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Sample records for ice water path

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

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

    Liu, Guosheng

    2008-01-15

    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.

  2. 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.

  3. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Comments?govInstrumentsnoaacrnBarrow, Alaska Outreach Home Roomparticle sizefraction ARMGeometrytypespath ARM Data

  4. Evaluation of Ice Water Content Retrievals from Cloud Radar Reflectivity and Temperature Using a Large Airborne In Situ Microphysical Database

    E-Print Network [OSTI]

    Protat, Alain

    Evaluation of Ice Water Content Retrievals from Cloud Radar Reflectivity and Temperature Using the performances of the proposed ice water content (IWC)­radar reflectivity Z and IWC­Z­temperature T relationships produce a very different ice water path, spanning an order of magnitude (Stephens et al. 2002). Clouds

  5. 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

    2015-01-01

    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 ...

  6. 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

    2014-11-14

    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.

  7. Viscosity of interfacial water regulates ice nucleation

    SciTech Connect (OSTI)

    Li, Kaiyong; Chen, Jing; Zhang, Qiaolan; Zhang, Yifan; University of Chinese Academy of Sciences, Beijing 100049 ; Xu, Shun; Zhou, Xin; Cui, Dapeng; Wang, Jianjun Song, Yanlin

    2014-03-10

    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. Crystalline water ice on the Kuiper belt object (50000) Quaoar

    E-Print Network [OSTI]

    Jewitt, David C.

    .............................................................. Crystalline water ice on the Kuiper the presence of crystalline water ice and ammonia hydrate. Crystallinity indicates that the ice has been heated to at least 110 K. Both ammonia hydrate and crystalline water ice should be destroyed by energetic particle

  9. 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)

    2012-06-15

    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.

  10. Relationship between ice water content and equivalent radar reflectivity for clouds consisting of nonspherical ice particles

    E-Print Network [OSTI]

    Baum, Bryan A.

    Relationship between ice water content and equivalent radar reflectivity for clouds consisting investigates the relationship between ice water content (IWC) and equivalent radar reflectivity (Ze) at 94 GHz. Baum, and A. J. Heymsfield (2008), Relationship between ice water content and equivalent radar

  11. Covered Product Category: Water-Cooled Ice Machines

    Office of Energy Efficiency and Renewable Energy (EERE)

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

  12. Turbulent heat exchange between water and ice at an evolving ice-water interface

    E-Print Network [OSTI]

    Ramudu, Eshwan; Olson, Peter; Gnanadesikan, Anand

    2015-01-01

    We conduct laboratory experiments on the time evolution of an ice layer cooled from below and subjected to a turbulent shear flow of warm water from above. Our study is motivated by observations of warm water intrusion into the ocean cavity under Antarctic ice shelves, accelerating the melting of their basal surfaces. The strength of the applied turbulent shear flow in our experiments is represented in terms of its Reynolds number $\\textit{Re}$, which is varied over the range $2.0\\times10^3 \\le \\textit{Re} \\le 1.0\\times10^4$. Depending on the water temperature, partial transient melting of the ice occurs at the lower end of this range of $\\textit{Re}$ and complete transient melting of the ice occurs at the higher end. Following these episodes of transient melting, the ice reforms at a rate that is independent of $\\textit{Re}$. We fit our experimental measurements of ice thickness and temperature to a one-dimensional model for the evolution of the ice thickness in which the turbulent heat transfer is parameter...

  13. Water Evaporation: A Transition Path Sampling Study

    E-Print Network [OSTI]

    Patrick Varilly; David Chandler

    2012-12-12

    We use transition path sampling to study evaporation in the SPC/E model of liquid water. Based on thousands of evaporation trajectories, we characterize the members of the transition state ensemble (TSE), which exhibit a liquid-vapor interface with predominantly negative mean curvature at the site of evaporation. We also find that after evaporation is complete, the distributions of translational and angular momenta of the evaporated water are Maxwellian with a temperature equal to that of the liquid. To characterize the evaporation trajectories in their entirety, we find that it suffices to project them onto just two coordinates: the distance of the evaporating molecule to the instantaneous liquid-vapor interface, and the velocity of the water along the average interface normal. In this projected space, we find that the TSE is well-captured by a simple model of ballistic escape from a deep potential well, with no additional barrier to evaporation beyond the cohesive strength of the liquid. Equivalently, they are consistent with a near-unity probability for a water molecule impinging upon a liquid droplet to condense. These results agree with previous simulations and with some, but not all, recent experiments.

  14. Direct Calculation of Ice Homogeneous Nucleation Rate for a Molecular Model of Water

    E-Print Network [OSTI]

    Amir Haji-Akbari; Pablo G. Debenedetti

    2015-07-08

    Ice formation is ubiquitous in nature, with important consequences in a variety of environments, including biological cells, soil, aircraft, transportation infrastructure and atmospheric clouds. However, its intrinsic kinetics and microscopic mechanism are difficult to discern with current experiments. Molecular simulations of ice nucleation are also challenging, and direct rate calculations have only been performed for coarse-grained models of wate. For molecular models, only indirect estimates have been obtained, e.g. by assuming the validity of classical nucleation theory. We use a path sampling approach to perform the first direct rate calculation of homogeneous nucleation of ice in a molecular model of water. We use TIP4P/Ice, the most accurate among existing molecular models for studying ice polymorphs. By using a novel topological approach to distinguish different polymorphs, we are able to identify a freezing mechanism that involves a competition between cubic and hexagonal ice in the early stages of nucleation. In this competition, the cubic polymorph takes over since the addition of new topological structural motifs consistent with cubic ice leads to the formation of more compact crystallites. This is not true for topological hexagonal motifs, which give rise to elongated crystallites that are not able to grow. This leads to transition states that are rich in cubic ice, and not the thermodynamically stable hexagonal polymorph. This mechanism provides a molecular explanation to the earlier experimental and computational observations of the preference for cubic ice in the literature.

  15. Liquid Water Oceans in Ice Giants

    E-Print Network [OSTI]

    Sloane J. Wiktorowicz; Andrew P. Ingersoll

    2006-09-26

    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.

  16. THE STICKINESS OF MICROMETER-SIZED WATER-ICE PARTICLES

    SciTech Connect (OSTI)

    Gundlach, B.; Blum, J.

    2015-01-01

    Water ice is one of the most abundant materials in dense molecular clouds and in the outer reaches of protoplanetary disks. In contrast to other materials (e.g., silicates), water ice is assumed to be stickier due to its higher specific surface energy, leading to faster or more efficient growth in mutual collisions. However, experiments investigating the stickiness of water ice have been scarce, particularly in the astrophysically relevant micrometer-sized region and at low temperatures. In this work, we present an experimental setup to grow aggregates composed of ?m-sized water-ice particles, which we used to measure the sticking and erosion thresholds of the ice particles at different temperatures between 114 K and 260 K. We show with our experiments that for low temperatures (below ?210 K), ?m-sized water-ice particles stick below a threshold velocity of 9.6 m s{sup –1}, which is approximately 10 times higher than the sticking threshold of ?m-sized silica particles. Furthermore, erosion of the grown ice aggregates is observed for velocities above 15.3 m s{sup –1}. A comparison of the experimentally derived sticking threshold with model predictions is performed to determine important material properties of water ice, i.e., the specific surface energy and the viscous relaxation time. Our experimental results indicate that the presence of water ice in the outer reaches of protoplanetary disks can enhance the growth of planetesimals by direct sticking of particles.

  17. Commercial Light Water Production of Tritium Update and Path...

    Office of Environmental Management (EM)

    Light Water Production of Tritium: Update and Path Forward Dave Senor April 23, 2013 Tritium Focus Group 1 PNNL-SA-94431 Background United States defense maintains a stockpile of...

