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Sample records for nato sym bol

  1. SymPowerco Corporation | Open Energy Information

    Open Energy Info (EERE)

    search Name: SymPowerco Corporation Place: Nevada Zip: 89031 Product: Focused on fuel cell hybrid power systems. References: SymPowerco Corporation1 This article is a stub. You...

  2. Kees Bol, a scientist on Project Matterhorn, PDX and numerous experiments,

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

    dies at 90 | Princeton Plasma Physics Lab Kees Bol, a scientist on Project Matterhorn, PDX and numerous experiments, dies at 90 By Jeanne Jackson DeVoe August 25, 2015 Tweet Widget Google Plus One Share on Facebook Photo courtesy of the Bol family. (Photo by Kees Bol ) Photo courtesy of the Bol family. Gallery: Kees Bol, second from left, at a conference with Soviet scientists in Sukhumi, Georgia in 1975. To his left is Gil Emmert, now a professor emeritus at the University of Wisconsin, and

  3. Derk Bol, Materials Innovation Institute M2i (Netherlands) M2i, Material

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

    Scarcity Report and Industrial Perspectives | Department of Energy Derk Bol, Materials Innovation Institute M2i (Netherlands) M2i, Material Scarcity Report and Industrial Perspectives Derk Bol, Materials Innovation Institute M2i (Netherlands) M2i, Material Scarcity Report and Industrial Perspectives Office presentation icon Session_A4_Bol.ppt More Documents & Publications Trans-Atlantic Workshop on Rare Earth Elements and Other Critical Materials for a Clean Energy Future Vehicle

  4. Regulation of BolA abundance mediates morphogenesis in Fremyella diplosiphon

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

    Singh, Shailendra P.; Montgomery, Beronda L.

    2015-11-05

    Filamentous cyanobacterium Fremyella diplosiphon is known to alter its pigmentation and morphology during complementary chromatic acclimation (CCA) to efficiently harvest available radiant energy for photosynthesis. F. diplosiphon cells are rectangular and filaments are longer under green light (GL), whereas smaller, spherical cells and short filaments are prevalent under red light (RL). Light regulation of bolA morphogene expression is correlated with photoregulation of cellular morphology in F. diplosiphon. Here, we investigate a role for quantitative regulation of cellular BolA protein levels in morphology determination. Overexpression of bolA in WT was associated with induction of RL-characteristic spherical morphology even when cultures weremore » grown under GL. Overexpression of bolA in a ΔrcaE background, which lacks cyanobacteriochrome photosensor RcaE and accumulates lower levels of BolA than WT, partially reverted the cellular morphology of the strain to a WT-like state. Overexpression of BolA in WT and ΔrcaE backgrounds was associated with decreased cellular reactive oxygen species (ROS) levels and an increase in filament length under both GL and RL. Morphological defects and high ROS levels commonly observed in ΔrcaE could, thus, be in part due to low accumulation of BolA. Together, these findings support an emerging model for RcaE-dependent photoregulation of BolA in controlling the cellular morphology of F. diplosiphon during CCA.« less

  5. Bag of Lines (BoL) for Improved Aerial Scene Representation

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

    Sridharan, Harini; Cheriyadat, Anil M.

    2014-09-22

    Feature representation is a key step in automated visual content interpretation. In this letter, we present a robust feature representation technique, referred to as bag of lines (BoL), for high-resolution aerial scenes. The proposed technique involves extracting and compactly representing low-level line primitives from the scene. The compact scene representation is generated by counting the different types of lines representing various linear structures in the scene. Through extensive experiments, we show that the proposed scene representation is invariant to scale changes and scene conditions and can discriminate urban scene categories accurately. We compare the BoL representation with the popular scalemore » invariant feature transform (SIFT) and Gabor wavelets for their classification and clustering performance on an aerial scene database consisting of images acquired by sensors with different spatial resolutions. The proposed BoL representation outperforms the SIFT- and Gabor-based representations.« less

  6. Thermal analysis for CVL's: Part 2, Final report. [VuSymP code

    SciTech Connect (OSTI)

    Not Available

    1987-06-01

    This report documents work carried out for the Copper Vapor Laser (CVL) technology group in the Atomic Vapor Laser Isotope Separation (AVLIS) program at LLNL. The problems addressed in this subcontract have focused on the efficient calculation of thermal viewfactors in three-dimensional configurations. Part I of this report provides a detailed description of the algorithms employed in the VuSymP code which has been developed under this subcontract, and has been delivered to LLNL. This volume describes several enhancements of VuSymP which have been implemented to make the code more useful to the CVL group at LLNL.

  7. The history of NATO TNF policy: The role of studies, analysis and exercises conference proceedings. Volume 2: Papers and presentations

    SciTech Connect (OSTI)

    Rinne, R.L.

    1994-02-01

    This conference was organized to study and analyze the role of simulation, analysis, modeling, and exercises in the history of NATO policy. The premise was not that the results of past studies will apply to future policy, but rather that understanding what influenced the decision process -- and how -- would be of value. The structure of the conference was built around discussion panels. The panels were augmented by a series of papers and presentations focusing on particular TNF events, issues, studies, or exercises. The conference proceedings consist of three volumes. Volume 1 contains the conference introduction, agenda, biographical sketches of principal participants, and analytical summary of the presentations and panels. This volume contains a short introduction and the papers and presentations from the conference. Volume 3 contains selected papers by Brig. Gen. Robert C. Richardson III (Ret.). Individual papers in this volume were abstracted and indexed for the database.

  8. The history of NATO TNF policy: The role of studies, analysis and exercises conference proceedings. Volume 3: Papers by Gen. Robert C. Richardson III (Ret.)

    SciTech Connect (OSTI)

    Rinne, R.L.

    1994-02-01

    This conference was organized to study and analyze the role of simulation, analysis, modeling, and exercises in the history of NATO policy. The premise was not that the results of past studies will apply to future policy, but rather that understanding what influenced the decision process-and how-would be of value. The structure of the conference was built around discussion panels. The panels were augmented by a series of papers and presentations focusing on particular TNF events, issues, studies, or exercises. The conference proceedings consist of three volumes. Volume 1 contains the conference introduction, agenda, biographical sketches of principal participants, and analytical summary of the presentations and discussion panels. Volume 2 contains a short introduction and the papers and presentations from the conference. This volume contains selected papers by Brig. Gen. Robert C. Richardson III (Ret.).

  9. Politics of NATO short-range nuclear modernization 1983-1990: The follow-on-to-Lance missile decisions. Doctoral thesis

    SciTech Connect (OSTI)

    Larsen, J.A.

    1991-06-01

    The follow-on to Lance (FOTL) missile was born in 1983 with a consensual decision by NATO, in the face of a worsening strategic situation, to pursue short-range nuclear force (SNF) modernization. The program continued despite increasing popular and political opposition in Europe. It ended with a May 1990 cancellation decision by the American bureaucracy that reflected converging pressures from the international system, from America's allies, and from the domestic arena. The thesis attempts to answer each question through the use of one of three analytical perspectives: systemic theory, alliance politics, or domestic politics. It concludes that during this time of diminishing threat at the systemic level, domestic-level factors within the German and American milieu became more important. While certain perspectives are better at explaining particular aspects or temporal periods of modernization cases, analysts should not focus on one perspective to the exclusion of others. Unexplained residual variables fall through the filter of each perspective, calling for further study by other approaches.

  10. Kees Bol, a scientist on Project Matterhorn, PDX and numerous...

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

    a scientist on Project Matterhorn, PDX and numerous experiments, dies at 90 By Jeanne Jackson DeVoe August 25, 2015 Tweet Widget Google Plus One Share on Facebook Photo courtesy...

  11. Support of the NATO Effects Task Group by Los Alamos National Laboratory

    SciTech Connect (OSTI)

    Lyons, P.B.

    1991-01-01

    A method is outlined for measuring the transient attenuation of optical fibers and/or cables exposed to a pulse of radiation (gamma rays, x-rays, electrons, protons, neutrons, etc). It can be employed to determine the level of radiation-induced attenuation (in units of dB/km as a function of time) produced in single-mode or multi-mode optical fibers, in either cabled or uncabled form, due to pulsed exposure to radiation. Co{sup 60} radiation-induced attenuation is measured by optical time domain reflectometry (OTDR) techniques and compared to conventional optical throughput measurements. Relative advantages and disadvantages of the OTDR technique are discussed.

  12. The One-Loop Six-Dimensional Hexagon Integral and its Relation to MHV Amplitudes in N=4 SYM

    SciTech Connect (OSTI)

    Dixon, Lance J.; Drummond, James M.; Henn, Johannes M.; /Humboldt U., Berlin

    2011-08-19

    We provide an analytic formula for the (rescaled) one-loop scalar hexagon integral {tilde {Phi}}{sub 6} with all external legs massless, in terms of classical polylogarithms. We show that this integral is closely connected to two integrals appearing in one- and two-loop amplitudes in planar N = 4 super-Yang-Mills theory, {Omega}{sup (1)} and {Omega}{sup (2)}. The derivative of {Omega}{sup (2)} with respect to one of the conformal invariants yields {tilde {Phi}}{sub 6}, while another first-order differential operator applied to {tilde {Phi}}{sub 6} yields {Omega}{sup (1)}. We also introduce some kinematic variables that rationalize the arguments of the polylogarithms, making it easy to verify the latter differential equation. We also give a further example of a six-dimensional integral relevant for amplitudes in N = 4 super-Yang-Mills.

  13. Second highest-ranking U.S. military officer gets classified...

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

    Fleet; commander NATO Allied Joint Command, Lisbon; and, commander, Striking and Support Forces NATO. He also served as the commander of North American Aerospace Defense Command...

  14. Instabilities and chaos in quantum optics II; Proceedings of the NATO Advanced Study Institute, Il Ciocco, Italy, June 28-July 7, 1987

    SciTech Connect (OSTI)

    Abraham, N.B.; Arecchi, F.T.; Lugiato, L.A.

    1988-01-01

    The following topics are considered: laser and maser instabilities, classical and quantum noise, transverse effects, dynamics in optical bistability and nonlinear optical media, and methods of analysis in nonlinear dynamics. Particular papers are presented on multistability and chaos in a two-photon microscopic maser, quantum chaos in quantum optics, spatial chaos in bistable optical arrays, four-wave mixing and dynamics, and bifurcation problems in nonlinear optics.

  15. Soviet short-range nuclear forces: flexible response or flexible aggression. Student essay

    SciTech Connect (OSTI)

    Smith, T.R.

    1987-03-23

    This essay takes a critical look at Soviet short-range nuclear forces in an effort to identify Soviet capabilities to fight a limited nuclear war with NATO. From an analysis of Soviet military art, weapon-system capabilities and tactics, the author concludes that the Soviets have developed a viable limited-nuclear-attack option. Unless NATO reacts to this option, the limited nuclear attack may become favored Soviet option and result in the rapid defeat of NATO.

  16. Energy Emergency Energy Emergency Preparedness Quarterly Preparedness...

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

    Assistant Secretary ISER William N. Bryan Director Infrastructure Reliability ISER Stewart Cedres DOE Supports 2012 NATO Summit Visit us at: http:energy.govoeservices...

  17. Reversible Acid Gas Capture Using CO2-Binding Organic Liquids

    SciTech Connect (OSTI)

    Heldebrant, David J.; Koech, Phillip K.; Yonker, Clement R.; Rainbolt, James E.; Zheng, Feng

    2010-08-31

    Acid gas scrubbing technology is predominantly aqueous alkanolamine based. Of the acid gases, CO2, H2S and SO2 have been shown to be reversible, however there are serious disadvantages with corrosion and high regeneration costs. The primary scrubbing system composed of monoethanolamine is limited to 30% by weight because of the highly corrosive solution. This gravimetric limitation limits the CO2 volumetric (?108 g/L) and gravimetric capacity (?7 wt%) of the system. Furthermore the scrubbing system has a large energy penalty from pumping and heating the excess water required to dissolve the MEA bicarbonate salt. Considering the high specific heat of water (4 j/g-1K-1), low capacities and the high corrosion we set out to design a fully organic solvent that can chemically bind all acid gases i.e. CO2 as reversible alkylcarbonate ionic liquids or analogues thereof. Having a liquid acid gas carrier improves process economics because there is no need for excess solvent to pump and to heat. We have demonstrated illustrated in Figure 1, that CO2-binding organic liquids (CO2BOLs) have a high CO2 solubility paired with a much lower specific heat (<1.5 J/g-1K-1) than aqueous systems. CO2BOLs are a subsection of a larger class of materials known as Binding Organic Liquids (BOLs). Our BOLs have been shown to reversibly bind and release COS, CS2, and SO2, which we denote COSBOLS, CS2BOLs and SO2BOLs. Our BOLs are highly tunable and can be designed for post or pre-combustion gas capture. The design and testing of the next generation zwitterionic CO2BOLs and SO2BOLs are presented.

  18. Bolivia: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Country Profile Name Bolivia Population 10,556,102 GDP 29,802 Energy Consumption 0.25 Quadrillion Btu 2-letter ISO code BO 3-letter ISO code BOL Numeric ISO...

  19. Improving the Regeneration of CO?-Binding Organic Liquids with a Polarity Change

    SciTech Connect (OSTI)

    Mathias, Paul M.; Afshar, Kash; Zheng, Feng; Bearden, Mark D.; Freeman, Charles J.; Andrea, Tamer; Koech, Phillip K.; Kutnyakov, Igor V.; Zwoster, Andy; Smith, Arnold R.; Jessop, Philip G.; Nik, Omid Ghafari; Heldebrant, David J.

