Sample records for ice nucleus abundance

  1. Mobile Ice Nucleus Spectrometer

    SciTech Connect (OSTI)

    Kulkarni, Gourihar R.; Kok, G. L.

    2012-05-07T23:59:59.000Z

    This first year report presents results from a computational fluid dynamics (CFD) study to assess the flow and temperature profiles within the mobile ice nucleus spectrometer.

  2. Development of a Mobile Ice Nucleus Counter

    SciTech Connect (OSTI)

    Kok, Gregory; Kulkarni, Gourihar

    2014-07-10T23:59:59.000Z

    An ice nucleus counter has been constructed. The instrument uses built-in refrigeration systems for wall cooling. A cascade refrigeration system will allow the cold wall to operate as low as -70 deg C, and a single stage system can operate the warm wall at -45 deg C. A unique optical particle counter has been constructed using polarization detection of the scattered light. This allows differentiation of the particles exiting the chamber to determine if they are ice or liquid.

  3. THE ABUNDANCE OF CARBON DIOXIDE ICE IN THE QUIESCENT INTRACLOUD MEDIUM D. C. B. Whittet,1,2

    E-Print Network [OSTI]

    Gerakines, Perry

    THE ABUNDANCE OF CARBON DIOXIDE ICE IN THE QUIESCENT INTRACLOUD MEDIUM D. C. B. Whittet,1,2 S. S: ISM: lines and bands -- ISM: molecules 1. INTRODUCTION Carbon dioxide (CO2) has proven to be a common embedded sources. Key properties include abundance relative to other ice constituents and dust extinction

  4. A New and Simple Approach to Determine the Abundance of Hydrogen Molecules on Interstellar Ice Mantles

    E-Print Network [OSTI]

    Hincelin, Ugo; Herbst, Eric

    2014-01-01T23:59:59.000Z

    Water is usually the main component of ice mantles, which cover the cores of dust grains in cold portions of dense interstellar clouds. When molecular hydrogen is adsorbed onto an icy mantle through physisorption, a common assumption in gas-grain rate equation models is to use an adsorption energy for molecular hydrogen on a pure water substrate. However, at high density and low temperature, when H2 is efficiently adsorbed onto the mantle, its surface abundance can be strongly overestimated if this assumption is still used. Unfortunately, the more detailed microscopic Monte Carlo treatment cannot be used to study the abundance of H2 in ice mantles if a full gas-grain network is utilized. We present a numerical method adapted for rate-equation models that takes into account the possibility that an H2 molecule can, while diffusing on the surface, find itself bound to another hydrogen molecule, with a far weaker bond than the H2-water bond, which can lead to more efficient desorption. We label the ensuing desorp...

  5. Sulfur depletion in dense clouds and circumstellar regions I. H2S ice abundance and UV-photochemical reactions in the H2O-matrix

    E-Print Network [OSTI]

    Jiménez-Escobar, A

    2011-01-01T23:59:59.000Z

    This work aims to study the unexplained sulfur depletion observed toward dense clouds and protostars. We made simulation experiments of the UV-photoprocessing and sublimation of H2S and H2S:H2O ice in dense clouds and circumstellar regions, using the Interstellar Astrochemistry Chamber (ISAC), a state-of-the-art ultra-high-vacuum setup. The ice was monitored in situ by mid-infrared spectroscopy in transmittance. Temperature-programmed desorption (TPD) of the ice was performed using a quadrupole mass spectrometer (QMS) to detect the volatiles desorbing from the ice. Comparing our laboratory data to infrared observations of protostars we obtained a more accurate upper limit of the abundance of H2S ice toward these objects. We determined the desorption temperature of H2S ice, which depends on the initial H2S:H2O ratio. UV-photoprocessing of H2S:H2O ice led to the formation of several species. Among them, H2S2 was found to photodissociate forming S2 and, by elongation, other species up to S8, which are refractory...

  6. Ice sheets

    E-Print Network [OSTI]

    Bentley, Charles G.; Thomas, Robert H.; Velicogna, Isabella

    2007-01-01T23:59:59.000Z

    is eroding West Antarctic Ice Sheet. Geophysical Researchand Yungel, J. (2000). Greenland Ice Sheet: High-Elevation2004). The west Antarctic ice sheet and long term climate

  7. Eccentricity distributions in nucleus-nucleus collisions

    E-Print Network [OSTI]

    Li Yan; Jean-Yves Ollitrault; Arthur M. Poskanzer

    2014-09-03T23:59:59.000Z

    We propose a new parametrization of the distribution of the initial eccentricity in a nucleus-nucleus collision at a fixed centrality, which we name the Elliptic Power distribution. It is a two-parameter distribution, where one of the parameters corresponds to the intrinsic eccentricity, while the other parameter controls the magnitude of eccentricity fluctuations. Unlike the previously used Bessel- Gaussian distribution, which becomes worse for more peripheral collisions, the new Elliptic Power distribution fits several Monte Carlo models of the initial state for all centralities.

  8. Interstellar Ices

    E-Print Network [OSTI]

    Boogert, A C A

    2003-01-01T23:59:59.000Z

    Currently ~36 different absorption bands have been detected in the infrared spectra of cold, dense interstellar and circumstellar environments. These are attributed to the vibrational transitions of ~17 different molecules frozen on dust grains. We review identification issues and summarize the techniques required to extract information on the physical and chemical evolution of these ices. Both laboratory simulations and line of sight studies are essential. Examples are given for ice bands observed toward high mass protostars, fields stars and recent work on ices in disks surrounding low mass protostars. A number of clear trends have emerged in recent years. One prominent ice component consists of an intimate mixture between H2O, CH3OH and CO2 molecules. Apparently a stable balance exists between low temperature hydrogenation and oxidation reactions on grain surfaces. In contrast, an equally prominent ice component, consisting almost entirely of CO, must have accreted directly from the gas phase. Thermal proc...

  9. Archimedean Ice

    E-Print Network [OSTI]

    Kari Eloranta

    2009-09-22T23:59:59.000Z

    The striking boundary dependency (the Arctic Circle phenomenon) exhibited in the ice model on the square lattice extends to other planar set-ups. We present these findings for the triangular and the Kagome lattices. Critical connectivity results guarantee that ice configurations can be generated using the simplest and most efficient local actions. Height functions are utilized throughout the analysis. At the end there is a surprise in store: on the remaining Archimedean lattice for which the ice model can be defined, the 3.4.6.4. lattice, the long range behavior is completely different from the other cases.

  10. Subthreshold Antiproton Production in Nucleus-Nucleus Collisions

    E-Print Network [OSTI]

    LI, GQ; Ko, Che Ming; Fang, X. S.; Zheng, Y. M.

    1994-01-01T23:59:59.000Z

    Antiproton production in nucleus-nucleus collisions at energies below the threshold for its production from the nucleon-nucleon interaction in free space is studied in the relativistic Vlasov-Uehling-Uhlenbeck model. The antiproton self-energies...

  11. Ice chemistry in starless molecular cores

    E-Print Network [OSTI]

    Kalvans, Juris

    2015-01-01T23:59:59.000Z

    Starless molecular cores are natural laboratories for interstellar molecular chemistry research. The chemistry of ices in such objects was investigated with a three-phase (gas, surface, and mantle) model. We considered the center part of five starless cores, with their physical conditions derived from observations. The ice chemistry of oxygen, nitrogen, sulfur, and complex organic molecules (COMs) was analyzed. We found that an ice-depth dimension, measured, e.g., in monolayers, is essential for modeling of chemistry in interstellar ices. Particularly, the H2O:CO:CO2:N2:NH3 ice abundance ratio regulates the production and destruction of minor species. It is suggested that photodesorption during core collapse period is responsible for high abundance of interstellar H2O2 and O2H, and other species synthesized on the surface. The calculated abundances of COMs in ice were compared to observed gas-phase values. Smaller activation barriers for CO and H2CO hydrogenation may help explain the production of a number of...

  12. UV Irradiation of Polycyclic Aromatic Hydrocarbons in Ices

    E-Print Network [OSTI]

    . Clemett,3 Richard N. Zare3 Polycyclic aromatic hydrocarbons (PAHs) in water ice were exposed to ultra meteorites. Hydrogen and deu- terium atoms exchange readily between the PAHs and the ice, which may explain abundant and widespread class of carbon-car- rying gaseous species is believed to be PAHs (3­5). In dense

  13. Iced Coffee Iced Yerba Mate "Tea"

    E-Print Network [OSTI]

    Iced Coffee Iced Yerba Mate "Tea" Iced Yerba Mate Latte Iced Chai Tea Latte Original, Green Tea Canned Soda Xing Tea Bottled Water Arizona Teas Energy Drinks Red Bull, SF Red Bull & Bing Jones Sodas $0 Cafe au Lait Hot Tea Yerba Mate "Tea" Yerba Mate Latte Chai Tea Latte - Original, Green Tea, or Sugar

  14. Nucleus-nucleus potential with shell-correction contribution

    E-Print Network [OSTI]

    V. Yu. Denisov

    2015-02-04T23:59:59.000Z

    The full relaxed-density potential between spherical nuclei is considered as a sum of the macroscopic and shell-correction contributions. The macroscopic part of the potential is related to a nucleus-nucleus potential obtained in the framework of the extended Thomas-Fermi approach with the Skyrme and Coulomb forces and the relaxed-density ansatz for evaluation of proton and neutron densities of interacting nuclei. A simple prescription for the shell-correction part of the total potential is discussed. The parameters of the shell-correction and macroscopic parts of the relaxed-density potential are found by fitting the empirical barrier heights of the 89 nucleus-nucleus systems as well as macroscopic potentials evaluated for 1485 nucleus-nucleus systems at 12 distances around touching points.

  15. Neutrino-nucleus interactions

    SciTech Connect (OSTI)

    Gallagher, H.; /Tufts U.; Garvey, G.; /Los Alamos; Zeller, G.P.; /Fermilab

    2011-01-01T23:59:59.000Z

    The study of neutrino oscillations has necessitated a new generation of neutrino experiments that are exploring neutrino-nuclear scattering processes. We focus in particular on charged-current quasi-elastic scattering, a particularly important channel that has been extensively investigated both in the bubble-chamber era and by current experiments. Recent results have led to theoretical reexamination of this process. We review the standard picture of quasi-elastic scattering as developed in electron scattering, review and discuss experimental results, and discuss additional nuclear effects such as exchange currents and short-range correlations that may play a significant role in neutrino-nucleus scattering.

  16. Planetary nebulae: abundances and abundance gradients

    E-Print Network [OSTI]

    W. J. Maciel

    1999-11-05T23:59:59.000Z

    In this work, a review is given of some recent results and problems involved in the determination of chemical abundances of galactic planetary nebulae, particularly regarding disk and bulge objects.

  17. Helioseismology and Solar Abundances

    E-Print Network [OSTI]

    Sarbani Basu; H. M. Antia

    2007-11-28T23:59:59.000Z

    Helioseismology has allowed us to study the structure of the Sun in unprecedented detail. One of the triumphs of the theory of stellar evolution was that helioseismic studies had shown that the structure of solar models is very similar to that of the Sun. However, this agreement has been spoiled by recent revisions of the solar heavy-element abundances. Heavy element abundances determine the opacity of the stellar material and hence, are an important input to stellar model calculations. The models with the new, low abundances do not satisfy helioseismic constraints. We review here how heavy-element abundances affect solar models, how these models are tested with helioseismology, and the impact of the new abundances on standard solar models. We also discuss the attempts made to improve the agreement of the low-abundance models with the Sun and discuss how helioseismology is being used to determine the solar heavy-element abundance. A review of current literature shows that attempts to improve agreement between solar models with low heavy-element abundances and seismic inference have been unsuccessful so far. The low-metallicity models that have the least disagreement with seismic data require changing all input physics to stellar models beyond their acceptable ranges. Seismic determinations of the solar heavy-element abundance yield results that are consistent with the older, higher values of the solar abundance, and hence, no major changes to the inputs to solar models are required to make higher-metallicity solar models consistent with helioseismic data.

  18. The Solar Argon Abundance

    E-Print Network [OSTI]

    Katharina Lodders

    2007-10-24T23:59:59.000Z

    The solar argon abundance cannot be directly derived by spectroscopic observations of the solar photosphere. The solar Ar abundance is evaluated from solar wind measurements, nucleosynthetic arguments, observations of B stars, HII regions, planetary nebulae, and noble gas abundances measured in Jupiter's atmosphere. These data lead to a recommended argon abundance of N(Ar) = 91,200(+/-)23,700 (on a scale where Si = 10^6 atoms). The recommended abundance for the solar photosphere (on a scale where log N(H) = 12) is A(Ar)photo = 6.50(+/-)0.10, and taking element settling into account, the solar system (protosolar) abundance is A(Ar)solsys = 6.57(+/-)0.10.

  19. How atmospheric ice forms | EMSL

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

    atmospheric ice forms How atmospheric ice forms Released: September 08, 2014 New insights into atmospheric ice formation could improve climate models This study advances our...

  20. Molecular Dynamics Simulations of CO2 Formation in Interstellar Ices

    E-Print Network [OSTI]

    Arasa, Carina; van Dishoeck, Ewine F; Kroes, Geert-Jan

    2013-01-01T23:59:59.000Z

    CO2 ice is one of the most abundant components in ice-coated interstellar ices besides H2O and CO, but the most favorable path to CO2 ice is still unclear. Molecular dynamics calculations on the ultraviolet photodissociation of different kinds of CO-H2O ice systems have been performed at 10 K in order to demonstrate that the reaction between CO and an OH molecule resulting from H2O photodissociation through the first excited state is a possible route to form CO2 ice. However, our calculations, which take into account different ice surface models, suggest that there is another product with a higher formation probability ((3.00+-0.07)x10-2), which is the HOCO complex, whereas the formation of CO2 has a probability of only (3.6+-0.7)x10-4. The initial location of the CO is key to obtain reaction and form CO2: the CO needs to be located deep into the ice. The HOCO complex becomes trapped in the cold ice surface in the trans-HOCO minimum because it quickly loses its internal energy to the surrounding ice, preventi...

  1. Arctic ice islands

    SciTech Connect (OSTI)

    Sackinger, W.M.; Jeffries, M.O.; Lu, M.C.; Li, F.C.

    1988-01-01T23:59:59.000Z

    The development of offshore oil and gas resources in the Arctic waters of Alaska requires offshore structures which successfully resist the lateral forces due to moving, drifting ice. Ice islands are floating, a tabular icebergs, up to 60 meters thick, of solid ice throughout their thickness. The ice islands are thus regarded as the strongest ice features in the Arctic; fixed offshore structures which can directly withstand the impact of ice islands are possible but in some locations may be so expensive as to make oilfield development uneconomic. The resolution of the ice island problem requires two research steps: (1) calculation of the probability of interaction between an ice island and an offshore structure in a given region; and (2) if the probability if sufficiently large, then the study of possible interactions between ice island and structure, to discover mitigative measures to deal with the moving ice island. The ice island research conducted during the 1983-1988 interval, which is summarized in this report, was concerned with the first step. Monte Carlo simulations of ice island generation and movement suggest that ice island lifetimes range from 0 to 70 years, and that 85% of the lifetimes are less then 35 years. The simulation shows a mean value of 18 ice islands present at any time in the Arctic Ocean, with a 90% probability of less than 30 ice islands. At this time, approximately 34 ice islands are known, from observations, to exist in the Arctic Ocean, not including the 10-meter thick class of ice islands. Return interval plots from the simulation show that coastal zones of the Beaufort and Chukchi Seas, already leased for oil development, have ice island recurrences of 10 to 100 years. This implies that the ice island hazard must be considered thoroughly, and appropriate safety measures adopted, when offshore oil production plans are formulated for the Alaskan Arctic offshore. 132 refs., 161 figs., 17 tabs.

  2. The Primordial Helium Abundance

    E-Print Network [OSTI]

    Manuel Peimbert

    2008-11-18T23:59:59.000Z

    I present a brief review on the determination of the primordial helium abundance by unit mass, Yp. I discuss the importance of the primordial helium abundance in: (a) cosmology, (b) testing the standard big bang nucleosynthesis, (c) studying the physical conditions in H II regions, (d) providing the initial conditions for stellar evolution models, and (e) testing the galactic chemical evolution models.

  3. Equations of state of ice VI and ice VII at high pressure and high temperature

    SciTech Connect (OSTI)

    Bezacier, Lucile; Hanfland, Michael [European Synchrotron Radiation Facility, 6 rue Jules Horowitz, 38000 Grenoble (France); Journaux, Baptiste; Perrillat, Jean-Philippe; Cardon, Hervé; Daniel, Isabelle [Laboratoire de Géologie de Lyon, UMR 5276 CNRS, Ecole Normale Supérieure de Lyon – Université Claude Bernard Lyon 1, 2 rue Raphael Dubois, 69622 Villeurbanne Cedex (France)

    2014-09-14T23:59:59.000Z

    High-pressure H{sub 2}O polymorphs among which ice VI and ice VII are abundant in the interiors of large icy satellites and exo-planets. Knowledge of the elastic properties of these pure H{sub 2}O ices at high-temperature and high-pressure is thus crucial to decipher the internal structure of icy bodies. In this study we assess for the first time the pressure-volume-temperature (PVT) relations of both polycrystalline pure ice VI and ice VII at high pressures and temperatures from 1 to 9 GPa and 300 to 450 K, respectively, by using in situ synchrotron X-ray diffraction. The PVT data are adjusted to a second-order Birch-Murnaghan equation of state and give V{sub 0} = 14.17(2) cm{sup 3}?mol{sup ?1}, K{sub 0} = 14.05(23) GPa, and ?{sub 0} = 14.6(14) × 10{sup ?5} K{sup ?1} for ice VI and V{sub 0} = 12.49(1) cm{sup 3}?mol{sup ?1}, K{sub 0} = 20.15(16) GPa, and ?{sub 0} = 11.6(5) × 10{sup ?5} K{sup ?1} for ice VII.

  4. Sensitivity of cross sections for elastic nucleus-nucleus scattering to halo nucleus density distributions

    SciTech Connect (OSTI)

    Alkhazov, G. D.; Sarantsev, V. V., E-mail: saran@pnpi.spb.ru [Petersburg Nuclear Physics Institute NRC KI (Russian Federation)

    2012-12-15T23:59:59.000Z

    In order to clear up the sensitivity of the nucleus-nucleus scattering to the nuclear matter distributions in exotic halo nuclei, we have calculated differential cross sections for elastic scattering of the {sup 6}He and {sup 11}Li nuclei on several nuclear targets at the energy of 0.8 GeV/nucleon with different assumed nuclear density distributions in {sup 6}He and {sup 11}Li.

  5. Double nucleus in M83

    E-Print Network [OSTI]

    D. Mast; R. J. Díaz; M. P. Aguero

    2006-04-06T23:59:59.000Z

    M 83 is one of the nearest galaxies with an enhanced nuclear star formation and it presents one of the best opportunities to study the kinematics and physical properties of a circumnuclear starburst. Our three-dimensional spectroscopy data in R band confirm the presence of a secondary nucleus or mass concentration (previously suggested by Thatte and coworkers). We determine the position of this hidden nucleus, which would be more massive than the visible one, and was not detected in the optical HST images due, probably, to the strong dust extinction. The optical nucleus has a mass of 5 x 10^6 M_Sun / sin i (r < 1''.5), and the hidden nucleus, located 3''.9 +/- 0''.5 at the NW (PA 271 +/- 15 deg) of the optical nucleus, would have a mass of 1 x 10^7 M_Sun / sin i (r < 1''.5). The emission line ratio map also unveils the presence of a second circumnuclear ring structure, previously discovered by IR imaging (Elmegreen and coworkers). The data allow us to resolve the behavior of the interstellar medium inside the circumnuclear ring and around the binary mass concentration.

  6. Subthreshold Antiproton Production in Nucleus-Nucleus Collisions

    E-Print Network [OSTI]

    Ko, Che Ming; Xia, L. H.

    1989-01-01T23:59:59.000Z

    77843 (Received 17 May 1989) Antiproton production from the secondary process pp~ pp is studied for nucleus-nucleus col- lisions at energies which are below the threshold for its production from the nucleon-nucleon reac- tion in the free space... of the Dirac sea in the presence of dense nuclear matter. The measured antiproton to negative pion ratio for the collision of two Si nuclei at an incident energy of 2. 1 GeV/nucleon has a surprisingly large value of about 4.3x10 . This is 3 orders...

  7. Ice electrode electrolytic cell

    DOE Patents [OSTI]

    Glenn, David F. (Idaho Falls, ID); Suciu, Dan F. (Idaho Falls, ID); Harris, Taryl L. (Idaho Falls, ID); Ingram, Jani C. (Idaho Falls, ID)

    1993-01-01T23:59:59.000Z

    This invention relates to a method and apparatus for removing heavy metals from waste water, soils, or process streams by electrolytic cell means. The method includes cooling a cell cathode to form an ice layer over the cathode and then applying an electric current to deposit a layer of the heavy metal over the ice. The metal is then easily removed after melting the ice. In a second embodiment, the same ice-covered electrode can be employed to form powdered metals.

  8. Ice electrode electrolytic cell

    DOE Patents [OSTI]

    Glenn, D.F.; Suciu, D.F.; Harris, T.L.; Ingram, J.C.

    1993-04-06T23:59:59.000Z

    This invention relates to a method and apparatus for removing heavy metals from waste water, soils, or process streams by electrolytic cell means. The method includes cooling a cell cathode to form an ice layer over the cathode and then applying an electric current to deposit a layer of the heavy metal over the ice. The metal is then easily removed after melting the ice. In a second embodiment, the same ice-covered electrode can be employed to form powdered metals.

  9. Using ice cores from the East Antarctic Ice Sheet, scientists have been able to study

    E-Print Network [OSTI]

    Using ice cores from the East Antarctic Ice Sheet, scientists have been able to study ice's ice sheets. Ice sheets are huge areas of permanent ice. There are only three ice sheets on Earth: the Greenland Ice Sheet, the West Antarctic Ice Sheet, and the East Antarctic Ice Sheet. The Greenland Ice Sheet

  10. CO diffusion into amorphous H2O ices

    E-Print Network [OSTI]

    Lauck, Trish; Shulenberger, Katherine; Rajappan, Mahesh; Oberg, Karin I; Cuppen, Herma M

    2015-01-01T23:59:59.000Z

    The mobility of atoms, molecules and radicals in icy grain mantles regulate ice restructuring, desorption, and chemistry in astrophysical environments. Interstellar ices are dominated by H2O, and diffusion on external and internal (pore) surfaces of H2O-rich ices is therefore a key process to constrain. This study aims to quantify the diffusion kinetics and barrier of the abundant ice constituent CO into H2O dominated ices at low temperatures (15-23 K), by measuring the mixing rate of initially layered H2O(:CO2)/CO ices. The mixed fraction of CO as a function of time is determined by monitoring the shape of the infrared CO stretching band. Mixing is observed at all investigated temperatures on minute time scales, and can be ascribed to CO diffusion in H2O ice pores. The diffusion coefficient and final mixed fraction depend on ice temperature, porosity, thickness and composition. The experiments are analyzed by applying Fick's diffusion equation under the assumption that mixing is due to CO diffusion into an i...

  11. Estimating and decomposing total uncertainty for survey-based abundance estimates of Norwegian spring-spawning herring

    E-Print Network [OSTI]

    Aldrin, Magne

    the Norwegian coast, feed in the Norwegian Sea and adjacent areas, and overwinter in various partsEstimating and decomposing total uncertainty for survey-based abundance estimates of Norwegian uncertainty for survey-based abundance estimates of Norwegian spring-spawning herring. ­ ICES Journal

  12. Transporting Dry Ice

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

    Requirements for Shipping Dry Ice IATA PI 904 Source: Reg of the Day from ERCweb 2006 Environmental Resource Center | 919-469-1585 | webmaster@ercweb.com http:...

  13. Ice Drilling Gallonmilkjugs

    E-Print Network [OSTI]

    Saffman, Mark

    Ice Drilling Materials · Gallonmilkjugs · Syringes,largeand small · Pitchers · Spraybottles · 13x9? ·Isitbettertosquirtthewaterslowlyorasquicklyaspossible? ·Doestherateatwhichyousquirtthewaterchangethediameteroftheholes? ·Doesthetypeof`drill

  14. Sandia National Laboratories: ICED

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

    Paper Presented at American Society of Mechanical Engineers' (ASME) 2012 Internal Combustion Engine Division (ICED) Conference On August 28, 2013, in CRF, Energy, Energy...

  15. Rate Analysis or a Possible Interpretation of Abundances

    E-Print Network [OSTI]

    Miklos Kiss

    2015-02-24T23:59:59.000Z

    Heavy elements are formed in nucleosynthesis processes. Abundances of these elements can be classified as elemental abundance, isotopic abundance, and abundance of nuclei. In this work we propose to change nucleon identification from the usual (Z,A) to (Z,N), which allows reading out new information from the measured abundances. We are interested in the neutron density required to reproduce the measured abundance of nuclei assuming equilibrium processes. This is only possible when two stable nuclei are separated by an unstable nucleus. At these places we investigated the neutron density required for equilibrium nucleosynthesis both isotopically and isotonically at temperatures of AGB interpulse and thermal pulse phases. We obtained an estimate for equilibrium nucleosynthesis neutron density in most of the cases. Next we investigated the possibility of partial formation of nuclei. We analyzed the meaning of the branching factor. We found a mathematical definition for the unified interpretation of a branching point closed at isotonic case and open at isotopic case. We introduce a more expressive variant of branching ratio called partial formation rate. With these we are capable of determining the characteristic neutron density values.

  16. Composition of Ices in Low-Mass Extrasolar Planets

    E-Print Network [OSTI]

    Ulysse Marboeuf; Olivier Mousis; David Ehrenreich; Yann Alibert; Arnaud Cassan; Valentine Wakelam; Jean-Philippe Beaulieu

    2008-04-02T23:59:59.000Z

    We study the formation conditions of icy planetesimals in protoplanetary disks in order to determine the composition of ices in small and cold extrasolar planets. Assuming that ices are formed from hydrates, clathrates, and pure condensates, we calculate their mass fractions with respect to the total quantity of ices included in planetesimals, for a grid of disk models. We find that the composition of ices weakly depends on the adopted disk thermodynamic conditions, and is rather influenced by the initial composition of the gas phase. The use of a plausible range of molecular abundance ratios and the variation of the relative elemental carbon over oxygen ratio in the gas phase of protoplanetary disks, allow us to apply our model to a wide range of planetary systems. Our results can thus be used to constrain the icy/volatile phase composition of cold planets evidenced by microlensing surveys, hypothetical ocean-planets and carbon planets, which could be detected by Corot or Kepler.

  17. Composition of Ices in Low-Mass Extrasolar Planets

    E-Print Network [OSTI]

    Marboeuf, Ulysse; Ehrenreich, David; Alibert, Yann; Cassan, Arnaud; Wakelam, Valentine; Beaulieu, Jean-Philippe

    2008-01-01T23:59:59.000Z

    We study the formation conditions of icy planetesimals in protoplanetary disks in order to determine the composition of ices in small and cold extrasolar planets. Assuming that ices are formed from hydrates, clathrates, and pure condensates, we calculate their mass fractions with respect to the total quantity of ices included in planetesimals, for a grid of disk models. We find that the composition of ices weakly depends on the adopted disk thermodynamic conditions, and is rather influenced by the initial composition of the gas phase. The use of a plausible range of molecular abundance ratios and the variation of the relative elemental carbon over oxygen ratio in the gas phase of protoplanetary disks, allow us to apply our model to a wide range of planetary systems. Our results can thus be used to constrain the icy/volatile phase composition of cold planets evidenced by microlensing surveys, hypothetical ocean-planets and carbon planets, which could be detected by Corot or Kepler.

  18. The effect of selective desorption mechanisms during interstellar ice formation

    E-Print Network [OSTI]

    Kalvans, Juris

    2015-01-01T23:59:59.000Z

    Major components of ices on interstellar grains in molecular clouds - water and carbon oxides - occur at various optical depths. This implies that selective desorption mechanisms are at work. An astrochemical model of a contracting low-mass molecular cloud core is presented. Ice was treated as consisting of the surface and three subsurface layers (sublayers). Photodesorption, reactive desorption, and indirect reactive desorption were investigated. The latter manifests itself through desorption from H+H reaction on grains. Desorption of shallow subsurface species was included. Modeling results suggest the existence of a "photon-dominated ice" during the early phases of core contraction. Subsurface ice is chemically processed by interstellar photons, which produces complex organic molecules. Desorption from the subsurface layer results in high COM gas-phase abundances at Av = 2.4...10mag. This may contribute towards an explanation for COM observations in dark cores. It was found that photodesorption mostly gove...

  19. Ice particle size matters | EMSL

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

    Ice particle size matters Ice particle size matters Released: May 04, 2014 Fine-tuning cloud models for improved climate predictions The Science Arctic clouds are widespread and...

  20. Reionization on ice

    E-Print Network [OSTI]

    C. C. Dudley; M. Imanishi; P. R. Maloney

    2006-02-15T23:59:59.000Z

    The case for substantial far infrared ice emission in local ultraluminous infrared galaxies, expected based on the presence of mid-infrared ice absorption in their spectra and the known far infrared optical properties of ice, is still largely unsupported by direct observation owing to insufficient far infrared spectral coverage. Some marginal supportive evidence is presented here. A clear consequence of far infrared ice emission is the need to extend the range of redshifts considered for submillimeter sources. This is demonstrated via the example of HDF 850.1. The solid phase of the ISM during reionization may be dominated by ice, and this could lead to the presence of reionization sources in submillimeter source catalogs. Submillimeter sources not detected at 24 micron in the GOODS-N field are examined. Two candidate reionization sources are identified at 3.6 micron through possible Gunn-Peterson saturation in the Z band.

  1. Life Cycle of Sea-Ice Frazil, or grease ice

    E-Print Network [OSTI]

    Washington at Seattle, University of

    of Sea Ice away from surface, long crystals as congelation ice (frozen on from below) Brine Channels within the ice (~width of human hair) Brine rejected from ice (4-10psu), but concentrates in brine from AWI #12;Brine Volume and Salinity From Thomas and Dieckmann 2002, Science .... adapted from papers

  2. Very ice rich permafrost Moderately ice rich permafrost

    E-Print Network [OSTI]

    Ruess, Roger W.

    TK lake Very ice rich permafrost Permafrost forest Moderately ice rich permafrost Open Bog Open Fen characteristics (mainly ice content) and burn severity determine trajectories of ecosystem succession post in the presence of moderately ice rich permafrost but have high resilience only under low burn severity in very

  3. Ice Cream with a Heart Create a new Clemson Ice

    E-Print Network [OSTI]

    Duchowski, Andrew T.

    Ice Cream with a Heart Contest! Create a new Clemson Ice Cream flavor! Raise money for your favorite charity! Win a free Clemson Ice Cream party for your organization! Enter at www organizations. The contest is called Ice Cream with a Heart and its purpose is to help student organizations

  4. Constraining solar abundances using helioseismology

    E-Print Network [OSTI]

    Sarbani Basu; H. M. Antia

    2004-03-19T23:59:59.000Z

    Recent analyses of solar photospheric abundances suggest that the oxygen abundance in the solar atmosphere needs to be revised downwards. In this study we investigate the consequence of this revision on helioseismic analyses of the depth of the solar convection zone and the helium abundance in the solar envelope and find no significant effect. We also find that the revised abundances along with the current OPAL opacity tables are not consistent with seismic data. A significant upward revision of the opacity tables is required to make solar models with lower oxygen abundance consistent with seismic observations.

  5. ON THE FORMATION OF INTERSTELLAR WATER ICE: CONSTRAINTS FROM A SEARCH FOR HYDROGEN PEROXIDE ICE IN MOLECULAR CLOUDS

    SciTech Connect (OSTI)

    Smith, R. G.; Wright, C. M.; Robinson, G. [School of Physical, Environmental and Mathematical Sciences, University of New South Wales, Australian Defence Force Academy, Canberra, ACT 2600 (Australia); Charnley, S. B. [Astrochemistry Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Pendleton, Y. J. [NASA Lunar Science Institute, NASA Ames Research Center, Moffett Field, CA 94035 (United States); Maldoni, M. M., E-mail: r.smith@adfa.edu.au, E-mail: c.wright@adfa.edu.au, E-mail: g.robinson@adfa.edu.au, E-mail: Steven.B.Charnley@nasa.gov, E-mail: yvonne.pendleton@nasa.gov [Geoscience Australia, Canberra, ACT 2601 (Australia)

    2011-12-20T23:59:59.000Z

    Recent surface chemistry experiments have shown that the hydrogenation of molecular oxygen on interstellar dust grains is a plausible formation mechanism, via hydrogen peroxide (H{sub 2}O{sub 2}), for the production of water (H{sub 2}O) ice mantles in the dense interstellar medium. Theoretical chemistry models also predict the formation of a significant abundance of H{sub 2}O{sub 2} ice in grain mantles by this route. At their upper limits, the predicted and experimental abundances are sufficiently high that H{sub 2}O{sub 2} should be detectable in molecular cloud ice spectra. To investigate this further, laboratory spectra have been obtained for H{sub 2}O{sub 2}/H{sub 2}O ice films between 2.5 and 200 {mu}m, from 10 to 180 K, containing 3%, 30%, and 97% H{sub 2}O{sub 2} ice. Integrated absorbances for all the absorption features in low-temperature H{sub 2}O{sub 2} ice have been derived from these spectra. For identifying H{sub 2}O{sub 2} ice, the key results are the presence of unique features near 3.5, 7.0, and 11.3 {mu}m. Comparing the laboratory spectra with the spectra of a group of 24 protostars and field stars, all of which have strong H{sub 2}O ice absorption bands, no absorption features are found that can definitely be identified with H{sub 2}O{sub 2} ice. In the absence of definite H{sub 2}O{sub 2} features, the H{sub 2}O{sub 2} abundance is constrained by its possible contribution to the weak absorption feature near 3.47 {mu}m found on the long-wavelength wing of the 3 {mu}m H{sub 2}O ice band. This gives an average upper limit for H{sub 2}O{sub 2}, as a percentage of H{sub 2}O, of 9% {+-} 4%. This is a strong constraint on parameters for surface chemistry experiments and dense cloud chemistry models.

  6. An ice shelf breakup

    SciTech Connect (OSTI)

    Fahnestock, M. [Univ. of Maryland, College Park, MD (United States)

    1996-02-09T23:59:59.000Z

    Glaciers and ice sheets are controlled by the climate and must change if the conditions that led to their current configurations are changing. These ice masses exist at the interface between the atmosphere, which provides sustaining snowfall and thermal regulation, and the land, which provides a stable base and in many cases the elevation required to reach suitably cold conditions. Ice sheets and glaciers are distributed around the globe and can serve as potential indicators of past climate variability and current climatic trends. 9 refs.

  7. Designing for effective stationkeeping in ice

    E-Print Network [OSTI]

    Nørvåg, Kjetil

    Designing for effective stationkeeping in ice CeSOS Highlights and AMOS Visions Conference DP Ice loads Ice #12;Effective stationkeeping in ice 1. Effective ship design. 2. An effective Ice Management system. 3. Effective strategies for the DP control system to compensate ice forces. #12;Ice

  8. Global ice sheet modeling

    SciTech Connect (OSTI)

    Hughes, T.J.; Fastook, J.L. [Univ. of Maine, Orono, ME (United States). Institute for Quaternary Studies

    1994-05-01T23:59:59.000Z

    The University of Maine conducted this study for Pacific Northwest Laboratory (PNL) as part of a global climate modeling task for site characterization of the potential nuclear waste respository site at Yucca Mountain, NV. The purpose of the study was to develop a global ice sheet dynamics model that will forecast the three-dimensional configuration of global ice sheets for specific climate change scenarios. The objective of the third (final) year of the work was to produce ice sheet data for glaciation scenarios covering the next 100,000 years. This was accomplished using both the map-plane and flowband solutions of our time-dependent, finite-element gridpoint model. The theory and equations used to develop the ice sheet models are presented. Three future scenarios were simulated by the model and results are discussed.

  9. Ice Formation in Gas-Diffusion Layers

    E-Print Network [OSTI]

    Dursch, Thomas

    2013-01-01T23:59:59.000Z

    the University of California. Ice Formation in Gas-Diffusionsub-freezing conditions, ice forms in the gas-diffusionstrategies exist to prevent ice formation, there is little

  10. Determining solar abundances using helioseismology

    E-Print Network [OSTI]

    H. M. Antia; Sarbani Basu

    2006-02-28T23:59:59.000Z

    The recent downward revision of solar photospheric abundances of Oxygen and other heavy elements has resulted in serious discrepancies between solar models and solar structure as determined through helioseismology. In this work we investigate the possibility of determining the solar heavy-element abundance without reference to spectroscopy by using helioseismic data. Using the dimensionless sound-speed derivative in the solar convection zone, we find that the heavy element abundance, Z, of 0.0172 +/- 0.002, which is closer to the older, higher value of the abundances.

  11. Ice Heating Up Cold Clouds | EMSL

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

    Ice Heating Up Cold Clouds Ice Heating Up Cold Clouds Released: October 04, 2011 In a heated battle, ice crystals win the competition for cloud water vapor The mighty cloud ice...

  12. Coherent radar ice thickness measurements over the Greenland ice sheet

    E-Print Network [OSTI]

    Gogineni, S. Prasad; Tammana, Dilip; Braaten, David A.; Leuschen, C.; Legarsky, J.; Kanagaratnam, P.; Stiles, J.; Allen, C.; Jezek, K.; Akins, T.

    2001-12-27T23:59:59.000Z

    We developed two 150-MHz coherent radar depth sounders for ice thickness measurements over the Greenland ice sheet. We developed one of these using connectorized components and the other using radio frequency integrated circuits (RFICs). Both...

  13. Hail ice impact on composite structures at glancing angles

    E-Print Network [OSTI]

    Funai, Sho

    2012-01-01T23:59:59.000Z

    investigation of high velocity ice impacts on woven carbon/and ice sphere. .by trailing ice fragments. ..

  14. Onset of Deconfinement in Nucleus-Nucleus Collisions - Past, Present and Future -

    E-Print Network [OSTI]

    Marek Gazdzicki

    2007-12-18T23:59:59.000Z

    In 2007 Mark I. Gorenstein celebrated his 60th birthday. This report is dedicated to Mark and it sketches the results obtained during the past ten years of our collaboration and friendship. They concern search for and study of the onset of deconfinement in high energy nucleus-nucleus collisions.

  15. Actomyosin contractility rotates the cell nucleus

    E-Print Network [OSTI]

    Abhishek Kumar; Ananyo Maitra; Madhuresh Sumit; Sriram Ramaswamy; G. V. Shivashankar

    2013-09-14T23:59:59.000Z

    The nucleus of the eukaryotic cell functions amidst active cytoskeletal filaments, but its response to the stresses carried by these filaments is largely unexplored. We report here the results of studies of the translational and rotational dynamics of the nuclei of single fibroblast cells, with the effects of cell migration suppressed by plating onto fibronectin-coated micro-fabricated patterns. Patterns of the same area but different shapes and/or aspect ratio were used to study the effect of cell geometry on the dynamics. On circles, squares and equilateral triangles, the nucleus undergoes persistent rotational motion, while on high-aspect-ratio rectangles of the same area it moves only back and forth. The circle and the triangle showed respectively the largest and the smallest angular speed. We show that our observations can be understood through a hydrodynamic approach in which the nucleus is treated as a highly viscous inclusion residing in a less viscous fluid of orientable filaments endowed with active stresses. Lowering actin contractility selectively by introducing blebbistatin at low concentrations drastically reduced the speed and persistence time of the angular motion of the nucleus. Time-lapse imaging of actin revealed a correlated hydrodynamic flow around the nucleus, with profile and magnitude consistent with the results of our theoretical approach. Coherent intracellular flows and consequent nuclear rotation thus appear to be a generic property that cells must balance by specific mechanisms in order to maintain nuclear homeostasis.

  16. Image Content Engine (ICE)

    SciTech Connect (OSTI)

    Brase, J M

    2007-03-26T23:59:59.000Z

    The Image Content Engine (ICE) is being developed to provide cueing assistance to human image analysts faced with increasingly large and intractable amounts of image data. The ICE architecture includes user configurable feature extraction pipelines which produce intermediate feature vector and match surface files which can then be accessed by interactive relational queries. Application of the feature extraction algorithms to large collections of images may be extremely time consuming and is launched as a batch job on a Linux cluster. The query interface accesses only the intermediate files and returns candidate hits nearly instantaneously. Queries may be posed for individual objects or collections. The query interface prompts the user for feedback, and applies relevance feedback algorithms to revise the feature vector weighting and focus on relevant search results. Examples of feature extraction and both model-based and search-by-example queries are presented.

  17. Gd Transition Probabilities and Abundances

    E-Print Network [OSTI]

    E. A. Den Hartog; J. E. Lawler; C. Sneden; J. J. Cowan

    2006-09-18T23:59:59.000Z

    Radiative lifetimes, accurate to +/- 5%, have been measured for 49 even-parity and 14 odd-parity levels of Gd II using laser-induced fluorescence. The lifetimes are combined with branching fractions measured using Fourier transform spectrometry to determine transition probabilities for 611 lines of Gd II. This work is the largest-scale laboratory study to date of Gd II transition probabilities and the first using a high performance Fourier transform spectrometer. This improved data set has been used to determine a new solar photospheric Gd abundance, log epsilon = 1.11 +/- 0.03. Revised Gd abundances have also been derived for the r-process-rich metal-poor giant stars CS 22892-052, BD+17 3248, and HD 115444. The resulting Gd/Eu abundance ratios are in very good agreement with the solar-system r-process ratio. We have employed the increasingly accurate stellar abundance determinations, resulting in large part from the more precise laboratory atomic data, to predict directly the Solar System r-process elemental abundances for Gd, Sm, Ho and Nd. Our analysis of the stellar data suggests slightly higher recommended values for the r-process contribution and total Solar System values, consistent with the photospheric determinations, for the elements for Gd, Sm, and Ho.

