WorldWideScience

Sample records for extremely high flux

  1. High photon flux table-top coherent extreme ultraviolet source

    CERN Document Server

    Hädrich, Steffen; Rothhardt, Jan; Krebs, Manuel; Hoffmann, Armin; Pronin, Oleg; Pervak, Vladimir; Limpert, Jens; Tünnermann, Andreas

    2014-01-01

    High harmonic generation (HHG) enables extreme ultraviolet radiation with table-top setups. Its exceptional properties, such as coherence and (sub)-femtosecond pulse durations, have led to a diversity of applications. Some of these require a high photon flux and megahertz repetition rates, e.g. to avoid space charge effects in photoelectron spectroscopy. To date this has only been achieved with enhancement cavities. Here, we establish a novel route towards powerful HHG sources. By achieving phase-matched HHG of a megahertz fibre laser we generate a broad plateau (25 eV - 40 eV) of strong harmonics, each containing more than $10^{12}$ photons/s, which constitutes an increase by more than one order of magnitude in that wavelength range. The strongest harmonic (H25, 30 eV) has an average power of 143 $\\mu$W ($3\\cdot10^{13}$ photons/s). This concept will greatly advance and facilitate applications in photoelectron or coincidence spectroscopy, coherent diffractive imaging or (multidimensional) surface science.

  2. Microsystem for remote sensing of high energy radiation with associated extremely low photon flux densities

    Science.gov (United States)

    Otten, A.; Jain, V. K.

    2015-08-01

    This paper presents a microsystem for remote sensing of high energy radiation in extremely low flux density conditions. With wide deployment in mind, potential applications range from nuclear non-proliferation, to hospital radiation-safety. The daunting challenge is the low level of photon flux densities - emerging from a Scintillation Crystal (SC) on to a ~1 mm-square detector, which are a factor of 10000 or so lower than those acceptable to recently reported photonic chips (including `single-photon detection' chips), due to a combination of low Lux, small detector size, and short duration SC output pulses - on the order of 1 μs. These challenges are attempted to be overcome by the design of an innovative `System on a Chip' type microchip, with high detector sensitivity, and effective coupling from the SC to the photodetector. The microchip houses a tiny n+ diff p-epi photodiode (PD) as well as the associated analog amplification and other related circuitry, all fabricated in 0.5micron, 3-metal 2-poly CMOS technology. The amplification, together with pulse-shaping of the photocurrent-induced voltage signal, is achieved through a tandem of two capacitively coupled, double-cascode amplifiers. Included in the paper are theoretical estimates and experimental results.

  3. Abundant carbon substrates drive extremely high sulfate reduction rates and methane fluxes in Prairie Pothole Wetlands.

    Science.gov (United States)

    Dalcin Martins, Paula; Hoyt, David W; Bansal, Sheel; Mills, Christopher T; Tfaily, Malak; Tangen, Brian A; Finocchiaro, Raymond G; Johnston, Michael D; McAdams, Brandon C; Solensky, Matthew J; Smith, Garrett J; Chin, Yu-Ping; Wilkins, Michael J

    2017-08-01

    Inland waters are increasingly recognized as critical sites of methane emissions to the atmosphere, but the biogeochemical reactions driving such fluxes are less well understood. The Prairie Pothole Region (PPR) of North America is one of the largest wetland complexes in the world, containing millions of small, shallow wetlands. The sediment pore waters of PPR wetlands contain some of the highest concentrations of dissolved organic carbon (DOC) and sulfur species ever recorded in terrestrial aquatic environments. Using a suite of geochemical and microbiological analyses, we measured the impact of sedimentary carbon and sulfur transformations in these wetlands on methane fluxes to the atmosphere. This research represents the first study of coupled geochemistry and microbiology within the PPR and demonstrates how the conversion of abundant labile DOC pools into methane results in some of the highest fluxes of this greenhouse gas to the atmosphere ever reported. Abundant DOC and sulfate additionally supported some of the highest sulfate reduction rates ever measured in terrestrial aquatic environments, which we infer to account for a large fraction of carbon mineralization in this system. Methane accumulations in zones of active sulfate reduction may be due to either the transport of free methane gas from deeper locations or the co-occurrence of methanogenesis and sulfate reduction. If both respiratory processes are concurrent, any competitive inhibition of methanogenesis by sulfate-reducing bacteria may be lessened by the presence of large labile DOC pools that yield noncompetitive substrates such as methanol. Our results reveal some of the underlying mechanisms that make PPR wetlands biogeochemical hotspots, which ultimately leads to their critical, but poorly recognized role in regional greenhouse gas emissions. © 2017 John Wiley & Sons Ltd.

  4. Abundant carbon substrates drive extremely high sulfate reduction rates and methane fluxes in Prairie Pothole Wetlands

    Science.gov (United States)

    Martins, Paula; Hoyt, David W.; Bansal, Sheel; Mills, Christopher; Tfaily, Malak; Tangen, Brian; Finocchiaro, Raymond; Johnston, Michael D.; McAdams, Brandon C.; Solensky, Matthew J.; Smith, Garrett J.; Chin, Yu-Ping; Wilkins, Michael J.

    2017-01-01

    Inland waters are increasingly recognized as critical sites of methane emissions to the atmosphere, but the biogeochemical reactions driving such fluxes are less well understood. The Prairie Pothole Region (PPR) of North America is one of the largest wetland complexes in the world, containing millions of small, shallow wetlands. The sediment pore waters of PPR wetlands contain some of the highest concentrations of dissolved organic carbon (DOC) and sulfur species ever recorded in terrestrial aquatic environments. Using a suite of geochemical and microbiological analyses, we measured the impact of sedimentary carbon and sulfur transformations in these wetlands on methane fluxes to the atmosphere. This research represents the first study of coupled geochemistry and microbiology within the PPR and demonstrates how the conversion of abundant labile DOC pools into methane results in some of the highest fluxes of this greenhouse gas to the atmosphere ever reported. Abundant DOC and sulfate additionally supported some of the highest sulfate reduction rates ever measured in terrestrial aquatic environments, which we infer to account for a large fraction of carbon mineralization in this system. Methane accumulations in zones of active sulfate reduction may be due to either the transport of free methane gas from deeper locations or the co-occurrence of methanogenesis and sulfate reduction. If both respiratory processes are concurrent, any competitive inhibition of methanogenesis by sulfate-reducing bacteria may be lessened by the presence of large labile DOC pools that yield noncompetitive substrates such as methanol. Our results reveal some of the underlying mechanisms that make PPR wetlands biogeochemical hotspots, which ultimately leads to their critical, but poorly recognized role in regional greenhouse gas emissions.

  5. Constraints on the extremely-high energy cosmic neutrino flux with the IceCube 2008-2009 data

    Science.gov (United States)

    Abbasi, R.; Abdou, Y.; Abu-Zayyad, T.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Andeen, K.; Auffenberg, J.; Bai, X.; Baker, M.; Barwick, S. W.; Bay, R.; Bazo Alba, J. L.; Beattie, K.; Beatty, J. J.; Bechet, S.; Becker, J. K.; Becker, K.-H.; Benabderrahmane, M. L.; Benzvi, S.; Berdermann, J.; Berghaus, P.; Berley, D.; Bernardini, E.; Bertrand, D.; Besson, D. Z.; Bindig, D.; Bissok, M.; Blaufuss, E.; Blumenthal, J.; Boersma, D. J.; Bohm, C.; Bose, D.; Böser, S.; Botner, O.; Braun, J.; Brown, A. M.; Buitink, S.; Carson, M.; Chirkin, D.; Christy, B.; Clem, J.; Clevermann, F.; Cohen, S.; Colnard, C.; Cowen, D. F.; D'Agostino, M. V.; Danninger, M.; Daughhetee, J.; Davis, J. C.; de Clercq, C.; Demirörs, L.; Denger, T.; Depaepe, O.; Descamps, F.; Desiati, P.; de Vries-Uiterweerd, G.; Deyoung, T.; Díaz-Vélez, J. C.; Dierckxsens, M.; Dreyer, J.; Dumm, J. P.; Ehrlich, R.; Eisch, J.; Ellsworth, R. W.; Engdegård, O.; Euler, S.; Evenson, P. A.; Fadiran, O.; Fazely, A. R.; Fedynitch, A.; Feusels, T.; Filimonov, K.; Finley, C.; Fischer-Wasels, T.; Foerster, M. M.; Fox, B. D.; Franckowiak, A.; Franke, R.; Gaisser, T. K.; Gallagher, J.; Geisler, M.; Gerhardt, L.; Gladstone, L.; Glüsenkamp, T.; Goldschmidt, A.; Goodman, J. A.; Gora, D.; Grant, D.; Griesel, T.; Groß, A.; Grullon, S.; Gurtner, M.; Ha, C.; Hallgren, A.; Halzen, F.; Han, K.; Hanson, K.; Heinen, D.; Helbing, K.; Herquet, P.; Hickford, S.; Hill, G. C.; Hoffman, K. D.; Homeier, A.; Hoshina, K.; Hubert, D.; Huelsnitz, W.; Hülß, J.-P.; Hulth, P. O.; Hultqvist, K.; Hussain, S.; Ishihara, A.; Jacobsen, J.; Japaridze, G. S.; Johansson, H.; Joseph, J. M.; Kampert, K.-H.; Kappes, A.; Karg, T.; Karle, A.; Kelley, J. L.; Kenny, P.; Kiryluk, J.; Kislat, F.; Klein, S. R.; Köhne, J.-H.; Kohnen, G.; Kolanoski, H.; Köpke, L.; Kopper, S.; Koskinen, D. J.; Kowalski, M.; Kowarik, T.; Krasberg, M.; Krings, T.; Kroll, G.; Kuwabara, T.; Labare, M.; Lafebre, S.; Laihem, K.; Landsman, H.; Larson, M. J.; Lauer, R.; Lünemann, J.; Madsen, J.; Majumdar, P.; Marotta, A.; Maruyama, R.; Mase, K.; Matis, H. S.; Meagher, K.; Merck, M.; Mészáros, P.; Meures, T.; Middell, E.; Milke, N.; Miller, J.; Montaruli, T.; Morse, R.; Movit, S. M.; Nahnhauer, R.; Nam, J. W.; Naumann, U.; Nießen, P.; Nygren, D. R.; Odrowski, S.; Olivas, A.; Olivo, M.; O'Murchadha, A.; Ono, M.; Panknin, S.; Paul, L.; Pérez de Los Heros, C.; Petrovic, J.; Piegsa, A.; Pieloth, D.; Porrata, R.; Posselt, J.; Price, P. B.; Przybylski, G. T.; Rawlins, K.; Redl, P.; Resconi, E.; Rhode, W.; Ribordy, M.; Rizzo, A.; Rodrigues, J. P.; Roth, P.; Rothmaier, F.; Rott, C.; Ruhe, T.; Rutledge, D.; Ruzybayev, B.; Ryckbosch, D.; Sander, H.-G.; Santander, M.; Sarkar, S.; Schatto, K.; Schmidt, T.; Schönwald, A.; Schukraft, A.; Schultes, A.; Schulz, O.; Schunck, M.; Seckel, D.; Semburg, B.; Seo, S. H.; Sestayo, Y.; Seunarine, S.; Silvestri, A.; Slipak, A.; Spiczak, G. M.; Spiering, C.; Stamatikos, M.; Stanev, T.; Stephens, G.; Stezelberger, T.; Stokstad, R. G.; Stössl, A.; Stoyanov, S.; Strahler, E. A.; Straszheim, T.; Stür, M.; Sullivan, G. W.; Swillens, Q.; Taavola, H.; Taboada, I.; Tamburro, A.; Tepe, A.; Ter-Antonyan, S.; Tilav, S.; Toale, P. A.; Toscano, S.; Tosi, D.; Turčan, D.; van Eijndhoven, N.; Vandenbroucke, J.; van Overloop, A.; van Santen, J.; Vehring, M.; Voge, M.; Walck, C.; Waldenmaier, T.; Wallraff, M.; Walter, M.; Weaver, Ch.; Wendt, C.; Westerhoff, S.; Whitehorn, N.; Wiebe, K.; Wiebusch, C. H.; Williams, D. R.; Wischnewski, R.; Wissing, H.; Wolf, M.; Wood, T. R.; Woschnagg, K.; Xu, C.; Xu, X. W.; Yodh, G.; Yoshida, S.; Zarzhitsky, P.

    2011-05-01

    We report on a search for extremely-high energy neutrinos with energies greater than 106GeV using the data taken with the IceCube detector at the South Pole. The data was collected between April 2008 and May 2009 with the half-completed IceCube array. The absence of signal candidate events in the sample of 333.5 days of live time significantly improves model-independent limits from previous searches and allows to place a limit on the diffuse flux of cosmic neutrinos with an E-2 spectrum in the energy range 2.0×106-6.3×109GeV to a level of E2ϕ≤3.6×10-8GeVcm-2sec-1sr-1.

  6. Constraints on the Extremely-high Energy Cosmic Neutrino Flux with the IceCube 2008-2009 Data

    CERN Document Server

    Abbasi, R; Abu-Zayyad, T; Adams, J; Aguilar, J A; Ahlers, M; Andeen, K; Auffenberg, J; Bai, X; Baker, M; Barwick, S W; Bay, R; Alba, J L Bazo; Beattie, K; Beatty, J J; Bechet, S; Becker, J K; Becker, K -H; Benabderrahmane, M L; BenZvi, S; Berdermann, J; Berghaus, P; Berley, D; Bernardini, E; Bertrand, D; Besson, D Z; Bindig, D; Bissok, M; Blaufuss, E; Blumenthal, J; Boersma, D J; Bohm, C; Bose, D; Böser, S; Botner, O; Braun, J; Brown, A M; Buitink, S; Carson, M; Chirkin, D; Christy, B; Clem, J; Clevermann, F; Cohen, S; Colnard, C; Cowen, D F; D'Agostino, M V; Danninger, M; Daughhetee, J; Davis, J C; De Clercq, C; Demirörs, L; Denger, T; Depaepe, O; Descamps, F; Desiati, P; de Vries-Uiterweerd, G; DeYoung, T; Díaz-Vélez, J C; Dierckxsens, M; Dreyer, J; Dumm, J P; Ehrlich, R; Eisch, J; Ellsworth, R W; Engdegård, O; Euler, S; Evenson, P A; Fadiran, O; Fazely, A R; Fedynitch, A; Feusels, T; Filimonov, K; Finley, C; Fischer-Wasels, T; Foerster, M M; Fox, B D; Franckowiak, A; Franke, R; Gaisser, T K; Gallagher, J; Geisler, M; Gerhardt, L; Gladstone, L; Glüsenkamp, T; Goldschmidt, A; Goodman, J A; Gora, D; Grant, D; Griesel, T; Groß, A; Grullon, S; Gurtner, M; Ha, C; Hallgren, A; Halzen, F; Han, K; Hanson, K; Heinen, D; Helbing, K; Herquet, P; Hickford, S; Hill, G C; Hoffman, K D; Homeier, A; Hoshina, K; Hubert, D; Huelsnitz, W; Hülß, J -P; Hulth, P O; Hultqvist, K; Hussain, S; Ishihara, A; Jacobsen, J; Japaridze, G S; Johansson, H; Joseph, J M; Kampert, K -H; Kappes, A; Karg, T; Karle, A; Kelley, J L; Kenny, P; Kiryluk, J; Kislat, F; Klein, S R; Köhne, J -H; Kohnen, G; Kolanoski, H; Köpke, L; Kopper, S; Koskinen, D J; Kowalski, M; Kowarik, T; Krasberg, M; Krings, T; Kroll, G; Kuwabara, T; Labare, M; Lafebre, S; Laihem, K; Landsman, H; Larson, M J; Lauer, R; Lünemann, J; Madsen, J; Majumdar, P; Marotta, A; Maruyama, R; Mase, K; Matis, H S; Meagher, K; Merck, M; Mészáros, P; Meures, T; Middell, E; Milke, N; Miller, J; Montaruli, T; Morse, R; Movit, S M; Nahnhauer, R; Nam, J W; Naumann, U; Nießen, P; Nygren, D R; Odrowski, S; Olivas, A; Olivo, M; O'Murchadha, A; Ono, M; Panknin, S; Paul, L; Heros, C Pérez de los; Petrovic, J; Piegsa, A; Pieloth, D; Porrata, R; Posselt, J; Price, P B; Przybylski, G T; Rawlins, K; Redl, P; Resconi, E; Rhode, W; Ribordy, M; Rizzo, A; Rodrigues, J P; Roth, P; Rothmaier, F; Rott, C; Ruhe, T; Rutledge, D; Ruzybayev, B; Ryckbosch, D; Sander, H -G; Santander, M; Sarkar, S; Schatto, K; Schmidt, T; Schönwald, A; Schukraft, A; Schultes, A; Schulz, O; Schunck, M; Seckel, D; Semburg, B; Seo, S H; Sestayo, Y; Seunarine, S; Silvestri, A; Slipak, A; Spiczak, G M; Spiering, C; Stamatikos, M; Stanev, T; Stephens, G; Stezelberger, T; Stokstad, R G; Stössl, A; Stoyanov, S; Strahler, E A; Straszheim, T; Stür, M; Sullivan, G W; Swillens, Q; Taavola, H; Taboada, I; Tamburro, A; Tepe, A; Ter-Antonyan, S; Tilav, S; Toale, P A; Toscano, S; Tosi, D; Turčan, D; van Eijndhoven, N; Vandenbroucke, J; Van Overloop, A; van Santen, J; Vehring, M; Voge, M; Walck, C; Waldenmaier, T; Wallraff, M; Walter, M; Weaver, Ch; Wendt, C; Westerhoff, S; Whitehorn, N; Wiebe, K; Wiebusch, C H; Williams, D R; Wischnewski, R; Wissing, H; Wolf, M; Wood, T R; Woschnagg, K; Xu, C; Xu, X W; Yodh, G; Yoshida, S; Zarzhitsky, P

    2011-01-01

    We report on a search for extremely-high energy neutrinos with energies greater than $10^6$ GeV using the data taken with the IceCube detector at the South Pole. The data was collected between April 2008 and May 2009 with the half completed IceCube array. The absence of signal candidate events in the sample of 333.5 days of livetime significantly improves model independent limit from previous searches and allows to place a limit on the diffuse flux of cosmic neutrinos with an $E^{-2}$ spectrum in the energy range $2.0 \\times 10^{6}$ $-$ $6.3 \\times 10^{9}$ GeV to a level of $E^2 \\phi \\leq 3.6 \\times 10^{-8}$ ${\\rm GeV cm^{-2} sec^{-1}sr^{-1}}$.

  7. Extremal Black Hole and Flux Vacua Attractors

    CERN Document Server

    Bellucci, S; Kallosh, R; Marrani, A

    2007-01-01

    These lectures provide a pedagogical, introductory review of the so-called Attractor Mechanism (AM) at work in two different 4-dimensional frameworks: extremal black holes in N=2 supergravity and N=1 flux compactifications. In the first case, AM determines the stabilization of scalars at the black hole event horizon purely in terms of the electric and magnetic charges, whereas in the second context the AM is responsible for the stabilization of the universal axion-dilaton and of the (complex structure) moduli purely in terms of the RR and NSNS fluxes. Two equivalent approaches to AM, namely the so-called ``criticality conditions'' and ``New Attractor'' ones, are analyzed in detail in both frameworks, whose analogies and differences are discussed. Also a stringy analysis of both frameworks (relying on Hodge-decomposition techniques) is performed, respectively considering Type IIB compactified on $CY_{3}$ and its orientifolded version, associated with $\\frac{CY_{3}\\times T^{2}}{\\mathbb{Z}_{2}}$. Finally, recent...

  8. Reconstruction of Solar Extreme Ultraviolet Flux 1740 - 2015

    Science.gov (United States)

    Svalgaard, Leif

    2016-11-01

    Solar extreme ultraviolet (EUV) radiation creates the conducting E-layer of the ionosphere, mainly by photo-ionization of molecular oxygen. Solar heating of the ionosphere creates thermal winds, which by dynamo action induce an electric field driving an electric current having a magnetic effect observable on the ground, as was discovered by G. Graham in 1722. The current rises and falls with the Sun, and thus causes a readily observable diurnal variation of the geomagnetic field, allowing us to deduce the conductivity and thus the EUV flux as far back as reliable magnetic data reach. High-quality data go back to the "Magnetic Crusade" of the 1830s and less reliable, but still usable, data are available for portions of the 100 years before that. J.R. Wolf and, independently, J.-A. Gautier discovered the dependence of the diurnal variation on solar activity, and today we understand and can invert that relationship to construct a reliable record of the EUV flux from the geomagnetic record. We compare that to the F_{10.7} flux and the sunspot number, and we find that the reconstructed EUV flux reproduces the F_{10.7} flux with great accuracy. On the other hand, it appears that the Relative Sunspot Number as currently defined is beginning to no longer be a faithful representation of solar magnetic activity, at least as measured by the EUV and related indices. The reconstruction suggests that the EUV flux reaches the same low (but non-zero) value at every sunspot minimum (possibly including Grand Minima), representing an invariant "solar magnetic ground state".

  9. Spectrophotometry of extreme helium stars - Ultraviolet fluxes and effective temperatures

    Science.gov (United States)

    Heber, U.; Drilling, J. S.; Schoenberner, D.; Lynas-Gray, A. E.

    1984-01-01

    Ultraviolet flux distributions are presented for the extremely helium rich stars BD +10 deg 2179, HD 124448, LSS 3378, BD -9 deg 4395, LSE 78, HD 160641, LSIV -1 deg 2, BD 1 deg 3438, HD 168476, MV Sgr, LS IV-14 deg 109 (CD -35 deg 11760), LSII +33 deg 5 and BD +1 deg 4381 (LSIV +2 deg 13) obtained with the International Ultraviolet Explorer (IUE). Broadband photometry and a newly computed grid of line blanketed model atmospheres were used to determine accurate angular diameters and total stellar fluxes. The resultant effective temperatures are in most cases in satisfactory agreement with those based on broadband photometry and/or high resolution spectroscopy in the visible. For two objects, LSII +33 deg 5 and LSE 78, disagreement was found between the IUE observations and broadband photometry: the colors predict temperatures around 20,000 K, whereas the UV spectra indicate much lower photospheric temperatures of 14,000 to 15,000 K. The new temperature scale for extreme helium stars extends to lower effective temperatures than that of Heber and Schoenberner (1981) and covers the range from 8,500 K to 32,000 K. Previously announced in STAR as N83-24433

  10. Extreme air-sea surface turbulent fluxes in mid latitudes - estimation, origins and mechanisms

    Science.gov (United States)

    Gulev, Sergey; Natalia, Tilinina

    2014-05-01

    Extreme turbulent heat fluxes in the North Atlantic and North Pacific mid latitudes were estimated from the modern era and first generation reanalyses (NCEP-DOE, ERA-Interim, MERRA NCEP-CFSR, JRA-25) for the period from 1979 onwards. We used direct surface turbulent flux output as well as reanalysis state variables from which fluxes have been computed using COARE-3 bulk algorithm. For estimation of extreme flux values we analyzed surface flux probability density distribution which was approximated by Modified Fisher-Tippett distribution. In all reanalyses extreme turbulent heat fluxes amount to 1500-2000 W/m2 (for the 99th percentile) and can exceed 2000 W/m2 for higher percentiles in the western boundary current extension (WBCE) regions. Different reanalyses show significantly different shape of MFT distribution, implying considerable differences in the estimates of extreme fluxes. The highest extreme turbulent latent heat fluxes are diagnosed in NCEP-DOE, ERA-Interim and NCEP-CFSR reanalyses with the smallest being in MERRA. These differences may not necessarily reflect the differences in mean values. Analysis shows that differences in statistical properties of the state variables are the major source of differences in the shape of PDF of fluxes and in the estimates of extreme fluxes while the contribution of computational schemes used in different reanalyses is minor. The strongest differences in the characteristics of probability distributions of surface fluxes and extreme surface flux values between different reanalyses are found in the WBCE extension regions and high latitudes. In the next instance we analyzed the mechanisms responsible for forming surface turbulent fluxes and their potential role in changes of midlatitudinal heat balance. Midlatitudinal cyclones were considered as the major mechanism responsible for extreme turbulent fluxes which are typically occur during the cold air outbreaks in the rear parts of cyclones when atmospheric conditions

  11. Reconstruction of Solar Extreme Ultraviolet Flux 1740-2015

    CERN Document Server

    Svalgaard, Leif

    2015-01-01

    Solar Extreme Ultraviolet (EUV) radiation creates the conducting E-layer of the ionosphere, mainly by photo ionization of molecular Oxygen. Solar heating of the ionosphere creates thermal winds which by dynamo action induce an electric field driving an electric current having a magnetic effect observable on the ground, as was discovered by G. Graham in 1722. The current rises and sets with the Sun and thus causes a readily observable diurnal variation of the geomagnetic field, allowing us the deduce the conductivity and thus the EUV flux as far back as reliable magnetic data reach. High-quality data go back to the 'Magnetic Crusade' of the 1830s and less reliable, but still usable, data are available for portions of the hundred years before that. J.R. Wolf and, independently, J.-A. Gautier discovered the dependence of the diurnal variation on solar activity, and today we understand and can invert that relationship to construct a reliable record of the EUV flux from the geomagnetic record. We compare that to t...

  12. Design and Fabrication of a Dielectric Total Internal Reflecting Solar Concentrator and Associated Flux Extractor for Extreme High Temperature (2500K) Applications

    Science.gov (United States)

    Soules, Jack A.; Buchele, Donald R.; Castle, Charles H.; Macosko, Robert P.

    1997-01-01

    The Analex Corporation, under contract to the NASA Lewis Research Center (LeRC), Cleveland, Ohio, recently evaluated the feasibility of utilizing refractive secondary concentrators for solar heat receivers operating at temperatures up to 2500K. The feasibility study pointed out a number of significant advantages provided by solid single crystal refractive devices over the more conventional hollow reflective compound parabolic concentrators (CPCs). In addition to the advantages of higher concentration ratio and efficiency, the refractive concentrator, when combined with a flux extractor rod, provides for flux tailoring within the heat receiver cavity. This is a highly desirable, almost mandatory, feature for solar thermal propulsion engine designs presently being considered for NASA and Air Force thermal applications. Following the feasibility evaluation, the NASA-LeRC, NASA-Marshall Space Flight Center (MSFC), and Analex Corporation teamed up to design, fabricate, and test a refractive secondary concentrator/flux extractor system for potential use in the NASA-MSFC "Shooting Star" flight experiment. This paper describes the advantages and technical challenges associated with the design methodologies developed and utilized and the material and fabrication limitations encountered.

  13. High Flux Calorimetry.

    Science.gov (United States)

    1984-05-05

    These approaches are based on proven principles which have served the thermal test community well for years. Other concepts hold promise of being able to...8217. --......- - ... .... - - The thermal test community has developed instrumentation which is quite suitable for the moderate, and relatively constant, flux...on the maximum phase II system fluence of 400 cal/cm2 . Second, the present thermal test community will have confidence in the performance of an

  14. A calculation of acetone temperature field under extremely high heat flux within a short time%超急速温升下丙酮液池的温度场计算

    Institute of Scientific and Technical Information of China (English)

    金仁喜; 华顺芳; 刘登瀛; 张正芳

    2001-01-01

    According to the experiment and numerical simulation, the temperature field and its variation law of acetone and the tiny metal grains are studied under the transient and extremely high heat flux condition, while the platinum film resistance is overlaid with tiny metal grains or nothing. The speed of temperature rise, temperature grads and the thickness of heat layer are calculated numerically. Some stranger phenomena that are different from abnormal boiling are observed. It points out that it is easy to get higher speed of temperature rise while the platinum film is overlaid with nothing than with tiny metal grains despite of its vehemently boiling behavior.%通过实验和数值模拟计算,研究了瞬时、强热流极端条件下铂薄膜表面覆盖和不覆盖细小金属颗粒时丙酮液体和金属颗粒温度场分布及其变化规律.确定了温升速率、温度梯度和温度边界层厚度,发现了常规沸腾难以解释的现象,并指出覆盖金属颗粒后虽然沸腾极为激烈,但难以达到极高的温升速率,而不覆盖金属颗粒却容易产生爆发沸腾.

  15. High Flux Isotope Reactor (HFIR)

    Data.gov (United States)

    Federal Laboratory Consortium — The HFIR at Oak Ridge National Laboratory is a light-water cooled and moderated reactor that is the United States’ highest flux reactor-based neutron source. HFIR...

  16. On extreme atmospheric and marine nitrogen fluxes and chlorophyll-a levels in the Kattegat Strait

    DEFF Research Database (Denmark)

    Hasager, C.B.; Carstensen, J.; Ellermann, T.

    2003-01-01

    A retrospective analysis is carried out to investigate the importance of the vertical fluxes of nitrogen to the marine sea surface layer in which high chlorophyll a levels may cause blooms of harmful algae and subsequent turn over and oxygen depletion at the bottom of the sea. Typically nitrogen...... are calculated by the periodic maximum method and the results are successfully compared to a map of chlorophyll return periods based on in-situ observations. The one-year return of extreme atmospheric wet deposition is around 60 mg N m(-2) day(-1) and 30 mg N m(-2) day(-1) for deep-water entrainment. Atmospheric......-water entrainment forced by high winds greatly exceeds the atmospheric pool of nitrogen washed out by precipitation. At the frontal zone of the Kattegat Strait and Skagerrak, the nitrogen deep-water entrainment is very high and this explains the high 10-year return chlorophyll level at 8 mg m(-3) in the Kattegat...

  17. Spectral photometry of extreme helium stars: Ultraviolet fluxes and effective temperature

    Science.gov (United States)

    Drilling, J. S.; Schoenberner, D.; Heber, U.; Lynas-Gray, A. E.

    1982-01-01

    Ultraviolet flux distributions are presented for the extremely helium rich stars BD +10 deg 2179, HD 124448, LSS 3378, BD -9 deg 4395, LSE 78, HD 160641, LSIV -1 deg 2, BD 1 deg 3438, HD 168476, MV Sgr, LS IV-14 deg 109 (CD -35 deg 11760), LSII +33 deg 5 and BD +1 deg 4381 (LSIV +2 deg 13) obtained with the International Ultraviolet Explorer (IUE). Broad band photometry and a newly computed grid of line blanketed model atmospheres were used to determine accurate angular diameters and total stellar fluxes. The resultant effective temperatures are in most cases in satisfactory agreement with those based on broad band photometry and/or high resolution spectroscopy in the visible. For two objects, LSII +33 deg 5 and LSE 78, disagreement was found between the IUE observations and broadband photometry: the colors predict temperatures around 20,000 K, whereas the UV spectra indicate much lower photospheric temperatures of 14,000 to 15,000 K. The new temperature scale for extreme helium stars extends to lower effective temperatures than that of Heber and Schoenberner (1981) and covers the range from 8,500 K to 32,000 K.

  18. Formation of extreme surface turbulent heat fluxes from the ocean to the atmosphere in the North Atlantic

    Science.gov (United States)

    Tilinina, N. D.; Gulev, S. K.; Gavrikov, A. V.

    2016-01-01

    The role of extreme surface turbulent fluxes in total oceanic heat loss in the North Atlantic is studied. The atmospheric circulation patterns enhancing ocean-atmosphere heat flux in regions with significant contributions of the extreme heat fluxes (up to 60% of the net heat loss) are analyzed. It is shown that extreme heat fluxes in the Gulf Stream and the Greenland and Labrador Seas occur in zones with maximal air pressure gradients, i.e., in cyclone-anticyclone interaction zones.

  19. Flux attenuation at NREL's High-Flux Solar Furnace

    Science.gov (United States)

    Bingham, Carl E.; Scholl, Kent L.; Lewandowski, Allan A.

    1994-10-01

    The High-Flux Solar Furnace (HFSF) at the National Renewable Energy Laboratory (NREL) has a faceted primary concentrator and a long focal-length-to-diameter ratio (due to its off-axis design). Each primary facet can be aimed individually to produce different flux distributions at the target plane. Two different types of attenuators are used depending on the flux distribution. A sliding-plate attenuator is used primarily when the facets are aimed at the same target point. The alternate attenuator resembles a venetian blind. Both attenuators are located between the concentrator and the focal point. The venetian-blind attenuator is primarily used to control the levels of sunlight failing on a target when the primary concentrators are not focused to a single point. This paper will demonstrate the problem of using the sliding-plate attenuator with a faceted concentrator when the facets are not aimed at the same target point. We will show that although the alternate attenuator necessarily blocks a certain amount of incoming sunlight, even when fully open, it provides a more even attenuation of the flux for alternate aiming strategies.

  20. The intrinsic extreme ultraviolet fluxes of F5 V to M5 V stars

    Energy Technology Data Exchange (ETDEWEB)

    Linsky, Jeffrey L. [JILA, University of Colorado and NIST, 440UCB Boulder, CO 80309-0440 (United States); Fontenla, Juan [NorthWest Research Associates Inc., 3380 Mitchell Ln, Boulder, CO 80301 (United States); France, Kevin, E-mail: jlinsky@jilau1.colorado.edu, E-mail: jfontenla@nwra.com, E-mail: Kevin.France@colorado.edu [CASA, University of Colorado, 593UCB Boulder, CO 80309-0593 (United States)

    2014-01-01

    Extreme ultraviolet (EUV) radiations (10-117 nm) from host stars play important roles in the ionization, heating, and mass loss from exoplanet atmospheres. Together with the host star's Lyα and far-UV (117-170 nm) radiation, EUV radiation photodissociates important molecules, thereby changing the chemistry in exoplanet atmospheres. Since stellar EUV fluxes cannot now be measured and interstellar neutral hydrogen completely obscures stellar radiation between 40 and 91.2 nm, even for the nearest stars, we must estimate the unobservable EUV flux by indirect methods. New non-LTE semiempirical models of the solar chromosphere and corona and solar irradiance measurements show that the ratio of EUV flux in a variety of wavelength bands to the Lyα flux varies slowly with the Lyα flux and thus with the magnetic heating rate. This suggests and we confirm that solar EUV/Lyα flux ratios based on the models and observations are similar to the available 10-40 nm flux ratios observed with the Extreme Ultraviolet Explorer (EUVE) satellite and the 91.2-117 nm flux observed with the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite for F5 V-M5 V stars. We provide formulae for predicting EUV flux ratios based on the EUVE and FUSE stellar data and on the solar models, which are essential input for modeling the atmospheres of exoplanets.

  1. Northern Hemisphere Stratospheric Polar Vortex Extremes in February under the Control of Downward Wave Flux in the Lower Stratosphere

    Institute of Scientific and Technical Information of China (English)

    WEI Ke; CHEN Wen

    2012-01-01

    Using ECWMF ERA-40 and Interim reanalysis data, the planetary wave fluxes associated with the February extreme stratospheric polar vortex were studied. Using the three-dimensional Eliassen-Palm (EP) flux as a measure of the wave activity propagation, the authors show that the unusual warm years in the Arctic feature an anomalous weak stratosphere-troposphere coupling and weak downward wave flux at the lower stratosphere, especially over the North America and North Atlantic (NANA) region. The extremely cold years are characterized by strong stratosphere-troposphere coupling and strong downward wave flux in this region. The refractive index is used to examine the conception of planetary wave reflection, which shows a large refractive index (low reflection) for the extremely warm years and a small refractive index (high reflection) for the extremely cold years. This study reveals the importance of the downward planetary wave propagation from the stratosphere to the troposphere for explaining the unusual state of the stratospheric polar vortex in February.

  2. Extreme flux states of NGC 4151 observed with INTEGRAL

    CERN Document Server

    Lubinski, P; Walter, R; Paltani, S; Beckmann, V; Soldi, S; Ferrigno, C; Courvoisier, T J -L

    2010-01-01

    We present a comprehensive spectral analysis of all INTEGRAL data obtained so far for the X-ray-bright Seyfert galaxy NGC 4151. We also use all contemporaneous data from RXTE, XMM-Newton, Swift and Suzaku. We find a linear correlation between the medium and hard-energy X-ray fluxes measured by INTEGRAL, which indicates an almost constant spectral index over six years. The majority of INTEGRAL observations were made when the source was either at a very bright or very dim hard-X-ray state. We find that thermal Comptonization models applied to the bright state yields the plasma temperature of ~ 50-70 keV and its optical depth of ~ 1.3-2.6, depending on the assumed source geometry. For the dim state, these parameters are in the ranges of ~ 180-230 keV and ~ 0.3-0.7, respectively. The Compton parameter is y ~ 1 for all the spectra, indicating a stable geometry. Using this result, we can determine the reflection effective solid angles associated with the close and distant reprocessing media as ~ 0.3x2pi and 0.2x2pi...

  3. Responses of greenhouse gas fluxes to climate extremes in a semiarid grassland

    Science.gov (United States)

    Li, Linfeng; Fan, Wenyu; Kang, Xiaoming; Wang, Yanfen; Cui, Xiaoyong; Xu, Chengyuan; Griffin, Kevin L.; Hao, Yanbin

    2016-10-01

    Climate extremes are expected to increase in frequency and intensity as a consequence of anthropogenic climate change attributed to the rise of atmospheric concentrations of greenhouse gases (GHGs). However, studies on the impacts of climate extremes on terrestrial ecosystems are limited. Here, we experimentally imposed extreme drought and a heat wave (∼60-year recurrence) to investigate their effects on GHGs fluxes of a semiarid grassland in China. We estimated a 16% and 38% percent reduction in net ecosystem CO2 uptake caused by the heat wave and drought respectively, but via different mechanisms. Drought reduced gross ecosystem productively (GEP) and to a lower extent ecosystem respiration (ER). By contrast, the simulated heat wave suppressed only GEP while ER remained stable. The climate extremes also created a legacy effect on GEP and NEE lasting until the end of the growing season, whereas ER recovered immediately. Although CH4 and N2O fluxes were unaffected by the heat wave, drought promoted CH4 uptake and suppressed N2O emission during the treatment period. The effect of drought on GHGs fluxes generally overwhelmed that of the heat wave treatment, and there were no interactive effects of these two types of climate extremes. Our results showed that responses of ecosystem GHGs exchange to climate extremes are strongly regulated by soil moisture status. In conclusion, future amplification of climate extremes could decrease the sink for GHGs, especially CO2, in this semiarid grasslands.

  4. Increase of mycorrhizal C flux in Siberian temperate forests during the extreme drought of 2012

    Science.gov (United States)

    Menyailo, Oleg; Matvienko, Anastasia; Cheng, Chih-Hsin

    2015-04-01

    Extreme climatic events have strong effect on the terrestrial carbon cycle. The soil C flux is the major uncertainty in the global C budget. Autotrophic (roots and mycorrhizae) component and heterotrophic microorganisms respond differently to altered precipitation and temperature, however their responses might vary in different ecosystems. We studied mycorrhizal, heterotrohic and total soil CO2 fluxes using in-growth mesh collars in forest soils under different tree species. The fluxes were measured between May and October of 2010-2012. The summer of 2012 was extremely hot and dry in Siberia, breaking records for the past 70 years of meteorological monitoring. The drought reduced soil surface CO2 flux for 20-30 % depending on the tree species. It is very surprising that the mycorrhizal flux in 2012 was under most species similar to the flux in a wetter years (2010-2011), under birch the mycorrhizal flux was even 1.5 times higher during the drought. Thus, decline in overall soil surface CO2 flux was mainly due to reduction of heterotrophic activities. Since the proportion of heterotrophic and autrophic activities is related to soil C sequestration, we conclude that under the most tree species in Siberia soil C will be accumulated during the drought. The most positive effect of the drought for soil carbon accrual is to be expected under birch.

  5. The impacts of '05.6' extreme flood event on riverine carbon fluxes in Xijiang River

    Institute of Scientific and Technical Information of China (English)

    SUN HuiGuo; HAN JingTai; ZHANG ShuRong; LU XiXi

    2007-01-01

    An extreme flood event with a frequency of nearly 200 year occurred in June of 2005 in the Xijiang River,the main trunk stream of the Zhujiang River. Samples were systematically collected during the flood event, and water quality parameters, including total suspended sediment (TSS), dissolved inorganic carbon (DIC), dissolved organic carbon (DOC), and particulate organic carbon (POC) were analyzed,and riverine carbon concentrations associated with its changing pattern through the flood process were discussed. These parameters reflect the changes in basin surface flow and subsurface flow during the flood. This flood event influenced annual flux estimations of POC, DOC, and DIC to great extents.Based on carbon flux estimations for the year 2005 and the flood event (June 21-28) in the Xijiang River, it was found that DIC, DOC, and POC fluxes during '05.6' flood event are 1.52x106 g.km-2.a-1,0.24x106 g.km-2.a-1, and 0.54x106 g.km-2.a-1, and account for 14.87%, 24.75% and 44.89% of the annual fluxes in 2005, respectively. The results suggested that carbon exports during extreme flood events had great contributions to the total carbon fluxes and composition of various carbon components, being important for accurate estimates of annual carbon fluxes in rivers with frequent floods.

  6. Plasma–Surface Interactions Under High Heat and Particle Fluxes

    Directory of Open Access Journals (Sweden)

    Gregory De Temmerman

    2013-01-01

    Full Text Available The plasma-surface interactions expected in the divertor of a future fusion reactor are characterized by extreme heat and particle fluxes interacting with the plasma-facing surfaces. Powerful linear plasma generators are used to reproduce the expected plasma conditions and allow plasma-surface interactions studies under those very harsh conditions. While the ion energies on the divertor surfaces of a fusion device are comparable to those used in various plasma-assited deposition and etching techniques, the ion (and energy fluxes are up to four orders of magnitude higher. This large upscale in particle flux maintains the surface under highly non-equilibrium conditions and bring new effects to light, some of which will be described in this paper.

  7. Comparison of the high temperature heat flux sensor to traditional heat flux gages under high heat flux conditions.

    Energy Technology Data Exchange (ETDEWEB)

    Blanchat, Thomas K.; Hanks, Charles R.

    2013-04-01

    Four types of heat flux gages (Gardon, Schmidt-Boelter, Directional Flame Temperature, and High Temperature Heat Flux Sensor) were assessed and compared under flux conditions ranging between 100-1000 kW/m2, such as those seen in hydrocarbon fire or propellant fire conditions. Short duration step and pulse boundary conditions were imposed using a six-panel cylindrical array of high-temperature tungsten lamps. Overall, agreement between all gages was acceptable for the pulse tests and also for the step tests. However, repeated tests with the HTHFS with relatively long durations at temperatures approaching 1000ÀC showed a substantial decrease (10-25%) in heat flux subsequent to the initial test, likely due to the mounting technique. New HTHFS gages have been ordered to allow additional tests to determine the cause of the flux reduction.

  8. Flux rope, hyperbolic flux tube, and late extreme ultraviolet phases in a non-eruptive circular-ribbon flare

    Science.gov (United States)

    Masson, Sophie; Pariat, Étienne; Valori, Gherardo; Deng, Na; Liu, Chang; Wang, Haimin; Reid, Hamish

    2017-08-01

    Context. The dynamics of ultraviolet (UV) emissions during solar flares provides constraints on the physical mechanisms involved in the trigger and the evolution of flares. In particular it provides some information on the location of the reconnection sites and the associated magnetic fluxes. In this respect, confined flares are far less understood than eruptive flares generating coronal mass ejections. Aims: We present a detailed study of a confined circular flare dynamics associated with three UV late phases in order to understand more precisely which topological elements are present and how they constrain the dynamics of the flare. Methods: We perform a non-linear force-free field extrapolation of the confined flare observed with the Helioseismic and Magnetic Imager (HMI) and Atmospheric Imaging Assembly (AIA) instruments on board Solar Dynamics Observatory (SDO). From the 3D magnetic field we compute the squashing factor and we analyse its distribution. Conjointly, we analyse the AIA extreme ultraviolet (EUV) light curves and images in order to identify the post-flare loops, and their temporal and thermal evolution. By combining the two analyses we are able to propose a detailed scenario that explains the dynamics of the flare. Results: Our topological analysis shows that in addition to a null-point topology with the fan separatrix, the spine lines and its surrounding quasi-separatix layer (QSL) halo (typical for a circular flare), a flux rope and its hyperbolic flux tube (HFT) are enclosed below the null. By comparing the magnetic field topology and the EUV post-flare loops we obtain an almost perfect match between the footpoints of the separatrices and the EUV 1600 Å ribbons and between the HFT field line footpoints and bright spots observed inside the circular ribbons. We show, for the first time in a confined flare, that magnetic reconnection occurred initially at the HFT below the flux rope. Reconnection at the null point between the flux rope and the

  9. Surf zone, infragravity wave energy flux, and runup in extreme conditions

    Science.gov (United States)

    Fiedler, J. W.; Brodie, K. L.; McNinch, J.; Guza, R. T.

    2014-12-01

    Waves, currents, and sand levels were observed on a 1.4 km-long cross-shore transect extending from the back beach to ~11 m water depth at Agate Beach, Oregon in Fall 2013. Wave runup and water table fluctuations on this low slope (1:80) beach were measured with a cliff-mounted scanning Lidar and buried pressure sensors. Significant wave heights at an offshore buoy in 128m depth ranged from small (0.5m) to extreme (7.5m), with peak periods between 4-22 seconds. Infragravity frequency (nominally 0.01 Hz) horizontal runup excursions exceeded 100m, and infragravity cross-shore velocity exceeded 3 m/s. Cross-shore patterns of infragravity wave energy flux, observed with seven co-located pressure and current meters, indicate 'proto-saturation' of the inner surfzone in extreme conditions. That is, the intensification of incident wave forcing (e.g. higher energy, longer swell) leads to a wider surfzone and an increase in the shoreward infragravity wave energy seaward of the surfzone, but produces more modest increases in flux in the inner surfzone, and in the runup. Nonlinear energy balances, based on the observations, show transfer of energy from sea-swell to infragravity waves, and vice-versa. The infragravity energy balance closes in cases with low energy incident sea-swell. With more energetic incident waves, there is an unexplained inner surfzone energy sink at the lowest IG frequencies (0.004-0.02 Hz). Ongoing work aims to quantify the effect on infragravity energy balances by infragravity wave breaking and bottom friction. Additionally, the estimates may be degraded by contamination with rotational velocities of surfzone eddies. Whatever the dynamical explanation, infragravity wave runup on a low slope beach in high-energy conditions is limited significantly by dissipation. The slow rate of runup increase suggests nascent, or 'proto' saturation. This work was supported by the U.S. Army Corps of Engineers.

  10. Variability of carbon and water fluxes following climate extremes over a tropical forest in southwestern Amazonia.

    Directory of Open Access Journals (Sweden)

    Marcelo Zeri

    Full Text Available The carbon and water cycles for a southwestern Amazonian forest site were investigated using the longest time series of fluxes of CO2 and water vapor ever reported for this site. The period from 2004 to 2010 included two severe droughts (2005 and 2010 and a flooding year (2009. The effects of such climate extremes were detected in annual sums of fluxes as well as in other components of the carbon and water cycles, such as gross primary production and water use efficiency. Gap-filling and flux-partitioning were applied in order to fill gaps due to missing data, and errors analysis made it possible to infer the uncertainty on the carbon balance. Overall, the site was found to have a net carbon uptake of ≈5 t C ha(-1 year(-1, but the effects of the drought of 2005 were still noticed in 2006, when the climate disturbance caused the site to become a net source of carbon to the atmosphere. Different regions of the Amazon forest might respond differently to climate extremes due to differences in dry season length, annual precipitation, species compositions, albedo and soil type. Longer time series of fluxes measured over several locations are required to better characterize the effects of climate anomalies on the carbon and water balances for the whole Amazon region. Such valuable datasets can also be used to calibrate biogeochemical models and infer on future scenarios of the Amazon forest carbon balance under the influence of climate change.

  11. Variability of carbon and water fluxes following climate extremes over a tropical forest in southwestern Amazonia.

    Science.gov (United States)

    Zeri, Marcelo; Sá, Leonardo D A; Manzi, Antônio O; Araújo, Alessandro C; Aguiar, Renata G; von Randow, Celso; Sampaio, Gilvan; Cardoso, Fernando L; Nobre, Carlos A

    2014-01-01

    The carbon and water cycles for a southwestern Amazonian forest site were investigated using the longest time series of fluxes of CO2 and water vapor ever reported for this site. The period from 2004 to 2010 included two severe droughts (2005 and 2010) and a flooding year (2009). The effects of such climate extremes were detected in annual sums of fluxes as well as in other components of the carbon and water cycles, such as gross primary production and water use efficiency. Gap-filling and flux-partitioning were applied in order to fill gaps due to missing data, and errors analysis made it possible to infer the uncertainty on the carbon balance. Overall, the site was found to have a net carbon uptake of ≈5 t C ha(-1) year(-1), but the effects of the drought of 2005 were still noticed in 2006, when the climate disturbance caused the site to become a net source of carbon to the atmosphere. Different regions of the Amazon forest might respond differently to climate extremes due to differences in dry season length, annual precipitation, species compositions, albedo and soil type. Longer time series of fluxes measured over several locations are required to better characterize the effects of climate anomalies on the carbon and water balances for the whole Amazon region. Such valuable datasets can also be used to calibrate biogeochemical models and infer on future scenarios of the Amazon forest carbon balance under the influence of climate change.

  12. High flux film and transition boiling

    Science.gov (United States)

    Witte, L. C.

    1993-02-01

    An investigation was conducted on the potential for altering the boiling curve through effects of high velocity and high subcooling. Experiments using water and Freon-113 flowing over cylindrical electrical heaters in crossflow were made to see how velocity and subcooling affect the boiling curve, especially the film and transition boiling regions. We sought subcooling levels down to near the freezing points of these two liquids to prove the concept that the critical heat flux and the minimum heat flux could be brought together, thereby averting the transition region altogether. Another emphasis was to gain insight into how the various boiling regions could be represented mathematically on various parts of the heating surface. Motivation for the research grew out of a realization that the effects of very high subcooling and velocity might be to avert the transition boiling altogether so that the unstable part of the boiling curve would not limit the application of high flux devices to temperatures less than the burnout temperatures. Summaries of results from the study are described. It shows that the potential for averting the transition region is good and points the way to further research that is needed to demonstrate the potential.

  13. Ecosystem-scale volatile organic compound fluxes during an extreme drought in a broadleaf temperate forest of the Missouri Ozarks (central USA)

    Energy Technology Data Exchange (ETDEWEB)

    Seco, Roger [Univ. of California, Irvine, CA (United States); Karl, Thomas [Univ. of Innsbruck (Austria); Guenther, Alex B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Washington State Univ., Pullman, WA (United States); Hosman, Kevin P. [Univ. of Missouri, Columbia, MO (United States); Pallardy, Stephen G. [Univ. of Missouri, Columbia, MO (United States); Gu, Lianhong [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Geron, Chris [U.S. Environmental Protection Agency, Research Triangle Park, NC (United States); Harley, Peter [National Center for Atmospheric Research, Boulder, CO (United States); Kim, Saewung [Univ. of California, Irvine, CA (United States)

    2015-07-07

    Considerable amounts and varieties of biogenic volatile organic compounds (BVOCs) are exchanged between vegeta-tion and the surrounding air. These BVOCs play key ecological and atmospheric roles that must be adequately repre-sented for accurately modeling the coupled biosphere–atmosphere–climate earth system. One key uncertainty in existing models is the response of BVOC fluxes to an important global change process: drought. We describe the diur-nal and seasonal variation in isoprene, monoterpene, and methanol fluxes from a temperate forest ecosystem before, during, and after an extreme 2012 drought event in the Ozark region of the central USA. BVOC fluxes were domi-nated by isoprene, which attained high emission rates of up to 35.4 mg m-2h-1 at midday. Methanol fluxes were characterized by net deposition in the morning, changing to a net emission flux through the rest of the daylight hours. Net flux of CO2 reached its seasonal maximum approximately a month earlier than isoprenoid fluxes, which high-lights the differential response of photosynthesis and isoprenoid emissions to progressing drought conditions. Never-theless, both processes were strongly suppressed under extreme drought, although isoprene fluxes remained relatively high compared to reported fluxes from other ecosystems. Methanol exchange was less affected by drought throughout the season, conflrming the complex processes driving biogenic methanol fluxes. The fraction of daytime (7–17 h) assimilated carbon released back to the atmosphere combining the three BVOCs measured was 2% of gross primary productivity (GPP) and 4.9% of net ecosystem exchange (NEE) on average for our whole measurement cam-paign, while exceeding 5% of GPP and 10% of NEE just before the strongest drought phase. The MEGANv2.1 model correctly predicted diurnal variations in fluxes driven mainly by light and temperature, although further research is needed to address model BVOC fluxes

  14. High heat flux loop heat pipes

    Science.gov (United States)

    North, Mark T.; Sarraf, David B.; Rosenfeld, John H.; Maidanik, Yuri F.; Vershinin, Sergey

    1997-01-01

    Loop Heat Pipes (LHPs) can transport very large thermal power loads, over long distances, through flexible, small diameter tubes and against high gravitational heads. While recent LHPs have transported as much as 1500 W, the peak heat flux through a LHP's evaporator has been limited to about 0.07 MW/m2. This limitation is due to the arrangement of vapor passages next to the heat load which is one of the conditions necessary to ensure self priming of the device. This paper describes work aimed at raising this limit by threefold to tenfold. Two approaches were pursued. One optimized the vapor passage geometry for the high heat flux conditions. The geometry improved the heat flow into the wick and working fluid. This approach also employed a finer pored wick to support higher vapor flow losses. The second approach used a bidisperse wick material within the circumferential vapor passages. The bidisperse material increased the thermal conductivity and the evaporative surface area in the region of highest heat flux, while providing a flow path for the vapor. Proof-of-concept devices were fabricated and tested for each approach. Both devices operated as designed and both demonstrated operation at a heat flux of 0.70 MW/m2. This performance exceeded the known state of the art by a factor of more than six for both conventional heat pipes and for loop heat pipes using ammonia. In addition, the bidisperse-wick device demonstrated boiling heat transfer coefficients up to 100,000 W/m2.K, and the fine pored device demonstrated an orientation independence with its performance essentially unaffected by whether its evaporator was positioned above, below or level with the condenser.

  15. Relativistic QED Plasma at Extremely High Temperature

    CERN Document Server

    Masood, Samina S

    2016-01-01

    Renormalization scheme of QED (Quantum Electrodynamics) at high temperatures is used to calculate the effective parameters of relativistic plasma in the early universe. Renormalization constants of QED play role of effective parameters of the theory and can be used to determine the collective behavior of the medium. We explicitly show that the dielectric constant, magnetic reluctivity, Debye length and the plasma frequency depend on temperature in the early universe. Propagation speed, refractive index, plasma frequency and Debye shielding length of a QED plasma are computed at extremely high temperatures in the early universe. We also found the favorable conditions for the relativistic plasma from this calculations.

  16. Extreme Transients in the High Energy Universe

    Science.gov (United States)

    Kouveliotou, Chryssa

    2013-01-01

    The High Energy Universe is rich in diverse populations of objects spanning the entire cosmological (time)scale, from our own present-day Milky Way to the re-ionization epoch. Several of these are associated with extreme conditions irreproducible in laboratories on Earth. Their study thus sheds light on the behavior of matter under extreme conditions, such as super-strong magnetic fields (in excess of 10^14 G), high gravitational potentials (e.g., Super Massive Black Holes), very energetic collimated explosions resulting in relativistic jet flows (e.g., Gamma Ray Bursts, exceeding 10^53 ergs). In the last thirty years, my work has been mostly focused on two apparently different but potentially linked populations of such transients: magnetars (highly magnetized neutron stars) and Gamma Ray Bursts (strongly beamed emission from relativistic jets), two populations that constitute unique astrophysical laboratories, while also giving us the tools to probe matter conditions in the Universe to redshifts beyond z=10, when the first stars and galaxies were assembled. I did not make this journey alone I have either led or participated in several international collaborations studying these phenomena in multi-wavelength observations; solitary perfection is not sufficient anymore in the world of High Energy Astrophysics. I will describe this journey, present crucial observational breakthroughs, discuss key results and muse on the future of this field.

  17. Extremely high frequency RF effects on electronics.

    Energy Technology Data Exchange (ETDEWEB)

    Loubriel, Guillermo Manuel; Vigliano, David; Coleman, Phillip Dale; Williams, Jeffery Thomas; Wouters, Gregg A.; Bacon, Larry Donald; Mar, Alan

    2012-01-01

    The objective of this work was to understand the fundamental physics of extremely high frequency RF effects on electronics. To accomplish this objective, we produced models, conducted simulations, and performed measurements to identify the mechanisms of effects as frequency increases into the millimeter-wave regime. Our purpose was to answer the questions, 'What are the tradeoffs between coupling, transmission losses, and device responses as frequency increases?', and, 'How high in frequency do effects on electronic systems continue to occur?' Using full wave electromagnetics codes and a transmission-line/circuit code, we investigated how extremely high-frequency RF propagates on wires and printed circuit board traces. We investigated both field-to-wire coupling and direct illumination of printed circuit boards to determine the significant mechanisms for inducing currents at device terminals. We measured coupling to wires and attenuation along wires for comparison to the simulations, looking at plane-wave coupling as it launches modes onto single and multiconductor structures. We simulated the response of discrete and integrated circuit semiconductor devices to those high-frequency currents and voltages, using SGFramework, the open-source General-purpose Semiconductor Simulator (gss), and Sandia's Charon semiconductor device physics codes. This report documents our findings.

  18. The Compton hump and variable blue wing in the extreme low-flux NuSTAR observations of 1H0707-495

    DEFF Research Database (Denmark)

    Kara, E.; Fabian, A. C.; Lohfink, A. M.;

    2015-01-01

    of a deep 250-ks NuSTAR (Nuclear Spectroscopic Telescope Array) observation of 1H0707-495, which includes the first sensitive observations above 10 keV. Even though the NuSTAR observations caught the source in an extreme low-flux state, the Compton hump is still significantly detected. NuSTAR, with its high...... is that the drop in flux is the blue wing of the relativistically broadened iron K alpha emission line. When the flux is low, the coronal source height is low, thus enhancing the most gravitationally redshifted emission....

  19. Extremely compliant and highly stretchable patterned graphene

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Shuze; Huang, Yinjun; Li, Teng, E-mail: LiT@umd.edu [Department of Mechanical Engineering and Maryland NanoCenter, University of Maryland, College Park, Maryland 20742 (United States)

    2014-04-28

    Graphene is intrinsically ultra-stiff in its plane. Its huge mechanical mismatch when interfacing with ultra-compliant biological tissues and elastomers (7–9 orders of magnitude difference in stiffness) poses significant challenge in its application to functional devices such as epidermal electronics and sensing prosthesis. We offer a feasible and promising solution to this significant challenge by suitably patterning graphene into a nanomesh. Through systematic coarse-grained simulations, we show that graphene nanomesh can be made extremely compliant with nearly zero stiffness up to about 20% elongation and then remain highly compliant up to about 50% elongation.

  20. Exploring the active galactic nuclei population with extreme X-ray-to-optical flux ratios (fx/fo > 50)

    Science.gov (United States)

    Della Ceca, R.; Carrera, F. J.; Caccianiga, A.; Severgnini, P.; Ballo, L.; Braito, V.; Corral, A.; Del Moro, A.; Mateos, S.; Ruiz, A.; Watson, M. G.

    2015-03-01

    The cosmic history of the growth of supermassive black holes in galactic centres parallels that of star formation in the Universe. However, an important fraction of this growth occurs inconspicuously in obscured objects, where ultraviolet/optical/near-infrared emission is heavily obscured by dust. Since the X-ray flux is less attenuated, a high X-ray-to-optical flux ratio (fx/fo) is expected to be an efficient tool to find out these obscured accreting sources. We explore here via optical spectroscopy, X-ray spectroscopy and infrared photometry the most extreme cases of this population (those with fx/fo > 50, EXO50 sources hereafter), using a well-defined sample of seven X-ray sources extracted from the 2XMM catalogue. Five EXO50 sources (˜70 per cent of the sample) in the bright flux regime explored by our survey (f(2-10 keV) ≥ 1.5 × 10-13 erg cm-2 s-1) are associated with obscured AGN (NH > 1022 cm-2), spanning a redshift range between 0.75 and 1 and characterized by 2-10 keV intrinsic luminosities in the QSO regime (e.g. well in excess to 1044 erg s-1). We did not find compelling evidence of Compton thick active galacic nuclei (AGN). Overall, the EXO50 type 2 QSOs do not seem to be different from standard X-ray-selected type 2 QSOs in terms of nuclear absorption; a very high AGN/host galaxy ratio seems to play a major role in explaining their extreme properties. Interestingly, three out of five EXO50 type 2 QSO objects can be classified as extreme dust-obscured galaxies (EDOGs, f24 μm/fR ≥ 2000), suggesting that a very high AGN/host ratios (along with the large amount of dust absorption) could be the natural explanation also for a part of the EDOG population. The remaining two EXO50 sources are classified as BL Lac objects, having rather extreme properties, and which are good candidates for TeV emission.

  1. Flux profile scanners for scattered high-energy electrons

    Science.gov (United States)

    Hicks, R. S.; Decowski, P.; Arroyo, C.; Breuer, M.; Celli, J.; Chudakov, E.; Kumar, K. S.; Olson, M.; Peterson, G. A.; Pope, K.; Ricci, J.; Savage, J.; Souder, P. A.

    2005-11-01

    The paper describes the design and performance of flux integrating Cherenkov scanners with air-core reflecting light guides used in a high-energy, high-flux electron scattering experiment at the Stanford Linear Accelerator Center. The scanners were highly radiation resistant and provided a good signal to background ratio leading to very good spatial resolution of the scattered electron flux profile scans.

  2. Extreme Precipitation and High-Impact Landslides

    Science.gov (United States)

    Kirschbaum, Dalia; Adler, Robert; Huffman, George; Peters-Lidard, Christa

    2012-01-01

    It is well known that extreme or prolonged rainfall is the dominant trigger of landslides; however, there remain large uncertainties in characterizing the distribution of these hazards and meteorological triggers at the global scale. Researchers have evaluated the spatiotemporal distribution of extreme rainfall and landslides at local and regional scale primarily using in situ data, yet few studies have mapped rainfall-triggered landslide distribution globally due to the dearth of landslide data and consistent precipitation information. This research uses a newly developed Global Landslide Catalog (GLC) and a 13-year satellite-based precipitation record from Tropical Rainfall Measuring Mission (TRMM) data. For the first time, these two unique products provide the foundation to quantitatively evaluate the co-occurence of precipitation and rainfall-triggered landslides globally. The GLC, available from 2007 to the present, contains information on reported rainfall-triggered landslide events around the world using online media reports, disaster databases, etc. When evaluating this database, we observed that 2010 had a large number of high-impact landslide events relative to previous years. This study considers how variations in extreme and prolonged satellite-based rainfall are related to the distribution of landslides over the same time scales for three active landslide areas: Central America, the Himalayan Arc, and central-eastern China. Several test statistics confirm that TRMM rainfall generally scales with the observed increase in landslide reports and fatal events for 2010 and previous years over each region. These findings suggest that the co-occurrence of satellite precipitation and landslide reports may serve as a valuable indicator for characterizing the spatiotemporal distribution of landslide-prone areas in order to establish a global rainfall-triggered landslide climatology. This research also considers the sources for this extreme rainfall, citing

  3. Exploring the Active Galactic Nuclei population with extreme X-ray to optical flux ratios (Fx/Fo >50)

    CERN Document Server

    Della Ceca, R; Caccianiga, A; Severgnini, P; Ballo, L; Braito, V; Corral, A; Del Moro, A; Mateos, S; Ruiz, A; Watson, M G

    2015-01-01

    The cosmic history of the growth of supermassive black holes in galactic centers parallels that of star-formation in the Universe. However, an important fraction of this growth occurs inconspicuously in obscured objects, where ultraviolet/optical/near-infrared emission is heavily obscured by dust. Since the X-ray flux is less attenuated, a high X-ray-to-optical flux ratio (Fx/Fo) is expected to be an efficient tool to find out these obscured accreting sources. We explore here via optical spectroscopy, X-ray spectroscopy and infrared photometry the most extreme cases of this population (those with Fx/Fo >50, EXO50 sources hereafter), using a well defined sample of seven X-ray sources extracted from the 2XMM catalogue. Five EXO50 sources (about 70 percent of the sample) in the bright flux regime explored by our survey (f(2-10 keV) > 1.5E-13 cgs) are associated with obscured AGN (Nh > 1.0E22 cm-2), spanning a redshift range between 0.75 and 1 and characterised by 2-10 keV intrinsic luminosities in the QSO regime...

  4. (13)C metabolic flux analysis of the extremely thermophilic, fast growing, xylose-utilizing Geobacillus strain LC300.

    Science.gov (United States)

    Cordova, Lauren T; Antoniewicz, Maciek R

    2016-01-01

    Thermophiles are increasingly used as versatile hosts in the biotechnology industry. One of the key advantages of thermophiles is the potential to achieve high rates of feedstock conversion at elevated temperatures. The recently isolated Geobacillus strain LC300 grows extremely fast on xylose, with a doubling time of less than 30 min. In the accompanying paper, the genome of Geobacillus LC300 was sequenced and annotated. In this work, we have experimentally validated the metabolic network model using parallel (13)C-labeling experiments and applied (13)C-metabolic flux analysis to quantify precise metabolic fluxes. Specifically, the complete set of singly labeled xylose tracers, [1-(13)C], [2-(13)C], [3-(13)C], [4-(13)C], and [5-(13)C]xylose, was used for the first time. Isotopic labeling of biomass amino acids was measured by gas chromatography mass spectrometry (GC-MS). Isotopic labeling of carbon dioxide in the off-gas was also measured by an on-line mass spectrometer. The (13)C-labeling data was then rigorously integrated for flux elucidation using the COMPLETE-MFA approach. The results provided important new insights into the metabolism of Geobacillus LC300, its efficient xylose utilization pathways, and the balance between carbon, redox and energy fluxes. The pentose phosphate pathway, glycolysis and TCA cycle were found to be highly active in Geobacillus LC300. The oxidative pentose phosphate pathway was also active and contributed significantly to NADPH production. No transhydrogenase activity was detected. Results from this work provide a solid foundation for future studies of this strain and its metabolic engineering and biotechnological applications.

  5. High-energy fluxes of atmospheric neutrinos

    CERN Document Server

    Sinegovskaya, T S; Sinegovsky, S I

    2013-01-01

    High-energy neutrinos from decays of mesons, produced in collisions of cosmic ray particles with air nuclei, form unavoidable background for detection of astrophysical neutrinos. More precise calculations of the high-energy neutrino spectrum are required since measurements in the IceCube experiment reach the intriguing energy region where a contribution of the prompt neutrinos and/or astrophysical ones should be discovered. Basing on the referent hadronic models QGSJET II-03, SIBYLL 2.1, we calculate high-energy spectra, both of the muon and electron atmospheric neutrinos, averaged over zenith-angles. The computation is made using three parameterizations of cosmic ray spectra which include the knee region. All calculations are compared with the atmospheric neutrino measurements by Frejus and IceCube. The prompt neutrino flux predictions obtained with thequark-gluon string model (QGSM) for the charm production by Kaidalov & Piskunova do not contradict to the IceCube measurements and upper limit on the astr...

  6. Turbulent, Extreme Multi-Zone Model for Simulating Flux and Polarization Variability in Blazars

    CERN Document Server

    Marscher, Alan P

    2013-01-01

    The author presents a model for variability of the flux and polarization of blazars in which turbulent plasma flowing at a relativistic speed down a jet crosses a standing conical shock. The shock compresses the plasma and accelerates electrons to energies up to gamma(max) > 1E4 times their rest-mass energy, with the value of gamma(max) determined by the direction of the magnetic field relative to the shock front. The turbulence is approximated in a computer code as many cells, each with a uniform magnetic field whose direction is selected randomly. The density of high-energy electrons in the plasma changes randomly with time in a manner consistent with the power spectral density of flux variations derived from observations of blazars. The variations in flux and polarization are therefore caused by continuous noise processes rather than by singular events such as explosive injection of energy at the base of the jet. Sample simulations illustrate the behavior of flux and linear polarization versus time that su...

  7. High heat flux engineering in solar energy applications

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, C.P.

    1993-07-01

    Solar thermal energy systems can produce heat fluxes in excess of 10,000 kW/m{sup 2}. This paper provides an introduction to the solar concentrators that produce high heat flux, the receivers that convert the flux into usable thermal energy, and the instrumentation systems used to measure flux in the solar environment. References are incorporated to direct the reader to detailed technical information.

  8. Impact of urban WWTP and CSO fluxes on river peak flow extremes under current and future climate conditions.

    Science.gov (United States)

    Keupers, Ingrid; Willems, Patrick

    2013-01-01

    The impact of urban water fluxes on the river system outflow of the Grote Nete catchment (Belgium) was studied. First the impact of the Waste Water Treatment Plant (WWTP) and the Combined Sewer Overflow (CSO) outflows on the river system for the current climatic conditions was determined by simulating the urban fluxes as point sources in a detailed, hydrodynamic river model. Comparison was made of the simulation results on peak flow extremes with and without the urban point sources. In a second step, the impact of climate change scenarios on the urban fluxes and the consequent impacts on the river flow extremes were studied. It is shown that the change in the 10-year return period hourly peak flow discharge due to climate change (-14% to +45%) was in the same order of magnitude as the change due to the urban fluxes (+5%) in current climate conditions. Different climate change scenarios do not change the impact of the urban fluxes much except for the climate scenario that involves a strong increase in rainfall extremes in summer. This scenario leads to a strong increase of the impact of the urban fluxes on the river system.

  9. Extreme Environment High Temperature Communication Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of this project is to develop and demonstrate a communications system capable of operation at extreme temperatures and pressures in hostile and corrosive...

  10. Anisotropic flux pinning in high Tc superconductors

    Science.gov (United States)

    Koleśnik, S.; Igalson, J.; Skośkiewicz, T.; Szymczak, R.; Baran, M.; Pytel, K.; Pytel, B.

    1995-02-01

    In this paper we present a comparison of the results of FC magnetization measurements on several PbSr(Y,Ca)CuO crystals representing various levels of flux pinning. The pinning centers in our crystals have been set up during the crystal growth process or introduced by neutron irradiation. Some possible explanations of the observed effects, including surface barrier, flux-center distribution and sample-shape effects, are discussed.

  11. Suspended sediment in a high-Arctic river: An appraisal of flux estimation methods.

    Science.gov (United States)

    Ladegaard-Pedersen, Pernille; Sigsgaard, Charlotte; Kroon, Aart; Abermann, Jakob; Skov, Kirstine; Elberling, Bo

    2017-02-15

    Quantifying fluxes of water, sediment and dissolved compounds through Arctic rivers is important for linking the glacial, terrestrial and marine ecosystems and to quantify the impact of a warming climate. The quantification of fluxes is not trivial. This study uses a 8-years data set (2005-2012) of daily measurements from the high-Artic Zackenberg River in Northeast Greenland to estimate annual suspended sediment fluxes based on four commonly used methods: M1) is the discharge weighted mean and uses direct measurements, while M2-M4) are one uncorrected and two bias corrected rating curves extrapolating a continuous concentration trace from measured values. All methods are tested on complete and reduced datasets. The average annual runoff in the period 2005-2012 was 190±25mio·m(3)y(-1). The different estimation methods gave a range of average annual suspended sediment fluxes between 43,000±10,000ty(-1) and 61,000±16,000ty(-1). Extreme events with high discharges had a mean duration of 1day. The average suspended sediment flux during extreme events was 17,000±5000ty(-1), which constitutes a year-to-year variation of 20-37% of the total annual flux. The most accurate sampling strategy was bi-daily sampling together with a sampling frequency of 2h during extreme events. The most consistent estimation method was an uncorrected rating curve of bi-daily measurements (M2), combined with a linear interpolation of extreme event fluxes. Sampling can be reduced to every fourth day, with both method-agreements and accuracies agreements were Arctic Zackenberg River, unless sampling was done bi-daily, every day and events sampled high-frequently.

  12. Flux pinning characteristics and irreversibility line in high temperature superconductors

    Science.gov (United States)

    Matsushita, T.; Ihara, N.; Kiuchi, M.

    1995-01-01

    The flux pinning properties in high temperature superconductors are strongly influenced by thermally activated flux motion. The scaling relation of the pinning force density and the irreversibility line in various high temperature superconductors are numerically analyzed in terms of the flux creep model. The effect of two factors, i.e., the flux pinning strength and the dimensionality of the material, on these properties are investigated. It is speculated that the irreversibility line in Bi-2212 superconductors is one order of magnitude smaller than that in Y-123, even if the flux pinning strength in Bi-2212 is improved up to the level of Y-123. It is concluded that these two factors are equally important in determination of the flux pinning characteristics at high temperatures.

  13. Periods of High Intensity Solar Proton Flux

    Science.gov (United States)

    Xapsos, Michael A.; Stauffer, Craig A.; Jordan, Thomas M.; Adams, James H.; Dietrich, William F.

    2012-01-01

    Analysis is presented for times during a space mission that specified solar proton flux levels are exceeded. This includes both total time and continuous time periods during missions. Results for the solar maximum and solar minimum phases of the solar cycle are presented and compared for a broad range of proton energies and shielding levels. This type of approach is more amenable to reliability analysis for spacecraft systems and instrumentation than standard statistical models.

  14. The Compton hump and variable blue wing in the extreme low-flux NuSTAR observations of 1H0707-495

    Science.gov (United States)

    Kara, E.; Fabian, A. C.; Lohfink, A. M.; Parker, M. L.; Walton, D. J.; Boggs, S. E.; Christensen, F. E.; Hailey, C. J.; Harrison, F. A.; Matt, G.; Reynolds, C. S.; Stern, D.; Zhang, W. W.

    2015-05-01

    The narrow-line Seyfert I galaxy, 1H0707-495, has been well observed in the 0.3-10 keV band, revealing a dramatic drop in flux in the iron Kα band, a strong soft excess, and short time-scale reverberation lags associated with these spectral features. In this paper, we present the first results of a deep 250-ks NuSTAR (Nuclear Spectroscopic Telescope Array) observation of 1H0707-495, which includes the first sensitive observations above 10 keV. Even though the NuSTAR observations caught the source in an extreme low-flux state, the Compton hump is still significantly detected. NuSTAR, with its high effective area above 7 keV, clearly detects the drop in flux in the iron Kα band, and by comparing these observations with archival XMM-Newton observations, we find that the energy of this drop increases with increasing flux. We discuss possible explanations for this, the most likely of which is that the drop in flux is the blue wing of the relativistically broadened iron Kα emission line. When the flux is low, the coronal source height is low, thus enhancing the most gravitationally redshifted emission.

  15. Effect of high-flux versus low-flux dialysis membranes on parathyroid hormone.

    Science.gov (United States)

    Makar, Samuel H; Sawires, Happy K; Farid, Tarek M; Ali, Waleed M; Schaalan, M

    2010-10-01

    INTRODUCTION. Hyperparathyroidism is a common finding in patients with renal insufficiency and parathyroid hormone (PTH) is considered a uremic toxin responsible for many of the abnormalities of the uremic state and bone disease. The aim of this study was to investigate the influence of permeability of low-flux versus high-flux dialysis membranes on intact PTH during hemodialysis in children. MATERIALS AND METHODS. Forty-four children aged between 4 and 13 years old on regular hemodialysis were enrolled in a prospective study. Low-flux polysulfone membranes were used for at least 6 months and then the patients were switched to use high-flux polysulfone membranes for 3 months. Serum electrolytes and intact PTH before and after dialysis were compared before and after changes in dialysis membrane. RESULTS. At the end of the 3-month use of high-flux filters, predialysis intact PTH level (49.40 ± 19.64 ng/dL) showed a highly significant decline (P dialysis membranes are more efficient in removal of intact PTH, one of the middle-sized uremic toxins, than low-flux membranes.

  16. CO2-Philic polymer membrane with extremely high separation performance

    KAUST Repository

    Yave, Wilfredo

    2010-01-12

    Polymeric membranes are attractive for CO2 separation and concentration from different gas streams because of their versatility and energy efficiency; they can compete with, and they may even replace, traditional absorption processes. Here we describe a simple and powerful method for developing nanostructured and CO2-philic polymer membranes for CO2 separation. A poly(ethylene oxide)-poly(butylene terephthalate) multiblock copolymer is used as membrane material. Smart additives such as polyethylene glycol dibutyl ether are incorporated as spacers or fillers for producing nanostructured materials. The addition of these specific additives produces CO2-philic membranes and increases the CO2 permeability (750 barrer) up to five-fold without the loss of selectivity. The membranes present outstanding performance for CO2 separation, and the measured CO2 flux is extremely high ( > 2 m3 m -2 h-1 bar-1) with selectivity over H2 and N2 of 10 and 40, respectively, making them attractive for CO 2 capture. © 2009 American Chemical Society.