    2013-01-01

    This paper describes an unusual solvent regeneration method unique to CO?BOLs and other switchable ionic liquids; utilizing changes in polarity to shift the free energy of the system. The degree of CO? loading in CO?BOLs is known to control the polarity of the solvent; conversely, polarity could be exploited as a means to control CO? loading. In this process, a chemically inert non-polar antisolvent is added to aid in de-complexing CO? from a CO?-rich CO?BOL. The addition of this polarity assist reduces temperatures required for regeneration of CO?BOLs by as much as 76 C. The lower regeneration temperatures realized with this polarity change allow for reduced solvent attrition and thermal degradation. Furthermore, the polarity assist shows considerable promise for reducing regeneration energy of CO?BOL solvents, and separation of the CO?BOL from the antisolvent is as simple as cooling the mixture below the upper critical solution temperature. Vapour-liquid equilibrium and liquid-liquid equilibrium measurements of a candidate CO?BOL with CO? with and without an antisolvent were completed. From this data, we present the evidence and impacts of a polarity change on a CO?BOL. Thermodynamic models and analysis of the system were constructed using ASPEN Plus, and forecasts preliminary process configurations and feasibility are also presented. Lastly, projections of solvent performance for removing CO? from a sub-critical coal fired power plant (total net power and parasitic load) are presented with and without this polarity assist and compared to DOEs Case 10 MEA baseline.

  20. Structure constant of twist-2 light-ray operators in the Regge limit

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

    Balitsky, Ian; Kazakov, Vladimir; Sobko, Evgeny

    2016-03-11

    We compute the correlation function of three twist-2 operators in N = 4 SYM in the leading BFKL approximation at any Nc. In this limit, the result is applicable to other gauge theories, including QCD.

  1. Chapter in Diakonov, D. (ed.): Subtleties in quantum field theory : Lev Lipatov Festschrift, pp. 104-149

    SciTech Connect (OSTI)

    Ian Balitsky

    2010-09-01

    I review the calculation of the next-to-leading order behavior of high-energy amplitudes in N=4 SYM and QCD using the operator expansion in Wilson lines.

  2. NLO BFKL and anomalous dimensions of light-ray operators

    SciTech Connect (OSTI)

    Balitsky, Ian

    2013-05-01

    This presentation covers: Regge limit in the coordinate space; BFKL representation of 4-point correlation function in N = 4 SYM; light-ray operators; DGLAP representation of 4-point correlation function; and anomalous dimensions from DGAP vs BFKL representations.

  3. Untitled Document

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

    Morning Talks coloWCI-3-sym.ppt verdeFragment-Fragment2.ppt shlomo.ppt verdeSpace-Time characterization.ppt verdeDirectionnalCorrelations.ppt WCI3kolomietz.pdf...

  4. CO2-Binding Organic Liquids Gas Capture with Polarity-Swing-Assisted Regeneration Full Technology Feasibility Study B1 - Solvent-based Systems

    SciTech Connect (OSTI)

    Heldebrant, David J

    2014-08-31

    PNNL, Fluor Corporation and Queens University (Kingston, ON) successfully completed a three year comprehensive study of the CO2BOL water-lean solvent platform with Polarity Swing Assisted Regeneration (PSAR). This study encompassed solvent synthesis, characterization, environmental toxicology, physical, thermodynamic and kinetic property measurements, Aspen Plus™ modeling and bench-scale testing of a candidate CO2BOL solvent molecule. Key Program Findings The key program findings are summarized as follows: • PSAR favorably reduced stripper duties and reboiler temperatures with little/no impact to absorption column • >90% CO2 capture was achievable at reasonable liquid-gas ratios in the absorber • High rich solvent viscosities (up to 600 cP) were successfully demonstrated in the bench-scale system. However, the projected impacts of high viscosity to capital cost and operational limits compromised the other levelized cost of electricity benefits. • Low thermal conductivity of organics significantly increased the required cross exchanger surface area, and potentially other heat exchange surfaces. • CO2BOL had low evaporative losses during bench-scale testing • There was no evidence of foaming during bench scale testing • Current CO2BOL formulation costs project to be $35/kg • Ecotoxicity (Water Daphnia) was comparable between CO2BOL and MEA (169.47 versus 103.63 mg/L) • Full dehydration of the flue gas was determined to not be economically feasible. However, modest refrigeration (13 MW for the 550 MW reference system) was determined to be potentially economically feasible, and still produce a water-lean condition for the CO2BOLs (5 wt% steady-state water loading). • CO2BOLs testing with 5 wt% water loading did not compromise anhydrous performance behavior, and showed actual enhancement of CO2 capture performance. • Mass transfer of CO2BOLs was not greatly impeded by viscosity • Facile separation of antisolvent from lean CO2BOL was demonstrated on the bench cart • No measurable solvent degradation was observed over 4 months of testing – even with 5 wt% water present

  5. Sciences and society

    SciTech Connect (OSTI)

    2008-01-10

    J.Luns des Pays-Bas, ancien sctaire gnral de NATO (OTAN=Organisation du trait de l'Atlantique Nord) parle du pass, prsent et future de la dfense europenne et des relations est et ouest

  6. Sciences and society

    ScienceCinema (OSTI)

    None

    2011-04-25

    J.Luns des Pays-Bas, ancien sécétaire général de NATO (OTAN=Organisation du traité de l'Atlantique Nord) parle du passé, présent et future de la défense européenne et des relations est et ouest

  7. CO2 Binding Organic Liquids Gas Capture with Polarity Swing Assisted Regeneration

    SciTech Connect (OSTI)

    Heldebrant, David

    2014-05-31

    This report outlines the comprehensive bench-scale testing of the CO2-binding organic liquids (CO2BOLs) solvent platform and its unique Polarity Swing Assisted Regeneration (PSAR). This study outlines all efforts on a candidate CO2BOL solvent molecule, including solvent synthesis, material characterization, preliminary toxicology studies, and measurement of all physical, thermodynamic and kinetic data, including bench-scale testing. Equilibrium and kinetic models and analysis were made using Aspen Plus™. Preliminary process configurations, a technoeconomic assessment and solvent performance projections for separating CO2 from a subcritical coal-fired power plant are compared to the U.S. Department of Energy's Case 10 monoethanolamine baseline.

  8. solvent-battelle | netl.doe.gov

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

    CO2 Binding Organic Liquids Gas Capture with Polarity-Swing-Assisted Regeneration Project No.: DE-FE0007466 Battelle Pacific Northwest Division is developing a new CO2 capture technology for treating post-combustion emissions. The new process couples the unique attributes of non-aqueous, switchable organic solvents (CO2 binding organic liquids - CO2BOLs) with the newly discovered polarity-swing-assisted regeneration (PSAR) process. The process requires significantly lower temperatures and

  9. Assessment of dynamic energy conversion systems for radioisotope heat sources

    SciTech Connect (OSTI)

    Thayer, G.R.; Mangeng, C.A.

    1985-06-01

    The use of dynamic conversion systems to convert the heat generated in a 7500 W(t) 90 Sr radioisotopic heat source to electricity is examined. The systems studies were Stirling; Brayton Cycle; three organic Rankines (ORCs) (Barber-Nichols/ORMAT, Sundstrand, and TRW); and an organic Rankine plus thermoelectrics. The systems were ranked for a North Warning System mission using a Los Alamos Multiattribute Decision Theory code. Three different heat source designs were used: case I with a beginning of life (BOL) source temperature of 640 C, case II with a BOL source temperature of 745/sup 0/C, and case III with a BOL source temperature of 945/sup 0/C. The Stirling engine system was the top-ranked system of cases I and II, closely followed by the ORC systems in case I and ORC plus thermoelectrics in case II. The Brayton cycle system was top-ranked for case III, with the Stirling engine system a close second. The use of /sup 238/Pu in heat source sizes of 7500 W(t) was examined and found to be questionable because of cost and material availability and because of additional requirements for analysis of safeguards and critical mass.

  10. EMBEDDED PROTOSTARS IN THE DUST, ICE, AND GAS IN TIME (DIGIT) HERSCHEL KEY PROGRAM: CONTINUUM SEDs, AND AN INVENTORY OF CHARACTERISTIC FAR-INFRARED LINES FROM PACS SPECTROSCOPY

    SciTech Connect (OSTI)

    Green, Joel D.; Evans, Neal J. II; Rascati, Michelle R.; Jorgensen, Jes K.; Dionatos, Odysseas; Lindberg, Johan E.; Herczeg, Gregory J.; Kristensen, Lars E.; Yildiz, Umut A.; Van Kempen, Tim A.; Lee, Jeong-Eun; Salyk, Colette; Meeus, Gwendolyn; Bouwman, Jeroen; Visser, Ruud; Bergin, Edwin A.; Van Dishoeck, Ewine F.; Karska, Agata; Fedele, Davide; Dunham, Michael M.; Collaboration: DIGIT Team1

    2013-06-20

    We present 50-210 {mu}m spectral scans of 30 Class 0/I protostellar sources, obtained with Herschel-PACS, and 0.5-1000 {mu}m spectral energy distributions, as part of the Dust, Ice, and Gas in Time Key Program. Some sources exhibit up to 75 H{sub 2}O lines ranging in excitation energy from 100 to 2000 K, 12 transitions of OH, and CO rotational lines ranging from J = 14 {yields} 13 up to J = 40 {yields} 39. [O I] is detected in all but one source in the entire sample; among the sources with detectable [O I] are two very low luminosity objects. The mean 63/145 {mu}m [O I] flux ratio is 17.2 {+-} 9.2. The [O I] 63 {mu}m line correlates with L{sub bol}, but not with the time-averaged outflow rate derived from low-J CO maps. [C II] emission is in general not local to the source. The sample L{sub bol} increased by 1.25 (1.06) and T{sub bol} decreased to 0.96 (0.96) of mean (median) values with the inclusion of the Herschel data. Most CO rotational diagrams are characterized by two optically thin components ( = (0.70 {+-} 1.12) x 10{sup 49} total particles). N{sub CO} correlates strongly with L{sub bol}, but neither T{sub rot} nor N{sub CO}(warm)/N{sub CO}(hot) correlates with L{sub bol}, suggesting that the total excited gas is related to the current source luminosity, but that the excitation is primarily determined by the physics of the interaction (e.g., UV-heating/shocks). Rotational temperatures for H{sub 2}O ( = 194 +/- 85 K) and OH ( = 183 +/- 117 K) are generally lower than for CO, and much of the scatter in the observations about the best fit is attributed to differences in excitation conditions and optical depths among the detected lines.

  11. Shooting string holography of jet quenching at RHIC and LHC

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

    Ficnar, Andrej; Gubser, Steven S.; Gyulassy, Miklos

    2014-10-13

    We derive a new formula for jet energy loss using finite endpoint momentum shooting strings initial conditions in SYM plasmas to overcome the difficulties of previous falling string holographic scenarios. We apply the new formula to compute the nuclear modification factor RAA and the elliptic flow parameter v2 of light hadrons at RHIC and LHC. We show furthermore that GaussBonnet quadratic curvature corrections to the AdS5 geometry improve the agreement with the recent data.

  12. Deep Challenges for Foundation Performance at Savannah River Site |

    Office of Environmental Management (EM)

    Department of Energy Deep Challenges for Foundation Performance at Savannah River Site Deep Challenges for Foundation Performance at Savannah River Site Deep Challenges for Foundation Performance at Savannah River Site Frank H. Syms and Brent Gutierrez October 22, 2014 PDF icon Deep Challenges for Foundation Performance at Savannah River Site More Documents & Publications H-Tank Farm Waste Determination SRS FTF Section 3116 Basis for Determination F-Tank Farm Performance Assessment, Rev

  13. (CO/sub 2/ chemistry and biochemistry, Ginosa Marina, Italy, June 17-28, 1989): Foreign trip report

    SciTech Connect (OSTI)

    Hartman, F.C.

    1989-07-11

    The traveler attended a conference organized by the NATO Advanced Study Institute on plant molecular biology and presented two invited addresses entitled ''Rubisco: Active-site characterization and mechanistic implications.'' Presentations concerning biological CO/sub 2/ fixation, chemical modifications of proteins, site-directed mutagenesis, CO/sub 2/ chemistry, carbonic anhydrase, biotin-requiring enzymes, and the greenhouse effect were relevant to ongoing investigations of the Protein Chemistry Group and the Protein Engineering Program at ORNL's Biology Division.

  14. National Security Science December 2014

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

    December 2014 In this issue Rethinking the Unthinkable Debunking Nuclear Weapons Myths December 2014 Los Alamos National Laboratory Los Alamos National Laboratory In this issue's cover story, "Rethinking the Unthinkable," Houston T. Hawkins, a retired Air Force colonel and a Laboratory senior fellow, points out that since Vladimir Putin returned to power in Russia, relations with the United States and its NATO allies have cooled down like a thermometer in December. The biting off of

  15. Energy Emergency Energy Emergency Preparedness Quarterly Preparedness Quarterly

    Office of Environmental Management (EM)

    3 J U L Y 1 5 , 2 0 1 2 U.S. DEPARTMENT OF ENERGY OE Hosts National Energy Assurance Conference Office of Electricity Delivery and Energy Reliability (OE) Infrastructure Security and Energy Restoration (ISER) Deputy Assistant Secretary ISER William N. Bryan Director Infrastructure Reliability ISER Stewart Cedres DOE Supports 2012 NATO Summit Visit us at: http://energy.gov/oe/services/energy-assurance/emergency-preparedness OE and the National Association of State Energy Officials (NASEO) hosted

  16. RADIATION MECHANISM AND JET COMPOSITION OF GAMMA-RAY BURSTS AND GeV-TeV-SELECTED RADIO-LOUD ACTIVE GALACTIC NUCLEI

    SciTech Connect (OSTI)

    Zhang Jin; Lu Ye; Zhang Shuangnan; Liang Enwei; Sun Xiaona; Zhang Bing

    2013-09-01

    Gamma-ray bursts (GRBs) and GeV-TeV-selected radio-loud active galactic nuclei (AGNs) are compared based on our systematic modeling of the observed spectral energy distributions of a sample of AGNs with a single-zone leptonic model. We show that the correlation between the jet power (P{sub jet}) and the prompt gamma-ray luminosity (L{sub jet}) of GRBs is consistent, within the uncertainties, with the correlation between jet power and the synchrotron peak luminosity (L{sub s,jet}) of flat spectrum radio quasars (FSRQs). Their radiation efficiencies ({epsilon}) are also comparable (>10% for most sources), which increase with the bolometric jet luminosity (L{sub bol,jet}) for FSRQs and with the L{sub jet} for GRBs with similar power-law indices. BL Lac objects (BL Lacs) do not follow the P{sub jet}-L{sub s,jet} relation of FSRQs. They have lower {epsilon} and L{sub bol,jet} values than FSRQs, and a tentative L{sub bol,jet}-{epsilon} relation is also found, with a power-law index different from that of the FSRQs. The magnetization parameters ({sigma}) of FSRQs are on average larger than that of BL Lacs. They are anti-correlated with {epsilon} for the FSRQs, but positively correlated with {epsilon} for the BL Lacs. GeV narrow-line Seyfert 1 galaxies potentially share similar properties with FSRQs. Based on the analogy between GRBs and FSRQs, we suggest that the prompt gamma-ray emission of GRBs is likely produced by the synchrotron process in a magnetized jet with high radiation efficiency, similar to FSRQs. The jets of BL Lacs, on the other hand, are less efficient and are likely more matter-dominated.