  18. Ice Cover on the Great Lakes NATIONALOCEANIC

    E-Print Network [OSTI]

    Ice Cover on the Great Lakes NATIONALOCEANIC AND ATMOSPHERIC ADMINISTRATION U.S. D EPARTMENT OF COMM ER CE Great Lakes Ice Cover facts since 1973 - 94.7% ice coverage in 1979 is the maximum on record - 9.5% ice coverage in 2002 is the lowest on record - 11.5% ice coverage in 1998, a strong El Nino

  19. Engineering Notes Ice Shape Characterization Using

    E-Print Network [OSTI]

    Tino, Peter

    Engineering Notes Ice Shape Characterization Using Self-Organizing Maps Stephen T. McClain Baylor. Introduction DURING the validation and verification of ice accretion codes, predicted ice shapes must be compared with experimental measurements of wind-tunnel or atmospheric ice shapes. Current methods for ice

  20. Hidden force floating ice

    E-Print Network [OSTI]

    Chang Q. Sun

    2015-01-17T23:59:59.000Z

    Because of the segmental specific-heat disparity of the hydrogen bond (O:H-O) and the Coulomb repulsion between oxygen ions, cooling elongates the O:H-O bond at freezing by stretching its containing angle and shortening the H-O bond with an association of larger O:H elongation, which makes ice less dense than water, allowing it to float.

  1. Ice Storm Supercomputer

    ScienceCinema (OSTI)

    None

    2013-05-28T23:59:59.000Z

    "A new Idaho National Laboratory supercomputer is helping scientists create more realistic simulations of nuclear fuel. Dubbed 'Ice Storm,' this 2048-processor machine allows researchers to model and predict the complex physics behind nuclear reactor behavior. And with a new visualization lab, the team can see the results of its simulations on the big screen." For more information about INL research, visit http://www.facebook.com/idahonationallaboratory.

  2. Greenland Ice Sheet Retreat Since the Little Ice Age

    E-Print Network [OSTI]

    Beitch, Marci Jillian

    2014-01-01T23:59:59.000Z

    and I. Willis (2012), Greenland's shrinking ice cover: "fastfluctuations in southeast Greenland, Nat. Geosci. , 5(6),T. Decker (2011), Analysis of Greenland marine- terminating

  3. Ice Mass Balance Buoy: An Instrument to Measure and Attribute Changes in Ice Thickness

    E-Print Network [OSTI]

    Geiger, Cathleen

    Ice Mass Balance Buoy: An Instrument to Measure and Attribute Changes in Ice Thickness Jacqueline A the Ice Mass Balance buoy (IMB) in response to the need for monitoring changes in the thickness of the Arctic sea ice cover. The IMB is an autonomous, ice-based system. IMB buoys provide a time series of ice

  4. NOTES AND CORRESPONDENCE Surface Melting over Ice Shelves and Ice Sheets as Assessed from Modeled

    E-Print Network [OSTI]

    Meissner, Katrin Juliane

    NOTES AND CORRESPONDENCE Surface Melting over Ice Shelves and Ice Sheets as Assessed from Modeled of ice shelves and their progenitor ice sheets. To explore the magnitude of surface melt occurring over modern ice shelves and ice sheets in a climate scenario forced by anthropogenic emissions of carbon

  5. Low energy antiproton-nucleus interactions

    SciTech Connect (OSTI)

    Clover, M.R.; DeVries, R.M.; DiGiacomo, N.J.; Yariv, Y.

    1982-11-01T23:59:59.000Z

    The interaction of 175-MeV antiprotons with nuclei is examined within the intranuclear cascade model. The experimental characteristics of nucleon-antinucleon annihilation and scattering are used as input, and the propagation of the resultant pions thru the nucleus is treated realistically. The effect of the antiproton-nucleus strong attraction is also included. Overall characteristics of antiproton annihilation within nuclei, particularly the large, well-defined energy deposition, indicate that such collisions constitute a unique laboratory for the study of nuclei at very high excitations. The calculations also identify promising experimental observables and triggers.

  6. ICE Pulse Oximeter Smart Alarm App Requirements

    E-Print Network [OSTI]

    Huth, Michael

    ICE Pulse Oximeter Smart Alarm App Requirements 6 March 2012 Revision 0 for an Integrated Clinical Environment (ICE) pulse oximetry monitoring app that provides.2 References [Purpose: List all ICE standards, and other standards and references

  7. ICE Raids: Compounding Production, Contradiction, and Capitalism

    E-Print Network [OSTI]

    Reas, Elizabeth I

    2009-01-01T23:59:59.000Z

    is just a cheap way of boosting ICE ‘criminal alien’ arrestRegardless of whether or not ICE is motivated by maintainingWorkers in America: Factories and ICE Raids Produce Citizens

  8. The ice sheet model The polythermal ice sheet

    E-Print Network [OSTI]

    Calov, Reinhard

    with a temperature at the pressure melting point, the latter being considered as a bi- nary mixture of ice and small a year. Sediment Sliding The sliding velocity over sediment reads which applies if the basal ice Hudson Bay and Hudson Strait has become temperate (see Figure 4d,e), fast basal sliding appears leading

  9. Hf Transition Probabilities and Abundances

    E-Print Network [OSTI]

    J. E. Lawler; E. A. Den Hartog; Z. E. Labby; C. Sneden; J. J. Cowan; I. I. Ivans

    2006-11-01T23:59:59.000Z

    Radiative lifetimes from laser-induced fluorescence measurements, accurate to about +/- 5 percent, are reported for 41 odd-parity levels of Hf II. The lifetimes are combined with branching fractions measured using Fourier transform spectrometry to determine transition probabilities for 150 lines of Hf II. Approximately half of these new transition probabilities overlap with recent independent measurements using a similar approach. The two sets of measurements are found to be in good agreement for measurements in common. Our new laboratory data are applied to refine the hafnium photospheric solar abundance and to determine hafnium abundances in 10 metal-poor giant stars with enhanced r-process abundances. For the Sun we derive log epsilon (Hf) = 0.88 +/- 0.08 from four lines; the uncertainty is dominated by the weakness of the lines and their blending by other spectral features. Within the uncertainties of our analysis, the r-process-rich stars possess constant Hf/La and Hf/Eu abundance ratios, log epsilon (Hf/La) = -0.13 +/- 0.02 (sigma = 0.06) and log epsilon (Hf/Eu) = +0.04 +/- 0.02 (sigma = 0.06). The observed average stellar abundance ratio of Hf/Eu and La/Eu is larger than previous estimates of the solar system r-process-only value, suggesting a somewhat larger contribution from the r-process to the production of Hf and La. The newly determined Hf values could be employed as part of the chronometer pair, Th/Hf, to determine radioactive stellar ages.

  10. Therapeutic Hypothermia: Protective Cooling Using Medical Ice...

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

    Therapeutic Hypothermia: Protective Cooling Using Medical Ice Slurry Technology available for licensing: Proprietary method and equipment for making an ice slurry coolant to induce...

  11. Sandia National Laboratories: critical marginal ice zone

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

    marginal ice zone NASA Award for Marginal Ice Zone Observations and Process Experiment (MIZOPEX) On February 24, 2015, in Analysis, Climate, Modeling & Analysis, Monitoring, News,...

  12. Sandia National Laboratories: Marginal Ice Zone Observations...

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

    Marginal Ice Zone Observations and Processes Experiment mission Sierra Unmanned Aerial Vehicle to Begin Flights Over Arctic Sea Ice On July 25, 2013, in Climate, Customers &...

  13. Sandia National Laboratories: Arctic sea ice

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

    Arctic sea ice Sierra Unmanned Aerial Vehicle to Begin Flights Over Arctic Sea Ice On July 25, 2013, in Climate, Customers & Partners, Global, Monitoring, News, News & Events,...

  14. ARM - Ice Cores

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006Datastreamstwrcam40m DocumentationJanuary 9, 2009 [Events, FeatureListGeneralPastIce Cores Outreach Home Room

  15. ARM - Measurement - Ice nuclei

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP : XDC documentationBarrow,ice particleSize Distributiontypes ARMnuclei

  16. ARM - Measurement - Column Ozone Abundance

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP : XDC documentationBarrow,ice particle ARM DatagovMeasurementsColumn

  17. Dynamics of ice shelf rift propagation and iceberg calving inferred from geodetic and seismic observations

    E-Print Network [OSTI]

    Bassis, Jeremy N.

    2007-01-01T23:59:59.000Z

    2. Ice Shelves . . . . . . . . . . . . . . . . .5. Ice Rheology . . . . . . . . . . . . . 6.vi Calving Glaciers and Ice

  18. MEAT, POULTRY, Still contains ice

    E-Print Network [OSTI]

    Liskiewicz, Maciej

    MEAT, POULTRY, SEAFOOD Still contains ice crystals and feels as cold, and ground meats Refreeze Discard Poultry and ground poultry Refreeze Discard Variety meats may safely re-freeze foods that s:ll contain ice crystals or that have been

  19. Element Abundances at High Redshifts

    E-Print Network [OSTI]

    Max Pettini

    1999-02-11T23:59:59.000Z

    I review measurements of element abundances in different components of the high redshift universe, including the Lyman alpha forest, damped Lyman alpha systems, and Lyman break galaxies. Although progress is being made in all three areas, recent work has also produced some surprises and shown that established ideas about the nature of the damped Lyman alpha systems in particular may be too simplistic. Overall, our knowledge of metal abundances at high z is still very sketchy. Most significantly, there seems to be an order of magnitude shortfall in the comoving density of metals which have been measured up to now compared with those produced by the star formation activity seen in Lyman break galaxies. At least some of the missing metals are likely to be in hot gas in galactic halos and proto-clusters.

  20. Sm Transition Probabilities and Abundances

    E-Print Network [OSTI]

    J. E. Lawler; E. A. Den Hartog; C. Sneden; J. J. Cowan

    2005-10-19T23:59:59.000Z

    Radiative lifetimes, accurate to +/- 5%, have been measured for 212 odd-parity levels of Sm II using laser-induced fluorescence. The lifetimes are combined with branching fractions measured using Fourier-transform spectrometry to determine transition probabilities for more than 900 lines of Sm II. This work is the largest-scale laboratory study to date of Sm II transition probabilities using modern methods. This improved data set has been used to determine a new solar photospheric Sm abundance, log epsilon = 1.00 +/- 0.03, from 26 lines. The spectra of three very metal-poor, neutron-capture-rich stars also have been analyzed, employing between 55 and 72 Sm II lines per star. The abundance ratios of Sm relative to other rare earth elements in these stars are in agreement, and are consistent with ratios expected from rapid neutron-capture nucleosynthesis (the r-process).

  1. r-Process Abundance Signatures

    E-Print Network [OSTI]

    J. J. Cowan; C. Sneden

    2002-12-05T23:59:59.000Z

    Abundance observations indicate the presence of rapid-neutron capture (i.e., r-process) elements in old Galactic halo and globular cluster stars. These observations demonstrate that the earliest generations of stars in the Galaxy, responsible for neutron-capture synthesis and the progenitors of the halo stars, were rapidly evolving. Abundance comparisons among large numbers of stars provide clues about the nature of neutron-capture element synthesis both during the earliest times and throughout the history of the Galaxy. In particular, these comparisons suggest differences in the way the heavier (including Ba and above) and lighter neutron capture elements are synthesized in nature. Understanding these differences will help to identify the astrophysical site (or sites) of and conditions in the r-process. The abundance comparisons also demonstrate a large star-to-star scatter in the neutron-capture/iron ratios at low metallicities- which disappears with increasing [Fe/H]- and suggests an early, chemically unmixed and inhomogeneous Galaxy. The very recent neutron-capture element observations indicate that the early phases of Galactic nucleosynthesis, and the associated chemical evolution, are quite complex, with the yields from different (progenitor) mass-range stars contributing to different chemical mixes. Stellar abundance comparisons suggest a change from the r-process to the slow neutron capture (i.e., s-) process at higher metallicities (and later times) in the Galaxy. Finally, the detection of thorium and uranium in halo and globular cluster stars offers a promising, independent age-dating technique that can put lower limits on the age of the Galaxy and thus the Universe.

  2. Electron Abundance in Protostellar Cores

    E-Print Network [OSTI]

    Paolo Padoan; Karen Willacy; William Langer; Mika Juvela

    2004-06-23T23:59:59.000Z

    The determination of the fractional electron abundance, Xe, in protostellar cores relies on observations of molecules, such as DCO+, H13CO+ and CO, and on chemical models to interpret their abundance. Studies of protostellar cores have revealed significant variations of Xe from core to core within a range 10^-8abundance from core to core as the combined effect of visual extinction and age variations. The range of electron abundances predicted by the models is relatively insenstive to density over 10^4 to 10^6 cm^{-3}.

  3. Nucleus-nucleus potential with shell-correction contribution and deep sub-barrier fusion of heavy nuclei

    E-Print Network [OSTI]

    V. Yu. Denisov

    2014-04-04T23:59:59.000Z

    It is suggested that the full nucleus-nucleus potential consists of the macroscopic and shell-correction parts. The deep sub-barrier fusion hindrance takes place in a nucleus-nucleus system with a strong negative shell-correction contribution to the full heavy-ion potential, while a strong positive shell-correction contribution to the full potential leads to weak enhancement of the deep sub-barrier fusion cross section.

  4. The oxygen abundance distribution in M101

    E-Print Network [OSTI]

    L. S. Pilyugin

    2001-05-07T23:59:59.000Z

    The well-observed spiral galaxy M101 was considered. The radial distributions of oxygen abundances determined in three different ways (with the classic Te - method, with the R23 - method, and with the P -- method) were compared. It was found that the parameters (the central oxygen abundance and the gradient) of the radial O/H(P) abundance distribution are close to those of the O/H(Te) abundance distribution. The parameters of the O/H(R23) abundance distribution differ significantly from those of the O/H(Te) abundance distribution: the central O/H(R23) oxygen abundance is higher by around 0.4dex and the gradient is steeper by a factor of around 1.5 as compared to those values in the O/H(Te) abundance distribution. The dispersion in O/H(P) abundance at fixed radius is rather small, around 0.08 dex, and is equal to that in O/H(Te) abundance. The dispersion in O/H(R23) abundance at fixed radius is appreciably larger, around 0.16 dex, compared to that in O/H(Te) abundance. It has been shown that the extra dispersion in O/H(R23) abundances is an artifact and reflects scatter in excitation parameter P at fixed radius.

  5. Global simulations of ice nucleation and ice supersaturation with an improved cloud scheme in the Community

    E-Print Network [OSTI]

    Gettelman, Andrew

    and supersaturation in CAM. The new model is able to reproduce field observations of ice mass and mixed phase cloud are sensitive to the parameterization of ice clouds. These results indicate that ice clouds are potentiallyGlobal simulations of ice nucleation and ice supersaturation with an improved cloud scheme

  6. Assimilation of Ice Concentration in an IceOcean Model R. W. LINDSAY AND J. ZHANG

    E-Print Network [OSTI]

    Zhang, Jinlun

    are now available to determine the ice drift velocity. In addition, the drift of the pack ice can CoAssimilation of Ice Concentration in an Ice­Ocean Model R. W. LINDSAY AND J. ZHANG Polar Science October 2004, in final form 27 June 2005) ABSTRACT Ice concentration is a critical parameter of the polar

  7. Sea-ice thickness measurement based on the dispersion of ice swell

    E-Print Network [OSTI]

    -year pack ice, although other char- acteristics (Young's modulus, shear modulus, and Poisson coefficientSea-ice thickness measurement based on the dispersion of ice swell David Marsana) ISTerre, CNRS propagating in the Arctic sea ice cover is exploited in order to locally measure the ice thickness

  8. Impact of underwater-ice evolution on Arctic summer sea ice

    E-Print Network [OSTI]

    Worster, M. Grae

    Impact of underwater-ice evolution on Arctic summer sea ice Dirk Notz,1,4 Miles G. McPhee,2 M. Grae the simultaneous growth and ablation of a layer of ice between an under-ice melt pond and the underlying ocean. Such ``false bottoms'' are the only significant source of ice formation in the Arctic during summer. Analytical

  9. Electrical properties of saline ices and ice-silicate mixtures: geophysical and astrobiological consequences (Invited)

    E-Print Network [OSTI]

    Stillman, David E.

    MR22A-05 Electrical properties of saline ices and ice-silicate mixtures: geophysical) electrical-properties measurements of laboratory- produced saline ice, salt hydrates, and ice-silicate cutoff. In ice-silicate mixtures, brine channels are evident above the eutectic temperature only when

  10. 2011-12 PROSPECTUS2011-12 PROSPECTUS WESLEYAN MEN'S ICE HOCKEYWESLEYAN MEN'S ICE HOCKEY

    E-Print Network [OSTI]

    Devoto, Stephen H.

    - ponents in its inaugural season. Former bench boss Dave Snyder, in whose honor the Wesleyan ice rink2011-12 PROSPECTUS2011-12 PROSPECTUS WESLEYAN MEN'S ICE HOCKEYWESLEYAN MEN'S ICE HOCKEY #12....................................Chris Potter/Jeff Gilarde Men's Ice Hockey..............Chris Potter Women's Ice Hockey.........Jodi Mc

  11. Actomyosin contractility rotates the cell nucleus

    E-Print Network [OSTI]

    Kumar, Abhishek; Sumit, Madhuresh; Ramaswamy, Sriram; Shivashankar, G V

    2013-01-01T23:59:59.000Z

    The nucleus of the eukaryotic cell functions amidst active cytoskeletal filaments, but its response to the stresses carried by these filaments is largely unexplored. We report here the results of studies of the translational and rotational dynamics of the nuclei of single fibroblast cells, with the effects of cell migration suppressed by plating onto fibronectin-coated micro-fabricated patterns. Patterns of the same area but different shapes and/or aspect ratio were used to study the effect of cell geometry on the dynamics. On circles, squares and equilateral triangles, the nucleus undergoes persistent rotational motion, while on high-aspect-ratio rectangles of the same area it moves only back and forth. The circle and the triangle showed respectively the largest and the smallest angular speed. We show that our observations can be understood through a hydrodynamic approach in which the nucleus is treated as a highly viscous inclusion residing in a less viscous fluid of orientable filaments endowed with active...

  12. Mathematics of Sea Ice K. M. Golden

    E-Print Network [OSTI]

    Golden, Kenneth M.

    , the sharp decline of the summer Arc- tic sea ice pack is probably the most dramatic. For example, the area and 1990's. While global climate models generally predict de- clines in the polar sea ice packs over the 21, such as the growth and decay of seasonal ice, the evolu- tion of ice pack reflectance, and biomass build

  13. 4, 709732, 2007 Ice-shelf ocean

    E-Print Network [OSTI]

    Boyer, Edmond

    OSD 4, 709­732, 2007 Ice-shelf ­ ocean interactions at Fimbul Ice Shelf M. R. Price Title Page published in Ocean Science Discussions are under open-access review for the journal Ocean Science Ice-shelf ­ ocean interactions at Fimbul Ice Shelf, Antarctica from oxygen isotope ratio measurements M. R. Price 1

  14. Climate Change and Variability Lake Ice, Fishes

    E-Print Network [OSTI]

    Sheridan, Jennifer

    #12;Climate Change and Variability Lake Ice, Fishes and Water Levels John J. Magnuson Center to everything else." #12;The Invisible Present The Invisible Place Magnuson 2006 #12;Ice-on Day 2007 Peter W. Schmitz Photo Local Lake Mendota #12;Ice Breakup 2010 Lake Mendota March 20 #12;March 21 Ice Breakup 2010

  15. Abundance measurements in stellar environments

    SciTech Connect (OSTI)

    Leone, F. [Università di Catania, Dipartimento di Fisica e Astronomia, Sezione Astrofisica, Via S. Sofia 78, 95123 Catania (Italy)

    2014-05-09T23:59:59.000Z

    Most of what we know about stars, and systems of stars, is derived from the analysis of their electromagnetic radiation. This lesson is an attempt to describe to Physicists, without any Astrophysical background, the framework to understand the present status of abundance determination in stellar environments and its limit. These notes are dedicated to the recently passed, November 21, 2013, Prof. Dimitri Mihalas who spent his life confuting the 19th century positivist philosopher Auguste Comte who stated that we shall not at all be able to determine the chemical composition of stars.

  16. Abundant Power | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual Siteof Energy 2,AUDITCaliforniaWeifangwiki HomeASN Power ProjectsAbraham HotAbundant Power

  17. Neglecting ice-atmosphere interactions underestimates ice sheet melt in millennial-scale deglaciation simulations

    E-Print Network [OSTI]

    Pritchard, M. S.; Bush, A. B.; Marshall, S. J.

    2008-01-01T23:59:59.000Z

    Laurentide and Innutian ice sheets during the Last Glacialclimate of the laurentide ice sheet at the LGM, J. Clim. ,1958), The flow law of ice: A discussion of the assumptions

  18. An experimental and theoretical study of the ice accretion process during artificial and natural icing conditions

    E-Print Network [OSTI]

    Kirby, Mark Samuel

    1986-01-01T23:59:59.000Z

    Real-time measurements of ice growth during artificial and natural icing conditions were conducted using an ultrasonic pulse-echo technique. This technique allows ice thickness to be measured with an accuracy of ?0.5 mm; ...

  19. Journal of Glaciology, Vol. 56, No. 199, 2010 805 Enhancement factors for grounded ice and ice shelves inferred

    E-Print Network [OSTI]

    Gagliardini, Olivier

    shelves inferred from an anisotropic ice-flow model Ying MA,1 Olivier GAGLIARDINI,1 Catherine RITZ,1 on the actual state of stress and strain rate. Within an ice sheet, grounded-ice parts and ice shelves have of ice anisotropy on the flow of grounded ice and ice shelves. For this purpose, a full

  20. Journal of Glaciology, Vol. 00, No. 000, 0000 1 Enhancement factors for grounded ice and ice shelves1

    E-Print Network [OSTI]

    Durand, Gaël

    shelves1 inferred from an anisotropic ice flow model2 Ying MA,1 Olivier GAGLIARDINI,1 Catherine RITZ,1 of stress and strain-rate. Within an ice sheet, grounded ice parts and ice shelves have com-11 pletely of ice anisotropy on the flow of grounded ice and ice shelves. To this pur-14 pose, a full

  1. Method of forming clathrate ice

    DOE Patents [OSTI]

    Hino, Toshiyuki (Tokyo, JP); Gorski, Anthony J. (Lemont, IL)

    1987-01-01T23:59:59.000Z

    A method of forming clathrate ice in a supercooled water-based liquid contained in a vessel is disclosed. Initially, an oscillator device is located in the liquid in the vessel. The oscillator device is then oscillated ultrasonically so that small crystals are formed in the liquid. These small crystals serve as seed crystals for ice formation in the liquid and thereby prevent supercooling of the liquid. Preferably, the oscillating device is controlled by a thermostat which initiates operation of the oscillator device when the temperature of the liquid is lowered to the freezing point. Thereafter, the operation of the oscillator device is terminated when ice is sensed in the liquid by an ice sensor.

  2. Method of forming calthrate ice

    DOE Patents [OSTI]

    Hino, T.; Gorski, A.J.

    1985-09-30T23:59:59.000Z

    A method of forming clathrate ice in a supercooled water-based liquid contained in a vessel is disclosed. Initially, an oscillator device is located in the liquid in the vessel. The oscillator device is then oscillated ultransonically so that small crystals are formed in the liquid. Thes small crystals serve as seed crystals for ice formation in the liquid and thereby prevent supercooling of the liquid. Preferably, the oscillating device is controlled by a thermostat which initiates operation of the oscillator device when the temperature of the liquid is lowered to the freezing point. Thereafter, the operation of the oscillator device is terminated when ice is sensed in the liquid by an ice sensor.

  3. Surface abundances of ON stars

    E-Print Network [OSTI]

    Martins, F; Palacios, A; Howarth, I; Georgy, C; Walborn, N R; Bouret, J -C; Barba, R

    2015-01-01T23:59:59.000Z

    Massive stars burn hydrogen through the CNO cycle during most of their evolution. When mixing is efficient, or when mass transfer in binary systems happens, chemically processed material is observed at the surface of O and B stars. ON stars show stronger lines of nitrogen than morphologically normal counterparts. Whether this corresponds to the presence of material processed through the CNO cycle or not is not known. Our goal is to answer this question. We perform a spectroscopic analysis of a sample of ON stars with atmosphere models. We determine the fundamental parameters as well as the He, C, N, and O surface abundances. We also measure the projected rotational velocities. We compare the properties of the ON stars to those of normal O stars. We show that ON stars are usually helium-rich. Their CNO surface abundances are fully consistent with predictions of nucleosynthesis. ON stars are more chemically evolved and rotate - on average - faster than normal O stars. Evolutionary models including rotation cann...

  4. amorphous water ice: Topics by E-print Network

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

    artificial and natural icing conditions MIT - DSpace Summary: Real-time measurements of ice growth during artificial and natural icing conditions were conducted using an...

  5. amery ice shelf: Topics by E-print Network

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

    artificial and natural icing conditions MIT - DSpace Summary: Real-time measurements of ice growth during artificial and natural icing conditions were conducted using an...

  6. amorphous ice transition: Topics by E-print Network

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

    artificial and natural icing conditions MIT - DSpace Summary: Real-time measurements of ice growth during artificial and natural icing conditions were conducted using an...

  7. antarctica larsen ice: Topics by E-print Network

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

    artificial and natural icing conditions MIT - DSpace Summary: Real-time measurements of ice growth during artificial and natural icing conditions were conducted using an...

  8. alpine deep ice: Topics by E-print Network

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

    artificial and natural icing conditions MIT - DSpace Summary: Real-time measurements of ice growth during artificial and natural icing conditions were conducted using an...

  9. airborne ice sounding: Topics by E-print Network

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

    artificial and natural icing conditions MIT - DSpace Summary: Real-time measurements of ice growth during artificial and natural icing conditions were conducted using an...

  10. Analysis of nucleus-nucleus collisions at high energies and Random Matrix Theory

    E-Print Network [OSTI]

    R. G. Nazmitdinov; E. I. Shahaliev; M. K. Suleymanov; S. Tomsovic

    2009-05-07T23:59:59.000Z

    We propose a novel statistical approach to the analysis of experimental data obtained in nucleus-nucleus collisions at high energies which borrows from methods developed within the context of Random Matrix Theory. It is applied to the detection of correlations in momentum distributions of emitted particles. We find good agreement between the results obtained in this way and a standard analysis based on the method of effective mass spectra and two-pair correlation function often used in high energy physics. The method introduced here is free from unwanted background contributions.

  11. Abundance Ratios in Early-Type Galaxies

    E-Print Network [OSTI]

    Reynier Peletier

    1999-04-21T23:59:59.000Z

    Although evidence is accumulating that abundance ratios in galaxies are often non-solar, they are far from understood. I resume the current evidence for non-solar abundance ratios, supplementing the recent review by Worthey (1998) with some new results. It appears that the Mg/Fe abundance ratio only depends on the mass of the galaxy, not on the formation time-scale. For massive galaxies [Mg/Fe] > 0, while small galaxies show solar abundance ratios. Information about abundances of other element is scarce, but new evidence is given that [Ca/Fe] is solar, or slightly lower than solar, contrary to what is expected for an alpha-element.

  12. Recent results on (anti)nucleus and (anti)hyperon production in nucleus-nucleus collisions at CERN SPS energies

    E-Print Network [OSTI]

    Melkumov, G L; Anticic, T; Baatar, B; Barna, D; Bartke, J; Betev, L; Bialkowska, H; Blume, C; Boimska, B; Botje, M; Bracinik, J; Bramm, R; Buncic, P; Cerny, V; Christakoglou, P; Chung, P; Chvala, O; Cramer, J G; Csató, P; Dinkelaker, P; Eckardt, V; Flierl, D; Fodor, Z; Foka, P; Friese, V; Gál, J; Gazdzicki, M; Genchev, V; Georgopoulos, G; Grebieszkow, K; Hegyi, S; Höhne, C; Kadija, K; Karev, A; Kikola, D; Gladysz-Dziadus, E; Kliemant, M; Kniege, S; Kolesnikov, V I; Kornas, E; Korus, R; Kowalski, M; Kraus, I; Kreps, M; Laszlo, A; Lacey, R; Van Leeuwen, M; Lvai, P; Litov, L; Lungwitz, B; Makariev, M; Malakhov, A I; Mateev, M; Melkumov, G L; Mischke, A; Mitrovski, M; Molnár, J; Mrówczynski, S; Nicolic, V; Pálla, G; Panagiotou, A D; Panayotov, D; Petridis, A; Peryt, W; Pikna, M; Pluta, J; Prindle, D; Pühlhofer, F; Renfordt, R; Roland, C; Roland5, G; Rybczynski, M; Rybicki, A; Sandoval, A; Schmitz, N; Schuster, T; Siklér, F; Sitár, B; Skrzypczak, E; Slodkowski, M; Stefanek, G; Stock, R; Seyboth, P; Strabel, C; Ströbele, H; Susa, T; Szentpetery, I; Sziklai, J; Szuba, M; Szymanski, P; Trubnikov, V; Varga, D; Vassiliou, M; Veres, G I; Vesztergombi, G; Vranic, D; Wlodarczyk, Z; Wojtaszek11, A; Yoo, I K; Zimnyi, J; Wetzler, A

    2007-01-01T23:59:59.000Z

    The NA49 experiment has collected comprehensive data on particle production in nucleus-nucleus collisions over the whole SPS beam energies range, the critical energy domain where the expected phase transition to a deconfined phase is expected to occur. The latest results from Pb+Pb collisions between 20$A$ GeV and 158$A$ GeV on baryon stopping and light nuclei production as well as those for strange hyperons are presented. The measured data on $p$, $\\bar{p}$, $\\Lambda$, $\\bar{\\Lambda}$, $\\Xi^-$ and $\\bar{\\Xi}^+$ production were used to evaluate the rapidity distributions of net-baryons at SPS energies and to compare with the results from the AGS and the RHIC for central Pb+Pb (Au+Au) collisions. The dependence of the yield ratios and the inverse slope parameter of the $m_t$ spectra on the collision energy and centrality, and the mass number of the produced nuclei $^3He$, $t$, $d$ and $\\bar{d}$ are discussed within coalescence and statistical approaches. Analysis of the total multiplicity exhibits remarkable a...

  13. Angular distributions of neutron-nucleus collisions

    SciTech Connect (OSTI)

    Mukhopadhyay, Tapan; Lahiri, Joydev; Basu, D. N. [Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata 700 064 (India)

    2011-06-15T23:59:59.000Z

    We derive the total and the differential cross sections with respect to angle for neutron-induced reactions from an analytical model having a simple functional form to demonstrate the quantitative agreement with the measured cross sections. The energy dependence of the neutron-nucleus interaction cross sections are estimated successfully for energies ranging from 5 to 600 MeV. In this work, the effect of the imaginary part of the nuclear potential is treated more appropriately compared to our earlier work. The angular distributions for neutron scattering also agree reasonably well with the experimental data at forward angles.

  14. BNL-65424-AB LIQUID TO LIQUID AND CRITICAL NUCLEUS TO CRITICAL NUCLEUS PHASE

    E-Print Network [OSTI]

    sulfate solution droplet in order to study its effect on the nucleation process. We find that a CaCO3 is increased to 1.86. The ammonium sulfate critical nucleus that forms on the 250nm CaCO3 impurity is composed

  15. Vapor deposition of water on graphitic surfaces: Formation of amorphous ice, bilayer ice, ice I, and liquid water

    SciTech Connect (OSTI)

    Lupi, Laura; Kastelowitz, Noah; Molinero, Valeria, E-mail: Valeria.Molinero@utah.edu [Department of Chemistry, The University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112-0850 (United States)

    2014-11-14T23:59:59.000Z

    Carbonaceous surfaces are a major source of atmospheric particles and could play an important role in the formation of ice. Here we investigate through molecular simulations the stability, metastability, and molecular pathways of deposition of amorphous ice, bilayer ice, and ice I from water vapor on graphitic and atomless Lennard-Jones surfaces as a function of temperature. We find that bilayer ice is the most stable ice polymorph for small cluster sizes, nevertheless it can grow metastable well above its region of thermodynamic stability. In agreement with experiments, the simulations predict that on increasing temperature the outcome of water deposition is amorphous ice, bilayer ice, ice I, and liquid water. The deposition nucleation of bilayer ice and ice I is preceded by the formation of small liquid clusters, which have two wetting states: bilayer pancake-like (wetting) at small cluster size and droplet-like (non-wetting) at larger cluster size. The wetting state of liquid clusters determines which ice polymorph is nucleated: bilayer ice nucleates from wetting bilayer liquid clusters and ice I from non-wetting liquid clusters. The maximum temperature for nucleation of bilayer ice on flat surfaces, T{sub B}{sup max} is given by the maximum temperature for which liquid water clusters reach the equilibrium melting line of bilayer ice as wetting bilayer clusters. Increasing water-surface attraction stabilizes the pancake-like wetting state of liquid clusters leading to larger T{sub B}{sup max} for the flat non-hydrogen bonding surfaces of this study. The findings of this study should be of relevance for the understanding of ice formation by deposition mode on carbonaceous atmospheric particles, including soot.

  16. NOAA Technical Memorandum GLERL-135 Great Lakes Ice Cover Climatology

    E-Print Network [OSTI]

    ____________________________________________________________________________ Great Lakes Ice Cover Climatology Update: Winters 2003, 2004, and 2005 Raymond A. Assel NOAA, Great..................................................................................................6 DATES OF FIRST (LAST) ICE AND ICE DURATION. .............................................................7 SEASONAL PROGRESSION OF ICE COVER

  17. Jefferson Lab - Final State Nucleons for Neutrino-Nucleus Interactions

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

    LBNF) could not succeed without better understanding of neutrino-nucleus interactions. Neutrino physics requires nuclear physics input in order to properly constrain its leading...

  18. Ross Ice Shelf in situ radio-frequency ice attenuation

    E-Print Network [OSTI]

    Taylor Barrella; Steven Barwick; David Saltzberg

    2012-05-01T23:59:59.000Z

    We have measured the in situ average electric field attenuation length for radio-frequency signals broadcast vertically through the Ross Ice Shelf. We chose a location, Moore Embayment, south of Minna Bluff, known for its high reflectivity at the ice-sea interface. We confirmed specular reflection and used the return pulses to measure the average attenuation length from 75-1250 MHz over the round-trip distance of 1155 m. We find the average electric field attenuation length to vary from 500 m at 75 MHz to 300 m at 1250 MHz, with an experimental uncertainty of 55 to 15 m. We discuss the implications for neutrino telescopes that use the radio technique and include the Ross Ice Shelf as part of their sensitive volume.

  19. Ice-condenser aerosol tests

    SciTech Connect (OSTI)

    Ligotke, M.W.; Eschbach, E.J.; Winegardner, W.K. (Pacific Northwest Lab., Richland, WA (United States))

    1991-09-01T23:59:59.000Z

    This report presents the results of an experimental investigation of aerosol particle transport and capture using a full-scale height and reduced-scale cross section test facility based on the design of the ice compartment of a pressurized water reactor (PWR) ice-condenser containment system. Results of 38 tests included thermal-hydraulic as well as aerosol particle data. Particle retention in the test section was greatly influenced by thermal-hydraulic and aerosol test parameters. Test-average decontamination factor (DF) ranged between 1.0 and 36 (retentions between {approximately}0 and 97.2%). The measured test-average particle retentions for tests without and with ice and steam ranged between DF = 1.0 and 2.2 and DF = 2.4 and 36, respectively. In order to apparent importance, parameters that caused particle retention in the test section in the presence of ice were steam mole fraction (SMF), noncondensible gas flow rate (residence time), particle solubility, and inlet particle size. Ice-basket section noncondensible flows greater than 0.1 m{sup 3}/s resulted in stable thermal stratification whereas flows less than 0.1 m{sup 3}/s resulted in thermal behavior termed meandering with frequent temperature crossovers between flow channels. 10 refs., 66 figs., 16 tabs.

  20. Stellar abundances of beryllium and CUBES

    E-Print Network [OSTI]

    Smiljanic, R

    2014-01-01T23:59:59.000Z

    Stellar abundances of beryllium are useful in different areas of astrophysics, including studies of the Galactic chemical evolution, of stellar evolution, and of the formation of globular clusters. Determining Be abundances in stars is, however, a challenging endeavor. The two Be II resonance lines useful for abundance analyses are in the near UV, a region strongly affected by atmospheric extinction. CUBES is a new spectrograph planned for the VLT that will be more sensitive than current instruments in the near UV spectral region. It will allow the observation of fainter stars, expanding the number of targets where Be abundances can be determined. Here, a brief review of stellar abundances of Be is presented together with a discussion of science cases for CUBES. In particular, preliminary simulations of CUBES spectra are presented, highlighting its possible impact in investigations of Be abundances of extremely metal-poor stars and of stars in globular clusters.

  1. Spatial mapping of ices in the Oph-F core: A direct measurement of CO depletion and the formation of CO2

    E-Print Network [OSTI]

    K. M. Pontoppidan

    2006-05-22T23:59:59.000Z

    Aims: Ices in dense star-forming cores contain the bulk of volatile molecules apart from H2 and thus represent a large fraction of dark cloud chemistry budget.To directly constrain the freeze-out profile of CO, the formation route of CO2 and the carrier of the 6.8 micron band, the spatial distribution of the CO/CO2 ice system and the 6.8 micron band carrier are measured in a nearby dense core. Methods: VLT-ISAAC, ISOCAM-CVF and Spitzer-IRS archival mid-infrared (3-20 micron) spectroscopy of young stellar objects is used to construct a map of the abundances of CO and CO2 ices in the Oph-F star-forming core, probing core radii from 2 10^3 to 14 10^3 AU or densities from 5 10^4 to 5 10^5 cm^-3 with a resolution of ~ 3000 AU. Results: The line-of-sight averaged abundances relative to water ice of both CO and CO2 ices increase monotonously with decreasing distance to the core center. The map traces the shape of the CO abundance profile between freeze-out ratios of 5-60% and shows that the CO2 ice abundance increases by a factor of 2 as the CO freezes out. It is suggested that this indicates a formation route of CO2 on a CO ice surface to produce a CO2 component dilute in CO ice, in addition to a fraction of the CO2 formed at lower densities along with the water ice mantle. It is predicted that the CO2 bending mode band profile should reflect a high CO:CO2 number ratio in the densest parts of dark clouds. In contrast to CO and CO2, the abundance of the carrier of the 6.8 micron band remains relatively constant throughout the core. A simple freeze-out model of the CO abundance profile is used to estimate the binding energy of CO on a CO ice surface to 814+/-30 K.

  2. Neutrino Physics and the Primordial Elemental Abundances

    E-Print Network [OSTI]

    Christian Y. Cardall; George M. Fuller

    1997-01-31T23:59:59.000Z

    Limits can be placed on nonstandard neutrino physics when big bang nucleosynthesis (BBN) calculations employing standard neutrino physics agree with the observationally inferred primordial abundances of deuterium (D), $^3$He, $^4$He, and $^7$Li. These constraints depend most sensitively on the abundances of D and $^4$He. New observational determinations of the primordial D and/or $^4$He abundances could force revisions in BBN constraints on nonstandard neutrino physics.

  3. The discrepancy between solar abundances and helioseismology

    E-Print Network [OSTI]

    H. M. Antia; Sarbani Basu

    2005-01-07T23:59:59.000Z

    There have been recent downward revisions of the solar photospheric abundances of Oxygen and other heavy elements. These revised abundances along with OPAL opacities are not consistent with seismic constraints. In this work we show that the recently released OP opacity tables cannot resolve this discrepancy either. While the revision in opacities does not seem to resolve this conflict, an upward revision of Neon abundance in solar photosphere offers a possible solution to this problem.

  4. Heavy ion irradiation of crystalline water ice

    E-Print Network [OSTI]

    Dartois, E; Boduch, P; Brunetto, R; Chabot, M; Domaracka, A; Ding, J J; Kamalou, O; Lv, X Y; Rothard, H; da Silveira, E F; Thomas, J C

    2015-01-01T23:59:59.000Z

    Under cosmic irradiation, the interstellar water ice mantles evolve towards a compact amorphous state. Crystalline ice amorphisation was previously monitored mainly in the keV to hundreds of keV ion energies. We experimentally investigate heavy ion irradiation amorphisation of crystalline ice, at high energies closer to true cosmic rays, and explore the water-ice sputtering yield. We irradiated thin crystalline ice films with MeV to GeV swift ion beams, produced at the GANIL accelerator. The ice infrared spectral evolution as a function of fluence is monitored with in-situ infrared spectroscopy (induced amorphisation of the initial crystalline state into a compact amorphous phase). The crystalline ice amorphisation cross-section is measured in the high electronic stopping-power range for different temperatures. At large fluence, the ice sputtering is measured on the infrared spectra, and the fitted sputtering-yield dependence, combined with previous measurements, is quadratic over three decades of electronic ...

  5. Thermal Storage with Ice Harvesting Systems

    E-Print Network [OSTI]

    Knebel, D. E.

    1986-01-01T23:59:59.000Z

    Application of Harvesting Ice Storage Systems. Thermal storage systems are becoming widely accepted techniques for utility load management. This paper discusses the principles of ice harvesting equipment and their application to the multi...

  6. Quantum Ice : a quantum Monte Carlo study

    E-Print Network [OSTI]

    Nic Shannon; Olga Sikora; Frank Pollmann; Karlo Penc; Peter Fulde

    2011-12-13T23:59:59.000Z

    Ice states, in which frustrated interactions lead to a macroscopic ground-state degeneracy, occur in water ice, in problems of frustrated charge order on the pyrochlore lattice, and in the family of rare-earth magnets collectively known as spin ice. Of particular interest at the moment are "quantum spin ice" materials, where large quantum fluctuations may permit tunnelling between a macroscopic number of different classical ground states. Here we use zero-temperature quantum Monte Carlo simulations to show how such tunnelling can lift the degeneracy of a spin or charge ice, stabilising a unique "quantum ice" ground state --- a quantum liquid with excitations described by the Maxwell action of 3+1-dimensional quantum electrodynamics. We further identify a competing ordered "squiggle" state, and show how both squiggle and quantum ice states might be distinguished in neutron scattering experiments on a spin ice material.