  17. Synoptic conditions leading to extremely high temperatures in Madrid

    Directory of Open Access Journals (Sweden)

    R. García

    Full Text Available Extremely hot days (EHD in Madrid have been analysed to determine the synoptic patterns that produce EHDs during the period of 1955–1998. An EHD is defined as a day with maximum temperature higher than 36.5°C, a value which is the threshold for the intense effects on mortatility and it coincides with the 95 percentile of the series. Two different situations have been detected as being responsible for an EHD occurrence, one more dynamical, produced by southern fluxes, and another associated with a stagnation situation over Iberia of a longer duration. Both account for 92% of the total number of days, thus providing an efficient classification framework. A circulation index has been derived to characterise and forecast an EHD occurrence. This paper shows that EHD occur in Madrid during short duration events, and no long heat waves, like those recorded in other cities, are present. Additionally, no clear pattern can be detected in the EHD frequency; the occurrence is tied to changes in the summer location of the Azores high.

    Key words. Meteorology and atmospheric dynamics (Climatology; synoptic-scale meteorology; general or miscellaneous

  18. Synoptic conditions leading to extremely high temperatures in Madrid

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, R.; Prieto, L.; Hernandez, E.; Teso, T. del [Dept. Fisica de la Tierra II, Fac. CC. Fisicas, Univ. Camplutense de Madrid (Spain); Diaz, J. [Centro Universitario de Salud Publica, Univ. Autonoma de Madrid (Spain)

    2002-02-01

    Extremely hot days (EHD) in Madrid have been analysed to determine the synoptic patterns that produce EHDs during the period of 1955-1998. An EHD is defined as a day with maximum temperature higher than 36.5 C, a value which is the threshold for the intense effects on mortatility and it coincides with the 95 percentile of the series. Two different situations have been detected as being responsible for an EHD occurrence, one more dynamical, produced by southern fluxes, and another associated with a stagnation situation over Iberia of a longer duration. Both account for 92% of the total number of days, thus providing an efficient classification framework. A circulation index has been derived to characterise and forecast an EHD occurrence. This paper shows that EHD occur in Madrid during short duration events, and no long heat waves, like those recorded in other cities, are present. Additionally, no clear pattern can be detected in the EHD frequency; the occurrence is tied to changes in the summer location of the Azores high. (orig.)

  19. Baseline high heat flux and plasma facing materials for fusion

    Science.gov (United States)

    Ueda, Y.; Schmid, K.; Balden, M.; Coenen, J. W.; Loewenhoff, Th.; Ito, A.; Hasegawa, A.; Hardie, C.; Porton, M.; Gilbert, M.

    2017-09-01

    In fusion reactors, surfaces of plasma facing components (PFCs) are exposed to high heat and particle flux. Tungsten and Copper alloys are primary candidates for plasma facing materials (PFMs) and coolant tube materials, respectively, mainly due to high thermal conductivity and, in the case of tungsten, its high melting point. In this paper, recent understandings and future issues on responses of tungsten and Cu alloys to fusion environments (high particle flux (including T and He), high heat flux, and high neutron doses) are reviewed. This review paper includes; Tritium retention in tungsten (K. Schmid and M. Balden), Impact of stationary and transient heat loads on tungsten (J.W. Coenen and Th. Loewenhoff), Helium effects on surface morphology of tungsten (Y. Ueda and A. Ito), Neutron radiation effects in tungsten (A. Hasegawa), and Copper and copper alloys development for high heat flux components (C. Hardie, M. Porton, and M. Gilbert).

  20. Widespread extreme drought events in Iberia and their relationship with North Atlantic moisture flux deficit

    Science.gov (United States)

    Liberato, Margarida L. R.; Montero, Irene; Russo, Ana; Gouveia, Célia; Ramos, Alexandre M.; Trigo, Ricardo M.

    2015-04-01

    Droughts represent one of the most frequent climatic extreme events on the Iberian Peninsula, often with widespread negative ecological and environmental impacts, resulting in major socio-economic damages such as large decreases in hydroelectricity and agricultural productions or increasing forest fire risk. Unlike other weather driven extreme events, droughts duration could be from few months to several years. Here we employ a recently developed climatic drought index, the Standardized Precipitation Evapotranspiration Index (SPEI; Vicente-Serrano et al. 2010a), based on the simultaneous use of precipitation and temperature fields. This index holds the advantage of combining a multi-scalar character with the capacity to include the effects of temperature variability on drought assessment (Vicente-Serrano et al., 2010a). In this study the SPEI was computed using the Climatic Research Unit (CRU) TS3.21 High Resolution Gridded Data (0.5°) for the period 1901-2012. At this resolution the study region of Iberian Peninsula corresponds to a square of 30x30 grid pixels. The CRU Potential Evapotranspiration (PET) was used, through the Penmann-Monteith equation and the log-logistic probability distribution. This formulation allows a very good fit to the series of differences between precipitation and PET (Vicente-Serrano et al., 2010b), using monthly averages of daily maximum and minimum temperature data and also monthly precipitation records. The parameters were estimated by means of the L-moment method. The application of multi-scalar indices to the high-resolution datasets allows identifying whether the Iberian Peninsula is in hydric stress and also whether drought is installed. Based on the gridded SPEI datasets, spanning from 1901 to 2012, obtained for timescales 6, 12, 18 and 24 months, an objective method is applied for ranking the most extensive extreme drought events that occurred on the Iberian Peninsula. This objective method is based on the evaluation of the

  1. High precision flux measurements with ENUBET

    Science.gov (United States)

    Pozzato, M.; ENUBET collaboration

    2017-09-01

    The challenges of precision neutrino physics (i.e the study of CP violation) require measurements of absolute ν cross sections at the GeV scale with exquisite (O(1)%) precision. Such precision is presently limited to about 10% by the uncertainties on neutrino flux at the source. A reduction of this uncertainty by one order of magnitude can be achieved monitoring the positron production in the decay tunnel originating from the Ke3 decays of charged kaons in a sign and momentum selected narrow band beam. This novel technique enables the measurement of the most relevant cross-sections for CP violation (νe and {\\displaystyle \\bar{ν }}e) with a precision of 1% and requires a special instrumented beam-line. Such non-conventional beam-line will be developed in the framework of the ENUBET Horizon-2020 Consolidator Grant (PI A. Longhin), recently approved by the European Research Council (grant agreement N° 681647). In this poster, we will present the Project and the early experimental results on ultra-compact calorimeters that can embedded in the instrumented decay tunnel.

  2. [Membranotropic effects of electromagnetic radiation of extremely high frequency on Escherichia coli].

    Science.gov (United States)

    Trchunian, A; Ogandzhanian, E; Sarkisian, E; Gonian, S; Oganesian, A; Oganesian, S

    2001-01-01

    It was found that "sound" electromagnetic radiations of extremely high frequencies (53.5-68 GHz) or millimeter waves (wavelength range of 4.2-5.6 mm) of low intensity (power density 0.01 mW) have a bactericidal effect on Escherichia coli bacteria. It was shown that exposure to irradiation of extremely high frequencies increases the electrokinetic potential and surface change density of bacteria and decreases of membrane potential. The total secretion of hydrogen ions was suppressed, the H+ flux from the cytoplasm to medium decreased, and the flux of N,N'-dicyclohexylcarbodiimide-sensitive potassium ions increased, which was accompanied by changes in the stoichiometry of these fluxes and an increase in the sensitivity of H+ ions to N,N'-dicyclohexylcarbodiimide. The effects depended on duration of exposure: as the time of exposure increased, the bactericidal effect increased, whereas the membranotropic effects decreased. The effects also depended on growth phase of bacteria: the irradiation affected the cells in the stationary but not in the logarithmic phase. It is assumed that the H(+)-ATPase complex F0F1 is involved in membranotropic effects of electromagnetic radiation of extremely high frequencies. Presumably, there are some compensatory mechanisms that eliminate the membranotropic effects.

  3. High Torque Density Transverse Flux Machine without the Need to Use SMC Material for 3D Flux Paths

    DEFF Research Database (Denmark)

    Lu, Kaiyuan; Wu, Weimin

    2015-01-01

    This paper presents a new transverse flux permanent magnet machine. In a normal transverse flux machine, complicated 3-D flux paths often exist. Such 3-D flux paths would require the use of soft magnetic composites material instead of laminations for construction of the machine stator. In the new...... machine topology proposed in this paper, by advantageously utilizing the magnetic flux path provided by an additional rotor, use of laminations that allow 2-D flux paths only will be sufficient to accomplish the required 3-D flux paths. The machine also has a high torque density and is therefore...

  4. Relation of middle molecules levels and oxidative stress to erythropoietin requirements in high-flux versus low-flux hemodialysis

    Directory of Open Access Journals (Sweden)

    Hala S El-Wakil

    2013-01-01

    Full Text Available The objective of this study is to investigate the serum beta-2-microglobulin (B2MG and advanced oxidation protein products (AOPP as middle molecule uremic toxins and protein carbonyl (PCO as oxidative stress marker in uremic patients undergoing high-flux versus low-flux hemodialysis (HD and to correlate their levels to the erythropoietin requirements for those patients. Twenty patients on chronic low-flux HD were recruited in the study. At the start of the study, all patients underwent high-flux HD for eight weeks, followed by low-flux HD for two weeks as a washout period. The patients were then subjected to another eight weeks of low-flux HD. Blood samples were obtained at the beginning and at the end of the high-flux period and the low-flux period. The mean erythropoietin dose for patients using high-flux HD was significantly lower than that for low-flux HD (P = 0.0062. Post-high flux, the B2MG and PCO levels were significantly lower than the pre-high-flux levels (P = 0.026 and 0.0005, respectively, but no significant change was observed in AOPP (P = 0.68. Post-low flux, the B2MG, AOPP and PCO were significantly higher than the pre-low-flux levels (P = 0.0002, 0.021 and <0.0001, respectively. Post-low flux, the B2MG and PCO were significantly higher than the post-high-flux levels (P <0.0001, but no significant difference was observed in AOPP (P = 0.11. High-flux HD results in reduction of some of the middle molecule toxins and PCO levels better than low-flux HD, and is associated with a better response to erythropoietin.

  5. Intraday evaporation and heat fluxes variation at air-water interface of extremely shallow lakes in Chilean Andean Plateau

    Science.gov (United States)

    Vergara, Jaime; de la Fuente, Alberto

    2016-04-01

    Salars are landscapes formed by evapo-concentration of salts that usually have extremely shallow terminal lagoons (de la Fuente & Niño, 2010). They are located in the altiplanic region of the Andes Mountains of Chile, Argentina, Bolivia and Peru, and they sustain highly vulnerable and isolated ecosystems in the Andean Desert. These ecosystems are sustained by benthic primary production, which is directly linked to mass, heat and momentum transfer between the water column and the atmosphere (de la Fuente, 2014). Despite the importance of these transport processes across the air-water interface, there are few studies describing their intraday variation and how they are influenced by the stability of the atmospheric boundary layer in the altiplano. The main objective of this work is to analyze the intraday vertical transport variation of water vapor, temperature and momentum between the atmosphere and a shallow water body on Salar del Huasco located in northern Chile (20°19'40"S, 68°51'25"W). To achieve this goal, we measured atmospheric and water variables in a campaign realized on late October 2015, using high frequency meteorological instruments (a sonic anemometer with an incorporated infrared gas analyzer, and a standard meteorological station) and water sensors. From these data, we characterize the intraday variation of water vapor, temperature and momentum fluxes, we quantify the influence of the atmospheric boundary layer stability on them, and we estimate transfer coefficients associated to latent heat, sensible heat, hydrodynamic drag and vertical transport of water vapor. As first results, we found that latent and sensible heat fluxes are highly influenced by wind speed rather buoyancy, and we can identify four intraday intervals with different thermo-hydrodynamic features: (1) cooling under stable condition with wind speed near 0 from midnight until sunrise; (2) free convection with nearly no wind speed under unstable condition from sunrise until midday

  6. High heat flux transport by microbubble emission boiling

    Science.gov (United States)

    Suzuki, Koichi

    2007-10-01

    In highly subcooled flow boiling, coalescing bubbles on the heating surface collapse to many microbubbles in the beginning of transition boiling and the heat flux increases higher than the ordinary critical heat flux. This phenomenon is called Microbubble Emission Boiling, MEB. It is generated in subcooled flow boiling and the maximum heat flux reaches about 1 kW/cm2(10 MW/m2) at liquid subcooling of 40 K and liquid velocity of 0.5 m/s for a small heating surface of 10 mm×10 mm which is placed at the bottom surface of horizontal rectangular channel. The high pressure in the channel is observed at collapse of the coalescing bubbles and it is closely related the size of coalescing bubbles. Periodic pressure waves are observed in MEB and the heat flux increases linearly in proportion to the pressure frequency. The frequency is considered the frequency of liquid-solid exchange on the heating surface. For the large sized heating surface of 50 mm length×20 mm width, the maximum heat flux obtained is 500 W/cm2 (5 MW/m2) at liquid subcooling of 40 K and liquid velocity of 0.5 m/s. This is considerably higher heat flux than the conventional cooling limit in power electronics. It is difficult to remove the high heat flux by MEB for a longer heating surface than 50 mm by single channel type. A model of advanced cooling device is introduced for power electronics by subcooled flow boiling with impinging jets. Themaxumum cooling heat flux is 500 W/cm2 (5 MW/m2). Microbubble emission boiling is useful for a high heat flux transport technology in future power electronics used in a fuel-cell power plant and a space facility.

  7. Common lower extremity injuries in female high school soccer ...

    African Journals Online (AJOL)

    Common lower extremity injuries in female high school soccer players in ... and fitness and not wearing shin guards are risk factors for injury in female soccer ... do not differ from the studies done in male adolescent and adult soccer players.

  8. Single-pass high harmonic generation at high repetition rate and photon flux

    Science.gov (United States)

    Hädrich, Steffen; Rothhardt, Jan; Krebs, Manuel; Demmler, Stefan; Klenke, Arno; Tünnermann, Andreas; Limpert, Jens

    2016-09-01

    Sources of short wavelength radiation with femtosecond to attosecond pulse durations, such as synchrotrons or free electron lasers, have already made possible numerous, and will facilitate more, seminal studies aimed at understanding atomic and molecular processes on fundamental length and time scales. Table-top sources of coherent extreme ultraviolet to soft x-ray radiation enabled by high harmonic generation (HHG) of ultrashort pulse lasers have also gained significant attention in the last few years due to their enormous potential for addressing a plethora of applications, therefore constituting a complementary source to large-scale facilities (synchrotrons and free electron lasers). Ti:sapphire based laser systems have been the workhorses for HHG for decades, but are limited in repetition rate and average power. On the other hand, it has been widely recognized that fostering applications in fields such as photoelectron spectroscopy and microscopy, coincidence detection, coherent diffractive imaging and frequency metrology requires a high repetition rate and high photon flux HHG sources. In this article we will review recent developments in realizing the demanding requirement of producing a high photon flux and repetition rate at the same time. Particular emphasis will be put on suitable ultrashort pulse and high average power lasers, which directly drive harmonic generation without the need for external enhancement cavities. To this end we describe two complementary schemes that have been successfully employed for high power fiber lasers, i.e. optical parametric chirped pulse amplifiers and nonlinear pulse compression. Moreover, the issue of phase-matching in tight focusing geometries will be discussed and connected to recent experiments. We will highlight the latest results in fiber laser driven high harmonic generation that currently produce the highest photon flux of all existing sources. In addition, we demonstrate the first promising applications and

  9. Advanced Extremely High Frequency Satellite (AEHF)

    Science.gov (United States)

    2015-12-01

    High Frequency Satellite (AEHF) is a joint service satellite communications system that provides global , survivable, secure, protected, and jam...three satellites fully integrated into the Milstar constellation. October 2014: On October 16, 2014, the program received PEO certification for the...Combined Orbital Operation, Logistics Sustainment ( COOLS ) contract, it will be completed and coordinated in CY 2016. The AEHF system being sustained

  10. Extremely high Q-factor toroidal metamaterials

    CERN Document Server

    Basharin, Alexey A; Volsky, Nikita; Kafesaki, Maria; Economou, Eleftherios N; Ustinov, Alexey V

    2016-01-01

    We demonstrate that, owing to the unique topology of the toroidal dipolar mode, its electric/magnetic field can be spatially confined within subwavelength, externally accessible regions of the metamolecules, which makes the toroidal planar metamaterials a viable platform for high Q-factor resonators due to interfering toroidal and other dipolar modes in metamolecules.

  11. Workshop on extremely high energy density plasmas and their diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Ishii, Shozo (ed.)

    2001-09-01

    Compiled are the papers presented at the workshop on 'Extremely High Energy Density Plasmas and Their Diagnostics' held at National Institute for Fusion Science. The papers cover physics and applications of extremely high-energy density plasmas such as dense z-pinch, plasma focus, and intense pulsed charged beams. Separate abstracts were presented for 7 of the papers in this report. The remaining 25 were considered outside the subject scope of INIS. (author)

  12. High precision photon flux determination for photon tagging experiments

    Science.gov (United States)

    Teymurazyan, A.; Ahmidouch, A.; Ambrozewicz, P.; Asratyan, A.; Baker, K.; Benton, L.; Burkert, V.; Clinton, E.; Cole, P.; Collins, P.; Dale, D.; Danagoulian, S.; Davidenko, G.; Demirchyan, R.; Deur, A.; Dolgolenko, A.; Dzyubenko, G.; Ent, R.; Evdokimov, A.; Feng, J.; Gabrielyan, M.; Gan, L.; Gasparian, A.; Glamazdin, A.; Goryachev, V.; Hardy, K.; He, J.; Ito, M.; Jiang, L.; Kashy, D.; Khandaker, M.; Kolarkar, A.; Konchatnyi, M.; Korchin, A.; Korsch, W.; Kosinov, O.; Kowalski, S.; Kubantsev, M.; Kubarovsky, V.; Larin, I.; Lawrence, D.; Li, X.; Martel, P.; Matveev, V.; McNulty, D.; Mecking, B.; Milbrath, B.; Minehart, R.; Miskimen, R.; Mochalov, V.; Nakagawa, I.; Overby, S.; Pasyuk, E.; Payen, M.; Pedroni, R.; Prok, Y.; Ritchie, B.; Salgado, C.; Shahinyan, A.; Sitnikov, A.; Sober, D.; Stepanyan, S.; Stevens, W.; Underwood, J.; Vasiliev, A.; Vishnyakov, V.; Wood, M.; Zhou, S.

    2014-12-01

    The Jefferson Laboratory PrimEx Collaboration has developed and implemented a method to control the tagged photon flux in photoproduction experiments at the 1% level over the photon energy range from 4.9 to 5.5 GeV. This method has been successfully implemented in a high precision measurement of the neutral pion lifetime. Here, we outline the experimental equipment and the analysis techniques used to accomplish this. These include the use of a total absorption counter for absolute flux calibration, a pair spectrometer for online relative flux monitoring, and a new method for post-bremsstrahlung electron counting.

  13. Comparing changes in plasma and skin autofluorescence in low-flux versus high-flux hemodialysis

    NARCIS (Netherlands)

    Ramsauer, Bernd; Engels, Gerwin; Arsov, Stefan; Hadimeri, Henrik; Sikole, Aleksandar; Graaff, Reindert; Stegmayr, Bernd

    2015-01-01

    Background: Tissue advanced glycation end products (AGE) are increased in hemodialysis (HD) patients, especially those with cardiovascular complications. Skin autofluorescence (skin-AF) can noninvasively estimate the accumulation of AGE in tissue. The aim was to clarify whether HD using a high-flux

  14. High resolution spectroscopy of six new extreme helium stars

    Science.gov (United States)

    Heber, U.; Jones, G.; Drilling, J. S.

    1986-01-01

    High resolution spectra of six newly discovered extreme helium stars are presented. LSS 5121 is shown to be a spectroscopical twin of the hot extreme helium star HD 160641. A preliminary LTE analysis of LSS 3184 yielded an effective temperature of 22,000 K and a surface gravity of log g = 3.2. Four stars form a new subgroup, classified by sharp-lined He I spectra and pronounced O II spectra, and it is conjectured that these lie close to the Eddington limit. The whole group of extreme helium stars apparently is inhomogeneous with respect to luminosity to mass ratio and chemical composition.

  15. Visualization Study on High Heat Flux Boiling and Critical Heat Flux

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Satbyoul; Kim, Hyungdae [Kyung Hee University, Yongin (Korea, Republic of)

    2015-10-15

    In this study, an integrated visible and infrared-based experimental method is introduced to simultaneously measure the details of high-resolution liquid-vapor phase and heat transfer distributions on a heated wall. The dynamics and heat transfer at high heat flux boiling and critical heat flux were observed. The experiment was conducted in pool of saturated water under atmospheric pressure. There have been many studies to examine the physical mechanisms of nucleation boiling and critical heat flux over several decades. Several visible and infrared-based optical techniques for time-resolved high resolution measurements for liquid-vapor phase and heater surface temperature during boiling have been introduced to understand the characteristics and mechanisms of them. Liquid-vapor phase, temperature, and heat flux distributions on the heated surface were measured during pool boiling of water using the integrated total reflection and infrared thermometry technique. Qualitative examination of the data for high heat flux boiling and CHF was performed. The main contributions of this work are summarized below. The existence and behavior of dry patches lead the way toward CHF condition. Therefore, the mechanistic modeling of the CHF phenomenon necessarily needs to include the physical parameters related to dynamics of the large dry patch such as life time and size. In addition to the dynamic behavior of the dry patch, the thermal behavior of the hot patch is also important. Even though the dry area was rewetted, the stored thermal energy in the hot patch can be remained if the rewetting time is short and the subsequent dry patch is regenerated quickly.

  16. OVERALL CONTROL SYSTEM FOR HIGH FLUX PILE

    Science.gov (United States)

    Newson, H.W.; Durham, N.C.; Wigner, E.P.; Princeton, N.J.; Epler, E.P.

    1961-05-23

    A control system is given for a high fiux reactor incorporating an anti- scram control feature whereby a neutron absorbing control rod acts as a fine adjustment while a neutron absorbing shim rod, actuated upon a command received from reactor period and level signals, has substantially greater effect on the neutron level and is moved prior to scram conditions to alter the reactor activity before a scram condition is created. Thus the probability that a scram will have to be initiated is substantially decreased.

  17. Extreme states of matter high energy density physics

    CERN Document Server

    Fortov, Vladimir E

    2016-01-01

    With its many beautiful colour pictures, this book gives fascinating insights into the unusual forms and behaviour of matter under extremely high pressures and temperatures. These extreme states are generated, among other things, by strong shock, detonation and electric explosion waves, dense laser beams,electron and ion beams, hypersonic entry of spacecraft into dense atmospheres of planets, and in many other situations characterized by extremely high pressures and temperatures.Written by one of the world's foremost experts on the topic, this book will inform and fascinate all scientists dealing with materials properties and physics, and also serve as an excellent introduction to plasma-, shock-wave and high-energy-density physics for students and newcomers seeking an overview. This second edition is thoroughly revised and expanded, in particular with new material on high energy-density physics, nuclear explosions and other nuclear transformation processes.

  18. High Field Seeking State Atom Laser and Properties of Flux

    Institute of Scientific and Technical Information of China (English)

    XIA Lin; XIONG Wei; YANG Fan; YI Lin; ZHOU Xiao-Ji; CHEN Xu-Zong

    2008-01-01

    We present an experimental study on the continuous atom laser. The experiments show that a high field seeking state atom laser with stable flux can be formed by increasing the strength of outcoupling before large density fluctuations appear. It is easy to obtain a long length or high speed output with this kind of atom laser.

  19. Flux attenuation at NREL`s High-Flux Solar Furnace

    Energy Technology Data Exchange (ETDEWEB)

    Bingham, C E; Scholl, K L; Lewandowski, A A

    1994-10-01

    The High-Flux Solar Furnace (HFSF) at the National Renewable Energy Laboratory (NREL) has a faceted primary concentrator and a long focal-length-to-diameter ratio (due to its off-axis design). Each primary facet can be aimed individually to produce different flux distributions at the target plane. Two different types of attenuators are used depending on the flux distribution. A sliding-plate attenuator is used primarily when the facets are aimed at the same target point. The alternate attenuator resembles a venetian blind. Both attenuators are located between the concentrator and the focal point. The venetian-blind attenuator is primarily used to control the levels of sunlight failing on a target when the primary concentrators are not focused to a single point. This paper will demonstrate the problem of using the sliding-plate attenuator with a faceted concentrator when the facets are not aimed at the same target point. We will show that although the alternate attenuator necessarily blocks a certain amount of incoming sunlight, even when fully open, it provides a more even attenuation of the flux for alternate aiming strategies.

  20. Search for Diffuse Astrophysical Neutrino Flux Using Ultra-High Energy Upward-Going Muons in Super-Kamiokande I

    CERN Document Server

    Swanson, M E C; Hosaka, J; Iida, T; Ishihara, K; Kameda, J; Koshio, Y; Minamino, A; Mitsuda, C; Miura, M; Moriyama, S; Nakahata, M; Obayashi, Y; Ogawa, H; Shiozawa, M; Suzuki, Y; Takeda, A; Takeuchi, Y; Ueshima, K; Higuchi, I; Ishihara, C; Ishitsuka, M; Kajita, T; Kaneyuki, K; Mitsuka, G; Nakayama, S; Nishino, H; Okada, A; Okumura, K; Saji, C; Takenaga, Y; Clark, S; Desai, S; Dufour, F; Kearns, E; Likhoded, S; Litos, M; Raaf, Jennifer L; Stone, J L; Sulak, L R; Wang, W; Goldhaber, M; Casper, D; Cravens, J P; Dunmore, J; Kropp, W R; Liu, D W; Mine, S; Regis, C; Smy, M B; Sobel, H W; Vagins, M R; Ganezer, K S; Hill, J E; Keig, W E; Jang, J S; Kim, J Y; Lim, I T; Scholberg, K; Tanimoto, N; Walter, C W; Wendell, R; Ellsworth, R W; Tasaka, S; Guillian, G; Learned, J G; Matsuno, S; Messier, M D; Hayato, Y; Ichikawa, A K; Ishida, T; Ishii, T; Iwashita, T; Kobayashi, T; Nakadaira, T; Nakamura, K; Nitta, K; Oyama, Y; Totsuka, Y; Suzuki, A T; Hasegawa, M; Hiraide, K; Kato, I; Maesaka, H; Nakaya, T; Nishikawa, K; Sasaki, T; Sato, H; Yamamoto, S; Yokoyama, M; Haines, T J; Dazeley, S; Hatakeyama, S; Svoboda, R; Sullivan, G W; Turcan, D; Cooley, J; Mahn, K B M; Habig, A; Fukuda, Y; Sato, T; Itow, Y; Koike, T; Jung, C K; Kato, T; Kobayashi, K; Malek, M; McGrew, C; Sarrat, A; Terri, R; Yanagisawa, C; Tamura, N; Sakuda, M; Sugihara, M; Kuno, Y; Yoshida, M; Kim, S B; Yang, B S; Yoo, J; Ishizuka, T; Okazawa, H; Choi, Y; Seo, H K; Gando, Y; Hasegawa, T; Inoue, K; Ishii, H; Nishijima, K; Ishino, H; Watanabe, Y; Koshiba, M; Kielczewska, D; Zalipska, J; Berns, H G; Gran, R; Shiraishi, K K; Stachyra, A; Thrane, E; Washburn, K; Wilkes, R J002626770 100 L; Adams, J

    2006-01-01

    Many astrophysical models predict a diffuse flux of high energy neutrinos from active galactic nuclei and other extra-galactic sources. At muon energies above a TeV, the upward-going muon flux induced by neutrinos from active galactic nuclei is expected to exceed the flux due to atmospheric neutrinos. We have performed a search for this astrophysical neutrino flux by looking for upward-going muons in the highest energy data sample from the Super-Kamiokande detector using 1679.6 live days of data. We found 1 extremely high energy upward-going muon event, compared with an expected atmospheric neutrino background of 0.46 plus or minus 0.23 events. Using this result, we set an upper limit on the diffuse flux of upward-going muons due to neutrinos from astrophysical sources in the muon energy range 3.16-100 TeV.

  1. Development activities of the high heat flux scraper element

    Energy Technology Data Exchange (ETDEWEB)

    Boscary, J., E-mail: jean.boscary@ipp.mpg.de [Max Planck Institute for Plasma Physics, Garching (Germany); Lore, J.; Lumsdaine, A. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Maier, M. [Max Planck Institute for Plasma Physics, Garching (Germany); McGinnis, D. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Peacock, A.; Tretter, J. [Max Planck Institute for Plasma Physics, Garching (Germany)

    2015-10-15

    The function of the high heat flux scraper element is to reduce the heat loads on the element ends of the actively cooled divertor of Wendelstein 7-X. The scraper element is actively water cooled to remove up to 550 kW steady state power load, with localized heat fluxes as high as 20 MW/m{sup 2}. Its surface area, 0.17 m{sup 2}, is contoured to optimally intercept both upstream and downstream particle fluxes. The plasma facing surface is made of 24 individual scraper fingers based on the monoblock technology. Each scraper finger is 247 mm long and 28 mm wide and has 13 monoblocks made of CFC NB31 bonded by hot isostatic pressing onto a CuCrZr cooling tube equipped with a copper twisted tape. Development activities, described here, include the design and fabrication of prototypes to validate the different technologies selected for the scraper element design to prepare a possible production.

  2. Performance characterization of the SERI High-Flux Solar Furnace

    Energy Technology Data Exchange (ETDEWEB)

    Lewandowski, A.; Bingham, C. (Solar Energy Research Inst., Golden, CO (United States)); O' Gallagher, J.; Winston, R.; Sagie, D. (Univ. of Chicago, IL (United States))

    1991-12-01

    This paper describes a unique, new solar furnace at the Solar Energy Research Institute (SERI) that can generate a wide range of flux concentrations to support research in areas including materials processing, high-temperature detoxification and high-flux optics. The furnace is unique in that it uses a flat, tracking heliostat along with a long focal length-to-diameter (f/D) primary concentrator in an off-axis configuration. The experiments are located inside a building completely outside the beam between the heliostat and primary concentrator. The long f/D ratio of the primary concentrator was designed to take advantage of a nonimaging secondary concentrator to significantly increase the flux concentration capabilities of the system. Results are reported for both the single-stage and two-stage configurations. (orig.).

  3. Extremely High Q-factor metamaterials due to Anapole Excitation

    CERN Document Server

    Basharin, Alexey A; Volsky, Nikita; Kafesaki, Maria; Economou, Eleftherios N

    2016-01-01

    We demonstrate that ideal anapole metamaterials have infinite Q-factor. We have designed and fabricated a metamaterial consisting of planar metamolecules which exhibit anapole behavior in the sense that the electric dipole radiation is almost cancelled by the toroidal dipole one, producing thus an extremely high Q-factor at the resonance frequency. The size of the system, at the mm range, and the parasitic magnetic quadrupole radiation are the factors limiting the size of the Q-factor. In spite of the very low radiation losses the local fields at the metamolecules are extremely high, of the order of higher than the external incoming field.

  4. Ionized sputter deposition using an extremely high plasma density pulsed magnetron discharge

    Energy Technology Data Exchange (ETDEWEB)

    Macak, Karol [Department of Physics, Linkoeping University, SE-581 83 Linkoeping, (Sweden); Kouznetsov, Vladimir [Department of Physics, Linkoeping University, SE-581 83 Linkoeping, (Sweden); Schneider, Jochen [Department of Physics, Linkoeping University, SE-581 83 Linkoeping, (Sweden); Helmersson, Ulf [Department of Physics, Linkoeping University, SE-581 83 Linkoeping, (Sweden); Petrov, Ivan [Materials Science Department and Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801 (United States)

    2000-07-01

    Time resolved plasma probe measurements of a novel high power density pulsed plasma discharge are presented. Extreme peak power densities in the pulse (on the order of several kW cm{sup -2}) result in a very dense plasma with substrate ionic flux densities of up to 1 A cm{sup -2} at source-to-substrate distances of several cm and at a pressure of 0.13 Pa (1 mTorr). The pulse duration was {approx}100 {mu}s with a pulse repetition frequency of 50 Hz. The plasma consists of metallic and inert gas ions, as determined from time resolved Langmuir probe measurements and in situ optical emission spectroscopy data. It was found that the plasma composition at the beginning of the pulse was dominated by Ar ions. As time elapsed metal ions were detected and finally dominated the ion composition. The effect of the process parameters on the temporal development of the ionic fluxes is discussed. The ionized portion of the sputtered metal flux was found to have an average velocity of 2500 m s{sup -1} at 6 cm distance from the source, which conforms to the collisional cascade sputtering theory. The degree of ionization of the sputtered metal flux at a pressure of 0.13 Pa was found to be 40%{+-}20% by comparing the total flux of deposited atoms with the charge measured for the metal ions in the pulse. (c) 2000 American Vacuum Society.

  5. Recent developments on micrometric fission chambers for high neutron fluxes

    Energy Technology Data Exchange (ETDEWEB)

    Letourneau, A. [Irfu, Service de Physique Nucleaire, CEA-Saclay, 91191 Gif-sur-Yvette (France); Bringer, O.; Dupont, E.; Marie, F.; Panebianco, S.; Toussaint, J. C.; Veyssiere, C. [Irfu, CEA-Saclay, 91191 Gif-sur-Yvette (France); Chabod, S. [LPSC, Universite Joseph Fourier Grenoble 1, CNRS/IN2P3 (France); Breaud, S.; Oriol, L. [DEN/DER/SPEX, CEA-Cadarache, Saint-Paul-lez-Durances (France)

    2009-07-01

    With the development of innovative nuclear systems and new generation neutron sources, the nuclear instrumentation should be adapted. Since several years, we developed microscopic fission chambers to study the transmutation of minor actinides in high thermal-neutron fluxes. The recent developments done to fulfill the drastic conditions of irradiations are described in this paper together with the feedback from the measurements. Two installations were used: the HFR of the ILL for its highest thermal neutron flux of the world and the MEGAPIE target which was the first 1 MW liquid Pb-Bi spallation target in the world. (authors)

  6. Is Extremely High Life Satisfaction during Adolescence Advantageous?

    Science.gov (United States)

    Suldo, Shannon M.; Huebner, E. Scott

    2006-01-01

    This study examined whether extremely high life satisfaction was associated with adaptive functioning or maladaptive functioning. Six hundred ninety-eight secondary level students completed the Students' Life Satisfaction Scale [Huebner, 1991a, School Psychology International, 12, pp. 231-240], Youth Self-Report of the Child Behavior Checklist…

  7. common lower extremity injuries in female high school soccer ...

    African Journals Online (AJOL)

    studies on soccer concentrate on male soccer players.5-7 Although participation ... the prevalence and injury profile of lower extremity injuries in female high school ... An extended duration of skills (p=0.0001) and fitness (p=0.02) training in this .... The results (Table V) show that shin guards were associated with a reduced ...

  8. Flux-freezing breakdown in high-conductivity magnetohydrodynamic turbulence.

    Science.gov (United States)

    Eyink, Gregory; Vishniac, Ethan; Lalescu, Cristian; Aluie, Hussein; Kanov, Kalin; Bürger, Kai; Burns, Randal; Meneveau, Charles; Szalay, Alexander

    2013-05-23

    The idea of 'frozen-in' magnetic field lines for ideal plasmas is useful to explain diverse astrophysical phenomena, for example the shedding of excess angular momentum from protostars by twisting of field lines frozen into the interstellar medium. Frozen-in field lines, however, preclude the rapid changes in magnetic topology observed at high conductivities, as in solar flares. Microphysical plasma processes are a proposed explanation of the observed high rates, but it is an open question whether such processes can rapidly reconnect astrophysical flux structures much greater in extent than several thousand ion gyroradii. An alternative explanation is that turbulent Richardson advection brings field lines implosively together from distances far apart to separations of the order of gyroradii. Here we report an analysis of a simulation of magnetohydrodynamic turbulence at high conductivity that exhibits Richardson dispersion. This effect of advection in rough velocity fields, which appear non-differentiable in space, leads to line motions that are completely indeterministic or 'spontaneously stochastic', as predicted in analytical studies. The turbulent breakdown of standard flux freezing at scales greater than the ion gyroradius can explain fast reconnection of very large-scale flux structures, both observed (solar flares and coronal mass ejections) and predicted (the inner heliosheath, accretion disks, γ-ray bursts and so on). For laminar plasma flows with smooth velocity fields or for low turbulence intensity, stochastic flux freezing reduces to the usual frozen-in condition.

  9. Extreme high-head portables provide more pumping options

    Energy Technology Data Exchange (ETDEWEB)

    Fiscor, S.

    2006-10-15

    Three years ago, Godwin Pumps, one of the largest manufacturers of portable pumps, introduced its Extreme Duty High Lift (HL) series of pumps and more mines are finding unique applications for these pumps. The Extreme HL series is a range single-stage Dri-Prime pumps with heads up to 600 feet and flows up to 5,000 gallons per minute. The American Coal Co.'s Galatia mine, an underground longwall mine in southern Illinois, used an HL 160 to replace a multiple-staged centrifugal pump. It provided Galatia with 1,500 gpm at 465 ft. 3 photos.

  10. Rapid Photocatalytic Degradation of Methylene Blue under High Photon Flux UV Irradiation: Characteristics and Comparison with Routine Low Photon Flux

    OpenAIRE

    2012-01-01

    This study examined the photocatalytic degradation efficiency under high UV photon flux (intensity normalized by photon energy) irradiation; the incident UV photon flux was 1 . 7 1 × 1 0 − 6 − 3 . 1 3 × 1 0 − 6 einstein c m − 2   s − 1 made by a super high-intensity UV apparatus. A comparative study between high photon flux photocatalytic process and routine low photon flux photocatalytic process for methylene blue degradation has been made in aqueous solution. The experimental results showed...

  11. Effective removal of methotrexate by high-flux hemodialysis.

    Science.gov (United States)

    Saland, Jeffrey M; Leavey, Patrick J; Bash, Robert O; Hansch, Eleonora; Arbus, Gerald S; Quigley, Raymond

    2002-10-01

    The purpose of the present study was to examine the clearance of methotrexate (MTX) by high-flux hemodialysis (HD) in pediatric oncology patients. We present three patients who experienced nephrotoxicity and prolonged exposure to toxic MTX concentrations following high-dose infusions during treatment for osteogenic sarcomas. Each patient was successfully treated with high-flux HD, followed by carboxypeptidase G2 (CPDG2) in two cases. Minimal systemic toxicity occurred. We review the literature and discuss guidelines for early and aggressive treatment for this complication of high-dose MTX therapy. Clinically important removal of MTX depends upon prompt initiation of HD after detection of nephrotoxicity and delayed clearance of MTX. Therapy is indicated in cases where compassionate use of CPDG(2) may not be available, or while awaiting its delivery.

  12. BVOC ecosystem flux measurements at a high latitude wetland site

    Directory of Open Access Journals (Sweden)

    T. Holst

    2010-02-01

    Full Text Available In this study, we present summertime concentrations and fluxes of biogenic volatile organic compounds (BVOCs measured at a sub-arctic wetland in northern Sweden using a disjunct eddy-covariance (DEC technique based on a proton transfer reaction mass spectrometer (PTR-MS. The vegetation at the site was dominated by Sphagnum, Carex and extit{Eriophorum} spp. The measurements reported here cover a period of 50 days (1 August to 19 September 2006, approximately one half of the growing season at the site, and allowed to investigate the effect of day-to-day variation in weather as well as of vegetation senescence on daily BVOC fluxes, and on their temperature and light responses. The sensitivity drift of the DEC system was assessed by comparing H3O+-ion cluster formed with water molecules (H3O+(H2O at m37 with water vapour concentration measurements made using an adjacent humidity sensor, and the applicability of the DEC method was analysed by a comparison of sensible heat fluxes for high frequency and DEC data obtained from the sonic anemometer. These analyses showed no significant PTR-MS sensor drift over a period of several weeks and only a small flux-loss due to high-frequency spectrum omissions. This loss was within the range expected from other studies and the theoretical considerations.

    Standardised (20 °C and 1000 μmol m−2 s−1 PAR summer isoprene emission rates found in this study of 329 μg C m−2 (ground area h−1 were comparable with findings from more southern boreal forests, and fen-like ecosystems. On a diel scale, measured fluxes indicated a stronger temperature dependence than emissions from temperate or (subtropical ecosystems. For the first time, to our knowledge, we report ecosystem methanol fluxes from a sub-arctic ecosystem. Maximum daytime emission fluxes were around 270 μg m−2 h−1

  13. Evaluation of an extreme-condition-inverse calibration remote sensing model for mapping energy balance fluxes in arid riparian areas

    Science.gov (United States)

    Hong, S.-H.; Hendrickx, J. M. H.; Kleissl, J.; Allen, R. G.; Bastiaanssen, W. G. M.; Scott, R. L.; Steinwand, A. L.

    2014-12-01

    Accurate information on the distribution of the surface energy balance components in arid riparian areas is needed for sustainable management of water resources as well as for a better understanding of water and heat exchange processes between the land surface and the atmosphere. Since the spatial and temporal distributions of these fluxes over large areas are difficult to determine from ground measurements alone, their prediction from remote sensing data is very attractive as it enables large area coverage and a high repetition rate. In this study the Surface Energy Balance Algorithm for Land (SEBAL) was used to estimate all the energy balance components in the arid riparian areas of the Middle Rio Grande Basin (New Mexico), San Pedro Basin (Arizona), and Owens Valley (California). We compare instantaneous and daily SEBAL fluxes derived from Landsat TM images to surface-based measurements with eddy covariance flux towers. This study presents evidence that SEBAL yields reliable estimates for actual evapotranspiration rates in riparian areas of the southwestern United States. The great strength of the SEBAL method is its internal calibration procedure that eliminates most of the bias in latent heat flux at the expense of increased bias in sensible heat flux.

  14. Evaluation of an extreme-condition-inverse calibration remote sensing model for mapping energy balance fluxes in arid riparian areas

    Directory of Open Access Journals (Sweden)

    S.-H. Hong

    2014-12-01

    Full Text Available Accurate information on the distribution of the surface energy balance components in arid riparian areas is needed for sustainable management of water resources as well as for a better understanding of water and heat exchange processes between the land surface and the atmosphere. Since the spatial and temporal distributions of these fluxes over large areas are difficult to determine from ground measurements alone, their prediction from remote sensing data is very attractive as it enables large area coverage and a high repetition rate. In this study the Surface Energy Balance Algorithm for Land (SEBAL was used to estimate all the energy balance components in the arid riparian areas of the Middle Rio Grande Basin (New Mexico, San Pedro Basin (Arizona, and Owens Valley (California. We compare instantaneous and daily SEBAL fluxes derived from Landsat TM images to surface-based measurements with eddy covariance flux towers. This study presents evidence that SEBAL yields reliable estimates for actual evapotranspiration rates in riparian areas of the southwestern United States. The great strength of the SEBAL method is its internal calibration procedure that eliminates most of the bias in latent heat flux at the expense of increased bias in sensible heat flux.

  15. Uncertainty of calorimeter measurements at NREL's high flux solar furnace

    Science.gov (United States)

    Bingham, C. E.

    1991-12-01

    The uncertainties of the calorimeter and concentration measurements at the High Flux Solar Furnace (HFSF) at the National Renewable Energy Laboratory (NREL) are discussed. Two calorimeter types have been used to date. One is an array of seven commercially available circular foil calorimeters (gardon or heat flux gages) for primary concentrator peak flux (up to 250 W/sq cm). The second is a cold-water calorimeter designed and built by the University of Chicago to measure the average exit power of the reflective compound parabolic secondary concentrator used at the HFSF (over 3.3 kW across a 1.6/sq cm) exit aperture, corresponding to a flux of about 2 kW/sq cm. This paper discussed the uncertainties of the calorimeter and pyrheliometer measurements and resulting concentration calculations. The measurement uncertainty analysis is performed according to the ASME/ANSI standard PTC 19.1 (1985). Random and bias errors for each portion of the measurement are analyzed. The results show that as either the power or the flux is reduced, the uncertainties increase. Another calorimeter is being designed for a new, refractive secondary which will use a refractive material to produce a higher average flux (5 kW/sq cm) than the reflective secondary. The new calorimeter will use a time derivative of the fluid temperature as a key measurement of the average power out of the secondary. A description of this calorimeter and test procedure is also presented, along with a pre-test estimate of major sources of uncertainty.

  16. Uncertainty of calorimeter measurements at NREL's high flux solar furnace

    Energy Technology Data Exchange (ETDEWEB)

    Bingham, C.E.

    1991-12-01

    The uncertainties of the calorimeter and concentration measurements at the High Flux Solar Furnace (HFSF) at the National Renewable Energy Laboratory (NREL) are discussed. Two calorimeter types have been used to date. One is an array of seven commercially available circular foil calorimeters (gardon or heat flux gages) for primary concentrator peak flux (up to 250 W/cm{sup 2}). The second is a cold-water calorimeter designed and built by the University of Chicago to measure the average exit power of the reflective compound parabolic secondary concentrator used at the HFSF (over 3.3 kW across a 1.6cm{sup {minus}2} exit aperture, corresponding to a flux of about 2 kW/cm{sup 2}). This paper discussed the uncertainties of the calorimeter and pyrheliometer measurements and resulting concentration calculations. The measurement uncertainty analysis is performed according to the ASME/ANSI standard PTC 19.1 (1985). Random and bias errors for each portion of the measurement are analyzed. The results show that as either the power or the flux is reduced, the uncertainties increase. Another calorimeter is being designed for a new, refractive secondary which will use a refractive material to produce a higher average flux (5 kW/cm{sup 2}) than the reflective secondary. The new calorimeter will use a time derivative of the fluid temperature as a key measurement of the average power out of the secondary. A description of this calorimeter and test procedure is also presented, along with a pre-test estimate of major sources of uncertainty. 8 refs., 4 figs., 3 tabs.

  17. High resolution modelling of extreme precipitation events in urban areas

    Science.gov (United States)

    Siemerink, Martijn; Volp, Nicolette; Schuurmans, Wytze; Deckers, Dave

    2015-04-01

    The present day society needs to adjust to the effects of climate change. More extreme weather conditions are expected, which can lead to longer periods of drought, but also to more extreme precipitation events. Urban water systems are not designed for such extreme events. Most sewer systems are not able to drain the excessive storm water, causing urban flooding. This leads to high economic damage. In order to take appropriate measures against extreme urban storms, detailed knowledge about the behaviour of the urban water system above and below the streets is required. To investigate the behaviour of urban water systems during extreme precipitation events new assessment tools are necessary. These tools should provide a detailed and integral description of the flow in the full domain of overland runoff, sewer flow, surface water flow and groundwater flow. We developed a new assessment tool, called 3Di, which provides detailed insight in the urban water system. This tool is based on a new numerical methodology that can accurately deal with the interaction between overland runoff, sewer flow and surface water flow. A one-dimensional model for the sewer system and open channel flow is fully coupled to a two-dimensional depth-averaged model that simulates the overland flow. The tool uses a subgrid-based approach in order to take high resolution information of the sewer system and of the terrain into account [1, 2]. The combination of using the high resolution information and the subgrid based approach results in an accurate and efficient modelling tool. It is now possible to simulate entire urban water systems using extreme high resolution (0.5m x 0.5m) terrain data in combination with a detailed sewer and surface water network representation. The new tool has been tested in several Dutch cities, such as Rotterdam, Amsterdam and The Hague. We will present the results of an extreme precipitation event in the city of Schiedam (The Netherlands). This city deals with

  18. Extremely high Q -factor metamaterials due to anapole excitation

    Science.gov (United States)

    Basharin, Alexey A.; Chuguevsky, Vitaly; Volsky, Nikita; Kafesaki, Maria; Economou, Eleftherios N.

    2017-01-01

    We have designed and fabricated a metamaterial consisting of planar metamolecules which exhibit unusual, almost perfect anapole behavior in the sense that the electric dipole radiation is almost canceled by the toroidal dipole one, producing thus an extremely high Q -factor at the resonance frequency. Thus we have demonstrated theoretically and experimentally that metamaterials approaching ideal anapole behavior have very high Q -factor. The size of the system, at the millimeter range, and the parasitic magnetic quadrupole radiation are the factors limiting the size of the Q -factor. In spite of the very low radiation losses the estimated local fields at the metamolecules are extremely high, of the order of 104 higher than the external incoming field.

  19. The high flux plasma generator Magnum-PSI

    Science.gov (United States)

    van Eck, H. J. N.; Kleyn, A. W.; Koppers, W. R.; Rapp, J.; Zeijlmans van Emmichoven, P. A.

    2010-11-01

    Magnum-PSI is a magnetized (3 T), high-flux (up to 10^24 H^+ ions m-2s-1) plasma generator, capable of delivering 10 MW m-2 steady-state power fluxes to a large area target. Magnum-PSI is a highly accessible laboratory experiment in which the interaction of magnetized plasma with different surfaces can be studied. This experiment will provide new insights in the complex physics and chemistry that will occur in the divertor region of the future experimental fusion reactor ITER and reactors beyond ITER. In this contribution, we will present the design and characterization of the Magnum-PSI experiment. The differentially pumped vacuum system, the superconducting magnet, the plasma source, the target plate and manipulator will be presented. Simulations and measurements of the neutral gas flow, as well as electron density and temperature measurements of the plasma beam will be presented. Furthermore, a flavor of upcoming PSI experiments will be given.

  20. High flux inductors for the rapid heating of steel products

    Energy Technology Data Exchange (ETDEWEB)

    Pierret, R.; Griffay, G.; Galbrun, F. [Institut de Recherches de la Siderurgie Francaise (IRSID), 78 - Saint-Germain-en-Laye (France); Hellegouaec`h, J.; Prost, G.

    1995-03-01

    To reduce investment and operating costs of electroheating processes of long products by induction, we developed a new multilayed inductor with high flux density which represents a real technological step in regard of conventional technics: 4 MV/m{sup 2} instead of 1MW/m{sup 2}, efficiency of 85% instead of 55%, compacity and low costs of maintenance. The new technology can also be used with success in flat products plants. (authors). 10 figs., 1 tab.

  1. Blistering on tungsten surface exposed to high flux deuterium plasma

    NARCIS (Netherlands)

    Xu, H.Y.; Liu, W.; Luo, G. N.; Yuan, Y.; Jia, Y. Z.; Fu, B. Q.; De Temmerman, G.

    2016-01-01

    The blistering behaviour of tungsten surfaces exposed to very high fluxes (1–2 × 1024/m2/s) of low energy (38 eV) deuterium plasmas was investigated as a function of ion fluence (0.2–7 × 1026 D/m2) and surface temperature (423–873 K). Blisters were observed under all conditions, especially up to

  2. Membrane requirements for high-flux and convective therapies.

    Science.gov (United States)

    Bowry, Sudhir Kumar

    2011-01-01

    Worldwide, high-flux dialysis (HF-HD) has now surpassed low-flux dialysis (LF-HD) as the predominant treatment modality, recognition that removal of larger uremic retention solutes is desirable for the treatment of patients with end-stage chronic kidney disease (CKD). An even more advanced form of HF-HD in terms of removal of a broad spectrum of uremic toxins is on-line hemodiafiltration (HDF), involving convective transport mechanisms for solute removal. With the modality reaching considerable technical maturity over the last two decades, on-line HDF is now recognized for its clinical efficiency and effectiveness, versatility and safety. Such has been the success of on-line HDF that, in Europe, more patients are treated with on-line HDF than even peritoneal dialysis. Fabrication of high-flux membranes for convective therapies is more than a matter of simply making the membrane 'more open' or of increasing the membrane pore size which is not the only determinant for achieving higher convection. While convective transport of larger uremic retention solutes primarily demands membranes with high hydraulic permeability and sieving capabilities, the making of a modern dialysis membrane involves several other considerations that culminate in the delivery of an effective and safe therapy. In this communication I outline the essential membrane requirements and principles for solute removal by convection, as well of meeting additional features related to the therapy. The basic principles of the membrane manufacturing processes by which desired membrane morphology is derived for the separation phenomena involved in dialysis are further described. An awareness of this enables one to appreciate that, depending on the individual constituents and variations of the manufacturing processes, fabrication of all high-flux membranes entails achieving a balance between the ideal or desired criteria for blood purification. Dialysis membranes for convective therapies, even from the same

  3. High Tc Superconductor Theoretical Models and Electromagnetic Flux Characteristics

    Institute of Scientific and Technical Information of China (English)

    JIN Jian-xun

    2006-01-01

    High Tc Superconductors (HTS) have special electromagnetic characteristics and phenomena. Effort has been made in order to theoretically understand the applied HTS superconductivity and HTS behaviors for practical applications, various theoretical models related to the HTS electromagnetic properties have been developed. The theoretical models and analytic methods are summarized with regard to understanding the HTS magnetic flux characteristic which is one of the most critical issues related to HTS applications such as for HTS magnetic levitation application.

  4. High Flux Metallic Membranes for Hydrogen Recovery and Membrane Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Buxbaum, Robert

    2010-06-30

    We made and tested over 250 new alloys for use as lower cost, higher flux hydrogen extraction membrane materials. Most of these were intermetallic, or contained significant intermetallic content, particularly based on B2 alloy compositions with at least one refractory component; B2 intermetallics resemble BCC alloys, in structure, but the atoms have relatively fixed positions, with one atom at the corners of the cube, the other at the centers. The target materals we were looking for would contain little or no expensive elements, no strongly toxic or radioactive elements, would have high flux to hydrogen, while being fabricable, brazable, and relatively immune to hydrogen embrittlement and corrosion in operation. The best combination of properties of the membrane materials we developed was, in my opinion, a Pd-coated membrane consisting of V -9 atomic % Pd. This material was relatively cheap, had 5 times the flux of Pd under the same pressure differential, was reasonably easy to fabricate and braze, and not bad in terms of embrittlement. Based on all these factors we project, about 1/3 the cost of Pd, on an area basis for a membrane designed to last 20 years, or 1/15 the cost on a flux basis. Alternatives to this membrane replaced significant fractions of the Pd with Ni and or Co. The cost for these membranes was lower, but so was the flux. We produced successful brazed products from the membrane materials, and made them into flat sheets. We tested, unsuccessfully, several means of fabricating thematerials into tubes, and eventually built a membrane reactor using a new, flat-plate design: a disc and doughnut arrangement, a design that seems well- suited to clean hydrogen production from coal. The membranes and reactor were tested successfully at Western Research. A larger equipment company (Chart Industries) produced similar results using a different flat-plate reactor design. Cost projections of the membrane are shown to be attractive.

  5. Extremely High Current, High-Brightness Energy Recovery Linac

    CERN Document Server

    Ben-Zvi, Ilan; Beavis, Dana; Blaskiewicz, Michael; Bluem, Hans; Brennan, Joseph M; Burger, Al; Burrill, Andrew; Calaga, Rama; Cameron, Peter; Chang, Xiangyun; Cole, Michael; Connolly, Roger; Delayen, Jean R; Favale, Anthony; Gassner, David M; Grimes, Jacob T; Hahn, Harald; Hershcovitch, Ady; Holmes, Douglas; Hseuh Hsiao Chaun; Johnson, Peter; Kayran, Dmitry; Kewisch, Jorg; Kneisel, Peter; Lambiase, Robert; Litvinenko, Vladimir N; McIntyre, Gary; Meng, Wuzheng; Nehring, Thomas; Nicoletti, Tony; Oerter, Brian; Pate, David; Phillips, Larry; Preble, Joseph P; Rank, Jim; Rao, Triveni; Rathke, John; Roser, Thomas; Russo, Thomas; Scaduto, Joseph; Schultheiss, Tom; Segalov, Zvi; Smith, Kevin T; Todd, Alan M M; Warren-Funk, L; Williams, Neville; Wu, Kuo-Chen; Yakimenko, Vitaly; Yip, Kin; Zaltsman, Alex; Zhao, Yongxiang

    2005-01-01

    Next generation ERL light-sources, high-energy electron coolers, high-power Free-Electron Lasers, powerful Compton X-ray sources and many other accelerators were made possible by the emerging technology of high-power, high-brightness electron beams. In order to get the anticipated performance level of ampere-class currents, many technological barriers are yet to be broken. BNL's Collider-Accelerator Department is pursuing some of these technologies for its electron cooling of RHIC application, as well as a possible future electron-hadron collider. We will describe work on CW, high-current and high-brightness electron beams. This will include a description of a superconducting, laser-photocathode RF gun and an accelerator cavity capable of producing low emittance (about 1 micron rms normalized) one nano-Coulomb bunches at currents of the order of one ampere average.

  6. High Energy Atmospheric Neutrino Fluxes From a Realistic Primary Spectrum

    Science.gov (United States)

    Campos Penha, Felipe; Dembinski, Hans; Gaisser, Thomas K.; Tilav, Serap

    2016-03-01

    Atmospheric neutrino fluxes depend on the energy spectrum of primary nucleons entering the top of the atmosphere. Before the advent of AMANDA and the IceCube Neutrino Observatory, measurements of the neutrino fluxes were generally below ~ 1TeV , a regime in which a simple energy power law sufficed to describe the primary spectrum. Now, IceCube's muon neutrino data extends beyond 1PeV , including a combination of neutrinos from astrophysical sources with background from atmospheric neutrinos. At such high energies, the steepening at the knee of the primary spectrum must be accounted for. Here, we describe a semi-analytical approach for calculating the atmospheric differential neutrino fluxes at high energies. The input is a realistic primary spectrum consisting of 4 populations with distinct energy cutoffs, each with up to 7 representative nuclei, where the parameters were extracted from a global fit. We show the effect of each component on the atmospheric neutrino spectra, above 10TeV . The resulting features follow directly from recent air shower measurements included in the fit. Felipe Campos Penha gratefully acknowledges financial support from CAPES (Processo BEX 5348/14-5), CNPq (Processo 142180/2012-2), and the Bartol Research Institute.

  7. Dialyzer Reuse and Outcomes of High Flux Dialysis.

    Science.gov (United States)

    Argyropoulos, Christos; Roumelioti, Maria-Eleni; Sattar, Abdus; Kellum, John A; Weissfeld, Lisa; Unruh, Mark L

    2015-01-01

    The bulk of randomized trial evidence for the expanding use of High Flux (HF) hemodialysis worldwide comes from two randomized controlled trials, one of which (HEMODIALYSIS, HEMO) allowed, while the other (Membrane Outcomes Permeability, MPO) excluded, the reuse of membranes. It is not known whether dialyzer reuse has a differential impact on outcomes with HF vs low flyx (LF) dialyzers. Proportional Hazards Models and Joint Models for longitudinal measures and survival outcomes were used in HEMO to analyze the relationship between β2-microglobulin (β2M) concentration, flux, and reuse. Meta-analysis and regression techniques were used to synthesize the evidence for HF dialysis from HEMO and MPO. In HEMO, minimally reused (dialysis and the reuse process on dialyzers may suggest novel biomarkers for uremic toxicity and may accelerate membrane technology innovations that will improve patient outcomes.

  8. High flux lithium antineutrino source with variable hard spectrum

    CERN Document Server

    Lyashuk, V I

    2016-01-01

    The high flux antineutrino source with hard antineutrino spectrum based on neutron activation of 7Li and subsequent fast beta-decay (T 1/2 = 0.84 s) of the 8Li isotope with emission of antineutrino with energy up to 13 MeV - is discussed. Creation of the intensive isotope neutrino source of hard spectrum will allow to increase the detection statistics of neutrino interaction and it is especially urgent for oscillation experiments. The scheme of the proposed neutrino source is based on the continuous transport of the created 8Li to the neutrino detector, which moved away from the place of neutron activation. Analytical expressions for lithium antineutrino flux is obtained. The discussed source will ensure to increase the cross section for reactions with deuteron from several times to tens compare to the reactor antineutrino spectrum. An another unique feature of the installation is the possibility to vary smoothly the hardness of the antineutrino spectrum.

  9. Detection and Attribution of Simulated Climatic Extreme Events and Impacts: High Sensitivity to Bias Correction

    Science.gov (United States)

    Sippel, S.; Otto, F. E. L.; Forkel, M.; Allen, M. R.; Guillod, B. P.; Heimann, M.; Reichstein, M.; Seneviratne, S. I.; Kirsten, T.; Mahecha, M. D.

    2015-12-01

    Understanding, quantifying and attributing the impacts of climatic extreme events and variability is crucial for societal adaptation in a changing climate. However, climate model simulations generated for this purpose typically exhibit pronounced biases in their output that hinders any straightforward assessment of impacts. To overcome this issue, various bias correction strategies are routinely used to alleviate climate model deficiencies most of which have been criticized for physical inconsistency and the non-preservation of the multivariate correlation structure. We assess how biases and their correction affect the quantification and attribution of simulated extremes and variability in i) climatological variables and ii) impacts on ecosystem functioning as simulated by a terrestrial biosphere model. Our study demonstrates that assessments of simulated climatic extreme events and impacts in the terrestrial biosphere are highly sensitive to bias correction schemes with major implications for the detection and attribution of these events. We introduce a novel ensemble-based resampling scheme based on a large regional climate model ensemble generated by the distributed weather@home setup[1], which fully preserves the physical consistency and multivariate correlation structure of the model output. We use extreme value statistics to show that this procedure considerably improves the representation of climatic extremes and variability. Subsequently, biosphere-atmosphere carbon fluxes are simulated using a terrestrial ecosystem model (LPJ-GSI) to further demonstrate the sensitivity of ecosystem impacts to the methodology of bias correcting climate model output. We find that uncertainties arising from bias correction schemes are comparable in magnitude to model structural and parameter uncertainties. The present study consists of a first attempt to alleviate climate model biases in a physically consistent way and demonstrates that this yields improved simulations of

  10. Characteristics of extreme ultraviolet emission from high-Z plasmas

    Science.gov (United States)

    Ohashi, H.; Higashiguchi, T.; Suzuki, Y.; Kawasaki, M.; Suzuki, C.; Tomita, K.; Nishikino, M.; Fujioka, S.; Endo, A.; Li, B.; Otsuka, T.; Dunne, P.; O'Sullivan, G.

    2016-03-01

    We demonstrate the extreme ultraviolet (EUV) and soft x-ray sources in the 2 to 7 nm spectral region related to the beyond EUV (BEUV) question at 6.x nm and the water window source based on laser-produced high-Z plasmas. Resonance emission from multiply charged ions merges to produce intense unresolved transition arrays (UTAs), extending below the carbon K edge (4.37 nm). An outline of a microscope design for single-shot live cell imaging is proposed based on high-Z plasma UTA source, coupled to multilayer mirror optics.

  11. Table-Top Milliwatt-Class Extreme Ultraviolet High Harmonic Light Source

    CERN Document Server

    Klas, Robert; Tschernajew, Maxim; Hädrich, Steffen; Shamir, Yariv; Tünnermann, Andreas; Rothhardt, Jan; Limpert, Jens

    2016-01-01

    Extreme ultraviolet (XUV) lasers are essential for the investigation of fundamental physics. Especially high repetition rate, high photon flux sources are of major interest for reducing acquisition times and improving signal to noise ratios in a plethora of applications. Here, an XUV source based on cascaded frequency conversion is presented, which delivers due to the drastic better single atom response for short wavelength drivers, an average output power of (832 +- 204) {\\mu}W at 21.7 eV. This is the highest average power produced by any HHG source in this spectral range surpassing precious demonstrations by more than a factor of four. Furthermore, a narrow-band harmonic at 26.6 eV with a relative energy bandwidth of only {\\Delta}E/E= 1.8 x 10E-3 has been generated, which is of high interest for high precision spectroscopy experiments.

  12. Solidification at the High and Low Rate Extreme

    Energy Technology Data Exchange (ETDEWEB)

    Meco, Halim [Iowa State Univ., Ames, IA (United States)

    2004-12-19

    The microstructures formed upon solidification are strongly influenced by the imposed growth rates on an alloy system. Depending on the characteristics of the solidification process, a wide range of growth rates is accessible. The prevailing solidification mechanisms, and thus the final microstructure of the alloy, are governed by these imposed growth rates. At the high rate extreme, for instance, one can have access to novel microstructures that are unattainable at low growth rates. While the low growth rates can be utilized for the study of the intrinsic growth behavior of a certain phase growing from the melt. Although the length scales associated with certain processes, such as capillarity, and the diffusion of heat and solute, are different at low and high rate extremes, the phenomena that govern the selection of a certain microstructural length scale or a growth mode are the same. Consequently, one can analyze the solidification phenomena at both high and low rates by using the same governing principles. In this study, we examined the microstructural control at both low and high extremes. For the high rate extreme, the formation of crystalline products and factors that control the microstructure during rapid solidification by free-jet melt spinning are examined in Fe-Si-B system. Particular attention was given to the behavior of the melt pool at different quench-wheel speeds. Since the solidification process takes place within the melt-pool that forms on the rotating quench-wheel, we examined the influence of melt-pool dynamics on nucleation and growth of crystalline solidification products and glass formation. High-speed imaging of the melt-pool, analysis of ribbon microstructure, and measurement of ribbon geometry and surface character all indicate upper and lower limits for melt-spinning rates for which nucleation can be avoided, and fully amorphous ribbons can be achieved. Comparison of the relevant time scales reveals that surface-controlled melt

  13. Monitoring Delamination of Thermal Barrier Coatings During Interrupted High-Heat-Flux Laser Testing using Luminescence Imaging

    Science.gov (United States)

    Eldridge, Jeffrey I.; Zhu, Dongming; Wolfe, Douglas E.

    2011-01-01

    This presentation showed progress made in extending luminescence-base delamination monitoring to TBCs exposed to high heat fluxes, which is an environment that much better simulates actual turbine engine conditions. This was done by performing upconversion luminescence imaging during interruptions in laser testing, where a high-power CO2 laser was employed to create the desired heat flux. Upconverison luminescence refers to luminescence where the emission is at a higher energy (shorter wavelength) than the excitation. Since there will be negligible background emission at higher energies than the excitation, this methods produces superb contrast. Delamination contrast is produced because both the excitation and emission wavelengths are reflected at delamination cracks so that substantially higher luminescence intensity is observed in regions containing delamination cracks. Erbium was selected as the dopant for luminescence specifically because it exhibits upconversion luminescence. The high power CO2 10.6 micron wavelength laser facility at NASA GRC was used to produce the heat flux in combination with forced air backside cooling. Testing was performed at a lower (95 W/sq cm) and higher (125 W/sq cm) heat flux as well as furnace cycling at 1163C for comparison. The lower heat flux showed the same general behavior as furnace cycling, a gradual, "spotty" increase in luminescence associated with debond progression; however, a significant difference was a pronounced incubation period followed by acceleration delamination progression. These results indicate that extrapolating behavior from furnace cycling measurements will grossly overestimate remaining life under high heat flux conditions. The higher heat flux results were not only accelerated, but much different in character. Extreme bond coat rumpling occurred, and delamination propagation extended over much larger areas before precipitating macroscopic TBC failure. This indicates that under the higher heat flux (and

  14. Laboratory Measurement of Enthalpy Flux in High Winds

    Science.gov (United States)

    Jeong, D.; Haus, B. K.; Donelan, M. A.; Zhang, J.

    2006-12-01

    The intensity of tropical cyclones is sensitive to the rates at which enthalpy and momentum are transferred between sea and air in the high-wind core of the storm. Present models of the wind dependence of these transfer rates, does not allow for storms of greater than marginal hurricane intensity. Recent studies have shown that there is a saturation of the bulk drag coefficient in high winds, however more information on the enthalpy flux is required. In particular the role that sea spray plays in enhancing the enthalpy transfer at very high wind speeds is not known. The coefficients for sensible and latent heat transfer (Stanton and Dalton numbers) were measured in the 15-m wind-wave facility at the University of Miami's Air-Sea Interaction Saltwater Tank (ASIST). The wind speed (referred to 10m) was explored over a range of 0 to 45 m/s, covering a full range of aerodynamic conditions from smooth to fully rough. Experiments were designed with water temperatures set between 2 and 5° C above/below the air temperature, with precision thermistors (± 0.002° C) to monitor temperature and Li-Cor infra-red absorption devices to monitor specific humidity changes at upstream and downstream ends of the wave tank during the experiment. The calorimetric use of a wind-wave tank gave precise flux estimates, and experiments were repeated at different Bowen ratios to allow the separation of the heat and moisture parts of the transfer. The effect of spray on the moisture flux was reflected in the drop in temperature along the air path from upstream to downstream and this made it possible to estimate the total spray evaporated in the air column.

  15. Forecasting extreme wave events in moderate and high sea states

    Science.gov (United States)

    Magnusson, Anne Karin; Reistad, Magnar; Bitner-Gregersen, Elzbieta Maria

    2013-04-01

    Empirical studies on measurements have not yet come to conclusive relations between occurrence of rogue waves and - parameters which could be forecasted . Theoretical and tank experiments have demonstrated that high spectral peakedness and low spectral width combined (high Benjamin-Feir instability index, Onorato et al., 2006) give higher probability of rogue wave occurrence. Directional spread seems to reduce the probability of occurrence of rogue waves in these studies. Many years of experience with forecasting and discussions with people working in ocean environment indicate that rogue waves may as well occur in crossing seas. This was also indicated in a study in the Maxwave project (Toffoli et al., 2003) and the EXTREME SEAS project (Toffoli et al., 2011). We have here experimented with some indexes describing both high BFI and crossing seas and run the WAM model for some North Sea storm cases. Wave distributions measured at Ekofisk are analysed in the different cases. References • Onorato, M., Osborne, A., Serio, M., Cavaleri, L., Brandini, C., and Stansberg, C.: Extreme waves, modulational instability and second order theory: wave flume experiments on irregular waves,Europ. J. Mech. B/Fluids, 25, 586-601, 2006. • Toffoli, A., Lefevre, J.M., Monbaliu, J., Savina, H., and Bitner-Gregersen, E., "Freak Waves:Clues for Prediction in Ship Accidents?", Proc. ISOPE'2003 Conf. Hawai, USA, 2003. • Toffoli A., Bitner-Gregersen E. M., Osborne A. R., Serio M. Monbaliu J., Onorato M. (2011) Extreme Waves in Random Crossing Seas: Laboratory Experiments and Numerical Simulations. Geophys. Res. Lett., Vol. 38, L06605, 5 pp. doi: 10.1029/2011.

  16. High-flux solar photon processes: Opportunities for applications

    Energy Technology Data Exchange (ETDEWEB)

    Steinfeld, J I; Coy, S L; Herzog, H; Shorter, J A; Schlamp, M; Tester, J W; Peters, W A [Massachusetts Inst. of Tech., Cambridge, MA (United States)

    1992-06-01

    The overall goal of this study was to identify new high-flux solar photon (HFSP) processes that show promise of being feasible and in the national interest. Electric power generation and hazardous waste destruction were excluded from this study at sponsor request. Our overall conclusion is that there is promise for new applications of concentrated solar photons, especially in certain aspects of materials processing and premium materials synthesis. Evaluation of the full potential of these and other possible applications, including opportunities for commercialization, requires further research and testing. 100 refs.

  17. Enzymatically active high-flux selectively gas-permeable membranes

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Ying-Bing; Cecchi, Joseph L.; Rempe, Susan; FU, Yaqin; Brinker, C. Jeffrey

    2016-01-26

    An ultra-thin, catalyzed liquid transport medium-based membrane structure fabricated with a porous supporting substrate may be used for separating an object species such as a carbon dioxide object species. Carbon dioxide flux through this membrane structures may be several orders of magnitude higher than traditional polymer membranes with a high selectivity to carbon dioxide. Other gases such as molecular oxygen, molecular hydrogen, and other species including non-gaseous species, for example ionic materials, may be separated using variations to the membrane discussed.

  18. BVOC ecosystem flux measurements at a high latitude wetland site

    Directory of Open Access Journals (Sweden)

    T. Holst

    2008-12-01

    Full Text Available In this study, we present summertime concentrations and fluxes of biogenic volatile organic compounds (BVOCs measured at a sub-arctic wetland in northern Sweden using a disjunct eddy-covariance (DEC technique based on a proton transfer reaction mass spectrometer (PTR-MS. The vegetation at the site was dominated by Sphagnum, Carex and Eriophorum spp. The performance of the DEC system was assessed by comparing H3O+-ion cluster formed with water molecules (H3O+(H2O at m37 with water vapour concentration measurements made using an adjacent humidity sensor, and from a comparison of sensible heat fluxes for high frequency and DEC data obtained from the sonic anemometer. These analyses showed no significant PTR-MS sensor drift over a period of several weeks and only a small flux-loss due to high-frequency spectrum omissions. This loss was within the range expected from other studies and the theoretical considerations.

    Standardised (20°C and 1000 μmol m−2 s−1 PAR summer isoprene emission rates of 323 μg C m−2 (ground area h−1 were comparable with findings from more southern boreal forests, and fen-like ecosystems. On a diel scale, measured fluxes indicated a stronger temperature dependence when compared with emissions from temperate or (subtropical ecosystems. For the first time, to our knowledge, we report ecosystem methanol fluxes from a sub-arctic ecosystem. Maximum daytime emission fluxes were around 270 μg m−2 h−1 (ca. 100 μg C m−2 h-1 and measurements indicated some nocturnal deposition.

    The measurements reported here covered a period of 50 days (1 August to 19 September 2006, approximately one half of the growing season at the site, and allowed to investigate the effect of vegetation senescence on daily BVOC fluxes and on their temperature and light

  19. Blistering on tungsten surface exposed to high flux deuterium plasma

    Energy Technology Data Exchange (ETDEWEB)

    Xu, H.Y., E-mail: donaxu@163.com [Center of Interface Dynamics for Sustainability, Institute of Materials, CAEP, Chengdu 610200 (China); Key Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Liu, W., E-mail: liuw@mail.tsinghua.edu.cn [Key Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Luo, G.N. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Yuan, Y. [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); Jia, Y.Z.; Fu, B.Q. [Key Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); De Temmerman, G. [FOM Institute DIFFER-Dutch Institute for Fundamental Energy Research, Trilateral Euregio Cluster, Edisonbaan 14, 3439 MN Nieuwegein (Netherlands); ITER Organization, Route de Vinon-sur-Verdon CS 90046-13067, St Paul Lez Durance Cedex (France)

    2016-04-01

    The blistering behaviour of tungsten surfaces exposed to very high fluxes (1–2 × 10{sup 24}/m{sup 2}/s) of low energy (38 eV) deuterium plasmas was investigated as a function of ion fluence (0.2–7 × 10{sup 26} D/m{sup 2}) and surface temperature (423–873 K). Blisters were observed under all conditions, especially up to temperatures of 873 K. The blister parameters are evaluated with blister size, blister density and surface coverage. The blister size always peaked at less than 0.5 μm and no blister larger than 10 μm is observed even at high fluence. The blister densities are found in high magnitude of 10{sup 6} blisters/m{sup 2}, with the surface coverages lower than 2%. The formation of cracks in the sub-surface region was observed by cross-section imaging. Changes in blister size and shape with fluence and temperature suggest processes of predominantly nucleation and subsequent growth of blisters. The smaller blister size is considered to be caused by a combination of flux-related effects such as enhanced defect formation in the near surface region, reduced deuterium diffusivity and relatively short exposure times.

  20. High-flux solar furnace processing of silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Tsuo, Y.S.; Pitts, J.R.; Landry, M.D.; Menna, P.; Bingham, C.E.; Lewandowski, A.; Ciszek, T.F. [National Renewable Energy Laboratory, Golden, CO (United States)

    1996-06-10

    We used a 10-kW, high-flux solar furnace (HFSF) to diffuse the front-surface n{sup +}-p junction and the back-surface p-p{sup +} junction of single-crystal silicon solar cells in one processing step. We found that all of these HFSF-processed cells have better conversion efficiencies than control cells of identical structures fabricated by conventional furnace diffusion methods. We also used the HFSF to crystallize a-Si:H thin films on glass, to texture crystalline silicon surfaces, to deposit gold contacts on silicon wafers, and to getter impurities from metallurgical grade silicon. HFSF processing offers several advantages over conventional furnace processing: (1) it provides a cold-wall process, which reduces contamination; (2) temperature versus time profiles can be precisely controlled; (3) wavelength, intensity, and spatial distribution of the incident solar flux can be controlled and changed rapidly; (4) a number of high-temperature processing steps can be performed simultaneously; and (5) combined quantum and thermal effects may benefit overall cell performance. We conclude that HFSF processing of silicon solar cells has the potential to improve cell efficiency, reduce cell fabrication costs, and also be an environmentally friendly manufacturing method. We have also demonstrated that the HFSF can be used to achieve solid-phase crystallization of a-Si:H at very high speed

  1. Blistering on tungsten surface exposed to high flux deuterium plasma

    Science.gov (United States)

    Xu, H. Y.; Liu, W.; Luo, G. N.; Yuan, Y.; Jia, Y. Z.; Fu, B. Q.; De Temmerman, G.