  17. THE SPITZER MID-INFRARED ACTIVE GALACTIC NUCLEUS SURVEY. I. OPTICAL AND NEAR-INFRARED SPECTROSCOPY OF OBSCURED CANDIDATES AND NORMAL ACTIVE GALACTIC NUCLEI SELECTED IN THE MID-INFRARED

    SciTech Connect (OSTI)

    Lacy, M.; Ridgway, S. E.; Gates, E. L.; Petric, A. O.; Sajina, A.; Urrutia, T.; Cox Drews, S.; Harrison, C.; Seymour, N.; Storrie-Lombardi, L. J.

    2013-10-01

    We present the results of a program of optical and near-infrared spectroscopic follow-up of candidate active galactic nuclei (AGNs) selected in the mid-infrared. This survey selects both normal and obscured AGNs closely matched in luminosity across a wide range, from Seyfert galaxies with bolometric luminosities L {sub bol} ? 10{sup 10} L {sub ?} to highly luminous quasars (L {sub bol} ? 10{sup 14} L {sub ?}), all with redshifts ranging from 0 to 4.3. Samples of candidate AGNs were selected with mid-infrared color cuts at several different 24 ?m flux density limits to ensure a range of luminosities at a given redshift. The survey consists of 786 candidate AGNs and quasars, of which 672 have spectroscopic redshifts and classifications. Of these, 137 (20%) are type 1 AGNs with blue continua, 294 (44%) are type 2 objects with extinctions A{sub V} ?> 5 toward their AGNs, 96 (14%) are AGNs with lower extinctions (A{sub V} ? 1), and 145 (22%) have redshifts, but no clear signs of AGN activity in their spectra. Of the survey objects 50% have L {sub bol} > 10{sup 12} L {sub ?}, in the quasar regime. We present composite spectra for type 2 quasars and objects with no signs of AGN activity in their spectra. We also discuss the mid-infraredemission-line luminosity correlation and present the results of cross correlations with serendipitous X-ray and radio sources. The results show that: (1) obscured objects dominate the overall AGN population, (2) mid-infrared selected AGN candidates exist which lack AGN signatures in their optical spectra but have AGN-like X-ray or radio counterparts, and (3) X-ray and optical classifications of obscured and unobscured AGNs often differ.

  18. jllletaIlurgitaI Haboratorp

    Office of Legacy Management (LM)

    jllletaIlurgitaI Haboratorp l ' \ frequent dmsaing rmr $ld it flllup. Althcugh lt 1~0 0-t ooarae, It e.wwd to ~~VIJ the best terulta of my n had trid. It war l onr-. bol' undua wheel numbu SBIE. OnIhylB, l a+ rhort plwer ofrod 2 01 in dlwekt mre ground at Oloba preliairmyto oladdl.n6rith ~tael~ OnMop 28, ,OLO S foot tube8 nm l oounfely ground at Olobeto b olad dthaminum. For mu~0rafulol0ddiry, apsriame ha* aboarthattb tuba should not or bo out of round awe than abut &02"~ 6 rwttuhu8

  19. CONCURRENC RTG. SYMBOL GC-34 Ms. Mary Beth Brado

    Office of Legacy Management (LM)

    MAY 2 9 1980 CONCURRENC RTG. SYMBOL GC-34 Ms. Mary Beth Brado "*N'W Town of Lewiston * i..,! 1375 Ridge Road ^r'8 Lewiston, New York 14092 RTG.SYuBOL Dear Ms. Brado: .- ,l13. INirIA Lss iQ. W'Mott This is in response to your letter of January 29, 1980, and subsequent ..... ,. telephone discussions with irr. Brazley of my office, concerning land use 5/ /8 restrictions on the 1,511 acres declared surplus in the Towns of Lewiston RGSYMOL. and Porter, New York. In regard to your question of

  20. The EOS of neutron matter, and the effect of Lambda hyperons to neutron star structure

    SciTech Connect (OSTI)

    Gandolfi, Stefano

    2015-01-13

    The following topics are addressed: the model and the method; equation of state of neutron matter, role of three-neutron force; symmetry energy; ?-hypernuclei; ?-neutron matter; and neutron star structure. In summary, quantum Monte Carlo methods are useful to study nuclear systems in a coherent framework; the three-neutron force is the bridge between Esym and neutron star structure; and neutron star observations are becoming competitive with experiments. ?-nucleon data are very limited, but ?NN is very important. The role of ? in neutron stars is far from understood; more ?N data are needed. The author's conclusion: We cannot conclude anything with present models.

  1. Fortran Example MUMPS

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

    Fortran Example MUMPS Fortran Example MUMPS C file dsimpletest.F C C This file is part of MUMPS 4.10.0 C To run: aprun -n 2 ./dsimpletest < input_simpletest_real C PROGRAM MUMPS_TEST IMPLICIT NONE INCLUDE 'mpif.h' INCLUDE 'dmumps_struc.h' TYPE (DMUMPS_STRUC) mumps_par INTEGER IERR, I CALL MPI_INIT(IERR) C Define a communicator for the package. mumps_par%COMM = MPI_COMM_WORLD C Initialize an instance of the package C for L U factorization (sym = 0, with working host) mumps_par%JOB = -1

  2. Toward the AdS/CFT gravity dual for high energy collisions. I. Falling into

    Office of Scientific and Technical Information (OSTI)

    the AdS space (Journal Article) | SciTech Connect I. Falling into the AdS space Citation Details In-Document Search Title: Toward the AdS/CFT gravity dual for high energy collisions. I. Falling into the AdS space In the context of the AdS/CFT correspondence we discuss the gravity dual of a high energy collision in a strongly coupled N=4 SYM gauge theory. We suggest a setting in which two colliding objects are made of nondynamical heavy quarks and antiquarks, which allows one to treat the

  3. WOCESSORS MOD DISTRIBUTORS OF REFIBED SOURCB MATWIAL

    Office of Legacy Management (LM)

    WOCESSORS MOD DISTRIBUTORS OF REFIBED SOURCB MATWIAL REFZR m SYmOL1 LILCB .' .. .",I:, ' ,,:r:~' ., " " In aooordame with our telephone oonvorsation of-this date, there is transmitted herewith for 'your um a few of the prooessora and distributors of' refined source material. i. PRocESSoRS~ DISTRIBUTOBS CJI-'GB&& Chemical Co. Pbilliprrburg, Uew Jersey Haywood Chemloal Uorke "' Maymod, bw Jermy City Chesical Company 132 Ploet Z2nd Street Uw York, Ber York Eiimr

  4. Improved Accelerated Stress Tests Based on Fuel Cell Vehicle Data

    SciTech Connect (OSTI)

    Patterson, Timothy; Motupally, Sathya

    2012-06-01

    UTC will led a top-tier team of industry and national laboratory participants to update and improve DOEs Accelerated Stress Tests (ASTs) for hydrogen fuel cells. This in-depth investigation will focused on critical fuel cell components (e.g. membrane electrode assemblies - MEA) whose durability represented barriers for widespread commercialization of hydrogen fuel cell technology. UTC had access to MEA materials that had accrued significant load time under real-world conditions in PureMotion 120 power plant used in transit buses. These materials are referred to as end-of-life (EOL) components in the rest of this document. Advanced characterization techniques were used to evaluate degradation mode progress using these critical cell components extracted from both bus power plants and corresponding materials tested using the DOE ASTs. These techniques were applied to samples at beginning-of-life (BOL) to serve as a baseline. These comparisons advised the progress of the various failure modes that these critical components were subjected to, such as membrane degradation, catalyst support corrosion, platinum group metal dissolution, and others. Gaps in the existing ASTs predicted the degradation observed in the field in terms of these modes were outlined. Using the gaps, new ASTs were recommended and tested to better reflect the degradation modes seen in field operation. Also, BOL components were degraded in a test vehicle at UTC designed to accelerate the bus field operation.

  5. Interpolating the Coulomb phase of little string theory

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

    Lin, Ying -Hsuan; Shao, Shu -Heng; Wang, Yifan; Yin, Xi

    2015-12-03

    We study up to 8-derivative terms in the Coulomb branch effective action of (1,1) little string theory, by collecting results of 4-gluon scattering amplitudes from both perturbative 6D super-Yang-Mills theory up to 4-loop order, and tree-level double scaled little string theory (DSLST). In previous work we have matched the 6-derivative term from the 6D gauge theory to DSLST, indicating that this term is protected on the entire Coulomb branch. The 8-derivative term, on the other hand, is unprotected. In this paper we compute the 8-derivative term by interpolating from the two limits, near the origin and near the infinity onmore » the Coulomb branch, numerically from SU(k) SYM and DSLST respectively, for k=2,3,4,5. We discuss the implication of this result on the UV completion of 6D SYM as well as the strong coupling completion of DSLST. As a result, we also comment on analogous interpolating functions in the Coulomb phase of circle-compactified (2,0) little string theory.« less

  6. (Use of carbon dioxide in inorganic, organic, and bioorganic reactions, Ginosa, Italy, June 17--28, 1989): Foreign trip report

    SciTech Connect (OSTI)

    Smith, H.B.

    1989-07-14

    The traveler attended the NATO Advanced Study Institute in Ginosa, Italy, and presented an oral summary of his research entitled ''Subtle Structural Perturbations at the Active Site of Rubisco by Concerted Site-Directed Mutagenesis and Chemical Modification.'' Topics of the Institute included the chemical fixation, electrochemical and chemical reduction of carbon dioxide, and enzymatic reactions of carbon dioxide. Discussion of ribulose bisphosphate carboxylase/oxygenase, the enzyme that catalyzes by far most of the earth's yearly carbon dioxide fixation, highlighted ongoing investigations of the enzyme within the Protein Engineering Program of ORNL's Biology Division.

  7. X-RAY EMISSION FROM THE SUPER-EARTH HOST GJ 1214

    SciTech Connect (OSTI)

    Lalitha, S.; Singh, K. P.; Poppenhaeger, K.; Czesla, S.; Schmitt, J. H. M. M.

    2014-07-20

    Stellar activity can produce large amounts of high-energy radiation, which is absorbed by the planetary atmosphere leading to irradiation-driven mass loss. We present the detection and an investigation of high-energy emission in a transiting super-Earth host system, GJ 1214, based on XMM-Newton observations. We derive an X-ray luminosity of L{sub X} = 7.4 10{sup 25}ergs{sup 1} and a corresponding activity level of log (L{sub X} /L {sub bol}) ? 5.3. Further, we determine a coronal temperature of about ?3.5MK, which is typical for coronal emission of moderately active low-mass stars. We estimate that GJ 1214 b evaporates at a rate of 1.3 10{sup 10}gs{sup 1} and has lost a total of ?2-5.6 M {sub ?}.

  8. CO2-Binding Organic Liquids, an Integrated Acid Gas Capture System

    SciTech Connect (OSTI)

    Heldebrant, David J.; Koech, Phillip K.; Rainbolt, James E.; Zheng, Feng

    2011-04-01

    Amine systems are effective for CO2 capture, but they are still inefficient because the solvent regeneration energy is largely defined by the amount of water in the process. Most amines form heat-stable salts with SO2 and COS resulting in parasitic solvent loss and degradation. Stripping the CO2-rich solvent is energy intensive it requires temperatures above 100 ?C due to the high specific heat and heat of vaporization of water. CO2-capture processes could be much more energy efficient in a water free amine process. In addition, if the capture-material is chemically compatible with other acid gases, less solvent would be lost to heat-stable salts and the process economics would be further improved. One such system that can address these concerns is Binding Organic Liquids (BOLs), a class of switchable ionic liquids.

