only simulation. Research supported in part by a grant from Philips HealthCare (Best, Netherlands)

  9. Evolution of rogue waves in dusty plasmas

    SciTech Connect (OSTI)

    Tolba, R. E. El-Bedwehy, N. A.; Moslem, W. M.; El-Labany, S. K.

    2015-04-15

    The evolution of rogue waves associated with the dynamics of positively charged dust grains that interact with streaming electrons and ions is investigated. Using a perturbation method, the basic set of fluid equations is reduced to a nonlinear Schrdinger equation (NLSE). The rational solution of the NLSE is presented, which proposed as an effective tool for studying the rogue waves in Jupiter. It is found that the existence region of rogue waves depends on the dust-acoustic speed and the streaming densities of the ions and electrons. Furthermore, the supersonic rogue waves are much taller than the subsonic rogue waves by ?25 times.

  10. Behavior of Concrete Panels Reinforced with Synthetic Fibers, Mild Steel, and GFRP Composites Subjected to Blasts

    SciTech Connect (OSTI)

    C. P. Pantelides; T. T. Garfield; W. D. Richins; T. K. Larson; J. E. Blakeley

    2012-03-01

    The paper presents experimental data generated for calibrating finite element models to predict the performance of reinforced concrete panels with a wide range of construction details under blast loading. The specimens were 1.2 m square panels constructed using Normal Weight Concrete (NWC) or Fiber Reinforced Concrete (FRC). FRC consisted of macro-synthetic fibers dispersed in NWC. Five types of panels were tested: NWC panels with steel bars; FRC panels without additional reinforcement; FRC panels with steel bars; NWC panels with glass fiber reinforced polymer (GFRP) bars; and NWC panels reinforced with steel bars and external GFRP laminates on both faces. Each panel type was constructed with three thicknesses: 152 mm, 254 mm, and 356 mm. FRC panels with steel bars had the best performance for new construction. NWC panels reinforced with steel bars and external GFRP laminates on both faces had the best performance for strengthening or rehabilitation of existing structures. The performance of NWC panels with GFRP bars was strongly influenced by the bar spacing. The behavior of the panels is classified in terms of damage using immediate occupancy, life safety, and near collapse performance levels. Preliminary dynamic simulations are compared to the experimental results.

  11. Transport of synthetic colloids through single saturated fractures: A literature review

    SciTech Connect (OSTI)

    Reimus, P.W.

    1995-07-01

    Colloids having the same surface charge sign as the bulk of the geologic media in a groundwater system may be able to travel through the system faster than soluble species because they will follow fluid streamlines more closely and they should have less tendency to diffuse into pores or dead spaces in the media than soluble species. Synthetic colloids with uniform, controlled properties may be ideal for serving as {open_quotes}worst-case{close_quotes} tracers that provide lower-bound estimates of contaminant travel times in hydrologic systems. This report discusses a review of the literature pertaining to colloid transport in single saturated natural fractures. After a brief background discussion to put the literature review in perspective, the phenomenon of colloid transport in saturated fractures is divided into three major topics, each of which is reviewed in detail: (1) saturated fluid flow through fractures; (2) colloid transport by convection, diffusion, and force fields; and (3) colloid interactions with surfaces. It is suggested that these phenomena be accounted for in colloid transport models by using (1) lubrication theory to describe water flow through fractures, (2) particle tracking methods to describe colloid transport in fractures, and (3) a kinetic boundary layer approximation to describe colloid interactions with fracture walls. These methods offer better computational efficiency and better experimental accessibility to model parameters than rigorously solving the complete governing equations.

  12. On the detection of crevasses in glacial ice with synthetic-aperture radar.

    SciTech Connect (OSTI)

    Brock, Billy C.

    2010-02-01

    The intent of this study is to provide an analysis of the scattering from a crevasse in Antarctic ice, utilizing a physics-based model for the scattering process. Of primary interest is a crevasse covered with a snow bridge, which makes the crevasse undetectable in visible-light images. It is demonstrated that a crevasse covered with a snow bridge can be visible in synthetic-aperture-radar (SAR) images. The model of the crevasse and snow bridge incorporates a complex dielectric permittivity model for dry snow and ice that takes into account the density profile of the glacier. The surface structure is based on a fractal model that can produce sastrugi-like features found on the surface of Antarctic glaciers. Simulated phase histories, computed with the Shooting and Bouncing Ray (SBR) method, are processed into SAR images. The viability of the SBR method for predicting scattering from a crevasse covered with a snow bridge is demonstrated. Some suggestions for improving the model are given.

  13. A High Resolution, Light-Weight, Synthetic Aperture Radar for UAV Application

    SciTech Connect (OSTI)

    Doerry, A.W.; Hensley, W.H.; Stence, J.; Tsunoda, S.I. Pace, F.; Walker, B,C.; Woodring, M.

    1999-05-27

    (U) Sandia National Laboratories in collaboration with General Atomics (GA) has designed and built a high resolution, light-weight, Ku-band Synthetic Aperture Radar (SAR) known as "Lynx". Although Lynx can be operated on a wide variety of manned and unmanned platforms, its design is optimized for use on medium altitude Unmanned Aerial Vehicles (UAVS). In particular, it can be operated on the Predator, I-GNAT, and Prowler II platforms manufactured by GA. (U) The radar production weight is less than 120 lb and operates within a 3 GHz band from 15.2 GHz to 18.2 GHz with a peak output power of 320 W. Operating range is resolution and mode dependent but can exceed 45 km in adverse weather (4 mm/hr rain). Lynx has operator selectable resolution and is capable of 0.1 m resolution in spotlight mode and 0.3 m resolution in stripmap mode, over substantial depression angles (5 to 60 deg) and squint angles (broadside 45 deg). Real-time Motion Compensation is implemented to allow high-quality image formation even during vehicle turns and other maneuvers.

  14. The Elephant in the Room: Dealing with Carbon Emissions from Synthetic Transportation Fuels Production

    SciTech Connect (OSTI)

    Parker, Graham B.; Dahowski, Robert T.

    2007-07-11

    Carbon dioxide (CO2), produced by conversion of hydrocarbons to energy, primarily via fossil fuel combustion, is one of the most ubiquitous and significant greenhouse gases (GHGs). Concerns over climate change precipitated by rising atmospheric GHG concentrations have prompted many industrialized nations to begin adopting limits on emissions to inhibit increases in atmospheric CO2 levels. The United Nations Framework Convention on Climate Change states as a key goal the stabilization of atmospheric CO2 at a level that prevents dangerous anthropogenic interference with the planets climate systems. This will require sharply reducing emissions growth rates in developing nations, and reducing CO2 emissions in the industrialized world to half current rates in the next 50 years. And ultimately, stabilization will require that annual emissions drop to almost zero.Recently, there has been interest in producing synthetic transportation fuels via coal-to-liquids (CTL) production, particularly in countries where there is an abundant supply of domestic coal, including the United States. This paper provides an overview of the current state of CTL technologies and deployment, a discussion of costs and technical requirements for mitigating the CO2 impacts associated with a CTL facility, and the challenges facing the CTL industry as it moves toward maturity.

  15. Large Hybrid Energy Systems for Making Low CO2 Load-Following Power and Synthetic Fuel

    SciTech Connect (OSTI)

    Robert S. Cherry; Richard D. Boardman; Steven Aumeier

    2012-02-01

    Hybrid energy systems using nuclear heat sources can economically produce load-following electrical power by exploiting the surplus generation capacity available at night or seasonally to make synthetic fuel. Vehicle fuel is the only current energy use large enough to absorb all the energy capacity that might be diverted from the power industry, and its ease of storage obviates problems with discontinuous synfuel production. The potential benefits and challenges of synfuels integration are illustrated by the production of methanol from natural gas (as a source of carbon) using steam from a light water nuclear power reactor which is assumed to be available in accord with a year's worth of power demand data. Methanol's synthesis process is easily adapted to using 300 C heat from a light water reactor and this simple compound can be further processed into gasoline, biodiesel, or dimethyl ether, fuels which can be used with the current vehicle fleet. A supplemental feed to the methanol process of natural gas (for energy) allows operation at constant full rate when the nuclear heat is being used to produce electrical power. The higher capital costs of such a system are offset by a lower cost of heat and power production from a large base load type of plant and by reduced costs associated with much lower CO2 emissions. Other less tangible economic benefits of this and similar hybrid systems include better use of natural resource for fuels and greater energy services security from the domestic production of vehicle fuel.

  16. Method and apparatus for reducing range ambiguity in synthetic aperture radar

    DOE Patents [OSTI]

    Kare, Jordin T. (San Ramon, CA)

    1999-10-26

    A modified Synthetic Aperture Radar (SAR) system with reduced sensitivity to range ambiguities, and which uses secondary receiver channels to detect the range ambiguous signals and subtract them from the signal received by the main channel. Both desired and range ambiguous signals are detected by a main receiver and by one or more identical secondary receivers. All receivers are connected to a common antenna with two or more feed systems offset in elevation (e.g., a reflector antenna with multiple feed horns or a phased array with multiple phase shift networks. The secondary receiver output(s) is (are) then subtracted from the main receiver output in such a way as to cancel the ambiguous signals while only slightly attenuating the desired signal and slightly increasing the noise in the main channel, and thus does not significantly affect the desired signal. This subtraction may be done in real time, or the outputs of the receivers may be recorded separately and combined during signal processing.

  17. Calibrating spectral estimation for the LISA Technology Package with multichannel synthetic noise generation

    SciTech Connect (OSTI)

    Ferraioli, Luigi; Hueller, Mauro; Vitale, Stefano; Heinzel, Gerhard; Hewitson, Martin; Monsky, Anneke; Nofrarias, Miquel

    2010-08-15

    The scientific objectives of the LISA Technology Package experiment on board of the LISA Pathfinder mission demand accurate calibration and validation of the data analysis tools in advance of the mission launch. The level of confidence required in the mission outcomes can be reached only by intensively testing the tools on synthetically generated data. A flexible procedure allowing the generation of a cross-correlated stationary noise time series was set up. A multichannel time series with the desired cross-correlation behavior can be generated once a model for a multichannel cross-spectral matrix is provided. The core of the procedure comprises a noise coloring, multichannel filter designed via a frequency-by-frequency eigendecomposition of the model cross-spectral matrix and a subsequent fit in the Z domain. The common problem of initial transients in a filtered time series is solved with a proper initialization of the filter recursion equations. The noise generator performance was tested in a two-dimensional case study of the closed-loop LISA Technology Package dynamics along the two principal degrees of freedom.

  18. Metagenomic Insights into Evolution of a Heavy Metal-Contaminated

    Office of Scientific and Technical Information (OSTI)

    Groundwater Microbial Community (Journal Article) | SciTech Connect Metagenomic Insights into Evolution of a Heavy Metal-Contaminated Groundwater Microbial Community Citation Details In-Document Search Title: Metagenomic Insights into Evolution of a Heavy Metal-Contaminated Groundwater Microbial Community Understanding adaptation of biological communities to environmental change is a central issue in ecology and evolution. Metagenomic analysis of a stressed groundwater microbial community

  19. Oldest hominid skeleton provides new evidence for human evolution

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    New evidence for human evolution Oldest hominid skeleton provides new evidence for human evolution The discovery reveals the biology of the first stage of human evolution better than anything seen to date. October 1, 2009 Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials. Los Alamos

  20. Solar Energy Evolution and Diffusion Studies | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Evolution and Diffusion Studies Solar Energy Evolution and Diffusion Studies Graphic of a map with pinpoints and a photo of a house with solar panels on the roof. Through the Solar Energy Evolution and Diffusion Studies, or SEEDS, program, seven projects are investigating strategies to accelerate the pace of change for solar energy technologies as they are developed and deployed. The projects integrate the use of cutting-edge analytical and computational tools with real-world market data and

  1. High-resolution measurements of the spatial and temporal evolution...

    Office of Scientific and Technical Information (OSTI)

    temporal evolution of megagauss magnetic fields created in intense short-pulse laser-plasma interactions Citation Details In-Document Search Title: High-resolution measurements...

  2. Chemical and Morphological Evolution of Nanoporous Pd/Rh Alloy...

    Office of Scientific and Technical Information (OSTI)

    Conference: Chemical and Morphological Evolution of Nanoporous PdRh Alloy Particles for ... Country of Publication: United States Language: English Word Cloud More Like This Full ...

  3. Verification of the Time Evolution of Cosmological Simulations...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Verification of the Time Evolution of Cosmological Simulations via Hypothesis-Driven Comparative and Quantitative Visualization Citation Details In-Document Search...

  4. HIV virus spread and evolution studied through computer modeling

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and the actual, rapid evolution of the virus (phylogenetics) within each patient's body. "We have developed novel ways of estimating epidemics dynamics such as who infected...

  5. Stress evolution during growth in direct-current-sputtered zinc...

    Office of Scientific and Technical Information (OSTI)

    zinc oxide films at various oxygen flows Citation Details In-Document Search Title: Stress evolution during growth in direct-current-sputtered zinc oxide films at ...

  6. Evolution Energy formerly Earth Biofuels Inc | Open Energy Information

    Open Energy Info (EERE)

    Energy formerly Earth Biofuels Inc Jump to: navigation, search Name: Evolution Energy (formerly Earth Biofuels Inc) Place: Dallas, Texas Zip: 75205 Sector: Renewable Energy...

  7. Hydrogen Evolution at Si-based Metal-Insulator-Semiconductor...

    Office of Scientific and Technical Information (OSTI)

    Hydrogen Evolution at Si-based Metal-Insulator-Semiconductor Photoelectrodes Enhanced by Inversion Channel Charge Collection and Hydrogen Spillover Citation Details In-Document...

  8. Dynamic Evolution of Cement Composition and Transport Properties...

    Office of Scientific and Technical Information (OSTI)

    Dynamic Evolution of Cement Composition and Transport Properties under Conditions Relevant to Geological Carbon Sequestration Citation Details In-Document Search Title: Dynamic ...

  9. On the Lack of Evolution in Galaxy Star Formation Efficiency...

    Office of Scientific and Technical Information (OSTI)

    Title: On the Lack of Evolution in Galaxy Star Formation Efficiency Authors: Behroozi, Peter S. ; Wechsler, Risa H. ; KIPAC, Menlo Park SLAC ; Conroy, Charlie ; UC, Santa Cruz, ...

  10. Integrated Operation of INL HYTEST System and High-Temperature Steam Electrolysis for Synthetic Natural Gas Production

    SciTech Connect (OSTI)

    Carl Marcel Stoots; Lee Shunn; James O'Brien

    2010-06-01

    The primary feedstock for synthetic fuel production is syngas, a mixture of carbon monoxide and hydrogen. Current hydrogen production technologies rely upon fossil fuels and produce significant quantities of greenhouse gases as a byproduct. This is not a sustainable means of satisfying future hydrogen demands, given the current projections for conventional world oil production and future targets for carbon emissions. For the past six years, the Idaho National Laboratory has been investigating the use of high-temperature steam electrolysis (HTSE) to produce the hydrogen feedstock required for synthetic fuel production. High-temperature electrolysis water-splitting technology, combined with non-carbon-emitting energy sources, can provide a sustainable, environmentally-friendly means of large-scale hydrogen production. Additionally, laboratory facilities are being developed at the INL for testing hybrid energy systems composed of several tightly-coupled chemical processes (HYTEST program). The first such test involved the coupling of HTSE, CO2 separation membrane, reverse shift reaction, and methanation reaction to demonstrate synthetic natural gas production from a feedstock of water and either CO or a simulated flue gas containing CO2. This paper will introduce the initial HTSE and HYTEST testing facilities, overall coupling of the technologies, testing results, and future plans.

  11. Genomic Evolution of the Ascomycete Yeasts

    SciTech Connect (OSTI)

    Riley, Robert; Haridas, Sajeet; Salamov, Asaf; Boundy-Mills, Kyria; Goker, Markus; Hittinger, Chris; Klenk, Hans-Peter; Lopes, Mariana; Meir-Kolthoff, Jan P.; Rokas, Antonis; Rosa, Carlos; Scheuner, Carmen; Soares, Marco; Stielow, Benjamin; Wisecaver, Jennifer H.; Wolfe, Ken; Blackwell, Meredith; Kurtzman, Cletus; Grigoriev, Igor; Jeffries, Thomas

    2015-03-16

    Yeasts are important for industrial and biotechnological processes and show remarkable metabolic and phylogenetic diversity despite morphological similarities. We have sequenced the genomes of 16 ascomycete yeasts of taxonomic and industrial importance including members of Saccharomycotina and Taphrinomycotina. Phylogenetic analysis of these and previously published yeast genomes helped resolve the placement of species including Saitoella complicata, Babjeviella inositovora, Hyphopichia burtonii, and Metschnikowia bicuspidata. Moreover, we find that alternative nuclear codon usage, where CUG encodes serine instead of leucine, are monophyletic within the Saccharomycotina. Most of the yeasts have compact genomes with a large fraction of single exon genes, and a tendency towards more introns in early-diverging species. Analysis of enzyme phylogeny gives insights into the evolution of metabolic capabilities such as methanol utilization and assimilation of alternative carbon sources.

  12. Magnetic island evolution in hot ion plasmas

    SciTech Connect (OSTI)

    Ishizawa, A.; Nakajima, N.; Waelbroeck, F. L.; Fitzpatrick, R.; Horton, W.

    2012-07-15

    Effects of finite ion temperature on magnetic island evolution are studied by means of numerical simulations of a reduced set of two-fluid equations which include ion as well as electron diamagnetism in slab geometry. The polarization current is found to be almost an order of magnitude larger in hot than in cold ion plasmas, due to the strong shear of ion velocity around the separatrix of the magnetic islands. As a function of the island width, the propagation speed decreases from the electron drift velocity (for islands thinner than the Larmor radius) to values close to the guiding-center velocity (for islands of order 10 times the Larmor radius). In the latter regime, the polarization current is destabilizing (i.e., it drives magnetic island growth). This is in contrast to cold ion plasmas, where the polarization current is generally found to have a healing effect on freely propagating magnetic island.

  13. Suitability of Synthetic Driving Profiles from Traffic Micro-Simulation for Real-World Energy Analysis: Preprint

    SciTech Connect (OSTI)

    Hou, Yunfei; Wood, Eric; Burton, Evan; Gonder, Jeffrey

    2015-10-14

    A shift towards increased levels of driving automation is generally expected to result in improved safety and traffic congestion outcomes. However, little empirical data exists to estimate the impact that automated driving could have on energy consumption and greenhouse gas emissions. In the absence of empirical data on differences between drive cycles from present day vehicles (primarily operated by humans) and future vehicles (partially or fully operated by computers) one approach is to model both situations over identical traffic conditions. Such an exercise requires traffic micro-simulation to not only accurately model vehicle operation under high levels of automation, but also (and potentially more challenging) vehicle operation under present day human drivers. This work seeks to quantify the ability of a commercial traffic micro-simulation program to accurately model real-world drive cycles in vehicles operated primarily by humans in terms of driving speed, acceleration, and simulated fuel economy. Synthetic profiles from models of freeway and arterial facilities near Atlanta, Georgia, are compared to empirical data collected from real-world drivers on the same facilities. Empirical and synthetic drive cycles are then simulated in a powertrain efficiency model to enable comparison on the basis of fuel economy. Synthetic profiles from traffic micro-simulation were found to exhibit low levels of transient behavior relative to the empirical data. Even with these differences, the synthetic and empirical data in this study agree well in terms of driving speed and simulated fuel economy. The differences in transient behavior between simulated and empirical data suggest that larger stochastic contributions in traffic micro-simulation (relative to those present in the traffic micro-simulation tool used in this study) are required to fully capture the arbitrary elements of human driving. Interestingly, the lack of stochastic contributions from models of human drivers in this study did not result in a significant discrepancy between fuel economy simulations based on synthetic and empirical data; a finding with implications on the potential energy efficiency gains of automated vehicle technology.

  14. SB6.0: The 6th International meeting on Synthetic Biology, July 9-11, 2013

    SciTech Connect (OSTI)

    Kahl, Linda J.

    2015-04-23

    The Synthetic Biology conference series (SBx.0) is the preeminent academic meeting in synthetic biology. Organized by the BioBricks Foundation, the SBx.0 conference series brings together leading researchers, students, industry executives, and policy makers from around the world to share, consider, debate, and plan efforts to make biology easier to engineer. Historically held every two years, the SBx.0 conferences are held in alternating locations in the United States, Europe, and Asia to encourage global participation and collaboration so that the ramifications of synthetic biology research and development are most likely to be safe ethical, and beneficial. On 9-11 July 2013, the 6th installment of the synthetic biology conference series (SB6.0) was held on the campus of Imperial College London (http://sb6.biobricks.org). The SB6.0 conference was attended by over 700 people, and many more were able to participate via video digital conference (http://sb6.biobricks.org/digital-conference/). Over the course of three days, the SB6.0 conference agenda included plenary sessions, workshops, and poster presentations covering topics ranging from the infrastructure needs arising when Systematic Engineering Meets Biological Complexity and design-led considerations for Connecting People and Technologies to discussions on Engineering Biology for New Materials, Assessing Risk and Managing Biocontainment, and New Directions for Energy and Sustainability. The $10,150 grant awarded by the U.S. Department of Energy (DE-SC0010233) to the BioBricks Foundation was used to provide partial reimbursement for the travel expenses of leading researchers from the United States to speak at the SB6.0 conference. A total of $9,450 was used to reimburse U.S. speakers for actual expenses related to the SB6.0 conference, including airfare (economy or coach only), ground transportation, hotel, and registration fees. In addition, $700 of the grant was used to offset direct administrative costs associated with selecting speakers (preparing announcements, evaluating abstract submissions) and handling travel arrangements. Leading U.S. researchers selected to speak at the SB6.0 conference included: Adam Arkin, Ph.D. Division Director of the Physical Biosciences Division at the Lawrence Berkeley National Laboratory and Professor in the Department of Bioengineering at UC Berkeley Jay Keasling, Ph.D. Professor in the Department of Bioengineering at Berkeley, Senior Faculty Scientist and Associate Laboratory Director of the Lawrence Berkeley National Laboratory, and Chief Executive Officer of the Joint BioEnergy Institute. Debra Mathews, Ph.D. Assistant Director for Science Programs for the Johns Hopkins Berman Institute of Bioethics, Assistant Professor in the Department of Pediatrics, and Affiliate Faculty in the McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins School of Medicine. Richard Murray, Ph.D. Thomas E. and Doris Everhart Professor of Control & Dynamical Systems and Bioengineering at Caltech. Sarah Richardson, Ph.D. Distinguished Postdoctoral Fellow in Genomics at the Lawrence Berkeley National Laboratory and the Department of Energy Joint Genome Institute. and others (for a complete listing of speakers presenting at the SB6.0 conference see http://sb6.biobricks.org/speakers/) The SB6.0 conference was the largest synthetic biology conference to date, and highlights of the SB6.0 conference have been published in a special issue of ACS Synthetic Biology (http://pubs.acs.org/toc/asbcd6/3/3). The BioBricks Foundation appreciates the support of the U.S. Department of Energy in helping to make this most influential and important conference in the field of synthetic biology a success.

  15. Project Profile: Understanding the Evolution of Customer Motivations and

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Adoption Barriers in Residential Photovoltaics Markets | Department of Energy Soft Costs » Project Profile: Understanding the Evolution of Customer Motivations and Adoption Barriers in Residential Photovoltaics Markets Project Profile: Understanding the Evolution of Customer Motivations and Adoption Barriers in Residential Photovoltaics Markets Logos of the National Renewable Energy Laboratory, the University of Arizona, the University of Michigan, the University of Colorado Boulder,

  16. Summary report : direct approaches for recycling carbon dioxide into synthetic fuel.

    SciTech Connect (OSTI)

    Allendorf, Mark D.; Ambrosini, Andrea; Diver, Richard B., Jr.; Siegel, Nathan Phillip; Miller, James Edward; Gelbard, Fred; Evans, Lindsey R.

    2009-01-01

    The consumption of petroleum by the transportation sector in the United States is roughly equivalent to petroleum imports into the country, which have totaled over 12 million barrels a day every year since 2004. This reliance on foreign oil is a strategic vulnerability for the economy and national security. Further, the effect of unmitigated CO{sub 2} releases on the global climate is a growing concern both here and abroad. Independence from problematic oil producers can be achieved to a great degree through the utilization of non-conventional hydrocarbon resources such as coal, oil-shale and tarsands. However, tapping into and converting these resources into liquid fuels exacerbates green house gas (GHG) emissions as they are carbon rich, but hydrogen deficient. Revolutionary thinking about energy and fuels must be adopted. We must recognize that hydrocarbon fuels are ideal energy carriers, but not primary energy sources. The energy stored in a chemical fuel is released for utilization by oxidation. In the case of hydrogen fuel the chemical product is water; in the case of a hydrocarbon fuel, water and carbon dioxide are produced. The hydrogen economy envisions a cycle in which H{sub 2}O is re-energized by splitting water into H{sub 2} and O{sub 2}, by electrolysis for example. We envision a hydrocarbon analogy in which both carbon dioxide and water are re-energized through the application of a persistent energy source (e.g. solar or nuclear). This is of course essentially what the process of photosynthesis accomplishes, albeit with a relatively low sunlight-to-hydrocarbon efficiency. The goal of this project then was the creation of a direct and efficient process for the solar or nuclear driven thermochemical conversion of CO{sub 2} to CO (and O{sub 2}), one of the basic building blocks of synthetic fuels. This process would potentially provide the basis for an alternate hydrocarbon economy that is carbon neutral, provides a pathway to energy independence, and is compatible with much of the existing fuel infrastructure.

  17. NLO evolution of 3-quark Wilson loop operator

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Balitsky, I.; Grabovsky, A. V.

    2015-01-07

    It is well known that high-energy scattering of a meson from some hadronic target can be described by the interaction of that target with a color dipole formed by two Wilson lines corresponding to fast quark-antiquark pair. Moreover, the energy dependence of the scattering amplitude is governed by the evolution equation of this color dipole with respect to rapidity. Similarly, the energy dependence of scattering of a baryon can be described in terms of evolution of a three-Wilson-lines operator with respect to the rapidity of the Wilson lines. We calculate the evolution of the 3-quark Wilson loop operator in themore » next-to-leading order (NLO) and present a quasi-conformal evolution equation for a composite 3-Wilson-lines operator. Thus we also obtain the linearized version of that evolution equation describing the amplitude of the odderon exchange at high energies.« less

  18. Synthetic Metagenomics: Converting digital information back to Biology (2013 DOE JGI Genomics of Energy and Environment 8th Annual User Meeting)

    SciTech Connect (OSTI)

    Deutsch, Sam [DOE Joint Genome Institute

    2013-03-01

    Sam Deutsch of the DOE JGI on "Synthetic Metagenomics: Converting digital information back to Biology" at the 8th Annual Genomics of Energy & Environment Meeting in Walnut Creek, Calif.

  19. THE COLLISIONAL EVOLUTION OF DEBRIS DISKS

    SciTech Connect (OSTI)

    Gaspar, Andras; Rieke, George H.; Balog, Zoltan E-mail: grieke@as.arizona.edu

    2013-05-01

    We explore the collisional decay of disk mass and infrared emission in debris disks. With models, we show that the rate of the decay varies throughout the evolution of the disks, increasing its rate up to a certain point, which is followed by a leveling off to a slower value. The total disk mass falls off {proportional_to}t {sup -0.35} at its fastest point (where t is time) for our reference model, while the dust mass and its proxy-the infrared excess emission-fades significantly faster ({proportional_to}t {sup -0.8}). These later level off to a decay rate of M{sub tot}(t){proportional_to}t {sup -0.08} and M{sub dust}(t) or L{sub ir}(t){proportional_to}t {sup -0.6}. This is slower than the {proportional_to}t {sup -1} decay given for all three system parameters by traditional analytic models. We also compile an extensive catalog of Spitzer and Herschel 24, 70, and 100 {mu}m observations. Assuming a log-normal distribution of initial disk masses, we generate model population decay curves for the fraction of stars harboring debris disks detected at 24 {mu}m. We also model the distribution of measured excesses at the far-IR wavelengths (70-100 {mu}m) at certain age regimes. We show general agreement at 24 {mu}m between the decay of our numerical collisional population synthesis model and observations up to a Gyr. We associate offsets above a Gyr to stochastic events in a few select systems. We cannot fit the decay in the far-infrared convincingly with grain strength properties appropriate for silicates, but those of water ice give fits more consistent with the observations (other relatively weak grain materials would presumably also be successful). The oldest disks have a higher incidence of large excesses than predicted by the model; again, a plausible explanation is very late phases of high dynamical activity around a small number of stars. Finally, we constrain the variables of our numerical model by comparing the evolutionary trends generated from the exploration of the full parameter space to observations. Amongst other results, we show that erosive collisions are dominant in setting the timescale of the evolution and that planetesimals on the order of 100 km in diameter are necessary in the cascades for our population synthesis models to reproduce the observations.

  20. Evolutions of nonsteady state magnetic reconnection

    SciTech Connect (OSTI)

    Wan, Weigang; Lapenta, Giovanni

    2008-01-01

    The full evolutions of collisionless non-steady-state magnetic reconnection are studied with full kinetic particle-in-cell simulations. There are different stages of reconnection: the onset or early growing stage when the out-of-plane electric field (Ey) structure is a monopole at the X-point, the bipolar stage when the Ey structure is bipolar and the outer electron diffusion region (EDR) is being elongated over time, and the possible final steady-state stage when E{sub y} is uniform in the reconnection plane. We find the change of reconnection rate is not empowered or dependent on the length of the EDR. During the early growing stage, the EDR is elongated while the reconnection rate is growing. During the later stage, the reconnection rate may significantly decrease but the length of the inner EDR is largely stable. The results indicate that reconnection is not controlled by the downstream physics, but rather by the availability of plasma inflows from upstream. The physical mechanism of the EDR elongation is studied. The Hall current induced by the quadrupole magnetic field (B{sub y}) is discovered to play an important role in this process. The condition of forming an extended electron super-Alfvenic outflow jet structure in nature is discussed. The jet structure could be elongated during the bipolar stage, and remains stable during steady state. The sufficiency of the electron inflow is crucial for the elongation. Open boundary conditions are applied in the outflow direction.

  1. A uniform history for galaxy evolution

    SciTech Connect (OSTI)

    Steinhardt, Charles L.; Speagle, Josh S.

    2014-11-20

    Recent observations indicate a remarkable similarity in the properties of evolving galaxies at fixed mass and redshift, prompting us to consider the possibility that most galaxies may evolve with a common history encompassing star formation, quasar accretion, and eventual quiescence. We quantify this by defining a synchronization timescale for galaxies as a function of mass and redshift that characterizes the extent to which different galaxies of a common mass are evolving in the same manner at various cosmic epochs. We measure this synchronization timescale using nine different star-forming galaxy observations from the literature and Sloan Digital Sky Survey quasar observations spanning 0 < z ? 6. Surprisingly, this synchronization timescale is a constant, approximately 1.5 Gyr for all combinations of mass and time. We also find that the ratio between the stellar mass of galaxies turning off star formation and black hole mass of turnoff quasars is approximately 30:1, much lower than the 500:1 for quiescent galaxies at low redshift. As a result, we propose a model in which the star-forming 'main sequence', analogous quasar behavior, and other observations form a galactic evolution 'main sequence', in which star formation occurs earliest, followed by supermassive black hole accretion, and feedback between the two are dominated by deterministic rather than stochastic processes.

  2. Dosimetry of cone-defined stereotactic radiosurgery fields with a commercial synthetic diamond detector

    SciTech Connect (OSTI)

    Morales, Johnny E.; Crowe, Scott B.; Trapp, J. V.; Hill, Robin; Freeman, Nigel

    2014-11-01

    Purpose: Small field x-ray beam dosimetry is difficult due to lack of lateral electronic equilibrium, source occlusion, high dose gradients, and detector volume averaging. Currently, there is no single definitive detector recommended for small field dosimetry. The objective of this work was to evaluate the performance of a new commercial synthetic diamond detector, namely, the PTW 60019 microDiamond, for the dosimetry of small x-ray fields as used in stereotactic radiosurgery (SRS). Methods: Small field sizes were defined by BrainLAB circular cones (430 mm diameter) on a Novalis Trilogy linear accelerator and using the 6 MV SRS x-ray beam mode for all measurements. Percentage depth doses (PDDs) were measured and compared to an IBA SFD and a PTW 60012 E diode. Cross profiles were measured and compared to an IBA SFD diode. Field factors, ?{sub Q{sub c{sub l{sub i{sub n,Q{sub m{sub s{sub r}{sup f{sub c}{sub l}{sub i}{sub n},f{sub m}{sub s}{sub r}}}}}}}}}, were calculated by Monte Carlo methods using BEAMnrc and correction factors, k{sub Q{sub c{sub l{sub i{sub n,Q{sub m{sub s{sub r}{sup f{sub c}{sub l}{sub i}{sub n},f{sub m}{sub s}{sub r}}}}}}}}}, were derived for the PTW 60019 microDiamond detector. Results: For the small fields of 430 mm diameter, there were dose differences in the PDDs of up to 1.5% when compared to an IBA SFD and PTW 60012 E diode detector. For the cross profile measurements the penumbra values varied, depending upon the orientation of the detector. The field factors, ?{sub Q{sub c{sub l{sub i{sub n,Q{sub m{sub s{sub r}{sup f{sub c}{sub l}{sub i}{sub n},f{sub m}{sub s}{sub r}}}}}}}}}, were calculated for these field diameters at a depth of 1.4 cm in water and they were within 2.7% of published values for a similar linear accelerator. The corrections factors, k{sub Q{sub c{sub l{sub i{sub n,Q{sub m{sub s{sub r}{sup f{sub c}{sub l}{sub i}{sub n},f{sub m}{sub s}{sub r}}}}}}}}}, were derived for the PTW 60019 microDiamond detector. Conclusions: The authors conclude that the new PTW 60019 microDiamond detector is generally suitable for relative dosimetry in small 6 MV SRS beams for a Novalis Trilogy linear equipped with circular cones.

  3. Effects of Water in Synthetic Lubricant Systems and Clathrate Formation: A Literature Search and Review

    SciTech Connect (OSTI)

    Rohatgi, Ngoc Dung T.

    2001-08-08

    An extensive literature search and a confidential survey were critically analyzed to determine the effects of water on the stability of hydrofluorocarbon/synthetic lubricant systems and to identify key areas requiring further investigation. Following are highlights from the analysis: Clathrate hydrates are solid solutions formed when water molecules are linked through hydrogen bonding creating cavities that can enclose various guest molecules from hydrate formers, such as hydrofluorocarbons R-32, R-125, R-134a, R-407C and R-410A. The four methods for preventing clathrate formation were drying the gas, heating it, reducing its pressure, or using inhibitors. The hydrolysis of polyolester lubricants was mostly acid-catalyzed and its reaction rate constant typically followed the Arrhenius equation of an activated process. Hydrolytic stability improved with hindered molecular structures, and with the presence of acid catcher additives and desiccants. Water vapor can effect the adsorption of long-chain fatty acids and the chemistry of formation of protective oxide film. However, these effects on lubrication can be either positive or negative. Fifty to sixty percent of the moisture injected into an air-conditioning system remained in the refrigerant and the rest mixed with the compressor oil. In an automotive air-conditioning system using R-134a, ice would form at 0 C evaporating temperature when the water content in the vapor refrigerant on the low-pressure side was more than 350 ppm. Moisture would cause the embrittlement of polyethylene terephthalate and the hydrolysis of polyesters, but would reduce the effect of amine additives on fluoroelastomer rubbers. The reactions of water with refrigerants and lubricants would cause formicary and large-pit corrosion in copper tubes, as well as copper plating and sludge formation. Moreover, blockage of capillary tubes increased rapidly in the presence of water. Twenty-four companies responded to the survey. From the responses, the water concentrations specified and expected for different refrigerant/lubricant systems varied depending on the products, their capacities and applications, and also on the companies. Among the problems associated with high moisture level, lubricant breakdown was of greatest concern, followed by acid formation, compressor failure and expansion valve sticking. The following research topics are suggested: 1. The air-conditioning and refrigeration industry needs to measure and record the water content and total acid number of the lubricant of newly installed systems as well as operating systems that are shutdown for service or repair. The reason for the shutdown needs to be documented. A database can then be established to correlate water content with type and cause of breakdown. 2. Detailed studies on the distribution of water in refrigeration and air-conditioning systems should be conducted to pinpoint problem areas associated with free water. 3. Research is needed to validate the current theories and mechanisms of formicary corrosion. Corrosion inhibitors need to be developed. 4. The conditions for clathrate formation and decomposition of other alternative refrigerants, such as R-23, R-41, R-116, R-125, R-143a, R-404A and R-507C, and water should be determined to avoid possible problems associated with tube plugging. The mechanism by which water facilitates or hinders lubrication needs to be studied.

  4. TMD factorization and evolution at large $b_T$

    SciTech Connect (OSTI)

    Collins, John; Rogers, Ted

    2015-07-01

    In using transverse-momentum-dependent (TMD) parton densities and fragmentation functions, important non-perturbative information is at large transverse position $b_T$. This concerns both the TMD functions and their evolution. Fits to high energy data tend to predict too rapid evolution when extrapolated to low energies where larger values of $b_T$ dominate. I summarize a new analysis of the issues. It results in a proposal for much weaker $b_T$ dependence at large $b_T$ for the evolution kernel, while preserving the accuracy of the existing fits. The results are particularly important for using transverse-spin-dependent functions like the Sivers function.

  5. A Unified Differential Evolution Algorithm for Global Optimization

    SciTech Connect (OSTI)

    Qiang, Ji; Mitchell, Chad

    2014-06-24

    Abstract?In this paper, we propose a new unified differential evolution (uDE) algorithm for single objective global optimization. Instead of selecting among multiple mutation strategies as in the conventional differential evolution algorithm, this algorithm employs a single equation as the mutation strategy. It has the virtue of mathematical simplicity and also provides users the flexbility for broader exploration of different mutation strategies. Numerical tests using twelve basic unimodal and multimodal functions show promising performance of the proposed algorithm in comparison to convential differential evolution algorithms.

  6. The Galaxy Evolution Explorer: Results from the First Year (Conference) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Conference: The Galaxy Evolution Explorer: Results from the First Year Citation Details In-Document Search Title: The Galaxy Evolution Explorer: Results from the First Year I will give an overview of the status, early data, and results from the Galaxy Evolution Explorer (GALEX), a NASA Explorer Mission launched in April 2003. GALEX is performing the first space UV sky-survey, including imaging and grism surveys in two bands (1350-1800 {angstrom} and 1800-2800 {angstrom}). I

  7. CHEMICAL EVOLUTION OF THE LARGE MAGELLANIC CLOUD

    SciTech Connect (OSTI)

    Bekki, Kenji [ICRAR, M468, University of Western Australia, 35 Stirling Highway, Crawley Western Australia 6009 (Australia); Tsujimoto, Takuji [National Astronomical Observatory of Japan, Mitaka-shi, Tokyo 181-8588 (Japan)

    2012-12-20

    We adopt a new chemical evolution model for the Large Magellanic Cloud (LMC) and thereby investigate its past star formation and chemical enrichment histories. The delay time distribution of Type Ia supernovae recently revealed by Type Ia supernova surveys is incorporated self-consistently into the new model. The principle results are summarized as follows. The present gas mass fraction and stellar metallicity as well as the higher [Ba/Fe] in metal-poor stars at [Fe/H] < -1.5 can be more self-consistently explained by models with steeper initial mass functions. The observed higher [Mg/Fe] ({>=}0.3) at [Fe/H] {approx} -0.6 and higher [Ba/Fe] (>0.5) at [Fe/H] {approx} -0.3 could be due to significantly enhanced star formation about 2 Gyr ago. The observed overall [Ca/Fe]-[Fe/H] relation and remarkably low [Ca/Fe] (< - 0.2) at [Fe/H] > -0.6 are consistent with models with short-delay supernova Ia and with the more efficient loss of Ca possibly caused by an explosion mechanism of Type II supernovae. Although the metallicity distribution functions do not show double peaks in the models with a starburst about 2 Gyr ago, they show characteristic double peaks in the models with double starbursts {approx}200 Myr and {approx}2 Gyr ago. The observed apparent dip of [Fe/H] around {approx}1.5 Gyr ago in the age-metallicity relation can be reproduced by models in which a large amount ({approx}10{sup 9} M{sub Sun }) of metal-poor ([Fe/H] < -1) gas can be accreted onto the LMC.