  7. Rubber friction on ice and snow surfaces 

    E-Print Network [OSTI]

    Skouvaklis, Gerasimos

    2011-06-28T23:59:59.000Z

    The friction of rubber on ice and snow surfaces is complex. Deeper scientific understanding is important for optimising performance of tyres in winter. Rubber, ice and snow systems exhibit frictional behaviour which ...

  8. Developing Great Lakes Ice Model (GLIM) using CIOM (Coupled Ice-Ocean Model) in Lake Erie

    E-Print Network [OSTI]

    Developing Great Lakes Ice Model (GLIM) using CIOM (Coupled Ice- Ocean Model) in Lake Erie Primary of the ice-ocean models, assistance with development of project reports and scientific presentations will first start the implementation of the CIOM in Lake Erie, assemble satellite observations of ice cover

  9. Ice Stream C slowdown is not stabilizing West Antarctic Ice Sheet S Anandakrishnan RB Alleyy

    E-Print Network [OSTI]

    Jacobel, Robert W.

    Ice Stream C slowdown is not stabilizing West Antarctic Ice Sheet S Anandakrishnan RB Alleyy RW Jacobelz H Conwayx March 24, 1999 Abstract Changes in the flow of ice stream C likely indicate a continuing part of ice stream C, West Antarctica largely stagnated over the last few centuries, while upglacier

  10. Quenched by ice: Transient grating measurements of vibronic dynamics in bromine-doped ice

    E-Print Network [OSTI]

    Apkarian, V. Ara

    Quenched by ice: Transient grating measurements of vibronic dynamics in bromine-doped ice I. U April 2006; published online 25 May 2006 In both water and in ice, the absorption spectra of bromine of the trapped molecule in its electronic B 3 0u state in ice. Independent of the initial excitation energy

  11. New study details glacier ice loss following ice shelf July 25, 2011

    E-Print Network [OSTI]

    Cambridge, University of

    of several ice shelves in Antarctica led to acceleration of the glaciers that feed into them. CombiningNew study details glacier ice loss following ice shelf collapse July 25, 2011 Contact: Anthony Lane further demonstrates how important ice shelves are to Antarctic glaciers.' Shuman is lead author

  12. 115GLACIERS AND ICE CAPSCHAPTER 6B Glaciers and Ice Caps

    E-Print Network [OSTI]

    Fountain, Andrew G.

    115GLACIERS AND ICE CAPSCHAPTER 6B 6B Glaciers and Ice Caps Michael Zemp (lead author, Department of Sciences, China) #12;116 GLOBAL OUTLOOK FOR ICE AND SNOW Summary Glaciers and ice caps are among the most hazards. Because they are close to the melting point and react strongly to climate change, glaciers

  13. Modeling the Jovian subnebula: II - Composition of regular satellites ices

    E-Print Network [OSTI]

    Olivier Mousis; Yann Alibert

    2005-10-28T23:59:59.000Z

    We use the evolutionary turbulent model of Jupiter's subnebula described by Alibert et al. (2005a) to constrain the composition of ices incorporated in its regular icy satellites. We consider CO2, CO, CH4, N2, NH3, H2S, Ar, Kr, and Xe as the major volatile species existing in the gas-phase of the solar nebula. All these volatile species, except CO2 which crystallized as a pure condensate, are assumed to be trapped by H2O to form hydrates or clathrate hydrates in the solar nebula. Once condensed, these ices were incorporated into the growing planetesimals produced in the feeding zone of proto-Jupiter. Some of these solids then flowed from the solar nebula to the subnebula, and may have been accreted by the forming Jovian regular satellites. We show that ices embedded in solids entering at early epochs into the Jovian subdisk were all vaporized. This leads us to consider two different scenarios of regular icy satellites formation in order to estimate the composition of the ices they contain. In the first scenario, icy satellites were accreted from planetesimals that have been produced in Jupiter's feeding zone without further vaporization, whereas, in the second scenario, icy satellites were accreted from planetesimals produced in the Jovian subnebula. In this latter case, we study the evolution of carbon and nitrogen gas-phase chemistries in the Jovian subnebula and we show that the conversions of N2 to NH3, of CO to CO2, and of CO to CH4 were all inhibited in the major part of the subdisk. Finally, we assess the mass abundances of the major volatile species with respect to H2O in the interiors of the Jovian regular icy satellites. Our results are then compatible with the detection of CO2 on the surfaces of Callisto and Ganymede and with the presence of NH3 envisaged in subsurface oceans within Ganymede and Callisto.

  14. Laser-Nucleus Interactions: The Quasiadiabatic Regime

    E-Print Network [OSTI]

    Pálffy, Adriana; Hoefer, Axel; Weidenmüller, Hans A

    2015-01-01T23:59:59.000Z

    The interaction between nuclei and a strong zeptosecond laser pulse with coherent MeV photons is investigated theoretically. We provide a first semi-quantitative study of the quasiadiabatic regime where the photon absorption rate is comparable to the nuclear equilibration rate. In that regime, multiple photon absorption leads to the formation of a compound nucleus in the so-far unexplored regime of excitation energies several hundred MeV above the yrast line. The temporal dynamics of the process is investigated by means of a set of master equations that account for dipole absorption, stimulated dipole emission, neutron decay and induced fission in a chain of nuclei. That set is solved numerically by means of state-of-the-art matrix exponential methods also used in nuclear fuel burnup and radioactivity transport calculations. Our quantitative estimates predict the excitation path and range of nuclei reached by neutron decay and provide relevant information for the layout of future experiments.

  15. Delta-nucleus dynamics: proceedings of symposium

    SciTech Connect (OSTI)

    Lee, T.S.H.; Geesaman, D.F.; Schiffer, J.P. (eds.)

    1983-10-01T23:59:59.000Z

    The appreciation of the role in nuclear physics of the first excited state of the nucleon, the delta ..delta..(1232), has grown rapidly in the past decade. The delta resonance dominates nuclear reactions induced by intermediate energy pions, nucleons, and electromagnetic probes. It is also the most important non-nucleonic degree of freedom needed to resolve many fundamental problems encountered in the study of low-energy nuclear phenomena. Clearly, a new phase of nuclear physics has emerged and conventional thinking must be extended to account for this new dimension of nuclear dynamics. The most challenging problem we are facing is how a unified theory can be developed to describe ..delta..-nucleus dynamics at all energies. In exploring this new direction, it is important to have direct discussions among researchers with different viewpoints. Separate entries were prepared for the 49 papers presented. (WHK)

  16. Laser-Nucleus Interactions: The Quasiadiabatic Regime

    E-Print Network [OSTI]

    Adriana Pálffy; Oliver Buss; Axel Hoefer; Hans A. Weidenmüller

    2015-06-12T23:59:59.000Z

    The interaction between nuclei and a strong zeptosecond laser pulse with coherent MeV photons is investigated theoretically. We provide a first semi-quantitative study of the quasiadiabatic regime where the photon absorption rate is comparable to the nuclear equilibration rate. In that regime, multiple photon absorption leads to the formation of a compound nucleus in the so-far unexplored regime of excitation energies several hundred MeV above the yrast line. The temporal dynamics of the process is investigated by means of a set of master equations that account for dipole absorption, stimulated dipole emission, neutron decay and induced fission in a chain of nuclei. That set is solved numerically by means of state-of-the-art matrix exponential methods also used in nuclear fuel burnup and radioactivity transport calculations. Our quantitative estimates predict the excitation path and range of nuclei reached by neutron decay and provide relevant information for the layout of future experiments.

  17. Photochemistry of the PAH pyrene in water ice: the case for ion-mediated solid-state astrochemistry

    E-Print Network [OSTI]

    Bouwman, J; Bakker, A; Allamandola, L J; Linnartz, H

    2009-01-01T23:59:59.000Z

    Context. Icy dust grains play an important role in the formation of complex inter- and circumstellar molecules. Observational studies show that polycyclic aromatic hydrocarbons (PAHs) are abundantly present in the ISM in the gas phase. It is likely that these non-volatile species freeze out onto dust grains as well and participate in the astrochemical solid-state network, but experimental PAH ice studies are largely lacking. Methods. Near UV/VIS spectroscopy is used to track the in situ VUV driven photochemistry of pyrene containing ices at temperatures ranging from 10 to 125 K. Results. The main photoproducts of VUV photolyzed pyrene ices are spectroscopically identified and their band positions are listed for two host ices, \\water and CO. Pyrene ionisation is found to be most efficient in \\water ices at low temperatures. The reaction products, triplet pyrene and the 1-hydro-1-pyrenyl radical are most efficiently formed in higher temperature water ices and in low temperature CO ice. Formation routes and band...

  18. Formation and character of an ancient 19-m ice cover and underlying trapped brine in an ``ice-sealed'' east

    E-Print Network [OSTI]

    Priscu, John C.

    Formation and character of an ancient 19-m ice cover and underlying trapped brine in an ``ice bed year-round. New ice-core analysis and tempera- ture data show that beneath 19 m of ice is a water°C. The ice cover thickens at both its base and surface, sealing concentrated brine beneath. The ice

  19. Ice Cream in a Bag Ingredients

    E-Print Network [OSTI]

    Liskiewicz, Maciej

    Ice Cream in a Bag Ingredients: 1 tablespoon sugar 1/4 teaspoon vanilla extract 2 tablespoons soft fruit 1/2 cup skim milk For the freezer bag; not to be eaten: 1/3 cup rock salt Ice cubes Directions 1. Open a gallon size plastic bag. Add rock salt and fill half way up with ice. Shake to mix the salt

  20. 3, 9991020, 2007 Summer sea ice

    E-Print Network [OSTI]

    Boyer, Edmond

    CPD 3, 999­1020, 2007 Summer sea ice during the early Holocene H. Goosse et al. Title Page Abstract on the early Holocene climate constrains the summer sea ice projections for the 21st century H. Goosse, E #12;CPD 3, 999­1020, 2007 Summer sea ice during the early Holocene H. Goosse et al. Title Page

  1. 2, 879921, 2006 Ice-sheet evolution

    E-Print Network [OSTI]

    Boyer, Edmond

    CPD 2, 879­921, 2006 Ice-sheet evolution during the last climatic cycle S. Charbit et al. Title reconstructions of the Northern Hemisphere ice sheets through the last glacial-interglacial cycle S. Charbit1 , C­921, 2006 Ice-sheet evolution during the last climatic cycle S. Charbit et al. Title Page Abstract

  2. Surface Impedance Tomography for Antarctic Sea Ice

    E-Print Network [OSTI]

    Golden, Kenneth M.

    Surface Impedance Tomography for Antarctic Sea Ice C. Sampsona , K. M. Goldena , A. Gullya , A. P, Australia Abstract During the 2007 SIPEX expedition in pack ice off the coast of East Antarctica, we measured the electrical conductivity of sea ice via surface impedance tomography. Resistance data from

  3. 8, 87438771, 2008 Inhibition of ice

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    ACPD 8, 8743­8771, 2008 Inhibition of ice crystallisation B. J. Murray Title Page Abstract Chemistry and Physics Discussions Inhibition of ice crystallisation in highly viscous aqueous organic acid­8771, 2008 Inhibition of ice crystallisation B. J. Murray Title Page Abstract Introduction Conclusions

  4. 5, 37233745, 2005 characteristics of ice

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    ACPD 5, 3723­3745, 2005 Chemical characteristics of ice nuclei in anvil cirrus clouds C. H. Twohy and Physics Discussions Chemical characteristics of ice residual nuclei in anvil cirrus clouds: evidence for homogeneous and heterogeneous ice formation C. H. Twohy 1 and M. R. Poellot 2 1 College of Oceanic

  5. The convective desalination of sea ice

    E-Print Network [OSTI]

    Rees Jones, David

    2014-07-01T23:59:59.000Z

    containing both liquid brine and solid (pure water) ice. Frad is the flux of penetrating solar radiation. Thus the thermal properties of sea ice are composed of those of the solid and liquid phases that make up sea ice. Fixed-salinity models used in older...

  6. IceCube Project Monthly Report Accomplishments

    E-Print Network [OSTI]

    Saffman, Mark

    staff from UW, IceCube collaborators, and Raytheon. · Conducted a Quarterly Status Meeting at UW-loaded schedule for on-ice activities that is coordinated with the Raytheon on-ice schedules. Construction Cost accurate application of escalation rates and revisions to actual cost data. Raytheon earned value data

  7. COMMUNICATION Are Residues in a Protein Folding Nucleus

    E-Print Network [OSTI]

    Dai, Yang

    COMMUNICATION Are Residues in a Protein Folding Nucleus Evolutionarily Conserved? Yan Yuan Tseng is the hallmark of life. It is important to understand how protein folding and evolution influence each other in protein folding nucleus as measured by experi- mental f-value and selection pressure as measured by v

  8. Production of cold fragments in nucleus-nucleus collisions in the Fermi-energy domain

    E-Print Network [OSTI]

    M. Veselsky; G. A. Souliotis

    2006-11-06T23:59:59.000Z

    The reaction mechanism of nucleus-nucleus collisions at projectile energies around the Fermi energy is investigated with emphasis on the production of fragmentation-like residues. The results of simulations are compared to experimental mass distributions of elements with Z = 21 - 29 observed in the reactions 86Kr+124,112Sn at 25 AMeV. The model of incomplete fusion is modified and a component of excitation energy of the cold fragment dependent on isospin asymmetry is introduced. The modifications in the model of incomplete fusion appear consistent with both overall model framework and available experimental data. A prediction is provided for the production of very neutron-rich nuclei using a secondary beam of 132Sn where e.g. the reaction 132Sn+238U at 28 AMeV appears as a possible alternative to the use of fragmentation reactions at higher energies.

  9. Production of cold fragments in nucleus-nucleus collisions in the Fermi-energy domain

    E-Print Network [OSTI]

    Veselsky, M

    2007-01-01T23:59:59.000Z

    The reaction mechanism of nucleus-nucleus collisions at projectile energies around the Fermi energy is investigated with emphasis on the production of fragmentation-like residues. The results of simulations are compared to experimental mass distributions of elements with Z = 21 - 29 observed in the reactions 86Kr+124,112Sn at 25 AMeV. The model of incomplete fusion is modified and a component of excitation energy of the cold fragment dependent on isospin asymmetry is introduced. The modifications in the model of incomplete fusion appear consistent with both overall model framework and available experimental data. A prediction is provided for the production of very neutron-rich nuclei using a secondary beam of 132Sn where e.g. the reaction 132Sn+238U at 28 AMeV appears as a possible alternative to the use of fragmentation reactions at higher energies.

  10. Effects of CO2 on H2O band profiles and band strengths in mixed H2O:CO2 ices

    E-Print Network [OSTI]

    Karin I. Oberg; Helen J. Fraser; A. C. Adwin Boogert; Suzanne E. Bisschop; Guido W. Fuchs; Ewine F. van Dishoeck; Harold Linnartz

    2006-10-25T23:59:59.000Z

    H2O is the most abundant component of astrophysical ices. In most lines of sight it is not possible to fit both the H2O 3 um stretching, the 6 um bending and the 13 um libration band intensities with a single pure H2O spectrum. Recent Spitzer observations have revealed CO2 ice in high abundances and it has been suggested that CO2 mixed into H2O ice can affect relative strengths of the 3 um and 6 um bands. We used laboratory infrared transmission spectroscopy of H2O:CO2 ice mixtures to investigate the effects of CO2 on H2O ice spectral features at 15-135 K. We find that the H2O peak profiles and band strengths are significantly different in H2O:CO2 ice mixtures compared to pure H2O ice. In all H2O:CO2 mixtures, a strong free-OH stretching band appears around 2.73 um, which can be used to put an upper limit on the CO2 concentration in the H2O ice. The H2O bending mode profile also changes drastically with CO2 concentration; the broad pure H2O band gives way to two narrow bands as the CO2 concentration is increased. This makes it crucial to constrain the environment of H2O ice to enable correct assignments of other species contributing to the interstellar 6 um absorption band. The amount of CO2 present in the H2O ice of B5:IRS1 is estimated by simultaneously comparing the H2O stretching and bending regions and the CO2 bending mode to laboratory spectra of H2O, CO2, H2O:CO2 and HCOOH.

  11. On the oxygen abundance in our Galaxy

    E-Print Network [OSTI]

    L. S. Pilyugin; F. Ferrini; R. V. Shkvarun

    2003-02-03T23:59:59.000Z

    The compilation of published spectra of Galactic HII regions with available diagnostic [OIII]4363 line has been carried out. Our list contains 71 individual measurements of 13 HII regions in the range of galactocentric distances from 6.6 to 14.8 kpc. The oxygen abundances in all the HII regions were recomputed in the same way, using the classic Te - method. The oxygen abundance at the solar galactocentric distance traced by those HII regions is in agreement with the oxygen abundance in the interstellar medium in the solar vicinity derived with high precision from the interstellar absorption lines towards stars. The derived radial oxygen abundance distribution was compared with that for HII regions from the Shaver et al. (1983) sample which is the basis of many models for the chemical evolution of our Galaxy. It was found that the original Shaver et al.'s oxygen abundances are overestimated by 0.2-0.3 dex. Oxygen abundances in HII regions from the Shaver et al. sample have been redetermined with the recently suggested P - method. The radial distribution of oxygen abundances from the Shaver et al. sample redetermined with the P - method is in agreement with our radial distribution of (O/H)_Te abundances.

  12. On the solar nickel and oxygen abundances

    E-Print Network [OSTI]

    Pat Scott; Martin Asplund; Nicolas Grevesse; A. Jacques Sauval

    2009-01-27T23:59:59.000Z

    Determinations of the solar oxygen content relying on the neutral forbidden transition at 630 nm depend upon the nickel abundance, due to a Ni I blend. Here we rederive the solar nickel abundance, using the same ab initio 3D hydrodynamic model of the solar photosphere employed in the recent revision of the abundances of C, N, O and other elements. Using 17 weak, unblended lines of Ni I together with the most accurate atomic and observational data available we find log epsilon_Ni = 6.17 +/- 0.02 (statistical) +/- 0.05 (systematic), a downwards shift of 0.06 to 0.08 dex relative to previous 1D-based abundances. We investigate the implications of the new nickel abundance for studies of the solar oxygen abundance based on the [O I] 630 nm line in the quiet Sun. Furthermore, we demonstrate that the oxygen abundance implied by the recent sunspot spectropolarimetric study of Centeno & Socas-Navarro needs to be revised downwards from log epsilon_O = 8.86 +/- 0.07 to 8.71 +/- 0.10. This revision is based on the new nickel abundance, application of the best available gf-value for the 630 nm forbidden oxygen line, and a more transparent treatment of CO formation. Determinations of the solar oxygen content relying on forbidden lines now appear to converge around log epsilon_O = 8.7.

  13. Microwave emissivity of fresh water ice--Lake ice and Antarctic ice pack--Radiative transfer simulations versus satellite radiances

    E-Print Network [OSTI]

    Mills, Peter

    2012-01-01T23:59:59.000Z

    Microwave emissivity models of sea ice are poorly validated empirically. Typical validation studies involve using averaged or stereotyped profiles of ice parameters against averaged radiance measurements. Measurement sites are rarely matched and even less often point-by-point. Because of saline content, complex permittivity of sea ice is highly variable and difficult to predict. Therefore, to check the validity of a typical, plane-parallel, radiative-transfer-based ice emissivity model, we apply it to fresh water ice instead of salt-water ice. Radiance simulations for lake ice are compared with measurements over Lake Superior from the Advanced Microwave Scanning Radiometer on EOS (AMSR-E). AMSR-E measurements are also collected over Antarctic icepack. For each pixel, a thermodynamic model is driven by four years of European Center for Medium Range Weather Forecasts (ECMWF) reanalysis data and the resulting temperature profiles used to drive the emissivity model. The results suggest that the relatively simple ...

  14. Medical ice slurry production device

    DOE Patents [OSTI]

    Kasza, Kenneth E. (Palos Park, IL); Oras, John (Des Plaines, IL); Son, HyunJin (Naperville, IL)

    2008-06-24T23:59:59.000Z

    The present invention relates to an apparatus for producing sterile ice slurries for medical cooling applications. The apparatus is capable of producing highly loaded slurries suitable for delivery to targeted internal organs of a patient, such as the brain, heart, lungs, stomach, kidneys, pancreas, and others, through medical size diameter tubing. The ice slurry production apparatus includes a slurry production reservoir adapted to contain a volume of a saline solution. A flexible membrane crystallization surface is provided within the slurry production reservoir. The crystallization surface is chilled to a temperature below a freezing point of the saline solution within the reservoir such that ice particles form on the crystallization surface. A deflector in the form of a reciprocating member is provided for periodically distorting the crystallization surface and dislodging the ice particles which form on the crystallization surface. Using reservoir mixing the slurry is conditioned for easy pumping directly out of the production reservoir via medical tubing or delivery through other means such as squeeze bottles, squeeze bags, hypodermic syringes, manual hand delivery, and the like.

  15. Investigation of HNCO isomers formation in ice mantles by UV and thermal processing: an experimental approach

    E-Print Network [OSTI]

    Jiménez-Escobar, A; Caro, G M Muñoz; Cernicharo, J; Marcelino, N

    2014-01-01T23:59:59.000Z

    Current gas phase models do not account for the abundances of HNCO isomers detected in various environments, suggesting a formation in icy grain mantles. We attempted to study a formation channel of HNCO and its possible isomers by vacuum-UV photoprocessing of interstellar ice analogues containing H$_2$O, NH$_3$, CO, HCN, CH$_3$OH, CH$_4$, and N$_2$ followed by warm-up, under astrophysically relevant conditions. Only the H$_2$O:NH$_3$:CO and H$_2$O:HCN ice mixtures led to the production of HNCO species. The possible isomerization of HNCO to its higher energy tautomers following irradiation or due to ice warm-up has been scrutinized. The photochemistry and thermal chemistry of H$_2$O:NH$_3$:CO and H$_2$O:HCN ices was simulated using the Interstellar Astrochemistry Chamber (ISAC), a state-of-the-art ultra-high-vacuum setup. The ice was monitored in situ by Fourier transform mid-infrared spectroscopy in transmittance. A quadrupole mass spectrometer (QMS) detected the desorption of the molecules in the gas phase....

  16. Modeling Interfacial Liquid Layers in Environmental Ices SUPPLEMENTARY MATERIAL

    E-Print Network [OSTI]

    Meskhidze, Nicholas

    Symbol Quantity ice wf Fugacity of pure ice brine wf^ Fugacity of water in brine layer vap wf Fugacity of water in vapor space above ice wf Fugacity of pure liquid water wx Mole fraction of water in brine layer ice wH Enthalpy of ice at T, P 0,ice wH Enthalpy of ice at reference state brine wH Partial molar

  17. Helioseismological Implications of Recent Solar Abundance Determinations

    E-Print Network [OSTI]

    John N. Bahcall; Sarbani Basu; Marc Pinsonneault; Aldo M. Serenelli

    2004-09-26T23:59:59.000Z

    We show that standard solar models are in good agreement with the helioseismologically determined sound speed and density as a function of solar radius, the depth of the convective zone, and the surface helium abundance, as long as those models do not incorporate the most recent heavy element abundance determinations. However, sophisticated new analyses of the solar atmosphere infer lower abundances of the lighter metals (like C, N, O, Ne, and Ar) than the previously widely used surface abundances. We show that solar models that include the lower heavy element abundances disagree with the solar profiles of sound speed and density as well as the depth of the convective zone and the helium abundance. The disagreements for models with the new abundances range from factors of several to many times the quoted uncertainties in the helioseismological measurements. The disagreements are at temperatures below what is required for solar interior fusion reactions and therefore do not significantly affect solar neutrino emission. If errors in thecalculated OPAL opacities are solely responsible for the disagreements, then the corrections in the opacity must extend from 2 times 10^6 K (R = 0.7R_Sun)to 5 times 10^6 K (R = 0.4 R_Sun), with opacity increases of order 10%.

  18. WHITE PAPER ON PROTON - NUCLEUS COLLISONS.

    SciTech Connect (OSTI)

    ARONSON,S.H.; PENG,J.C.

    2001-03-01T23:59:59.000Z

    The role of proton-nucleus (p-A) collisions in the study of strong interactions has a long history. It has been an important testing ground for QCD. At RHIC p-A studies have been recognized since the beginning as important elements of the program. These include so-called baseline measurements in cold nuclear matter, essential (along with p-p studies) to a systematic study of QCD at high temperatures and densities in the search for the quark gluon plasma. Also accessible is a study of QCD in the small x (parton saturation) regime, complementary to physics accessible in high-energy e-p and e-A collisions. The role of p-A physics at RHIC was reviewed and brought into sharp focus at a workshop conducted in October 2000 at BNL; the agenda is shown in Appendix 1. This document summarizes the case for p-A at RHIC during the period covered by the next Nuclear Physics Long Range Plan. In subsequent sections we cover the Physics Issues, Experiment Run Plans and Schedule, Detector Upgrade Issues, and Machine Issues & Upgrades.

  19. On the solar abundance of indium

    E-Print Network [OSTI]

    N. Vitas; I. Vince; M. Lugaro; O. Andriyenko; M. Gosic; R. J. Rutten

    2007-11-14T23:59:59.000Z

    The generally adopted value for the solar abundance of indium is over six times higher than the meteoritic value. We address this discrepancy through numerical synthesis of the 451.13 nm line on which all indium abundance studies are based, both for the quiet-sun and the sunspot umbra spectrum, employing standard atmosphere models and accounting for hyperfine structure and Zeeman splitting in detail. The results, as well as a re-appraisal of indium nucleosynthesis, suggest that the solar indium abundance is close to the meteoritic value, and that some unidentified ion line causes the 451.13 nm feature in the quiet-sun spectrum.

  20. The confined hydrogen atom with a moving nucleus

    E-Print Network [OSTI]

    Francisco M. Fernandez

    2010-01-21T23:59:59.000Z

    We study the hydrogen atom confined to a spherical box with impenetrable walls but, unlike earlier pedagogical articles on the subject, we assume that the nucleus also moves. We obtain the ground-state energy approximately by means of first--order perturbation theory and by a more accurate variational approach. We show that it is greater than the one for the case in which the nucleus is clamped at the center of the box. Present approach resembles the well-known treatment of the helium atom with clamped nucleus.

  1. The Water Vapor Abundance in Orion KL Outflows

    E-Print Network [OSTI]

    J. Cernicharo; J. R. Goicoechea; F. Daniel; M. R. Lerate; M. J. Barlow; B. M. Swinyard; E. van Dishoeck; T. L. Lim; S. Viti; J. Yates

    2006-08-16T23:59:59.000Z

    We present the detection and modeling of more than 70 far-IR pure rotational lines of water vapor, including the 18O and 17O isotopologues, towards Orion KL. Observations were performed with the Long Wavelength Spectrometer Fabry-Perot (LWS/FP; R~6800-9700) on board the Infrared Space Observatory (ISO) between ~43 and ~197 um. The water line profiles evolve from P-Cygni type profiles (even for the H2O18 lines) to pure emission at wavelengths above ~100 um. We find that most of the water emission/absorption arises from an extended flow of gas expanding at 25+-5 kms^-1. Non-local radiative transfer models show that much of the water excitation and line profile formation is driven by the dust continuum emission. The derived beam averaged water abundance is 2-3x10^-5. The inferred gas temperature Tk=80-100 K suggests that: (i) water could have been formed in the "plateau" by gas phase neutral-neutral reactions with activation barriers if the gas was previously heated (e.g. by shocks) to >500 K and/or (ii) H2O formation in the outflow is dominated by in-situ evaporation of grain water-ice mantles and/or (iii) H2O was formed in the innermost and warmer regions (e.g. the hot core) and was swept up in ~1000 yr, the dynamical timescale of the outflow.

  2. New ice rules for nanoconfined monolayer ice from first principles

    E-Print Network [OSTI]

    Corsetti, Fabiano; Artacho, Emilio

    2015-01-01T23:59:59.000Z

    Understanding the structural tendencies of nanoconfined water is of great interest for nanoscience and biology, where nano/micro-sized objects may be separated by very few layers of water. Here we investigate the properties of ice confined to a quasi-2D monolayer by a featureless, chemically neutral potential, using density-functional theory simulations with a non-local van der Waals density functional. An ab initio random structure search reveals all the energetically competitive monolayer configurations to belong to only two of the previously-identified families, characterized by a square or honeycomb hydrogen-bonding network, respectively. From an in-depth analysis we show that the well-known ice rules for bulk ice need to be revised for the monolayer, with distinct new rules appearing for the two networks. All identified stable phases for both are found to be non-polar (but with a topologically non-trivial texture for the square) and, hence, non-ferroelectric, in contrast to the predictions of empirical f...

  3. The oxygen abundance deficiency in irregular galaxies

    E-Print Network [OSTI]

    L. S. Pilyugin; F. Ferrini

    2000-01-05T23:59:59.000Z

    The observed oxygen abundances in a number of irregular galaxies have been compared with predictions of the closed-box model of chemical and photometric evolution of galaxies. Oxygen is found to be deficient with respect to the predicted abundances. This is an indicator in favor of loss of heavy elements via galactic winds or/and of infall of low--abundance gas onto the galaxy. The oxygen abundance deficiency observed within the optical edge of a galaxy cannot be explained by mixing with the gas envelope observed outside the optical limit. We confirm the widespread idea that a significant part of the heavy elements is ejected by irregular galaxies in the intergalactic medium.

  4. Beryllium abundances in metal-poor stars

    E-Print Network [OSTI]

    K. F. Tan; J. R. Shi; G. Zhao

    2008-10-15T23:59:59.000Z

    We have determined beryllium abundances for 25 metal-poor stars based on the high resolution and high signal-to-noise ratio spectra from the VLT/UVES database. Our results confirm that Be abundances increase with Fe, supporting the global enrichment of Be in the Galaxy. Oxygen abundances based on [O I] forbidden line implies a linear relation with a slope close to one for the Be vs. O trend, which indicates that Be is probably produced in a primary process. Some strong evidences are found for the intrinsic dispersion of Be abundances at a given metallicity. The deviation of HD132475 and HD126681 from the general Be vs. Fe and Be vs. O trend favours the predictions of the superbubble model, though the possibility that such dispersion originates from the inhomogeneous enrichment in Fe and O of the protogalactic gas cannot be excluded.

  5. Liquid Water Oceans in Ice Giants

    E-Print Network [OSTI]

    Sloane J. Wiktorowicz; Andrew P. Ingersoll

    2006-09-26T23:59:59.000Z

    Aptly named, ice giants such as Uranus and Neptune contain significant amounts of water. While this water cannot be present near the cloud tops, it must be abundant in the deep interior. We investigate the likelihood of a liquid water ocean existing in the hydrogen-rich region between the cloud tops and deep interior. Starting from an assumed temperature at a given upper tropospheric pressure (the photosphere), we follow a moist adiabat downward. The mixing ratio of water to hydrogen in the gas phase is small in the photosphere and increases with depth. The mixing ratio in the condensed phase is near unity in the photosphere and decreases with depth; this gives two possible outcomes. If at some pressure level the mixing ratio of water in the gas phase is equal to that in the deep interior, then that level is the cloud base. Alternately, if the mixing ratio of water in the condensed phase reaches that in the deep interior, then the surface of a liquid ocean will occur. We find that Neptune is both too warm (photospheric temperature too high) and too dry (mixing ratio of water in the deep interior too low) for liquid oceans to exist at present. To have a liquid ocean, Neptune's deep interior water to gas ratio would have to be higher than current models allow, and the density at 19 kbar would have to be ~ 0.8 g/cm^3. Such a high density is inconsistent with gravitational data obtained during the Voyager flyby. As Neptune cools, the probability of a liquid ocean increases. Extrasolar "hot Neptunes," which presumably migrate inward toward their parent stars, cannot harbor liquid water oceans unless they have lost almost all of the hydrogen and helium from their deep interiors.

  6. Hydrogen ICE Vehicle Testing Activities

    SciTech Connect (OSTI)

    J. Francfort; D. Karner

    2006-04-01T23:59:59.000Z

    The Advanced Vehicle Testing Activity teamed with Electric Transportation Applications and Arizona Public Service to develop and monitor the operations of the APS Alternative Fuel (Hydrogen) Pilot Plant. The Pilot Plant provides 100% hydrogen, and hydrogen and compressed natural gas (H/CNG)-blended fuels for the evaluation of hydrogen and H/CNG internal combustion engine (ICE) vehicles in controlled and fleet testing environments. Since June 2002, twenty hydrogen and H/CNG vehicles have accumulated 300,000 test miles and 5,700 fueling events. The AVTA is part of the Department of Energy’s FreedomCAR and Vehicle Technologies Program. These testing activities are managed by the Idaho National Laboratory. This paper discusses the Pilot Plant design and monitoring, and hydrogen ICE vehicle testing methods and results.

  7. Sea Ice Enhancements to Polar WRF* Keith M. Hines1**

    E-Print Network [OSTI]

    Howat, Ian M.

    of Arctic multi-year ice is30 decreasing with more of the ice pack represented by seasonal sea iceSea Ice Enhancements to Polar WRF* Keith M. Hines1** , David H. Bromwich,1,2 , Lesheng Bai1 to6 WRF Version 3.4 include modified Noah land surface model sea ice treatment, allowing7 specified

  8. GREAT LAKES ICE COVER RaymondA. Asset'

    E-Print Network [OSTI]

    Chapter 6 GREAT LAKES ICE COVER RaymondA. Asset' ABSTRACT: Theformation of ice on the Lallrentian (~rthe Great Lakes anel local weather and climate. The (I1Inllal seasonal and ~'Patialprogression of ice Lake (Section 6.2) incillding ice thickness, the different types of iceformed, and ice classification

  9. An Ice Lithography Instrument Anpan Han 1, John Chervinsky2

    E-Print Network [OSTI]

    Page 1 An Ice Lithography Instrument Anpan Han 1, John Chervinsky2 , Daniel Branton3 , and J. A a new nano-patterning method called ice lithography, where ice is used as the resist. Water vapor. The vapor condenses, covering the sample with an amorphous layer of ice. To form a lift-off mask, ice

  10. Neutrino-nucleus reactions in the delta resonance region

    E-Print Network [OSTI]

    B. Szczerbinska; T. Sato; K. Kubodera; T. -S. H. Lee

    2007-05-27T23:59:59.000Z

    Reliable estimates of neutrino-nucleus reactions in the resonance-excitation region play an important role in many of the on-going and planned neutrino oscillation experiments. We study here neutrino-nucleus reactions in the delta-particle excitation region with the use of neutrino pion-production amplitudes calculated in a formalism in which the resonance contributions and the background amplitudes are treated on the same footing. Our approach leads to the neutrino-nucleus reaction cross sections that are significantly different from those obtained in the conventional approach wherein only the pure resonance amplitudes are taken into account. To assess the reliability of our formalism, we calculate the electron-nucleus scattering cross sections in the same theoretical framework; the calculated cross sections agree reasonably well with the existing data.

  11. Oxygen abundance of open cluster dwarfs

    E-Print Network [OSTI]

    Z. -X. Shen; X. -W. Liu; H. -W. Zhang; B. Jones; D. N. C. Lin

    2007-03-30T23:59:59.000Z

    We present oxygen abundances of dwarfs in the young open cluster IC 4665 deduced from the OI $\\lambda$7774 triplet lines and of dwarfs in the open cluster Pleiades derived from the [OI] $\\lambda$6300 forbidden line. Stellar parameters and oxygen abundances were derived using the spectroscopic synthesis tool SME (Spectroscopy Made Easy). We find a dramatic increase in the upper boundary of the OI triplet abundances with decreasing temperature in the dwarfs of IC 4665, consistent with the trend found by Schuler et al. in the open clusters Pleiades and M 34, and to a less extent in the cool dwarfs of Hyades (Schuler et al. 2006a) and UMa (King & Schuler 2005). By contrast, oxygen abundances derived from the [OI] $\\lambda$6300 forbidden line for stars in Pleiades and Hyades (Schuler et al. 2006b) are constant within the errors. Possible mechanisms that may lead a varying oxygen triplet line abundance are examined, including systematic errors in the stellar parameter determinations, the NLTE effects, surface activities and granulation. The age-related effects stellar surface activities (especially the chromospheric activities) are suggested by our analysis to blame for the large spreads of oxygen triplet line abundances.

  12. FAFCO Ice Storage test report

    SciTech Connect (OSTI)

    Stovall, T.K.

    1993-11-01T23:59:59.000Z

    The Ice Storage Test Facility (ISTF) is designed to test commercial ice storage systems. FAFCO provided a storage tank equipped with coils designed for use with a secondary fluid system. The FAFCO ice storage system was tested over a wide range of operating conditions. Measured system performance during charging showed the ability to freeze the tank fully, storing from 150 to 200 ton-h. However, the charging rate showed significant variations during the latter portion of the charge cycle. During discharge cycles, the storage tank outlet temperature was strongly affected by the discharge rate and tank state of charge. The discharge capacity was dependent upon both the selected discharge rate and maximum allowable tank outlet temperature. Based on these tests, storage tank selection must depend on both charge and discharge conditions. This report describes FAFCO system performance fully under both charging and discharging conditions. While the test results reported here are accurate for the prototype 1990 FAFCO Model 200, currently available FAFCO models incorporate significant design enhancements beyond the Model 200. At least one major modification was instituted as a direct result of the ISTF tests. Such design improvements were one of EPRI`s primary goals in founding the ISTF.

  13. Evaporation of alpha particles from $^31$P nucleus

    E-Print Network [OSTI]

    D. Bandyopadhyay; S. K. Basu; C. Bhattacharya; S. Bhattacharya; K. Krishan; A. Chatterjee; S. Kailas; A. Navin; A. Srivastava

    1998-07-24T23:59:59.000Z

    The energy spectra of alpha particles have been measured in coincidence with the evaporation residues for the decay of the compound nucleus $^31$P produced in the reaction $^19$F (96 MeV) + $^12$C. The data have been compared with the predictions of the statistical model code CASCADE. It has been observed that significant deformation effect in the compound nucleus need to be considered in order to explain the shape of the evaporated alpha particle energy spectra.

  14. Total neutron-nucleus cross sections and color transparency

    SciTech Connect (OSTI)

    Jennings, B.K. (TRIUMF, Vancouver, V6T2A3 (Canada)); Miller, G.A. (Nuclear Theory Group, Department of Physics, FM-15, University of Washington, Seattle, Washington 98195 (United States))

    1994-05-01T23:59:59.000Z

    The neutron-nucleus cross section at Fermi lab energies is computed using Glauber-Gribov multiple scattering theory. The effects of higher moments in the cross section fluctuations are included and their physical origin discussed. The validity of the frozen approximation is critically examined. These studies of the nucleon-nucleus total cross sections provide a test of the [ital pp][r arrow][ital Xp] diffractive amplitudes used in calculations of color transparency effects.

  15. Energy dependence of nucleus-nucleus potential close to the Coulomb barrier

    E-Print Network [OSTI]

    Kouhei Washiyama; Denis Lacroix

    2008-08-12T23:59:59.000Z

    The nucleus-nucleus interaction potentials in heavy-ion fusion reactions are extracted from the microscopic time-dependent Hartree-Fock theory for mass symmetric reactions $^{16}$O${}+^{16}$O, $^{40}$Ca${}+^{40}$Ca, $^{48}$Ca${}+^{48}$Ca and mass asymmetric reactions $^{16}$O$ +^{40,48}$Ca, $^{40}$Ca${}+^{48}$Ca, $^{16}$O+$^{208}$Pb, $^{40}$Ca+$^{90}$Zr. When the center-of-mass energy is much higher than the Coulomb barrier energy, potentials deduced with the microscopic theory identify with the frozen density approximation. As the center-of-mass energy decreases and approaches the Coulomb barrier, potentials become energy dependent. This dependence signs dynamical reorganization of internal degrees of freedom and leads to a reduction of the "apparent" barrier felt by the two nuclei during fusion of the order of $2-3 %$ compared to the frozen density case. Several examples illustrate that the potential landscape changes rapidly when the center-of-mass energy is in the vicinity of the Coulomb barrier energy. The energy dependence is expected to have a significant role on fusion around the Coulomb barrier.

  16. Energy-Dependence of Nucleus-Nucleus Potential and Friction Parameter in Fusion Reactions

    E-Print Network [OSTI]

    Kai Wen; Fumihiko Sakata; Zhu-Xia Li; Xi-Zhen Wu; Ying-Xun Zhang; Shan-Gui Zhou

    2014-11-08T23:59:59.000Z

    Applying a macroscopic reduction procedure on the improved quantum molecular dynamics (ImQMD) model, the energy dependences of the nucleus-nucleus potential, the friction parameter, and the random force characterizing a one-dimensional Langevin-type description of the heavy-ion fusion process are investigated. Systematic calculations with the ImQMD model show that the fluctuation-dissipation relation found in the symmetric head-on fusion reactions at energies just above the Coulomb barrier fades out when the incident energy increases. It turns out that this dynamical change with increasing incident energy is caused by a specific behavior of the friction parameter which directly depends on the microscopic dynamical process, i.e., on how the collective energy of the relative motion is transferred into the intrinsic excitation energy. It is shown microscopically that the energy dissipation in the fusion process is governed by two mechanisms: One is caused by the nucleon exchanges between two fusing nuclei, and the other is due to a rearrangement of nucleons in the intrinsic system. The former mechanism monotonically increases the dissipative energy and shows a weak dependence on the incident energy, while the latter depends on both the relative distance between two fusing nuclei and the incident energy. It is shown that the latter mechanism is responsible for the energy dependence of the fusion potential and explains the fading out of the fluctuation-dissipation relation.