  18. The future of water, ice, snow underThe future of water, ice, snow under global warmingglobal warming

    E-Print Network [OSTI]

    Hurricane Katrina, the Kerry--Gingrich debate over globalGingrich debate over global warming, the local and regional warming.effects of global warming. Climate extends beyond temperature and rainfall, toClimate extendsThe future of water, ice, snow underThe future of water, ice, snow under global warmingglobal

  19. On the correlation between ice water content and ice crystal size and its application to radiative transfer and general circulation models

    E-Print Network [OSTI]

    Liou, K. N.

    On the correlation between ice water content and ice crystal size and its application to radiative analysis involving ice water content (IWC) and mean effective ice crystal size (De) intended, K. N., Y. Gu, Q. Yue, and G. McFarguhar (2008), On the correlation between ice water content and ice

  20. Ship-based liquid water path estimates in marine stratocumulus

    E-Print Network [OSTI]

    Zuidema, Paquita

    October 2005. [1] We examine liquid water paths (LWPs) derived from ship-based microwave radiometer to microwave absorption model differences are 10­25 g mÀ2 , increasing with LWP. The most recent models produce cycle, through the longwave cloud top radiative cooling and liquid water's ability to absorb solar

  1. THE PHASES OF WATER ICE IN THE SOLAR NEBULA

    SciTech Connect (OSTI)

    Ciesla, Fred J.

    2014-03-20

    Understanding the phases of water ice that were present in the solar nebula has implications for understanding cometary and planetary compositions as well as the internal evolution of these bodies. Here we show that amorphous ice formed more readily than previously recognized, with formation at temperatures <70 K being possible under protoplanetary disk conditions. We further argue that photodesorption and freeze-out of water molecules near the surface layers of the solar nebula would have provided the conditions needed for amorphous 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.

  2. Relationships between Water Wettability and Ice Adhesion

    E-Print Network [OSTI]

    Meuler, Adam J.

    Ice formation and accretion may hinder the operation of many systems critical to national infrastructure, including airplanes, power lines, windmills, ships, and telecommunications equipment. Yet despite the pervasiveness ...

  3. Interface limited growth of heterogeneously nucleated ice in supercooled water

    E-Print Network [OSTI]

    Razvan A. Nistor; Thomas E. Markland; B. J. Berne

    2013-12-30

    Heterogeneous ice growth exhibits a maximum in freezing rate arising from the competition between kinetics and the thermodynamic driving force between the solid and liquid states. Here, we use molecular dynamics simulations to elucidate the atomistic details of this competition, focusing on water properties in the interfacial region along the secondary prismatic direction. The crystal growth velocity is maximized when the efficiency of converting interfacial water molecules to ice, collectively known as the attachment kinetics, is greatest. We find water molecules that contact the intermediate ice layer in concave regions along the atomistically roughened surface are more likely to freeze directly. The increased roughening of the solid surface at large undercoolings consequently plays an important limiting role on the rate of ice growth, as water molecules are unable to integrate into increasingly deeper surface pockets. These results provide insights into the molecular mechanisms for self-assembly of solid phases that are important in many biological and atmospheric processes.

  4. Structure order, local potentials, and physical anomalies of water ice

    E-Print Network [OSTI]

    Chang Q Sun

    2014-07-11

    Hydrogen-bond forms a pair of asymmetric, coupled, H-bridged oscillators with ultra-short-range interactions and memory. hydrogen bond cooperative relaxation and the associated binding electron entrapment and nonbonding electron polarization discriminate water and ice from other usual materials in the physical anomalies. As a strongly correlated fluctuating system, water prefers the statistically mean of tetrahedrally-coordinated structure with a supersolid skin that is elastic, polarized, ice like, hydrophobic, with 3/4 density.

  5. CO and N$_2$ desorption energies from water ice

    E-Print Network [OSTI]

    Fayolle, Edith C; Loomis, Ryan; Bergner, Jennifer; Graninger, Dawn M; Rajappan, Mahesh; Öberg, Karin I

    2015-01-01

    The relative desorption energies of CO and N$_2$ are key to interpretations of observed interstellar CO and N$_2$ abundance patterns, including the well-documented CO and N$_2$H$^+$ anti-correlations in disks, protostars and molecular cloud cores. Based on laboratory experiments on pure CO and N$_2$ ice desorption, the difference between CO and N$_2$ desorption energies is small; the N$_2$-to-CO desorption energy ratio is 0.93$\\pm$0.03. Interstellar ices are not pure, however, and in this study we explore the effect of water ice on the desorption energy ratio of the two molecules. We present temperature programmed desorption experiments of different coverages of $^{13}$CO and $^{15}$N$_2$ on porous and compact amorphous water ices and, for reference, of pure ices. In all experiments, $^{15}$N$_2$ desorption begins a few degrees before the onset of $^{13}$CO desorption. The $^{15}$N$_2$ and $^{13}$CO energy barriers are 770 and 866 K for the pure ices, 1034-1143 K and 1155-1298 K for different sub-monolayer co...

  6. Oil spreading in surface waters with an ice cover

    SciTech Connect (OSTI)

    Yapa, P.D.; Weerasuriya, S.A.; Belaskas, D.P.; Chowdhury, T.

    1993-02-01

    A study of oil spreading in surface waters in the presence of a floating ice cover is presented. The ice can be solid or fragmented. Both axi-symmetrical and uni-directional spreading are studied. The report describes the analytical and numerical model development, the experimental set-up, results from the laboratory experiments, and their comparison with the derived theory and the numerical simulation. To analyze the spreading of oil under solid ice, new equations are derived. These equations consider gravity (buoyancy) - inertia phase, gravity (buoyancy) - viscous phase, and the termination of spreading during the buoyancy - surface tension phase. The derivation considers both the constant discharge mode and the constant volume mode. Therefore, a complete description of the spreading phenomena from the time of initial spill to termination of spreading is presented. The emphasis of the study is on the dominant spreading mechanism for oil under ice, which is the buoyancy-viscous phase.

  7. ARM - PI Product - Large Scale Ice Water Path and 3-D Ice Water Content

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

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  8. Water and Ice Dielectric Spectra Scaling at 0 °C

    E-Print Network [OSTI]

    V. G. Artemov; A. A. Volkov

    2013-08-06

    Dielectric spectra (10^4-10^11 Hz) of water and ice at 0 {\\deg}C are considered in terms of proton conductivity and compared to each other. In this picture, the Debye relaxations, centered at 1/{\\tau}_W ~ 20 GHz (in water) and 1/{\\tau}_I ~ 5 kHz (in ice), are seen as manifestations of diffusion of separated charges in the form of H3O+ and OH- ions. The charge separation results from the self-dissociation of H2O molecules, and is accompanied by recombination in order to maintain the equilibrium concentration, N. The charge recombination is a diffusion-controlled process with characteristic lifetimes of {\\tau}_W and {\\tau}_I, for water and ice respectively. The static permittivity, {\\epsilon}(0), is solely determined by N. Both, N and {\\epsilon}(0), are roughly constant at the water-ice phase transition, and both increase, due to a slowing down of the diffusion rate, as the temperature is lowered. The transformation of the broadband dielectric spectra at 0 {\\deg}C with the drastic change from {\\tau}_W to {\\tau}_I is mainly due to an abrupt (by 0.4 eV) change of the activation energy of the charge diffusion.

  9. Localization of water monomers inside ice-like clusters

    E-Print Network [OSTI]

    V. L. Golo; S. M. Pershin

    2012-04-04

    On the basis of the experimental data we suggest that water monomers could be trapped in channels running through ice-like clusters in water. Our argument relies on a simple model that describes the motion of a dipole particle inside a channel in the presence of an electric field with linear gradient. The model admits of both finite and infinite regimes of motion so that the finite one could correspond to the particle being confined to a channel.