  8. Stellar Evolution/Supernova Research Data Archives from the SciDAC...

    Office of Scientific and Technical Information (OSTI)

    Stellar EvolutionSupernova Research Data Archives from the SciDAC Computational Astrophysics Consortium Title: Stellar EvolutionSupernova Research Data Archives from the SciDAC ...

  9. Evolution of magnetic properties and microstructure of Hf2Co11B...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Evolution of magnetic properties and microstructure of Hf2Co11B alloys Citation Details In-Document Search Title: Evolution of magnetic properties and ...

  10. Evolution of a Mineralized Geothermal System, Valles Caldera...

    Open Energy Info (EERE)

    Journal Article: Evolution of a Mineralized Geothermal System, Valles Caldera, New Mexico Abstract The 20-km-diam Valles caldera formed at 1.13 Ma and had continuous...

  11. Evolution of quasiparticle states with and without a Zn impurity...

    Office of Scientific and Technical Information (OSTI)

    Title: Evolution of quasiparticle states with and without a Zn impurity in doped 122 iron pnictides Authors: Pan, Lihua ; Li, Jian ; Tai, Yuan-Yen ; Graf, Matthias J. ; Zhu, ...

  12. Fracture Evolution Following a Hydraulic Stimulation within an EGS Reservoir

    Broader source: Energy.gov [DOE]

    DOE Geothermal Peer Review 2010 - Presentation. This project will provide the first ever formal evaluation of fracture and fracture flow evolution in an EGS reservoir following a hydraulic stimulation.

  13. Investigation of Microscale Damage Evolution in High Strength...

    Office of Scientific and Technical Information (OSTI)

    Damage Evolution in High Strength A1 Alloy. Authors: Jin, Huiqing ; Lu, Wei-Yang ; Mota, Alejandro ; Foulk, James W., III ; johnson, george Publication Date: 2012-09-01 OSTI...

  14. Investigation of Microscale Damage Evolution in High-Strength...

    Office of Scientific and Technical Information (OSTI)

    Damage Evolution in High-Strength Al Alloy. Authors: Jin, Huiqing ; Lu, Wei-Yang ; Mota, Alejandro ; Foulk, James W., III Publication Date: 2012-10-01 OSTI Identifier: 1072668...

  15. Analytic Evolution of Singular Distribution Amplitudes in QCD

    SciTech Connect (OSTI)

    Radyushkin, Anatoly V.; Tandogan Kunkel, Asli

    2014-03-01

    We describe a method of analytic evolution of distribution amplitudes (DA) that have singularities, such as non-zero values at the end-points of the support region, jumps at some points inside the support region and cusps. We illustrate the method by applying it to the evolution of a flat (constant) DA, anti-symmetric at DA and then use it for evolution of the two-photon generalized distribution amplitude. Our approach has advantages over the standard method of expansion in Gegenbauer polynomials, which requires infinite number of terms in order to accurately reproduce functions in the vicinity of singular points, and over a straightforward iteration of an initial distribution with evolution kernel. The latter produces logarithmically divergent terms at each iteration, while in our method the logarithmic singularities are summed from the start, which immediately produces a continuous curve, with only one or two iterations needed afterwards in order to get rather precise results.

  16. Evolution of the electronic structure in ultrathin Bi(111) films...

    Office of Scientific and Technical Information (OSTI)

    This content will become publicly available on May 11, 2016 Title: Evolution of the ... will become publicly available on May 11, 2016 Publisher's Version of Record 10.1103...

  17. Structural evolution of zirconia nanopowders as a coagulation process

    SciTech Connect (OSTI)

    Doroshkevich, A. S. Danilenko, I. A.; Konstantinova, T. E.; Volkova, G. K.; Glazunova, V. A.

    2010-09-15

    The coagulation character of structural evolution in zirconia nanopowders is shown within the Brownian dynamics model for dispersed media (based on electron microscopy and X-ray diffraction data).

  18. Elucidating Hydrogen Oxidation/Evolution Kinetics in Base and...

    Office of Scientific and Technical Information (OSTI)

    Elucidating Hydrogen OxidationEvolution Kinetics in Base and Acid by Enhanced Activities at the Optimized Pt Shell Thickness on the Ru Core Citation Details In-Document Search...

  19. Separation of americium, curium, and rare earths from high-level wastes by oxalate precipitation: experiments with synthetic waste solutions

    SciTech Connect (OSTI)

    Forsberg, C.W.

    1980-01-01

    The separation of trivalent actinides and rare earths from other fission products in high-level nuclear wastes by oxalate precipitation followed by ion exchange (OPIX) was experimentally investigated using synthetic wastes and a small-scale, continuous-flow oxalic acid precipitation and solid-liquid separation system. Trivalent actinide and rare earth oxalates are relatively insoluble in 0.5 to 1.0 M HNO/sub 3/ whereas other fission product oxalates are not. The continuous-flow system consisted of one or two stirred-tank reactors in series for crystal growth. Oxalic acid and waste solutions were mixed in the first tank, with the product solid-liquid slurry leaving the second tank. Solid-liquid separation was tested by filters and by a gravity settler. The experiments determined the fraction of rare earths precipitated and separated from synthetic waste streams as a function of number of reactors, system temperature, oxalic acid concentration, liquid residence time in the process, power input to the stirred-tank reactors, and method of solid-liquid separation. The crystalline precipitate was characterized with respect to form, size, and chemical composition. These experiments are only the first step in converting a proposed chemical flowsheet into a process flowsheet suitable for large-scale remote operations at high activity levels.

  20. Terra Sigillata: Evolution of Roman Ceramics Reflect Changes in Technology,

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Life Terra Sigillata: Evolution of Roman Ceramics Reflect Changes in Technology, Life Terra Sigillata: Evolution of Roman Ceramics Reflect Changes in Technology, Life Print Wednesday, 18 March 2015 15:38 Terra sigillata ceramics were the most famous ancient tableware produced during the Roman period owing to the mass production of standardized shapes and the widespread distribution of the vessels. The beautiful ceramics were characterized by their reddish coloration, glossy coating, and the

  1. Biomass-derived Hydrogen-evolution catalyst and electrode - Energy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Innovation Portal Biomass-derived Hydrogen-evolution catalyst and electrode Brookhaven National Laboratory Contact BNL About This Technology Publications: PDF Document Publication Biomass-derived electrocatalytic composites for hydrogen evolution (1,122 KB) Representation of catalyst formation and activity. Representation of catalyst formation and activity. Technology Marketing Summary A simply made, inexpensive combination of biomass and earth-abundant metals has resulted in a durable

  2. Intergranular Strain Evolution near Fatigue Crack Tips in Polycrystalline

    Office of Scientific and Technical Information (OSTI)

    Metals (Journal Article) | SciTech Connect Intergranular Strain Evolution near Fatigue Crack Tips in Polycrystalline Metals Citation Details In-Document Search Title: Intergranular Strain Evolution near Fatigue Crack Tips in Polycrystalline Metals The deformation field near a steady fatigue crack includes a plastic zone in front of the crack tip and a plastic wake behind it, and the magnitude, distribution, and history of the residual strain along the crack path depend on the stress

  3. MARTINI event generator for heavy quarks: Initialization, parton evolution,

    Office of Scientific and Technical Information (OSTI)

    and hadronization (Journal Article) | DOE PAGES MARTINI event generator for heavy quarks: Initialization, parton evolution, and hadronization « Prev Next » Title: MARTINI event generator for heavy quarks: Initialization, parton evolution, and hadronization Authors: Young, Clint ; Schenke, Björn ; Jeon, Sangyong ; Gale, Charles Publication Date: 2012-09-10 OSTI Identifier: 1103304 Type: Publisher's Accepted Manuscript Journal Name: Physical Review C Additional Journal Information: Journal

  4. HyDIVE (Hydrogen Dynamic Infrastructure and Vehicle Evolution) Model

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Analysis | Department of Energy HyDIVE (Hydrogen Dynamic Infrastructure and Vehicle Evolution) Model Analysis HyDIVE (Hydrogen Dynamic Infrastructure and Vehicle Evolution) Model Analysis Presentation by NREL's Cory Welch at the 2010 - 2025 Scenario Analysis for Hydrogen Fuel Cell Vehicles and Infrastructure Meeting on August 9 - 10, 2006 in Washington, D.C. PDF icon welch_hydive.pdf More Documents & Publications Discrete Choice Analysis: Hydrogen FCV Demand Potential Technical Workshop:

  5. Detection and characterization of multi-filament evolution during resistive

    Office of Scientific and Technical Information (OSTI)

    switching. (Journal Article) | SciTech Connect Detection and characterization of multi-filament evolution during resistive switching. Citation Details In-Document Search Title: Detection and characterization of multi-filament evolution during resistive switching. Abstract not provided. Authors: Mickel, Patrick R. ; Lohn, Andrew ; Marinella, Matthew Publication Date: 2014-05-01 OSTI Identifier: 1145719 Report Number(s): SAND2014-4055J 518013 DOE Contract Number: DE-AC04-94AL85000 Resource

  6. Direct in situ measurement of coupled magnetostructural evolution in a

    Office of Scientific and Technical Information (OSTI)

    ferromagnetic shape memory alloy and its theoretical modeling (Journal Article) | SciTech Connect in situ measurement of coupled magnetostructural evolution in a ferromagnetic shape memory alloy and its theoretical modeling Citation Details In-Document Search This content will become publicly available on October 14, 2016 Title: Direct in situ measurement of coupled magnetostructural evolution in a ferromagnetic shape memory alloy and its theoretical modeling In this study, ferromagnetic

  7. Dynamic Evolution of Cement Composition and Transport Properties under

    Office of Scientific and Technical Information (OSTI)

    Conditions Relevant to Geological Carbon Sequestration (Journal Article) | SciTech Connect Dynamic Evolution of Cement Composition and Transport Properties under Conditions Relevant to Geological Carbon Sequestration Citation Details In-Document Search Title: Dynamic Evolution of Cement Composition and Transport Properties under Conditions Relevant to Geological Carbon Sequestration Assessing the possibility of CO{sub 2} leakage is one of the major challenges for geological carbon

  8. Evaluation of Thermal Evolution Profiles and Estimation of Kinetic

    Office of Scientific and Technical Information (OSTI)

    Parameters for Pyrolysis of Coal/Corn Stover Blends Using Thermogravimetric Analysis (Journal Article) | SciTech Connect Journal Article: Evaluation of Thermal Evolution Profiles and Estimation of Kinetic Parameters for Pyrolysis of Coal/Corn Stover Blends Using Thermogravimetric Analysis Citation Details In-Document Search Title: Evaluation of Thermal Evolution Profiles and Estimation of Kinetic Parameters for Pyrolysis of Coal/Corn Stover Blends Using Thermogravimetric Analysis Authors:

  9. Evolution of extreme resistance to ionizing radiation via genetic

    Office of Scientific and Technical Information (OSTI)

    adaptation of DNA repair (Journal Article) | DOE PAGES DOE PAGES Search Results Published Article: Evolution of extreme resistance to ionizing radiation via genetic adaptation of DNA repair « Prev Next » Title: Evolution of extreme resistance to ionizing radiation via genetic adaptation of DNA repair Authors: Byrne, Rose T. ; Klingele, Audrey J. ; Cabot, Eric L. ; Schackwitz, Wendy S. ; Martin, Jeffrey A. ; Martin, Joel ; Wang, Zhong ; Wood, Elizabeth A. ; Pennacchio, Christa ; Pennacchio,

  10. Evolution of twist-3 multiparton correlation functions relevant to single

    Office of Scientific and Technical Information (OSTI)

    transverse-spin asymmetry (Journal Article) | SciTech Connect Evolution of twist-3 multiparton correlation functions relevant to single transverse-spin asymmetry Citation Details In-Document Search Title: Evolution of twist-3 multiparton correlation functions relevant to single transverse-spin asymmetry We construct two sets of twist-3 correlation functions that are responsible for generating the novel single transverse-spin asymmetry in the QCD collinear factorization approach. We derive

  11. MARTINI event generator for heavy quarks: Initialization, parton evolution,

    Office of Scientific and Technical Information (OSTI)

    and hadronization (Journal Article) | SciTech Connect MARTINI event generator for heavy quarks: Initialization, parton evolution, and hadronization Citation Details In-Document Search Title: MARTINI event generator for heavy quarks: Initialization, parton evolution, and hadronization Authors: Young, Clint ; Schenke, Björn ; Jeon, Sangyong ; Gale, Charles Publication Date: 2012-09-10 OSTI Identifier: 1103304 Type: Publisher's Accepted Manuscript Journal Name: Physical Review C Additional

  12. Advancing Reactive Tracer Methods for Measurement of Thermal Evolution in

    Office of Scientific and Technical Information (OSTI)

    Geothermal Reservoirs: Final Report (Technical Report) | SciTech Connect Technical Report: Advancing Reactive Tracer Methods for Measurement of Thermal Evolution in Geothermal Reservoirs: Final Report Citation Details In-Document Search Title: Advancing Reactive Tracer Methods for Measurement of Thermal Evolution in Geothermal Reservoirs: Final Report The injection of cold fluids into engineered geothermal system (EGS) and conventional geothermal reservoirs may be done to help extract heat

  13. Direct in situ measurement of coupled magnetostructural evolution in a

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ferromagnetic shape memory alloy and its theoretical modeling (Journal Article) | DOE PAGES Direct in situ measurement of coupled magnetostructural evolution in a ferromagnetic shape memory alloy and its theoretical modeling This content will become publicly available on October 14, 2016 Title: Direct in situ measurement of coupled magnetostructural evolution in a ferromagnetic shape memory alloy and its theoretical modeling In this study, ferromagnetic shape memory alloys (FSMAs) have shown

  14. HIV virus spread and evolution studied through computer modeling

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    HIV and evolution studied through computer modeling HIV virus spread and evolution studied through computer modeling This approach distinguishes between susceptible and infected individuals to capture the full infection history, including contact tracing data for infected individuals. November 19, 2013 Scanning electron micrograph of HIV-1 budding (in green) from cultured lymphocytes. The image has been colored to highlight important features. Scanning electron micrograph of HIV-1 budding (in

  15. Los Alamos offers new insights into radiation damage evolution

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    New insights into radiation damage evolution Los Alamos offers new insights into radiation damage evolution Two reports are helping crack the code of how certain materials respond in the highly-damaging radiation environments within a nuclear reactor. March 16, 2015 Researchers at Los Alamos are studying complex materials issues, in this case the defects deep inside certain types of cubic metals. This image shows a reaction between two "stacking fault tetrahedra," a perfect SFT

  16. NAS Report and Microsite Trace SSL Evolution and Future Promise |

    Energy Savers [EERE]

    Department of Energy NAS Report and Microsite Trace SSL Evolution and Future Promise NAS Report and Microsite Trace SSL Evolution and Future Promise February 10, 2014 - 12:00am Addthis The National Academy of Sciences (NAS) has added a new microsite to complement its 2013 report, Assessment of Advanced Solid State Lighting. The report explores the history of public policy on lighting, evaluates costs and consumer acceptance issues, assesses the development of LED and OLED technologies, and

  17. Stress evolution during electrodeposition of Ni thin films. (Conference) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Conference: Stress evolution during electrodeposition of Ni thin films. Citation Details In-Document Search Title: Stress evolution during electrodeposition of Ni thin films. Abstract not provided. Authors: Hearne, Sean Joseph ; Floro, Jerrold Anthony Publication Date: 2004-10-01 OSTI Identifier: 1144066 Report Number(s): SAND2004-5595C 266981 DOE Contract Number: DE-AC04-94AL85000 Resource Type: Conference Resource Relation: Conference: MRS Spring Meeting held March 28-April

  18. Structure Evolution and Pulverization of Tin Nanoparticles during

    Office of Scientific and Technical Information (OSTI)

    Lithiation-Delithiation Cycling. (Journal Article) | SciTech Connect Journal Article: Structure Evolution and Pulverization of Tin Nanoparticles during Lithiation-Delithiation Cycling. Citation Details In-Document Search Title: Structure Evolution and Pulverization of Tin Nanoparticles during Lithiation-Delithiation Cycling. Abstract not provided. Authors: Jungjohann, Katherine Leigh ; Liu, Yang ; Wang, Jiangwei ; Fan, Feifei ; Mao, Scott ; Liu, Xiaohua ; Zhu, Ting Publication Date:

  19. The Evolution in Pu Nanocluster Electronic Structure: from Atomicity to

    Office of Scientific and Technical Information (OSTI)

    Three Dimensionality (Conference) | SciTech Connect Conference: The Evolution in Pu Nanocluster Electronic Structure: from Atomicity to Three Dimensionality Citation Details In-Document Search Title: The Evolution in Pu Nanocluster Electronic Structure: from Atomicity to Three Dimensionality Authors: Tobin, J G ; Yu, S W ; Chung, B W ; Ryzhkov, M V ; Mirmelstein, A V Publication Date: 2013-07-18 OSTI Identifier: 1149047 Report Number(s): LLNL-CONF-642076 DOE Contract Number:

  20. The Evolution in Pu Nanocluster Electronic Structure: from Atomicity to

    Office of Scientific and Technical Information (OSTI)

    Three Dimensionality (Conference) | SciTech Connect Conference: The Evolution in Pu Nanocluster Electronic Structure: from Atomicity to Three Dimensionality Citation Details In-Document Search Title: The Evolution in Pu Nanocluster Electronic Structure: from Atomicity to Three Dimensionality × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public

  1. Verification of the Time Evolution of Cosmological Simulations via

    Office of Scientific and Technical Information (OSTI)

    Hypothesis-Driven Comparative and Quantitative Visualization (Conference) | SciTech Connect Conference: Verification of the Time Evolution of Cosmological Simulations via Hypothesis-Driven Comparative and Quantitative Visualization Citation Details In-Document Search Title: Verification of the Time Evolution of Cosmological Simulations via Hypothesis-Driven Comparative and Quantitative Visualization We describe a visualization-assisted process for the verification of cosmological simulation

  2. Verification of the Time Evolution of Cosmological Simulations via

    Office of Scientific and Technical Information (OSTI)

    Hypothesis-Driven Comparative and Quantitative Visualization (Journal Article) | SciTech Connect Journal Article: Verification of the Time Evolution of Cosmological Simulations via Hypothesis-Driven Comparative and Quantitative Visualization Citation Details In-Document Search Title: Verification of the Time Evolution of Cosmological Simulations via Hypothesis-Driven Comparative and Quantitative Visualization Authors: Hsu, Chung-hsing [1] ; Ahrens, James P [1] ; Heitmann, Katrin [1] + Show

  3. Human immunodeficiency virus contains an epitope immunoreactive with thymosin. cap alpha. /sub 1/ and the 30-amino acid synthetic p17 group-specific antigen peptide HGP-30

    SciTech Connect (OSTI)

    Naylor, P.H.; Naylor, C.W.; Badamchian, M.; Wada, S.; Goldstein, A.L.; Wang, S.S.; Sun, D.K.; Thornton, A.H.; Sarin, P.S.

    1987-05-01

    The authors have reported that an antiserum prepared against thymosin ..cap alpha../sub 1/ (which shares a region of homology with the p17 protein of the acquired immunodeficiency syndrome (AIDS)-associated human immunodeficiency virus) effectively neutralized the AIDs virus and prevented its replication in H9 cells. Using HPLC and immunoblot analysis, they have identified from a clone B, type III human T-lymphotropic virus (HTLV-IIIB) extracts a protein with a molecular weight of 17,000 that is immunoreactive with thymosin ..cap alpha../sub 1/. In contrast, no immunoreactivity was found in retroviral extracts from a number of nonhuman species including feline, bovine, simian, gibbon, and murine retroviruses. Heterologous antiserum prepared against a 30-amino acid synthetic peptide analogue (HGP-30) does not cross-react with thymosin ..cap alpha../sub 1/ but does react specifically with the p17 protein of the AIDS virus in a manner identical to that seen with an HTLV-IIIB p17-specific monoclonal antibody. The demonstration that this synthetic analogue is immunogenic and that antibodies to HGP-30 cross-react not only with synthetic peptide but also with the HTLV-IIIB p17 viral protein provides an additional, and potentially more specific, candidate for development of a synthetic peptide vaccine for AIDS. In addition, the p17 synthetic peptide (HGP-3) may prove to be useful in a diagnostic assay for the detection of AIDS virus infection in seronegative individuals.

  4. Solid phase evolution in the Biosphere 2 hillslope experiment as predicted by modeling of hydrologic and geochemical fluxes

    SciTech Connect (OSTI)

    Dontsova, K.; Steefel, C.I.; Desilets, S.; Thompson, A.; Chorover, J.

    2009-07-15

    A reactive transport geochemical modeling study was conducted to help predict the mineral transformations occurring over a ten year time-scale that are expected to impact soil hydraulic properties in the Biosphere 2 (B2) synthetic hillslope experiment. The modeling sought to predict the rate and extent of weathering of a granular basalt (selected for hillslope construction) as a function of climatic drivers, and to assess the feedback effects of such weathering processes on the hydraulic properties of the hillslope. Flow vectors were imported from HYDRUS into a reactive transport code, CrunchFlow2007, which was then used to model mineral weathering coupled to reactive solute transport. Associated particle size evolution was translated into changes in saturated hydraulic conductivity using Rosetta software. We found that flow characteristics, including velocity and saturation, strongly influenced the predicted extent of incongruent mineral weathering and neo-phase precipitation on the hillslope. Results were also highly sensitive to specific surface areas of the soil media, consistent with surface reaction controls on dissolution. Effects of fluid flow on weathering resulted in significant differences in the prediction of soil particle size distributions, which should feedback to alter hillslope hydraulic conductivities.

  5. On the Radio and Optical Luminosity Evolution of Quasars

    SciTech Connect (OSTI)

    Singal, J.; Petrosian, V.; Lawrence, A.; Stawarz, L.; /JAXA, Sagamihara /Jagiellonian U., Astron. Observ.

    2011-05-20

    We calculate simultaneously the radio and optical luminosity evolutions of quasars, and the distribution in radio loudness R defined as the ratio of radio and optical luminosities, using a flux limited data set containing 636 quasars with radio and optical fluxes from White et al. We first note that when dealing with multivariate data it is imperative to first determine the true correlations among the variables, not those introduced by the observational selection effects, before obtaining the individual distributions of the variables. We use the methods developed by Efron and Petrosian which are designed to obtain unbiased correlations, distributions, and evolution with redshift from a data set truncated due to observational biases. It is found that as expected the population of quasars exhibits strong positive correlation between the radio and optical luminosities and that this correlation deviates from a simple linear relation in a way indicating that more luminous quasars are more radio loud. We also find that there is a strong luminosity evolution with redshift in both wavebands, with significantly higher radio than optical evolution. We conclude that the luminosity evolution obtained by arbitrarily separating the sources into radio loud (R > 10) and radio quiet (R < 10) populations introduces significant biases that skew the result considerably. We also construct the local radio and optical luminosity functions and the density evolution. Finally, we consider the distribution of the radio loudness parameter R obtained from careful treatment of the selection effects and luminosity evolutions with that obtained from the raw data without such considerations. We find a significant difference between the two distributions and no clear sign of bi-modality in the true distribution. Our results indicate therefore, somewhat surprisingly, that there is no critical switch in the efficiency of the production of disk outflows/jets between very radio quiet and very radio loud quasars, but rather a smooth transition. Also, this efficiency seems higher for the high-redshift and more luminous sources in the considered sample.

  6. Reservoir monitoring and characterization using satellite geodetic data: Interferometric Synthetic Aperture Radar observations from the Krechba field, Algeria

    SciTech Connect (OSTI)

    Vasco, D.W.; Ferretti, Alessandro; Novali, Fabrizio

    2008-05-01

    Deformation in the material overlying an active reservoir is used to monitor pressure change at depth. A sequence of pressure field estimates, eleven in all, allow us to construct a measure of diffusive travel time throughout the reservoir. The dense distribution of travel time values means that we can construct an exactly linear inverse problem for reservoir flow properties. Application to Interferometric Synthetic Aperture Radar (InSAR) data gathered over a CO{sub 2} injection in Algeria reveals pressure propagation along two northwest trending corridors. An inversion of the travel times indicates the existence of two northwest-trending high permeability zones. The high permeability features trend in the same direction as the regional fault and fracture zones. Model parameter resolution estimates indicate that the features are well resolved.

  7. Single nanopore transport of synthetic and biological polyelectrolytes in three-dimensional hybrid microfluidic/nanofluidic devices

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    King, Travis L.; Gatimu, Enid N.; Bohn, Paul W.

    2009-01-02

    This paper presents a study of electrokinetic transport in single nanopores integrated into vertically-stacked three-dimensional hybrid microfluidic/nanofluidic structures. In these devices single nanopores, created by focused ion beam (FIB) milling in thin polymer films, provide fluidic connection between two vertically separated, perpendicular microfluidic channels. Experiments address both systems in which the nanoporous membrane is composed of the same (homojunction) or different (heterojunction) polymer as the microfluidic channels. These devices are then used to study the electrokinetic transport properties of synthetic (i.e., polystyrene sulfonate and polyallylamine) and biological (i.e.,DNA) polyelectrolytes across these nanopores. Single nanopore transport of polyelectrolytes across these nanoporesmore » using both electrical current measurements and confocal microscopy. Both optical and electrical measurements indicate that electroosmotic transport is predominant over electrophoresis in single nanopores with d > 180 nm, consistent with results obtained under similar conditions for nanocapillary array membranes.« less

  8. Effects of Measurement Materials and Oxygen Partial Pressure on the Viscosity of synthetic Eastern and Western United States Coal Slags

    SciTech Connect (OSTI)

    Zhu, Jingxi; Tetsuya, Kenneth; Mu, Haoyuan; Bennett, James P.; Sridhar, Seetharaman

    2012-07-01

    The viscosity of the molten ash (slag) resulting from the mineral constituents in carbon feedstock used in slagging gasifiers is critical for controlling the gasification process. The viscosity of two synthetic slags with compositions resembling the mineral impurities in average eastern and western coal feedstock was examined at temperatures from 13001500 C using a rotating bob viscometer. A few combinations of atmospheres and experimental materials were investigated with respect to one another to determine slag viscosity. A CO/CO{sub 2} atmosphere (CO/CO{sub 2} = 1.8, corresponding to a P{sub O{sub 2}} = 108 atm) is required to sustain ferrous ions in FeO-containing slags, an environment that is oxidizing to most metals. Iron oxide in the slag prevents usage of Fe parts. In unpurified Ar, the Fe metal surface oxidizes. Using purified argon prevents iron measurement components from oxidation; however, the metallic surfaces act as nucleation sites for the reduction of the Fe oxide in the slag into metallic Fe. Dissolution of ceramic materials into the slag, including Al{sub 2}O{sub 3} and ZrO{sub 2}, occurs in both atmospheres. Therefore, evaluating slag properties in the laboratory is challenging. The measured viscosities of two synthetic slags in this study diverged depending upon material selection. This difference is likely attributable to container/spindle-slag interactions. Viscosity measurements of the eastern coal slag using all ceramic parts agreed best with FactSage prediction above 1350 C, with an average activation energy of 271.2 kJ. For western coal slag, the dissolution of container/spindle materials was substantial during the measurement, with precipitation of crystalline phase noted. The experimental viscosity data of the western coal slag agreed best with Kalmanovitch prediction above 1350 C. The activation energy changed dramatically for both data sets of western coal slag, likely indicating the Newtonian-to-non-Newtonian transition.

  9. Calculation of TMD Evolution for Transverse Single Spin Asymmetry Measurements

    SciTech Connect (OSTI)

    Mert Aybat, Ted Rogers, Alexey Prokudin

    2012-06-01

    In this letter, we show that it is necessary to include the full treatment of QCD evolution of Transverse Momentum Dependent parton densities to explain discrepancies between HERMES data and recent COMPASS data on a proton target for the Sivers transverse single spin asymmetry in Semi-Inclusive Deep Inelastic Scattering (SIDIS). Calculations based on existing fits to TMDs in SIDIS, and including evolution within the Collins-Soper-Sterman with properly defined TMD PDFs are shown to provide a good explanation for the discrepancy. The non-perturbative input needed for the implementation of evolution is taken from earlier analyses of unpolarized Drell-Yan (DY) scattering at high energy. Its success in describing the Sivers function in SIDIS data at much lower energies is strong evidence in support of the unifying aspect of the QCD TMD-factorization formalism.

  10. An Adaptive Unified Differential Evolution Algorithm for Global Optimization

    SciTech Connect (OSTI)

    Qiang, Ji; Mitchell, Chad

    2014-11-03

    In this paper, we propose a new adaptive unified differential evolution algorithm for single-objective global optimization. Instead of the multiple mutation strate- gies proposed in conventional differential evolution algorithms, this algorithm employs a single equation unifying multiple strategies into one expression. It has the virtue of mathematical simplicity and also provides users the flexibility for broader exploration of the space of mutation operators. By making all control parameters in the proposed algorithm self-adaptively evolve during the process of optimization, it frees the application users from the burden of choosing appro- priate control parameters and also improves the performance of the algorithm. In numerical tests using thirteen basic unimodal and multimodal functions, the proposed adaptive unified algorithm shows promising performance in compari- son to several conventional differential evolution algorithms.

  11. Time evolution of entangled biatomic states in a cavity

    SciTech Connect (OSTI)

    Figueiredo, E. G.; Linhares, C. A.; Malbouisson, A. P. C.

    2011-10-15

    We study the time evolution of entangled states of a pair of identical atoms, considered in the harmonic approximation, coupled to an environment represented by an infinite set of free oscillators, with the whole system confined within a spherical cavity of radius R. Taking the center-of-mass and the relative-position coordinates, and using the dressed-state approach, we present the time evolution of some quantities measuring the entanglement for both limits of a very large and a small cavity; the chosen examples are simple and illustrate these very distinct behaviors.

  12. Pump-Intensity- and Shell-Thickness-Dependent Evolution of

    Office of Scientific and Technical Information (OSTI)

    Photoluminescence Blinking in Individual Core/Shell CdSe/CdS Nanocrystals (Journal Article) | SciTech Connect Journal Article: Pump-Intensity- and Shell-Thickness-Dependent Evolution of Photoluminescence Blinking in Individual Core/Shell CdSe/CdS Nanocrystals Citation Details In-Document Search Title: Pump-Intensity- and Shell-Thickness-Dependent Evolution of Photoluminescence Blinking in Individual Core/Shell CdSe/CdS Nanocrystals Authors: Malko, Anton V. ; Park, Young-Shin ; Sampat,

  13. Spatiotemporal evolution of dielectric driven cogenerated dust density waves

    SciTech Connect (OSTI)

    Sarkar, Sanjib; Bose, M. [Department of Physics, Jadavpur University, Kolkata 700032 (India)] [Department of Physics, Jadavpur University, Kolkata 700032 (India); Mukherjee, S. [FCIPT, Institute for Plasma Research, Gandhinagar 382428 (India)] [FCIPT, Institute for Plasma Research, Gandhinagar 382428 (India); Pramanik, J. [Kharagpur College, Kharagpur 721305, West Bengal (India)] [Kharagpur College, Kharagpur 721305, West Bengal (India)

    2013-06-15

    An experimental observation of spatiotemporal evolution of dust density waves (DDWs) in cogenerated dusty plasma in the presence of modified field induced by glass plate is reported. Various DDWs, such as vertical, oblique, and stationary, were detected simultaneously for the first time. Evolution of spatiotemporal complexity like bifurcation in propagating wavefronts is also observed. As dust concentration reaches extremely high value, the DDW collapses. Also, the oblique and nonpropagating mode vanishes when we increase the number of glass plates, while dust particles were trapped above each glass plates showing only vertical DDWs.

  14. Hydrodynamic evolution and jet energy loss in Cu + Cu collisions

    SciTech Connect (OSTI)

    Schenke, Bjoern; Jeon, Sangyong; Gale, Charles

    2011-04-15

    We present results from a hybrid description of Cu + Cu collisions using (3 + 1)-dimensional hydrodynamics (music) for the bulk evolution and a Monte Carlo simulation (martini) for the evolution of high-momentum partons in the hydrodynamical background. We explore the limits of this description by going to small system sizes and determine the dependence on different fractions of wounded nucleon and binary collisions scaling of the initial energy density. We find that Cu + Cu collisions are well described by the hybrid description at least up to 20% central collisions.

  15. Beam energy evolution of HBT systematics at the AGS

    SciTech Connect (OSTI)

    Best, D.; Ajitanand, N.N.; Alexander, J.M.; Anderson, M.; Brady,F.P.; Case, T.; Caskey, W.; Cebra, D.; Chance, J.L.; Chung, P.; Cole, B.; Crowe, K.; Das, A.C.; Draper, J.E.; Gilkes, M.L.; Gushue, S.; Heffner,M.; Hirsch, A.S.; Hjort, E.L.; Huo, L.; Justice, M.; Kaplan, M.; Keane,D.; Kintner, J.C.; Klay, J.; Krofcheck, D.; Lacey, R.A.; Lisa, M.A.; Liu,H.; Liu, Y.M.; McGrath, R.; Milosevich, Z.; Odyniec, G.; Olson, D.L.; Panitkin, S.Y.; Pinkenburg, C.; Porile, N.T.; Rai, G.; Ritter, H.G.; Romero, J.L.; Scharenberg, R.P.; Schroeder, L.S.; Srivastava, B.; Stone,N.T.B.; Symons, T.J.M.; Wang, S.; Wells, R.; Whitfield, J.; Wienold, T.; Witt, R.; Wood, L.; Yang, X.; Zhang, W.; Zhang, Y.; E895 Collaboration

    1999-07-31

    We present preliminary results of the first pi interferometry (HBT) excitation function at intermediate AGS energies. The beam energy evolution of the correlations' dependence on mr:centrality, and emission angle with respect to the reaction I,lane are discussed. Comparisons with predictions of the RQMD cascade model are made.

  16. COSMIC EVOLUTION OF DUST IN GALAXIES: METHODS AND PRELIMINARY RESULTS

    SciTech Connect (OSTI)

    Bekki, Kenji

    2015-02-01

    We investigate the redshift (z) evolution of dust mass and abundance, their dependences on initial conditions of galaxy formation, and physical correlations between dust, gas, and stellar contents at different z based on our original chemodynamical simulations of galaxy formation with dust growth and destruction. In this preliminary investigation, we first determine the reasonable ranges of the most important two parameters for dust evolution, i.e., the timescales of dust growth and destruction, by comparing the observed and simulated dust mass and abundances and molecular hydrogen (H{sub 2}) content of the Galaxy. We then investigate the z-evolution of dust-to-gas ratios (D), H{sub 2} gas fraction (f{sub H{sub 2}}), and gas-phase chemical abundances (e.g., A {sub O} = 12 + log (O/H)) in the simulated disk and dwarf galaxies. The principal results are as follows. Both D and f{sub H{sub 2}} can rapidly increase during the early dissipative formation of galactic disks (z ? 2-3), and the z-evolution of these depends on initial mass densities, spin parameters, and masses of galaxies. The observed A {sub O}-D relation can be qualitatively reproduced, but the simulated dispersion of D at a given A {sub O} is smaller. The simulated galaxies with larger total dust masses show larger H{sub 2} and stellar masses and higher f{sub H{sub 2}}. Disk galaxies show negative radial gradients of D and the gradients are steeper for more massive galaxies. The observed evolution of dust masses and dust-to-stellar-mass ratios between z = 0 and 0.4 cannot be reproduced so well by the simulated disks. Very extended dusty gaseous halos can be formed during hierarchical buildup of disk galaxies. Dust-to-metal ratios (i.e., dust-depletion levels) are different within a single galaxy and between different galaxies at different z.

  17. Effect of 1-hydroxyethane-1,1-diphosphonic acid (HEDPA) on Partitioning of Np and Pu to Synthetic Boehmite

    SciTech Connect (OSTI)

    Powell, Brian A.; Rao, Linfeng; Nash, Kenneth L.

    2009-05-01

    The effect of 1-hydroxyethane-1,1-diphosphonic acid (HEDPA) on sorption of Np(V) and Pu(V) to synthetic boehmite ({gamma}-AlOOH) was examined a function of time and pH (between 4 to 11). Sorption of both elements in boehmite suspensions (1 M NaCl, 600 mg L{sup -1} boehmite) increased with increasing pH. Sorption edges for neptunium and plutonium occurred at approximately pH 8.0 and 6.6, respectively. After steady state partitioning was reached, HEDPA was added to the neptunium-boehmite and plutonium-boehmite suspensions. Neptunium and plutonium partitioning appears to be primarily affected by the formation of soluble Np:HEDPA and Pu:HEDPA complexes, the dissolution of boehmite promoted by HEDPA, and the precipitation of Np:HEDPA and Pu:HEDPA colloids. The results are discussed in terms of applicability of HEDPA-promoted dissolution as a waste reduction method in the treatment of sludge phases contained within high-level nuclear waste storage tanks.

  18. CuCo2O4 ORR/OER Bi-functional catalyst: Influence of synthetic approach on performance

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Serov, Alexey; Andersen, Nalin I.; Roy, Aaron J.; Matanovic, Ivana; Artyushkova, Kateryna; Atanassov, Plamen

    2015-02-07

    A series of CuCo2O4 catalysts were synthesized by pore forming, sol-gel, spray pyrolysis and sacrificial support methods. Catalysts were characterized by XRD, SEM, XPS and BET techniques. The electrochemical activity for the oxygen reduction and oxygen evolution reactions (ORR and OER) was evaluated in alkaline media by RRDE. Density Functional Theory was used to identify two different types of active sites responsible for ORR/OER activity of CuCo2O4 and it was found that CuCo2O4 can activate the O-O bond by binding molecular oxygen in bridging positions between Co or Co and Cu atoms. It was found that the sacrificial support methodmore » (SSM) catalyst has the highest performance in both ORR and OER and has the highest content of phase-pure CuCo2O4. It was shown that the presence of CuO significantly decreases the activity in oxygen reduction and oxygen evolution reactions. As a result, the half-wave potential (E1/2) of CuCo2O4-SSM was found as 0.8 V, making this material a state-of-the-art, unsupported oxide catalyst.« less

  19. Problems with propagation and time evolution inf(T)gravity (Journal...

    Office of Scientific and Technical Information (OSTI)

    Problems with propagation and time evolution inf(T)gravity Citation Details In-Document Search Title: Problems with propagation and time evolution inf(T)gravity Authors: Ong, Yen...