  17. Measurement of South Pole ice transparency with the IceCube LED calibration system

    E-Print Network [OSTI]

    IceCube Collaboration; M. G. Aartsen; R. Abbasi; Y. Abdou; M. Ackermann; J. Adams; J. A. Aguilar; M. Ahlers; D. Altmann; J. Auffenberg; X. Bai; M. Baker; S. W. Barwick; V. Baum; R. Bay; J. J. Beatty; S. Bechet; J. Becker Tjus; K. -H. Becker; M. Bell; M. L. Benabderrahmane; S. BenZvi; J. Berdermann; P. Berghaus; D. Berley; E. Bernardini; A. Bernhard; D. Bertrand; D. Z. Besson; G. Binder; D. Bindig; M. Bissok; E. Blaufuss; J. Blumenthal; D. J. Boersma; S. Bohaichuk; C. Bohm; D. Bose; S. Böser; O. Botner; L. Brayeur; A. M. Brown; R. Bruijn; J. Brunner; S. Buitink; M. Carson; J. Casey; M. Casier; D. Chirkin; B. Christy; K. Clark; F. Clevermann; S. Cohen; D. F. Cowen; A. H. Cruz Silva; M. Danninger; J. Daughhetee; J. C. Davis; C. De Clercq; S. De Ridder; P. Desiati; M. de With; T. DeYoung; J. C. Díaz-Vélez; M. Dunkman; R. Eagan; B. Eberhardt; J. Eisch; R. W. Ellsworth; S. Euler; P. A. Evenson; O. Fadiran; A. R. Fazely; A. Fedynitch; J. Feintzeig; T. Feusels; K. Filimonov; C. Finley; T. Fischer-Wasels; S. Flis; A. Franckowiak; R. Franke; K. Frantzen; T. Fuchs; T. K. Gaisser; J. Gallagher; L. Gerhardt; L. Gladstone; T. Glüsenkamp; A. Goldschmidt; G. Golup; J. A. Goodman; D. Góra; D. Grant; A. Groß; M. Gurtner; C. Ha; A. Haj Ismail; A. Hallgren; F. Halzen; K. Hanson; D. Heereman; P. Heimann; D. Heinen; K. Helbing; R. Hellauer; S. Hickford; G. C. Hill; K. D. Hoffman; R. Hoffmann; A. Homeier; K. Hoshina; W. Huelsnitz; P. O. Hulth; K. Hultqvist; S. Hussain; A. Ishihara; E. Jacobi; J. Jacobsen; G. S. Japaridze; K. Jero; O. Jlelati; B. Kaminsky; A. Kappes; T. Karg; A. Karle; J. L. Kelley; J. Kiryluk; F. Kislat; J. Kläs; S. R. Klein; J. -H. Köhne; G. Kohnen; H. Kolanoski; L. Köpke; C. Kopper; S. Kopper; D. J. Koskinen; M. Kowalski; M. Krasberg; G. Kroll; J. Kunnen; N. Kurahashi; T. Kuwabara; M. Labare; H. Landsman; M. J. Larson; M. Lesiak-Bzdak; J. Leute; J. Lünemann; J. Madsen; R. Maruyama; K. Mase; H. S. Matis; F. McNally; K. Meagher; M. Merck; P. Mészáros; T. Meures; S. Miarecki; E. Middell; N. Milke; J. Miller; L. Mohrmann; T. Montaruli; R. Morse; R. Nahnhauer; U. Naumann; H. Niederhausen; S. C. Nowicki; D. R. Nygren; A. Obertacke; S. Odrowski; A. Olivas; M. Olivo; A. O'Murchadha; L. Paul; J. A. Pepper; C. Pérez de los Heros; C. Pfendner; D. Pieloth; N. Pirk; J. Posselt; P. B. Price; G. T. Przybylski; L. Rädel; K. Rawlins; P. Redl; E. Resconi; W. Rhode; M. Ribordy; M. Richman; B. Riedel; J. P. Rodrigues; C. Rott; T. Ruhe; B. Ruzybayev; D. Ryckbosch; S. M. Saba; T. Salameh; H. -G. Sander; M. Santander; S. Sarkar; K. Schatto; M. Scheel; F. Scheriau; T. Schmidt; M. Schmitz; S. Schoenen; S. Schöneberg; L. Schönherr; A. Schönwald; A. Schukraft; L. Schulte; O. Schulz; D. Seckel; S. H. Seo; Y. Sestayo; S. Seunarine; C. Sheremata; M. W. E. Smith; M. Soiron; D. Soldin; G. M. Spiczak; C. Spiering; M. Stamatikos; T. Stanev; A. Stasik; T. Stezelberger; R. G. Stokstad; A. Stößl; E. A. Strahler; R. Ström; G. W. Sullivan; H. Taavola; I. Taboada; A. Tamburro; S. Ter-Antonyan; S. Tilav; P. A. Toale; S. Toscano; M. Usner; D. van der Drift; N. van Eijndhoven; A. Van Overloop; J. van Santen; M. Vehring; M. Voge; M. Vraeghe; C. Walck; T. Waldenmaier; M. Wallraff; R. Wasserman; Ch. Weaver; M. Wellons; C. Wendt; S. Westerhoff; N. Whitehorn; K. Wiebe; C. H. Wiebusch; D. R. Williams; H. Wissing; M. Wolf; T. R. Wood; C. Xu; D. L. Xu; X. W. Xu; J. P. Yanez; G. Yodh; S. Yoshida; P. Zarzhitsky; J. Ziemann; S. Zierke; A. Zilles; M. Zoll

    2013-01-22T23:59:59.000Z

    The IceCube Neutrino Observatory, approximately 1 km^3 in size, is now complete with 86 strings deployed in the Antarctic ice. IceCube detects the Cherenkov radiation emitted by charged particles passing through or created in the ice. To realize the full potential of the detector, the properties of light propagation in the ice in and around the detector must be well understood. This report presents a new method of fitting the model of light propagation in the ice to a data set of in-situ light source events collected with IceCube. The resulting set of derived parameters, namely the measured values of scattering and absorption coefficients vs. depth, is presented and a comparison of IceCube data with simulations based on the new model is shown.

  18. Ice Shelf Water plume flow beneath Filchner-Ronne Ice Shelf, Antarctica

    E-Print Network [OSTI]

    Feltham, Daniel

    the thinning of Pine Island Glacier in West Antarctica and the collapse of parts of the Larsen Ice Shelf temperature variation is called the ``ice pump'' [Lewis and Perkin, 1983; Jenkins and Bombosch, 1995]. [5

  19. Controlling ice nucleation through surface hydrophilicity

    E-Print Network [OSTI]

    Stephen J. Cox; Shawn M. Kathmann; Ben Slater; Angelos Michaelides

    2015-01-08T23:59:59.000Z

    Ice formation is one of the most common and important processes on Earth and almost always occurs at the surface of a material. A basic understanding of how the physiochemical properties of a material's surface affects its ability to form ice has remained elusive. Here we use molecular dynamics simulations to directly probe heterogeneous ice nucleation at an hexagonal surface of a nanoparticle of varying hydrophilicity. Surprisingly, we find that structurally identical surfaces can both inhibit and promote ice formation and analogous to a chemical catalyst, it is found that an optimal interaction between the surface and the water exists for promoting ice nucleation. We use our microscopic understanding of the mechanism to design a modified surface in silico with enhanced ice nucleating ability.

  20. Element abundances in solar energetic particles: two physical processes, two abundance patterns

    E-Print Network [OSTI]

    Reames, Donald V

    2015-01-01T23:59:59.000Z

    Abundances of elements comprising solar energetic particles (SEPs) come with two very different patterns. Historically called "impulsive" and "gradual" events, they have been studied for 40 years, 20 years by the Wind spacecraft. Gradual SEP events measure coronal abundances. They are produced when shock waves, driven by coronal mass ejections (CMEs), accelerate the ambient coronal plasma; we discuss the average abundances of 21 elements that differ from corresponding solar photospheric abundances by a well-known dependence on the first ionization potential (FIP) of the element. The smaller impulsive ("3He-rich") SEP events are associated with magnetic reconnection involving open field lines from solar flares or jets that also eject plasma to produce accompanying CMEs. These events produce striking heavy-element abundance enhancements, relative to coronal abundances, by an average factor of 3 at Ne, 9 at Fe, and 900 for elements with 76 0.1 are even more strongly associated with narrow, slow CMEs, cooler coro...

  1. Ice Nuclei in Marine Air: Biogenic Particles or Dust?

    SciTech Connect (OSTI)

    Burrows, Susannah M.; Hoose, C.; Poschl, U.; Lawrence, M.

    2013-01-11T23:59:59.000Z

    Ice nuclei impact clouds, but their sources and distribution in the atmosphere are still not well known. Particularly little attention has been paid to IN sources in marine environments, although evidence from field studies suggests that IN populations in remote marine regions may be dominated by primary biogenic particles associated with sea spray. In this exploratory model study, we aim to bring attention to this long-neglected topic and identify promising target regions for future field campaigns. We assess the likely global distribution of marine biogenic ice nuclei using a combination of historical observations, satellite data and model output. By comparing simulated marine biogenic immersion IN distributions and dust immersion IN distributions, we predict strong regional differences in the importance of marine biogenic IN relative to dust IN. Our analysis suggests that marine biogenic IN are most likely to play a dominant role in determining IN concentrations in near-surface-air over the Southern Ocean, so future field campaigns aimed at investigating marine biogenic IN should target that region. Climate related changes in the abundance and emission of biogenic marine IN could affect marine cloud properties, thereby introducing previously unconsidered feedbacks that influence the hydrological cycle and the Earth’s energy balance. Furthermore, marine biogenic IN may be an important aspect to consider in proposals for marine cloud brightening by artificial sea spray production.

  2. Observations of ice thickness and frazil ice in the St. Lawrence Island polynya from satellite imagery, upward looking sonar, and

    E-Print Network [OSTI]

    Washington at Seattle, University of

    . The combination of the SAR imagery and ULS observations also allow measurement of the pack ice advection velocityObservations of ice thickness and frazil ice in the St. Lawrence Island polynya from satellite define a thermal ice thickness from the AVHRR retrieval of ice surface temperature combined

  3. INDICATOR: LAKE ERIE ICE COVER Winter ice cover on Lake Erie affects the amount of heat and moisture transferred

    E-Print Network [OSTI]

    102 INDICATOR: LAKE ERIE ICE COVER Background Winter ice cover on Lake Erie affects the amount of heat and moisture transferred between the lake and the atmosphere. During winter, ice and snow can decrease the amount of light available below the ice surface for photosynthesis. In the absence of an ice

  4. 4, 107128, 2007 Sea-ice-drift

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    OSD 4, 107­128, 2007 Sea-ice-drift dynamics and pack fracture A. Chmel et al. Title Page Abstract aspects of the sea-ice-drift dynamics and pack fracture A. Chmel 1 , V. N. Smirnov 2 , and L. V. Panov 2 1 to: A. Chmel (chmel@mail.ioffe.ru) 107 #12;OSD 4, 107­128, 2007 Sea-ice-drift dynamics and pack

  5. Summer ICE@Tech Computing Camps

    E-Print Network [OSTI]

    Guzdial, Mark

    Summer ICE@Tech Computing Camps Session I: June 5th - June 9th Session II: July 10th ­ July 14th (404) 385-2273 Fax (404) 385-0965 http://www.cc.gatech.edu/campice 1 #12;2 Summer ICE@Tech Program Handbook #12;3 Summer ICE@Tech is a computing and technology program for students entering 10th , 11th

  6. H2 ICE Combustion | Argonne National Laboratory

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

    H2 ICE Combustion Share Description Hydrogen combustion inside a direct injection H2 engine Topic Energy Energy efficiency Vehicles Hydrogen & fuel cells Credit S. Ciatti This...

  7. Viscosity of interfacial water regulates ice nucleation

    SciTech Connect (OSTI)

    Li, Kaiyong; Chen, Jing; Zhang, Qiaolan; Zhang, Yifan [Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Green Printing, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China) [Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Green Printing, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Xu, Shun; Zhou, Xin [School of Physics, University of Chinese Academy of Sciences, Beijing 100049 (China)] [School of Physics, University of Chinese Academy of Sciences, Beijing 100049 (China); Cui, Dapeng; Wang, Jianjun, E-mail: wangj220@iccas.ac.cn; Song, Yanlin [Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Green Printing, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China)] [Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Green Printing, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China)

    2014-03-10T23:59:59.000Z

    Ice formation on solid surfaces is an important phenomenon in many fields, such as cloud formation and atmospheric icing, and a key factor for applications in preventing freezing. Here, we report temperature-dependent nucleation rates of ice for hydrophilic and hydrophobic surfaces. The results show that hydrophilic surface presents a lower ice nucleation rate. We develop a strategy to extract the thermodynamic parameters, J{sub 0} and ?, in the context of classical nucleation theory. From the extracted J{sub 0} and ?, we reveal the dominant role played by interfacial water. The results provide an insight into freezing mechanism on solid surfaces.

  8. Dynamics of colloidal particles in ice

    E-Print Network [OSTI]

    Melissa Spannuth; S. G. J. Mochrie; S. S. L. Peppin; J. S. Wettlaufer

    2010-12-31T23:59:59.000Z

    We use X-ray Photon Correlation Spectroscopy (XPCS) to probe the dynamics of colloidal particles in polycrystalline ice. During freezing, the dendritic ice morphology and rejection of particles from the ice created regions of high-particle-density, where some of the colloids were forced into contact and formed disordered aggregates. We find that the particles in these high density regions underwent ballistic motion coupled with both stretched and compressed exponential decays of the intensity autocorrelation function, and that the particles' characteristic velocity increased with temperature. We explain this behavior in terms of ice grain boundary migration.

  9. BISICLES Captures Details of Retreating Antarctic Ice

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

    of Retreating Antarctic Ice March 30, 2013 | Tags: Climate Research, Hopper, Math & Computer Science Contact: Linda Vu, lvu@lbl.gov, +1 510 495 2402 Berkeley Lab Contributes...

  10. Past Accumulation Rates of the Western Antarctic Ice Sheet Near an Ice Divide 

    E-Print Network [OSTI]

    Child, Sarah

    2009-08-12T23:59:59.000Z

    The study of accumulation rates of ice is a direct link to the evolution of ice sheet. It is believed by scientists that ice sheet evolution will aid in the mystery of climate change and may lead to predictions about climates in the future...

  11. Satellite SAR Remote Sensing of Great Lakes Ice Cover, Part 2. Ice Classification and Mapping

    E-Print Network [OSTI]

    Satellite SAR Remote Sensing of Great Lakes Ice Cover, Part 2. Ice Classification and Mapping° to 60° for all polarizations, was processed to radar cross-section to establish a library of signatures (look-up table) for different ice types. The library is used in the computer classifica- tion

  12. white paper, 9 March 2009 An ice core to reconstruct Greenland ice sheet mass balance

    E-Print Network [OSTI]

    Box, Jason E.

    white paper, 9 March 2009 1 An ice core to reconstruct Greenland a handful of years suggest a profound Greenland ice sheet mass balance sensitivity (2000) found that the Greenland ice sheet lost as much as 2/3 its current

  13. ARKTOS: An intelligent system for SAR sea ice image classification

    E-Print Network [OSTI]

    Soh, L. K.; Tsatsoulis, Costas; Gineris, D.; Bertoia, C.

    2004-01-01T23:59:59.000Z

    We present an intelligent system for satellite sea ice image analysis named Advanced Reasoning using Knowledge for T ping Of Sea ice (ARKTOS). ARKTOS performs fully automated analysis of synthetic aperture radar (SAR) sea ice images by mimicking...

  14. Hail Ice Damage of Stringer-Stiffened Curved Composite Panels /

    E-Print Network [OSTI]

    Le, Jacqueline Linh

    2013-01-01T23:59:59.000Z

    Damage. Composite Structures 2003;62:213–21. Ice Drop.How to make clear ice. 28 February 2011. Victoria, BC,2011/02/how-to- make-clear-ice-that-actually-works/ Graham,

  15. Dust takes detour on ice-cloud journey | EMSL

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

    Dust takes detour on ice-cloud journey Dust takes detour on ice-cloud journey Pollution-coated particles bypass ice formation, but influence clouds Cirrus clouds are composed of...

  16. Sandia National Laboratories: Ice-Sheet Simulation Code Matures...

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

    Research & Capabilities Ice-flow velocity magnitude myr on the surface of the Greenland Ice Sheet, as computed by the AlbanyFELIX finite element code. Ice-flow velocity...

  17. Dual spatial maps of transcript and protein abundance in the...

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

    Dual spatial maps of transcript and protein abundance in the mouse brain. Dual spatial maps of transcript and protein abundance in the mouse brain. Abstract: Integrating...

  18. Mapping protein abundance patterns in the brain using voxelation...

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

    protein abundance patterns in the brain using voxelation combined with liquid chromatography and mass spectrometry. Mapping protein abundance patterns in the brain using voxelation...

  19. Topological Analysis of Protein Co-Abundance Networks Identifies...

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

    Topological Analysis of Protein Co-Abundance Networks Identifies Novel Host Targets Important for HCV Infection and Pathogenesis Topological Analysis of Protein Co-Abundance...

  20. Engineering Density of States of Earth Abundant Semiconductors...

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

    of States of Earth Abundant Semiconductors for Enhanced Thermoelectric Power Factor Engineering Density of States of Earth Abundant Semiconductors for Enhanced Thermoelectric...

  1. abundance life history: Topics by E-print Network

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

    of ectoparasite community and abundance across life history stages of avian host Environmental Sciences and Ecology Websites Summary: and abundance are often associated with the...

  2. The Patty Ice Arena User Responsibilities and Conduct is designed to create better communication between the patrons of the Patty Ice Arena and the Facilities Services' Patty Ice

    E-Print Network [OSTI]

    Wagner, Diane

    PURPOSE: The Patty Ice Arena User Responsibilities and Conduct is designed to create better communication between the patrons of the Patty Ice Arena and the Facilities Services' Patty Ice Arena management or other misuse of any part of the Patty Ice Arena may result in an individual, team, or organization being

  3. Nucleus-nucleus cold fusion reactions analyzed with the l-dependent 'fusion by diffusion' model

    SciTech Connect (OSTI)

    Cap, T.; Siwek-Wilczynska, K.; Wilczynski, J. [Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Hoza 69, PL-00-681 Warsaw (Poland); Andrzej Soltan Institute for Nuclear Studies, PL-05-400 Otwock-Swierk (Poland)

    2011-05-15T23:59:59.000Z

    We present a modified version of the Fusion by Diffusion (FBD) model aimed at describing the synthesis of superheavy nuclei in cold fusion reactions, in which a low excited compound nucleus emits only one neutron. The modified FBD model accounts for the angular momentum dependence of three basic factors determining the evaporation residue cross section: the capture cross section {sigma}{sub cap}(l), the fusion probability P{sub fus}(l), and the survival probability P{sub surv}(l). The fusion hindrance factor, the inverse of P{sub fus}(l), is treated in terms of thermal fluctuations in the shape degrees of freedom and is expressed as a solution of the Smoluchowski diffusion equation. The l dependence of P{sub fus}(l) results from the l-dependent potential energy surface of the colliding system. A new parametrization of the distance of starting point of the diffusion process is introduced. An analysis of a complete set of 27 excitation functions for production of superheavy nuclei in cold fusion reactions, studied in experiments at GSI Darmstadt, RIKEN Tokyo, and LBNL Berkeley, is presented. The FBD model satisfactorily reproduces shapes and absolute cross sections of all the cold fusion excitation functions. It is shown that the peak position of the excitation function for a given 1n reaction is determined by the Q value of the reaction and the height of the fission barrier of the final nucleus. This fact could possibly be used in future experiments (with well-defined beam energy) for experimental determination of the fission barrier heights.

  4. Heterogeneous Nucleation of Ice on Anthropogenic Organic Particles...

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

    Nucleation of Ice on Anthropogenic Organic Particles Collected in Mexico City. Heterogeneous Nucleation of Ice on Anthropogenic Organic Particles Collected in Mexico City....

  5. Heterogeneous ice nucleation and water uptake by field-collected...

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

    ice nucleation and water uptake by field-collected atmospheric particles below 273 K. Heterogeneous ice nucleation and water uptake by field-collected atmospheric particles below...

  6. Crystalline Ice Growth on Pt(111): Observation of a Hydrophobic...

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

    Crystalline Ice Growth on Pt(111): Observation of a Hydrophobic Water Monolayer. Crystalline Ice Growth on Pt(111): Observation of a Hydrophobic Water Monolayer. Abstract: The...

  7. The dependence of ice microphysics on aerosol concentration in...

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

    The dependence of ice microphysics on aerosol concentration in arctic mixed-phase stratus clouds during ISDAC and M-PACE. The dependence of ice microphysics on aerosol...

  8. Complex systems influence melting of Greenland ice sheet

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

    Complex systems influence melting of Greenland ice sheet Complex systems influence melting of Greenland ice sheet International research team's field work shows that, well, things...

  9. Unlocking a Sea Ice Secret

    SciTech Connect (OSTI)

    Dr. Rachel Obbard

    2013-04-22T23:59:59.000Z

    Dr. Rachel Obbard and her research group from Dartmouth College traveled to the Antarctic to collect samples of sea ice. Next stop: the GeoSoilEnviroCARS x-ray beamline at the Advanced Photon Source at Argonne National Laboratory in Illinois. This U.S. Department of Energy Office of Science synchrotron x-ray research facility gave the Obbard team the frontier scientific tools they needed to study the path bromide takes as it travels from the ocean to the atmosphere.

  10. ARM - Measurement - Cloud ice particle

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP : XDC documentationBarrow,ice particle ARM Data Discovery Browse Data

  11. ARM - Measurement - Ice water content

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP : XDC documentationBarrow,ice particleSize Distributiontypes

  12. ARM - Measurement - Ice water path

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP : XDC documentationBarrow,ice particleSize Distributiontypespath ARM

  13. ARM - TWP-ICE Maps

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP :ProductsVaisalaAlaskaInstruments NSASteeringContactsTWP-ICE Maps

  14. Ice Energy | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are8COaBulkTransmissionSitingProcess.pdfGetecGtel JumpCounty, Texas:ITC Transmission Jump to: navigation,IbervilleIce

  15. Abundances of massive stars: some recent developments

    E-Print Network [OSTI]

    T. Morel

    2008-11-25T23:59:59.000Z

    Thanks to their usefulness in various fields of astrophysics (e.g. mixing processes in stars, chemical evolution of galaxies), the last few years have witnessed a large increase in the amount of abundance data for early-type stars. Two intriguing results emerging since the last reviews on this topic will be discussed: (a) nearby OB stars exhibit metal abundances generally lower than the solar/meteoritic estimates; (b) evolutionary models of single objects including rotation are largely unsuccessful in explaining the CNO properties of stars in the Galaxy and in the Magellanic clouds.

  16. Passive ice freezing-releasing heat pipe

    DOE Patents [OSTI]

    Gorski, Anthony J. (Lemont, IL); Schertz, William W. (Batavia, IL)

    1982-01-01T23:59:59.000Z

    A heat pipe device has been developed which permits completely passive ice formation and periodic release of ice without requiring the ambient temperature to rise above the melting point of water. This passive design enables the maximum amount of cooling capacity to be stored in the tank.

  17. IceCube Project Monthly Report Accomplishments

    E-Print Network [OSTI]

    Saffman, Mark

    ;3 The latest revised estimates were modified to reflect the anticipated changes resulting from the Raytheon in Raytheon Polar Services completing the IceCube Laboratory. $1 million is from the lagging receipts. The on-ice Integrated Master Schedule is underway and being worked on this week with Raytheon Polar

  18. Parameterizing Size Distribution in Ice Clouds

    SciTech Connect (OSTI)

    DeSlover, Daniel; Mitchell, David L.

    2009-09-25T23:59:59.000Z

    PARAMETERIZING SIZE DISTRIBUTIONS IN ICE CLOUDS David L. Mitchell and Daniel H. DeSlover ABSTRACT An outstanding problem that contributes considerable uncertainty to Global Climate Model (GCM) predictions of future climate is the characterization of ice particle sizes in cirrus clouds. Recent parameterizations of ice cloud effective diameter differ by a factor of three, which, for overcast conditions, often translate to changes in outgoing longwave radiation (OLR) of 55 W m-2 or more. Much of this uncertainty in cirrus particle sizes is related to the problem of ice particle shattering during in situ sampling of the ice particle size distribution (PSD). Ice particles often shatter into many smaller ice fragments upon collision with the rim of the probe inlet tube. These small ice artifacts are counted as real ice crystals, resulting in anomalously high concentrations of small ice crystals (D < 100 µm) and underestimates of the mean and effective size of the PSD. Half of the cirrus cloud optical depth calculated from these in situ measurements can be due to this shattering phenomenon. Another challenge is the determination of ice and liquid water amounts in mixed phase clouds. Mixed phase clouds in the Arctic contain mostly liquid water, and the presence of ice is important for determining their lifecycle. Colder high clouds between -20 and -36 oC may also be mixed phase but in this case their condensate is mostly ice with low levels of liquid water. Rather than affecting their lifecycle, the presence of liquid dramatically affects the cloud optical properties, which affects cloud-climate feedback processes in GCMs. This project has made advancements in solving both of these problems. Regarding the first problem, PSD in ice clouds are uncertain due to the inability to reliably measure the concentrations of the smallest crystals (D < 100 µm), known as the “small mode”. Rather than using in situ probe measurements aboard aircraft, we employed a treatment of ice cloud optical properties formulated in terms of PSD parameters in combination with remote measurements of thermal radiances to characterize the small mode. This is possible since the absorption efficiency (Qabs) of small mode crystals is larger at 12 µm wavelength relative to 11 µm wavelength due to the process of wave resonance or photon tunneling more active at 12 µm. This makes the 12/11 µm absorption optical depth ratio (or equivalently the 12/11 µm Qabs ratio) a means for detecting the relative concentration of small ice particles in cirrus. Using this principle, this project tested and developed PSD schemes that can help characterize cirrus clouds at each of the three ARM sites: SGP, NSA and TWP. This was the main effort of this project. These PSD schemes and ice sedimentation velocities predicted from them have been used to test the new cirrus microphysics parameterization in the GCM known as the Community Climate Systems Model (CCSM) as part of an ongoing collaboration with NCAR. Regarding the second problem, we developed and did preliminary testing on a passive thermal method for retrieving the total water path (TWP) of Arctic mixed phase clouds where TWPs are often in the range of 20 to 130 g m-2 (difficult for microwave radiometers to accurately measure). We also developed a new radar method for retrieving the cloud ice water content (IWC), which can be vertically integrated to yield the ice water path (IWP). These techniques were combined to determine the IWP and liquid water path (LWP) in Arctic clouds, and hence the fraction of ice and liquid water. We have tested this approach using a case study from the ARM field campaign called M-PACE (Mixed-Phase Arctic Cloud Experiment). This research led to a new satellite remote sensing method that appears promising for detecting low levels of liquid water in high clouds typically between -20 and -36 oC. We hope to develop this method in future research.

  19. Theory of ice-skating

    E-Print Network [OSTI]

    Berre, Martine Le

    2015-01-01T23:59:59.000Z

    Almost frictionless skating on ice relies on a thin layer of melted water insulating mechanically the blade of the skate from ice. Using the basic equations of fluid mechanics and Stefan law, we derive a set of two coupled equations for the thickness of the film and the length of contact, a length scale which cannot be taken as its value at rest. The analytical study of these equations allows to define a small a-dimensional parameter depending on the longitudinal coordinate which can be neglected everywhere except close to the contact points at the front and the end of the blade, where a boundary layer solution is given. This solution provides without any calculation the order of magnitude of the film thickness, and its dependence with respect to external parameters like the velocity and mass of the skater and the radius of profile and bite angle of the blade, in good agreement with the numerical study. Moreover this solution also shows that a lubricating water layer of macroscopic thickness always exists for...

  20. Magnetic Monopoles in Spin Ice

    E-Print Network [OSTI]

    Claudio Castelnovo; Roderich Moessner; Shivaji L. Sondhi

    2007-10-31T23:59:59.000Z

    Electrically charged particles, such as the electron, are ubiquitous. By contrast, no elementary particles with a net magnetic charge have ever been observed, despite intensive and prolonged searches. We pursue an alternative strategy, namely that of realising them not as elementary but rather as emergent particles, i.e., as manifestations of the correlations present in a strongly interacting many-body system. The most prominent examples of emergent quasiparticles are the ones with fractional electric charge e/3 in quantum Hall physics. Here we show that magnetic monopoles do emerge in a class of exotic magnets known collectively as spin ice: the dipole moment of the underlying electronic degrees of freedom fractionalises into monopoles. This enables us to account for a mysterious phase transition observed experimentally in spin ice in a magnetic field, which is a liquid-gas transition of the magnetic monopoles. These monopoles can also be detected by other means, e.g., in an experiment modelled after the celebrated Stanford magnetic monopole search.

  1. Inferring Ecological Networks From Species Abundance Data

    E-Print Network [OSTI]

    Edinburgh, University of

    (LASSO), Sparse Bayesian Regression (SBR), Graphical Gaussian Models (GGMs) and Bayesian Networks (BNs to thank Marco Grzegorczyk for the answering my question about Bayesian networks and the MCMC methodsInferring Ecological Networks From Species Abundance Data Frank Dondelinger Master of Science

  2. Separable Representation of Proton-Nucleus Optical Potentials

    E-Print Network [OSTI]

    L. Hlophe; V. Eremenko; Ch. Elster; F. M. Nunes; G. Arbanas; J. E. Escher; I. J. Thompson

    2014-09-14T23:59:59.000Z

    Recently, a new approach for solving the three-body problem for (d,p) reactions in the Coulomb-distorted basis in momentum space was proposed. Important input quantities for such calculations are the scattering matrix elements for proton- and neutron-nucleus scattering. We present a generalization of the Ernst-Shakin-Thaler scheme in which a momentum space separable representation of proton-nucleus scattering matrix elements can be calculated in the Coulomb basis. The viability of this method is demonstrated by comparing S-matrix elements obtained for p$+^{48}$Ca and p$+^{208}$Pb for a phenomenological optical potential with corresponding coordinate space calculations.

  3. Meson production in high-energy electron-nucleus scattering

    E-Print Network [OSTI]

    Göran Fäldt

    2010-06-09T23:59:59.000Z

    Experimental studies of meson production through two-photon fusion in inelastic electron-nucleus scattering is now under way. A high-energy photon radiated by the incident electron is fused with a soft photon radiated by the nucleus. The process takes place in the small-angle-Coulomb region of nuclear scattering. We expound the theory for this production process as well as its interference with coherent-radiative-meson production. In particular, we investigate the distortion of the electron wave function due to multiple-Coulomb scattering.

  4. Non-localities in nucleon-nucleus potentials

    E-Print Network [OSTI]

    P. Fraser; K. Amos; S. Karataglidis; L. Canton; G. Pisent; J. P. Svenne

    2007-08-09T23:59:59.000Z

    Two causes of non-locality inherent in nucleon-nucleus scattering are considered. They are the results of two-nucleon antisymmetry of the projectile with each nucleon in the nucleus and the dynamic polarization potential representation of channel coupling. For energies $\\sim 40 - 300$ MeV, a g-folding model of the optical potential is used to show the influence of the knock-out process that is a result of the two-nucleon antisymmetry. To explore the dynamic polarization potential caused by channel coupling, a multichannel algebraic scattering model has been used for low-energy scattering.

  5. Isotopic abundance in atom trap trace analysis

    DOE Patents [OSTI]

    Lu, Zheng-Tian; Hu, Shiu-Ming; Jiang, Wei; Mueller, Peter

    2014-03-18T23:59:59.000Z

    A method and system for detecting ratios and amounts of isotopes of noble gases. The method and system is constructed to be able to measure noble gas isotopes in water and ice, which helps reveal the geological age of the samples and understand their movements. The method and system uses a combination of a cooled discharge source, a beam collimator, a beam slower and magneto-optic trap with a laser to apply resonance frequency energy to the noble gas to be quenched and detected.

  6. First data from DM-Ice17

    E-Print Network [OSTI]

    DM-Ice Collaboration; :; J. Cherwinka; D. Grant; F. Halzen; K. M. Heeger; L. Hsu; A. J. F. Hubbard; A. Karle; M. Kauer; V. A. Kudryavtsev; C. Macdonald; R. H. Maruyama; S. Paling; W. Pettus; Z. P. Pierpoint; B. N. Reilly; M. Robinson; P. Sandstrom; N. J. C. Spooner; S. Telfer; L. Yang

    2014-11-13T23:59:59.000Z

    We report the first analysis of background data from DM-Ice17, a direct-detection dark matter experiment consisting of 17 kg of NaI(Tl) target material. It was codeployed with IceCube 2457 m deep in the South Pole glacial ice in December 2010 and is the first such detector operating in the Southern Hemisphere. The background rate in the 6.5 - 8.0 keVee region is measured to be 7.9 +/- 0.4 counts/day/keV/kg. This is consistent with the expected background from the detector assemblies with negligible contributions from the surrounding ice. The successful deployment and operation of DM-Ice17 establishes the South Pole ice as a viable location for future underground, low-background experiments in the Southern Hemisphere. The detector assembly and deployment are described here, as well as the analysis of the DM-Ice17 backgrounds based on data from the first two years of operation after commissioning, July 2011 - June 2013.

  7. First Data from DM-Ice17

    E-Print Network [OSTI]

    :,; Grant, D; Halzen, F; Heeger, K M; Hsu, L; Hubbard, A J F; Karle, A; Kauer, M; Kudryavtsev, V A; Maruyama, R H; MacDonald, C; Paling, S; Pettus, W C; Pierpoint, Z P; Reilly, B N; Robinson, M; Sandstrom, P; Spooner, N J C; Telfer, S; Yang, L

    2014-01-01T23:59:59.000Z

    We report the first analysis of background data from DM-Ice17 a direct-detection dark matter experiment consisting of 17 kg of NaI(Tl) target material. It was successfully deployed 2457 m deep in South Pole glacial ice at the bottom of two IceCube strings in December 2010 and is the first such detector to be operating in the Southern Hemisphere. Data from the first two years of operation after commissioning, July 2011 - June 2013, are presented here. The background rate in the 6.5 - 8.0 kevee region is measured to be 7.9 +/- 0.4 counts/day/keV/kg. This is in agreement with the expected background from the crystal assemblies and is consistent with simulation. Background contributions from the surrounding ice were demonstrated to be negligible. The successful deployment and operation of DM-Ice17 establishes the South Pole ice as a location for future underground, low-background experiments in the Southern Hemisphere. The detector assembly, deployment, and analysis of the DM-Ice17 backgrounds are described.

  8. Modelling Sea Ice Growth Mark J. McGuinness

    E-Print Network [OSTI]

    McGuinness, Mark

    salinity. The saltier the brine, the lower the freezing point. When salinity is above the critical value is rejected by growing ice as a dense brine, but the brine cannot escape as rapidly as heat at the ice, trapping brine in the ice-brine mixture. This constitutional supercooling causes the ice-ocean interface

  9. Introduction Microorganisms in sea ice function ecologically in the

    E-Print Network [OSTI]

    Stewart, Frank

    of the pack via brine drainage, ice melting, or ice break-up (Garrison & Buck 1989 and references thereinIntroduction Microorganisms in sea ice function ecologically in the Antarctic marine ecosystem where pelagic and sea ice habitats are intrinsically coupled (Laws 1985, Garrison 1991, Eicken 1992

  10. FIRST PRINCIPLES MODELING FOR LIDAR SENSING OF COMPLEX ICE SURFACES

    E-Print Network [OSTI]

    Kerekes, John

    FIRST PRINCIPLES MODELING FOR LIDAR SENSING OF COMPLEX ICE SURFACES J. Kerekes, A. Goodenough, S of monitoring the dynamics and mass balance of glaciers, ice caps, and ice sheets. However, it is also known that ice surfaces can have complex 3-dimensional structure, which can challenge their accurate retrieval

  11. Microstructure through an ice sheet Tobias Binder1, a

    E-Print Network [OSTI]

    Garbe, Christoph S.

    Microstructure through an ice sheet Tobias Binder1, a , Ilka Weikusat2, b , Johannes Freitag2, c.Garbe@iwr.uni-heidelberg.de, e Dietmar.Wagenbach@iup.uni-heidelberg.de, f Sepp.Kipfstuhl@awi.de Keywords: Ice, microstructure characterization, grain boundary curvature, image processing Abstract. Ice cores through an ice sheet can

  12. ORIGINAL ARTICLE Diatom assemblages promote ice formation in large

    E-Print Network [OSTI]

    Lee Jr., Richard E.

    ORIGINAL ARTICLE Diatom assemblages promote ice formation in large lakes NA D'souza1,3 , Y evidence for the directed formation of ice by planktonic communities dominated by filamentous diatoms sampled from the ice-covered Laurentian Great Lakes. We hypothesize that ice formation promotes attachment

  13. Age characteristics in a multidecadal Arctic sea ice simulation

    SciTech Connect (OSTI)

    Hunke, Elizabeth C [Los Alamos National Laboratory; Bitz, Cecllia M [UNIV. OF WASHINGTON

    2008-01-01T23:59:59.000Z

    Results from adding a tracer for age of sea ice to a sophisticated sea ice model that is widely used for climate studies are presented. The consistent simulation of ice age, dynamics, and thermodynamics in the model shows explicitly that the loss of Arctic perennial ice has accelerated in the past three decades, as has been seen in satellite-derived observations. Our model shows that the September ice age average across the Northern Hemisphere varies from about 5 to 8 years, and the ice is much younger (about 2--3 years) in late winter because of the expansion of first-year ice. We find seasonal ice on average comprises about 5% of the total ice area in September, but as much as 1.34 x 10{sup 6} km{sup 2} survives in some years. Our simulated ice age in the late 1980s and early 1990s declined markedly in agreement with other studies. After this period of decline, the ice age began to recover, but in the final years of the simulation very little young ice remains after the melt season, a strong indication that the age of the pack will again decline in the future as older ice classes fail to be replenished. The Arctic ice pack has fluctuated between older and younger ice types over the past 30 years, while ice area, thickness, and volume all declined over the same period, with an apparent acceleration in the last decade.

  14. Dynamics of Ice Nucleation on Water Repellent Surfaces Azar Alizadeh,*,

    E-Print Network [OSTI]

    Dhinojwala, Ali

    for nonicing applications. 1. INTRODUCTION Ice accretion on surfaces of aircraft, wind turbine blades, oil

  15. Self-excited oscillations in sea ice and evaluation of the ice forces

    SciTech Connect (OSTI)

    Smirnov, V.N. [Arctic and Antarctic Research Inst., St. Petersburg (Russian Federation)

    1996-12-01T23:59:59.000Z

    The processes of the dynamical interactions of the ice are described. Special attention is given to the self-excited oscillating processes when the ice goes through periodical deformations similar to these which appear in the structures in the sea ice. The range of the self-excited oscillations periods is from 0.1 s to 20 s. The jump-like processes transform themselves into the quasi-harmonical ones up to sound frequency range. For comparison purposes the spectra of the frictional self-excited oscillations in the glaciers are presented. An iceberg interacting with the drifting ice also forms self-excited oscillating system with period of up to 10 s. An example of numerical evaluation of the forces of interaction between a drifting ice island and the sea ice is given.

  16. RGPS/Model Ice Deformation July 3, 2003 1 Sea Ice Deformation Rates From Satellite Measurements and in a Model

    E-Print Network [OSTI]

    Lindsay, Ron

    of the Arctic geophysical environment. The deformation rate of pack ice, determined from the spatial gradientsRGPS/Model Ice Deformation July 3, 2003 1 Sea Ice Deformation Rates From Satellite Measurements The deformation of sea ice is an important element of the Arctic climate system because of its influence

  17. Communication: On the stability of ice 0, ice i, and I h D. Quigley, D. Alf, and B. Slater

    E-Print Network [OSTI]

    Alfè, Dario

    Communication: On the stability of ice 0, ice i, and I h D. Quigley, D. Alfè, and B. Slater (2014) Communication: On the stability of ice 0, ice i, and Ih D. Quigley,1,a) D. Alfè,2 and B. Slater3

  18. ice-surface lowering or some regional climate change induced by ice-surface lowering. If attributed solely to a

    E-Print Network [OSTI]

    Flint-Garcia, Sherry

    ice-surface lowering or some regional climate change induced by ice-surface lowering. If attributed solely to a change in ice-surface elevation, the 3° to 4°C warming at Siple Dome (16) would indicate 500 to 650 m of ice-surface lowering, assuming a free atmospheric lapse rate of 6°C per 1000 m

  19. Inter-annual sea-ice dynamics and micro-algal biomass in winter pack ice of Marguerite Bay, Antarctica

    E-Print Network [OSTI]

    Stewart, Frank

    in this region (Stammerjohn et al., 2003; Stammerjohn and Smith, 1996). Changes in mesoscale ice dynamics

  20. Pomeron with a running coupling in the nucleus

    E-Print Network [OSTI]

    M. A. Braun

    2007-03-09T23:59:59.000Z

    The running coupling is introduced into the equation for propagation of the pomeron in the nucleus via the bootstrap relation. The resulting equation coincides with the one obtained in the colour dipole formalism by summing contributions from quark-antiquark loops, with a general choice of the regularization scheme.

  1. CLIC Drive Beam and LHC Based Fel-Nucleus Collider

    E-Print Network [OSTI]

    H. Braun; R. Corsini; S. Sultansoy; O. Yavas

    2005-08-09T23:59:59.000Z

    The feasibility of a CLIC-LHC based FEL-nucleus collider is investigated. It is shown that the proposed scheme satisfies all requirements of an ideal photon source for the Nuclear Resonance Fluorescence method. The physics potential of the proposed collider is illustrated for a beam of Pb nuclei.

  2. The Isotopic Abundances of Magnesium in Stars

    E-Print Network [OSTI]

    Pamela Gay; David L. Lambert

    1999-11-11T23:59:59.000Z

    Isotopic abundance ratios 24^Mg:25^Mg:26^Mg are derived for 20 stars from high- resolution spectra of the MgH A-X 0-0 band at 5140AA. With the exception of the weak g-band giant HR 1299, the stars are dwarfs that sample the metallicity range -1.8 < [Fe/H] <0.0. The abundance of 25^Mg amd 26^Mg relative to the dominant isotope 24^Mg decreases with decreasing [Fe/H] in fair accord with predictions from a recent model of galactic chemical evolution in which the Mg isotopes are synthesised by massive stars. Several stars appear especially enriched in the heavier Mg isotopes suggesting contamination by material from the envelopes of intermediate-mass AGB stars.