    2016-04-01

    The blistering behaviour of tungsten surfaces exposed to very high fluxes (1-2 × 1024/m2/s) of low energy (38 eV) deuterium plasmas was investigated as a function of ion fluence (0.2-7 × 1026 D/m2) and surface temperature (423-873 K). Blisters were observed under all conditions, especially up to temperatures of 873 K. The blister parameters are evaluated with blister size, blister density and surface coverage. The blister size always peaked at less than 0.5 μm and no blister larger than 10 μm is observed even at high fluence. The blister densities are found in high magnitude of 106 blisters/m2, with the surface coverages lower than 2%. The formation of cracks in the sub-surface region was observed by cross-section imaging. Changes in blister size and shape with fluence and temperature suggest processes of predominantly nucleation and subsequent growth of blisters. The smaller blister size is considered to be caused by a combination of flux-related effects such as enhanced defect formation in the near surface region, reduced deuterium diffusivity and relatively short exposure times.

  2. High-flux solar furnace processing of silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Tsuo, Y.S.; Pitts, J.R.; Landry, M.D.; Bingham, C.E.; Lewandowski, A.; Ciszek, T.F. [National Renewable Energy Lab., Golden, CO (United States)

    1994-12-31

    The authors used a 10-kW high-flux solar furnace (HFSF) to diffuse the front-surface n{sup +}-p junction and the back-surface p-p{sup +} junction of single-crystal silicon solar cells in one processing step. They found that all of the HFSF-processed cells have better conversion efficiencies than control cells of identical structures fabricated by conventional furnace diffusion methods. HFSF processing offers several advantages that may contribute to improved solar cell efficiency: (1) it provides a cold-wall process, which reduces contamination; (2) temperature versus time profiles can be precisely controlled; (3) wavelength, intensity, and spatial distribution of the incident solar flux can be controlled and changed rapidly; (4) a number of high-temperature processing steps can be performed simultaneously; and (5) combined quantum and thermal effects may benefit overall cell performance. The HFSF has also been successfully used to texture the surface of silicon wafers and to crystallize a-Si:H thin films on glass.

  3. Advanced Tethersonde for High-Speed Flux Measurements Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Flux measurements of trace gases and other quantities, such as latent heat, are of great importance in scientific field research. One typical flux measurement setup...

  4. Dialyzer Reuse and Outcomes of High Flux Dialysis.

    Directory of Open Access Journals (Sweden)

    Christos Argyropoulos

    Full Text Available The bulk of randomized trial evidence for the expanding use of High Flux (HF hemodialysis worldwide comes from two randomized controlled trials, one of which (HEMODIALYSIS, HEMO allowed, while the other (Membrane Outcomes Permeability, MPO excluded, the reuse of membranes. It is not known whether dialyzer reuse has a differential impact on outcomes with HF vs low flyx (LF dialyzers.Proportional Hazards Models and Joint Models for longitudinal measures and survival outcomes were used in HEMO to analyze the relationship between β2-microglobulin (β2M concentration, flux, and reuse. Meta-analysis and regression techniques were used to synthesize the evidence for HF dialysis from HEMO and MPO.In HEMO, minimally reused (< 6 times HF dialyzers were associated with a hazard ratio (HR of 0.67 (95% confidence interval, 95%CI: 0.48-0.92, p = 0.015, 0.64 (95%CI: 0.44 - 0.95, p = 0.03, 0.61 (95%CI: 0.41 - 0.90, p = 0.012, 0.53 (95%CI: 0.28 - 1.02, p = 0.057 relative to minimally reused LF ones for all cause, cardiovascular, cardiac and infectious mortality respectively. These relationships reversed for extensively reused membranes (p for interaction between reuse and flux < 0.001, p = 0.005 for death from all cause and cardiovascular causes, while similar trends were noted for cardiac and infectious mortality (p of interaction between reuse and flux of 0.10 and 0.08 respectively. Reduction of β2M explained only 1/3 of the effect of minimally reused HF dialyzers on all cause mortality, while non-β2M related factors explained the apparent attenuation of the benefit with more extensively reused dialyzers. Meta-regression of HEMO and MPO estimated an adjusted HR of 0.63 (95% CI: 0.51-0.78 for non-reused HF dialyzers compared with non-reused LF membranes.This secondary analysis and synthesis of two large hemodialysis trials supports the widespread use of HF dialyzers in clinical hemodialysis over the last decade. A mechanistic understanding of the effects of

  5. A regional high-resolution carbon flux inversion of North America for 2004

    Directory of Open Access Journals (Sweden)

    A. E. Schuh

    2010-05-01

    Full Text Available Resolving the discrepancies between NEE estimates based upon (1 ground studies and (2 atmospheric inversion results, demands increasingly sophisticated techniques. In this paper we present a high-resolution inversion based upon a regional meteorology model (RAMS and an underlying biosphere (SiB3 model, both running on an identical 40 km grid over most of North America. Current operational systems like CarbonTracker as well as many previous global inversions including the Transcom suite of inversions have utilized inversion regions formed by collapsing biome-similar grid cells into larger aggregated regions. An extreme example of this might be where corrections to NEE imposed on forested regions on the east coast of the United States might be the same as that imposed on forests on the west coast of the United States while, in reality, there likely exist subtle differences in the two areas, both natural and anthropogenic. Our current inversion framework utilizes a combination of previously employed inversion techniques while allowing carbon flux corrections to be biome independent. Temporally and spatially high-resolution results utilizing biome-independent corrections provide insight into carbon dynamics in North America. In particular, we analyze hourly CO2 mixing ratio data from a sparse network of eight towers in North America for 2004. A prior estimate of carbon fluxes due to Gross Primary Productivity (GPP and Ecosystem Respiration (ER is constructed from the SiB3 biosphere model on a 40 km grid. A combination of transport from the RAMS and the Parameterized Chemical Transport Model (PCTM models is used to forge a connection between upwind biosphere fluxes and downwind observed CO2 mixing ratio data. A Kalman filter procedure is used to estimate weekly corrections to biosphere fluxes based upon observed CO2. RMSE-weighted annual NEE estimates, over an ensemble of potential inversion parameter sets, show a

  6. Treatment algorithms for high-energy traumas of lower extremities

    Directory of Open Access Journals (Sweden)

    Jovanović Mladen

    2002-01-01

    Full Text Available Introduction High-energy traumas are open or closed injuries caused by force (missile, traffic injuries, crush or blust injuries, falling from heights, affecting the body surface and transferring high amount of kinetic energy inducing great damage to the tissue. Management of such lower extremity injuries has evolved over past several decades, but still remains a difficult task for every surgical team. Specific anatomic and functional characteristics combined with extensive injuries demands specific treatment protocols. Multiple injuries In a multiple injured patient the first priority is management of life-threatening trauma. Despite other injuries, surgical treatment of limb-threatening injuries must start as soon as life-threatening condition has been managed. Treatment algorithms Algorithms are especially beneficial in management of severely injured, but salvageable extremities and in making decision on amputation. Insight into mechanisms of injury, as well as systematic examination of the affected limb, should help us understand the extensiveness of trauma and make an adequate management plan. Prevention of infection and surgical approach Prevention of wound infection and surgical approach to high- energy limb trauma, which includes wound extension, wound excision, skeletal stabilization and if necessary muscle compartment release, should be done in the first 6 hours after injury. Methods of soft tissue reconstruction Commonly used methods for soft tissue defects must provide wound coverage in less than five days following injury. Rehabilitation Early passive and active mobilization and verticalization of patients is very important for successful treatment. Conclusion Good and timely evaluation of the injured and collaboration between plastic and orthopedic surgeons from the beginning of treatment, are crucial for final outcome.

  7. The Sedentary Survey of Extreme High Energy Peaked BL Lacs. II. The Catalog and Spectral Properties

    CERN Document Server

    Giommi, P; Perri, M; Padovani, P

    2004-01-01

    The multi-frequency `Sedentary Survey' is a deep, statistically complete, radio flux limited sample comprising 150 BL Lacertae objects distinguished by their extremely high X-ray to radio flux ratio, ranging from five hundred to over five thousand times that of typical BL Lacs discovered in radio surveys. This paper presents the final, 100% identified, catalog together with the optical, X-ray and broad-band SEDs constructed combining literature multi-frequency data with non-simultaneous optical observations and BeppoSAX X-ray data, when available. The SEDs confirm that the peak of the synchrotron power in these objects is located at very high energies. BeppoSAX wide band X-ray observations show that, in most cases, the X-ray spectra are convex and well described by a logarithmic parabola model peaking (in a E f(E) vs E representation) between 0.02 to several keV. Owing to the high synchrotron energies involved most of the sources in the catalog are likely to be TeV emitters, with the closest and brightest one...

  8. Design and Calibration of a Novel High Temperature Heat Flux Sensor

    OpenAIRE

    Raphael-Mabel, Sujay Anand

    2005-01-01

    Heat flux gages are important in applications where measurement of the transfer of energy is more important than measurement of the temperature itself. There is a need for a heat flux sensor that can perform reliably for long periods of time in high temperature and high heat flux environment. The primary objective is to design and build a heat flux sensor that is capable of operating for extended periods of time in a high heat flux and high temperature environment. A High Temperature Heat F...

  9. Ptychographic hyperspectral spectromicroscopy with an extreme ultraviolet high harmonic comb

    CERN Document Server

    Zhang, Bosheng; Seaberg, Matthew H; Shanblatt, Elisabeth R; Porter, Christina L; Karl,, Robert; Mancuso, Christopher A; Kapteyn, Henry C; Murnane, Margaret M; Adams, Daniel E

    2016-01-01

    We demonstrate a new scheme of spectromicroscopy in the extreme ultraviolet (EUV) spectral range, where the spectral response of the sample at different wavelengths is imaged simultaneously. It is enabled by applying ptychographical information multiplexing (PIM) to a tabletop EUV source based on high harmonic generation, where four spectrally narrow harmonics near 30 nm form a spectral comb structure. Extending PIM from previously demonstrated visible wavelengths to the EUV/X-ray wavelengths promises much higher spatial resolution and more powerful spectral contrast mechanism, making PIM an attractive spectromicroscopy method in both the microscopy and the spectroscopy aspects. Besides the sample, the multicolor EUV beam is also imaged in situ, making our method a powerful beam characterization technique. No hardware is used to separate or narrow down the wavelengths, leading to efficient use of the EUV radiation.

  10. CLASH: Extreme Emission Line Galaxies and Their Implication on Selection of High-Redshift Galaxies

    CERN Document Server

    Huang, Xingxing; Wang, Junxian; Ford, Holland; Lemze, Doron; Moustakas, John; Shu, Xinwen; Van der Wel, Arjen; Zitrin, Adi; Frye, Brenda L; Postman, Marc; Bartelmann, Matthias; Benitez, Narciso; Bradley, Larry; Broadhurst, Tom; Coe, Dan; Donahue, Megan; Infante, Leopoldo; Kelson, Daniel; Koekemoer, Anton; Lahav, Ofer; Medezinski, Elinor; Moustakas, Leonidas; Rosati, Piero; Seitz, Stella; Umetsu, Keiichi

    2014-01-01

    We utilize the CLASH (Cluster Lensing And Supernova survey with Hubble) observations of 25 clusters to search for extreme emission-line galaxies (EELGs). The selections are carried out in two central bands: F105W (Y105) and F125W (J125), as the flux of the central bands could be enhanced by the presence of [O III] 4959, 5007 at redshift of about 0.93-1.14 and 1.57-1.79, respectively. The multi-band observations help to constrain the equivalent widths of emission lines. Thanks to cluster lensing, we are able to identify 52 candidates down to an intrinsic limiting magnitude of 28.5 and to a rest-frame [O III] 4959,5007 equivalent width of about 3737 angstrom. Our samples include a number of EELGs at lower luminosities that are missed in other surveys, and the extremely high equivalent width can be only found in such faint galaxies. These EELGs can mimic the dropout feature similar to that of high redshift galaxies and contaminate the color-color selection of high redshift galaxies when the S/N ratio is limited ...

  11. CLASH: EXTREME EMISSION-LINE GALAXIES AND THEIR IMPLICATION ON SELECTION OF HIGH-REDSHIFT GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Xingxing; Wang, Junxian; Shu, Xinwen [CAS Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China, Hefei, Anhui 230026 (China); Zheng, Wei; Ford, Holland; Lemze, Doron [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Moustakas, John [Department of Physics and Astronomy, Siena College, 515 Loudon Road, Loudonville, NY 12211 (United States); Van der Wel, Arjen [Max-Planck Institute for Astronomy, Königstuhl 17, D-69117, Heidelberg (Germany); Zitrin, Adi [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, MS 249-17, Pasadena, CA 91125 (United States); Frye, Brenda L. [Steward Observatory/Department of Astronomy, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721-0065 (United States); Postman, Marc; Bradley, Larry; Coe, Dan [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21208 (United States); Bartelmann, Matthias [Leiden Observatory, Leiden University, P. O. Box 9513, 2300 RA Leiden (Netherlands); Benítez, Narciso [Instituto de Astrofísica de Andalucía (CSIC), C/Camino Bajo de Huétor 24, Granada E-18008 (Spain); Broadhurst, Tom [Department of Theoretical Physics, University of Basque Country UPV/EHU E-Bilbao (Spain); Donahue, Megan [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Infante, Leopoldo, E-mail: hxx@mail.ustc.edu.cn [Departamento de Astronoía y Astrofísica, Pontificia Universidad Católica de Chile, V. Mackenna 4860 Santiago 22 (Chile); and others

    2015-03-01

    We utilize the Cluster Lensing And Supernova survey with Hubble observations of 25 clusters to search for extreme emission-line galaxies (EELGs). The selections are carried out in two central bands: F105W (Y {sub 105}) and F125W (J {sub 125}), as the flux of the central bands could be enhanced by the presence of [O III] λλ4959, 5007 at redshifts of ∼0.93-1.14 and 1.57-1.79, respectively. The multiband observations help to constrain the equivalent widths (EWs) of emission lines. Thanks to cluster lensing, we are able to identify 52 candidates down to an intrinsic limiting magnitude of 28.5 and to a rest-frame [O III] λλ4959, 5007 EW of ≅ 3700 Å. Our samples include a number of EELGs at lower luminosities that are missed in other surveys, and the extremely high EW can only be found in such faint galaxies. These EELGs can mimic a dropout feature similar to that of high-redshift galaxies and contaminate the color-color selection of high-redshift galaxies when the signal-to-noise ratio is limited or the band coverage is incomplete.

  12. High-quality Critical Heat Flux in Horizontally Coiled Tubes

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    An investigation on the high-quality dryout in two electrically heated coiled tubes with horizontally helix axes is reported.The temperature profiles both along the tube and around the circumference are measured.and it is found that the temperature profiles around the circumference are not identical for the corss-sections at different parts of the coil.The “local condition hypothesis” seems applicable under present conditions,and the critical heat flux qcr decreases with increasing critical quality xcr.The CHF increases as mass velocity and ratio of tube diameter to coil diameter(d/D) increases,and it seems not to be affected hby the system pressure.The CHF is larger with coils than that with straight tubes,and the difference increases with increasing mass velocity and d/D.

  13. High Flux Commercial Illumination Solution with Intelligent Controls

    Energy Technology Data Exchange (ETDEWEB)

    Camil Ghiu

    2012-04-30

    This report summarizes the work performed at OSRAM SYLVANIA under US Department of Energy contract DE-EE0003241 for developing a high efficiency LED-based luminaire. A novel light engine module (two versions: standard and super), power supply and luminaire mechanical parts were designed and tested. At steady-state, the luminaire luminous flux is 3156 lumens (lm), luminous efficacy 97.4 LPW and CRI (Ra) 88 at a correlated color temperature (CCT) of 3507K. When the luminaire is fitted with the super version of the light engine the efficacy reaches 130 LPW. In addition, the luminaire is provided with an intelligent control network capable of additional energy savings. The technology developed during the course of this project has been incorporated into a family of products. Recently, the first product in the family has been launched.

  14. MCO Membranes: Enhanced Selectivity in High-Flux Class

    Science.gov (United States)

    Boschetti-de-Fierro, Adriana; Voigt, Manuel; Storr, Markus; Krause, Bernd

    2015-12-01

    Novel MCO high-flux membranes for hemodialysis have been developed with optimized permeability, allowing for filtration close to that of the natural kidney. A comprehensive in vitro characterization of the membrane properties by dextran filtration is presented. The sieving profile of pristine membranes, as well as that of membranes exposed to blood for 40 minutes, are described. The effective pore size (Stokes-Einstein radius) was estimated from filtration experiments before and after blood exposure, and results were compared to hydrodynamic radii of middle and large uremic toxins and essential proteins. The results indicate that the tailored pore sizes of the MCO membranes promote removal of large toxins while ensuring the retention of albumin.

  15. Magnetic properties of high-T(sub c) superconductors: Rigid levitation, flux pinning, thermal depinning, and fluctuation

    Science.gov (United States)

    Brandt, E. H.

    1990-01-01

    The levitation of high-T(sub c) superconductors is quite conspicuous: Above magnets of low symmetry a disk of these ceramics floats motionless, without vibration or rotation; it has a continuous range of stable positions and orientations as if it were stuck in sand. Some specimens may even be suspended above or below the same magnet. This fascinating stability, inherent to no other type of levitation, is caused by the pinning of magnetic flux lines by inhomogeneities inside these extreme type-2 superconductors. The talk deals with pinning of magnetic flux in these materials, with flux flow, flux creep, thermally activated depinning, and the thermal fluctuation of the vortex positions in the flux line lattice (often called flux lattice melting). Also discussed are the fluctuations of the (nearly periodic) magnetic field inside these superconductors which are caused by random pinning sites and by the finite temperature. These fluctuations broaden the van-Hove singularities observed in the density of the magnetic field by nuclear magnetic resonance and by muon spin rotation.

  16. High Flux Isotope Reactor cold neutron source reference design concept

    Energy Technology Data Exchange (ETDEWEB)

    Selby, D.L.; Lucas, A.T.; Hyman, C.R. [and others

    1998-05-01

    In February 1995, Oak Ridge National Laboratory`s (ORNL`s) deputy director formed a group to examine the need for upgrades to the High Flux Isotope Reactor (HFIR) system in light of the cancellation of the Advanced neutron Source Project. One of the major findings of this study was that there was an immediate need for the installation of a cold neutron source facility in the HFIR complex. In May 1995, a team was formed to examine the feasibility of retrofitting a liquid hydrogen (LH{sub 2}) cold source facility into an existing HFIR beam tube. The results of this feasibility study indicated that the most practical location for such a cold source was the HB-4 beam tube. This location provides a potential flux environment higher than the Institut Laue-Langevin (ILL) vertical cold source and maximizes the space available for a future cold neutron guide hall expansion. It was determined that this cold neutron beam would be comparable, in cold neutron brightness, to the best facilities in the world, and a decision was made to complete a preconceptual design study with the intention of proceeding with an activity to install a working LH{sub 2} cold source in the HFIR HB-4 beam tube. During the development of the reference design the liquid hydrogen concept was changed to a supercritical hydrogen system for a number of reasons. This report documents the reference supercritical hydrogen design and its performance. The cold source project has been divided into four phases: (1) preconceptual, (2) conceptual design and testing, (3) detailed design and procurement, and (4) installation and operation. This report marks the conclusion of the conceptual design phase and establishes the baseline reference concept.

  17. A cost-effective high-flux source of cold ytterbium atoms

    Science.gov (United States)

    Song, Bo; Zou, Yueyang; Zhang, Shanchao; Cho, Chang-woo; Jo, Gyu-Boong

    2016-10-01

    We report a cost-effective way to prepare high-flux slow ytterbium atoms with extremely low-power 399-nm light suitable for the production of quantum degenerate ytterbium gases. By collimating an atomic beam through an array of micro-capillary tubes, we obtain a bright atomic beam through the Zeeman slower operating at low light power of only 15 mW for the source. We achieve the loading rate of 2 × 107 s-1 into the intercombination magneto-optical trap (MOT) and a sufficient steady-state MOT atom number of 2 × 108 for 174Yb atoms. Our apparatus highlights an efficient method to obtain slow ytterbium atoms using a simple low-power 399-nm laser system.

  18. Super-High Heat Flux Removal Using Sintered Metal Porous Media

    Institute of Scientific and Technical Information of China (English)

    Kazuhisa YUKI; Jun ABEI; Hidetoshi HASHIZUME; Saburo TODA

    2005-01-01

    Heat transfer experiments using various porous materials are performed to verify the possibility of extremely highheat flux removal (several dozens of MW/m2). The porous media introduced in this experiment are bronze particle-sintered ones and copper fibers-sintered ones that have high thermal conductivity, each of which can enhance the thermal diffusion in the porous material. From the heat transfer experiments using a non-transferredtype of plasma arcjet as a high heat flux source, the steady heat removal of 66.0 MW/m2 is proved by using the bronze porous medium whose pore size and porosity are 100 μm and 0.38, respectively. Furthermore, as the result of eveluating the heat removal performance for various copper fiber porous media with the porosity from 0.5 to 0.7 and the fiber diameter from 30 to 90 μm, it is clarified that the maximum cooling performance exceeds 70.0MW/m2 at the porosity of 0.7 and the fiber diameter of 90 μm, and that using the lower porosity material is useful for improving an evaporation rate in the porous media.

  19. Small-scale characteristics of extremely high latitude aurora

    Directory of Open Access Journals (Sweden)

    J. A. Cumnock

    2009-09-01

    Full Text Available We examine 14 cases of an interesting type of extremely high latitude aurora as identified in the precipitating particles measured by the DMSP F13 satellite. In particular we investigate structures within large-scale arcs for which the particle signatures are made up of a group of multiple distinct thin arcs. These cases are chosen without regard to IMF orientation and are part of a group of 87 events where DMSP F13 SSJ/4 measures emissions which occur near the noon-midnight meridian and are spatially separated from both the dawnside and duskside auroral ovals by wide regions with precipitating particles typical of the polar cap. For 73 of these events the high-latitude aurora consists of a continuous region of precipitating particles. We focus on the remaining 14 of these events where the particle signatures show multiple distinct thin arcs. These events occur during northward or weakly southward IMF conditions and follow a change in IMF By. Correlations are seen between the field-aligned currents and plasma flows associated with the arcs, implying local closure of the FACs. Strong correlations are seen only in the sunlit hemisphere. The convection associated with the multiple thin arcs is localized and has little influence on the large-scale convection. This also implies that the sunward flow along the arcs is unrelated to the overall ionospheric convection.

  20. Extremely high-frequency micro-Doppler measurements of humans

    Science.gov (United States)

    Hedden, Abigail S.; Silvious, Jerry L.; Dietlein, Charles R.; Green, Jeremy A.; Wikner, David A.

    2014-05-01

    The development of sensors that are capable of penetrating smoke, dust, fog, clouds, and rain is critical for maintaining situational awareness in degraded visual environments and for providing support to the Warfighter. Atmospheric penetration properties, the ability to form high-resolution imagery with modest apertures, and available source power make the extremely high-frequency (EHF) portion of the spectrum promising for the development of radio frequency (RF) sensors capable of penetrating visual obscurants. Comprehensive phenomenology studies including polarization and backscatter properties of relevant targets are lacking at these frequencies. The Army Research Laboratory (ARL) is developing a fully-polarimetric frequency-modulated continuous-wave (FMCW) instrumentation radar to explore polarization and backscatter properties of in-situ rain, scattering from natural and man-made surfaces, and the radar cross section and micro-Doppler signatures of humans at EHF frequencies, specifically, around the 220 GHz atmospheric window. This work presents an overview of the design and construction of the radar system, hardware performance, data acquisition software, and initial results including an analysis of human micro-Doppler signatures.

  1. A new high-flux solar furnace for high-temperature thermochemical research

    Energy Technology Data Exchange (ETDEWEB)

    Haueter, P.; Seitz, T.; Steinfeld, A. [Paul Scherrer Inst., Villigen (Switzerland). Solar Process Technology Group

    1999-02-01

    A new high-flux solar furnace, capable of delivering up to 40 kW at peak concentration ratios exceeding 5000, is operational at PSI. Its optical design characteristics, main engineering features, and operating performance are described. This solar concentrating facility will be used principally for investigating the thermochemical processing of solar fuels at temperatures as high as 2500 K.

  2. A Compact, High-Flux Cold Atom Beam Source

    Science.gov (United States)

    Kellogg, James R.; Kohel, James M.; Thompson, Robert J.; Aveline, David C.; Yu, Nan; Schlippert, Dennis

    2012-01-01

    The performance of cold atom experiments relying on three-dimensional magneto-optical trap techniques can be greatly enhanced by employing a highflux cold atom beam to obtain high atom loading rates while maintaining low background pressures in the UHV MOT (ultra-high vacuum magneto-optical trap) regions. Several techniques exist for generating slow beams of cold atoms. However, one of the technically simplest approaches is a two-dimensional (2D) MOT. Such an atom source typically employs at least two orthogonal trapping beams, plus an additional longitudinal "push" beam to yield maximum atomic flux. A 2D atom source was created with angled trapping collimators that not only traps atoms in two orthogonal directions, but also provides a longitudinal pushing component that eliminates the need for an additional push beam. This development reduces the overall package size, which in turn, makes the 2D trap simpler, and requires less total optical power. The atom source is more compact than a previously published effort, and has greater than an order of magnitude improved loading performance.

  3. Flux-measuring approach of high temperature metal liquid based on BP neural networks

    Institute of Scientific and Technical Information of China (English)

    胡燕瑜; 桂卫华; 李勇刚

    2003-01-01

    A soft-measuring approach is presented to measure the flux of liquid zinc with high temperature andcausticity. By constructing mathematical model based on neural networks, weighing the mass of liquid zinc, the fluxof liquid zinc is acquired indirectly, the measuring on line and flux control are realized. Simulation results and indus-trial practice demonstrate that the relative error between the estimated flux value and practical measured flux value islower than 1.5%, meeting the need of industrial process.

  4. Extremely high-intensity laser interactions with fundamental quantum systems

    CERN Document Server

    Di Piazza, A; Hatsagortsyan, K Z; Keitel, C H

    2011-01-01

    The field of laser-matter interaction traditionally deals with the response of atoms, molecules and plasmas to an external light wave. However, the recent sustained technological progress is opening the possibility of employing intense laser radiation to prompt or substantially influence physical processes beyond atomic-physics energy scales. Available optical laser intensities exceeding $10^{22}\\;\\text{W/cm$^2$}$ can push the fundamental light-electron interaction to the extreme limit where radiation-reaction effects dominate the electron dynamics, can shed light on the structure of the quantum vacuum and can prime the creation of particles like electrons, muons and pions and the corresponding antiparticles. Also, novel sources of intense coherent high-energy photons and laser-based particle colliders can pave the way to nuclear quantum optics and can even allow for potential discovery of new particles beyond the Standard Model. These are the main topics of the present article, which is devoted to a review o...

  5. Fabrication of control rods for the High Flux Isotope Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Sease, J.D.

    1998-03-01

    The High Flux Isotope Reactor (HFIR) is a research-type nuclear reactor that was designed and built in the early 1960s and has been in continuous operation since its initial criticality in 1965. Under current plans, the HFIR is expected to continue in operation until 2035. This report updates ORNL/TM-9365, Fabrication Procedure for HFIR Control Plates, which was mainly prepared in the early 1970's but was not issued until 1984, and reflects process changes, lessons learned in the latest control rod fabrication campaign, and suggested process improvements to be considered in future campaigns. Most of the personnel involved with the initial development of the processes and in part campaigns have retired or will retire soon. Because their unlikely availability in future campaigns, emphasis has been placed on providing some explanation of why the processes were selected and some discussions about the importance of controlling critical process parameters. Contained in this report is a description of the function of control rods in the reactor, the brief history of the development of control rod fabrication processes, and a description of procedures used in the fabrication of control rods. A listing of the controlled documents and procedures used in the last fabrication campaigns is referenced in Appendix A.

  6. High Flux Isotope Reactor system RELAP5 input model

    Energy Technology Data Exchange (ETDEWEB)

    Morris, D.G.; Wendel, M.W.

    1993-01-01

    A thermal-hydraulic computational model of the High Flux Isotope Reactor (HFIR) has been developed using the RELAP5 program. The purpose of the model is to provide a state-of-the art thermal-hydraulic simulation tool for analyzing selected hypothetical accident scenarios for a revised HFIR Safety Analysis Report (SAR). The model includes (1) a detailed representation of the reactor core and other vessel components, (2) three heat exchanger/pump cells, (3) pressurizing pumps and letdown valves, and (4) secondary coolant system (with less detail than the primary system). Data from HFIR operation, component tests, tests in facility mockups and the HFIR, HFIR specific experiments, and other pertinent experiments performed independent of HFIR were used to construct the model and validate it to the extent permitted by the data. The detailed version of the model has been used to simulate loss-of-coolant accidents (LOCAs), while the abbreviated version has been developed for the operational transients that allow use of a less detailed nodalization. Analysis of station blackout with core long-term decay heat removal via natural convection has been performed using the core and vessel portions of the detailed model.

  7. Decommissioning of the High Flux Beam Reactor at Brookhaven Lab

    Energy Technology Data Exchange (ETDEWEB)

    Hu, J. P. [Brookhaven National Lab. (BNL), Upton, NY (United States); Reciniello, R. N. [Brookhaven National Lab. (BNL), Upton, NY (United States); Holden, N. E. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2011-05-27

    The High Flux Beam Reactor at the Brookhaven National Laboratory was a heavy water cooled and moderated reactor that achieved criticality on October 31, 1965. It operated at a power level of 40 mega-watts. An equipment upgrade in 1982 allowed operations at 60 mega-watts. After a 1989 reactor shutdown to reanalyze safety impact of a hypothetical loss of coolant accident, the reactor was restarted in 1991 at 30 mega-watts. The HFBR was shutdown in December 1996 for routine maintenance and refueling. At that time, a leak of tritiated water was identified by routine sampling of ground water from wells located adjacent to the reactor’s spent fuel pool. The reactor remained shutdown for almost three years for safety and environmental reviews. In November 1999 the United States Department of Energy decided to permanently shutdown the HFBR. The decontamination and decommissioning of the HFBR complex, consisting of multiple structures and systems to operate and maintain the reactor, were complete in 2009 after removing and shipping off all the control rod blades. The emptied and cleaned HFBR dome which still contains the irradiated reactor vessel is presently under 24/7 surveillance for safety. Details of the HFBR cleanup conducted during 1999-2009 will be described in the paper.

  8. Decommissioning of the high flux beam reactor at Brookhaven Lab

    Energy Technology Data Exchange (ETDEWEB)

    Hu, J.P. [National Synchrotron Light Source, Brookhaven Laboratory, Upton, NY 11973 (United States); Reciniello, R.N. [Radiological Control Div., Brookhaven Laboratory, Upton, NY 11973 (United States); Holden, N.E. [National Nuclear Data Center, Brookhaven Laboratory, Upton, NY 11973 (United States)

    2011-07-01

    The high-flux beam reactor (HFBR) at the Brookhaven National Laboratory was a heavy water cooled and moderated reactor that achieved criticality on Oct. 31, 1965. It operated at a power level of 40 megawatts. An equipment upgrade in 1982 allowed operations at 60 megawatts. After a 1989 reactor shutdown to reanalyze safety impact of a hypothetical loss of coolant accident, the reactor was restarted in 1991 at 30 megawatts. The HFBR was shut down in December 1996 for routine maintenance and refueling. At that time, a leak of tritiated water was identified by routine sampling of groundwater from wells located adjacent to the reactor's spent fuel pool. The reactor remained shut down for almost three years for safety and environmental reviews. In November 1999 the United States Dept. of Energy decided to permanently shut down the HFBR. The decontamination and decommissioning of the HFBR complex, consisting of multiple structures and systems to operate and maintain the reactor, were complete in 2009 after removing and shipping off all the control rod blades. The emptied and cleaned HFBR dome, which still contains the irradiated reactor vessel, is presently under 24/7 surveillance for safety. Detailed dosimetry performed for the HFBR decommissioning during 1996-2009 is described in the paper. (authors)

  9. No snow for Christmas: the impact of the 2015 extreme winter on CO2 fluxes in European mountain grasslands

    Science.gov (United States)

    Cremonese, Edoardo; Galvagno, Marta; Hammerle, Albin; Filippa, Gianluca; Wohlfahrt, Georg

    2016-04-01

    The increasing frequency in extreme climate events is very likely to impact the Alps since this region is characterized by very sensitive ecosystems. Typical alpine ecosystems such as mountain grasslands, show a strong seasonality in carbon uptake and release mostly driven by the onset and the end of the snow season. Extreme climate events, such as long warm and/or dry periods, could change typical snow cover temporal pattern, thereby altering the duration of the period of CO2 uptake and release. In recent years many studies have analyzed the impact of delayed or anticipated snowmelt on alpine plant phenology, growth and carbon cycling. However, little is known on the effects of a delayed onset of the snow season. During 2015 the whole planet witnessed several record-breaking warm spells which exceptionally warmed the Alps where the temperature anomaly reached +4°C during both the autumn and winter periods. In particular, the onset of the 2015 winter in the Alps was marked by one of the most prolonged lack of snow in years. In this study, we investigate and discuss the impact of the altered temperature and precipitation pattern during the autumn/winter 2015 on the net ecosystem CO2 exchange of mountain grasslands at high and low altitudes measured by means of the eddy covariance method. In particular we test the following hypotheses: (i) The presence of a snowpack impedes plant photosynthesis, while without a snowpack, plant net CO2 uptake may be possible even during wintertime provided temperatures are warm enough. (ii) Below a snowpack, soil temperatures are around zero degrees Celsius, allowing for microbial activity resulting in intermediate soil respiration; without a snow cover soil temperatures may be either lower or higher than zero degrees Celsius, decreasing or increasing soil respiration. The magnitude and direction of the net ecosystem CO2 exchange of mountain grassland ecosystems is governed by the complex interplay of the factors addressed in

  10. Anisotropic flux pinning in high T{sub c} superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Kolesnik, S. [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, PL-02668, Warszawa (Poland); Igalson, J. [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, PL-02668, Warszawa (Poland); Skoskiewicz, T. [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, PL-02668, Warszawa (Poland); Szymczak, R. [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, PL-02668, Warszawa (Poland); Baran, M. [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, PL-02668, Warszawa (Poland); Pytel, K. [Institute of Atomic Energy, Swierk (Poland); Pytel, B. [Institute of Atomic Energy, Swierk (Poland)

    1995-02-09

    In this paper we present a comparison of the results of FC magnetization measurements on several Pb-Sr-(Y,Ca)-Cu-O crystals representing various levels of flux pinning. The pinning centers in our crystals have been set up during the crystal growth process or introduced by neutron irradiation. Some possible explanations of the observed effects, including surface barrier, flux-center distribution and sample-shape effects, are discussed. ((orig.)).

  11. Spontaneous synthesis of carbon nanowalls, nanotubes and nanotips using high flux density plasmas

    NARCIS (Netherlands)

    Bystrov, K.; M. C. M. van de Sanden,; Arnas, C.; Marot, L.; Mathys, D.; Liu, F.; L.K. Xu,; X.B. Li,; A.V. Shalpegin,; De Temmerman, G.

    2014-01-01

    We have investigated the formation of various carbon nanostructures using extreme plasma fluxes up to four orders of magnitude larger than in conventional plasma-enhanced chemical vapor deposition processing. Carbon nanowalls, multi-wall nanotubes, spherical nanoparticles and nanotips are among the

  12. High Resolution Simulation of a Colorado Rockies Extreme Snow and Rain Event in both a Current and Future Climate

    Science.gov (United States)

    Rasmussen, Roy; Ikeda, Kyoko; Liu, Changhai; Gutmann, Ethan; Gochis, David

    2016-04-01

    Modeling of extreme weather events often require very finely resolved treatment of atmospheric circulation structures in order to produce and localize the large moisture fluxes that result in extreme precipitation. This is particularly true for cool season orographic precipitation processes where the representation of the landform can significantly impact vertical velocity profiles and cloud moisture entrainment rates. This study presents results for high resolution regional climate modeling study of the Colorado Headwaters region using an updated version of the Weather Research and Forecasting (WRF) model run at 4 km horizontal resolution and a hydrological extension package called WRF-Hydro. Previous work has shown that the WRF modeling system can produce credible depictions of winter orographic precipitation over the Colorado Rockies if run at horizontal resolutions warming on total precipitation, snow-rain partitioning and surface hydrological fluxes (evapotranspiration and runoff) will be discussed in the context of how potential changes in temperature impact the amount of precipitation, the phase of precipitation (rain vs. snow) and the timing and amplitude of streamflow responses. The results show using the Pseudo Global Warming technique that intense precipitation rates significantly increased during the event and a significant fraction of the snowfall converts to rain which significantly amplifies the runoff response from one where runoff is produced gradually to one in which runoff is rapidly translated into streamflow values that approach significant flooding risks. Results from a new, CONUS scale high resolution climate simulation of extreme events in a current and future climate will be presented as time permits.

  13. Surface morphology and deuterium retention in tungsten exposed to high flux D plasma at high temperatures

    NARCIS (Netherlands)

    Jia, Y. Z.; De Temmerman, G.; Luo, G. N.; Xu, H.Y.; Li, C.; Fu, B. Q.; Liu, W.

    2015-01-01

    Surface modifications and deuterium retention induced in tungsten by high fluxes (1024 m−2 s−1) low energy (38 eV) deuterium ions were studied as a function of surface temperature. Blister formation was studied by scanning electron microscopy and electron backscatter diffraction, while deuterium ret

  14. Bright high-repetition-rate source of narrowband extreme-ultraviolet harmonics beyond 22 eV

    Energy Technology Data Exchange (ETDEWEB)

    Wang, He [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Xu, Yiming [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Ulonska, Stefan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Robinson, Joseph S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Ranitovic, Predrag [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Kaindl, Robert A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division

    2015-06-11

    Novel table-top sources of extreme-ultraviolet light based on high-harmonic generation yield unique insight into the fundamental properties of molecules, nanomaterials or correlated solids, and enable advanced applications in imaging or metrology. Extending high-harmonic generation to high repetition rates portends great experimental benefits, yet efficient extreme-ultraviolet conversion of correspondingly weak driving pulses is challenging. In this article, we demonstrate a highly-efficient source of femtosecond extreme-ultraviolet pulses at 50-kHz repetition rate, utilizing the ultraviolet second-harmonic focused tightly into Kr gas. In this cascaded scheme, a photon flux beyond ≈3 × 1013 s-1 is generated at 22.3 eV, with 5 × 10-5 conversion efficiency that surpasses similar harmonics directly driven by the fundamental by two orders-of-magnitude. The enhancement arises from both wavelength scaling of the atomic dipole and improved spatio-temporal phase matching, confirmed by simulations. Finally, spectral isolation of a single 72-meV-wide harmonic renders this bright, 50-kHz extreme-ultraviolet source a powerful tool for ultrafast photoemission, nanoscale imaging and other applications.

  15. High-resolution Sonographic Measurements of Lower Extremity Bursae in Chinese Healthy Young Men

    Directory of Open Access Journals (Sweden)

    Yong-Yan Gao

    2016-01-01

    Conclusions: Using HR-US imaging, we were able to analyze lower extremity bursae with high detection rates in healthy young men. The normal ranges of lower extremity bursa dimensions in healthy young men measured by HR-US in this study could be used as reference values for evaluation of bursa abnormalities in the lower extremity.

  16. High resolution simulations of extreme weather event in south Sardinia

    Science.gov (United States)

    Dessy, C.

    2010-05-01

    In the last decade, like most region of Mediterranean Europe, Sardinia has experienced severe precipitation events generating flash floods resulting in loss of lives and large economic damage. A numerical meteorological operational set-up is applied in the local weather service with the aim to improve the operational short range weather forecast of the Service with particular attention to intense, mostly rare and potentially severe, events. On the early hours of 22 October 2008 an intense and almost stationary mesoscale convective system interested particularly the south of Sardinia, heavy precipitation caused a flash flood with fatalities and numerous property damages. The event was particularly intense: about 400 mm of rain in 12 hours (a peak of 150 mm in an hour) were misured by the regional network of weather stations and these values appear extremely meaningfulls since those are about seven times the climatological monthly rainfall for that area and nearly the climatological annual rainfall. With the aim to improve significantly quantitative precipitation forecasting, it was evaluated a different set-up of a high resolution convection resolving model (MM5) initialised with different initial and boundary conditions (ECMWF and NCAR). In this paper it is discussed the meteorological system related to the mentioned event by using different numerical weather models (GCM and LAM) combined with conventional data, radar Doppler and Meteosat images. Preliminary results say that a different set-up of a non hydrostatic model can forecast severe convection events in advance of about one day and produce more realistic rainfall than that current operational and also improve the weather forecasts to respect the ECMWF-GCM. So it could drive an operational alert system in order to limit the risks associated with heavy precipitation events.

  17. Autonomous, high-resolution observations of particle flux in the oligotrophic ocean

    Directory of Open Access Journals (Sweden)

    M. L. Estapa

    2013-01-01

    Full Text Available Observational gaps limit our understanding of particle flux attenuation through the upper mesopelagic because available measurements (sediment traps and radiochemical tracers have limited temporal resolution, are labor-intensive, and require ship support. Here, we conceptually evaluate an autonomous, optical proxy-based method for high-resolution observations of particle flux. We present four continuous records of particle flux collected with autonomous, profiling floats in the western Sargasso Sea and the subtropical North Pacific, as well as one shorter record of depth-resolved particle flux near the Bermuda Atlantic Timeseries Study (BATS and Oceanic Flux Program (OFP sites. These observations illustrate strong variability in particle flux over very short (~1 day timescales, but at longer timescales they reflect patterns of variability previously recorded during sediment trap timeseries. While particle flux attenuation at BATS/OFP agreed with the canonical power-law model when observations were averaged over a month, flux attenuation was highly variable on timescales of 1–3 days. Particle fluxes at different depths were decoupled from one another and from particle concentrations and chlorophyll fluorescence in the immediately-overlying surface water, consistent with horizontal advection of settling particles. We finally present an approach for calibrating this optical proxy in units of carbon flux, discuss in detail the related, inherent physical and optical assumptions, and look forward toward the requirements for the quantitative application of this method in highly time-resolved studies of particle export and flux attenuation.

  18. Autonomous, high-resolution observations of particle flux in the oligotrophic ocean

    Directory of Open Access Journals (Sweden)

    M. L. Estapa

    2013-08-01

    Full Text Available Observational gaps limit our understanding of particle flux attenuation through the upper mesopelagic because available measurements (sediment traps and radiochemical tracers have limited temporal resolution, are labor-intensive, and require ship support. Here, we conceptually evaluate an autonomous, optical proxy-based method for high-resolution observations of particle flux. We present four continuous records of particle flux collected with autonomous profiling floats in the western Sargasso Sea and the subtropical North Pacific, as well as one shorter record of depth-resolved particle flux near the Bermuda Atlantic Time-series Study (BATS and Oceanic Flux Program (OFP sites. These observations illustrate strong variability in particle flux over very short (~1-day timescales, but at longer timescales they reflect patterns of variability previously recorded during sediment trap time series. While particle flux attenuation at BATS/OFP agreed with the canonical power-law model when observations were averaged over a month, flux attenuation was highly variable on timescales of 1–3 days. Particle fluxes at different depths were decoupled from one another and from particle concentrations and chlorophyll fluorescence in the immediately overlying surface water, consistent with horizontal advection of settling particles. We finally present an approach for calibrating this optical proxy in units of carbon flux, discuss in detail the related, inherent physical and optical assumptions, and look forward toward the requirements for the quantitative application of this method in highly time-resolved studies of particle export and flux attenuation.

  19. Critical Heat Flux Phenomena at HighPressure & Low Mass Fluxes: NEUP Final Report Part I: Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Corradini, Michael [Univ. of Wisconsin, Madison, WI (United States); Wu, Qiao [Oregon State Univ., Corvallis, OR (United States)

    2015-04-30

    This report is a preliminary document presenting an overview of the Critical Heat Flux (CHF) phenomenon, the High Pressure Critical Heat Flux facility (HPCHF), preliminary CHF data acquired, and the future direction of the research. The HPCHF facility has been designed and built to study CHF at high pressure and low mass flux ranges in a rod bundle prototypical of conceptual Small Modular Reactor (SMR) designs. The rod bundle is comprised of four electrically heated rods in a 2x2 square rod bundle with a prototypic chopped-cosine axial power profile and equipped with thermocouples at various axial and circumferential positions embedded in each rod for CHF detection. Experimental test parameters for CHF detection range from pressures of ~80 – 160 bar, mass fluxes of ~400 – 1500 kg/m2s, and inlet water subcooling from ~30 – 70°C. The preliminary data base established will be further extended in the future along with comparisons to existing CHF correlations, models, etc. whose application ranges may be applicable to the conditions of SMRs.

  20. High flux isotope reactor cold source preconceptual design study report

    Energy Technology Data Exchange (ETDEWEB)

    Selby, D.L.; Bucholz, J.A.; Burnette, S.E. [and others

    1995-12-01

    In February 1995, the deputy director of Oak Ridge National Laboratory (ORNL) formed a group to examine the need for upgrades to the High Flux Isotope Reactor (HFIR) system in light of the cancellation of the Advanced Neutron Source Project. One of the major findings of this study was that there was an immediate need for the installation of a cold neutron source facility in the HFIR complex. The anticipated cold source will consist of a cryogenic LH{sub 2} moderator plug, a cryogenic pump system, a refrigerator that uses helium gas as a refrigerant, a heat exchanger to interface the refrigerant with the hydrogen loop, liquid hydrogen transfer lines, a gas handling system that includes vacuum lines, and an instrumentation and control system to provide constant system status monitoring and to maintain system stability. The scope of this project includes the development, design, safety analysis, procurement/fabrication, testing, and installation of all of the components necessary to produce a working cold source within an existing HFIR beam tube. This project will also include those activities necessary to transport the cold neutron beam to the front face of the present HFIR beam room. The cold source project has been divided into four phases: (1) preconceptual, (2) conceptual design and research and development (R and D), (3) detailed design and procurement, and (4) installation and operation. This report marks the conclusion of the preconceptual phase and establishes the concept feasibility. The information presented includes the project scope, the preliminary design requirements, the preliminary cost and schedule, the preliminary performance data, and an outline of the various plans for completing the project.

  1. Level 1 Tornado PRA for the High Flux Beam Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Bozoki, G.E.; Conrad, C.S.

    1994-05-01

    This report describes a risk analysis primarily directed at providing an estimate for the frequency of tornado induced damage to the core of the High Flux Beam Reactor (HFBR), and thus it constitutes a Level 1 Probabilistic Risk Assessment (PRA) covering tornado induced accident sequences. The basic methodology of the risk analysis was to develop a ``tornado specific`` plant logic model that integrates the internal random hardware failures with failures caused externally by the tornado strike and includes operator errors worsened by the tornado modified environment. The tornado hazard frequency, as well as earlier prepared structural and equipment fragility data, were used as input data to the model. To keep modeling/calculational complexity as simple as reasonable a ``bounding`` type, slightly conservative, approach was applied. By a thorough screening process a single dominant initiating event was selected as a representative initiator, defined as: ``Tornado Induced Loss of Offsite Power.`` The frequency of this initiator was determined to be 6.37E-5/year. The safety response of the HFBR facility resulted in a total Conditional Core Damage Probability of .621. Thus, the point estimate of the HFBR`s Tornado Induced Core Damage Frequency (CDF) was found to be: (CDF){sub Tornado} = 3.96E-5/year. This value represents only 7.8% of the internal CDF and thus is considered to be a small contribution to the overall facility risk expressed in terms of total Core Damage Frequency. In addition to providing the estimate of (CDF){sub Tornado}, the report documents, the relative importance of various tornado induced system, component, and operator failures that contribute most to (CDF){sub Tornado}.

  2. High speed digital phonoscopy of selected extreme vocalization (Conference Presentation)

    Science.gov (United States)

    Izdebski, Krzysztof; Blanco, Matthew; Di Lorenzo, Enrico; Yan, Yuling

    2017-02-01

    We used HSDP (KayPENTAX Model 9710, NJ, USA) to capture the kinematics of vocal folds in the production of extreme vocalization used by heavy metal performers. The vibrations of the VF were captured at 4000 f/s using transoral rigid scope. Growl, scream and inhalatory phonations were recoded. Results showed that these extreme sounds are produced predominantly by supraglottic tissues rather than by the true vocal folds, which explains while these sounds do not injure the mucosa of the true vocal folds. In addition, the HSDI were processed using custom software (Vocalizer®) that clearly demonstrated the contribution of each vocal fold to the generation of the sound.

  3. Inelastic X-ray scattering experiments at extreme conditions: high temperatures and high pressures

    Directory of Open Access Journals (Sweden)

    S.Hosokawa

    2008-03-01

    Full Text Available In this article, we review the present status of experimental techniques under extreme conditions of high temperature and high pressure used for inelastic X-ray scattering (IXS experiments of liquid metals, semiconductors, molten salts, molecular liquids, and supercritical water and methanol. For high temperature experiments, some types of single-crystal sapphire cells were designed depending on the temperature of interest and the sample thickness for the X-ray transmission. Single-crystal diamond X-ray windows attached to the externally heated high-pressure vessel were used for the IXS experiment of supercritical water and methanol. Some typical experimental results are also given, and the perspective of IXS technique under extreme conditions is discussed.

  4. Neutron-diffraction investigations of flux-lines in superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Forgan, E.M. [Birmingham Univ. (United Kingdom); Lee, S.L. [Saint Andrews Univ. (United Kingdom); McKPaul, D. [Warwick Univ., Coventry (United Kingdom); Mook, H.A. [Oak Ridge National Lab., TN (United States); Cubitt, R. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)

    1997-04-01

    SANS has proved an extremely useful tool for investigating flux-line structures within the bulk of superconductors. With high-T{sub c} materials, the scattered intensities are weak, but careful measurements are giving important new information about flux lattices, flux pinning and flux-lattice melting. (author). 10 refs.

  5. Dissipative flux motion in high-temperature superconductors

    NARCIS (Netherlands)

    Palstra, T.T.M.; Batlogg, B.; Dover, R.B. van; Schneemeyer, L.F.; Waszczak, J.V.

    1990-01-01

    The dissipation below Tc has been studied for representatives of all classes of cuprate hightemperature superconductors, including Ba2YCu3O7–δ, and Bi and Tl compounds. The results are parametrized in the framework of flux creep, with the largest activation energies found in Ba2YCu3O7. It is argued

  6. Surface morphology and deuterium retention in tungsten exposed to high flux D plasma at high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Y.Z. [Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); De Temmerman, G. [FOM Institute DIFFER-Dutch Institute for Fundamental Energy Research, Edisonbaan 14, 3439 MN Nieuwegein (Netherlands); ITER Organization, Route de Vinon-sur-Verdon-CS90046, 13067 St Paul Lez Durance Cedex (France); Luo, G.-N. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Xu, H.Y. [Science and Technology on Surface Physics and Chemistry Laboratory, Mianyang, Sichuan 621907 (China); Li, C.; Fu, B.Q. [Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Liu, W., E-mail: liuw@mail.tsinghua.edu.cn [Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2015-02-15

    Surface modifications and deuterium retention induced in tungsten by high fluxes (10{sup 24} m{sup −2} s{sup −1}) low energy (38 eV) deuterium ions were studied as a function of surface temperature. Blister formation was studied by scanning electron microscopy and electron backscatter diffraction, while deuterium retention was measured by thermal desorption spectroscopy. Blisters are observed on the surface exposed at different temperatures, ranging from 493 K to 1273 K. The blister density and D retention decrease with the increasing exposure temperature. The formation of blisters at high temperatures is attributed to the high flux of D plasma. At 943 K, with the increasing fluence, there is trend to the saturation of D retention and blister density. The defects caused by plasma exposure have an important effect on the D trapping and blistering behavior. The formation of blisters has a strong relationship with slipping system of tungsten.

  7. High Flux Isotopes Reactor (HFIR) Cooling Towers Demolition Waste Management

    Energy Technology Data Exchange (ETDEWEB)

    Pudelek, R. E.; Gilbert, W. C.

    2002-02-26

    This paper describes the results of a joint initiative between Oak Ridge National Laboratory, operated by UT-Battelle, and Bechtel Jacobs Company, LLC (BJC) to characterize, package, transport, treat, and dispose of demolition waste from the High Flux Isotope Reactor (HFIR), Cooling Tower. The demolition and removal of waste from the site was the first critical step in the planned HFIR beryllium reflector replacement outage scheduled. The outage was scheduled to last a maximum of six months. Demolition and removal of the waste was critical because a new tower was to be constructed over the old concrete water basin. A detailed sampling and analysis plan was developed to characterize the hazardous and radiological constituents of the components of the Cooling Tower. Analyses were performed for Resource Conservation and Recovery Act (RCRA) heavy metals and semi-volatile constituents as defined by 40 CFR 261 and radiological parameters including gross alpha, gross beta, gross gamma, alpha-emitting isotopes and beta-emitting isotopes. Analysis of metals and semi-volatile constituents indicated no exceedances of regulatory limits. Analysis of radionuclides identified uranium and thorium and associated daughters. In addition 60Co, 99Tc, 226Rm, and 228Rm were identified. Most of the tower materials were determined to be low level radioactive waste. A small quantity was determined not to be radioactive, or could be decontaminated. The tower was dismantled October 2000 to January 2001 using a detailed step-by-step process to aid waste segregation and container loading. The volume of waste as packaged for treatment was approximately 1982 cubic meters (70,000 cubic feet). This volume was comprised of plastic ({approx}47%), wood ({approx}38%) and asbestos transite ({approx}14%). The remaining {approx}1% consisted of the fire protection piping (contaminated with lead-based paint) and incidental metal from conduit, nails and braces/supports, and sludge from the basin. The waste

  8. Countercurrent flow limited (CCFL) heat flux in the high flux isotope reactor (HFIR) fuel element

    Energy Technology Data Exchange (ETDEWEB)

    Ruggles, A.E.

    1990-10-12

    The countercurrent flow (CCF) performance in the fuel element region of the HFIR is examined experimentally and theoretically. The fuel element consists of two concentric annuli filled with aluminum clad fuel plates of 1.27 mm thickness separated by 1.27 mm flow channels. The plates are curved as they go radially outward to accomplish constant flow channel width and constant metal-to-coolant ratio. A full-scale HFIR fuel element mock-up is studied in an adiabatic air-water CCF experiment. A review of CCF models for narrow channels is presented along with the treatment of CCFs in system of parallel channels. The experimental results are related to the existing models and a mechanistic model for the annular'' CCF in a narrow channel is developed that captures the data trends well. The results of the experiment are used to calculate the CCFL heat flux of the HFIR fuel assembly. It was determined that the HFIR fuel assembly can reject 0.62 Mw of thermal power in the CCFL situation. 31 refs., 17 figs.

  9. Development of advanced high heat flux and plasma-facing materials

    Science.gov (United States)

    Linsmeier, Ch.; Rieth, M.; Aktaa, J.; Chikada, T.; Hoffmann, A.; Hoffmann, J.; Houben, A.; Kurishita, H.; Jin, X.; Li, M.; Litnovsky, A.; Matsuo, S.; von Müller, A.; Nikolic, V.; Palacios, T.; Pippan, R.; Qu, D.; Reiser, J.; Riesch, J.; Shikama, T.; Stieglitz, R.; Weber, T.; Wurster, S.; You, J.-H.; Zhou, Z.

    2017-09-01

    Plasma-facing materials and components in a fusion reactor are the interface between the plasma and the material part. The operational conditions in this environment are probably the most challenging parameters for any material: high power loads and large particle and neutron fluxes are simultaneously impinging at their surfaces. To realize fusion in a tokamak or stellarator reactor, given the proven geometries and technological solutions, requires an improvement of the thermo-mechanical capabilities of currently available materials. In its first part this article describes the requirements and needs for new, advanced materials for the plasma-facing components. Starting points are capabilities and limitations of tungsten-based alloys and structurally stabilized materials. Furthermore, material requirements from the fusion-specific loading scenarios of a divertor in a water-cooled configuration are described, defining directions for the material development. Finally, safety requirements for a fusion reactor with its specific accident scenarios and their potential environmental impact lead to the definition of inherently passive materials, avoiding release of radioactive material through intrinsic material properties. The second part of this article demonstrates current material development lines answering the fusion-specific requirements for high heat flux materials. New composite materials, in particular fiber-reinforced and laminated structures, as well as mechanically alloyed tungsten materials, allow the extension of the thermo-mechanical operation space towards regions of extreme steady-state and transient loads. Self-passivating tungsten alloys, demonstrating favorable tungsten-like plasma-wall interaction behavior under normal operation conditions, are an intrinsic solution to otherwise catastrophic consequences of loss-of-coolant and air ingress events in a fusion reactor. Permeation barrier layers avoid the escape of tritium into structural and cooling

  10. Time Exceedances for High Intensity Solar Proton Fluxes

    Science.gov (United States)

    Xapsos, Michael A.; Stauffer, Craig A.; Jordan, Thomas M.; Adam, James H., Jr.; Dietrich, William F.

    2011-01-01

    A model is presented for times during a space mission that specified solar proton flux levels are exceeded. This includes both total time and continuous time periods during missions. Results for the solar maximum and solar minimum phases of the solar cycle are presented and compared for a broad range of proton energies and shielding levels. This type of approach is more amenable to reliability analysis for spacecraft systems and instrumentation than standard statistical models.

  11. High Flux, Fouling Resistant Membranes for RO Pretreatment

    Science.gov (United States)

    2012-05-31

    improved flux and fouling resistance . This in turn will lead to more compact and efficient filtration systems that reduce maintenance and downtime...size, and resistance to protein fouling by BSA filtration . Hollow Fiber Development and Testing Hollow fibers were produced by a generally...layer during dead- end filtration . The shear forces in cross-flow operation can impact the effective particle size in the feed and compact the cake

  12. Reliability of High I/O High Density CCGA Interconnect Electronic Packages under Extreme Thermal Environment

    Science.gov (United States)

    Ramesham, Rajeshuni

    2012-01-01

    This paper provides the experimental test results of advanced CCGA packages tested in extreme temperature thermal environments. Standard optical inspection and x-ray non-destructive inspection tools were used to assess the reliability of high density CCGA packages for deep space extreme temperature missions. Ceramic column grid array (CCGA) packages have been increasing in use based on their advantages such as high interconnect density, very good thermal and electrical performances, compatibility with standard surface-mount packaging assembly processes, and so on. CCGA packages are used in space applications such as in logic and microprocessor functions, telecommunications, payload electronics, and flight avionics. As these packages tend to have less solder joint strain relief than leaded packages or more strain relief over lead-less chip carrier packages, the reliability of CCGA packages is very important for short-term and long-term deep space missions. We have employed high density CCGA 1152 and 1272 daisy chained electronic packages in this preliminary reliability study. Each package is divided into several daisy-chained sections. The physical dimensions of CCGA1152 package is 35 mm x 35 mm with a 34 x 34 array of columns with a 1 mm pitch. The dimension of the CCGA1272 package is 37.5 mm x 37.5 mm with a 36 x 36 array with a 1 mm pitch. The columns are made up of 80% Pb/20%Sn material. CCGA interconnect electronic package printed wiring polyimide boards have been assembled and inspected using non-destructive x-ray imaging techniques. The assembled CCGA boards were subjected to extreme temperature thermal atmospheric cycling to assess their reliability for future deep space missions. The resistance of daisy-chained interconnect sections were monitored continuously during thermal cycling. This paper provides the experimental test results of advanced CCGA packages tested in extreme temperature thermal environments. Standard optical inspection and x-ray non

  13. Reliability of High I/O High Density CCGA Interconnect Electronic Packages under Extreme Thermal Environment

    Science.gov (United States)

    Ramesham, Rajeshuni

    2012-01-01

    This paper provides the experimental test results of advanced CCGA packages tested in extreme temperature thermal environments. Standard optical inspection and x-ray non-destructive inspection tools were used to assess the reliability of high density CCGA packages for deep space extreme temperature missions. Ceramic column grid array (CCGA) packages have been increasing in use based on their advantages such as high interconnect density, very good thermal and electrical performances, compatibility with standard surface-mount packaging assembly processes, and so on. CCGA packages are used in space applications such as in logic and microprocessor functions, telecommunications, payload electronics, and flight avionics. As these packages tend to have less solder joint strain relief than leaded packages or more strain relief over lead-less chip carrier packages, the reliability of CCGA packages is very important for short-term and long-term deep space missions. We have employed high density CCGA 1152 and 1272 daisy chained electronic packages in this preliminary reliability study. Each package is divided into several daisy-chained sections. The physical dimensions of CCGA1152 package is 35 mm x 35 mm with a 34 x 34 array of columns with a 1 mm pitch. The dimension of the CCGA1272 package is 37.5 mm x 37.5 mm with a 36 x 36 array with a 1 mm pitch. The columns are made up of 80% Pb/20%Sn material. CCGA interconnect electronic package printed wiring polyimide boards have been assembled and inspected using non-destructive x-ray imaging techniques. The assembled CCGA boards were subjected to extreme temperature thermal atmospheric cycling to assess their reliability for future deep space missions. The resistance of daisy-chained interconnect sections were monitored continuously during thermal cycling. This paper provides the experimental test results of advanced CCGA packages tested in extreme temperature thermal environments. Standard optical inspection and x-ray non

  14. Effect of extremely low frequency electromagnetic field exposure on sleep quality in high voltage substations.

    Science.gov (United States)

    Barsam, Tayebeh; Monazzam, Mohammad Reza; Haghdoost, Ali Akbar; Ghotbi, Mohammad Reza; Dehghan, Somayeh Farhang

    2012-11-30

    This study aims to investigate the effect of extremely low frequency electromagnetic fields exposure on sleep quality in high voltage substations (132, 230 and 400 KV) in Kerman city and the suburbs. For this purpose, the electric field intensity and magnetic flux density were measured in different parts of substations, and then the occupational exposure was estimated by averaging electric field intensity and magnetic flux density in a shift work. The cases comprised 67 workers who had been exposed to electromagnetic fields in age range of 24-57 and the controls were 110 persons the age ranged 24-50 years. Sleep quality of both groups was evaluated by the Pittsburgh Sleep Quality Index questionnaire (PSQI). Finally, these data were subjected to statistical analysis. The results indicated that 90.5% of cases and 85.3% of controls had the poor quality sleep according to PSQI (P-value=0.615). Total sleep quality score mean for the case and control groups were 10.22 ± 3.4 and 9.74 ± 3.62 (P-value=0.415) ,respectively. Meantime to fall asleep for cases(35.68 ± 26.25 min) was significantly higher than for controls (28.89 ± 20.18 min) (P-value=0.002). Cases had average sleep duration of 5.49 ± 1.31 hours, which was lower ascompared with control subjects (5.90 ± 1.67hours). Although there was a higher percentage for the case group with poor sleep quality than the control group, but no statistically significant difference was observed.

  15. Effect of extremely low frequency electromagnetic field exposure on sleep quality in high voltage substations

    Directory of Open Access Journals (Sweden)

    Barsam Tayebeh

    2012-11-01

    Full Text Available Abstract This study aims to investigate the effect of extremely low frequency electromagnetic fields exposure on sleep quality in high voltage substations (132, 230 and 400 KV in Kerman city and the suburbs. For this purpose, the electric field intensity and magnetic flux density were measured in different parts of substations, and then the occupational exposure was estimated by averaging electric field intensity and magnetic flux density in a shift work. The cases comprised 67 workers who had been exposed to electromagnetic fields in age range of 24–57 and the controls were 110 persons the age ranged 24–50 years. Sleep quality of both groups was evaluated by the Pittsburgh Sleep Quality Index questionnaire (PSQI. Finally, these data were subjected to statistical analysis. The results indicated that 90.5% of cases and 85.3% of controls had the poor quality sleep according to PSQI (P-value=0.615. Total sleep quality score mean for the case and control groups were 10.22 ± 3.4 and 9.74 ± 3.62 (P-value=0.415 ,respectively. Meantime to fall asleep for cases(35.68 ± 26.25 min was significantly higher than for controls (28.89 ± 20.18 min (P-value=0.002. Cases had average sleep duration of 5.49 ± 1.31 hours, which was lower ascompared with control subjects (5.90 ± 1.67hours. Although there was a higher percentage for the case group with poor sleep quality than the control group, but no statistically significant difference was observed.

  16. Effect of high-flux astronomical sources on the constellation-X microcalorimeter spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Figueroa-Feliciano, E. E-mail: enectali.figueroa@gsfc.nasa.gov; Bandler, S.; Boyce, K.; Chervenak, J.; Finkbeiner, F.; Kelley, R.; Lindeman, M.A.; Porter, S.F.; Saab, T.; Stahle, C.K

    2004-03-11

    We study the effects of high flux on transition-edge sensors by using a non-linear microcalorimeter model with parameters suitable for the Constellation-X mission. A photon event list was created that simulated the flux and spectrum of the Crab nebula incident on the detector when folded through the Constellation-X optics and filters. Simulations show that even at Crab levels of flux, the Con-X microcalorimeter does not 'latch' into the normal state.

  17. Instrument for thermal radiation flux measurement in high temperature gas flow (Cuernavaca instrument)

    Energy Technology Data Exchange (ETDEWEB)

    Afgan, N.H. [Universidade Tecnica, Lisbon (Portugal); Leontiev, A.I. [Moscow State Technical University (Russian Federation)

    1995-05-01

    A new instrument for hemispherical radiation heat flux measurement is proposed. It is based on the theory of blow of the boundary layer, taking into account that at the critical mass flow rate through the porous surface the thermal boundary layer is blown off and only radiation flux from high temperature gases reaches the porous surface. With the measurement of blow of gas flow and the temperature of the porous material, the respective heat flux is obtained. (author)

  18. Modelling deuterium release from tungsten after high flux high temperature deuterium plasma exposure

    Science.gov (United States)

    Grigorev, Petr; Matveev, Dmitry; Bakaeva, Anastasiia; Terentyev, Dmitry; Zhurkin, Evgeny E.; Van Oost, Guido; Noterdaeme, Jean-Marie

    2016-12-01

    Tungsten is a primary candidate for plasma facing materials for future fusion devices. An important safety concern in the design of plasma facing components is the retention of hydrogen isotopes. Available experimental data is vast and scattered, and a consistent physical model of retention of hydrogen isotopes in tungsten is still missing. In this work we propose a model of non-equilibrium hydrogen isotopes trapping under fusion relevant plasma exposure conditions. The model is coupled to a diffusion-trapping simulation tool and is used to interpret recent experiments involving high plasma flux exposures. From the computational analysis performed, it is concluded that high flux high temperature exposures (T = 1000 K, flux = 1024 D/m2/s and fluence of 1026 D/m2) result in generation of sub-surface damage and bulk diffusion, so that the retention is driven by both sub-surface plasma-induced defects (bubbles) and trapping at natural defects. On the basis of the non-equilibrium trapping model we have estimated the amount of H stored in the sub-surface region to be ∼10-5 at-1, while the bulk retention is about 4 × 10-7 at-1, calculated by assuming the sub-surface layer thickness of about 10 μm and adjusting the trap concentration to comply with the experimental results for the integral retention.

  19. Thermal barrier coatings (TBC's) for high heat flux thrust chambers

    Science.gov (United States)

    Bradley, Christopher M.

    -section components has become critical, but at the same time the service conditions have put our best alloy systems to their limits. As a result, implementation of cooling holes and thermal barrier coatings are new advances in hot-section technologies now looked at for modifications to reach higher temperature applications. Current thermal barrier coatings used in today's turbine applications is known as 8%yttria-stabilized zirconia (YSZ) and there are no coatings for current thrust chambers. Current research is looking at the applicability of 8%yttria-stabilized hafnia (YSH) for turbine applications and the implementation of 8%YSZ onto thrust chambers. This study intends to determine if the use of thermal barrier coatings are applicable for high heat flux thrust chambers using industrial YSZ will be advantageous for improvements in efficiency, thrust and longer service life by allowing the thrust chambers to be used more than once.

  20. A Review of Mold Flux Development for the Casting of High-Al Steels

    Science.gov (United States)

    Wang, Wanlin; Lu, Boxun; Xiao, Dan

    2016-02-01

    Mold flux plays key roles during the continuous casting process of molten steel, which accounts for the quality of final slabs. With the development of advanced high strength steels (AHSS), certain amounts of Al have been added into steels that would introduce severe slag/metal interaction problems during process of continuous casting. The reaction is between Al and SiO2 that is the major component in the mold flux system. Intensive efforts have been conducted to optimize the mold flux and a CaO-Al2O3-based mold flux system has been proposed, which shows the potential to be applied for the casting process of AHSS. The latest developments for this new mold flux system were summarized with the aim to offer technical guidance for the design of new generation mold flux system for the casting of AHSS.

  1. Translational symmetry of high order tokamak flux surface shaping in gyrokinetics

    CERN Document Server

    Ball, Justin; Barnes, Michael

    2015-01-01

    A particular translational symmetry of the local nonlinear $\\delta f$ gyrokinetic model is demonstrated analytically and verified numerically. This symmetry shows that poloidally translating all the flux surface shaping effects with large poloidal mode number by a single tilt angle has an exponentially small effect on the transport properties of a tokamak. This is shown using a generalization of the Miller local equilibrium model to specify an arbitrary flux surface geometry. With this geometry specification we find that, when performing an expansion in large flux surface shaping mode number, the governing equations of gyrokinetics are symmetric in the poloidal translation of the high order shaping effects. This allows us to take the fluxes from a single configuration and calculate the fluxes in any configuration that can be produced by translating the large mode number shaping effects. This creates a distinction between tokamaks with mirror symmetric flux surfaces and tokamaks without mirror symmetry, which ...

  2. Extremely high frequency electromagnetic radiation enforces bacterial effects of inhibitors and antibiotics.

    Science.gov (United States)

    Tadevosyan, Hasmik; Kalantaryan, Vitaly; Trchounian, Armen

    2008-01-01

    The coherent electromagnetic radiation (EMR) of the frequency of 51.8 and 53 GHz with low intensity (the power flux density of 0.06 mW/cm(2)) affected the growth of Escherichia coli K12(lambda) under fermentation conditions: the lowering of the growth specific rate was considerably (approximately 2-fold) increased with exposure duration of 30-60 min; a significant decrease in the number of viable cells was also shown. Moreover, the enforced effects of the N,N'-dicyclohexylcarbodiimide (DCCD), inhibitor of H(+)-transporting F(0)F(1)-ATPase, on energy-dependent H(+) efflux by whole cells and of antibiotics like tetracycline and chloramphenicol on the following bacterial growth and survival were also determined after radiation. In addition, the lowering in DCCD-inhibited ATPase activity of membrane vesicles from exposed cells was defined. The results confirmed the input of membranous changes in bacterial action of low intensity extremely high frequency EMR, when the F(0)F(1)-ATPase is probably playing a key role. The radiation of bacteria might lead to changed metabolic pathways and to antibiotic resistance. It may also give bacteria with a specific role in biosphere.

  3. A high-flux BEC source for mobile atom interferometers

    CERN Document Server

    Rudolph, Jan; Grzeschik, Christoph; Sternke, Tammo; Grote, Alexander; Popp, Manuel; Becker, Dennis; Müntinga, Hauke; Ahlers, Holger; Peters, Achim; Lämmerzahl, Claus; Sengstock, Klaus; Gaaloul, Naceur; Ertmer, Wolfgang; Rasel, Ernst M

    2015-01-01

    Quantum sensors based on coherent matter-waves are precise measurement devices whose ultimate accuracy is achieved with Bose-Einstein condensates (BEC) in extended free fall. This is ideally realized in microgravity environments such as drop towers, ballistic rockets and space platforms. However, the transition from lab-based BEC machines to robust and mobile sources with comparable performance is a technological challenge. Here we report on the realization of a miniaturized setup, generating a flux of $4 \\times 10^5$ quantum degenerate $^{87}$Rb atoms every 1.6 s. Ensembles of $1 \\times 10^5$ atoms can be produced at a 1 Hz rate. This is achieved by loading a cold atomic beam directly into a multi-layer atom chip that is designed for efficient transfer from laser-cooled to magnetically trapped clouds. The attained flux of degenerate atoms is on par with current lab-based experiments while offering significantly higher repetition rates. The compact and robust design allows for mobile operation in a variety of...

  4. Creep strength of iridium at extremely high temperatures; Zeitstandfestigkeit von Iridium bei extrem hohen Temperaturen

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, B. [Fachhochschule Jena (Germany). Fachbereich Werkstofftechnik; Lupton, D. [Heraeus (W.C.) GmbH, Hanau (Germany). Produktbereich Materialtechnik; Braun, F. [Heraeus (W.C.) GmbH, Hanau (Germany). Produktbereich Materialtechnik; Merker, J. [Jena Univ. (Germany). Technisches Inst.; Helmich, R. [Jena Univ. (Germany). Technisches Inst.

    1994-12-31

    On iridium in the initial state and after carrying out creep tests, apart from metallographic and fractographic work, investigations on the distribution of trace impurities were done by means of secondary ion mass spectroscopy and investigations of the crystal structure were carried out with the aid of Kossel technique, a special field of X-ray bending. Although iridium of high purity was used for the investigations, enrichment of hydrogen, carbon, sodium, potassium, calcium, magnesium, silicon, iron, nickel and chromium was proved by means of secondary ion mass spectroscopy at the grain boundaries, where the average contents in iridium were only about 1 {mu}g/g. In the creep test, creep fracture lines were found in the range of 1800 to 2300 C and about 0.5 to 12 hours on iridium samples with a square cross section of 1 mm. It follows from the results that this noble metal has a considerable resistance to heat at these temperatures, which makes its use up to 2300 C possible. (orig./RHM) [Deutsch] Es erfolgten am Iridium im Ausgangszustand und nach Durchfuehrung der Zeitstandversuche neben metallographischen und fraktographischen Arbeiten Untersuchungen zur Verteilung der Spurenverunreinigungen mittels Sekundaerionen-Massenspektroskopie sowie Untersuchungen der Kristallstruktur mit Hilfe der Kossel-Technik, einem Spezialgebiet der Roentgenbeugung. Obwohl fuer die Untersuchungen hochreines Iridium verwendet wurde, konnten mittels Sekundaerionen-Massenspektroskopie in den Korngrenzen Anreicherungen von Wasserstoff, Kohlenstoff, Natrium, Kalium, Calcium, Magnesium, Silizium, Eisen, Nickel und Chrom nachgewiesen werden, wobei die durchschnittlichen Gehalte in Iridium nur um 1 {mu}g/g lagen. Im Zeitstandversuch wurden an Iridiumproben mit 1 mm Vierkantquerschnitt Zeitbruchlinien im Bereich von 1800 bis 2300 C und etwa 0,5 bis 12 Stunden aufgenommen. Aus den Ergebnissen folgt, dass das Edelmetall bei diesen Temperaturen noch eine beachtliche Warmfestigkeit besitzt, die

  5. Development of in-vessel neutron flux monitor equipped with microfission chambers to withstand the extreme ITER environment

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, Masao, E-mail: ishikawa.masao@jaea.go.jp; Takeda, Keigo; Itami, Kiyoshi

    2016-11-01

    Highlights: • The in-vessel components of MFC system must withstand the extreme ITER environment. • To verify this, the thermal cycle test and the vibration tests were conducted. • Both tests were conducted under much severer conditions than ITER environment. • Soundness verification tests after the tests indicated that no problemswere found. • It is shown that the in-vessel component is sufficiently robust ITER environment. - Abstract: Via thermal cycling and vibration tests, this study aims to demonstrate that the in-vessel components of the microfission chamber (MFC) system can withstand the extreme International Thermonuclear Experimental Reactor (ITER) environment. In thermal cycle tests, the signal cable of the device was bent into a smaller radius and it was given more bends than those in its actual configuration within ITER. A faster rate of temperature change than that under the typical ITER baking scenario was then imposed on in-vessel components. For the vibration tests, strong 10 G vibrational accelerations with frequencies ranging from 30 Hz to 2000 Hz were imposed to the detector and the connector of the in-vessel components to simulate various types of electromagnetic events. Soundness verification tests of the in-vessel components conducted after thermal cycling and vibration testing indicated that problems related to the signal transmission cable functioning were not found. Thus, it was demonstrated that the in-vessel components of the MFC can withstand the extreme environment within ITER.