  20. The compact Selaginella genome identifies changes in gene content associated with the evolution of vascular plants

    SciTech Connect (OSTI)

    Grigoriev, Igor V.; Banks, Jo Ann; Nishiyama, Tomoaki; Hasebe, Mitsuyasu; Bowman, John L.; Gribskov, Michael; dePamphilis, Claude; Albert, Victor A.; Aono, Naoki; Aoyama, Tsuyoshi; Ambrose, Barbara A.; Ashton, Neil W.; Axtell, Michael J.; Barker, Elizabeth; Barker, Michael S.; Bennetzen, Jeffrey L.; Bonawitz, Nicholas D.; Chapple, Clint; Cheng, Chaoyang; Correa, Luiz Gustavo Guedes; Dacre, Michael; DeBarry, Jeremy; Dreyer, Ingo; Elias, Marek; Engstrom, Eric M.; Estelle, Mark; Feng, Liang; Finet, Cedric; Floyd, Sandra K.; Frommer, Wolf B.; Fujita, Tomomichi; Gramzow, Lydia; Gutensohn, Michael; Harholt, Jesper; Hattori, Mitsuru; Heyl, Alexander; Hirai, Tadayoshi; Hiwatashi, Yuji; Ishikawa, Masaki; Iwata, Mineko; Karol, Kenneth G.; Koehler, Barbara; Kolukisaoglu, Uener; Kubo, Minoru; Kurata, Tetsuya; Lalonde, Sylvie; Li, Kejie; Li, Ying; Litt, Amy; Lyons, Eric; Manning, Gerard; Maruyama, Takeshi; Michael, Todd P.; Mikami, Koji; Miyazaki, Saori; Morinaga, Shin-ichi; Murata, Takashi; Mueller-Roeber, Bernd; Nelson, David R.; Obara, Mari; Oguri, Yasuko; Olmstead, Richard G.; Onodera, Naoko; Petersen, Bent Larsen; Pils, Birgit; Prigge, Michael; Rensing, Stefan A.; Riano-Pachon, Diego Mauricio; Roberts, Alison W.; Sato, Yoshikatsu; Scheller, Henrik Vibe; Schulz, Burkhard; Schulz, Christian; Shakirov, Eugene V.; Shibagaki, Nakako; Shinohara, Naoki; Shippen, Dorothy E.; Sorensen, Iben; Sotooka, Ryo; Sugimoto, Nagisa; Sugita, Mamoru; Sumikawa, Naomi; Tanurdzic, Milos; Theilsen, Gunter; Ulvskov, Peter; Wakazuki, Sachiko; Weng, Jing-Ke; Willats, William W.G.T.; Wipf, Daniel; Wolf, Paul G.; Yang, Lixing; Zimmer, Andreas D.; Zhu, Qihui; Mitros, Therese; Hellsten, Uffe; Loque, Dominique; Otillar, Robert; Salamov, Asaf; Schmutz, Jeremy; Shapiro, Harris; Lindquist, Erika; Lucas, Susan; Rokhsar, Daniel

    2011-04-28

    We report the genome sequence of the nonseed vascular plant, Selaginella moellendorffii, and by comparative genomics identify genes that likely played important roles in the early evolution of vascular plants and their subsequent evolution

  1. Evolution of the phonon density of states of LaCoO3 over the...

    Office of Scientific and Technical Information (OSTI)

    Evolution of the phonon density of states of LaCoO3 over the spin state transition Citation Details In-Document Search Title: Evolution of the phonon density of states of LaCoO3 ...

  2. Structure symmetry determination and magnetic evolution in Sr2Ir1...

    Office of Scientific and Technical Information (OSTI)

    evolution in Sr2Ir1-xRhxO4 This content will become publicly available on November 23, 2016 Prev Next Title: Structure symmetry determination and magnetic evolution in ...

  3. EVOLUTION OF GALAXY LUMINOSITY FUNCTION USING PHOTOMETRIC REDSHIFTS

    SciTech Connect (OSTI)

    Ramos, B. H. F.; Pellegrini, P. S.; Da Costa, L. N.; Maia, M. A. G.; Ogando, R. L. C.; De Simoni, F.; Benoist, C.; Makler, M.; Mesquita, A. A. E-mail: pssp@linea.gov.br E-mail: maia@linea.gov.br E-mail: fsimoni@linea.gov.br E-mail: martin@cbpf.br

    2011-08-15

    We examine the impact of using photometric redshifts for studying the evolution of both the global galaxy luminosity function (LF) and that for different galaxy types. To this end, we compare the LFs obtained using photometric redshifts from the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) D1 field with those from the spectroscopic survey VIMOS VLT Deep Survey (VVDS) comprising {approx}4800 galaxies. We find that for z {<=} 2.0, in the interval of magnitudes considered by this survey, the LFs obtained using photometric and spectroscopic redshifts show a remarkable agreement. This good agreement led us to use all four Deep fields of the CFHTLS comprising {approx}386,000 galaxies to compute the LF of the combined fields and directly estimate the error in the parameters based on the field-to-field variation. We find that the characteristic absolute magnitude M* of Schechter fits fades by {approx}0.7 mag from z {approx} 1.8 to z {approx} 0.3, while the characteristic density {phi}* increases by a factor of {approx}4 in the same redshift interval. We use the galaxy classification provided by the template fitting program used to compute photometric redshifts and split the sample into galaxy types. We find that these Schechter parameters evolve differently for each galaxy type, an indication that their evolution is a combination of several effects: galaxy merging, star formation quenching, and mass assembly. All these results are compatible with those obtained by different spectroscopic surveys such as VVDS, DEEP2, and zCosmos, which reinforces the fact that photometric redshifts can be used to study galaxy evolution, at least for the redshift bins adopted so far. This is of great interest since future very large imaging surveys containing hundreds of millions of galaxies will allow us to obtain important precise measurements to constrain the evolution of the LF and to explore the dependence of this evolution on morphology and/or color helping constrain the mechanisms of galaxy evolution.

  4. THE EVOLUTION OF BRIGHTEST CLUSTER GALAXIES IN A HIERARCHICAL UNIVERSE

    SciTech Connect (OSTI)

    Tonini, Chiara; Bernyk, Maksym; Croton, Darren [Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Melbourne, VIC 3122 (Australia); Maraston, Claudia; Thomas, Daniel [Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth PO1 3FX (United Kingdom)

    2012-11-01

    We investigate the evolution of brightest cluster galaxies (BCGs) from redshift z {approx} 1.6 to z = 0. We upgrade the hierarchical semi-analytic model of Croton et al. with a new spectro-photometric model that produces realistic galaxy spectra, making use of the Maraston stellar populations and a new recipe for the dust extinction. We compare the model predictions of the K-band luminosity evolution and the J - K, V - I, and I - K color evolution with a series of data sets, including those of Collins et al. who argued that semi-analytic models based on the Millennium simulation cannot reproduce the red colors and high luminosity of BCGs at z > 1. We show instead that the model is well in range of the observed luminosity and correctly reproduces the color evolution of BCGs in the whole redshift range up to z {approx} 1.6. We argue that the success of the semi-analytic model is in large part due to the implementation of a more sophisticated spectro-photometric model. An analysis of the model BCGs shows an increase in mass by a factor of 2-3 since z {approx} 1, and star formation activity down to low redshifts. While the consensus regarding BCGs is that they are passively evolving, we argue that this conclusion is affected by the degeneracy between star formation history and stellar population models used in spectral energy distribution fitting, and by the inefficacy of toy models of passive evolution to capture the complexity of real galaxies, especially those with rich merger histories like BCGs. Following this argument, we also show that in the semi-analytic model the BCGs show a realistic mix of stellar populations, and that these stellar populations are mostly old. In addition, the age-redshift relation of the model BCGs follows that of the universe, meaning that given their merger history and star formation history, the ageing of BCGs is always dominated by the ageing of their stellar populations. In a {Lambda}CDM universe, we define such evolution as 'passive in the hierarchical sense'.

  5. Evolution and History of the Department of Energy and the Office of Environmental Management

    Broader source: Energy.gov [DOE]

    An overview of the Evolution and History of the Department of Energy and the Office of Environmental Management.

  6. The amphioxus genome and the evolution of the chordate karyotype

    SciTech Connect (OSTI)

    Putnam, Nicholas H.; Butts, Thomas; Ferrier, David E.K.; Furlong, Rebecca F.; Hellsten, Uffe; Kawashima, Takeshi; Robinson-Rechavi, Marc; Shoguchi, Eiichi; Terry, Astrid; Yu, Jr-Kai; Benito-Gutierrez, Elia; Dubchak, Inna; Garcia-Fernandez, Jordi; Gibson-Brown, Jeremy J.; Grigoriev, Igor V.; Horton, Amy C.; de Jong, Pieter J.; Jurka, Jerzy; Kapitonov, Vladimir; Kohara, Yuji; Kuroki, Yoko; Lindquist, Erika; Lucas, Susan; Osoegawa, Kazutoyo; Pennacchio, Len A.; Salamov, Asaf A.; Satou, Yutaka; Sauka-Spengler, Tatjana; Schmutz [, Jeremy; Shin-I, Tadasu; Toyoda, Atsushi; Bronner-Fraser, Marianne; Fujiyama, Asao; Holland, Linda Z.; Holland, Peter W. H.; Satoh, Nori; Rokhsar, Daniel S.

    2008-04-01

    Lancelets ('amphioxus') are the modern survivors of an ancient chordate lineage with a fossil record dating back to the Cambrian. We describe the structure and gene content of the highly polymorphic {approx}520 million base pair genome of the Florida lancelet Branchiostoma floridae, and analyze it in the context of chordate evolution. Whole genome comparisons illuminate the murky relationships among the three chordate groups (tunicates, lancelets, and vertebrates), and allow reconstruction of not only the gene complement of the last common chordate ancestor, but also a partial reconstruction of its genomic organization, as well as a description of two genome-wide duplications and subsequent reorganizations in the vertebrate lineage. These genome-scale events shaped the vertebrate genome and provided additional genetic variation for exploitation during vertebrate evolution.

  7. The Ginibre evolution in the large-N limit

    SciTech Connect (OSTI)

    Tribe, Roger Zaboronski, Oleg

    2014-06-15

    We analyse statistics of the real eigenvalues of gl(N, R)-valued Brownian motion (the Ginibre evolution) in the limit of large N. In particular, we calculate the limiting two-time correlation function of spin variables associated with real eigenvalues of the Ginibre evolution. We also show how the formalism of spin variables can be used to compute the fixed time correlation functions of real eigenvalues discovered originally by Forrester and Nagao [“Eigenvalue statistics of the real Ginibre ensemble,” Phys. Rev. Lett. 99(5), 050603 (2007)] and Borodin and Sinclair [“The Ginibre ensemble of real random matrices and its scaling limits,” Commun. Math. Phys. 291(1), 177–224 (2009)].

  8. Metabolic evolution of Escherichia coli strains that produce organic acids

    DOE Patents [OSTI]

    Grabar, Tammy; Gong, Wei; Yocum, R Rogers

    2014-10-28

    This invention relates to the metabolic evolution of a microbial organism previously optimized for producing an organic acid in commercially significant quantities under fermentative conditions using a hexose sugar as sole source of carbon in a minimal mineral medium. As a result of this metabolic evolution, the microbial organism acquires the ability to use pentose sugars derived from cellulosic materials for its growth while retaining the original growth kinetics, the rate of organic acid production and the ability to use hexose sugars as a source of carbon. This invention also discloses the genetic change in the microorganism that confers the ability to use both the hexose and pentose sugars simultaneously in the production of commercially significant quantities of organic acids.

  9. Asymmetric evolution of magnetic reconnection in collisionless accretion disk

    SciTech Connect (OSTI)

    Shirakawa, Keisuke Hoshino, Masahiro

    2014-05-15

    An evolution of a magnetic reconnection in a collisionless accretion disk is investigated using a 2.5 dimensional hybrid code simulation. In astrophysical disks, magnetorotational instability (MRI) is considered to play an important role by generating turbulence in the disk and contributes to an effective angular momentum transport through a turbulent viscosity. Magnetic reconnection, on the other hand, also plays an important role on the evolution of the disk through a dissipation of a magnetic field enhanced by a dynamo effect of MRI. In this study, we developed a hybrid code to calculate an evolution of a differentially rotating system. With this code, we first confirmed a linear growth of MRI. We also investigated a behavior of a particular structure of a current sheet, which would exist in the turbulence in the disk. From the calculation of the magnetic reconnection, we found an asymmetric structure in the out-of-plane magnetic field during the evolution of reconnection, which can be understood by a coupling of the Hall effect and the differential rotation. We also found a migration of X-point whose direction is determined only by an initial sign of J{sub 0}×Ω{sub 0}, where J{sub 0} is the initial current density in the neutral sheet and Ω{sub 0} is the rotational vector of the background Keplerian rotation. Associated with the migration of X-point, we also found a significant enhancement of the perpendicular magnetic field compared to an ordinary MRI. MRI-Magnetic reconnection coupling and the resulting magnetic field enhancement can be an effective process to sustain a strong turbulence in the accretion disk and to a transport of angular momentum.

  10. Directed Evolution of Microbe Producing Biofuels Using in Vivo

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Transcription Factor Based Biosensors - Energy Innovation Portal Directed Evolution of Microbe Producing Biofuels Using in Vivo Transcription Factor Based Biosensors Lawrence Berkeley National Laboratory Contact LBL About This Technology Technology Marketing SummaryResearchers at the Joint BioEnergy Institute (JBEI) have invented a method of using transcription factors expressed in vivo to evolve, screen, and select for microorganisms producing an intracellular small molecule of interest,

  11. Evolution of droplet size distribution and autoconversion parameterization

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    in turbulent clouds Evolution of droplet size distribution and autoconversion parameterization in turbulent clouds McGraw, Robert Brookhaven National Laboratory Liu, Yangang Brookhaven National Laboratory Category: Modeling Effects from turbulence-induced fluctuations in water vapor saturation on cloud droplet growth are examined using a Brownian diffusion model [McGraw and Liu, 2006]. The model predicts diffusive broadening of the droplet size distribution, tempered by enhanced

  12. COLLOQUIUM: Seeing the Big Bang More Clearly: The Evolution of

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Observational Techniques in CMB Studies | Princeton Plasma Physics Lab October 28, 2015, 4:00pm to 5:30pm Colloquia MBG AUDITORIUM COLLOQUIUM: Seeing the Big Bang More Clearly: The Evolution of Observational Techniques in CMB Studies Professor Bruce Partridge Haverford College Since 2015 marks the fiftieth anniversary of the discovery of the cosmic microwave background (CMB), I will begin by analyzing the very early experiments that established the properties of the CMB. What experimental

  13. The Structural Evolution and Diffusion During the Chemical Transformation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    from Cobalt to Cobalt Phosphide Nanoparticles > Research Highlights > Research > The Energy Materials Center at Cornell Research Highlights In This Section The Structural Evolution and Diffusion During the Chemical Transformation from Cobalt to Cobalt Phosphide Nanoparticles Joint Density-Functional Theory of Electrochemistry Double-band Electrode Channel Flow DEMS Cell Sulfur@Carbon Cathodes for Lithium Sulfur Batteries Better Ham & Cheese: Enhanced Anodes and Cathodes for Fuel

  14. Synthetic and Mechanistic Chemistry

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    22(3), 189-198 (2009). Ramesh R. Kale, Harshini Mukundan, Dominique N. Price, J. Foster Harris, Daniel M. Lewallen, Basil I. Swanson, Jurgen G. Schmidt, and Suri S. Iyer,...

  15. Synthetic laser medium

    DOE Patents [OSTI]

    Stokowski, Stanley E. (Danville, CA)

    1989-01-01

    A laser medium is particularly useful in high average power solid state lasers. The laser medium includes a chormium dopant and preferably neodymium ions as codopant, and is primarily a gadolinium scandium gallium garnet, or an analog thereof. Divalent cations inhibit spiral morphology as large boules from which the laser medium is derived are grown, and a source of ions convertible between a trivalent state and a tetravalent state at a low ionization energy are in the laser medium to reduce an absorption coefficient at about one micron wavelength otherwise caused by the divalent cations. These divalent cations and convertible ions are dispersed in the laser medium. Preferred convertible ions are provided from titanium or cerium sources.

  16. Synthetic laser medium

    DOE Patents [OSTI]

    Stokowski, S.E.

    1987-10-20

    A laser medium is particularly useful in high average power solid state lasers. The laser medium includes a chromium dopant and preferably neodymium ions as codopant, and is primarily a gadolinium scandium gallium garnet, or an analog thereof. Divalent cations inhibit spiral morphology as large boules from which the laser medium is derived are grown, and a source of ions convertible between a trivalent state and a tetravalent state at a low ionization energy are in the laser medium to reduce an absorption coefficient at about one micron wavelength otherwise caused by the divalent cations. These divalent cations and convertible ions are dispersed in the laser medium. Preferred convertible ions are provided from titanium or cerium sources.

  17. Cameron synthetic fuels report

    SciTech Connect (OSTI)

    Not Available

    1980-06-01

    The increasing scarcity of conventional crude oil resources, as well as the sharply higher prices of crude oil, will generate increased interest in heavy oil, tar sands, and oil shale as potential substitutes. For all of these unconventional oil resources, extraction will be much more difficult, time consuming, and costly than for conventional crude oil. Although the inplace resources are vast and exist in many areas including the United States, the USSR, western Europe, Canada, and Latin America, probably only a small fraction of the inplace resources will prove to be economically extractable. These unconventional oil resources are now being developed in several locations around the world, and depending upon the exact definition probably account for less than 1 percent of current world oil supplies. The major current developments include: Canadian tar sands. Heavy oil production at Yarega in the Komi Autonomous Republic in the Soviet Union. The USSR also burns shale for power generation in Estonia. Venezuelan production of heavy oil in the Orinoco Heavy Oil Belt is currently about 15,000 b/d. Oil shale is likely to prove much less important than heavy oil and tar sands over the next 20 years. Further development of these unconventional resources is planned, and many projects are under way or under study. On the basis of current planning, world output of heavy oils and oil from tar sands and shale will be unlikely to exceed 2 million b/d by 1990, roughly five time today's level. However, both of these resources will require the development of new technologies for any large increases in output above what is now planned. The bulk of Canada's tar sands exists at great depths and will require the development of in situ processes for extraction. In the Orinoco, heavy metals contained in the oil make it difficult to refine with existing technology.

  18. Imaging synthetic aperture radar

    DOE Patents [OSTI]

    Burns, Bryan L.; Cordaro, J. Thomas

    1997-01-01

    A linear-FM SAR imaging radar method and apparatus to produce a real-time image by first arranging the returned signals into a plurality of subaperture arrays, the columns of each subaperture array having samples of dechirped baseband pulses, and further including a processing of each subaperture array to obtain coarse-resolution in azimuth, then fine-resolution in range, and lastly, to combine the processed subapertures to obtain the final fine-resolution in azimuth. Greater efficiency is achieved because both the transmitted signal and a local oscillator signal mixed with the returned signal can be varied on a pulse-to-pulse basis as a function of radar motion. Moreover, a novel circuit can adjust the sampling location and the A/D sample rate of the combined dechirped baseband signal which greatly reduces processing time and hardware. The processing steps include implementing a window function, stabilizing either a central reference point and/or all other points of a subaperture with respect to doppler frequency and/or range as a function of radar motion, sorting and compressing the signals using a standard fourier transforms. The stabilization of each processing part is accomplished with vector multiplication using waveforms generated as a function of radar motion wherein these waveforms may be synthesized in integrated circuits. Stabilization of range migration as a function of doppler frequency by simple vector multiplication is a particularly useful feature of the invention; as is stabilization of azimuth migration by correcting for spatially varying phase errors prior to the application of an autofocus process.

  19. Synthetic and Mechanistic Chemistry

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and catalysts for energy applications and mechanistic chemistry for biofuel production. ... to develop magnetic algae, thus making it much easier to harvest for biofuel production. ...

  20. The synthetic elements

    SciTech Connect (OSTI)

    Hoffman, D.C.

    1990-05-01

    Prior to 1940, the heaviest element known was uranium, discovered in 1789. Since that time the elements 93 through 109 have been synthesized and identified and the elements 43, 61, 85, and 87 which were missing form the periodic tables of the 1930's have been discovered. The techniques and problems involved in these discoveries and the placement of the transuranium elements in the periodic table will be discussed. The production and positive identification of elements heavier than Md (Z=101), which have very short half-lives and can only be produced an atom-at-a-time, are very difficult and there have been controversies concerning their discovery. Some of the new methods which have been developed and used in these studies will be described. The prospects for production of still heavier elements will be considered.

  1. Predicting the performance of system for the co-production of Fischer-Tropsch synthetic liquid and power from coal

    SciTech Connect (OSTI)

    Wang, X.; Xiao, Y.; Xu, S.; Guo, Z.

    2008-01-15

    A co-production system based on Fischer-Tropsch (FT) synthesis reactor and gas turbine was simulated and analyzed. Syngas from entrained bed coal gasification was used as feedstock of the low-temperature slurry phase Fischer-Tropsch reactor. Raw synthetic liquid produced was fractioned and upgraded to diesel, gasoline, and liquid petrol gas (LPG). Tail gas composed of unconverted syngas and FT light components was fed to the gas turbine. Supplemental fuel (NG, or refinery mine gas) might be necessary, which was dependent on gas turbine capacity expander through flow capacity, etc. FT yield information was important to the simulation of this co-production system. A correlation model based on Mobil's two step pilot plant was applied. User models that can predict product yields and cooperate with other units were embedded into Aspen plus simulation. Performance prediction of syngas fired gas turbine was the other key of this system. The increase in mass flow through the turbine affects the match between compressor and turbine operating conditions. The calculation was carried out by GS software developed by Politecnico Di Milano and Princeton University. Various cases were investigated to match the FT synthesis island, power island, and gasification island in co-production systems. Effects of CO{sub 2} removal/LPG recovery, co-firing, and CH{sub 4} content variation were studied. Simulation results indicated that more than 50% of input energy was converted to electricity and FT products. Total yield of gasoline, diesel, and LPG was 136-155 g/N m{sup 3} (CO+H{sub 2}). At coal feed of 21.9 kg/s, net electricity exported to the grid was higher than 100 MW. Total production of diesel and gasoline (and LPG) was 118,000 t (134,000 t)/year. Under the economic analysis conditions assumed in this paper the co-production system was economically feasible.

  2. A NEW SYNTHETIC LIBRARY OF THE NEAR-INFRARED Ca II TRIPLET INDICES. I. INDEX DEFINITION, CALIBRATION, AND RELATIONS WITH STELLAR ATMOSPHERIC PARAMETERS

    SciTech Connect (OSTI)

    Du, W.; Luo, A. L.; Zhao, Y. H. E-mail: lal@nao.cas.cn

    2012-02-15

    Adopting the SPECTRUM package, which is a stellar spectral synthesis program, we have synthesized a comprehensive set of 2890 near-infrared (NIR) synthetic spectra with a resolution and wavelength sampling similar to the Sloan Digital Sky Survey (SDSS) and the forthcoming Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) spectra. During the synthesis, we applied the 'New grids of ATLAS9 Model Atmosphere' to develop a grid of local thermodynamic equilibrium model atmospheres for effective temperatures (T{sub eff}) ranging from 3500 to 7500 K, for surface gravities (log g) from 0.5 to 5.0 dex, for metallicities ([Fe/H]) from -4.0 to 0.5 dex, and for solar ([{alpha}/Fe] = 0.0 dex) and non-solar ([{alpha}/Fe] = +0.4 dex) abundances. This synthetic stellar library is composed of 1350 solar scaled abundance (SSA) and 1530 non-solar scaled abundance (NSSA) spectra, grounding on which we have defined a new set of NIR Ca II triplet indices and an index CaT as the sum of the three. These defined indices were automatically measured on every spectrum of the synthetic stellar library and calibrated with the indices computed on the observational spectra from the INDO-U.S. stellar library. In order to check the effect of {alpha}-element enhancement on the so-defined Ca II indices, we compared indices measured on the SSA spectra with those on the NSSA ones at the same trine of stellar parameters (T{sub eff}, log g, [Fe/H]); luckily, little influences of {alpha}-element enhancement were found. Furthermore, comparisons of our synthetic indices with the observational ones from measurements on the INDO-U.S. stellar library, the SDSS-DR7 and SDSS-DR8 spectroscopic survey are presented, respectively, for dwarfs and giants in specific. For dwarfs, our synthetic indices could well reproduce the behaviors of the observational indices versus stellar parameters, which verifies the validity of our index definitions for dwarfs. For giants, the consistency between our synthetic indices and the observational ones does not appear to be as good. However, a new synthetic library of NIR Ca II indices has been founded for deeper studies on the NIR wave band of stellar spectra, and this library is particularly appropriate for the SDSS and the forthcoming LAMOST stellar spectra. We have regressed the strength of the CaT index as a function of stellar parameters for both dwarfs and giants after a series of experimental investigations into relations of the indices with stellar parameters. For dwarfs, log g has little effect on the indices, while [Fe/H] and T{sub eff} play a role together. The leading factor is probably [Fe/H], which changes the strength of the indices by a positive trend. For giants, log g starts to influence the strength of the indices by a negative trend for the metal-poor, and even impact deeply for the metal-rich; besides, [Fe/H] and T{sub eff} still matter. In addition, we briefly discussed the major differences between our Ca II triplet indices and the CaHK doublet indices. Ultimately, a supplemental experiment was carried out to show that spectral noises do have effects on our set of NIR Ca II indices. However, the influence is not weak enough to be ignored if the signal-to-noise ratio falls below 20.

  3. A SIMPLE TECHNIQUE FOR PREDICTING HIGH-REDSHIFT GALAXY EVOLUTION

    SciTech Connect (OSTI)

    Behroozi, Peter S.; Silk, Joseph

    2015-01-20

    We show that the ratio of galaxies' specific star formation rates (SSFRs) to their host halos' specific mass accretion rates (SMARs) strongly constrains how the galaxies' stellar masses, SSFRs, and host halo masses evolve over cosmic time. This evolutionary constraint provides a simple way to probe z > 8 galaxy populations without direct observations. Tests of the method with galaxy properties at z = 4 successfully reproduce the known evolution of the stellar mass-halo mass (SMHM) relation, galaxy SSFRs, and the cosmic star formation rate (CSFR) for 5 < z < 8. We then predict the continued evolution of these properties for 8 < z < 15. In contrast to the nonevolution in the SMHM relation at z < 4, the median galaxy mass at fixed halo mass increases strongly at z > 4. We show that this result is closely linked to the flattening in galaxy SSFRs at z > 2 compared to halo SMARs; we expect that average galaxy SSFRs at fixed stellar mass will continue their mild evolution to z ? 15. The expected CSFR shows no breaks or features at z > 8.5; this constrains both reionization and the possibility of a steep falloff in the CSFR at z = 9-10. Finally, we make predictions for stellar mass and luminosity functions for the James Webb Space Telescope, which should be able to observe one galaxy with M {sub *} ? 10{sup 8} M {sub ?} per 10{sup 3}Mpc{sup 3} at z = 9.6 and one such galaxy per 10{sup 4}Mpc{sup 3} at z = 15.

  4. Electronically induced surface reactions: Evolution, concepts, and perspectives

    SciTech Connect (OSTI)

    Menzel, Dietrich

    2012-09-07

    This is a personal account of the development of the title subject which is the broader field encompassing surface photochemistry. It describes the early times when the main interest centered on desorption induced by slow electrons, follows its evolution in experiment (use of synchrotron radiation and connections to electron spectroscopies; use of lasers) and mechanisms, and briefly mentions the many different subfields that have evolved. It discusses some practically important aspects and applications and ends with an account of an evolving new subfield, the application to photochemistry on nanoparticles.

  5. Evolution of Grain Boundary Networks in Extreme Radiation Environments

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Recent Publications Evolution of Grain Boundary Networks in Extreme Radiation Environments Recent Publications J. K. Mason, O. K. Johnson, B. W. Reed, S. F. Li, J. S. Stolken, and M. Kumar; "Statistics of twin related domains and the grain boundary network," Acta Materialia, in press (2013) Y. M. Wang, F. Sansoz, T. LaGrange, R. T. Ott, J. Marian, T. W. Barbee Jr and A. V. Hamza; "Defective twin boundaries in nanotwinned metals", Nature Materials, 12, pp. 697 (2013).

  6. COLLOQUIUM: Evolution of Coil Design and Manufacturing at PPPL | Princeton

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Plasma Physics Lab September 24, 2014, 4:00pm to 5:30pm Colloquia MBG Auditorium COLLOQUIUM: Evolution of Coil Design and Manufacturing at PPPL James Chrzanowski Princeton University Presentation: File WC24SEP2014_JChrzanowski.pptx WC24SEP2014_JChrzanowski Colloquium Committee: The Princeton Plasma Physics Laboratory 2015-2016 Colloquium Committee is comprised of the following people. Please feel free to contact them by e-mail regarding any possible speakers or topics for future colloquia.

  7. Evolution of subsea production systems: A worldwide overview

    SciTech Connect (OSTI)

    Hansen, R.L.; Rickey, W.P.

    1995-08-01

    The evolution in the use of subsea technology has seen advancement from one well in the Gulf of Mexico in 1961 to more than 750 wells in a wide variety of locations by the end of 1993. Along with the growth in numbers, the industry has seen rapid advances in technology, increased distances from the host facility, and water depth records. This paper gives an overview of the evolutionary changes in subsea applications, with emphasis on the most active regions and on some of the milestone installations that shaped the technology advance.

  8. Metal Nitride Catalysts to Enhance Hydrogen Evolution Reactions - Energy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Innovation Portal Solar Photovoltaic Solar Photovoltaic Hydrogen and Fuel Cell Hydrogen and Fuel Cell Find More Like This Return to Search Metal Nitride Catalysts to Enhance Hydrogen Evolution Reactions Brookhaven National Laboratory Contact BNL About This Technology TEM image of catalyst ink comprised of Co<sub>0.6</sub>Mo<sub>1.4</sub>N<sub>2</sub> dispersed on carbon black TEM image of catalyst ink comprised of Co0.6Mo1.4N2 dispersed on carbon black

  9. Insights into bilaterian evolution from three spiralian genomes

    SciTech Connect (OSTI)

    Simakov, Oleg; Marletaz, Ferdinand; Cho, Sung-Jin; Edsinger-Gonzales, Eric; Havlak, Paul; Hellsten, Uffe; Kuo, Dian-Han; Larsson, Tomas; Lv, Jie; Arendt, Detlev; Savage, Robert; Osoegawa, Kazutoyo; de Jong, Pieter; Grimwood, Jane; Chapman, Jarrod A.; Shapiro, Harris; Otillar, Robert P.; Terry, Astrid Y.; Boore, Jeffrey L.; Grigoriev, Igor V.; Lindberg, David R.; Seaver, Elaine C.; Weisblat, David A.; Putnam, Nicholas H.; Rokhsar, Daniel S.; Aerts, Andrea

    2012-01-07

    Current genomic perspectives on animal diversity neglect two prominent phyla, the molluscs and annelids, that together account for nearly one-third of known marine species and are important both ecologically and as experimental systems in classical embryology1, 2, 3. Here we describe the draft genomes of the owl limpet (Lottia gigantea), a marine polychaete (Capitella teleta) and a freshwater leech (Helobdella robusta), and compare them with other animal genomes to investigate the origin and diversification of bilaterians from a genomic perspective. We find that the genome organization, gene structure and functional content of these species are more similar to those of some invertebrate deuterostome genomes (for example, amphioxus and sea urchin) than those of other protostomes that have been sequenced to date (flies, nematodes and flatworms). The conservation of these genomic features enables us to expand the inventory of genes present in the last common bilaterian ancestor, establish the tripartite diversification of bilaterians using multiple genomic characteristics and identify ancient conserved long- and short-range genetic linkages across metazoans. Superimposed on this broadly conserved pan-bilaterian background we find examples of lineage-specific genome evolution, including varying rates of rearrangement, intron gain and loss, expansions and contractions of gene families, and the evolution of clade-specific genes that produce the unique content of each genome.

  10. Evolution and resilience of the nuclear nonproliferation regime

    SciTech Connect (OSTI)

    Pregenzer, Arian L.

    2014-05-09

    This paper introduces the concept of systems resilience as a new framework for thinking about the future of the nonproliferation regime. Resilience refers to the ability of a system to maintain its vital functions in the face of continuous and unpredictable change. First, I make the case that the nonproliferation regime can be viewed as a complex system. Next, I discuss key themes from the literature on systems resilience and apply them to the nonproliferation system: the difference between resilience and stability; the need for evolution to maintain function; the importance of functional diversity; and the concept of the adaptive cycle. I show that most existing nonproliferation strategies are aimed at stability rather than resilience and that the current nonproliferation system may be over-constrained by the cumulative evolution of strategies. According to the literature on systems resilience, this increases its vulnerability to collapse. I argue that the resilience of the nonproliferation system can be enhanced by increasing international participation in setting the nonproliferation agenda, developing general international response capabilities, focusing on non-coercive approaches to decreasing demand, and applying systems thinking more rigorously to nonproliferation.

  11. Kinematic evolution of simulated star-forming galaxies

    SciTech Connect (OSTI)

    Kassin, Susan A.; Brooks, Alyson; Governato, Fabio; Weiner, Benjamin J.; Gardner, Jonathan P.

    2014-08-01

    Recent observations have shown that star-forming galaxies like our own Milky Way evolve kinematically into ordered thin disks over the last ?8 billion years since z = 1.2, undergoing a process of 'disk settling'. For the first time, we study the kinematic evolution of a suite of four state of the art 'zoom in' hydrodynamic simulations of galaxy formation and evolution in a fully cosmological context and compare with these observations. Until now, robust measurements of the internal kinematics of simulated galaxies were lacking because the simulations suffered from low resolution, overproduction of stars, and overly massive bulges. The current generation of simulations has made great progress in overcoming these difficulties and is ready for a kinematic analysis. We show that simulated galaxies follow the same kinematic trends as real galaxies: they progressively decrease in disordered motions (?{sub g}) and increase in ordered rotation (V{sub rot}) with time. The slopes of the relations between both ?{sub g} and V{sub rot} with redshift are consistent between the simulations and the observations. In addition, the morphologies of the simulated galaxies become less disturbed with time, also consistent with observations. This match between the simulated and observed trends is a significant success for the current generation of simulations, and a first step in determining the physical processes behind disk settling'.

  12. Comparing range data across the slow-time dimension to correct motion measurement errors beyond the range resolution of a synthetic aperture radar

    DOE Patents [OSTI]

    Doerry, Armin W. (Albuquerque, NM); Heard, Freddie E. (Albuquerque, NM); Cordaro, J. Thomas (Albuquerque, NM)

    2010-08-17

    Motion measurement errors that extend beyond the range resolution of a synthetic aperture radar (SAR) can be corrected by effectively decreasing the range resolution of the SAR in order to permit measurement of the error. Range profiles can be compared across the slow-time dimension of the input data in order to estimate the error. Once the error has been determined, appropriate frequency and phase correction can be applied to the uncompressed input data, after which range and azimuth compression can be performed to produce a desired SAR image.

  13. Defect and damage evolution quantification in dynamically-deformed metals using orientation-imaging microscopy

    SciTech Connect (OSTI)

    Gray, George T., III; Livescu, Veronica; Cerreta, Ellen K

    2010-03-18

    Orientation-imaging microscopy offers unique capabilities to quantify the defects and damage evolution occurring in metals following dynamic and shock loading. Examples of the quantification of the types of deformation twins activated, volume fraction of twinning, and damage evolution as a function of shock loading in Ta are presented. Electron back-scatter diffraction (EBSD) examination of the damage evolution in sweeping-detonation-wave shock loading to study spallation in Cu is also presented.

  14. Stellar Evolution/Supernova Research Data Archives from the SciDAC

    Office of Scientific and Technical Information (OSTI)

    Computational Astrophysics Consortium () | Data Explorer Stellar Evolution/Supernova Research Data Archives from the SciDAC Computational Astrophysics Consortium Title: Stellar Evolution/Supernova Research Data Archives from the SciDAC Computational Astrophysics Consortium Theoretical high-energy astrophysics studies the most violent explosions in the universe - supernovae (the massive explosions of dying stars) and gamma ray bursts (mysterious blasts of intense radiation). The evolution of

  15. Stellar Evolution/Supernova Research Data Archives from the SciDAC

    Office of Scientific and Technical Information (OSTI)

    Computational Astrophysics Consortium () | Data Explorer Stellar Evolution/Supernova Research Data Archives from the SciDAC Computational Astrophysics Consortium Title: Stellar Evolution/Supernova Research Data Archives from the SciDAC Computational Astrophysics Consortium Theoretical high-energy astrophysics studies the most violent explosions in the universe - supernovae (the massive explosions of dying stars) and gamma ray bursts (mysterious blasts of intense radiation). The evolution of

  16. Temperature evolution of electromotive force from Pt on yttrium-iron-garnet

    Office of Scientific and Technical Information (OSTI)

    under ferromagnetic resonance (Journal Article) | SciTech Connect Temperature evolution of electromotive force from Pt on yttrium-iron-garnet under ferromagnetic resonance Citation Details In-Document Search Title: Temperature evolution of electromotive force from Pt on yttrium-iron-garnet under ferromagnetic resonance Temperature evolution of electromotive force from Pt due to the inverse spin Hall effect is studied. Pure spin current is injected from yttrium-iron-garnet by using spin

  17. Evolution Of USDOE Performance Assessments Over 20 Years

    SciTech Connect (OSTI)

    Seitz, Roger R.; Suttora, Linda C.

    2013-02-26

    Performance assessments (PAs) have been used for many years for the analysis of post-closure hazards associated with a radioactive waste disposal facility and to provide a reasonable expectation of the ability of the site and facility design to meet objectives for the protection of members of the public and the environment. The use of PA to support decision-making for LLW disposal facilities has been mandated in United States Department of Energy (USDOE) directives governing radioactive waste management since 1988 (currently DOE Order 435.1, Radioactive Waste Management). Prior to that time, PAs were also used in a less formal role. Over the past 20+ years, the USDOE approach to conduct, review and apply PAs has evolved into an efficient, rigorous and mature process that includes specific requirements for continuous improvement and independent reviews. The PA process has evolved through refinement of a graded and iterative approach designed to help focus efforts on those aspects of the problem expected to have the greatest influence on the decision being made. Many of the evolutionary changes to the PA process are linked to the refinement of the PA maintenance concept that has proven to be an important element of USDOE PA requirements in the context of supporting decision-making for safe disposal of LLW. The PA maintenance concept represents the evolution of the graded and iterative philosophy and has helped to drive the evolution of PAs from a deterministic compliance calculation into a systematic approach that helps to focus on critical aspects of the disposal system in a manner designed to provide a more informed basis for decision-making throughout the life of a disposal facility (e.g., monitoring, research and testing, waste acceptance criteria, design improvements, data collection, model refinements). A significant evolution in PA modeling has been associated with improved use of uncertainty and sensitivity analysis techniques to support efficient implementation of the graded and iterative approach. Rather than attempt to exactly predict the migration of radionuclides in a disposal unit, the best PAs have evolved into tools that provide a range of results to guide decision-makers in planning the most efficient, cost effective, and safe disposal of radionuclides.

  18. Primate-specific evolution of an LDLR enhancer

    SciTech Connect (OSTI)

    Wang, Qian-Fei; Prabhakar, Shyam; Wang, Qianben; Moses, Alan M.; Chanan, Sumita; Brown, Myles; Eisen, Michael B.; Cheng, Jan-Fang; Rubin,Edward M.; Boffelli, Dario

    2005-12-01

    Sequence changes in regulatory regions have often been invoked to explain phenotypic divergence among species, but molecular examples of this have been difficult to obtain. In this study we identified an anthropoid primate-specific sequence element that contributed to the regulatory evolution of the low-density lipoprotein receptor. Using a combination of close and distant species genomic sequence comparisons coupled with in vivo and in vitro studies, we found that a functional cholesterol-sensing sequence motif arose and was fixed within a pre-existing enhancer in the common ancestor of anthropoid primates. Our study demonstrates one molecular mechanism by which ancestral mammalian regulatory elements can evolve to perform new functions in the primate lineage leading to human.

  19. The Amphimedon queenslandica genome and the evolution of animal complexity

    SciTech Connect (OSTI)

    Srivastava, Mansi; Simakov, Oleg; Chapman, Jarrod; Fahey, Bryony; Gauthier, Marie E.A.; Mitros, Therese; Richards, Gemma S.; Conaco, Cecilia; Dacre, Michael; Hellsten, Uffe; Larroux, Claire; Putnam, Nicholas H.; Stanke, Mario; Adamska, Maja; Darling, Aaron; Degnan, Sandie M.; Oakley, Todd H.; Plachetzki, David C.; Zhai, Yufeng; Adamski, Marcin; Calcino, Andrew; Cummins, Scott F.; Goodstein, David M.; Harris, Christina; Jackson, Daniel J.; Leys, Sally P.; Shu, Shengqiang; Woodcroft, Ben J.; Vervoort, Michel; Kosik, Kenneth S.; Manning, Gerard; Degnan, Bernard M.; Rokhsar, Daniel S.