  9. AIN MAXL

    Office of Legacy Management (LM)

    - ----.-..-. ..- -.__-..-__ -- ._... ----_ ._ _..._ .____.. _. . ' 1 AIN MAXL c 8. I 4 r' l k- 7 : $-' :;y";:-i::. .: I ;,y. I ' . .i c. L. B[arl, &mm Markagm3?, Fernrld Arm Cinotnaati, Ohio NOVEMBER 2 0 ?$#@ F. W. B~EIOPO, Uireetor, Produution Ditirkon, H6r Yark Operationa Offioa mxi n&i BOL1XBE) - 8TyOHl38 wudr fmmf, axPAW SIfkBQL I m t#bmum); 4 PfP~ ' s" This 56 in rr+W8mti~ of a trluphona aonrurcurtian an &m13ber Zg betwese 8. 18. ~iObtif$on fUid ii. ii. HOtO 6oPl66ming

  10. IMPLICATIONS OF MASS AND ENERGY LOSS DUE TO CORONAL MASS EJECTIONS ON MAGNETICALLY ACTIVE STARS

    SciTech Connect (OSTI)

    Drake, Jeremy J.; Cohen, Ofer; Yashiro, Seiji; Gopalswamy, Nat

    2013-02-20

    Analysis of a database of solar coronal mass ejections (CMEs) and associated flares over the period 1996-2007 finds well-behaved power-law relationships between the 1-8 A flare X-ray fluence and CME mass and kinetic energy. We extrapolate these relationships to lower and higher flare energies to estimate the mass and energy loss due to CMEs from stellar coronae, assuming that the observed X-ray emission of the latter is dominated by flares with a frequency as a function of energy dn/dE = kE {sup -{alpha}}. For solar-like stars at saturated levels of X-ray activity, the implied losses depend fairly weakly on the assumed value of {alpha} and are very large: M-dot {approx}5 Multiplication-Sign 10{sup -10} M{sub sun} yr{sup -1} and E-dot {approx}0.1 L{sub sun}. In order to avoid such large energy requirements, either the relationships between CME mass and speed and flare energy must flatten for X-ray fluence {approx}> 10{sup 31} erg, or the flare-CME association must drop significantly below 1 for more energetic events. If active coronae are dominated by flares, then the total coronal energy budget is likely to be up to an order of magnitude larger than the canonical 10{sup -3} L {sub bol} X-ray saturation threshold. This raises the question of what is the maximum energy a magnetic dynamo can extract from a star? For an energy budget of 1% of L {sub bol}, the CME mass loss rate is about 5 Multiplication-Sign 10{sup -11} M {sub Sun} yr{sup -1}.

  11. Method of making fine-grained triaminotrinitrobenzene

    DOE Patents [OSTI]

    Benziger, Theodore M. (Santa Fe, NM)

    1984-01-01

    A method of forming a fine-grained species of the insensitive high explosive sym-triaminotrinitrobenzene (TATB) without grinding. In accordance with the method, 1,3,5-trichloro-2,4,6-trinitrobenzene (TCTNB) is aminated by reaction with gaseous ammonia in an emulsion of toluene in water. The ratio of water to toluene in the emulsion is selected so that toluene is the dispersed phase in the emulsion. The size of the dispersed TCTNB-containing toluene droplets determines the particle size of the resulting TATB. The emulsion is preferably formed with an emulsifier such as ammonium oleate, which may be generated in situ from oleic acid, and stabilized with a protective colloid such as polyvinyl alcohol.

  12. Method of making fine-grained triaminotrinitrobenzene

    DOE Patents [OSTI]

    Benziger, T.M.

    1983-07-26

    A method is given for forming a fine-grained species of the insensitive high explosive sym-triaminotrinitrobenzene (TATB) without grinding. In accordance with the method, 1,3,5-trichloro-2,4,6-trinitrobenzene (TCTNB) is aminated by reaction with gaseous ammonia in an emulsion of toluene in water. The ratio of water to toluene in the emulsion is selected so that toluene is the dispersed phase in the emulsion. The size of the dispersed TCTNB-containing toluene droplets determines the particle size of the resulting TATB. The emulsion is preferably formed with an emulsifier such as ammonium oleate, which may be generated in situ from oleic acid, and stabilized with a protective colloid such as polyvinyl alcohol.

  13. Novel bimetallic dispersed catalysts for temperature-programmed coal liquefaction. Technical progress report, October--December 1993

    SciTech Connect (OSTI)

    Schmidt, E.; Kirby, S.; Song, Chunshan; Schobert, H.H.

    1994-04-01

    Development of new catalysts is a promising approach to more, efficient coal liquefaction. It has been recognized that dispersed catalysts can be superior to supported catalysts for primary liquefaction of coals, because the control of initial coal dissolution or depolymerization requires infinite contact between the catalyst and coal. The primary objective of this research is to explore the potential of bimetallic dispersed catalysts from heterometallic molecular precursors in their use in model compound liquefaction reactions. This quarterly report describes the use of three precursors in model compound reactions. The first catalyst is a heterometallic complex consisting of two transition metals, Mo and Ni, and sulfur in a single molecule. The second is a thiocubane type complex consisting of cobalt, molybdenum and sulfur. The third is a thiocubane type cluster consisting of iron and sulfur and the fourth, the pure inorganic salt ammonium tetrathiomolybdate (ATM). It was found that the structure and the ligands in the model complexes affect the activity of the resulting catalyst significantly. The optimum reaction at a pressure of 6.9 MPa hydrogen gas varied for different catalysts. The bimetallic catalysts generated in situ from the organometallic precursor are more active than monometallic catalysts like ATTM and the thiocubane type cluster Fe{sub 4}. Main products are hydrogenated phenanthrene derivatives, like DBP, THP, sym-OHP, cis- and trans-unsym-OHP with minor isomerization products such as sym-OHA. Our results indicate that other transition metal and ligand combinations in the organometallic precursors and the use of another model compound could result in substantially higher conversion activity.

  14. The CFE Treaty and changed conditions in Europe

    SciTech Connect (OSTI)

    Allentuck, J.

    1994-08-01

    The Treaty on Conventional Forces in Europe (CFE) was signed in November 1990 by sixteen nations, members of the North Atlantic Treaty Organization (NATO), and six nations, members of the Warsaw Treaty Organization (WTO). It was resigned to prevent a major surprise attack in Europe by the conventional forces of one Treaty Organization against those of the other and was the first major arms control treaty to address conventional weapons. This paper focuses on how CFE adapted to changes in the military-political situation in Europe which occurred after 1990 and failed to adapt to others. Suggestions are offered on how it might be changed to make it more relevant under these changed conditions.

  15. TORUS AND ACTIVE GALACTIC NUCLEUS PROPERTIES OF NEARBY SEYFERT GALAXIES: RESULTS FROM FITTING INFRARED SPECTRAL ENERGY DISTRIBUTIONS AND SPECTROSCOPY

    SciTech Connect (OSTI)

    Alonso-Herrero, Almudena; Ramos Almeida, Cristina; Mason, Rachel; Asensio Ramos, Andres; Rodriguez Espinosa, Jose Miguel; Perez-Garcia, Ana M.; Roche, Patrick F.; Levenson, Nancy A.; Elitzur, Moshe; Packham, Christopher; Young, Stuart; Diaz-Santos, Tanio

    2011-08-01

    We used the CLUMPY torus models and a Bayesian approach to fit the infrared spectral energy distributions and ground-based high angular resolution mid-infrared spectroscopy of 13 nearby Seyfert galaxies. This allowed us to put tight constraints on torus model parameters such as the viewing angle i, the radial thickness of the torus Y, the angular size of the cloud distribution {sigma}{sub torus}, and the average number of clouds along radial equatorial rays N{sub 0}. We found that the viewing angle i is not the only parameter controlling the classification of a galaxy into type 1 or type 2. In principle, type 2s could be viewed at any viewing angle i as long as there is one cloud along the line of sight. A more relevant quantity for clumpy media is the probability for an active galactic nucleus (AGN) photon to escape unabsorbed. In our sample, type 1s have relatively high escape probabilities, P{sub esc} {approx} 12%-44%, while type 2s, as expected, tend to have very low escape probabilities. Our fits also confirmed that the tori of Seyfert galaxies are compact with torus model radii in the range 1-6 pc. The scaling of the models to the data also provided the AGN bolometric luminosities L{sub bol}(AGN), which were found to be in good agreement with estimates from the literature. When we combined our sample of Seyfert galaxies with a sample of PG quasars from the literature to span a range of L{sub bol}(AGN) {approx} 10{sup 43}-10{sup 47} erg s{sup -1}, we found plausible evidence of the receding torus. That is, there is a tendency for the torus geometrical covering factor to be lower (f{sub 2} {approx} 0.1-0.3) at high AGN luminosities than at low AGN luminosities (f{sub 2} {approx} 0.9-1 at {approx}10{sup 43}-10{sup 44} erg s{sup -1}). This is because at low AGN luminosities the tori appear to have wider angular sizes (larger {sigma}{sub torus}) and more clouds along radial equatorial rays. We cannot, however, rule out the possibility that this is due to contamination by extended dust structures not associated with the dusty torus at low AGN luminosities, since most of these in our sample are hosted in highly inclined galaxies.

  16. The factory and the beehive. II. Activity and rotation in Praesepe and the Hyades

    SciTech Connect (OSTI)

    Douglas, S. T.; Ageros, M. A.; Bowsher, E. C.; Lemonias, J. J.; Fierroz, D. F.; Covey, K. R.; Bochanski, J. J.; Cargile, P. A.; Kraus, A.; Law, N. M.; Arce, H. G.; Kundert, A.

    2014-11-10

    Open clusters are collections of stars with a single, well-determined age, and can be used to investigate the connections between angular-momentum evolution and magnetic activity over a star's lifetime. We present the results of a comparative study of the relationship between stellar rotation and activity in two benchmark open clusters: Praesepe and the Hyades. As they have the same age and roughly solar metallicity, these clusters serve as an ideal laboratory for testing the agreement between theoretical and empirical rotation-activity relations at ?600 Myr. We have compiled a sample of 720 spectramore than half of which are new observationsfor 516 high-confidence members of Praesepe; we have also obtained 139 new spectra for 130 high-confidence Hyads. We have also collected rotation periods (P {sub rot}) for 135 Praesepe members and 87 Hyads. To compare H? emission, an indicator of chromospheric activity, as a function of color, mass, and Rossby number R{sub o} , we first calculate an expanded set of ? values, with which we can obtain the H? to bolometric luminosity ratio, L {sub H?}/L {sub bol}, even when spectra are not flux-calibrated and/or stars lack reliable distances. Our ? values cover a broader range of stellar masses and colors (roughly equivalent to spectral types from K0 to M9), and exhibit better agreement between independent calculations, than existing values. Unlike previous authors, we find no difference between the two clusters in their H? equivalent width or L {sub H?}/L {sub bol} distributions, and therefore take the merged H? and P {sub rot} data to be representative of 600 Myr old stars. Our analysis shows that H? activity in these stars is saturated for R{sub o}?0.11{sub ?0.03}{sup +0.02}. Above that value activity declines as a power-law with slope ?=?0.73{sub ?0.12}{sup +0.16}, before dropping off rapidly at R{sub o} ? 0.4. These data provide a useful anchor for calibrating the age-activity-rotation relation beyond 600 Myr.

  17. Recovery Act: Web-based CO{sub 2} Subsurface Modeling

    SciTech Connect (OSTI)

    Paolini, Christopher; Castillo, Jose

    2012-11-30

    The Web-based CO{sub 2} Subsurface Modeling project focused primarily on extending an existing text-only, command-line driven, isothermal and isobaric, geochemical reaction-transport simulation code, developed and donated by Sienna Geodynamics, into an easier-to-use Web-based application for simulating long-term storage of CO{sub 2} in geologic reservoirs. The Web-based interface developed through this project, publically accessible via URL http://symc.sdsu.edu/, enables rapid prototyping of CO{sub 2} injection scenarios and allows students without advanced knowledge of geochemistry to setup a typical sequestration scenario, invoke a simulation, analyze results, and then vary one or more problem parameters and quickly re-run a simulation to answer what-if questions. symc.sdsu.edu has 2x12 core AMD Opteron 6174 2.20GHz processors and 16GB RAM. The Web-based application was used to develop a new computational science course at San Diego State University, COMP 670: Numerical Simulation of CO{sub 2} Sequestration, which was taught during the fall semester of 2012. The purpose of the class was to introduce graduate students to Carbon Capture, Use and Storage (CCUS) through numerical modeling and simulation, and to teach students how to interpret simulation results to make predictions about long-term CO{sub 2} storage capacity in deep brine reservoirs. In addition to the training and education component of the project, significant software development efforts took place. Two computational science doctoral and one geological science masters student, under the direction of the PIs, extended the original code developed by Sienna Geodynamics, named Sym.8. New capabilities were added to Sym.8 to simulate non-isothermal and non-isobaric flows of charged aqueous solutes in porous media, in addition to incorporating HPC support into the code for execution on many-core XSEDE clusters. A successful outcome of this project was the funding and training of three new computational science students and one geological science student in technologies relevant to carbon sequestration and problems involving flow in subsurface media. The three computational science students are currently finishing their doctorial studies on different aspects of modeling CO{sub 2} sequestration, while the geological science student completed his masters thesis in modeling the thermal response of CO{sub 2} injection in brine and, as a direct result of participation in this project, is now employed at ExxonMobil as a full-time staff geologist.

  18. Quarterly Report, Dec. 1, 1999-Feb. 29, 2000, Novel, Integrated Reactor

    SciTech Connect (OSTI)

    Paramono, D.V.

    2000-03-29

    The basic core design requirements were defined in the previous reporting period. During the second quarter, several series of neutronic calculations were performed. Monte Carlo BOL (Beginning-of-Life) simulations were performed to evaluate the impact of various design alternatives on key core parameters. Fuel design alternatives that were examined by these studies included: fuel form (oxide, carbide and nitride) (note that due to the AMTEC high temperature requirement, metal fuel was eliminated from further considerations); fissile fuel content, and fuel rod and lattice pitch. The key neutronic parameters that were compared include: core reactivity, neutron spectrum, fast neutron flux and projected lifetime fast fluence (E > 0.1 MeV), and material damage indicator, dpa (displacement-per-atom) and dpa rate. These analyses indicated that the fast neutron fluence will probably be the most limiting factor, with estimated fast fluence ranging between 3 x 10{sup 23} n/cm{sup 2} and up to 9 x 10{sup 23} n/cm{sup 2}, depending on the fuel characteristics. Therefore, different fuel forms were examined and the projected fast fluence and dpa compared. Using MOX fuel results in the highest fast fluence and dpa, about 10% higher than for the carbide or nitride fuel. The nitride fuel leads to the lowest dpa, for the same reactor power density, up to {approx} 4% and {approx} 7% lower than for the carbide and MOX fuel, respectively.