  6. Dissolution Flowsheet for High Flux Isotope Reactor Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Daniel, W. E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Rudisill, T. S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); O' Rourke, P. E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Karay, N. S [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-09-27

    As part of the Spent Nuclear Fuel (SNF) processing campaign, H-Canyon is planning to begin dissolving High Flux Isotope Reactor (HFIR) fuel in late FY17 or early FY18. Each HFIR fuel core contains inner and outer fuel elements which were fabricated from uranium oxide (U3O8) dispersed in a continuous Al phase using traditional powder metallurgy techniques. Fuels fabricated in this manner, like other SNF’s processed in H-Canyon, dissolve by the same general mechanisms with similar gas generation rates and the production of H2. The HFIR fuel cores will be dissolved and the recovered U will be down-blended into low-enriched U. HFIR fuel was previously processed in H-Canyon using a unique insert in both the 6.1D and 6.4D dissolvers. Multiple cores will be charged to the same dissolver solution maximizing the concentration of dissolved Al. The objective of this study was to identify flowsheet conditions through literature review and laboratory experimentation to safely and efficiently dissolve the HFIR fuel in H-Canyon. Laboratory-scale experiments were performed to evaluate the dissolution of HFIR fuel using both Al 1100 and Al 6061 T6 alloy coupons. The Al 1100 alloy was considered a representative surrogate which provided an upper bound on the generation of flammable (i.e., H2) gas during the dissolution process. The dissolution of the Al 6061 T6 alloy proceeded at a slower rate than the Al 1100 alloy and was used to verify that the target Al concentration in solution could be achieved for the selected Hg concentration. Mass spectrometry and Raman spectroscopy were used to provide continuous monitoring of the concentration of H2 and other permanent gases in the dissolution offgas allowing the development of H2 generation rate profiles. The H2 generation rates were subsequently used to evaluate if a full HFIR core could be dissolved in an H-Canyon dissolver without exceeding 60% of the calculated lower

  7. Dissolution Flowsheet for High Flux Isotope Reactor Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Daniel, W. E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Rudisill, T. S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); O' Rourke, P. E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Karay, N. S [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-09-27

    As part of the Spent Nuclear Fuel (SNF) processing campaign, H-Canyon is planning to begin dissolving High Flux Isotope Reactor (HFIR) fuel in late FY17 or early FY18. Each HFIR fuel core contains inner and outer fuel elements which were fabricated from uranium oxide (U3O8) dispersed in a continuous Al phase using traditional powder metallurgy techniques. Fuels fabricated in this manner, like other SNF’s processed in H-Canyon, dissolve by the same general mechanisms with similar gas generation rates and the production of H2. The HFIR fuel cores will be dissolved and the recovered U will be down-blended into low-enriched U. HFIR fuel was previously processed in H-Canyon using a unique insert in both the 6.1D and 6.4D dissolvers. Multiple cores will be charged to the same dissolver solution maximizing the concentration of dissolved Al. The objective of this study was to identify flowsheet conditions through literature review and laboratory experimentation to safely and efficiently dissolve the HFIR fuel in H-Canyon. Laboratory-scale experiments were performed to evaluate the dissolution of HFIR fuel using both Al 1100 and Al 6061 T6 alloy coupons. The Al 1100 alloy was considered a representative surrogate which provided an upper bound on the generation of flammable (i.e., H2) gas during the dissolution process. The dissolution of the Al 6061 T6 alloy proceeded at a slower rate than the Al 1100 alloy, and was used to verify that the target Al concentration in solution could be achieved for the selected Hg concentration. Mass spectrometry and Raman spectroscopy were used to provide continuous monitoring of the concentration of H2 and other permanent gases in the dissolution offgas, allowing the development of H2 generation rate profiles. The H2 generation rates were subsequently used to evaluate if a full HFIR core could be dissolved in an H-Canyon dissolver without exceeding 60% of the

  8. Accuracy of the post-Newtonian approximation. II. Optimal asymptotic expansion of the energy flux for quasicircular, extreme mass-ratio inspirals into a Kerr black hole

    CERN Document Server

    Zhang, Zhongyang; Berti, Emanuele

    2011-01-01

    We study the effect of black hole spin on the accuracy of the post-Newtonian approximation. We focus on the gravitational energy flux for the quasicircular, equatorial, extreme mass-ratio inspiral of a compact object into a Kerr black hole of mass M and spin J. For a given dimensionless spin a=J/M^2 (in geometrical units), the energy flux depends only on the orbital velocity v or (equivalently) on the Boyer-Lindquist orbital radius r. We investigate the formal region of validity of the Taylor post-Newtonian expansion of the energy flux (which is known up to order v^8 beyond the quadrupole formula), generalizing previous work by two of us. The "error function" used to determine the region of validity of the post-Newtonian expansion can have two qualitatively different kinds of behavior, and we deal with these two cases separately. We find that, at any fixed post-Newtonian order, the edge of the region of validity (as measured by v/v_{ISCO}, where v_{ISCO} is the orbital velocity at the innermost stable circula...

  9. Extremely short duration high intensity interval training substantially improves insulin action in young healthy males

    DEFF Research Database (Denmark)

    Babraj, John A; Vollaard, Niels B J; Keast, Cameron

    2009-01-01

    BACKGROUND: Traditional high volume aerobic exercise training reduces cardiovascular and metabolic disease risk but involves a substantial time commitment. Extremely low volume high-intensity interval training (HIT) has recently been demonstrated to produce improvements to aerobic function, but i...

  10. High precision, medium flux rate CZT spectroscopy for coherent scatter imaging

    Science.gov (United States)

    Greenberg, Joel A.; Hassan, Mehadi; Brady, David J.; Iniewski, Kris

    2016-05-01

    CZT detectors are primary candidates for many next-generation X-ray imaging systems. These detectors are typically operated in either a high precision, low flux spectroscopy mode or a low precision, high flux photon counting mode. We demonstrate a new detector configuration that enables operation in a high precision, medium flux spectroscopy mode, which opens the potential for a variety of new applications in medical imaging, non-destructive testing and baggage scanning. In particular, we describe the requirements of a coded aperture coherent scattering X-ray system that can perform fast imaging with accurate material discrimination.

  11. In-situ SEOP polarizer and initial tests on a high flux neutron beam

    Energy Technology Data Exchange (ETDEWEB)

    Babcock, E., E-mail: e.babcock@fz-juelich.d [Institut Laue Langevin, Grenoble (France); Jeulich Centre for Neutron Science, Garching (Germany); Boag, S. [ISIS, Chilton, Didcot, OX11 QX (United Kingdom); Andersen, K.H.; Becker, M. [Institut Laue Langevin, Grenoble (France); Beecham, C. [ISIS, Chilton, Didcot, OX11 QX (United Kingdom); Institut Laue Langevin, Grenoble (France); Bordenave, F.; Chastagnier, J. [Institut Laue Langevin, Grenoble (France); Chen, W.C. [NIST Gaithersburg, MD (United States); Chung, R. [Institut Laue Langevin, Grenoble (France); Chupp, T.E. [FOCUS, University of Michigan, Ann Arbor, MI (United States); Elmore, S. [ISIS, Chilton, Didcot, OX11 QX (United Kingdom); Fouilloux, P. [Institut Laue Langevin, Grenoble (France); Gentile, T.R. [NIST Gaithersburg, MD (United States); Jullien, D.; Lelievre-Berna, E.; Mouveau, P.; Petoukhov, A.; Revert, M.; Soldner, T. [Institut Laue Langevin, Grenoble (France)

    2009-09-01

    Polarized {sup 3}He has shown its unique characteristics in many areas of polarized neutron scattering, its ability to polarize neutrons at short wavelengths, accept wide-angle and divergent beams and low backgrounds enable new classes of experiments. While polarized {sup 3}He is not a steady state solution as commonly applied, the benefits have been shown to offset the drawbacks of polarizing and refreshing the polarization in the neutron spin filter cells. As an extension of this work, in-situ polarization using the spin-exchange optical pumping (SEOP) method was explored as a means to construct a system which could be used to polarize {sup 3}He in the state used for an effective neutron spin filter to constant polarization while on the neutron beam. An in-situ SEOP polarizer was constructed. This device utilized many devices and principles developed for neutron spin filters which are polarized off the beam line using either SEOP or metastability exchange optical pumping (MEOP) under the same research program. As a collimation of this work effects of extremely high neutron capture flux density >1x10{sup 10}cm{sup -2}s{sup -1} incident on the in-situ polarizer were explored.

  12. Compact high-flux source of cold sodium atoms

    Science.gov (United States)

    Lamporesi, G.; Donadello, S.; Serafini, S.; Ferrari, G.

    2013-06-01

    We present a compact source of cold sodium atoms suitable for the production of quantum degenerate gases and versatile for a multi-species experiment. The magnetic field produced by permanent magnets allows to simultaneously realize a Zeeman slower and a two-dimensional magneto-optical trap (MOT) within an order of magnitude smaller length than standard sodium sources. We achieve an atomic flux exceeding 4 × 109 atoms/s loaded in a MOT, with a most probable longitudinal velocity of 20 m/s, and a brightness larger than 2.5 × 1012 atoms/s/sr. This atomic source allows us to produce pure Bose-Einstein condensates with more than 107 atoms and a background pressure limited lifetime of 5 min.

  13. Nanostructures and pinholes on W surfaces exposed to high flux D plasma at high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Y.Z., E-mail: jaja880816@aliyun.com [Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Liu, W., E-mail: liuw@mail.tsinghua.edu.cn [Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Xu, B. [Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Luo, G.-N. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Li, C.; Fu, B.Q. [Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); De Temmerman, G. [FOM Institute DIFFER-Dutch Institute for Fundamental Energy Research, Edisonbaan 14, 3439 MN Nieuwegein (Netherlands); ITER Organization, Route de Vinon-Sur-Verdon, CS 90 046, 13067 St Paul Lez Durance Cedex (France)

    2015-08-15

    Nanostructures and pinholes formed on tungsten surface exposed to high fluxes (10{sup 24} m{sup −2} s{sup −1}) deuterium ions at 943 K and 1073 K were studied by scanning electron microscopy and electron backscatter diffraction. Nanostructure formation is observed at 943 K and 1073 K, and exhibits a strong dependence on the surface orientation. With increasing fluence, pinholes appear on the surface and are mainly observed on grains with surface normal near [1 1 1]. The pinholes are speculated to be caused by the rupture of bubbles formed near the surface. The formation of pinholes has no obvious relationship with the surface nanostructures.

  14. Properties of High Basicity Mold Fluxes for Peritectic Steel Slab Casting

    Institute of Scientific and Technical Information of China (English)

    LONG Xiao; HE Sheng-ping; XU Jian-fei; HUO Xu-ling; WANG Qian

    2012-01-01

    In high speed continuous casting of peritectic steel slabs, mold fluxes with high basicity are required for less surface defect product. However, the basicity of remaining liquid slag film tends to decrease in casting process because of the crystallization of 3CaO ·2SiO2 · CaF2. Thus, a way is put forward to improve mold fluxesr properties by raising the original basicity. In order to confirm the possibility of this method, the effect of rising original basicity on the properties of mold fluxes is discussed. Properties of high fluorine based mold fluxes with different basicities and contents of CaF2 , Na2 O, and MgO were measured, respectively. Then, properties of higher basicity mold fluxes were discussed and compared with traditional ones. The results show that increasing the basicity index can improve the melting and flow property of mold fluxes. With the increasing basicity, crystallization rate of mold fluxes increases obviously and crystallization temperature tends to decrease when the basicity exceeds 1.35. The method presen- ted before is proved as a potential way to resolve the contradiction between horizontal heat transfer controlling and solidified shell lubricating for peritectic steel slab casting. But further study on improving the flow property of liquid slag is needed. This work can be used to guide mold fluxes design for high speed continuous casting of peritectic steel slabs.

  15. 13C labeling analysis of sugars by high resolution-mass spectrometry for metabolic flux analysis.

    Science.gov (United States)

    Acket, Sébastien; Degournay, Anthony; Merlier, Franck; Thomasset, Brigitte

    2017-02-14

    Metabolic flux analysis is particularly complex in plant cells because of highly compartmented metabolism. Analysis of free sugars is interesting because it provides data to define fluxes around hexose, pentose, and triose phosphate pools in different compartment. In this work, we present a method to analyze the isotopomer distribution of free sugars labeled with carbon 13 using a liquid chromatography-high resolution mass spectrometry, without derivatized procedure, adapted for Metabolic flux analysis. Our results showed a good sensitivity, reproducibility and better accuracy to determine isotopic enrichments of free sugars compared to our previous methods [5, 6].

  16. Plasma resonance and flux dynamics in layered high-Tc superconductors

    DEFF Research Database (Denmark)

    Pedersen, Niels Falsig; Sakai, S.

    2000-01-01

    Flux dynamics of layered high Tc superconductors are considered with special emphasis on the small oscillation modes. In particular we find the dispersion relation for the plasma modes and discuss the spectra to be observed in microwave experiments.......Flux dynamics of layered high Tc superconductors are considered with special emphasis on the small oscillation modes. In particular we find the dispersion relation for the plasma modes and discuss the spectra to be observed in microwave experiments....

  17. COMPARISON OF COOLING SCHEMES FOR HIGH HEAT FLUX COMPONENTS COOLING IN FUSION REACTORS

    Directory of Open Access Journals (Sweden)

    Phani Kumar Domalapally

    2015-04-01

    Full Text Available Some components of the fusion reactor receives high heat fluxes either during the startup and shutdown or during the operation of the machine. This paper analyzes different ways of enhancing heat transfer using helium and water for cooling of these high heat flux components and then conclusions are drawn to decide the best choice of coolant, for usage in near and long term applications.

  18. Extremely High Suction Performance Inducers for Space Propulsion Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced pump inducer design technology that uses high inlet diffusion blades, operates at a very low flow coefficient, and employs a cavitation control and...

  19. Effect of low-intensity extremely high frequency radiation on reproductive function in wistar rats.

    Science.gov (United States)

    Subbotina, T I; Tereshkina, O V; Khadartsev, A A; Yashin, A A

    2006-08-01

    The exposure to low-intensity extremely high frequency electromagnetic radiation during spermatogenesis was accompanied by pathological changes, which resulted in degeneration and polymorphism of spermatozoa. The number of newborn rats increased in the progeny of irradiated animals.

  20. Extreme Environment Circuit Blocks for Spacecraft Power & Propulsion System & Other High Reliability Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Chronos Technology (DIv of FMI, Inc.) proposes to design, fabricate, and deliver a performance proven, and commercially available set of extreme high operating...

  1. Control of Crystal Morphology for Mold Flux During High-Aluminum AHSS Continuous Casting Process

    Science.gov (United States)

    GUO, Jing; SEO, Myung-Duk; SHI, Cheng-Bin; CHO, Jung-Wook; KIM, Seon-Hyo

    2016-08-01

    In the present manuscript, the efforts to control the crystal morphology are carried out aiming at improving the lubrication of lime-alumina-based mold flux for casting advanced high-strength steel with high aluminum. Jackson α factors for crystals of melt crystallization in multi-component mold fluxes are established and reasonably evaluated by applying thermodynamic databases to understand the crystal morphology control both in lime-alumina-based and lime-silica-based mold fluxes. The results show that Jackson α factor and supercooling are the most critical factors to determine the crystal morphology in a mold flux. Crystals precipitating in mold fluxes appear with different morphologies due to their different Jackson α factors and are likely to be more faceted with higher Jackson α factor. In addition, there is a critical supercooling degree for crystal morphology dendritic transition. When the supercooling over the critical value, the crystals transform from faceted shape to dendritic ones in morphology as the kinetic roughening occurs. Typically, the critical supercooling degrees for cuspidine dendritic transition in the lime-silica-based mold fluxes are evaluated to be between 0.05 and 0.06. Finally, addition of a small amount of Li2O in the mold flux can increase the Jackson α factor and decrease the supercooling for cuspidine precipitation; thus, it is favorable to enhance a faceted cuspidine crystal.

  2. Fractal Pattern Growth in Ti-Implanted Steel with High Ion Flux

    Institute of Scientific and Technical Information of China (English)

    张通和; 吴瑜光; 刘安东

    2002-01-01

    We report on the formation of metal nanometre phase and fractal patterns in steel using metal vapour vacuum arc source ion implantation with high ion flux. The dense nanometre phases are cylindrical and well dispersed in the Ti-implanted layer with an ion flux up to 50μA/cm2. The collision fractal pattern is formed in Ti-implanted steel with an ion flux of 25μA/cm2 and the disconnected fractal pattern is observed with an ion flux of 50μA/cm2.The average density ofnanometre phases decreases from 1.2 × 1011/cm2 to 6.5 × 1010/cm2 as the ion flux increases from 25 μA/cm2 to 50 μA/cm2. Fractal pattern growth is in remarkable agreement with Sander's diffusion-limited aggregation model. The alloy clusters have diffused and aggregated in chains forming branches to grow a beautiful tree during Ti implantation with an ion flux ranging from 75μA/cm2 to 85μA/cm2. We discuss the model of fractal pattern growth during ion implantation with high ion flux.

  3. Solar cosmic rays during the extremely high ground level enhancement on 23 February 1956

    Directory of Open Access Journals (Sweden)

    A. Belov

    2005-09-01

    Full Text Available The 23 February 1956 ground level enhancement of the solar cosmic ray intensity (GLE05 is the most famous among the proton events observed since 1942. But we do not have a great deal of information on this event due to the absence of solar wind and interplanetary magnetic field measurements at that time. Furthermore, there were no X-Ray or gamma observations and the information on the associated flare is limited. Cosmic ray data was obtained exclusively by ground level detectors of small size and in some cases of a non-standard design. In the present work all available data from neutron monitors operating in 1956 were analyzed, in order to develop a model of the solar cosmic ray behavior during the event. The time-dependent characteristics of the cosmic ray energy spectrum, cosmic ray anisotropy, and differential and integral fluxes have been evaluated utilizing different isotropic and anisotropic models. It is shown that the most outstanding features of this proton enhancement were a narrow and extremely intense beam of ultra-relativistic particles arriving at Earth just after the onset and the unusually high maximum solar particle energy. However, the contribution of this beam to the overall solar particle density and fluency was not significant because of its very short duration and small width. Our estimate of the integral flux for particles with energies over 100 MeV places this event above all subsequent. Perhaps the number of accelerated low energy particles was closer to a record value, but these particles passed mainly to the west of Earth.

    Many features of this GLE are apparently explained by the peculiarity of the particle interplanetary propagation from a remote (near the limb source. The quality of the available neutron monitor data does not allow us to be certain of some details; these may be cleared up by the incorporation into the analysis of data from muonic telescopes and ionization chambers

  4. Extremely high-power tongue projection in plethodontid salamanders

    NARCIS (Netherlands)

    Deban, S.M.; O'Reilly, J.C.; Dicke, U.; Leeuwen, van J.L.

    2007-01-01

    Many plethodontid salamanders project their tongues ballistically at high speed and for relatively great distances. Capturing evasive prey relies on the tongue reaching the target in minimum time, therefore it is expected that power production, or the rate of energy release, is maximized during tong

  5. RADIATION DOSIMETRY AT THE BNL HIGH FLUX BEAM REACTOR AND MEDICAL RESEARCH REACTOR.

    Energy Technology Data Exchange (ETDEWEB)

    HOLDEN,N.E.

    1999-09-10

    RADIATION DOSIMETRY MEASUREMENTS HAVE BEEN PERFORMED OVER A PERIOD OF MANY YEARS AT THE HIGH FLUX BEAM REACTOR (HFBR) AND THE MEDICAL RESEARCH REACTOR (BMRR) AT BROOKHAVEN NATIONAL LABORATORY TO PROVIDE INFORMATION ON THE ENERGY DISTRIBUTION OF THE NEUTRON FLUX, NEUTRON DOSE RATES, GAMMA-RAY FLUXES AND GAMMA-RAY DOSE RATES. THE MCNP PARTICLE TRANSPORT CODE PROVIDED MONTE CARLO RESULTS TO COMPARE WITH VARIOUS DOSIMETRY MEASUREMENTS PERFORMED AT THE EXPERIMENTAL PORTS, AT THE TREATMENT ROOMS AND IN THE THIMBLES AT BOTH HFBR AND BMRR.

  6. GRCop-84: A High-Temperature Copper Alloy for High-Heat-Flux Applications

    Science.gov (United States)

    Ellis, David L.

    2005-01-01

    GRCop-84 (Cu-8 at.% Cr-4 at.% Nb) is a new high-temperature copper-based alloy. It possesses excellent high-temperature strength, creep resistance and low-cycle fatigue up to 700 C (1292 F) along with low thermal expansion and good conductivity. GRCop-84 can be processed and joined by a variety of methods such as extrusion, rolling, bending, stamping, brazing, friction stir welding, and electron beam welding. Considerable mechanical property data has been generated for as-produced material and following simulated braze cycles. The data shows that the alloy is extremely stable during thermal exposures. This paper reviews the major GRCop-84 mechanical and thermophysical properties and compares them to literature values for a variety of other high-temperature copper-based alloys.

  7. High Energy Ion Acceleration by Extreme Laser Radiation Pressure

    Science.gov (United States)

    2017-03-14

    was used instead. This code makes the assumption that the background ion and electron behaviour can be approximated with a fluid model whilst...electron behaviour occurring from this aperture was also published in High Power Laser Science and Engineering [4]. A significant breakthrough was also...acceleration to transparency. This was published in Physics of Plasmas [12]. Through one- dimensional modelling of the interaction, it was also

  8. The extremely high stability of carbofuran pesticide in acidic media

    Directory of Open Access Journals (Sweden)

    Tomašević Anđelka V.

    2007-01-01

    Full Text Available Environment friendly iron catalysts were applied in the decomposition reactions of some toxic compounds like phenol, methomyl and corbofuran pesticide. The applied catalytic processes belong to photo-Fenton reactions. Heterogeneous iron catalysts showed significant activity in phenol and methomyl conversion, however, these catalysts were completely inactive in destruction of carbofuran molecule, even in the catalytic reaction promoted with UV light at high temperature.

  9. Adaptation potential of naturally ventilated barns to high temperature extremes: The OptiBarn project

    Science.gov (United States)

    Menz, Christoph

    2016-04-01

    Climate change interferes with various aspects of the socio-economic system. One important aspect is its influence on animal husbandry, especially dairy faming. Dairy cows are usually kept in naturally ventilated barns (NVBs) which are particular vulnerable to extreme events due to their low adaptation capabilities. An effective adaptation to high outdoor temperatures for example, is only possible under certain wind and humidity conditions. High temperature extremes are expected to increase in number and strength under climate change. To assess the impact of this change on NVBs and dairy cows also the changes in wind and humidity needs to be considered. Hence we need to consider the multivariate structure of future temperature extremes. The OptiBarn project aims to develop sustainable adaptation strategies for dairy housings under climate change for Europe, by considering the multivariate structure of high temperature extremes. In a first step we identify various multivariate high temperature extremes for three core regions in Europe. With respect to dairy cows in NVBs we will focus on the wind and humidity field during high temperature events. In a second step we will use the CORDEX-EUR-11 ensemble to evaluate the capability of the RCMs to model such events and assess their future change potential. By transferring the outdoor conditions to indoor climate and animal wellbeing the results of this assessment can be used to develop technical, architectural and animal specific adaptation strategies for high temperature extremes.

  10. High temperature thermocouple and heat flux gauge using a unique thin film-hardware hot juncture

    Science.gov (United States)

    Liebert, C. H.; Holanda, R.; Hippensteele, S. A.; Andracchio, C. A.

    1984-01-01

    A special thin film-hardware material thermocouple (TC) and heat flux gauge concept for a reasonably high temperature and high flux flat plate heat transfer experiment was fabricated and tested to gauge temperatures of 911 K. This concept was developed for minimal disturbance of boundary layer temperature and flow over the plates and minimal disturbance of heat flux through the plates. Comparison of special heat flux gauge Stanton number output at steady-state conditions with benchmark literature data was good and agreement was within a calculated uncertainty of the measurement system. Also, good agreement of special TC and standard TC outputs was obtained and the results are encouraging. Oxidation of thin film thermoelements was a primary failure mode after about 5 of operation.

  11. Superconducting flux pump for high-temperature superconductor insert coils of NMR magnets

    Science.gov (United States)

    Jeong, S.; Lee, H.; Iwasa, Y.

    2002-05-01

    This paper describes a prototype flux pump recently operated at the MIT Francis Bitter Magnet Laboratory. The results of the prototype flux pump will be used in the development of a full-scale flux pump that will be coupled to a high-temperature superconductor (HTS) insert coil of a high-field NMR magnet. Such an HTS insert is unlikely to operate in persistent mode because of the conductor's low index (n). The flux pump can compensate for field decay in the HTS insert coil and make the insert operate effectively in persistent mode. The flux pump, comprised essentially of a transformer and two switches, all made of superconductor, transfers into the insert coil a fraction of a magnetic energy that is first introduced in the secondary circuit of the transformer by a current supplied to the primary circuit. A prototype flux pump has been designed, fabricated, and operated to demonstrate that a flux pump can indeed supply a small metered current into a load superconducting magnet. A current increment in the range of microamperes has been measured in the magnet after each pumping action. The superconducting prototype flux pump is made of Nb3Sn tape. The pump is placed in a gaseous environment above the liquid helium level to keep its heat dissipation from directly discharged in the liquid; the effluent helium vapor maintains the thermal stability of the flux pump. [This paper is also published in Advances in Cryogenic Engineering Volume 47A, AIP Conference Proceedings Volume 613, pp. 441-448.

  12. Reflectance-Based Estimation of Soil Heat Fluxes in the Texas High Plains

    Science.gov (United States)

    Gowda, P. H.; Colaizzi, P. D.; O'Shaughnessy, S.; Ha, W.; Howell, T. A.

    2010-12-01

    Soil heat flux (G) is one of the terms required for estimating evapotranspiration rates using an energy balance. Numerous reflectance-based models are available in the literature for estimating G fluxes. However, these models have shown wide variation in their performance. Therefore, operational ET remote sensing programs may require locally developed/calibrated models for accurately estimating G. The objective of this study was to develop and evaluate reflectance-based empirical G models for the semi-arid Texas High Plains. Soil heat flux was measured at 0.15 hz interval and averaged every 15 minutes at five different locations within a 4.7 ha lysimeter field with Pullman clay loam soil during the 2010 summer growing season. The field was planted to soybean and managed under dryland conditions. In each location, G was measured at 8 cm depth with two Campbell Scientific HFT3 soil heat flux plates. Soil temperature was measured at 2 and 6 cm above the soil heat flux plates. Soil moisture was measured in the 2-8 cm layer using Acclima SDI-12 sensors. Hourly G fluxes at the surface were calculated by adding the measured G fluxes at 8 cm to the energy stored above the heat flux plates. A multispectral radiometer (MSR, CROPSCAN, Inc.) and hand-held thermometer (EVEREST Interscience Inc.) measured surface reflectance in red and near infrared bandwidths and surface temperature (ST), respectively, daily at 11:30 AM CST to be consistent with the Landsat 5 overpass time. Fraction crop cover (FC) was measured by digital photographs taken twice a week. A set of G models was developed for estimating hourly fluxes based on measured reflectance, net radiation, ST, NDVI, and FC,. Resulting models were compared for performance with existing models available in the literature. In this presentation, we will discuss our G models for the Texas High Plains and the statistical results.

  13. HIGH-ENERGY PARTICLES FLUX ORIGIN IN THE CLOUDS, DARK LIGHTNING

    Directory of Open Access Journals (Sweden)

    Kuznetsov, V.V.

    2016-11-01

    Full Text Available Problem of high-energy particles flux origin in clouds is discussed. Conditions in which dark lightning preceding the ordinary one and creating additional ionization, fluxes of fast electrons with MeV energy prior to the earthquake detected among lightning initiating ball-lightning, glow, sprites are considered. All above phenomena appear to be of general nature founded on quantum entanglement of hydrogen bonds protons in water clasters inside clouds.

  14. Autophagic flux is highly active in early mitosis and differentially regulated throughout the cell cycle

    OpenAIRE

    Li, Zhiyuan; Ji, Xinmiao; Wang, Dongmei; Liu, Juanjuan; Zhang, Xin

    2016-01-01

    Mitosis is a fast process that involves dramatic cellular remodeling and has a high energy demand. Whether autophagy is active or inactive during the early stages of mitosis in a naturally dividing cell is still debated. Here we aimed to use multiple assays to resolve this apparent discrepancy. Although the LC3 puncta number was reduced in mitosis, the four different cell lines we tested all have active autophagic flux in both interphase and mitosis. In addition, the autophagic flux was highl...

  15. Thermal evaluation of uranium silicide miniplates irradiated at high heat flux

    Energy Technology Data Exchange (ETDEWEB)

    Post Guillen, Donna, E-mail: Donna.Guillen@inl.gov [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-3710 (United States)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer Best estimate of thermal conditions during irradiation experiment. Black-Right-Pointing-Pointer Thermal evaluation of 25% enriched, high-density U{sub 3}Si{sub 2}/Al dispersion fuel miniplates. Black-Right-Pointing-Pointer Predictions of heat flux and temperature for as-run, high heat flux conditions. Black-Right-Pointing-Pointer Finite-element analysis uses measured values of hydroxide layer thickness. - Abstract: The Gas Test Loop (GTL)-1 irradiation experiment was conducted in the Advanced Test Reactor (ATR) to assess corrosion performance of proposed booster fuel at heat flux levels {approx}30% above the design operating condition. Sixteen miniplates fabricated from 25% enriched, high-density (4.8 g U/cm{sup 3}) U{sub 3}Si{sub 2}/Al dispersion fuel with 6061 aluminum cladding were subjected to peak beginning of cycle (BOC) heat fluxes ranging from 411 to 593 W/cm{sup 2}. No adverse impacts to the miniplates were observed at these high heat flux levels. A detailed finite element model was constructed to calculate temperatures and heat flux for an as-run cycle average effective ATR south lobe power of 25.4 MW(t). Miniplate heat flux levels and fuel, cladding, hydroxide, and coolant-hydroxide interface temperatures were calculated using the average hydroxide thickness on each miniplate measured during post-irradiation examination. The purpose of this study was to obtain a best estimate of the as-run experiment temperatures to aid in establishing acceptable heat flux levels and designing fuel qualification experiments for this fuel type.

  16. Behavior of TPC`s in a high particle flux environment

    Energy Technology Data Exchange (ETDEWEB)

    Etkin, A.; Eisemann, S.E.; Foley, K.J.; Hackenburg, R.W.; Longacre, R.S.; Love, W.A.; Morris, T.W.; Platner, E.D.; Saulys, A.C. [Brookhaven National Lab., Upton, NY (United States); Lindenbaum, S.J. [Brookhaven National Lab., Upton, NY (United States)]|[City Coll., New York, NY (United States); Chan, C.S.; Kramer, M.A.; Zhao, K.H.; Zhu, Y. [City Coll., New York, NY (United States); Hallman, T.J.; Madansky, L. [Johns Hopkins Univ., Baltimore, MD (United States); Ahmad, S.; Bonner, B.E.; Buchanan, J.A.; Chiou, C.N.; Clement, J.M.; Mutchler, G.S.; Roberts, J.B. [Rice Univ., Houston, TX (United States). Bonner Nuclear Labs.

    1991-12-13

    TPC`s (Time Projection Chamber) used in E-810 at the AGS (Alternating Gradient Synchrotron) were exposed to fluxes equivalent to more than 10{sup 7} minimum ionizing particles per second to find if such high fluxes cause gain changes or distortions of the electric field. Initial results of these and other tests are presented and the consequences for the RHIC (Relativistic Heavy Ion Collider) TPC-based experiments are discussed.

  17. Behavior of TPC`s in a high particle flux environment

    Energy Technology Data Exchange (ETDEWEB)

    Etkin, A.; Eiseman, S.E.; Foley, K.J.; Hackenburg, R.W.; Longacre, R.S.; Love, W.A.; Morris, T.W.; Platner, E.D.; Saulys, A.C. [Brookhaven National Lab., Upton, NY (United States); Lindenbaum, S.J. [Brookhaven National Lab., Upton, NY (United States)]|[City Coll., New York, NY (United States); Chan, C.S.; Kramer, M.A.; Zhao, K.H.; Zhu, Y. [City Coll., New York, NY (United States); Hallman, T.J.; Madansky, L. [Johns Hopkins Univ., Baltimore, MD (United States); Ahmad, S.; Bonner, B.E.; Buchanan, J.A.; Chiou, C.N.; Clement, J.M.; Mutchler, G.S.; Roberts, J.B. [Rice Univ., Houston, TX (United States)

    1992-07-08

    TPC`s (Time Projection Chamber) used in E-810 at the AGS (Alternating Gradient Synchrotron) were exposed to fluxes equivalent to more than 10{sup 7} minimum ionizing particles per second to find if such high fluxes cause gain changes or distortions of the electric field. Initial results of these and other tests are presented and the consequences for the RHIC (Relativistic Heavy Ion collider) TPC-based experiments are discussed.

  18. Behavior of TPC`s in a high particle flux environment

    Energy Technology Data Exchange (ETDEWEB)

    Etkin, A.; Eiseman, S.E.; Foley, K.J.; Hackenburg, R.W.; Longacre, R.S.; Love, W.A.; Morris, T.W.; Platner, E.D.; Saulys, A.C.; Lindenbaum, S.J. [Brookhaven National Lab., Upton, NY (United States); Chan, C.S.; Kramer, M.A.; Zhao, K.H.; Zhu, Y. [City College of New York, New York (United States); Hallman, T.J.; Madansky, L. [Johns Hopkins Univ., Baltimore, MD (United States); Ahmad, S.; Bonner, B.E.; Buchanan, J.A.; Chiou, C.N.; Clement, J.M.; Mutchler, G.S.; Roberts, J.B. [Bonner Nuclear Lab., Houston, TX (United States)

    1991-12-31

    TPC`s (Time Projection Chamber) used in E-810 at the TAGS (Alternating Gradient Synchrotron) were exposed to fluxes equivalent to more than 10 minimum ionizing particles per second to find if such high fluxes cause gain changes or distortions of the electric field. Initial results of these and other tests are presented and the consequences for the RHIC (Relativistic Heavy Ion Collider) TPC-based experiments are discussed.

  19. Behavior of TPC`s in a high particle flux environment

    Energy Technology Data Exchange (ETDEWEB)

    Etkin, A.; Eiseman, S.E.; Foley, K.J.; Hackenburg, R.W.; Longacre, R.S.; Love, W.A.; Morris, T.W.; Platner, E.D.; Saulys, A.C. [Brookhaven National Lab., Upton, NY (United States); Lindenbaum, S.J. [Brookhaven National Lab., Upton, NY (United States)]|[City Coll., New York, NY (United States); Chan, C.S.; Kramer, M.A.; Zhao, K.H.; Zhu, Y. [City Coll., New York, NY (United States); Hallman, T.J.; Madansky, L. [Johns Hopkins Univ., Baltimore, MD (United States); Ahmad, S.; Bonner, B.E.; Buchanan, J.A.; Chiou, C.N.; Clement, J.M.; Mutchler, G.S.; Roberts, J.B. [Rice Univ., Houston, TX (United States). Bonner Nuclear Labs.

    1991-12-31

    TPC`s (Time Projection Chamber) used in E-810 at the AGS (Alternating Gradient Synchrotron) were exposed to fluxes equivalent to more than 10{sup 7} minimum ionizing particles per second to find if such high fluxes cause gain changes or distortions of the electric field. Initial results of these and other tests are presented and the consequences for the RHIC (Relativistic Heavy Ion Collider) TPC-based experiments are discussed.

  20. CATARACT: Computer code for improving power calculations at NREL's high-flux solar furnace

    Science.gov (United States)

    Scholl, K.; Bingham, C.; Lewandowski, A.

    1994-01-01

    The High-Flux Solar Furnace (HFSF), operated by the National Renewable Energy Laboratory, uses a camera-based, flux-mapping system to analyze the distribution and to determine total power at the focal point. The flux-mapping system consists of a diffusively reflecting plate with seven circular foil calorimeters, a charge-coupled device (CCD) camera, an IBM-compatible personal computer with a frame-grabber board, and commercial image analysis software. The calorimeters provide flux readings that are used to scale the image captured from the plate by the camera. The image analysis software can estimate total power incident on the plate by integrating under the 3-dimensional image. Because of the physical layout of the HFSF, the camera is positioned at a 20 angle to the flux mapping plate normal. The foreshortening of the captured images that results represents a systematic error in the power calculations because the software incorrectly assumes the image is parallel to the camera's array. We have written a FORTRAN computer program called CATARACT (camera/target angle correction) that we use to transform the original flux-mapper image to a plane that is normal to the camera's optical axis. A description of the code and the results of experiments performed to verify it are presented. Also presented are comparisons of the total power available from the HFSF as determined from the flux mapping system and theoretical considerations.

  1. High Performance Multivariate Visual Data Exploration for Extremely Large Data

    Energy Technology Data Exchange (ETDEWEB)

    Rubel, Oliver; Wu, Kesheng; Childs, Hank; Meredith, Jeremy; Geddes, Cameron G.R.; Cormier-Michel, Estelle; Ahern, Sean; Weber, Gunther H.; Messmer, Peter; Hagen, Hans; Hamann, Bernd; Bethel, E. Wes; Prabhat,

    2008-08-22

    One of the central challenges in modern science is the need to quickly derive knowledge and understanding from large, complex collections of data. We present a new approach that deals with this challenge by combining and extending techniques from high performance visual data analysis and scientific data management. This approach is demonstrated within the context of gaining insight from complex, time-varying datasets produced by a laser wakefield accelerator simulation. Our approach leverages histogram-based parallel coordinates for both visual information display as well as a vehicle for guiding a data mining operation. Data extraction and subsetting are implemented with state-of-the-art index/query technology. This approach, while applied here to accelerator science, is generally applicable to a broad set of science applications, and is implemented in a production-quality visual data analysis infrastructure. We conduct a detailed performance analysis and demonstrate good scalability on a distributed memory Cray XT4 system.

  2. Nanoengineering of Flux Pinning Sites in High-Tc Superconductors

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Volume pinning forces were determined for a variety of bulk high-Tcsuperconductors of the 123-type from magnetization measurements. By means of scaling of the pinning forces, the acting pinning mechanisms in various temperature ranges were identified. The Nd-based superconductors and some YBCO crystalsexhibited a dominating pinning of the δTc-type (i.e., small, superconducting pinning sites). In contrast to this, the addition of insulating 211 particles provided pinning of the δl-type; providing effective pinning in the entire temperature range acting as a "background" pinning mechanism for the peak effect. Due to the small coherence lengths of the high-Tc compounds, effective pinning sites are defects or particles of nanometer size relative to ξ3. Integral magnetic measurements of the magnetization as a function of temperature in large applied magnetic fields (up to 7 T) revealed that practically all high-Tc compounds were spatially inhomogeneous, which could be caused byoxygen deficiency (YBCO), solid solutions of Nd/Ba (NdBCO and other light rare earth compounds), intergrowths (Bi-based superconductors), and doping by pair-breaking dopants like Zn, Pr. This implies that the superconducting sample consists of stronger and weaker superconducting areas, coupled together. In large appliedfields, this coupling gets broken and the magnetization versus temperature curves revealed more than one superconducting transition. In contrast, irradiation experiments by neutrons, protons, and heavy-ions enabled the artificial introduction of very effective pinning sites into the high-Tc superconductors, thus creating a large variety of different observations using magnetic data. From all these observations, we construct a pinning diagram for bulk high-Tc superconductors explaining many features observed in high-Tc samples.

  3. Magnetic flux annihilation waves in inhomogeneous high-temperature superconductors

    NARCIS (Netherlands)

    Rudnev, IA; Khodot, AE; Eremin, AV; Mikhailov, BP

    2004-01-01

    The process of magnetic field penetration into polycrystalline high-T-c superconductors of the YBa2Cu3O7 - x and Bi2Sr2Ca2Cu3O10 - x systems has been studied using traditional magnetooptical methods and scanning Hall probe microscopy. It is established that remagnetization of a sample is accompanied

  4. Flux flow in high-Tc Josephson junctions

    DEFF Research Database (Denmark)

    Filatrella, G.; Pedersen, Niels Falsig

    1993-01-01

    The possibility of achieving fluxon nucleation in nonhysteretic high-T(c) Josephson junctions due to the presence of inhomogeneities is investigated numerically. For a large range of parameters the I- V characteristics in presence of such discontinuities show a strong similarity with those obtain...

  5. An extremely high altitude plume seen at Mars morning terminator

    Science.gov (United States)

    Sanchez-Lavega, Agustin; Garcia-Muñoz, Antonio; Garcia-Melendo, Enrique; Perez-Hoyos, Santiago; Gomez-Forrellad, Josep M.; Pellier, Christophe; Delcroix, Marc; Lopez-Valverde, Miguel Angel; Gonzalez-Galindo, Francisco; Jaeschke, Wayne; Parker, Donald C.; Phillips, James H.; Peach, Damian

    2014-11-01

    We report the occurrence in March and April 2012 of two bright very high altitude plumes at the Martian terminator at 250 km or more above the surface, thus well into the ionosphere and bordering on the exosphere. They were located at about 195 deg West longitude and -45 deg latitude (at Terra Cimmeria) and lasted for about 10 days. The features showed day-to-day variability, and were seen at the morning terminator but not at the evening limb, which indicates rapid evolution in less than 10 hours and a cyclic behavior. Photometric measurements are used to explore two possible scenarios to explain their nature. If the phenomenon is due to suspended particles (dust, CO2 or H2O ice clouds) reflecting solar radiation, the mean size is about 0.1 microns with a nadir optical depth > 0.06. Alternatively, the plume could be auroral emission above a region with a strong magnetic anomaly and where aurora has previously been detected. Importantly, both explanations defy our current understanding of the Mars upper atmosphere.AcknowledgementsThis work was supported by the Spanish MINECO projects AYA2012-36666 with FEDER support, CONSOLIDER program ASTROMOL CSD2009-00038 and AYA2011-30613-CO2-1. Grupos Gobierno Vasco IT765-13 and UPV/EHU UFI11/55.

  6. Growth of a dry spot under a vapor bubble at high heat flux and high pressure

    CERN Document Server

    Nikolayev, Vadim; Lagier, G -L; Hegseth, J

    2016-01-01

    We report a 2D modeling of the thermal diffusion-controlled growth of a vapor bubble attached to a heating surface during saturated boiling. The heat conduction problem is solved in a liquid that surrounds a bubble with a free boundary and in a semi-infinite solid heater by the boundary element method. At high system pressure the bubble is assumed to grow slowly, its shape being defined by the surface tension and the vapor recoil force, a force coming from the liquid evaporating into the bubble. It is shown that at some typical time the dry spot under the bubble begins to grow rapidly under the action of the vapor recoil. Such a bubble can eventually spread into a vapor film that can separate the liquid from the heater thus triggering the boiling crisis (critical heat flux).

  7. A new frontier in CO2 flux measurements using a highly portable DIAL laser system

    Science.gov (United States)

    Queiβer, Manuel; Granieri, Domenico; Burton, Mike

    2016-01-01

    Volcanic CO2 emissions play a key role in the geological carbon cycle, and monitoring of volcanic CO2 fluxes helps to forecast eruptions. The quantification of CO2 fluxes is challenging due to rapid dilution of magmatic CO2 in CO2-rich ambient air and the diffuse nature of many emissions, leading to large uncertainties in the global magmatic CO2 flux inventory. Here, we report measurements using a new DIAL laser remote sensing system for volcanic CO2 (CO2DIAL). Two sites in the volcanic zone of Campi Flegrei (Italy) were scanned, yielding CO2 path-amount profiles used to compute fluxes. Our results reveal a relatively high CO2 flux from Campi Flegrei, consistent with an increasing trend. Unlike previous methods, the CO2DIAL is able to measure integrated CO2 path-amounts at distances up to 2000 m using virtually any solid surface as a reflector, whilst also being highly portable. This opens a new frontier in quantification of geological and anthropogenic CO2 fluxes. PMID:27652775

  8. Mathematical analysis for internal filtration of convection-enhanced high-flux hemodialyzer.

    Science.gov (United States)

    Lee, Jung Chan; Lee, Kyungsoo; Kim, Hee Chan

    2012-10-01

    Structural modifications using a conventional hemodialyzer improved the internal filtration and clearance of middle molecular weight wastes by enhanced convection effect. In this study, we employed a mathematical model describing the internal filtration rate as well as the hemodynamic and hematologic parameters in highflux dialyzer to interpret the previous reported experimental results. Conventional high-flux hemodialysis and convection-enhanced high-flux hemodialysis were configured in the mathematical forms and integrated into the iterative numerical method to predict the internal filtration phenomena inside the dialyzers during dialysis. The distributions of blood pressure, dialysate pressure, oncotic pressure, blood flow rates, dialysate flow rates, local ultrafiltration, hematocrit, protein concentration and blood viscosity along the axial length of dialyzer were calculated in order to estimate the internal filtration volume. The results show that the filtration volumes by internal filtration is two times higher in a convection-enhanced high-flux hemodialyzer than in a conventional high-flux hemodialzer and explains the experimental result of improved clearance of middle molecular size waste in convection-enhanced high-flux hemodialyzer.

  9. High heat flux capabilities of the Magnum-PSI linear plasma device

    Energy Technology Data Exchange (ETDEWEB)

    De Temmerman, G., E-mail: g.c.detemmerman@differ.nl; Berg, M.A. van den; Scholten, J.; Lof, A.; Meiden, H.J. van der; Eck, H.J.N. van; Morgan, T.W.; Kruijf, T.M. de; Zeijlmans van Emmichoven, P.A.; Zielinski, J.J.

    2013-10-15

    Magnum-PSI is an advanced linear plasma device uniquely capable of producing plasma conditions similar to those expected in the divertor of ITER both steady-state and transients. The machine is designed both for fundamental studies of plasma–surface interactions under high heat and particle fluxes, and as a high-heat flux facility for the tests of plasma-facing components under realistic plasma conditions. To study the effects of transient heat loads on a plasma-facing surface, a novel pulsed plasma source system as well as a high power laser is available. In this article, we will describe the capabilities of Magnum-PSI for high-heat flux tests of plasma-facing materials.

  10. Methods to assess high-resolution subsurface gas concentrations and gas fluxes in wetland ecosystems

    DEFF Research Database (Denmark)

    Elberling, Bo; Kühl, Michael; Glud, Ronnie N.

    2013-01-01

    The need for measurements of soil gas concentrations and surface fluxes of greenhouse gases at high temporal and spatial resolution in wetland ecosystem has lead to the introduction of several new analytical techniques and methods. In addition to the automated flux chamber methodology for high......-resolution estimates of greenhouse gas fluxes across the soil-atmosphere interface, these high-resolution methods include microsensors for quantification of spatiotemporal concentration dynamics in O2 and N2O at micrometer scales, fiber-optic optodes for long-term continuous point measurements of O2 concentrations...... and peat soils are highly heterogeneous, containing a mosaic of dynamic macropore systems created by both macrofauna and flora leading to distinct spatial and temporal variations in gas concentration on a scale of millimeters and minutes. Applications of these new methodologies allow measurements...

  11. A conceptual high flux reactor design with scope for use in ADS applications

    Science.gov (United States)

    Pal, Usha; Jagannathan, V.

    2007-02-01

    A 100 MWt reactor design has been conceived to support flux level of the order of 1015 n/cm2/s in selected flux trap zones. The physics design considers high enriched metallic alloy fuel in the form of annular plates placed in a D2O moderator tank in a hexagonal lattice arrangement. By choosing a tight lattice pitch in the central region and double the lattice pitch in the outer region, it is possible to have both high fast flux and thermal flux trap zones. By design the flux level in the seed fuel has been kept lower than in the high flux trap zones so that the burning rate of the seed is reduced. Another important objective of the design is to maximize the time interval of refueling. As against a typical refueling interval of a few weeks in such high flux reactor cores, it is desired to maximize this period to as much as six months or even one year. This is possible to achieve by eliminating the conventional control absorbers and replacing them with a suitable amount of fertile material loading in the reactor. Requisite number of seedless thorium-aluminum alloy plates are placed at regular lattice locations vacated by seed fuel in alternate fuel layers. It is seen that these thorium plates are capable of acquiring asymptotic fissile content of 14 g/kg in about 100 days of irradiation at a flux level of 8 x 1014 n/cm2/s. In summary, the core has a relatively higher fast flux in the central region and high thermal flux in the outer region. The present physics design envisages a flat core excess reactivity for the longest possible cycle length of 6 months to one year. It is also possible to modify the design for constant subcriticality for about the same period or longer duration by considering neutron spallation source at the centre and curtailing the power density in the inner core region by shielding it with a layer of thoria fuel loading.

  12. A conceptual high flux reactor design with scope for use in ADS applications

    Indian Academy of Sciences (India)

    Usha Pal; V Jagannathan

    2007-02-01

    A 100 MWt reactor design has been conceived to support flux level of the order of 1015 n/cm2/s in selected flux trap zones. The physics design considers high enriched metallic alloy fuel in the form of annular plates placed in a D2O moderator tank in a hexagonal lattice arrangement. By choosing a tight lattice pitch in the central region and double the lattice pitch in the outer region, it is possible to have both high fast flux and thermal flux trap zones. By design the flux level in the seed fuel has been kept lower than in the high flux trap zones so that the burning rate of the seed is reduced. Another important objective of the design is to maximize the time interval of refueling. As against a typical refueling interval of a few weeks in such high flux reactor cores, it is desired to maximize this period to as much as six months or even one year. This is possible to achieve by eliminating the conventional control absorbers and replacing them with a suitable amount of fertile material loading in the reactor. Requisite number of seedless thorium–aluminum alloy plates are placed at regular lattice locations vacated by seed fuel in alternate fuel layers. It is seen that these thorium plates are capable of acquiring asymptotic fissile content of 14 g/kg in about 100 days of irradiation at a flux level of 8 × 1014 n/cm2 /s. In summary, the core has a relatively higher fast flux in the central region and high thermal flux in the outer region. The present physics design envisages a flat core excess reactivity for the longest possible cycle length of 6 months to one year. It is also possible to modify the design for constant subcriticality for about the same period or longer duration by considering neutron spallation source at the centre and curtailing the power density in the inner core region by shielding it with a layer of thoria fuel loading.

  13. A high resolution Passive Flux Meter approach based on colorimetric responses

    Science.gov (United States)

    Chardi, K.; Dombrowski, K.; Cho, J.; Hatfield, K.; Newman, M.; Annable, M. D.

    2016-12-01

    Subsurface water and contaminant mass flux measurements are critical in determining risk, optimizing remediation strategies, and monitoring contaminant attenuation. The standard Passive Flux Meter, hereafter knows as a (PFM), is a well-developed device used for determining and monitoring rates of groundwater and contaminant mass flux in screened wells. The current PFM is a permeable device that contains granular activated carbon impregnated with alcohol tracers which is deployed in a flow field for a designated period of time. Once extracted, sampling requires laboratory analysis to quantify Darcy flux, which can be time consuming and have significant cost. To expedite test results, a modified PFM based on the image analysis of colorimetric responses, herein referred to as a colorimetric Passive Flux Meter (cPFM), was developed. Various dyes and sorbents were selected and evaluated to determine colorimetric response to water flow. Rhodamine, fluorescent yellow, fluorescent orange, and turmeric were the dye candidates while 100% wool and a 35% wool blend with 65% rayon were the sorbent candidates selected for use in the cPFM. Ultraviolet light image analysis was used to calculate average color intensity using ImageJ, a Java-based image processing program. These results were then used to quantify Darcy flux. Error ranges evaluated for Darcy flux using the cPFM are comparable to those with the standard, activated carbon based, PFM. The cPFM has the potential to accomplish the goal of obtaining high resolution Darcy flux data while eliminating high costs and analysis time. Implications of groundwater characteristics, such as PH and contaminant concentrations, on image analysis are to be tested through laboratory analysis followed by field testing of the cPFM.

  14. High Heat Flux Burnout in Subcooled Flow Boiling

    Institute of Scientific and Technical Information of China (English)

    G.P.Celata; M.Cumo; 等

    1995-01-01

    The paper reports the results of an experimental research carried out at the Heat transfer divison of the Energy Department,C.R.Casaccia,on the thermal hydraulic characterization of subcooled flow boiling CHF under typical conditions of thermonuclear fusion reactors.I.e.high liquid velocity and subcooling.The experiment was carried out exploring the following parameters:channel diameter(from 2.5to 8.0 mm),heated length(10 and 15cm) ,liquid velocity (from 2 to 40m/s),exit pressure(from atmospheric to 5.0 MPa),inlet temperature(from 30 to 80℃),channel orientation (vertical and horizontal),A maximum CHF value of 60.6MW/m2 has been obtained under the following conditions:Tin-30°,p=2.5MPa,u=40m/s,D=2.5mm(smooth channel) Turbulence promoters(helically coiled wires)have been employed to further enhance the CHF attainable with subcooled flow boiling.Helically coiled wires allow an increase of 50% of the maximum CHF obtained with smooth channels.

  15. Prospects of hydroacoustic detection of ultra-high and extremely high energy cosmic neutrinos

    Science.gov (United States)

    Dedenko, L. G.; Karlik, Ya. S.; Learned, J. G.; Svet, V. D.; Zheleznykh, I. M.

    2001-07-01

    The prospects of construction of deep underwater neutrino telescopes in the world's oceans for the goals of ultra-high and super-high energy neutrino astrophysics (astronomy) using acoustic technologies are reviewed. The effective detection volume of the acoustic neutrino telescopes can be far greater than a cubic kilometer for extreme energies. In recent years, it was proposed that an existing hydroacoustic array of 2400 hydrophones in the Pacific Ocean near Kamchatka Peninsula could be used as a test base for an acoustic neutrino telescope SADCO (Sea-based Acoustic Detector of Cosmic Objects) which should be capable of detecting acoustic signals produced in water by the cosmic neutrinos with energies 1019-21 eV (e.g., topological defect neutrinos). We report on simulations of super-high energy electron-hadron and electron-photon cascades with the Landau-Pomeranchuk-Migdal effect taken into account. Acoustic signals emitted by neutrino-induced cascades with energies 1020-21 eV were calculated. The possibilities of using a converted hydroacoustic station MG-10 (MG-10M) of 132 hydrophones as a basic module for a deep water acoustic neutrino detector with the threshold detection energy 1015 eV in the Mediterranean Sea are analyzed (with the aim of searching for neutrinos with energies 1015-16 eV from Active Galactic Nuclei). .

  16. Global anthropogenic heat flux database with high spatial resolution

    Science.gov (United States)

    Dong, Y.; Varquez, A. C. G.; Kanda, M.

    2017-02-01

    This study developed a top-down method for estimating global anthropogenic heat emission (AHE), with a high spatial resolution of 30 arc-seconds and temporal resolution of 1 h. Annual average AHE was derived from human metabolic heating and primary energy consumption, which was further divided into three components based on consumer sector. The first and second components were heat loss and heat emissions from industrial sectors equally distributed throughout the country and populated areas, respectively. The third component comprised the sum of emissions from commercial, residential, and transportation sectors (CRT). Bulk AHE from the CRT was proportionally distributed using a global population dataset, with a radiance-calibrated nighttime lights adjustment. An empirical function to estimate monthly fluctuations of AHE based on gridded monthly temperatures was derived from various Japanese and American city measurements. Finally, an AHE database with a global coverage was constructed for the year 2013. Comparisons between our proposed AHE and other existing datasets revealed that the problem of overestimation of AHE intensity in previous top-down models was mitigated by the separation of energy consumption sectors; furthermore, the problem of AHE underestimation at central urban areas was solved by the nighttime lights adjustment. A strong agreement in the monthly profiles of AHE between our database and other bottom-up datasets further proved the validity of the current methodology. Investigations of AHE for the 29 largest urban agglomerations globally highlighted that the share of heat emissions from CRT sectors to the total AHE at the city level was 40-95%; whereas that of metabolic heating varied with the city's level of development by a range of 2-60%. A negative correlation between gross domestic product (GDP) and the share of metabolic heating to a city's total AHE was found. Globally, peak AHE values were found to occur between December and February, while

  17. Explanation for the low flux of high energy astrophysical muon-neutrinos

    CERN Document Server

    Pakvasa, Sandip; Mohanty, Subhendra

    2012-01-01

    We consider the possibility that some exotic neutrino property is responsible for reducing the muon neutrino flux at high energies from distant neutrino sources; specifically, we consider (i) neutrino decay and (ii) neutrinos being pseudo-Dirac particles. This would provide a mechanism for the lack of high energy muons in the Icecube detector.

  18. High photon flux XUV and soft x-ray sources enabled by high harmonic generation of high power fiber lasers

    Science.gov (United States)

    Rothhardt, Jan; Hädrich, Steffen; Krebs, Manuel; Limpert, Jens; Tünnermann, Andreas

    2015-07-01

    This contribution reports on the recent advances in high harmonic generation (HHG) with high power femtosecond fiber lasers at high repetition rates. The capabilities of high power fiber lasers, the challenges of phase matching in the tight-focusing regime and recent experimental results will be discussed. In particular, post compressed pules as short as 30 fs, with ~150 μJ pulse energy at 0.6 MHz repetition rate have been used for efficient HHG into the XUV. Despite the tight focusing phase matching is ensured by providing the target gas with adequately high density. A conversion efficiency in excess of 10-6 at ~30 eV has been achieved in xenon gas. This resulted in more than 100μW of average power (>1013 photons per second), which represents the highest photon flux achieved by any HHG source in this spectral region so far. In addition, further pulse compression yielded few-cycle pulses at high average power that have enabled efficient soft Xray generation in neon and helium. HHG in neon provided more than 3·109 photons/s within a 1% bandwidth at 120 eV and helium allowed for HHG up to the water window spectral region beyond 283 eV. These compact sources provide highest photon flux on a table-top and will enable exciting applications such as nanometer-resolution imaging or coincidence spectroscopy in the near future.

  19. Multifield measurement of magnetic fluctuation-induced particle flux in a high-temperature toroidal plasma

    Science.gov (United States)

    Lin, L.; Ding, W. X.; Brower, D. L.

    2016-12-01

    Magnetic fluctuation-induced particle transport is explored in the high-temperature, high-beta interior of the Madison symmetric torus (MST) reversed-field pinch by performing a multifield measurement of the correlated product of magnetic and density fluctuations associated with global resistive tearing modes. Local density fluctuations are obtained by inverting the line-integrated interferometry data after resolving the mode helicity through correlation techniques. The local magnetic and current density fluctuations are then reconstructed using a parameterized fit of Faraday-effect polarimetry measurements. Reconstructed 2D images of density and current density perturbations in a poloidal cross section exhibit significantly different spatial structure. Combined with their relative phase, the magnetic-fluctuation-induced particle transport flux and its spatial distribution are resolved. The convective magnetic fluctuation-induced particle flux profile is measured for both standard and high-performance plasmas in MST with tokamak-like confinement, showing large reduction in the flux during improved confinement.

  20. High geothermal heat flux measured below the West Antarctic Ice Sheet.

    Science.gov (United States)

    Fisher, Andrew T; Mankoff, Kenneth D; Tulaczyk, Slawek M; Tyler, Scott W; Foley, Neil

    2015-07-01

    The geothermal heat flux is a critical thermal boundary condition that influences the melting, flow, and mass balance of ice sheets, but measurements of this parameter are difficult to make in ice-covered regions. We report the first direct measurement of geothermal heat flux into the base of the West Antarctic Ice Sheet (WAIS), below Subglacial Lake Whillans, determined from the thermal gradient and the thermal conductivity of sediment under the lake. The heat flux at this site is 285 ± 80 mW/m(2), significantly higher than the continental and regional averages estimated for this site using regional geophysical and glaciological models. Independent temperature measurements in the ice indicate an upward heat flux through the WAIS of 105 ± 13 mW/m(2). The difference between these heat flux values could contribute to basal melting and/or be advected from Subglacial Lake Whillans by flowing water. The high geothermal heat flux may help to explain why ice streams and subglacial lakes are so abundant and dynamic in this region.

  1. The Influence of Non-Uniform High Heat Flux on Thermal Stress of Thermoelectric Power Generator

    Directory of Open Access Journals (Sweden)

    Tingzhen Ming

    2015-11-01

    Full Text Available A thermoelectric generator (TEG device which uses solar energy as heat source would achieve higher efficiency if there is a higher temperature difference between the hot-cold ends. However, higher temperature or higher heat flux being imposed upon the hot end will cause strong thermal stress, which will have a negative influence on the life cycle of the thermoelectric module. Meanwhile, in order to get high heat flux, a Fresnel lens is required to concentrate solar energy, which will cause non-uniformity of heat flux on the hot end of the TEG and further influence the thermal stress of the device. This phenomenon is very common in solar TEG devices but seldom research work has been reported. In this paper, numerical analysis on the heat transfer and thermal stress performance of a TEG module has been performed considering the variation on the power of the heat flux being imposed upon the hot-end; the influence of non-uniform high heat flux on thermal stress has also been analyzed. It is found that non-uniformity of high heat flux being imposed upon the hot end has a significant effect on the thermal stress of TEG and life expectation of the device. Taking the uniformity of 100% as standard, when the heating uniformity is 70%, 50%, 30%, and 10%, respectively, the maximum thermal stress of TEG module increased by 3%, 6%, 12%, and 22% respectively. If we increase the heat flux on the hot end, the influence of non-uniformity on the thermal stress will be more remarkable.

  2. Surface modifications induced by high fluxes of low energy helium ions.

    Science.gov (United States)

    Tanyeli, İrem; Marot, Laurent; Mathys, Daniel; van de Sanden, Mauritius C M; De Temmerman, Gregory

    2015-04-28

    Several metal surfaces, such as titanium, aluminum and copper, were exposed to high fluxes (in the range of 10(23) m(-2) s(-1)) of low energy (pillars, are observed on these metals. The differences and similarities in the development of surface morphologies are discussed in terms of the material properties and compared with the results of similar experimental studies. The results show that He ions induced void growth and physical sputtering play a significant role in surface modification using high fluxes of low energy He ions.

  3. GRCop-84: A High Temperature Copper-based Alloy For High Heat Flux Applications

    Science.gov (United States)

    Ellis, David L.

    2005-01-01

    While designed for rocket engine main combustion chamber liners, GRCop-84 (Cu-8 at.% Cr-4 at.% Nb) offers potential for high heat flux applications in industrial applications requiring a temperature capability up to approximately 700 C (1292 F). GRCop-84 is a copper-based alloy with excellent elevated temperature strength, good creep resistance, long LCF lives and enhanced oxidation resistance. It also has a lower thermal expansion than copper and many other low alloy copper-based alloys. GRCop-84 can be manufactured into a variety of shapes such as tubing, bar, plate and sheet using standard production techniques and requires no special production techniques. GRCop-84 forms well, so conventional fabrication methods including stamping and bending can be used. GRCop-84 has demonstrated an ability to be friction stir welded, brazed, inertia welded, diffusion bonded and electron beam welded for joining to itself and other materials. Potential applications include plastic injection molds, resistance welding electrodes and holders, permanent metal casting molds, vacuum plasma spray nozzles and high temperature heat exchanger applications.

  4. A combined sensor for simultaneous high resolution 2-D imaging of oxygen and trace metals fluxes

    DEFF Research Database (Denmark)

    Stahl, Henrik; Warnken, Kent W.; Sochaczewski, Lukasz

    2012-01-01

    A new sandwich sensor, consisting of an O-2 planar optode overlain by a thin (90 mu m) DGT layer is presented. This sensor can simultaneously resolve 2-D O-2 dynamics and trace metal fluxes in benthic substrates at a high spatial resolution. The DGT layer accumulates metals on a small particle size...... (0.2 mu m) chelating resin and records the locally induced trace metal flux during the deployment, whereas the planar optode resolves the O-2 dynamic in near real time at the same location in the sediment. Despite its ultrathin composition, the DGT layer has high carrying capacity for trace metals...... with no saturation problems during application to typical coastal-or contaminated sediments. Combined with laser ablation, accumulated metal fluxes could be resolved at a resolution of similar to 200 mu m, whereas the O-2 images had a resolution of similar to 100 mu m. A 2-D diffusion-reaction model showed...

  5. Model-dependent high-energy neutrino flux from gamma-ray bursts.

    Science.gov (United States)

    Zhang, Bing; Kumar, Pawan

    2013-03-22

    The IceCube Collaboration recently reported a stringent upper limit on the high energy neutrino flux from gamma-ray bursts (GRBs), which provides a meaningful constraint on the standard internal shock model. Recent broadband electromagnetic observations of GRBs also challenge the internal shock paradigm for GRBs, and some competing models for γ-ray prompt emission have been proposed. We describe a general scheme for calculating the GRB neutrino flux, and compare the predicted neutrino flux levels for different models. We point out that the current neutrino flux upper limit starts to constrain the standard internal shock model. The dissipative photosphere models are also challenged if the cosmic ray luminosity from GRBs is at least 10 times larger than the γ-ray luminosity. If the neutrino flux upper limit continues to go down in the next few years, then it would suggest the following possibilities: (i) the photon-to-proton luminosity ratio in GRBs is anomalously high for shocks, which may be achieved in some dissipative photosphere models and magnetic dissipation models; or (ii) the GRB emission site is at a larger radius than the internal shock radius, as expected in some magnetic dissipation models such as the internal collision-induced magnetic reconnection and turbulence model.

  6. Autophagic flux is highly active in early mitosis and differentially regulated throughout the cell cycle

    Science.gov (United States)

    Li, Zhiyuan; Ji, Xinmiao; Wang, Dongmei; Liu, Juanjuan; Zhang, Xin

    2016-01-01

    Mitosis is a fast process that involves dramatic cellular remodeling and has a high energy demand. Whether autophagy is active or inactive during the early stages of mitosis in a naturally dividing cell is still debated. Here we aimed to use multiple assays to resolve this apparent discrepancy. Although the LC3 puncta number was reduced in mitosis, the four different cell lines we tested all have active autophagic flux in both interphase and mitosis. In addition, the autophagic flux was highly active in nocodazole-induced, double-thymidine synchronization released as well as naturally occurring mitosis in HeLa cells. Multiple autophagy proteins are upregulated in mitosis and the increased Beclin-1 level likely contributes to the active autophagic flux in early mitosis. It is interesting that although the autophagic flux is active throughout the cell cycle, early mitosis and S phase have relatively higher autophagic flux than G1 and late G2 phases, which might be helpful to degrade the damaged organelles and provide energy during S phase and mitosis. PMID:27213594

  7. Analysis of heat transfer under high heat flux nucleate boiling conditions

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Y.; Dinh, N. [3145 Burlington Laboratories, Raleigh, NC (United States)

    2016-07-15

    Analysis was performed for a heater infrared thermometric imaging temperature data obtained from high heat flux pool boiling and liquid film boiling experiments BETA. With the OpenFOAM solver, heat flux distribution towards the coolant was obtained by solving transient heat conduction of heater substrate given the heater surface temperature data as boundary condition. The so-obtained heat flux data was used to validate them against the state-of-art wall boiling model developed by D. R. Shaver (2015) with the assumption of micro-layer hydrodynamics. Good agreement was found between the model prediction and data for conditions away from the critical heat flux (CHF). However, the data indicate a different heat transfer pattern under CHF, which is not captured by the current model. Experimental data strengthen the notion of burnout caused by the irreversible hot spot due to failure of rewetting. The observation forms a basis for a detailed modeling of micro-layer hydrodynamics under high heat flux.

  8. How extreme are extremes?

    Science.gov (United States)

    Cucchi, Marco; Petitta, Marcello; Calmanti, Sandro

    2016-04-01

    High temperatures have an impact on the energy balance of any living organism and on the operational capabilities of critical infrastructures. Heat-wave indicators have been mainly developed with the aim of capturing the potential impacts on specific sectors (agriculture, health, wildfires, transport, power generation and distribution). However, the ability to capture the occurrence of extreme temperature events is an essential property of a multi-hazard extreme climate indicator. Aim of this study is to develop a standardized heat-wave indicator, that can be combined with other indices in order to describe multiple hazards in a single indicator. The proposed approach can be used in order to have a quantified indicator of the strenght of a certain extreme. As a matter of fact, extremes are usually distributed in exponential or exponential-exponential functions and it is difficult to quickly asses how strong was an extreme events considering only its magnitude. The proposed approach simplify the quantitative and qualitative communication of extreme magnitude

  9. Generation of bright circularly-polarized extreme ultraviolet high harmonics for magnetic circular dichroism spectroscopy

    CERN Document Server

    Kfir, Ofer; Turgut, Emrah; Knut, Ronny; Zusin, Dmitriy; Popmintchev, Dimitar; Popmintchev, Tenio; Nembach, Hans; Shaw, Justin M; Fleicher, Avner; Kapteyn, Henry; Murnane, Margaret; Cohen, Oren

    2014-01-01

    Circularly-polarized extreme UV and X-ray radiation provides valuable access to the structural, electronic and magnetic properties of materials. To date, such experiments have been possible only using large-scale free-electron lasers or synchrotrons. Here we demonstrate the first bright extreme UV circularly-polarized high harmonics and use this new light source for magnetic circular dichroism measurements at the M-shell absorption edges of cobalt. This work paves the way towards element-specific imaging and spectroscopy of multiple elements simultaneously in magnetic and other chiral media with very high spatio-temporal resolution, all on a tabletop.

  10. High diversity of methanotrophic bacteria in geothermal soils affected by high methane fluxes

    Science.gov (United States)

    D'Alessandro, Walter; Gagliano, Antonina Lisa; Quatrini, Paola; Parello, Francesco

    2014-05-01

    Volcanic and geothermal systems emit endogenous gases by widespread degassing from soils, including CH4, a greenhouse gas 25 times as potent as CO2. Recently, it has been demonstrated that volcanic/geothermal soils act as source, but also as biological filter for methane release to the atmosphere. For long time, volcanic/geothermal soils has been considered inhospitable for methanotrophic microorganisms, but new extremophile methanotrophs belonging to Verrucomicrobia were identified in three different areas (Pozzuoli, Italy; Hell's Gate, New Zealand; Kamchatka, Russia), explaining anomalous behaviours in methane leakages of several geothermal/volcanic sites. Our aim was to increase the knowledge of the relationship between methane emissions from volcanic/geothermal areas and biological methane oxidation, by investigating a geothermal site of Pantelleria island (Italy). Pantelleria Island hosts a high enthalpy geothermal system characterized by high temperature, high CH4 and very low H2S fluxes. Such characteristics are reflected in potentially great supply of methane for methanotrophs and scarce presence of inhibitors of their activity (H2S and NH3) in the Pantelleria soils. Potential methanotrophic activity within these soils was already evidenced by the CH4/CO2 ratio of the flux measurements which was lower than that of the respective fumarolic manifestations indicating a loss of CH4 during the gas travel towards the earth's surface. In this study laboratory incubation experiments using soils sampled at Favara Grande, the main hydrothermal area of Pantelleria, showed very high methane consumption rates (up to 9500 ng CH4 h-1 g-1). Furthermore, microbiological and culture-independent molecular analyses allowed to detect the presence of methanotrophs affiliated to Gamma- and Alpha-Proteobacteria and to the newly discovered acidothermophilic methanotrophs Verrucomicrobia. Culturable methanotrophic Alpha-proteobacteria of the genus Methylocystis were isolated by

  11. The Southeast Asia Regional Climate Downscaling (SEACLID) / CORDEX Southeast Asia Project and The Results of Its Sensitivity Experiments of RegCM4 Cumulus and Ocean Fluxes Parameterization Schemes on Temperature and Extremes.

    Science.gov (United States)

    Tangang, Fredolin; Juneng, Liew; Cruz, Faye; Narisma, Gemma; Dado, Julie; Van, Tan-Phan; Ngo-Duc, Thanh; Trinh-Tuan, Long; Nguyen-Xuan, Thanh; Santisirisomboon, Jerasorn; Singhruck, Patama; Gunawan, Dodo; Aldrian, Edvin

    2015-04-01

    The Southeast Asia (SEA) region is one of the more vulnerable regions to the impacts of climate change because of the large population exposed to climate-related hazards, mostly living in countries with low adaptive capabilities. In order to adequately prepare and adapt to these future climate change impacts, it is therefore crucial for high-resolution climate projections to be available for this region. The Southeast Asia Regional Climate Downscaling/CORDEX Southeast Asia (SEACLID/CORDEX-SEA) project aims to provide these projections through a collaborative effort in regional climate downscaling. As a first step, model simulations with the 4th version of Regional Climate Model system (RegCM4) developed by International Centre for Theoretical Physics (ICTP) were performed for the SEA domain (80°E-145°E; 15°S-40°N) at 36 km spatial resolution, to determine an optimal configuration of the model for the region. Using the ECMWF ERA Interim data as boundary condition, a total of 18 sensitivity experiments were done with different cumulus parameterization and ocean flux schemes for the period of 1989-2008. In this study, the model's performance in simulating mean temperature is evaluated against APHRODITE, a gridded observed temperature dataset. Initial results showed that RegCM4 tends to enhance the cold bias from the boundary forcing. There is also a consistent cold bias among all simulations over the Tibetan plateau and Indochina, especially during the boreal winter. Consequently, simulations had the smallest biases during boreal summer. The correlation of the model with the observed data is high over the northern half of the region, in contrast with the low correlation over the southern half, which may be due to uncertainties in the APHRODITE dataset over this region. Consistent with the spatial analysis, the analysis of the regional means indicates an overall better performance of the MIT Emanuel scheme, in terms of seasonality and spatial distribution. The

  12. Performance of High-frequency High-flux Magnetic Cores at Cryogenic Temperatures

    Science.gov (United States)

    Gerber, Scott S.; Hammoud, Ahmad; Elbuluk, Malik E.; Patterson, Richard L.

    2002-01-01

    Three magnetic powder cores and one ferrite core, which are commonly used in inductor and transformer design for switch mode power supplies, were selected for investigation at cryogenic temperatures. The powder cores are Molypermalloy Core (MPC), High Flux Core (HFC), and Kool Mu Core (KMC). The performance of four inductors utilizing these cores has been evaluated as a function of temperature from 20 C to -180 C. All cores were wound with the same wire type and gauge to obtain equal values of inductance at room temperature. Each inductor was evaluated in terms of its inductance, quality (Q) factor, resistance, and dynamic hysteresis characteristics (B-H loop) as a function of temperature and frequency. Both sinusoidal and square wave excitations were used in these investigations. Measured data obtained on the inductance showed that both the MPC and the HFC cores maintain a constant inductance value, whereas with the KMC and ferrite core hold a steady value in inductance with frequency but decrease as temperature is decreased. All cores exhibited dependency, with varying degrees, in their quality factor and resistance on test frequency and temperature. Except for the ferrite, all cores exhibited good stability in the investigated properties with temperature as well as frequency. Details of the experimental procedures and test results are presented and discussed in the paper.

  13. Effects of high-flux hemodialysis on plasma adrenomedullin and sustained hypotension in elderly hemodialysis patients

    Institute of Scientific and Technical Information of China (English)

    ZHANG Dong; SUN Xue-feng; MA Zhi-fang; ZHU Han-yu; WANG Yuan-da; CHEN Xiang-mei

    2011-01-01

    Background Sustained hypotension during hemodialysis (HD) is an important clinical issue. Plasma adrenomedullin (AM) is increased in HD patients with sustained hypotension, but little is known about whether removing AM can improve hypotension. The objective of this study was to investigate the beneficial effects of hemodialysis using a high-flux dialyzer on removal of increased plasma AM levels and improving low blood pressure in elderly HD patients with sustained hypotension.Methods Forty-eight elderly patients (age 65 or older) who had undergone maintenance HD for more than one year were recruited and studied. We evaluated plasma levels of AM in sustained hypotension (SH; n=28) and normotensive (NT; n=20) patients. The patients with hypotension were further divided into two subgroups and treated with eitherhigh-flux dialyzer or low-flux dialyzer for 3 months. Plasma adrenomedullin levels and blood pressure were analyzed at days 0 and 181.Results Plasma levels of AM were significantly higher in SH than in NT patients ((24.92±3.7) ng/L vs. (15.52±6.01) ng/L,P<0.05), and were inversely correlated with mean arterial blood pressure (MAP) at pre-HD. After 3 months, the level of plasma AM in high-flux group was decreased ((24.58±4.36) ng/L vs. (16.18±5.08) ng/L, P <0.05), but MAP was increased ((67.37±4.31) mmHg vs. (74.79±3.59) mmHg, P<0.05). There was no obvious change in low-flux group.Conclusions Plasma AM levels were significantly elevated in elderly HD patients with SH. High-flux dialyzer therapy can decrease plasma AM level and improve hypotension.

  14. High aspect ratio tungsten grating on ultrathin Si membranes for extreme UV lithography

    Science.gov (United States)

    Peng, Xinsheng; Ying, Yulong

    2016-09-01

    Extreme ultraviolet lithography is one of the modern lithography tools for high-volume manufacturing with 22 nm resolution and beyond. But critical challenges exist to the design and fabrication of large-scale and highly efficient diffraction transmission gratings, significantly reducing the feature sizes down to 22 nm and beyond. To achieve such a grating, the surface flatness, the line edge roughness, the transmission efficiency and aspect ratio should be improved significantly. Delachat et al (2015 Nanotechnology 26 108262) develop a full process to fabricate a tungsten diffraction grating on an ultrathin silicon membrane with higher aspect ratio up to 8.75 that met all the aforementioned requirements for extreme ultraviolet lithography. This process is fully compatible with standard industrial extreme ultraviolet lithography.

  15. High aspect ratio tungsten grating on ultrathin Si membranes for extreme UV lithography.

    Science.gov (United States)

    Peng, Xinsheng; Ying, Yulong

    2016-09-02

    Extreme ultraviolet lithography is one of the modern lithography tools for high-volume manufacturing with 22 nm resolution and beyond. But critical challenges exist to the design and fabrication of large-scale and highly efficient diffraction transmission gratings, significantly reducing the feature sizes down to 22 nm and beyond. To achieve such a grating, the surface flatness, the line edge roughness, the transmission efficiency and aspect ratio should be improved significantly. Delachat et al (2015 Nanotechnology 26 108262) develop a full process to fabricate a tungsten diffraction grating on an ultrathin silicon membrane with higher aspect ratio up to 8.75 that met all the aforementioned requirements for extreme ultraviolet lithography. This process is fully compatible with standard industrial extreme ultraviolet lithography.