  3. The Phases of Water Ice in the Solar Nebula

    E-Print Network [OSTI]

    Ciesla, Fred J

    2014-01-01T23:59:59.000Z

    Understanding the phases of water ice that were present in the solar nebula has implications for understanding cometary and planetary compositions as well as internal evolution of these bodies. Here we show that amorphous ice formed more readily than previously recognized, with formation at temperatures ice to form. This processing would be a natural consequence of ice dynamics, and would allow for the trapping of noble gases and other volatiles in water ice in the outer solar nebula.

  4. Topology in QCD and the axion abundance

    E-Print Network [OSTI]

    Ryuichiro Kitano; Norikazu Yamada

    2015-06-01T23:59:59.000Z

    The temperature dependence of the topological susceptibility (chi_t) in QCD essentially determines the abundance of the QCD axion in the Universe, and is commonly estimated, based on the instanton picture, to be a certain negative power of temperature. While lattice QCD should be able to check the instanton picture in principle, the region of the temperature where lattice calculations of chi_t are reliable is rather limited in practice, because existing methods on the lattice will probably fail when chi_t decreases rapidly with temperatures. In this work, two exploratory studies are presented. First, to realize the limitation of temperature we perform lattice calculations of chi_t in the quenched approximation and find that it becomes difficult with a given resource when T > 2 T_c. A possible way out is proposed and some test calculations are given. The absolute value and the temperature dependence of chi_t in real QCD can be significantly different from that in the quenched approximation, and is not well established over a wide range of the temperature above its critical value. Motivated by this fact and precedent arguments which disagree with the conventional instanton picture, we estimate the axion abundance in an extreme case where chi_t decreases much faster than the conventional power-like function. We find a significant enhancement of the axion abundance in such a case.

  5. Relative Abundance Measurements in Plumes and Interplumes

    E-Print Network [OSTI]

    Guennou, Chloé; Savin, Daniel Wolf

    2015-01-01T23:59:59.000Z

    We present measurements of relative elemental abundances in plumes and interplumes. Plumes are bright, narrow structures in coronal holes that extend along open magnetic field lines far out into the corona. Previous work has found that in some coronal structures the abundances of elements with a low first ionization potential (FIP) 10 eV). We have used EIS spectroscopic observations made on 2007 March 13 and 14 over an ~24 hour period to characterize abundance variations in plumes and interplumes. To assess their elemental composition, we have used a differential emission measure (DEM) analysis, which accounts for the thermal structure of the observed plasma. We have used lines from ions of iron, silicon, and sulfur. From these we have estimated the ratio of the iron and silicon FIP bias relative to that for sulfur. From the results, we have created FIP-bias-ratio maps. We find that the FIP-bias ratio is sometimes higher in plumes than in interplumes and that this enhancement can be time dependent. These res...

  6. Observations of the Askaryan Effect in Ice

    SciTech Connect (OSTI)

    Gorham, P.W.

    2007-01-16T23:59:59.000Z

    We report on the first observations of the Askaryan effect in ice: coherent impulsive radio Cherenkov radiation from the charge asymmetry in an electromagnetic (EM) shower. Such radiation has been observed in silica sand and rock salt, but this is the first direct observation from an EM shower in ice. These measurements are important since the majority of experiments to date that rely on the effect for ultra-high energy neutrino detection are being performed using ice as the target medium. As part of the complete validation process for the Antarctic Impulsive Transient Antenna (ANITA) experiment, we performed an experiment at the Stanford Linear Accelerator Center (SLAC) in June 2006 using a 7.5 metric ton ice target, yielding results fully consistent with theoretical expectations.

  7. Neutrino Oscillation Measurements with IceCube

    E-Print Network [OSTI]

    Carsten Rott; for the IceCube Collaboration

    2008-10-20T23:59:59.000Z

    We present preliminary results for a neutrino oscillation analysis in progress on data collected with the IceCube 22-string detector during 2007 and 2008. The goal of this analysis is to measure muon neutrino disappearance as a function of energy for a constant baseline length of the diameter of the Earth by studying vertically up-going muon neutrinos. At this baseline disappearance effects are expected to become sizable at neutrino energies below 100 GeV. This energy range has not been previously explored with IceCube, however due to IceCube's vertical geometry there is some sensitivity for this specific class of events. Based on preliminary selection criteria, we show that IceCube has the potential to detect these events and we estimate the sensitivity to determining oscillation parameters.

  8. Scattering Properties of Oriented Hexagonal Ice Crystals

    E-Print Network [OSTI]

    Zhang, Feng

    2010-01-14T23:59:59.000Z

    To interpret the data from spaceborn lidar measurements, one must have a basic understanding of the backscattering of oriented ice particles. The conventional raytracing method is not applicable to the scattering of light by oriented particles...

  9. Observations of the Askaryan Effect in Ice

    E-Print Network [OSTI]

    ANITA collaboration; P. W. Gorham; S. W. Barwick; J. J. Beatty; D. Z. Besson; W. R. Binns; C. Chen; P. Chen; J. M. Clem; A. Connolly; P. F. Dowkontt; M. A. DuVernois; R. C. Field; D. Goldstein; A. Goodhue; C. Hast; C. L. Hebert; S. Hoover; M. H. Israel; J. Kowalski; J. G. Learned; K. M. Liewer; J. T. Link; E. Lusczek; S. Matsuno; B. Mercurio; C. Miki; P. Miocinovic; J. Nam; C. J. Naudet; J. Ng; R. Nichol; K. Palladino; K. Reil; A. Romero-Wolf; M. Rosen; D. Saltzberg; D. Seckel; G. S. Varner; D. Walz; F. Wu

    2007-01-12T23:59:59.000Z

    We report on the first observations of the Askaryan effect in ice: coherent impulsive radio Cherenkov radiation from the charge asymmetry in an electromagnetic (EM) shower. Such radiation has been observed in silica sand and rock salt, but this is the first direct observation from an EM shower in ice. These measurements are important since the majority of experiments to date that rely on the effect for ultra-high energy neutrino detection are being performed using ice as the target medium. As part of the complete validation process for the Antarctic Impulsive Transient Antenna (ANITA) experiment, we performed an experiment at the Stanford Linear Accelerator Center (SLAC) in June 2006 using a 7.5 metric ton ice target, yielding results fully consistent with theoretical expectations.

  10. Observations of the Askaryan Effect in Ice

    E-Print Network [OSTI]

    Barwick, S W; Besson, D Z; Binns, W R; Chen, P; Clem, J M; Connolly, A; Dowkontt, P F; Duvernois, M A; Field, R C; Goldstein, D; Goodhue, A; Gorham, P W; Hast, C; Hebert, C L; Hoover, S; Israel, M H; Kowalski, J; Learned, J G; Liewer, K M; Link, J T; Lusczek, E; Matsuno, S; Mercurio, B; Miki, C; Miocinovic, P; Nam, J; Naudet, C J; Ng, J; Nichol, R; Palladino, K J; Reil, K; Romero-Wolf, A; Rosen, M; Saltzberg, D; Secke, D; Varner, G S; Walz, D; Wu, F

    2006-01-01T23:59:59.000Z

    We report on the first observations of the Askaryan effect in ice: coherent impulsive radio Cherenkov radiation from the charge asymmetry in an electromagnetic (EM) shower. Such radiation has been observed in silica sand and rock salt, but this is the first direct observation from an EM shower in ice. These measurements are important since the majority of experiments to date that rely on the effect for ultra-high energy neutrino detection are being performed using ice as the target medium. As part of the complete validation process for the Antarctic Impulsive Transient Antenna (ANITA) experiment, we performed an experiment at the Stanford Linear Accelerator Center (SLAC) in June 2006 using a 7.5 metric ton ice target, yielding results fully consistent with theoretical expectations.

  11. Weakening of ice by magnesium perchlorate hydrate

    E-Print Network [OSTI]

    Lenferink, Hendrik J., 1985-

    2012-01-01T23:59:59.000Z

    I show that perchlorate hydrates, which have been indirectly detected at high Martian circumpolar latitudes by the Phoenix Mars Lander, have a dramatic effect upon the rheological behavior of polycrystalline water ice under ...

  12. Soft X-ray irradiation of methanol ice: Formation of products as a function of photon energy

    SciTech Connect (OSTI)

    Chen, Y.-J.; Juang, K.-J.; Yih, T.-S. [Department of Physics, National Central University, Jhongli City, Taoyuan County 32054, Taiwan (China); Ciaravella, A.; Cecchi-Pestellini, C. [INAF-Osservatorio Astronomico di Palermo, P.za Parlamento 1, I-90134 Palermo (Italy); Muñoz Caro, G. M.; Jiménez-Escobar, A., E-mail: aciaravella@astropa.unipa.it [Centro de Astrobiología (INTA-CSIC), Carretera de Ajalvir, km 4, Torrejón de Ardoz, E-28850 Madrid (Spain)

    2013-12-01T23:59:59.000Z

    Pure methanol ices have been irradiated with monochromatic soft X-rays of 300 and 550 eV close to the 1s resonance edges of C and O, respectively, and with a broadband spectrum (250-1200 eV). The infrared (IR) spectra of the irradiated ices show several new products of astrophysical interest such as CH{sub 2}OH, H{sub 2}CO, CH{sub 4}, HCOOH, HCOCH{sub 2}OH, CH{sub 3}COOH, CH{sub 3}OCH{sub 3}, HCOOCH{sub 3}, and (CH{sub 2}OH){sub 2}, as well as HCO, CO, and CO{sub 2}. The effect of X-rays is the result of the combined interactions of photons and electrons with the ice. A significant contribution to the formation and growth of new species in the CH{sub 3}OH ice irradiated with X-rays is given by secondary electrons, whose energy distribution depends on the energy of X-ray photons. Within a single experiment, the abundances of the new products increase with the absorbed energy. Monochromatic experiments show that product abundances also increase with the photon energy. However, the abundances per unit energy of newly formed species show a marked decrease in the broadband experiment as compared to irradiations with monochromatic photons, suggesting a possible regulatory role of the energy deposition rate. The number of new molecules produced per absorbed eV in the X-ray experiments has been compared to those obtained with electron and ultraviolet (UV) irradiation experiments.

  13. Bedmap2: improved ice bed, surface and thickness datasets for Antarctica

    E-Print Network [OSTI]

    2013-01-01T23:59:59.000Z

    Subglacial topography inferred from ice surface ter- rainSubglacial topography inferred from ice surface ter- rainsurface eleva- tion, ice thickness and subglacial topography

  14. Spread of ice mass loss into northwest Greenland observed by GRACE and GPS

    E-Print Network [OSTI]

    Khan, Shfaqat Abbas; Wahr, John; Bevis, Michael; Velicogna, Isabella; Kendrick, Eric

    2010-01-01T23:59:59.000Z

    oscillations and seasonal ice mass fluctuations, Eos Trans.2007), Rapid changes in ice discharge from Greenland outletW. et al. (2004), Greenland Ice Sheet: Increased coastal

  15. Diversity of the diatom genus Fragilariopsis in the Argentine Sea and Antarctic waters: morphology, distribution and abundance

    E-Print Network [OSTI]

    Cefarelli, Adrián O.; Ferrario, Martha E.; Almandoz, Gastón O.; Atencio, Adrián G.; Akselman, Rut; Vernet, María

    2010-01-01T23:59:59.000Z

    1989) The biota of Antarctic pack ice in the Weddell Sea andassemblages in Antarctic pack ice and in ice-edge plankton.

  16. Regelation: why does ice melt under pressure?

    E-Print Network [OSTI]

    Chang Q Sun

    2015-01-28T23:59:59.000Z

    Unlike other unusual materials whose bonds contract under compression, the O:H nonbond undergoes contraction and the H-O bond elongation towards O:H and H-O length symmetry in water and ice. The energy drop of the H-O bond dictates the melting point Tm depression of ice. Once the pressure is relieved, the O:H-O bond fully recovers its initial state, resulting in Regelation.

  17. Regelation: why does ice melt under pressure?

    E-Print Network [OSTI]

    Sun, Chang Q

    2015-01-01T23:59:59.000Z

    Unlike other unusual materials whose bonds contract under compression, the O:H nonbond undergoes contraction and the H-O bond elongation towards O:H and H-O length symmetry in water and ice. The energy drop of the H-O bond dictates the melting point Tm depression of ice. Once the pressure is relieved, the O:H-O bond fully recovers its initial state, resulting in Regelation.

  18. First Results from IceCube

    E-Print Network [OSTI]

    Spencer R. Klein; for the IceCube Collaboration

    2006-01-12T23:59:59.000Z

    IceCube is a 1 km$^3$ neutrino observatory being built to study neutrino production in active galactic nuclei, gamma-ray bursts, supernova remnants, and a host of other astrophysical sources. High-energy neutrinos may signal the sources of ultra-high energy cosmic rays. IceCube will also study many particle-physics topics: searches for WIMP annihilation in the Earth or the Sun, and for signatures of supersymmetry in neutrino interactions, studies of neutrino properties, including searches for extra dimensions, and searches for exotica such as magnetic monopoles or Q-balls. IceCube will also study the cosmic-ray composition. In January, 2005, 60 digital optical modules (DOMs) were deployed in the South Polar ice at depths ranging from 1450 to 2450 meters, and 8 ice-tanks, each containing 2 DOMs were deployed as part of a surface air-shower array. All 76 DOMs are collecting high-quality data. After discussing the IceCube physics program and hardware, I will present some initial results with the first DOMs.

  19. abundance depth distribution: Topics by E-print Network

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

    12: 488-501 I N T R O DU C T I O N The species abundance distribution (SAD Enquist, Brian Joseph 4 Fauna, Distribution, Habitat Preference and Abundance CiteSeer Summary:...

  20. abundance distribution composition: Topics by E-print Network

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

    12: 488-501 I N T R O DU C T I O N The species abundance distribution (SAD Enquist, Brian Joseph 6 Fauna, Distribution, Habitat Preference and Abundance CiteSeer Summary:...

  1. abundance distribution results: Topics by E-print Network

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

    12: 488-501 I N T R O DU C T I O N The species abundance distribution (SAD Enquist, Brian Joseph 4 Fauna, Distribution, Habitat Preference and Abundance CiteSeer Summary:...

  2. Oxygen abundances in planet-harbouring stars. Comparison of different abundance indicators

    E-Print Network [OSTI]

    A. Ecuvillon; G. Israelian; N. C. Santos; N. G. Shchukina; M. Mayor; R. Rebolo

    2005-09-13T23:59:59.000Z

    We present a detailed and uniform study of oxygen abundances in 155 solar type stars, 96 of which are planet hosts and 59 of which form part of a volume-limited comparison sample with no known planets. EW measurements were carried out for the [O I] 6300 \\AA line and the O I triplet, and spectral synthesis was performed for several OH lines. NLTE corrections were calculated and applied to the LTE abundance results derived from the O I 7771-5 \\AA\\ triplet. Abundances from [O I], the O I triplet and near-UV OH were obtained in 103, 87 and 77 dwarfs, respectively. We present the first detailed and uniform comparison of these three oxygen indicators in a large sample of solar-type stars. There is good agreement between the [O/H] ratios from forbidden and OH lines, while the NLTE triplet shows a systematically lower abundance. We found that discrepancies between OH, [O I] and the O I triplet do not exceed 0.2 dex in most cases. We have studied abundance trends in planet host and comparison sample stars, and no obvious anomalies related to the presence of planets have been detected. All three indicators show that, on average, [O/Fe] decreases with [Fe/H] in the metallicity range -0.8oxygen overabundance of 0.1-0.2dex with respect to the comparison sample.

  3. Modeling of Antarctic sea ice in a general circulation model

    SciTech Connect (OSTI)

    Wu, Xingren; Budd, W.F. [Antarctic Cooperative Research Centre, Tasmania (Australia)] [Antarctic Cooperative Research Centre, Tasmania (Australia); Simmonds, I. [School of Earth Sciences, Victoria (Australia)] [School of Earth Sciences, Victoria (Australia)

    1997-04-01T23:59:59.000Z

    A dynamic-thermodynamic sea ice model is developed and coupled with the Melbourne University general circulation model to simulate the seasonal cycle of the Antarctic sea ice distributions The model is efficient, rapid to compute, and useful for a range of climate studies. The thermodynamic part of the sea ice model is similar to that developed by Parkinson and Washington, the dynamics contain a simplified ice rheology that resists compression. The thermodynamics is based on energy conservation at the top surface of the ice/snow, the ice/water interface, and the open water area to determine the ice formation, accretion, and ablation. A lead parameterization is introduced with an effective partitioning scheme for freezing between and under the ice floes. The dynamic calculation determines the motion of ice, which is forced with the atmospheric wind, taking account of ice resistance and rafting. The simulated sea ice distribution compares reasonably well with observations. The seasonal cycle of ice extent is well simulated in phase as well as in magnitude. Simulated sea ice thickness and concentration are also in good agreement with observations over most regions and serve to indicate the importance of advection and ocean drift in the determination of the sea ice distribution. 64 refs., 15 figs., 2 tabs.

  4. Quantification of summertime water ice deposition on the Martian north polar ice cap

    E-Print Network [OSTI]

    Brown, Adrian J; Becerra, Patricio; Byrne, Shane

    2015-01-01T23:59:59.000Z

    We use observations from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) of the north polar cap during late summer for two Martian years, to monitor the complete summer cycle of albedo and water ice grain size in order to place quantitative limits of the amount of water ice deposited in late summer. We establish here for the first time the complete spring to summer cycle of water ice grain sizes on the north polar cap. The apparent grain sizes grow until Ls=132, when they appear to shrink again, until they are obscured at the end of summer by the north polar hood. Under the assumption that the shrinking of grain sizes is due to the deposition of find grained ice, we quantify the amount of water ice deposited per Martian boreal summer, and estimate the amount of water ice that must be transported equatorward. Interestingly, we find that the relative amount of water ice deposited in the north cap during boreal summer (0.7-7 microns) is roughly equivalent to the average amount of water ice depos...

  5. Home Atmosphere Sea Ice Ocean Land Greenland Biology Greenland Ice Sheet Mass Balance

    E-Print Network [OSTI]

    Box, Jason E.

    , thinning and breakup of Jakobshavn Glacier's (SW Greenland) floating ice tongue and acceleration-to-year variability in GrIS mass turnover, e.g. sudden glacier accelerations (Rignot and Kanagartnam 2006). Since or 2005. Physical response mechanisms, such as hydraulic acceleration of the ice sheet from continued

  6. Ice nucleation and overseeding of ice in volcanic clouds A. J. Durant,1,2

    E-Print Network [OSTI]

    Rose, William I.

    that such ``overseeded'' volcanic clouds will exhibit enhanced ice crystal concentrations and smaller average ice crystal nucleation in volcanic plumes and clouds affects dynamics [Glaze et al., 1997; Herzog et al., 1998; Mastin- porting water to the stratosphere [Glaze et al., 1997] and these fluxes depend in part on the microphysics

  7. ICED'09/148 INTERNATIONAL CONFERENCE ON ENGINEERING DESIGN, ICED'09

    E-Print Network [OSTI]

    Papalambros, Panos

    derived from the diversity of disciplines that contribute to design, including engineering, economics with the usual engineering requirements. This article describes the basic ideas in constructing the designICED'09/148 INTERNATIONAL CONFERENCE ON ENGINEERING DESIGN, ICED'09 24 - 27 AUGUST 2009, STANFORD

  8. Primordial Li abundance and massive particles

    SciTech Connect (OSTI)

    Latin-Capital-Letter-Eth apo, H. [Department of Physics, Akdeniz University, TR-07058, Antalya (Turkey)

    2012-10-20T23:59:59.000Z

    The problem of the observed lithium abundance coming from the Big Bang Nucleosynthesis is as of yet unsolved. One of the proposed solutions is including relic massive particles into the Big Bang Nucleosynthesis. We investigated the effects of such particles on {sup 4}HeX{sup -}+{sup 2}H{yields}{sup 6}Li+X{sup -}, where the X{sup -} is the negatively charged massive particle. We demonstrate the dominance of long-range part of the potential on the cross-section.

  9. Lithium abundances in exoplanet-hosts stars

    E-Print Network [OSTI]

    M. Castro; S. Vauclair; O. Richard; N. C. Santos

    2008-03-20T23:59:59.000Z

    Exoplanet-host stars (EHS) are known to present surface chemical abundances different from those of stars without any detected planet (NEHS). EHS are, on the average, overmetallic compared to the Sun. The observations also show that, for cool stars, lithium is more depleted in EHS than in NEHS. The overmetallicity of EHS may be studied in the framework of two different scenarii. We have computed main sequence stellar models with various masses, metallicities and accretion rates. The results show different profiles for the lithium destruction according to the scenario. We compare these results to the spectroscopic observations of lithium.

  10. SAFS-UW-1001 Abundance of Adult Hatchery and Wild

    E-Print Network [OSTI]

    Washington at Seattle, University of

    SAFS-UW-1001 July 2010 Abundance of Adult Hatchery and Wild Salmon by Region of the North Pacific Moore Foundation #12;Hatchery and Wild Salmon Abundance Page ii TABLE OF CONTENTS Page Introduction .............................................................................................................................. 1 Approaches to estimating wild salmon spawner abundances......................................... 1

  11. Heat transfer in ice hockey halls: measurements, energy analysis and analytical ice pad temperature profile

    E-Print Network [OSTI]

    Andrea Ferrantelli; Klaus Viljanen

    2015-06-30T23:59:59.000Z

    We consider heat transfer processes in an ice hockey hall, during operating conditions, with a bottom-up approach based upon on-site measurements. Detailed temperature data of both the ice pad and the air above the ice rink are used for a heat balance calculation in the steady-state regime, which quantifies the impact of each single heat source. We solve the heat equation in the ice slab in transient regime, and obtain a general analytical formula for the temperature profile. This solution is then applied to the resurfacing process by using our measurements as (time-dependent) boundary conditions (b.c.), and compared to an analogous numerical computation with good agreement. Our analytical formula is given with implicit initial condition and b.c., therefore it can be used not only in ice halls, but in a large variety of engineering applications.

  12. Heat transfer in ice hockey halls: measurements, energy analysis and analytical ice pad temperature profile

    E-Print Network [OSTI]

    Ferrantelli, Andrea

    2015-01-01T23:59:59.000Z

    We consider heat transfer processes in an ice hockey hall, during operating conditions, with a bottom-up approach based upon on-site measurements. Detailed temperature data of both the ice pad and the air above the ice rink are used for a heat balance calculation in the steady-state regime, which quantifies the impact of each single heat source. We solve the heat equation in the ice slab in transient regime, and obtain a general analytical formula for the temperature profile. This solution is then applied to the resurfacing process by using our measurements as (time-dependent) boundary conditions (b.c.), and compared to an analogous numerical computation with good agreement. Our analytical formula is given with implicit initial condition and b.c., therefore it can be used not only in ice halls, but in a large variety of engineering applications.

  13. Formation of Hydrogen, Oxygen, and Hydrogen Peroxide in Electron Irradiated Crystalline Water Ice

    E-Print Network [OSTI]

    Weijun Zheng; David Jewitt; Ralf I. Kaiser

    2005-11-18T23:59:59.000Z

    Water ice is abundant both astrophysically, for example in molecular clouds, and in planetary systems. The Kuiper belt objects, many satellites of the outer solar system, the nuclei of comets and some planetary rings are all known to be water-rich. Processing of water ice by energetic particles and ultraviolet photons plays an important role in astrochemistry. To explore the detailed nature of this processing, we have conducted a systematic laboratory study of the irradiation of crystalline water ice in an ultrahigh vacuum setup by energetic electrons holding a linear energy transfer of 4.3 +/- 0.1 keV mm-1. The irradiated samples were monitored during the experiment both on line and in situ via mass spectrometry (gas phase) and Fourier transform infrared spectroscopy (solid state). We observed the production of hydrogen and oxygen, both molecular and atomic, and of hydrogen peroxide. The likely reaction mechanisms responsible for these species are discussed. Additional formation routes were derived from the sublimation profiles of molecular hydrogen (90-140 K), molecular oxygen (147 -151 K) and hydrogen peroxide (170 K). We also present evidence on the involvement of hydroxyl radicals and possibly oxygen atoms as building blocks to yield hydrogen peroxide at low temperatures (12 K) and via a diffusion-controlled mechanism in the warming up phase of the irradiated sample.

  14. Molecular Gas Distribution in Double-Nucleus Ultraluminous Infrared Galaxies

    E-Print Network [OSTI]

    A. S. Evans; J. A. Surace; J. M. Mazzarella; D. B Sanders

    1999-12-22T23:59:59.000Z

    Millimeter (CO) observations of 5 double-nucleus ultraluminous infrared galaxy (ULIG) mergers are presented. With nuclear separations of 3-5 kpc, these galaxies are in the ``intermediate'' stages of the merger process. A preliminary comparison of the distribution of molecular gas (the likely fuel source for both starbursts and active galactic nuclei: AGN) shows a tendency for molecular gas to be associated with the AGN nucleus of ULIGs with ``warm'', Seyfert-like infrared colors ($f_{25 microns}/f_{60 microns} >~ 0.20) and associated with both stellar nuclei of ULIGs with ``cool'' infrared colors (f_{25 microns} /f_{60 microns} < 0.2). Studies of ULIGs with a wide range of nuclear separations using the high resolution and increased sensitivity of ALMA will provide a larger statistical sample with which the gas distribution, molecular gas masses, and densities can be determined as a function of the evolutionary stage, starburst and AGN activity, and lookback time.

  15. The Role of Snow and Ice in the Climate System

    SciTech Connect (OSTI)

    Barry, Roger (NSIDC) [NSIDC

    2007-12-19T23:59:59.000Z

    Global snow and ice cover (the 'cryosphere') plays a major role in global climate and hydrology through a range of complex interactions and feedbacks, the best known of which is the ice - albedo feedback. Snow and ice cover undergo marked seasonal and long term changes in extent and thickness. The perennial elements - the major ice sheets and permafrost - play a role in present-day regional and local climate and hydrology, but the large seasonal variations in snow cover and sea ice are of importance on continental to hemispheric scales. The characteristics of these variations, especially in the Northern Hemisphere, and evidence for recent trends in snow and ice extent are discussed.

  16. Methods and compositions for targeting macromolecules into the nucleus

    DOE Patents [OSTI]

    Chook, Yuh Min

    2013-06-25T23:59:59.000Z

    The present invention includes compositions, methods and kits for directing an agent across the nuclear membrane of a cell. The present invention includes a Karyopherin beta2 translocation motif in a polypeptide having a slightly positively charged region or a slightly hydrophobic region and one or more R/K/H-X.sub.(2-5)-P-Y motifs. The polypeptide targets the agent into the cell nucleus.

  17. Distribution of linearly polarized gluons inside a large nucleus

    E-Print Network [OSTI]

    Andreas Metz; Jian Zhou

    2011-09-08T23:59:59.000Z

    The distribution of linearly polarized gluons inside a large nucleus is studied in the framework of the color glass condensate. We find that the Weizs\\"acker-Williams distribution saturates the positivity bound at large transverse momenta and is suppressed at small transverse momenta, whereas the dipole distribution saturates the bound for any value of the transverse momentum. We also discuss processes in which both distributions of linearly polarized gluons can be probed.

  18. Element Abundances through the Cosmic Ages

    E-Print Network [OSTI]

    Max Pettini

    2003-03-12T23:59:59.000Z

    The horizon for studies of element abundances has expanded dramatically in the last ten years. Once the domain of astronomers concerned chiefly with stars and nearby galaxies, this field has now become a key component of observational cosmology, as technological advances have made it possible to measure the abundances of several chemical elements in a variety of environments at redshifts up to z = 4, when the universe was in its infancy. In this series of lectures I summarise current knowledge on the chemical make-up of distant galaxies observed directly in their starlight, and of interstellar and intergalactic gas seen in absorption against the spectra of bright background sources. The picture which is emerging is one where the universe at z = 3 already included many of the constituents of today's galaxies-even at these early times we see evidence for Population I and II stars, while the `smoking gun' for Population III objects may be hidden in the chemical composition of the lowest density regions of the intergalactic medium, yet to be deciphered.

  19. Beryllium abundances in stars hosting giant planets

    E-Print Network [OSTI]

    N. C. Santos; R. J. Garcia Lopez; G. Israelian; M. Mayor; R. Rebolo; A. Garcia-Gil; M. R. Perez de Taoro; S. Randich

    2002-02-25T23:59:59.000Z

    We have derived beryllium abundances in a wide sample of stars hosting planets, with spectral types in the range F7V-K0V, aimed at studying in detail the effects of the presence of planets on the structure and evolution of the associated stars. Predictions from current models are compared with the derived abundances and suggestions are provided to explain the observed inconsistencies. We show that while still not clear, the results suggest that theoretical models may have to be revised for stars with Teff<5500K. On the other hand, a comparison between planet host and non-planet host stars shows no clear difference between both populations. Although preliminary, this result favors a ``primordial'' origin for the metallicity ``excess'' observed for the planetary host stars. Under this assumption, i.e. that there would be no differences between stars with and without giant planets, the light element depletion pattern of our sample of stars may also be used to further investigate and constraint Li and Be depletion mechanisms.

  20. Oxygen Abundance Measurements of SHIELD Galaxies

    E-Print Network [OSTI]

    Haurberg, Nathalie C; Cannon, John M; Marshall, Melissa V

    2015-01-01T23:59:59.000Z

    We have derived oxygen abundances for 8 galaxies from the Survey of HI in Extremely Low-mass Dwarfs (SHIELD). The SHIELD survey is an ongoing study of very low-mass galaxies, with M$_{\\rm HI}$ between 10$^{6.5}$ and 10$^{7.5}$ M$_{\\odot}$, that were detected by the Arecibo Legacy Fast ALFA (ALFALFA) survey. H$\\alpha$ images from the WIYN 3.5m telescope show that these 8 SHIELD galaxies each possess one or two active star-forming regions which were targeted with long-slit spectral observations using the Mayall 4m telescope at KPNO. We obtained a direct measurement of the electron temperature by detection of the weak [O III] $\\lambda$4363 line in 2 of the HII regions. Oxygen abundances for the other HII regions were estimated using a strong-line method. When the SHIELD galaxies are plotted on a B-band luminosity-metallicity diagram they appear to suggest a slightly shallower slope to the relationship than normally seen. However, that offset is systematically reduced when the near-infrared luminosity is used ins...

  1. Correlation between thermodynamic anomalies and pathways of ice nucleation in supercooled water

    SciTech Connect (OSTI)

    Singh, Rakesh S.; Bagchi, Biman, E-mail: bbagchi@sscu.iisc.ernet.in [Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012 (India)] [Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012 (India)

    2014-04-28T23:59:59.000Z

    The well-known classical nucleation theory (CNT) for the free energy barrier towards formation of a nucleus of critical size of the new stable phase within the parent metastable phase fails to take into account the influence of other metastable phases having density/order intermediate between the parent metastable phase and the final stable phase. This lacuna can be more serious than capillary approximation or spherical shape assumption made in CNT. This issue is particularly significant in ice nucleation because liquid water shows rich phase diagram consisting of two (high and low density) liquid phases in supercooled state. The explanations of thermodynamic and dynamic anomalies of supercooled water often invoke the possible influence of a liquid-liquid transition between two metastable liquid phases. To investigate both the role of thermodynamic anomalies and presence of distinct metastable liquid phases in supercooled water on ice nucleation, we employ density functional theoretical approach to find nucleation free energy barrier in different regions of phase diagram. The theory makes a number of striking predictions, such as a dramatic lowering of nucleation barrier due to presence of a metastable intermediate phase and crossover in the dependence of free energy barrier on temperature near liquid-liquid critical point. These predictions can be tested by computer simulations as well as by controlled experiments.

  2. Longitudinal boost-invariance of charge balance function in hadron-hadron and nucleus-nucleus collisions

    E-Print Network [OSTI]

    Na LI Zhiming LI Yuanfang WU

    2009-10-10T23:59:59.000Z

    Using Monte Carlo generators of the PYTHIA model for hadron-hadron collisions and a multi-phase transport (AMPT) model for nucleus-nucleus collisions, the longitudinal boost-invariance of charge balance function and its transverse momentum dependence are carefully studied. It shows that the charge balance function is boost-invariant in both {\\it p}+{\\it p} and Au+Au collisions in these two models, consistent with experimental data. The balance function properly scaled by the width of the pseudorapidity window is independent of the position or the size of the window and is corresponding to the balance function of the whole pseudorapidity range. This longitudinal property of balance function also holds for particles in small transverse momentum ranges in the PYTHIA and the AMPT default models, but is violated in the AMPT with string melting. The physical origin of the results are discussed.

  3. Production of Kaon and $?$ in nucleus-nucleus collisions at ultra-relativistic energy from a blast wave model

    E-Print Network [OSTI]

    Song Zhang; Yu-Gang Ma; Jin-Hui Chen; Chen Zhong

    2014-11-06T23:59:59.000Z

    The particle production of Kaon and $\\Lambda$ are studied in nucleus-nucleus collisions at relativistic energy based on a chemical equilibrium blast-wave model. The transverse momentum spectra of Kaon and $\\Lambda$ at the kinetic freeze-out stage from our model are in good agreement with the experimental results. The kinetic freeze-out parameters of temperature ($T_{kin}$) and radial flow parameter $\\rho_{0}$ are presented for the FOPI, RHIC and LHC energies. And the resonance decay effect is also discussed. The systematic study for beam energy dependence of the strangeness particle production will help us to better understand the properties of the matter created in heavy-ion collisions at the kinetic freeze-out stage.

  4. WATER ICE IN THE KUIPER BELT

    SciTech Connect (OSTI)

    Brown, M. E.; Fraser, W. C. [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States); Schaller, E. L., E-mail: mbrown@caltech.edu [NASA Dryden Aircraft Operations Facility, Palmdale, CA 93550 (United States)

    2012-06-15T23:59:59.000Z

    We examine a large collection of low-resolution near-infrared spectra of Kuiper Belt objects (KBOs) and centaurs in an attempt to understand the presence of water ice in the Kuiper Belt. We find that water ice on the surface of these objects occurs in three separate manners: (1) Haumea family members uniquely show surfaces of nearly pure water ice, presumably a consequence of the fragmentation of the icy mantle of a larger differentiated proto-Haumea; (2) large objects with absolute magnitudes of H < 3 (and a limited number to H = 4.5) have surface coverings of water ice-perhaps mixed with ammonia-that appears to be related to possibly ancient cryovolcanism on these large objects; and (3) smaller KBOs and centaurs which are neither Haumea family members nor cold-classical KBOs appear to divide into two families (which we refer to as 'neutral' and 'red'), each of which is a mixture of a common nearly neutral component and either a slightly red or very red component that also includes water ice. A model suggesting that the difference between neutral and red objects due to formation in an early compact solar system either inside or outside, respectively, of the {approx}20 AU methanol evaporation line is supported by the observation that methanol is only detected on the reddest objects, which are those which would be expected to have the most of the methanol containing mixture.

  5. The Solar Heavy Element Abundances: I. Constraints from Stellar Interiors

    E-Print Network [OSTI]

    Delahaye, F; Delahaye, Franck; Pinsonneault, Marc

    2005-01-01T23:59:59.000Z

    The latest solar atmosphere models include non-LTE corrections and 3D hydrodynamic convection simulations. These models predict a significant reduction in the solar metal abundance, which leads to a serious conflict between helioseismic data and the predictions of solar interiors models. We demonstrate that the helioseismic constraints on the surface convection zone depth and helium abundance combined with stellar interiors models can be used to define the goodness of fit for a given chemical composition. After a detailed examination of the errors in the theoretical models we conclude that models constructed with the older solar abundances are consistent (seismic data. Models constructed with the proposed new low abundance scale are strongly disfavored, disagreeing at the 15 \\sigma level. We then use the sensitivity of the seismic properties to abundance changes to invert the problem and infer a seismic solar heavy element abundance mix with two components: meteoritic abundances, and th...

  6. Maneuverability of ships in ice: numerical simulation and comparison with field measurements

    E-Print Network [OSTI]

    Nørvåg, Kjetil

    Maneuverability of ships in ice: numerical simulation and comparison with field measurements Biao Su Department of Marine Technology, NTNU May 28, 2013 #12;Motivation Local ice load Global ice load Ship's performance · Ice-hull interaction · Local ice load · Global ice load · Ship's performance #12

  7. Development of the Great Lakes Ice-circulation Model (GLIM): Application to Lake Erie in 20032004

    E-Print Network [OSTI]

    Development of the Great Lakes Ice-circulation Model (GLIM): Application to Lake Erie in 2003: Received 4 May 2009 Accepted 30 November 2009 Communicated by Dr. Ram Yerubandi Index words: Coupled Ice-Ocean Model Ice modeling Lake ice cover Ice thickness Ice speed Lake surface temperature Great Lakes Lake Erie

  8. Numerical simulation of ice-induced loads on ships and comparison with field measurements

    E-Print Network [OSTI]

    Nørvåg, Kjetil

    Numerical simulation of ice-induced loads on ships and comparison with field measurements Biao Su Department of Marine Technology, NTNU May 28, 2013 #12;Motivation Local ice load Global ice load Ship's performance · Ice-hull interaction · Local ice load · Global ice load · Ship's performance #12;Outline

  9. Postdoctoral position Antarctic ice sheet modelling Free University of Brussels (VUB)

    E-Print Network [OSTI]

    Huybrechts, Philippe

    systems and ice caps, and in ice sheets in both polar regions (Greenland and Antarctica). The project as improved treatments for basal processes (basal sliding below ice sheet, basal melting below ice shelvesPostdoctoral position ­ Antarctic ice sheet modelling Free University of Brussels (VUB) The Ice

  10. Basal melt rates beneath Whillans Ice Stream, West Antarctica

    E-Print Network [OSTI]

    Beem, Lucas H.; Jezek, Ken C.; Van Der Veen, C. J.

    2010-08-05T23:59:59.000Z

    Basal water lubricates and enables the fast flow of the West Antarctic ice streams which exist under low gravitational driving stress. Identification of sources and rates of basal meltwater production can provide insight into the dynamics of ice...

  11. Study of ice cloud properties using infrared spectral data

    E-Print Network [OSTI]

    Garrett, Kevin James

    2009-05-15T23:59:59.000Z

    The research presented in this thesis involves the study of ice cloud microphysical and optical properties using both hyperspectral and narrowband infrared spectral data. First, ice cloud models are developed for the Infrared Atmospheric Sounding...

  12. arctic ocean ice: Topics by E-print Network

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

    AD of transient model simulations and a new type of sen- sitivity experiments with artificial sea ice growth Born, Andreas 320 The Thinning of Arctic Sea Ice, 19882003: Have...

  13. Study of ice cloud properties using infrared spectral data 

    E-Print Network [OSTI]

    Garrett, Kevin James

    2009-05-15T23:59:59.000Z

    The research presented in this thesis involves the study of ice cloud microphysical and optical properties using both hyperspectral and narrowband infrared spectral data. First, ice cloud models are developed for the Infrared Atmospheric Sounding...

  14. aircraft icing training: Topics by E-print Network

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

    Completed all Enhanced Hot Water Drill staff from UW, IceCube collaborators, and Raytheon. Conducted a Quarterly Status Meeting at UW-loaded schedule for on-ice...

  15. andrill mcmurdo ice: Topics by E-print Network

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

    Completed all Enhanced Hot Water Drill staff from UW, IceCube collaborators, and Raytheon. Conducted a Quarterly Status Meeting at UW-loaded schedule for on-ice...

  16. aterrizamiento del ice: Topics by E-print Network

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

    Completed all Enhanced Hot Water Drill staff from UW, IceCube collaborators, and Raytheon. Conducted a Quarterly Status Meeting at UW-loaded schedule for on-ice...

  17. aircraft icing hazards: Topics by E-print Network

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

    Completed all Enhanced Hot Water Drill staff from UW, IceCube collaborators, and Raytheon. Conducted a Quarterly Status Meeting at UW-loaded schedule for on-ice...

  18. aircraft icing nowcasting: Topics by E-print Network

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

    Completed all Enhanced Hot Water Drill staff from UW, IceCube collaborators, and Raytheon. Conducted a Quarterly Status Meeting at UW-loaded schedule for on-ice...

  19. adsorption ice maker: Topics by E-print Network

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

    Completed all Enhanced Hot Water Drill staff from UW, IceCube collaborators, and Raytheon. Conducted a Quarterly Status Meeting at UW-loaded schedule for on-ice...

  20. ancient 19-m ice: Topics by E-print Network

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

    Completed all Enhanced Hot Water Drill staff from UW, IceCube collaborators, and Raytheon. Conducted a Quarterly Status Meeting at UW-loaded schedule for on-ice...

  1. IceCube Project Monthly Report -November 2009 Accomplishments

    E-Print Network [OSTI]

    Saffman, Mark

    -speaking researchers. · IceCube participated with Raytheon Polar Services Company in an extremely successful emergency principally due to lower labor and on-ice support costs for Raytheon Polar Services Corporation and the Air

  2. Cirrus cloud formation and the role of heterogeneous ice nuclei

    E-Print Network [OSTI]

    Froyd, Karl D.

    2013-01-01T23:59:59.000Z

    Composition, size, and phase are key properties that define the ability of an aerosol particle to initiate ice in cirrus clouds. Properties of cirrus ice nuclei (IN) have not been well constrained due to a lack of systematic ...

  3. Abundance ratios in hierarchical galaxy formation

    E-Print Network [OSTI]

    D. Thomas

    1999-01-18T23:59:59.000Z

    The chemical enrichment and stellar abundance ratios of galaxies which form in a hierarchical clustering scheme are calculated. For this purpose I adopt the star formation histories (SFH) as they are delivered by semi-analytic models in Kauffmann (1996}. It turns out that the average SFH of cluster ellipticals does not yield globally alpha-enhanced stellar populations. The star burst that occurs when the elliptical forms in the major merger plays therefore a crucial role in producing alpha-enhancement. Only under the assumption that the IMF is significantly flattened with respect to the Salpeter value during the burst, a Mg/Fe overabundant population can be obtained. In particular for the interpretation of radial gradients in metallicity and alpha-enhancement, the mixing of global and burst populations are of great importance. The model predicts bright field galaxies to be less alpha-enhanced than their counterparts in clusters.