    2010-07-01

    Sponges are an ancient group of animals that diverged from other metazoans over 600 million years ago. Here we present the draft genome sequence of Amphimedon queenslandica, a demosponge from the Great Barrier Reef, and show that it is remarkably similar to other animal genomes in content, structure and organization. Comparative analysis enabled by the sponge sequence reveals genomic events linked to the origin and early evolution of animals, including the appearance, expansion, and diversification of pan-metazoan transcription factor, signaling pathway, and structural genes. This diverse 'toolkit' of genes correlates with critical aspects of all metazoan body plans, and comprises cell cycle control and growth, development, somatic and germ cell specification, cell adhesion, innate immunity, and allorecognition. Notably, many of the genes associated with the emergence of animals are also implicated in cancer, which arises from defects in basic processes associated with metazoan multicellularity.

  20. Progress toward the evolution of a Stirling Space Engine

    SciTech Connect (OSTI)

    Alger, D.L.

    1994-09-01

    Following the successful testing of the 25 kWe Space Power Demonstrator (SPD) engine in 1985, a Stirling Space Engine (SSE) technology advancement program was initiated. The program`s objective was to advance free-piston Stirling engine/alternator technology sufficiently so that a Stirling engine system may become a viable candidate for space power applications. Evolution of the SSE technology is planned to occur at three different engine heater temperature levels: 650, 1050, and 1300 K. These temperatures define three phases of technology development with the first phase involving the 650 K SPD engine. Technology development of the 650 K engine and preliminary design of the 1050 K engine will be discussed in this paper.

  1. Domain evolution and polarization of continuously graded ferroelectric films

    SciTech Connect (OSTI)

    Roytburd, A.; Roytburd, V.

    2008-01-01

    A thermodynamic analysis of graded ferroelectric films demonstrates that in the equilibrium state the films are subdivided into a single-domain band and a polydomain band which consists of wedge-shape domains. Polarization under an external electrostatic field proceeds through an inter-band boundary movement due to growth or shrinkage of the wedge domains. It is shown how the domain structure and evolution are determined by the principal characteristics of the film: the distribution of the spontaneous polarization and dielectric constant. Graded films exhibit a sharp increase of polarization with the field for weak fields, with a drop of the dielectric constant when the field is increasing. A general approach to finding the dependence of the displacement and the wedge-domain shape on the field as well as analytical solutions for the p{sup 4} Landau-Devonshire and parabolic potentials are presented.

  2. Evolution of velocity dispersion along cold collisionless flows

    SciTech Connect (OSTI)

    Banik, Nilanjan; Sikivie, Pierre

    2015-11-17

    We found that the infall of cold dark matter onto a galaxy produces cold collisionless flows and caustics in its halo. If a signal is found in the cavity detector of dark matter axions, the flows will be readily apparent as peaks in the energy spectrum of photons from axion conversion, allowing the densities, velocity vectors and velocity dispersions of the flows to be determined. We also discuss the evolution of velocity dispersion along cold collisionless flows in one and two dimensions. A technique is presented for obtaining the leading behaviour of the velocity dispersion near caustics. The results are used to derive an upper limit on the energy dispersion of the Big Flow from the sharpness of its nearby caustic, and a prediction for the dispersions in its velocity components.

  3. Soft evolution of multi-jet final states

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gerwick, Erik; Schumann, Steffen; Höche, Stefan; Marzani, Simone

    2015-02-16

    We present a new framework for computing resummed and matched distributions in processes with many hard QCD jets. The intricate color structure of soft gluon emission at large angles renders resummed calculations highly non-trivial in this case. We automate all ingredients necessary for the color evolution of the soft function at next-to-leading-logarithmic accuracy, namely the selection of the color bases and the projections of color operators and Born amplitudes onto those bases. Explicit results for all QCD processes with up to 2 → 5 partons are given. We also devise a new tree-level matching scheme for resummed calculations which exploitsmore » a quasi-local subtraction based on the Catani-Seymour dipole formalism. We implement both resummation and matching in the Sherpa event generator. As a proof of concept, we compute the resummed and matched transverse-thrust distribution for hadronic collisions.« less

  4. Extended space expectation values in quantum dynamical system evolutions

    SciTech Connect (OSTI)

    Demiralp, Metin

    2014-10-06

    The time variant power series expansion for the expectation value of a given quantum dynamical operator is well-known and well-investigated issue in quantum dynamics. However, depending on the operator and Hamiltonian singularities this expansion either may not exist or may not converge for all time instances except the beginning of the evolution. This work focuses on this issue and seeks certain cures for the negativities. We work in the extended space obtained by adding all images of the initial wave function under the system Hamiltonians positive integer powers. This requires the introduction of certain appropriately defined weight operators. The resulting better convergence in the temporal power series urges us to call the new defined entities extended space expectation values even though they are constructed over certain weight operators and are somehow pseudo expectation values.

  5. Laser assisted high entropy alloy coating on aluminum: Microstructural evolution

    SciTech Connect (OSTI)

    Katakam, Shravana; Joshi, Sameehan S.; Mridha, Sanghita; Mukherjee, Sundeep; Dahotre, Narendra B.

    2014-09-14

    High entropy alloy (Al-Fe-Co-Cr-Ni) coatings were synthesized using laser surface engineering on aluminum substrate. Electron diffraction analysis confirmed the formation of solid solution of body centered cubic high entropy alloy phase along with phases with long range periodic structures within the coating. Evolution of such type of microstructure was a result of kinetics associated with laser process, which generates higher temperatures and rapid cooling resulting in retention of high entropy alloy phase followed by reheating and/or annealing in subsequent passes of the laser track giving rise to partial decomposition. The partial decomposition resulted in formation of precipitates having layered morphology with a mixture of high entropy alloy rich phases, compounds, and long range ordered phases.

  6. Soft evolution of multi-jet final states

    SciTech Connect (OSTI)

    Gerwick, Erik; Schumann, Steffen; Hche, Stefan; Marzani, Simone

    2015-02-16

    We present a new framework for computing resummed and matched distributions in processes with many hard QCD jets. The intricate color structure of soft gluon emission at large angles renders resummed calculations highly non-trivial in this case. We automate all ingredients necessary for the color evolution of the soft function at next-to-leading-logarithmic accuracy, namely the selection of the color bases and the projections of color operators and Born amplitudes onto those bases. Explicit results for all QCD processes with up to 2 ? 5 partons are given. We also devise a new tree-level matching scheme for resummed calculations which exploits a quasi-local subtraction based on the Catani-Seymour dipole formalism. We implement both resummation and matching in the Sherpa event generator. As a proof of concept, we compute the resummed and matched transverse-thrust distribution for hadronic collisions.

  7. Co-evolution of galactic nuclei and globular cluster systems

    SciTech Connect (OSTI)

    Gnedin, Oleg Y.; Ostriker, Jeremiah P.; Tremaine, Scott

    2014-04-10

    We revisit the hypothesis that dense galactic nuclei are formed from inspiraling globular clusters. Recent advances in the understanding of the continuous formation of globular clusters over cosmic time and the concurrent evolution of the galaxy stellar distribution allow us to construct a simple model that matches the observed spatial and mass distributions of clusters in the Galaxy and the giant elliptical galaxy M87. In order to compare with observations, we model the effects of dynamical friction and dynamical evolution, including stellar mass loss, tidal stripping of stars, and tidal disruption of clusters by the growing galactic nucleus. We find that inspiraling globular clusters form a dense central structure, with mass and radius comparable to the typical values in observed nuclear star clusters (NSCs) in late-type and low-mass early-type galaxies. The density contrast associated with the NSC is less pronounced in giant elliptical galaxies. Our results indicate that the NSC mass as a fraction of mass of the galaxy stellar spheroid scales as M{sub NSC}/M{sub ?}?0.0025 M{sub ?,11}{sup ?0.5}. Thus disrupted globular clusters could contribute most of the mass of NSCs in galaxies with stellar mass below 10{sup 11} M {sub ?}. The inner part of the accumulated cluster may seed the growth of a central black hole via stellar dynamical core collapse, thereby relieving the problem of how to form luminous quasars at high redshift. The seed black hole may reach ?10{sup 5} M {sub ?} within ? 1 Gyr of the beginning of globular cluster formation.

  8. X-ray absorption spectroscopy on the calcium cofactor to the manganese cluster in photosynthetic oxygen evolution

    SciTech Connect (OSTI)

    Cinco, Roehl M.

    1999-12-16

    Along with Mn, calcium and chloride ions are necessary cofactors for oxygen evolution in Photosystem II (PS II). To further test and verify whether Ca is close to the Mn cluster, the authors substituted strontium for Ca and probed from the Sr point of view for any nearby Mn. The extended X-ray absorption fine structure (EXAFS) of Sr-reactivated PS II indicates major differences between the intact and NH{sub 2}OH-treated samples. In intact samples, the Fourier transform of the Sr EXAFS shows a Fourier peak that is missing in inactive samples. This peak II is best simulated by two Mn neighbors at a distance of 3.5 Angstrom, confirming the proximity of Ca (Sr) cofactor to the Mn cluster. In addition, polarized Sr EXAFS on oriented Sr-reactivated samples shows this peak II is dichroic: large magnitude at 10 degrees (angle between the PS II membrane normal and the x-ray electric field vector) and small at 80 degrees. Analysis of the dichroism yields the relative angle between the Sr-Mn vector and membrane normal (23 degrees {+-} 4 degrees), and the isotropic coordination number for these layered samples. X-ray absorption spectroscopy has also been employed to assess the degree of similarity between the manganese cluster in PS II and a family of synthetic manganese complexes containing the distorted cubane [Mn{sub 4}O{sub 3}X] core (X = benzoate, acetate, methoxide, hydroxide, azide, fluoride, chloride or bromide). In addition, Mn{sub 4}O{sub 3}Cl complexes containing three or six terminal Cl ligands at three of the Mn were included in this study. The EXAFS method detects the small changes in the core structures as X is varied in this series, and serves to exclude these distorted cubanes of C3v symmetry as a topological model for the Mn catalytic cluster. The sulfur K-edge x-ray absorption near-edge structure (XANES) spectra for the amino acids cysteine, methionine, their corresponding oxidized forms cystine and methionine sulfoxide, and glutathione show distinct differences between the thiol and disulfide forms. Sulfur XANES is also used to detect changes (within 5%) of the thiol-to-disulfide ratio in whole human blood, plasma, and erythrocytes.

  9. Constraint propagation of C{sup 2}-adjusted formulation: Another recipe for robust ADM evolution system

    SciTech Connect (OSTI)

    Tsuchiya, Takuya; Yoneda, Gen; Shinkai, Hisa-aki [Department of Mathematical Sciences, Waseda University, Okubo, Shinjuku, Tokyo 169-8555 (Japan); Faculty of Information Science and Technology, Osaka Institute of Technology, 1-79-1 Kitayama, Hirakata, Osaka 573-0196 (Japan) and Computational Astrophysics Laboratory, Institute of Physical and Chemical Research (RIKEN), Hirosawa, Wako, Saitama 351-0198 (Japan)

    2011-03-15

    With a purpose of constructing a robust evolution system against numerical instability for integrating the Einstein equations, we propose a new formulation by adjusting the ADM evolution equations with constraints. We apply an adjusting method proposed by Fiske (2004) which uses the norm of the constraints, C{sup 2}. One of the advantages of this method is that the effective signature of adjusted terms (Lagrange multipliers) for constraint-damping evolution is predetermined. We demonstrate this fact by showing the eigenvalues of constraint propagation equations. We also perform numerical tests of this adjusted evolution system using polarized Gowdy-wave propagation, which show robust evolutions against the violation of the constraints than that of the standard ADM formulation.

  10. THREE-DIMENSIONAL SHAPE AND EVOLUTION OF TWO ERUPTIVE FILAMENTS

    SciTech Connect (OSTI)

    Li Ting; Zhang Jun; Yang Shuhong; Zhao Hui E-mail: zjun@nao.cas.c E-mail: v00975@phys.nthu.edu.t

    2010-09-01

    On 2009 September 26, a dramatic and large filament (LF) eruption and a small filament (SF) eruption were observed in the He II 304 A line by the two EUVI telescopes aboard the STEREO A and B spacecraft. The LF heads out into space and becomes the bright core of a gradual coronal mass ejection (CME), while the eruption of the SF is characterized by motions of the filament materials. Using stereoscopic analysis of EUVI data, we reconstruct the three-dimensional shape and evolution of two eruptive filaments. For the first time, we investigate the true velocities and accelerations of 12 points along the axis of the LF, and find that the velocity and acceleration vary with the measured location. The highest points among the 12 points are the fastest in the first half hour, and then the points at the low-latitude leg of the LF become the fastest. For the SF, it is an asymmetric whip-like filament eruption, and the downward motions of the material lead to the disappearance of the former high-latitude endpoint and the formation of a new low-latitude endpoint. Based on the temporal evolution of the two filaments, we infer that the two filaments lie in the same filament channel. By combining the EUVI, COR1, and COR2 data of STEREO A together, we find that there is no impulsive or fast acceleration in this event. It displays a weak and persistent acceleration for more than 17 hr. The average velocity and acceleration of the LF are 101.8 km s{sup -1} and 2.9 m s{sup -2}, respectively. The filament eruptions are associated with a slow CME with an average velocity of 177.4 km s{sup -1}. The velocity of the CME is nearly 1.6 times as large as that of the filament material. This event is one example of a gradual filament eruption associated with a gradual CME. In addition, the moving direction of the LF changes from a non-radial to a nearly radial direction with a variation of inclination angle of nearly 38.{sup 0}2.

  11. Evolution of the macromolecular structure of sporopollenin during thermal degradation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bernard, S.; Benzerara, K.; Beyssac, O.; Balan, E.; G. E. Brown, Jr.

    2015-10-01

    Reconstructing the original biogeochemistry of organic microfossils requires quantifying the extent of the chemical transformations they experienced during burial and maturation processes. In the present study, fossilization experiments have been performed using modern sporopollenin chosen as an analogue for the resistant biocompounds possibly constituting the wall of many organic microfossils. Sporopollenin powder has been processed thermally under argon atmosphere at different temperatures (up to 1000 °C) for varying durations (up to 900 min). Solid residues of each experiment have been characterized using infrared, Raman and synchrotron-based XANES spectroscopies. Results indicate that significant defunctionalisation and aromatization affect the molecular structure ofmore » sporopollenin with increasing temperature. Two distinct stages of evolution with temperature are observed: in a first stage, sporopollenin experiences dehydrogenation and deoxygenation simultaneously (below 500 °C); in a second stage (above 500 °C) an increasing concentration in aromatic groups and a lateral growth of aromatic layers are observed. With increasing heating duration (up to 900 min) at a constant temperature (360 °C), oxygen is progressively lost and conjugated carbon–carbon chains or domains grow progressively, following a log-linear kinetic behavior. Based on the comparison with natural spores fossilized within metasediments which experienced intense metamorphism, we show that the present experimental simulations may not perfectly mimic natural diagenesis and metamorphism. Moreover, performing such laboratory experiments provides key insights on the processes transforming biogenic molecules into molecular fossils.« less

  12. Texture evolution during nitinol martensite detwinning and phase transformation

    SciTech Connect (OSTI)

    Cai, S.; Schaffer, J. E.; Ren, Y.

    2013-12-09

    Nitinol has been widely used to make medical devices for years due to its unique shape memory and superelastic properties. However, the texture of the nitinol wires has been largely ignored due to inherent complexity. In this study, in situ synchrotron X-ray diffraction has been carried out during uniaxial tensile testing to investigate the texture evolution of the nitinol wires during martensite detwinning, variant reorientation, and phase transformation. It was found that the thermal martensitic nitinol wire comprised primarily an axial (1{sup }20), (120), and (102)-fiber texture. Detwinning initially converted the (120) and (102) fibers to the (1{sup }20) fiber and progressed to a (1{sup }30)-fiber texture by rigid body rotation. At strains above 10%, the (1{sup }30)-fiber was shifted to the (110) fiber by (21{sup }0) deformation twinning. The austenitic wire exhibited an axial (334)-fiber, which transformed to the near-(1{sup }30) martensite texture after the stress-induced phase transformation.

  13. Evolution of the macromolecular structure of sporopollenin during thermal degradation

    SciTech Connect (OSTI)

    Bernard, S.; Benzerara, K.; Beyssac, O.; Balan, E.; G. E. Brown, Jr.

    2015-10-01

    Reconstructing the original biogeochemistry of organic microfossils requires quantifying the extent of the chemical transformations they experienced during burial and maturation processes. In the present study, fossilization experiments have been performed using modern sporopollenin chosen as an analogue for the resistant biocompounds possibly constituting the wall of many organic microfossils. Sporopollenin powder has been processed thermally under argon atmosphere at different temperatures (up to 1000 C) for varying durations (up to 900 min). Solid residues of each experiment have been characterized using infrared, Raman and synchrotron-based XANES spectroscopies. Results indicate that significant defunctionalisation and aromatization affect the molecular structure of sporopollenin with increasing temperature. Two distinct stages of evolution with temperature are observed: in a first stage, sporopollenin experiences dehydrogenation and deoxygenation simultaneously (below 500 C); in a second stage (above 500 C) an increasing concentration in aromatic groups and a lateral growth of aromatic layers are observed. With increasing heating duration (up to 900 min) at a constant temperature (360 C), oxygen is progressively lost and conjugated carboncarbon chains or domains grow progressively, following a log-linear kinetic behavior. Based on the comparison with natural spores fossilized within metasediments which experienced intense metamorphism, we show that the present experimental simulations may not perfectly mimic natural diagenesis and metamorphism. Moreover, performing such laboratory experiments provides key insights on the processes transforming biogenic molecules into molecular fossils.

  14. Role of methyl groups in dynamics and evolution of biomolecules

    SciTech Connect (OSTI)

    Nickels, Jonathan D [ORNL; Curtis, J. E. [National Institute of Standards and Technology (NIST), Gaithersburg, MD; Oneill, Hugh [Oak Ridge National Laboratory (ORNL); Sokolov, Alexei P [ORNL

    2012-01-01

    Recent studies have discovered strong differences between the dynamics of nucleic acids (RNA and DNA) and proteins, especially at low hydration and low temperatures. This difference is caused primarily by dynamics of methyl groups that are abundant in proteins, but are absent or very rare in RNA and DNA. In this paper, we present a hypothesis regarding the role of methyl groups as intrinsic plasticizers in proteins and their evolutionary selection to facilitate protein dynamics and activity. We demonstrate the profound effect methyl groups have on protein dynamics relative to nucleic acid dynamics, and note the apparent correlation of methyl group content in protein classes and their need for molecular flexibility. Moreover, we note the fastest methyl groups of some enzymes appear around dynamical centers such as hinges or active sites. Methyl groups are also of tremendous importance from a ydrophobicity/folding/entropy perspective. These significant roles, however, complement our hypothesis rather than preclude the recognition of methyl groups in the dynamics and evolution of biomolecules.

  15. THE STRUCTURAL EVOLUTION OF FORMING AND EARLY STAGE STAR CLUSTERS

    SciTech Connect (OSTI)

    Jaehnig, Karl O.; Da Rio, Nicola; Tan, Jonathan C. E-mail: ndario@ufl.edu

    2015-01-10

    We study the degree of angular substructure in the stellar position distribution of young members of Galactic star-forming regions, looking for correlations with distance from cluster center, surface number density of stars, and local dynamical age. To this end we adopt the catalog of members in 18 young (?1-3Myr) clusters from the Massive Young Star-Forming Complex Study in Infrared and X-ray Survey and the statistical analysis of the angular dispersion parameter, ?{sub ADP,} {sub N}. We find statistically significant correlation between ?{sub ADP,} {sub N} and physical projected distance from the center of the clusters, with the centers appearing smoother than the outskirts, consistent with more rapid dynamical processing on local dynamical, free-fall or orbital timescales. Similarly, smoother distributions are seen in regions of higher surface density, or older dynamical ages. These results indicate that dynamical processing that erases substructure is already well-advanced in young, sometimes still-forming, clusters. Such observations of the dissipation of substructure have the potential to constrain theoretical models of the dynamical evolution of young and forming clusters.

  16. Tracking the Performance Evolution of Blue Gene Systems

    SciTech Connect (OSTI)

    Kerbyson, Darren J.; Barker, Kevin J.; Gallo, Diego S.; Chen, Dong; Brunheroto, Jose R.; Ryu, Kyung D.; Chiu, George L.; Hoisie, Adolfy

    2013-06-17

    IBMs Blue Gene supercomputer has evolved through three generations from the original Blue Gene/L to P to Q. A higher level of integration has enabled greater single-core performance, and a larger concurrency per compute node. Although these changes have brought with them a higher overall system peak-performance, no study has examined in detail the evolution of perfor-mance across system generations. In this work we make two significant contri-butions that of providing a comparative performance analysis across Blue Gene generations using a consistent set of tests, and also in providing a validat-ed performance model of the NEK-Bone proxy application. The combination of empirical analysis and the predictive performance model enable us to not only directly compare measured performance but also allow for a comparison of sys-tem configurations that cannot currently be measured. We provide insights into how the changing characteristics of Blue Gene have impacted on the application performance, as well as what future systems may be able to achieve.

  17. Evolution of the pygmy dipole resonance in Sn isotopes

    SciTech Connect (OSTI)

    Toft, H. K.; Larsen, A. C.; Buerger, A.; Guttormsen, M.; Goergen, A.; Nyhus, H. T.; Renstroem, T.; Siem, S.; Tveten, G. M.; Voinov, A.

    2011-04-15

    Nuclear level density and {gamma}-ray strength functions of {sup 121,122}Sn below the neutron separation energy are extracted with the Oslo method using the ({sup 3}He,{sup 3}He{sup '{gamma}}) and ({sup 3}He,{alpha}{gamma}) reactions. The level densities of {sup 121,122}Sn display steplike structures, interpreted as signatures of neutron pair breaking. An enhancement in both strength functions, compared to standard models for radiative strength, is observed in our measurements for E{sub {gamma}} > or approx. 5.2 MeV. This enhancement is compatible with pygmy resonances centered at {approx_equal}8.4(1) and {approx_equal}8.6(2) MeV, respectively, and with integrated strengths corresponding to {approx_equal}1.8{sub -5}{sup +1}% of the classical Thomas-Reiche-Kuhn sum rule. Similar resonances were also seen in {sup 116-119}Sn. Experimental neutron-capture cross reactions are well reproduced by our pygmy resonance predictions, while standard strength models are less successful. The evolution as a function of neutron number of the pygmy resonance in {sup 116-122}Sn is described as a clear increase of centroid energy from 8.0(1) to 8.6(2) MeV, but with no observable difference in integrated strengths.

  18. On the evolution of vortex rings with swirl

    SciTech Connect (OSTI)

    Naitoh, Takashi, E-mail: naitoh.takashi@nitech.ac.jp [Department of Engineering Physics, Electronics and Mechanics, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Okura, Nobuyuki, E-mail: ohkura@meijo-u.ac.jp [Department of Vehicle and Mechanical Engineering, Meijo University, 1-501 Shiogamaguchi Tempaku-ku, Nagoya 468-8502 (Japan); Gotoh, Toshiyuki, E-mail: gotoh.toshiyuki@nitech.ac.jp [Department of Scientific and Engineering Simulation, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Kato, Yusuke [Controller Business Unit Engineering Division 1, Engineering Department 3, Denso Wave Incorporated, 1 Yoshiike Kusagi Agui-cho, Chita-gun Aichi 470-2297 (Japan)

    2014-06-15

    A laminar vortex ring with swirl, which has the meridional velocity component inside the vortex core, was experimentally generated by the brief fluid ejection from a rotating outlet. The evolution of the vortex ring was investigated with flow visualizations and particle image velocimetry measurements in order to find the influence of swirling flow in particular upon the transition to turbulence. Immediately after the formation of a vortex ring with swirl, a columnar strong vortex along the symmetric axis is observed in all cases of the present experiment. Then the characteristic fluid discharging from a vortex ring with swirl referred to as peeling off appears. The amount of discharging fluid due to the peeling off increases with the angular velocity of the rotating outlet. We conjectured that the mechanism generating the peeling off is related to the columnar strong vortex by close observations of the spatio-temporal development of the vorticity distribution and the cutting 3D images constructed from the successive cross sections of a vortex ring. While a laminar vortex ring without swirl may develop azimuthal waves around its circumference at some later time and the ring structure subsequently breaks, the swirling flow in a vortex ring core reduces the amplification rate of the azimuthal wavy deformation and preserved its ring structure. Then the traveling distance of a vortex ring can be extended using the swirl flow under certain conditions.

  19. Semi-synthetic preparation of 1-O-(1'-/sup 14/C)hexadecyl-2-acetyl-sn-glycero-3-phosphocholine (platelet activating factor) using plant cell cultures

    SciTech Connect (OSTI)

    Weber, N.; Mangold, H.K.

    1985-04-01

    Incubation of photomixotrophic cell suspension cultures of rape (Brassica napus) and heterotrophic cell suspension cultures of soya (Glycine max) with 1-O-(1'-/sup 14/C)hexadecyl-sn-glycerol or rac-1-O-(1'-/sup 14/C)hexadecylglycerol leads in high yield (up to 78%) to labeled 1-O-hexadecyl-2-acyl-sn-glycero-3-phosphocholines. Alkaline hydrolysis of the choline glycerophospholipids yields pure 1-O-(1'-/sup 14/C)hexadecyl-sn-glycero-3-phosphocholine. 1-O-(1'-14C)Hexadecyl-2-acetyl-sn-glycero-3-phosphocholine (platelet activating factor) is obtained by acetylating the lyso compound. The semi-synthetic preparation described leads to labeled platelet activating factor in an overall yield of 50-60% without loss of specific activity.

  20. Production Pathways and Separation Procedures for High-Diagnostic-Value Activation Species, Fission Products, and Actinides Required for Preparation of Realistic Synthetic Post-Detonation Nuclear Debris

    SciTech Connect (OSTI)

    Faye, S A; Shaughnessy, D A

    2015-08-19

    The objective of this project is to provide a comprehensive study on the production routes and chemical separation requirements for activation products, fission products, and actinides required for the creation of realistic post-detonation surrogate debris. Isotopes that have been prioritized by debris diagnosticians will be examined for their ability to be produced at existing irradiation sources, production rates, and availability of target materials, and chemical separation procedures required to rapidly remove the products from the bulk target matrix for subsequent addition into synthetic debris samples. The characteristics and implications of the irradiation facilities on the isotopes of interest will be addressed in addition to a summary of the isotopes that are already regularly produced.

  1. Preparation of water soluble L-arginine capped CdSe/ZnS QDs and their interaction with synthetic DNA: Picosecond-resolved FRET study

    SciTech Connect (OSTI)

    Giri, Anupam; Goswami, Nirmal; Lemmens, Peter; Pal, Samir Kumar

    2012-08-15

    Graphical abstract: Frster resonance energy transfer (FRET) studies on the interaction of water soluble arginine-capped CdSe/ZnS QDs with ethidium bromide (EB) labeled synthetic dodecamer DNA. Highlights: ? We have solubilized CdSe/ZnS QD in water replacing their TOPO ligand by L-arginine. ? We have studied arginine@QDDNA interaction using FRET technique. ? Arginine@QDs act as energy donor and ethidium bromide-DNA acts as energy acceptor. ? We have applied a kinetic model to understand the kinetics of energy transfer. ? Circular dichroism studies revealed negligible perturbation in the DNA B-form in the arg@QD-DNA complex. -- Abstract: We have exchanged TOPO (trioctylphosphine oxide) ligand of CdSe/ZnS core/shell quantum dots (QDs) with an amino acid L-arginine (Arg) at the toluene/water interface and eventually rendered the QDs from toluene to aqueous phase. We have studied the interaction of the water soluble Arg-capped QDs (energy donor) with ethidium (EB) labeled synthetic dodecamer DNA (energy acceptor) using picoseconds resolved Frster resonance energy transfer (FRET) technique. Furthermore, we have applied a model developed by M. Tachiya to understand the kinetics of energy transfer and the distribution of acceptor (EB-DNA) molecules around the donor QDs. Circular dichroism (CD) studies revealed a negligible perturbation in the native B-form structure of the DNA upon interaction with Arg-capped QDs. The melting and the rehybridization pathways of the DNA attached to the QDs have been monitored by the CD which reveals hydrogen bonding is the associative mechanism for interaction between Arg-capped QDs and DNA.

  2. Complex temperature evolution of the electronic structure of CaFe{sub

    Office of Scientific and Technical Information (OSTI)

    2}As{sub 2} (Journal Article) | SciTech Connect Complex temperature evolution of the electronic structure of CaFe{sub 2}As{sub 2} Citation Details In-Document Search Title: Complex temperature evolution of the electronic structure of CaFe{sub 2}As{sub 2} Employing high resolution photoemission spectroscopy, we investigate the temperature evolution of the electronic structure of CaFe{sub 2}As{sub 2}, which is a parent compound of high temperature superconductors-CaFe{sub 2}As{sub 2} exhibits

  3. COLLOQUIUM: Comets and the Origin and Evolution of the Solar System |

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Princeton Plasma Physics Lab June 17, 2015, 4:15pm to 6:30pm Colloquia MBG Auditorium COLLOQUIUM: Comets and the Origin and Evolution of the Solar System Professor David Jewitt University of California - Los Angeles I will give a broad introduction to modern comet science, with a focus on new results and the big picture, relating to the origin and evolution of the solar system. Wednesday Colloquium, June 17, 2015, "Comets & the Origin & Evolution of the Solar System",

  4. In Situ and Ex Situ Studies of Platinum Nanocrystals: Growth and Evolution

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    in Solution In Situ and Ex Situ Studies of Platinum Nanocrystals: Growth and Evolution in Solution figure 1 Figure 1. Time-resolved XRD results obtained for both low and high concentration reactions. (A) In situ XRD plots; the position of the (111) and (200) reflections for bulk fcc platinum is shown by the lines at bottom; (B) time evolution of area under the Pt(111) peak. I - IV denote the growth stages of the high concentration reaction; (C) evolution of X-ray correlation length (L)

  5. Stress evolution during growth in direct-current-sputtered zinc oxide films

    Office of Scientific and Technical Information (OSTI)

    at various oxygen flows (Journal Article) | SciTech Connect Stress evolution during growth in direct-current-sputtered zinc oxide films at various oxygen flows Citation Details In-Document Search Title: Stress evolution during growth in direct-current-sputtered zinc oxide films at various oxygen flows The evolution of stress during the growth of zinc and zinc oxide films deposited from a metallic target using direct-current magnetron sputtering has been analyzed in situ. For this purpose a

  6. Structure symmetry determination and magnetic evolution in Sr2Ir1-xRhxO4

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | DOE PAGES Structure symmetry determination and magnetic evolution in Sr2Ir1-xRhxO4 This content will become publicly available on November 23, 2016 « Prev Next » Title: Structure symmetry determination and magnetic evolution in Sr2Ir1-xRhxO4 We use single-crystal neutron diffraction to determine the crystal structure symmetry and to study the magnetic evolution in the rhodium doped iridates Sr2Ir1-xRhxO4 (0 ≤ x ≤ 0.16). Throughout this doping range, the crystal

  7. The phage-host arms-race: Shaping the evolution of microbes (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect The phage-host arms-race: Shaping the evolution of microbes Citation Details In-Document Search Title: The phage-host arms-race: Shaping the evolution of microbes Bacteria, the most abundant organisms on the planet, are outnumbered by a factor of 10 to 1 by phages that infect them. Faced with the rapid evolution and turnover of phage particles, bacteria have evolved various mechanisms to evade phage infection and killing, leading to an evolutionary arms-race. The

  8. Big Data Projects on Solar Tech Evolution and Diffusion | Department of

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Energy Big Data Projects on Solar Tech Evolution and Diffusion Big Data Projects on Solar Tech Evolution and Diffusion This is the meeting agenda from the Big Data Projects on Solar Technology Evolution and Diffusion kickoff meeting, held on July 15, 2013 in Arlington, VA and facilitated by the SunShot Initiative. PDF icon seeds_agenda.pdf More Documents & Publications 2014 SunShot Initiative Soft Costs Subprogram Overview The New Science of Soft Costs Breakout Session Flier Download the

  9. Tectonic and sedimentary evolution of the Luna field area, Italy

    SciTech Connect (OSTI)

    Roveri, M. )

    1990-05-01

    The Luna gas field is located near Crotone (Calabria region, southern Italy) in a shallow-water/onshore area. It was discovered and put into production during the early 1970s. Up to now it has produced 19 {times} 10{sup 9} sm{sup 3} of gas; its productivity (50 {times} 10{sup 6} sm{sup 3}/y) has remained virtually unaltered since the beginning. The field is located on the axial culmination of a thrust-related anticline of the Apennine postcollisional thrust belt; it can be roughly subdivided into two areas characterized by different stratigraphic contexts. In the northern and central parts of the field is a structural trap. Reservoir rocks are Serravallian to Tortonian deep marine resedimented conglomerates and sandstones. These deposits represent part of the infill of a middle-upper Miocene foredeep. Reservoir rocks are now thrusted, eroded, and unconformably overlain by lower Pliocene shales, which are the most important seal in this part of the field. In the southern part of the field is a combination trap. Reservoir rocks are upper Tortonian shallow-water sandstones. They lap onto a Tortonian unconformity related to a tectonic phase which split the previous foredeep into minor piggyback basins. The upper Tortonian sandstones are overlain and sealed by Messinian shales and evaporites. Tectonosedimentary evolution of the area and, consequently, areal distribution and geometry of sedimentary bodies - both potential reservoirs and seals - have been reconstructed using a sequence stratigraphy approach. The sedimentary record has been informally subdivided into five main depositional sequences bounded by unconformities or their correlative conformities; classic facies analysis and petrophysical, seismic, and biostratigraphic data have been utilized to define the internal characteristics of each sequence.

  10. Evolution of spatial resolution in breast CT at UC Davis

    SciTech Connect (OSTI)

    Gazi, Peymon M.; Yang, Kai; Burkett, George W.; Aminololama-Shakeri, Shadi; Anthony Seibert, J.; Boone, John M.

    2015-04-15

    Purpose: Dedicated breast computed tomography (bCT) technology for the purpose of breast cancer screening has been a focus of research at UC Davis since the late 1990s. Previous studies have shown that improvement in spatial resolution characteristics of this modality correlates with greater microcalcification detection, a factor considered a potential limitation of bCT. The aim of this study is to improve spatial resolution as characterized by the modulation transfer function (MTF) via changes in the scanner hardware components and operational schema. Methods: Four prototypes of pendant-geometry, cone-beam breast CT scanners were designed and developed spanning three generations of design evolution. To improve the system MTF in each bCT generation, modifications were made to the imaging components (x-ray tube and flat-panel detector), system geometry (source-to-isocenter and detector distance), and image acquisition parameters (technique factors, number of projections, system synchronization scheme, and gantry rotational speed). Results: Characterization of different generations of bCT systems shows these modifications resulted in a 188% improvement of the limiting MTF properties from the first to second generation and an additional 110% from the second to third. The intrinsic resolution degradation in the azimuthal direction observed in the first generation was corrected by changing the acquisition from continuous to pulsed x-ray acquisition. Utilizing a high resolution detector in the third generation, along with modifications made in system geometry and scan protocol, resulted in a 125% improvement in limiting resolution. An additional 39% improvement was obtained by changing the detector binning mode from 2 2 to 1 1. Conclusions: These results underscore the advancement in spatial resolution characteristics of breast CT technology. The combined use of a pulsed x-ray system, higher resolution flat-panel detector and changing the scanner geometry and image acquisition logic resulted in a significant fourfold improvement in MTF.

  11. UNDERSTANDING THE EVOLUTION OF CLOSE BINARY SYSTEMS WITH RADIO PULSARS

    SciTech Connect (OSTI)

    Benvenuto, O. G.; De Vito, M. A.

    2014-05-01

    We calculate the evolution of close binary systems (CBSs) formed by a neutron star (behaving as a radio pulsar) and a normal donor star, which evolve either to a helium white dwarf (HeWD) or to ultra-short orbital period systems. We consider X-ray irradiation feedback and evaporation due to radio pulsar irradiation. We show that irradiation feedback leads to cyclic mass transfer episodes, allowing CBSs to be observed in between episodes as binary radio pulsars under conditions in which standard, non-irradiated models predict the occurrence of a low-mass X-ray binary. This behavior accounts for the existence of a family of eclipsing binary systems known as redbacks. We predict that redback companions should almost fill their Roche lobe, as observed in PSR J1723-2837. This state is also possible for systems evolving with larger orbital periods. Therefore, binary radio pulsars with companion star masses usually interpreted as larger than expected to produce HeWDs may also result in such quasi-Roche lobe overflow states, rather than hosting a carbon-oxygen WD. We found that CBSs with initial orbital periods of P{sub i} < 1day evolve into redbacks. Some of them produce low-mass HeWDs, and a subgroup with shorter P{sub i} becomes black widows (BWs). Thus, BWs descend from redbacks, although not all redbacks evolve into BWs. There is mounting observational evidence favoring BW pulsars to be very massive (? 2 M {sub ?}). As they should be redback descendants, redback pulsars should also be very massive, since most of the mass is transferred before this stage.

  12. Evolution of accretion disks in tidal disruption events

    SciTech Connect (OSTI)

    Shen, Rong-Feng; Matzner, Christopher D. E-mail: matzner@astro.utoronto.ca

    2014-04-01

    During a stellar tidal disruption event (TDE), an accretion disk forms as stellar debris returns to the disruption site and circularizes. Rather than being confined within the circularizing radius, the disk can spread to larger radii to conserve angular momentum. A spreading disk is a source of matter for re-accretion at rates that may exceed the later stellar fallback rate, although a disk wind can suppress its contribution to the central black hole accretion rate. A spreading disk is detectible through a break in the central accretion rate history or, at longer wavelengths, by its own emission. We model the evolution of TDE disk size and accretion rate by accounting for the time-dependent fallback rate, for the influence of wind losses in the early advective stage, and for the possibility of thermal instability for accretion rates intermediate between the advection-dominated and gas-pressure-dominated states. The model provides a dynamic basis for modeling TDE light curves. All or part of a young TDE disk will precess as a solid body because of the Lense-Thirring effect, and precession may manifest itself as a quasi-periodic modulation of the light curve. The precession period increases with time. Applying our results to the jetted TDE candidate Swift J1644+57, whose X-ray light curve shows numerous quasi-periodic dips, we argue that the data best fit a scenario in which a main-sequence star was fully disrupted by an intermediate mass black hole on an orbit significantly inclined from the black hole equator, with the apparent jet shutoff at t = 500 days corresponding to a disk transition from the advective state to the gas-pressure-dominated state.

  13. Cenozoic stratigraphic evolution, North Sea and Labrador Sea

    SciTech Connect (OSTI)

    Gradstein, F.M.; Grant, A.C.; Mudford, B.S. ); Berggren, W.A. ); Kaminski, M.A. ); D'Lorio, M.A. ); Cloetingh, S. ); Griffiths, C.M. )

    1990-05-01

    The authors are studying Cenozoic correlation patterns, burial trends, and subsidence history of the Central North Sea, Labrador, and Orphan basins. The authors objectives are (1) to detail intraregional mid-high latitude biozonations using noise filtering and probabilistic zonation techniques; (2) to detail paleobathymetric trends from basin margins to centers; (3) to apply this knowledge to model basin evolution, in the perspective of the evolving North Atlantic Ocean; (4) to evaluate causes for the occurrence of major hiatuses and rapid changes of subsidence; and (5) to relate rapid changes in sedimentation in the last few millions of years to model observed undercompaction trends. Cenozoic microfossil assemblages in these basins are similar, related to similarities in sedimentary and paleoeceanographic conditions. In more basinal wells, flysch-type agglutinated foraminiferal assemblages occur, also known from Carpathians, Trinidad, and Moroccan foredeeps. Over 90% of agglutinated taxa are common between these basins, although local stratigraphic ranges vary sufficiently to rely on the concept of average ranges, rather than total ones for correlations. Cenozoic stratigraphic resolution in the North Sea and Labrador basins generally is in 3-5-Ma units. and paleobathymetric zonations define a minimum of five niches, from inner shelf to middle slope regimes. Significant hiatuses occurred in the late Eocene through the Miocene, particularly in northern Labrador and northern North Sea. Subsidence in the Labrador/Grand Banks passive margin half grabens was strongly influenced by Labrador Sea opening between anomalies 34 (Campanian) and 13 (early Oligocene), when subsidence exceeded sedimentation and bathyal conditions prevailed along the margin. Thermally induced subsidence in the central North Sea grabens was considerable in the late Paleocene, when the Norwegian Sea started to open.