  16. Flux jumps in high-J c MgB2 bulks during pulsed field magnetization

    Science.gov (United States)

    Fujishiro, H.; Mochizuki, H.; Naito, T.; Ainslie, M. D.; Giunchi, G.

    2016-03-01

    Pulsed field magnetization (PFM) of a high-J c MgB2 bulk disk has been investigated at 20 K, in which flux jumps frequently occur for high pulsed fields. Using a numerical simulation of the PFM procedure, we estimated the time dependence of the local magnetic field and temperature during PFM. We analyzed the electromagnetic and thermal instability of the high-J c MgB2 bulk to avoid flux jumps using the time dependence of the critical thickness, d c(t), which shows the upper safety thickness to stabilize the superconductor magnetically, and the minimum propagation zone length, l m(t), to obtain dynamical stability. The values of d c(t) and l m(t) change along the thermally-stabilized direction with increasing temperature below the critical temperature, T c. However, the flux jump can be qualitatively understood by the local temperature, T(t), which exceeds T c in the bulk. Finally, possible solutions to avoid flux jumps in high-J c MgB2 bulks are discussed.

  17. Magnetic-flux dynamics of high-Tc superconductors in weak magnetic fields

    DEFF Research Database (Denmark)

    Il’ichev, E. V.; Jacobsen, Claus Schelde

    1994-01-01

    Aspects of magnetic-flux dynamics in different types of samples of the high-temperature superconductor YBa2Cu3Ox have been investigated in magnetic fields below 1 Oe and at 77 K. The experiments were carried out in an arrangement including a field coil, a flat sample perpendicular to the field...

  18. Saturation of deuterium retention in self-damaged tungsten exposed to high-flux plasmas.

    NARCIS (Netherlands)

    't Hoen, M. H. J.; Tyburska-Pueschel, B.; Ertl, K.; Mayer, M.; Rapp, J.; Kleijn, A.W.; Zeijlmans van Emmichoven, P.A.

    2012-01-01

    Polycrystalline, annealed tungsten targets were bombarded with 12.3 MeV W4+ ions to various damage levels. Deuterium was implanted by high-flux plasmas in Pilot-PSI (>1024 m−2 s−1) at a surface temperature below 525 K. Deuterium retention has been studied by nuclear reaction analysis and by thermal

  19. Saturation of deuterium retention in self-damaged tungsten exposed to high-flux plasmas

    NARCIS (Netherlands)

    Hoen, M. H. J. 't; Tyburska-Puschel, B.; Ertl, K.; Mayer, M.; Rapp, J.; Kleyn, A. W.; van Emmichoven, P. A. Zeijlma

    2012-01-01

    Polycrystalline, annealed tungsten targets were bombarded with 12.3MeV W4+ ions to various damage levels. Deuterium was implanted by high-flux plasmas in Pilot-PSI (>10(24) m(-2) s(-1)) at a surface temperature below 525 K. Deuterium retention has been studied by nuclear reaction analysis and by

  20. Production of high transient heat and particle fluxes in a linear plasma device

    NARCIS (Netherlands)

    De Temmerman, G.; Zielinski, J. J.; van der Meiden, H.; Melissen, W.; Rapp, J.

    2010-01-01

    We report on the generation of high transient heat and particle fluxes in a linear plasma device by pulsed operation of the plasma source. A capacitor bank is discharged into the source to transiently increase the discharge current up to 1.7 kA, allowing peak densities and temperature of 70x10(20) m

  1. The clincal research of high-flux hemodialysis for improvement of prognosis in patients with uremia

    Institute of Scientific and Technical Information of China (English)

    常明

    2013-01-01

    To explore whether high-flux hemodialysis(HFHD) can improve the prognosis in patients with uremia and the possible mechanism. Methods Thirty-three uremia patients in Dalian Central Hospital were selected and changed treatment of 6-month HFHD,with themselves as

  2. Operating manual for the High Flux Isotope Reactor. Volume I. Description of the facility

    Energy Technology Data Exchange (ETDEWEB)

    1982-09-01

    This volume contains a comprehensive description of the High Flux Isotope Reactor Facility. Its primary purpose is to supplement the detailed operating procedures, providing the reactor operators with background information on the various HFIR systems. The detailed operating procdures are presented in another report.

  3. High flux, narrow bandwidth compton light sources via extended laser-electron interactions

    Science.gov (United States)

    Barty, V P

    2015-01-13

    New configurations of lasers and electron beams efficiently and robustly produce high flux beams of bright, tunable, polarized quasi-monoenergetic x-rays and gamma-rays via laser-Compton scattering. Specifically, the use of long-duration, pulsed lasers and closely-spaced, low-charge and low emittance bunches of electron beams increase the spectral flux of the Compton-scattered x-rays and gamma rays, increase efficiency of the laser-electron interaction and significantly reduce the overall complexity of Compton based light sources.

  4. Neutron Spectral Brightness of Cold Guide 4 at the High Flux Isotope Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Winn, B L; Robertson, J L; Iverson, E B; Selby, D L, E-mail: winnbl@ornl.gov

    2010-11-01

    The High Flux Isotope Reactor resumed operation in June of 2007 with a supercritical hydrogen cold source in horizontal beam tube 4. Cold guide 4 is a guide system designed to deliver neutrons from this source with a reasonable flux at wavelengths greater than 4 A to several instruments, and includes a 15-m, 96-section, 4-channel bender. A time-of-flight spectrum with calibrated detector was recorded at port C of cold guide 4, and compared to McStas simulations, to generate a brightness spectrum.

  5. Neutron Spectral Brightness of Cold Guide 4 at the High Flux Isotope Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Winn, B. L. [Brookhaven National Lab. (BNL), Upton, NY (United States). Neutron Scattering Group; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Neutron Facilities Development Div.; Robertson, J. L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Neutron Facilities Development Div.; Iverson, Erik B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Neutron Facilities Development Div.; Selby, D. L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Neutron Facilities Development Div.

    2009-05-03

    The High Flux Isotope Reactor resumed operation in June of 2007 with a super-critical hydrogen cold source in horizontal beam tube 4. Cold guide 4 is a guide system designed to deliver neutrons from this source at reasonable flux at wavelengths greater than 4 Å to several instruments, and includes a 15-m, 96-section, 4-channel bender. A time-of-flight spectrum with calibrated detector was recorded at port C of cold guide 4, and compared to McStas simulations, to generate a brightness spectrum.

  6. Neutron Spectral Brightness of Cold Guide 4 at the High Flux Isotope Reactor

    Science.gov (United States)

    Winn, B. L.; Robertson, J. L.; Iverson, E. B.; Selby, D. L.

    2010-11-01

    The High Flux Isotope Reactor resumed operation in June of 2007 with a supercritical hydrogen cold source in horizontal beam tube 4. Cold guide 4 is a guide system designed to deliver neutrons from this source with a reasonable flux at wavelengths greater than 4 Å to several instruments, and includes a 15-m, 96-section, 4-channel bender. A time-of-flight spectrum with calibrated detector was recorded at port C of cold guide 4, and compared to McStas simulations, to generate a brightness spectrum.

  7. Diffuse Ultra-High Energy Neutrino Fluxes and Physics Beyond the Standard Model

    CERN Document Server

    Bhattacharya, Atri; Gandhi, Raj; Watanabe, Atsushi

    2009-01-01

    We study the effects of physics beyond the Standard Model on diffuse fluxes of neutrino flavours from ultra-high-energy (UHE) sources. Using neutrino decay and Lorentz symmetry violation (LV) as examples, we show that they would result in significant spectral distortion of the well-known bounds on such fluxes. This would allow UHE detectors with some flavour detection sensitivity to probe lifetimes and LV parameters over a broad range beyond present bounds and the neutrino mass hierarchy via distinctive signatures. We indicate how this method may be used to study other new physics scenarios.

  8. Diffuse ultra-high energy neutrino fluxes and physics beyond the Standard Model

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharya, Atri, E-mail: atri@hri.res.i [Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad 211 019 (India); Choubey, Sandhya; Gandhi, Raj [Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad 211 019 (India); Watanabe, Atsushi [Department of Physics, Kyushu University, Fukuoka 812-8581 (Japan)

    2010-06-07

    We study spectral distortions of diffuse ultra-high energy (UHE) neutrino flavour fluxes resulting due to physics beyond the Standard Model (SM). Even large spectral differences between flavours at the source are massaged into a common shape at earth by SM oscillations, thus, any significant observed spectral differences are an indicator of new physics present in the oscillation probability during propagation. Lorentz symmetry violation (LV) and neutrino decay are examples, and result in significant distortion of the fluxes and of the well-known bounds on them, which may allow UHE detectors to probe LV parameters, lifetimes and the mass hierarchy over a broad range.

  9. Probability modeling of high flow extremes in Yingluoxia watershed, the upper reaches of Heihe River basin

    Science.gov (United States)

    Li, Zhanling; Li, Zhanjie; Li, Chengcheng

    2014-05-01

    Probability modeling of hydrological extremes is one of the major research areas in hydrological science. Most basins in humid and semi-humid south and east of China are concerned for probability modeling analysis of high flow extremes. While, for the inland river basin which occupies about 35% of the country area, there is a limited presence of such studies partly due to the limited data availability and a relatively low mean annual flow. The objective of this study is to carry out probability modeling of high flow extremes in the upper reach of Heihe River basin, the second largest inland river basin in China, by using the peak over threshold (POT) method and Generalized Pareto Distribution (GPD), in which the selection of threshold and inherent assumptions for POT series are elaborated in details. For comparison, other widely used probability distributions including generalized extreme value (GEV), Lognormal, Log-logistic and Gamma are employed as well. Maximum likelihood estimate is used for parameter estimations. Daily flow data at Yingluoxia station from 1978 to 2008 are used. Results show that, synthesizing the approaches of mean excess plot, stability features of model parameters, return level plot and the inherent independence assumption of POT series, an optimum threshold of 340m3/s is finally determined for high flow extremes in Yingluoxia watershed. The resulting POT series is proved to be stationary and independent based on Mann-Kendall test, Pettitt test and autocorrelation test. In terms of Kolmogorov-Smirnov test, Anderson-Darling test and several graphical diagnostics such as quantile and cumulative density function plots, GPD provides the best fit to high flow extremes in the study area. The estimated high flows for long return periods demonstrate that, as the return period increasing, the return level estimates are probably more uncertain. The frequency of high flow extremes exhibits a very slight but not significant decreasing trend from 1978 to

  10. Homopolar dc motor and trapped flux brushless dc motor using high temperature superconductor materials

    Science.gov (United States)

    Crapo, Alan D.; Lloyd, Jerry D.

    1991-03-01

    Two motors have been designed and built for use with high-temperature superconductor (HTSC) materials. They are a homopolar dc motor that uses HTSC field windings and a brushless dc motor that uses bulk HTSC materials to trap flux in steel rotor poles. The HTSC field windings of the homopolar dc motor are designed to operate at 1000 A/sq cm in a 0.010-T field. In order to maximize torque in the homopolar dc motor, an iron magnetic circuit with small air gaps gives maximum flux for minimum Ampere turns in the field. A copper field winding version of the homopolar dc motor has been tested while waiting for 575 A turn HTSC coils. The trapped flux brushless dc motor has been built and is ready to test melt textured bulk HTSC rings that are currently being prepared. The stator of the trapped flux motor will impress a magnetic field in the steel rotor poles with warm HTSC bulk rings. The rings are then cooled to 77 K to trap the flux in the rotor. The motor can then operate as a brushless dc motor.

  11. A genome-wide analysis of putative functional and exonic variation associated with extremely high intelligence.

    Science.gov (United States)

    Spain, S L; Pedroso, I; Kadeva, N; Miller, M B; Iacono, W G; McGue, M; Stergiakouli, E; Smith, G D; Putallaz, M; Lubinski, D; Meaburn, E L; Plomin, R; Simpson, M A

    2016-08-01

    Although individual differences in intelligence (general cognitive ability) are highly heritable, molecular genetic analyses to date have had limited success in identifying specific loci responsible for its heritability. This study is the first to investigate exome variation in individuals of extremely high intelligence. Under the quantitative genetic model, sampling from the high extreme of the distribution should provide increased power to detect associations. We therefore performed a case-control association analysis with 1409 individuals drawn from the top 0.0003 (IQ >170) of the population distribution of intelligence and 3253 unselected population-based controls. Our analysis focused on putative functional exonic variants assayed on the Illumina HumanExome BeadChip. We did not observe any individual protein-altering variants that are reproducibly associated with extremely high intelligence and within the entire distribution of intelligence. Moreover, no significant associations were found for multiple rare alleles within individual genes. However, analyses using genome-wide similarity between unrelated individuals (genome-wide complex trait analysis) indicate that the genotyped functional protein-altering variation yields a heritability estimate of 17.4% (s.e. 1.7%) based on a liability model. In addition, investigation of nominally significant associations revealed fewer rare alleles associated with extremely high intelligence than would be expected under the null hypothesis. This observation is consistent with the hypothesis that rare functional alleles are more frequently detrimental than beneficial to intelligence.

  12. High-flux first-wall design for a small reversed-field pinch reactor

    Science.gov (United States)

    Cort, G. E.; Graham, A. L.; Christensen, K. E.

    To achieve the goal of a commercially economical fusion power reactor, small physical size and high power density should be combined with simplicity (minimized use of high technology systems). The Reversed-Field Pinch (RFP) is a magnetic confinement device that promises to meet these requirements with power densities comparable to those in existing fission power plants. To establish feasibility of such an RFP reactor, a practical design for a first wall capable of withstanding high levels of cyclic neutron wall loadings is needed. Associated with the neutron flux in the proposed RFP reactor is a time averaged heat flux of 4.5 MW/sq m with a conservatively estimated transient peak approximately twice the average value. The design for a modular first wall made from a high-strength copper alloy that will meet these requirements of cyclic thermal loading is presented. The heat removal from the wall is by subcooled water flowing in straight tubes at high linear velocities.

  13. High-Flux Hemodialysis and High-Volume Hemodiafiltration Improve Serum Calcification Propensity.

    Directory of Open Access Journals (Sweden)

    Marijke Dekker

    Full Text Available Calciprotein particles (CPPs may play an important role in the calcification process. The calcification propensity of serum (T50 is highly predictive of all-cause mortality in chronic kidney disease patients. Whether T50 is therapeutically improvable, by high-flux hemodialysis (HD or hemodiafiltration (HDF, has not been studied yet.We designed a cross-sectional single center study, and included stable prevalent in-center dialysis patients on HD or HDF. Patients were divided into two groups based on dialysis modality, were on a thrice-weekly schedule, had a dialysis vintage of > 3 months and vascular access providing a blood flow rate > 300 ml/min. Calcification propensity of serum was measured by the time of transformation from primary to secondary CPP (T50 test, by time-resolved nephelometry.We included 64 patients, mean convective volume was 21.7L (SD 3.3L. In the pooled analysis, T50 levels increased in both the HD and HDF group with pre- and post-dialysis (mean (SD of 244(64 - 301(57 and 253(55 - 304(61 min respectively (P = 0.43(HD vs. HDF. The mean increase in T50 was 26.29% for HD and 21.97% for HDF patients (P = 0.61 (HD vs. HDF. The delta values (Δ of calcium, phosphate and serum albumin were equal in both groups. Baseline T50 was negatively correlated with phosphate, and positively correlated with serum magnesium and fetuin-A. The ΔT50 was mostly influenced by Δ phosphate (r = -0.342; P = 0.002 HD and r = -0.396; P<0.001 HDF in both groups.HD and HDF patients present with same baseline T50 calcification propensity values pre-dialysis. Calcification propensity is significantly improved during both HD and HDF sessions without significant differences between both modalities.

  14. The Role and Detectability of the Charm Contribution to Ultra High Energy Neutrino Fluxes

    CERN Document Server

    Gandhi, Raj; Watanabe, Atsushi

    2009-01-01

    It is widely believed that charm meson production and decay may play an important role in high energy astrophysical sources of neutrinos, especially those that are baryon-rich, providing an environment conducive to pp interactions. Using slow-jet supernovae (SJS) as an example of such a source, we study the detectability of high-energy neutrinos, paying particular attention to those produced from charmed-mesons. We highlight important distinguishing features in the ultra-high energy neutrino flux which would act as markers for the role of charm in the source. In particular, charm leads to significant event rates at higher energies, after the conventional (pi, K) neutrino fluxes fall off. We calculate event rates both for a nearby single source and for diffuse SJS fluxes for an IceCube-like detector. By comparing muon event rates for the conventional and prompt fluxes in different energy bins, we demonstrate the striking energy dependence in the rates induced by the presence of charm. We also show that it lead...

  15. Prototyping phase of the high heat flux scraper element of Wendelstein 7-X

    Energy Technology Data Exchange (ETDEWEB)

    Boscary, J., E-mail: jean.boscary@ipp.mpg.de [Max Planck Institute for Plasma Physics, Garching (Germany); Greuner, H. [Max Planck Institute for Plasma Physics, Garching (Germany); Ehrke, G. [Max Planck Institute for Plasma Physics, Greifswald (Germany); Böswirth, B.; Wang, Z. [Max Planck Institute for Plasma Physics, Garching (Germany); Clark, E. [University of Tennessee, Knoxville (United States); Lumsdaine, A. [Oak Ridge National Laboratory, USA National Laboratory, Oak Ridge, Tennessee (United States); Tretter, J. [Max Planck Institute for Plasma Physics, Garching (Germany); McGinnis, D.; Lore, J. [Oak Ridge National Laboratory, USA National Laboratory, Oak Ridge, Tennessee (United States); Ekici, K. [University of Tennessee, Knoxville (United States)

    2016-11-01

    Highlights: • Aim of scraper element: reduction of heat loads on high heat flux divertor ends. • Design: actively water-cooled for 20 MW/m{sup 2} local heat loads. • Technology: CFC NB31 monoblocks bonded by HIP to CuCrZr cooling tube. • Successful high heat flux testing up to 20 MW/m{sup 2}. - Abstract: The water-cooled high heat flux scraper element aims to reduce excessive heat loads on the target element ends of the actively cooled divertor of Wendelstein 7-X. Its purpose is to intercept some of the plasma fluxes both upstream and downstream before they reach the divertor surface. The scraper element has 24 identical plasma facing components (PFCs) divided into 6 modules. One module has 4 PFCs hydraulically connected in series by 2 water boxes. A PFC, 247 mm long and 28 mm wide, has 13 monoblocks made of CFC NB31 bonded by hot isostatic pressing onto a CuCrZr cooling tube equipped with a copper twisted tape. 4 full-scale prototypes of PFCs have been successfully tested in the GLADIS facility up to 20 MW/m{sup 2}. The difference observed between measured and calculated surface temperatures is probably due to the inhomogeneity of CFC properties. The design of the water box prototypes has been detailed to allow the junction between the cooling pipe of the PFCs and the water boxes by internal orbital welding. The prototypes are presently under fabrication.

  16. Institute for High Heat Flux Removal (IHHFR). Phases I, II, and III

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, Ronald D. [Prairie View A& M Univ., TX (United States)

    2014-08-31

    The IHHFR focused on interdisciplinary applications as it relates to high heat flux engineering issues and problems which arise due to engineering systems being miniaturized, optimized, or requiring increased high heat flux performance. The work in the IHHFR focused on water as a coolant and includes: (1) the development, design, and construction of the high heat flux flow loop and facility; (2) test section development, design, and fabrication; and, (3) single-side heat flux experiments to produce 2-D boiling curves and 3-D conjugate heat transfer measurements for single-side heated test sections. This work provides data for comparisons with previously developed and new single-side heated correlations and approaches that address the single-side heated effect on heat transfer. In addition, this work includes the addition of single-side heated circular TS and a monoblock test section with a helical wire insert. Finally, the present work includes: (1) data base expansion for the monoblock with a helical wire insert (only for the latter geometry), (2) prediction and verification using finite element, (3) monoblock model and methodology development analyses, and (4) an alternate model development for a hypervapotron and related conjugate heat transfer controlling parameters.

  17. High-resolution analysis of 1 day extreme precipitation in Sicily

    Science.gov (United States)

    Maugeri, M.; Brunetti, M.; Garzoglio, M.; Simolo, C.

    2015-04-01

    Sicily, the major Mediterranean island, experienced several exceptional precipitation episodes and floods during the last century, with dramatic consequences on human life and environment. A long term, rational planning of urban development is mandatory for protecting population and avoiding huge economic losses in the future. This requires a deep knowledge of the distributional features of extreme precipitation over the complex territory of Sicily. In the present study, we address this issue, and attempt a detailed investigation of observed 1-day precipitation extremes and their frequency distribution, based on a dense data-set of high-quality, homogenized station records in 1921-2005. We extrapolate very high quantiles (return levels) corresponding to 10-, 50- and 100-year return periods, as predicted by a generalized extreme value distribution. Return level estimates are produced on a regular high-resolution grid (30 arcsec) using a variant of regional frequency analysis combined with regression techniques. Results clearly reflect the complexity of this region, and make evident the high vulnerability of its eastern and northeastern parts as those prone to the most intense and potentially damaging events. This analysis thus provides an operational tool for extreme precipitation risk assessment and, at the same time, is an useful basis for validation and downscaling of regional climate models.

  18. Influence of High Harmonics of Magnetic Fields on Trapped Magnetic Fluxes in HTS Bulk

    Science.gov (United States)

    Yamagishi, K.; Miyagi, D.; Tsukamoto, O.

    Various kinds of HTS bulk motors are proposed and have been developed. Generally, those motors are driven by semiconductor inverters and currents fed to the armature windings contain high harmonics. Therefore, the bulks are exposed to high harmonics magnetic fields and AC losses are produced in the bulks. The AC losses deteriorate the efficiency of the motors and cause temperature rise of the bulks which decrease the trapped magnetic fluxes of the bulks. Usually, electro-magnetic shielding devices are inserted between the bulks and armature windings. However, the shielding devices degrade compactness of the motors. Therefore, it is important to have knowledge of the influence of the high harmonics magnetic fields on the AC losses and trapped magnetic fluxes of the bulk for optimum design of the shielding devices. In this work, the authors experimentally study the influence of high harmonics magnetic fields.

  19. Characteristics of Magnetic Tribology on High Flux Pair of Magnetic Driving Mechanism

    Institute of Scientific and Technical Information of China (English)

    ZHOUQiang; XURui-qing; XUHong-qiu

    2004-01-01

    The rectangle-like pulsed magnetic field acted on the rubbing pair was presents through analyzing the exciting property in the reciprocationg travel the test of wear in NG-x tester shows that the wear between the electromagnetic core and down magnetic board distributes in the high veloctity slip region of reciprocating travel,an the adhesive wear in the low velocity slip region nearby up and down dead points is depressed owing to the presence of high flux magnetic field.the lubrication by magnetic fluid with high permeability effectively reduces the friction and wear of high flux rubbing pair and mproves the conductiong property of magnetic circuit constructed by the rubbing pair which is beneficial to increase the operation performance of magnetic driving mechanism.

  20. High-resolution hot-film measurement of surface heat flux to an impinging jet

    Science.gov (United States)

    O'Donovan, T. S.; Persoons, T.; Murray, D. B.

    2011-10-01

    To investigate the complex coupling between surface heat transfer and local fluid velocity in convective heat transfer, advanced techniques are required to measure the surface heat flux at high spatial and temporal resolution. Several established flow velocity techniques such as laser Doppler anemometry, particle image velocimetry and hot wire anemometry can measure fluid velocities at high spatial resolution (µm) and have a high-frequency response (up to 100 kHz) characteristic. Equivalent advanced surface heat transfer measurement techniques, however, are not available; even the latest advances in high speed thermal imaging do not offer equivalent data capture rates. The current research presents a method of measuring point surface heat flux with a hot film that is flush mounted on a heated flat surface. The film works in conjunction with a constant temperature anemometer which has a bandwidth of 100 kHz. The bandwidth of this technique therefore is likely to be in excess of more established surface heat flux measurement techniques. Although the frequency response of the sensor is not reported here, it is expected to be significantly less than 100 kHz due to its physical size and capacitance. To demonstrate the efficacy of the technique, a cooling impinging air jet is directed at the heated surface, and the power required to maintain the hot-film temperature is related to the local heat flux to the fluid air flow. The technique is validated experimentally using a more established surface heat flux measurement technique. The thermal performance of the sensor is also investigated numerically. It has been shown that, with some limitations, the measurement technique accurately measures the surface heat transfer to an impinging air jet with improved spatial resolution for a wide range of experimental parameters.

  1. Extreme deformations and clusterization at high spin in the A ~ 40 mass region

    Science.gov (United States)

    Ray, Debisree; Afanasjev, Anatoli

    2015-10-01

    Recent revival of the interest to the study of superdeformation and clusterization in light nuclei has motivated us to undertake the study of extreme deformations in the A ~ 32 - 50 N ~ Z nuclei. Unfortunately, at spin zero the predicted structures with extreme deformation are located at high excitation energies which prevents their experimental observation. On the other hand, the rotation brings such structures closer to the yrast line and, in principle, makes their observation possible with future generation of facilities such as GRETA. Thus, the systematic study of the extremely deformed structures and clusterization has been performed in the framework of cranked relativistic mean field theory. The major features of such structures, the spins at which they become yrast and the possiblities of their experimental observation will be discussed in this presentation. This work has been supported by the U.S. Department of Energy under the Grant DE-FG02-07ER41459.

  2. Detection of extreme climate events in semi-arid biomes using a combination of near-field and satellite based remote sensing across the New Mexico Elevation Gradient network of flux towers

    Science.gov (United States)

    Litvak, M. E.; Krofcheck, D. J.; Maurer, G.

    2015-12-01

    Semi-arid biomes in the Southwestern U.S. over the past decade have experienced high inter- and intra-annual variability in precipitation and vapor-pressure deficit (VPD), and from recent observations, are particularly vulnerable to both VPD and drought. Given the large land area occupied by semi-arid biomes in the U.S., the ability to quantify how climate extremes alter ecosystem function, in addition to being able to use satellites to remotely detect when these climate extremes occur, is crucial to scale the impact of these events on regional carbon dynamics. In an effort to understand how well commonly employed remote sensing platforms capture the impact of extreme events on semi-arid biomes, we coupled a 9-year record of eddy-covariance measurements made across an elevation/aridity gradient in NM with remote sensing data sets from tower-based phenocams, MODIS and Landsat 7 ETM+. We compared anomalies in air temperature, vapor pressure deficit, and precipitation, to the degree in variability of remote sensing vegetation indices (e.g, NDVI, EVI, 2G-Rbi, LST, etc.), and tower-derived gross primary productivity (GPP), across a range of temporal lags to quantify : 1) how sensitive vegetation indices from various platforms, LST, and carbon uptake are to climate disturbances, and the extremity of the disturbance; 2) how well correlated vegetation indices and tower fluxes are on monthly, seasonal and annual time scales, and if the degree to which they are correlated is related to the extent of climate anomalies during that period; and 3) the lags in the response of both GPP and vegetation indices to climate-anomalies and how well correlated these were on various time scales. Our initial results show differential sensitivities across a range of semi-arid ecosystems to drought and vapor pressure deficit. We see the strongest sensitivity of vegetation indices, and correlations between vegetation indices and tower GPP in the low and high elevation biomes that have a more

  3. Recent testing of secondary concentrators at NREL`s high-flux solar furnace

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, D.; Winston, R.; O`Gallagher, J. [Univ. of Chicago, IL (United States); Bingham, C.; Lewandowski, A.; Pitts, R.; Scholl, K. [National Renewable Energy Lab., Golden, CO (United States)

    1996-12-31

    Several tests have been completed on new secondary concentrators at the High-Flux Solar Furnace (HFSF) at the National Renewable Energy Laboratory (NREL). The first test measured the power from the exit of a High-Index secondary that achieves an average concentration of 50,000 suns. The second concentrator tested pumped an Nd:YAG laser crystal. The concentrator designs are presented, along with data from on-sun testing at the HFSF.

  4. Signal photon flux generated by high-frequency relic gravitational waves

    Science.gov (United States)

    Li, Xin; Wang, Sai; Wen, Hao

    2016-08-01

    The power spectrum of primordial tensor perturbations increases rapidly in the high frequency region if the spectral index n t > 0. It is shown that the amplitude of relic gravitational waves h t(5 × 109 Hz) varies from 10-36 to 10-25 while n t varies from -6.25 × 10-3 to 0.87. A high frequency gravitational wave detector proposed by F.-Y. Li detects gravitational waves through observing the perturbed photon flux that is generated by interaction between relic gravitational waves and electromagnetic field. It is shown that the perturbative photon flux (5 × 109 Hz) varies from 1.40 × 10-4 s-1 to 2.85 × 107 s-1 while n t varies from -6.25 × 10-3 to 0.87. Correspondingly, the ratio of the transverse perturbative photon flux to the background photon flux varies from 10-28 to 10-16. Supported by National Natural Science Foundation of China (11305181,11322545,11335012) and Open Project Program of State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, China (Y5KF181CJ1)

  5. Thunderstorms as probable reason of high background neutron fluxes on L<1.2

    Science.gov (United States)

    Bratolyubova-Tsulukidze, L.; Grachev, E.; Grigoryan, O.; Kunitsyn, V.; Kuzhevskiy, B.; Nechaev, O.; Usanova, M.

    In this paper we analyze the neutron emission observations made in the experiment onboard MIR orbital station (1991), ISS (2002) and Colibri-2002 satellite (2002) at the altitude of 400 km. The helium discharge detectors made it possible to detect neutrons with energies ranging from 0.25eV to 1.9MeV. The spatial distribution of high background neutron fluxes has a longitude dependence. These events have been observed at -200 ... 600 and 1350 ...1800 ...- 1350 longitudinal intervals. The most intensive fluxes near the geomagnetic equator were registered in the African region. They are not found to be associated with increases of proton fluxes (Ep >50MeV). As a statistical set, the events appear to coincide with the most active region of atmospheric weather. In this paper we assess the possibility that the occurrence of high background neutron fluxes in the African region is connected with lightning discharges. To observe neutron emission at the altitude of 400 km ~101 0 neutrons are required to be produced by lightning discharge. These theoretical predictions suggest cloud charge values of about 250-300 Coulomb.

  6. Extremely high thermal conductivity anisotropy of double-walled carbon nanotubes

    Directory of Open Access Journals (Sweden)

    Zhaoji Ma

    2017-06-01

    Full Text Available Based on molecular dynamics simulations, we reveal that double-walled carbon nanotubes can possess an extremely high anisotropy ratio of radial to axial thermal conductivities. The mechanism is basically the same as that for the high thermal conductivity anisotropy of graphene layers - the in-plane strong sp2 bonds lead to a very high intralayer thermal conductivity while the weak van der Waals interactions to a very low interlayer thermal conductivity. However, different from flat graphene layers, the tubular structures of carbon nanotubes result in a diameter dependent thermal conductivity. The smaller the diameter, the larger the axial thermal conductivity but the smaller the radial thermal conductivity. As a result, a DWCNT with a small diameter may have an anisotropy ratio of thermal conductivity significantly higher than that for graphene layers. The extremely high thermal conductivity anisotropy allows DWCNTs to be a promising candidate for thermal management materials.

  7. Extremely high thermal conductivity anisotropy of double-walled carbon nanotubes

    Science.gov (United States)

    Ma, Zhaoji; Guo, Zhengrong; Zhang, Hongwei; Chang, Tienchong

    2017-06-01

    Based on molecular dynamics simulations, we reveal that double-walled carbon nanotubes can possess an extremely high anisotropy ratio of radial to axial thermal conductivities. The mechanism is basically the same as that for the high thermal conductivity anisotropy of graphene layers - the in-plane strong sp2 bonds lead to a very high intralayer thermal conductivity while the weak van der Waals interactions to a very low interlayer thermal conductivity. However, different from flat graphene layers, the tubular structures of carbon nanotubes result in a diameter dependent thermal conductivity. The smaller the diameter, the larger the axial thermal conductivity but the smaller the radial thermal conductivity. As a result, a DWCNT with a small diameter may have an anisotropy ratio of thermal conductivity significantly higher than that for graphene layers. The extremely high thermal conductivity anisotropy allows DWCNTs to be a promising candidate for thermal management materials.

  8. Green house gas flux at high latitudes - constraints and susceptibility to a changing climate

    Science.gov (United States)

    Nilsson, M. B.

    2015-12-01

    High latitude boreal forests and peatlands contribute importantly to the land-atmosphere exchange of both carbon dioxide and methane. High latitude biomes are also identified as most vulnerable to changing climate. High latitudes are characterized by a strong seasonality in incoming solar radiation, weather conditions and biogeochemical processes. The strong seasonality in incoming solar radiation, not to change in response to a changing climate, constitute firm constraints on how changes in air temperature, evapotranspiration and precipitation will affect biogeochemical processes underlying the land atmosphere exchange of green house gases. Timing of the soil frost thaw and plant phenology thus constitutes two master controls on how fluxes of both CO2 and CH4 will be affected by weather conditions. In addition also the wintertime conditions importantly affect GHG fluxes both during winter time as well as during the succeeding summer. Examples will primarily be given for peatlands and coniferous forests.

  9. Deuterium-induced nanostructure formation on tungsten exposed to high-flux plasma

    Energy Technology Data Exchange (ETDEWEB)

    Xu, H.Y., E-mail: donaxu@163.com [Key Laboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Science and Technology on Surface Physics and Chemistry Laboratory, Mianyang, Sichuan 621907 (China); De Temmerman, G. [FOM Institute DIFFER, Dutch Institute For Fundamental Energy Research, Ass. EURATOM-FOM, Trilateral Euregio Cluster, Postbus 1207, 3430BE Nieuwegein (Netherlands); ITER Organization, Route de Vinon-sur-Verdon CS 90046-13067, St Paul Lez Durance Cedex (France); Luo, G.-N. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Jia, Y.Z.; Yuan, Y.; Fu, B.Q.; Godfrey, A. [Key Laboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Liu, W., E-mail: liuw@mail.tsinghua.edu.cn [Key Laboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2015-08-15

    Surface topography of polycrystalline tungsten (W) have been examined after exposure to a low-energy (38 eV/D), high-flux (∼1.1–1.5 × 10{sup 24} m{sup −2} s{sup −1}) deuterium plasma in the Pilot-PSI linear plasma device. The methods used were scanning electron microscopy (SEM), transmission electron microscopy (TEM), positron annihilation Doppler broadening (PADB) and grazing incident X-ray diffraction (GI-XRD). After exposure to high flux D plasma, blisters and nanostructures are formed on the W surface. Generation of defects was evidenced by PADB, while high stress and mixture of phases were detected in depth of 50 nm by GI-XRD. TEM observation revealed fluctuations and disordered microstructure on the outmost surface layer. Based on these results, surface reconstruction is considered as a possible mechanism for the formation of defects and nanostructures.

  10. High-throughput data pipelines for metabolic flux analysis in plants.

    Science.gov (United States)

    Poskar, C Hart; Huege, Jan; Krach, Christian; Shachar-Hill, Yair; Junker, Björn H

    2014-01-01

    In this chapter we illustrate the methodology for high-throughput metabolic flux analysis. Central to this is developing an end to end data pipeline, crucial for integrating the wet lab experiments and analytics, combining hardware and software automation, and standardizing data representation providing importers and exporters to support third party tools. The use of existing software at the start, data extraction from the chromatogram, and the end, MFA analysis, allows for the most flexibility in this workflow. Developing iMS2Flux provided a standard, extensible, platform independent tool to act as the "glue" between these end points. Most importantly this tool can be easily adapted to support different data formats, data verification and data correction steps allowing it to be central to managing the data necessary for high-throughput MFA. An additional tool was needed to automate the MFA software and in particular to take advantage of the course grained parallel nature of high-throughput analysis and available high performance computing facilities.In combination these methods show the development of high-throughput pipelines that allow metabolic flux analysis to join as a full member of the omics family.

  11. Physical Exam Risk Factors for Lower Extremity Injury in High School Athletes: A Systematic Review.

    Science.gov (United States)

    Onate, James A; Everhart, Joshua S; Clifton, Daniel R; Best, Thomas M; Borchers, James R; Chaudhari, Ajit M W

    2016-11-01

    A stated goal of the preparticipation physical evaluation (PPE) is to reduce musculoskeletal injury, yet the musculoskeletal portion of the PPE is reportedly of questionable use in assessing lower extremity injury risk in high school-aged athletes. The objectives of this study are: (1) identify clinical assessment tools demonstrated to effectively determine lower extremity injury risk in a prospective setting, and (2) critically assess the methodological quality of prospective lower extremity risk assessment studies that use these tools. A systematic search was performed in PubMed, CINAHL, UptoDate, Google Scholar, Cochrane Reviews, and SportDiscus. Inclusion criteria were prospective injury risk assessment studies involving athletes primarily ages 13 to 19 that used screening methods that did not require highly specialized equipment. Methodological quality was evaluated with a modified physiotherapy evidence database (PEDro) scale. Nine studies were included. The mean modified PEDro score was 6.0/10 (SD, 1.5). Multidirectional balance (odds ratio [OR], 3.0; CI, 1.5-6.1; P < 0.05) and physical maturation status (P < 0.05) were predictive of overall injury risk, knee hyperextension was predictive of anterior cruciate ligament injury (OR, 5.0; CI, 1.2-18.4; P < 0.05), hip external:internal rotator strength ratio of patellofemoral pain syndrome (P = 0.02), and foot posture index of ankle sprain (r = -0.339, P = 0.008). Minimal prospective evidence supports or refutes the use of the functional musculoskeletal exam portion of the current PPE to assess lower extremity injury risk in high school athletes. Limited evidence does support inclusion of multidirectional balance assessment and physical maturation status in a musculoskeletal exam as both are generalizable risk factors for lower extremity injury.

  12. Physical Exam Risk Factors for Lower Extremity Injury in High School Athletes: A Systematic Review

    Science.gov (United States)

    Onate, James A.; Everhart, Joshua S.; Clifton, Daniel R.; Best, Thomas M.; Borchers, James R.; Chaudhari, Ajit M.W.

    2016-01-01

    Objective A stated goal of the preparticipation physical evaluation (PPE) is to reduce musculoskeletal injury, yet the musculoskeletal portion of the PPE is reportedly of questionable use in assessing lower extremity injury risk in high school-aged athletes. The objectives of this study are: (1) identify clinical assessment tools demonstrated to effectively determine lower extremity injury risk in a prospective setting, and (2) critically assess the methodological quality of prospective lower extremity risk assessment studies that use these tools. Data Sources A systematic search was performed in PubMed, CINAHL, UptoDate, Google Scholar, Cochrane Reviews, and SportDiscus. Inclusion criteria were prospective injury risk assessment studies involving athletes primarily ages 13 to 19 that used screening methods that did not require highly specialized equipment. Methodological quality was evaluated with a modified physiotherapy evidence database (PEDro) scale. Main Results Nine studies were included. The mean modified PEDro score was 6.0/10 (SD, 1.5). Multidirectional balance (odds ratio [OR], 3.0; CI, 1.5–6.1; P anterior cruciate ligament injury (OR, 5.0; CI, 1.2–18.4; P < 0.05), hip external: internal rotator strength ratio of patellofemoral pain syndrome (P = 0.02), and foot posture index of ankle sprain (r = −0.339, P = 0.008). Conclusions Minimal prospective evidence supports or refutes the use of the functional musculoskeletal exam portion of the current PPE to assess lower extremity injury risk in high school athletes. Limited evidence does support inclusion of multidirectional balance assessment and physical maturation status in a musculoskeletal exam as both are generalizable risk factors for lower extremity injury. PMID:26978166

  13. A high-resolution optical measurement system for rapid acquisition of radiation flux density maps

    Science.gov (United States)

    Thelen, Martin; Raeder, Christian; Willsch, Christian; Dibowski, Gerd

    2017-06-01

    To identify the power and flux density of concentrated solar radiation the Institute of Solar Research at the German Aerospace Center (DLR - Deutsches Zentrum für Luft-und Raumfahrt e. V.) has used the camera-based measurement system FATMES (Flux and Temperature Measurement System) since 1995. The disadvantages of low resolution, difficult handling and poor computing power required a revision of the existing measurement system. The measurement system FMAS (Flux Mapping Acquisition system) is equipped with state-of-the-art-hardware, is compatible with computers off-the-shelf and is programmed in LabView. The expenditure of time for an image evaluation is reduced by the factor 60 compared to FATMES. The new measurement system is no longer associated with the facilities Solar Furnace and High Flux Solar Simulator at the DLR in Cologne but is also applicable as a mobile system. The data and the algorithms are transparent throughout the complete process. The measurement accuracy of FMAS is determined to at most ±3 % until now. The error of measurement of FATMES is at least 2 % higher according to the conducted comparison tests.

  14. High flux pinning efficiency by columnar defects dispersed in three directions in YBCO thin films

    Science.gov (United States)

    Sueyoshi, Tetsuro; Nishimura, Takahiro; Fujiyoshi, Takanori; Mitsugi, Fumiaki; Ikegami, Tomoaki; Ishikawa, Norito

    2016-10-01

    A systematic investigation of flux pinning by widely direction-dispersed columnar defects (CDs) in YBa2Cu3O y thin films was carried out by using heavy-ion irradiation: a parallel configuration of CDs aligned along the c-axis, and two trimodal splay configurations composed of CDs crossing at 0° and ± 45° relative to the c-axis, where the splay plane defined by the three irradiation angles is perpendicular (trimodal-A) or parallel (trimodal-B) to the transport current direction. The trimodal configurations show high pinning efficiency over a wide range of magnetic field orientations compared to the parallel one at low magnetic field. In particular, trimodal-B shows the higher critical current density of the two trimodal configurations. The crossed CDs at ± 45° in the trimodal configurations provide uncorrelated flux pinning at B || c due to the large tilting angle off the c-axis, which effectively reinforce the flux pinning of CDs parallel to the c-axis. This assist effect is more remarkable for trimodal-B: a kink sliding motion of flux lines along the CDs is more effectively reduced by the splay plane, not only at B || c but also at inclined magnetic fields off the c-axis.

  15. Development of Advanced Thermal and Environmental Barrier Coatings Using a High-Heat-Flux Testing Approach

    Science.gov (United States)

    Zhu, Dongming; Miller, Robert A.

    2003-01-01

    The development of low conductivity, robust thermal and environmental barrier coatings requires advanced testing techniques that can accurately and effectively evaluate coating thermal conductivity and cyclic resistance at very high surface temperatures (up to 1700 C) under large thermal gradients. In this study, a laser high-heat-flux test approach is established for evaluating advanced low conductivity, high temperature capability thermal and environmental barrier coatings under the NASA Ultra Efficient Engine Technology (UEET) program. The test approach emphasizes the real-time monitoring and assessment of the coating thermal conductivity, which initially rises under the steady-state high temperature thermal gradient test due to coating sintering, and later drops under the cyclic thermal gradient test due to coating cracking/delamination. The coating system is then evaluated based on damage accumulation and failure after the combined steady-state and cyclic thermal gradient tests. The lattice and radiation thermal conductivity of advanced ceramic coatings can also be evaluated using laser heat-flux techniques. The external radiation resistance of the coating is assessed based on the measured specimen temperature response under a laser- heated intense radiation-flux source. The coating internal radiation contribution is investigated based on the measured apparent coating conductivity increases with the coating surface test temperature under large thermal gradient test conditions. Since an increased radiation contribution is observed at these very high surface test temperatures, by varying the laser heat-flux and coating average test temperature, the complex relation between the lattice and radiation conductivity as a function of surface and interface test temperature may be derived.

  16. High-Heat-Flux Cyclic Durability of Thermal and Environmental Barrier Coatings

    Science.gov (United States)

    Zhu, Dongming; Ghosn, Louis L.; Miller, Robert A.

    2007-01-01

    Advanced ceramic thermal and environmental barrier coatings will play an increasingly important role in future gas turbine engines because of their ability to protect the engine components and further raise engine temperatures. For the supersonic vehicles currently envisioned in the NASA fundamental aeronautics program, advanced gas turbine engines will be used to provide high power density thrust during the extended supersonic flight of the aircraft, while meeting stringent low emission requirements. Advanced ceramic coating systems are critical to the performance, life and durability of the hot-section components of the engine systems. In this work, the laser and burner rig based high-heat-flux testing approaches were developed to investigate the coating cyclic response and failure mechanisms under simulated supersonic long-duration cruise mission. The accelerated coating cracking and delamination mechanism under the engine high-heat-flux, and extended supersonic cruise time conditions will be addressed. A coating life prediction framework may be realized by examining the crack initiation and propagation in conjunction with environmental degradation under high-heat-flux test conditions.

  17. Influence of high flux hydrogen-plasma exposure on the thermal shock induced crack formation in tungsten

    NARCIS (Netherlands)

    Wirtz, M.; Linke, J.; Pintsuk, G.; Rapp, J.; Wright, G. M.

    2012-01-01

    The influence of high flux hydrogen-plasma on the thermal shock behaviour of tungsten was investigated in a combined experiment using the linear plasma device Pilot-PSI and the electron beam facility JUDITH 1. Tungsten targets were exposed to high flux hydrogen plasma, cyclic thermal shock tests and

  18. A simple recipe for setting up the flux equations of cyclic and linear reaction schemes of ion transport with a high number of states: The arrow scheme.

    Science.gov (United States)

    Hansen, Ulf-Peter; Rauh, Oliver; Schroeder, Indra

    2016-01-01

    The calculation of flux equations or current-voltage relationships in reaction kinetic models with a high number of states can be very cumbersome. Here, a recipe based on an arrow scheme is presented, which yields a straightforward access to the minimum form of the flux equations and the occupation probability of the involved states in cyclic and linear reaction schemes. This is extremely simple for cyclic schemes without branches. If branches are involved, the effort of setting up the equations is a little bit higher. However, also here a straightforward recipe making use of so-called reserve factors is provided for implementing the branches into the cyclic scheme, thus enabling also a simple treatment of such cases.

  19. Quasi-B-mode generated by high-frequency gravitational waves and corresponding perturbative photon fluxes

    Energy Technology Data Exchange (ETDEWEB)

    Li, Fangyu, E-mail: cqufangyuli@hotmail.com [Institute of Gravitational Physics, Department of Physics, Chongqing University, Chongqing 400044 (China); Wen, Hao [Institute of Gravitational Physics, Department of Physics, Chongqing University, Chongqing 400044 (China); State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China); Fang, Zhenyun [Institute of Gravitational Physics, Department of Physics, Chongqing University, Chongqing 400044 (China); Wei, Lianfu; Wang, Yiwen; Zhang, Miao [Quantum Optoelectronics Laboratory, Southwest Jiaotong University, Chengdu 610031 (China)

    2016-10-15

    Interaction of very low-frequency primordial (relic) gravitational waves (GWs) to cosmic microwave background (CMB) can generate B-mode polarization. Here, for the first time we point out that the electromagnetic (EM) response to high-frequency GWs (HFGWs) would produce quasi-B-mode distribution of the perturbative photon fluxes. We study the duality and high complementarity between such two B-modes, and it is shown that such two effects are from the same physical origin: the tensor perturbation of the GWs and not the density perturbation. Based on this quasi-B-mode in HFGWs and related numerical calculation, it is shown that the distinguishing and observing of HFGWs from the braneworld would be quite possible due to their large amplitude, higher frequency and very different physical behaviors between the perturbative photon fluxes and background photons, and the measurement of relic HFGWs may also be possible though face to enormous challenge.

  20. Quasi-B-mode generated by high-frequency gravitational waves and corresponding perturbative photon fluxes

    Science.gov (United States)

    Li, Fangyu; Wen, Hao; Fang, Zhenyun; Wei, Lianfu; Wang, Yiwen; Zhang, Miao

    2016-10-01

    Interaction of very low-frequency primordial (relic) gravitational waves (GWs) to cosmic microwave background (CMB) can generate B-mode polarization. Here, for the first time we point out that the electromagnetic (EM) response to high-frequency GWs (HFGWs) would produce quasi-B-mode distribution of the perturbative photon fluxes. We study the duality and high complementarity between such two B-modes, and it is shown that such two effects are from the same physical origin: the tensor perturbation of the GWs and not the density perturbation. Based on this quasi-B-mode in HFGWs and related numerical calculation, it is shown that the distinguishing and observing of HFGWs from the braneworld would be quite possible due to their large amplitude, higher frequency and very different physical behaviors between the perturbative photon fluxes and background photons, and the measurement of relic HFGWs may also be possible though face to enormous challenge.

  1. Successful Utilization of High-Flux Hemodialysis for Treatment of Vancomycin Toxicity in a Child

    Directory of Open Access Journals (Sweden)

    Timothy Stidham

    2011-01-01

    Full Text Available Vancomycin is routinely used for empiric antibiotic therapy in children. Higher-serum-concentration targets for serious infections are now being recommended. This recommendation may result in aggressive dosing with increased potential for toxicity. We report a case of a pediatric patient who developed vancomycin toxicity and associated oliguric renal failure who was treated effectively with high-flux hemodialysis for vancomycin toxicity, clearing serum concentrations of vancomycin by over 75% in only 6 hours (213.2 mcg/mL to 51.8 mcg/mL with subsequent return to baseline renal function and without adverse sequelae. While not historically considered a viable option for drug removal in cases of toxicity, new high-flux hemodialysis techniques can remove significant percentages of vancomycin in short periods of time.

  2. Comparative assessment of surface fluxes from different sources using probability density distributions

    Science.gov (United States)

    Gulev, Sergey; Tilinina, Natalia; Belyaev, Konstantin

    2015-04-01

    Surface turbulent heat fluxes from modern era and first generation reanalyses (NCEP-DOE, ERA-Interim, MERRA NCEP-CFSR, JRA) as well as from satellite products (SEAFLUX, IFREMER, HOAPS) were intercompared using framework of probability distributions for sensible and latent heat fluxes. For approximation of probability distributions and estimation of extreme flux values Modified Fisher-Tippett (MFT) distribution has been used. Besides mean flux values, consideration is given to the comparative analysis of (i) parameters of the MFT probability density functions (scale and location), (ii) extreme flux values corresponding high order percentiles of fluxes (e.g. 99th and higher) and (iii) fractional contribution of extreme surface flux events in the total surface turbulent fluxes integrated over months and seasons. The latter was estimated using both fractional distribution derived from MFT and empirical estimates based upon occurrence histograms. The strongest differences in the parameters of probability distributions of surface fluxes and extreme surface flux values between different reanalyses are found in the western boundary current extension regions and high latitudes, while the highest differences in the fractional contributions of surface fluxes may occur in mid ocean regions being closely associated with atmospheric synoptic dynamics. Generally, satellite surface flux products demonstrate relatively stronger extreme fluxes compared to reanalyses, even in the Northern Hemisphere midlatitudes where data assimilation input in reanalyses is quite dense compared to the Southern Ocean regions.

  3. Review of current status of high flux heat transfer techniques. Volume I. Text + Appendix A

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, W.H.; Gordon, H.S.; Lackner, H.; Mettling, J.R.; Miller, J.E.

    1980-09-01

    The scope of this work comprised two tasks. The first was to review high heat flux technology with consideration given to heat transfer panel configuration, diagnostics techniques and coolant supply. The second task was to prepare a report describing the findings of the review, to recommend the technology offering the least uncertainty for scale-up for the MFTF-B requirement and to recommend any new or perceived requirements for R and D effort.

  4. Concepts for using trapped-flux bulk high-temperature superconductor in motors and generators

    Science.gov (United States)

    Hull, John R.; Strasik, Michael

    2010-12-01

    We review previous concepts for using bulk high-temperature superconductors (HTSs) in motors and generators and discuss methods for using trapped-flux (TF) HTSs in motors and generators that have been recently investigated in our laboratory. We examine the expected performance of a brushless motor/generator that uses TF bulk HTSs to provide magnetomotive force, where the stator windings are used to create the TF. A key feature is the use of dysprosium for the stator and rotor cores.

  5. Concepts for using trapped-flux bulk high-temperature superconductor in motors and generators

    Energy Technology Data Exchange (ETDEWEB)

    Hull, John R; Strasik, Michael [Boeing Research and Technology, PO Box 3707, MC 2T-50, Seattle, WA 98124-2207 (United States)

    2010-12-15

    We review previous concepts for using bulk high-temperature superconductors (HTSs) in motors and generators and discuss methods for using trapped-flux (TF) HTSs in motors and generators that have been recently investigated in our laboratory. We examine the expected performance of a brushless motor/generator that uses TF bulk HTSs to provide magnetomotive force, where the stator windings are used to create the TF. A key feature is the use of dysprosium for the stator and rotor cores.

  6. Flux flow resistivity and vortex viscosity of high-$T_{c}$ films

    CERN Document Server

    Martin, J I; Guinea, F; Vicent, J L

    1996-01-01

    The flux flow regime of high-T$_{\\rm c}$ samples of different normal state resistivities is studied in the temperature range where the sign of the Hall effect is reversed. The scaling of the vortex viscosity with normal state resistivity is consistent with the Bardeen-Stephen theory. Estimates of the influence of possible mechanisms suggested for the sign reversal of the Hall effect are also given.

  7. Numerical prediction of nucleate pool boiling heat transfer coefficient under high heat fluxes

    OpenAIRE

    Pezo Milada L.; Stevanović Vladimir D.

    2016-01-01

    This paper presents CFD (Computational Fluid Dynamics) approach to prediction of the heat transfer coefficient for nucleate pool boiling under high heat fluxes. Three-dimensional numerical simulations of the atmospheric saturated pool boiling are performed. Mathematical modelling of pool boiling requires a treatment of vapor-liquid two-phase mixture on the macro level, as well as on the micro level, such as bubble growth and departure from the heating surfa...

  8. Neutron Radiography Facility at IBR-2 High Flux Pulsed Reactor: First Results

    Science.gov (United States)

    Kozlenko, D. P.; Kichanov, S. E.; Lukin, E. V.; Rutkauskas, A. V.; Bokuchava, G. D.; Savenko, B. N.; Pakhnevich, A. V.; Rozanov, A. Yu.

    A neutron radiography and tomography facilityhave been developed recently at the IBR-2 high flux pulsed reactor. The facility is operated with the CCD-camera based detector having maximal field of view of 20x20 cm, and the L/D ratio can be varied in the range 200 - 2000. The first results of the radiography and tomography experiments with industrial materials and products, paleontological and geophysical objects, meteorites, are presented.

  9. Deuterium-induced nanostructure formation on tungsten exposed to high-flux plasma

    NARCIS (Netherlands)

    Xu, H.Y.; De Temmerman, G.; Luo, G. N.; Jia, Y. Z.; Yuan, Y.; Fu, B. Q.; Godfrey, A.; Liu, W.

    2015-01-01

    Surface topography of polycrystalline tungsten (W) have been examined after exposure to a low-energy (38 eV/D), high-flux (∼1.1–1.5 × 1024 m−2 s−1) deuterium plasma in the Pilot-PSI linear plasma device. The methods used were scanning electron microscopy

  10. On the Relationship Between High Speed Solar Wind Streams and Radiation Belt Electron Fluxes

    Science.gov (United States)

    Zheng, Yihua

    2011-01-01

    Both past and recent research results indicate that solar wind speed has a close connection to radiation belt electron fluxes [e.g., Paulikas and Blake, 1979; Reeves et aI., 2011]: a higher solar wind speed is often associated with a higher level of radiation electron fluxes. But the relationship can be very complex [Reeves et aI., 2011]. The study presented here provides further corroboration of this viewpoint by emphasizing the importance of a global perspective and time history. We find that all the events during years 2010 and 2011 where the >0.8 MeV integral electron flux exceeds 10(exp 5) particles/sq cm/sr/s (pfu) at GEO orbit are associated with the high speed streams (HSS) following the onset of the Stream Interaction Region (SIR), with most of them belonging to the long-lasting Corotating Interaction Region (CIR). Our preliminary results indicate that during HSS events, a maximum speed of 700 km/s and above is a sufficient but not necessary condition for the > 0.8 MeV electron flux to reach 10(exp 5) pfu. But in the exception cases of HSS events where the electron flux level exceeds the 10(exp 5) pfu value but the maximum solar wind speed is less than 700 km/s, a prior impact can be noted either from a CME or a transient SIR within 3-4 days before the arrival of the HSS - stressing the importance of time history. Through superposed epoch analysis and studies providing comparisons with the CME events and the HSS events where the flux level fails to reach the 10(exp 5) pfu, we will present the quantitative assessment of behaviors and relationships of various quantities, such as the time it takes to reach the flux threshold value from the stream interface and its dependence on different physical parameters (e.g., duration of the HSS event, its maximum or average of the solar wind speed, IMF Bz, Kp). The ultimate goal is to apply what is derived to space weather forecasting.

  11. Advanced Multiphysics Thermal-Hydraulics Models for the High Flux Isotope Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Prashant K [ORNL; Freels, James D [ORNL

    2015-01-01

    Engineering design studies to determine the feasibility of converting the High Flux Isotope Reactor (HFIR) from using highly enriched uranium (HEU) to low-enriched uranium (LEU) fuel are ongoing at Oak Ridge National Laboratory (ORNL). This work is part of an effort sponsored by the US Department of Energy (DOE) Reactor Conversion Program. HFIR is a very high flux pressurized light-water-cooled and moderated flux-trap type research reactor. HFIR s current missions are to support neutron scattering experiments, isotope production, and materials irradiation, including neutron activation analysis. Advanced three-dimensional multiphysics models of HFIR fuel were developed in COMSOL software for safety basis (worst case) operating conditions. Several types of physics including multilayer heat conduction, conjugate heat transfer, turbulent flows (RANS model) and structural mechanics were combined and solved for HFIR s inner and outer fuel elements. Alternate design features of the new LEU fuel were evaluated using these multiphysics models. This work led to a new, preliminary reference LEU design that combines a permanent absorber in the lower unfueled region of all of the fuel plates, a burnable absorber in the inner element side plates, and a relocated and reshaped (but still radially contoured) fuel zone. Preliminary results of estimated thermal safety margins are presented. Fuel design studies and model enhancement continue.

  12. Thermal shock behaviour of tungsten after high flux H-plasma loading

    Science.gov (United States)

    Wirtz, M.; Linke, J.; Pintsuk, G.; De Temmerman, G.; Wright, G. M.

    2013-11-01

    Previous studies have shown that transient thermal shock loads induce crack networks on tungsten samples especially at low base temperatures. To achieve test conditions which are more relevant for the performance of tungsten-armoured plasma facing components in next step thermonuclear fusion devices tungsten tiles were exposed to high flux hydrogen-plasma in the linear plasma generator Pilot-PSI and the high heat flux ion beam test facility MARION. Subsequently, the cyclic transient heat load tests were done in the electron beam facility JUDITH 1. The induced damages after these combined tests were examined by microscopically means, profilometry and metallography. The comparison of the obtained results and damage characteristics with those obtained after thermal shock loading show that the preloading of tungsten targets with high flux hydrogen-plasma has significant influence on the thermal shock behaviour of tungsten in terms of crack distance, width, and depth as well as cracked area. Furthermore the plasma parameters, in particular pulse duration and sample temperature during loading, have strong impact on the damage pattern after thermal shock loading.

  13. Application of the successive linear programming technique to the optimum design of a high flux reactor using LEU fuel

    Energy Technology Data Exchange (ETDEWEB)

    Mo, S.C.

    1991-01-01

    The successive linear programming technique is applied to obtain the optimum thermal flux in the reflector region of a high flux reactor using LEU fuel. The design variables are the reactor power, core radius and coolant channel thickness. The constraints are the cycle length, average heat flux and peak/average power density ratio. The characteristics of the optimum solutions with various constraints are discussed.

  14. Application of the successive linear programming technique to the optimum design of a high flux reactor using LEU fuel

    Energy Technology Data Exchange (ETDEWEB)

    Mo, S.C.

    1991-12-31

    The successive linear programming technique is applied to obtain the optimum thermal flux in the reflector region of a high flux reactor using LEU fuel. The design variables are the reactor power, core radius and coolant channel thickness. The constraints are the cycle length, average heat flux and peak/average power density ratio. The characteristics of the optimum solutions with various constraints are discussed.

  15. Explanation for the Low Flux of High Energy Astrophysical Muon Neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Pakvasa, Sandip [Department of Physics and Astronomy, University of Hawaii, Honolulu, HI 96822 (United States); Joshipura, Anjan; Mohanty, Subhendra [Physical Research Laboratory, Ahmedabad, India 380009 (India)

    2014-01-15

    There has been some concern about the unexpected paucity of cosmic high energy muon neutrinos in detectors probing the energy region beyond 1 PeV. As a possible solution we consider the possibility that some exotic neutrino property is responsible for reducing the muon neutrino flux at high energies from distant sources; specifically, we consider: (i) neutrino decay and (ii) neutrinos being pseudo-Dirac particles. This would provide a mechanism for the reduction of high energy muon events in the IceCube detector, for example.

  16. Explanation for the low flux of high-energy astrophysical muon neutrinos.

    Science.gov (United States)

    Pakvasa, Sandip; Joshipura, Anjan; Mohanty, Subhendra

    2013-04-26

    There has been some concern about the unexpected paucity of cosmic high-energy muon neutrinos in detectors probing the energy region beyond 1 PeV. As a possible solution we consider the possibility that some exotic neutrino property is responsible for reducing the muon neutrino flux at high energies from distant sources; specifically, we consider (i) neutrino decay and (ii) neutrinos being pseudo-Dirac-particles. This would provide a mechanism for the reduction of high-energy muon events in the IceCube detector, for example.

  17. Large Differences in Bacterial Community Composition among Three Nearby Extreme Waterbodies of the High Andean Plateau.

    Science.gov (United States)

    Aguilar, Pablo; Acosta, Eduardo; Dorador, Cristina; Sommaruga, Ruben

    2016-01-01

    The high Andean plateau or Altiplano contains different waterbodies that are subjected to extreme fluctuations in abiotic conditions on a daily and an annual scale. The bacterial diversity and community composition of those shallow waterbodies is largely unexplored, particularly, of the ponds embedded within the peatland landscape (i.e., Bofedales). Here we compare the small-scale spatial variability (Altiplano peatland ponds represent a hitherto unknown source of microbial diversity.

  18. B-2 Extremely High Frequency SATCOM and Computer Increment 1 (B-2 EHF Inc 1)

    Science.gov (United States)

    2015-12-01

    Selected Acquisition Report (SAR) RCS: DD-A&T(Q&A)823-224 B-2 Extremely High Frequency SATCOM and Computer Increment 1 (B-2 EHF Inc 1) As of FY...10 Track to Budget 11 Cost and Funding 13 Low Rate Initial Production 19 Foreign Military Sales 20 Nuclear Costs 20 Unit Cost...Document CLIN - Contract Line Item Number CPD - Capability Production Document CY - Calendar Year DAB - Defense Acquisition Board DAE - Defense

  19. Environmental Assessment for the Advanced Extremely High Frequency Satellite Beddown and Deployment Program

    Science.gov (United States)

    2010-07-01

    Fish and Wildlife Service Advanced Extremely High Frequency Satellite Final Environmental Assessment v VIF Vehicle Integration Facility WMO World...Vehicle Mate Operations Upon arrival on CCAFS, the transporter would take the encapsulated payload to the Vehicle Integration Facility ( VIF ), which...is located just south of LC-41 (Figure 2-2). At the VIF , the encapsulated payload would be mated to the Atlas V Launch Vehicle (LV) using a mobile

  20. Limits to the thermal tolerance of corals adapted to a highly fluctuating, naturally extreme temperature environment

    Science.gov (United States)

    Schoepf, Verena; Stat, Michael; Falter, James L.; McCulloch, Malcolm T.

    2015-12-01

    Naturally extreme temperature environments can provide important insights into the processes underlying coral thermal tolerance. We determined the bleaching resistance of Acropora aspera and Dipsastraea sp. from both intertidal and subtidal environments of the naturally extreme Kimberley region in northwest Australia. Here tides of up to 10 m can cause aerial exposure of corals and temperatures as high as 37 °C that fluctuate daily by up to 7 °C. Control corals were maintained at ambient nearshore temperatures which varied diurnally by 4-5 °C, while treatment corals were exposed to similar diurnal variations and heat stress corresponding to ~20 degree heating days. All corals hosted Symbiodinium clade C independent of treatment or origin. Detailed physiological measurements showed that these corals were nevertheless highly sensitive to daily average temperatures exceeding their maximum monthly mean of ~31 °C by 1 °C for only a few days. Generally, Acropora was much more susceptible to bleaching than Dipsastraea and experienced up to 75% mortality, whereas all Dipsastraea survived. Furthermore, subtidal corals, which originated from a more thermally stable environment compared to intertidal corals, were more susceptible to bleaching. This demonstrates that while highly fluctuating temperatures enhance coral resilience to thermal stress, they do not provide immunity to extreme heat stress events.

  1. Limits to the thermal tolerance of corals adapted to a highly fluctuating, naturally extreme temperature environment.

    Science.gov (United States)

    Schoepf, Verena; Stat, Michael; Falter, James L; McCulloch, Malcolm T

    2015-12-02

    Naturally extreme temperature environments can provide important insights into the processes underlying coral thermal tolerance. We determined the bleaching resistance of Acropora aspera and Dipsastraea sp. from both intertidal and subtidal environments of the naturally extreme Kimberley region in northwest Australia. Here tides of up to 10 m can cause aerial exposure of corals and temperatures as high as 37 °C that fluctuate daily by up to 7 °C. Control corals were maintained at ambient nearshore temperatures which varied diurnally by 4-5 °C, while treatment corals were exposed to similar diurnal variations and heat stress corresponding to ~20 degree heating days. All corals hosted Symbiodinium clade C independent of treatment or origin. Detailed physiological measurements showed that these corals were nevertheless highly sensitive to daily average temperatures exceeding their maximum monthly mean of ~31 °C by 1 °C for only a few days. Generally, Acropora was much more susceptible to bleaching than Dipsastraea and experienced up to 75% mortality, whereas all Dipsastraea survived. Furthermore, subtidal corals, which originated from a more thermally stable environment compared to intertidal corals, were more susceptible to bleaching. This demonstrates that while highly fluctuating temperatures enhance coral resilience to thermal stress, they do not provide immunity to extreme heat stress events.

  2. Eddy covariance flux measurements of ammonia by high temperature chemical ionisation mass spectrometry

    Directory of Open Access Journals (Sweden)

    J. Sintermann

    2011-03-01

    Full Text Available A system for fast ammonia (NH3 measurements with chemical ionisation mass spectrometry (CIMS based on a commercial Proton Transfer Reaction-Mass Spectrometer (PTR-MS is presented. It uses electron transfer reaction as ionisation pathway and features a drift tube of polyetheretherketone (PEEK and silica-coated steel. Heating the instrumental inlet and the drift tube to 180 °C enabled an effective time resolution of ~1 s and made it possible to apply the instrument for eddy covariance (EC measurements. EC fluxes of NH3 were measured over two agricultural fields in Oensingen, Switzerland, following fertilisations with cattle slurry. Air was aspirated close to a sonic anemometer at a flow of 100 STP L min−1 and was directed through a 23 m long 1/2" PFA tube heated to 150 °C to an air-conditioned trailer where the gas was sub-sampled from the large bypass stream. This setup minimised damping of fast NH3 concentration changes between the sampling point and the actual measurement. High-frequency attenuation loss of the NH3 fluxes of 20 to 40% was quantified and corrected for using an empirical ogive method. The instrumental NH3 background signal showed a minor interference with H2O which was characterised in the laboratory. The resulting correction of the NH3 flux after slurry spreading was less than 1‰. The flux detection limit of the EC system was about 5 ng m−2 s−1 while the accuracy of individual flux measurements was estimated 16% for the high-flux regime during these experiments. The NH3 emissions after broad spreading of the slurry showed an initial maximum of 150 μg m−2 s−1 with a fast decline in the following hours.

  3. Advantages and Limits of 4H-SIC Detectors for High- and Low-Flux Radiations

    Science.gov (United States)

    Sciuto, A.; Torrisi, L.; Cannavò, A.; Mazzillo, M.; Calcagno, L.

    2017-07-01

    Silicon carbide (SiC) detectors based on Schottky diodes were used to monitor low and high fluxes of photons and ions. An appropriate choice of the epilayer thickness and geometry of the surface Schottky contact allows the tailoring and optimizing the detector efficiency. SiC detectors with a continuous front electrode were employed to monitor alpha particles in a low-flux regime emitted by a radioactive source with high energy (>5.0 MeV) or generated in an ion implanter with sub-MeV energy. An energy resolution value of 0.5% was measured in the high energy range, while, at energy below 1.0 MeV, the resolution becomes 10%; these values are close to those measured with a traditional silicon detector. The same SiC devices were used in a high-flux regime to monitor high-energy ions, x-rays and electrons of the plasma generated by a high-intensity (1016 W/cm2) pulsed laser. Furthermore, SiC devices with an interdigit Schottky front electrode were proposed and studied to overcome the limits of the such SiC detectors in the detection of low-energy (˜1.0 keV) ions and photons of the plasmas generated by a low-intensity (1010 W/cm2) pulsed laser. SiC detectors are expected to be a powerful tool for the monitoring of radioactive sources and ion beams produced by accelerators, for a complete characterization of radiations emitted from laser-generated plasmas at high and low temperatures, and for dosimetry in a radioprotection field.

  4. Nitrogen accumulation and partitioning in a High Arctic tundra ecosystem from extreme atmospheric N deposition events.

    Science.gov (United States)

    Choudhary, Sonal; Blaud, Aimeric; Osborn, A Mark; Press, Malcolm C; Phoenix, Gareth K

    2016-06-01

    Arctic ecosystems are threatened by pollution from recently detected extreme atmospheric nitrogen (N) deposition events in which up to 90% of the annual N deposition can occur in just a few days. We undertook the first assessment of the fate of N from extreme deposition in High Arctic tundra and are presenting the results from the whole ecosystem (15)N labelling experiment. In 2010, we simulated N depositions at rates of 0, 0.04, 0.4 and 1.2 g Nm(-2)yr(-1), applied as (15)NH4(15)NO3 in Svalbard (79(°)N), during the summer. Separate applications of (15)NO3(-) and (15)NH4(+) were also made to determine the importance of N form in their retention. More than 95% of the total (15)N applied was recovered after one growing season (~90% after two), demonstrating a considerable capacity of Arctic tundra to retain N from these deposition events. Important sinks for the deposited N, regardless of its application rate or form, were non-vascular plants>vascular plants>organic soil>litter>mineral soil, suggesting that non-vascular plants could be the primary component of this ecosystem to undergo measurable changes due to N enrichment from extreme deposition events. Substantial retention of N by soil microbial biomass (70% and 39% of (15)N in organic and mineral horizon, respectively) during the initial partitioning demonstrated their capacity to act as effective buffers for N leaching. Between the two N forms, vascular plants (Salix polaris) in particular showed difference in their N recovery, incorporating four times greater (15)NO3(-) than (15)NH4(+), suggesting deposition rich in nitrate will impact them more. Overall, these findings show that despite the deposition rates being extreme in statistical terms, biologically they do not exceed the capacity of tundra to sequester pollutant N during the growing season. Therefore, current and future extreme events may represent a major source of eutrophication.

  5. Nitrogen accumulation and partitioning in a High Arctic tundra ecosystem from extreme atmospheric N deposition events

    Energy Technology Data Exchange (ETDEWEB)

    Choudhary, Sonal, E-mail: S.Choudhary@sheffield.ac.uk [Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN (United Kingdom); Management School, University of Sheffield, Conduit Road, Sheffield S10 1FL (United Kingdom); Blaud, Aimeric [Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN (United Kingdom); Osborn, A. Mark [Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN (United Kingdom); School of Applied Sciences, RMIT University, PO Box 71, Bundoora, VIC 3083 (Australia); Press, Malcolm C. [School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Manchester Metropolitan University, Manchester, M15 6BH (United Kingdom); Phoenix, Gareth K. [Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN (United Kingdom)

    2016-06-01

    Arctic ecosystems are threatened by pollution from recently detected extreme atmospheric nitrogen (N) deposition events in which up to 90% of the annual N deposition can occur in just a few days. We undertook the first assessment of the fate of N from extreme deposition in High Arctic tundra and are presenting the results from the whole ecosystem {sup 15}N labelling experiment. In 2010, we simulated N depositions at rates of 0, 0.04, 0.4 and 1.2 g N m{sup −2} yr{sup −1}, applied as {sup 15}NH{sub 4}{sup 15}NO{sub 3} in Svalbard (79{sup °}N), during the summer. Separate applications of {sup 15}NO{sub 3}{sup −} and {sup 15}NH{sub 4}{sup +} were also made to determine the importance of N form in their retention. More than 95% of the total {sup 15}N applied was recovered after one growing season (~ 90% after two), demonstrating a considerable capacity of Arctic tundra to retain N from these deposition events. Important sinks for the deposited N, regardless of its application rate or form, were non-vascular plants > vascular plants > organic soil > litter > mineral soil, suggesting that non-vascular plants could be the primary component of this ecosystem to undergo measurable changes due to N enrichment from extreme deposition events. Substantial retention of N by soil microbial biomass (70% and 39% of {sup 15}N in organic and mineral horizon, respectively) during the initial partitioning demonstrated their capacity to act as effective buffers for N leaching. Between the two N forms, vascular plants (Salix polaris) in particular showed difference in their N recovery, incorporating four times greater {sup 15}NO{sub 3}{sup −} than {sup 15}NH{sub 4}{sup +}, suggesting deposition rich in nitrate will impact them more. Overall, these findings show that despite the deposition rates being extreme in statistical terms, biologically they do not exceed the capacity of tundra to sequester pollutant N during the growing season. Therefore, current and future extreme events

  6. High-resolution projections of mean and extreme precipitations over China through PRECIS under RCPs

    Science.gov (United States)

    Zhu, Jinxin; Huang, Gordon; Wang, Xiuquan; Cheng, Guanhui; Wu, Yinghui

    2017-08-01

    The impact of global warming on the characteristics of mean and extreme precipitations over China is investigated by using the Providing REgional Climate Impacts for Studies (PRECIS) model. The PRECIS model was driven by the Hadley Centre Global Environment Model version 2 with Earth System components and coupling (HadGEM2-ES). The results of both models are analyzed in terms of mean precipitation and indices of precipitation extremes (R95p, R99p, SDII, WDF, and CWD) over China at the resolution of 25 km under the Representative Concentration Pathways 4.5 and 8.5 (RCP4.5 and RCP8.5) scenarios for the baseline period (1976-2005) and two future periods (2036-2065 and 2070-2099). With improved resolution, the PRECIS model is able to better represent the fine-scale physical process than HadGEM2-ES. It can provide reliable spatial patterns of precipitation and its related extremes with high correlations to observations. Moreover, there is a notable improvement in temporal patterns simulation through the PRECIS model. The PRECIS model better reproduces the regional annual cycle and frequencies of daily precipitation intensity than its driving GCM. Under RCP4.5 and RCP8.5, both the HadGEM2-ES and the precis project increasing annual precipitation over the entire country for two future periods. Precipitation increase in winter is greater than the increase in summer. The results suggest that increased radiative forcing from RCP4.5 to RCP8.5 would further intensify the magnitude of projected precipitation changes by both PRECIS and HadGEM2-ES. For example, some parts of south China with decreased precipitation under RCP4.5 would expect even less precipitation under RCP8.5; regions (northwest, northcentral and northeast China) with increased precipitation under RCP4.5 would expect more precipitation under RCP8.5. Apart from the projected increase in annual total precipitation, the results also suggest that there will be an increase in the days with precipitation higher than

  7. Modeling high-energy cosmic ray induced terrestrial muon flux: A lookup table

    CERN Document Server

    Atri, Dimitra

    2010-01-01

    On geological timescales, the Earth is likely to be exposed to an increased flux of high energy cosmic rays (HECRs) from astrophysical sources such as nearby supernovae, gamma ray bursts or by galactic shocks. Typical cosmic ray energies may be much higher than the ~ 1 GeV flux which normally dominates. These high-energy particles strike the Earth's atmosphere initiating an extensive air shower. As the air shower propagates deeper, it ionizes the atmosphere by producing charged secondary particles. Secondary particles such as muons and thermal neutrons produced as a result of nuclear interactions are able to reach the ground, enhancing the radiation dose. Muons contribute 85% to the radiation dose from cosmic rays. This enhanced dose could be potentially harmful to the biosphere. This mechanism has been discussed extensively in literature but has never been quantified. Here, we have developed a lookup table that can be used to quantify this effect by modeling terrestrial muon flux from any arbitrary cosmic ra...