  4. Learn to Skate at UAF Patty Ice Arena

    E-Print Network [OSTI]

    Wagner, Diane

    Learn to Skate at UAF Patty Ice Arena Tots(age 3-6)& Beginners/Pre-Alpha(age 6-up) 4 Sessions for non-members; $20/day Alpha-Freestyle 3:30-5:00pm One year membership to Ice Skating Institute - $15BreakSkatingCamp Skating for Hockey 3:30-5:00pm March 12-15 3:30-3:45 - O -ice:Warm up 4:00-4:45 - On Ice Skills 15 min

  5. Covered Product Category: Water-Cooled Ice Machines

    Broader source: Energy.gov [DOE]

    The Federal Energy Management Program (FEMP) provides acquisition guidance and federal efficiency requirements for water-cooled ice machines.

  6. An update on land-ice modeling in the CESM

    SciTech Connect (OSTI)

    Lipscomb, William H [Los Alamos National Laboratory

    2011-01-18T23:59:59.000Z

    Mass loss from land ice, including the Greenland and Antarctic ice sheets as well as smaller glacier and ice caps, is making a large and growing contribution to global sea-level rise. Land ice is only beginning to be incorporated in climate models. The goal of the Land Ice Working Group (LIWG) is to develop improved land-ice models and incorporate them in CESM, in order to provide useful, physically-based sea-level predictions. LJWG efforts to date have led to the inclusion of a dynamic ice-sheet model (the Glimmer Community Ice Sheet Model, or Glimmer-CISM) in the Community Earth System Model (CESM), which was released in June 2010. CESM also includes a new surface-mass-balance scheme for ice sheets in the Community Land Model. Initial modeling efforts are focused on the Greenland ice sheet. Preliminary results are promising. In particular, the simulated surface mass balance for Greenland is in good agreement with observations and regional model results. The current model, however, has significant limitations: The land-ice coupling is one-way; we are using a serial version of Glimmer-CISM with the shallow-ice approximation; and there is no ice-ocean coupling. During the next year we plan to implement two-way coupling (including ice-ocean coupling with a dynamic Antarctic ice sheet) with a parallel , higher-order version of Glimmer-CISM. We will also add parameterizations of small glaciers and ice caps. With these model improvements, CESM will be able to simulate all the major contributors to 21st century global sea-level rise. Results of the first round of simulations should be available in time to be included in the Fifth Assessment Report (ARS) of the Intergovernmental Panel on Climate Change.

  7. Electron decay at IceCube

    E-Print Network [OSTI]

    Lynch, Morgan H

    2015-01-01T23:59:59.000Z

    In this paper we apply the formalism of Accelerated Quantum Dynamics (AQD) to the radiative stopping of highly relativistic electrons in ice. We compute the lifetime of electrons to decay into muons as well as the spectrum of the emitted muons. The energy of the emitted muon depends on the deceleration of the electron and this correlation can be used to tag the event and confirm the prediction. The results predict the acceleration-induced decay of electrons at IceCube energies. This experimental setting has the potential to establish the existence of the Unruh effect as well investigate the role of high acceleration in particle physics.

  8. The effect of ice crystal surface roughness on the retrieval of ice cloud microphysical and optical properties

    E-Print Network [OSTI]

    Xie, Yu

    2007-09-17T23:59:59.000Z

    The effect of the surface roughness of ice crystals is not routinely accounted for in current cloud retrieval algorithms that are based on pre-computed lookup libraries. In this study, we investigate the effect of ice crystal surface roughness...

  9. Observations: Changes in Snow, Ice and Frozen Ground

    E-Print Network [OSTI]

    Jellinek, Mark

    ................................................ 352 4.4.4 Pack Ice Motion................................................... 355 4.5 Changes4 Observations: Changes in Snow, Ice and Frozen Ground Coordinating Lead Authors: Peter Lemke. Kaser, P. Mote, R.H. Thomas and T. Zhang, 2007: Observations: Changes in Snow, Ice and Frozen Ground. In

  10. Contemporary Lake Superior Ice Cover Climatology Raymond A. Assel

    E-Print Network [OSTI]

    Contemporary Lake Superior Ice Cover Climatology Raymond A. Assel NOAA Great Lakes Environmental Introduction A brief discussion of Lake Superior ice cover climatology (Phillips, 1978) was included) almost three decades ago. Much additional information (and analysis) of Great Lakes ice cover has been

  11. The Integrated Computer Engineering Design (ICED) Curriculum Augustus K. Uht

    E-Print Network [OSTI]

    Uht, Augustus K.

    The Integrated Computer Engineering Design (ICED) Curriculum Augustus K. Uht Department computer engineering curriculum, ICED, is being introduced at the University of Rhode Island. The main. This paper gives the rationale of ICED in depth, and describes the core courses, their activities and use

  12. Ice-Floe Simulation Viewer Tool Justin Adams

    E-Print Network [OSTI]

    Peters, Dennis

    Ice-Floe Simulation Viewer Tool Justin Adams Computer Engineering Memorial University St. John's, Newfoundland dpeters@mun.ca Abstract--We are developing software to simulate the be- haviour of sea ice the ability to set up the initial conditions, run the simulation, and display the simulated ice- floe data

  13. Bacteria beneath the West Antarctic Ice Sheet Brian Lanoil,1

    E-Print Network [OSTI]

    Priscu, John C.

    Bacteria beneath the West Antarctic Ice Sheet Brian Lanoil,1 * Mark Skidmore,1 John C. Priscu,2, particularly those that lie beneath polar ice sheets, are beginning to be recog- nized as an important part Vostok, Antarctica, no sub-ice sheet environments have been shown to support microbial ecosystems. Here

  14. Ice Simulation Using GPGPU Shadi Alawneh and Dennis Peters

    E-Print Network [OSTI]

    Peters, Dennis

    Ice Simulation Using GPGPU Shadi Alawneh and Dennis Peters Electrical and Computer Engineering.alawneh, dpeters}@mun.ca Abstract-- Simulation of the behaviour of a ship operating in pack ice on several different ice fields for several iterations to compare the performance. Our results show speed up

  15. A Computer Tutorial for Great Lakes Ice Cover Climatology

    E-Print Network [OSTI]

    A Computer Tutorial for Great Lakes Ice Cover Climatology R.A. ASSELL U.S. Department of Commerce tutorial was developed to provide an overview of the annual ~ r e a fLakes ice cycle. The tutorial includes an animation to aid in visualizing the normal seasonal progression and the spatial patterns of ice cover

  16. Implementing an ICE: A methodology for the design, development

    E-Print Network [OSTI]

    Deussen, Oliver

    Implementing an ICE: A methodology for the design, development and installation of Interactive for the design, development and implementation of ICEs (Interactive Collaborative Environments) in real world with the Edinburgh Napier ICE, a multi-user, multi-surface, multi-touch blended interaction digitally augmented space

  17. Modeling Lake Erie ice dynamics: Process studies , Haoguo Hu2

    E-Print Network [OSTI]

    Modeling Lake Erie ice dynamics: Process studies Jia Wang1 , Haoguo Hu2 , and Xuezhi Bai2 1 NOAA of Michigan 4840 S. State Road, Ann Arbor, MI 48108 Abstract. A Great Lakes Ice-circulation Model (GLIM derived from meteorological measurements. After the seasonal cycles of ice concentration, thickness

  18. ICE Algorithm for the Shocktube Problem Oren E. Livne

    E-Print Network [OSTI]

    Utah, University of

    1 ICE Algorithm for the Shocktube Problem Oren E. Livne UUSCI-2006-007 Scientific Computing the main ICE advection algorithm for scalar advection problems (advection and Burg- ers step in this original Kashiwa ICE algorithm [Kas00], and its relation of both the Davis scheme [Dav87

  19. A lattice model to simulate ice-structure interaction

    E-Print Network [OSTI]

    Boyer, Edmond

    A lattice model to simulate ice-structure interaction O. Dorival, A. V. Metrikine, A. Simone of Technology P. O. Box 5048, 2600 GA Delft, Netherlands Abstract The interaction between ice sheets, due to the complexity of ice material the use of small-scale experiments is problematic if one aims

  20. Operation and Control of Full Ice-storage System

    E-Print Network [OSTI]

    Liu, Q.; Liu, Y.

    2006-01-01T23:59:59.000Z

    In a dividing time ice-storage system, the refrigerator does not operate during power's on-peak period, and all the cooling is supplied by the ice stored in off-peak period, so that the use of electricity can be maintained. When the ice is thawing...

  1. Global Ice and Land Climate Studies Using Scatterometer Image Data

    E-Print Network [OSTI]

    Long, David G.

    1 Global Ice and Land Climate Studies Using Scatterometer Image Data David G. Long Brigham Young CA 91109 ben@pacific.jpl.nasa.gov Sasan.Saatchi@jpl.nasa.gov Cheryl Bertoia U. S. National Ice Center: Long, D. G., M. R. Drinkwater, B. Holt, S. Saatchi, and C. Bertoia, Global ice and land climate studies

  2. Is the Missing Ultra-Red Material Colorless Ice?

    E-Print Network [OSTI]

    W. M. Grundy

    2008-11-14T23:59:59.000Z

    The extremely red colors of some transneptunian objects and Centaurs are not seen among the Jupiter family comets which supposedly derive from them. Could this mismatch result from sublimation loss of colorless ice? Radiative transfer models show that mixtures of volatile ice and nonvolatile organics could be extremely red, but become progressively darker and less red as the ice sublimates away.

  3. STATE OF CALIFORNIA ICE STORAGE AIR CONDITIONING (ISAC) UNITS

    E-Print Network [OSTI]

    cooling with the compressor). Yes No #12;STATE OF CALIFORNIA ICE STORAGE AIR CONDITIONING (ISAC) UNITS CEC/09) CALIFORNIA ENERGY COMMISSION INSTALLATION CERTIFICATE CF-6R-MECH-08 Ice Storage Air Conditioning (ISAC) Units being full of ice. Verify that the system is operates properly in the Idle mode (i.e., the compressor

  4. THE CONTRIBUTION OF GREENLAND ICE SHEET MELTING TO

    E-Print Network [OSTI]

    THE CONTRIBUTION OF GREENLAND ICE SHEET MELTING TO GLOBAL SEA-LEVEL CHANGE Conor Mc three major sources, the Greenland ice sheet, Antarctica, and other eustatic components. Each has its own predictable spatial signal, and particular attention was paid to the Greenland ice sheet, given

  5. The Ice Rink Problem 1 Bernard M.E. Moret,

    E-Print Network [OSTI]

    Moret, Bernard

    The Ice Rink Problem 1 Bernard M.E. Moret, Michael Collins, Jared Saia, and Ling Yu Department the sensor footprint. A similar task with a simpler geometry consists of cleaning an ice rink. We prove that the method used in ice rinks (the ``Zamboni algorithm'') is optimal and use it to develop heuristics

  6. Integrated navigation for AUV operations under ice shelves

    E-Print Network [OSTI]

    Griffiths, Gwyn

    Integrated navigation for AUV operations under ice shelves Gwyn Griffiths and Steve Mc One-slide summary of the Autosub AUV J Why explore beneath ice shelves? J Technology challenges: the Halliburton `Geosub' #12;Why explore beneath ice shelves? Gl oba l Wa r mi ng Li nke d t o Me l t i ng I c e c

  7. ICE SHEET SOURCES OF SEA LEVEL RISE AND FRESHWATER DISCHARGE

    E-Print Network [OSTI]

    Carlson, Anders

    ICE SHEET SOURCES OF SEA LEVEL RISE AND FRESHWATER DISCHARGE DURING THE LAST DEGLACIATION Anders E the sources of sea level rise and freshwater dis- charge to the global oceans associated with retreat of ice­10 m sea level rise at 19.0­19.5 ka, sourced largely from Northern Hemisphere ice sheet retreat

  8. Historical and future black carbon deposition on the three ice caps: Ice core measurements and model simulations from 1850 to 2100

    E-Print Network [OSTI]

    Historical and future black carbon deposition on the three ice caps: Ice core measurements black carbon deposition on the three ice caps: Ice core measurements and model simulations from 1850 tends to enhance snow and ice melting due to the absorption caused by the increased BC deposition

  9. Neutrino-nucleus interactions and the determination of oscillation parameters

    E-Print Network [OSTI]

    Omar Benhar; Patrick Huber; Camillo Mariani; Davide Meloni

    2015-01-26T23:59:59.000Z

    We review the status and prospects of theoretical studies of neutrino-nucleus interactions, and discuss the influence of the treatment of nuclear effects on the determination of oscillation parameters. The models developed to describe the variety of reaction mechanisms contributing to the nuclear cross sections are analysed, with emphasis placed on their capability to reproduce the available electron scattering data.The impact of the uncertainties associated with the description of nuclear dynamics on the the oscillation parameters is illustrated through examples, and possible avenues towards a better understanding of the signals detected by long baseline experiments are outlined.

  10. Neutrino-nucleus interactions and the determination of oscillation parameters

    E-Print Network [OSTI]

    Benhar, Omar; Mariani, Camillo; Meloni, Davide

    2015-01-01T23:59:59.000Z

    We review the status and prospects of theoretical studies of neutrino-nucleus interactions, and discuss the influence of the treatment of nuclear effects on the determination of oscillation parameters. The models developed to describe the variety of reaction mechanisms contributing to the nuclear cross sections are analysed, with emphasis placed on their capability to reproduce the available electron scattering data.The impact of the uncertainties associated with the description of nuclear dynamics on the the oscillation parameters is illustrated through examples, and possible avenues towards a better understanding of the signals detected by long baseline experiments are outlined.

  11. Nuclear medium effects in $?(\\bar?)$-nucleus deep inelastic scattering

    E-Print Network [OSTI]

    H. Haider; I. Ruiz Simo; M. Sajjad Athar; M. J. Vicente Vacas

    2011-08-16T23:59:59.000Z

    We study the nuclear medium effects in the weak structure functions $F_2(x,Q^2)$ and $F_3(x,Q^2)$ in the deep inelastic neutrino/antineutrino reactions in nuclei. We use a theoretical model for the nuclear spectral functions which incorporates the conventional nuclear effects, such as Fermi motion, binding and nucleon correlations. We also consider the pion and rho meson cloud contributions calculated from a microscopic model for meson-nucleus self-energies. The calculations have been performed using relativistic nuclear spectral functions which include nucleon correlations. Our results are compared with the experimental data of NuTeV and CDHSW.

  12. Dynamics and energetics of the cloudy boundary layer in simulations of off-ice flow in the marginal ice zone

    E-Print Network [OSTI]

    Harrington, Jerry Y.

    kinetic energy even in the present case where very strong surface heat fluxes occur. Ice-phase. Inclusion of the ice phase significantly affected the radiative budget as compared to purely liquid clouds, illustrating the importance of ice-phase­radiative couplings for accurate simulations of arctic clouds

  13. Where might we find evidence of a Last Interglacial West Antarctic Ice Sheet collapse in Antarctic ice core records?

    E-Print Network [OSTI]

    Siddall, Mark

    increased melting from valley glaciers and small ice caps (estimated ~0.6±0.1 m, Radi and Hock, 2010), oceanWhere might we find evidence of a Last Interglacial West Antarctic Ice Sheet collapse in Antarctic ice core records? S.L. Bradley a, , M. Siddall a , G.A. Milne b , V. Masson-Delmotte c , E. Wolff d

  14. Decadal-scale variations in ice flow along Whillans Ice Stream and its tributaries, West Antarctica

    E-Print Network [OSTI]

    Stearns, Leigh; Jezek, K.A.; Van der Veen, C.J.

    2005-01-01T23:59:59.000Z

    We investigate velocity changes occurring along Whillans Ice Stream (WIS) by comparing velocities derived from repeat aerial photographs acquired in 1985–89 (average date of 1987) to interferometric satellite radar (InSAR) velocities collected...

  15. Focused synthetic aperture radar processing of ice-sounder data collected over the Greenland ice sheet

    E-Print Network [OSTI]

    Legarsky, J.; Gogineni, Sivaprasad; Akins, T. L.

    2001-10-01T23:59:59.000Z

    We developed a synthetic aperture radar (SAR) processing algorithm for airborne/spaceborne ice-sounding radar systems and applied it to data collected in Greenland. By using focused SAR (phase-corrected coherent averaging), we improved along...

  16. The Solar Heavy Element Abundances: I. Constraints from Stellar Interiors

    E-Print Network [OSTI]

    Franck Delahaye; Marc Pinsonneault

    2005-11-29T23:59:59.000Z

    The latest solar atmosphere models include non-LTE corrections and 3D hydrodynamic convection simulations. These models predict a significant reduction in the solar metal abundance, which leads to a serious conflict between helioseismic data and the predictions of solar interiors models. We demonstrate that the helioseismic constraints on the surface convection zone depth and helium abundance combined with stellar interiors models can be used to define the goodness of fit for a given chemical composition. After a detailed examination of the errors in the theoretical models we conclude that models constructed with the older solar abundances are consistent (seismic data. Models constructed with the proposed new low abundance scale are strongly disfavored, disagreeing at the 15 \\sigma level. We then use the sensitivity of the seismic properties to abundance changes to invert the problem and infer a seismic solar heavy element abundance mix with two components: meteoritic abundances, and the light metals CNONe. Seismic degeneracies between the best solutions for the elements arise for changes in the relative CNONe abundances and their effects are quantified. We obtain Fe/H=7.50+/-0.045+/-0.003(CNNe) and O/H=8.86+/-0.041+/-0.025(CNNe) for the relative CNNe in the GS98 mixture. The inferred solar oxygen abundance disagree with the abundance inferred from the 3D hydro models. Changes in the Ne abundance can mimic changes in O for the purposes of scalar constraints.Models constructed with low oxygen and high neon are inconsistent with the solar sound speed profile. The implications for the solar abundance scale are discussed.

  17. Ice surfaces: macroscopic effects of microscopic structure

    E-Print Network [OSTI]

    Wettlaufer, John S.

    in the large tropical and subtropical belt, and between -20 and -40 C in the small polar caps. Water becomes ice at just around the middle of that temperature range. Only a small shift in temperature determines microphysics and chemistry have large-scale consequences. The difficulties associated with observing processes

  18. Ocean Atmosphere Sea Ice Soil User's Guide

    E-Print Network [OSTI]

    OASIS3 Ocean Atmosphere Sea Ice Soil User's Guide oasis3 prism 2­2, June 2004 Sophie Valcke 1 to realize a coupled simulation with OASIS3. The aim of OASIS3 is to provide a flexible and user friendly. OASIS3 synchronizes the exchanges of coupling fields between the models being coupled, and performs 2D

  19. Ocean Atmosphere Sea Ice Soil User's Guide

    E-Print Network [OSTI]

    OASIS3 Ocean Atmosphere Sea Ice Soil User's Guide oasis3 prism 2­3, August 2004 Sophie Valcke 1 to realize a coupled simulation with OASIS3. The aim of OASIS3 is to provide a flexible and user friendly. OASIS3 synchronizes the exchanges of coupling fields between the models being coupled, and performs 2D

  20. Ocean Atmosphere Sea Ice Soil User's Guide

    E-Print Network [OSTI]

    OASIS 2.0 Ocean Atmosphere Sea Ice Soil User's Guide and Reference Manual November 1995 Laurent for the straightforward use of OASIS 2.0. As far as we know, it is the best way to use it! The aim of OASIS is to provide been particularly emphasized in the OASIS design. The use of OASIS does not change the way the models

  1. IceCube Project Monthly Report Accomplishments

    E-Print Network [OSTI]

    Saffman, Mark

    .2% complete, as measured using earned value techniques. The contingency % of the remaining work is 28.3%. #12 with critical dates and activities managed by both Raytheon Polar Services Company and the UW is set Division Management, and FY08 Actual costs for On-Ice Support that were less than planned. 5/31/08 Change

  2. IceCube Project Monthly Report Accomplishments

    E-Print Network [OSTI]

    Saffman, Mark

    versus the planned performance of 55.8% complete as measured using earned value techniques. The earned safety training for drilling and installation managers, safety leads and a few other on- ice personnel Project Cost $274.3 Value of Foreign Contributions $32.2 NSF Funding $242.1 Contingency as % of Remaining

  3. Largest Ice-Bank Promotes Load Management

    E-Print Network [OSTI]

    Brarmann, G. L.

    1983-01-01T23:59:59.000Z

    of both the 30-year old, 265,000 square foot facility and the new 156,000 square foot Fred L. Hartley Research Center. The energy and demand savings resulting from the installation of the ice-bank system are significant. Large commercial and industrial...

  4. Toward Extraplanetary Under-Ice Exploration

    E-Print Network [OSTI]

    Eustice, Ryan

    .jhu@gmail.com Ryan Eustice Department of Naval Architecture and Marine Engineering University of Michigan Ann Arbor· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · Toward Extraplanetary Under-Ice@whoi.edu, rsohn@whoi.edu, ssingh@whoi.edu Taichi Sato Ocean Research Institute University of Tokyo Nakano, Tokyo

  5. Planning Amid Abundance: Alaska’s FY 2013 Budget Process

    E-Print Network [OSTI]

    McBeath, Jerry

    2013-01-01T23:59:59.000Z

    state’s incentives for oil investment are excessive” (FDNM,increased oil industry investment. Planning Amid Abundance:oil corporations said that additional investment was

  6. Earth's most abundant mineral finally has a name | Argonne National...

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

    clarified the definition of Bridgmanite, a high-density form of magnesium iron silicate and the Earth's most abundant mineral - using Argonne National Laboratory's Advanced...

  7. Oxygen abundances in the most oxygen-rich spiral galaxies

    E-Print Network [OSTI]

    L. S. Pilyugin; T. X. Thuan; J. M. Vilchez

    2006-01-06T23:59:59.000Z

    Oxygen abundances in the spiral galaxies expected to be richest in oxygen are estimated. The new abundance determinations are based on the recently discovered ff-relation between auroral and nebular oxygen line fluxes in HII regions. We find that the maximum gas-phase oxygen abundance in the central regions of spiral galaxies is 12+log(O/H)~8.75. This value is significantly lower than the previously accepted value. The central oxygen abundance in the Milky Way is similar to that in other large spirals.

  8. Enhanced Detection of Low Abundant Human Plasma Proteins using...

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

    it especially difficult to detect low-abundant proteins in human biofluids such as blood plasma, an essential aspect for successful biomarker discovery efforts. Here we...

  9. High-Performance Thermoelectric Devices Based on Abundant Silicide...

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

    Development of high-performance thermoelectric devices for vehicle waste heat recovery will include fundamental research to use abundant promising low-cost thermoelectric...

  10. Modeling the Fracture of Ice Sheets on Parallel Computers

    SciTech Connect (OSTI)

    Waisman, Haim [Columbia University] [Columbia University; Tuminaro, Ray [Sandia National Labs] [Sandia National Labs

    2013-10-10T23:59:59.000Z

    The objective of this project was to investigate the complex fracture of ice and understand its role within larger ice sheet simulations and global climate change. This objective was achieved by developing novel physics based models for ice, novel numerical tools to enable the modeling of the physics and by collaboration with the ice community experts. At the present time, ice fracture is not explicitly considered within ice sheet models due in part to large computational costs associated with the accurate modeling of this complex phenomena. However, fracture not only plays an extremely important role in regional behavior but also influences ice dynamics over much larger zones in ways that are currently not well understood. To this end, our research findings through this project offers significant advancement to the field and closes a large gap of knowledge in understanding and modeling the fracture of ice sheets in the polar regions. Thus, we believe that our objective has been achieved and our research accomplishments are significant. This is corroborated through a set of published papers, posters and presentations at technical conferences in the field. In particular significant progress has been made in the mechanics of ice, fracture of ice sheets and ice shelves in polar regions and sophisticated numerical methods that enable the solution of the physics in an efficient way.

  11. Comparing halo bias from abundance and clustering

    E-Print Network [OSTI]

    Hoffmann, Kai; Gaztanaga, Enrique

    2015-01-01T23:59:59.000Z

    We model the abundance of haloes in the $\\sim(3 \\ \\text{Gpc}/h)^3$ volume of the MICE Grand Challenge simulation by fitting the universal mass function with an improved Jack-Knife error covariance estimator that matches theory predictions. We present unifying relations between different fitting models and new predictions for linear ($b_1$) and non-linear ($c_2$ and $c_3$) halo clustering bias. Different mass function fits show strong variations in their overall poor performance when including the low mass range ($M_h \\lesssim 3 \\ 10^{12} \\ M_{\\odot}/h$) in the analysis, which indicates noisy friends-of-friends halo detection given the MICE resolution ($m_p \\simeq 3 \\ 10^{10} \\ M_{\\odot}$/h). Together with fits from the literature we find an overall variance in the amplitudes of around $10%$ in the low mass and up to $50%$ in the high mass (galaxy cluster) range ($M_h > 10^{14} \\ M_{\\odot}/h$). These variations propagate into a $10%$ change in $b_1$ predictions and a $50%$ change in $c_2$ or $c_3$. Despite the...

  12. Topology in QCD and the axion abundance

    E-Print Network [OSTI]

    Kitano, Ryuichiro

    2015-01-01T23:59:59.000Z

    The temperature dependence of the topological susceptibility (chi_t) in QCD essentially determines the abundance of the QCD axion in the Universe, and is commonly estimated, based on the instanton picture, to be a certain negative power of temperature. While lattice QCD should be able to check the instanton picture in principle, the region of the temperature where lattice calculations of chi_t are reliable is rather limited in practice, because existing methods on the lattice will probably fail when chi_t decreases rapidly with temperatures. In this work, two exploratory studies are presented. First, to realize the limitation of temperature we perform lattice calculations of chi_t in the quenched approximation and find that it becomes difficult with a given resource when T > 2 T_c. A possible way out is proposed and some test calculations are given. The absolute value and the temperature dependence of chi_t in real QCD can be significantly different from that in the quenched approximation, and is not well est...

  13. CHEMICAL ABUNDANCES IN CLUSTERS OF GALAXIES

    E-Print Network [OSTI]

    Francesca Matteucci; Brad K. Gibson

    1995-03-14T23:59:59.000Z

    We study the origin of iron and alpha-elements (O, Mg, Si) in clusters of galaxies. In particular, we discuss the [O/Fe] ratio and the iron mass-to-luminosity ratio in the intracluster medium (ICM) and their link to the chemical and dynamical evolution of elliptical and lenticular galaxies. We adopt a detailed model of galactic evolution incorporating the development of supernovae- driven galactic winds which pollute the ICM with enriched ejecta. We demonstrate \\it quantitatively \\rm the crucial dependence upon the assumed stellar initial mass function in determining the evolution of the mass and abundances ratios of heavy elements in typical model ICMs. We show that completely opposite behaviours of [alpha/Fe] ratios (\\ie positive versus negative ratios) can be obtained by varying the initial mass function without altering the classic assumptions regarding type Ia supernovae progenitors or their nucleosynthesis. Our results indicate that models incorporating somewhat flatter-than-Salpeter initial mass functions (ie x approx 1, as opposed to x=1.35) are preferred, provided the intracluster medium iron mass-to-luminosity ratio, preliminary [alpha/Fe]>0 ASCA results, and present-day type Ia supernovae rates, are to be matched. A simple Virgo cluster simulation which adheres to these constraints shows that approx 70% of the measured ICM iron mass has its origin in type II supernovae, with the remainder being synthesized in type Ia systems.

  14. West antarctic ice sheet collapse: Chimera or clear danger

    SciTech Connect (OSTI)

    Alley, R.B. (Pennsylvania State Univ., University Park, PA (United States)); MacAyeal, D.R. (Univ. of Chicago, IL (United States))

    1993-01-01T23:59:59.000Z

    The specter of a west antarctic collapse has been with us for 25 years. Recently, certain official assessments concerned primarily with the future response to projected global warming have concluded that Antarctica will not cause much sea-level rise within the planning horizon of a century or so. At the same time startling new results on ice sheet (in)stability have been emerging, pointing to less stability then previously believed. Some recent results are reviewed briefly: Heinrich layers in the North Atlantic show basally lubricated surges of the Laurentide ice sheet; the west antarctic ice sheet collapsed recently; the modern west antarctic ice sheet is changing rapidly locally; the bed of ice stream B is exceptionally well lubricated by water and water-saturated soft sediments; the modern ice sheet is thinning slowly on average; a model west antarctic ice sheet undergoes rapid collapses long after forcing and probably related to penetration of warmth to the bed. 23 refs.

  15. Determining Greenland Ice Sheet sensitivity to regional climate change: one-way coupling of a 3-D thermo-mechanical ice sheet model with a mesoscale climate model

    E-Print Network [OSTI]

    Schlegel, Nicole-Jeanne

    2011-01-01T23:59:59.000Z

    Jakobshavn I. Rinks Observed Historic Flux (km 3 ice/year)I. Rinks * Outlets fed by the Northeast Greenland Ice StreamRinks, measured in 2000). Figure 3.1: Steady-state (A) topography (m) and (C) ice

  16. E-Print Network 3.0 - atomic nucleus theory Sample Search Results

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

    of the Folding Nucleus Summary: , 177-196. 32. Mirny, L. & Shakhnovich, E. (2001). Protein folding theory: from lattice to all-atom... COMMUNICATION Evolutionary Conservation of...

  17. THE THERMAL EVOLUTION OF ICES IN THE ENVIRONMENTS OF NEWLY FORMED STARS: THE CO{sub 2} DIAGNOSTIC

    SciTech Connect (OSTI)

    Cook, A. M.; Whittet, D. C. B. [New York Center for Astrobiology and Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, 110 Eighth Street, Troy, NY 12180 (United States); Shenoy, S. S. [Spitzer Science Center, Mail Code 220-6, California Institute of Technology, Pasadena, CA 91125 (United States); Gerakines, P. A.; White, D. W. [Department of Physics, University of Alabama at Birmingham, 310 Campbell Hall, 1300 University Boulevard, Birmingham, AL 35294 (United States); Chiar, J. E. [SETI Institute, 189 Bernardo Avenue, Mountain View, CA 94043 (United States)

    2011-04-01T23:59:59.000Z

    Archival data from the Infrared Spectrometer of the Spitzer Space Telescope are used to study the 15 {mu}m absorption feature of solid CO{sub 2} toward 28 young stellar objects (YSOs) of approximately solar mass. Fits to the absorption profile using laboratory spectra enable categorization according to the degree of thermal processing of the ice matrix that contains the CO{sub 2}. The majority of YSOs in our sample (20 out of 28) are found to be consistent with a combination of polar (H{sub 2}O-rich) and nonpolar (CO-rich) ices at low temperature; the remainder exhibit profile structure consistent with partial crystallization as the result of significant heating. Ice-phase column densities of CO{sub 2} are determined and compared with those of other species. Lines of sight with crystallization signatures in their spectra are found to be systematically deficient in solid-phase CO, as expected if CO is being sublimated in regions where the ices are heated to crystallization temperatures. Significant variation is found in the CO{sub 2} abundance with respect to both H{sub 2}O (the dominant ice constituent) and total dust column (quantified by the extinction, A{sub V}). YSOs in our sample display typically higher CO{sub 2} concentrations (independent of evidence for thermal processing) in comparison to quiescent regions of the prototypical cold molecular cloud. This suggests that enhanced CO{sub 2} production is driven by photochemical reactions in proximity to some YSOs, and that photoprocessing and thermal processing may occur independently.

  18. The water ice rich surface of (145453) 2005 RR43: a case for a carbon-depleted population of TNOs?

    E-Print Network [OSTI]

    N. Pinilla-Alonso; J. Licandro; R. Gil-Hutton; R. Brunetto

    2007-05-26T23:59:59.000Z

    Recent results suggest that there is a group of TNOs (2003 EL61 being the biggest member), with surfaces composed of almost pure water ice and with very similar orbital elements. We study the surface composition of another TNO that moves in a similar orbit, 2005 RR43, and compare it with the surface composition of the other members of this group. We report visible and near-infrared spectra, obtained with the 4.2m William Herschel Telescope and the 3.58m Telescopio Nazionale Galileo at the "Roque de los Muchachos" Observatory (La Palma, Spain). The spectrum of 2005 RR43 is neutral in color in the visible and dominated by very deep water ice absorption bands in the near infrared (D= 70.3 +/- 2.1 % and 82.8 +/- 4.9 % at 1.5 \\mu and 2.0 \\mu respectively). It is very similar to the spectrum of the group of TNOs already mentioned. All of them present much deeper water ice absorption bands (D>40 %) than any other TNO except Charon. Scattering models show that its surface is covered by water ice, a significant fraction in crytalline state with no trace (5 % upper limit) of complex organics. Possible scenarios to explain the existence of this population of TNOs are discussed: a giant collision, an originally carbon depleted composition, or a common process of continuous resurfacing. We conclude that TNO 2005 RR43 is member of a group, may be a population, of TNOs clustered in the space of orbital parameters that show abundant water ice and no signs of complex organics. The lack of complex organics in their surfaces suggests a significant smaller fraction of carbonaceous volatiles like CH4 in this population than in "normal" TNOs. A carbon depleted population of TNOs could be the origin of the population of carbon depleted Jupiter family comets already noticed by A'Hearn et al. (1995).

  19. Global Simulations of Ice nucleation and Ice Supersaturation with an Improved Cloud Scheme in the Community Atmosphere Model

    SciTech Connect (OSTI)

    Gettelman, A.; Liu, Xiaohong; Ghan, Steven J.; Morrison, H.; Park, Sungsu; Conley, Andrew; Klein, Stephen A.; Boyle, James; Mitchell, David; Li, J-L F.

    2010-09-28T23:59:59.000Z

    A process-based treatment of ice supersaturation and ice-nucleation is implemented in the National Center for Atmospheric Research (NCAR) Community Atmosphere Model (CAM). The new scheme is designed to allow (1) supersaturation with respect to ice, (2) ice nucleation by aerosol particles and (3) ice cloud cover consistent with ice microphysics. The scheme is implemented with a 4-class 2 moment microphysics code and is used to evaluate ice cloud nucleation mechanisms and supersaturation in CAM. The new model is able to reproduce field observations of ice mass and mixed phase cloud occurrence better than previous versions of the model. Simulations indicate heterogeneous freezing and contact nucleation on dust are both potentially important over remote areas of the Arctic. Cloud forcing and hence climate is sensitive to different formulations of the ice microphysics. Arctic radiative fluxes are sensitive to the parameterization of ice clouds. These results indicate that ice clouds are potentially an important part of understanding cloud forcing and potential cloud feedbacks, particularly in the Arctic.

  20. Europium Isotopic Abundances in Very Metal-poor Stars

    E-Print Network [OSTI]

    Christopher Sneden; John J. Cowan; James E. Lawler; Scott Burles; Timothy C. Beers; George M. Fuller

    2002-01-28T23:59:59.000Z

    Europium isotopic abundance fractions are reported for the very metal-poor, neutron-capture-rich giant stars CS 22892-052, HD 115444, and BD +17 3248. The abundance fractions, derived from analysis of several strong Eu II lines appearing in high-resolution spectra of these stars, are in excellent agreement with each other and with their values in the Solar System: fraction(\\iso{Eu}{151}) ~= fraction(\\iso{Eu}{153}) ~= 0.5. Detailed abundance studies of very metal-poor stars have previously shown that the total elemental abundances of stable atoms with atomic numbers z >= 56 typically match very closely those of a scaled solar-system r-process abundance distribution. The present results for the first time extend this agreement to the isotopic level.

  1. Semi-inclusive charged-current neutrino-nucleus reactions

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

    Moreno, Omar [California State Univ., Los Angeles, CA (United States); Donnelly, T. W. [California State Univ., Los Angeles, CA (United States); Van Orden, Jay Wallace [Old Dominion Univ., Norfolk, VA (United States); Jefferson Lab., Newport News, VA (United States); Ford, William P. [Univ. of Southern Mississippi, Hattiesburg, MS (United States)

    2014-07-01T23:59:59.000Z

    The general, universal formalism for semi-inclusive charged-current (anti)neutrino-nucleus reactions is given for studies of any hadronic system, namely, either nuclei or the nucleon itself. The detailed developments are presented with the former in mind and are further specialized to cases where the final-state charged lepton and an ejected nucleon are presumed to be detected. General kinematics for such processes are summarized and then explicit expressions are developed for the leptonic and hadronic tensors involved and for the corresponding responses according to the usual charge, longitudinal and transverse projections, keeping finite the masses of all particles involved. In the case of the hadronic responses, general symmetry principles are invoked to determine which contributions can occur. Finally, the general leptonic-hadronic tensor contraction is given as well as the cross section for the process.

  2. Theoretical estimates of cross sections for neutron-nucleus collisions

    E-Print Network [OSTI]

    Tapan Mukhopadhyay; Joydev Lahiri; D. N. Basu

    2011-03-14T23:59:59.000Z

    We construct an analytical model derived from nuclear reaction theory and having a simple functional form to demonstrate the quantitative agreement with the measured cross sections for neutron induced reactions. The neutron-nucleus total, reaction and scattering cross sections, for energies ranging from 5 to 700 MeV and for several nuclei spanning a wide mass range are estimated. Systematics of neutron scattering cross sections on various materials for neutron energies upto several hundred MeV are important for ADSS applications. The reaction cross sections of neutrons are useful for determining the neutron induced fission yields in actinides and pre-actinides. The present model based on nuclear reaction theory provides good estimates of the total cross section for neutron induced reaction.

  3. Ferrofluid nucleus phase transitions in an external uniform magnetic field

    E-Print Network [OSTI]

    B. M. Tanygin; S. I. Shulyma; V. F. Kovalenko; M. V. Petrychuk

    2015-02-18T23:59:59.000Z

    Phase transition between massive dense phase and diluted superparamagnetic phase is studied by means of direct molecular dynamics simulation. Equilibrium structures of ferrofluid aggregate nucleus are obtained for different values of temperature and external magnetic field magnitude. For the ferrofluid phase diagram (coordinates "field-temperature"): approximate match of experiment and simulation is shown. Obtained phase coexistence curve has opposite trend compare to some of known theoretical results. This contradiction is related to postulating and comparing of the free energy of only simplest ferrofluid structures: diluted superparamagnetic phase, linear chains of the particles, and dense globes. The present results provide more fine structure of transition from "linear chains" to "dense globes" phase, e.g. through the ring assembly structure.

  4. Pion-nucleus reactions in a microscopic transport model

    E-Print Network [OSTI]

    A. Engel; W. Cassing; U. Mosel; M. Schäfer; Gy. Wolf

    1993-07-07T23:59:59.000Z

    We analyse pion-nucleus reactions in a microscopic transport model of the BUU type, which propagates nucleons, pions, deltas and N(1440)-resonances explicitly in space and time. In particular we examine pion absorption and inelastic scattering cross sections for pion kinetic energies T(pi) =85-315MeV and various target masses. In general, the mass-dependence of the experimental data is well described for energies up to the delta-resonance (\\approx 160 MeV) while the absorption cross sections are somewhat overestimated for the higher energies. In addition we study the possible dynamical effects of delta- and pion-potentials in the medium on various observables as well as alternative models for the in-medium delta-width.

  5. Hadron dynamics in high-energy pion-nucleus scattering

    SciTech Connect (OSTI)

    Johnson, M.B.

    1992-12-31T23:59:59.000Z

    It is argued that pion-nucleus scattering at high energy (above 300 MeV) is likely to be easier to interpret than it has been at lower energies where the {Delta}{sub 33} resonance dominates. We establish this by examining the relative importance of various dynamic ingredients of scattering theory for high-energy pions and comparing different versions of the theory: a ``model-exact`` microscopic optical model and an eikonal approximation. For nuclei as heavy as Ca, the eikonal theory is an excellent approximation to the full theory for the angular distribution out to the position of the second minimum in the cross section. The prospects for using high-energy pions to examine modifications of nucleons and baryon resonances in nuclei, nuclear structure, exchange currents, short-range correlations, and to characterize pion propagation are discussed.

  6. Hadron dynamics in high-energy pion-nucleus scattering

    SciTech Connect (OSTI)

    Johnson, M.B.

    1992-01-01T23:59:59.000Z

    It is argued that pion-nucleus scattering at high energy (above 300 MeV) is likely to be easier to interpret than it has been at lower energies where the [Delta][sub 33] resonance dominates. We establish this by examining the relative importance of various dynamic ingredients of scattering theory for high-energy pions and comparing different versions of the theory: a model-exact'' microscopic optical model and an eikonal approximation. For nuclei as heavy as Ca, the eikonal theory is an excellent approximation to the full theory for the angular distribution out to the position of the second minimum in the cross section. The prospects for using high-energy pions to examine modifications of nucleons and baryon resonances in nuclei, nuclear structure, exchange currents, short-range correlations, and to characterize pion propagation are discussed.

  7. Neutron capture by 15N nucleus at astrophysical energies

    E-Print Network [OSTI]

    S. B. Dubovichenko; N. V. Afanasyeva

    2013-04-07T23:59:59.000Z

    Within the potential cluster model with the forbidden states and an orbital states classification according to the Young diagrams the possibility of description of experimental data for the total cross-sections of radiative n15N-capture at energies from 25 to 370 keV was considered. It was shown that only on basis of the E1-transitions from the different states of n15N-scattering to the ground state of 16N nucleus in n15N-channel it is well succeed to explain the value of the total cross-sections in the considered energy range and to prognosticate its behavior at energy E 1 eV. These cross-sections at energies E 10 keV are approximated by the simple analytical form.

  8. Large Scale Ice Water Path and 3-D Ice Water Content

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

    Liu, Guosheng

    Cloud ice water concentration is one of the most important, yet poorly observed, cloud properties. Developing physical parameterizations used in general circulation models through single-column modeling is one of the key foci of the ARM program. In addition to the vertical profiles of temperature, water vapor and condensed water at the model grids, large-scale horizontal advective tendencies of these variables are also required as forcing terms in the single-column models. Observed horizontal advection of condensed water has not been available because the radar/lidar/radiometer observations at the ARM site are single-point measurement, therefore, do not provide horizontal distribution of condensed water. The intention of this product is to provide large-scale distribution of cloud ice water by merging available surface and satellite measurements. The satellite cloud ice water algorithm uses ARM ground-based measurements as baseline, produces datasets for 3-D cloud ice water distributions in a 10 deg x 10 deg area near ARM site. The approach of the study is to expand a (surface) point measurement to an (satellite) areal measurement. That is, this study takes the advantage of the high quality cloud measurements at the point of ARM site. We use the cloud characteristics derived from the point measurement to guide/constrain satellite retrieval, then use the satellite algorithm to derive the cloud ice water distributions within an area, i.e., 10 deg x 10 deg centered at ARM site.