  10. TRMM observations of the global relationship between ice water content and lightning

    E-Print Network [OSTI]

    Rutledge, Steven

    TRMM observations of the global relationship between ice water content and lightning Walter A to retrieve ice water content. Citation: Petersen, W. A., H. J. Christian, and S. A. Rutledge (2005), TRMM observations of the global relationship between ice water content and lightning, Geophys. Res. Lett., 32, L

  11. Electric fields in ice and near water clusters

    SciTech Connect (OSTI)

    Batista, Enrique R. [Department of Physics, P.O. Box 351560, University of Washington, Seattle, Washington 98195-1560 (United States) [Department of Physics, P.O. Box 351560, University of Washington, Seattle, Washington 98195-1560 (United States); Department of Chemistry, P.O. Box 351700, University of Washington, Seattle, Washington 98195-1700 (United States); Xantheas, Sotiris S. [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 906 Battelle Boulevard, P.O. Box 999, MS K8-91, Richland, Washington 99352 (United States)] [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 906 Battelle Boulevard, P.O. Box 999, MS K8-91, Richland, Washington 99352 (United States); Jonsson, Hannes [Department of Chemistry, P.O. Box 351700, University of Washington, Seattle, Washington 98195-1700 (United States)] [Department of Chemistry, P.O. Box 351700, University of Washington, Seattle, Washington 98195-1700 (United States)

    2000-02-15

    We have studied the electric field near water clusters and in ice Ih using first principles calculations. We employed Moeller-Plesset perturbation theory (MP2) for the calculations of the clusters up to and including the hexamer, and density functional theory (DFT) with a gradient dependent functional [Perdew-Wang (PW91)] for ice Ih as well as the clusters. The electric field obtained from the first principles calculations was used to test the predictions of an induction model based on single center multipole moments and polarizabilities of an isolated water molecule. We found that the fields obtained from the induction model agree well with the first principles results when the multipole expansion is carried out up to and including the hexadecapole moment, and when polarizable dipole and quadrupole moments are included. This implies that accurate empirical water interaction potential functions transferable to various environments such as water clusters and ice surfaces could be based on a single center multipole expansion carried out up to the hexadecapole. Since point charges are not included, the computationally intensive Ewald summations can be avoided. Molecular multipole moments were also extracted from the first principles charge density using zero flux dividing surfaces as proposed by Bader. Although the values of the various molecular multipoles obtained with this method are quite different from the ones resulting from the induction model, the rate of convergence of the electric field is, nevertheless, quite similar. (c) 2000 American Institute of Physics.

  12. Calculation of heat capacities of light and heavy water by path-integral molecular dynamics

    E-Print Network [OSTI]

    Nielsen, Steven O.

    Calculation of heat capacities of light and heavy water by path-integral molecular dynamics 30 September 2005 As an application of atomistic simulation methods to heat capacities, path-integral has estimated the heat capacities too high, the quantum simulation based on path-integral molecular

  13. Peakons arising as particle paths beneath small-amplitude water waves

    E-Print Network [OSTI]

    Delia Ionescu-Kruse

    2011-06-20

    We present a new kind of particle path in constant vorticity water of finite depth, within the framework of small-amplitude waves.

  14. Decomposing aerosol cloud radiative effects into cloud cover, liquid water path and Twomey components

    E-Print Network [OSTI]

    Daniel, Rosenfeld

    Decomposing aerosol cloud radiative effects into cloud cover, liquid water path and Twomey December 2013 A method for separating the three components of the marine stratocumulus (MSC) aerosol cloud interactions radiative effects, i.e., the cloud cover, liquid water path (LWP) and cloud drop radius (Twomey

  15. Spatial association between the locations of roots and water flow paths in highly structured soil 

    E-Print Network [OSTI]

    Gardiner, Nathan Thomas

    2005-02-17

    relative to the location of water flow paths is important in understanding how plants obtain nutrients and water for growth, and it would also be of considerable importance in phytoremediation research and research into the prevention of groundwater...

  16. Water, O2 and Ice in Molecular Clouds

    E-Print Network [OSTI]

    David Hollenbach; Michael J. Kaufman; Edwin A. Bergin; Gary J. Melnick

    2009-03-02

    We model the temperature and chemical structure of molecular clouds as a function of depth into the cloud, assuming a cloud of constant density n illuminated by an external FUV (6 eV < E < 13.6 eV) flux G_0 (scaling factor in multiples of the local interstellar field). Extending previous photodissociation region models, we include the freezing of species, simple grain surface chemistry, and desorption (including FUV photodesorption) of ices. We also treat the opaque cloud interior with time-dependent chemistry. Here, under certain conditions, gas phase elemental oxygen freezes out as water ice and the elemental C/O abundance ratio can exceed unity, leading to complex carbon chemistry. Gas phase H2O and O2 peak in abundance at intermediate depth into the cloud, roughly A_V~3-8 from the surface, the depth proportional to ln(G_0/n). Closer to the surface, molecules are photodissociated. Deeper into the cloud, molecules freeze to grain surfaces. At intermediate depths photodissociation rates are attenuated by dust extinction, but photodesorption prevents total freezeout. For G_0 < 500, abundances of H2O and O2 peak at values ~10^(-7), producing columns ~10^(15) per cm^2, independent of G_0 and n. The peak abundances depend primarily on the product of the photodesorption yield of water ice and the grain surface area per H nucleus. At higher values of G_0, thermal desorption of O atoms from grains enhances the gas phase H2O peak abundance and column slightly, whereas the gas phase O2 peak abundance rises to ~10^(-5) and the column to ~2x10^(16) per cm^2. We present simple analytic equations for the abundances as a function of depth which clarify the dependence on parameters. The models are applied to observations of H2O, O2, and water ice in a number of sources, including B68, NGC 2024, and Rho Oph.

  17. A PHOTOMETRIC SYSTEM FOR DETECTION OF WATER AND METHANE ICES ON KUIPER BELT OBJECTS

    SciTech Connect (OSTI)

    Trujillo, Chadwick A.; Sheppard, Scott S.; Schaller, Emily L. E-mail: sheppard@dtm.ciw.edu

    2011-04-01

    We present a new near-infrared photometric system for detection of water ice and methane ice in the solar system. The system consists of two medium-band filters in the K-band region of the near-infrared, which are sensitive to water ice and methane ice, plus continuum observations in the J band and Y band. The primary purpose of this system is to distinguish between three basic types of Kuiper Belt Objects (KBOs)-those rich in water ice, those rich in methane ice, and those with little absorbance. In this work, we present proof-of-concept observations of 51 KBOs using our filter system, 21 of which have never been observed in the near-infrared spectroscopically. We show that our custom photometric system is consistent with previous spectroscopic observations while reducing telescope observing time by a factor of {approx}3. We use our filters to identify Haumea collisional family members, which are thought to be collisional remnants of a much larger body and are characterized by large fractions of water ice on their surfaces. We add 2009 YE{sub 7} to the Haumea collisional family based on our water ice band observations (J - H{sub 2}O = -1.03 {+-} 0.27) which indicate a high amount of water ice absorption, our calculated proper orbital elements, and the neutral optical colors we measured, V - R = 0.38 {+-} 0.04, which are all consistent with the rest of the Haumea family. We identify several objects dynamically similar to Haumea as being distinct from the Haumea family as they do not have water ice on their surfaces. In addition, we find that only the largest KBOs have methane ice, and Haumea itself has significantly less water ice absorption than the smaller Haumea family members. We find no evidence for other families in the Kuiper Belt.