  8. High flux filtration medium based on nanofibrous substrate with hydrophilic nanocomposite coating.

    Science.gov (United States)

    Wang, Xuefen; Chen, Xuming; Yoon, Kyunghwan; Fang, Dufei; Hsiao, Benjamin S; Chu, Benjamin

    2005-10-01

    A novel high flux filtration medium, consisting of a three-tier composite structure, i.e., a nonporous hydrophilic nanocomposite coating top layer, an electrospun nanofibrous substrate midlayer, and a conventional nonwoven microfibrous support, was demonstrated for oil/water emulsion separations for the first time. The nanofibrous substrate was prepared by electrospinning of poly(vinyl alcohol) (PVA) followed by chemical cross-linking with glutaraldehyde (GA) in acetone. The resulting cross-linked PVA substrates showed excellent water resistance and good mechanical properties. The top coating was based on a nanocomposite layer containing hydrophilic polyether-b-polyamide copolymer or a cross-linked PVA hydrogel incorporated with surface-oxidized multiwalled carbon nanotubes (MWNTs). Scanning electron microscopy (SEM) examinations indicated that the nanocomposite layer was nonporous within the instrumental resolution and MWNTs were well dispersed in the polymer matrix. Oil/ water emulsion tests showed that this unique type of filtration media exhibited a high flux rate (up to 330 L/m2-h at the feed pressure of 100 psi) and an excellent total organic solute rejection rate (99.8%) without appreciable fouling. The increase in the concentration of surface-oxidized MWNT in the coating layer generally improves the flux rate, which can be attributed to the generation of more effective hydrophilic nanochannels for water passage in the composite membranes.

  9. High-energy neutrino fluxes and flavor ratio in the Earth atmosphere

    CERN Document Server

    Sinegovskaya, T S; Sinegovsky, S I

    2014-01-01

    High-energy neutrinos from decays of mesons, produced in collisions of cosmic-ray particles with air nuclei, form unavoidable background for detection of astrophysical neutrinos. More precise calculations of the high-energy neutrino spectrum are required since measurements in the IceCube experiment reach the intriguing energy range where a contribution of the prompt neutrinos and/or astrophysical ones should be uncovered. The calculation of muon and electron neutrino fluxes in the energy range 100 GeV - 10 PeV is performed for three hadronic models, QGSJET II, SIBYll 2.1 and Kimel & Mokhov, taking into consideration the "knee" of the cosmic-ray spectrum. All calculations are compared with the atmospheric neutrino measurements by Frejus, AMANDA, IceCube and ANTARES. The prompt neutrino flux predictions obtained with the quark-gluon string model (QGSM) for the charm production by Kaidalov & Piskunova do not contradict to the measurements and upper limits on the astrophysical muon neutrino flux obtained ...

  10. High-accuracy determination of the neutron flux at n{sub T}OF

    Energy Technology Data Exchange (ETDEWEB)

    Barbagallo, M.; Colonna, N.; Mastromarco, M.; Meaze, M.; Tagliente, G.; Variale, V. [Sezione di Bari, INFN, Bari (Italy); Guerrero, C.; Andriamonje, S.; Boccone, V.; Brugger, M.; Calviani, M.; Cerutti, F.; Chin, M.; Ferrari, A.; Kadi, Y.; Losito, R.; Versaci, R.; Vlachoudis, V. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Tsinganis, A. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); National Technical University of Athens (NTUA), Athens (Greece); Tarrio, D.; Duran, I.; Leal-Cidoncha, E.; Paradela, C. [Universidade de Santiago de Compostela, Santiago (Spain); Altstadt, S.; Goebel, K.; Langer, C.; Reifarth, R.; Schmidt, S.; Weigand, M. [Johann-Wolfgang-Goethe Universitaet, Frankfurt (Germany); Andrzejewski, J.; Marganiec, J.; Perkowski, J. [Uniwersytet Lodzki, Lodz (Poland); Audouin, L.; Leong, L.S.; Tassan-Got, L. [Centre National de la Recherche Scientifique/IN2P3 - IPN, Orsay (France); Becares, V.; Cano-Ott, D.; Garcia, A.R.; Gonzalez-Romero, E.; Martinez, T.; Mendoza, E. [Centro de Investigaciones Energeticas Medioambientales y Tecnologicas (CIEMAT), Madrid (Spain); Becvar, F.; Krticka, M.; Kroll, J.; Valenta, S. [Charles University, Prague (Czech Republic); Belloni, F.; Fraval, K.; Gunsing, F.; Lampoudis, C.; Papaevangelou, T. [Commissariata l' Energie Atomique (CEA) Saclay - Irfu, Gif-sur-Yvette (France); Berthoumieux, E.; Chiaveri, E. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Commissariata l' Energie Atomique (CEA) Saclay - Irfu, Gif-sur-Yvette (France); Billowes, J.; Ware, T.; Wright, T. [University of Manchester, Manchester (United Kingdom); Bosnar, D.; Zugec, P. [University of Zagreb, Department of Physics, Faculty of Science, Zagreb (Croatia); Calvino, F.; Cortes, G.; Gomez-Hornillos, M.B.; Riego, A. [Universitat Politecnica de Catalunya, Barcelona (Spain); Carrapico, C.; Goncalves, I.F.; Sarmento, R.; Vaz, P. [Universidade Tecnica de Lisboa, Instituto Tecnologico e Nuclear, Instituto Superior Tecnico, Lisboa (Portugal); Cortes-Giraldo, M.A.; Praena, J.; Quesada, J.M.; Sabate-Gilarte, M. [Universidad de Sevilla, Sevilla (Spain); Diakaki, M.; Karadimos, D.; Kokkoris, M.; Vlastou, R. [National Technical University of Athens (NTUA), Athens (Greece); Domingo-Pardo, C.; Giubrone, G.; Tain, J.L. [CSIC-Universidad de Valencia, Instituto de Fisica Corpuscular, Valencia (Spain); Dressler, R.; Kivel, N.; Schumann, D.; Steinegger, P. [Paul Scherrer Institut, Villigen PSI (Switzerland); Dzysiuk, N.; Mastinu, P.F. [Laboratori Nazionali di Legnaro, INFN, Rome (Italy); Eleftheriadis, C.; Manousos, A. [Aristotle University of Thessaloniki, Thessaloniki (Greece); Ganesan, S.; Gurusamy, P.; Saxena, A. [Bhabha Atomic Research Centre (BARC), Mumbai (IN); Griesmayer, E.; Jericha, E.; Leeb, H. [Technische Universitaet Wien, Atominstitut, Wien (AT); Hernandez-Prieto, A. [European Organization for Nuclear Research (CERN), Geneva (CH); Universitat Politecnica de Catalunya, Barcelona (ES); Jenkins, D.G.; Vermeulen, M.J. [University of York, Heslington, York (GB); Kaeppeler, F. [Institut fuer Kernphysik, Karlsruhe Institute of Technology, Campus Nord, Karlsruhe (DE); Koehler, P. [Oak Ridge National Laboratory (ORNL), Oak Ridge (US); Lederer, C. [Johann-Wolfgang-Goethe Universitaet, Frankfurt (DE); University of Vienna, Faculty of Physics, Vienna (AT); Massimi, C.; Mingrone, F.; Vannini, G. [Universita di Bologna (IT); INFN, Sezione di Bologna, Dipartimento di Fisica, Bologna (IT); Mengoni, A.; Ventura, A. [Agenzia nazionale per le nuove tecnologie, l' energia e lo sviluppo economico sostenibile (ENEA), Bologna (IT); Milazzo, P.M. [Sezione di Trieste, INFN, Trieste (IT); Mirea, M. [Horia Hulubei National Institute of Physics and Nuclear Engineering - IFIN HH, Bucharest - Magurele (RO); Mondalaers, W.; Plompen, A.; Schillebeeckx, P. [Institute for Reference Materials and Measurements, European Commission JRC, Geel (BE); Pavlik, A.; Wallner, A. [University of Vienna, Faculty of Physics, Vienna (AT); Rauscher, T. [University of Basel, Department of Physics and Astronomy, Basel (CH); Roman, F. [European Organization for Nuclear Research (CERN), Geneva (CH); Horia Hulubei National Institute of Physics and Nuclear Engineering - IFIN HH, Bucharest - Magurele (RO); Rubbia, C. [European Organization for Nuclear Research (CERN), Geneva (CH); Laboratori Nazionali del Gran Sasso dell' INFN, Assergi (AQ) (IT); Weiss, C. [European Organization for Nuclear Research (CERN), Geneva (CH); Johann-Wolfgang-Goethe Universitaet, Frankfurt (DE)

    2013-12-15

    The neutron flux of the n{sub T}OF facility at CERN was measured, after installation of the new spallation target, with four different systems based on three neutron-converting reactions, which represent accepted cross sections standards in different energy regions. A careful comparison and combination of the different measurements allowed us to reach an unprecedented accuracy on the energy dependence of the neutron flux in the very wide range (thermal to 1 GeV) that characterizes the n{sub T}OF neutron beam. This is a pre-requisite for the high accuracy of cross section measurements at n{sub T}OF. An unexpected anomaly in the neutron-induced fission cross section of {sup 235}U is observed in the energy region between 10 and 30keV, hinting at a possible overestimation of this important cross section, well above currently assigned uncertainties. (orig.)

  11. Limits on diffuse fluxes of high energy extraterrestrial neutrinos with the AMANDA-B10 detector

    Energy Technology Data Exchange (ETDEWEB)

    Ahrens, J.; Bai, X.; Barwick, S.W.; Bay, R.C.; Becka, T.; Becker, K.-H.; Bernardini, E.; Bertrand, D.; Binon, F.; Boeser, S.; Botner, O.; Bouchta, A.; Bouhali, O.; Burgess, T.; Carius, S.; Castermans, T.; Chirkin, D.; Conrad, J.; Cooley, J.; Cowen, D.F.; Davour, A.; De Clercq, C.; DeYoung, T.; Desiati, P.; Doksus, P.; Ekstrom, P.; Feser, T.; Gaisser, T.K.; Ganugapati, R.; Gaug, M.; Geenen, H.; Gerhardt, L.; Goldschmidt, A.; Hallgren, A.; Halzen, F.; Hanson, K.; Hardtke, R.; Hauschildt, T.; Hellwig, M.; Herquet, P.; Hill, G.C.; Hulth, P.O.; Hughey, B.; Hultqvist, K.; Hundertmark, S.; Jacobsen, J.; Karle, A.; Kuehn, K.; Kim, J.; Kopke, L.; Kowalski, M.; Lamoureux, J.I.; Leich, H.; Leuthold, M.; Lindahl, P.; Liubarsky, I.; Madsen, J.; Mandli, K.; Marciniewski, P.; Matis, H.S.; McParland, C.P.; Messarius, T.; Miller, T.C.; Minaeva, Y.; Miocinovic, P.; Mock, P.C.; Morse, R.; Neunhoffer, T.; Niessen, P.; Nygren, D.R.; Ogelman, H.; Olbrechts, P.; Perez de los Heros, C.; Pohl, A.C.; Porrata, R.; Price, P.B.; Przybylski, G.T.; Rawlins, K.; Resconi, E.; Rhode, W.; Ribordy, M.; Richter, S.; Rodriguez Martino, J.; Romenesko, P.; Ross, D.; Sander, H.-G.; Schlenstedt, S.; Schinarakis, K.; Schmidt, T.; Schneider, D.; Schwarz, R.; Silvestri, A.; Solarz, M.; Stamatikos, M.; Spiczak, G.M.; Spiering, C.; Steele, D.; Steffen, P.; Stokstad, R.G.; Sulanke, K.-H.; Taboada, I.; Tilav, S.; Wagner, W.; Walck, C.; Wang, Y.-R.; Wiebusch, C.H.; Wiedemann, C.; Wischnewski, R.; Wissing, H.; Woschnagg, K.; Wu, W.; Yodh, G.; Young, S.

    2003-03-11

    Data from the AMANDA-B10 detector taken during the austral winter of 1997 have been searched for a diffuse flux of high energy extraterrestrial muon-neutrinos, as predicted from, e.g., the sum of all active galaxies in the universe. This search yielded no excess events above those expected from the background atmospheric neutrinos, leading to upper limits on the extraterrestrial neutrino flux. For an assumed E{sup -2} spectrum, a 90 percent classical confidence level upper limit has been placed at a level E{sup 2} Phi(E) = 8.4 x 10{sup -7} GeV cm{sup -2} s{sup -1}1 sr{sup -1} (for a predominant neutrino energy range 6-1000 TeV) which is the most restrictive bound placed by any neutrino detector. When specific predicted spectral forms are considered, it is found that some are excluded.

  12. Double-cavity radiometer for high-flux density solar radiation measurements.

    Science.gov (United States)

    Parretta, A; Antonini, A; Armani, M; Nenna, G; Flaminio, G; Pellegrino, M

    2007-04-20

    A radiometric method has been developed, suitable for both total power and flux density profile measurement of concentrated solar radiation. The high-flux density radiation is collected by a first optical cavity, integrated, and driven to a second optical cavity, where, attenuated, it is measured by a conventional radiometer operating under a stationary irradiation regime. The attenuation factor is regulated by properly selecting the aperture areas in the two cavities. The radiometer has been calibrated by a pulsed solar simulator at concentration levels of hundreds of suns. An optical model and a ray-tracing study have also been developed and validated, by which the potentialities of the radiometer have been largely explored.

  13. A Simulator for Producing of High Flux Atomic Oxygen Beam by Using ECR Plasma Source

    Institute of Scientific and Technical Information of China (English)

    Shuwang DUO; Meishuan LI; Yaming ZHANG

    2004-01-01

    In order to study the atomic oxygen corrosion of spacecraft materials in low earth orbit environment, an atomic oxygen simulator was established. In the simulator, a 2.45 GHz microwave source with maximum power of 600 W was launched into the circular cavity to generate ECR (electron cyclotron resonance) plasma. The oxygen ion beam moved onto a negatively biased Mo plate under the condition of symmetry magnetic mirror field confine, then was neutralized and reflected to form oxygen atom beam. The properties of plasma density, electron temperature, plasma space potential and ion incident energy were characterized. The atomic oxygen beam flux was calibrated by measuring the mass loss rate of Kapton during the atomic 5~30 eV and a cross section of φ80 mm could be obtained under the operating pressure of 10-1~10-3 Pa. Such a high flux source can provide accelerated simulation tests of materials and coatings for space applications.

  14. Development of a Scale Model for High Flux Isotope Reactor Cycle 400

    Energy Technology Data Exchange (ETDEWEB)

    Ilas, Dan [ORNL

    2012-03-01

    The development of a comprehensive SCALE computational model for the High Flux Isotope Reactor (HFIR) is documented and discussed in this report. The SCALE model has equivalent features and functionality as the reference MCNP model for Cycle 400 that has been used extensively for HFIR safety analyses and for HFIR experiment design and analyses. Numerical comparisons of the SCALE and MCNP models for the multiplication constant, power density distribution in the fuel, and neutron fluxes at several locations in HFIR indicate excellent agreement between the results predicted with the two models. The SCALE HFIR model is presented in sufficient detail to provide the users of the model with a tool that can be easily customized for various safety analysis or experiment design requirements.

  15. High-flux solar absorber concept for central receiver power plants

    Science.gov (United States)

    Pomeroy, B. D.; Roberts, J. M.; Narayanan, T. V.

    1981-02-01

    For cylindrical receivers with a capacity of about 400 MW/t, an aim-at-the belt focusing strategy can produce average fluxes the order of 0.5 MW/sq m with peaks as high as 2 MW/sq m. An absorber concept is described which uses liquid sodium coolant and a three-header configuration to efficiently capture this solar power. The mechanical design of this absorber is discussed and thermal performance estimates are presented showing the solar-capture efficiency over a range of solar intensities. The sodium-flow characteristics and some potential flow-control problems are also described. A thermal-stress analysis is presented which shows that a limiting factor on the flux capability may be tube-wall creep/fatigue failure and not the heat-transfer capability of sodium.

  16. Optical design of a high radiative flux solar furnace for Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Riveros-Rosas, D.; Perez-Rabago, C.A.; Arancibia-Bulnes, C.A.; Jaramillo, O.A.; Estrada, C.A. [Centro de Investigacion en Energia, Universidad Nacional Autonoma de Mexico, Av. Xochicalco s/n, A.P. 34, Temixco, 62580 Morelos (Mexico); Herrera-Vazquez, J.; Vazquez-Montiel, S.; Granados-Agustin, F. [Instituto Nacional de Astrofisica, Optica y Electronica, Luis Enrique Erro 1, Tonantzintla, A.P. 216, 72000 Puebla (Mexico); Sanchez-Gonzalez, M. [Centro Nacional de Energias Renovables, Calle Somera 7-9, 28026 Madrid (Spain)

    2010-05-15

    In the present work, the optical design of a new high radiative flux solar furnace is described. Several optical configurations for the concentrator of the system have been considered. Ray tracing simulations were carried out in order to determine the concentrated radiative flux distributions in the focal zone of the system, for comparing the different proposals. The best configuration was chosen in terms of maximum peak concentration, but also in terms of economical and other practical considerations. It consists of an arrangement of 409 first surface spherical facets with hexagonal shape, mounted on a spherical frame. The individual orientation of the facets is corrected in order to compensate for aberrations. The design considers an intercepted power of 30 kW and a target peak concentration above 10,000 suns. The effect of optical errors was also considered in the simulations. (author)

  17. A high flux pulsed source of energetic atomic oxygen. [for spacecraft materials ground testing

    Science.gov (United States)

    Krech, Robert H.; Caledonia, George E.

    1986-01-01

    The design and demonstration of a pulsed high flux source of nearly monoenergetic atomic oxygen are reported. In the present test setup, molecular oxygen under several atmospheres of pressure is introduced into an evacuated supersonic expansion nozzle through a pulsed molecular beam valve. A 10J CO2 TEA laser is focused to intensities greater than 10 to the 9th W/sq cm in the nozzle throat, generating a laser-induced breakdown with a resulting 20,000-K plasma. Plasma expansion is confined by the nozzle geometry to promote rapid electron-ion recombination. Average O-atom beam velocities from 5-13 km/s at fluxes up to 10 to the 18th atoms/pulse are measured, and a similar surface oxygen enrichment in polyethylene samples to that obtained on the STS-8 mission is found.

  18. Sputtering yields of carbon based materials under high particle flux with low energy

    Science.gov (United States)

    Nakamura, K.; Nagase, A.; Dairaku, M.; Akiba, M.; Araki, M.; Okumura, Y.

    1995-04-01

    A new ion source which can produce high particle flux beams at low energies has been developed. This paper presents preliminary results on the sputtering yield of the carbon fiber reinforced composites (CFCs) measured with the new ion source. The sputtering yields of 1D and 2D CFCs, which are candidate materials for the divertor armour tiles, have been measured by the weight loss method under the hydrogen and deuterium particle fluxes of 2 ˜ 7 × 10 20/m 2 s at 50 ˜ 150 eV. Preferential sputtering of the matrix was observed on CFCs which included the matrix of 40 ˜ 60 w%. The energy dependence of the sputtering yields was weak. The sputtering yields of CFCs normally irradiated with deuterium beam were from 0.073 to 0.095, and were around three times larger than those with hydrogen beam.

  19. High-flux water desalination with interfacial salt sieving effect in nanoporous carbon composite membranes

    CERN Document Server

    Chen, Wei; Zhang, Qiang; Fan, Zhongli; Huang, Kuo-Wei; Zhang, Xixiang; Lai, Zhiping; Sheng, Ping

    2016-01-01

    Nanoporous carbon composite membranes, comprising a layer of porous carbon fiber structures with an average channel width of 30-60 nm grown on a porous ceramic substrate, are found to exhibit robust desalination effect with high freshwater flux. In three different membrane processes of vacuum membrane distillation, reverse osmosis and forward osmosis, the carbon composite membrane showed 100% salt rejection with 3.5 to 20 times higher freshwater flux compared to existing polymeric membranes. Thermal accounting experiments found that at least 80% of the freshwater pass through the carbon composite membrane with no phase change. Molecular dynamics simulations revealed a unique salt rejection mechanism. When seawater is interfaced with either vapor or the surface of carbon, one to three interfacial atomic layers contain no salt ions. Below the liquid entry pressure, the salt solution is stopped at the openings to the porous channels and forms a meniscus, while the surface layer of freshwater can feed the surface...

  20. Multiplex APLP System for High-Resolution Haplogrouping of Extremely Degraded East-Asian Mitochondrial DNAs

    Science.gov (United States)

    Kakuda, Tsuneo; Shojo, Hideki; Tanaka, Mayumi; Nambiar, Phrabhakaran; Minaguchi, Kiyoshi; Umetsu, Kazuo; Adachi, Noboru

    2016-01-01

    Mitochondrial DNA (mtDNA) serves as a powerful tool for exploring matrilineal phylogeographic ancestry, as well as for analyzing highly degraded samples, because of its polymorphic nature and high copy numbers per cell. The recent advent of complete mitochondrial genome sequencing has led to improved techniques for phylogenetic analyses based on mtDNA, and many multiplex genotyping methods have been developed for the hierarchical analysis of phylogenetically important mutations. However, few high-resolution multiplex genotyping systems for analyzing East-Asian mtDNA can be applied to extremely degraded samples. Here, we present a multiplex system for analyzing mitochondrial single nucleotide polymorphisms (mtSNPs), which relies on a novel amplified product-length polymorphisms (APLP) method that uses inosine-flapped primers and is specifically designed for the detailed haplogrouping of extremely degraded East-Asian mtDNAs. We used fourteen 6-plex polymerase chain reactions (PCRs) and subsequent electrophoresis to examine 81 haplogroup-defining SNPs and 3 insertion/deletion sites, and we were able to securely assign the studied mtDNAs to relevant haplogroups. Our system requires only 1×10−13 g (100 fg) of crude DNA to obtain a full profile. Owing to its small amplicon size (<110 bp), this new APLP system was successfully applied to extremely degraded samples for which direct sequencing of hypervariable segments using mini-primer sets was unsuccessful, and proved to be more robust than conventional APLP analysis. Thus, our new APLP system is effective for retrieving reliable data from extremely degraded East-Asian mtDNAs. PMID:27355212

  1. Potential for improvement in high heat flux HyperVapotron element performance using nanofluids

    Science.gov (United States)

    Sergis, A.; Hardalupas, Y.; Barrett, T. R.

    2013-11-01

    HyperVapotron (HV) elements have been used extensively as high heat flux beam stopping components in nuclear fusion research facilities. These water-cooled heat exchangers use a boiling heat transfer mechanism and so are inherently limited by their critical heat flux (CHF). The use of a nanofluid as the coolant, instead of water, promises to enhance the heat transfer performance of the HV and increase the CHF by a factor of 2 or 3, which would lead to a step-change improvement in the power handling capability. This paper reports on computational and experimental analyses which have indicated mechanisms for the enhanced thermal performance of nanofluids. A molecular dynamics simulation code has been developed which has identified heat transfer augmentation mechanisms that depart from classical thermodynamics associated with the presence of nanoparticles. In addition, an experiment has been conducted which uses particle image velocimetry to measure the flow field in a full-scale HV. Past studies have yielded qualitative experimental results, but the measurements reported here provide quantitative data to aid the understanding of the initial flow field inside the HV (i.e., before a heat flux is applied). Further, the experiment is conducted using both water and Al2O3-water nanofluid as the flow medium. Thus, these velocity measurements offer a first indication for potentially enhanced heat transfer in HV devices when nanofluids are used as the coolant. The improved understanding of the HV flow regime and the cooling advantage of nanofluids could assist the design of advanced high heat flux components for future fusion machines.

  2. Impact of the extreme 2009 wildfire Victoria the wettability of naturally highly water repellent soils

    Science.gov (United States)

    Doerr, Stefan H.; Shakesby, Richard A.; Sheridan, Gary J.; Lane, Patrick Nj; Smith, Hugh G.; Bell, Tina; Blake, William H.

    2010-05-01

    The recent catastrophic wildfires near Melbourne, which peaked on Feb. 7 2009, burned ca 400,000 ha and caused the tragic loss of 173 people. They occurred during unprecedented extreme fire weather where dry northerly winds gusting up to 100 km/h coincided with the highest temperatures ever recorded in this region. These conditions, combined with the very high biomass of mature eucalypt forests, very low fuel moisture conditions and steep slopes, generated extreme burning conditions. A rapid response project was launched under the NERC Urgency Scheme aimed at determining the effects of this extreme event on soil properties. Three replicate sites each were sampled for extremely high burn severity, high burn severity and unburnt control terrain, within mature mixed-species eucalypt forests near Marysville in April 2009. Ash and surface soil (0-2.5 cm and 2.5-5 cm) were collected at 20 sample grid points at each site. Here we report on outcomes from Water Drop Penetration Time (WDPT) tests carried out on soil samples to determine the impact of this extreme event on the wettability of a naturally highly water repellent soil. Field assessment suggested that the impact of this extreme wildfire on the soil was less than might be supposed given the extreme burn severity (indicated by the complete elimination of the ground vegetation). This was confirmed by the laboratory results. No major difference in WDPT was detected between (i) burned and control samples, and (ii) between surface and subsurface WDPT patterns, indicating that soil temperatures in the top 0-2.5 cm did not exceed ~200° C. Seedling germination in burned soil was reduced by at least 2/3 compared to the control samples, however, this reduction is indicative an only modest heat input into the soil. The limited heat input into the soil stands in stark contrast to the extreme burn severity (based on vegetation destruction parameters). We speculate that limited soil heating resulted perhaps from the unusually

  3. Dispersive nature of high mach number collisionless plasma shocks: Poynting flux of oblique whistler waves.

    Science.gov (United States)

    Sundkvist, David; Krasnoselskikh, V; Bale, S D; Schwartz, S J; Soucek, J; Mozer, F

    2012-01-13

    Whistler wave trains are observed in the foot region of high Mach number quasiperpendicular shocks. The waves are oblique with respect to the ambient magnetic field as well as the shock normal. The Poynting flux of the waves is directed upstream in the shock normal frame starting from the ramp of the shock. This suggests that the waves are an integral part of the shock structure with the dispersive shock as the source of the waves. These observations lead to the conclusion that the shock ramp structure of supercritical high Mach number shocks is formed as a balance of dispersion and nonlinearity.

  4. Experimental study of thermal crisis in connection with Tokamak reactor high heat flux components

    Science.gov (United States)

    Gallo, D.; Giardina, M.; Castiglia, F.; Celata, G. P.; Mariani, A.; Zummo, G.; Cumo, M.

    2000-04-01

    The results of an experimental research on high heat flux thermal crisis in forced convective subcooled water flow, under operative conditions of interest to the thermal-hydraulic design of TOKAMAK fusion reactors, are here reported. These experiments, carried out in the framework of a collaboration between the Nuclear Engineering Department of Palermo University and the National Institute of Thermal - Fluid Dynamics of the ENEA - Casaccia (Rome), were performed on the STAF (Scambio Termico Alti Flussi) water loop and consisted, essentially, in a high speed photographic study which enabled focusing several information on bubble characteristics and flow patterns taking place during the burnout phenomenology.

  5. High luminous flux from single crystal phosphor-converted laser-based white lighting system

    KAUST Repository

    Cantore, Michael

    2015-12-14

    The efficiency droop of light emitting diodes (LEDs) with increasing current density limits the amount of light emitted per wafer area. Since low current densities are required for high efficiency operation, many LED die are needed for high power white light illumination systems. In contrast, the carrier density of laser diodes (LDs) clamps at threshold, so the efficiency of LDs does not droop above threshold and high efficiencies can be achieved at very high current densities. The use of a high power blue GaN-based LD coupled with a single crystal Ce-doped yttrium aluminum garnet (YAG:Ce) sample was investigated for white light illumination applications. Under CW operation, a single phosphor-converted LD (pc-LD) die produced a peak luminous efficacy of 86.7 lm/W at 1.4 A and 4.24 V and a peak luminous flux of 1100 lm at 3.0 A and 4.85 V with a luminous efficacy of 75.6 lm/W. Simulations of a pc-LD confirm that the single crystal YAG:Ce sample did not experience thermal quenching at peak LD operating efficiency. These results show that a single pc-LD die is capable of emitting enough luminous flux for use in a high power white light illumination system.

  6. Design of high-speed data collecting system for pipeline magnetic flux leakage inspection

    Science.gov (United States)

    Qu, Weidong; Xu, Hongbing

    2013-03-01

    In the process of high-speed magnetic flux leakage inspection, a large amount of signals containing pipeline status, characteristics and defects need to be collected and transmitted. High sampling frequency, high real-time, high precision and intellectualization for data collecting are long-term trend. This paper proposed a new design method of high speed data collecting system. In the system, dual CPU structure is applied in main controller and the high-speed communication between DSP and MCU is realized through dual-port RAM technology. With the Dual CPU structure being applied, the measurement, control and the communication are charged by two CPUs respectively, which can improve the system adaptability. Dual-port RAM can raise communication efficiency by improving the parallel processing ability among different type of multiprocessors.

  7. Extreme risk taker who wants to continue taking part in high risk sports after serious injury.

    Science.gov (United States)

    Pain, M; Kerr, J H

    2004-06-01

    The case is reported of a 40 year old male high risk sport athlete who had seriously injured himself several times and as a result was partially physically disabled and had trouble with mental tasks requiring concentration such as spelling, reading numbers, and writing. The athlete was referred to a sports psychologist. In consultations, it became clear that he was having difficulty reconciling the difference between his life as it used to be and as it would be in the future. Part of his difficulty was dealing with the frustration and anger "outbursts" which resulted from not being able to perform straightforward everyday motor skills. In spite of his injuries and disability, the patient badly wanted to continue participating in extreme sports. Reversal theory is used in the discussion to provide theoretical explanations of the motivation for his extreme risk taking behaviour.

  8. Carbon coatings for extreme-ultraviolet high-order laser harmonics

    Energy Technology Data Exchange (ETDEWEB)

    Coraggia, S.; Frassetto, F. [CNR-Institute of Photonics and Nanotechnologies, Laboratory for UV and X-Ray Optical Research, via Trasea 7, 35131 Padova (Italy); Aznarez, J.A.; Larruquert, J.I.; Mendez, J.A. [GOLD-Instituto de Optica-Consejo Superior de Investigaciones Cientificas, Serrano 144, 28006 Madrid (Spain); Negro, M.; Stagira, S.; Vozzi, C. [Department of Physics-Politecnico of Milano and CNR-Institute of Photonics and Nanotechnologies, Piazza Leonardo Da Vinci 32, 20133 Milano (Italy); Poletto, L., E-mail: poletto@dei.unipd.i [CNR-Institute of Photonics and Nanotechnologies, Laboratory for UV and X-Ray Optical Research, via Trasea 7, 35131 Padova (Italy)

    2011-04-11

    The experimental study of the optical properties of thin carbon films to be used as grazing-incidence coatings for extreme-ultraviolet high-order harmonics is presented. The carbon samples were deposited on plane glass substrates by the electron beam evaporation technique. The optical constants (real and imaginary parts of the refraction index) have been calculated through reflectivity measurements. The results are in good agreement with what reported in the literature, and confirm that carbon-coated optics operated at grazing incidence have a remarkable gain over conventional metallic coatings in the extreme ultraviolet. Since the harmonics co-propagate with the intense infrared laser generating beam, the carbon damage threshold when exposed to ultrashort infrared laser pulses has been measured.

  9. Phase Quantization Study of Spatial Light Modulator for Extreme High contrast Imaging

    CERN Document Server

    Dou, Jiangpei

    2016-01-01

    Direct imaging of exoplanets by reflected starlight is extremely challenging due to the large luminosity ratio to the primary star. Wave front control is a critical technique to attenuate the speckle noise in order to achieve an extreme high contrast. We present the phase quantization study of spatial light modulator for wave front control to meet the contrast requirement of detection of a terrestrial planet in the habitable zone of a solar-type star. We perform the numerical simulation by employing the SLM with different phase accuracy and actuator numbers, which are related to the achievable contrast. We use an optimization algorithm to solve the quantization problems that is matched to the controllable phase step of the SLM. Two optical configurations are discussed with the SLM located before and after the coronagraph focal plane mask, respectively. The simulation result has constrained the specification for phase accuracy of SLM in above two optical configurations. Finally, we have demonstrated that the S...

  10. Early Science with the Large Millimeter Telescope: Observations of Extremely Luminous High-z Sources Identified by Planck

    CERN Document Server

    Harrington, K C; Cybulski, R; Wilson, G W; Aretxaga, I; Chavez, M; De la Luz, V; Erickson, N; Ferrusca, D; Gallup, A D; Hughes, D H; Montaña, A; Narayanan, G; Sánchez-Argüelles, D; Schloerb, F P; Souccar, K; Terlevich, E; Terlevich, R; Zeballos, M; Zavala, J A

    2016-01-01

    We present 8.5 arcsec resolution 1.1mm continuum imaging and CO spectroscopic redshift measurements of eight extremely bright submillimetre galaxies identified from the Planck and Herschel surveys, taken with the Large Millimeter Telescope's AzTEC and Redshift Search Receiver instruments. We compiled a candidate list of high redshift galaxies by cross-correlating the Planck Surveyor mission's highest frequency channel (857 GHz, FWHM = 4.5 arcmin) with the archival Herschel Spectral and Photometric Imaging Receiver (SPIRE) imaging data, and requiring the presence of a unique, single Herschel counterpart within the 150 arcsec search radius of the Planck source positions with 350 micron flux density larger than 100 mJy, excluding known blazars and foreground galaxies. All eight candidate objects observed are detected in 1.1mm continuum by AzTEC bolometer camera, and at least one CO line is detected in all cases with a spectroscopic redshift between 1.3 < z(CO) < 3.3. Their infrared spectral energy distribu...

  11. Energy fluxes in a high Arctic tundra heath subjected to strong climate warming

    Science.gov (United States)

    Lund, M.; Hansen, B. U.; Pedersen, S. H.; Stiegler, C.; Tamstorf, M. P.

    2012-12-01

    During recent decades the observed warming in the Arctic has been almost twice as large as the global average. The implications of such strong warming on surface energy balance, regulating permafrost thaw, hydrology, soil stability and carbon mineralization, need to be assessed. In Zackenberg, northeast Greenland, measurements of energy balance components in various environments have been performed since late 90's, coordinated by Zackenberg Ecological Research Operations. During 1996-2009, mean annual temperature in the area has increased by ca. 0.15 °C yr-1; while maximum thaw depth has increased by 1.4-1.8 cm yr-1. Eddy covariance measurements of energy fluxes have been performed in a Cassiope heath plant community, a commonly occurring tundra ecosystem type in circumpolar middle and high Arctic areas, in Zackenberg allowing for detailed investigations of relationships between energy fluxes and meteorological and soil physical characteristics. As the available data set spans more than a decade, possible trends in energy flux components resulting from warming related changes such as earlier snow melt, increased active layer depth and higher temperatures can be investigated. This presentation will focus on the mid-summer period from which eddy covariance measurements are available. The summer-time energy partitioning at the Zackenberg tundra heath site will be characterized using ratios of sensible, latent and ground heat flux to net radiation and Bowen ratio, whereas the surface characteristics will be described using surface resistance, McNaughton and Jarvis Ω value and Priestley-Taylor α coefficient. Furthermore, we aim to estimate the full year, all energy balance components for the tundra heath site using Snow Model (Liston and Elder 2006) for the dark winter period during which no eddy covariance measurements are available. The snow cover duration in the area is a major regulator of the energy partitioning. Early results point towards high summer

  12. Warmer and wetter winters: characteristics and implications of an extreme weather event in the High Arctic

    Science.gov (United States)

    Hansen, Brage B.; Isaksen, Ketil; Benestad, Rasmus E.; Kohler, Jack; Pedersen, Åshild Ø.; Loe, Leif E.; Coulson, Stephen J.; Larsen, Jan Otto; Varpe, Øystein

    2014-11-01

    One predicted consequence of global warming is an increased frequency of extreme weather events, such as heat waves, droughts, or heavy rainfalls. In parts of the Arctic, extreme warm spells and heavy rain-on-snow (ROS) events in winter are already more frequent. How these weather events impact snow-pack and permafrost characteristics is rarely documented empirically, and the implications for wildlife and society are hence far from understood. Here we characterize and document the effects of an extreme warm spell and ROS event that occurred in High Arctic Svalbard in January-February 2012, during the polar night. In this normally cold semi-desert environment, we recorded above-zero temperatures (up to 7 °C) across the entire archipelago and record-breaking precipitation, with up to 98 mm rainfall in one day (return period of >500 years prior to this event) and 272 mm over the two-week long warm spell. These precipitation amounts are equivalent to 25 and 70% respectively of the mean annual total precipitation. The extreme event caused significant increase in permafrost temperatures down to at least 5 m depth, induced slush avalanches with resultant damage to infrastructure, and left a significant ground-ice cover (˜5-20 cm thick basal ice). The ground-ice not only affected inhabitants by closing roads and airports as well as reducing mobility and thereby tourism income, but it also led to high starvation-induced mortality in all monitored populations of the wild reindeer by blocking access to the winter food source. Based on empirical-statistical downscaling of global climate models run under the moderate RCP4.5 emission scenario, we predict strong future warming with average mid-winter temperatures even approaching 0 °C, suggesting increased frequency of ROS. This will have far-reaching implications for Arctic ecosystems and societies through the changes in snow-pack and permafrost properties.

  13. High heat flux actively cooled plasma facing components development, realization and first results in Tore Supra

    Energy Technology Data Exchange (ETDEWEB)

    Grosman, A. [Association Euratom-CEA, Centre d' Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee

    2004-07-01

    The development, design, manufacture and testing of actively cooled high heat flux plasma facing components (PFC) has been an essential stage towards long powerful tokamak operations for Tore-Supra, it lasted about 10 years. This paper deals with the toroidal pumped limiter (TPL) that is able to sustain up to 10 MW/m{sup 2} of nominal heat flux. This device is based on hardened copper alloy heat sink structures covered by a carbon fiber composite armour, it resulted in the manufacturing of 600 elementary components, called finger elements, to achieve the 7.6 m{sup 2} TPL. This assembly has been operating in Tore-Supra since spring 2002. Some difficulties occurred during the manufacturing phase, the valuable industrial experience is summarized in the section 2. The permanent monitoring of PFC surface temperature all along the discharge is performed by a set of 6 actively cooled infrared endoscopes. The heat flux monitoring and control issue but also the progress made in our understanding of the deuterium retention in long discharges are described in the section 3. (A.C.)

  14. Polarization in CdTe radiation detectors at high X-ray photon fluxes (Conference Presentation)

    Science.gov (United States)

    Franc, Jan; Dědič, Václav; Pekárek, Jakub; Belas, Eduard; Touš, Jan

    2016-09-01

    In this contribution we show an improvement of a spectroscopic response of CZT X-ray detector operating at high fluxes of X-ray tube by simultaneous infrared light illumination with a wavelength of 1200 nm. CZT detectors usually suffer from a polarization effect while their internal electric field can be strongly deformed due to a trapping of photogenerated holes. We describe a mechanism of an optically induced depolarization peaking at photon energy of about 1 eV ( 1240 nm) due to an optical transition of electrons from the valence band to the deep level. The depolarization effect is accompanied by a decrease of the detector current which results in a lower noise entering the preamplifier of detector readout circuit. We have observed that it is possible to restore originally distorted X-ray spectra using additional 1200 nm LED illumination with a photon flux of 10^16 cm^-2s^-1 at approximately two times higher X-ray flux than without LED. The number of detected counts was in the range of 10^5-10^6mm^2s^-1. The restoration of the spectrum by continuous infrared light is accompanied by decrease of dark current. We explain this effect by light induced changes of profile of the electric filed that leads to decrease of the electron current injected from the cathode.

  15. SIRHEX—A new experimental facility for high heat flux testing of plasma facing components

    Energy Technology Data Exchange (ETDEWEB)

    Kunze, André, E-mail: andre.kunze@kit.edu [Karlsruhe Institute of Technology (KIT), Institute for Neutron Physics and Reactor Technology (Germany); Ghidersa, Bradut-Eugen [Karlsruhe Institute of Technology (KIT), Institute for Neutron Physics and Reactor Technology (Germany); Bonelli, Flavia [Politecnico di Torino, Dipartimento Energia (Italy)

    2015-10-15

    Highlights: • Commercial infrared heaters have been qualified for future First Wall experiments. • In first tests surface heat flux densities up to 470 kW/m were achieved. • The homogeneity of the heat distribution stayed within ±5% of the nominal value. • With the heaters a typical ITER pulse can be reproduced. • An adequate testing strategy will be required to improve heater lifetime. - Abstract: SIRHEX (“Surface Infrared Radiation Heating Experiment”) is a small-scale experimental facility at KIT, which has been built for testing and qualifying high heat flux radiation heaters for blanket specific conditions using an instrumented water cooled target. This paper describes the SIRHEX facility and the experimental set-up for the heater tests. The results of a series of tests focused on reproducing homogeneous surface heat flux densities up to 500 kW/m{sup 2} will be presented and the impact of the heater performance on the design of the First Wall test rig will be discussed.

  16. High heat flux x-ray monochromators: What are the limits?

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, C.S.

    1997-06-01

    First optical elements at third-generation, hard x-ray synchrotrons, such as the Advanced Photon Source (APS), are subjected to immense heat fluxes. The optical elements include crystal monochromators, multilayers and mirrors. This paper presents a mathematical model of the thermal strain of a three-layer (faceplate, heat exchanger, and baseplate), cylindrical optic subjected to narrow beam of uniform heat flux. This model is used to calculate the strain gradient of a liquid-gallium-cooled x-ray monochromator previously tested on an undulator at the Cornell High Energy Synchrotron Source (CHESS). The resulting thermally broadened rocking curves are calculated and compared to experimental data. The calculated rocking curve widths agree to within a few percent of the measured values over the entire current range tested (0 to 60 mA). The thermal strain gradient under the beam footprint varies linearly with the heat flux and the ratio of the thermal expansion coefficient to the thermal conductivity. The strain gradient is insensitive to the heat exchanger properties and the optic geometry. This formulation provides direct insight into the governing parameters, greatly reduces the analysis time, and provides a measure of the ultimate performance of a given monochromator.

  17. Extreme ultraviolet radiation for coherent diffractive imaging with high spatial resolution

    Institute of Scientific and Technical Information of China (English)

    L.V.; DAO; S.; TEICHMANN; B.; CHEN; R.A.; DILANIAN; K.B.; DINH; P.; HANNAFORD

    2010-01-01

    Using different noble gases,argon,neon and helium,we are able to generate by high-harmonic generation(HHG) just a few harmonic orders in the spectral range 10-35 nm with a photon flux of~2.10 12 photons/(harmonic cm2 s) for argon and~10 10 photons/(harmonic cm2 s) for helium. The few-harmonic-order radiation is used for coherent diffractive imaging directly without any spectral filter. A spatial resolution of~100 nm is achieved using a~30 nm HHG source.

  18. Effect of blood flow rate on internal filtration in a high-flux dialyzer with polysulfone membrane.

    Science.gov (United States)

    Sakiyama, Ryoichi; Ishimori, Isamu; Akiba, Takashi; Mineshima, Michio

    2012-09-01

    Internal filtration/backfiltration (IF/BF) of a dialyzer depends on several parameters. This study evaluated the effect of the blood flow rate (Q (B)) on the internal filtration flow rate (Q (IF)) measured using Doppler ultrasonography for a high-flux dialyzer with a polysulfone membrane, APS-15E. In an in vitro study, bovine blood was circulated through the dialyzer, at a Q (B) of 100-350 mL/min. The clearances (CL) of creatinine, β(2)-microglobulin, and α(1)-microglobulin were then investigated. Q (IF) increased with the Q (B) value. A good correlation was obtained between Q (IF) and the pressure difference between the pressures at the inlet of the blood compartment and the pressure at the outlet of the dialysate compartment. The creatinine CL values strongly depended on Q (B) because molecular diffusion was dominant. The β(2)-microglobulin CL also depended on Q (B), because its removal rate seemed to be affected by both diffusive and convective transport caused by the IF/BF. An extremely low CL value was obtained for α(1)-microglobulin because of its low diffusivity and membrane fouling induced by proteins plugging the membrane. In conclusion, the IF/BF in the dialyzer strongly depends on Q (B). Furthermore, the dependence of the solute clearance on Q (B) decreased with increasing molecular size of the solute because of the decrease in diffusivity through the membrane.

  19. Lower Extremity Function following Partial Calcanectomy in High-Risk Limb Salvage Patients

    Directory of Open Access Journals (Sweden)

    Noah G. Oliver

    2015-01-01

    Full Text Available Partial calcanectomy (PC is an established limb salvage procedure for treatment of deep heel ulceration with concomitant calcaneal osteomyelitis. The purpose of this study is to determine if a relationship exists between the amount of calcaneus removed during PC and the resulting lower extremity function and limb salvage outcomes. Consecutive PC patients were retrospectively divided into two cohorts defined by the amount of calcaneus resected before wound closure: patients in cohort 1 retained = 50% of calcaneus, while patients in cohort 2 underwent resection of >50% of the calcaneus. The Lower Extremity Function Scale (LEFS was used to assess postoperative lower extremity function. The average amount of calcaneus resected was 13% ± 9.2 (1–39% and 74% ± 19.5 (51–100 in cohorts 1 and 2, respectively (P<0.0001. Below knee amputation was performed in 7 (28% and 5 (29% of subjects in cohorts 1 and 2, respectively (P=1.0. The average LEFS score was 33.9 ± 15.0 for subjects in cohort 1 and 36.2 ± 19.9 for the subjects cohort 2 (P=0.8257 which correlates to “moderate to quite a bit of difficulty.” Our study suggests that regardless of the amount of calcaneus resected, PC provides a viable treatment option for high-risk patients with calcaneal osteomyelitis.

  20. Performance of High Temperature Operational Amplifier, Type LM2904WH, under Extreme Temperatures

    Science.gov (United States)

    Patterson, Richard; Hammoud, Ahmad; Elbuluk, Malik

    2008-01-01

    Operation of electronic parts and circuits under extreme temperatures is anticipated in NASA space exploration missions as well as terrestrial applications. Exposure of electronics to extreme temperatures and wide-range thermal swings greatly affects their performance via induced changes in the semiconductor material properties, packaging and interconnects, or due to incompatibility issues between interfaces that result from thermal expansion/contraction mismatch. Electronics that are designed to withstand operation and perform efficiently in extreme temperatures would mitigate risks for failure due to thermal stresses and, therefore, improve system reliability. In addition, they contribute to reducing system size and weight, simplifying its design, and reducing development cost through the elimination of otherwise required thermal control elements for proper ambient operation. A large DC voltage gain (100 dB) operational amplifier with a maximum junction temperature of 150 C was recently introduced by STMicroelectronics [1]. This LM2904WH chip comes in a plastic package and is designed specifically for automotive and industrial control systems. It operates from a single power supply over a wide range of voltages, and it consists of two independent, high gain, internally frequency compensated operational amplifiers. Table I shows some of the device manufacturer s specifications.

  1. Modeling and Depletion Simulations for a High Flux Isotope Reactor Cycle with a Representative Experiment Loading

    Energy Technology Data Exchange (ETDEWEB)

    Chandler, David [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Reactor and Nuclear Systems Division; Betzler, Ben [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Reactor and Nuclear Systems Division; Hirtz, Gregory John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Reactor and Nuclear Systems Division; Ilas, Germina [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Reactor and Nuclear Systems Division; Sunny, Eva [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Reactor and Nuclear Systems Division

    2016-09-01

    The purpose of this report is to document a high-fidelity VESTA/MCNP High Flux Isotope Reactor (HFIR) core model that features a new, representative experiment loading. This model, which represents the current, high-enriched uranium fuel core, will serve as a reference for low-enriched uranium conversion studies, safety-basis calculations, and other research activities. A new experiment loading model was developed to better represent current, typical experiment loadings, in comparison to the experiment loading included in the model for Cycle 400 (operated in 2004). The new experiment loading model for the flux trap target region includes full length 252Cf production targets, 75Se production capsules, 63Ni production capsules, a 188W production capsule, and various materials irradiation targets. Fully loaded 238Pu production targets are modeled in eleven vertical experiment facilities located in the beryllium reflector. Other changes compared to the Cycle 400 model are the high-fidelity modeling of the fuel element side plates and the material composition of the control elements. Results obtained from the depletion simulations with the new model are presented, with a focus on time-dependent isotopic composition of irradiated fuel and single cycle isotope production metrics.

  2. A High-Flux, Flexible Membrane with Parylene-encapsulated Carbon Nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Park, H G; In, J; Kim, S; Fornasiero, F; Holt, J K; Grigoropoulos, C P; Noy, A; Bakajin, O

    2008-03-14

    We present fabrication and characterization of a membrane based on carbon nanotubes (CNTs) and parylene. Carbon nanotubes have shown orders of magnitude enhancement in gas and water permeability compared to estimates generated by conventional theories [1, 2]. Large area membranes that exhibit flux enhancement characteristics of carbon nanotubes may provide an economical solution to a variety of technologies including water desalination [3] and gas sequestration [4]. We report a novel method of making carbon nanotube-based, robust membranes with large areas. A vertically aligned dense carbon nanotube array is infiltrated with parylene. Parylene polymer creates a pinhole free transparent film by exhibiting high surface conformity and excellent crevice penetration. Using this moisture-, chemical- and solvent-resistant polymer creates carbon nanotube membranes that promise to exhibit high stability and biocompatibility. CNT membranes are formed by releasing a free-standing film that consists of parylene-infiltrated CNTs, followed by CNT uncapping on both sides of the composite material. Thus fabricated membranes show flexibility and ductility due to the parylene matrix material, as well as high permeability attributed to embedded carbon nanotubes. These membranes have a potential for applications that may require high flux, flexibility and durability.

  3. [Treatment of acute lithium intoxication with high-flux haemodialysis membranes].

    Science.gov (United States)

    Peces, R; Fernández, E J; Regidor, D; Peces, C; Sánchez, R; Montero, A; Selgas, R

    2006-01-01

    Lithium carbonate is commonly prescribed for the treatment of bipolar (manic-depressive) disorders. However, because of its narrow therapeutic index an excessive elevation of serum lithium concentration, either during chronic maintenance therapy or after an acute overdose, can result in serious toxicity. In addition to supportive care, the established treatment of severe lithium toxicity is haemodialysis. Conventional haemodialysis can reduce serum lithium rapidly, but post-dialysis rebound elevations with recurrent toxicity have been documented in old publications. High-flux membranes should be capable of removing more lithium per hour of haemodialysis, but published values are not available. We report here three patients with acute lithium intoxication who were treated successfully with bicarbonate and high-flux haemodialysis membranes. Our patients presented with a severe degree of intoxication, based on the amount of drug ingested, the initial serum lithium level, the severity of neurologic symptoms and systemic manifestations. Two patients developed acute renal failure probably as a result of volume depletion since it was rapidly reversible by haemodialysis and infusion therapy. In addition, consecutive haemodialysis sessions and improvement of renal function allowed a rapid decrease in serum lithium levels without haemodynamic instability or rebound elevations in lithium concentration. The effectiveness of the procedure in these cases can be attributed to the use of bicarbonate dialysate and high-efficiency dialysers. This is the first report describing the effect of high-efficiency dialysers on lithium pharmacokinetic. Using this technique the elimination rate of lithium was found to be greater than previously reported with haemodialysis.

  4. A Stable, Extreme Temperature, High Radiation, Compact. Low Power Clock Oscillator for Space, Geothermal, Down-Hole & other High Reliability Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Efficient and stable clock signal generation requirements at extreme temperatures and high radiation are not met with the current solutions. Chronos Technology...

  5. Template-particle stabilized bicontinuous emulsion yielding controlled assembly of hierarchical high-flux filtration membranes.

    Science.gov (United States)

    Hess, Samuel C; Kohll, A Xavier; Raso, Renzo A; Schumacher, Christoph M; Grass, Robert N; Stark, Wendelin J

    2015-01-14

    A novel solvent-evaporation-based process that exploits template-particle stabilized bicontinuous emulsions for the formation of previously unreached membrane morphologies is reported in this article. Porous membranes have a wide range of applications spanning from water filtration, pharmaceutical purification, and battery separators to scaffolds for tissue engineering. Different situations require different membrane morphologies including various pore sizes and pore gradients. However, most of the previously reported membrane preparation procedures are restricted to specific morphologies and morphology alterations require an extensive optimization process. The tertiary system presented in this article, which consists of a poly(ether sulfone)/dimethylacetamide (PES/DMAc) solution, glycerol, and ZnO-nanoparticles, allows simple and exact tuning of pore diameters ranging from sub-20 nm, up to 100 nm. At the same time, the pore size gradient is controlled from 0 up to 840%/μm yielding extreme asymmetry. In addition to structural analysis, water flux rates of over 5600 L m(-2) h(-1) are measured for membranes retaining 45 nm silica beads.

  6. A low-frequency wave motion mechanism enables efficient energy transport in carbon nanotubes at high heat fluxes.

    Science.gov (United States)

    Zhang, Xiaoliang; Hu, Ming; Poulikakos, Dimos

    2012-07-11

    The great majority of investigations of thermal transport in carbon nanotubes (CNTs) in the open literature focus on low heat fluxes, that is, in the regime of validity of the Fourier heat conduction law. In this paper, by performing nonequilibrium molecular dynamics simulations we investigated thermal transport in a single-walled CNT bridging two Si slabs under constant high heat flux. An anomalous wave-like kinetic energy profile was observed, and a previously unexplored, wave-dominated energy transport mechanism is identified for high heat fluxes in CNTs, originated from excited low frequency transverse acoustic waves. The transported energy, in terms of a one-dimensional low frequency mechanical wave, is quantified as a function of the total heat flux applied and is compared to the energy transported by traditional Fourier heat conduction. The results show that the low frequency wave actually overtakes traditional Fourier heat conduction and efficiently transports the energy at high heat flux. Our findings reveal an important new mechanism for high heat flux energy transport in low-dimensional nanostructures, such as one-dimensional (1-D) nanotubes and nanowires, which could be very relevant to high heat flux dissipation such as in micro/nanoelectronics applications.

  7. Fabrication of surfaces with extremely high contact angle hysteresis from polyelectrolyte multilayer.

    Science.gov (United States)

    Wang, Liming; Wei, Jingjing; Su, Zhaohui

    2011-12-20

    High contact angle hysteresis on polyelectrolyte multilayers (PEMs) ion-paired with hydrophobic perfluorooctanoate anions is reported. Both the bilayer number of PEMs and the ionic strength of deposition solutions have significant influence on contact angle hysteresis: higher ionic strength and greater bilayer number cause increased contact angle hysteresis values. The hysteresis values of ~100° were observed on smooth PEMs and pinning of the receding contact line on hydrophilic defects is implicated as the cause of hysteresis. Surface roughness can be used to further tune the contact angle hysteresis on the PEMs. A surface with extremely high contact angle hysteresis of 156° was fabricated when a PEM was deposited on a rough substrate coated with submicrometer scale silica spheres. It was demonstrated that this extremely high value of contact angle hysteresis resulted from the penetration of water into the rough asperities on the substrate. The same substrate hydrophobized by chemical vapor deposition of 1H,1H,2H,2H-perfluorooctyltriethoxysilane exhibits high advancing contact angle and low hysteresis.

  8. A High-Speed Baseline Restorer for Neutron Flux Detection in ITER

    Institute of Scientific and Technical Information of China (English)

    曹宏睿; 李世平; 徐修峰; 袁国梁; 杨青巍; 阴泽杰

    2012-01-01

    A neutron flux monitor .(NFM) is a key diagnostic system in the International Ther- monuclear Experimental Reactor (ITER), and may provide readings of a series of important parameters in fusion reaction processes. As a valuable part of the main electronics system of the NFM, the high-speed baseline restorer we designed is an important signal conversion plug-in which can restore the input signal baseline offset to a zero level, while keeping the output pulse signal waveform from the preamplifier basically unchanged.

  9. Flux lattice behavior in high- T sub c materials studied by neutron depolarization

    Energy Technology Data Exchange (ETDEWEB)

    Crow, M.L.; Goyette, R.J.; Nunes, A.C.; Pickart, S.J. (University of Rhode Island, Kingston, Rhode Island 02881 (USA)); McGuire, T.R.; Shinde, S.; Shaw, T.M. (IBM Thomas J. Watson Research Center, Yorktown Heights, New York 10598 (USA))

    1990-05-01

    The depolarization of a neutron beam passing through a sample of the high-{ital T}{sub {ital c}} superconductor YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} has been measured as a function of temperature and applied field. The difference in behavior between field-cooled and zero-field-cooled states, the observation of hysteresis correlated with {ital H}{sub {ital c}1}, and the disappearance of the effect near 55 K (below {ital T}{sub {ital c}}) suggest an explanation in terms of vortex line lattice formation with possible connection to recently proposed flux line entanglement and melting.

  10. Resolving mass flux at high spatial and temporal resolution using GRACE intersatellite measurements

    DEFF Research Database (Denmark)

    Rowlands, D. D.; Luthcke, S. B.; Klosko, S. M.

    2005-01-01

    The GRACE mission is designed to monitor mass flux on the Earth's surface at one month and high spatial resolution through the estimation of monthly gravity fields. Although this approach has been largely successful, information at submonthly time scales can be lost or even aliased through...... resolution. Using 4° × 4° blocks at 10-day intervals, we estimate the mass of surplus or deficit water over a 52° × 60° grid centered on the Amazon basin for July 2003. We demonstrate that the recovered signals are coherent and correlate well with the expected hydrological signal....

  11. Flux jump-assisted pulsed field magnetisation of high-J c bulk high-temperature superconductors

    Science.gov (United States)

    Ainslie, M. D.; Zhou, D.; Fujishiro, H.; Takahashi, K.; Shi, Y.-H.; Durrell, J. H.

    2016-12-01

    Investigating, predicting and optimising practical magnetisation techniques for charging bulk superconductors is a crucial prerequisite to their use as high performance ‘psuedo’ permanent magnets. The leading technique for such magnetisation is the pulsed field magnetisation (PFM) technique, in which a large magnetic field is applied via an external magnetic field pulse of duration of the order of milliseconds. Recently ‘giant field leaps’ have been observed during charging by PFM: this effect greatly aids magnetisation as flux jumps occur in the superconductor leading to magnetic flux suddenly intruding into the centre of the superconductor. This results in a large increase in the measured trapped field at the centre of the top surface of the bulk sample and full magnetisation. Due to the complex nature of the magnetic flux dynamics during the PFM process, simple analytical methods, such as those based on the Bean critical state model, are not applicable. Consequently, in order to successfully model this process, a multi-physical numerical model is required, including both electromagnetic and thermal considerations over short time scales. In this paper, we show that a standard numerical modelling technique, based on a 2D axisymmetric finite-element model implementing the H -formulation, can model this behaviour. In order to reproduce the observed behaviour in our model all that is required is the insertion of a bulk sample of high critical current density, J c. We further explore the consequences of this observation by examining the applicability of the model to a range of previously reported experimental results. Our key conclusion is that the ‘giant field leaps’ reported by Weinstein et al and others need no new physical explanation in terms of the behaviour of bulk superconductors: it is clear the ‘giant field leap’ or flux jump-assisted magnetisation of bulk superconductors will be a key enabling technology for practical applications.

  12. A simple calculation algorithm to separate high-resolution CH4 flux measurements into ebullition and diffusion-derived components

    Science.gov (United States)

    Hoffmann, Mathias; Schulz-Hanke, Maximilian; Garcia Alba, Joana; Jurisch, Nicole; Hagemann, Ulrike; Sachs, Torsten; Sommer, Michael; Augustin, Jürgen

    2016-04-01

    Processes driving methane (CH4) emissions in wetland ecosystems are highly complex. Especially, the separation of CH4 emissions into ebullition and diffusion derived flux components, a perquisite for the mechanistic process understanding and identification of potential environmental driver is rather challenging. We present a simple calculation algorithm, based on an adaptive R-script, which separates open-water, closed chamber CH4 flux measurements into diffusion- and ebullition-derived components. Hence, flux component specific dynamics are revealed and potential environmental driver identified. Flux separation is based on a statistical approach, using ebullition related sudden concentration changes obtained during high resolution CH4 concentration measurements. By applying the lower and upper quartile ± the interquartile range (IQR) as a variable threshold, diffusion dominated periods of the flux measurement are filtered. Subsequently, flux calculation and separation is performed. The algorithm was verified in a laboratory experiment and tested under field conditions, using flux measurement data (July to September 2013) from a flooded, former fen grassland site. Erratic ebullition events contributed 46% to total CH4 emissions, which is comparable to values reported by literature. Additionally, a shift in the diurnal trend of diffusive fluxes throughout the measurement period, driven by the water temperature gradient, was revealed.

  13. In situ observation and measurement of composites subjected to extremely high temperature

    Science.gov (United States)

    Fang, Xufei; Yu, Helong; Zhang, Guobing; Su, Hengqiang; Tang, Hongxiang; Feng, Xue

    2014-03-01

    In this work, we develop an instrument to study the ablation and oxidation process of materials such as C/SiC (carbon fiber reinforced silicon carbide composites) and ultra-high temperature ceramic in extremely high temperature environment. The instrument is integrated with high speed cameras with filtering lens, infrared thermometers and water vapor generator for image capture, temperature measurement, and humid atmosphere, respectively. The ablation process and thermal shock as well as the temperature on both sides of the specimen can be in situ monitored. The results show clearly the dynamic ablation and liquid oxide flowing. In addition, we develop an algorithm for the post-processing of the captured images to obtain the deformation of the specimens, in order to better understand the behavior of the specimen subjected to high temperature.

  14. Foundations of high-energy-density physics physical processes of matter at extreme conditions

    CERN Document Server

    Larsen, Jon

    2017-01-01

    High-energy-density physics explores the dynamics of matter at extreme conditions. This encompasses temperatures and densities far greater than we experience on Earth. It applies to normal stars, exploding stars, active galaxies, and planetary interiors. High-energy-density matter is found on Earth in the explosion of nuclear weapons and in laboratories with high-powered lasers or pulsed-power machines. The physics explored in this book is the basis for large-scale simulation codes needed to interpret experimental results whether from astrophysical observations or laboratory-scale experiments. The key elements of high-energy-density physics covered are gas dynamics, ionization, thermal energy transport, and radiation transfer, intense electromagnetic waves, and their dynamical coupling. Implicit in this is a fundamental understanding of hydrodynamics, plasma physics, atomic physics, quantum mechanics, and electromagnetic theory. Beginning with a summary of the topics and exploring the major ones in depth, thi...

  15. Poly(acrylamide-MWNTs hybrid hydrogel with extremely high mechanical strength

    Directory of Open Access Journals (Sweden)

    Feng Huanhuan

    2016-01-01

    Full Text Available Poly(acrylamide-multiwalled carbon nanotubes (PAAm-MWNTs hybrid hydrogels were prepared through the radiation-induced polymerization and crosslinking of the aqueous solution of acrylamide and well-dispersed MWNTs for the first time. The PAAm gels obtained by the radiation-induced polymerization and cosslinking showed very high mechanical strengths, and the PAAm-MWNTs hybrid hydrogels had improved mechanical properties compared with the PAAm gels, and hence the PAAm-MWNTs hybrid hydrogels showed extremely high compressive and tensile strengths. The hybrid hydrogels with water contents more than 80 wt.% usually did not fracture even at compressive strengths close to or even more than 60 MPa and strains more than 97%. And the hybrid hydrogels had very high elongations (more than 2000% in some cases, especially when the water content was high. The tensile strengths were in sub-MPa. The hybrid PAAm-MWNTs hydrogel is one of the strongest hydrogel even made.

  16. EEE - Extreme Energy Events: an astroparticle physics experiment in Italian High Schools

    Science.gov (United States)

    Abbrescia, M.; Avanzini, C.; Baldini, L.; Baldini Ferroli, R.; Batignani, G.; Bencivenni, G.; Bossini, E.; Bressan, E.; Chiavassa, A.; Cicalò, C.; Cifarelli, L.; Coccia, E.; Corvaglia, A.; De Gruttola, D.; De Pasquale, S.; Di Giovanni, A.; D'Incecco, M.; Dreucci, M.; Fabbri, F. L.; Fattibene, E.; Ferrarov, A.; Forster, R.; Frolov, V.; Galeotti, P.; Garbini, M.; Gemme, G.; Gnesi, I.; Grazzi, S.; Gustavino, C.; Hatzifotiadou, D.; La Rocca, P.; Maggiora, A.; Maron, G.; Mazziotta, M. N.; Miozzi, S.; Noferini, F.; Nozzoli, F.; Panareo, M.; Panetta, M. P.; Paoletti, R.; Perasso, L.; Pilo, F.; Piragino, G.; Riggi, F.; Righini, G. C.; Rodriguez Rodriguez, A.; Sartorelli, G.; Scapparone, E.; Schioppa, M.; Scribano, A.; Selvi, M.; Serci, S.; Siddi, E.; Squarcia, S.; Taiuti, M.; Terreni, G.; Vistoli, M. C.; Votano, L.; Williams, M. C. S.; Zani, S.; Zichichi, A.; Zuyeuski, R.

    2016-05-01

    The Extreme Energy Events project (EEE) is aimed to study Extensive Air Showers (EAS) from primary cosmic rays of more than 1018 eV energy detecting the ground secondary muon component using an array of telescopes with high spatial and time resolution. The second goal of the EEE project is to involve High School teachers and students in this advanced research work and to initiate them in scientific culture: to reach both purposes the telescopes are located inside High School buildings and the detector construction, assembling and monitoring - together with data taking and analysis - are done by researchers from scientific institutions in close collaboration with them. At present there are 42 telescopes in just as many High Schools scattered all over Italy, islands included, plus two at CERN and three in INFN units. We report here some preliminary physics results from the first two common data taking periods together with the outreach impact of the project.

  17. Image-based motion compensation for high-resolution extremities cone-beam CT

    Science.gov (United States)

    Sisniega, A.; Stayman, J. W.; Cao, Q.; Yorkston, J.; Siewerdsen, J. H.; Zbijewski, W.

    2016-03-01

    Purpose: Cone-beam CT (CBCT) of the extremities provides high spatial resolution, but its quantitative accuracy may be challenged by involuntary sub-mm patient motion that cannot be eliminated with simple means of external immobilization. We investigate a two-step iterative motion compensation based on a multi-component metric of image sharpness. Methods: Motion is considered with respect to locally rigid motion within a particular region of interest, and the method supports application to multiple locally rigid regions. Motion is estimated by maximizing a cost function with three components: a gradient metric encouraging image sharpness, an entropy term that favors high contrast and penalizes streaks, and a penalty term encouraging smooth motion. Motion compensation involved initial coarse estimation of gross motion followed by estimation of fine-scale displacements using high resolution reconstructions. The method was evaluated in simulations with synthetic motion (1-4 mm) applied to a wrist volume obtained on a CMOS-based CBCT testbench. Structural similarity index (SSIM) quantified the agreement between motion-compensated and static data. The algorithm was also tested on a motion contaminated patient scan from dedicated extremities CBCT. Results: Excellent correction was achieved for the investigated range of displacements, indicated by good visual agreement with the static data. 10-15% improvement in SSIM was attained for 2-4 mm motions. The compensation was robust against increasing motion (4% decrease in SSIM across the investigated range, compared to 14% with no compensation). Consistent performance was achieved across a range of noise levels. Significant mitigation of artifacts was shown in patient data. Conclusion: The results indicate feasibility of image-based motion correction in extremities CBCT without the need for a priori motion models, external trackers, or fiducials.

  18. High yield simultaneous hydrogen and ethanol production under extreme-thermophilic (70 C) mixed culture environment

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Chenxi [Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084 (China); Department of Environmental Engineering, Technical University of Denmark, DK-2800, Kgs Lyngby (Denmark); O-Thong, Sompong [Department of Biology, Faculty of Science, Thaksin University, Patthalung 93110 (Thailand); Karakashev, Dimitar; Angelidaki, Irini [Department of Environmental Engineering, Technical University of Denmark, DK-2800, Kgs Lyngby (Denmark); Lu, Wenjing; Wang, Hongtao [Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2009-07-15

    The effect of pH and medium composition on extreme-thermophilic (70 C) dark fermentative simultaneous hydrogen and ethanol production (process performance and microbial ecology) was investigated. Hydrogen and ethanol yields were optimized with respect to glucose, peptone, FeSO{sub 4}, NaHCO{sub 3}, yeast extract, trace mineral salts, vitamins, and phosphate buffer concentrations as well as initial pH as independent variables. A combination of low levels of both glucose ({<=}2 g/L) and vitamin solutions ({<=}1 mL/L) and high levels of initial pH ({>=}7), mineral salts solution ({>=}5 mL/L) and FeSO{sub 4} ({>=}100 mg/L) stimulated the hydrogen production, while high level of glucose ({>=}5 g/L) and low levels of both initial pH ({<=}5.5) and mineral salts solution ({<=}1 mL/L) enhanced the ethanol production. High yield of simultaneous hydrogen and ethanol production (1.58 mol H{sub 2}/mol glucose combined with an ethanol yield of 0.90 mol ethanol/mol glucose) was achieved under extreme-thermophilic mixed culture environment. Results obtained showed that the shift of the metabolic pathways favouring either hydrogen or ethanol production was affected by the change in cultivation conditions (pH and medium composition). The mixed culture in this study demonstrated flexible ability for simultaneous hydrogen and ethanol production, depending on pH and nutrients formulation. The microorganisms involved could be regarded as simultaneous hydrogen/ethanol producers, as hydrogen and ethanol fermentation under all conditions was carried out by a group of extreme-thermophilic bacterial species related to Thermoanaerobacter, Thermoanaerobacterium and Caldanaerobacter. (author)

  19. Total Reflection X-ray Fluorescence Analysis (TXRF) using the high flux SAXS camera

    CERN Document Server

    Wobrauschek, P; Pepponi, G; Bergmann, A; Glatter, O

    2002-01-01

    Combining the high photon flux from a rotating anode X-ray tube with an X-ray optical component to focus and monochromatize the X-ray beam is the most promising instrumentation for best detection limits in the modern XRF laboratory. This is realized by using the design of a high flux SAXS camera in combination with a 4 kW high brilliant rotating Cu anode X-ray tube with a graded elliptically bent multilayer and including a new designed module for excitation in total reflection geometry within the beam path. The system can be evacuated thus reducing absorption and scattering of air and removing the argon peak in the spectra. Another novelty is the use of a Peltier cooled drift detector with an energy resolution of 148 eV at 5.9 keV and 5 mm sup 2 area. For Co detection limits of about 300 fg determined by a single element standard have been achieved. Testing a real sample NIST 1643d led to detection limits in the range of 300 ng/l for the medium Z.

  20. The impact of nebular emission on the broadband fluxes of high-redshift galaxies

    CERN Document Server

    Zackrisson, E; Leitet, E

    2008-01-01

    A substantial fraction of the light emitted from young or star-forming galaxies at ultraviolet to near-infrared wavelengths comes from the ionized interstellar medium in the form of emission lines and a nebular continuum. At high redshifts, star formation rates are on average higher and stellar populations younger than in the local Universe. Both of these effects act to boost the impact of nebular emission on the overall spectrum of galaxies. Even so, the broadband fluxes and colours of high-redshift galaxies are routinely analyzed under the assumption that the light observed originates directly from stars. Here, we assess the impact of nebular emission on broadband fluxes in Johnson/Cousins BVRIJHK, Sloan Digital Sky Survey griz and Spitzer IRAC/MIPS filters as a function of observed redshift (up to z=15) for galaxies with different star formation histories. We find that nebular emission may account for a non-negligible fraction of the light received from high-redshift galaxies. The ages and masses inferred ...

  1. Application of (13)C flux analysis to identify high-productivity CHO metabolic phenotypes.

    Science.gov (United States)

    Templeton, Neil; Smith, Kevin D; McAtee-Pereira, Allison G; Dorai, Haimanti; Betenbaugh, Michael J; Lang, Steven E; Young, Jamey D

    2017-01-23

    Industrial bioprocesses place high demands on the energy metabolism of host cells to meet biosynthetic requirements for maximal protein expression. Identifying metabolic phenotypes that promote high expression is therefore a major goal of the biotech industry. We conducted a series of (13)C flux analysis studies to examine the metabolic response to IgG expression during early stationary phase of CHO cell cultures grown in 3L fed-batch bioreactors. We examined eight clones expressing four different IgGs and compared with three non-expressing host-cell controls. Some clones were genetically manipulated to be apoptosis-resistant by expressing Bcl-2Δ, which correlated with increased IgG production and elevated glucose metabolism. The metabolic phenotypes of the non-expressing, IgG-expressing, and Bcl-2Δ/IgG-expressing clones were fully segregated by hierarchical clustering analysis. Lactate consumption and citric acid cycle fluxes were most strongly associated with specific IgG productivity. These studies indicate that enhanced oxidative metabolism is a characteristic of high-producing CHO cell lines.

  2. Association of Beta-2 Microglobulin with Inflammation and Dislipidemia in High-Flux Membrane Hemodialysis Patients.

    Science.gov (United States)

    Topçiu-Shufta, Valdete; Miftari, Ramë; Haxhibeqiri, Valdete; Haxhibeqiri, Shpend

    2016-10-01

    Higher than expected cardiovascular mortality in hemodialysis patients, has been attributed to dyslipidemia as well as inflammation. Beta2-Microglobulin (β2M) is an independent predictor of outcome for hemodialysis patients and a representative substance of middle molecules. In 40 patients in high-flux membrane hemodialysis, we found negative correlation of β2M with high density lipoprotein (r=-0.73, p<0.001) and albumin (r= -0.53, p<0.001) and positive correlation with triglycerides (r=0.69, p<0.001), parathyroid hormone (r=0.58, p < 0.05) and phosphorus (r= 0.53, p<0.001). There was no correlation of β2M with C- reactive protein (CRP) and interleukin-6 (IL-6). During the follow-up period of three years, 6 out of 40 patients have died from cardiovascular events. In high-flux membrane hemodialysis patients, we observed a significant relationship of β2M with dyslipidemia and mineral bone disorders, but there was no correlation with inflammation.

  3. Prospects of extreme ultraviolet radiation sources based on microwave discharge for high-resolution lithography

    Science.gov (United States)

    Abramov, I. S.; Gospodchikov, E. D.; Shalashov, A. G.

    2017-07-01

    In this paper, inspired by the success of recent experiments, we discuss a new possible type of sources of extreme ultraviolet radiation for the semiconductor industry, based on the radiating plasma with multiply charged ions supported in a mirror magnetic trap by high-power microwaves. We propose a simple theory that describes the main features of such source, perform modeling for a wide range of plasma parameters and magnetic configurations, compare the results to the existing experimental data, and study the prospects of the new scheme in present technological circumstances.

  4. Extremely high reflection of solar wind protons as neutral hydrogen atoms from regolith in space

    CERN Document Server

    Wieser, Martin; Futaana, Yoshifumi; Holmström, Mats; Bhardwaj, Anil; Sridharan, R; Dhanya, MB; Wurz, Peter; Schaufelberger, Audrey; Asamura, Kazushi; 10.1016/j.pss.2009.09.012

    2010-01-01

    We report on measurements of extremely high reflection rates of solar wind particles from regolith-covered lunar surfaces. Measurements by the Sub-keV Atom Reflecting Analyzer (SARA) instrument on the Indian Chandrayaan-1 spacecraft in orbit around the Moon show that up to 20% of the impinging solar wind protons are reflected from the lunar surface back to space as neutral hydrogen atoms. This finding, generally applicable to regolith-covered atmosphereless bodies, invalidates the widely accepted assumption that regolith almost completely absorbs the impinging solar wind.

  5. High mountain water fluxes, a trans-Himalayan base-flow perspective

    Science.gov (United States)

    Andermann, C.; Stieglitz, T. C.; Hovius, N.; Sharma, R.; Labasque, T.

    2013-12-01

    Large scale hydrological processes in mountain areas underlain by bedrock are not well constrained. Groundwater is commonly considered to be of little importance in the mountain water balance, with direct runoff, snow and ice melt thought to be the principal hydrological buffer. We present new insights into hydrological fluxes between major reservoirs and their associated time scales in a trans-Himalayan catchment. The study area is the Kali Gandaki catchment, rising in the dry Tibetan interior, carving through the high Himalayas and draining the full width of the foothills to the Ganges foreland. The catchment has a well-defined monsoon climate, with pronounced annual wet and dry seasons and a clear separation of windward and lee regions. From December to end of March rainfall is minimal. This offers an opportunity to resolve the spatial contribution of hydrological fluxes, other than direct runoff to river discharge, using geochemical tracers. In February 2013 we have sampled the river over its full 350 km length at ~10 km intervals, all main tributaries and several springs in each lithological unit. We have measured major element abundances, CFC's and noble gases for age determination, trace elements and stable isotopes. We also measured 222Rn in situ, as a tracer for groundwater contribution. These measurements are placed in a context of topographic analyses and continuous discharge and precipitation measurements. We have observed large variations of chemical fluxes over several orders of magnitude, showing a systematic downstream dilution trend for most major elements. High initial concentrations derive from evaporite deposits in the uppermost part of the catchment, constituting a large scale, natural salt tracer experiment. The well-defined decline of solute concentrations along the main river, paired with constraints on the composition of lateral water inputs downstream allows the calculation of the spatial distribution of additional hydrological fluxes, by

  6. Heat flux mitigation by impurity seeding in high-field tokamaks

    Science.gov (United States)

    Reinke, M. L.