  14. Quantization of systems with temporally varying discretization. II. Local evolution moves

    SciTech Connect (OSTI)

    Hhn, Philipp A.

    2014-10-15

    Several quantum gravity approaches and field theory on an evolving lattice involve a discretization changing dynamics generated by evolution moves. Local evolution moves in variational discrete systems (1) are a generalization of the Pachner evolution moves of simplicial gravity models, (2) update only a small subset of the dynamical data, (3) change the number of kinematical and physical degrees of freedom, and (4) generate a dynamical (or canonical) coarse graining or refining of the underlying discretization. To systematically explore such local moves and their implications in the quantum theory, this article suitably expands the quantum formalism for global evolution moves, constructed in Paper I [P. A. Hhn, Quantization of systems with temporally varying discretization. I. Evolving Hilbert spaces, J. Math. Phys. 55, 083508 (2014); e-print http://arxiv.org/abs/arXiv:1401.6062 [gr-qc

  15. Time evolution of the total electric-field strength in multimode lasers

    SciTech Connect (OSTI)

    Brunner, W.; Fischer, R.; Paul, H.

    1988-05-01

    Our previous numerical studies of the output characteristics of multimode lasers are extended to include the evolution of the total electric-field strength. The regular or irregular behavior of the system, which becomes manifest in the evolution of the amplitudes and the phases in the different modes, is reflected also in the evolution of the total electric-field strength in a stroboscopic view. (The total electric-field strength, with its high-frequency time dependence suppressed, is considered at times t, t+..delta..t, t+2..delta..t,..., where ..delta..t is a multiple of the round-trip time in the resonator.) Moreover, it is demonstrated that the evolution of the system is very sensitive to slight changes in the initial conditions. This finding supports the view that the irregularity falls in the class of the so-called deterministic chaos.

  16. Very deep IRAS survey - constraints on the evolution of starburst galaxies

    SciTech Connect (OSTI)

    Hacking, P.; Houck, J.R.; Condon, J.J.

    1987-05-01

    Counts of sources (primarily starburst galaxies) from a deep 60 microns IRAS survey published by Hacking and Houck (1987) are compared with four evolutionary models. The counts below 100 mJy are higher than expected if no evolution has taken place out to a redshift of approximately 0.2. Redshift measurements of the survey sources should be able to distinguish between luminosity-evolution and density-evolution models and detect as little as a 20 percent brightening or increase in density of infrared sources per billion years ago (H/0/ = 100 km/s per Mpc). Starburst galaxies cannot account for the reported 100 microns background without extreme evolution at high redshifts. 21 references.

  17. Microstructural evolution of type 304 and 316 stainless steels under neutron irradiation at LWR relevant conditions

    SciTech Connect (OSTI)

    Tan, Lizhen; Stoller, Roger E.; Field, Kevin G.; Yang, Ying; Morgan, Dane; Wirth, Brian D.; Gussev, Maxim N.; Busby, Jeremy T.; Nam, H.

    2015-12-11

    Life extension of light water reactors will expose austenitic internal core components to irradiation damage levels beyond 100 displacements per atom (dpa), leading to profound microstructural evolution and consequent degradation of macroscopic properties. Microstructural evolution, including Frank loops, cavities, precipitates, and segregation at boundaries and the resultant radiation hardening in type 304 and 316 stainless steel (SS) variants were studied in this work via experimental characterization and multiple simulation methods. Experimental data for up to 40 heats of type 304SS and 316SS variants irradiated in different reactors to 0.6120 dpa at 275375C were generated from this work or collected from literature reports. These experimental data were then combined with models of Frank loop and cavity evolution, computational thermodynamics and precipitation, and ab initio and rate theory integrated radiation-induced segregation models to provide insights into microstructural evolution and degradation at higher doses.

  18. Doping evolution of the electronic structure in the single-layer...

    Office of Scientific and Technical Information (OSTI)

    Doping evolution of the electronic structure in the single-layer cuprates Bi2Sr2- delta: Comparison with other single-layer cuprates Citation Details In-Document Search Title:...

  19. Code dependencies of pre-supernova evolution and nucleosynthesis in massive stars: evolution to the end of core helium burning

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Jones, S.; Hirschi, R.; Pignatari, M.; Heger, A.; Georgy, C.; Nishimura, N.; Fryer, C.; Herwig, F.

    2015-01-15

    We present a comparison of 15M⊙ , 20M⊙ and 25M⊙ stellar models from three different codes|GENEC, KEPLER and MESA|and their nucleosynthetic yields. The models are calculated from the main sequence up to the pre-supernova (pre-SN) stage and do not include rotation. The GENEC and KEPLER models hold physics assumptions that are characteristic of the two codes. The MESA code is generally more flexible; overshooting of the convective core during the hydrogen and helium burning phases in MESA is chosen such that the CO core masses are consistent with those in the GENEC models. Full nucleosynthesis calculations are performed for allmore » models using the NuGrid post-processing tool MPPNP and the key energy-generating nuclear reaction rates are the same for all codes. We are thus able to highlight the key diferences between the models that are caused by the contrasting physics assumptions and numerical implementations of the three codes. A reasonable agreement is found between the surface abundances predicted by the models computed using the different codes, with GENEC exhibiting the strongest enrichment of H-burning products and KEPLER exhibiting the weakest. There are large variations in both the structure and composition of the models—the 15M⊙ and 20M⊙ in particular—at the pre-SN stage from code to code caused primarily by convective shell merging during the advanced stages. For example the C-shell abundances of O, Ne and Mg predicted by the three codes span one order of magnitude in the 15M⊙ models. For the alpha elements between Si and Fe the differences are even larger. The s-process abundances in the C shell are modified by the merging of convective shells; the modification is strongest in the 15M⊙ model in which the C-shell material is exposed to O-burning temperatures and the γ -process is activated. The variation in the s-process abundances across the codes is smallest in the 25M⊙ models, where it is comparable to the impact of nuclear reaction rate uncertainties. In general the differences in the results from the three codes are due to their contrasting physics assumptions (e.g. prescriptions for mass loss and convection). The broadly similar evolution of the 25M⊙ models gives us reassurance that different stellar evolution codes do produce similar results. For the 15M⊙ and 20M⊙ models, however, the different input physics and the interplay between the various convective zones lead to important differences in both the pre-supernova structure and nucleosynthesis predicted by the three codes. For the KEPLER models the core masses are different and therefore an exact match could not be expected.« less

  20. Global and regional evolution of short-lived radiatively-active gases and

    Office of Scientific and Technical Information (OSTI)

    aerosols in the Representative Concentration Pathways (Journal Article) | SciTech Connect Global and regional evolution of short-lived radiatively-active gases and aerosols in the Representative Concentration Pathways Citation Details In-Document Search Title: Global and regional evolution of short-lived radiatively-active gases and aerosols in the Representative Concentration Pathways In this paper, we discuss the results of 2000-2100 simulations with a chemistry-climate model, focusing on

  1. Hydrodynamic evolution and jet energy loss in Cu + Cu collisions (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | DOE PAGES Hydrodynamic evolution and jet energy loss in Cu + Cu collisions « Prev Next » Title: Hydrodynamic evolution and jet energy loss in Cu + Cu collisions Authors: Schenke, Björn ; Jeon, Sangyong ; Gale, Charles Publication Date: 2011-04-18 OSTI Identifier: 1100252 Type: Publisher's Accepted Manuscript Journal Name: Physical review C. Nuclear physics Additional Journal Information: Journal Volume: 83; Journal Issue: 4; Journal ID: ISSN 0556-2813 Publisher: American

  2. ON THE EVOLUTION OF THE SPECTRAL BREAK IN THE AFTERGLOW OF GAMMA-RAY BURSTS

    SciTech Connect (OSTI)

    Dado, Shlomo; Dar, Arnon [Physics Department, Technion, Haifa 32000 (Israel)

    2012-02-20

    The temporal evolution of the spectral break in the time-resolved spectral energy density of the broadband afterglow of gamma-ray bursts (GRBs) 091127 and 080319B was shown recently to be inconsistent with that expected for the cooling break in the standard fireball model of GRBs. Here we show that it is, however, in good agreement with the predicted temporal evolution of the smooth injection break/bend in the cannonball model of GRBs.

  3. Evolution of an interfacial crack on the concrete-embankment boundary

    Office of Scientific and Technical Information (OSTI)

    (Technical Report) | SciTech Connect Technical Report: Evolution of an interfacial crack on the concrete-embankment boundary Citation Details In-Document Search Title: Evolution of an interfacial crack on the concrete-embankment boundary Authors: Glascoe, L ; Antoun, T ; Kanarska, Y ; Lomove, I ; Hall, R ; Woodson, S ; Smith, J Publication Date: 2013-07-10 OSTI Identifier: 1119958 Report Number(s): LLNL-TR-645956 DOE Contract Number: W-7405-ENG-48 Resource Type: Technical Report Research

  4. Evolution of magnetic properties and microstructure of Hf2Co11B alloys

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Journal Article: Evolution of magnetic properties and microstructure of Hf2Co11B alloys Citation Details In-Document Search Title: Evolution of magnetic properties and microstructure of Hf2Co11B alloys Authors: McGuire, Michael A. [1] ; Rios, Orlando [1] + Show Author Affiliations Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA Publication Date: 2015-02-07 OSTI Identifier: 1228520 Type: Publisher's Accepted Manuscript Journal Name: Journal

  5. Evolution of novel wood decay mechanisms in Agaricales revealed by the

    Office of Scientific and Technical Information (OSTI)

    genome sequences of Fistulina hepatica and Cylindrobasidium torrendii (Journal Article) | DOE PAGES Evolution of novel wood decay mechanisms in Agaricales revealed by the genome sequences of Fistulina hepatica and Cylindrobasidium torrendii « Prev Next » Title: Evolution of novel wood decay mechanisms in Agaricales revealed by the genome sequences of Fistulina hepatica and Cylindrobasidium torrendii Authors: Floudas, Dimitrios ; Held, Benjamin W. ; Riley, Robert ; Nagy, Laszlo G. ;

  6. Hydrodynamic evolution and jet energy loss in Cu + Cu collisions (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect Hydrodynamic evolution and jet energy loss in Cu + Cu collisions Citation Details In-Document Search Title: Hydrodynamic evolution and jet energy loss in Cu + Cu collisions Authors: Schenke, Björn ; Jeon, Sangyong ; Gale, Charles Publication Date: 2011-04-18 OSTI Identifier: 1100252 Type: Publisher's Accepted Manuscript Journal Name: Physical review C. Nuclear physics Additional Journal Information: Journal Volume: 83; Journal Issue: 4; Journal ID: ISSN 0556-2813

  7. Energy Dissipation to Defect Evolution (EDDE) | U.S. DOE Office of Science

    Office of Science (SC) Website

    (SC) Dissipation to Defect Evolution (EDDE) Energy Frontier Research Centers (EFRCs) EFRCs Home Centers EFRC External Websites Research Science Highlights News & Events Publications History Contact BES Home Centers Energy Dissipation to Defect Evolution (EDDE) Print Text Size: A A A FeedbackShare Page EDDE Header Director Yanwen Zhang Lead Institution Oak Ridge National Laboratory Year Established 2014 Mission To develop a fundamental understanding of energy dissipation mechanisms

  8. EVOLUTION OF SOME PARTICLE DETECTORS BASED ON THE DISCHARGE IN GASES

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    61 - EVOLUTION OF SOME PARTICLE DETECTORS BASED ON THE DISCHARGE IN GASES G. Charpak CERN, Geneva, Switzerland. INTRODUCTION In this year 1969, if we look into the experimental techniques used around high-energy accelerators we observe the following situation: the bubble chamber is still an important tool, absorbing a large fraction of the activity of the community of experimentalists. Its evolution is directed towards a greater efficiency and rapidity in the automatic evalu- ation of pictures,

  9. Rapidity evolution of Wilson lines at the next-to-leading order

    SciTech Connect (OSTI)

    Balitsky, Ian; Chirilli, Giovanni

    2013-12-01

    At high energies particles move very fast so the proper degrees of freedom for the fast gluons moving along the straight lines are Wilson-line operators - infinite gauge factors ordered along the line. In the framework of operator expansion in Wilson lines the energy dependence of the amplitudes is determined by the rapidity evolution of Wilson lines. We present the next-to-leading order hierarchy of the evolution equations for Wilson-line operators.

  10. Synthesis of Transient Climate Evolution of the last 21-kyr (SynTraCE-21)

    SciTech Connect (OSTI)

    Zhengyu Liu

    2011-05-06

    Climate evolution in the last 21,000 years provides critical observations for testing state-of-the-art climate models on the simulation of climate evolution and abrupt climate changes. Proxy evidences and new modeling activities have led to rapid advances in our understanding of climate change for this past time period. This funding helps to support the first international SynTraCE-21k workshop at Mount Hood, Oregon from 10-13 October, 2010.

  11. Spillover-Assisted Hydrogen Evolution at Si-based Metal-Oxide-Semiconductor

    Office of Scientific and Technical Information (OSTI)

    Photoelectrodes. (Journal Article) | SciTech Connect Spillover-Assisted Hydrogen Evolution at Si-based Metal-Oxide-Semiconductor Photoelectrodes. Citation Details In-Document Search Title: Spillover-Assisted Hydrogen Evolution at Si-based Metal-Oxide-Semiconductor Photoelectrodes. Authors: Talin, Albert Alec ; Esposito, Daniel V. ; Levin, Igor ; Moffat, Thomas P. Publication Date: 2012-12-01 OSTI Identifier: 1063415 Report Number(s): SAND2012-10868J DOE Contract Number: AC04-94AL85000

  12. THE REDSHIFT EVOLUTION OF THE RELATION BETWEEN STELLAR MASS, STAR FORMATION

    Office of Scientific and Technical Information (OSTI)

    RATE, AND GAS METALLICITY OF GALAXIES (Journal Article) | SciTech Connect REDSHIFT EVOLUTION OF THE RELATION BETWEEN STELLAR MASS, STAR FORMATION RATE, AND GAS METALLICITY OF GALAXIES Citation Details In-Document Search Title: THE REDSHIFT EVOLUTION OF THE RELATION BETWEEN STELLAR MASS, STAR FORMATION RATE, AND GAS METALLICITY OF GALAXIES We investigate the relation between stellar mass (M{sub *}), star formation rate (SFR), and metallicity (Z) of galaxies, the so-called fundamental

  13. Hawai'i's Evolution: Hawai'i Powered. Technology Driven. | Department of

    Office of Environmental Management (EM)

    Energy Hawai'i's Evolution: Hawai'i Powered. Technology Driven. Hawai'i's Evolution: Hawai'i Powered. Technology Driven. Outlines Hawaii's energy and transportation goals and the implementation of electric vehicles (EV) and electric vehicle infrastructure since HCEI began in 2008. Includes information about Hawaii's role in leading the nation in available EV charging infrastructure per capita; challenges for continuing to implement EV technology; features on various successful EV users and

  14. Normal and abnormal evolution of argon metastable density in high-density plasmas

    SciTech Connect (OSTI)

    Seo, B. H.; Kim, J. H.; You, S. J.

    2015-05-15

    A controversial problem on the evolution of Ar metastable density as a function of electron density (increasing trend versus decreasing trend) was resolved by discovering the anomalous evolution of the argon metastable density with increasing electron density (discharge power), including both trends of the metastable density [Daltrini et al., Appl. Phys. Lett. 92, 061504 (2008)]. Later, by virtue of an adequate physical explanation based on a simple global model, both evolutions of the metastable density were comprehensively understood as part of the abnormal evolution occurring at low- and high-density regimes, respectively, and thus the physics behind the metastable evolution has seemed to be clearly disclosed. In this study, however, a remarkable result for the metastable density behavior with increasing electron density was observed: even in the same electron density regime, there are both normal and abnormal evolutions of metastable-state density with electron density depending on the measurement position: The metastable density increases with increasing electron density at a position far from the inductively coupled plasma antenna but decreases at a position close to the antenna. The effect of electron temperature, which is spatially nonuniform in the plasma, on the electron population and depopulation processes of Argon metastable atoms with increasing electron density is a clue to understanding the results. The calculated results of the global model, including multistep ionization for the argon metastable state and measured electron temperature, are in a good agreement with the experimental results.

  15. Final Report: Detection and Characterization of Underground Facilities by Stochastic Inversion and Modeling of Data from the New Generation of Synthetic Aperture Satellites

    SciTech Connect (OSTI)

    Foxall, W; Cunningham, C; Mellors, R; Templeton, D; Dyer, K; White, J

    2012-02-27

    Many clandestine development and production activities can be conducted underground to evade surveillance. The purpose of the study reported here was to develop a technique to detect underground facilities by broad-area search and then to characterize the facilities by inversion of the collected data. This would enable constraints to be placed on the types of activities that would be feasible at each underground site, providing a basis the design of targeted surveillance and analysis for more complete characterization. Excavation of underground cavities causes deformation in the host material and overburden that produces displacements at the ground surface. Such displacements are often measurable by a variety of surveying or geodetic techniques. One measurement technique, Interferometric Synthetic Aperture Radar (InSAR), uses data from satellite-borne (or airborne) synthetic aperture radars (SARs) and so is ideal for detecting and measuring surface displacements in denied access regions. Depending on the radar frequency and the acquisition mode and the surface conditions, displacement maps derived from SAR interferograms can provide millimeter- to centimeter-level measurement accuracy on regional and local scales at spatial resolution of {approx}1-10 m. Relatively low-resolution ({approx}20 m, say) maps covering large regions can be used for broad-area detection, while finer resolutions ({approx}1 m) can be used to image details of displacement fields over targeted small areas. Surface displacements are generally expected to be largest during or a relatively short time after active excavation, but, depending on the material properties, measurable displacement may continue at a decreasing rate for a considerable time after completion. For a given excavated volume in a given geological setting, the amplitude of the surface displacements decreases as the depth of excavation increases, while the area of the discernable displacement pattern increases. Therefore, the ability to detect evidence for an underground facility using InSAR depends on the displacement sensitivity and spatial resolution of the interferogram, as well as on the size and depth of the facility and the time since its completion. The methodology development described in this report focuses on the exploitation of synthetic aperture radar data that are available commercially from a number of satellite missions. Development of the method involves three components: (1) Evaluation of the capability of InSAR to detect and characterize underground facilities ; (2) inversion of InSAR data to infer the location, depth, shape and volume of a subsurface facility; and (3) evaluation and selection of suitable geomechanical forward models to use in the inversion. We adapted LLNL's general-purpose Bayesian Markov Chain-Monte Carlo procedure, the 'Stochastic Engine' (SE), to carry out inversions to characterize subsurface void geometries. The SE performs forward simulations for a large number of trial source models to identify the set of models that are consistent with the observations and prior constraints. The inverse solution produced by this kind of stochastic method is a posterior probability density function (pdf) over alternative models, which forms an appropriate input to risk-based decision analyses to evaluate subsequent response strategies. One major advantage of a stochastic inversion approach is its ability to deal with complex, non-linear forward models employing empirical, analytical or numerical methods. However, while a geomechanical model must incorporate adequate physics to enable sufficiently accurate prediction of surface displacements, it must also be computationally fast enough to render the large number of forward realizations needed in stochastic inversion feasible. This latter requirement prompted us first to investigate computationally efficient empirical relations and closed-form analytical solutions. However, our evaluation revealed severe limitations in the ability of existing empirical and analytical forms to predict deformations from undergro

  16. The Evolution of Swift/BAT blazars and the origin of the MeV background

    SciTech Connect (OSTI)

    Ajello, M.; Costamante, L.; Sambruna, R.M.; Gehrels, N.; Chiang, J.; Rau, A.; Escala, A.; Greiner, J.; Tueller, J.; Wall, J.V.; Mushotzky, R.F.; /NASA, Goddard

    2009-10-17

    We use 3 years of data from the Swift/BAT survey to select a complete sample of X-ray blazars above 15 keV. This sample comprises 26 Flat-Spectrum Radio Quasars (FSRQs) and 12 BL Lac objects detected over a redshift range of 0.03 < z < 4.0. We use this sample to determine, for the first time in the 15-55 keV band, the evolution of blazars. We find that, contrary to the Seyfert-like AGNs detected by BAT, the population of blazars shows strong positive evolution. This evolution is comparable to the evolution of luminous optical QSOs and luminous X-ray selected AGNs. We also find evidence for an epoch-dependence of the evolution as determined previously for radio-quiet AGNs. We interpret both these findings as a strong link between accretion and jet activity. In our sample, the FSRQs evolve strongly, while our best-fit shows that BL Lacs might not evolve at all. The blazar population accounts for 10-20% (depending on the evolution of the BL Lacs) of the Cosmic X-ray background (CXB) in the 15-55 keV band. We find that FSRQs can explain the entire CXB emission for energies above 500 keV solving the mystery of the generation of the MeV background. The evolution of luminous FSRQs shows a peak in redshift (z{sub c} = 4.3 {+-} 0.5) which is larger than the one observed in QSOs and X-ray selected AGNs. We argue that FSRQs can be used as tracers of massive elliptical galaxies in the early Universe.

  17. Dissolution Kinetics of Synthetic and Natural Meta-Autunite Minerals, X??n????[(UO?)(PO?)]? ? xH?O, Under Acidic Conditions

    SciTech Connect (OSTI)

    Wellman, Dawn M.; Gunderson, Katie M.; Icenhower, Jonathan P.; Forrester, Steven W.

    2007-11-01

    Mass transport within the uranium geochemical cycle is impacted by the availability of phosphorous. In oxidizing environments, in which the uranyl ionic species is typically mobile, formation of sparingly soluble uranyl phosphate minerals exert a strong influence on uranium transport. Autunite group minerals have been identified as the long-term uranium controlling phases in many systems of geochemical interest. Anthropogenic operations related to uranium mining operations have created acidic environments, exposing uranyl phosphate minerals to low pH groundwaters. Investigations regarding the dissolution behavior of autunite group minerals under acidic conditions have not been reported; consequently, knowledge of the longevity of uranium controlling solids is incomplete. The purpose of this investigation was to: 1) quantify the dissolution kinetics of natural calcium and synthetic sodium meta-autunite, under acidic conditions, 2) measure the effect of temperature and pH on meta-autunite mineral dissolution, and 3) investigate the formation of secondary uranyl phosphate phases as long-term controls on uranium migration. Single-pass flow-through (SPFT) dissolution tests were conducted over the pH range of 2 to 5 and from 5 to 70C. Results presented here illustrate meta-autunite dissolution kinetics are strongly dependent on pH, but are relatively insensitive to temperature variations. In addition, the formation of secondary uranyl-phosphate phases such as, uranyl phosphate, (UO2)3(PO4)2 ? 4 H2O, may serve as a secondary phase limiting the migration of uranium in the environment.

  18. CuCo2O4 ORR/OER Bi-functional catalyst: Influence of synthetic approach on performance

    SciTech Connect (OSTI)

    Serov, Alexey; Andersen, Nalin I.; Roy, Aaron J.; Matanovic, Ivana; Artyushkova, Kateryna; Atanassov, Plamen

    2015-02-07

    A series of CuCo2O4 catalysts were synthesized by pore forming, sol-gel, spray pyrolysis and sacrificial support methods. Catalysts were characterized by XRD, SEM, XPS and BET techniques. The electrochemical activity for the oxygen reduction and oxygen evolution reactions (ORR and OER) was evaluated in alkaline media by RRDE. Density Functional Theory was used to identify two different types of active sites responsible for ORR/OER activity of CuCo2O4 and it was found that CuCo2O4 can activate the O-O bond by binding molecular oxygen in bridging positions between Co or Co and Cu atoms. It was found that the sacrificial support method (SSM) catalyst has the highest performance in both ORR and OER and has the highest content of phase-pure CuCo2O4. It was shown that the presence of CuO significantly decreases the activity in oxygen reduction and oxygen evolution reactions. As a result, the half-wave potential (E1/2) of CuCo2O4-SSM was found as 0.8 V, making this material a state-of-the-art, unsupported oxide catalyst.

  19. The Radio and Optical Luminosity Evolution of Quasars II - The SDSS Sample

    SciTech Connect (OSTI)

    Singal, J.; Petrosian, V.; Stawarz, L.; Lawrence, A.

    2012-12-28

    We determine the radio and optical luminosity evolutions and the true distribution of the radio loudness parameter R, defined as the ratio of the radio to optical luminosity, for a set of more than 5000 quasars combining SDSS optical and FIRST radio data. We apply the method of Efron and Petrosian to access the intrinsic distribution parameters, taking into account the truncations and correlations inherent in the data. We find that the population exhibits strong positive evolution with redshift in both wavebands, with somewhat greater radio evolution than optical. With the luminosity evolutions accounted for, we determine the density evolutions and local radio and optical luminosity functions. The intrinsic distribution of the radio loudness parameter R is found to be quite different than the observed one, and is smooth with no evidence of a bi-modality in radio loudness. The results we find are in general agreement with the previous analysis of Singal et al., 2011 which used POSS-I optical and FIRST radio data.

  20. Hybrid models for the simulation of microstructural evolution influenced by coupled, multiple physical processes.

    SciTech Connect (OSTI)

    Tikare, Veena; Hernandez-Rivera, Efrain; Madison, Jonathan D.; Holm, Elizabeth Ann; Patterson, Burton R.; Homer, Eric R.

    2013-09-01

    Most materials microstructural evolution processes progress with multiple processes occurring simultaneously. In this work, we have concentrated on the processes that are active in nuclear materials, in particular, nuclear fuels. These processes are coarsening, nucleation, differential diffusion, phase transformation, radiation-induced defect formation and swelling, often with temperature gradients present. All these couple and contribute to evolution that is unique to nuclear fuels and materials. Hybrid model that combines elements from the Potts Monte Carlo, phase-field models and others have been developed to address these multiple physical processes. These models are described and applied to several processes in this report. An important feature of the models developed are that they are coded as applications within SPPARKS, a Sandiadeveloped framework for simulation at the mesoscale of microstructural evolution processes by kinetic Monte Carlo methods. This makes these codes readily accessible and adaptable for future applications.

  1. Size and habit evolution of PETN crystals - a lattice Monte Carlo study

    SciTech Connect (OSTI)

    Zepeda-Ruiz, L A; Maiti, A; Gee, R; Gilmer, G H; Weeks, B

    2006-02-28

    Starting from an accurate inter-atomic potential we develop a simple scheme of generating an ''on-lattice'' molecular potential of short range, which is then incorporated into a lattice Monte Carlo code for simulating size and shape evolution of nanocrystallites. As a specific example, we test such a procedure on the morphological evolution of a molecular crystal of interest to us, e.g., Pentaerythritol Tetranitrate, or PETN, and obtain realistic facetted structures in excellent agreement with experimental morphologies. We investigate several interesting effects including, the evolution of the initial shape of a ''seed'' to an equilibrium configuration, and the variation of growth morphology as a function of the rate of particle addition relative to diffusion.

  2. Method of producing synthetic pitch

    DOE Patents [OSTI]

    Kennel, Elliot B. (Morgantown, WV); Stansberry, Peter G. (North Olmsted, OH); Stiller, Alfred H. (Morgantown, WV); Zondlo, John W. (Albright, WV)

    2012-07-24

    Embodiments of a method are described for modifying pitches, oils, tars, and binders by using these materials as solvents to extract organic chemicals from coal.

  3. Fully synthetic taped insulation cables

    DOE Patents [OSTI]

    Forsyth, E.B.; Muller, A.C.

    1983-07-15

    The present invention is a cable which, although constructed from inexpensive polyolefin tapes and using typical impregnating oils, furnishes high voltage capability up to 765 kV, and has such excellent dielectric characteristics and heat transfer properties that it is capable of operation at capacities equal to or higher than presently available cables at a given voltage. This is accomplished by using polyethylene, polybutene or polypropylene insulating tape which has been specially processed to attain properties which are not generally found in these materials, but are required for their use in impregnated electrical cables. Chief among these properties is compatibility with impregnating oil.

  4. Fully synthetic taped insulation cables

    DOE Patents [OSTI]

    Forsyth, Eric B. (Brookhaven, NY); Muller, Albert C. (Center Moriches, NY)

    1984-01-01

    A high voltage oil-impregnated electrical cable with fully polymer taped insulation operable to 765 kV. Biaxially oriented, specially processed, polyethylene, polybutene or polypropylene tape with an embossed pattern is wound in multiple layers over a conductive core with a permeable screen around the insulation. Conventional oil which closely matches the dielectric constant of the tape is used, and the cable can be impregnated after field installation because of its excellent impregnation characteristics.

  5. Synthetic and Mechanistic Chemistry publications

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Microelectronics and Nanometer Structures 26(5), 1718-1722 (2008). Bethany N. Wigington, Michael L. Drummond, Thomas R. Cundari, David L. Thorn, Susan K. Hanson, and Susannah L....

  6. A one-pot synthetic approach to prepare palladium nanoparticles embedded hierarchically porous TiO{sub 2} hollow spheres for hydrogen peroxide sensing

    SciTech Connect (OSTI)

    Kong Lirong; Lu Xiaofeng; Bian Xiujie; Zhang Wanjin; Wang Ce

    2010-10-15

    A simple one-step method to fabricate hierarchically porous TiO{sub 2}/Pd composite hollow spheres without any template was developed by using solvothermal treatment. Pd nanoparticles (2-5 nm) were well dispersed in the mesopores of the TiO{sub 2} hollow spheres via in-situ reduction. In our experiment, polyvinylpyrrolidone played an important role in the synthetic process as the reducing agent and the connective material between TiO{sub 2} and Pd nanoparticles. HF species generated from solvothermal reaction leaded to the formation of TiO{sub 2} hollow spheres and Ostwald ripening was another main factor that affected the size and structure of the hollow spheres. The as-prepared TiO{sub 2}/Pd composite hollow spheres exhibited high electrocatalytic activity towards the reduction of H{sub 2}O{sub 2}. The sensitivity was about 226.72 {mu}A mM{sup -1} cm{sup -2} with a detection limit of 3.81 {mu}M at a signal-to-noise ratio of 3. These results made the hierarchically porous TiO{sub 2}/Pd composite a promising platform for fabricating new nonenzymic biosensors. - Graphical Abstract: A new one-step solvothermal method was developed to prepare Pd nanoparticles embedded hierarchically porous TiO{sub 2} hollow spheres. Due to its unique nanostructure, the prepared TiO{sub 2}/Pd modified GC electrode exhibit a high sensitivity (226.72 {mu}A mM{sup -1} cm{sup -2}), a relatively low reduction potential (-0.2 V), a fast response time (<3 s) and a relatively low detection limit of 3.81 {mu}M (S/N=3) towards H{sub 2}O{sub 2}.

  7. Observation of Rayleigh-Taylor-instability evolution in a plasma with magnetic and viscous effects

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Adams, Colin S.; Moser, Auna L.; Hsu, Scott C.

    2015-11-06

    We present time-resolved observations of Rayleigh-Taylor-instability (RTI) evolution at the interface between an unmagnetized plasma jet colliding with a stagnated, magnetized plasma. The observed instability growth time (~10μs) is consistent with the estimated linear RTI growth rate calculated using experimentally inferred values of density (~1014cm–3) and deceleration (~109 m/s2). The observed mode wavelength (≳1 cm) nearly doubles within a linear growth time. Furthermore, theoretical estimates of magnetic and viscous stabilization and idealized magnetohydrodynamic simulations including a physical viscosity model both suggest that the observed instability evolution is subject to magnetic and/or viscous effects.

  8. 70 Years of Evolution: Special Anniversary Issue | Y-12 National Security

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Complex 70 Years of Evolution: ... 70 Years of Evolution: Special Anniversary Issue Posted: February 7, 2013 - 6:01pm | Y-12 Report | Volume 9, Issue 2 | 2013 Y-12 has been a symbol of national strength and global security for 70 years. Though missions have evolved and facilities have been transformed, the site's purpose remains clear: make the world safer. In war and peace, Y-12 has responded to the nation's needs. During the decades-long Cold War, the site ramped up weapons production to

  9. On a hierarchy of nonlinearly dispersive generalized Korteweg - de Vries evolution equations

    SciTech Connect (OSTI)

    Christov, Ivan C.

    2015-08-20

    We propose a hierarchy of nonlinearly dispersive generalized Kortewegde Vries (KdV) evolution equations based on a modification of the Lagrangian density whose induced action functional the KdV equation extremizes. Two recent nonlinear evolution equations describing wave propagation in certain generalized continua with an inherent material length scale are members of the proposed hierarchy. Like KdV, the equations from the proposed hierarchy possess Hamiltonian structure. Unlike KdV, the solutions to these equations can be compact (i.e., they vanish outside of some open interval) and, in addition, peaked. Implicit solutions for these peaked, compact traveling waves (peakompactons) are presented.

  10. LATE SPECTRAL EVOLUTION OF THE EJECTA AND REVERSE SHOCK IN SN 1987A

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect LATE SPECTRAL EVOLUTION OF THE EJECTA AND REVERSE SHOCK IN SN 1987A Citation Details In-Document Search Title: LATE SPECTRAL EVOLUTION OF THE EJECTA AND REVERSE SHOCK IN SN 1987A We present observations with the Very Large Telescope and Hubble Space Telescope (HST) of the broad emission lines from the inner ejecta and reverse shock of SN 1987A from 1999 February until 2012 January (days 4381-9100 after explosion). We detect broad lines from H{alpha},

  11. Doping evolution of the electronic structure in the single-layer cuprates

    Office of Scientific and Technical Information (OSTI)

    Bi2Sr2- delta: Comparison with other single-layer cuprates (Journal Article) | SciTech Connect Doping evolution of the electronic structure in the single-layer cuprates Bi2Sr2&#8722xLaxCuO6 delta: Comparison with other single-layer cuprates Citation Details In-Document Search Title: Doping evolution of the electronic structure in the single-layer cuprates Bi2Sr2&#8722xLaxCuO6 delta: Comparison with other single-layer cuprates We have performed angle-resolved photoemission and

  12. Evolution of magnetic properties and microstructure of Hf2Co11B alloys

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Journal Article: Evolution of magnetic properties and microstructure of Hf2Co11B alloys Citation Details In-Document Search Title: Evolution of magnetic properties and microstructure of Hf2Co11B alloys Authors: McGuire, Michael A [1] ; Rios, Orlando [1] + Show Author Affiliations ORNL Publication Date: 2015-01-01 OSTI Identifier: 1185598 DOE Contract Number: DE-AC05-00OR22725 Resource Type: Journal Article Resource Relation: Journal Name: Journal of

  13. Evolution of magnetic properties and microstructure of Hf{sub 2}Co{sub 11}B

    Office of Scientific and Technical Information (OSTI)

    alloys (Journal Article) | SciTech Connect Journal Article: Evolution of magnetic properties and microstructure of Hf{sub 2}Co{sub 11}B alloys Citation Details In-Document Search Title: Evolution of magnetic properties and microstructure of Hf{sub 2}Co{sub 11}B alloys Amorphous Hf{sub 2}Co{sub 11}B alloys produced by melt-spinning have been crystallized by annealing at 500-800 °C, and the products have been investigated using magnetization measurements, x-ray diffraction, and scanning

  14. Centrality evolution of the charged-particle pseudorapidity density over a

    Office of Scientific and Technical Information (OSTI)

    broad pseudorapidity range in Pb-Pb collisions at sNN=2.76 TeV (Journal Article) | SciTech Connect Centrality evolution of the charged-particle pseudorapidity density over a broad pseudorapidity range in Pb-Pb collisions at sNN=2.76 TeV Citation Details In-Document Search Title: Centrality evolution of the charged-particle pseudorapidity density over a broad pseudorapidity range in Pb-Pb collisions at s NN = 2.76 TeV Publication Date: 2016-03-01 OSTI Identifier: 1236106 Type: Published

  15. Evolution of reaction center mimics to systems capable of generating solar

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    fuel Evolution of reaction center mimics to systems capable of generating solar fuel Authors: Sherman, B.D., Vaughn, M.D., Bergkamp, J.J., Gust, D., Moore, A.L., Moore, T.A. Title: Evolution of reaction center mimics to systems capable of generating solar fuel Source: Photosynthesis Research Year: 2014 Volume: 120 (1-2) Pages: 59-70 ABSTRACT: Capturing and converting solar energy via artificial photosynthesis offers an ideal way to limit society's dependence on fossil fuel and its myriad

  16. Center for Understanding and Control of Acid Gas-induced Evolution of

    Office of Science (SC) Website

    Materials for Energy (UNCAGE-ME) | U.S. DOE Office of Science (SC) Understanding and Control of Acid Gas-induced Evolution of Materials for Energy (UNCAGE-ME) Energy Frontier Research Centers (EFRCs) EFRCs Home Centers EFRC External Websites Research Science Highlights News & Events Publications History Contact BES Home Centers Center for Understanding and Control of Acid Gas-induced Evolution of Materials for Energy (UNCAGE-ME) Print Text Size: A A A FeedbackShare Page UNCAGE ME

  17. On a hierarchy of nonlinearly dispersive generalized Korteweg - de Vries evolution equations

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Christov, Ivan C.

    2015-08-20

    We propose a hierarchy of nonlinearly dispersive generalized Korteweg–de Vries (KdV) evolution equations based on a modification of the Lagrangian density whose induced action functional the KdV equation extremizes. Two recent nonlinear evolution equations describing wave propagation in certain generalized continua with an inherent material length scale are members of the proposed hierarchy. Like KdV, the equations from the proposed hierarchy possess Hamiltonian structure. Unlike KdV, the solutions to these equations can be compact (i.e., they vanish outside of some open interval) and, in addition, peaked. Implicit solutions for these peaked, compact traveling waves (“peakompactons”) are presented.

  18. Joint Summer School on "The Evolution and Impact of Microstructural Defects

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    on In-Reactor Material Response" | U.S. DOE Office of Science (SC) Joint Summer School on "The Evolution and Impact of Microstructural Defects on In-Reactor Material Response" Energy Frontier Research Centers (EFRCs) EFRCs Home Centers Research Science Highlights News & Events EFRC News EFRC Events DOE Announcements Publications History Contact BES Home 11.08.10 Joint Summer School on "The Evolution and Impact of Microstructural Defects on In-Reactor Material

  19. Microstructure evolution in Xe-irradiated UO2 at room temperature

    SciTech Connect (OSTI)

    L.F. He; J. Pakarinen; M.A. Kirk; J. Gan; A.T. Nelson; X.-M. Bai; A. El-Azab; T.R. Allen

    2014-07-01

    In situ Transmission Electron Microscopy was conducted for single crystal UO2 to understand the microstructure evolution during 300 keV Xe irradiation at room temperature. The dislocation microstructure evolution was shown to occur as nucleation and growth of dislocation loops at low irradiation doses, followed by transformation to extended dislocation segments and tangles at higher doses. Xe bubbles with dimensions of 1-2 nm were observed after room-temperature irradiation. Electron Energy Loss Spectroscopy indicated that UO2 remained stoichiometric under room temperature Xe irradiation.