  19. RELAP5 model of the high flux isotope reactor with low enriched fuel thermal flux profiles

    SciTech Connect (OSTI)

    Banfield, J.; Mervin, B.; Hart, S.; Ritchie, J.; Walker, S.; Ruggles, A.; Maldonado, G. I. [Dept. of Nuclear Engineering, Univ. of Tennessee Knoxville, Knoxville, TN 37996-2300 (United States)

    2012-07-01

    The High Flux Isotope Reactor (HFIR) currently uses highly enriched uranium (HEU) fabricated into involute-shaped fuel plates. It is desired that HFIR be able to use low enriched uranium (LEU) fuel while preserving the current performance capability for its diverse missions in material irradiation studies, isotope production, and the use of neutron beam lines for basic research. Preliminary neutronics and depletion simulations of HFIR with LEU fuel have arrived to feasible fuel loadings that maintain the neutronics performance of the reactor. This article illustrates preliminary models developed for the analysis of the thermal-hydraulic characteristics of the LEU core to ensure safe operation of the reactor. The beginning of life (BOL) LEU thermal flux profile has been modeled in RELAP5 to facilitate steady state simulation of the core cooling, and of anticipated and unanticipated transients. Steady state results are presented to validate the new thermal power profile inputs. A power ramp, slow depressurization at the outlet, and flow coast down transients are also evaluated. (authors)

  20. Microstructural evolution of U(Mo)Al(Si) dispersion fuel under irradiation Destructive analyses of the LEONIDAS E-FUTURE plates

    SciTech Connect (OSTI)

    A. Leenaers; S. Van den Berghe; J. Van Eyken; E. Koonen; F. Charollais; P. Lemoine; Y. Calzavara; H. Guyon; C. Jarousse; D. Geslin; D. Wachs; D. Keiser; A. Robinson; G. Hofman; Y. S. Kim

    2013-10-01

    Several irradiation experiments have confirmed the positive effect of adding Si to the matrix of an U(Mo) dispersion fuel plate on its in-pile irradiation behavior. E-FUTURE, the first experiment of the LEONIDAS program, was performed to select an optimum Si concentration and fuel plate heat treatment parameters for further qualification. It consisted of the irradiation of 4 distinct (regarding Si content and heat treatments), full size flat fuel plates in the BR2 reactor under bounding conditions (470 W/cm2 peak BOL power, approximately 70% peak burn-up). After the irradiation, the E-FUTURE plates were examined non-destructively and found to have pillowed in the highest burn-up positions. The destructive post-irradiation examination confirmed that the fuel evolves in a stable way up to a burn-up of 60%235U. Even in the deformed area (pillow) the U(Mo) fuel itself shows stable behavior and remaining matrix material was present. From the calculation of the volume fractions, the positive effect of a higher Si amount added to the matrix and the higher annealing temperature can be derived.

  1. 1-MeV-Electron Irradiation of GaInAsN Cells: Preprint

    SciTech Connect (OSTI)

    Kurtz, S.; King, R. R.; Edmondson, K. M.; Friedman, D. J.; Karam, N. H.

    2002-05-01

    This conference paper describes the GaInAsN cells that are measured to retain 933% and 894% of their original efficiency after exposure to 5 X 1014 and 1 X 1015 cm-2 1-MeV electrons, respectively. The rate of degradation is not correlated with the performance at beginning of life (BOL). The depletion width remains essentially unchanged, increasing by< 1%. Temperature-coefficient data for GaInAsN cells are also presented. These numbers are used to project the efficiency of GaInAsN-containing multijunction cells. The GaInAsN junction is not currently predicted to increase the efficiencies of the multijunction cells. Nevertheless, GaInAsN-containing multijunction cell efficiencies are predicted to be comparable to those of the conventional structures, and even small improvements in the GaInAsN cell may lead to higher multijunction cell efficiencies, especially for high-radiation applications and when cell operating temperature is low.

  2. The high-efficiency jets magnetically accelerated from a thin disk in powerful lobe-dominated FRII radio galaxies

    SciTech Connect (OSTI)

    Li, Shuang-Liang

    2014-06-10

    A maximum jet efficiency line R ? 25 (R = L {sub jet}/L {sub bol}), found in FRII radio galaxies by Fernandes et al., was extended to cover the full range of jet power by Punsly. Recent general relativistic magnetohydrodynamic simulations of jet formation have mainly focused on the enhancement of jet power. In this work, we suggest that the jet efficiency could be very high even for conventional jet power if the radiative efficiency of disks was much smaller. We adopt the model of a thin disk with magnetically driven winds to investigate the observational high-efficiency jets in FRII radio galaxies. It is found that the structure of a thin disk can be significantly altered by the feedback of winds. The temperature of a disk gradually decreases with increasing magnetic field; the disk density, surface density, and pressure also change enormously. The lower temperature and higher surface density in the inner disk result in the rapid decrease of radiative efficiency. Thus, the jet efficiency is greatly improved even if the jet power is conventional. Our results can explain the observations quite well. The theoretical maximum jet efficiency of R ? 1000 suggested by our calculations is large enough to explain all of the high jet efficiency in observations, even considering the episodic activity of jets.

  3. A Maximally Supersymmetric Kondo Model

    SciTech Connect (OSTI)

    Harrison, Sarah; Kachru, Shamit; Torroba, Gonzalo; /Stanford U., Phys. Dept. /SLAC

    2012-02-17

    We study the maximally supersymmetric Kondo model obtained by adding a fermionic impurity to N = 4 supersymmetric Yang-Mills theory. While the original Kondo problem describes a defect interacting with a free Fermi liquid of itinerant electrons, here the ambient theory is an interacting CFT, and this introduces qualitatively new features into the system. The model arises in string theory by considering the intersection of a stack of M D5-branes with a stack of N D3-branes, at a point in the D3 worldvolume. We analyze the theory holographically, and propose a dictionary between the Kondo problem and antisymmetric Wilson loops in N = 4 SYM. We perform an explicit calculation of the D5 fluctuations in the D3 geometry and determine the spectrum of defect operators. This establishes the stability of the Kondo fixed point together with its basic thermodynamic properties. Known supergravity solutions for Wilson loops allow us to go beyond the probe approximation: the D5s disappear and are replaced by three-form flux piercing a new topologically non-trivial S3 in the corrected geometry. This describes the Kondo model in terms of a geometric transition. A dual matrix model reflects the basic properties of the corrected gravity solution in its eigenvalue distribution.

  4. Interactions between ingredients in IMX-101: Reactive Chemical Processes Control Insensitive Munitions Properties

    SciTech Connect (OSTI)

    Maharrey, Sean P.; Wiese-Smith, Deneille; Highley, Aaron M.; Behrens, Richard; Kay, Jeffrey J

    2014-03-01

    Simultaneous Thermogravimetric Modulated Beam Mass Spectrometry (STMBMS) measurements have been conducted on a new Insensitive Munitions (IM) formulation. IMX-101 is the first explosive to be fully IM qualified under new NATO STANAG guidelines for fielded munitions. The formulation uses dinitroanisole (DNAN) as a new melt cast material to replace TNT, and shows excellent IM performance when formulated with other energetic ingredients. The scope of this work is to explain this superior IM performance by investigating the reactive processes occurring in the material when subjected to a well-controlled thermal environment. The dominant reactive processes observed were a series of complex chemical interactions between the three main ingredients (DNAN, NQ, and NTO) that occurs well below the onset of the normal decomposition process of any of the individual ingredients. This process shifts the thermal response of the formulations to a much lower temperature, where the kinetically controlled reaction processes are much slower. This low temperature shift has the effect of allowing the reactions to consume the reactive solids (NQ, NTO) well before the reaction rates increase and reach thermal runaway, resulting in a relatively benign response to the external stimuli. The main findings on the interaction processes are presented.

  5. Development and Validation of a Lifecycle-based Prognostics Architecture with Test Bed Validation

    SciTech Connect (OSTI)

    Hines, J. Wesley; Upadhyaya, Belle; Sharp, Michael; Ramuhalli, Pradeep; Jeffries, Brien; Nam, Alan; Strong, Eric; Tong, Matthew; Welz, Zachary; Barbieri, Federico; Langford, Seth; Meinweiser, Gregory; Weeks, Matthew

    2014-11-06

    On-line monitoring and tracking of nuclear plant system and component degradation is being investigated as a method for improving the safety, reliability, and maintainability of aging nuclear power plants. Accurate prediction of the current degradation state of system components and structures is important for accurate estimates of their remaining useful life (RUL). The correct quantification and propagation of both the measurement uncertainty and model uncertainty is necessary for quantifying the uncertainty of the RUL prediction. This research project developed and validated methods to perform RUL estimation throughout the lifecycle of plant components. Prognostic methods should seamlessly operate from beginning of component life (BOL) to end of component life (EOL). We term this "Lifecycle Prognostics." When a component is put into use, the only information available may be past failure times of similar components used in similar conditions, and the predicted failure distribution can be estimated with reliability methods such as Weibull Analysis (Type I Prognostics). As the component operates, it begins to degrade and consume its available life. This life consumption may be a function of system stresses, and the failure distribution should be updated to account for the system operational stress levels (Type II Prognostics). When degradation becomes apparent, this information can be used to again improve the RUL estimate (Type III Prognostics). This research focused on developing prognostics algorithms for the three types of prognostics, developing uncertainty quantification methods for each of the algorithms, and, most importantly, developing a framework using Bayesian methods to transition between prognostic model types and update failure distribution estimates as new information becomes available. The developed methods were then validated on a range of accelerated degradation test beds. The ultimate goal of prognostics is to provide an accurate assessment for RUL predictions, with as little uncertainty as possible. From a reliability and maintenance standpoint, there would be improved safety by avoiding all failures. Calculated risk would decrease, saving money by avoiding unnecessary maintenance. One major bottleneck for data-driven prognostics is the availability of run-to-failure degradation data. Without enough degradation data leading to failure, prognostic models can yield RUL distributions with large uncertainty or mathematically unsound predictions. To address these issues a "Lifecycle Prognostics" method was developed to create RUL distributions from Beginning of Life (BOL) to End of Life (EOL). This employs established Type I, II, and III prognostic methods, and Bayesian transitioning between each Type. Bayesian methods, as opposed to classical frequency statistics, show how an expected value, a priori, changes with new data to form a posterior distribution. For example, when you purchase a component you have a prior belief, or estimation, of how long it will operate before failing. As you operate it, you may collect information related to its condition that will allow you to update your estimated failure time. Bayesian methods are best used when limited data are available. The use of a prior also means that information is conserved when new data are available. The weightings of the prior belief and information contained in the sampled data are dependent on the variance (uncertainty) of the prior, the variance (uncertainty) of the data, and the amount of measured data (number of samples). If the variance of the prior is small compared to the uncertainty of the data, the prior will be weighed more heavily. However, as more data are collected, the data will be weighted more heavily and will eventually swamp out the prior in calculating the posterior distribution of model parameters. Fundamentally Bayesian analysis updates a prior belief with new data to get a posterior belief. The general approach to applying the Bayesian method to lifecycle prognostics consisted of identifying the prior, which is the RUL es

  6. Neutronic evaluation of a non-fertile fuel for the disposition of weapons-grade plutonium in a boiling water reactor

    SciTech Connect (OSTI)

    Sterbentz, J.W.

    1994-10-01

    A new non-fertile, weapons-grade plutonium oxide fuel concept is developed and evaluated for deep burn applications in a boiling water reactor environment using the General Electric 8x8 Advanced Boiling Water Reactor (ABWR) fuel assembly dimensions and pitch. Detailed infinite lattice fuel burnup results and neutronic performance characteristics are given and although preliminary in nature, clearly demonstrate the fuel`s potential as an effective means to expedite the disposition of plutonium in existing light water reactors. The new non-fertile fuel concept is an all oxide composition containing plutonia, zirconia, calcia, and erbia having the following design weight percentages: 8.3; 80.4; 9.7; and 1.6. This fuel composition in an infinite fuel lattice operating at linear heat generation rates of 6.0 or 12.0 kW/ft per rod can remain critical for up to 1,200 and 600 Effective Full Power Days (EFPD), respectively, and achieve a burnup of 7.45 {times} 10{sup 20} f/cc. These burnups correspond to a 71--73% total plutonium isotope destruction and a 91--94% destruction of the {sup 239}Pu isotope for the 0--40% moderator steam void condition. Total plutonium destruction greater than 73% is possible with a fuel management scheme that allows subcritical fuel assemblies to be driven by adjacent high reactivity assemblies. The fuel exhibits very favorable neutron characteristics from beginning-of-life (BOL) to end-of-life (EOL). Prompt fuel Doppler coefficient of reactivity are negative, with values ranging between {minus}0.4 to {minus}2.0 pcm/K over the temperature range of 900 to 2,200 K. The ABWR fuel lattice remains in an undermoderated condition for both hot operational and cold startup conditions over the entire fuel burnup lifetime.

  7. Offset active galactic nuclei as tracers of galaxy mergers and supermassive black hole growth

    SciTech Connect (OSTI)

    Comerford, Julia M.; Greene, Jenny E.

    2014-07-10

    Offset active galactic nuclei (AGNs) are AGNs that are in ongoing galaxy mergers, which produce kinematic offsets in the AGNs relative to their host galaxies. Offset AGNs are also close relatives of dual AGNs. We conduct a systematic search for offset AGNs in the Sloan Digital Sky Survey by selecting AGN emission lines that exhibit statistically significant line-of-sight velocity offsets relative to systemic. From a parent sample of 18,314 Type 2 AGNs at z < 0.21, we identify 351 offset AGN candidates with velocity offsets of 50 km s{sup 1} < |?v| < 410 km s{sup 1}. When we account for projection effects in the observed velocities, we estimate that 4%-8% of AGNs are offset AGNs. We designed our selection criteria to bypass velocity offsets produced by rotating gas disks, AGN outflows, and gravitational recoil of supermassive black holes, but follow-up observations are still required to confirm our candidates as offset AGNs. We find that the fraction of AGNs that are offset candidates increases with AGN bolometric luminosity, from 0.7% to 6% over the luminosity range 43 < log (L{sub bol}) [erg s{sup 1}] <46. If these candidates are shown to be bona fide offset AGNs, then this would be direct observational evidence that galaxy mergers preferentially trigger high-luminosity AGNs. Finally, we find that the fraction of AGNs that are offset AGN candidates increases from 1.9% at z = 0.1 to 32% at z = 0.7, in step with the growth in the galaxy merger fraction over the same redshift range.