  18. A study of the ice-water interface using the TIP4P/2005 water model

    E-Print Network [OSTI]

    Jorge Benet; Luis G. MacDowell; Eduardo Sanz

    2014-10-01

    In this work we study the ice-water interface under coexistence conditions by means of molecular simulations using the TIP4P/2005 water model. Following the methodology proposed by Hoyt and co-workers [J. J. Hoyt, M. Asta and A. Karma, Phys. Rev. Lett., 86, 5530, (2001)] we measure the interfacial free energy of ice with liquid water by analysing the spectrum of capillary fluctuations of the interface. We get an orientationally averaged interfacial free energy of 27(2) mN/m, in good agreement with a recent estimate obtained from simulation data of the size of critical clusters [E. Sanz, C. Vega, J. R. Espinosa, R. Caballero-Bernal, J. L. F. Abascal and C. Valeriani, JACS, 135, 15008, (2013)]. We also estimate the interfacial free energy of different planes and obtain 27(2), 28(2)and 28(2) mN/m for the basal, the primary prismatic and the secondary prismatic planes respectively. Finally, we inspect the structure of the interface and find that its thickness is of approximately 4-5 molecular diameters. Moreover, we find that when the basal plane is exposed to the fluid the interface alternates regions of cubic ice with regions of hexagonal ice.

  19. Ice, Snow and Water: impacts of climate change on California and Himalayan Asia

    E-Print Network [OSTI]

    Fenner, R. A.

    2009-01-01

    BRIEFING NOTE  Ice, Snow  and Water: impacts of climate of declining mountain snows and glacier retreat  in impacts of declining mountain snows on water availability in

  20. What Determines the Sticking Probability of Water Molecules on Ice?

    SciTech Connect (OSTI)

    Batista, Enrique; Ayotte, Patrick; Bilic , Ante; Kay, Bruce D.; Jonsson, Hannes

    2005-11-22

    We present both experimental and theoretical studies of the sticking of water molecules on ice. The sticking probability is unity over a wide range in energy (0.5 eV–1.5 eV) when the molecules are incident along the surface normal, but drops as the angle increases at high incident energy. This is explained in terms of the strong orientational dependence of the interaction of the molecule with the surface and the time required for the reorientation of the molecule. The sticking probability is found to scale with the component of the incident velocity in the plane of the surface, unlike the commonly assumed normal or total energy scaling.

  1. Molecular multipole moments of water molecules in ice Ih

    SciTech Connect (OSTI)

    Batista, E.R. [Department of Physics, Box 351560, University of Washington, Seattle, Washington 98195-1560 (United States)] [Department of Physics, Box 351560, University of Washington, Seattle, Washington 98195-1560 (United States); [Department of Chemistry, Box 351700, University of Washington, Seattle, Washington 98195-1700 (United States); Xantheas, S.S. [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 906 Battelle Boulevard, PO Box 999, MS K1-96, Richland, Washington 99352 (United States)] [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 906 Battelle Boulevard, PO Box 999, MS K1-96, Richland, Washington 99352 (United States); Jonsson, H. [Department of Chemistry, Box 351700, University of Washington, Seattle, Washington 98195-1700 (United States)] [Department of Chemistry, Box 351700, University of Washington, Seattle, Washington 98195-1700 (United States)

    1998-09-01

    We have used an induction model including dipole, dipole{endash}quadrupole, quadrupole{endash}quadrupole polarizability and first hyperpolarizability as well as fixed octopole and hexadecapole moments to study the electric field in ice. The self-consistent induction calculations gave an average total dipole moment of 3.09 D, a 67{percent} increase over the dipole moment of an isolated water molecule. A previous, more approximate induction model study by Coulson and Eisenberg [Proc. R. Soc. Lond. A {bold 291}, 445 (1966)] suggested a significantly smaller average value of 2.6 D. This value has been used extensively in recent years as a reference point in the development of various polarizable interaction potentials for water as well as for assessment of the convergence of water cluster properties to those of bulk. The reason for this difference is not due to approximations made in the computational scheme of Coulson and Eisenberg but rather due to the use of less accurate values for the molecular multipoles in these earlier calculations. {copyright} {ital 1998 American Institute of Physics.}

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

    SciTech Connect (OSTI)

    Wang, Bingbing; Laskin, Alexander; Roedel, Tobias R.; Gilles, Marry K.; Moffet, Ryan C.; Tivanski, Alexei V.; Knopf, Daniel A.

    2012-09-25

    Atmospheric ice formation induced by particles with complex chemical and physical properties through heterogeneous nucleation is not well understood. Heterogeneous ice nucleation and water uptake by ambient particles collected from urban environments in Los Angeles and Mexico City are presented. Using a vapour controlled cooling system equipped with an optical microscopy, the range of onset conditions for ice nucleation and water uptake by the collected particles was determined as a function of temperature (200{273 K) and relative humidity with respect to ice (RHice) up to water saturation. Three distinctly different types of authentic atmospheric particles were investigated including soot particles associated with organics/inorganics, inorganic particles of marine origin coated with organic material, and Pb/Zn containing inorganic particles apportioned to anthropogenic emissions relevant to waste incineration. Single particle characterization was provided by micro-spectroscopic analyses using computer controlled scanning electron microscopy with energy dispersive analysis of X-rays (CCSEM/EDX) and scanning transmission X-ray microscopy with near edge X-ray absorption ne structure spectroscopy (STXM/NEXAFS). Above 230 K, signicant differences in water uptake and immersion freezing effciencies of the different particle types were observed. Below 230 K, the particles exhibited high deposition ice nucleation effciencies and formed ice at RHice values well below homogeneous ice nucleation limits. The data show that the chemical composition of these eld{collected particles plays an important role in determining water uptake and immersion freezing. Heterogeneous ice nucleation rate coeffcients, cumulative ice nuclei (IN) spectrum, and IN activated fraction for deposition ice nucleation are derived. The presented ice nucleation data demonstrate that anthropogenic and marine particles comprising of various chemical and physical properties exhibit distinctly different ice nucleation effciencies and can serve as effcient IN at atmospheric conditions typical for cirrus and mixed phase clouds. This indicates a potential link between human activities and cloud formation, and thus climate.

  3. VOLATILE TRANSPORT INSIDE SUPER-EARTHS BY ENTRAPMENT IN THE WATER-ICE MATRIX

    SciTech Connect (OSTI)

    Levi, A.; Podolak, M.; Sasselov, D.

    2013-05-20

    Whether volatiles can be entrapped in a background matrix composing planetary envelopes and be dragged via convection to the surface is a key question in understanding atmospheric fluxes, cycles, and composition. In this paper, we consider super-Earths with an extensive water mantle (i.e., water planets), and the possibility of entrapment of methane in their extensive water-ice envelopes. We adopt the theory developed by van der Waals and Platteeuw for modeling solid solutions, often used for modeling clathrate hydrates, and modify it in order to estimate the thermodynamic stability field of a new phase called methane filled ice Ih. We find that in comparison to water ice VII the filled ice Ih structure may be stable not only at the high pressures but also at the high temperatures expected at the core-water mantle transition boundary of water planets.

  4. Hydrogen isotope exchanges between water and methanol in interstellar ices

    E-Print Network [OSTI]

    Faure, A; Theulé, P; Quirico, E; Schmitt, B

    2015-01-01

    The deuterium fractionation of gas-phase molecules in hot cores is believed to reflect the composition of interstellar ices. The deuteration of methanol is a major puzzle, however, because the isotopologue ratio [CH2DOH]/[CH3OD], which is predicted to be equal to 3 by standard grain chemistry models, is much larger (~20) in low-mass hot corinos and significantly lower (~1) in high-mass hot cores. This dichotomy in methanol deuteration between low-mass and massive protostars is currently not understood. In this study, we report a simplified rate equation model of the deuterium chemistry occurring in the icy mantles of interstellar grains. We apply this model to the chemistry of hot corinos and hot cores, with IRAS 16293-2422 and the Orion~KL Compact Ridge as prototypes, respectively. The chemistry is based on a statistical initial deuteration at low temperature followed by a warm-up phase during which thermal hydrogen/deuterium (H/D) exchanges occur between water and methanol. The exchange kinetics is incorpor...