  20. Microsoft PowerPoint - Elisabeth_Cohen_Cirrus_Evolution.ppt [Compatibility Mode]

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Cirrus Evolution from Convective Outflow during the Convective Outflow during the Tropical Warm Pool International Cloud Experiment (TWP-ICE) (TWP ICE) Lis Cohen * Jay Mace G M F h * S ll B Greg McFarquhar * Sally Benson Based on contributions from Brian Soden and Min Deng. Contact: Lis Cohen liscohen@met.utah.edu Cirrus Evolution Study The goal is to discover how tropical cirrus clouds are maintained and either evolve into persistent cloud entities or dissipate soon after leaving a convective

  1. Microstructural evolution of type 304 and 316 stainless steels under neutron irradiation at LWR relevant conditions

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Tan, Lizhen; Stoller, Roger E.; Field, Kevin G.; Yang, Ying; Morgan, Dane; Wirth, Brian D.; Gussev, Maxim N.; Busby, Jeremy T.; Nam, H.

    2015-12-11

    Extension of light water reactors' useful life will expose austenitic internal core components to irradiation damage levels beyond 100 displacements per atom (dpa), which will lead to profound microstructural evolution and consequent degradation of macroscopic properties. Microstructural evolution, including Frank loops, cavities, precipitates, and segregation at boundaries and the resultant radiation hardening in type 304 and 316 stainless steel (SS) variants, were studied in this work via experimental characterization and multiple simulation methods. Experimental data for up to 40 heats of type 304SS and 316SS variants irradiated in different reactors to 0.6–120 dpa at 275–375°C were either generated from thismore » work or collected from literature reports. These experimental data were then combined with models of Frank loop and cavity evolution, computational thermodynamics and precipitation, and ab initio and rate theory integrated radiation-induced segregation models to provide insights into microstructural evolution and degradation at higher radiation doses.« less

  2. Kinematic morphology of large-scale structure: evolution from potential to rotational flow

    SciTech Connect (OSTI)

    Wang, Xin; Szalay, Alex; Aragn-Calvo, Miguel A.; Neyrinck, Mark C.; Eyink, Gregory L.

    2014-09-20

    As an alternative way to describe the cosmological velocity field, we discuss the evolution of rotational invariants constructed from the velocity gradient tensor. Compared with the traditional divergence-vorticity decomposition, these invariants, defined as coefficients of the characteristic equation of the velocity gradient tensor, enable a complete classification of all possible flow patterns in the dark-matter comoving frame, including both potential and vortical flows. We show that this tool, first introduced in turbulence two decades ago, is very useful for understanding the evolution of the cosmic web structure, and in classifying its morphology. Before shell crossing, different categories of potential flow are highly associated with the cosmic web structure because of the coherent evolution of density and velocity. This correspondence is even preserved at some level when vorticity is generated after shell crossing. The evolution from the potential to vortical flow can be traced continuously by these invariants. With the help of this tool, we show that the vorticity is generated in a particular way that is highly correlated with the large-scale structure. This includes a distinct spatial distribution and different types of alignment between the cosmic web and vorticity direction for various vortical flows. Incorporating shell crossing into closed dynamical systems is highly non-trivial, but we propose a possible statistical explanation for some of the phenomena relating to the internal structure of the three-dimensional invariant space.

  3. Evolution of the helicity and transversity Transverse-Momentum-Dependent parton distributions

    SciTech Connect (OSTI)

    Prokudin, Alexei; Bacchetta, Alessandro

    2013-07-01

    We examine the QCD evolution of the helicity and transversity parton distribution functions when including also their dependence on transverse momentum. Using an appropriate definition of these polarized transverse momentum distributions (TMDs), we describe their dependence on the factorization scale and rapidity cutoff, which is essential for phenomenological applications.

  4. Temperature evolution of electromotive force from Pt on yttrium-iron-garnet under ferromagnetic resonance

    SciTech Connect (OSTI)

    Ohshima, Ryo; Emoto, Hiroyuki; Shinjo, Teruya; Ando, Yuichiro; Shiraishi, Masashi

    2015-05-07

    Temperature evolution of electromotive force from Pt due to the inverse spin Hall effect is studied. Pure spin current is injected from yttrium-iron-garnet by using spin pumping technique. The electromotive force from the Pt monotonically decreases with decreasing temperature, and it is showed that there is a deviation between the measured and the calculated electromotive forces.

  5. Bubble Density Dependent Functionals to Describe Deformation and Stress Equilibrium Evolution for In-Reactor Nuclear Fuel Materials

    SciTech Connect (OSTI)

    Stout, Ray B.

    2008-07-01

    Future designs of nuclear fuels require an increased understanding of fission gas bubble density evolution. Derivations will be provided for a generic Boltzmann bubble density evolution equation, a bubble density deformation field equation, and a Cauchy stress/bubble-pressure equilibrium equation. (author)

  6. Sorption-Enhanced Synthetic Natural Gas (SNG) Production from Syngas. A Novel Process Combining CO Methanation, Water-Gas Shift, and CO2 Capture

    SciTech Connect (OSTI)

    Lebarbier, Vanessa M.C.; Dagle, Robert A.; Kovarik, Libor; Albrecht, Karl O.; Li, Xiaohong S.; Li, Liyu; Taylor, Charles E.; Bao, Xinhe; Wang, Yong

    2013-07-08

    Synthetic natural gas (SNG) production from syngas is under investigation again due to the desire for less dependency from imports and the opportunity for increasing coal utilization and reducing green house gas emission. CO methanation is highly exothermic and substantial heat is liberated which can lead to process thermal imbalance and deactivation of the catalyst. As a result, conversion per pass is limited and substantial syngas recycle is employed in conventional processes. Furthermore, the conversion of syngas to SNG is typically performed at moderate temperatures (275 to 325C) to ensure high CH4 yields since this reaction is thermodynamically limited. In this study, the effectiveness of a novel integrated process for the SNG production from syngas at high temperature (i.e. 600?C) was investigated. This integrated process consists of combining a CO methanation nickel-based catalyst with a high temperature CO2 capture sorbent in a single reactor. Integration with CO2 separation eliminates the reverse-water-gas shift and the requirement for a separate water-gas shift (WGS) unit. Easing of thermodynamic constraint offers the opportunity of enhancing yield to CH4 at higher operating temperature (500-700C) which also favors methanation kinetics and improves the overall process efficiency due to exploitation of reaction heat at higher temperatures. Furthermore, simultaneous CO2 capture eliminates green house gas emission. In this work, sorption-enhanced CO methanation was demonstrated using a mixture of a 68% CaO/32% MgAl2O4 sorbent and a CO methanation catalyst (Ni/Al2O3, Ni/MgAl2O4, or Ni/SiC) utilizing a syngas ratio (H2/CO) of 1, gas-hour-space velocity (GHSV) of 22 000 hr-1, pressure of 1 bar and a temperature of 600oC. These conditions resulted in ~90% yield to methane, which was maintained until the sorbent became saturated with CO2. By contrast, without the use of sorbent, equilibrium yield to methane is only 22%. Cyclic stability of the methanation catalyst and durability of the sorbent were also studied in the multiple carbonation-decarbonation cycle studies proving the potential of this integrated process in a practical application.

  7. Evolution of structure in Na{sub 0.5}Bi{sub 0.5}TiO{sub 3} single...

    Office of Scientific and Technical Information (OSTI)

    Evolution of structure in Nasub 0.5Bisub 0.5TiOsub 3 single crystals with BaTiOsub 3 Citation Details In-Document Search Title: Evolution of structure in Nasub 0.5Bisub ...

  8. NUMERICAL MODELING OF THE COAGULATION AND POROSITY EVOLUTION OF DUST AGGREGATES

    SciTech Connect (OSTI)

    Okuzumi, Satoshi; Sakagami, Masa-aki [Graduate School of Human and Environmental Studies, Kyoto University, Yoshida-nihonmatsu-cho, Sakyo-ku, Kyoto 606-8501 (Japan); Tanaka, Hidekazu, E-mail: satoshi.okuzumi@ax2.ecs.kyoto-u.ac.j [Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819 (Japan)

    2009-12-20

    Porosity evolution of dust aggregates is crucial in understanding dust evolution in protoplanetary disks. In this study, we present useful tools to study the coagulation and porosity evolution of dust aggregates. First, we present a new numerical method for simulating dust coagulation and porosity evolution as an extension of the conventional Smoluchowski equation. This method follows the evolution of the mean porosity for each aggregate mass simultaneously with the evolution of the mass distribution function. This method reproduces the results of previous Monte Carlo simulations with much less computational expense. Second, we propose a new collision model for porous dust aggregates on the basis of our N-body experiments on aggregate collisions. As the first step, we focus on 'hit-and-stick' collisions, which involve neither compression nor fragmentation of aggregates. We first obtain empirical data on porosity changes between the classical limits of ballistic cluster-cluster and particle-cluster aggregation. Using the data, we construct a recipe for the porosity change due to general hit-and-stick collisions as well as formulae for the aerodynamical and collisional cross sections. Our collision model is thus more realistic than a previous model of Ormel et al. based on the classical aggregation limits only. Simple coagulation simulations using the extended Smoluchowski method show that our collision model explains the fractal dimensions of porous aggregates observed in a full N-body simulation and a laboratory experiment. By contrast, similar simulations using the collision model of Ormel et al. result in much less porous aggregates, meaning that this model underestimates the porosity increase upon unequal-sized collisions. Besides, we discover that aggregates at the high-mass end of the distribution can have a considerably small aerodynamical cross section per unit mass compared with aggregates of lower masses. This occurs when aggregates drift under uniform acceleration (e.g., gravity) and their collision is induced by the difference in their terminal velocities. We point out an important implication of this discovery for dust growth in protoplanetary disks.

  9. Genome sequence analysis of the model grass Brachypodium distachyon: insights into grass genome evolution

    SciTech Connect (OSTI)

    Schulman, Al

    2009-08-09

    Three subfamilies of grasses, the Erhardtoideae (rice), the Panicoideae (maize, sorghum, sugar cane and millet), and the Pooideae (wheat, barley and cool season forage grasses) provide the basis of human nutrition and are poised to become major sources of renewable energy. Here we describe the complete genome sequence of the wild grass Brachypodium distachyon (Brachypodium), the first member of the Pooideae subfamily to be completely sequenced. Comparison of the Brachypodium, rice and sorghum genomes reveals a precise sequence- based history of genome evolution across a broad diversity of the grass family and identifies nested insertions of whole chromosomes into centromeric regions as a predominant mechanism driving chromosome evolution in the grasses. The relatively compact genome of Brachypodium is maintained by a balance of retroelement replication and loss. The complete genome sequence of Brachypodium, coupled to its exceptional promise as a model system for grass research, will support the development of new energy and food crops

  10. Investigation of the electrocatalytic oxygen reduction and evolution reactions in lithium–oxygen batteries

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zheng, Dong; Zhang, Xuran; Qu, Deyu; Yang, Xiao -Qing; Lee, Hung -Sui; Qu, Deyang

    2015-04-21

    Oxygen reduction and oxygen evolution reactions were examined on graphite electrodes with different crystal orientations. The kinetics for the redox couple O2/O2•- are very fast, therefore no catalyst seems necessary to assist the charge transfer process. Apparently, the main source of the overpotential for the O2 reduction reaction is from mass diffusion. Li2O2 becomes soluble in non-aqueous electrolytes in the presence of the tetraethylammonium tetrafluoroborate additive. The soluble B-O22- ions can be oxidized electro-catalytically. The edge orientation of graphite demonstrates superior catalytic activity for the oxidation over basal orientation. The findings reveal an opportunity for recharging Li-air batteries efficiently andmore » a new strategy of developing the catalyst for oxygen evolution reaction.« less

  11. An interpolation between the wave and diffusion equations through the fractional evolution equations Dirac like

    SciTech Connect (OSTI)

    Pierantozzi, T.; Vazquez, L.

    2005-11-01

    Through fractional calculus and following the method used by Dirac to obtain his well-known equation from the Klein-Gordon equation, we analyze a possible interpolation between the Dirac and the diffusion equations in one space dimension. We study the transition between the hyperbolic and parabolic behaviors by means of the generalization of the D'Alembert formula for the classical wave equation and the invariance under space and time inversions of the interpolating fractional evolution equations Dirac like. Such invariance depends on the values of the fractional index and is related to the nonlocal property of the time fractional differential operator. For this system of fractional evolution equations, we also find an associated conserved quantity analogous to the Hamiltonian for the classical Dirac case.

  12. Spectral evolution of two-dimensional kinetic plasma turbulence in the wavenumber-frequency domain

    SciTech Connect (OSTI)

    Comi?el, H.; Institute for Space Sciences, Atomi?tilor 409, P.O. Box MG-23, Bucharest-M?gurele RO-077125 ; Verscharen, D.; Narita, Y.; Motschmann, U.; Deutsches Zentrum fr Luft- und Raumfahrt, Institut fr Planetenforschung, Rutherfordstr. 2, D-12489 Berlin

    2013-09-15

    We present a method for studying the evolution of plasma turbulence by tracking dispersion relations in the energy spectrum in the wavenumber-frequency domain. We apply hybrid plasma simulations in a simplified two-dimensional geometry to demonstrate our method and its applicability to plasma turbulence in the ion kinetic regime. We identify four dispersion relations: ion-Bernstein waves, oblique whistler waves, oblique Alfvn/ion-cyclotron waves, and a zero-frequency mode. The energy partition and frequency broadening are evaluated for these modes. The method allows us to determine the evolution of decaying plasma turbulence in our restricted geometry and shows that it cascades along the dispersion relations during the early phase with an increasing broadening around the dispersion relations.

  13. Observation of Rayleigh-Taylor-instability evolution in a plasma with magnetic and viscous effects

    SciTech Connect (OSTI)

    Adams, Colin S.; Moser, Auna L.; Hsu, Scott C.

    2015-11-06

    We present time-resolved observations of Rayleigh-Taylor-instability (RTI) evolution at the interface between an unmagnetized plasma jet colliding with a stagnated, magnetized plasma. The observed instability growth time (~10μs) is consistent with the estimated linear RTI growth rate calculated using experimentally inferred values of density (~1014cm–3) and deceleration (~109 m/s2). The observed mode wavelength (≳1 cm) nearly doubles within a linear growth time. Furthermore, theoretical estimates of magnetic and viscous stabilization and idealized magnetohydrodynamic simulations including a physical viscosity model both suggest that the observed instability evolution is subject to magnetic and/or viscous effects.

  14. Investigation of the electrocatalytic oxygen reduction and evolution reactions in lithiumoxygen batteries

    SciTech Connect (OSTI)

    Zheng, Dong; Zhang, Xuran; Qu, Deyu; Yang, Xiao -Qing; Lee, Hung -Sui; Qu, Deyang

    2015-04-21

    Oxygen reduction and oxygen evolution reactions were examined on graphite electrodes with different crystal orientations. The kinetics for the redox couple O2/O2- are very fast, therefore no catalyst seems necessary to assist the charge transfer process. Apparently, the main source of the overpotential for the O2 reduction reaction is from mass diffusion. Li2O2 becomes soluble in non-aqueous electrolytes in the presence of the tetraethylammonium tetrafluoroborate additive. The soluble B-O22- ions can be oxidized electro-catalytically. The edge orientation of graphite demonstrates superior catalytic activity for the oxidation over basal orientation. The findings reveal an opportunity for recharging Li-air batteries efficiently and a new strategy of developing the catalyst for oxygen evolution reaction.

  15. dynamical evolution of an ultra-relativistic fireball colliding with a freely expanding gas

    SciTech Connect (OSTI)

    Suzuki, Akihiro [Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Shigeyama, Toshikazu [Research Center for the Early Universe, School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2014-11-20

    We investigate the hydrodynamical evolution of an ultra-relativistic fireball colliding with a freely expanding gas. The hydrodynamical interaction of the fireball and the gas results in the formation of a geometrically thin shell. We study the dynamical evolution of the shell analytically and perform a numerical simulation equipped with adaptive mesh refinement to investigate the internal structure of the shell. The shocked gas can give rise to bright emission in the X-ray and gamma-ray energy range. We propose that the breakout emission from the forward shock and the photospheric emission from the reverse-shocked fireball contribute to early gamma-ray emission from gamma-ray bursts.

  16. Spatial and temporal evolution of filamentation instability in a current-carrying plasma

    SciTech Connect (OSTI)

    Mohammadhosseini, B. [Laser-Plasma Research Institute, Shahid Beheshti University, G. C., Evin, Tehran 19839-63113 (Iran, Islamic Republic of); Department of Physics, Imam Khomeini International University, Qazvin 34149-16818 (Iran, Islamic Republic of); Niknam, A. R. [Laser-Plasma Research Institute, Shahid Beheshti University, G. C., Evin, Tehran 19839-63113 (Iran, Islamic Republic of); Shokri, B. [Laser-Plasma Research Institute, Shahid Beheshti University, G. C., Evin, Tehran 19839-63113 (Iran, Islamic Republic of); Department of Physics, Shahid Beheshti University, G. C., Evin, Tehran 19839-63113 (Iran, Islamic Republic of)

    2010-12-15

    The spatial and temporal evolution of the electric and magnetic fields in a current-carrying plasma is investigated in the nonlinear regime. Using the magnetohydrodynamic equations, a nonlinear diffusion equation for the magnetic field in the plasma is obtained. This nonlinear equation is numerically solved and the spatiotemporal evolution of the electric and magnetic fields and the electron density distribution are plotted. It is shown that as the time passes, the profile of the electric and magnetic fields changes from a sinusoidal shape to a saw-tooth one and the electron density distribution becomes very steepened. Also, the mechanism of the filament formation is then discussed. Furthermore, the effects of the thermal motion, collisions, and ion mass on growth rate of filaments as well as the saturation time are argued. Finally, it is found that the energy dissipation is associated with the aforementioned effects and strong plasma density gradient.

  17. Low-dimensional hyperthin FeS2 nanostructures for efficient and stable hydrogen evolution electrocatalysis

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Jasion, Daniel; Qiao, Qiao; Barforoush, Joseph M.; Zhu, Yimei; Ren, Shenqiang; Leonard, Kevin C.

    2015-10-05

    We report a scalable, solution-processing method for synthesizing low-dimensional hyperthin FeS2 nanostructures, and we show that 2D FeS2 disc nanostructures are an efficient and stable hydrogen evolution electrocatalyst. By changing the Fe:S ratio in the precursor solution, we were able to preferentially synthesize either 1D wire or 2D disc nanostructures. The 2D FeS2 disc structure has the highest electrocatalytic activity for the hydrogen evolution reaction, comparable to platinum in neutral pH conditions. Moreover, the ability of the FeS2 nanostructures to generate hydrogen was confirmed by scanning electrochemical microscopy, and the 2D disc nanostructures were able to generate hydrogen for overmore » 125 h.« less

  18. Application of Phase-field Method in Predicting Gas Bubble Microstructure Evolution in Nuclear Fuels

    SciTech Connect (OSTI)

    Hu, Shenyang Y.; Li, Yulan; Sun, Xin; Gao, Fei; Devanathan, Ramaswami; Henager, Charles H.; Khaleel, Mohammad A.

    2010-04-30

    Fission product accumulation and gas bubble microstructure evolution in nuclear fuels strongly affect thermo-mechanical properties such as thermal conductivity, gas release, volumetric swelling and cracking, and hence the fuel performance. In this paper, a general phase-field model is developed to predict gas bubble formation and evolution. Important materials processes and thermodynamic properties including the generation of gas atoms and vacancies, sinks for vacancies and gas atoms, the elastic interaction among defects, gas re-solution, and inhomogeneity of elasticity and diffusivity are accounted for in the model. The simulations demonstrate the potential application of the phase-field method in investigating 1) heterogeneous nucleation of gas bubbles at defects; 2) effect of elastic interaction, inhomogeneity of material properties, and gas re-solution on gas bubble microstructures; and 3) effective properties from the output of phase-field simulations such as distribution of defects, gas bubbles, and stress fields.

  19. Measurement of concrete E-modulus evolution since casting: A novel method based on ambient vibration

    SciTech Connect (OSTI)

    Azenha, Miguel, E-mail: miguel.azenha@civil.uminho.p [LABEST - Laboratory for the Concrete Technology and Structural Behaviour, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); ISISE - Institute for Sustainability and Innovation in Structural Engineering, Universidade do Minho, Escola de Engenharia, Campus de Azurem, 4800-058 Guimaraes (Portugal); Magalhaes, Filipe [VIBEST - Laboratory of Vibrations and Structural Monitoring, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); Faria, Rui [LABEST - Laboratory for the Concrete Technology and Structural Behaviour, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); Cunha, Alvaro [VIBEST - Laboratory of Vibrations and Structural Monitoring, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal)

    2010-07-15

    The use of ambient vibration tests to characterize the evolution of E-modulus of concrete right after casting is investigated in this paper. A new methodology is proposed, which starts by casting a concrete cylindrical beam inside a hollow acrylic formwork. This beam is then placed horizontally, simply supported at both extremities, and vertical accelerations resulting from ambient vibration are measured at mid-span. Processing these mid-span acceleration time series using power spectral density functions allows a continuous identification of the first flexural frequency of vibration of the composite beam, which in turn is correlated with the evolutive E-modulus of concrete since casting. Together with experiments conducted with the proposed methodology, a complementary validation campaign for concrete E-modulus determination was undertaken by static loading tests performed on the composite beam, as well as by standard compressive tests of concrete cylinders of the same batch loaded at different ages.

  20. Influence of interface mobility on the evolution of Austenite-Martensite grain assemblies during annealing

    SciTech Connect (OSTI)

    Clarke, Amy J; Santofimia, Maria J; Speer, John G; Zhao, L; Sietsma, Jilt

    2009-01-01

    The quenching and partitioning (Q&P) process is a new heat treatment for the creation of advanced high-strength steels. This treatment consists of an initial partial or full austenitization, followed by a quench to form a controlled amount of martensite and an annealing step to partition carbon atoms from the martensite to the austenite. In this work, the microstructural evolution during annealing of martensite-austenite grain assemblies has been analyzed by means of a modeling approach that considers the influence of martensite-austenite interface migration on the kinetics of carbon partitioning. Carbide precipitation is precluded in the model, and three different assumptions about interface mobility are considered, ranging from a completely immobile interface to the relatively high mobility of an incoherent ferrite-austenite interface. Simulations indicate that different interface mobilities lead to profound differences in the evolution of microstructure that is predicted during annealing.

  1. Tectonosedimentary evolution of the Crotone basin, Italy: Implications for Calabrian Arc geodynamics

    SciTech Connect (OSTI)

    Smale, J.L. ); Rio, D. ); Thunell, R.C. )

    1990-05-01

    Analysis of outcrop, well, and offshore seismic data has allowed the Neogene tectonosedimentary evolution of an Ionian Sea satellite basin to be outlined. The Crotone basin contains a series of postorogenic sediments deposited since Serravallian time atop a complex nappe system emplaced in the early Miocene. The basin's evolution can be considered predominantly one of distension in a fore-arc setting punctuated by compressional events. The earliest sediments (middle-late Miocene) consist of conglomerates, marls, and evaporites infilling a rapidly subsiding basin. A basin-wide Messinian unconformity and associated intraformational folding mark the close of this sedimentary cycle. Reestablishment of marine conditions in the early Pliocene is documented by sediments which show a distinct color banding and apparent rhythmicity, which may represent the basin margin to lowermost Pliocene marl/limestone rhythmic couplets present in southern Calabria. A bounding unconformity surface of middle Pliocene age (3.0 Ma), which corresponds to a major northwest-southeast compressional event, closes this depositional sequence. The basin depocenter shifted markedly toward the southeast, and both chaotic and strong subparallel reflector seismic facies of wide-ranging thicknesses fill the depositional topography created during this tectonic episode. Basin subsidence decreases dramatically in the late Pliocene and cessates in response to basin margin uplift in the early Pleistocene. The chronostratigraphic hierarchy of these depositional sequences allows them to constrain the deformational history of the basin. In addition, similar depositional hierarchies in adjacent basins (i.e., Paola, Cefalu, and Tyrrhenian Sea) allow them to tie the stratigraphy and evolution of the Crotone basin to the geodynamic evolution of the Calabrian arc system.

  2. The Evolution of Research and Education Networks and their Essential Role in

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    be published in: "Trends in High Performance & Large Scale Computing" Lucio Grandinetti and Gerhard Joubert editors, IOS Press publisher The Evolution of Research and Education Networks and their Essential Role in Modern Science William JOHNSTON, Evangelos CHANIOTAKIS, Eli DART, Chin GUOK, Joe METZGER, Brian TIERNEY ESnet, Lawrence Berkeley National Laboratory † Abstract. ESnet - the Energy Sciences Network - has the mission of enabling the aspects of the US Department of

  3. Evolution of Nuclear Observables in the Spherical-Deformed Phase Transition and the Interacting Boson Model

    SciTech Connect (OSTI)

    Zamfir, N.V.; McCutchan, E.A.; Casten, R.F.

    2004-09-13

    We discuss the empirical evolution of structure in the spherical-deformed phase transition region in the context of the behavior of basic structural signatures in the IBA symmetry triangle. The main signatures of a phase/shape transition are a sharp increase in R{sub 4/2} {identical_to} E(4{sub 1}{sup +})/E(2{sub 1}{sup +}) and minima in E(0{sub 2}{sup +}) and E(2{sub {gamma}}{sup +})

  4. Microsoft Word - Motivation, Design, Deployment and Evolution of OSCARS - Johnston.v1.4.docx

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    TERENA Networking Conference 16 - 19 May, 2011 Prague, Czech Republic Motivation, Design, Deployment and Evolution of a Guaranteed Bandwidth Network Service William E. Johnston, Chin Guok, Evangelos Chaniotakis ESnet and Lawrence Berkeley National Laboratory, Berkeley California, U.S.A Paper type Technical paper Abstract Much of modern science is dependent on high performance distributed computing and data handling. This distributed infrastructure, in turn, depends on high speed networks and

  5. Evolution of Ion Implantation Technology and its Contribution to Semiconductor Industry

    SciTech Connect (OSTI)

    Tsukamoto, Katsuhiro; Kuroi, Takashi; Kawasaki, Yoji

    2011-01-07

    Industrial aspects of the evolution of ion implantation technology will be reviewed, and their impact on the semiconductor industry will be discussed. The main topics will be the technology's application to the most advanced, ultra scaled CMOS, and to power devices, as well as productivity improvements in implantation technology. Technological insights into future developments in ion-related technologies for emerging industries will also be presented.

  6. Flexible Coal: Evolution from Baseload to Peaking Plant (Brochure), 21st Century Power Partnership

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Accelerating the transformation of power systems Flexible Coal Evolution from Baseload to Peaking Plant The experience cited in this paper is from a generating station with multiple units located in North America referred to here as the CGS plant. For commercial reasons, the station has not been identified. Jaquelin Cochran, a Debra Lew, a Nikhil Kumar b a National Renewable Energy Laboratory, b Intertek Summary for Policymakers: Key Findings from a North American Coal Generating Station (CGS)

  7. THE INFLUENCE OF THERMAL EVOLUTION IN THE MAGNETIC PROTECTION OF TERRESTRIAL PLANETS

    SciTech Connect (OSTI)

    Zuluaga, Jorge I.; Bustamante, Sebastian; Cuartas, Pablo A.; Hoyos, Jaime H. E-mail: sbustama@pegasus.udea.edu.co E-mail: jhhoyos@udem.edu.co

    2013-06-10

    Magnetic protection of potentially habitable planets plays a central role in determining their actual habitability and/or the chances of detecting atmospheric biosignatures. Here we develop a thermal evolution model of potentially habitable Earth-like planets and super-Earths (SEs). Using up-to-date dynamo-scaling laws, we predict the properties of core dynamo magnetic fields and study the influence of thermal evolution on their properties. The level of magnetic protection of tidally locked and unlocked planets is estimated by combining simplified models of the planetary magnetosphere and a phenomenological description of the stellar wind. Thermal evolution introduces a strong dependence of magnetic protection on planetary mass and rotation rate. Tidally locked terrestrial planets with an Earth-like composition would have early dayside magnetopause distances between 1.5 and 4.0 R{sub p} , larger than previously estimated. Unlocked planets with periods of rotation {approx}1 day are protected by magnetospheres extending between 3 and 8 R{sub p} . Our results are robust in comparison with variations in planetary bulk composition and uncertainties in other critical model parameters. For illustration purposes, the thermal evolution and magnetic protection of the potentially habitable SEs GL 581d, GJ 667Cc, and HD 40307g were also studied. Assuming an Earth-like composition, we found that the dynamos of these planets are already extinct or close to being shut down. While GL 581d is the best protected, the protection of HD 40307g cannot be reliably estimated. GJ 667Cc, even under optimistic conditions, seems to be severely exposed to the stellar wind, and, under the conditions of our model, has probably suffered massive atmospheric losses.

  8. EIA Financial and Physical Oil Market Workshop on Evolution of Petroleum Market and Price Dynamics

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Financial and Physical Oil Market Workshop on Evolution of Petroleum Market and Price Dynamics September 29, 2015 Room 2E-069, Forrestal Building 1000 Independence Ave., SW Washington, DC 20585 Crude oil prices have fallen nearly 50% since the middle of last year. The price continues to hover around $50/b. Yet, projections for global oil production remain robust in the coming years. However, the question whether the lower price is a transitional phenomenon or different regime has not yet been

  9. Microscopic investigation of structural evolution in even-even N = 60 isotones

    SciTech Connect (OSTI)

    Oudih, M. R.; Fellah, M.; Allal, N. H.; Benhamouda, N.

    2012-10-20

    The ground state properties of even-even N=60 isotones from the neutron-rich to the proton-rich side are investigated within the self-consistent Skyrme-Hartree-Fock-Bogoliubov theory in the triaxial landscape. Quantities such as binding energies and root-mean-square radii are investigated and compared with available experimental data. The evolution of the potential energy surfaces in the ({beta},{gamma}) deformation plane is presented and discussed.

  10. Anti-hierarchical evolution of the active galactic nucleus space density in a hierarchical universe

    SciTech Connect (OSTI)

    Enoki, Motohiro; Ishiyama, Tomoaki; Kobayashi, Masakazu A. R.; Nagashima, Masahiro

    2014-10-10

    Recent observations show that the space density of luminous active galactic nuclei (AGNs) peaks at higher redshifts than that of faint AGNs. This downsizing trend in the AGN evolution seems to be contradictory to the hierarchical structure formation scenario. In this study, we present the AGN space density evolution predicted by a semi-analytic model of galaxy and AGN formation based on the hierarchical structure formation scenario. We demonstrate that our model can reproduce the downsizing trend of the AGN space density evolution. The reason for the downsizing trend in our model is a combination of the cold gas depletion as a consequence of star formation, the gas cooling suppression in massive halos, and the AGN lifetime scaling with the dynamical timescale. We assume that a major merger of galaxies causes a starburst, spheroid formation, and cold gas accretion onto a supermassive black hole (SMBH). We also assume that this cold gas accretion triggers AGN activity. Since the cold gas is mainly depleted by star formation and gas cooling is suppressed in massive dark halos, the amount of cold gas accreted onto SMBHs decreases with cosmic time. Moreover, AGN lifetime increases with cosmic time. Thus, at low redshifts, major mergers do not always lead to luminous AGNs. Because the luminosity of AGNs is correlated with the mass of accreted gas onto SMBHs, the space density of luminous AGNs decreases more quickly than that of faint AGNs. We conclude that the anti-hierarchical evolution of the AGN space density is not contradictory to the hierarchical structure formation scenario.

  11. Rayleigh-Taylor-Instability Evolution in Colliding-Plasma-Jet Experiments with Magnetic and Viscous Stabilization

    SciTech Connect (OSTI)

    Adams, Colin Stuart

    2015-01-15

    The Rayleigh-Taylor instability causes mixing in plasmas throughout the universe, from micron-scale plasmas in inertial confinement fusion implosions to parsec-scale supernova remnants. The evolution of this interchange instability in a plasma is influenced by the presence of viscosity and magnetic fields, both of which have the potential to stabilize short-wavelength modes. Very few experimental observations of Rayleigh-Taylor growth in plasmas with stabilizing mechanisms are reported in the literature, and those that are reported are in sub-millimeter scale plasmas that are difficult to diagnose. Experimental observations in well-characterized plasmas are important for validation of computational models used to make design predictions for inertial confinement fusion efforts. This dissertation presents observations of instability growth during the interaction between a high Mach-number, initially un-magnetized plasma jet and a stagnated, magnetized plasma. A multi-frame fast camera captures Rayleigh-Taylor-instability growth while interferometry, spectroscopy, photodiode, and magnetic probe diagnostics are employed to estimate plasma parameters in the vicinity of the collision. As the instability grows, an evolution to longer mode wavelength is observed. Comparisons of experimental data with idealized magnetohydrodynamic simulations including a physical viscosity model suggest that the observed instability evolution is consistent with both magnetic and viscous stabilization. These data provide the opportunity to benchmark computational models used in astrophysics and fusion research.

  12. Detecting regular sound changes in linguistics as events of concerted evolution

    SciTech Connect (OSTI)

    Hruschka, Daniel J.; Branford, Simon; Smith, Eric D.; Wilkins, Jon; Meade, Andrew; Pagel, Mark; Bhattacharya, Tanmoy

    2014-12-18

    Background: Concerted evolution is normally used to describe parallel changes at different sites in a genome, but it is also observed in languages where a specific phoneme changes to the same other phoneme in many words in the lexicona phenomenon known as regular sound change. We develop a general statistical model that can detect concerted changes in aligned sequence data and apply it to study regular sound changes in the Turkic language family. Results: Linguistic evolution, unlike the genetic substitutional process, is dominated by events of concerted evolutionary change. Our model identified more than 70 historical events of regular sound change that occurred throughout the evolution of the Turkic language family, while simultaneously inferring a dated phylogenetic tree. Including regular sound changes yielded an approximately 4-fold improvement in the characterization of linguistic change over a simpler model of sporadic change, improved phylogenetic inference, and returned more reliable and plausible dates for events on the phylogenies. The historical timings of the concerted changes closely follow a Poisson process model, and the sound transition networks derived from our model mirror linguistic expectations. Conclusions: We demonstrate that a model with no prior knowledge of complex concerted or regular changes can nevertheless infer the historical timings and genealogical placements of events of concerted change from the signals left in contemporary data. Our model can be applied wherever discrete elementssuch as genes, words, cultural trends, technologies, or morphological traitscan change in parallel within an organism or other evolving group.

  13. Development of efficient time-evolution method based on three-term recurrence relation

    SciTech Connect (OSTI)

    Akama, Tomoko Kobayashi, Osamu; Nanbu, Shinkoh

    2015-05-28

    The advantage of the real-time (RT) propagation method is a direct solution of the time-dependent Schrödinger equation which describes frequency properties as well as all dynamics of a molecular system composed of electrons and nuclei in quantum physics and chemistry. Its applications have been limited by computational feasibility, as the evaluation of the time-evolution operator is computationally demanding. In this article, a new efficient time-evolution method based on the three-term recurrence relation (3TRR) was proposed to reduce the time-consuming numerical procedure. The basic formula of this approach was derived by introducing a transformation of the operator using the arcsine function. Since this operator transformation causes transformation of time, we derived the relation between original and transformed time. The formula was adapted to assess the performance of the RT time-dependent Hartree-Fock (RT-TDHF) method and the time-dependent density functional theory. Compared to the commonly used fourth-order Runge-Kutta method, our new approach decreased computational time of the RT-TDHF calculation by about factor of four, showing the 3TRR formula to be an efficient time-evolution method for reducing computational cost.

  14. Extraction of quark transversity distribution and Collins fragmentation functions with QCD evolution

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kang, Zhong-Bo; Prokudin, Alexei; Sun, Peng; Yuan, Feng

    2016-01-13

    In this paper, we study the transverse momentum dependent (TMD) evolution of the Collins azimuthal asymmetries in e+e- annihilations and semi-inclusive hadron production in deep inelastic scattering (SIDIS) processes. All the relevant coefficients are calculated up to the next-to-leading logarithmic (NLL) order accuracy. By applying the TMD evolution at the approximate NLL order in the Collins- Soper-Sterman (CSS) formalism, we extract transversity distributions for u and d quarks and Collins fragmentation functions from current experimental data by a global analysis of the Collins asymmetries in back-to-back di-hadron productions in e+e- annihilations measured by BELLE and BABAR Collaborations and SIDIS datamore » from HERMES, COMPASS, and JLab HALL A experiments. The impact of the evolution effects and the relevant theoretical uncertainties are discussed. We further discuss the TMD interpretation for our results, and illustrate the unpolarized quark distribution, transversity distribution, unpolarized quark fragmentation and Collins fragmentation functions depending on the transverse momentum and the hard momentum scale. Finally, we give predictions and discuss impact of future experiments.« less

  15. Self-similar space-time evolution of an initial density discontinuity

    SciTech Connect (OSTI)

    Rekaa, V. L.; Pcseli, H. L.; Trulsen, J. K.

    2013-07-15

    The space-time evolution of an initial step-like plasma density variation is studied. We give particular attention to formulate the problem in a way that opens for the possibility of realizing the conditions experimentally. After a short transient time interval of the order of the electron plasma period, the solution is self-similar as illustrated by a video where the space-time evolution is reduced to be a function of the ratio x/t. Solutions of this form are usually found for problems without characteristic length and time scales, in our case the quasi-neutral limit. By introducing ion collisions with neutrals into the numerical analysis, we introduce a length scale, the collisional mean free path. We study the breakdown of the self-similarity of the solution as the mean free path is made shorter than the system length. Analytical results are presented for charge exchange collisions, demonstrating a short time collisionless evolution with an ensuing long time diffusive relaxation of the initial perturbation. For large times, we find a diffusion equation as the limiting analytical form for a charge-exchange collisional plasma, with a diffusion coefficient defined as the square of the ion sound speed divided by the (constant) ion collision frequency. The ion-neutral collision frequency acts as a parameter that allows a collisionless result to be obtained in one limit, while the solution of a diffusion equation is recovered in the opposite limit of large collision frequencies.

  16. Damage evolution of yttria-stabilized zirconia induced by He irradiation

    SciTech Connect (OSTI)

    Yang, Tengfei; Huang, Xuejun; Gao, Yuan; Wang, Chenxu; Zhang, Yanwen; Xue, Jianming; Yan, Sha; Wang, Yugang

    2012-01-01

    The study presents an investigation of damage evolution of yttria-stabilized zirconia (YSZ) induced by irradiation of 100 keV He ions at room temperature as a function of fluence. Transmission electron microscopy (TEM), X-ray diffraction (XRD) and atomic force microscopy (AFM) were used in order to study the nature and evolution of structural damage at different levels. Our study shows that various kinds of defects are formed with the increasing fluence. Firstly, at low fluences, from 1 1016 to 4 1016 cm 2, of which maximum values of displacement per atom (dpa) range from 0.29 to 1.17, an elastic strain which is attributed to the accumulation of irradiation-induced discrete point defects, is presented. Secondly, in the intermediate fluences ranging from 8 1016 to 1 1017 cm 2 with corresponding dpa varying from 2.33 to 2.91, a large drop of elastic strain occurs accompanied by presence of an intensive damage region, which is comprised by large and interacted defect clusters. Thirdly, at the two high fluences of 2 1017 and 4 1017 cm 2, of which dpa are 5.83 and 11.65 respectively, a great amount of ribbon-like He bubbles with granular structure and cracks are presented at the depth of maximum concentration of deposited He atoms. The structural damage evolution and the mechanism of formation of He bubbles are discussed.