  8. Pan-STARRS1 DISCOVERY OF TWO ULTRALUMINOUS SUPERNOVAE AT z Almost-Equal-To 0.9

    SciTech Connect (OSTI)

    Chomiuk, L.; Chornock, R.; Soderberg, A. M.; Berger, E.; Foley, R. J.; Kirshner, R. P.; Czekala, I.; Chevalier, R. A.; Huber, M. E.; Gezari, S.; Riess, A.; Rodney, S. A.; Narayan, G.; Stubbs, C. W.; Rest, A.; Smartt, S. J.; Tonry, J. L.; Burgett, W. S.; Chambers, K. C.; Wood-Vasey, W. M.; and others

    2011-12-20

    We present the discovery of two ultraluminous supernovae (SNe) at z Almost-Equal-To 0.9 with the Pan-STARRS1 Medium Deep Survey. These SNe, PS1-10ky and PS1-10awh, are among the most luminous SNe ever discovered, comparable to the unusual transients SN 2005ap and SCP 06F6. Like SN 2005ap and SCP 06F6, they show characteristic high luminosities (M{sub bol} Almost-Equal-To -22.5 mag), blue spectra with a few broad absorption lines, and no evidence for H or He. We have constructed a full multi-color light curve sensitive to the peak of the spectral energy distribution in the rest-frame ultraviolet, and we have obtained time series spectroscopy for these SNe. Given the similarities between the SNe, we combine their light curves to estimate a total radiated energy over the course of explosion of (0.9-1.4) Multiplication-Sign 10{sup 51} erg. We find photospheric velocities of 12,000-19,000 km s{sup -1} with no evidence for deceleration measured across {approx}3 rest-frame weeks around light curve peak, consistent with the expansion of an optically thick massive shell of material. We show that, consistent with findings for other ultraluminous SNe in this class, radioactive decay is not sufficient to power PS1-10ky, and we discuss two plausible origins for these events: the initial spin-down of a newborn magnetar in a core-collapse SN, or SN shock breakout from the dense circumstellar wind surrounding a Wolf-Rayet star.

  9. MN Lup: X-RAYS FROM A WEAKLY ACCRETING T TAURI STAR

    SciTech Connect (OSTI)

    Guenther, H. M.; Wolk, S. J.; Wolter, U.; Robrade, J.

    2013-07-01

    Young T Tauri stars (TTS) are surrounded by an accretion disk, which over time disperses due to photoevaporation, accretion, and possibly planet formation. The accretion shock on the central star produces an UV/optical veiling continuum, line emission, and X-ray signatures. As the accretion rate decreases, the impact on the central star must change. In this article we study MN Lup, a young star where no indications of a disk are seen in IR observations. We present XMM-Newton and VLT/UVES observations, some of them taken simultaneously. The X-ray data show that MN Lup is an active star with L{sub X} /L{sub bol} close to the saturation limit. However, we find high densities (n{sub e} > 3 Multiplication-Sign 10{sup 10} cm{sup -3}) in the X-ray grating spectrum. This can be well fitted using an accretion shock model with an accretion rate of 2 Multiplication-Sign 10{sup -11} M{sub Sun} yr{sup -1}. Despite the simple H{alpha} line profile which has a broad component, but no absorption signatures as typically seen on accreting TTS, we find rotational modulation in Ca II K and in photospheric absorption lines. These line profile modulations do not clearly indicate the presence of a localized hot accretion spot on the star. In the H{alpha} line we see a prominence in absorption about 2R{sub *} above the stellar surface-the first of its kind on a TTS. MN Lup is also the only TTS where accretion is seen, but no dust disk is detected that could fuel it. We suggest that MN Lup presents a unique and short-lived state in the disk evolution. It may have lost its dust disk only recently and is now accreting the remaining gas at a very low rate.

  10. Revisiting the axion bounds from the Galactic white dwarf luminosity function

    SciTech Connect (OSTI)

    Bertolami, M.M. Miller [Max-Planck-Institut fr Astrophysik, Karl-Schwarzschild-Str. 1, 85748, Garching (Germany); Melendez, B.E.; Althaus, L.G. [Instituto de Astrofsica de La Plata, UNLP-CONICET, Paseo del Bosque s/n, 1900 La Plata (Argentina); Isern, J., E-mail: marcelo@MPA-Garching.MPG.DE, E-mail: brenmele@gmail.com, E-mail: althaus@fcaglp.fcaglp.unlp.edu.ar, E-mail: isern@ieec.cat [Institut de Cincies de l'Espai (CSIC), Facultat de Cincies, Campus UAB, Torre C5-parell, 08193 Bellaterra (Spain)

    2014-10-01

    It has been shown that the shape of the luminosity function of white dwarfs (WDLF) is a powerful tool to check for the possible existence of DFSZ-axions, a proposed but not yet detected type of weakly interacting particles. With the aim of deriving new constraints on the axion mass, we compute in this paper new theoretical WDLFs on the basis of WD evolving models that incorporate the feedback of axions on the thermal structure of the white dwarf. We find that the impact of the axion emission into the neutrino emission can not be neglected at high luminosities M{sub Bol}?<8) and that the axion emission needs to be incorporated self-consistently into the evolution of the white dwarfs when dealing with axion masses larger than m{sub a} cos {sup 2}??>5 meV (i.e. axion-electron coupling constant g{sub ae}?>1.4נ10{sup -13}). We went beyond previous works by including 5 different derivations of the WDLF in our analysis. Then we have performed ?{sup 2}-tests to have a quantitative measure of the agreement between the theoretical WDLFs computed under the assumptions of different axion masses and normalization methods --- and the observed WDLFs of the Galactic disk. While all the WDLF studied in this work disfavour axion masses in the range suggested by asteroseismology m{sub a} cos {sup 2}??>10 meV; g{sub ae}?>2.8נ10{sup -13}) lower axion masses can not be discarded from our current knowledge of the WDLF of the Galactic Disk. A larger set of completely independent derivations of the WDLF of the galactic disk as well as a detailed study of the uncertainties of the theoretical WDLFs is needed before quantitative constraints on the axion-electron coupling constant can be made.

  11. THERMAL AND RADIATIVE ACTIVE GALACTIC NUCLEUS FEEDBACK HAVE A LIMITED IMPACT ON STAR FORMATION IN HIGH-REDSHIFT GALAXIES

    SciTech Connect (OSTI)

    Roos, Orianne; Juneau, Stphanie; Bournaud, Frdric; Gabor, Jared M.

    2015-02-10

    The effects of active galactic nuclei (AGNs) on their host galaxies depend on the coupling between the injected energy and the interstellar medium (ISM). Here, we model and quantify the impact of long-range AGN ionizing radiationin addition to the often considered small-scale energy depositionon the physical state of the multi-phase ISM of the host galaxy and on its total star formation rate (SFR). We formulate an AGN spectral energy distribution matched with observations, which we use with the radiative transfer (RT) code Cloudy to compute AGN ionization in a simulated high-redshift disk galaxy. We use a high-resolution (?6 pc) simulation including standard thermal AGN feedback and calculate RT in post-processing. Surprisingly, while these models produce significant AGN-driven outflows, we find that AGN ionizing radiation and heating reduce the SFR by a few percent at most for a quasar luminosity (L {sub bol} = 10{sup 46.5} erg s{sup 1}). Although the circumgalactic gaseous halo can be kept almost entirely ionized by the AGN, most star-forming clouds (n ? 10{sup 2} {sup } {sup 3} cm{sup 3}) and even the reservoirs of cool atomic gas (n ? 0.3-10 cm{sup 3})which are the sites of future star formation (SF; 100-200 Myr), are generally too dense to be significantly affected. Our analysis ignores any absorption from a putative torus, making our results upper limits on the effects of ionizing radiation. Therefore, while the AGN-driven outflows can remove substantial amounts of gas in the long term, the impact of AGN feedback on the SF efficiency in the interstellar gas in high-redshift galaxies is marginal, even when long-range radiative effects are accounted for.

  12. The identification of extreme asymptotic giant branch stars and red supergiants in M33 with 24??m variability

    SciTech Connect (OSTI)

    Montiel, Edward J.; Clayton, Geoffrey C.; Johnson, Christopher B.; Srinivasan, Sundar; Engelbracht, Charles W.

    2015-02-01

    We present the first detection of 24 ?m variability in 24 sources in the Local Group galaxy M33. These results are based on 4 epochs of Multiband Imaging Photometer for Spitzer observations, which are irregularly spaced over ?750 days. We find that these sources are constrained exclusively to the Holmberg radius of the galaxy, which increases their chances of being members of M33. We have constructed spectral energy distributions (SEDs) ranging from the optical to the submillimeter to investigate the nature of these objects. We find that 23 of our objects are most likely heavily self-obscured, evolved stars, while the remaining source is the Giant H ii region, NGC 604. We believe that the observed variability is the intrinsic variability of the central star reprocessed through their circumstellar dust shells. Radiative transfer modeling was carried out to determine their likely chemical composition, luminosity, and dust production rate (DPR). As a sample, our modeling has determined an average luminosity of (3.80.9)10{sup 4} L{sub ?} and a total DPR of (2.30.1)10{sup ?5} M{sub ?} yr{sup ?1}. Most of the sources, given the high DPRs and short wavelength obscuration, are likely extreme asymptotic giant branch (XAGB) stars. Five of the sources are found to have luminosities above the classical AGB limit (M{sub bol} 54,000 L{sub ?}), which classifies them as probable red supergiants (RSGs). Almost all of the sources are classified as oxygen-rich. As also seen in the LMC, a significant fraction of the dust in M33 is produced by a handful of XAGB and RSG stars.

  13. SEARCH FOR IONIZED JETS TOWARD HIGH-MASS YOUNG STELLAR OBJECTS

    SciTech Connect (OSTI)

    Guzman, Andres E.; Garay, Guido; Brooks, Kate J.; Voronkov, Maxim A.

    2012-07-01

    We are carrying out multi-frequency radio continuum observations, using the Australia Telescope Compact Array, to systematically search for collimated ionized jets toward high-mass young stellar objects (HMYSOs). Here we report observations at 1.4, 2.4, 4.8, and 8.6 GHz, made with angular resolutions of about 7'', 4'', 2'', and 1'', respectively, toward six objects of a sample of 33 southern HMYSOs thought to be in very early stages of evolution. The objects in the sample were selected from radio and infrared catalogs by having positive radio spectral indices and being luminous (L{sub bol} > 2 Multiplication-Sign 10{sup 4} L{sub Sun }), but underluminous in radio emission compared with that expected from its bolometric luminosity. This criterion makes the radio sources good candidates for being ionized jets. As part of this systematic search, two ionized jets have been discovered: one previously published and the other reported here. The rest of the observed candidates correspond to three hypercompact H II regions and two ultracompact H II regions. The two jets discovered are associated with two of the most luminous (7 Multiplication-Sign 10{sup 4} and 1.0 Multiplication-Sign 10{sup 5} L{sub Sun }) HMYSOs known to harbor this type of object, showing that the phenomena of collimated ionized winds appear in the formation process of stars at least up to masses of {approx}20 M{sub Sun} and provide strong evidence for a disk-mediated accretion scenario for the formation of high-mass stars. From the incidence of jets in our sample, we estimate that the jet phase in high-mass protostars lasts for {approx}4 Multiplication-Sign 10{sup 4} yr.

  14. CONSTRAINING JET PRODUCTION SCENARIOS BY STUDIES OF NARROW-LINE RADIO GALAXIES

    SciTech Connect (OSTI)

    Sikora, Marek; Stasinska, Grazyna; Koziel-Wierzbowska, Dorota; Madejski, Greg M.; Asari, Natalia V.

    2013-03-01

    We study a large sample of narrow-line radio galaxies (NLRGs) with extended radio structures. Using 1.4 GHz radio luminosities L {sub 1.4}, narrow optical emission line luminosities L {sub [OIII]} and L{sub H{sub {alpha}}}, as well as black hole masses M {sub BH} derived from stellar velocity dispersions measured from the optical spectra obtained with the Sloan Digital Sky Survey, we find that (1) NLRGs cover about four decades of the Eddington ratio, {lambda} {identical_to} L {sub bol}/L {sub Edd}{proportional_to}L {sub line}/M {sub BH}; (2) L {sub 1.4}/M {sub BH} strongly correlates with {lambda}; and (3) radio loudness, R{identical_to}L{sub 1.4}/L{sub line}, strongly anti-correlates with {lambda}. A very broad range of the Eddington ratio indicates that the parent population of NLRGs includes both radio-loud quasars (RLQs) and broad-line radio galaxies (BLRGs). The correlations they obey and their high jet production efficiencies favor a jet production model which involves the so-called magnetically choked accretion scenario. In this model, production of the jet is dominated by the Blandford-Znajek mechanism, and the magnetic fields in the vicinity of the central black hole are confined by the ram pressure of the accretion flow. Since large net magnetic flux accumulated in central regions of the accretion flow required by the model can take place only via geometrically thick accretion, we speculate that the massive, 'cold' accretion events associated with luminous emission-line active galactic nucleus can be accompanied by an efficient jet production only if preceded by a hot, very sub-Eddington accretion phase.