  5. Water Drops Dancing on Ice: How Sublimation Leads to Drop Rebound C. Antonini,1,2

    E-Print Network [OSTI]

    Daraio, Chiara

    physical mechanisms, which apparently share nothing in common (superhydrophobicity, evaporation Marconi 5, 24044 Dalmine (BG), Italy 2 Mechanical and Process Engineering Department, Laboratory] and spray cooling [5]), or highly beneficial to avoid water and ice accumulation (e.g., self

  6. Water Ice on the Satellite of Kuiper Belt Object 2003 EL61

    E-Print Network [OSTI]

    K. M Barkume; M. E. Brown; E. L. Schaller

    2006-01-24

    We have obtained a near infrared spectrum of the brightest satellite of the large Kuiper Belt Object, 2003 EL61. The spectrum has absorption features at 1.5 and 2.0 microns, indicating that water ice is present on the surface. We find that the satellite's absorption lines are much deeper than water ice features typically found on Kuiper Belt Objects. We argue that the unusual spectrum indicates that the satellite was likely formed by impact and not by capture.

  7. Iced Coffee Iced Chai Tea Latte

    E-Print Network [OSTI]

    Iced Coffee Iced Chai Tea Latte Iced Americano Iced Cappuccino Iced Latte Iced Mocha Iced White the Cooler Canned Soda Bottled Water Arizona Teas Energy Drinks Red Bull, SF Red Bull & Bing Jones Sodas $0.50 Listed prices do not include applicable sales tax. #12;Brewed Coffee Cafe au Lait Hot Tea Chai Tea Latte

  8. Periodic fluctuations in deep water formation due to sea ice

    E-Print Network [OSTI]

    Saha, Raj

    2015-01-01

    During the last ice age several quasi-periodic abrupt warming events took place. Known as Dansgaard-Oeschger (DO) events their effects were felt globally, although the North Atlantic experienced the largest temperature anomalies. Paleoclimate data shows that the fluctuations often occurred right after massive glacial meltwater releases in the North Atlantic and in bursts of three or four with progressively decreasing strengths. In this study a simple dynamical model of an overturning circulation and sea ice is developed with the goal of understanding the fundamental mechanisms that could have caused the DO events. Interaction between sea ice and the overturning circulation in the model produces self-sustained oscillations. Analysis and numerical experiments reveal that the insulating effect of sea ice causes the ocean to periodically vent out accumulated heat in the deep ocean into the atmosphere. Subjecting the model to idealized freshwater forcing mimicking Heinrich events causes modulation of the natural p...

  9. Structural transformation in supercooled water controls the crystallization rate of ice

    E-Print Network [OSTI]

    Emily B. Moore; Valeria Molinero

    2011-09-27

    One of water's unsolved puzzles is the question of what determines the lowest temperature to which it can be cooled before freezing to ice. The supercooled liquid has been probed experimentally to near the homogeneous nucleation temperature TH{\\approx}232 K, yet the mechanism of ice crystallization - including the size and structure of critical nuclei - has not yet been resolved. The heat capacity and compressibility of liquid water anomalously increase upon moving into the supercooled region according to a power law that would diverge at Ts{\\approx}225 K,(1,2) so there may be a link between water's thermodynamic anomalies and the crystallization rate of ice. But probing this link is challenging because fast crystallization prevents experimental studies of the liquid below TH. And while atomistic studies have captured water crystallization(3), the computational costs involved have so far prevented an assessment of the rates and mechanism involved. Here we report coarse-grained molecular simulations with the mW water model(4) in the supercooled regime around TH, which reveal that a sharp increase in the fraction of four-coordinated molecules in supercooled liquid water explains its anomalous thermodynamics and also controls the rate and mechanism of ice formation. The simulations reveal that the crystallization rate of water reaches a maximum around 225 K, below which ice nuclei form faster than liquid water can equilibrate. This implies a lower limit of metastability of liquid water just below TH and well above its glass transition temperature Tg{\\approx}136 K. By providing a relationship between the structural transformation in liquid water, its anomalous thermodynamics and its crystallization rate, this work provides a microscopic foundation to the experimental finding that the thermodynamics of water determines the rates of homogeneous nucleation of ice.(5)

  10. Periodic fluctuations in deep water formation due to sea ice

    E-Print Network [OSTI]

    Raj Saha

    2015-02-21

    During the last ice age several quasi-periodic abrupt warming events took place. Known as Dansgaard-Oeschger (DO) events their effects were felt globally, although the North Atlantic experienced the largest temperature anomalies. Paleoclimate data shows that the fluctuations often occurred right after massive glacial meltwater releases in the North Atlantic and in bursts of three or four with progressively decreasing strengths. In this study a simple dynamical model of an overturning circulation and sea ice is developed with the goal of understanding the fundamental mechanisms that could have caused the DO events. Interaction between sea ice and the overturning circulation in the model produces self-sustained oscillations. Analysis and numerical experiments reveal that the insulating effect of sea ice causes the ocean to periodically vent out accumulated heat in the deep ocean into the atmosphere. Subjecting the model to idealized freshwater forcing mimicking Heinrich events causes modulation of the natural periodicity and produces burst patterns very similar to what is observed in temperature proxy data. Numerical experiments with the model also suggests that the characteristic period of 1,500 years is due to the geometry, or the effective heat capacity, of the ocean that comes under sea ice cover.

  11. On the streamlines and particle paths of gravitational water waves

    E-Print Network [OSTI]

    Mats Ehrnstrom

    2007-12-04

    We investigate steady symmetric gravity water waves on finite depth. For non-positive vorticity it is shown that the particles display a mean forward drift, and for a class of waves we prove that the size of this drift is strictly increasing from bottom to surface. We also provide detailed information concerning the streamlines and the particle trajectories. This includes the case of particles within irrotational waves.

  12. Water ice in the dark dune spots of Richardson crater on Mars

    E-Print Network [OSTI]

    Kereszturi, A; Schmidt, F

    2010-01-01

    In this study we assess the presence, nature and properties of ices - in particular water ice - that occur within these spots using HIRISE and CRISM observations, as well as the LMD Global Climate Model. Our studies focus on Richardson crater (72{\\deg}S, 179{\\deg}E) and cover southern spring and summer (LS 175{\\deg} - 17 341{\\deg}). Three units have been identified of these spots: dark core, gray ring and bright halo. Each unit show characteristic changes as the season progress. In winter, the whole area is covered by CO2 ice with H2O ice contamination. Dark spots form during late winter and early spring. During spring, the dark spots are located in a 10 cm thick depression compared to the surrounding bright ice-rich layer. They are spectrally characterized by weak CO2 ice signatures that probably result from spatial mixing of CO2 ice rich and ice free regions within pixels, and from mixing of surface signatures due to aerosols scattering. The bright halo shaped by winds shows stronger CO2 absorptions than th...

  13. The sticking of atomic hydrogen on amorphous water ice

    SciTech Connect (OSTI)

    Veeraghattam, Vijay K.; Manrodt, Katie; Lewis, Steven P.; Stancil, P. C. E-mail: lewis@physast.uga.edu

    2014-07-20

    Using classical molecular dynamics, we have simulated the sticking and scattering process of a hydrogen atom on an amorphous ice film to predict the sticking probability of hydrogen on ice surfaces. A wide range of initial kinetic energies of the incident hydrogen atom (10 K-600 K) and two different ice temperatures (10 K and 70 K) were used to investigate this fundamental process in interstellar chemistry. We report here the sticking probability of atomic hydrogen as a function of incident kinetic energy, gas temperature, and substrate temperature, which can be used in astrophysical models. The current results are compared to previous theoretical and experimental studies that have reported a wide range in the sticking coefficient.