  17. Plant cell walls throughout evolution: towards a molecular understanding of their design principles

    SciTech Connect (OSTI)

    Sarkar, Purbasha; Bosneaga, Elena; Auer, Manfred

    2009-02-16

    Throughout their life, plants typically remain in one location utilizing sunlight for the synthesis of carbohydrates, which serve as their sole source of energy as well as building blocks of a protective extracellular matrix, called the cell wall. During the course of evolution, plants have repeatedly adapted to their respective niche,which is reflected in the changes of their body plan and the specific design of cell walls. Cell walls not only changed throughout evolution but also are constantly remodelled and reconstructed during the development of an individual plant, and in response to environmental stress or pathogen attacks. Carbohydrate-rich cell walls display complex designs, which together with the presence of phenolic polymers constitutes a barrier for microbes, fungi, and animals. Throughout evolution microbes have co-evolved strategies for efficient breakdown of cell walls. Our current understanding of cell walls and their evolutionary changes are limited as our knowledge is mainly derived from biochemical and genetic studies, complemented by a few targeted yet very informative imaging studies. Comprehensive plant cell wall models will aid in the re-design of plant cell walls for the purpose of commercially viable lignocellulosic biofuel production as well as for the timber, textile, and paper industries. Such knowledge will also be of great interest in the context of agriculture and to plant biologists in general. It is expected that detailed plant cell wall models will require integrated correlative multimodal, multiscale imaging and modelling approaches, which are currently underway.

  18. Evolution of flux ropes in the magnetotail: A three-dimensional global hybrid simulation

    SciTech Connect (OSTI)

    Lu, S.; Lin, Y.; Wang, X. Y.; Lu, Q. M. Huang, C.; Wu, M. Y.; Wang, S.; Wang, R. S.

    2015-05-15

    Flux ropes in the Earth's magnetotail are widely believed to play a crucial role in energy transport during substorms and the generation of energetic particles. Previous kinetic simulations are limited to the local-scale regime, and thus cannot be used to study the structure associated with the geomagnetic field and the global-scale evolution of the flux ropes. Here, the evolution of flux ropes in the magnetotail under a steady southward interplanetary magnetic field are studied with a newly developed three-dimensional global hybrid simulation model for dynamics ranging from the ion Larmor radius to the global convection time scales. Magnetic reconnection with multiple X-lines is found to take place in the near-tail current sheet at geocentric solar magnetospheric distances x=?30R{sub E}??15R{sub E} around the equatorial plane (z=0). The magnetotail reconnection layer is turbulent, with a nonuniform structure and unsteady evolution, and exhibits properties of typical collisionless fast reconnection with the Hall effect. A number of small-scale flux ropes are generated through the multiple X-line reconnection. The diameter of the flux ropes is several R{sub E}, and the spatial scale of the flux ropes in the dawn-dusk direction is on the order of several R{sub E} and does not extend across the entire section of the magnetotail, contrary to previous models and MHD simulation results and showing the importance of the three-dimensional effects. The nonuniform and unsteady multiple X-line reconnection with particle kinetic effects leads to various kinds of flux rope evolution: The small-scale flux ropes propagate earthward or tailward after formation, and eventually merge into the near-Earth region or the mid-/distant-tail plasmoid, respectively. During the propagation, some of the flux ropes can be tilted in the geocentric solar magnetospheric (x,y) plane with respect to the y (dawn-dusk) axis. Coalescence between flux ropes is also observed. At the same time, the evolution of the flux ropes in the multiple X-line reconnection layer can also lead to the acceleration and heating of ions.

  19. The Sunflower Genome and its Evolution (JGI Seventh Annual User Meeting 2012: Genomics of Energy and Environment)

    ScienceCinema (OSTI)

    Rieseberg, Loren [University of British Columbia

    2013-01-15

    Loren Rieseberg from the University of British Columbia on "The Sunflower Genome and its Evolution" at the 7th Annual Genomics of Energy & Environment Meeting on March 21, 2012 in Walnut Creek, California.

  20. The Sunflower Genome and its Evolution (JGI Seventh Annual User Meeting 2012: Genomics of Energy and Environment)

    SciTech Connect (OSTI)

    Rieseberg, Loren [University of British Columbia] [University of British Columbia

    2012-03-21

    Loren Rieseberg from the University of British Columbia on "The Sunflower Genome and its Evolution" at the 7th Annual Genomics of Energy & Environment Meeting on March 21, 2012 in Walnut Creek, California.

  1. Evaluations in support of regulatory and research decisions by the U. S. Environmental Protection Agency for the control of toxic hazards from hazardous wastes, glyphosate, dalapon, and synthetic fuels

    SciTech Connect (OSTI)

    Scofield, R.

    1984-01-01

    This report includes toxicological and regulatory evaluations performed in support of U.S. EPA regulation of toxic materials and hazardous wastes. The first section of the report describes evaluations which support: (a) the regulation of small-volume generators of hazardous wastes, (b) the regulation of hazardous wastes from pesticide manufacturing, and (c) the disposal of the herbicide, silvex. The second section describes the environmental fate, transport, and effect of glyphosate and dalapon. The third section deals with synthetic fuels, including evaluations of synfuel-product toxicity, uncontrolled air emissions, and particular focus on the toxicity of products from several indirect coal liquefaction processes including methanol synthesis, Fischer-Tropsch, Mobil M-Gasoline, and Lurgi gasification technologies. Three direct coal liquefaction processes were examined for product toxicity and air emissions: Solvent Refined Coal (I and II) and the Exxon Donor Solvent Process. Also described in the third section is an evaluation of environmental and health hazards associated with the use of synthetic fuels from indirect coal liquefaction, direct coal liquefaction, and shale oil. Finally, the fourth section discusses some problems associated with performing, on a contractual basis, scientific and technical evaluations in support of U.S. EPA regulatory and research decisions.

  2. Effects of twin boundary mobility on domain microstructure evolution in magnetic shape memory alloys: Phase field simulation

    SciTech Connect (OSTI)

    Jin, Yongmei M.

    2009-02-09

    Effects of twin boundary mobility on domain microstructure evolution during magnetic field-induced deformation in magnetic shape memory alloys are studied by phase field micromagnetic microelastic modeling. The simulations show that different twin boundary mobilities lead to drastically different domain microstructures and evolution pathways, yielding very different magnetization and strain responses, even with opposite signs. The study also reveals complex domain phenomena in magnetic shape memory alloys.

  3. Understanding the large-distance behavior of transverse-momentum-dependent parton densities and the Collins-Soper evolution kernel

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Collins, John; Rogers, Ted

    2015-04-01

    There is considerable controversy about the size and importance of non-perturbative contributions to the evolution of transverse momentum dependent (TMD) parton distribution functions. Standard fits to relatively high-energy Drell-Yan data give evolution that when taken to lower Q is too rapid to be consistent with recent data in semi-inclusive deeply inelastic scattering. Some authors provide very different forms for TMD evolution, even arguing that non-perturbative contributions at large transverse distance bT are not needed or are irrelevant. Here, we systematically analyze the issues, both perturbative and non-perturbative. We make a motivated proposal for the parameterization of the non-perturbative part ofmore » the TMD evolution kernel that could give consistency: with the variety of apparently conflicting data, with theoretical perturbative calculations where they are applicable, and with general theoretical non-perturbative constraints on correlation functions at large distances. We propose and use a scheme- and scale-independent function A(bT) that gives a tool to compare and diagnose different proposals for TMD evolution. We also advocate for phenomenological studies of A(bT) as a probe of TMD evolution. The results are important generally for applications of TMD factorization. In particular, they are important to making predictions for proposed polarized Drell- Yan experiments to measure the Sivers function.« less

  4. Correlating hydrogen oxidation and evolution activity on platinum at different pH with measured hydrogen binding energy

    SciTech Connect (OSTI)

    Sheng, WC; Zhuang, ZB; Gao, MR; Zheng, J; Chen, JGG; Yan, YS

    2015-01-08

    The hydrogen oxidation/evolution reactions are two of the most fundamental reactions in distributed renewable electrochemical energy conversion and storage systems. The identification of the reaction descriptor is therefore of critical importance for the rational catalyst design and development. Here we report the correlation between hydrogen oxidation/evolution activity and experimentally measured hydrogen binding energy for polycrystalline platinum examined in several buffer solutions in a wide range of electrolyte pH from 0 to 13. The hydrogen oxidation/evolution activity obtained using the rotating disk electrode method is found to decrease with the pH, while the hydrogen binding energy, obtained from cyclic voltammograms, linearly increases with the pH. Correlating the hydrogen oxidation/evolution activity to the hydrogen binding energy renders a monotonic decreasing hydrogen oxidation/evolution activity with the hydrogen binding energy, strongly supporting the hypothesis that hydrogen binding energy is the sole reaction descriptor for the hydrogen oxidation/evolution activity on monometallic platinum.

  5. HAZMAT. I. The evolution of far-UV and near-UV emission from early M stars

    SciTech Connect (OSTI)

    Shkolnik, Evgenya L.; Barman, Travis S. E-mail: barman@lpl.arizona.edu

    2014-10-01

    The spectral energy distribution, variability, and evolution of the high-energy radiation from an M dwarf planet host is crucial in understanding the planet's atmospheric evolution and habitability and in interpreting the planet's spectrum. The star's extreme-UV (EUV), far-UV (FUV), and near-UV (NUV) emission can chemically modify, ionize, and erode the atmosphere over time. This makes determining the lifetime exposure of such planets to stellar UV radiation critical for both the evolution of a planet's atmosphere and our potential to characterize it. Using the early M star members of nearby young moving groups, which sample critical ages in planet formation and evolution, we measure the evolution of the GALEX NUV and FUV flux as a function of age. The median UV flux remains at a 'saturated' level for a few hundred million years, analogous to that observed for X-ray emission. By the age of the Hyades Cluster (650 Myr), we measure a drop in UV flux by a factor of 2-3 followed by a steep drop from old (several Gyrs) field stars. This decline in activity beyond 300 Myr follows roughly t {sup –1}. Despite this clear evolution, there remains a wide range, of 1-2 orders of magnitude, in observed emission levels at every age. These UV data supply the much-needed constraints to M dwarf upper-atmosphere models, which will provide empirically motivated EUV predictions and more accurate age-dependent UV spectra as inputs to planetary photochemical models.

  6. Detecting regular sound changes in linguistics as events of concerted evolution

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hruschka, Daniel  J.; Branford, Simon; Smith, Eric  D.; Wilkins, Jon; Meade, Andrew; Pagel, Mark; Bhattacharya, Tanmoy

    2014-12-18

    Background: Concerted evolution is normally used to describe parallel changes at different sites in a genome, but it is also observed in languages where a specific phoneme changes to the same other phoneme in many words in the lexicon—a phenomenon known as regular sound change. We develop a general statistical model that can detect concerted changes in aligned sequence data and apply it to study regular sound changes in the Turkic language family. Results: Linguistic evolution, unlike the genetic substitutional process, is dominated by events of concerted evolutionary change. Our model identified more than 70 historical events of regular soundmore » change that occurred throughout the evolution of the Turkic language family, while simultaneously inferring a dated phylogenetic tree. Including regular sound changes yielded an approximately 4-fold improvement in the characterization of linguistic change over a simpler model of sporadic change, improved phylogenetic inference, and returned more reliable and plausible dates for events on the phylogenies. The historical timings of the concerted changes closely follow a Poisson process model, and the sound transition networks derived from our model mirror linguistic expectations. Conclusions: We demonstrate that a model with no prior knowledge of complex concerted or regular changes can nevertheless infer the historical timings and genealogical placements of events of concerted change from the signals left in contemporary data. Our model can be applied wherever discrete elements—such as genes, words, cultural trends, technologies, or morphological traits—can change in parallel within an organism or other evolving group.« less

  7. A stochastic model for tumor geometry evolution during radiation therapy in cervical cancer

    SciTech Connect (OSTI)

    Liu, Yifang; Lee, Chi-Guhn; Chan, Timothy C. Y.; Cho, Young-Bin; Islam, Mohammad K.; Department of Radiation Oncology, University of Toronto, 148-150 College Street, Toronto, Ontario M5S 3S2; Techna Institute for the Advancement of Technology for Health, 124-100 College Street, Toronto, Ontario M5G 1P5

    2014-02-15

    Purpose: To develop mathematical models to predict the evolution of tumor geometry in cervical cancer undergoing radiation therapy. Methods: The authors develop two mathematical models to estimate tumor geometry change: a Markov model and an isomorphic shrinkage model. The Markov model describes tumor evolution by investigating the change in state (either tumor or nontumor) of voxels on the tumor surface. It assumes that the evolution follows a Markov process. Transition probabilities are obtained using maximum likelihood estimation and depend on the states of neighboring voxels. The isomorphic shrinkage model describes tumor shrinkage or growth in terms of layers of voxels on the tumor surface, instead of modeling individual voxels. The two proposed models were applied to data from 29 cervical cancer patients treated at Princess Margaret Cancer Centre and then compared to a constant volume approach. Model performance was measured using sensitivity and specificity. Results: The Markov model outperformed both the isomorphic shrinkage and constant volume models in terms of the trade-off between sensitivity (target coverage) and specificity (normal tissue sparing). Generally, the Markov model achieved a few percentage points in improvement in either sensitivity or specificity compared to the other models. The isomorphic shrinkage model was comparable to the Markov approach under certain parameter settings. Convex tumor shapes were easier to predict. Conclusions: By modeling tumor geometry change at the voxel level using a probabilistic model, improvements in target coverage and normal tissue sparing are possible. Our Markov model is flexible and has tunable parameters to adjust model performance to meet a range of criteria. Such a model may support the development of an adaptive paradigm for radiation therapy of cervical cancer.

  8. Rapid Evolution of Coral Proteins Responsible for Interaction with the Environment

    SciTech Connect (OSTI)

    Voolstra, Christian R.; Sunagawa, Shinichi; Matz, Mikhail V.; Bayer, Till; Aranda, Manuel; Buschiazzo, Emmanuel; DeSalvo, Michael K.; Lindquist, Erika; Szmant, Alina M.; Coffroth, Mary Alice; Medina, Monica

    2011-01-31

    Background: Corals worldwide are in decline due to climate change effects (e.g., rising seawater temperatures), pollution, and exploitation. The ability of corals to cope with these stressors in the long run depends on the evolvability of the underlying genetic networks and proteins, which remain largely unknown. A genome-wide scan for positively selected genes between related coral species can help to narrow down the search space considerably. Methodology/Principal Findings: We screened a set of 2,604 putative orthologs from EST-based sequence datasets of the coral species Acropora millepora and Acropora palmata to determine the fraction and identity of proteins that may experience adaptive evolution. 7percent of the orthologs show elevated rates of evolution. Taxonomically-restricted (i.e. lineagespecific) genes show a positive selection signature more frequently than genes that are found across many animal phyla. The class of proteins that displayed elevated evolutionary rates was significantly enriched for proteins involved in immunity and defense, reproduction, and sensory perception. We also found elevated rates of evolution in several other functional groups such as management of membrane vesicles, transmembrane transport of ions and organic molecules, cell adhesion, and oxidative stress response. Proteins in these processes might be related to the endosymbiotic relationship corals maintain with dinoflagellates in the genus Symbiodinium. Conclusion/Relevance: This study provides a birds-eye view of the processes potentially underlying coral adaptation, which will serve as a foundation for future work to elucidate the rates, patterns, and mechanisms of corals? evolutionary response to global climate change.

  9. INNER HELIOSPHERIC FLUX ROPE EVOLUTION VIA IMAGING OF CORONAL MASS EJECTIONS

    SciTech Connect (OSTI)

    Howard, T. A.; DeForest, C. E.

    2012-02-10

    Understanding the evolution of flux ropes in coronal mass ejections (CMEs) is of importance both to the scientific and technological communities. Scientifically their presence is critical to models describing CME launch and they likely play a role in CME evolution. Technologically they are the major contributor to severe geomagnetic storms. Using a new processing technique on the STEREO/SECCHI heliospheric imaging data, we have tracked a magnetic flux rope observed by the Wind spacecraft in December 2008 to its origins observed by coronagraphs. We thereby establish that the cavity in the classic three-part coronagraph CME is the feature that becomes the magnetic cloud. This implies that the bright material ahead of the cavity is piled-up coronal or solar wind material. We track the evolution of the cavity en-route and find that its structure transforms from concave inward (curving away from the Sun) to concave outward (toward the Sun) around 0.065 AU from the Sun. The pileup was tracked and its leading edge remained concave inward throughout its journey. Two other CMEs in January 2009 are also inspected and a similar cavity is observed in each, suggesting that they too each contained a flux rope. The results presented here are the first direct observation, through continuous tracking, associating a particular flux rope observed in situ with the same flux rope before ejection from the corona. We speculate that detailed heliospheric imagery of CMEs may lead to a means by which flux ropes can be identified remotely in the heliosphere.

  10. Dynamic Evolution of Cement Composition and Transport Properties under Conditions Relevant to Geological Carbon Sequestration

    SciTech Connect (OSTI)

    Brunet, Jean-Patrick Leopold; Li, Li; Karpyn, Zuleima T.; Strazisar, Brian; Bromhal Grant

    2013-08-01

    Assessing the possibility of CO{sub 2} leakage is one of the major challenges for geological carbon sequestration. Injected CO{sub 2} can react with wellbore cement, which can potentially change cement composition and transport properties. In this work, we develop a reactive transport model based on experimental observations to understand and predict the property evolution of cement in direct contact with CO{sub 2}-saturated brine under diffusion-controlled conditions. The model reproduced the observed zones of portlandite depletion and calcite formation. Cement alteration is initially fast and slows down at later times. This work also quantified the role of initial cement properties, in particular the ratio of the initial portlandite content to porosity (defined here as ?), in determining the evolution of cement properties. Portlandite-rich cement with large ? values results in a localized sharp reactive diffusive front characterized by calcite precipitation, leading to significant porosity reduction, which eventually clogs the pore space and prevents further acid penetration. Severe degradation occurs at the cementbrine interface with large ? values. This alteration increases effective permeability by orders of magnitude for fluids that preferentially flow through the degraded zone. The significant porosity decrease in the calcite zone also leads to orders of magnitude decrease in effective permeability, where fluids flow through the low-permeability calcite zone. The developed reactive transport model provides a valuable tool to link cementCO{sub 2} reactions with the evolution of porosity and permeability. It can be used to quantify and predict long-term wellbore cement behavior and can facilitate the risk assessment associated with geological CO{sub 2} sequestration.

  11. Observation of spectral evolution during the formation of a Ni2 kondo molecule

    SciTech Connect (OSTI)

    Madhavan, V.; Jamneala, T.; Nagaoka, K.; Chen, W.; Li, Je-Luen; Louie, Steven G.; Crommie, M.F.

    2002-04-15

    We have used atomic manipulation and scanning tunneling spectroscopy to study the evolution in electronic properties that occurs as two Ni atoms are merged into a single magnetic molecule on Au(111). We observe energetic shifting of molecular d-orbitals and a strong decrease in the molecular Kondo temperature as Ni-Ni separation is reduced to 3.4+ or -0.3Angstroms. These results are qualitatively explained by a combination of spin-1/2-s-d model and density-functional calculations.

  12. Structural evolution in Ti-Cu-Ni metallic glasses during heating

    SciTech Connect (OSTI)

    Gargarella, P.; Pauly, S.; Stoica, M.; Khn, U.; Vaughan, G.; Afonso, C. R. M.; Eckert, J.

    2015-01-01

    The structural evolution of Ti{sub 50}Cu{sub 43}Ni{sub 7} and Ti{sub 55}Cu{sub 35}Ni{sub 10} metallic glasses during heating was investigated by in-situ synchrotron X-ray diffraction. The width of the most intense diffraction maximum of the glassy phase decreases slightly during relaxation below the glass transition temperature. Significant structural changes only occur above the glass transition manifesting in a change in the respective peak positions. At even higher temperatures, nanocrystals of the shape memory B2-Ti(Cu,Ni) phase precipitate, and their small size hampers the occurrence of a martensitic transformation.

  13. Evolution of small-space plasma in a microthruster designed for small spacecraft

    SciTech Connect (OSTI)

    Farahat, A. M., E-mail: farahata@kfupm.edu.sa [King Fahd University of Petroleum and Minerals, College of Applied and Supporting Studies (Saudi Arabia); Ramadan, E. [King Fahd University of Petroleum and Minerals, Department of Information and Computer Science (Saudi Arabia)

    2014-12-15

    Plasma and gas particle dynamics in atmospheric pressure helium-filled small volume are investigated using a two-dimensional model. The model includes the conservation equations for the plasma and the neutral gas. In this paper, results are presented from simulation of the interaction between gas and charged species, which in turn causes heating and thrust generation for this microengine. Gas heating and neutral depletion initiations are observed, highlighting the close interaction between gas and charged species in governing the evolution of the small-space plasma inside a microthruster designed for microsatellites.

  14. Environment-Assisted Speed-up of the Field Evolution in Cavity Quantum Electrodynamics

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Cimmarusti, A. D.; Yan, Z.; Patterson, B. D.; Corcos, L. P.; Orozco, L. A.; Deffner, S.

    2015-06-11

    We measure the quantum speed of the state evolution of the field in a weakly-driven optical cavity QED system. To this end, the mode of the electromagnetic field is considered as a quantum system of interest with a preferential coupling to a tunable environment: the atoms. By controlling the environment, i.e., changing the number of atoms coupled to the optical cavity mode, an environment assisted speed-up is realized: the quantum speed of the state re-population in the optical cavity increases with the coupling strength between the optical cavity mode and this non-Markovian environment (the number of atoms).

  15. Time evolution analysis of the electron distribution in Thomson/Compton back-scattering

    SciTech Connect (OSTI)

    Petrillo, V.; Bacci, A.; Curatolo, C.; Maroli, C.; Serafini, L.; Rossi, A. R.

    2013-07-28

    We present the time evolution of the energy distribution of a relativistic electron beam after the Compton back-scattering with a counter-propagating laser field, performed in the framework of the Quantum Electrodynamics, by means of the code CAIN. As the correct angular distribution of the spontaneous emission is accounted, the main effect is the formation of few stripes, followed by the diffusion of the more energetic particles toward lower values in the longitudinal phase space. The Chapman-Kolmogorov master equation gives results in striking agreement with the numerical ones. An experiment on the Thomson source at SPARC-LAB is proposed.

  16. Assembly and Evolution of Complex Fe-S Clusters as Revealed by X-ray

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Crystallography Assembly and Evolution of Complex Fe-S Clusters as Revealed by X-ray Crystallography Complex Fe-S cluster-containing enzymes are ubiquitous in nature where they are involved in a number of fundamental reactions for life including carbon dioxide fixation, nitrogen fixation, and hydrogen metabolism. One of the more complex and unusual biological clusters is found in the [FeFe]-hydrogenase. The active-site H-cluster in these enzymes has a [4Fe-4S] subcluster bridged via a

  17. Evolution of Wholesale Electricity Market Design with Increasing Levels of Renewable Generation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Evolution of Wholesale Electricity Market Design with Increasing Levels of Renewable Generation E. Ela, 1 M. Milligan, 1 A. Bloom, 1 A. Botterud, 2 A. Townsend, 1 and T. Levin 2 1 National Renewable Energy Laboratory 2 Argonne National Laboratory Technical Report NREL/TP-5D00-61765 September 2014 NREL is a national laboratory of the U.S. Department of Energy Office of Energy Efficiency & Renewable Energy Operated by the Alliance for Sustainable Energy, LLC This report is available at no cost

  18. Damage evolution and residual stresses in plasma-sprayed zirconia thermal barrier coatings.

    SciTech Connect (OSTI)

    Singh, J. P.

    1999-02-03

    Air-plasma-sprayed zirconia thermal barrier coatings were subjected to thermal cycling and residual stress evolution in thermally grown oxide scale was studied by micro- and macro-ruby fluorescence spectroscopy. The macro approach reveals that compressive stress in the oxide scale increases with increasing number of thermal cycles (and thus increasing scale thickness), reaching a value of 1.8 GPa at a scale thickness of 3-4 {micro}m (80 cycles). Micro-ruby fluorescence spectroscopy indicates that protrusions of the zirconia top coat into the bond coat act as localized areas of high stress concentration, leading to damage initiation during thermal cycling.

  19. Microstructure evolution of hot-deformed Nd-Fe-B anisotropic magnets

    SciTech Connect (OSTI)

    Liu, J. Hono, K.; Sepehri-Amin, H.; Ohkubo, T.; Hioki, K.; Hattori, A.

    2014-05-07

    The microstructural evolution of hot-deformed Nd-Fe-B magnets in each stage of hot-deformation process was studied using transmission electron microscopy and three dimensional atom probe (3DAP). The anisotropic growth of initially isotropic grains in rapidly solidified alloy occurs by annealing without pressing. 3DAP analyses showed a higher concentration of rare-earth elements in the intergranular phase parallel to the flat surface of platelet shaped Nd{sub 2}Fe{sub 14}B grains compared to that in the intergranular phase at the side of platelets.

  20. Design Insights for Tuning the Electrocatalytic Activity of Perovskite Oxides for the Oxygen Evolution Reaction

    SciTech Connect (OSTI)

    Malkhandi, S; Trinh, P; Manohar, AK; Manivannan, A; Balasubramanian, M; Prakash, GKS; Narayanan, SR

    2015-04-16

    Rechargeable metal-air batteries and water electrolyzers based on aqueous alkaline electrolytes hold the potential to be sustainable solutions to address the challenge of storing large amounts of electrical energy generated from solar and wind resources. For these batteries and electrolyzers to be economically viable, it is essential to have efficient, durable, and inexpensive electrocatalysts for the oxygen evolution reaction. In this article, we describe new insights for predicting and tuning the activity of inexpensive transition metal oxides for designing efficient and inexpensive electrocatalysts. We have focused on understanding the factors determining the electrocatalytic activity for oxygen evolution in a strong alkaline medium. To this end, we have conducted a systematic investigation of nanophase calcium-doped lanthanum cobalt manganese oxide, an example of a mixed metal oxide that can be tuned for its electrocatalytic activity by varying the transition metal composition. Using X-ray absorption spectroscopy (XANES), X-ray photoelectron spectroscopy (XPS), electrochemical polarization experiments, and analysis of mechanisms, we have identified the key determinants of electrocatalytic activity. We have found that the Tafel slopes are determined by the oxidation states and the bond energy of the surface intermediates of Mn-OH and Co-OH bonds while the catalytic activity increased with the average d-electron occupancy of the sigma* orbital of the M-OH bond. We anticipate that such understanding will be very useful in predicting the behavior of other transition metal oxide catalysts.

  1. Deformation Behavior and TExture Evolution of Steel Alloys under Axial-Torsional Loading

    SciTech Connect (OSTI)

    Siriruk, A.; Kant, M.; Penumadu, D.; Garlea, E.; Vogel, S.

    2011-06-01

    Using hollow cylinder samples with suitable geometry obtained from round bar stock, the deformation behavior of bcc Fe based 12L14 steel alloy is evaluated under multi-axial conditions. A stacked strain gage rosette and extensometer mounted on the cylindrical surface at the mid height of the specimen provided strain tensor as a function of applied stress for pure tensile and torsion tests prior to yielding. This study examines elastic and yield behavior and effects of these with respect to texture evolution. Hollow cylinder specimen geometry (tubes) with small wall thickness and relatively (to its thickness) large inner diameter is used. The variation of observed yield surface in deviatoric plane and the effect on mode of deformation (tension versus torsion versus its combination) on stress-strain behavior is discussed. Bulk texture was studied using neutron time-of-flight diffractometer at High-Pressure-Preferred Orientation (HIPPO) - Los Alamos Neutron Science Center (LANSCE) instrument and the evolution of texture and related anisotropy for pure tension versus torsion are also included.

  2. Cold-Air-Pool Structure and Evolution in a Mountain Basin: Peter Sinks, Utah

    SciTech Connect (OSTI)

    Clements, Craig B.; Whiteman, Charles D.; Horel, John D.

    2003-06-01

    The evolution of potential temperature and wind structure during the buildup of nocturnal cold-air pools was investigated during clear, dry, September nights in Utah's Peter Sinks basin, a 1-km-diameter limestone sinkhole that holds the Utah minimum temperature record of -56 C. The evolution of cold-pool characteristics depended on the strength of prevailing flows above the basin. On an undisturbed day, a 30 C diurnal temperature range and a strong nocturnal potential temperature inversion (22 K in 100 m) were observed in the basin. Initially, downslope flows formed on the basin sidewalls. As a very strong potential temperature jump (17 K) developed at the top of the cold pool, however, the winds died within the basin and over the sidewalls. A persistent turbulent sublayer formed below the jump. Turbulent sensible heat flux on the basin floor became negligible shortly after sunset while the basin atmosphere continued to cool. Temperatures over the slopes, except for a 1 to 2-m-deep layer, became warmer than over the basin center at the same altitude. Cooling rates for the entire basin near sunset were comparable to the 90 W m-2 rate of loss of net longwave radiation at the basin floor, but these rates decreased to only a few watts per square meter by sunrise. This paper compares the observed cold-pool buildup in basins with inversion buildup in valleys.

  3. Weak decay processes in pre-supernova core evolution within the gross theory

    SciTech Connect (OSTI)

    Ferreira, R. C.; Dimarco, A. J.; Samana, A. R.; Barbero, C. A.

    2014-03-20

    The beta decay and electron capture rates are of fundamental importance in the evolution of massive stars in a pre-supernova core. The beta decay process gives its contribution by emitting electrons in the plasma of the stellar core, thereby increasing pressure, which in turn increases the temperature. From the other side, the electron capture removes free electrons from the plasma of the star core contributing to the reduction of pressure and temperature. In this work we calculate the beta decay and electron capture rates in stellar conditions for 63 nuclei of relevance in the pre-supernova stage, employing Gross Theory as the nuclear model. We use the abundances calculated with the Saha equations in the hypothesis of nuclear statistical equilibrium to evaluate the time derivative of the fraction of electrons. Our results are compared with other evaluations available in the literature. They have shown to be one order less or equal than the calculated within other models. Our results indicate that these differences may influence the evolution of the star in the later stages of pre-supernova.

  4. Morphological and kinematic evolution of three interacting coronal mass ejections of 2011 February 13-15

    SciTech Connect (OSTI)

    Mishra, Wageesh; Srivastava, Nandita

    2014-10-10

    During 2011 February 13-15, three Earth-directed coronal mass ejections (CMEs) launched in succession were recorded as limb CMEs by STEREO/SECCHI coronagraphs (COR). These CMEs provided an opportunity to study their geometrical and kinematic evolution from multiple vantage points. In this paper, we examine the differences in geometrical evolution of slow and fast CMEs during their propagation in the heliosphere. We also study their interaction and collision using STEREO/SECCHI COR and Heliospheric Imager (HI) observations. We have found evidence of interaction and collision between the CMEs of February 15 and 14 in the COR2 and HI1 field of view (FOV), respectively, while the CME of February 14 caught up with the CME of February 13 in the HI2 FOV. By estimating the true mass of these CMEs and using their pre- and post-collision dynamics, the momentum and energy exchange between them during the collision phase are studied. We classify the nature of the observed collision between the CMEs of February 14 and 15 as inelastic, reaching close to the elastic regime. Relating imaging observations with in situ WIND measurements at L1, we find that the CMEs move adjacent to each other after their collision in the heliosphere and are recognized as distinct structures in in situ observations. Our results highlight the significance of HI observations in studying CME-CME collision for the purpose of improved space weather forecasting.

  5. KINEMATIC PROPERTIES AS PROBES OF THE EVOLUTION OF DWARF GALAXIES IN THE VIRGO CLUSTER

    SciTech Connect (OSTI)

    Toloba, E.; Gorgas, J.; De Paz, A. Gil; Boselli, A.; Peletier, R. F.; Yildiz, U.; Cenarro, A. J.; Gadotti, D. A.; Pedraz, S.

    2009-12-10

    We present new observational results on the kinematical, morphological, and stellar population properties of a sample of 21 dEs located both in the Virgo Cluster and in the field, which show that 52% of the dEs (1) are rotationally supported, (2) exhibit structural signs of typical rotating systems such as disks, bars, or spiral arms, (3) are younger (approx3 Gyr) than non-rotating dEs, and (4) are preferentially located either in the outskirts of Virgo or in the field. This evidence is consistent with the idea that rotationally supported dwarfs are late-type spirals or irregulars that recently entered the cluster and lost their gas through a ram pressure stripping event, quenching their star formation and becoming dEs through passive evolution. We also find that all, but one, galaxies without photometric hints for hosting disks are pressure supported and are all situated in the inner regions of the cluster. This suggests a different evolution from the rotationally supported systems. Three different scenarios for these non-rotating galaxies are discussed (in situ formation, harassment, and ram pressure stripping).

  6. Charge state evolution in the solar wind. III. Model comparison with observations

    SciTech Connect (OSTI)

    Landi, E.; Oran, R.; Lepri, S. T.; Zurbuchen, T. H.; Fisk, L. A.; Van der Holst, B.

    2014-08-01

    We test three theoretical models of the fast solar wind with a set of remote sensing observations and in-situ measurements taken during the minimum of solar cycle 23. First, the model electron density and temperature are compared to SOHO/SUMER spectroscopic measurements. Second, the model electron density, temperature, and wind speed are used to predict the charge state evolution of the wind plasma from the source regions to the freeze-in point. Frozen-in charge states are compared with Ulysses/SWICS measurements at 1 AU, while charge states close to the Sun are combined with the CHIANTI spectral code to calculate the intensities of selected spectral lines, to be compared with SOHO/SUMER observations in the north polar coronal hole. We find that none of the theoretical models are able to completely reproduce all observations; namely, all of them underestimate the charge state distribution of the solar wind everywhere, although the levels of disagreement vary from model to model. We discuss possible causes of the disagreement, namely, uncertainties in the calculation of the charge state evolution and of line intensities, in the atomic data, and in the assumptions on the wind plasma conditions. Last, we discuss the scenario where the wind is accelerated from a region located in the solar corona rather than in the chromosphere as assumed in the three theoretical models, and find that a wind originating from the corona is in much closer agreement with observations.

  7. Bioinspired Molecular Co-Catalysts Bonded to a Silicon Photocathode for Solar Hydrogen Evolution

    SciTech Connect (OSTI)

    Hou, Yidong

    2011-11-08

    The production of fuels from sunlight represents one of the main challenges in the development of a sustainable energy system. Hydrogen is the simplest fuel to produce and although platinum and other noble metals are efficient catalysts for photoelectrochemical hydrogen evolution earth-abundant alternatives are needed for large-scale use. We show that bioinspired molecular clusters based on molybdenum and sulphur evolve hydrogen at rates comparable to that of platinum. The incomplete cubane-like clusters (Mo{sub 3}S{sub 4}) efficiently catalyse the evolution of hydrogen when coupled to a p-type Si semiconductor that harvests red photons in the solar spectrum. The current densities at the reversible potential match the requirement of a photoelectrochemical hydrogen production system with a solar-to-hydrogen efficiency in excess of 10% (ref. 16). The experimental observations are supported by density functional theory calculations of the Mo{sub 3}S{sub 4} clusters adsorbed on the hydrogen-terminated Si(100) surface, providing insights into the nature of the active site.

  8. Evolution, Interaction, and Intrinsic Properties of Dislocations in Intermetallics: Anisotropic 3D Dislocation Dynamics Approach

    SciTech Connect (OSTI)

    Qian Chen

    2008-08-18

    The generation, motion, and interaction of dislocations play key roles during the plastic deformation process of crystalline solids. 3D Dislocation Dynamics has been employed as a mesoscale simulation algorithm to investigate the collective and cooperative behavior of dislocations. Most current research on 3D Dislocation Dynamics is based on the solutions available in the framework of classical isotropic elasticity. However, due to some degree of elastic anisotropy in almost all crystalline solids, it is very necessary to extend 3D Dislocation Dynamics into anisotropic elasticity. In this study, first, the details of efficient and accurate incorporation of the fully anisotropic elasticity into 3D discrete Dislocation Dynamics by numerically evaluating the derivatives of Green's functions are described. Then the intrinsic properties of perfect dislocations, including their stability, their core properties and disassociation characteristics, in newly discovered rare earth-based intermetallics and in conventional intermetallics are investigated, within the framework of fully anisotropic elasticity supplemented with the atomistic information obtained from the ab initio calculations. Moreover, the evolution and interaction of dislocations in these intermetallics as well as the role of solute segregation are presented by utilizing fully anisotropic 3D dislocation dynamics. The results from this work clearly indicate the role and the importance of elastic anisotropy on the evolution of dislocation microstructures, the overall ductility and the hardening behavior in these systems.

  9. Landau electron in a rotating environment: A general factorization of time evolution

    SciTech Connect (OSTI)

    Chee, J.

    2012-11-15

    For the Landau problem with a rotating magnetic field and a confining potential in the (changing) direction of the field, we derive a general factorization of the time evolution operator that includes the adiabatic factorization as a special case. The confining potential is assumed to be of a general form and it can correspond to nonlinear Heisenberg equations of motion. The rotation operator associated with the solid angle Berry phase is used to transform the problem to a rotating reference frame. In the rotating reference frame, we derive a natural factorization of the time evolution operator by recognizing the crucial role played by a gauge transformation. The major complexity of the problem arises from the coupling between motion in the direction of the magnetic field and motion perpendicular to the field. In the factorization, this complexity is consolidated into a single operator which approaches the identity operator when the potential confines the particle sufficiently close to a rotating plane perpendicular to the magnetic field. The structure of this operator is clarified by deriving an expression for its generating Hamiltonian. The adiabatic limit and non-adiabatic effects follow as consequences of the general factorization which are clarified using the magnetic translation concept.

  10. Kinetic Effects on the Stability Properties of Field-reversed Configurations: II. Nonlinear Evolution

    SciTech Connect (OSTI)

    Elena V. Belova; Ronald C. Davidson; Hantao Ji; Masaaki Yamada

    2003-11-25

    Results of three-dimensional hybrid simulations of the field-reversed configuration (FRC) are presented. Emphasis of this work is on the nonlinear evolution of magnetohydrodynamic (MHD) instabilities in kinetic FRCs. A wide range of ''bar s'' values is considered, where the ''bar s'' is the FRC kinetic parameter, which measures the number of ion gyroradii in the configuration. The linear and nonlinear stability of MHD modes with toroidal mode numbers n greater than or equal to 1 is investigated, including the effects of ion rotation, finite electron pressure, and weak toroidal field. Low-''bar s'' simulations show nonlinear saturation of the n = 1 tilt mode. The n greater than or equal to 2 rotational modes are observed to grow during the nonlinear phase of the tilt instability due to ion spin-up in the toroidal direction. Large-''bar s'' simulations show no saturation of the tilt mode, and there is a slow nonlinear evolution of the instability after the initial fast linear growth. Overall, the hybrid simulations demonstrate the importance of nonlinear effects, which are responsible for the saturation of instabilities in low-''bar s'' configurations, and also for the increase in FRC life-time compared to MHD models in high-''bar s'' configurations.

  11. TIME EVOLUTION OF FLARES IN GRB 130925A: JET PRECESSION IN A BLACK HOLE ACCRETION SYSTEM

    SciTech Connect (OSTI)

    Hou, Shu-Jin; Liu, Tong; Gu, Wei-Min; Sun, Mou-Yuan; Lu, Ju-Fu [Department of Astronomy and Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen, Fujian 361005 (China); Lin, Da-Bin [Department of Physics and GXU-NAOC Center for Astrophysics and Space Sciences, Guangxi University, Nanning, Guangxi 530004 (China); Wu, Xue-Feng, E-mail: tongliu@xmu.edu.cn [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China)

    2014-01-20

    GRB 130925A, composed of three gamma-ray emission episodes and a series of orderly flares, has been detected by Swift, Fermi, Konus-Wind, and INTEGRAL. If the third weakest gamma-ray episode can be considered a giant flare, we find that after the second gamma-ray episode observed by INTEGRAL located at about 2000s, a positive relation exists between the time intervals of the adjacent flares and the time since the episode. We suggest that the second gamma-ray episode and its flares originate from the resumption of the accretion process due to the fragments from the collapsar falling back; such a relation may be related to a hyperaccretion disk around a precessed black hole (BH). We propose that the origin and time evolution of the flares, and the approximately symmetrical temporal structure and spectral evolution of the single flare can be explained well by a jet precession model. In addition, the mass and spin of the BH can be constrained, which indicates a stellar-mass, fast-rotating BH located in the center of GRB 130925A.