  15. Modeling The Shock Initiation of PBX-9501 in ALE3D

    SciTech Connect (OSTI)

    Leininger, L; Springer, H K; Mace, J; Mas, E

    2008-07-01

    The SMIS (Specific Munitions Impact Scenario) experimental series performed at Los Alamos National Laboratory has determined the 3-dimensional shock initiation behavior of the HMX-based heterogeneous high explosive, PBX 9501. A series of finite element impact calculations have been performed in the ALE3D [1] hydrodynamic code and compared to the SMIS results to validate the code predictions. The SMIS tests use a powder gun to shoot scaled NATO standard fragments at a cylinder of PBX 9501, which has a PMMA case and a steel impact cover. The SMIS real-world shot scenario creates a unique test-bed because many of the fragments arrive at the impact plate off-center and at an angle of impact. The goal of this model validation experiments is to demonstrate the predictive capability of the Tarver-Lee Ignition and Growth (I&G) reactive flow model [2] in this fully 3-dimensional regime of Shock to Detonation Transition (SDT). The 3-dimensional Arbitrary Lagrange Eulerian hydrodynamic model in ALE3D applies the Ignition and Growth (I&G) reactive flow model with PBX 9501 parameters derived from historical 1-dimensional experimental data. The model includes the off-center and angle of impact variations seen in the experiments. Qualitatively, the ALE3D I&G calculations accurately reproduce the 'Go/No-Go' threshold of the Shock to Detonation Transition (SDT) reaction in the explosive, as well as the case expansion recorded by a high-speed optical camera. Quantitatively, the calculations show good agreement with the shock time of arrival at internal and external diagnostic pins. This exercise demonstrates the utility of the Ignition and Growth model applied in a predictive fashion for the response of heterogeneous high explosives in the SDT regime.

  16. Modeling Three-Dimensional Shock Initiation of PBX 9501 in ALE3D

    SciTech Connect (OSTI)

    Leininger, L; Springer, H K; Mace, J; Mas, E

    2008-07-08

    A recent SMIS (Specific Munitions Impact Scenario) experimental series performed at Los Alamos National Laboratory has provided 3-dimensional shock initiation behavior of the HMX-based heterogeneous high explosive, PBX 9501. A series of finite element impact calculations have been performed in the ALE3D [1] hydrodynamic code and compared to the SMIS results to validate and study code predictions. These SMIS tests used a powder gun to shoot scaled NATO standard fragments into a cylinder of PBX 9501, which has a PMMA case and a steel impact cover. This SMIS real-world shot scenario creates a unique test-bed because (1) SMIS tests facilitate the investigation of 3D Shock to Detonation Transition (SDT) within the context of a considerable suite of diagnostics, and (2) many of the fragments arrive at the impact plate off-center and at an angle of impact. A particular goal of these model validation experiments is to demonstrate the predictive capability of the ALE3D implementation of the Tarver-Lee Ignition and Growth reactive flow model [2] within a fully 3-dimensional regime of SDT. The 3-dimensional Arbitrary Lagrange Eulerian (ALE) hydrodynamic model in ALE3D applies the Ignition and Growth (I&G) reactive flow model with PBX 9501 parameters derived from historical 1-dimensional experimental data. The model includes the off-center and angle of impact variations seen in the experiments. Qualitatively, the ALE3D I&G calculations reproduce observed 'Go/No-Go' 3D Shock to Detonation Transition (SDT) reaction in the explosive, as well as the case expansion recorded by a high-speed optical camera. Quantitatively, the calculations show good agreement with the shock time of arrival at internal and external diagnostic pins. This exercise demonstrates the utility of the Ignition and Growth model applied for the response of heterogeneous high explosives in the SDT regime.

  17. SUPERNOVA 2008bk AND ITS RED SUPERGIANT PROGENITOR

    SciTech Connect (OSTI)

    Van Dyk, Schuyler D.; Elias-Rosa, Nancy [Spitzer Science Center/Caltech, Mailcode 220-6, Pasadena, CA 91125 (United States); Davidge, Tim J., E-mail: vandyk@ipac.caltech.edu, E-mail: tim.davidge@nrc.ca [Herzberg Institute of Astrophysics, National Research Council of Canada, Victoria, B.C., V9E 2E7 (Canada); and others

    2012-01-15

    We have obtained limited photometric and spectroscopic data for supernova (SN) 2008bk in NGC 7793, primarily at {approx}> 150 days after explosion. We find that it is a Type II-Plateau (II-P) SN that most closely resembles the low-luminosity SN 1999br in NGC 4900. Given the overall similarity between the observed light curves and colors of SNe 2008bk and 1999br, we infer that the total visual extinction to SN 2008bk (A{sub V} = 0.065 mag) must be almost entirely due to the Galactic foreground, similar to what has been assumed for SN 1999br. We confirm the identification of the putative red supergiant (RSG) progenitor star of the SN in high-quality g'r'i' images we had obtained in 2007 at the Gemini-South 8 m telescope. Little ambiguity exists in this progenitor identification, qualifying it as the best example to date, next to the identification of the star Sk -69 Degree-Sign 202 as the progenitor of SN 1987A. From a combination of photometry of the Gemini images with that of archival, pre-SN, Very Large Telescope JHK{sub s} images, we derive an accurate observed spectral energy distribution (SED) for the progenitor. We find from nebular strong-intensity emission-line indices for several H II regions near the SN that the metallicity in the environment is likely subsolar (Z Almost-Equal-To 0.6 Z{sub Sun }). The observed SED of the star agrees quite well with synthetic SEDs obtained from model RSG atmospheres with effective temperature T{sub eff} = 3600 {+-} 50 K. We find, therefore, that the star had a bolometric luminosity with respect to the Sun of log (L{sub bol}/L{sub Sun} ) = 4.57 {+-} 0.06 and radius R{sub *} = 496 {+-} 34 R{sub Sun} at {approx}6 months prior to explosion. Comparing the progenitor's properties with theoretical massive-star evolutionary models, we conclude that the RSG progenitor had an initial mass in the range of 8-8.5 M{sub Sun }. This mass is consistent with, albeit at the low end of, the inferred range of initial masses for SN II-P progenitors. It is also consistent with the estimated upper limit on the initial mass of the progenitor of SN 1999br, and it agrees with the low initial masses found for the RSG progenitors of other low-luminosity SNe II-P.

  18. Full-length U-xPu-10Zr (x=0, 8, 19 wt%) Fast Reactor Fuel Test in FFTF

    SciTech Connect (OSTI)

    D. L. Porter; H.C. Tsai

    2012-08-01

    The Integral Fast Reactor-1 (IFR-1) experiment performed in the Fast Flux Test Facility (FFTF) was the only U-Pu-10Zr (Pu-0, 8 and 19 wt%) metallic fast reactor test with commercial-length (91.4 cm active fuel column length) conducted to date. With few remaining test reactors there is little opportunity for performing another test with a long active fuel column. The assembly was irradiated to the goal burnup of 10 at.%. The beginning of life (BOL) peak cladding temperature of the hottest pin was 608?C, cooling to 522?C at end of life (EOL). Selected fuel pins were examined non destructively using neutron radiography, precision axial gamma scanning, and both laser and spiral contact cladding profilometry. Destructive exams included plenum gas pressure, volume, and gas composition determinations on a number of pins followed by optical metallography, electron probe microanalysis (EPMA), and alpha and beta gamma autoradiography on a single U-19Pu-10Zr pin. The post-irradiation examinations (PIEs) showed very few differences compared to the short-pin (34.3 cm fuel column) testing performed on fuels of similar composition in Experimental Breeder Reactor-II (EBR-II). The fuel column grew axially slightly less than observed in the short pins, but with the same pattern of decreasing growth with increasing Pu content. There was a difference in the fuel-cladding chemical interaction (FCCI) in that the maximum cladding penetration by interdiffusion with fuel/fission products did not occur at the top of the fuel column where the cladding temperature is highest, as observed in EBR-II tests. Instead, the more exaggerated fission-rate profile of the FFTF pins resulted in a peak FCCI at ~0.7 X/L axial location along the fuel column. This resulted from a lower production of rare earth fission products higher in the fuel column as well as a much smaller delta-T between fuel center and cladding, and therefore less FCCI, despite the higher cladding temperature. This behavior could actually help extend the life of a fuel pin in a long pin reactor design to a higher peak fuel burnup.

  19. Clustering of moderate luminosity X-ray-selected type 1 and type 2 AGNs at z ? 3

    SciTech Connect (OSTI)

    Allevato, V.; Finoguenov, A. [Department of Physics, University of Helsinki, Gustaf Hllstrmin katu 2a, FI-00014 Helsinki (Finland); Civano, F. [Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, NH 03755 (United States); Cappelluti, N. [University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250 (United States); Shankar, F. [Department of Physics and Astronomy, University of Southampton, Highfield SO17 1BJ (United Kingdom); Miyaji, T. [Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, Ensenada (Mexico); Hasinger, G. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Gilli, R.; Zamorani, G.; Comastri, A. [INAF-Osservatorio Astronomico di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); Lanzuisi, G. [National Observatory of Athens I. Metaxa and Vas. Pavlou St. GR-15236 Penteli (Greece); Salvato, M. [Max-Planck-Institute fr Extraterrestrische Physik, Giessenbachstrasse 1, D-85748 Garching (Germany); Elvis, M. [Harvard Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Silverman, J. [Institute for the Physics and Mathematics of the Universe, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwashi, Chiba 277-8583 (Japan)

    2014-11-20

    We investigate, for the first time at z ? 3, the clustering properties of 189 Type 1 and 157 Type 2 X-ray active galactic nuclei (AGNs) of moderate luminosity ((L {sub bol}) = 10{sup 45.3} erg s{sup 1}), with photometric or spectroscopic redshifts in the range 2.2 < z < 6.8. These samples are based on Chandra and XMM-Newton data in COSMOS. We find that Type 1 and Type 2 COSMOS AGNs at z ? 3 inhabit DMHs with typical mass of log M{sub h} = 12.84{sub ?0.11}{sup +0.10} and 11.73{sub ?0.45}{sup +0.39} h {sup 1} M {sub ?}, respectively. This result requires a drop in the halo masses of Type 1 and 2 COSMOS AGNs at z ? 3 compared to z ? 2 XMM-COSMOS AGNs with similar luminosities. Additionally, we infer that unobscured COSMOS AGNs at z ? 3 reside in 10 times more massive halos compared to obscured COSMOS AGNs, at the 2.6? level. This result extends to z ? 3 the results found in COSMOS at z ? 2, and rules out the picture in which obscuration is purely an orientation effect. A model which assumes that the AGNs activity is triggered by major mergers is quite successful in predicting both the low halo mass of COSMOS AGNs and the typical mass of luminous SDSS quasars at z ? 3, with the latter inhabiting more massive halos respect to moderate luminosity AGNs. Alternatively we can argue, at least for Type 1 COSMOS AGNs, that they are possibly representative of an early phase of fast (i.e., Eddington limited) BH growth induced by cosmic cold flows or disk instabilities. Given the moderate luminosity, these new fast growing BHs have masses of ?10{sup 7-8} M {sub ?} at z ? 3 which might evolve into ?10{sup 8.5-9} M {sub ?} mass BHs at z = 0. Following our clustering measurements, we argue that this fast BH growth at z ? 3 in AGNs with moderate luminosity occurs in DMHs with typical mass of ? 6 10{sup 12} h {sup 1} M {sub ?}.

  20. Improved Miscible Nitrogen Flood Performance Utilizing Advanced Reservoir Characterization and Horizontal Laterals in a Class I Reservoir - East Binger (Marchand) Unit

    SciTech Connect (OSTI)

    Joe Sinner

    2004-06-30

    The DOE-sponsored project at the East Binger Unit is an investigation into the benefits of reservoir characterization and horizontal wells in this particular setting of geologic and recovery method. The geologic setting is a tight (average porosity of 7% and average permeability of less than 1 millidarcy) Pennsylvanian-age sandstone at about 10,000 feet, and the recovery method is a miscible nitrogen flood. The projected oil recovery of the East Binger Unit, prior to the initiation of this project, was about 25%. Gravity segregation of nitrogen and crude oil was believed to be the principal cause of the poor sweep efficiency, and it was envisioned that with horizontal producing wells in the lower portion of the reservoir and horizontal injection wells near the top, the process could be converted from a lateral displacement process to a vertical displacement/gravity assisted process. Through the characterization and field development work completed in Budget Periods 1 and 2, Binger Operations, LLC (BOL) has developed a different interpretation of the sweep problem as well as a different approach to improving recovery. The sweep problem is now believed to be one of an areal nature, due to a combination of natural and hydraulic fracturing. Vertical wells have provided a much better economic return than have the horizontal wells. The natural and hydraulic fracturing manifests itself as a direction of higher permeability, and the flood is being converted to a line drive flood aligned with this orientation. Consistent with this concept, horizontal wells have been drilled along the line of the fracture orientation, such that hydraulic fracturing leads to 'longitudinal' fractures, in line with the wellbore. As such, the hydraulically fractured horizontal wells are not significantly different than hydraulically fractured vertical wells - save for the potential for a much longer fracture face. This Topical Report contains data from new wells, plus new and updated production, pressure, and gas analysis data that was not included in the Topical Report provided at the end of Budget Period 1. The analysis and interpretation of these data are provided in the many technical reports submitted throughout this project.

  1. REDUCTIONS WITHOUT REGRET: HISTORICAL PERSPECTIVES

    SciTech Connect (OSTI)

    Swegle, J.; Tincher, D.

    2013-09-09

    This is the first of three papers (in addition to an introductory summary) aimed at providing a framework for evaluating future reductions or modifications of the U.S. nuclear force, first by considering previous instances in which nuclear-force capabilities were eliminated; second by looking forward into at least the foreseeable future at the features of global and regional deterrence (recognizing that new weapon systems currently projected will have expected lifetimes stretching beyond our ability to predict the future); and third by providing examples of past or possible undesirable outcomes in the shaping of the future nuclear force, as well as some closing thoughts for the future. This paper examines the circumstances and consequences of the elimination of ? The INF-range Pershing II ballistic missile and Gryphon Ground-Launched Cruise Missile (GLCM), deployed by NATO under a dual-track strategy to counter Soviet intermediate-range missiles while pursuing negotiations to limit or eliminate all of these missiles. ? The Short-Range Attack Missile (SRAM), which was actually a family of missiles including SRAM A, SRAM B (never deployed), and SRAM II and SRAM T, these last two cancelled during an over-budget/behind-schedule development phase as part of the Presidential Nuclear Initiatives of 1991 and 1992. ? The nuclear-armed version of the Tomahawk Land-Attack Cruise Missile (TLAM/N), first limited to shore-based storage by the PNIs, and finally eliminated in deliberations surrounding the 2010 Nuclear Posture Review Report. ? The Missile-X (MX), or Peacekeeper, a heavy MIRVed ICBM, deployed in fixed silos, rather than in an originally proposed mobile mode. Peacekeeper was likely intended as a bargaining chip to facilitate elimination of Russian heavy missiles. The plan failed when START II did not enter into force, and the missiles were eliminated at the end of their intended service life. ? The Small ICBM (SICBM), or Midgetman, a road-mobile, single-warhead missile for which per-unit costs were climbing when it was eliminated under the PNIs. Although there were liabilities associated with each of these systems, there were also unique capabilities; this paper lays out the pros and cons for each. Further, we articulate the capabilities that were eliminated with these systems.