    2017-03-01

    The ability for tokamaks to exhaust power in the boundary via impurity radiation is explored using empirical scalings and a simple 0D exhaust model, focusing on the scaling with toroidal field and major radius. By combining a scaling for the heat flux width and the L-H threshold power, the parallel heat flux in the SOL is shown to scale strongly with magnetic field, {{q}\\parallel}∼ B\\text{T}2.52 while having little to no scaling with machine size, {{q}\\parallel}∼ {{R}0.16} . Despite the increased heat flux at high field, it is shown that target temperatures relevant to detachment can be reached with finite main-ion dilution for a variety of impurity seeding gases, although non-equilibrium ionization balance is required in most cases. The necessary impurity fractions are estimated to scale like {{f}Z}∼ B\\text{T}0.88{{R}1.33} , a result that is facilitated by an increase in upstream temperature at high {{q}\\parallel} relative to peaks in the impurity cooling-curves. This scaling indicates that for optimizing reactors, minimizing device size while maximizing toroidal field, an approach shown to be consistent with energy confinement scaling, will also maximize the feasibility of reaching detachment at the lowest dilution. Despite this, analysis suggests an increase in the impurity fractions relative to existing devices will be required to exhaust power in a reactor-scale tokamak, with validation of impurity radiation physics required before both simple and detailed models can make reliable predictions of absolute f Z .

  7. A high sensitivity momentum flux measuring instrument for plasma thruster exhausts and diffusive plasmas

    Energy Technology Data Exchange (ETDEWEB)

    West, Michael D.; Charles, Christine; Boswell, Rod W. [Space Plasma, Power and Propulsion Group, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia)

    2009-05-15

    A high sensitivity momentum flux measuring instrument based on a compound pendulum has been developed for use with electric propulsion devices and radio frequency driven plasmas. A laser displacement system, which builds upon techniques used by the materials science community for surface stress measurements, is used to measure with high sensitivity the displacement of a target plate placed in a plasma thruster exhaust. The instrument has been installed inside a vacuum chamber and calibrated via two different methods and is able to measure forces in the range of 0.02-0.5 mN with a resolution of 15 {mu}N. Measurements have been made of the force produced from the cold gas flow and with a discharge ignited using argon propellant. The plasma is generated using a Helicon Double Layer Thruster prototype. The instrument target is placed about 1 mean free path for ion-neutral charge exchange collisions downstream of the thruster exit. At this position, the plasma consists of a low density ion beam (10%) and a much larger downstream component (90%). The results are in good agreement with those determined from the plasma parameters measured with diagnostic probes. Measurements at various flow rates show that variations in ion beam velocity and plasma density and the resulting momentum flux can be measured with this instrument. The instrument target is a simple, low cost device, and since the laser displacement system used is located outside the vacuum chamber, the measurement technique is free from radio frequency interference and thermal effects. It could be used to measure the thrust in the exhaust of other electric propulsion devices and the momentum flux of ion beams formed by expanding plasmas or fusion experiments.

  8. A high sensitivity momentum flux measuring instrument for plasma thruster exhausts and diffusive plasmas

    Science.gov (United States)

    West, Michael D.; Charles, Christine; Boswell, Rod W.

    2009-05-01

    A high sensitivity momentum flux measuring instrument based on a compound pendulum has been developed for use with electric propulsion devices and radio frequency driven plasmas. A laser displacement system, which builds upon techniques used by the materials science community for surface stress measurements, is used to measure with high sensitivity the displacement of a target plate placed in a plasma thruster exhaust. The instrument has been installed inside a vacuum chamber and calibrated via two different methods and is able to measure forces in the range of 0.02-0.5mN with a resolution of 15μN. Measurements have been made of the force produced from the cold gas flow and with a discharge ignited using argon propellant. The plasma is generated using a Helicon Double Layer Thruster prototype. The instrument target is placed about 1 mean free path for ion-neutral charge exchange collisions downstream of the thruster exit. At this position, the plasma consists of a low density ion beam (10%) and a much larger downstream component (90%). The results are in good agreement with those determined from the plasma parameters measured with diagnostic probes. Measurements at various flow rates show that variations in ion beam velocity and plasma density and the resulting momentum flux can be measured with this instrument. The instrument target is a simple, low cost device, and since the laser displacement system used is located outside the vacuum chamber, the measurement technique is free from radio frequency interference and thermal effects. It could be used to measure the thrust in the exhaust of other electric propulsion devices and the momentum flux of ion beams formed by expanding plasmas or fusion experiments.

  9. Transport coefficients and heat fluxes in non-equilibrium high-temperature flows with electronic excitation

    Science.gov (United States)

    Istomin, V. A.; Kustova, E. V.

    2017-02-01

    The influence of electronic excitation on transport processes in non-equilibrium high-temperature ionized mixture flows is studied. Two five-component mixtures, N 2 / N2 + / N / N + / e - and O 2 / O2 + / O / O + / e - , are considered taking into account the electronic degrees of freedom for atomic species as well as the rotational-vibrational-electronic degrees of freedom for molecular species, both neutral and ionized. Using the modified Chapman-Enskog method, the transport coefficients (thermal conductivity, shear viscosity and bulk viscosity, diffusion and thermal diffusion) are calculated in the temperature range 500-50 000 K. Thermal conductivity and bulk viscosity coefficients are strongly affected by electronic states, especially for neutral atomic species. Shear viscosity, diffusion, and thermal diffusion coefficients are not sensible to electronic excitation if the size of excited states is assumed to be constant. The limits of applicability for the Stokes relation are discussed; at high temperatures, this relation is violated not only for molecular species but also for electronically excited atomic gases. Two test cases of strongly non-equilibrium flows behind plane shock waves corresponding to the spacecraft re-entry (Hermes and Fire II) are simulated numerically. Fluid-dynamic variables and heat fluxes are evaluated in gases with electronic excitation. In inviscid flows without chemical-radiative coupling, the flow-field is weakly affected by electronic states; however, in viscous flows, their influence can be more important, in particular, on the convective heat flux. The contribution of different dissipative processes to the heat transfer is evaluated as well as the effect of reaction rate coefficients. The competition of diffusion and heat conduction processes reduces the overall effect of electronic excitation on the convective heating, especially for the Fire II test case. It is shown that reliable models of chemical reaction rates are of great

  10. Laboratory measurements of materials in extreme conditions; The use of high energy radiation sources for high pressure studies

    Energy Technology Data Exchange (ETDEWEB)

    Cauble, R.; Remington, B.A.

    1998-06-01

    High energy lasers can be used to study material conditions that are appropriate fort inertial confinement fusion: that is, materials at high densities, temperatures, and pressures. Pulsed power devices can offer similar opportunities. The National Ignition Facility (NIF) will be a high energy multi-beam laser designed to achieve the thermonuclear ignition of a mm-scale DT-filled target in the laboratory. At the same time, NE will provide the physics community with a unique tool for the study of high energy density matter at states unreachable by any other laboratory technique. Here we describe how these lasers and pulsed power tools can contribute to investigations of high energy density matter in the areas of material properties and equations of state, extend present laboratory shock techniques such as high-speed jets to new regimes, and allow study of extreme conditions found in astrophysical phenomena.

  11. Modeling of a heat sink and high heat flux vapor chamber

    Science.gov (United States)

    Vadnjal, Aleksander

    An increasing demand for a higher heat flux removal capability within a smaller volume for high power electronics led us to focus on a novel cold plate design. A high heat flux evaporator and micro channel heat sink are the main components of a cold plate which is capable of removing couple of 100 W/cm2. In order to describe performance of such porous media device a proper modeling has to be addressed. A universal approach based on the volume average theory (VAT) to transport phenomena in porous media is shown. An approach on how to treat the closure for momentum and energy equations is addressed and a proper definition for friction factors and heat transfer coefficients are discussed. A numerical scheme using a solution to Navier-Stokes equations over a representative elementary volume (REV) and the use of VAT is developed to show how to compute friction factors and heat transfer coefficients. The calculation show good agreement with the experimental data. For the heat transfer coefficient closure, a proper average for both fluid and solid is investigated. Different types of heating are also investigated in order to determine how it influences the heat transfer coefficient. A higher heat fluxes in small area condensers led us to the micro channels in contrast to the classical heat fin design. A micro channel can have various shapes to enhance heat transfer, but the shape that will lead to a higher heat flux removal with a moderate pumping power needs to be determined. The standard micro-channel terminology is usually used for channels with a simple cross section, e.g. square, round, triangle, etc., but here the micro channel cross section is going to be expanded to describe more complicated and interconnected micro scale channel cross sections. The micro channel geometries explored are pin fins (in-line and staggered) and sintered porous micro channels. The problem solved here is a conjugate problem involving two heat transfer mechanisms; (1) porous media

  12. High-energy neutrino fluxes from AGN populations inferred from X-ray surveys

    CERN Document Server

    Jacobsen, Idunn B; On, Alvina Y L; Saxton, Curtis J

    2015-01-01

    High-energy neutrinos and photons are complementary messengers, probing violent astrophysical processes and structural evolution of the Universe. X-ray and neutrino observations jointly constrain conditions in active galactic nuclei (AGN) jets: their baryonic and leptonic contents, and particle production efficiency. Testing two standard neutrino production models for local source Cen A \\citep{KT2008,BB2009}, we calculate the high-energy neutrino spectra of single AGN sources and derive the flux of high-energy neutrinos expected for the current epoch. Assuming that accretion determines both X-rays and particle creation, our parametric scaling relations predict neutrino yield in various AGN classes. We derive redshift-dependent number densities of each class, from {\\it Chandra} and {\\it Swift}/BAT X-ray luminosity functions \\citep{SGB2008,ACS2009}. We integrate the neutrino spectrum expected from the cumulative history of AGN (correcting for cosmological and source effects, e.g. jet orientation and beaming). B...

  13. Calibration of high-heat-flux sensors in a solar furnace

    Energy Technology Data Exchange (ETDEWEB)

    Ballestrin, J.; Rodriguez-Alonso, M.; Rodriguez, J.; Canadas, I. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT), Almeria (Spain); Barbero, F.J. [Almeria Univ., Dept. de Fisica (Spain); Langley, L.W.; Barnes, A. [Vatell Corporation, Christiansburg, VA (United States)

    2006-12-15

    The most common sensors used for the measurement of high solar irradiance are the Gardon gauges, which are usually calibrated using a black body at a certain temperature as the radiant source. This calibration procedure is assumed to produce a systematic error when solar irradiance measurements are taken using these sensors. This paper demonstrates a calorimetric method for calibrating these high-heat-flux gauges in a solar furnace. This procedure has enabled these sensors to be calibrated under concentrated solar radiation at higher irradiances under non-laboratory conditions in the CIEMAT solar furnace at the Plataforma Solar de Almeria. Working at higher irradiances has allowed the uncertainty in the calibration constant of these sensors to be reduced. This work experimentally confirms the predicted systematic errors committed when measuring high solar irradiances using Gardon sensors calibrated with a black body. (authors)

  14. Calibration of high-heat-flux sensors in a solar furnace

    Science.gov (United States)

    Ballestrín, J.; Rodríguez-Alonso, M.; Rodríguez, J.; Cañadas, I.; Barbero, F. J.; Langley, L. W.; Barnes, A.

    2006-12-01

    The most common sensors used for the measurement of high solar irradiance are the Gardon gauges, which are usually calibrated using a black body at a certain temperature as the radiant source. This calibration procedure is assumed to produce a systematic error when solar irradiance measurements are taken using these sensors. This paper demonstrates a calorimetric method for calibrating these high-heat-flux gauges in a solar furnace. This procedure has enabled these sensors to be calibrated under concentrated solar radiation at higher irradiances under non-laboratory conditions in the CIEMAT solar furnace at the Plataforma Solar de Almería. Working at higher irradiances has allowed the uncertainty in the calibration constant of these sensors to be reduced. This work experimentally confirms the predicted systematic errors committed when measuring high solar irradiances using Gardon sensors calibrated with a black body.

  15. RADIATION DOSIMETRY OF THE PRESSURE VESSEL INTERNALS OF THE HIGH FLUX BEAM REACTOR.

    Energy Technology Data Exchange (ETDEWEB)

    HOLDEN,N.E.; RECINIELLO,R.N.; HU,J.P.; RORER,D.C.

    2002-08-18

    In preparation for the eventual decommissioning of the High Flux Beam Reactor after the permanent removal of its fuel elements from the Brookhaven National Laboratory, both measurements and calculations of the decay gamma-ray dose rate have been performed for the reactor pressure vessel and vessel internal structures which included the upper and lower thermal shields, the transition plate, and the control rod blades. The measurements were made using Red Perspex{trademark} polymethyl methacrylate high-level film dosimeters, a Radcal ''peanut'' ion chamber, and Eberline's high-range ion chamber. To compare with measured gamma-ray dose rate, the Monte Carlo MCNP code and geometric progressive Microshield code were used to model the gamma transport and dose buildup.

  16. Subsurface deuterium bubble formation in W due to low-energy high flux deuterium plasma exposure

    Science.gov (United States)

    Jia, Y. Z.; Liu, W.; Xu, B.; Qu, S. L.; Shi, L. Q.; Morgan, T. W.

    2017-03-01

    The deuterium (D) bubbles formed in W exposed to high flux D plasma were researched by scanning electron microscopy and transmission electron microscopy. After D plasma exposure at 500 K and 1000 K, a layer of nano-sized bubbles were homogenously distributed in W subsurface region. The D bubbles were homogenously nucleated due to the high D concentration, and the nucleation process is not related to the vacancy defects. At low temperature (500 K), D bubbles can grow by surface blistering, which caused different nano scale morphologies on different surfaces. At high temperature (1000 K), D bubbles mainly grow by vacancy clustering, which caused pinholes on the surface.

  17. Silicon-Carbide Power MOSFET Performance in High Efficiency Boost Power Processing Unit for Extreme Environments

    Science.gov (United States)

    Ikpe, Stanley A.; Lauenstein, Jean-Marie; Carr, Gregory A.; Hunter, Don; Ludwig, Lawrence L.; Wood, William; Del Castillo, Linda Y.; Fitzpatrick, Fred; Chen, Yuan

    2016-01-01

    Silicon-Carbide device technology has generated much interest in recent years. With superior thermal performance, power ratings and potential switching frequencies over its Silicon counterpart, Silicon-Carbide offers a greater possibility for high powered switching applications in extreme environment. In particular, Silicon-Carbide Metal-Oxide- Semiconductor Field-Effect Transistors' (MOSFETs) maturing process technology has produced a plethora of commercially available power dense, low on-state resistance devices capable of switching at high frequencies. A novel hard-switched power processing unit (PPU) is implemented utilizing Silicon-Carbide power devices. Accelerated life data is captured and assessed in conjunction with a damage accumulation model of gate oxide and drain-source junction lifetime to evaluate potential system performance at high temperature environments.

  18. Three new nondestructive evaluation tools based on high flux neutron sources

    Energy Technology Data Exchange (ETDEWEB)

    Hubbard, C.R.; Raine, D.; Peascoe, R.; Wright, M. [and others

    1997-03-01

    Nondestructive evaluation methods and systems based on specific attributes of neutron interactions with materials are being developed. The special attributes of neutrons are low attenuation in most engineering materials, strong interaction with low Z elements, and epithermal neutron absorption resonances. The three methods under development at ORNL include neutron based tomography and radiography; through thickness, nondestructive texture mapping; and internal, noninvasive temperature measurement. All three techniques require high flux sources such as the High Flux Isotope Reactor, a steady state source, or the Oak Ridge Electron Linear Accelerator, a pulsed neutron source. Neutrons are quite penetrating in most engineering materials and thus can be useful to detect internal flaws and features. Hydrogen atoms, such as in a hydrocarbon fuel, lubricant, or a metal hydride, are relatively opaque to neutron transmission and thus neutron based tomography/radiography is ideal to image their presence. Texture, the nonrandom orientation of crystalline grains within materials, can be mapped nondestructively using neutron diffraction methods. Epithermal neutron resonance absorption is being studied as a noncontacting temperature sensor. This paper highlights the underlying physics of the methods, progress in development, and the potential benefits for science and industry of the three facilities.

  19. Thermo-mechanical study of high heat flux component mock-ups for ITER TBM

    Energy Technology Data Exchange (ETDEWEB)

    Bonelli, Flavia [Institute for Neutron Physics and Reactor Technology, Karlsruhe Institute of Technology (Germany); Dipartimento Energia, Politecnico di Torino (Italy); Boccaccini, Lorenzo Virgilio, E-mail: lorenzo.boccaccini@kit.edu [Institute for Neutron Physics and Reactor Technology, Karlsruhe Institute of Technology (Germany); Kunze, André; Maione, Ivan Alessio [Institute for Neutron Physics and Reactor Technology, Karlsruhe Institute of Technology (Germany); Savoldi, Laura; Zanino, Roberto [Dipartimento Energia, Politecnico di Torino (Italy)

    2015-10-15

    Highlights: • Infrared radiation heaters for test of plasma facing component available at KIT. • Numerical model developed and validated to check uniformity of heat flux. • Thermo-mechanical calculations performed on a mock-up of the HCPB TBM FW. • Assessment done of representativity of stress conditions for the ITER TBMs. - Abstract: Commercial infrared heaters have been proposed to be used in the HELOKA facility under construction at Karlsruhe Institute of Technology (KIT) to test a mock-up of the first wall (FW), called thermo-cycle mock-up (TCM) plate, under stress loading comparable to those experienced by the test blanket modules (TBMs) in ITER. Two related issues are analyzed in this paper, in relation to the ongoing European project aimed at the design of the two EU TBMs: (1) the possibility to reproduce, by means of those heaters, high heat flux loading conditions on the TCM plate similar to those expected on the ITER TBMs, and (2) the thermo-mechanical analysis of the TCM itself, in order to define a suitable choice of experimental parameters and mechanical constraints leading to a relevant stress condition. A suitable heater model is developed and validated against experimental data from an ad-hoc test campaign. A thermo-mechanical study of the TCM plate is presented, showing that the structure is able to withstand high thermal loads, even in the most constrained case, reaching stress levels comparable to the ITER TBM.

  20. Operational characteristics of the high flux plasma generator Magnum-PSI

    Energy Technology Data Exchange (ETDEWEB)

    Eck, H.J.N. van, E-mail: h.j.n.vaneck@differ.nl [FOM Institute DIFFER, Dutch Institute For Fundamental Energy Research, Association EURATOM-FOM, Trilateral Euregio Cluster, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands); Abrams, T. [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); Berg, M.A. van den; Brons, S.; Eden, G.G. van [FOM Institute DIFFER, Dutch Institute For Fundamental Energy Research, Association EURATOM-FOM, Trilateral Euregio Cluster, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands); Jaworski, M.A.; Kaita, R. [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); Meiden, H.J. van der; Morgan, T.W.; Pol, M.J. van de; Scholten, J.; Smeets, P.H.M.; De Temmerman, G.; Vries, P.C. de; Zeijlmans van Emmichoven, P.A. [FOM Institute DIFFER, Dutch Institute For Fundamental Energy Research, Association EURATOM-FOM, Trilateral Euregio Cluster, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands)

    2014-10-15

    Highlights: •We have described the design and capabilities of the plasma experiment Magnum-PSI. •The plasma conditions are well suited for PSI studies in support of ITER. •Quasi steady state heat fluxes over 10 MW m{sup −2} have been achieved. •Transient heat and particle loads can be generated to simulate ELM instabilities. •Lithium coating can be applied to the surfaces of samples under vacuum. -- Abstract: In Magnum-PSI (MAgnetized plasma Generator and NUMerical modeling for Plasma Surface Interactions), the high density, low temperature plasma of a wall stabilized dc cascaded arc is confined to a magnetized plasma beam by a quasi-steady state axial magnetic field up to 1.3 T. It aims at conditions that enable fundamental studies of plasma–surface interactions in the regime relevant for fusion reactors such as ITER: 10{sup 23}–10{sup 25} m{sup −2} s{sup −1} hydrogen plasma flux densities at 1–5 eV. To study the effects of transient heat loads on a plasma-facing surface, a high power pulsed magnetized arc discharge has been developed. Additionally, the target surface can be transiently heated with a pulsed laser system during plasma exposure. In this contribution, the current status, capabilities and performance of Magnum-PSI are presented.

  1. FORTE satellite constraints on ultra-high energy cosmic particle fluxes

    CERN Document Server

    Lehtinen, N G; Jacobson, A R; Roussel-Dupre, R A; Lehtinen, Nikolai G.; Gorham, Peter W.; Jacobson, Abram R.; Roussel-Dupre, Robert A.

    2004-01-01

    The FORTE (Fast On-orbit Recording of Transient Events) satellite records bursts of electromagnetic waves arising from near the Earth's surface in the radio frequency (RF) range of 30 to 300 MHz with a dual polarization antenna. We investigate the possible RF signature of ultra-high energy cosmic-ray particles in the form of coherent Cherenkov radiation from cascades in ice. We calculate the sensitivity of the FORTE satellite to ultra-high energy (UHE) neutrino fluxes at different energies beyond the Greisen-Zatsepin-Kuzmin (GZK) cutoff. Some constraints on supersymmetry model parameters are also estimated due to the limits that FORTE sets on the UHE neutralino flux. The FORTE database consists of over 4 million recorded events to date, including in principle some events associated with UHE neutrinos. We search for candidate FORTE events in the period from September 1997 to December 1999. The candidate production mechanism is via coherent VHF radiation from a UHE neutrino shower in the Greenland ice sheet. We...

  2. Design, performance, and early results from extremely high Doppler precision instruments in a global network

    Science.gov (United States)

    Ge, Jian; Zhao, Bo; Groot, John; Chang, Liang; Varosi, Frank; Wan, Xiaoke; Powell, Scott; Jiang, Peng; Hanna, Kevin; Wang, Ji; Pais, Rohan; Liu, Jian; Dou, Liming; Schofield, Sidney; McDowell, Shaun; Costello, Erin; Delgado-Navarro, Adriana; Fleming, Scott; Lee, Brian; Bollampally, Sandeep R.; Bosman, Troy; Jakeman, Hali; Fletcher, Adam; Marquez, Gabriel

    2010-07-01

    We report design, performance and early results from two of the Extremely High Precision Extrasolar Planet Tracker Instruments (EXPERT) as part of a global network for hunting for low mass planets in the next decade. EXPERT is a combination of a thermally compensated monolithic Michelson interferometer and a cross-dispersed echelle spectrograph for extremely high precision Doppler measurements for nearby bright stars (e.g., 1m/s for a V=8 solar type star in 15 min exposure). It has R=18,000 with a 72 micron slit and a simultaneous coverage of 390-694 nm. The commissioning results show that the instrument has already produced a Doppler precision of about 1 m/s for a solar type star with S/N~100 per pixel. The instrument has reached ~4 mK (P-V) temperature stability, ~1 mpsi pressure stability over a week and a total instrument throughput of ~30% at 550 nm from the fiber input to the detector. EXPERT also has a direct cross-dispersed echelle spectroscopy mode fed with 50 micron fibers. It has spectral resolution of R=27,000 and a simultaneous wavelength coverage of 390-1000 nm.

  3. High heat flux testing of EU tungsten monoblock mock-ups for the ITER divertor

    Energy Technology Data Exchange (ETDEWEB)

    Gavila, P., E-mail: pierre.gavila@f4e.europa.eu [Fusion for Energy, 08019 Barcelona (Spain); Riccardi, B. [Fusion for Energy, 08019 Barcelona (Spain); Pintsuk, G. [Forschungszentrum Juelich, 52425 Juelich (Germany); Ritz, G. [AREVA NP, Centre Technique France, 71205 Le Creusot (France); Kuznetsov, V. [JCS “Efremov Institute”, Doroga na Metallostroy 3, Metallostroy, Saint-Petersburg 196641 (Russian Federation); Durocher, A. [ITER Organization, Route de Vinon sur Verdon, CS 90 046, 13067 Saint Paul-lez-Durance (France)

    2015-10-15

    Highlights: • All the tested items sustained the ITER Full W divertor qualification program requirements. This confirms that the technology for the manufacturing of the first set of the ITER Divertor is available in Europe. • The surface roughening and local melting of the W surface under high heat flux was proven to be significantly reduced for an armour thickness lower or equal to 6 mm. • However, this campaign highlighted some specific areas of improvement to be implemented ideally before the upcoming ITER Divertor IVT serial production. • The issue of the self-castellation of the W monoblocks, which typically appears after a few tenths of cycles at 20 MW/m{sup 2}, is critical because it generates some uncontrolled defects at the amour to heat sink joints. Besides, they create a gap which exposure is almost perpendicular to the magnetic field lines and which might lead to local W melting in the strike point region. • This campaign also evidenced that the minimum IO requirements on the CuCrZr ductility could be revised to avoid the occurrence of rather early fatigue failures. Although the W material characterization program has been set up by the IO, the strategy on the CuCrZr still needs to be defined. - Abstract: With the aim to assess the option to start the ITER operation with a full tungsten divertor, an R&D program was launched in order to evaluate the performances of tungsten (W) armoured plasma facing components (PFCs) under high heat flux. The F4E program consisted in the manufacturing and high heat flux (HHF) testing of W monoblock mock-ups and medium scale prototypes up to 20 MW/m{sup 2}. During the test campaign, 26 W mock-ups and two medium scale prototypes manufactured by Plansee SE (Austria) and by Ansaldo Nucleare (Italy) have been tested at the FE200 (AREVA, Le Creusot, France) and ITER Divertor Test Facility (IDTF) (Efremov Institute Saint Petersburg, Russian Federation) electron beam test facilities. The high heat flux (HHF) testing

  4. Global Distribution of Extreme Precipitation and High-Impact Landslides in 2010 Relative to Previous Years

    Science.gov (United States)

    Kirschbaum, Dalia; Adler, Robert; Adler, David; Peters-Lidard, Christa; Huffman, George

    2012-01-01

    It is well known that extreme or prolonged rainfall is the dominant trigger of landslides worldwide. While research has evaluated the spatiotemporal distribution of extreme rainfall and landslides at local or regional scales using in situ data, few studies have mapped rainfall-triggered landslide distribution globally due to the dearth of landslide data and consistent precipitation information. This study uses a newly developed Global Landslide Catalog (GLC) and a 13-year satellite-based precipitation record from TRMM data. For the first time, these two unique products provide the foundation to quantitatively evaluate the co-occurrence of precipitation and landslides globally. Evaluation of the GLC indicates that 2010 had a large number of high-impact landslide events relative to previous years. This study considers how variations in extreme and prolonged satellite-based rainfall are related to the distribution of landslides over the same time scales for three active landslide areas: Central America, the Himalayan Arc, and central-eastern China. Several test statistics confirm that TRMM rainfall generally scales with the observed increase in landslide reports and fatal events for 2010 and previous years over each region. These findings suggest that the co-occurrence of satellite precipitation and landslide reports may serve as a valuable indicator for characterizing the spatiotemporal distribution of landslide-prone areas in order to establish a global rainfall-triggered landslide climatology. This study characterizes the variability of satellite precipitation data and reported landslide activity at the globally scale in order to improve landslide cataloging, forecasting and quantify potential triggering sources at daily, monthly and yearly time scales.

  5. Establishing Specifications for Low Enriched Uranium Fuel Operations Conducted Outside the High Flux Isotope Reactor Site

    Energy Technology Data Exchange (ETDEWEB)

    Pinkston, Daniel [ORNL; Primm, Trent [ORNL; Renfro, David G [ORNL; Sease, John D [ORNL

    2010-10-01

    The National Nuclear Security Administration (NNSA) has funded staff at Oak Ridge National Laboratory (ORNL) to study the conversion of the High Flux Isotope Reactor (HFIR) from the current, high enriched uranium fuel to low enriched uranium fuel. The LEU fuel form is a metal alloy that has never been used in HFIR or any HFIR-like reactor. This report provides documentation of a process for the creation of a fuel specification that will meet all applicable regulations and guidelines to which UT-Battelle, LLC (UTB) the operating contractor for ORNL - must adhere. This process will allow UTB to purchase LEU fuel for HFIR and be assured of the quality of the fuel being procured.

  6. O on the Crystallization Behavior of Lime-Alumina-Based Mold Flux for Casting High-Al Steels

    Science.gov (United States)

    Lu, Boxun; Chen, Kun; Wang, Wanlin; Jiang, Binbin

    2014-08-01

    With the development of advanced high strength steel (AHSS), a large amount of aluminum was added into steels. The reaction between aluminum in the molten steel and silica based mold flux in the continuous-casting process would tend to cause a series of problems and influence the quality of slabs. To solve the above problems caused by the slag-steel reaction, nonreactive lime-alumina-based mold flux system has been proposed. In this article, the effect of Li2O and Na2O on the crystallization behavior of the lime-alumina-silica-based mold flux has been studied by using the single hot thermocouple technology (SHTT) and double hot thermocouple technology (DHTT). The results indicated that Li2O and Na2O in the above mold flux system play different roles as they behaved in traditional lime-silica based mold flux, which would tend to inhibit general mold flux crystallization by lowering the initial crystallization temperature and increasing incubation time, especially in the high-temperature region. However, when their content exceeds a critical value, the crystallization process of mold fluxes in low temperature zone would be greatly accelerated by the new phase formation of LiAlO2 and Na x Al y Si z O4 crystals, respectively. The crystalline phases precipitated in all samples during the experiments are discussed in the article.

  7. A Novel and Inexpensive Method for Measuring Volcanic Plume Water Fluxes at High Temporal Resolution

    Directory of Open Access Journals (Sweden)

    Tom D. Pering

    2017-02-01

    Full Text Available Water vapour (H2O is the dominant species in volcanic gas plumes. Therefore, measurements of H2O fluxes could provide valuable constraints on subsurface degassing and magmatic processes. However, due to the large and variable concentration of this species in the background atmosphere, little attention has been devoted to monitoring the emission rates of this species from volcanoes. Instead, the focus has been placed on remote measurements of SO2, which is present in far lower abundances in plumes, and therefore provides poorer single flux proxies for overall degassing conditions. Here, we present a new technique for the measurement of H2O emissions at degassing volcanoes at high temporal resolution (≈1 Hz, via remote sensing with low cost digital cameras. This approach is analogous to the use of dual band ultraviolet (UV cameras for measurements of volcanic SO2 release, but is focused on near infrared absorption by H2O. We report on the field deployment of these devices on La Fossa crater, Vulcano Island, and the North East Crater of Mt. Etna, during which in-plume calibration was performed using a humidity sensor, resulting in estimated mean H2O fluxes of ≈15 kg·s−1 and ≈34 kg·s−1, respectively, in accordance with previously reported literature values. By combining the Etna data with parallel UV camera and Multi-GAS observations, we also derived, for the first time, a combined record of 1 Hz gas fluxes for the three most abundant volcanic gas species: H2O, CO2, and SO2. Spectral analysis of the Etna data revealed oscillations in the passive emissions of all three species, with periods spanning ≈40–175 s, and a strong degree of correlation between the periodicity manifested in the SO2 and H2O data, potentially related to the similar exsolution depths of these two gases. In contrast, there was a poorer linkage between oscillations in these species and those of CO2, possibly due to the deeper exsolution of carbon dioxide, giving

  8. High-frequency analysis of the complex linkage between soil CO(2) fluxes, photosynthesis and environmental variables.

    Science.gov (United States)

    Martin, Jonathan G; Phillips, Claire L; Schmidt, Andres; Irvine, James; Law, Beverly E

    2012-01-01

    High-frequency soil CO(2) flux data are valuable for providing new insights into the processes of soil CO(2) production. A record of hourly soil CO(2) fluxes from a semi-arid ponderosa pine stand was spatially and temporally deconstructed in attempts to determine if variation could be explained by logical drivers using (i) CO(2) production depths, (ii) relationships and lags between fluxes and soil temperatures, or (iii) the role of canopy assimilation in soil CO(2) flux variation. Relationships between temperature and soil fluxes were difficult to establish at the hourly scale because diel cycles of soil fluxes varied seasonally, with the peak of flux rates occurring later in the day as soil water content decreased. Using a simple heat transport/gas diffusion model to estimate the time and depth of CO(2) flux production, we determined that the variation in diel soil CO(2) flux patterns could not be explained by changes in diffusion rates or production from deeper soil profiles. We tested for the effect of gross ecosystem productivity (GEP) by minimizing soil flux covariance with temperature and moisture using only data from discrete bins of environmental conditions (±1 °C soil temperature at multiple depths, precipitation-free periods and stable soil moisture). Gross ecosystem productivity was identified as a possible driver of variability at the hourly scale during the growing season, with multiple lags between ~5, 15 and 23 days. Additionally, the chamber-specific lags between GEP and soil CO(2) fluxes appeared to relate to combined path length for carbon flow (top of tree to chamber center). In this sparse and heterogeneous forested system, the potential link between CO(2) assimilation and soil CO(2) flux may be quite variable both temporally and spatially. For model applications, it is important to note that soil CO(2) fluxes are influenced by many biophysical factors, which may confound or obscure relationships with logical environmental drivers and act at

  9. Extreme Learning Machines on High Dimensional and Large Data Applications: A Survey

    Directory of Open Access Journals (Sweden)

    Jiuwen Cao

    2015-01-01

    Full Text Available Extreme learning machine (ELM has been developed for single hidden layer feedforward neural networks (SLFNs. In ELM algorithm, the connections between the input layer and the hidden neurons are randomly assigned and remain unchanged during the learning process. The output connections are then tuned via minimizing the cost function through a linear system. The computational burden of ELM has been significantly reduced as the only cost is solving a linear system. The low computational complexity attracted a great deal of attention from the research community, especially for high dimensional and large data applications. This paper provides an up-to-date survey on the recent developments of ELM and its applications in high dimensional and large data. Comprehensive reviews on image processing, video processing, medical signal processing, and other popular large data applications with ELM are presented in the paper.

  10. Extreme ultraviolet spectroscopy and atomic models of highly charged heavy ions in the Large Helical Device

    Science.gov (United States)

    Suzuki, C.; Murakami, I.; Koike, F.; Tamura, N.; Sakaue, H. A.; Morita, S.; Goto, M.; Kato, D.; Ohashi, H.; Higashiguchi, T.; Sudo, S.; O'Sullivan, G.

    2017-01-01

    We report recent results of extreme ultraviolet (EUV) spectroscopy of highly charged heavy ions in plasmas produced in the Large Helical Device (LHD). The LHD is an ideal source of experimental databases of EUV spectra because of high brightness and low opacity, combined with the availability of pellet injection systems and reliable diagnostic tools. The measured heavy elements include tungsten, tin, lanthanides and bismuth, which are motivated by ITER as well as a variety of plasma applications such as EUV lithography and biological microscopy. The observed spectral features drastically change between quasicontinuum and discrete depending on the plasma temperature, which leads to some new experimental identifications of spectral lines. We have developed collisional-radiative models for some of these ions based on the measurements. The atomic number dependence of the spectral feature is also discussed.

  11. Extreme Energy Events Project: Construction of the detectors and installation in Italian High Schools

    CERN Document Server

    Abbrescia, M; An, S; Antolini, R; Badalà, A; Baldini Ferroli, R; Bencivenni, G; Blanco, F; Bressan, E; Chiavassa, A; Chiri, C; Cifarelli, L; Cindolo, F; Coccia, E; De Pasquale, S; Di Giovanni, A; D’Incecco, M; Fabbri, F L; Frolov, V; Garbini, M; Gustavino, C; Hatzifotiadou, D; Imponente, G; Kim, J; La Rocca, P; Librizzi, F; Maggiora, A; Menghetti, H; Miozzi, S; Moro, R; Panareo, M; Pappalardo, G S; Piragino, G; Riggi, F; Romano, F; Sartorelli, G; Sbarra, C; Selvi, M; Serci, S; Williams, C; Zuyeuski, R

    2008-01-01

    The EEE Project, conceived by its leader Antonino Zichichi, aims to detect Extreme Energy Events of cosmic rays with an array of muon telescopes distributed over the Italian territory. The Project involves Italian High Schools in order to introduce young people to Physics, also countervailing the recent crisis of university scientific classes inscriptions. The detectors for the EEE telescopes are Multigap Resistive Plate Chambers (MRPC) and have been constructed by teams of High School students who went in shift at the CERN laboratories. The mechanics and the electronics were developed by groups of researchers from CERN, the Italian Centro Fermi and INFN. The first group of schools of the EEE Project has inaugurated their telescopes recently. A status report of the Project and the preliminary results are presented.

  12. The physiology of extremes: Ancel Keys and the International High Altitude Expedition of 1935.

    Science.gov (United States)

    Tracy, Sarah W

    2012-01-01

    This article examines the International High Altitude Expedition of 1935 and its significance in the life and science of Ancel Keys. Both the expedition and Keys's story afford excellent opportunities to explore the growing reach of interwar physiology into extreme climates-whether built or natural. As IHAE scientists assessed human performance and adaptation to hypoxia, low barometric pressure, and cold, they not only illuminated the physiological and psychological processes of high altitude acclimatization, but they also drew borderlines between the normal and the pathological, paved the way for the neocolonial exploitation of natural and human resources in Latin America, and pioneered field methods in physiology that were adapted and adopted by the Allied Forces during the Second World War. This case study in the physiology of place reveals the power and persistence of environmental determinism within biomedicine well into the twentieth century.

  13. Feasibility of High-Repetition, Task-Specific Training for Individuals With Upper-Extremity Paresis

    Science.gov (United States)

    Waddell, Kimberly J.; Birkenmeier, Rebecca L.; Moore, Jennifer L.; Hornby, T. George

    2014-01-01

    OBJECTIVE. We investigated the feasibility of delivering an individualized, progressive, high-repetition upper-extremity (UE) task-specific training protocol for people with stroke in the inpatient rehabilitation setting. METHOD. Fifteen patients with UE paresis participated in this study. Task-specific UE training was scheduled for 60 min/day, 4 days/wk, during occupational therapy for the duration of a participant’s inpatient stay. During each session, participants were challenged to complete ≥300 repetitions of various tasks. RESULTS. Participants averaged 289 repetitions/session, spending 47 of 60 min in active training. Participants improved on impairment and activity level outcome measures. CONCLUSION. People with stroke in an inpatient setting can achieve hundreds of repetitions of task-specific training in 1-hr sessions. As expected, all participants improved on functional outcome measures. Future studies are needed to determine whether this high-repetition training program results in better outcomes than current UE interventions. PMID:25005508

  14. Beyond Extreme Ultra Violet (BEUV) Radiation from Spherically symmetrical High-Z plasmas

    Science.gov (United States)

    Yoshida, Kensuke; Fujioka, Shinsuke; Higashiguchi, Takeshi; Ugomori, Teruyuki; Tanaka, Nozomi; Kawasaki, Masato; Suzuki, Yuhei; Suzuki, Chihiro; Tomita, Kentaro; Hirose, Ryouichi; Eshima, Takeo; Ohashi, Hayato; Nishikino, Masaharu; Scally, Enda; Nshimura, Hiroaki; Azechi, Hiroshi; O'Sullivan, Gerard

    2016-03-01

    Photo-lithography is a key technology for volume manufacture of high performance and compact semiconductor devices. Smaller and more complex structures can be fabricated by using shorter wavelength light in the photolithography. One of the most critical issues in development of the next generation photo-lithography is to increase energy conversion efficiency (CE) from laser to shorter wavelength light. Experimental database of beyond extreme ultraviolet (BEUV) radiation was obtained by using spherically symmetrical high-Z plasmas generated with spherically allocated laser beams. Absolute energy and spectra of BEUV light emitted from Tb, Gd, and Mo plasmas were measured with a absolutely calibrated BEUV calorimeter and a transmission grating spectrometer. 1.0 x 1012 W/cm2 is the optimal laser intensity to produced efficient BEUV light source plasmas with Tb and Gd targets. Maximum CE is achieved at 0.8% that is two times higher than the published CEs obtained with planar targets.

  15. Carbon dioxide in northern high latitude oceans: Anthropogenic increase and air-sea flux variability

    Energy Technology Data Exchange (ETDEWEB)

    Omar, Abdirahman M.

    2003-07-01

    The aim of this thesis is to further our knowledge of carbon dioxide in the northern high latitude oceans (northern North Atlantic, Barents Sea, and Arctic Ocean) by studying the anthropogenic change in the oceanic CO2, the inter-annual variability of the air-sea CO2 flux, and the relationship between this variability and changes in other oceanic processes. An introductory chapter and four papers are presented. Descriptions of the seawater carbonate system parameters, air-sea exchange of CO2, and related processes are given in the introduction chapter. The anthropogenic increase in partial pressure of CO2 (pCO2) in the surface water of the Barents Sea is evaluated in paper I. The effect of alternations of the Barents Sea climate between cold and warm modes on the annual cycles of seawater fugacity and air-sea flux of CO2 is investigated in paper II. Oceanic uptake of atmospheric CO2 associated with the seasonal formation of sea ice in Storfjorden and the implication for the entire Arctic Ocean is studied in paper III. An assessment of the variations of the air-sea flux of CO2 in the northern North Atlantic for 20 winters (1981-2001) is carried out in paper IV. PCO2 in the surface water of the Barents Sea is shown to have increased parallel with the atmospheric pCO2 between 1967 and 2000-2001 (paper I). This was determined by comparing seawater pCO2 from 1967 with that from 2000-2001. The former was estimated from surface seawater temperature (SST) while the latter was computed from data of total dissolved inorganic carbon and alkalinity. A procedure which accounts for the natural variability was applied and the difference between seawater pC02 of 1967 and that of 2000-2001 is attributed to the uptake of excess CO2. In the Atlantic sector of the Barents Sea, the surface seawater fugacity of CO2 (fCO s''w) is shown to be lower than the atmospheric fCO2 throughout the year, implying that the area is an annual sink of atmospheric CO2 (paper II). Additionally

  16. Phosphoglycerate Mutase Is a Highly Efficient Enzyme without Flux Control in Lactococcus lactis

    DEFF Research Database (Denmark)

    Solem, Christian; Petranovic, D.; Købmann, Brian

    2010-01-01

    The glycolytic enzyme phosphoglycerate mutase (PGM), which catalyzes the conversion of 3-phosphoglycerate to 2-phosphoglycerate, was examined in Lactococcus lactis with respect to its function, kinetics and glycolytic flux control. A library of strains with PGM activities ranging between 15......-465% of the wild-type level was constructed by replacing the native promoter of pgm with synthetic promoters of varying strengths. The specific growth rate and glucose flux were found to be maximal at the wild-type level at which PGM had no flux control. Low flux control of PGM was found on mixed acid fluxes...

  17. Constraints on the flux of Ultra-High Energy neutrinos from WSRT observations

    CERN Document Server

    Buitink, S; Bacelar, J; Braun, R; de Bruyn, A G; Falcke, H; Singh, K; Stappers, B; Strom, R G; Yahyaoui, R al

    2010-01-01

    Ultra-high energy (UHE) neutrinos and cosmic rays initiate particle cascades underneath the Moon's surface. These cascades have a negative charge excess and radiate Cherenkov radio emission in a process known as the Askaryan effect. The optimal frequency window for observation of these pulses with radio telescopes on the Earth is around 150 MHz. By observing the Moon with the Westerbork Synthesis Radio Telescope array we are able to set a new limit on the UHE neutrino flux. The PuMa II backend is used to monitor the Moon in 4 frequency bands between 113 and 175 MHz with a sampling frequency of 40 MHz. The narrowband radio interference is digitally filtered out and the dispersive effect of the Earth's ionosphere is compensated for. A trigger system is implemented to search for short pulses. By inserting simulated pulses in the raw data, the detection efficiency for pulses of various strength is calculated. With 47.6 hours of observation time, we are able to set a limit on the UHE neutrino flux. This new limit ...

  18. Characterization of neutron yield and x-ray spectra of a High Flux Neutron Generator (HFNG)

    Science.gov (United States)

    Nnamani, Nnaemeka; HFNG Collaboration

    2015-04-01

    The High Flux Neutron Generator (HFNG) is a DD plasma-based source, with a self-loading target intended for fundamental science and engineering applications, including 40 Ar/39 Ar geochronology, neutron cross section measurements, and radiation hardness testing of electronics. Our first estimate of the neutron yield, based on the population of the 4.486 hour 115 In isomer gave a neutron yield of the order 108 n/sec; optimization is ongoing to achieve the design target of 1011 n/sec. Preliminary x-ray spectra showed prominent energy peaks which are likely due to atomic line-emission from back-streaming electrons accelerated up to 100 keV impinging on various components of the HFNG chamber. Our x-ray and neutron diagnostics will aid us as we continue to evolve the design to suppress back-streaming electrons, necessary to achieve higher plasma beam currents, and thus higher neutron flux. This talk will focus on the characterization of the neutron yield and x-ray spectra during our tests. A collimation system is being installed near one of the chamber ports for improved observation of the x-ray spectra. This work is supported by NSF Grant No. EAR-0960138, U.S. DOE LBNL Contract No. DE-AC02-05CH11231, U.S. DOE LLNL Contract No. DE-AC52-07NA27344, and the UC Office of the President Award 12-LR-238745.

  19. High Time Resolution Measurements of Methane Fluxes From Enteric Fermentation in Cattle Rumen

    Science.gov (United States)

    Floerchinger, C. R.; Herndon, S.; Fortner, E.; Roscioli, J. R.; Kolb, C. E.; Knighton, W. B.; Molina, L. T.; Zavala, M.; Castelán, O.; Ku Vera, J.; Castillo, E.

    2013-12-01

    Methane accounts for roughly 20% of the global radiative climate forcing in the last two and a half centuries. Methane emissions arise from a number of anthropogenic and biogenic sources. In some areas enteric fermentation in livestock produces over 90% of agricultural methane. In the spring of 2013, as a part of the Short Lived Climate Forcer-Mexico field campaign, the Aerodyne Mobile Laboratory in partnership with the Molina Center for the Environment studied methane production associated with enteric fermentation in the rumen of cattle. A variety of different breeds and stocks being raised in two agricultural and veterinary research facilities located in different areas of Mexico were examined. Methane fluxes were quantified using two methods: 1) an atmospherically stable gaseous tracer release was collocated with small herds in a pasture, allowing tracer ratio flux measurements; 2) respiratory CO2 was measured in tandem with methane in the breath of individual animals allowing methane production to be related to metabolism. The use of an extensive suite of very high time response instruments allows for differentiation of individual methane producing rumination events and respiratory CO2 from possible background interferences. The results of these studies will be presented and compared to data from traditional chamber experiments.

  20. Isotopically non-stationary metabolic flux analysis: complex yet highly informative.

    Science.gov (United States)

    Wiechert, Wolfgang; Nöh, Katharina

    2013-12-01

    Metabolic flux analysis (MFA) using isotopic tracers aims at the experimental determination of in vivo reaction rates (fluxes). In recent years, the well-established 13C-MFA method based on metabolic and isotopic steady state was extended to INST-MFA (isotopically non-stationary MFA), which is performed in a transient labeling state. INST-MFA offers short-time experiments with a maximal information gain, and can moreover be applied to a wider range of growth conditions or organisms. Some of these conditions are not accessible by conventional methods. This comes at the price of significant methodological complexity involving high-frequency sampling and quenching, precise analysis of many samples and an extraordinary computational effort. This review gives a brief overview of basic principles, experimental workflows, and recent progress in this field. Special emphasis is laid on the trade-off between total effort and information gain, particularly on the suitability of INST-MFA for certain types of biological questions. In order to integrate INST-MFA as a viable method into the toolbox of MFA, some major challenges must be addressed in the coming years. These are discussed in the outlook. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. High fidelity simulation of nucleate boiling and transition to critical heat flux on enhanced structures

    Science.gov (United States)

    Yazdani, Miad; Alahyari, Abbas; Radcliff, Thomas; Soteriou, Marios

    2015-11-01

    Surface enhancement is often is the primary approach for improved heat transfer performance of two-phase thermal systems particularly when they operate in nucleate boiling regime. This paper exploits the modeling capability developed by Yazdani et al. for simulation of nucleate boiling and transition to critical heat flux to study the nucleation phenomenon on various enhanced structures. The multi-scale of two-phase flow associated with boiling phenomena is addressed through combination of deterministic CFD for the macro-scale transport, asymptotic based representation of micro-layer, and stochastic representation of surface roughness so as to allow a high-fidelity simulation of boiling on an arbitrary surface. In addition, given the excessive complexity of surface structures often used for enhancement of boiling heat transfer, a phase-field-based method is developed to generate the structures where the numerical parameters in the phase-field model determine the topology of a given structure. The ``generated'' structure is then embedded into the two-phase flow model through virtual boundary method for the boiling simulation. The model is validated against experimental data for the boiling curve and the critical heat flux as well as nucleation and bubble dynamics characteristics.

  2. Progress toward coupled flux qubits with high connectivity and long coherence times

    Science.gov (United States)

    Weber, Steven; Hover, David; Rosenberg, Danna; Samach, Gabriel; Yoder, Jonilyn; Kerman, Andrew; Oliver, William

    The ability to engineer interactions between qubits is essential to all areas of quantum information science. The capability to tune qubit-qubit couplings in situ is desirable for gate-based quantum computing and analog quantum simulation and necessary for quantum annealing. Consequently, tunable coupling has been the subject of several experimental efforts using both transmon qubits and flux qubits. Recently, our group has demonstrated robust and long-lived capacitively shunted (C-shunt) flux qubits. Here, we discuss our efforts to develop architectures for tunably coupling these qubits. In particular, we focus on optimizing the RF SQUID coupler to achieve high connectivity. This research was funded by the Office of the Director of National Intelligence (ODNI), Intelligence Advanced Research Projects Activity (IARPA) and by the Assistant Secretary of Defense for Research & Engineering under Air Force Contract No. FA8721-05-C-0002. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of ODNI, IARPA, or the US Government.

  3. Molecular Imprinted Membrane with High Flux by Surface Photo-grafting Copolymerization

    Institute of Scientific and Technical Information of China (English)

    李爽; 张凤宝; 张国亮; 王燕

    2005-01-01

    Molecular imprinted polymer membranes (MIM) combine the merits of molecular imprint and membrane technology. In this work, a very thin of imprinted polymer that can specifically and selectively absorb the basic template (adenine) was grafted on the surface of polyvinylidene fluoride membrane by photo-grafting copolymerization. Because the molecular imprinted polymer is grafted on the surface of the matrix membrane without blocking the membrane pores, the resultant MIMs have high flux as microfiltration membrane (0.26 mol·m-2·h-1 of template and flux for distilled water was 3.6 ml·mim-1·cm-2 at 0.8 MPa). Moreover, the MIMs can absorb/desorb template molecules rapidly. Usually, it only takes several minutes for MIMs to absorb more than 75% of the template (adenine) in aqueous solution. And the influences of the type and amount of the functional monomers, the amount of the cross-linker on the absorption capability are discussed to determine the optimal preparation conditions。

  4. Modeling the reduction of gross lithium erosion observed under high-flux deuterium bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Abrams, T., E-mail: tabrams@pppl.gov [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); Jaworski, M.A.; Kaita, R.; Nichols, J.H.; Stotler, D.P. [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); De Temmerman, G.; Berg, M.A. van den; Meiden, H.J. van der; Morgan, T.W. [FOM Institute DIFFER – Dutch Institute for Fundamental Energy Research, Trilateral Euregio Cluster, Associate EURATOM-FOM, BL-3430 BE Nieuwegein (Netherlands)

    2015-08-15

    Both thin (<1 μm) and thick (∼500 μm) lithium films under high-flux deuterium and neon plasma bombardment were studied in the linear plasma device Magnum-PSI at ion fluxes >10{sup 24} m{sup −2} s{sup −1} and surface temperatures <700 °C. During Ne plasma exposures, Li erosion rates inferred from measurements of Li–I radiation exceed Langmuir Law evaporation, but no previous results exist to benchmark the binary collision approximation (BCA) and thermal sputtering measurements. Measured Li erosion rates during D plasma bombardment were compared to the adatom-evaporation model of thermal sputtering with an additional reduction term to account for the relative D/Li composition of the Li film. This model captures the qualitative evolution of the Li erosion yield but still overestimates the measured erosion by a factor of 5–10. This suggests that additional refinements to the mixed-material model are needed.

  5. The wave energy flux of high frequency diffracting beams in complex geometrical optics

    Science.gov (United States)

    Maj, Omar; Mariani, Alberto; Poli, Emanuele; Farina, Daniela

    2013-04-01

    We consider the construction of asymptotic solutions of Maxwell's equations for a diffracting wave beam in the high frequency limit and address the description of the wave energy flux transported by the beam. With this aim, the complex eikonal method is applied. That is a generalization of the standard geometrical optics method in which the phase function is assumed to be complex valued, with the non-negative imaginary part accounting for the finite width of the beam cross section. In this framework, we propose an argument which simplifies significantly the analysis of the transport equation for the wave field amplitude and allows us to derive the wave energy flux. The theoretical analysis is illustrated numerically for the case of electron cyclotron beams in tokamak plasmas by using the GRAY code [D. Farina, Fusion Sci. Technol. 52, 154 (2007)], which is based upon the complex eikonal theory. The results are compared to those of the paraxial beam tracing code TORBEAM [E. Poli et al., Comput. Phys. Commun. 136, 90 (2001)], which provides an independent calculation of the energy flow.

  6. The wave energy flux of high frequency diffracting beams in complex geometrical optics

    Energy Technology Data Exchange (ETDEWEB)

    Maj, Omar; Poli, Emanuele [Max Planck Institute for Plasma Physics, EURATOM Association, Boltzmannstr. 2, 85748 Garching (Germany); Mariani, Alberto [Istituto di Fisica del Plasma ' P. Caldirola,' Consiglio Nazionale delle Ricerche, EURATOM-ENEA-CNR Association, via R. Cozzi 53, I-20125 Milano (Italy); Universita degli Studi di Milano, Dipartimento di Fisica, Via Celoria 16, 20133 Milano (Italy); Farina, Daniela [Istituto di Fisica del Plasma ' P. Caldirola,' Consiglio Nazionale delle Ricerche, EURATOM-ENEA-CNR Association, via R. Cozzi 53, I-20125 Milano (Italy)

    2013-04-15

    We consider the construction of asymptotic solutions of Maxwell's equations for a diffracting wave beam in the high frequency limit and address the description of the wave energy flux transported by the beam. With this aim, the complex eikonal method is applied. That is a generalization of the standard geometrical optics method in which the phase function is assumed to be complex valued, with the non-negative imaginary part accounting for the finite width of the beam cross section. In this framework, we propose an argument which simplifies significantly the analysis of the transport equation for the wave field amplitude and allows us to derive the wave energy flux. The theoretical analysis is illustrated numerically for the case of electron cyclotron beams in tokamak plasmas by using the GRAY code [D. Farina, Fusion Sci. Technol. 52, 154 (2007)], which is based upon the complex eikonal theory. The results are compared to those of the paraxial beam tracing code TORBEAM [E. Poli et al., Comput. Phys. Commun. 136, 90 (2001)], which provides an independent calculation of the energy flow.

  7. Constraints on the flux of Ultra-High Energy neutrinos from WSRT observations

    Energy Technology Data Exchange (ETDEWEB)

    Scholten, O; Bacelar, J; Braun, R; de Bruyn, A G; Falcke, H; Singh, K; Stappers, B; Strom, R G; al Yahyaoui, R

    2010-04-02

    Context. Ultra-high energy (UHE) neutrinos and cosmic rays initiate particle cascades underneath the Moon's surface. These cascades have a negative charge excess and radiate Cherenkov radio emission in a process known as the Askaryan effect. The optimal frequency window for observation of these pulses with radio telescopes on the Earth is around 150 MHz. Aims. By observing the Moon with the Westerbork Synthesis Radio Telescope array we are able to set a new limit on the UHEneutrino flux. Methods. The PuMa II backend is used to monitor the Moon in 4 frequency bands between 113 and 175 MHz with a sampling frequency of 40 MHz. The narrow band radio interference is digitally filtered out and the dispersive effect of the Earth?s ionosphere is compensated for. A trigger system is implemented to search for short pulses. By inserting simulated pulses in the raw data, the detection efficiency for pulses of various strength is calculated. Results. With 47.6 hours of observation time, we are able to set a limit on the UHE neutrino flux. This new limit is an order of magnitude lower than existing limits. In the near future, the digital radio array LOFAR will be used to achieve an even lower limit.

  8. High-temperature thermocouple and heat flux gauge using a unique thin film-hardware hot junction

    Science.gov (United States)

    Liebert, C. H.; Holanda, R.; Hippensteele, S. A.; Andracchio, C. A.

    1985-01-01

    A special thin film-hardware material thermocouple (TC) and heat flux gauge concept for a reasonably high temperature and high flux flat plate heat transfer experiment was fabricated and tested to gauge temperatures of 911 K. This concept was developed for minimal disturbance of boundary layer temperature and flow over the plates and minimal disturbance of heat flux through the plates. Comparison of special heat flux gauge Stanton number output at steady-state conditions with benchmark literature data was good and agreement was within a calculated uncertainty of the measurement system. Also, good agreement of special TC and standard TC outputs was obtained and the results are encouraging. Oxidation of thin film thermoelements was a primary failure mode after about 5 of operation.

  9. Phthalocyanine dye as an extremely photostable and highly fluorescent near-infrared labeling reagent

    Science.gov (United States)

    Peng, Xinzhan; Draney, Daniel R.; Volcheck, William M.; Bashford, Gregory R.; Lamb, Donald T.; Grone, Daniel L.; Zhang, Yonghong; Johnson, Craig M.

    2006-02-01

    Current organic fluorophores used as labeling reagents for biomolecule conjugation have significant limitations in photostability. This compromises their performance in applications that require a photostable fluorescent reporting group. For example, in molecular imaging and single molecule microscopy, photostable fluorescent labels are important for observing and tracking individual molecular events over extended period of time. We report in this paper an extremely photostable and highly fluorescent phthalocyanine dye, IRDye TM 700DX, as a near-infrared fluorescence labeling reagent to conjugate with biomolecules. This novel water-soluble silicon phthalocyanine dye has an isomericly pure chemical structure. The dye is about 45 to 128 times more photostable than current near-IR fluorophores, e.g. Alexa Fluor"R"680, Cy TM 5.5, Cy TM 7 and IRDye TM 800CW dyes; and about 27 times more photostable than tetramethylrhodamine (TMR), one of the most photostable organic dyes. This dye also meets all the other stringent requirements as an ideal fluorophore for biomolecules labeling such as excellent water solubility, no aggregation in high ionic strength buffer, large extinction coefficient and high fluorescent quantum yield. Antibodies conjugated with IRDye TM 700DX at high D/P ratio exist as monomeric species in high ionic buffer and have bright fluorescence. The IRDye TM 700DX conjugated antibodies generate sensitive, highly specific detection with very low background in Western blot and cytoblot assays.

  10. Seasonal and diurnal variability of the meteor flux at high latitudes observed using PFISR

    Science.gov (United States)

    Sparks, J. J.; Janches, D.; Nicolls, M. J.; Heinselman, C. J.

    2009-05-01

    We report in this and a companion paper [Fentzke, J.T., Janches, D., Sparks, J.J., 2008. Latitudinal and seasonal variability of the micrometeor input function: A study using model predictions and observations from Arecibo and PFISR. Journal of Atmospheric and Solar-Terrestrial Physics, this issue, doi:10.1016/j.jastp.2008.07.015] a complete seasonal study of the micrometeor input function (MIF) at high latitudes using meteor head-echo radar observations performed with the Poker Flat Incoherent Scatter Radar (PFISR). This flux is responsible for a number of atmospheric phenomena; for example, it could be the source of meteoric smoke that is thought to act as condensation nuclei in the formation of ice particles in the polar mesosphere. The observations presented here were performed for full 24-h periods near the summer and winter solstices and spring and autumn equinoxes, times at which the seasonal variability of the MIF is predicted to be large at high latitudes [Janches, D., Heinselman, C.J., Chau, J.L., Chandran, A., Woodman, R., 2006. Modeling of the micrometeor input function in the upper atmosphere observed by High Power and Large Aperture Radars, JGR, 11, A07317, doi:10.1029/2006JA011628]. Precise altitude and radar instantaneous line-of-sight (radial) Doppler velocity information are obtained for each of the hundreds of events detected every day. We show that meteor rates, altitude, and radial velocity distributions have a large seasonal dependence. This seasonal variability can be explained by a change in the relative location of the meteoroid sources with respect to the observer. Our results show that the meteor flux into the upper atmosphere is strongly anisotropic and its characteristics must be accounted for when including this flux into models attempting to explain related aeronomical phenomena. In addition, the measured acceleration and received signal strength distribution do not seem to depend on season; which may suggest that these observed

  11. A combined maximum-likelihood analysis of the high-energy astrophysical neutrino flux measured with IceCube

    CERN Document Server

    Aartsen, M G; Ackermann, M; Adams, J; Aguilar, J A; Ahlers, M; Ahrens, M; Altmann, D; Anderson, T; Archinger, M; Arguelles, C; Arlen, T C; Auffenberg, J; Bai, X; Barwick, S W; Baum, V; Bay, R; Beatty, J J; Tjus, J Becker; Becker, K -H; Beiser, E; BenZvi, S; Berghaus, P; Berley, D; Bernardini, E; Bernhard, A; Besson, D Z; Binder, G; Bindig, D; Bissok, M; Blaufuss, E; Blumenthal, J; Boersma, D J; Bohm, C; Börner, M; Bos, F; Bose, D; Böser, S; Botner, O; Braun, J; Brayeur, L; Bretz, H -P; Brown, A M; Buzinsky, N; Casey, J; Casier, M; Cheung, E; Chirkin, D; Christov, A; Christy, B; Clark, K; Classen, L; Coenders, S; Cowen, D F; Silva, A H Cruz; Daughhetee, J; Davis, J C; Day, M; de André, J P A M; De Clercq, C; Dembinski, H; De Ridder, S; Desiati, P; de Vries, K D; de Wasseige, G; de With, M; DeYoung, T; Díaz-Vélez, J C; Dumm, J P; Dunkman, M; Eagan, R; Eberhardt, B; Ehrhardt, T; Eichmann, B; Euler, S; Evenson, P A; Fadiran, O; Fahey, S; Fazely, A R; Fedynitch, A; Feintzeig, J; Felde, J; Filimonov, K; Finley, C; Fischer-Wasels, T; Flis, S; Fuchs, T; Gaisser, T K; Gaior, R; Gallagher, J; Gerhardt, L; Ghorbani, K; Gier, D; Gladstone, L; Glagla, M; Glüsenkamp, T; Goldschmidt, A; Golup, G; Gonzalez, J G; Goodman, J A; Góra, D; Grant, D; Gretskov, P; Groh, J C; Groß, A; Ha, C; Haack, C; Ismail, A Haj; Hallgren, A; Halzen, F; Hansmann, B; Hanson, K; Hebecker, D; Heereman, D; Helbing, K; Hellauer, R; Hellwig, D; Hickford, S; Hignight, J; Hill, G C; Hoffman, K D; Hoffmann, R; Holzapfel, K; Homeier, A; Hoshina, K; Huang, F; Huber, M; Huelsnitz, W; Hulth, P O; Hultqvist, K; In, S; Ishihara, A; Jacobi, E; Japaridze, G S; Jero, K; Jurkovic, M; Kaminsky, B; Kappes, A; Karg, T; Karle, A; Kauer, M; Keivani, A; Kelley, J L; Kemp, J; Kheirandish, A; Kiryluk, J; Kläs, J; Klein, S R; Kohnen, G; Kolanoski, H; Konietz, R; Koob, A; Köpke, L; Kopper, C; Kopper, S; Koskinen, D J; Kowalski, M; Krings, K; Kroll, G; Kroll, M; Kunnen, J; Kurahashi, N; Kuwabara, T; Labare, M; Lanfranchi, J L; Larson, M J; Lesiak-Bzdak, M; Leuermann, M; Leuner, J; Lünemann, J; Madsen, J; Maggi, G; Mahn, K B M; Maruyama, R; Mase, K; Matis, H S; Maunu, R; McNally, F; Meagher, K; Medici, M; Meli, A; Menne, T; Merino, G; Meures, T; Miarecki, S; Middell, E; Middlemas, E; Miller, J; Mohrmann, L; Montaruli, T; Morse, R; Nahnhauer, R; Naumann, U; Niederhausen, H; Nowicki, S C; Nygren, D R; Obertacke, A; Olivas, A; Omairat, A; O'Murchadha, A; Palczewski, T; Paul, L; Pepper, J A; Heros, C Pérez de los; Pfendner, C; Pieloth, D; Pinat, E; Posselt, J; Price, P B; Przybylski, G T; Pütz, J; Quinnan, M; Rädel, L; Rameez, M; Rawlins, K; Redl, P; Reimann, R; Relich, M; Resconi, E; Rhode, W; Richman, M; Richter, S; Riedel, B; Robertson, S; Rongen, M; Rott, C; Ruhe, T; Ruzybayev, B; Ryckbosch, D; Saba, S M; Sabbatini, L; Sander, H -G; Sandrock, A; Sandroos, J; Sarkar, S; Schatto, K; Scheriau, F; Schimp, M; Schmidt, T; Schmitz, M; Schoenen, S; Schöneberg, S; Schönwald, A; Schukraft, A; Schulte, L; Seckel, D; Seunarine, S; Shanidze, R; Smith, M W E; Soldin, D; Spiczak, G M; Spiering, C; Stahlberg, M; Stamatikos, M; Stanev, T; Stanisha, N A; Stasik, A; Stezelberger, T; Stokstad, R G; Stößl, A; Strahler, E A; Ström, R; Strotjohann, N L; Sullivan, G W; Sutherland, M; Taavola, H; Taboada, I; Ter-Antonyan, S; Terliuk, A; Tešić, G; Tilav, S; Toale, P A; Tobin, M N; Tosi, D; Tselengidou, M; Unger, E; Usner, M; Vallecorsa, S; Vandenbroucke, J; van Eijndhoven, N; Vanheule, S; van Santen, J; Veenkamp, J; Vehring, M; Voge, M; Vraeghe, M; Walck, C; Wallace, A; Wallraff, M; Wandkowsky, N; Weaver, C; Wendt, C; Westerhoff, S; Whelan, B J; Whitehorn, N; Wichary, C; Wiebe, K; Wiebusch, C H; Wille, L; Williams, D R; Wissing, H; Wolf, M; Wood, T R; Woschnagg, K; Xu, D L; Xu, X W; Xu, Y; Yanez, J P; Yodh, G; Yoshida, S; Zarzhitsky, P; Zoll, M

    2015-01-01

    Evidence for an extraterrestrial flux of high-energy neutrinos has now been found in multiple searches with the IceCube detector. The first solid evidence was provided by a search for neutrino events with deposited energies $\\gtrsim30$~TeV and interaction vertices inside the instrumented volume. Recent analyses suggest that the extraterrestrial flux extends to lower energies and is also visible with throughgoing, $\

  12. Environmental extremes versus ecological extremes: impact of a massive iceberg on the population dynamics of a high-level Antarctic marine predator†

    Science.gov (United States)

    Chambert, Thierry; Rotella, Jay J.; Garrott, Robert A.

    2012-01-01

    Extreme events have been suggested to play a disproportionate role in shaping ecological processes, but our understanding of the types of environmental conditions that elicit extreme consequences in natural ecosystems is limited. Here, we investigated the impact of a massive iceberg on the dynamics of a population of Weddell seals. Reproductive rates of females were reduced, but survival appeared unaffected. We also found suggestive evidence for a prolonged shift towards higher variability in reproductive rates. The annual number of females attending colonies showed unusual swings during the iceberg period, a pattern that was apparently the consequence of changes in sea-ice conditions. In contrast to the dramatic effects that were recorded in nearby populations of emperor penguins, our results suggest that this unusual environmental event did not have an extreme impact on the population of seals in the short-term, as they managed to avoid survival costs and were able to rapidly re-achieve high levels of reproduction by the end of the perturbation. Nevertheless, population projections suggest that even this modest impact on reproductive rates could negatively affect the population in the long run if such events were to occur more frequently, as is predicted by models of climate change. PMID:23015628

  13. Microscopic Deformation of Tungsten Surfaces by High Energy and High Flux Helium/Hydrogen Particle Bombardment with Short Pulses

    Science.gov (United States)

    Tokitani, Masayuki; Yoshida, Naoaki; Tokunaga, Kazutoshi; Sakakita, Hajime; Kiyama, Satoru; Koguchi, Haruhisa; Hirano, Yoichi; Masuzaki, Suguru

    The neutral beam injection facility in the National Institute of Advanced Industrial Science and Technology was used to irradiate a polycrystalline tungsten specimen with high energy and high flux helium and hydrogen particles. The incidence energy and flux of the beam shot were 25 keV and 8.8 × 1022 particles/m2 s, respectively. The duration of each shot was approximately 30 ms, with 6 min intervals between each shot. Surface temperatures over 1800 K were attained. In the two cases of helium irradiation, total fluence of either 1.5 × 1022 He/m2 or 4.0 × 1022 He/m2 was selected. In the former case, large sized blisters with diameter of 500 nm were densely observed. While, the latter case, the blisters were disappeared and fine nanobranch structures appeared instead. Cross-sectional observations using a transmission electron microscope (TEM) with the focused ion beam (FIB) technique were performed. According to the TEM image, after irradiation with a beam shot of total fluence 4.0 × 1022 He/m2 , there were very dense fine helium bubbles in the tungsten of sizes 1-50 nm. As the helium bubbles grew the density of the tungsten matrix drastically decreased as a result of void swelling. These effects were not seen in hydrogen irradiation case.

  14. Numerical simulation in a subcooled water flow boiling for one-sided high heat flux in reactor divertor

    Energy Technology Data Exchange (ETDEWEB)

    Liu, P., E-mail: pinliu@aust.edu.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); University of Science and Technology of China, Hefei 230026 (China); School of Mechanical Engineering, Anhui University of Science and Technology, Huainan 232001 (China); Peng, X.B., E-mail: pengxb@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Song, Y.T. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); University of Science and Technology of China, Hefei 230026 (China); Fang, X.D. [Institute of Air Conditioning and Refrigeration, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Huang, S.H. [University of Science and Technology of China, Hefei 230026 (China); Mao, X. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2016-11-15

    Highlights: • The Eulerian multiphase models coupled with Non-equilibrium Boiling model can effectively simulate the subcooled water flow boiling. • ONB and FDB appear earlier and earlier with the increase of heat fluxes. • The void fraction increases gradually along the flow direction. • The inner CuCrZr tube deteriorates earlier than the outer tungsten layer and the middle OFHC copper layer. - Abstract: In order to remove high heat fluxes for plasma facing components in International Thermonuclear Experimental Reactor (ITER) divertor, a numerical simulation of subcooled water flow boiling heat transfer in a vertically upward smooth tube was conducted in this paper on the condition of one-sided high heat fluxes. The Eulerian multiphase model coupled with Non-equilibrium Boiling model was adopted in numerical simulation of the subcooled boiling two-phase flow. The heat transfer regions, thermodynamic vapor quality (x{sub th}), void fraction and temperatures of three components on the condition of the different heat fluxes were analyzed. Numerical results indicate that the onset of nucleate boiling (ONB) and fully developed boiling (FDB) appear earlier and earlier with increasing heat flux. With the increase of heat fluxes, the inner CuCrZr tube will deteriorate earlier than the outer tungsten layer and the middle oxygen-free high-conductivity (OFHC) copper layer. These results provide a valuable reference for the thermal-hydraulic design of a water-cooled W/Cu divertor.

  15. High-Resolution Observations of a Flux Rope with the Interface Region Imaging Spectrograph

    Science.gov (United States)

    Li, Ting; Zhang, Jun

    2015-10-01

    We report the observations of a flux rope at transition region temperatures with the Interface Region Imaging Spectrograph (IRIS) on 30 August 2014. Initially, magnetic flux cancellation continually took place and a filament was activated. Then the bright material from the filament moved southward and tracked out several fine structures. These fine structures were twisted and tangled with each other, and appeared as a small flux rope at 1330 Å, with a total twist of about 4π. Afterwards, the flux rope underwent a counterclockwise (viewed top-down) unwinding motion around its axis. Spectral observations of C ii 1335.71 Å at the southern leg of the flux rope revealed Doppler redshifts of 6 - 24 km s^{-1} at the western side of the axis, which is consistent with the counterclockwise rotation motion. We suggest that the magnetic flux cancellation initiates reconnection and activation of the flux rope. The stored twist and magnetic helicity of the flux rope are transported into the upper atmosphere by the unwinding motion in the late stage. The small-scale flux rope (width of 8.3^'') had a cylindrical shape with helical field lines, similar to the morphology of the large-scale CME core (width of 1.54 {R}_{⊙}) on 2 June 1998. This similarity shows the presence of flux ropes of different scales on the Sun.

  16. High-flux Thin-film Nanofibrous Composite Ultrafiltration Membranes Containing Cellulose Barrier Layer

    Energy Technology Data Exchange (ETDEWEB)

    Ma, H.; Yoon, K; Rong, L; Mao, Y; Mo, Z; Fang, D; Hollander, Z; Gaiteri, J; Hsiao , B; Chu, B

    2010-01-01

    A novel class of thin-film nanofibrous composite (TFNC) membrane consisting of a cellulose barrier layer, a nanofibrous mid-layer scaffold, and a melt-blown non-woven substrate was successfully fabricated and tested as an ultrafiltration (UF) filter to separate an emulsified oil and water mixture, a model bilge water for on-board ship bilge water purification. Two ionic liquids: 1-butyl-3-methylimidazolium chloride and 1-ethyl-3-methylimidazolium acetate, were chosen as the solvent to dissolve cellulose under mild conditions. The regenerated cellulose barrier layer exhibited less crystallinity (determined by wide-angle X-ray diffraction, WAXD) than the original cotton linter pulps, but good thermal stability (determined by thermal gravimetric analysis, TGA). The morphology, water permeation, and mechanical stability of the chosen TFNCmembranes were thoroughly investigated. The results indicated that the polyacrylonitrile (PAN) nanofibrous scaffold was partially imbedded in the cellulose barrier layer, which enhanced the mechanical strength of the top barrier layer. The permeation flux of the cellulose-based TFNCmembrane was significantly higher (e.g. 10x) than comparable commercial UFmembranes (PAN10 and PAN400, Sepro) with similar rejection ratios for separation of oil/water emulsions. The molecular weight cut-off (MWCO) of TFNC membranes with cellulose barrier layer was evaluated using dextran feed solutions. The rejection was found to be higher than 90% with a dextran molecular weight of 2000 KDa, implying that the nominal pore size of the membrane was less than 50 nm. High permeation flux was also observed in the filtration of an emulsified oil/water mixture as well as of a sodium alginate aqueous solution, while high rejection ratio (above 99.5%) was maintained after prolonged operation. A variation of the barrier layer thickness could dramatically affect the permeation flux and the rejection ratio of the TFNCmembranes, while different sources of cellulose

  17. High-latitude electromagnetic and particle energy flux during an event with sustained strongly northward IMF

    Directory of Open Access Journals (Sweden)

    H. Korth

    2005-06-01

    Full Text Available We present a case study of a prolonged interval of strongly northward orientation of the interplanetary magnetic field on 16 July 2000, 16:00-19:00 UT to characterize the energy exchange between the magnetosphere and ionosphere for conditions associated with minimum solar wind-magnetosphere coupling. With reconnection occurring tailward of the cusp under northward IMF conditions, the reconnection dynamo should be separated from the viscous dynamo, presumably driven by the Kelvin-Helmholtz (KH instability. Thus, these conditions are also ideal for evaluating the contribution of a viscous interaction to the coupling process. We derive the two-dimensional distribution of the Poynting vector radial component in the northern sunlit polar ionosphere from magnetic field observations by the constellation of Iridium satellites together with drift meter and magnetometer observations from the Defense Meteorological Satellite Program (DMSP F13 and F15 satellites. The electromagnetic energy flux is then compared with the particle energy flux obtained from auroral images taken by the far-ultraviolet (FUV instrument on the Imager for Magnetopause to Aurora Global Exploration (IMAGE spacecraft. The electromagnetic energy input to the ionosphere of 51 GW calculated from the Iridium/DMSP observations is eight times larger than the 6 GW due to particle precipitation all poleward of 78° MLAT. This result indicates that the energy transport is significant, particularly as it is concentrated in a small region near the magnetic pole, even under conditions traditionally considered to be quiet and is dominated by the electromagnetic flux. We estimate the contributions of the high and mid-latitude dynamos to both the Birkeland currents and electric potentials finding that high-latitude reconnection accounts for 0.8 MA and 45kV while we attribute <0.2MA and ~5kV to an interaction at lower latitudes having the sense of a viscous interaction. Given that these

  18. High-latitude poynting flux from combined Iridium and SuperDARN data

    Directory of Open Access Journals (Sweden)

    C. L. Waters

    2004-09-01

    Full Text Available Field-aligned currents convey stress between the magnetosphere and ionosphere, and the associated low altitude magnetic and electric fields reflect the flow of electromagnetic energy to the polar ionosphere. We introduce a new technique to measure the global distribution of high latitude Poynting flux, S||, by combining electric field estimates from the Super Dual Auroral Radar Network (SuperDARN with magnetic perturbations derived using magnetometer data from the Iridium satellite constellation. Spherical harmonic methods are used to merge the data sets and calculate S|| for any magnetic local time (MLT from the pole to 60° magnetic latitude (MLAT. The effective spatial resolutions are 2° MLAT, 2h MLT, and the time resolution is about one hour due to the telemetry rate of the Iridium magnetometer data. The technique allows for the assessment of high-latitude net S|| and its spatial distribution on one hour time scales with two key advantages: (1 it yields the net S|| including the contribution of neutral winds; and (2 the results are obtained without recourse to estimates of ionosphere conductivity. We present two examples, 23 November 1999, 14:00-15:00 UT, and 11 March 2000, 16:00-17:00 UT, to test the accuracy of the technique and to illustrate the distributions of S|| that it gives. Comparisons with in-situ S|| estimates from DMSP satellites show agreement to a few mW/m2 and in the locations of S|| enhancements to within the technique's resolution. The total electromagnetic energy flux was 50GW for these events. At auroral latitudes, S|| tends to maximize in the morning and afternoon in regions less than 5° in MLAT by two hours in MLT having S||=10 to 20mW/m2 and total power up to 10GW. The power poleward of the Region 1 currents is about one

  19. Laser-driven magnetic-flux compression in high-energy-density plasmas.

    Science.gov (United States)

    Gotchev, O V; Chang, P Y; Knauer, J P; Meyerhofer, D D; Polomarov, O; Frenje, J; Li, C K; Manuel, M J-E; Petrasso, R D; Rygg, J R; Séguin, F H; Betti, R

    2009-11-20

    The demonstration of magnetic field compression to many tens of megagauss in cylindrical implosions of inertial confinement fusion targets is reported for the first time. The OMEGA laser [T. R. Boehly, Opt. Commun. 133, 495 (1997)10.1016/S0030-4018(96)00325-2] was used to implode cylindrical CH targets filled with deuterium gas and seeded with a strong external field (>50 kG) from a specially developed magnetic pulse generator. This seed field was trapped (frozen) in the shock-heated gas fill and compressed by the imploding shell at a high implosion velocity, minimizing the effect of resistive flux diffusion. The magnetic fields in the compressed core were probed via proton deflectrometry using the fusion products from an imploding D3He target. Line-averaged magnetic fields between 30 and 40 MG were observed.