  9. Searching for sterile neutrinos in ice

    E-Print Network [OSTI]

    Soebur Razzaque; A. Yu. Smirnov

    2011-07-04T23:59:59.000Z

    Oscillation interpretation of the results from the LSND, MiniBooNE and some other experiments requires existence of sterile neutrino with mass $\\sim 1$ eV and mixing with the active neutrinos $|U_{\\mu 0}|^2 \\sim (0.02 - 0.04)$. It has been realized some time ago that existence of such a neutrino affects significantly the fluxes of atmospheric neutrinos in the TeV range which can be tested by the IceCube Neutrino Observatory. In view of the first IceCube data release we have revisited the oscillations of high energy atmospheric neutrinos in the presence of one sterile neutrino. Properties of the oscillation probabilities are studied in details for various mixing schemes both analytically and numerically. The energy spectra and angular distributions of the $\

  10. Under consideration for publication in J. Fluid Mech. 1 Ocean waves and ice sheets

    E-Print Network [OSTI]

    Craster, Richard

    ; Wadhams & Holt, 1991) to pack ice (Robin, 1963) and even glacial ice tongues (Holdsworth, 1969; Squire etUnder consideration for publication in J. Fluid Mech. 1 Ocean waves and ice sheets By N. J waves incident on ice­covered ocean. The ice cover is idealized as a plate of elastic material for which

  11. Evidence for atmospheric control of sea-ice motion through Nares Strait

    E-Print Network [OSTI]

    Kurapov, Alexander

    Arctic pack ice, a critical element of the global climate system. The general flow of seawater through be sufficient to halt ice drift, despite strong forcing. Pack ice often consolidates in winter behind an ice mobility of pack ice in Fram Strait and the more persistently static conditions in the western CAA. We

  12. Evaluation of Arctic sea ice thickness simulated by Arctic Ocean Model Intercomparison Project models

    E-Print Network [OSTI]

    Zhang, Jinlun

    of fast ice formation and growth. Instead, the modeled fast ice is replaced with pack ice which driftsEvaluation of Arctic sea ice thickness simulated by Arctic Ocean Model Intercomparison Project with estimates of sea ice thickness derived from pan-Arctic satellite freeboard measurements (2004

  13. Classification of Annual Great Lakes Ice Cycles: Winters of 19732002* RAYMOND A. ASSEL

    E-Print Network [OSTI]

    Classification of Annual Great Lakes Ice Cycles: Winters of 1973­2002* RAYMOND A. ASSEL National (Manuscript received 12 July 2004, in final form 13 June 2005) ABSTRACT Annual seasonal average ice cover from 1973 to 2002 and associated dates of first ice, last ice, and ice duration are presented and discussed

  14. MCM LTER METADATA FILE TITLE: Lake ice thickness in the McMurdo Dry Valleys

    E-Print Network [OSTI]

    Priscu, John C.

    MCM LTER METADATA FILE TITLE: Lake ice thickness in the McMurdo Dry Valleys ABSTRACT: Ice thickness was measured from the bottom of the ice cover to the piezometric water level and to the top of the ice cover-2360 achiuchiolo@montana.edu VARIABLES: Location Name, Location Code, Limno Run, Collection Date, z-water, z-ice, z

  15. NOAA Technical Memorandum ERL GLERL-48 LAKE ERIE REGIONAL ICE COVER ANALYSIS: PRELIMINARY RESULTS

    E-Print Network [OSTI]

    NOAA Technical Memorandum ERL GLERL-48 LAKE ERIE REGIONAL ICE COVER ANALYSIS: PRELIMINARY RESULTS R.2 2.3 2.4 2.5 Observation density Average regional ice cover Percentage exceedance from average regional ice cover for discrete ice cover values Contour analysis of percentage ice cover exceedance

  16. Polar Sea Ice Mapping Using SeaWinds Data Hyrum S. Anderson and David G. Long

    E-Print Network [OSTI]

    Long, David G.

    Polar Sea Ice Mapping Using SeaWinds Data Hyrum S. Anderson and David G. Long Brigham Young for mapping polar sea ice extent. In this study, a new al- gorithm for polar sea ice mapping is developed of Bayes detection to produce sea ice extent maps. Statistical models for sea ice and ocean are represented

  17. ORIGINAL PAPER Sedimentary pellets as an ice-cover proxy in a High Arctic

    E-Print Network [OSTI]

    Vincent, Warwick F.

    ORIGINAL PAPER Sedimentary pellets as an ice-cover proxy in a High Arctic ice-covered lake Jessica-cover extent and dynamics on this perennially ice-covered, High Arctic lake. These pellets are interpreted growth. The pellets remain frozen in the ice until a summer or series of summers with reduced ice cover

  18. NAO influence on net sea ice production and exchanges in the Arctic region

    E-Print Network [OSTI]

    Hu, Aixue

    NAO influence on net sea ice production and exchanges in the Arctic region Aixue Hu National Center of the net sea ice production and the sea ice exchanges between the Arctic and its adjacent seas are studied) is the major factor controlling the net sea ice production in the Arctic region since a thinning ice cover

  19. Holocene-Late Pleistocene Climatic Ice Core Records from Qinghai-Tibetan Plateau

    E-Print Network [OSTI]

    Howat, Ian M.

    for affecting large-scale climate. In 1987, three ice cores were recovered to bedrock from the Dunde ice cap. XIE Three ice cores to bedrock from the Dunde ice cap on the north-central Qinghai- Tibetan Plateau of ago. T HE DUNDE ICE CAP (38°06'N, 96°24'E) is located in a desert envi- ronment between the highest

  20. XXII ICTAM, 2529 August 2008, Adelaide, Australia EXPERIMENTAL AND THEORETICAL MODELLING OF ICE SHEETSHELF GROUNDING

    E-Print Network [OSTI]

    Worster, M. Grae

    melting of the polar ice caps due to global warming, a dynamical collapse of the ice sheets has the dynamical stability of shelving ice sheets. INTRODUCTION The Antarctic ice cap contains several tensXXII ICTAM, 25­29 August 2008, Adelaide, Australia EXPERIMENTAL AND THEORETICAL MODELLING OF ICE

  1. Melting of small Arctic ice caps observed from ERS scatterometer time series

    E-Print Network [OSTI]

    Smith, Laurence C.

    Melting of small Arctic ice caps observed from ERS scatterometer time series Laurence C. Smith,1 of melt onset can be observed over small ice caps, as well as the major ice sheets and multi-year sea ice for 14 small Arctic ice caps from 1992­2000. Interannual and regional variability in the timing of melt

  2. Contractor SOW Template - ICE | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE: Alternative FuelsNovember 13, 2014 BuildingEnergyEnergyConsortiumContacts Contacts2012ICE

  3. Plasticity in the Rat Posterior Auditory Field Following Nucleus Basalis Stimulation

    E-Print Network [OSTI]

    Kilgard, Michael P.

    Plasticity in the Rat Posterior Auditory Field Following Nucleus Basalis Stimulation Amanda C. Plasticity in the rat posterior auditory field following nucleus basalis stimulation. J Neurophysiol 98: 253 have been shown to cause frequency-specific plasticity in both primary and secondary cortical areas

  4. A radio air shower surface detector as an extension for IceCube and IceTop

    E-Print Network [OSTI]

    J. Auffenberg; T. Gaisser; K. Helbing; T. Huege; T. Karg; A. Karle

    2007-08-24T23:59:59.000Z

    The IceCube neutrino detector is built into the Antarctic ice sheet at the South Pole to measure high energy neutrinos. For this, 4800 photomultiplier tubes (PMTs) are being deployed at depths between 1450 and 2450 meters into the ice to measure neutrino induced charged particles like muons. IceTop is a surface air shower detector consisting of 160 Cherenkov ice tanks located on top of IceCube. To extend IceTop, a radio air shower detector could be built to significantly increase the sensitivity at higher shower energies and for inclined showers. As air showers induced by cosmic rays are a major part of the muonic background in IceCube, IceTop is not only an air shower detector, but also a veto to reduce the background in IceCube. Air showers are detectable by radio signals with a radio surface detector. The major emission process is the coherent synchrotron radiation emitted by e+ e- shower particles in the Earths magnetic field (geosynchrotron effect). Simulations of the expected radio signals of air showers are shown. The sensitivity and the energy threshold of different antenna field configurations are estimated.

  5. On water ice formation in interstellar clouds

    E-Print Network [OSTI]

    Renaud Papoular

    2005-07-06T23:59:59.000Z

    A model is proposed for the formation of water ice mantles on grains in interstellar clouds. This occurs by direct accretion of monomers from the gas, be they formed by gas or surface reactions. The model predicts the existence of a threshold in interstellar light extinction, A(v), which is mainly determined by the adsorption energy of water molecules on the grain material; for hydrocarbon material, chemical simulation places this energy between 0.5 and 2 kcal/mole, which sets the visible exctinction threshold at a few magnitudes, as observed. Once the threshold is crossed, all available water molecules in the gas are quickly adsorbed, forming an ice mantle, because the grain cools down and the adsorption energy on ice is higher than on bare grain. The model also predicts that the thickness of the mantle, and, hence, the optical thickness at 3 mu, grow linearly with A(v), as observed, with a slope which depends upon the total amount of water in the gas. Chemical simulation was also used to determine the adsorption sites and energies of O and OH on hydrocarbons, and study the dynamics of formation of water molecules by surface reactions with gaseous H atoms, as well as their chances of sticking in situ.

  6. Toward a Deterministic Model of Planetary Formation V. Accumulation Near the Ice Line

    E-Print Network [OSTI]

    Shigeru Ida; D. N. C. Lin

    2008-06-01T23:59:59.000Z

    We address two outstanding issues in the sequential accretion scenario for gas giant planet formation, the retention of dust grains in the presence of gas drag and that of cores despite type I migration. The efficiency of these processes is determined by the disk structure. Theoretical models suggest that planets form in protostellar disk regions with an inactive neutral ``dead zone'' near the mid plane, sandwiched together by partially ionized surface layers where magnetorotational instability is active. Due to a transition in the abundance of dust grains, the active layer's thickness decreases abruptly near the ice line. Over a range of modest accretion rates ($\\sim 10^{-9}-10^{-8} M_\\odot$ yr$^{-1}$), the change in the angular momentum transfer rate leads to local surface density and pressure distribution maxima near the ice line. The azimuthal velocity becomes super-Keplerian and the grains accumulate in this transition zone. This barrier locally retains protoplanetary cores and enhances the heavy element surface density to the critical value needed to initiate efficient gas accretion. It leads to a preferred location and epoch of gas giant formation. We simulate and reproduce the observed frequency and mass-period distribution of gas giants around solar type stars without having to greatly reduce the type I migration strength. The mass function of the short-period planets can be utilized to calibrate the efficiency of type I migration and to extrapolate the fraction of stars with habitable terrestrial planets.

  7. Beryllium Abundances in Stars of One-Solar-Mass

    E-Print Network [OSTI]

    Ann Merchant Boesgaard; Julie A. Krugler

    2008-09-26T23:59:59.000Z

    We have determined Be abundances in 50 F and G dwarfs in the mass range of 0.9 $\\leq$ M$_\\odot$ $\\leq$ 1.1 as determined by Lambert & Reddy. The effective temperatures are 5600 to 6400 K and metallicities from $-$0.65 to +0.11. The spectra were taken primarily with Keck I + HIRES. The Be abundances were found via spectral synthesis of Be II lines near 3130 \\AA. The Be abundances were investigated as a function of age, temperature, metallicity and Li abundance in this narrow mass range. Even though our stars are similar in mass, they show a range in Be abundances of a factor of $>$40. We find that [Be/Fe] has no dependence on temperature, but does show a spread of a factor of 6 at a given temperature. The reality of the spread is shown by two identical stars which differ from each other by a factor of two only in their abundances of Li and Be. Our thin-disk-star sample fits the trend between Be abundance and [Fe/H] found for halo and thick disk stars, extending it to about 4 orders of magnitude in the two logarithmic quantities. Both Fe and Be appear to increase similarly over time in the Galaxy. One-third of our sample may be classified as subgiants; these more-evolved stars have lower Be abundances than the dwarfs. They have undergone Be depletion by slow mixing on the main sequence and Be dilution during their trip toward the red giant base. There are both Li and Be detections in 60 field stars in the "Li-plateau" of 5900 - 6300 K now and the abundances of the two light elements are correlated with a slope of 0.34 $\\pm$0.05, with greater Li depletion than Be depletion.

  8. Analytical determination of propeller performance degradation due to ice accretion

    E-Print Network [OSTI]

    Miller, Thomas Lloyd

    1984-01-01T23:59:59.000Z

    result of exposing an airfoil in forward motion to supercooled water droplets in a sub-freezing environment. The type of ice which will form may be determined by a variety of factors including freestream velocity, liquid water content of the cloud... as rime ice, occurs at relatively low velocities, low liquid water content values (typically 0. 5 to 1. 0 grams per cubic meter), and temperature well below freezing. Due primarily to the very cold temperatures associated with rime ice formation...

  9. Calibration and Characterization of the IceCube Photomultiplier Tube

    E-Print Network [OSTI]

    Abbasi, R.

    2010-01-01T23:59:59.000Z

    Calibration and Characterization of the IceCubeUniversity of California. Calibration and Characterizationchar- acterization and calibration of these PMTs before

  10. Optimal Control of Harvesting Ice Thermal Storage Systems

    E-Print Network [OSTI]

    Knebel, D. E.

    1988-01-01T23:59:59.000Z

    for optimal control of a harvesting ice storage system. A simplified procedure is used to develop 24 hour load data. Example installations will be shown....

  11. Covered Product Category: Air-Cooled Ice Machines

    Broader source: Energy.gov [DOE]

    The Federal Energy Management Program (FEMP) provides acquisition guidance for air-cooled ice machines, which are covered by the ENERGY STAR program.

  12. Artificial Spin Ice - A New Playground to Better Understand Magnetism...

    Office of Science (SC) Website

    Artificial Spin Ice - A New Playground to Better Understand Magnetism Basic Energy Sciences (BES) BES Home About Research Facilities Science Highlights Benefits of BES Funding...

  13. antarctic sea ice: Topics by E-print Network

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

    AD of transient model simulations and a new type of sen- sitivity experiments with artificial sea ice growth Born, Andreas 327 Sedimentation and particle dynamics in the...

  14. arctic sea ice: Topics by E-print Network

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

    AD of transient model simulations and a new type of sen- sitivity experiments with artificial sea ice growth Born, Andreas 388 Sedimentation and particle dynamics in the...

  15. altimeter sea ice: Topics by E-print Network

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

    AD of transient model simulations and a new type of sen- sitivity experiments with artificial sea ice growth Born, Andreas 218 Sedimentation and particle dynamics in the...

  16. artic sea ice: Topics by E-print Network

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

    AD of transient model simulations and a new type of sen- sitivity experiments with artificial sea ice growth Born, Andreas 214 Sedimentation and particle dynamics in the...

  17. arctic ice dynamics: Topics by E-print Network

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

    W. F. Vincent (2008), Seasonal dynamics of bacterial Vincent, Warwick F. 168 Dynamics of artificial spin ice: a continuous honeycomb network MIT - DSpace Summary: We model the...

  18. arctic ice islands: Topics by E-print Network

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

    analogous to the effects of the Arctic region; KEYWORDS: Arctic Ocean, ice rafting, climate change Citation: Darby, D. A., and J. F. Bischof (2004), A Holocene record of...

  19. Reducing uncertainty in high-resolution sea ice models.

    SciTech Connect (OSTI)

    Peterson, Kara J.; Bochev, Pavel Blagoveston

    2013-07-01T23:59:59.000Z

    Arctic sea ice is an important component of the global climate system, reflecting a significant amount of solar radiation, insulating the ocean from the atmosphere and influencing ocean circulation by modifying the salinity of the upper ocean. The thickness and extent of Arctic sea ice have shown a significant decline in recent decades with implications for global climate as well as regional geopolitics. Increasing interest in exploration as well as climate feedback effects make predictive mathematical modeling of sea ice a task of tremendous practical import. Satellite data obtained over the last few decades have provided a wealth of information on sea ice motion and deformation. The data clearly show that ice deformation is focused along narrow linear features and this type of deformation is not well-represented in existing models. To improve sea ice dynamics we have incorporated an anisotropic rheology into the Los Alamos National Laboratory global sea ice model, CICE. Sensitivity analyses were performed using the Design Analysis Kit for Optimization and Terascale Applications (DAKOTA) to determine the impact of material parameters on sea ice response functions. Two material strength parameters that exhibited the most significant impact on responses were further analyzed to evaluate their influence on quantitative comparisons between model output and data. The sensitivity analysis along with ten year model runs indicate that while the anisotropic rheology provides some benefit in velocity predictions, additional improvements are required to make this material model a viable alternative for global sea ice simulations.

  20. About International Cruise & Excursions International Cruise & Excursions, Inc. (ICE) is a worldwide travel and

    E-Print Network [OSTI]

    Fisher, Kathleen

    About International Cruise & Excursions International Cruise & Excursions, Inc. (ICE corporations, resorts, cruise lines and leisure travel providers. ICE provides cruise and travel programs-commerce platform, state of the art call centers and customer service and fulfillment operations. Situation ICE

  1. Web-Ice: Integrated Data Collection and Analysis for Macromolecular Crystallography

    E-Print Network [OSTI]

    Gonzalez, Ana

    2008-01-01T23:59:59.000Z

    results. A summary list is also available in Blu-Ice.Figure 7: SSRL Web-Ice interface displaying the summarizedTable 1: Programs used by Web-Ice for data analysis. Program

  2. The influence of subglacial hydrology on the flow of West Antarctic ice streams

    E-Print Network [OSTI]

    Baker, Narelle Paula Marie

    2012-04-10T23:59:59.000Z

    Subglacial hydrology is known to influence the flow of ice. However, difficulty in accessing the base of large ice sheets has made determining the interaction between ice streams, basal sediment and water difficult to discern. The aim of this thesis...

  3. Incorporation of particulates into accreted ice above subglacial Vostok lake, Antarctica 

    E-Print Network [OSTI]

    Siegert, M. J.; Royston-Bishop, G.; Priscu, J. C.; Tranter, M.; Christner, B.; Lee, V.

    2005-01-01T23:59:59.000Z

    The nature of microscopic particulates in meteoric and accreted ice from the Vostok (Antarctica) ice core is assessed in conjunction with existing ice-core data to investigate the mechanism by which particulates are ...

  4. APPROVED ICE STORAGE AIR CONDITIONERS Revised as of 06-18-2008

    E-Print Network [OSTI]

    APPROVED ICE STORAGE AIR CONDITIONERS Revised as of 06-18-2008 The following vendors and their ice storage air conditioners models can be used in the ice storage air conditioner compliance option. Input

  5. Ice stream basal conditions from block-wise surface data inversion and simple regression models of ice stream flow: Application to

    E-Print Network [OSTI]

    Boyce, C. Kevin

    Ice stream basal conditions from block-wise surface data inversion and simple regression models of ice stream flow: Application to Bindschadler Ice Stream O. V. Sergienko,1 R. A. Bindschadler,2 P. L; published 4 December 2008. [1] Widespread basal conditions controlling ice stream flows are still beyond

  6. Ice in the Environment: Proceedings of the 16th IAHR International Symposium on Ice Dunedin, New Zealand, 2nd6th December 2002

    E-Print Network [OSTI]

    Feltham, Daniel

    Ice in the Environment: Proceedings of the 16th IAHR International Symposium on Ice Dunedin, New OF DETERMINING A GEOPHYSICAL-SCALE SEA ICE RHEOLOGY FROM LABORATORY EXPERIMENTS Daniel Feltham1 and Peter Sammonds2 and Daniel Hatton2 ABSTRACT We present a methodology that allows a sea ice rheology, suitable

  7. ICE IGERT Mission The mission of the ICE IGERT program is to exploit the synergistic interface between engineering and the life sciences to enable

    E-Print Network [OSTI]

    Mountziaris, T. J.

    1 ICE IGERT Mission The mission of the ICE IGERT program is to exploit the synergistic interface foundation for future interdisciplinary research success. ICE IGERT Curriculum Structure (minimum of 19 credits) ICE IGERT promotes broad-based graduate training in cellular engineering through the following

  8. Ice Nucleation of Fungal Spores from the Classes Agaricomycetes, Ustilaginomycetes, and Eurotiomycetes, and the effect on the Atmospheric Transport of these Spores

    SciTech Connect (OSTI)

    Haga, D. I.; Burrows, Susannah M.; Iannone, R.; Wheeler, M. J.; Mason, R.; Chen, J.; Polishchuk, E. A.; Poschl, U.; Bertram, Allan K.

    2014-08-26T23:59:59.000Z

    Ice nucleation on fungal spores may affect the frequency and properties of ice and mixed-phase clouds. We studied the ice nucleation properties of 12 different species of fungal spores chosen from three classes: Agaricomycetes, Ustilagomycetes, and Eurotiomycetes. Agaricomycetes include many types of mushroom species and are cosmopolitan all over the globe. Ustilagomycetes are agricultural pathogens and have caused widespread damage to crops. Eurotiomycetes are found on all types of decaying material and include important human allergens. We focused on these classes since they are thought to be abundant in the atmosphere and because there is very little information on the ice nucleation ability of these classes of spores in the literature. All of the fungal spores investigated were found to cause freezing of water droplets at temperatures warmer than homogeneous freezing. The cumulative number of ice nuclei per spore was 0.001 at temperatures between -19 °C and -29 °C, 0.01 between -25.5 °C and -31 °C, and 0.1 between -26 °C and -36 °C. On average, the order of ice nucleating ability for these spores is Ustilagomycetes > Agaricomycetes ? Eurotiomycetes. We show that at temperatures below -20 °C, all of the fungal spores studied here are less efficient ice nuclei compared to Asian mineral dust on a per surface area basis. We used our new freezing results together with data in the literature to compare the freezing temperatures of spores from the phyla Basidiomycota and Ascomycota, which together make up 98 % of known fungal species found on Earth. The data show that within both phyla (Ascomycota and Basidiomycota) there is a wide range of freezing properties, and also that the variation within a phylum is greater than the variation between the average freezing properties of the phyla. Using a global chemistry-climate transport model, we investigated whether ice nucleation on the studied spores, followed by precipitation, can influence the atmospheric transport and global distributions of these spores in the atmosphere. Simulations show that inclusion of ice nucleation scavenging of fungal spores in mixed-phase clouds can decrease the surface annual mean mixing ratios of fungal spores over the oceans and polar regions and decrease annual mean mixing ratios in the upper troposphere.

  9. Oxygen and nitrogen abundances in Virgo and field spirals

    E-Print Network [OSTI]

    L. S. Pilyugin; Mercedes Molla; Federico Ferrini; Jose M. Vilchez

    2001-12-03T23:59:59.000Z

    The oxygen and nitrogen abundances in the HII regions of the nine Virgo spirals of the sample from Skillman et al (1996) and in nine field spiral galaxies are re-determined with the recently suggested P - method. We confirm that there is an abundance segregation in the sample of Virgo spirals in the sense that the HI deficient Virgo spirals near the core of the cluster have higher oxygen abundances in comparison to the spirals at the periphery of the Virgo cluster. At the same time both the Virgo periphery and core spirals have counterparts among field spirals. We conclude that if there is a difference in the abundance properties of the Virgo and field spirals, this difference appears to be small and masked by the observational errors.

  10. astrophysically abundant atoms: Topics by E-print Network

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

    atomic data available so far and check the Mg abundances from individual lines in the Sun, four well studied A-type stars, and three reference metal-poor stars. With the adopted...

  11. abundance element: Topics by E-print Network

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

    physics, enable us to infer the temperature and hydrogen abundance profiles inside the Sun. These profiles also help in setting constraints on the input physics as well as on...

  12. Fundamental constraints on the abundances of chemotaxis proteins

    E-Print Network [OSTI]

    Bitbol, Anne-Florence

    2015-01-01T23:59:59.000Z

    Flagellated bacteria, such as Escherichia coli, perform directed motion in gradients of concentration of attractants and repellents in a process called chemotaxis. The E. coli chemotaxis signaling pathway is a model for signal transduction, but it has unique features. We demonstrate that the need for fast signaling necessitates high abundances of the proteins involved in this pathway. We show that further constraints on the abundances of chemotaxis proteins arise from the requirements of self-assembly, both of flagellar motors and of chemoreceptor arrays. All these constraints are specific to chemotaxis, and published data confirm that chemotaxis proteins tend to be more highly expressed than their homologs in other pathways. Employing a chemotaxis pathway model, we show that the gain of the pathway at the level of the response regulator CheY increases with overall chemotaxis protein abundances. This may explain why, at least in one E. coli strain, the abundance of all chemotaxis proteins is higher in media w...

  13. animal prey abundance: Topics by E-print Network

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

    overall abundance was higher overall during the August 1997 cruise than during the October 1996 cruise... Cady, Robert B 2012-06-07 42 The camp will expose students to local...

  14. abundance mineral: Topics by E-print Network

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

    between 55 and 72 Sm II lines per star. The abundance ratios of Sm relative to other rare earth elements in these stars are in agreement, and are consistent with ratios...

  15. Relative abundance of desert tortoises on the Nevada Test Site

    SciTech Connect (OSTI)

    Rautenstrauch, K.R.; O`Farrell, T.P.

    1993-12-31T23:59:59.000Z

    Seven hundred fifty-nine transects having a total length of 1,191 km were walked during 1981--1986 to determine the distribution and relative abundance of desert tortoises (Gopherus agassizii) on the Nevada Test Site (NTS). The abundance of tortoises on NTS was low to very low relative to other populations in the Mojave Desert. Sign of tortoises was found from 880 to 1,570 m elevation and was more abundant above 1,200 m than has been reported previously for Nevada. Tortoises were more abundant on NTS on the upper alluvial fans and slopes of mountains than in valley bottoms. They also were more common on or near limestone and dolomite mountains than on mountains of volcanic origin.

  16. A Temperature and Abundance Retrieval Method for Exoplanet Atmospheres

    E-Print Network [OSTI]

    Madhusudhan, Nikku

    We present a new method to retrieve molecular abundances and temperature profiles from exoplanet atmosphere photometry and spectroscopy. We run millions of one-dimensional (1D) atmosphere models in order to cover the large ...

  17. Relationships between body size and abundance in ecology

    E-Print Network [OSTI]

    Enquist, Brian Joseph

    , but interrelated, relation- ships between size and abundance that are often con- fused in the literature. Here, we and the structure and dynamics of eco- logical communities [3­5]. In addition, because body size is one

  18. Planning Amid Abundance: Alaska’s FY 2013 Budget Process

    E-Print Network [OSTI]

    McBeath, Jerry

    2013-01-01T23:59:59.000Z

    2011) “The Outlier State: Alaska’s FY 2012 Budget,” AnnualWestern States Budget Review. New York Times, selectedAbundance: Alaska’s FY 2013 Budget Process Abstract: This

  19. abundance isotopic: Topics by E-print Network

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

    24 Abundances and Isotope Ratios in the Magellanic Clouds: The Star Forming Environment of N113 Astrophysics (arXiv) Summary: With the goal of deriving the physical and...

  20. Modeling the evolution of polar ice sheets: Ice sheet system model workshop; Bergen, Norway, 2-4 June 2014

    E-Print Network [OSTI]

    Larour, E; Schlegel, N; Morlighem, M

    2014-01-01T23:59:59.000Z

    Model Workshop; Bergen, Norway, 2?4 June 2014 The Ice SheetUniversity of Bergen in Norway, in June 2014. This is the

  1. Nucleus-Nucleus 2000

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del SolStrengtheningWildfiresImpurity Transport,12, 20103, 2014FORTop-UpNew0)16.0

  2. Beryllium, Lithium and Oxygen Abundances in F-type Stars

    E-Print Network [OSTI]

    R. J. Garcia Lopez; M. C. Dominguez Herrera; M. R. Perez de Taoro; C. Casares; J. L. Rasilla; R. Rebolo; C. Allende Prieto

    1997-10-07T23:59:59.000Z

    Beryllium and oxygen abundances have been derived in a sample of F-type field stars for which lithium abundances had been measured previously, with the aim of obtaining observational constraints to discriminate between the different mixing mechanisms proposed. Mixing associated with the transport of angular momentum in the stellar interior and internal gravity waves within the framework of rotating evolutionary models, appear to be promising ways to explain the observations.

  3. Massive stars vs. nebular abundances in the Orion nebula

    E-Print Network [OSTI]

    Sergio Simón Díaz

    2006-11-16T23:59:59.000Z

    The search of consistency between nebular and massive star abundances has been a longstanding problem. I briefly review what has been done regarding to this topic, also presenting a recent study focused on the Orion nebula: the O and Si stellar abundances resulting from a detailed and fully consistent spectroscopic analysis of the group of B stars associated with the Orion nebula are compared with the most recent nebular gas-phase results.

  4. JOURNAL OF GEOPHYSICAL RESEARCH, VOL. ???, XXXX, DOI:10.1029/, Frazil Deposition Under Growing Sea Ice

    E-Print Network [OSTI]

    McGuinness, Mark

    Ice M.J. McGuinness,1,4 M.J.M. Williams,2 P.J. Langhorne,3 C. Purdie,3 J. Crook4 Abstract. Platelet ice may be an important component of Antarctic land-fast sea ice. Typically, it is found at depth in first-year landfast sea ice cover, near ice shelves. To explain why platelet ice is not commonly

  5. DIRECT EVALUATION OF THE HELIUM ABUNDANCES IN OMEGA CENTAURI

    SciTech Connect (OSTI)

    Dupree, A. K.; Avrett, E. H., E-mail: dupree@cfa.harvard.edu, E-mail: eavrett@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)

    2013-08-20T23:59:59.000Z

    A direct measure of the helium abundances from the near-infrared transition of He I at 1.08 {mu}m is obtained for two nearly identical red giant stars in the globular cluster Omega Centauri. One star exhibits the He I line; the line is weak or absent in the other star. Detailed non-local thermal equilibrium semi-empirical models including expansion in spherical geometry are developed to match the chromospheric H{alpha}, H{beta}, and Ca II K lines, in order to predict the helium profile and derive a helium abundance. The red giant spectra suggest a helium abundance of Y {<=} 0.22 (LEID 54064) and Y = 0.39-0.44 (LEID 54084) corresponding to a difference in the abundance {Delta}Y {>=} 0.17. Helium is enhanced in the giant star (LEID 54084) that also contains enhanced aluminum and magnesium. This direct evaluation of the helium abundances gives observational support to the theoretical conjecture that multiple populations harbor enhanced helium in addition to light elements that are products of high-temperature hydrogen burning. We demonstrate that the 1.08 {mu}m He I line can yield a helium abundance in cool stars when constraints on the semi-empirical chromospheric model are provided by other spectroscopic features.

  6. Primordial Lithium Abundance in Catalyzed Big Bang Nucleosynthesis

    E-Print Network [OSTI]

    Chris Bird; Kristen Koopmans; Maxim Pospelov

    2008-05-19T23:59:59.000Z

    There exists a well known problem with the Li7+Be7 abundance predicted by standard big bang nucleosynthesis being larger than the value observed in population II stars. The catalysis of big bang nucleosynthesis by metastable, \\tau_X \\ge 10^3 sec, charged particles X^- is capable of suppressing the primordial Li7+Be7, abundance and making it consistent with the observations. We show that to produce the correct abundance, this mechanism of suppression places a requirement on the initial abundance of X^- at temperatures of 4\\times 10^8 K to be on the order of or larger than 0.02 per baryon, which is within the natural range of abundances in models with metastable electroweak-scale particles. The suppression of Li7+Be7, is triggered by the formation of (Be7X^-), compound nuclei, with fast depletion of their abundances by catalyzed proton reactions, and in some models by direct capture of X^- on Be7. The combination of Li7+Be7 and Li6 constraints favours the window of lifetimes, 1000s \\la tau_X \\leq 2000 s.

  7. Carbon and Strontium Abundances of Metal-Poor Stars

    E-Print Network [OSTI]

    David K. Lai; Jennifer A. Johnson; Michael Bolte; Sara Lucatello

    2007-06-20T23:59:59.000Z

    We present carbon and strontium abundances for 100 metal-poor stars measured from R$\\sim $7000 spectra obtained with the Echellette Spectrograph and Imager at the Keck Observatory. Using spectral synthesis of the G-band region, we have derived carbon abundances for stars ranging from [Fe/H]$=-1.3$ to [Fe/H]$=-3.8$. The formal errors are $\\sim 0.2$ dex in [C/Fe]. The strontium abundance in these stars was measured using spectral synthesis of the resonance line at 4215 {\\AA}. Using these two abundance measurments along with the barium abundances from our previous study of these stars, we show it is possible to identify neutron-capture-rich stars with our spectra. We find, as in other studies, a large scatter in [C/Fe] below [Fe/H]$ = -2$. Of the stars with [Fe/H]$carbon-rich metal-poor stars. The Sr and Ba abundances show that three of the carbon-rich stars are neutron-capture-rich, while two have normal Ba and Sr. This fraction of carbon enhanced stars is consistent with other studies that include this metallicity range.

  8. A SIGNIFICANTLY LOW CO ABUNDANCE TOWARD THE TW Hya PROTOPLANETARY DISK: A PATH TO ACTIVE CARBON CHEMISTRY?

    SciTech Connect (OSTI)

    Favre, Cécile; Cleeves, L. Ilsedore; Bergin, Edwin A. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States)] [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Qi, Chunhua [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)] [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Blake, Geoffrey A., E-mail: cfavre@umich.edu [California Institute of Technology, Division of Geological and Planetary Sciences, MS 150-21, Pasadena, CA 91125 (United States)

    2013-10-20T23:59:59.000Z

    In this Letter we report the CO abundance relative to H{sub 2} derived toward the circumstellar disk of the T-Tauri star TW Hya from the HD (1 – 0) and C{sup 18}O (2 – 1) emission lines. The HD (1 – 0) line was observed by the Herschel Space Observatory Photodetector Array Camera and Spectrometer whereas C{sup 18}O (2 – 1) observations were carried out with the Submillimeter Array at a spatial resolution of 2.''8 × 1.''9 (corresponding to ?151 × 103 AU). In the disk's warm molecular layer (T > 20 K) we measure a disk-averaged gas-phase CO abundance relative to H{sub 2} of ?(CO) = (0.1-3) × 10{sup –5}, substantially lower than the canonical value of ?(CO) = 10{sup –4}. We infer that the best explanation of this low ?(CO) is the chemical destruction of CO followed by rapid formation of carbon chains, or perhaps CO{sub 2}, that can subsequently freeze-out, resulting in the bulk mass of carbon locked up in ice grain mantles and oxygen in water. As a consequence of this likely time-dependent carbon sink mechanism, CO may be an unreliable tracer of H{sub 2} gas mass.

  9. Nuclear effects on J/? production in proton-nucleus collisions

    E-Print Network [OSTI]

    Chun-Gui Duan; Jian-Chao Xu; Li-Hua Song

    2011-09-25T23:59:59.000Z

    The study of nuclear effects for J/{\\psi} production in proton-nucleus collisions is crucial for a correct interpretation of the J/{\\psi} suppression patterns experimentally observed in heavy-ion collisions. By means of three representative sets of nuclear parton distribution, the energy loss effect in the initial state and the nuclear absorption effect in the final state are taken into account in the uniform framework of the Glauber model. A leading order phenomenological analysis is performed on J/{\\psi} production cross-section ratios RW/Be(xF) for the E866 experimental data. The J/{\\psi} suppression is investigated quantitatively due to the different nuclear effects. It is shown that the energy loss effect with resulting in the suppression on RW/Be(xF) is more important than the nuclear effects on parton distributions in high xF region. The E866 data in the small xF keep out the nuclear gluon distribution with a large anti-shadowing effect. However, the new HERA-B measurement is not in support of the anti-shadowing effect in the nuclear gluon distribution. It is found that the J/{\\psi}-nucleon inelastic cross section {\\sigma} J/{\\psi} abs depends on the kinematical variable xF, and increases as xF in the region xF > 0.2. 1 Introduction

  10. IceCube Project Monthly Report Accomplishments

    E-Print Network [OSTI]

    Saffman, Mark

    is the culmination of a series of ICECUBE - TOTAL US and NON-US 20.8% 19.4% 17.6% 6.6% 20.4% 19.0% 16.9% 6.6% 0.0% 10.0% 20.0% 30.0% 40.0% 50.0% 60.0% 70.0% 80.0% 90.0% 100.0% 3FY02-2FY03 3FY03-2FY04 A-04 M -04 J-04 J-04 A and Safety ­ This month the IceCube Safety and Quality Assurance Manager participated in site visits

  11. Climate, Ocean and Sea Ice Modeling (COSIM)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisiting the TWPSuccessAlamosCharacterization2Climate, Ocean and Sea Ice Modeling

  12. ARM - Lesson Plans: When Land Ice Melts

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP : XDC documentationBarrow, AlaskaWhen Floating Ice Melts in the SeaWhen

  13. Developing and Evaluating Ice Cloud Parameterizations by

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField Campaign: Potential Application toDevelopingand Evaluating Ice Cloud

  14. A search for stars of very low metal abundance. VI. Detailed abundances of 313 metal-poor stars

    SciTech Connect (OSTI)

    Roederer, Ian U.; Preston, George W.; Thompson, Ian B.; Shectman, Stephen A.; Burley, Gregory S.; Kelson, Daniel D. [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Sneden, Christopher, E-mail: iur@umich.edu [Department of Astronomy, University of Texas at Austin, 1 University Station, C1400, Austin, TX 78712 (United States)

    2014-06-01T23:59:59.000Z

    We present radial velocities, equivalent widths, model atmosphere parameters, and abundances or upper limits for 53 species of 48 elements derived from high resolution optical spectroscopy of 313 metal-poor stars. A majority of these stars were selected from the metal-poor candidates of the HK Survey of Beers, Preston, and Shectman. We derive detailed abundances for 61% of these stars for the first time. Spectra were obtained during a 10 yr observing campaign using the Magellan Inamori Kyocera Echelle spectrograph on the Magellan Telescopes at Las Campanas Observatory, the Robert G. Tull Coudé Spectrograph on the Harlan J. Smith Telescope at McDonald Observatory, and the High Resolution Spectrograph on the Hobby-Eberly Telescope at McDonald Observatory. We perform a standard LTE abundance analysis using MARCS model atmospheres, and we apply line-by-line statistical corrections to minimize systematic abundance differences arising when different sets of lines are available for analysis. We identify several abundance correlations with effective temperature. A comparison with previous abundance analyses reveals significant differences in stellar parameters, which we investigate in detail. Our metallicities are, on average, lower by ?0.25 dex for red giants and ?0.04 dex for subgiants. Our sample contains 19 stars with [Fe/H] ?–3.5, 84 stars with [Fe/H] ?–3.0, and 210 stars with [Fe/H] ?–2.5. Detailed abundances are presented here or elsewhere for 91% of the 209 stars with [Fe/H] ?–2.5 as estimated from medium resolution spectroscopy by Beers, Preston, and Shectman. We will discuss the interpretation of these abundances in subsequent papers.

  15. Passive ice freezing-releasing heat pipe. [Patent application

    DOE Patents [OSTI]

    Gorski, A.J.; Schertz, W.W.

    1980-09-29T23:59:59.000Z

    A heat pipe device has been developed which permits completely passive ice formation and periodic release of ice without requiring the ambient temperature to rise above the melting point of water. This passive design enables the maximum amount of cooling capacity to be stored in the tank.

  16. Proton ordering in tetragonal and monoclinic H2O ice

    E-Print Network [OSTI]

    Yen, Fei; Berlie, Adam; Liu, Xiaodi; Goncharov, Alexander F

    2015-01-01T23:59:59.000Z

    H2O ice remains one of the most enigmatic materials as its phase diagram reveals up to sixteen solid phases. While the crystal structure of these phases has been determined, the phase boundaries and mechanisms of formation of the proton-ordered phases remain unclear. From high precision measurements of the complex dielectric constant, we probe directly the degree of ordering of the protons in H2O tetragonal ice III and monoclinic ice V down to 80 K. A broadened first-order phase transition is found to occur near 202 K we attribute to a quenched disorder of the protons which causes a continuous disordering of the protons during cooling and metastable behavior. At 126 K the protons in ice III become fully ordered, and for the case of ice V becoming fully ordered at 113 K forming ice XIII. Two triple points are proposed to exist: one at 0.35 GPa and 126 K where ices III, IX and V coexist; and another at 0.35 GPa and 113 K where ices V, IX and XIII coexist. Our findings unravel the underlying mechanism driving th...

  17. Dynamical mechanism of antifreeze proteins to prevent ice growth

    E-Print Network [OSTI]

    B. Kutschan; K. Morawetz; S. Thoms

    2014-07-24T23:59:59.000Z

    The fascinating ability of algae, insects and fishes to survive at temperatures below normal freezing is realized by antifreeze proteins (AFPs). These are surface-active molecules and interact with the diffusive water/ice interface thus preventing complete solidification. We propose a new dynamical mechanism on how these proteins inhibit the freezing of water. We apply a Ginzburg-Landau type approach to describe the phase separation in the two-component system (ice, AFP). The free energy density involves two fields: one for the ice phase with a low AFP concentration, and one for liquid water with a high AFP concentration. The time evolution of the ice reveals microstructures resulting from phase separation in the presence of AFPs. We observed a faster clustering of pre-ice structure connected to a locking of grain size by the action of AFP, which is an essentially dynamical process. The adsorption of additional water molecules is inhibited and the further growth of ice grains stopped. The interfacial energy between ice and water is lowered allowing the AFPs to form smaller critical ice nuclei. Similar to a hysteresis in magnetic materials we observe a thermodynamic hysteresis leading to a nonlinear density dependence of the freezing point depression in agreement with the experiments.