  2. Nonproliferation, arms control and disarmament and extended deterrence in the new security environment

    SciTech Connect (OSTI)

    Pilat, Joseph F

    2009-01-01

    With the end of the Cold War, in a dramatically changed security environment, the advances in nonnuclear strategic capabilities along with reduced numbers and roles for nuclear forces has altered the calculus of deterrence and defense, at least for the United States. For many, this opened up a realistic possibility of a nuclear-free world. It soon became clear that the initial post-Cold War hopes were exaggerated. The world did change fundamentally, but it did not become more secure and stable. In place of the old Soviet threat, there has been growing concern about proliferation and terrorism involving nuclear and other weapons of mass destruction (WMD), regional conflicts, global instability and increasingly serious new and emerging threats, including cyber attacks and attacks on satellites. For the United States at least, in this emerging environment, the political rationales for nuclear weapons, from deterrence to reassurance to alliance management, are changing and less central than during the Cold War to the security of the United States, its friends and allies. Nuclear weapons remain important for the US, but for a far more limited set of roles and missions. As the Perry-Schlesinger Commission report reveals, there is a domestic US consensus on nuclear policy and posture at the highest level and for the near term, including the continued role of nuclear arms in deterring WMD use and in reassuring allies. Although the value of nuclear weapons has declined for the United States, the value of these weapons for Russia, China and so-called 'rogue' states is seen to be rising. The nuclear logic of NATO during Cold War - the need for nuclear weapons to counter vastly superior conventional capabilities of the Soviet Union and the Warsaw Pact - is today heard from Russians and even some proliferants. Moreover, these weapons present a way for rogues to achieve regional hegemony and possibly to deter interventions by the United States or others. While the vision of a nuclear-free world is powerful, both existing nuclear powers and proliferators are unlikely to forego nuclear weapons entirely in a world that is dangerous and uncertain. And the emerging world would not necessarily be more secure and stable without nuclear weapons. Even if nuclear weapons were given up by the United States and other nuclear-weapon states, there would continue to be concerns about the proliferation of nuclear, chemical and biological weapons, which would not disappear and could worsen. WMD terrorism would remain a concern that was largely unaffected by US and other nuclear-weapon decisions. Conventional capabilities would not disappear and the prospects for warfare could rise. In addition, new problems could arise if rogue states or other non-status-quo powers attempted to take advantage of moves toward disarmament, while friends and allies who are not reassured as in the past could reconsider their options if deterrence declined. To address these challenges, non- and counter-proliferation and counterterrorismincluding defenses and consequence management-are priorities, especially in light of an anticipated 'renaissance' in civil nuclear power. The current agenda of the United States and others includes efforts to: (1) Strengthen International Atomic Energy Agency (IAEA) and its safeguards system; (2) Strengthen export controls, especially for sensitive technologies, by limiting the development of reprocessing and enrichment technologies and by requiring the Additional Protocol as a condition of supply; (3) Establish a reliable supply regime, including the possibility of multilateral or multinational ownership of fuel cycle facilities, as a means to promote nuclear energy without increasing the risks of proliferation or terrorism; (4) Implement effectively UN Security Council Resolution 1540; and (5) Strengthen and institutionalize the Proliferation Security Initiative and the Global Initiative to Combat Nuclear Terrorism. These and other activities are important in themselves, and are essential to maintaining and strengthening the Nonproliferati

  3. Storage and turnover of organic matter in soil

    SciTech Connect (OSTI)

    Torn, M.S.; Swanston, C.W.; Castanha, C.; Trumbore, S.E.

    2008-07-15

    Historically, attention on soil organic matter (SOM) has focused on the central role that it plays in ecosystem fertility and soil properties, but in the past two decades the role of soil organic carbon in moderating atmospheric CO{sub 2} concentrations has emerged as a critical research area. This chapter will focus on the storage and turnover of natural organic matter in soil (SOM), in the context of the global carbon cycle. Organic matter in soils is the largest carbon reservoir in rapid exchange with atmospheric CO{sub 2}, and is thus important as a potential source and sink of greenhouse gases over time scales of human concern (Fischlin and Gyalistras 1997). SOM is also an important human resource under active management in agricultural and range lands worldwide. Questions driving present research on the soil C cycle include: Are soils now acting as a net source or sink of carbon to the atmosphere? What role will soils play as a natural modulator or amplifier of climatic warming? How is C stabilized and sequestered, and what are effective management techniques to foster these processes? Answering these questions will require a mechanistic understanding of how and where C is stored in soils. The quantity and composition of organic matter in soil reflect the long-term balance between plant carbon inputs and microbial decomposition, as well as other loss processes such as fire, erosion, and leaching. The processes driving soil carbon storage and turnover are complex and involve influences at molecular to global scales. Moreover, the relative importance of these processes varies according to the temporal and spatial scales being considered; a process that is important at the regional scale may not be critical at the pedon scale. At the regional scale, SOM cycling is influenced by factors such as climate and parent material, which affect plant productivity and soil development. More locally, factors such as plant tissue quality and soil mineralogy affect decomposition pathways and stabilization. These factors influence the stability of SOM in part by shaping its molecular characteristics, which play a fundamental role in nearly all processes governing SOM stability but are not the focus of this chapter. We review here the most important controls on the distribution and dynamics of SOM at plot to global scales, and methods used to study them. We also explore the concepts of controls, processes, and mechanisms, and how they operate across scales. The concept of SOM turnover, or mean residence time, is central to this chapter and so it is described in some detail. The Appendix details the use of radiocarbon ({sup 14}C), a powerful isotopic tool for studying SOM dynamics. Much of the material here was originally presented at a NATO Advanced Study Institute on 'Soils and Global Change: Carbon Cycle, Trace Gas Exchange and Hydrology', held June 16-27, 1997, at the Chateau de Bonas, France.

  4. Stationary Liquid Fuel Fast Reactor

    SciTech Connect (OSTI)

    Yang, Won Sik; Grandy, Andrew; Boroski, Andrew; Krajtl, Lubomir; Johnson, Terry

    2015-09-30

    For effective burning of hazardous transuranic (TRU) elements of used nuclear fuel, a transformational advanced reactor concept named SLFFR (Stationary Liquid Fuel Fast Reactor) was proposed based on stationary molten metallic fuel. The fuel enters the reactor vessel in a solid form, and then it is heated to molten temperature in a small melting heater. The fuel is contained within a closed, thick container with penetrating coolant channels, and thus it is not mixed with coolant nor flow through the primary heat transfer circuit. The makeup fuel is semi- continuously added to the system, and thus a very small excess reactivity is required. Gaseous fission products are also removed continuously, and a fraction of the fuel is periodically drawn off from the fuel container to a processing facility where non-gaseous mixed fission products and other impurities are removed and then the cleaned fuel is recycled into the fuel container. A reference core design and a preliminary plant system design of a 1000 MWt TRU- burning SLFFR concept were developed using TRU-Ce-Co fuel, Ta-10W fuel container, and sodium coolant. Conservative design approaches were adopted to stay within the current material performance database. Detailed neutronics and thermal-fluidic analyses were performed to develop a reference core design. Region-dependent 33-group cross sections were generated based on the ENDF/B-VII.0 data using the MC2-3 code. Core and fuel cycle analyses were performed in theta-r-z geometries using the DIF3D and REBUS-3 codes. Reactivity coefficients and kinetics parameters were calculated using the VARI3D perturbation theory code. Thermo-fluidic analyses were performed using the ANSYS FLUENT computational fluid dynamics (CFD) code. Figure 0.1 shows a schematic radial layout of the reference 1000 MWt SLFFR core, and Table 0.1 summarizes the main design parameters of SLFFR-1000 loop plant. The fuel container is a 2.5 cm thick cylinder with an inner radius of 87.5 cm. The fuel container is penetrated by twelve hexagonal control assembly (CA) guide tubes, each of which has 3.0 mm thickness and 69.4 mm flat-to-flat outer distance. The distance between two neighboring CA guide tube is selected to be 26 cm to provide an adequate space for CA driving systems. The fuel container has 18181 penetrating coolant tubes of 6.0 mm inner diameter and 2.0 mm thickness. The coolant tubes are arranged in a triangular lattice with a lattice pitch of 1.21 cm. The fuel, structure, and coolant volume fractions inside the fuel container are 0.386, 0.383, and 0.231, respectively. Separate steel reflectors and B4C shields are used outside of the fuel container. Six gas expansion modules (GEMs) of 5.0 cm thickness are introduced in the radial reflector region. Between the radial reflector and the fuel container is a 2.5 cm sodium gap. The TRU inventory at the beginning of equilibrium cycle (BOEC) is 5081 kg, whereas the TRU inventory at the beginning of life (BOL) was 3541 kg. This is because the equilibrium cycle fuel contains a significantly smaller fissile fraction than the LWR TRU feed. The fuel inventory at BOEC is composed of 34.0 a/o TRU, 41.4 a/o Ce, 23.6 a/o Co, and 1.03 a/o solid fission products. Since uranium-free fuel is used, a theoretical maximum TRU consumption rate of 1.011 kg/day is achieved. The semi-continuous fuel cycle based on the 300-batch, 1- day cycle approximation yields a burnup reactivity loss of 26 pcm/day, and requires a daily reprocessing of 32.5 kg of SLFFR fuel. This yields a daily TRU charge rate of 17.45 kg, including a makeup TRU feed of 1.011 kg recovered from the LWR used fuel. The charged TRU-Ce-Co fuel is composed of 34.4 a/o TRU, 40.6 a/o Ce, and 25.0 a/o Co.

  5. Changes in Russia's Military and Nuclear Doctrine

    SciTech Connect (OSTI)

    Wolkov, Benjamin M.; Balatsky, Galya I.

    2012-07-26

    In 1993, the Russian Federation set out a new military doctrine that would determine the direction of its armed forces until President Putin set out the next doctrine in 2000. The Russian Federation creating the doctrine was new; the USSR had recently collapsed, Gorbachev - the creator of the predecessor to this doctrine in 1987 - was out of office, and the new Russian military had only been formed in May, 1992.1 The analysis of the 1993 doctrine is as follows: a definition of how doctrine is defined; a short history of Russian military doctrine leading up to the 1993 doctrine (officially the Basic Provisions of the Military Doctrine of the Russian Federation); and finally, what the doctrine established. An overview of the 1993 doctrine is: (1) Russia's 1993 doctrine was a return to older, more aggressive doctrine as a result of stability concerns surrounding the recent collapse of the USSR; (2) Russia turned from Gorbachev's 'defensive defense' in the 1987 doctrine to aggressive defense with the option of preempting or striking back against an aggressor; (3) Russia was deeply concerned about how nationalism would affect the former Soviet Republics, particularly in respect to the ethnic Russians still living abroad; and (4) Nuclear doctrine pledged to not be the first to use nuclear weapons but provided for the potential for escalation from a conventional to a nuclear war. The 2000 doctrine (officially the Russian Federation Military Doctrine) was created in a more stable world than the 1993 doctrine was. The Russian Federation had survived independence and the 'threat of direct military aggression against the Russian Federation and its allies' had diminished. It had secured all of the nuclear weapons from its neighbors Ukraine, Belarus, and Kazakhstan, and had elected a new president, Vladimir Putin, to replace Boris Yeltsin. Yet, even as the doctrine took more defensive tones than the 1993 doctrine, it expanded its nuclear options. Below are a new definition of what doctrine meant in 2000 and an outline of the 2000 doctrine. An overview of the 2000 doctrine is: (1) The 2000 doctrine was a return to a more defensive posture; the threat of nuclear retaliation, rather than that of preemptive force, would be its deterrence; (2) In order to strengthen its nuclear deterrence, Russia extended and redefined the cases in which nuclear weapons could be used to include a wider range of conflict types and a larger spectrum of attackers; and (3) Russia's threats changed to reflect its latest fear of engaging in a limited conflict with no prospect of the use of nuclear deterrence. In 2006, the defense minister and deputy prime minister Sergei Ivanov announced that the government was starting on a draft of a future doctrine. Four years later, in 2010, the Military Doctrine of the Russian Federation was put into effect with the intent of determining Russian doctrine until 2020. The 2010 doctrine, like all previous doctrines, was a product of the times in which it was written. Gone were many of the fears that had followed Russia for the past two decades. Below are an examination of the 2010 definition of doctrine as well as a brief analysis of the 2010 doctrine and its deviations from past doctrines. An overview of the 2010 doctrine is: (1) The new doctrine emphasizes the political centralization of command both in military policy and the use of nuclear weapons; (2) Nuclear doctrine remains the same in many aspects including the retention of first-use; (3) At the same time, doctrine was narrowed to using nuclear weapons only when the Russian state's existence is in danger; to continue strong deterrence, Russia also opted to follow the United States by introducing precision conventional weapons; (4) NATO is defined as Russia's primary external threat because of its increased global presence and its attempt to recruit states that are part of the Russian 'bloc'; and (5) The 2000 doctrine's defensive stance was left out of the doctrine; rumored options for use of nuclear weapons in local wars and in preemptive strikes were also left out.