  14. Millennial-scale stable oscillations between sea ice and convective deep water formation

    E-Print Network [OSTI]

    Saha, Raj

    2015-01-01

    During the last ice age there were several quasi-periodic abrupt warming events. The climatic effects of the so-called Dansgaard-Oeschger (DO) events were felt globally, although the North Atlantic experienced the largest and most abrupt temperature anomalies. Similar but weaker oscillations also took place during the interglacial period. This paper proposes an auto-oscillatory mechanism between sea ice and convective deep water formation in the north Atlantic as the source of the persistent cycles. A simple dynamical model is constructed by coupling and slightly modifying two existing models of ocean circulation and sea ice. The model exhibits mixed mode oscillations, consisting of decadal scale small amplitude oscillations, and a large amplitude relaxation fluctuation. The decadal oscillations occur due to the insulating effect of sea ice and leads to periodic ventilation of heat from the polar ocean. Gradually an instability builds up in the polar column and results in an abrupt initiation of convection an...

  15. Multipole moments of water molecules in clusters and ice Ih from first principles calculations

    SciTech Connect (OSTI)

    Batista, E.R. [Department of Physics, Box 351560, University of Washington, Seattle, Washington 98195-1560 (United States)] [Department of Physics, Box 351560, University of Washington, Seattle, Washington 98195-1560 (United States); [Department of Chemistry, Box 351700, University of Washington, Seattle, Washington 98195-1700 (United States); Xantheas, S.S. [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 906 Battelle Boulevard, PO Box 999, MS K8-91, Richland, Washington 99352 (United States)] [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 906 Battelle Boulevard, PO Box 999, MS K8-91, Richland, Washington 99352 (United States); Jonsson, H. [Department of Chemistry, Box 351700, University of Washington, Seattle, Washington 98195-1700 (United States)] [Department of Chemistry, Box 351700, University of Washington, Seattle, Washington 98195-1700 (United States)

    1999-10-01

    We have calculated {ital molecular} multipole moments for water molecules in clusters and in ice Ih by partitioning the charge density obtained from first principles calculations. Various schemes for dividing the electronic charge density among the water molecules were used. They include Bader{close_quote}s zero flux surfaces and Voronoi partitioning schemes. A comparison was also made with an induction model including dipole, dipole-quadrupole, quadrupole-quadrupole polarizability and first hyperpolarizability as well as fixed octopole and hexadecapole moments. We have found that the different density partitioning schemes lead to widely different values for the molecular multipoles, illustrating how poorly defined molecular multipoles are in clusters and condensed environments. For instance, the magnitude of the molecular dipole moment in ice Ih ranges between 2.3 D and 3.1 D depending on the partitioning scheme used. Within each scheme, though, the value for the molecular dipole moment in ice is larger than in the hexamer. The magnitude of the molecular dipole moment in the clusters shows a monotonic increase from the gas phase value to the one in ice Ih, with the molecular dipole moment in the water ring hexamer being smaller than the one in ice Ih for all the partitioning schemes used. {copyright} {ital 1999 American Institute of Physics.}

  16. "Ice cubes" in the center of the Milky Way - Water ice and hydrocarbons in the central parsec

    E-Print Network [OSTI]

    Moultaka, Jihane; Muzic, Koralka

    2015-01-01

    The close environment of the central supermassive black hole of our Galaxy is studied thoroughly since decades in order to shed light on the behavior of the central regions of galaxies in general and of active galaxies in particular. The Galactic Center has shown a wealth of structures on different scales with a complicated mixture of early- and late-type stars, ionized and molecular gas, dust and winds. Here we aim at studying the distribution of water ices and hydrocarbons in the central parsec as well as along the line of sight. This study is made possible thanks to L-band spectroscopy. This spectral band, from 2.8 to 4.2$\\mu m$, hosts important signatures of the circumstellar medium and interstellar dense and diffuse media among which deep absorption features are attributed to water ices and hydrocarbons. We observed the Galactic Center in the L-band of ISAAC spectrograph located on UT1/VLT ESO telescope. By mapping the central half parsec using 27 slit positions, we were able to build the first data cube...

  17. Measurement of freezing point depression of water in glass capillaries and the associated ice front shape

    E-Print Network [OSTI]

    Wan, Richard G.

    Measurement of freezing point depression of water in glass capillaries and the associated ice front Variations of the Kelvin equation W. Thomson, Philos. Mag. 42, 448 1871 to describe the freezing point. The capillary freezing point depression for glass tubes with radii of 87 m­3 m was successfully measured

  18. On the particle paths and the stagnation points in small-amplitude deep-water waves

    E-Print Network [OSTI]

    Delia Ionescu-Kruse

    2012-02-22

    In order to obtain quite precise information about the shape of the particle paths below small-amplitude gravity waves travelling on irrotational deep water, analytic solutions of the nonlinear differential equation system describing the particle motion are provided. All these solutions are not closed curves. Some particle trajectories are peakon-like, others can be expressed with the aid of the Jacobi elliptic functions or with the aid of the hyperelliptic functions. Remarks on the stagnation points of the small-amplitude irrotational deep-water waves are also made.

  19. Water ice deuteration: a tracer of the chemical history of protostars

    E-Print Network [OSTI]

    Taquet, Vianney; Kahane, Claudine; Ceccarelli, Cecilia; Lòpez-Sepulcre, Ana; Toubin, Céline; Duflot, Denis; Wiesenfeld, Laurent

    2012-01-01

    Context. Millimetric observations have measured large degrees of molecular deuteration in several species seen around low-mass protostars. The Herschel Space Telescope, launched in 2009, is now providing new measures of the deuterium fractionation of water, the main constituent of interstellar ices. Aims. We aim at theoretically studying the formation and the deuteration of water which is believed to be formed on interstellar grain surfaces in molecular clouds. Methods. We used our gas-grain astrochemical model GRAINOBLE which considers the multilayer formation of interstellar ices. We varied several input parameters to study their impact on water deuteration. We included the treatment of ortho and para states of key species, including H2, that affects the deuterium fractionation of all molecules. The model also includes relevant laboratory and theoretical works on water formation and deuteration on grain surfaces. In particular, we computed the transmission probabilities of surface reactions using the Eckart...

  20. Laboratory Determination of the Infrared Band Strengths of Pyrene Frozen in Water Ice: Implications for the Composition of Interstellar Ices

    E-Print Network [OSTI]

    Hardegree-Ullman, E E; Boogert, A C A; Lignell, H; Allamandola, L J; Stapelfeldt, K R; Werner, M

    2014-01-01

    Broad infrared emission features (e.g., at 3.3, 6.2, 7.7, 8.6, and 11.3 microns) from the gas phase interstellar medium have long been attributed to polycyclic aromatic hydrocarbons (PAHs). A significant portion (10%-20%) of the Milky Way's carbon reservoir is locked in PAH molecules, which makes their characterization integral to our understanding of astrochemistry. In molecular clouds and the dense envelopes and disks of young stellar objects (YSOs), PAHs are expected to be frozen in the icy mantles of dust grains where they should reveal themselves through infrared absorption. To facilitate the search for frozen interstellar PAHs, laboratory experiments were conducted to determine the positions and strengths of the bands of pyrene mixed with H2O and D2O ices. The D2O mixtures are used to measure pyrene bands that are masked by the strong bands of H2O, leading to the first laboratory determination of the band strength for the CH stretching mode of pyrene in water ice near 3.25 microns. Our infrared band str...