  12. X-ray enhancement and long-term evolution of swift J1822.31606

    SciTech Connect (OSTI)

    Benli, Onur; al??kan, ?.; Ertan, .; Alpar, M. A. [Sabanc? University, Orhanl?-Tuzla, ?stanbul 34956 (Turkey); Trmper, J. E. [Max-Planck-Institut fr extraterrestrische Physik, Geissenbachstrasse, 85740 Garching bei Mnchen (Germany); Kylafis, N. D., E-mail: onurbenli@sabanciuniv.edu [Physics Department and Institute of Theoretical and Computational Physics, University of Crete, 71003 Heraklion, Crete (Greece)

    2013-12-01

    We investigate the X-ray enhancement and the long-term evolution of the recently discovered second 'low-B magnetar' Swift J1822.3-1606 in the frame of the fallback disk model. During a soft gamma burst episode, the inner disk matter is pushed back to larger radii, forming a density gradient at the inner disk. Subsequent relaxation of the inner disk could account for the observed X-ray enhancement light curve of Swift J1822.3-1606. We obtain model fits to the X-ray data with basic disk parameters similar to those employed to explain the X-ray outburst light curves of other anomalous X-ray pulsars and soft gamma repeaters. The long period (8.4 s) of the neutron star can be reached by the effect of the disk torques in the long-term accretion phase ((1-3) 10{sup 5} yr). The currently ongoing X-ray enhancement could be due to a transient accretion epoch, or the source could still be in the accretion phase in quiescence. Considering these different possibilities, we determine the model curves that could represent the long-term rotational and the X-ray luminosity evolution of Swift J1822.3-1606, which constrain the strength of the magnetic dipole field to the range of (1-2) 10{sup 12} G on the surface of the neutron star.

  13. Stellar Evolution/Supernova Research Data Archives from the SciDAC Computational Astrophysics Consortium

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Woosley, Stan [University of California, Santa Cruz

    Theoretical high-energy astrophysics studies the most violent explosions in the universe - supernovae (the massive explosions of dying stars) and gamma ray bursts (mysterious blasts of intense radiation). The evolution of massive stars and their explosion as supernovae and/or gamma ray bursts describes how the "heavy" elements needed for life, such as oxygen and iron, are forged (nucleosynthesis) and ejected to later form new stars and planets. The Computational Astrophysics Consortium's project includes a Science Application Partnership on Adaptive Algorithms that develops software involved. The principal science topics are - in order of priority - 1) models for Type Ia supernovae, 2) radiation transport, spectrum formation, and nucleosynthesis in model supernovae of all types; 3) the observational implications of these results for experiments in which DOE has an interest, especially the Joint Dark Energy Mission, Supernova/Acceleration Probe (SNAP) satellite observatory, the Large Synoptic Survey Telescope (LSST), and ground based supernova searches; 4) core collapse supernovae; 5) gamma-ray bursts; 6) hypernovae from Population III stars; and 7) x-ray bursts. Models of these phenomena share a common need for nuclear reactions and radiation transport coupled to multi-dimensional fluid flow. The team has developed and used supernovae simulation codes to study Type 1A and core-collapse supernovae. (Taken from http://www.scidac.gov/physics/grb.html) The Stellar Evolution Data Archives contains more than 225 Pre-SN models that can be freely accessed.

  14. Temporal evolution characteristics of an annular-mode gliding arc discharge in a vortex flow

    SciTech Connect (OSTI)

    Zhao, Tian-Liang; Liu, Jing-Lin; Li, Xiao-Song; Liu, Jin-Bao; Song, Yuan-Hong; Xu, Yong; Zhu, Ai-Min

    2014-05-15

    An annular-mode gliding arc discharge powered by a 50?Hz alternating current (ac) supply was studied in a vortex flow of dry and humid air. Its temporal evolution characteristics were investigated by electrical measurement, temporally resolved imaging, and temporally resolved optical emission spectroscopic measurements. Three discharge stages of arc-ignition, arc-gliding, and arc-extinction were clearly observed in each half-cycle of the discharge. During the arc-gliding stage, the intensity of light emission from the arc root at the cathode was remarkably higher than that at other areas. The spectral intensity of N{sub 2}(C{sup 3}?{sub u}?B{sup 3}?{sub g}) during the arc-ignition stage was much higher than that during the arc-gliding stage, which was contrary to the temporal evolutions of spectral intensities for N{sub 2}{sup +}(B{sup 2}?{sub u}{sup +}?X{sup 2}?{sub g}{sup +}) and OH(A{sup 2}?{sup +}?X{sup 2}?{sub i}). Temporally resolved vibrational and rotational temperatures of N{sub 2} were also presented and decreased with increasing the water vapor content.

  15. THMC Modeling of EGS Reservoirs -- Continuum through Discontinuum Representations. Capturing Reservoir Stimulation, Evolution and Induced Seismicity

    SciTech Connect (OSTI)

    Elsworth, Derek; Izadi, Ghazal; Gan, Quan; Fang, Yi; Taron, Josh; Sonnenthal, Eric

    2015-07-28

    This work has investigated the roles of effective stress induced by changes in fluid pressure, temperature and chemistry in contributing to the evolution of permeability and induced seismicity in geothermal reservoirs. This work has developed continuum models [1] to represent the progress or seismicity during both stimulation [2] and production [3]. These methods have been used to resolve anomalous observations of induced seismicity at the Newberry Volcano demonstration project [4] through the application of modeling and experimentation. Later work then focuses on the occurrence of late stage seismicity induced by thermal stresses [5] including the codifying of the timing and severity of such responses [6]. Furthermore, mechanistic linkages between observed seismicity and the evolution of permeability have been developed using data from the Newberry project [7] and benchmarked against field injection experiments. Finally, discontinuum models [8] incorporating the roles of discrete fracture networks have been applied to represent stimulation and then thermal recovery for new arrangements of geothermal wells incorporating the development of flow manifolds [9] in order to increase thermal output and longevity in EGS systems.

  16. Radial evolution of the intermittency of density fluctuations in the fast solar wind

    SciTech Connect (OSTI)

    Bruno, R.; D'Amicis, R.; Telloni, D.; Primavera, L.; Sorriso-Valvo, L.; Carbone, V.; Malara, F.; Veltri, P.

    2014-05-01

    We study the radial evolution of the intermittency of density fluctuations in the fast solar wind. The study is performed by analyzing the plasma density measurements provided by Helios 2 in the inner heliosphere between 0.3 and 0.9 AU. The analysis is carried out by means of a complete set of diagnostic tools, including the flatness factor at different timescales to estimate intermittency, the Kolmogorov-Smirnov test to estimate the degree of intermittency, and the Fourier transform to estimate the power spectral densities of these fluctuations. Density fluctuations within the fast wind are rather intermittent and their level of intermittency, together with the amplitude of intermittent events, decreases with the distance from the Sun, at odds with the intermittency of both magnetic field and all other plasma parameters. Furthermore, the intermittent events are strongly correlated, exhibiting temporal clustering. This indicates that the mechanism underlying their generation departs from a time-varying Poisson process. A remarkable, qualitative similarity with the behavior of plasma density fluctuations obtained from a numerical study of the nonlinear evolution of parametric instability in the solar wind supports the idea that this mechanism has an important role in governing density fluctuations in the inner heliosphere.

  17. Structural evolution of epitaxial SrCoOx films near topotactic phase transition

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Jeen, Hyoung Jeen; Lee, Ho Nyung

    2015-12-18

    Control of oxygen stoichiometry in complex oxides via topotactic phase transition is an interesting avenue to not only modifying the physical properties, but utilizing in many energy technologies, such as energy storage and catalysts. However, detailed structural evolution in the close proximity of the topotactic phase transition in multivalent oxides has not been much studied. In this work, we used strontium cobaltites (SrCoOx) epitaxially grown by pulsed laser epitaxy (PLE) as a model system to study the oxidation-driven evolution of the structure, electronic, and magnetic properties. We grew coherently strained SrCoO2.5thin films and performed post-annealing at various temperatures for topotacticmore » conversion into the perovskite phase (SrCoO3-δ). We clearly observed significant changes in electronic transport, magnetism, and microstructure near the critical temperature for the topotactic transformation from the brownmillerite to the perovskite phase. Furthermore, the overall crystallinity was well maintained without much structural degradation, indicating that topotactic phase control can be a useful tool to control the physical properties repeatedly via redox reactions.« less

  18. Accelerating Markov chain Monte Carlo simulation by differential evolution with self-adaptive randomized subspace sampling

    SciTech Connect (OSTI)

    Vrugt, Jasper A; Hyman, James M; Robinson, Bruce A; Higdon, Dave; Ter Braak, Cajo J F; Diks, Cees G H

    2008-01-01

    Markov chain Monte Carlo (MCMC) methods have found widespread use in many fields of study to estimate the average properties of complex systems, and for posterior inference in a Bayesian framework. Existing theory and experiments prove convergence of well constructed MCMC schemes to the appropriate limiting distribution under a variety of different conditions. In practice, however this convergence is often observed to be disturbingly slow. This is frequently caused by an inappropriate selection of the proposal distribution used to generate trial moves in the Markov Chain. Here we show that significant improvements to the efficiency of MCMC simulation can be made by using a self-adaptive Differential Evolution learning strategy within a population-based evolutionary framework. This scheme, entitled DiffeRential Evolution Adaptive Metropolis or DREAM, runs multiple different chains simultaneously for global exploration, and automatically tunes the scale and orientation of the proposal distribution in randomized subspaces during the search. Ergodicity of the algorithm is proved, and various examples involving nonlinearity, high-dimensionality, and multimodality show that DREAM is generally superior to other adaptive MCMC sampling approaches. The DREAM scheme significantly enhances the applicability of MCMC simulation to complex, multi-modal search problems.

  19. ENTHALPY-BASED THERMAL EVOLUTION OF LOOPS. II. IMPROVEMENTS TO THE MODEL

    SciTech Connect (OSTI)

    Cargill, P. J.; Bradshaw, S. J.; Klimchuk, J. A.

    2012-06-20

    This paper develops the zero-dimensional (0D) hydrodynamic coronal loop model 'Enthalpy-based Thermal Evolution of Loops' (EBTEL) proposed by Klimchuk et al., which studies the plasma response to evolving coronal heating, especially impulsive heating events. The basis of EBTEL is the modeling of mass exchange between the corona and transition region (TR) and chromosphere in response to heating variations, with the key parameter being the ratio of the TR to coronal radiation. We develop new models for this parameter that now include gravitational stratification and a physically motivated approach to radiative cooling. A number of examples are presented, including nanoflares in short and long loops, and a small flare. The new features in EBTEL are important for accurate tracking of, in particular, the density. The 0D results are compared to a 1D hydro code (Hydrad) with generally good agreement. EBTEL is suitable for general use as a tool for (1) quick-look results of loop evolution in response to a given heating function, (2) extensive parameter surveys, and (3) situations where the modeling of hundreds or thousands of elemental loops is needed. A single run takes a few seconds on a contemporary laptop.

  20. Horizontal gene transfer and the evolution of transcriptionalregulation in Escherichia coli

    SciTech Connect (OSTI)

    Price, Morgan N.; Dehal, Paramvir S.; Arkin, Adam P.

    2007-12-20

    Background: Most bacterial genes were acquired by horizontalgene transfer from other bacteria instead of being inherited bycontinuous vertical descent from an ancient ancestor}. To understand howthe regulation of these {acquired} genes evolved, we examined theevolutionary histories of transcription factors and of regulatoryinteractions from the model bacterium Escherichia coli K12. Results:Although most transcription factors have paralogs, these usually arose byhorizontal gene transfer rather than by duplication within the E. colilineage, as previously believed. In general, most neighbor regulators --regulators that are adjacent to genes that they regulate -- were acquiredby horizontal gene transfer, while most global regulators evolvedvertically within the gamma-Proteobacteria. Neighbor regulators wereoften acquired together with the adjacent operon that they regulate, sothe proximity might be maintained by repeated transfers (like "selfishoperons"). Many of the as-yet-uncharacterized (putative) regulators havealso been acquired together with adjacent genes, so we predict that theseare neighbor regulators as well. When we analyzed the histories ofregulatory interactions, we found that the evolution of regulation byduplication was rare, and surprisingly, many of the regulatoryinteractions that are shared between paralogs result from convergentevolution. Another surprise was that horizontally transferred genes aremore likely than other genes to be regulated by multiple regulators, andmost of this complex regulation probably evolved after the transfer.Conclusions: Our results highlight the rapid evolution of niche-specificgene regulation in bacteria.

  1. Forward dijets in high-energy collisions: Evolution of QCD n-point functions beyond the dipole approximation

    SciTech Connect (OSTI)

    Dumitru, Adrian; Jalilian-Marian, Jamal

    2010-10-01

    Present knowledge of QCD n-point functions of Wilson lines at high energies is rather limited. In practical applications, it is therefore customary to factorize higher n-point functions into products of two-point functions (dipoles) which satisfy the Balitsky-Kovchegov-evolution equation. We employ the Jalilian-Marian-Iancu-McLerran-Weigert-Leonidov-Kovner formalism to derive explicit evolution equations for the 4- and 6-point functions of fundamental Wilson lines and show that if the Gaussian approximation is carried out before the rapidity evolution step is taken, then many leading order N{sub c} contributions are missed. Our evolution equations could specifically be used to improve calculations of forward dijet angular correlations, recently measured by the STAR Collaboration in deuteron-gold collisions at the RHIC collider. Forward dijets in proton-proton collisions at the LHC probe QCD evolution at even smaller light-cone momentum fractions. Such correlations may provide insight into genuine differences between the Jalilian-Marian-Iancu-McLerran-Weigert-Leonidov-Kovner and Balitsky-Kovchegov approaches.

  2. Phase-field simulations of intragranular fission gas bubble evolution in UO2 under post-irradiation thermal annealing

    SciTech Connect (OSTI)

    Li, Yulan; Hu, Shenyang Y.; Montgomery, Robert O.; Gao, Fei; Sun, Xin

    2013-05-15

    Fission gas bubble is one of evolving microstructures, which affect thermal mechanical properties such as thermo-conductivity, gas release, volume swelling, and cracking, in operating nuclear fuels. Therefore, fundamental understanding of gas bubble evolution kinetics is essential to predict the thermodynamic property and performance changes of fuels. In this work, a generic phasefield model was developed to describe the evolution kinetics of intra-granular fission gas bubbles in UO2 fuels under post-irradiation thermal annealing conditions. Free energy functional and model parameters are evaluated from atomistic simulations and experiments. Critical nuclei size of the gas bubble and gas bubble evolution were simulated. A linear relationship between logarithmic bubble number density and logarithmic mean bubble diameter is predicted which is in a good agreement with experimental data.

  3. Temporal evolution of surface ripples on a finite plasma slab subject to the magneto-Rayleigh-Taylor instability

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Weis, Matthew Robert; Zhang, Peng; Lau, Yue Ying; Rittersdorf, Ian; Zier, Jacob; Gilgenbach, Ronald; Mark Harry Hess; Peterson, Kyle J.

    2014-12-17

    Using the ideal magnetohydrodynamic model, we calculate the temporal evolution of initial ripples on the boundaries of a planar plasma slab that is subjected to the magneto-Rayleigh-Taylor instability. The plasma slab consists of three regions. We assume that in each region the plasma density is constant with an arbitrary value and the magnetic field is also constant with an arbitrary magnitude and an arbitrary direction parallel to the interfaces. Then, the instability may be driven by a combination of magnetic pressure and kinetic pressure. Thus the general dispersion relation is derived, together with the feedthrough factor between the two interfaces.more » The temporal evolution is constructed from the superposition of the eigenmodes. Those previously established results are recovered in the various limits. Numerical examples are given on the temporal evolution of ripples on the interfaces of the finite plasma slab.« less

  4. Temporal evolution of surface ripples on a finite plasma slab subject to the magneto-Rayleigh-Taylor instability

    SciTech Connect (OSTI)

    Weis, Matthew Robert; Zhang, Peng; Lau, Yue Ying; Rittersdorf, Ian; Zier, Jacob; Gilgenbach, Ronald; Mark Harry Hess; Peterson, Kyle J.

    2014-12-17

    Using the ideal magnetohydrodynamic model, we calculate the temporal evolution of initial ripples on the boundaries of a planar plasma slab that is subjected to the magneto-Rayleigh-Taylor instability. The plasma slab consists of three regions. We assume that in each region the plasma density is constant with an arbitrary value and the magnetic field is also constant with an arbitrary magnitude and an arbitrary direction parallel to the interfaces. Then, the instability may be driven by a combination of magnetic pressure and kinetic pressure. Thus the general dispersion relation is derived, together with the feedthrough factor between the two interfaces. The temporal evolution is constructed from the superposition of the eigenmodes. Those previously established results are recovered in the various limits. Numerical examples are given on the temporal evolution of ripples on the interfaces of the finite plasma slab.

  5. Galaxy Evolution Insights from Spectral Modeling of Large Data Sets from the Sloan Digital Sky Survey

    SciTech Connect (OSTI)

    Hoversten, Erik A.; /Johns Hopkins U.

    2007-10-01

    This thesis centers on the use of spectral modeling techniques on data from the Sloan Digital Sky Survey (SDSS) to gain new insights into current questions in galaxy evolution. The SDSS provides a large, uniform, high quality data set which can be exploited in a number of ways. One avenue pursued here is to use the large sample size to measure precisely the mean properties of galaxies of increasingly narrow parameter ranges. The other route taken is to look for rare objects which open up for exploration new areas in galaxy parameter space. The crux of this thesis is revisiting the classical Kennicutt method for inferring the stellar initial mass function (IMF) from the integrated light properties of galaxies. A large data set ({approx} 10{sup 5} galaxies) from the SDSS DR4 is combined with more in-depth modeling and quantitative statistical analysis to search for systematic IMF variations as a function of galaxy luminosity. Galaxy H{alpha} equivalent widths are compared to a broadband color index to constrain the IMF. It is found that for the sample as a whole the best fitting IMF power law slope above 0.5 M{sub {circle_dot}} is {Lambda} = 1.5 {+-} 0.1 with the error dominated by systematics. Galaxies brighter than around M{sub r,0.1} = -20 (including galaxies like the Milky Way which has M{sub r,0.1} {approx} -21) are well fit by a universal {Lambda} {approx} 1.4 IMF, similar to the classical Salpeter slope, and smooth, exponential star formation histories (SFH). Fainter galaxies prefer steeper IMFs and the quality of the fits reveal that for these galaxies a universal IMF with smooth SFHs is actually a poor assumption. Related projects are also pursued. A targeted photometric search is conducted for strongly lensed Lyman break galaxies (LBG) similar to MS1512-cB58. The evolution of the photometric selection technique is described as are the results of spectroscopic follow-up of the best targets. The serendipitous discovery of two interesting blue compact dwarf galaxies is reported. These galaxies were identified by their extremely weak (< 150) [N {pi}] {lambda}6584 to H{alpha} emission line ratios. Abundance analysis from emission line fluxes reveals that these galaxies have gas phase oxygen abundances 12 + log(O/H) {approx} 7.7 to 7.9, not remarkably low, and near infrared imaging detects an old stellar population. However, the measured nitrogen to oxygen ratios log(N/O) < 1.7 are anomalously low for blue compact dwarf galaxies. These objects may be useful for understanding the chemical evolution of nitrogen.

  6. Inviscid evolution of large amplitude filaments in a uniform gravity field

    SciTech Connect (OSTI)

    Angus, J. R.; Krasheninnikov, S. I.

    2014-11-15

    The inviscid evolution of localized density stratifications under the influence of a uniform gravity field in a homogeneous, ambient background is studied. The fluid is assumed to be incompressible, and the stratification, or filament, is assumed to be initially isotropic and at rest. It is shown that the center of mass energy can be related to the center of mass position in a form analogous to that of a solid object in a gravity field g by introducing an effective gravity field g{sub eff}, which is less than g due to energy that goes into the background and into non-center of mass motion of the filament. During the early stages of the evolution, g{sub eff} is constant in time and can be determined from the solution of a 1D differential equation that depends on the initial, radially varying density profile of the filament. For small amplitude filaments such that ?{sub 0} ? 1, where ?{sub 0} is the relative amplitude of the filament to the background, the early stage g{sub eff} scales linearly with ?{sub 0}, but as ?{sub 0}??,?g{sub eff}?g and is thus independent of ?{sub 0}. Fully nonlinear simulations are performed for the evolution of Gaussian filaments, and it is found that the time t{sub max}, which is defined as the time for the center of mass velocity to reach its maximum value U{sub max}, occurs very soon after the constant acceleration phase and so U{sub max}?g{sub eff}(t=0)t{sub max}. The simulation results show that U{sub max}?1/t{sub max}??(?{sub 0}) for ?{sub 0} ? 1, in agreement with theory and results from previous authors, but that U{sub max} and t{sub max} both scale approximately with ?(?{sub 0}) for ?{sub 0} ? 1. The fact that U{sub max} and t{sub max} have the same scaling with ?{sub 0} for large amplitude filaments is in agreement with the theory presented in this paper.

  7. Chemical evolution of volatile organic compounds in the outflow of the Mexico City Metropolitan area

    SciTech Connect (OSTI)

    Apel, Eric; Emmons, L.; Karl, Thomas G.; Flocke, Frank M.; Hills, A. J.; Madronich, Sasha; Lee-Taylor, J.; Fried, Alan; Weibring, P.; Walega, J.; Richter, Dirk; Tie, X.; Mauldin, L.; Campos, Teresa; Weinheimer, Andrew J.; Knapp, David; Sive, B.; Kleinman, Lawrence I.; Springston, S.; Zaveri, Rahul A.; Ortega, John V.; Voss, Paul B.; Blake, D. R.; Baker, Angela K.; Warneke, Carsten; Welsh-Bon, Daniel; de Gouw, Joost A.; Zheng, J.; Zhang, Renyi; Rudolph, Jochen; Junkermann, W.; Riemer, D.

    2010-01-01

    The volatile organic compound (VOC) distribution in the Mexico City Metropolitan Area (MCMA) and its evolution as it is uplifted and transported out of the MCMA basin was studied during the 2006 MILAGRO/MIRAGE-Mex field campaign. The results show that in the morning hours in the city center, the VOC distribution is dominated by non-methane hydrocarbons (NMHCs) but with a substantial contribution from oxygenated volatile organic compounds (OVOCs), predominantly from primary emissions. Alkanes account for a large part of the NMHC distribution in terms of mixing ratios. In terms of reactivity, NMHCs also dominate overall, especially in the morning hours. However, in the afternoon, as the boundary layer lifts and air is mixed and aged within the basin, the distribution changes as secondary products are formed. The WRF-Chem (Weather Research and Forecasting with Chemistry) model and MOZART (Model for Ozone and Related chemical Tracers) were able to reproduce the general features of the daytime cycle of the VOC OH reactivity distribution showing that NMHCs dominate the distribution except in the afternoon hours and that the VOC OH reactivity peaks in the early morning due to high morning emissions from the city into a shallow boundary layer. The WRF-Chem and MOZART models showed higher reactivity than the experimental data during the nighttime cycle, perhaps indicating problems with the modeled nighttime boundary layer height. In addition, a plume was studied in which air was advected out of the MCMA and intercepted downwind with the DOE G1 on March 18 and the NCAR C130 one day later on March 19. A number of identical species measured aboard each aircraft gave insight into the chemical evolution of the plume as it aged and was transported as far as 1000 km downwind. Ozone and many OVOCs were photochemically produced in the plume. The WRF-Chem and MOZART models were used to examine the spatial and temporal extent of the March 19 plume and to help interpret the OH reactivity in the downwind plume. The model results generally showed good agreement with experimental results for the total VOC OH reactivity downwind and gave insight into the distributions of VOC chemical classes downwind. A box model with detailed gas phase chemistry (NCAR Master Mechanism), initialized with concentrations observed at one of the ground sites in the MCMA, was used to examine the expected evolution of specific VOCs over a 1-2 day period. The models clearly supported the experimental evidence for NMHC oxidation leading to the formation of OVOCs downwind, which then become the primary fuel for ozone production far away from the MCMA.

  8. Chemical evolution of volatile organic compounds in the outflow of the Mexico City Metropolitan area

    SciTech Connect (OSTI)

    Apel, E.; Springston, S.; Karl, T.; Emmons, L.; Flocke, F.; Hills, A. J.; Madronich, S.; Lee-Taylor, J.; Fried, A.; Weibring, P.; Walega, J.; Richter, D., Tie, X.; Mauldin, L.; Campos, T.; Sive, B.; Kleinman, L.; Springston, S., Zaveri, R.; deGouw, J.; Zheng, J.; Zhang, R.; Rudolph, J.; Junkermann, W.; Riemer, D. D.

    2009-11-01

    The volatile organic compound (VOC) distribution in the Mexico City Metropolitan Area (MCMA) and its evolution as it is uplifted and transported out of the MCMA basin was studied during the 2006 MILAGRO/MIRAGE-Mex field campaign. The results show that in the morning hours in the city center, the VOC distribution is dominated by non-methane hydrocarbons (NMHCs) but with a substantial contribution from oxygenated volatile organic compounds (OVOCs), predominantly from primary emissions. Alkanes account for a large part of the NMHC distribution in terms of mixing ratios. In terms of reactivity, NMHCs also dominate overall, especially in the morning hours. However, in the afternoon, as the boundary layer lifts and air is mixed and aged within the basin, the distribution changes as secondary products are formed. The WRF-Chem (Weather Research and Forecasting with Chemistry) model and MOZART (Model for Ozone and Related chemical Tracers) were able to reproduce the general features of the daytime cycle of the VOC OH reactivity distribution showing that NMHCs dominate the distribution except in the afternoon hours and that the VOC OH reactivity peaks in the early morning due to high morning emissions from the city into a shallow boundary layer. The WRF-Chem and MOZART models showed higher reactivity than the experimental data during the nighttime cycle, perhaps indicating problems with the modeled nighttime boundary layer height. In addition, a plume was studied in which air was advected out of the MCMA and intercepted downwind with the DOE G1 on 18 March and the NCAR C130 one day later on 19 March. A number of identical species measured aboard each aircraft gave insight into the chemical evolution of the plume as it aged and was transported as far as 1000 km downwind. Ozone and many OVOCs were photochemically produced in the plume. The WRF-Chem and MOZART models were used to examine the spatial and temporal extent of the 19 March plume and to help interpret the OH reactivity in the downwind plume. The model results generally showed good agreement with experimental results for the total VOC OH reactivity downwind and gave insight into the distributions of VOC chemical classes downwind. A box model with detailed gas phase chemistry (NCAR Master Mechanism), initialized with concentrations observed at one of the ground sites in the MCMA, was used to examine the expected evolution of specific VOCs over a 1-2 day period. The models clearly supported the experimental evidence for NMHC oxidation leading to the formation of OVOCs downwind, which then become the primary fuel for ozone production far away from the MCMA.

  9. Temporal evolution of bubble tip velocity in classical Rayleigh-Taylor instability at arbitrary Atwood numbers

    SciTech Connect (OSTI)

    Liu, W. H.; HEDPS and CAPT, Peking University, Beijing 100871 ; Wang, L. F.; Ye, W. H.; Institute of Applied Physics and Computational Mathematics, Beijing 100088; Department of Physics, Zhejiang University, Hangzhou 310027 ; He, X. T.; Institute of Applied Physics and Computational Mathematics, Beijing 100088

    2013-06-15

    In this research, the temporal evolution of the bubble tip velocity in Rayleigh-Taylor instability (RTI) at arbitrary Atwood numbers and different initial perturbation velocities with a discontinuous profile in irrotational, incompressible, and inviscid fluids (i.e., classical RTI) is investigated. Potential models from Layzer [Astrophys. J. 122, 1 (1955)] and perturbation velocity potentials from Goncharov [Phys. Rev. Lett. 88, 134502 (2002)] are introduced. It is found that the temporal evolution of bubble tip velocity [u(t)] depends essentially on the initial perturbation velocity [u(0)]. First, when the u(0)evolution in astrophysics where the deflagration wave front propagating outwardly from the star is subject to the combined RMI and RTI.

  10. STRONTIUM ISOTOPE EVOLUTION OF PORE WATER AND CALCITE IN THE TOPOPAH SPRING TUFF, YUCCA MOUNTAIN , NEVADA

    SciTech Connect (OSTI)

    B.D. Marshall; K. Futa

    2001-02-07

    Yucca Mountain, a ridge of Miocene volcanic rocks in southwest Nevada, is being characterized as a site for a potential high-level radioactive waste repository. One issue of concern for the future performance of the potential repository is the movement of water in and around the potential repository horizon. Past water movement in this unsaturated zone is indicated by fluid inclusions trapped in calcite coatings on fracture footwall surfaces and in some lithophysal cavities. Some of the fluid inclusions have homogenization temperatures above the present-day geotherm (J.F. Whelan, written communication), so determining the ages of the calcite associated with those fluid inclusions is important in understanding the thermal history of the potential repository site. Calcite ages have been constrained by uranium-lead dating of silica polymorphs (opal and chalcedony) that are present in most coatings. The opal and chalcedony ages indicate that deposition of the calcite and opal coatings in the welded part of the Topopah Spring Tuff (TSw hydrogeologic unit) spanned nearly the entire history of the 12.8-million-year-old rock mass at fairly uniform overall long-term rates of deposition (within a factor of five). Constraining the age of a layer of calcite associated with specific fluid inclusions is complicated. Calcite is commonly bladed with complex textural relations, and datable opal or chalcedony may be millions of years older or younger than the calcite layer or may be absent from the coating entirely. Therefore, a more direct method of dating the calcite is presented in this paper by developing a model for strontium evolution in pore water in the TSw as recorded by the strontium coprecipitated with calcium in the calcite. Although the water that precipitated the calcite in fractures and cavities may not have been in local isotopic equilibrium with the pore water, the strontium isotope composition of all water in the TSw is primarily controlled by water-rock interaction in the overlying nonwelded and essentially unfractured Paintbrush Group tuffs (PTn). The method of dating secondary minerals from known strontium evolution rates in rocks cannot be used in this study because it assumes the water that deposited the minerals was in isotopic equilibrium with the rock, which is not the case for the pore water in the TSw. Therefore, the evolution of the strontium isotope composition of the water that deposited the calcite, as recorded by the strontium coprecipitated with calcium in the calcite, was used to develop a model for determining the age of the calcite.

  11. Evolution of the phonon density of states of LaCoO3 over the spin state

    Office of Scientific and Technical Information (OSTI)

    transition (Journal Article) | SciTech Connect Evolution of the phonon density of states of LaCoO3 over the spin state transition Citation Details In-Document Search Title: Evolution of the phonon density of states of LaCoO3 over the spin state transition Authors: Golosova, N. O. ; Kozlenko, D. P. ; Kolesnikov, A. I. ; Kazimirov, V. Yu. ; Smirnov, M. B. ; Jirák, Z. ; Savenko, B. N. Publication Date: 2011-06-30 OSTI Identifier: 1099698 Type: Publisher's Accepted Manuscript Journal Name:

  12. The effect of nuclear reaction rates and convective mixing on the evolution of a 6M{sub ?} star

    SciTech Connect (OSTI)

    Halabi, Ghina M.

    2014-05-09

    We present the evolution of a 6M{sub ?} star, of solar-like initial metallicity, and investigate the effects of key nuclear reaction rates, as well as the treatment of the convective mixing on its evolution along the Cepheid instability strip. In particular, we study the effect of recent estimates of the {sup 14}N(p,?){sup 15}O reaction on the formation and extension of the blue loop during core helium burning. We also investigate the effects induced on this blue loop by the adoption of non-standard convective mixing prescriptions, as well as the implications of modifying the Mixing Length Theory.

  13. Indications of negative evolution for the sources of the highest energy cosmic rays

    SciTech Connect (OSTI)

    Taylor, Andrew M.; Ahlers, Markus; Hooper, Dan

    2015-09-14

    Using recent measurements of the spectrum and chemical composition of the highest energy cosmic rays, we consider the sources of these particles. We find that these data strongly prefer models in which the sources of the ultra-high-energy cosmic rays inject predominantly intermediate mass nuclei, with comparatively few protons or heavy nuclei, such as iron or silicon. If the number density of sources per comoving volume does not evolve with redshift, the injected spectrum must be very hard (α≃1) in order to fit the spectrum observed from Earth. Such a hard spectral index would be surprising and difficult to accommodate theoretically. In contrast, much softer spectral indices, consistent with the predictions of Fermi acceleration (α≃2), are favored in models with negative source evolution. Furthermore with this theoretical bias, these observations thus favor models in which the sources of the highest energy cosmic rays are preferentially located within the low-redshift universe.

  14. Response of microscale turbulence and transport to the evolution of resistive magnetohydrodynamic magnetic island

    SciTech Connect (OSTI)

    Li, Jiquan, E-mail: lijq@energy.kyoto-u.ac.jp; Kishimoto, Y. [Graduate School of Energy Science, Kyoto University, Uji, Kyoto 611-0011 (Japan)] [Graduate School of Energy Science, Kyoto University, Uji, Kyoto 611-0011 (Japan); Wang, Z. X. [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)] [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

    2014-02-15

    Nonlinear evolution of microscale turbulence interacting with a naturally growing MHD magnetic island is simulated based on a Landau-fluid model. Here, we report on a new short wavelength magnetic-island-induced ion temperature gradient (ITG) instability triggered by a critical threshold of magnetic island width in multiscale turbulence, which is referred to as sw-MITG mode. The sw-MITG mode is characterized by a substantially low stability threshold and a global structure propagating along the ion diamagnetic drift direction. Its generation results from the response of microscale fluctuations to turbulent cross-field heat transport associated with increasing boundary layer width about the island separatrix. An intermittency of heat transport is caused by the sw-MITG mode interacting with dynamical magnetic island and microturbulence.

  15. Numerical simulation of temperature field, microstructure evolution and mechanical properties of HSS during hot stamping

    SciTech Connect (OSTI)

    Shi, Dongyong; Liu, Wenquan [Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Dalian University of Technology, Dalian, 116024, P.R. (China); Ying, Liang, E-mail: pinghu@dlut.edu.cn; Hu, Ping, E-mail: pinghu@dlut.edu.cn; Shen, Guozhe [Key Laboratory of Structural Analysis for Industrial Equipment, School of Automotive Engineering, Dalian University of Technology, Dalian, 116024, P.R. (China)

    2013-12-16

    The hot stamping of boron steels is widely used to produce ultra high strength automobile components without any spring back. The ultra high strength of final products is attributed to the fully martensitic microstructure that is obtained through the simultaneous forming and quenching of the hot blanks after austenization. In the present study, a mathematical model incorporating both heat transfer and the transformation of austenite is presented. A FORTRAN program based on finite element technique has been developed which permits the temperature distribution and microstructure evolution of high strength steel during hot stamping process. Two empirical diffusion-dependent transformation models under isothermal conditions were employed respectively, and the prediction capability on mechanical properties of the models were compared with the hot stamping experiment of an automobile B-pillar part.

  16. Microstructure evolution in solution treated Ti15Mo alloy processed by high pressure torsion

    SciTech Connect (OSTI)

    Jane?ek, Milo; ?ek, Jakub; Strsk, Josef; Vclavov, Kristna; Hruka, Petr; Polyakova, Veronika; Gatina, Svetlana; Semenova, Irina

    2014-12-15

    Microstructure evolution and mechanical properties of ultra-fine grained Ti15Mo alloy processed by high pressure torsion were investigated. High pressure torsion straining resulted in strong grain refinement as-observed by transmission electron microscopy. Microhardness and light microscopy showed two distinct regions (i) a central region with radial material flow and low microhardness (340 HV) and (ii) a peripheral region with rotational material flow and high microhardness (430 HV). Positron annihilation spectroscopy showed that the only detectable defects in the material are dislocations, whose density increases with the radial distance and the number of high pressure torsion revolutions. The local chemical environment around defects does not differ significantly from the average composition. - Highlights: Beta-Ti alloy Ti15Mo was processed by high pressure torsion (HPT). Lateral inhomogeneity of the microstructure and microhardness was found. Dislocations are the only lattice defects detectable by positron annihilation. Molybdenum is not preferentially segregated along dislocation cores.

  17. Constraints on a f(R) gravity dark energy model with early scaling evolution

    SciTech Connect (OSTI)

    Park, Chan-Gyung; Hwang, Jai-chan; Noh, Hyerim E-mail: jchan@knu.ac.kr

    2011-09-01

    The modified gravity with f(R) = R{sup 1+?} (? > 0) allows a scaling solution where the energy density of gravity sector follows the energy density of the dominant fluid. We present initial conditions of background and perturbation variables during the scaling evolution regime in the modified gravity. As a possible dark energy model we consider a gravity with a form f(R) = R{sup 1+?}+qR{sup ?n} (?1 < n ? 0) where the second term drives the late-time acceleration. We show that our f(R) gravity parameters are very sensitive to the baryon perturbation growth and baryon density power spectrum, and present observational constraints on the model parameters. We consider full perturbations of f(R) gravity. Our analysis suggests that only the parameter space extremely close to the ?CDM model is allowed with ??<5 10{sup ?6} and n?>?10{sup ?4}.

  18. ON THE EVOLUTION OF THE CO SNOW LINE IN PROTOPLANETARY DISKS

    SciTech Connect (OSTI)

    Martin, Rebecca G. [JILA, University of Colorado and NIST, UCB 440, Boulder, CO 80309 (United States); Livio, Mario [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

    2014-03-10

    CO is thought to be a vital building block for prebiotic molecules that are necessary for life. Thus, understanding where CO existed in a solid phase within the solar nebula is important for understanding the origin of life. We model the evolution of the CO snow line in a protoplanetary disk. We find that the current observed location of the CO snow line in our solar system, and in the solar system analog TW Hydra, cannot be explained by a fully turbulent disk model. With time-dependent disk models we find that the inclusion of a dead zone (a region of low turbulence) can resolve this problem. Furthermore, we obtain a fully analytic solution for the CO snow line radius for late disk evolutionary times. This will be useful for future observational attempts to characterize the demographics and predict the composition and habitability of exoplanets.

  19. Aging of niobium and tantalum tritides: Evolution of hardness in comparison with other properties

    SciTech Connect (OSTI)

    Schober, T.; Dieker, C.; Trinkaus, H.

    1989-01-01

    Vickers hardness measurements on niobium and tantalum tritides of initial composition NbT/sub 0.0225/ and TaT/sub 0.097/, respectively, performed over the first 20 months after T charging, are reported and interpreted. For both tritides, the hardness increases monotonically, but in a decelerating rate, with the /sup 3/ He concentration built up upon T transmutation. At given /sup 3/ He concentration, the increase per unit /sup 3/ He concentration is stronger for Nb than for Ta. To interpret the observed hardness evolution, existing hardening theories are adjusted to the present microstructural situations. It is concluded that the microstructure developing on /sup 3/ He precipitation is more disperse in the Nb tritide than in the Ta tritide. These findings are supported by conclusions drawn previously from swelling, acoustic emission, and x-ray diffraction measurements of these materials.

  20. Evolution of superclusters and delocalized states in GaAs1–xNx

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Fluegel, B.; Alberi, K.; Beaton, D. A.; Crooker, S. A.; Ptak, A. J.; Mascarenhas, A.

    2012-11-21

    The evolution of individual nitrogen cluster bound states into an extended state infinite supercluster in dilute GaAs1–xNx was probed through temperature and intensity-dependent, time-resolved and magnetophotoluminescence (PL) measurements. Samples with compositions less than 0.23% N exhibit PL behavior that is consistent with emission from the extended states of the conduction band. Near a composition of 0.23% N, a discontinuity develops between the extended state PL peak energy and the photoluminescence excitation absorption edge. The existence of dual localized/delocalized state behavior near this composition signals the formation of an N supercluster just below the conduction band edge. The infinite supercluster ismore » fully developed by 0.32% N.« less