  18. How Do Cultural Differences Affect Utilization of the ICE Approach?

    E-Print Network [OSTI]

    de Weck, Olivier L.

    with permission. Abstract. Integrated Concurrent Engineering (ICE) is a design approach initially developed process: "Integrated Concurrent Engineering (ICE) is a real-time collaborative process in which-understood procedures for real-time collaboration; concurrent quantitative engineering and qualitative conversation. 4

  19. ENERGY BASED ICE COLLISION FORCES Claude Daley1

    E-Print Network [OSTI]

    Daley, Claude

    1 ENERGY BASED ICE COLLISION FORCES Claude Daley1 1 Memorial University of Newfoundland, St. John's, Newfoundland, Canada A1C 3X5 ABSTRACT Ice collision forces can be determined by energy considerations. A variety of interaction geometry cases are considered. The indentation energy functions for eight different

  20. ENERGY BASED ICE COLLISION FORCES Claude Daley1

    E-Print Network [OSTI]

    Daley, Claude

    ENERGY BASED ICE COLLISION FORCES Claude Daley1 1 Memorial University of Newfoundland, St. John's, Newfoundland, Canada A1C 3X5 ABSTRACT Ice collision forces can be determined by energy considerations. A variety of interaction geometry cases are considered. The indentation energy functions for eight different

  1. Ice Storm Damage Greater Along the Terrestrial-Aquatic Interface

    E-Print Network [OSTI]

    Kraft, Clifford E.

    Ice Storm Damage Greater Along the Terrestrial-Aquatic Interface in Forested Landscapes Andrew A- tems. In 1998, a severe ice storm damaged over ten million hectares of forest across northern New York investigated the spatial arrangement of forest damage at the terrestrial-aquatic interface, an ecological edge

  2. IceCube Project Monthly Report November 2007

    E-Print Network [OSTI]

    Saffman, Mark

    the current budgets or the budgets modified by the cost performance index. Change Log - IceCube Total Project IceCube array with a detector uptime of 97%, above the internal monthly goal of 95%. #12;Cost design, development, procured materials, and the construction of the infrastructure that supports

  3. Azimuth Variation in Microwave Backscatter over the Greenland Ice Sheet

    E-Print Network [OSTI]

    Long, David G.

    Azimuth Variation in Microwave Backscatter over the Greenland Ice Sheet Ivan S. Ashcraft and David backscatter measurements are becoming an important tool for monitoring the dynamic behavior of the Greenland ice sheet. However, most Greenland studies assume constant backscatter for varying azimuth angles

  4. Arctic catastrophes in an idealized sea ice model Ian Eisenman

    E-Print Network [OSTI]

    Eisenman, Ian

    thermodynamics, varying open water fraction, an energy balance atmosphere, and scalable CO2. We find that summer.e., reflectiveness) between sea ice and the open water that is exposed when it melts. Bare or snow-covered sea ice reflects most sunlight back to space, while the dark ocean surface absorbs most incident light. Global

  5. Optimization of Ice Thermal Storage Systems Design for HVAC Systems

    E-Print Network [OSTI]

    Nassif, N.; Hall, C.; Freelnad, D.

    2013-01-01T23:59:59.000Z

    Ice thermal storage is promising technology to reduce energy costs by shifting the cooling cost from on-peak to off-peak periods. The paper discusses the optimal design of ice thermal storage and its impact on energy consumption, demand, and total...

  6. IceCube Project Monthly Report -June 2010 Accomplishments

    E-Print Network [OSTI]

    Saffman, Mark

    (April 29-30) and an ice drilling technology meeting (April 27-28). Cost and Schedule Performance Service Corporation and New York Air National Guard FY10 on-ice fuel and labor cost savings. Contingency. $125K WBS 1.2 Implementation Additional UW & PSL Labor to replace and refurbish drill hardware. On

  7. absorption scale ice: Topics by E-print Network

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

    absorption scale ice First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Optical properties of deep ice at...

  8. Lithium Abundances of the Local Thin Disk Stars

    E-Print Network [OSTI]

    David L. Lambert; Bacham E. Reddy

    2004-01-14T23:59:59.000Z

    Lithium abundances are presented for a sample of 181 nearby F and G dwarfs with accurate {\\it Hipparcos} parallaxes. The stars are on circular orbits about the Galactic centre and, hence, are identified as belonging to the thin disk. This sample is combined with two published surveys to provide a catalogue of lithium abundances, metallicities ([Fe/H]), masses, and ages for 451 F-G dwarfs, almost all belonging to the thin disk. The lithium abundances are compared and contrasted with published lithium abundances for F and G stars in local open clusters. The field stars span a larger range in [Fe/H] than the clusters for which [Fe/H] $\\simeq 0.0\\pm0.2$. The initial (i.e., interstellar) lithium abundance of the solar neighborhood, as derived from stars for which astration of lithium is believed to be unimportant, is traced from $\\log\\epsilon$(Li) = 2.2 at [Fe/H] = -1 to $\\log\\epsilon$(Li) = 3.2 at $+0.1$. This form for the evolution is dependent on the assumption that astration of lit hium is negligible for the stars defining the relation. An argument is advanced that this latter assumption may not be entirely correct, and, the evolution of lithium with [Fe/H] may be flatter than previously supposed. A sharp Hyades-like Li-dip is not seen among the field stars and appears to be replaced by a large spread among lithium abundances of stars more massive than the lower mass limit of the dip. Astration of lithium by stars of masses too low to participate in the Li-dip is discussed. These stars show little to no spread in lithium abundance at a given [Fe/H] and mass.

  9. Field demonstration of the ICE 250{trademark} Cleaning System

    SciTech Connect (OSTI)

    Johnston, J.L.; Jackson, L.M.

    1999-10-05T23:59:59.000Z

    The ICE 250{trademark} Cleaning System was engineered to convert water into small ice particles for use in cleaning and decontamination applications. Ice crystals are produced in a special icemaker and pressured through a hose-nozzle onto the surface to be cleaned. The Rocky Mountain Oilfield Testing Center and Ice Cleaning Systems, Inc., conducted a test of this system at Naval Petroleum Reserve No. 3 to evaluate the system's cleaning capabilities in an oil field environment. Equipment cleaned included an oil storage tank, a rod pumping unit, a road grader, and a wellhead. Contaminants were unrefined sour crude oil, hydraulic fluid, paraffin, and dirt, occurring separately and as mixtures. In all four demonstration cleaning tasks, the ICE 250 System effectively removed surface contaminant mixtures in a timely manner and left no oily residue. A minimal amount of waste moisture was generated, thereby reducing cleanup and disposal costs.

  10. Field demonstration of the ICE 250[trademark] Cleaning System

    SciTech Connect (OSTI)

    Johnston, J.L.; Jackson, L.M.

    1999-10-05T23:59:59.000Z

    The ICE 250[trademark] Cleaning System was engineered to convert water into small ice particles for use in cleaning and decontamination applications. Ice crystals are produced in a special icemaker and pressured through a hose-nozzle onto the surface to be cleaned. The Rocky Mountain Oilfield Testing Center and Ice Cleaning Systems, Inc., conducted a test of this system at Naval Petroleum Reserve No. 3 to evaluate the system's cleaning capabilities in an oil field environment. Equipment cleaned included an oil storage tank, a rod pumping unit, a road grader, and a wellhead. Contaminants were unrefined sour crude oil, hydraulic fluid, paraffin, and dirt, occurring separately and as mixtures. In all four demonstration cleaning tasks, the ICE 250 System effectively removed surface contaminant mixtures in a timely manner and left no oily residue. A minimal amount of waste moistur2048s generated, thereby reducing cleanup and disposal costs.

  11. Methods and apparatus for rotor blade ice detection

    DOE Patents [OSTI]

    LeMieux, David Lawrence

    2006-08-08T23:59:59.000Z

    A method for detecting ice on a wind turbine having a rotor and one or more rotor blades each having blade roots includes monitoring meteorological conditions relating to icing conditions and monitoring one or more physical characteristics of the wind turbine in operation that vary in accordance with at least one of the mass of the one or more rotor blades or a mass imbalance between the rotor blades. The method also includes using the one or more monitored physical characteristics to determine whether a blade mass anomaly exists, determining whether the monitored meteorological conditions are consistent with blade icing; and signaling an icing-related blade mass anomaly when a blade mass anomaly is determined to exist and the monitored meteorological conditions are determined to be consistent with icing.

  12. Fast-flowing outlet glaciers on Svalbard ice caps

    SciTech Connect (OSTI)

    Dowdeswell, J.A. (Univ. of Cambridge (England)); Collin, R.L. (University College of Wales, Aberystwyth (England))

    1990-08-01T23:59:59.000Z

    Four well-defined outlet glaciers are present on the 2510 km{sup 2} cap of Vestfonna in Nordaustlandet, Svalbard. Airborne radio echo sounding and aerial-photograph and satellite-image analysis methods are used to analyze the morphology and dynamics of the ice cap and its component outlet glaciers. The heavily crevassed outlets form linear depressions in the ice-cap surface and flow an order of magnitude faster than the ridges of uncrevassed ice between them. Ice flow on the ridges is accounted for by internal deformation alone, whereas rates of outlet glacier flow require basal motion. One outlet has recently switched into and out of a faster mode of flow. Rapid terminal advance, a change from longitudinal compression to tension, and thinning in the upper basin indicate surge behavior. Observed outlet glacier discharge is significantly greater than current inputs of mass of the ice cap, indicating that present rates of flow cannot be sustained under the contemporary climate.

  13. Spatial Mapping of Protein Abundances in the Mouse Brain by Voxelation...

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

    Mapping of Protein Abundances in the Mouse Brain by Voxelation Integrated with High-Throughput Liquid Chromatography Spatial Mapping of Protein Abundances in the Mouse Brain by...

  14. Ice emission and the redshifts of submillimeter sources

    E-Print Network [OSTI]

    C. C. Dudley; M. Imanishi; P. R. Maloney

    2008-02-12T23:59:59.000Z

    Observations at submillimeter wavelengths have revealed a population of sources thought to be at relatively large redshifts. The position of the 850 $\\mu$m passband on the Rayleigh-Jeans portion of the Planck function leads to a maximum redshift estimate of $z\\sim$4.5 since sources will not retain their redshift independent brightness close to the peak of the Planck function and thus drop out of surveys. Here we review evidence that ice absorption is present in the spectra of local ultraluminous infrared galaxies which are often taken as analogs for the 850 $\\mu$m source population. We consider the implication of this absorption for ice induced spectral structure at far infrared wavelengths and present marginal astronomical evidence that amorphous ice may have a feature similar to crystalline ice near 150 $\\mu$m. Recent corroborative laboratory evidence is supportive of this conclusion. It is argued that early metal enrichment by pair instability SN may lead to a high ice content relative to refractory dust at high redshift and a fairly robust detection of ice emission in a $z=6.42$ quasar is presented. It is further shown that ice emission is needed to understand the 450 $\\mu$m sources observed in the GOODS-N field. We are thus encouraged to apply far infrared ice emission models to the available observations of HDF 850.1, the brightest submillimeter source in the {\\it Hubble Deep Field}. We suggest that a redshift as large as 13 may need to be considered for this source, nearly a factor of three above the usual top estimate. Inclusion of the possibility of far infrared ice emission in the spectral energy distributions of model sources generally broadens the range of redshifts to be considered for submillimeter sources compared to models without ice emission.

  15. Synthesis and Characterization of Earth Abundant and Nontoxic Metal Chalcogenides Produced via Aerosol Spray Pyrolysis for Photovoltaic Applications

    E-Print Network [OSTI]

    Davis, Patrick John

    2013-01-01T23:59:59.000Z

    and Characterization of Earth Abundant and Nontoxic Metaland Characterization of Earth Abundant and Nontoxic Metalalternatives to CIGS with all earth abundant and non-toxic

  16. ?FosB differentially modulates nucleus accumbens direct and indirect pathway function

    E-Print Network [OSTI]

    Neve, Rachael L.

    Synaptic modifications in nucleus accumbens (NAc) medium spiny neurons (MSNs) play a key role in adaptive and pathological reward-dependent learning, including maladaptive responses involved in drug addiction. NAc MSNs ...

  17. Molecular gas streamers feeding and obscuring the active nucleus of NGC1068

    E-Print Network [OSTI]

    Sanchez, F Mueller; Genzel, R; Tacconi, L J; Eisenhauer, F; Hicks, E K S; Friedrich, S; Sternberg, A

    2008-01-01T23:59:59.000Z

    We report the first direct observations of neutral, molecular gas streaming in the nucleus of NGC1068 on scales of hydrogen emission around the nucleus in the central arcsec reveals two prominent linear structures leading to the AGN from the north and south. The kinematics of the gas in these features are dominated by non-circular motions and indicate that material is streaming towards the nucleus on highly elliptical or parabolic trajectories whose orientations are compatible with that of the disk plane of the galaxy. We interpret the data as evidence for fueling of gas to the central region. The radial transport rate from ~30 pc to a few parsec from the nucleus is ~15 M$_\\sun$ yr$^{-1}$. One of the infalling clouds lies directly in front of the central engine. We interpret it as a tidally disrupted streamer that forms the optically thick outerpart of an amorphous clump...

  18. Molecular gas streamers feeding and obscuring the active nucleus of NGC1068

    E-Print Network [OSTI]

    F. Mueller Sanchez; R. I. Davies; R. Genzel; L. J. Tacconi; F. Eisenhauer; E. K. S. Hicks; S. Friedrich; A. Sternberg

    2008-09-29T23:59:59.000Z

    We report the first direct observations of neutral, molecular gas streaming in the nucleus of NGC1068 on scales of hydrogen emission around the nucleus in the central arcsec reveals two prominent linear structures leading to the AGN from the north and south. The kinematics of the gas in these features are dominated by non-circular motions and indicate that material is streaming towards the nucleus on highly elliptical or parabolic trajectories whose orientations are compatible with that of the disk plane of the galaxy. We interpret the data as evidence for fueling of gas to the central region. The radial transport rate from ~30 pc to a few parsec from the nucleus is ~15 M$_\\sun$ yr$^{-1}$. One of the infalling clouds lies directly in front of the central engine. We interpret it as a tidally disrupted streamer that forms the optically thick outerpart of an amorphous clumpy molecular/dusty structure which contributes to the nuclear obscuration.

  19. Overexpression of CREB in the Nucleus Accumbens Shell Increases Cocaine Reinforcement in Self-Administering Rats

    E-Print Network [OSTI]

    Larson, Erin B.

    Chronic exposure to addictive drugs enhances cAMP response element binding protein (CREB)-regulated gene expression in nucleus accumbens (NAc), and these effects are thought to reduce the positive hedonic effects of passive ...

  20. Human Bed Nucleus of the Stria Terminalis Indexes Hypervigilant Threat Monitoring

    E-Print Network [OSTI]

    Whalen, Paul J.

    Human Bed Nucleus of the Stria Terminalis Indexes Hypervigilant Threat Monitoring Leah H disorders is hypervigilant threat monitoring, its biological bases in humans remain poorly understood. Animal models suggest that anxious processes such as hypervigilant threat monitoring are distinct from

  1. Communication Between the Cell Membrane and the Nucleus: Role of Protein Compartmentalization

    E-Print Network [OSTI]

    Lelievre, Sophie A

    2011-01-01T23:59:59.000Z

    Cell 3:699–709. Schmidt-Zachmann MS, Dargemont C, Ku¨hn LC,specific signal [Schmidt-Zachmann et al. , 1993], while ato the nucleus [Schmidt-Zachmann et al. , 1993]. Although

  2. Producing a compound Nucleus via Inelastic Scattering: The 90Zr(alpha,alpha')90Zr* Case

    SciTech Connect (OSTI)

    Escher, J E; Dietrich, F S

    2008-05-23T23:59:59.000Z

    In a Surrogate reaction a compound nucleus is produced via a direct reaction (pickup, stripping, or inelastic scattering). For a proper application of the Surrogate approach it is necessary to predict the resulting angular momentum and parity distribution in the compound nucleus. A model for determining these distributions is developed for the case of inelastic alpha scattering off a spherical nucleus. The focus is on obtaining a first, simple description of the direct-reaction process that produces the compound nucleus and on providing the basis for a more complete treatment of the problem. The approximations employed in the present description are discussed and the extensions required for a more rigorous treatment of the problem are outlined. To illustrate the formalism, an application to {sup 90}Zr({alpha},{alpha}{prime}){sup 90}Zr* is presented.

  3. Breeding for hygienic behaviour in honeybees (Apis mellifera) using free-mated nucleus colonies

    E-Print Network [OSTI]

    Breeding for hygienic behaviour in honeybees (Apis mellifera) using free-mated nucleus colonies 2011 ­ Accepted 14 October 2011 Abstract ­ Gains in hygienic behaviour based on maternal selection generation, levels of hygienic behaviour among progeny remained relatively unchanged. Estimated breeding

  4. Nucleon binding corrections to lepton-nucleus deep inelastic scattering: Use of a realistic spectral function

    SciTech Connect (OSTI)

    Dieperink, A.E.L.; Miller, G.A. (Department of Physics, FM-15, University of Washington, Seattle, Washington (USA))

    1991-08-01T23:59:59.000Z

    Nuclear spectral functions computed with realistic nuclear forces are used to compute mean separation energies and to estimate the binding corrections to lepton-nucleus deep inelastic scattering. The separation energies are large and significant binding effects are obtained.

  5. New solar opacities, abundances, helioseismology, and neutrino fluxes

    E-Print Network [OSTI]

    John N. Bahcall; Aldo M. Serenelli; Sarbani Basu

    2005-01-19T23:59:59.000Z

    We construct solar models with the newly calculated radiative opacities from the Opacity Project (OP) and recently determined (lower) heavy element abundances. We compare results from the new models with predictions of a series of models that use OPAL radiative opacities, older determinations of the surface heavy element abundances, and refinements of nuclear reaction rates. For all the variations we consider, solar models that are constructed with the newer and lower heavy element abundances advocated by Asplund et al. (2005) disagree by much more than the estimated measuring errors with helioseismological determinations of the depth of the solar convective zone, the surface helium composition, the internal sound speeds, and the density profile. Using the new OP radiative opacities, the ratio of the 8B neutrino flux calculated with the older and larger heavy element abundances (or with the newer and lower heavy element abundances) to the total neutrino flux measured by the Sudbury Neutrino Observatory is 1.09 (0.87) with a 9% experimental uncertainty and a 16% theoretical uncertainty, 1 sigma errors.

  6. Spectroscopic Study on the Beryllium Abundances of Red Giant Stars

    E-Print Network [OSTI]

    Takeda, Yoichi

    2014-01-01T23:59:59.000Z

    An extensive spectroscopic study was carried out for the beryllium abundances of 200 red giants (mostly of late G and early K type), which were determined from the near-UV Be II 3131.066 line based on high-dispersion spectra obtained by Subaru/HDS, with an aim of investigating the nature of surface Be contents in these evolved giants; e.g., dependence upon stellar parameters, degree of peculiarity along with its origin and build-up timing. We found that Be is considerably deficient (to widely different degree from star to star) in the photosphere of these evolved giants by ~1-3 dex (or more) compared to the initial abundance. While the resulting Be abundances (A(Be)) appear to weakly depend upon T_eff, log g, [Fe/H], M, age, and v_sin i, this may be attributed to the metallicity dependence of A(Be) coupled with the mutual correlation between these stellar parameters, since such tendencies almost disappear in the metallicity-scaled Be abundance ([Be/Fe]). By comparing the Be abundances (as well as their correl...

  7. Oxygen abundance in the Sloan Digital Sky Survey

    E-Print Network [OSTI]

    F. Shi; X. Kong; F. Z. Cheng

    2006-03-10T23:59:59.000Z

    We present two samples of $\\hii$ galaxies from the Sloan Digital Sky Survey (SDSS) spectroscopic observations data release 3. The electron temperatures($T_e$) of 225 galaxies are calculated with the photoionized $\\hii$ model and $T_e$ of 3997 galaxies are calculated with an empirical method. The oxygen abundances from the $T_e$ methods of the two samples are determined reliably. The oxygen abundances from a strong line metallicity indicator, such as $R_{23}$, $P$, $N2$, and $O3N2$, are also calculated. We compared oxygen abundances of $\\hii$ galaxies obtained with the $T_e$ method, $R_{23}$ method, $P$ method, $N2$ method, and $O3N2$method. The oxygen abundances derived with the $T_e$ method are systematically lower by $\\sim$0.2 dex than those derived with the $R_{23}$ method, consistent with previous studies based on $\\hii$ region samples. No clear offset for oxygen abundance was found between $T_e$ metallicity and $P$, $N2$ and $O3N2$ metallicity. When we studied the relation between N/O and O/H, we found that in the metallicity regime of $\\zoh > 7.95$, the large scatter of the relation can be explained by the contribution of small mass stars to the production of nitrogen. In the high metallicity regime, $\\zoh > 8.2$, nitrogen is primarily a secondary element produced by stars of all masses.

  8. Variational and perturbative approaches to the confined hydrogen atom with a moving nucleus

    E-Print Network [OSTI]

    Francisco M. Fernández; N. Aquino; A. Flores-Riveros

    2010-09-11T23:59:59.000Z

    We calculate the ground--state energy and other physical properties of the hydrogen atom inside a spherical box with an impenetrable wall. We apply the variational method and perturbation theory and compare both approximate results. We show that the total, kinetic and potential energies for the moving--nucleus model are greater than those for the case in which the nucleus is clamped at the box center.

  9. Using Neutrino Nucleus Interactions as a Probe of the Strong Interaction

    SciTech Connect (OSTI)

    Morfin, Jorge G. [Fermi National Accelerator Laboratory (United States)

    2011-11-23T23:59:59.000Z

    Neutrino scattering experiments have been studying QCD for over 30 years. From the Gargamelle experiments in the early 70's, through the subsequent bubble chamber and electronic detector experiments in the 80's and 90's, neutrino scattering experiments have steadily accumulated increasing statistics and minimized their systematic errors. An example of the more recent studies of QCD with neutrinos is from the TeVatron neutrino beam--the NuTeV {nu}-Fe experiment. The problem the community faces in trying to study QCD with modern neutrino data is that there is no experimentally verified way to scale neutrino-nucleus (for example, Fe) results to the equivalent neutrino-nucleon values making it difficult to combine neutrino nucleus scattering data with charged-lepton nucleus and nucleon scattering data in QCD global fits to extract parton distribution functions. This is particularly crucial since there is now indications that nuclear effects in neutrino nucleus interactions are different than those measured in charged-lepton nucleus scattering. To better understand this situation, the MINER{nu}A neutrino-nucleus scattering experiment at Fermilab, a collaboration of elementary-particle and nuclear physicists, is systematically studying neutrino nuclear effects off of He, C, Fe and Pb for a more thorough A-dependent study of nuclear PDFs and these correction factors.

  10. What Is The Neon Abundance Of The Sun?

    E-Print Network [OSTI]

    John N. Bahcall; Sarbani Basu; Aldo M. Serenelli

    2005-05-16T23:59:59.000Z

    We have evolved a series of thirteen complete solar models that utilize different assumed heavy element compositions. Models that are based upon the heavy element abundances recently determined by Asplund, Grevesse, and Sauval (2005) are inconsistent with helioseismological measurements. However, models in which the neon abundance is increased by 0.4-0.5 dex to log N(Ne) = 8.29 +- 0.05 (on the scale in which log N(H) = 12) are consistent with the helioseismological measurements even though the other heavy element abundances are in agreement with the determinations of Asplund et al. (2005). These results sharpen and strengthen an earlier study by Antia and Basu (2005). The predicted solar neutrino fluxes are affected by the uncertainties in the composition by less than their 1sigma theoretical uncertainties.

  11. The chemical abundances of the Ap star HD94660

    SciTech Connect (OSTI)

    Giarrusso, M. [Università di Catania, Dipartimento di Fisica e Astronomia, Sezione Astrofisica, Via S. Sofia 78, 95123 Catania (Italy); INAF - Osservatorio Astrofisico di Catania, via S. Sofia 78, 95123 Catania (Italy); INFN - Laboratori Nazionali del Sud (Italy)

    2014-05-09T23:59:59.000Z

    In this work I present the determination of chemical abundances of the Ap star HD94660, a possible rapid oscillating star. As all the magnetic chemically peculiar objects, it presents CNO underabundance and overabundance of iron peak elements of ?100 times and of rare earths up to 4 dex with respect to the Sun. The determination was based on the conversion of the observed equivalent widths into abundances simultaneously to the determination of effective temperature and gravity. Since the Balmer lines of early type stars are very sensitive to the surface gravity while the flux distribution is sensitive to the effective temperature, I have adopted an iterative procedure to match the H{sub ?} line profile and the observed UV-Vis-NIR magnitudes of HD94660 looking for a consistency between the metallicity of the atmosphere model and the derived abundances. From my spectroscopic analysis, this star belongs to the no-rapid oscillating class.

  12. The effects of He I 10830 on helium abundance determinations

    E-Print Network [OSTI]

    Aver, Erik; Skillman, Evan D

    2015-01-01T23:59:59.000Z

    Observations of helium and hydrogen emission lines from metal-poor extragalactic H II regions provide an independent method for determining the primordial helium abundance, Y_p. Traditionally, the emission lines employed are in the visible wavelength range, and the number of suitable lines is limited. Furthermore, when using these lines, large systematic uncertainties in helium abundance determinations arise due to the degeneracy of physical parameters, such as temperature and density. Recently, Izotov, Thuan, & Guseva (2014) have pioneered adding the He 10830 infrared emission line in helium abundance determinations. The strong electron density dependence of He 10830 makes it ideal for better constraining density, potentially breaking the degeneracy with temperature. We revisit our analysis of the dataset published by Izotov, Thuan, & Stasinska (2007) and incorporate the newly available observations of He 10830 by scaling them using the observed-to-theoretical Paschen-gamma ratio. The solutions are b...

  13. Abundant p-singular elements in finite classical groups

    E-Print Network [OSTI]

    Niemeyer, Alice C; Praeger, Cheryl E

    2012-01-01T23:59:59.000Z

    In 1995, Isaacs, Kantor and Spaltenstein proved that for a finite simple d-dimensional classical group G, and for any prime divisor p of |G| distinct from the characteristic, the proportion of p-singular elements (elements with order divisible by p) is at least c/d for some constant c. We define a new subfamily of p-singular elements, called p-abundant elements, which leave invariant certain "large" subspaces of the natural G-module. We find explicit upper and lower bounds for the proportion of p-abundant elements in G, and prove that it approaches a (positive) limiting value as d \\rightarrow \\infty. It turns out that the limiting proportion of p-abundant elements is at least a constant multiple of the lower bound for the proportion of all p-singular elements derived by Issacs, Kantor and Spaltenstein.

  14. Spectroscopic Abundances and Membership in the Wolf 630 Moving Group

    E-Print Network [OSTI]

    Bubar, Eric J

    2010-01-01T23:59:59.000Z

    The concept of kinematic assemblages evolving from dispersed stellar clusters has remained contentious since Eggen's initial formulation of moving groups in the 1960's. With high quality parallaxes from the Hipparcos space astrometry mission, distance measurements for thousands of nearby, seemingly isolated stars are currently available. With these distances, a high resolution spectroscopic abundance analysis can be brought to bear on the alleged members of these moving groups. If a structure is a relic of an open cluster, the members can be expected to be monolithic in age and abundance inasmuch as homogeneity is observed in young open clusters. In this work we have examined 34 putative members of the proposed Wolf 630 moving group using high resolution stellar spectroscopy. The stars of the sample have been chemically tagged to determine abundance homogeneity and confirm the existence of a homogeneous subsample of 19 stars. Fitting the homogeneous subsample with Yale-Yonsei isochrones yields a single evolut...

  15. DETERMINING THE INITIAL HELIUM ABUNDANCE OF THE SUN

    SciTech Connect (OSTI)

    Serenelli, Aldo M. [Max Planck Institute for Astrophysics, Karl Schwarzschild Str. 1, Garching D-85471 (Germany); Basu, Sarbani, E-mail: aldos@mpa-garching.mpg.d [Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520-8101 (United States)

    2010-08-10T23:59:59.000Z

    We determine the dependence of the initial helium abundance and the present-day helium abundance in the convective envelope of solar models (Y {sub ini} and Y {sub surf}, respectively) on the parameters that are used to construct the models. We do so by using reference standard solar models (SSMs) to compute the power-law coefficients of the dependence of Y {sub ini} and Y {sub surf} on the input parameters. We use these dependencies to determine the correlation between Y {sub ini} and Y {sub surf} and use this correlation to eliminate uncertainties in Y {sub ini} from all solar model input parameters except the microscopic diffusion rate. We find an expression for Y {sub ini} that depends only on Y {sub surf} and the diffusion rate. By adopting the helioseismic determination of solar surface helium abundance, Y {sup surf} {sub sun} = 0.2485 {+-} 0.0035, and an uncertainty of 20% for the diffusion rate, we find that the initial solar helium abundance, Y {sup ini} {sub sun}, is 0.278 {+-} 0.006 independently of the reference SSMs (and particularly on the adopted solar abundances) used in the derivation of the correlation between Y {sub ini} and Y {sub surf}. When non-SSMs with extra mixing are used, then we derive Y {sup ini} {sub sun} = 0.273 {+-} 0.006. In both cases, the derived Y {sup ini} {sub sun} value is higher than that directly derived from solar model calibrations when the low-metallicity solar abundances (e.g., by Asplund et al.) are adopted in the models.

  16. Air conditioning system with supplemental ice storing and cooling capacity

    DOE Patents [OSTI]

    Weng, Kuo-Lianq (Taichung, TW); Weng, Kuo-Liang (Taichung, TW)

    1998-01-01T23:59:59.000Z

    The present air conditioning system with ice storing and cooling capacity can generate and store ice in its pipe assembly or in an ice storage tank particularly equipped for the system, depending on the type of the air conditioning system. The system is characterized in particular in that ice can be produced and stored in the air conditioning system whereby the time of supplying cooled air can be effectively extended with the merit that the operation cycle of the on and off of the compressor can be prolonged, extending the operation lifespan of the compressor in one aspect. In another aspect, ice production and storage in great amount can be performed in an off-peak period of the electrical power consumption and the stored ice can be utilized in the peak period of the power consumption so as to provide supplemental cooling capacity for the compressor of the air conditioning system whereby the shift of peak and off-peak power consumption can be effected with ease. The present air conditioning system can lower the installation expense for an ice-storing air conditioning system and can also be applied to an old conventional air conditioning system.

  17. GRAPH-BASED METHOD FOR MULTITEMPORAL SEGMENTATION OF SEA ICE FLOES FROM SATELLITE DATA

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    the Arc- tic sea ice pack in December 2007, continuously moved with the Arctic ocean currents and meltedGRAPH-BASED METHOD FOR MULTITEMPORAL SEGMENTATION OF SEA ICE FLOES FROM SATELLITE DATA Claudio, MODIS, Sea Ice Floes. ABSTRACT: Automated segmentation of the sea ice evolution would allow scientists

  18. Arctic Ice Dynamics Joint Experiment (AIDJEX) assumptions revisited and found inadequate

    E-Print Network [OSTI]

    Sulsky, Deborah L.

    the Arctic Ice Dynamics Joint Experiment (AIDJEX) assumptions about pack ice behavior with an eye to modeling the behavior of pack ice. A model based on these assumptions is needed to represent the deformation and stress in pack ice on scales from 10 to 100 km, and would need to explicitly resolve discontinuities

  19. Effect of air-sea-ice interaction on winter 1996 Southern Ocean subpolar storm distribution

    E-Print Network [OSTI]

    Columbia University

    is the baroclinic instability caused by the cold air blown from the ice pack to the warm open-ocean waters. Where with the entire pack ice/open-water region. The heat flux changes considerably in the area from continental ice to pack ice, resulting in strong baroclinicity that leads to the enhanced development of vortices. Streten

  20. Gas ageice age differences and the chronology of the Vostok ice core, M. L. Bender,1

    E-Print Network [OSTI]

    Chappellaz, Jérôme

    Gas age­ice age differences and the chronology of the Vostok ice core, 0­100 ka M. L. Bender,1 G. [1] Gas is trapped in polar ice at depths of $50­120 m and is therefore significantly younger than cores (Vostok, Dome Fuji, and Dome C). We recorrelate the gas records of Vostok and Greenland Ice Sheet

  1. CMU-ITC-83-029 WHITE PAPER: The ICE Execution Environment

    E-Print Network [OSTI]

    CMU-ITC-83-029 WHITE PAPER: The ICE Execution Environment Document Number 003-001/002.01 DRAFT-Mellon University Schenley Park Pittsburgh, PA 15213 #12;The ICE Execution Environment DRAFT 003- 001/002.01 U ncla ssified ( 2 The ICE Execution Environment #12;The ICE Execution Environment DRAFT 003

  2. IDENTIFYING ICE HYDROMETEOR SIGNATURES ABOVE SUMMIT, GREENLAND USING A MULTI-INSTRUMENT APPROACH

    E-Print Network [OSTI]

    Wisconsin at Madison, University of

    IDENTIFYING ICE HYDROMETEOR SIGNATURES ABOVE SUMMIT, GREENLAND USING A MULTI. These retrievals, however, may be adversely affected by ice hydrometeors commonly observed in mixed phase clouds. Research on the effect of ice hydrometeors on the microwave signal is insufficient. We establish that ice

  3. Adaptive mesh, finite volume modeling of marine ice sheets Stephen L. Cornforda

    E-Print Network [OSTI]

    Adaptive mesh, finite volume modeling of marine ice sheets Stephen L. Cornforda , Daniel F. Martinb Abstract Continental scale marine ice sheets such as the present day West Antarctic Ice Sheet are strongly phenomenon of this kind is the migration of the grounding line -- the division between ice in contact

  4. Sessions 1526 & 2526 The URI Integrated Computer Engineering Design (ICED) Curriculum

    E-Print Network [OSTI]

    Uht, Augustus K.

    Sessions 1526 & 2526 The URI Integrated Computer Engineering Design (ICED) Curriculum: Progress the ICED curriculum in the Fall of 1997. The key feature of ICED is a substantial 2-3 year long project of ICED after two years of startup operation. Some custom hardware was required for the curriculum

  5. IMPLICATIONS OF CO, GLOBAL WARMING O N GREAT LAKES ICE COVER

    E-Print Network [OSTI]

    IMPLICATIONS OF CO, GLOBAL WARMING O N GREAT LAKES ICE COVER RAYMOND A. ASSEL US. Department to project daily mean basin ice cover and annual ice cover duration for Lakes Superior and Erie. Models were), and the Oregon State University (OSU)general circulationmodels. Ice cover estimateswere made for the West

  6. OTC Paper Number 24645 GPU-Event-Mechanics Evaluation of Ice Impact Load Statistics

    E-Print Network [OSTI]

    Peters, Dennis

    OTC Paper Number 24645 GPU-Event-Mechanics Evaluation of Ice Impact Load Statistics Claude Daley of a GPU-Event-Mechanics (GEM) simulation to assess local ice loads on a vessel operating in pack ice workstation. The simulation domain contains hundreds of discrete and interacting ice floes. A simple vessel

  7. Ice-associated phytoplankton blooms in the southeastern Bering Sea Meibing Jin,1

    E-Print Network [OSTI]

    Ice-associated phytoplankton blooms in the southeastern Bering Sea Meibing Jin,1 Clara Deal,1 Jia 2007. [1] Ice-associated phytoplankton blooms in the south- eastern Bering Sea can critically impact ice algal components, our 1-D ecosystem model successfully reproduced the observed ice

  8. ESTIMATING BEDROCK AND SURFACE LAYER BOUNDARIES AND CONFIDENCE INTERVALS IN ICE SHEET RADAR IMAGERY USING MCMC

    E-Print Network [OSTI]

    Menczer, Filippo

    ESTIMATING BEDROCK AND SURFACE LAYER BOUNDARIES AND CONFIDENCE INTERVALS IN ICE SHEET RADAR IMAGERY and Computing Indiana University Bloomington, Indiana USA ABSTRACT Climate models that predict polar ice sheet behavior require accurate measurements of the bedrock-ice and ice-air bound- aries in ground

  9. Ice sheets and their dynamics Continuum thermo-mechanical model of a glacier

    E-Print Network [OSTI]

    Cerveny, Vlastislav

    Ice sheets and their dynamics Continuum thermo-mechanical model of a glacier Shallow Ice Approximation (SIA) SIA-I Iterative Improvement Technique Benchmarks Numerical modeling of ice-sheet dynamics and Cartography, Zdiby 1.6.2010 Ondej Soucek Ph.D. defense #12;Ice sheets and their dynamics Continuum thermo

  10. Ice-assisted electron beam lithography of graphene Jules A Gardener1

    E-Print Network [OSTI]

    1 Ice-assisted electron beam lithography of graphene Jules A Gardener1 and Jene A Golovchenko1 with a thin ice layer. The irradiated ice plays a crucial role in the process by providing activated species that locally remove graphene from a silicon dioxide substrate. After patterning the graphene, the ice resist

  11. Pleistocene ice and paleo-strain rates at Taylor Glacier, Antarctica S.M. Aciego a

    E-Print Network [OSTI]

    Severinghaus, Jeffrey P.

    Pleistocene ice and paleo-strain rates at Taylor Glacier, Antarctica S.M. Aciego a , K.M. Cuffey b September 2006 Abstract Ice exposed in ablation zones of ice sheets can be a valuable source of samples for paleoclimate studies and information about long-term ice dynamics. We report a 28-km long stable isotope

  12. Ice Climbing in Clear Creek Canyon A climbing trip report by Glenn Murray

    E-Print Network [OSTI]

    Ice Climbing in Clear Creek Canyon A climbing trip report by Glenn Murray SUMMARY: I climb ice in to ask about local climbing. The guys there told me there was ice nearby, in Clear Creek Canyon. I. Four pitches? Five? It was time to find a partner. The only ice climber I knew in Denver was a friend

  13. Snow and Ice Control Best Management Practices Parking Lots, Sidewalks, Roads

    E-Print Network [OSTI]

    Minnesota, University of

    Snow and Ice Control Best Management Practices Parking Lots, Sidewalks, Roads Minnesota Circuit opportunity to improve the way we manage snow and ice in Minnesota. By using snow and ice control best safer--while saving money and protecting water quality. Current Situation The snow and ice maintenance

  14. SEA ICE MAPPING ALGORITHM FOR QUIKSCAT AND SEAWINDS Quinn P. Remund and David G. Long

    E-Print Network [OSTI]

    Long, David G.

    SEA ICE MAPPING ALGORITHM FOR QUIKSCAT AND SEAWINDS Quinn P. Remund and David G. Long Brigham Young@ee.byu.edu Abstruct- Polar sea ice extent is an important input to global climate models and is considered are sensitive to the pres- ence of sea ice. An algorithm has been developed for sea ice extent detection using

  15. The ice flow behavior in the neighborhood of the grounding line. Non-Newtonian case.

    E-Print Network [OSTI]

    Fontelos, Marco

    The ice flow behavior in the neighborhood of the grounding line. Non-Newtonian case. Marco A line dynamics. The grounding line is the line where tran- sition between ice attached to the solid ground and ice floating over the sea takes place. We analyze a mathematical model describing the ice flow

  16. Instruments and Methods Intermediate-depth ice coring of high-altitude and polar glaciers

    E-Print Network [OSTI]

    Howat, Ian M.

    an electromechanical drill (EMD) and an ethanol thermal electric drill (ETED). The EMD permitted an average ice in cold and temperate ice and in clean and particle-laden ice. The influence of the ethanol drilling fluid- arctica, 2000) and an ethanol thermal electric drill (ETED; Zagorodnov and others, 1998)). Ice thicknesses

  17. Recent ice loss from the Fleming and other glaciers, Wordie Bay, West Antarctic Peninsula

    E-Print Network [OSTI]

    Kansas, University of

    that the glaciers accelerated following ice shelf removal, and have been thinning and losing mass to the ocean overRecent ice loss from the Fleming and other glaciers, Wordie Bay, West Antarctic Peninsula E. Rignot ice thickness data from 2002, reveal that the glaciers flowing into former Wordie Ice Shelf, West

  18. Development, sensitivity analysis, and uncertainty quantification of high-fidelity arctic sea ice models.

    SciTech Connect (OSTI)

    Peterson, Kara J.; Bochev, Pavel Blagoveston; Paskaleva, Biliana S.

    2010-09-01T23:59:59.000Z

    Arctic sea ice is an important component of the global climate system and due to feedback effects the Arctic ice cover is changing rapidly. Predictive mathematical models are of paramount importance for accurate estimates of the future ice trajectory. However, the sea ice components of Global Climate Models (GCMs) vary significantly in their prediction of the future state of Arctic sea ice and have generally underestimated the rate of decline in minimum sea ice extent seen over the past thirty years. One of the contributing factors to this variability is the sensitivity of the sea ice to model physical parameters. A new sea ice model that has the potential to improve sea ice predictions incorporates an anisotropic elastic-decohesive rheology and dynamics solved using the material-point method (MPM), which combines Lagrangian particles for advection with a background grid for gradient computations. We evaluate the variability of the Los Alamos National Laboratory CICE code and the MPM sea ice code for a single year simulation of the Arctic basin using consistent ocean and atmospheric forcing. Sensitivities of ice volume, ice area, ice extent, root mean square (RMS) ice speed, central Arctic ice thickness, and central Arctic ice speed with respect to ten different dynamic and thermodynamic parameters are evaluated both individually and in combination using the Design Analysis Kit for Optimization and Terascale Applications (DAKOTA). We find similar responses for the two codes and some interesting seasonal variability in the strength of the parameters on the solution.

  19. Using Satellite Radar Data to Map and Monitor Variations in Great Lakes Ice Cover

    E-Print Network [OSTI]

    , for image-to-image classification, a library of backscatter signatures of different ice types is needed) classification technique has shown that different ice types in the ice cover can be identified and mapped for use with calibrated SAR imagery. III. SAR ICE CLASSIFICATION AND MAPPING During the 1997 winter season

  20. Elastic uplift in southeast Greenland due to rapid ice mass loss Shfaqat A. Khan,1

    E-Print Network [OSTI]

    Larson, Kristine

    Elastic uplift in southeast Greenland due to rapid ice mass loss Shfaqat A. Khan,1 John Wahr,2] The rapid unloading of ice from the southeastern sector of the Greenland ice sheet between 2001 and 2006), Elastic uplift in southeast Greenland due to rapid ice mass loss, Geophys. Res. Lett., 34, L21701, doi:10