  1. Mobility of D atoms on porous amorphous water ice surfaces under interstellar conditions

    E-Print Network [OSTI]

    E. Matar; E. Congiu; F. Dulieu; A. Momeni; J. L. Lemaire

    2008-10-13

    Aims. The mobility of H atoms on the surface of interstellar dust grains at low temperature is still a matter of debate. In dense clouds, the hydrogenation of adsorbed species (i.e., CO), as well as the subsequent deuteration of the accreted molecules depend on the mobility of H atoms on water ice. Astrochemical models widely assume that H atoms are mobile on the surface of dust grains even if controversy still exists. We present here direct experimental evidence of the mobility of H atoms on porous water ice surfaces at 10 K. Methods. In a UHV chamber, O2 is deposited on a porous amorphous water ice substrate. Then D atoms are deposited onto the surface held at 10 K. Temperature-Programmed Desorption (TPD) is used and desorptions of O2 and D2 are simultaneously monitored. Results. We find that the amount of O2 that desorb during the TPD diminishes if we increase the deposition time of D atoms. O2 is thus destroyed by D atoms even though these molecules have previously diffused inside the pores of thick water ice. Our results can be easily interpreted if D is mobile at 10 K on the water ice surface. A simple rate equation model fits our experimental data and best fit curves were obtained for a D atoms diffusion barrier of 22(+-)2 meV. Therefore hydrogenation can take place efficiently on interstellar dust grains. These experimental results are in line with most calculations and validate the hypothesis used in several models.

  2. Interactive Evolution of Multiple Water-Ice Reservoirs on Mars: Insights from Hydrogen Isotope Compositions

    E-Print Network [OSTI]

    Kurokawa, Hiroyuki; Sato, Masahiko

    2015-01-01

    Remote sensing data from orbiter missions have proposed that ground ice may currently exist on Mars, although the volume is still uncertain. Recent analyses of Martian meteorites have suggested that the water reservoirs have at least three distinct hydrogen isotope compositions (D/H ratios): primordial and high D/H ratios, which are approximately the same and six times that of ocean water on Earth, respectively, and a newly identified intermediate D/H ratio, which is approximately two to three times higher than that in ocean water on Earth. We calculate the evolution of the D/H ratios and the volumes of the water reservoirs on Mars by modeling the exchange of hydrogen isotopes between multiple water reservoirs and the atmospheric escape. The D/H ratio is slightly higher in the topmost thin surface-ice layer than that in the atmosphere because of isotopic fractionation by sublimation, whereas the water-ice reservoir just below the exchangeable topmost surface layer retains the intermediate D/H signature found ...

  3. Microwave Heating of Water, Ice and Saline Solution: Molecular Dynamics Study

    E-Print Network [OSTI]

    Motohiko Tanaka; Motoyasu Sato

    2006-09-24

    In order to study the heating process of water by the microwaves of 2.5-20GHz frequencies, we have performed molecular dynamics simulations by adopting a non-polarized water model that have fixed point charges on rigid-body molecules. All runs are started from the equilibrated states derived from the I$_{c}$ ice with given density and temperature. In the presence of microwaves, the molecules of liquid water exhibit rotational motion whose average phase is delayed from the microwave electric field. Microwave energy is transferred to the kinetic and inter-molecular energies of water, where one third of the absorbed microwave energy is stored as the latter energy. The water in ice phase is scarcely heated by microwaves because of the tight hydrogen-bonded network of water molecules. Addition of small amount of salt to pure water substantially increases the heating rate because of the weakening by defects in the water network due to sloshing large-size negative ions.

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

    E-Print Network [OSTI]

    Weijun Zheng; David Jewitt; Ralf I. Kaiser

    2005-11-18

    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.

  5. Laboratory determination of the infrared band strengths of pyrene frozen in water ice: Implications for the composition of interstellar ices

    SciTech Connect (OSTI)

    Hardegree-Ullman, E. E. [New York Center for Astrobiology and Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180 (United States); Gudipati, M. S.; Werner, M. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Boogert, A. C. A. [Infrared Processing and Analysis Center, Mail Code 100-22, California Institute of Technology, Pasadena, CA 91125 (United States); Lignell, H. [Department of Chemistry, University of California Irvine, Irvine, CA 92697-2025 (United States); Allamandola, L. J. [Space Science Division, Mail Stop 245-6, NASA Ames Research Center, Moffett Field, CA 94035 (United States); Stapelfeldt, K. R., E-mail: hardee@rpi.edu, E-mail: gudipati@jpl.nasa.gov [NASA Goddard Space Flight Center, Exoplanets and Stellar Astrophysics Laboratory, Code 667, Greenbelt, MD 20771 (United States)

    2014-04-01

    Broad infrared emission features (e.g., at 3.3, 6.2, 7.7, 8.6, and 11.3 ?m) from the gas phase interstellar medium have long been attributed to polycyclic aromatic hydrocarbons (PAHs). A significant portion (10%-20%) of the Milky Way's carbon reservoir is locked in PAH molecules, which makes their characterization integral to our understanding of astrochemistry. In molecular clouds and the dense envelopes and disks of young stellar objects (YSOs), PAHs are expected to be frozen in the icy mantles of dust grains where they should reveal themselves through infrared absorption. To facilitate the search for frozen interstellar PAHs, laboratory experiments were conducted to determine the positions and strengths of the bands of pyrene mixed with H{sub 2}O and D{sub 2}O ices. The D{sub 2}O mixtures are used to measure pyrene bands that are masked by the strong bands of H{sub 2}O, leading to the first laboratory determination of the band strength for the CH stretching mode of pyrene in water ice near 3.25 ?m. Our infrared band strengths were normalized to experimentally determined ultraviolet band strengths, and we find that they are generally ?50% larger than those reported by Bouwman et al. based on theoretical strengths. These improved band strengths were used to reexamine YSO spectra published by Boogert et al. to estimate the contribution of frozen PAHs to absorption in the 5-8 ?m spectral region, taking into account the strength of the 3.25 ?m CH stretching mode. It is found that frozen neutral PAHs contain 5%-9% of the cosmic carbon budget and account for 2%-9% of the unidentified absorption in the 5-8 ?m region.

  6. Molecular origin of the difference in the HOH bend of the IR spectra between liquid water and ice

    SciTech Connect (OSTI)

    Imoto, Sho; Xantheas, Sotiris S.; Saito, Shinji

    2013-02-07

    The intensity of the HOH bend in the IR spectrum of ice is significantly smaller than the corresponding one in liquid water. This difference in the IR intensities of the HOH bend in the two systems is investigated using MD simulations with the flexible, polarizable, ab-initio based TTM3-F model for water, a potential that correctly reproduces the experimentally observed increase of the HOH bend in liquid water and ice from the water monomer value. We have identified two factors that are responsible for the difference in the intensity of the HOH bend in liquid water and ice: (i) the decrease of the intensity of the HOH bend in ice caused by the strong anti-correlation between the permanent dipole moment of a molecule and the induced dipole moment of a neighboring hydrogen bond acceptor molecule and (ii) the weakening of this anti-correlation by the disordered hydrogen bond network in liquid water. The presence of the anti-correlation in ice is further confirmed by ab initio electronic structure calculations of water pentamer clusters extracted from the trajectories of the MD simulations for ice and liquid water.

  7. Determination of Ice Water Path Over the ARM SGP Using Combined Surface and Satellite Datasets

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalent BondingMeeting |Design CompetitionsFuelofSources fromDetermination

  8. Determining Cloud Ice Water Path from High-Frequency Microwave Measurements

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalent BondingMeeting |Design CompetitionsFuelofSourcesalbedo

  9. Observations of high energy neutrinos with water/ice neutrino telescopes

    E-Print Network [OSTI]

    Albrecht Karle

    2006-02-01

    The search for high energy neutrinos of astrophysical origin is being conducted today with two water/ice Cherenkov experiments. New instruments of higher performance are now in construction and more are in the R&D phase. No sources have been found to date. Upper limits on neutrino fluxes are approaching model predictions. Results are reported on the search for point sources, diffuse fluxes, gamma ray bursts, dark matter and other sources.