  20. Investigating the use of nanofluids to improve high heat flux cooling systems

    CERN Document Server

    Barrett, T R; Flinders, K; Sergis, A; Hardalupas, Y

    2013-01-01

    The thermal performance of high heat flux components in a fusion reactor could be enhanced significantly by the use of nanofluid coolants, suspensions of a liquid with low concentrations of solid nanoparticles. However, before they are considered viable for fusion, the long-term behaviour of nanofluids must be investigated. This paper reports an experiment which is being prepared to provide data on nanofluid stability, settling and erosion in a HyperVapotron device. Procedures are demonstrated for nanofluid synthesis and quality assessment, and the fluid sample analysis methods are described. The end results from this long-running experiment are expected to allow an initial assessment of the suitability of nanofluids as coolants in a fusion reactor.

  1. Detailed studies of Minor Actinide transmutation-incineration in high-intensity neutron fluxes

    Energy Technology Data Exchange (ETDEWEB)

    Bringer, O. [CEA/Saclay/DSM/DAPNIA, Gif-sur-Yvette (France); Al Mahamid, I. [Lawrence Berkeley National Laboratory, E.H. and S. Div., CA (United States); Blandin, C. [CEA/Cadarache/DEN/DER/SPEX, Saint-Paul-lez-Durances (France); Chabod, S. [CEA/Saclay/DSM/DAPNIA, Gif-sur-Yvette (France); Chartier, F. [CEA/Cadarache/DEN/DPC/SECR, Gif-sur-Yvette (France); Dupont, E.; Fioni, G. [CEA/Saclay/DSM/DAPNIA, Gif-sur-Yvette (France); Isnard, H. [CEA/Cadarache/DEN/DPC/SECR, Gif-sur-Yvette (France); Letourneau, A.; Marie, F. [CEA/Saclay/DSM/DAPNIA, Gif-sur-Yvette (France); Mutti, P. [Institut Laue-Langevin, Grenoble (France); Oriol, L. [CEA/Cadarache/DEN/DER/SPEX, Saint-Paul-lez-Durances (France); Panebianco, S.; Veyssiere, C. [CEA/Saclay/DSM/DAPNIA, Gif-sur-Yvette (France)

    2006-07-01

    The Mini-INCA project is dedicated to the measurement of incineration-transmutation chains and potentials of minor actinides in high-intensity thermal neutron fluxes. In this context, new types of detectors and methods of analysis have been developed. The {sup 241}Am and {sup 232}Th transmutation-incineration chains have been studied and several capture and fission cross sections measured very precisely, showing some discrepancies with existing data or evaluated data. An impact study was made on different based-like GEN-IV reactors. It underlines the necessity to proceed to precise measurements for a large number of minor-actinides that contribute to these future incineration scenarios. (authors)

  2. Structural biology facilities at Brookhaven National Laboratory`s high flux beam reactor

    Energy Technology Data Exchange (ETDEWEB)

    Korszun, Z.R.; Saxena, A.M.; Schneider, D.K. [Brookhaven National Laboratory, Upton, NY (United States)

    1994-12-31

    The techniques for determining the structure of biological molecules and larger biological assemblies depend on the extent of order in the particular system. At the High Flux Beam Reactor at the Brookhaven National Laboratory, the Biology Department operates three beam lines dedicated to biological structure studies. These beam lines span the resolution range from approximately 700{Angstrom} to approximately 1.5{Angstrom} and are designed to perform structural studies on a wide range of biological systems. Beam line H3A is dedicated to single crystal diffraction studies of macromolecules, while beam line H3B is designed to study diffraction from partially ordered systems such as biological membranes. Beam line H9B is located on the cold source and is designed for small angle scattering experiments on oligomeric biological systems.

  3. Heat Transfer Calculation on Plate-Type Fuel Assembly of High Flux Research Reactor

    Directory of Open Access Journals (Sweden)

    Daxin Gong

    2015-01-01

    Full Text Available Heat transfer characteristics of fuel assemblies for a high flux research reactor with a neutron trap are numerically investigated in this study. Single-phase turbulence flow is calculated by a commercial code, FLUENT, where the computational objective covers standard and control fuel assemblies. The simulation is carried out with an inlet coolant velocity varying from 4.5 m/s to 7.5 m/s in hot assemblies. The results indicate that the cladding temperature is always lower than the saturation temperature in the calculated ranges. The temperature rise in the control fuel assembly is smaller than that of the standard fuel assembly. Additionally, the assembly with a hot spot is specially studied, and the safety of the research reactor is also approved.

  4. Searches for high frequency variations in the 8-B neutrino flux at the Sudbury neutrino observatory

    Energy Technology Data Exchange (ETDEWEB)

    Rielage, Keith [Los Alamos National Laboratory; Seibert, Stanley R [Los Alamos National Laboratory; Hime, Andrew [Los Alamos National Laboratory; Elliott, Steven R [Los Alamos National Laboratory; Stonehill, L C [Los Alamos National Laboratory; Wouters, J M [Los Alamos National Laboratory; Aharmim, B [LAURENTIAN UNIV; Ahmed, S N [QUEEN' S UNIV; Anthony, A E [UNIV OF TEXAS; Barros, N [PORTUGAL; Beier, E W [UNIV OF PA; Bellerive, A [CARLETON UNIV; Belttran, B [UNIV OF ALBERTA; Bergevin, M [LBNL; Biller, S D [UNIV OF OXFORD; Boudjemline, K [CARLETON UNIV; Burritt, T H [UNIV OF WASHINGTON; Cai, B [QUEEN' S UNIV; Chan, Y D [LBNL; Chauhan, D [LAURENTIAN UNIV; Chen, M [QUEEN' S UNIV; Cleveland, B T [UNIV OF OXFORD; Cox - Mobrand, G A [UNIV OF WASHINGTON; Dai, X [QUEEN' S UNIV; Deng, H [UNIV OF PA; Detwiler, J [LBNL; Dimarco, M [QUEEN' S UNIV; Doe, P J [UNIV OF WASHINGTON; Drouin, P - L [CARLTON UNIV; Duba, C A [UNIV OF WASHINGTON; Duncan, F A [SNOLAB, SUDBURY; Dunford, M [UNIV OF PA; Earle, E D [QUEEN' S UNIV; Evans, H C [QUEEN' S UNIV; Ewan, G T [QUEEN' S UNIV; Farine, J [LAURENTTIAN UNIV; Fergani, H [UNIV OF OXFORD; Fleurot, F [LAURENTIAN UNIV; Ford, R J [SNOLAB, SUDBURY; Formaggilo, J A [MASSACHUSETTS INST. OF TECH.; Gagnon, N [UNIV OF WASHINGTON; Goon, J Tm [LOUISIANA STATE UNIV; Guillian, E [QUEEN' S UNIV; Habib, S [UNIV OF ALBERTA; Hahn, R L [BNL; Hallin, A L [UNIV OF ALBERTA; Hallman, E D [LAURENTIAN UNIV; Harvey, P J [QUEEN' S UNIV; Hazama, R [UNIV OF WASHINGTON; Heintzelman, W J [UNIV OF PA; Heise, J [SNOLAB, SUDBURY; Helmer, R L [TRIUMF; Howard, C [UNIV OF ALBERTA; Howe, M A [UNIV OF WASHINGTON; Huang, M [UNIV OF TEXAS; Jamieson, B [UNIV OF BRITISH COLUMBIA; Jelley, N A [UNIV OF OXFORD; Keeter, K J [SNOLAB, SUDBURY; Klein, J R [UNIV OF TEXAS; Kos, M [QUEEN' S UNIV; Kraus, C [QUEEN' S UNIV; Krauss, C B [UNIV OF ALBERTA; Kutter, T [LOUISIANA STATE UNIV; Kyba, C C M [UNIV OF PA; Law, J [UNIV OF GUELPH; Lawson, I T [SNOLAB, SUDBURY; Lesko, K T [LBNL; Leslie, J R [QUEEN' S UNIV; Loach, J C [UNIV OF OXFORD; Maclellan, R [QUEEN' S UNIV; Majerus, S [UNIV OF OXFORD; Mak, H B [QUEEN' S UNIV; Maneira, J [PORTUGAL; Martin, R [QUEEN' S UNIV; Mccauley, N [UNIV OF PA; Mc Donald, A B [QUEEN' S UNIV; Mcgee, S [UNIV OF WASHINGTON; Miffin, C [CARLETON UNIV; Miller, M L [MASSACHUSETTS INST. OF TECH.; Monreal, B [MASSACHUSETTS INST. OF TECH.; Monroe, J [MASSACHUSETTS INST. OF TECH; Morissette, B [SNOLAB, SUDBURY; Nickel, B G [UNIV OF GUELPH; Noble, A J [QUEEN' S UNIV; O' Keeffe, H M [UNIV OF OXFORD; Oblath, N S [UNIV OF WASHINGTON; Orebi Gann, G D [UNIV OF OXFORD; Oser, S M [UNIV OF BRITISH COLUMBIA; Ott, R A [MASSACHUSETTS INST. OF TECH.; Peeters, S J M [UNIV OF OXFORD; Poon, A W P [LBNL; Prior, G [LBNL; Reitzner, S D [UNIV OF GUELPH; Robertson, B C [QUEEN' S UNIV; Robertson, R G H [UNIV OF WASHINGTON; Rollin, E [CARLETON UNIV; Schwendener, M H [LAURENTIAN UNIV; Secrest, J A [UNIV OF PA; Seibert, S R [UNIV OF TEXAS; Simard, O [CARLETON UNIV; Sinclair, D [CARLETON UNIV; Sinclair, L [CARLETON UNIV; Skensved, P [QUEEN' S UNIV; Sonley, T J [MASSACHUSETTS INST. OF TECH.; Tesic, G [CARLETON UNIV; Tolich, N [UNIV OF WASHINGTON; Tsui, T [UNIV OF BRITISH COLUMBIA; Tunnell, C D [UNIV OF TEXAS; Van Berg, R [UNIV OF PA; Van Devender, B A [UNIV OF WASHINGTON; Virtue, C J [LAURENTIAN UNIV; Wall, B L [UNIV OF WASHINGTON; Waller, D [CARLETON UNIV; Wan Chan Tseung, H [UNIV OF OXFORD; West, N [UNIV OF OXFORD; Wilkerson, J F [UNIV OF WASHINGTON; Wilson, J R [UNIV OF OXFORD; Wright, A [QUEEN' S UNIV; Yeh, M [BNL; Zhang, F [CARLETON UNIV; Zuber, K [UNIV OF OXFORD

    2009-01-01

    We have peformed three searches for high-frequency signals in the solar neutrino flux measured by the Sudbury Neutrino Observatory (SNO), motivated by the possibility that solar g-mode oscillations could affect the production or propagation of solar {sup 8}B neutrinos. The first search looked for any significant peak in the frequency range l/day to 144/day, with a sensitivity to sinusoidal signals with amplitudes of 12% or greater. The second search focused on regions in which g-mode signals have been claimed by experiments aboard the SoHO satellite, and was sensitive to signals with amplitudes of 10% or greater. The third search looked for extra power across the entire frequency band. No statistically significant signal was detected in any of the three searches.

  5. The contribution of advective fluxes to net ecosystem exchange in a high-elevation, subalpine forest.

    Science.gov (United States)

    Yi, Chuixiang; Anderson, Dean E; Turnipseed, Andrew A; Burns, Sean P; Sparks, Jed P; Stannard, David I; Monson, Russell K

    2008-09-01

    The eddy covariance technique, which is used in the determination of net ecosystem CO2 exchange (NEE), is subject to significant errors when advection that carries CO2 in the mean flow is ignored. We measured horizontal and vertical advective CO2 fluxes at the Niwot Ridge AmeriFlux site (Colorado, USA) using a measurement approach consisting of multiple towers. We observed relatively high rates of both horizontal (F(hadv)) and vertical (F(vadv)) advective fluxes at low surface friction velocities (u(*)) which were associated with downslope katabatic flows. We observed that F(hadv) was confined to a relatively thin layer (0-6 m thick) of subcanopy air that flowed beneath the eddy covariance sensors principally at night, carrying with it respired CO2 from the soil and lower parts of the canopy. The observed F(vadv) came from above the canopy and was presumably due to the convergence of drainage flows at the tower site. The magnitudes of both F(hadv) and F(vadv) were similar, of opposite sign, and increased with decreasing u(*), meaning that they most affected estimates of the total CO2 flux on calm nights with low wind speeds. The mathematical sign, temporal variation and dependence on u(*) of both F(hadv) and F(vadv) were determined by the unique terrain of the Niwot Ridge site. Therefore, the patterns we observed may not be broadly applicable to other sites. We evaluated the influence of advection on the cumulative annual and monthly estimates of the total CO2 flux (F(c)), which is often used as an estimate of NEE, over six years using the dependence of F(hadv) and F(vadv) on u(*). When the sum of F(hadv) and F(vadv) was used to correct monthly F(c), we observed values that were different from the monthly F(c) calculated using the traditional u(*)-filter correction by--16 to 20 g C x m(-2) x mo(-1); the mean percentage difference in monthly Fc for these two methods over the six-year period was 10%. When the sum of F(hadv) and F(vadv) was used to correct annual Fc

  6. Measurements and identifications of extreme ultraviolet spectra of highly-charged Sm and Er

    CERN Document Server

    Podpaly, Y A; Reader, J; Ralchenko, Yu

    2014-01-01

    We report spectroscopic measurements of highly charged samarium and erbium performed at the National Institute of Standards and Technology (NIST) Electron Beam Ion Trap (EBIT). These measurements are in the extreme ultraviolet (EUV) range, and span electron beam energies from 0.98 keV to 3.00 keV. We observed 71 lines from Kr-like Sm$^{26+}$ to Ni-like Sm$^{34+}$, connecting 83 energy levels, and 64 lines from Rb-like Er$^{32+}$ to Ni-like Er$^{40+}$, connecting 78 energy levels. Of these lines, 64 in Sm and 60 in Er are new. Line identifications are performed using collisional-radiative modeling of the EBIT plasma. All spectral lines are assigned individual uncertainties, most in the $\\sim$0.001 nm range. Energy levels are derived from the wavelength measurements.

  7. High-Resolution Spectroscopy of G191-B2B in the Extreme Ultraviolet

    CERN Document Server

    Cruddace, R G; Yentis, D J; Brown, C M; Gursky, H; Barstow, M A; Bannister, N P; Fraser, G W; Spragg, J E; Lapington, J S; Tandy, J A; Sanderson, B; Culhane, J L; Barbee, T W; Kordas, J F; Goldstein, W H; Fritz, G G

    2001-01-01

    We report a high-resolution (R=3000-4000) spectroscopic observation of the DA white dwarf G191-B2B in the extreme ultraviolet band 220-245 A. A low- density ionised He component is clearly present along the line-of-sight, which if completely interstellar implies a He ionisation fraction considerably higher than is typical of the local interstellar medium. However, some of this material may be associated with circumstellar gas, which has been detected by analysis of the C IV absorption line doublet in an HST STIS spectrum. A stellar atmosphere model assuming a uniform element distribution yields a best fit to the data which includes a significant abundance of photospheric He. The 99-percent confidence contour for the fit parameters excludes solutions in which photospheric He is absent, but this result needs to be tested using models allowing abundance gradients.

  8. Nano-materials for adhesive-free adsorbers for bakable extreme high vacuum cryopump surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Stutzman, Marcy; Jordan, Kevin; Whitney, Roy R.

    2016-10-11

    A cryosorber panel having nanomaterials used for the cryosorption material, with nanomaterial either grown directly on the cryopanel or freestanding nanomaterials attached to the cryopanel mechanically without the use of adhesives. Such nanomaterial cryosorber materials can be used in place of conventional charcoals that are attached to cryosorber panels with special low outgassing, low temperature capable adhesives. Carbon nanotubes and other nanomaterials could serve the same purpose as conventional charcoal cryosorbers, providing a large surface area for cryosorption without the need for adhesive since the nanomaterials can be grown directly on a metallic substrate or mechanically attached. The nanomaterials would be capable of being fully baked by heating above 100.degree. C., thereby eliminating water vapor from the system, eliminating adhesives from the system, and allowing a full bake of the system to reduce hydrogen outgassing, with the goal of obtaining extreme high vacuum where the pump can produce pressures below 1.times.10.sup.-12 Torr.

  9. First search for extremely high energy cosmogenic neutrinos with the IceCube Neutrino Observatory

    Science.gov (United States)

    Abbasi, R.; Abdou, Y.; Abu-Zayyad, T.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Andeen, K.; Auffenberg, J.; Bai, X.; Baker, M.; Barwick, S. W.; Bay, R.; Bazo Alba, J. L.; Beattie, K.; Beatty, J. J.; Bechet, S.; Becker, J. K.; Becker, K.-H.; Benabderrahmane, M. L.; Berdermann, J.; Berghaus, P.; Berley, D.; Bernardini, E.; Bertrand, D.; Besson, D. Z.; Bissok, M.; Blaufuss, E.; Boersma, D. J.; Bohm, C.; Böser, S.; Botner, O.; Bradley, L.; Braun, J.; Buitink, S.; Carson, M.; Chirkin, D.; Christy, B.; Clem, J.; Clevermann, F.; Cohen, S.; Colnard, C.; Cowen, D. F.; D'Agostino, M. V.; Danninger, M.; Davis, J. C.; de Clercq, C.; Demirörs, L.; Depaepe, O.; Descamps, F.; Desiati, P.; de Vries-Uiterweerd, G.; Deyoung, T.; Díaz-Vélez, J. C.; Dreyer, J.; Dumm, J. P.; Duvoort, M. R.; Ehrlich, R.; Eisch, J.; Ellsworth, R. W.; Engdegård, O.; Euler, S.; Evenson, P. A.; Fadiran, O.; Fazely, A. R.; Feusels, T.; Filimonov, K.; Finley, C.; Foerster, M. M.; Fox, B. D.; Franckowiak, A.; Franke, R.; Gaisser, T. K.; Gallagher, J.; Ganugapati, R.; Geisler, M.; Gerhardt, L.; Gladstone, L.; Glüsenkamp, T.; Goldschmidt, A.; Goodman, J. A.; Grant, D.; Griesel, T.; Groß, A.; Grullon, S.; Gurtner, M.; Ha, C.; Hallgren, A.; Halzen, F.; Han, K.; Hanson, K.; Helbing, K.; Herquet, P.; Hickford, S.; Hill, G. C.; Hoffman, K. D.; Homeier, A.; Hoshina, K.; Hubert, D.; Huelsnitz, W.; Hülß, J.-P.; Hulth, P. O.; Hultqvist, K.; Hussain, S.; Imlay, R. L.; Ishihara, A.; Jacobsen, J.; Japaridze, G. S.; Johansson, H.; Joseph, J. M.; Kampert, K.-H.; Kappes, A.; Karg, T.; Karle, A.; Kelley, J. L.; Kemming, N.; Kenny, P.; Kiryluk, J.; Kislat, F.; Klein, S. R.; Knops, S.; Köhne, J.-H.; Kohnen, G.; Kolanoski, H.; Köpke, L.; Koskinen, D. J.; Kowalski, M.; Kowarik, T.; Krasberg, M.; Krings, T.; Kroll, G.; Kuehn, K.; Kuwabara, T.; Labare, M.; Lafebre, S.; Laihem, K.; Landsman, H.; Lauer, R.; Lehmann, R.; Lennarz, D.; Lünemann, J.; Madsen, J.; Majumdar, P.; Maruyama, R.; Mase, K.; Matis, H. S.; Matusik, M.; Meagher, K.; Merck, M.; Mészáros, P.; Meures, T.; Middell, E.; Milke, N.; Miller, J.; Montaruli, T.; Morse, R.; Movit, S. M.; Nahnhauer, R.; Nam, J. W.; Naumann, U.; Nießen, P.; Nygren, D. R.; Odrowski, S.; Olivas, A.; Olivo, M.; Ono, M.; Panknin, S.; Paul, L.; Pérez de Los Heros, C.; Petrovic, J.; Piegsa, A.; Pieloth, D.; Porrata, R.; Posselt, J.; Price, P. B.; Prikockis, M.; Przybylski, G. T.; Rawlins, K.; Redl, P.; Resconi, E.; Rhode, W.; Ribordy, M.; Rizzo, A.; Rodrigues, J. P.; Roth, P.; Rothmaier, F.; Rott, C.; Roucelle, C.; Ruhe, T.; Rutledge, D.; Ruzybayev, B.; Ryckbosch, D.; Sander, H.-G.; Sarkar, S.; Schatto, K.; Schlenstedt, S.; Schmidt, T.; Schneider, D.; Schukraft, A.; Schultes, A.; Schulz, O.; Schunck, M.; Seckel, D.; Semburg, B.; Seo, S. H.; Sestayo, Y.; Seunarine, S.; Silvestri, A.; Slipak, A.; Spiczak, G. M.; Spiering, C.; Stamatikos, M.; Stanev, T.; Stephens, G.; Stezelberger, T.; Stokstad, R. G.; Stoyanov, S.; Strahler, E. A.; Straszheim, T.; Sullivan, G. W.; Swillens, Q.; Taboada, I.; Tamburro, A.; Tarasova, O.; Tepe, A.; Ter-Antonyan, S.; Tilav, S.; Toale, P. A.; Tosi, D.; Turčan, D.; van Eijndhoven, N.; Vandenbroucke, J.; van Overloop, A.; van Santen, J.; Voigt, B.; Walck, C.; Waldenmaier, T.; Wallraff, M.; Walter, M.; Wendt, C.; Westerhoff, S.; Whitehorn, N.; Wiebe, K.; Wiebusch, C. H.; Wikström, G.; Williams, D. R.; Wischnewski, R.; Wissing, H.; Woschnagg, K.; Xu, C.; Xu, X. W.; Yodh, G.; Yoshida, S.; Zarzhitsky, P.; IceCube Collaboration

    2010-10-01

    We report on the results of the search for extremely-high energy neutrinos with energies above 107GeV obtained with the partially (˜30%) constructed IceCube in 2007. From the absence of signal events in the sample of 242.1 days of effective live time, we derive a 90% C.L. model independent differential upper limit based on the number of signal events per energy decade at E2ϕνe+νμ+ντ≃1.4×10-6GeVcm-2sec⁡-1sr-1 for neutrinos in the energy range from 3×107 to 3×109GeV.

  10. Acclimation to extremely high ammonia levels in continuous biomethanation process and the associated microbial community dynamics

    DEFF Research Database (Denmark)

    Tian, Hailin; Fotidis, Ioannis; Mancini, Enrico

    2017-01-01

    Acclimatized anaerobic communities to high ammonia levels can offer a solution to the ammonia toxicity problem in biogas reactors. In the current study, a stepwise acclimation strategy up to 10 g NH4+-N L−1, was performed in mesophilic (37 ± 1 °C) continuously stirred tank reactors. The reactors...... were co-digesting (20/80 based on volatile solid) cattle slurry and microalgae, a protein-rich, 3rd generation biomass. Throughout the acclimation period, methane production was stable with more than 95% of the uninhibited yield. Next generation 16S rRNA gene sequencing revealed a dramatic microbiome...... change throughout the ammonia acclimation process. Clostridium ultunense, a syntrophic acetate oxidizing bacteria, increased significantly alongside with hydrogenotrophic methanogen Methanoculleus spp., indicating strong hydrogenotrophic methanogenic activity at extreme ammonia levels (>7 g NH4+-N L−1...

  11. Hydraulic testing of helium cooled irradiation rigs of the IFMIF High Flux Test Module

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Christine, E-mail: Christine.Klein@kit.edu [Karlsruhe Institute of Technology, INR, Eggenstein-Leopoldshafen (Germany); Arbeiter, Frederik; Jackowski, Thomas; Martin, Thomas; Schlindwein, Georg [Karlsruhe Institute of Technology, INR, Eggenstein-Leopoldshafen (Germany)

    2012-08-15

    Highlights: Black-Right-Pointing-Pointer Uniform perfusion of the multiple parallel minichannels of the rig model B by helium gas, which is of importance to obtain uniform and predictable temperatures, could be verified by measuring the mean velocity profiles of the rectangular jets are measured using hot-wire anemometry. Black-Right-Pointing-Pointer The pressure drop in the test section with rig model B was measured and delivers data for the validation of computational fluid dynamics (CFD) modeling approach for application in the IFMIF High Flux Test Module. The pressure drop depends significantly on the pressure level; acceleration resulting from the volumetric expansion of helium gas has to be modeled carefully in simulations. Black-Right-Pointing-Pointer Measurements with strain gage show the pressure depending deformation of the compartment container without the rig. The results agree well with simulations and approximation calculations. - Abstract: The hydraulic testing of a single 1:1 irradiation rig inside a mock-up container is part of the validation activities which support the engineering design of the High Flux Test Module. Uniform perfusion of the multiple parallel minichannels of the irradiation rigs by helium gas is of importance to obtain uniform and predictable temperatures. To evaluate the uniform distribution to the different parallel minichannels, the mean velocity profiles of the rectangular jets are measured using hot-wire anemometry. The velocity profiles show a symmetric and constant distribution of the mass flow to the parallel minichannels. The pressure drop in the test section with one of the candidate rig shapes is measured. The pressure drop depends significantly on the entrance pressure level; acceleration resulting from the volumetric expansion of helium gas has to be taken into account in simulations. Measurements with strain gage show the pressure depending deformation of the compartment container without the rig. The results agree

  12. Overview of results of the first phase of validation activities for the IFMIF High Flux Test Module

    Energy Technology Data Exchange (ETDEWEB)

    Arbeiter, Frederik, E-mail: frederik.arbeiter@kit.edu [Karlsruhe Institute of Technology, Karlsruhe (Germany); Chen Yuming; Dolensky, Bernhard; Freund, Jana; Heupel, Tobias; Klein, Christine; Scheel, Nicola; Schlindwein, Georg [Karlsruhe Institute of Technology, Karlsruhe (Germany)

    2012-08-15

    Highlights: Black-Right-Pointing-Pointer Validation of computational fluid dynamics (CFD) modeling approach for application in the IFMIF High Flux Test Module. Black-Right-Pointing-Pointer Fabrication of prototypes of the irradiation capsules of the IFMIF High Flux Test Module. - Abstract: The international fusion materials irradiation facility (IFMIF) is projected to create an experimentally validated database of material properties relevant for fusion reactor designs. The IFMIF High Flux Test Module is the dedicated experiment to irradiate alloys in the temperature range 250-550 Degree-Sign C and up to 50 displacements per atom per irradiation cycle. The High Flux Test Module is developed to maximize the specimen payload in the restricted irradiation volume, and to minimize the temperature spread within each specimen bundle. Low pressure helium mini-channel cooling is used to offer a high integration density. Due to the demanding thermo-hydraulic and mechanical conditions, the engineering design process (involving numerical neutronic, thermo-hydraulic and mechanical analyses) is supported by extensive experimental validation activities. This paper reports on the prototype manufacturing, thermo-hydraulic modeling experiments and component tests, as well as on mechanical testing. For the testing of the 1:1 prototype of the High Flux Test Module, a dedicated test facility, the Helium Loop Karlsruhe-Low Pressure (HELOKA-LP) has been taken into service.

  13. High current density ion beam obtained by a transition to a highly focused state in extremely low-energy region.

    Science.gov (United States)

    Hirano, Y; Kiyama, S; Fujiwara, Y; Koguchi, H; Sakakita, H

    2015-11-01

    A high current density (≈3 mA/cm(2)) hydrogen ion beam source operating in an extremely low-energy region (E(ib) ≈ 150-200 eV) has been realized by using a transition to a highly focused state, where the beam is extracted from the ion source chamber through three concave electrodes with nominal focal lengths of ≈350 mm. The transition occurs when the beam energy exceeds a threshold value between 145 and 170 eV. Low-level hysteresis is observed in the transition when E(ib) is being reduced. The radial profiles of the ion beam current density and the low temperature ion current density can be obtained separately using a Faraday cup with a grid in front. The measured profiles confirm that more than a half of the extracted beam ions reaches the target plate with a good focusing profile with a full width at half maximum of ≈3 cm. Estimation of the particle balances in beam ions, the slow ions, and the electrons indicates the possibility that the secondary electron emission from the target plate and electron impact ionization of hydrogen may play roles as particle sources in this extremely low-energy beam after the compensation of beam ion space charge.

  14. Remote, Real-time Investigations of Extreme Environments Using High Power and Bandwidth Cabled Observatories: The OOI Regional Scale Nodes

    Science.gov (United States)

    Kelley, D. S.; Delaney, J. R.

    2012-12-01

    Methane hydrate deposits and hydrothermal vents are two of the most extreme environments on Earth. Seismic events and flow of gases from the seafloor support and modulate novel microbial communities within these systems. Although studied intensely for several decades, significant questions remain about the flux of heat, volatiles and microbial material from the subsurface to the hydrosphere in these dynamic environments. Quantification of microbial communities, their structure and abundances, and metabolic activities is in an infant state. To better understand these systems, the National Science Foundation's Ocean Observatory Initiative has installed high power (8 kW), high bandwidth (10 Gb/s) nodes on the seafloor that provide access to active methane seeps at Southern Hydrate Ridge, and at the most magmatically robust volcano on the Juan de Fuca Ridge - Axial Seamount. The real-time interactive capabilities of the cabled observatory are critical to studying gas-hydrate systems because many of the key processes occur over short time scales. Events such as bubble plume formation, the creation of collapse zones, and increased seepage in response to earthquakes require adaptive response and sampling capabilities. To meet these challenges a suite of instruments will be connected to the cable in 2013. These sensors include full resolution sampling by upward-looking sonars, fluid and gas chemical characterization by mass spectrometers and osmo samplers, long-term duration collection of seep imagery from cameras, and in situ manipulation of chemical sensors coupled with flow meters. In concert, this instrument suite will provide quantification of transient and more stable chemical fluxes. Similarly, at Axial Seamount the high bandwidth and high power fiber optic cables will be used to communicate with and power a diverse array of sensors at the summit of the volcano. Real-time high definition video will provide unprecedented views of macrofaunal and microbial communities

  15. Multiresolution iterative reconstruction in high-resolution extremity cone-beam CT

    Science.gov (United States)

    Cao, Qian; Zbijewski, Wojciech; Sisniega, Alejandro; Yorkston, John; Siewerdsen, Jeffrey H.; Webster Stayman, J.

    2016-10-01

    Application of model-based iterative reconstruction (MBIR) to high resolution cone-beam CT (CBCT) is computationally challenging because of the very fine discretization (voxel size  <100 µm) of the reconstructed volume. Moreover, standard MBIR techniques require that the complete transaxial support for the acquired projections is reconstructed, thus precluding acceleration by restricting the reconstruction to a region-of-interest. To reduce the computational burden of high resolution MBIR, we propose a multiresolution penalized-weighted least squares (PWLS) algorithm, where the volume is parameterized as a union of fine and coarse voxel grids as well as selective binning of detector pixels. We introduce a penalty function designed to regularize across the boundaries between the two grids. The algorithm was evaluated in simulation studies emulating an extremity CBCT system and in a physical study on a test-bench. Artifacts arising from the mismatched discretization of the fine and coarse sub-volumes were investigated. The fine grid region was parameterized using 0.15 mm voxels and the voxel size in the coarse grid region was varied by changing a downsampling factor. No significant artifacts were found in either of the regions for downsampling factors of up to 4×. For a typical extremities CBCT volume size, this downsampling corresponds to an acceleration of the reconstruction that is more than five times faster than a brute force solution that applies fine voxel parameterization to the entire volume. For certain configurations of the coarse and fine grid regions, in particular when the boundary between the regions does not cross high attenuation gradients, downsampling factors as high as 10×  can be used without introducing artifacts, yielding a ~50×  speedup in PWLS. The proposed multiresolution algorithm significantly reduces the computational burden of high resolution iterative CBCT reconstruction and can be extended to other applications of

  16. Comparative assessment of surface fluxes from different sources: a framework based on probability distributions

    Science.gov (United States)

    Gulev, S.

    2015-12-01

    Surface turbulent heat fluxes from modern era and first generation reanalyses (NCEP-DOE, ERA-Interim, MERRA NCEP-CFSR, JRA) as well as from satellite products (SEAFLUX, IFREMER, HOAPS) were intercompared using framework of probability distributions for sensible and latent heat fluxes. For approximation of probability distributions and estimation of extreme flux values Modified Fisher-Tippett (MFT) distribution has been used. Besides mean flux values, consideration is given to the comparative analysis of (i) parameters of the MFT probability density functions (scale and location), (ii) extreme flux values corresponding high order percentiles of fluxes (e.g. 99th and higher) and (iii) fractional contribution of extreme surface flux events in the total surface turbulent fluxes integrated over months and seasons. The latter was estimated using both fractional distribution derived from MFT and empirical estimates based upon occurrence histograms. The strongest differences in the parameters of probability distributions of surface fluxes and extreme surface flux values between different reanalyses are found in the western boundary current extension regions and high latitudes, while the highest differences in the fractional contributions of surface fluxes may occur in mid ocean regions being closely associated with atmospheric synoptic dynamics. Generally, satellite surface flux products demonstrate relatively stronger extreme fluxes compared to reanalyses, even in the Northern Hemisphere midlatitudes where data assimilation input in reanalyses is quite dense compared to the Southern Ocean regions. Our assessment also discriminated different reanalyses and satellite products with respect to their ability to quantify the role of extreme surface turbulent fluxes in forming ocean heat release in different regions.

  17. Droplet-based, high-brightness extreme ultraviolet laser plasma source for metrology

    Science.gov (United States)

    Vinokhodov, A. Yu.; Krivokorytov, M. S.; Sidelnikov, Yu. V.; Krivtsun, V. M.; Medvedev, V. V.; Koshelev, K. N.

    2016-10-01

    We report on the development of a high brightness source of extreme ultraviolet radiation (EUV) with a working wavelength of 13.5 nm. The source is based on a laser-produced plasma driven by pulsed radiation of a Nd:YAG laser system. Liquid droplets of Sn-In eutectic alloy were used as the source fuel. The droplets were created by a droplet generator operating in the jet break-up regime. The EUV emission properties of the plasma, including the emission spectrum, time profile, and conversion efficiency of laser radiation into useful 13.5 nm photons, have been characterized. Using the shadowgraphy technique, we demonstrated the production of corpuscular debris by the plasma source and the influence of the plasma on the neighboring droplet targets. The high-frequency laser operation was simulated by usage of the dual pulse regime. Based on the experimental results, we discuss the physical phenomena that could affect the source operation at high repetition rates. Finally, we estimate that an average source brightness of 1.2 kW/mm2 sr is feasible at a high repetition rate.

  18. Benchmark analysis on diabetics at high risk for lower extremity amputation.

    Science.gov (United States)

    Pinzur, M S; Stuck, R; Sage, R; Pocius, L; Trout, B; Wolf, B; Vrbos, L

    1996-11-01

    After the 1990 establishment of a multidisciplinary foot salvage clinic, 1346 diabetic patients, at high risk for the development of foot ulcers and eventual lower limb amputation, were followed for 4 years. Of the 224 high-risk patients admitted to the hospital, 74 amputations (5.5%) of all or part of a lower limb were performed. Patients undergoing amputation were younger, more severely ill, and required more frequent hospitalizations because of greater organ system involvement. They were also more likely to be institutionalized after discharge. Overall, patients with long-standing adult-onset diabetes, identified as at high risk for foot ulcer development, have a substantially increased risk for lower limb amputation, multiple organ system failure, hospitalization, and institutionalization than do diabetic patients as a whole. Clinical benchmarking facilitates the identification and reduction of unnecessary variations in patient care practices. Here, a formal benchmark analysis provides the current outcome expectations for amputation rates and co-morbidities in patients with diabetes who are classified as at high risk for lower extremity amputation. Management of these patients in a structured, multidisciplinary foot salvage clinic, augmentation of baseline services, and preliminary benchmark data may provide a standard for the measurement of therapeutic interventions that improve patient care.

  19. High-resolution Observations of a Flux Rope with the Interface Region Imaging Spectrograph

    OpenAIRE

    Li, Ting; ZHANG, JUN

    2015-01-01

    We report the observations of a flux rope at transition region temperatures with the \\emph{Interface Region Imaging Spectrograph} (IRIS) on 30 August 2014. Initially, magnetic flux cancellation constantly took place and a filament was activated. Then the bright material from the filament moved southward and tracked out several fine structures. These fine structures were twisted and tangled with each other, and appeared as a small flux rope at 1330 {\\AA}, with a total twist of about 4$\\pi$. Af...

  20. A dynamic aerodynamic resistance approach to calculate high resolution sensible heat fluxes in urban areas

    Science.gov (United States)

    Crawford, Ben; Grimmond, Sue; Kent, Christoph; Gabey, Andrew; Ward, Helen; Sun, Ting; Morrison, William

    2017-04-01

    Remotely sensed data from satellites have potential to enable high-resolution, automated calculation of urban surface energy balance terms and inform decisions about urban adaptations to environmental change. However, aerodynamic resistance methods to estimate sensible heat flux (QH) in cities using satellite-derived observations of surface temperature are difficult in part due to spatial and temporal variability of the thermal aerodynamic resistance term (rah). In this work, we extend an empirical function to estimate rah using observational data from several cities with a broad range of surface vegetation land cover properties. We then use this function to calculate spatially and temporally variable rah in London based on high-resolution (100 m) land cover datasets and in situ meteorological observations. In order to calculate high-resolution QH based on satellite-observed land surface temperatures, we also develop and employ novel methods to i) apply source area-weighted averaging of surface and meteorological variables across the study spatial domain, ii) calculate spatially variable, high-resolution meteorological variables (wind speed, friction velocity, and Obukhov length), iii) incorporate spatially interpolated urban air temperatures from a distributed sensor network, and iv) apply a modified Monte Carlo approach to assess uncertainties with our results, methods, and input variables. Modeled QH using the aerodynamic resistance method is then compared to in situ observations in central London from a unique network of scintillometers and eddy-covariance measurements.

  1. High-flux neutron source based on a liquid-lithium target

    Science.gov (United States)

    Halfon, S.; Feinberg, G.; Paul, M.; Arenshtam, A.; Berkovits, D.; Kijel, D.; Nagler, A.; Eliyahu, I.; Silverman, I.

    2013-04-01

    A prototype compact Liquid Lithium Target (LiLiT), able to constitute an accelerator-based intense neutron source, was built. The neutron source is intended for nuclear astrophysical research, boron neutron capture therapy (BNCT) in hospitals and material studies for fusion reactors. The LiLiT setup is presently being commissioned at Soreq Nuclear research Center (SNRC). The lithium target will produce neutrons through the 7Li(p,n)7Be reaction and it will overcome the major problem of removing the thermal power generated by a high-intensity proton beam, necessary for intense neutron flux for the above applications. The liquid-lithium loop of LiLiT is designed to generate a stable lithium jet at high velocity on a concave supporting wall with free surface toward the incident proton beam (up to 10 kW). During off-line tests, liquid lithium was flown through the loop and generated a stable jet at velocity higher than 5 m/s on the concave supporting wall. The target is now under extensive test program using a high-power electron-gun. Up to 2 kW electron beam was applied on the lithium flow at velocity of 4 m/s without any flow instabilities or excessive evaporation. High-intensity proton beam irradiation will take place at SARAF (Soreq Applied Research Accelerator Facility) superconducting linear accelerator currently in commissioning at SNRC.

  2. Hypersonic Engine Leading Edge Experiments in a High Heat Flux, Supersonic Flow Environment

    Science.gov (United States)

    Gladden, Herbert J.; Melis, Matthew E.

    1994-01-01

    A major concern in advancing the state-of-the-art technologies for hypersonic vehicles is the development of an aeropropulsion system capable of withstanding the sustained high thermal loads expected during hypersonic flight. Three aerothermal load related concerns are the boundary layer transition from laminar to turbulent flow, articulating panel seals in high temperature environments, and strut (or cowl) leading edges with shock-on-shock interactions. A multidisciplinary approach is required to address these technical concerns. A hydrogen/oxygen rocket engine heat source has been developed at the NASA Lewis Research Center as one element in a series of facilities at national laboratories designed to experimentally evaluate the heat transfer and structural response of the strut (or cowl) leading edge. A recent experimental program conducted in this facility is discussed and related to cooling technology capability. The specific objective of the experiment discussed is to evaluate the erosion and oxidation characteristics of a coating on a cowl leading edge (or strut leading edge) in a supersonic, high heat flux environment. Heat transfer analyses of a similar leading edge concept cooled with gaseous hydrogen is included to demonstrate the complexity of the problem resulting from plastic deformation of the structures. Macro-photographic data from a coated leading edge model show progressive degradation over several thermal cycles at aerothermal conditions representative of high Mach number flight.

  3. High-field paramagnetic Meissner effect and flux creep in low-T c Ti-V alloy superconductors

    Science.gov (United States)

    Matin, M.; Chattopadhyay, M. K.; Sharath Chandra, L. S.; Roy, S. B.

    2016-02-01

    We report an experimental study on the high-field paramagnetic Meissner effect (HFPME) performed by measuring both the temperature and time dependence of magnetization in the two compositions of superconducting Ti-V alloys where certain secondary phases are non-superconducting, and thereby act as efficient pinning centres for the flux lines. While spatially non-uniform flux density driven by flux line pinning at these secondary phases is the necessary condition for the observation of the HFPME, our study indicates that the flux creep effect plays a supplementary role to reinforce the HFPME. It is found that in the temperature and magnetic field regime of the HFPME, the field-cooled magnetization of these samples relaxes monotonically towards a more positive value with elapsed time. We comment on how this paramagnetic relaxation behaviour of the field-cooled magnetization is correlated with the unusual thermo-magnetic responses related to the HFPME.

  4. Measurements with the high flux lead slowing-down spectrometer at LANL

    Energy Technology Data Exchange (ETDEWEB)

    Danon, Y. [Rensselaer Polytechnic Intstitute, 110 8th Street, Troy, NY 12180 (United States)]. E-mail: danony@rpi.edu; Romano, C. [Rensselaer Polytechnic Intstitute, 110 8th Street, Troy, NY 12180 (United States); Thompson, J. [Rensselaer Polytechnic Intstitute, 110 8th Street, Troy, NY 12180 (United States); Watson, T. [Rensselaer Polytechnic Intstitute, 110 8th Street, Troy, NY 12180 (United States); Haight, R.C. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Wender, S.A. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Vieira, D.J. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Bond, E. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Wilhelmy, J.B. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); O' Donnell, J.M. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Michaudon, A. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Bredeweg, T.A. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Schurman, T. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Rochman, D. [Brookhaven National Laboratory National Nuclear Data Center (NNDC), Upton, NY 11973-5000 (United States); Granier, T. [CEA-DAM, BP 12, 91680 Bruyeres-le-Chatel (France); Ethvignot, T. [CEA-DAM, BP 12, 91680 Bruyeres-le-Chatel (France); Taieb, J. [CEA-DAM, BP 12, 91680 Bruyeres-le-Chatel (France); Becker, J.A. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States)

    2007-08-15

    A Lead Slowing-Down Spectrometer (LSDS) was recently installed at LANL [D. Rochman, R.C. Haight, J.M. O'Donnell, A. Michaudon, S.A. Wender, D.J. Vieira, E.M. Bond, T.A. Bredeweg, A. Kronenberg, J.B. Wilhelmy, T. Ethvignot, T. Granier, M. Petit, Y. Danon, Characteristics of a lead slowing-down spectrometer coupled to the LANSCE accelerator, Nucl. Instr. and Meth. A 550 (2005) 397]. The LSDS is comprised of a cube of pure lead 1.2 m on the side, with a spallation pulsed neutron source in its center. The LSDS is driven by 800 MeV protons with a time-averaged current of up to 1 {mu}A, pulse widths of 0.05-0.25 {mu}s and a repetition rate of 20-40 Hz. Spallation neutrons are created by directing the proton beam into an air-cooled tungsten target in the center of the lead cube. The neutrons slow down by scattering interactions with the lead and thus enable measurements of neutron-induced reaction rates as a function of the slowing-down time, which correlates to neutron energy. The advantage of an LSDS as a neutron spectrometer is that the neutron flux is 3-4 orders of magnitude higher than a standard time-of-flight experiment at the equivalent flight path, 5.6 m. The effective energy range is 0.1 eV to 100 keV with a typical energy resolution of 30% from 1 eV to 10 keV. The average neutron flux between 1 and 10 keV is about 1.7 x 10{sup 9} n/cm{sup 2}/s/{mu}A. This high flux makes the LSDS an important tool for neutron-induced cross section measurements of ultra-small samples (nanograms) or of samples with very low cross sections. The LSDS at LANL was initially built in order to measure the fission cross section of the short-lived metastable isotope of U-235, however it can also be used to measure (n, {alpha}) and (n, p) reactions. Fission cross section measurements were made with samples of {sup 235}U, {sup 236}U, {sup 238}U and {sup 239}Pu. The smallest sample measured was 10 ng of {sup 239}Pu. Measurement of (n, {alpha}) cross section with 760 ng of Li-6 was also

  5. Measurements with the high flux lead slowing-down spectrometer at LANL

    Science.gov (United States)

    Danon, Y.; Romano, C.; Thompson, J.; Watson, T.; Haight, R. C.; Wender, S. A.; Vieira, D. J.; Bond, E.; Wilhelmy, J. B.; O'Donnell, J. M.; Michaudon, A.; Bredeweg, T. A.; Schurman, T.; Rochman, D.; Granier, T.; Ethvignot, T.; Taieb, J.; Becker, J. A.

    2007-08-01

    A Lead Slowing-Down Spectrometer (LSDS) was recently installed at LANL [D. Rochman, R.C. Haight, J.M. O'Donnell, A. Michaudon, S.A. Wender, D.J. Vieira, E.M. Bond, T.A. Bredeweg, A. Kronenberg, J.B. Wilhelmy, T. Ethvignot, T. Granier, M. Petit, Y. Danon, Characteristics of a lead slowing-down spectrometer coupled to the LANSCE accelerator, Nucl. Instr. and Meth. A 550 (2005) 397]. The LSDS is comprised of a cube of pure lead 1.2 m on the side, with a spallation pulsed neutron source in its center. The LSDS is driven by 800 MeV protons with a time-averaged current of up to 1 μA, pulse widths of 0.05-0.25 μs and a repetition rate of 20-40 Hz. Spallation neutrons are created by directing the proton beam into an air-cooled tungsten target in the center of the lead cube. The neutrons slow down by scattering interactions with the lead and thus enable measurements of neutron-induced reaction rates as a function of the slowing-down time, which correlates to neutron energy. The advantage of an LSDS as a neutron spectrometer is that the neutron flux is 3-4 orders of magnitude higher than a standard time-of-flight experiment at the equivalent flight path, 5.6 m. The effective energy range is 0.1 eV to 100 keV with a typical energy resolution of 30% from 1 eV to 10 keV. The average neutron flux between 1 and 10 keV is about 1.7 × 109 n/cm2/s/μA. This high flux makes the LSDS an important tool for neutron-induced cross section measurements of ultra-small samples (nanograms) or of samples with very low cross sections. The LSDS at LANL was initially built in order to measure the fission cross section of the short-lived metastable isotope of U-235, however it can also be used to measure (n, α) and (n, p) reactions. Fission cross section measurements were made with samples of 235U, 236U, 238U and 239Pu. The smallest sample measured was 10 ng of 239Pu. Measurement of (n, α) cross section with 760 ng of Li-6 was also demonstrated. Possible future cross section measurements

  6. High diversity and suggested endemicity of culturable Actinobacteria in an extremely oligotrophic desert oasis

    Directory of Open Access Journals (Sweden)

    Hector Fernando Arocha-Garza

    2017-05-01

    shows that our isolation effort produced 38 unique OTUs in six new monophyletic clades. This high biodiversity and uniqueness of Actinobacteria in an extreme oligotrophic environment, which has previously been reported for its diversity and endemicity, is a suggestive sign of microbial biogeography of Actinobacteria and it also represents an invaluable source of biological material for future ecological and bioprospecting studies.

  7. High diversity and suggested endemicity of culturable Actinobacteria in an extremely oligotrophic desert oasis.

    Science.gov (United States)

    Arocha-Garza, Hector Fernando; Canales-Del Castillo, Ricardo; Eguiarte, Luis E; Souza, Valeria; De la Torre-Zavala, Susana

    2017-01-01

    isolation effort produced 38 unique OTUs in six new monophyletic clades. This high biodiversity and uniqueness of Actinobacteria in an extreme oligotrophic environment, which has previously been reported for its diversity and endemicity, is a suggestive sign of microbial biogeography of Actinobacteria and it also represents an invaluable source of biological material for future ecological and bioprospecting studies.

  8. Quantifying imaging performance bounds of extreme dipole illumination in high NA optical lithography

    Science.gov (United States)

    Lee, Myungjun; Smith, Mark D.; Biafore, John; Graves, Trey; Levy, Ady

    2016-10-01

    We present a framework to analyze the performance of optical imaging in a hyper numerical aperture (NA) immersion lithography scanner. We investigate the method to quantify imaging performance by computing upperand lower-bounds on the threshold normalized image log-slope (NILS) and the depth of focus (DOF) in conjunction with the traditional image quality metrics such as the mask error enhancement factor (MEEF) and the linearity for various different pitches and line to space (LS) duty cycles. The effects of the interaction between the light illumination and the feature size are extensively characterized based on the aerial image (AI) behavior in particular for the extreme dipole illumination that is one of the commonly used off-axis illuminations for sub-100nm logic and memory devices, providing resolution near the physical limit of an optical single patterning step. The proposed aerial imaging-based DOF bounds are compared to the results obtained from an experimentally calibrated resist model, and we observed good agreement. In general, the extreme dipole illumination is only optimal for a single particular pitch, therefore understanding the through-pitch imaging performance bound, which depends on the illumination shape, pattern size, and process conditions, is critically important. We find that overall imaging performance varies depending upon the number of diffracted beams passing through the scanner optics. An even number of beams provides very different trends compared to the results from an odd-number of beams. This significant non-linear behavior occurs in certain pitch regions corresponding to 3 beam interference imaging. In this region the imaging performance and the pattern printability become extremely sensitive to the LS duty cycle. In addition, there is a notable tradeoff between the DOF and the NILS that is observed in the problematic 3-beam region and this tradeoff eventually affects the achievable process window (PW). Given the practical real

  9. The revised electromagnetic fields directive and worker exposure in environments with high magnetic flux densities.

    Science.gov (United States)

    Stam, Rianne

    2014-06-01

    Some of the strongest electromagnetic fields (EMF) are found in the workplace. A European Directive sets limits to workers' exposure to EMF. This review summarizes its origin and contents and compares magnetic field exposure levels in high-risk workplaces with the limits set in the revised Directive. Pubmed, Scopus, grey literature databases, and websites of organizations involved in occupational exposure measurements were searched. The focus was on EMF with frequencies up to 10 MHz, which can cause stimulation of the nervous system. Selected studies had to provide individual maximum exposure levels at the workplace, either in terms of the external magnetic field strength or flux density or as induced electric field strength or current density. Indicative action levels and the corresponding exposure limit values for magnetic fields in the revised European Directive will be higher than those in the previous version. Nevertheless, magnetic flux densities in excess of the action levels for peripheral nerve stimulation are reported for workers involved in welding, induction heating, transcranial magnetic stimulation, and magnetic resonance imaging (MRI). The corresponding health effects exposure limit values for the electric fields in the worker's body can be exceeded for welding and MRI, but calculations for induction heating and transcranial magnetic stimulation are lacking. Since the revised European Directive conditionally exempts MRI-related activities from the exposure limits, measures to reduce exposure may be necessary for welding, induction heating, and transcranial nerve stimulation. Since such measures can be complicated, there is a clear need for exposure databases for different workplace scenarios with significant EMF exposure and guidance on good practices.

  10. Simulating high frequency water quality monitoring data using a catchment runoff attenuation flux tool (CRAFT).

    Science.gov (United States)

    Adams, Russell; Quinn, Paul F; Perks, Matthew; Barber, Nicholas J; Jonczyk, Jennine; Owen, Gareth J

    2016-12-01

    High resolution water quality data has recently become widely available from numerous catchment based monitoring schemes. However, the models that can reproduce time series of concentrations or fluxes have not kept pace with the advances in monitoring data. Model performance at predicting phosphorus (P) and sediment concentrations has frequently been poor with models not fit for purpose except for predicting annual losses. Here, the data from the Eden Demonstration Test Catchments (DTC) project have been used to calibrate the Catchment Runoff Attenuation Flux Tool (CRAFT), a new, parsimonious model developed with the aim of modelling both the generation and attenuation of nutrients and sediments in small to medium sized catchments. The CRAFT has the ability to run on an hourly timestep and can calculate the mass of sediments and nutrients transported by three flow pathways representing rapid surface runoff, fast subsurface drainage and slow groundwater flow (baseflow). The attenuation feature of the model is introduced here; this enables surface runoff and contaminants transported via this pathway to be delayed in reaching the catchment outlet. It was used to investigate some hypotheses of nutrient and sediment transport in the Newby Beck Catchment (NBC) Model performance was assessed using a suite of metrics including visual best fit and the Nash-Sutcliffe efficiency. It was found that this approach for water quality models may be the best assessment method as opposed to using a single metric. Furthermore, it was found that, when the aim of the simulations was to reproduce the time series of total P (TP) or total reactive P (TRP) to get the best visual fit, that attenuation was required. The model will be used in the future to explore the impacts on water quality of different mitigation options in the catchment; these will include attenuation of surface runoff. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. The Sedentary Survey of Extreme High Energy Peaked BL Lacs III. Results from Optical Spectroscopy

    CERN Document Server

    Piranomonte, S; Giommi, P; Landt, H; Padovani, P

    2007-01-01

    The multi-frequency Sedentary Survey is a flux limited, statistically well-defined sample of highly X-ray dominated BL Lacertae objects (HBLs) which includes 150 sources. In this paper, the third of the series, we report the results of a dedicated optical spectroscopy campaign that, together with results from other independent optical follow up programs, led to the spectroscopic identification of all sources in the sample. We carried out a systematic spectroscopic campaign for the observation of all unidentified objects of the sample using the ESO 3.6m, the KPNO 4m, and the TNG optical telescopes. We present new identifications and optical spectra for 76 sources, 50 of which are new BL Lac objects, 18 are sources previously referred as BL Lacs but for which no redshift information was available, and 8 are broad emission lines AGNs. We find that the multi-frequency selection technique used to build the survey is highly efficient (about 90%) in selecting BL Lacs objects. We present positional and spectroscopic ...

  12. The paradox of extreme high-altitude migration in bar-headed geese Anser indicus

    Science.gov (United States)

    Hawkes, L.A.; Balachandran, S.; Batbayar, N.; Butler, P.J.; Chua, B.; Douglas, D.C.; Frappell, P.B.; Hou, Y.; Milsom, W.K.; Newman, S.H.; Prosser, D.J.; Sathiyaselvam, P.; Scott, G.R.; Takekawa, John Y.; Natsagdorj, T.; Wikelski, M.; Witt, M.J.; Yan, B.; Bishop, C.M.

    2012-01-01

    Bar-headed geese are renowned for migratory flights at extremely high altitudes over the world's tallest mountains, the Himalayas, where partial pressure of oxygen is dramatically reduced while flight costs, in terms of rate of oxygen consumption, are greatly increased. Such a mismatch is paradoxical, and it is not clear why geese might fly higher than is absolutely necessary. In addition, direct empirical measurements of high-altitude flight are lacking. We test whether migrating bar-headed geese actually minimize flight altitude and make use of favourable winds to reduce flight costs. By tracking 91 geese, we show that these birds typically travel through the valleys of the Himalayas and not over the summits. We report maximum flight altitudes of 7290 m and 6540 m for southbound and northbound geese, respectively, but with 95 per cent of locations received from less than 5489 m. Geese travelled along a route that was 112 km longer than the great circle (shortest distance) route, with transit ground speeds suggesting that they rarely profited from tailwinds. Bar-headed geese from these eastern populations generally travel only as high as the terrain beneath them dictates and rarely in profitable winds. Nevertheless, their migration represents an enormous challenge in conditions where humans and other mammals are only able to operate at levels well below their sea-level maxima.

  13. Atmospheric and Fog Effects on Ultra-Wide Band Radar Operating at Extremely High Frequencies.

    Science.gov (United States)

    Balal, Nezah; Pinhasi, Gad A; Pinhasi, Yosef

    2016-05-23

    The wide band at extremely high frequencies (EHF) above 30 GHz is applicable for high resolution directive radars, resolving the lack of free frequency bands within the lower part of the electromagnetic spectrum. Utilization of ultra-wideband signals in this EHF band is of interest, since it covers a relatively large spectrum, which is free of users, resulting in better resolution in both the longitudinal and transverse dimensions. Noting that frequencies in the millimeter band are subjected to high atmospheric attenuation and dispersion effects, a study of the degradation in the accuracy and resolution is presented. The fact that solid-state millimeter and sub-millimeter radiation sources are producing low power, the method of continuous-wave wideband frequency modulation becomes the natural technique for remote sensing and detection. Millimeter wave radars are used as complementary sensors for the detection of small radar cross-section objects under bad weather conditions, when small objects cannot be seen by optical cameras and infrared detectors. Theoretical analysis for the propagation of a wide "chirped" Frequency-Modulated Continuous-Wave (FMCW) radar signal in a dielectric medium is presented. It is shown that the frequency-dependent (complex) refractivity of the atmospheric medium causes distortions in the phase of the reflected signal, introducing noticeable errors in the longitudinal distance estimations, and at some frequencies may also degrade the resolution.

  14. A method of batch-purifying microalgae with multiple antibiotics at extremely high concentrations

    Science.gov (United States)

    Han, Jichang; Wang, Song; Zhang, Lin; Yang, Guanpin; Zhao, Lu; Pan, Kehou

    2016-01-01

    Axenic microalgal strains are highly valued in diverse microalgal studies and applications. Antibiotics, alone or in combination, are often used to avoid bacterial contamination during microalgal isolation and culture. In our preliminary trials, we found that many microalgae ceased growing in antibiotics at extremely high concentrations but could resume growth quickly when returned to an antibiotics-free liquid medium and formed colonies when spread on a solid medium. We developed a simple and highly efficient method of obtaining axenic microalgal cultures based on this observation. First, microalgal strains of different species or strains were treated with a mixture of ampicillin, gentamycin sulfate, kanamycin, neomycin and streptomycin (each at a concentration of 600 mg/L) for 3 days; they were then transferred to antibiotics-free medium for 5 days; and finally they were spread on solid f/2 media to allow algal colonies to form. With this method, five strains of Nannochloropsis sp. (Eustigmatophyceae), two strains of Cylindrotheca sp. (Bacillariophyceae), two strains of Tetraselmis sp. (Chlorodendrophyceae) and one strain of Amphikrikos sp. (Trebouxiophyceae) were purified successfully. The method shows promise for batch-purifying microalgal cultures.

  15. A Novel Gravity Compensation Method for High Precision Free-INS Based on "Extreme Learning Machine".

    Science.gov (United States)

    Zhou, Xiao; Yang, Gongliu; Cai, Qingzhong; Wang, Jing

    2016-11-29

    In recent years, with the emergency of high precision inertial sensors (accelerometers and gyros), gravity compensation has become a major source influencing the navigation accuracy in inertial navigation systems (INS), especially for high-precision INS. This paper presents preliminary results concerning the effect of gravity disturbance on INS. Meanwhile, this paper proposes a novel gravity compensation method for high-precision INS, which estimates the gravity disturbance on the track using the extreme learning machine (ELM) method based on measured gravity data on the geoid and processes the gravity disturbance to the height where INS has an upward continuation, then compensates the obtained gravity disturbance into the error equations of INS to restrain the INS error propagation. The estimation accuracy of the gravity disturbance data is verified by numerical tests. The root mean square error (RMSE) of the ELM estimation method can be improved by 23% and 44% compared with the bilinear interpolation method in plain and mountain areas, respectively. To further validate the proposed gravity compensation method, field experiments with an experimental vehicle were carried out in two regions. Test 1 was carried out in a plain area and Test 2 in a mountain area. The field experiment results also prove that the proposed gravity compensation method can significantly improve the positioning accuracy. During the 2-h field experiments, the positioning accuracy can be improved by 13% and 29% respectively, in Tests 1 and 2, when the navigation scheme is compensated by the proposed gravity compensation method.

  16. Molecular dynamics simulation of the formation, growth and bursting of bubbles in tungsten exposed to high fluxes of low energy deuterium

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Shengguang, E-mail: sgliu@dlut.edu.cn [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Ministry of Education), School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Dai, Shuyu; Sang, Chaofeng [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Ministry of Education), School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Sun, Jizhong, E-mail: jsun@dlut.edu.cn [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Ministry of Education), School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Stirner, Thomas [University of Applied Sciences Deggendorf, Edlmairstr. 6+8, D-94469 Deggendorf (Germany); Wang, Dezhen [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Ministry of Education), School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

    2015-08-15

    Molecular dynamics simulations are carried out to investigate the formation, growth and bursting of bubbles in tungsten exposed to the irradiation of an extremely high deuterium flux. It is found that the bubbles form in the region near the location of the implanted ion distribution peaks, and that the effect of the substrate temperature on the bubble formation depth is negligible; it is also found that the percentage of deuterium that is found in D{sub 2} molecules increases as the bubble grows, and that the evolution of the bubble’s internal pressure is strongly associated with the properties of its surrounding structure. The simulations display the development of a dome-shaped structure at the tungsten surface during the bubble growth. The merging of two deuterium bubbles is also observed. The present simulations also show that the bubble bursts by generating a partially opened lid, which has already been observed in previous independent experiments.

  17. Molecular dynamics simulation of the formation, growth and bursting of bubbles in tungsten exposed to high fluxes of low energy deuterium

    Science.gov (United States)

    Liu, Shengguang; Dai, Shuyu; Sang, Chaofeng; Sun, Jizhong; Stirner, Thomas; Wang, Dezhen

    2015-08-01

    Molecular dynamics simulations are carried out to investigate the formation, growth and bursting of bubbles in tungsten exposed to the irradiation of an extremely high deuterium flux. It is found that the bubbles form in the region near the location of the implanted ion distribution peaks, and that the effect of the substrate temperature on the bubble formation depth is negligible; it is also found that the percentage of deuterium that is found in D2 molecules increases as the bubble grows, and that the evolution of the bubble's internal pressure is strongly associated with the properties of its surrounding structure. The simulations display the development of a dome-shaped structure at the tungsten surface during the bubble growth. The merging of two deuterium bubbles is also observed. The present simulations also show that the bubble bursts by generating a partially opened lid, which has already been observed in previous independent experiments.

  18. Next generation fuel irradiation capability in the High Flux Reactor Petten

    Energy Technology Data Exchange (ETDEWEB)

    Fuetterer, Michael A., E-mail: michael.fuetterer@jrc.n [European Commission, Joint Research Centre, Institute for Energy (JRC-IE), P.O. Box 2, NL-1755 ZG Petten (Netherlands); D' Agata, Elio; Laurie, Mathias; Marmier, Alain; Scaffidi-Argentina, Francesco [European Commission, Joint Research Centre, Institute for Energy (JRC-IE), P.O. Box 2, NL-1755 ZG Petten (Netherlands); Raison, Philippe [European Commission, Joint Research Centre, Institute for Transuranium Elements (JRC-ITU), D-76334 Eggenstein-Leopoldshafen (Germany); Bakker, Klaas; Groot, Sander de; Klaassen, Frodo [Nuclear Research and consultancy Group (NRG), P.O. Box 25, NL-1755 ZG Petten (Netherlands)

    2009-07-15

    This paper describes selected equipment and expertise on fuel irradiation testing at the High Flux Reactor (HFR) in Petten, The Netherlands. The reactor went critical in 1961 and holds an operating license up to at least 2015. While HFR has initially focused on Light Water Reactor fuel and materials, it also played a decisive role since the 1970s in the German High Temperature Reactor (HTR) development program. A variety of tests related to fast reactor development in Europe were carried out for next generation fuel and materials, in particular for Very High Temperature Reactor (V/HTR) fuel, fuel for closed fuel cycles (U-Pu and Th-U fuel cycle) and transmutation, as well as for other innovative fuel types. The HFR constitutes a significant European infrastructure tool for the development of next generation reactors. Experimental facilities addressed include V/HTR fuel tests, a coated particle irradiation rig, and tests on fast reactor, transmutation and thorium fuel. The rationales for these tests are given, results are provided and further work is outlined.

  19. K2-66b and K2-106b: Two Extremely Hot Sub-Neptune-size Planets with High Densities

    Science.gov (United States)

    Sinukoff, Evan; Howard, Andrew W.; Petigura, Erik A.; Fulton, Benjamin J.; Crossfield, Ian J. M.; Isaacson, Howard; Gonzales, Erica; Crepp, Justin R.; Brewer, John M.; Hirsch, Lea; Weiss, Lauren M.; Ciardi, David R.; Schlieder, Joshua E.; Benneke, Bjoern; Christiansen, Jessie L.; Dressing, Courtney D.; Hansen, Brad M. S.; Knutson, Heather A.; Kosiarek, Molly; Livingston, John H.; Greene, Thomas P.; Rogers, Leslie A.; Lépine, Sébastien

    2017-06-01

    We report precise mass and density measurements of two extremely hot sub-Neptune-size planets from the K2 mission using radial velocities, K2 photometry, and adaptive optics imaging. K2-66 harbors a close-in sub-Neptune-sized ({2.49}-0.24+0.34 {R}\\oplus ) planet (K2-66b) with a mass of 21.3+/- 3.6 {M}\\oplus . Because the star is evolving up the subgiant branch, K2-66b receives a high level of irradiation, roughly twice the main-sequence value. K2-66b may reside within the so-called “photoevaporation desert,” a domain of planet size and incident flux that is almost completely devoid of planets. Its mass and radius imply that K2-66b has, at most, a meager envelope fraction (radiation environments. Their high densities reflect the challenge of retaining a substantial gas envelope in such extreme environments.

  20. High-resolution Observations of a Flux Rope with the Interface Region Imaging Spectrograph

    CERN Document Server

    Li, Ting

    2015-01-01

    We report the observations of a flux rope at transition region temperatures with the \\emph{Interface Region Imaging Spectrograph} (IRIS) on 30 August 2014. Initially, magnetic flux cancellation constantly took place and a filament was activated. Then the bright material from the filament moved southward and tracked out several fine structures. These fine structures were twisted and tangled with each other, and appeared as a small flux rope at 1330 {\\AA}, with a total twist of about 4$\\pi$. Afterwards, the flux rope underwent a counter-clockwise (viewed top-down) unwinding motion around its axis. Spectral observations of C {\\sc ii} 1335.71 {\\AA} at the southern leg of the flux rope showed that Doppler redshifts of 6$-$24 km s$^{-1}$ appeared at the western side of the axis, which is consistent with the counter-clockwise rotation motion. We suggest that the magnetic flux cancellation initiates reconnection and some activation of the flux rope. The stored twist and magnetic helicity of the flux rope are transpor...

  1. Carbon flux from plants to soil microbes is highly sensitive to nitrogen addition and biochar amendment

    Science.gov (United States)

    Kaiser, C.; Solaiman, Z. M.; Kilburn, M. R.; Clode, P. L.; Fuchslueger, L.; Koranda, M.; Murphy, D. V.

    2012-04-01

    material, microbial biomass and dissolved organic matter by IRMS, 13C and 15N in plant roots cells and intraradical mycorrhizal hyphae by NanoSims). Our results show that (1) C assimilated by plants was delivered within 4 hours to the soil microbial community both via roots and the mycorrhizal network (2) N addition during the labeling period strongly and rapidly increased the 13C flux of recently assimilated carbohydrates to the soil microbial biomass (3) the effect of N addition was not as rapid but was of the same magnitude when N was delivered to the plant exclusively by mycorrhizal hyphae as compared to taken up by roots (4) soils which had been amended with biochar (which were characterized by an increased abundance of mycorrhizal fungi) also showed a significant increase of C flux from plants to the soil. We conclude that plant belowground C allocation is highly sensitive to alterations of microbial community structure and nutritional status in the soil. Moreover, our results indicate that plants respond rapidly (within hours) to changing soil N availability by altering the rate of C transported belowground. Our results emphasise the ecological significance of plant-belowground interactions for ecosystem C cycling.

  2. Generation of high-photon flux-coherent soft x-ray radiation with few-cycle pulses.

    Science.gov (United States)

    Demmler, Stefan; Rothhardt, Jan; Hädrich, Steffen; Krebs, Manuel; Hage, Arvid; Limpert, Jens; Tünnermann, Andreas

    2013-12-01

    We present a tabletop source of coherent soft x-ray radiation with high-photon flux. Two-cycle pulses delivered by a fiber-laser-pumped optical parametric chirped-pulse amplifier operating at 180 kHz repetition rate are upconverted via high harmonic generation in neon to photon energies beyond 200 eV. A maximum photon flux of 1.3·10(8) photons/s is achieved within a 1% bandwidth at 125 eV photon energy. This corresponds to a conversion efficiency of ~10(-9), which can be reached due to a gas jet simultaneously providing a high target density and phase matching. Further scaling potential toward higher photon flux as well as higher photon energies are discussed.

  3. Fluxed-melting of shallow and hot high-grade metamorphic rocks in the Namcha Barwa Massif: A new mechanism for the generation of adakitic melts

    Science.gov (United States)

    Zeng, L.; Liu, J.; Hou, Z.; Gao, L.; Xie, K.

    2008-12-01

    Extremely rapid exhumation has been a major factor leading to rapid advection of relatively hot crustal rocks into shallow crustal levels in the Namcha Barwa massif. In such a hot tectonic regime, it is conceivable that hot crustal material can undergo partial melting assisted by excessive water. Previous studies indeed have documented extremely young Na-rich granitic rocks (63.5 and up to 237.1), consistent with garnet either as a non-reactant phase or as a residue phase; (2) these leucosomes have similar Sr isotope compositions to their host rocks, but some of them have Nd isotope compositions significantly deviated from their host by ~4-5 epsilon units. Since high-grade metamorphic rocks in the Namcha Barwa were already shallower than 10 km in the past 5 million years, these data is best explained by water- fluxed melting of granitic components in the source rocks. This interpretation is also consistent with at water- present and relatively lower temperature conditions, both apatite and garnet behaves as non-reactant phases during a partial melting event, which could lead to depletion of garnet-compatible elements as well as negative shift in Nd isotope compositions in the amphibolite- or metapelite-derived melts. Our data emphasize that at rapidly exhumed and relatively hot tectonic regimes (e.g. the Nanga Parbat and Namcha Barwa areas), fluxed-melting of high-graded metamorphic rocks at relatively shallower crustal levels could be another important mechanism to produced adakitic magma and associated porphyritic Cu-Au deposits.

  4. Scaling and Intensification of Extreme Precipitation in High-Resolution Climate Change Simulations

    Science.gov (United States)

    Ban, Nikolina; Leutwyler, David; Lüthi, Daniel; Schär, Christoph

    2017-04-01

    Climate change projections of extreme precipitation are of great interest due to hydrological impacts such as droughts, floods, erosion, landslides and debris flows. Despite the trend towards dryer conditions over Europe, many climate simulations project increases of heavy precipitation events, while some theoretical studies have raised the possibility of dramatic increases in hourly events (by up to 14% per degree warming). However, conventional climate models are not suited to assess short-term heavy events due to the need to parameterize deep convection. High-resolution climate models with kilometer-scale grid spacing at which parameterization of convection can be switched off, significantly improve the simulation of heavy precipitation and can alter the climate change signal (e.g., Ban et al., 2015). Here we present decade-long high-resolution climate change simulations at horizontal resolution of 2.2 km over Europe on a computational domain with 1536x1536x60 grid points. These simulations have become feasible with a new version of the COSMO model that runs entirely on Graphics Processing Units. We compare a present-day climate simulation, driven by ERA-Interim reanalysis (Leutwyler at al., 2016), with a Pseudo-Global Warming (PGW) simulation The PGW simulation is driven by the slowly evolving mean seasonal cycle of the climate changes (derived from the CMIP5 model), superimposed on the ERA-Interim reanalysis. With this approach, the resulting changes are due to large scale warming of the atmosphere and due to slow-varying circulation changes. We will present the differences in climate change signal between conventional and high-resolution climate models, and discuss the thermodynamic effects on intensification of extreme precipitation. Ban N., J. Schmidli and C. Schär, 2015: Heavy precipitation in a changing climate: Does short-term summer precipitation increase faster? Geophys. Res. Lett., 42 (4), 1165-1172 Leutwyler, D., D. Lüthi, N. Ban, O. Fuhrer and C

  5. High Performance of Space Vector Modulation Direct Torque Control SVM-DTC Based on Amplitude Voltage and Stator Flux Angle

    Directory of Open Access Journals (Sweden)

    Hassan Farhan Rashag

    2013-04-01

    Full Text Available Various aspects related to controlling induction motor are investigated. Direct torque control is an original high performance control strategy in the field of AC drive. In this proposed method, the control system is based on Space Vector Modulation (SVM, amplitude of voltage in direct- quadrature reference frame (d-q reference and angle of stator flux. Amplitude of stator voltage is controlled by PI torque and PI flux controller. The stator flux angle is adjusted by rotor angular frequency and slip angular frequency. Then, the reference torque and the estimated torque is applied to the input of PI torque controller and the control quadrature axis voltage is determined. The control d-axis voltage is determined from the flux calculator. These q and d axis voltage are converted into amplitude voltage. By applying polar to Cartesian on amplitude voltage and stator flux angle, direct voltage and quadratures voltage are generated. The reference stator voltages in d-q are calculated based on forcing the stator voltage error to zero at next sampling period. By applying inverse park transformation on d-q voltages, the stator voltages in &alpha and &beta frame are generated and apply to SVM. From the output of SVM, the motor control signal is generated and the speed of the induction motor regulated toward the rated speed. The simulation Results have demonstrated exceptional performance in steady and transient states and shows that decrease of torque and flux ripples is achieved in a complete speed range.

  6. Characterizing the Chemical Stability of High Temperature Materials for Application in Extreme Environments

    Science.gov (United States)

    Opila, Elizabeth

    2005-01-01

    The chemical stability of high temperature materials must be known for use in the extreme environments of combustion applications. The characterization techniques available at NASA Glenn Research Center