  10. The interaction of radio frequency electromagnetic fields with atmospheric water droplets and application to aircraft ice prevention

    E-Print Network [OSTI]

    Hansman, Robert John

    1982-01-01

    In this work the physics of advanced microwave anti-icing systems, which pre-heat impinging supercooled water droplets prior to impact, is studied by means of a computer simulation and is found to be feasible. In order to ...

  11. The Hierarchic Theory of Liquids and Solids. Computerized applications for ice, water, and Biosystems

    E-Print Network [OSTI]

    Alex Kaivarainen

    2008-06-05

    This is a new book of quantum Hierarchic theory of condensed matter, general for liquids and solids, developed by this author during 20 years and its numerous applications. Computer program, based on new theory, was used for simulations of big number of physical properties of water and ice. Condensed matter is considered as a superposition of 3D standing waves (collective excitations) of different nature: thermal de Broglie waves, IR photons and thermal phonons. New theories of total internal energy, heat capacity, surface tension, vapor pressure, thermal conductivity, viscosity and self-diffusion are described. Hierarchic theory of osmotic pressure, based on new state equation, new theories of light refraction, Brillouin light scattering and Mossbauer effect are presented also and compared with available experimental data for water and ice. The agreement between theoretical and available experimental results for water and ice is very good. New approach to the turbulence, superfluidity and superconductivity is developed. A lot of applications of new theory to biophysics, including model of Quantum of Mind are described. New optoacoustic device: Comprehensive Analyzer of Matter Properties (CAMP) is proposed.

  12. Parameterizing Size Distribution in Ice Clouds

    SciTech Connect (OSTI)

    DeSlover, Daniel; Mitchell, David L.

    2009-09-25

    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.

  13. Water droplet behavior on superhydrophobic SiO{sub 2} nanocomposite films during icing/deicing cycles

    SciTech Connect (OSTI)

    Lazauskas, A.; Guobien?, A.; Prosy?evas, I.; Baltrušaitis, V.; Grigali?nas, V.; Narmontas, P.; Baltrusaitis, J.

    2013-08-15

    This work investigates water droplet behavior on superhydrophobic (water contact angle value of 162 ± 1°) SiO{sub 2} nanocomposite films subjected to repetitive icing/deicing treatments, changes in SiO{sub 2} nanocomposite film surface morphology and their non-wetting characteristics. During the experiment, water droplets on SiO{sub 2} nanocomposite film surface are subjected to a series of icing and deicing cycles in a humid (? 70% relative humidity) atmosphere and the resulting morphological changes are monitored and characterized using atomic force microscopy (AFM) and contact angle measurements. Our data show that the formation of the frozen or thawed water droplet, with no further shape change, on superhydrophobic SiO{sub 2} nanocomposite film, is obtained faster within each cycle as the number of the icing/deicing cycles increases. After 10 icing and deicing cycles, the superhydrophobic SiO{sub 2} nanocomposite film had a water contact angle value of 146 ± 2° which is effectively non-superhydrophobic. AFM analysis showed that the superhydrophobic SiO{sub 2} nanocomposite film surface area under the water droplet undergoes gradual mechanical damage during the repetitive icing/deicing cycles. We propose a possible mechanism of the morphological changes to the film surface that take place during the consecutive icing/deicing experiments. - Highlights: • Superhydrophobic film is subjected to repetitive icing/deicing treatments. • Water droplet shape transition is recorded and characterized thereafter. • Atomic force microscopy and contact angle measurements are performed. • The surface undergoes gradual mechanical damage during repetitive icing/deicing. • Mechanism for the observed surface morphological changes is suggested.

  14. 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

    2009-01-01

    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...

  15. A parameterisation of single and multiple muons in the deep water or ice

    E-Print Network [OSTI]

    Y. Becherini; A. Margiotta; M. Sioli; M. Spurio

    2005-07-19

    Atmospheric muons play an important role in underwater/ice neutrino detectors. In this paper, a parameterisation of the flux of single and multiple muon events, their lateral distribution and of their energy spectrum is presented. The kinematics parameters were modelled starting from a full Monte Carlo simulation of the interaction of primary cosmic rays with atmospheric nuclei; secondary muons reaching the sea level were propagated in the deep water. The parametric formulas are valid for a vertical depth of 1.5-5 km w.e. and up to 85 deg for the zenith angle, and can be used as input for a fast simulation of atmospheric muons in underwater/ice detectors.

  16. A Compact, Backscattering Deplolarization Cloud Spectrometer for Ice and Water Discrimination

    SciTech Connect (OSTI)

    Thomson, David

    2014-05-15

    This project was to develop a compact optical particle spectrometer, small enough for operation on UAVS, that measures the optical diameter of cloud hydrometeors and differentiates their water phase (liquid or solid). To reach this goal, a work plan was laid out that would complete three objectives: 1) Evaluation of designs for an optical particle spectrometer that measures the component of light backscattered at two polarization angles. 2) Testing of selected designs on an optical bench. 3) Construction and preliminary testing of a prototype instrument based on the selected, optimum design. A protoype instrument was developed and tested in an icing wind tunnel where the results showed good measurement of cloud droplets and ice particles.

  17. Total reflection infrared spectroscopy of water-ice and frozen aqueous NaCl solutions

    SciTech Connect (OSTI)

    Walker, Rachel L.; Searles, Keith; Willard, Jesse A.; Michelsen, Rebecca R. H., E-mail: RMichelsen@rmc.edu [Department of Chemistry, Randolph-Macon College, P.O. Box 5005, Ashland, Virginia 23005 (United States)] [Department of Chemistry, Randolph-Macon College, P.O. Box 5005, Ashland, Virginia 23005 (United States)

    2013-12-28

    Liquid-like and liquid water at and near the surface of water-ice and frozen aqueous sodium chloride films were observed using attenuated total reflection infrared spectroscopy (ATR-IR). The concentration of NaCl ranged from 0.0001 to 0.01 M and the temperature varied from the melting point of water down to 256 K. The amount of liquid brine at the interface of the frozen films with the germanium ATR crystal increased with salt concentration and temperature. Experimental spectra are compared to reflection spectra calculated for a simplified morphology of a uniform liquid layer between the germanium crystal and the frozen film. This morphology allows for the amount of liquid observed in an experimental spectrum to be converted to the thickness of a homogenous layer with an equivalent amount of liquid. These equivalent thickness ranges from a nanometer for water-ice at 260 K to 170 nm for 0.01 M NaCl close to the melting point. The amounts of brine observed are over an order of magnitude less than the total liquid predicted by equilibrium thermodynamic models, implying that the vast majority of the liquid fraction of frozen solutions may be found in internal inclusions, grain boundaries, and the like. Thus, the amount of liquid and the solutes dissolved in them that are available to react with atmospheric gases on the surfaces of snow and ice are not well described by thermodynamic equilibrium models which assume the liquid phase is located entirely at the surface.

  18. Outgassing of icy bodies in the solar system - I. The sublimation of hexagonal water ice through dust layers

    E-Print Network [OSTI]

    Gundlach, Bastian; Blum, Jürgen

    2011-01-01

    Our knowledge about the physical processes determining the activity of comets were mainly influenced by several extremely successful space missions, the predictions of theoretical models and the results of laboratory experiments. However, novel computer models should not be treated in isolation but should be based on experimental results. Therefore, a new experimental setup was constructed to investigate the temperature dependent sublimation properties of hexagonal water ice and the gas diffusion through a dry dust layer covering the ice surface. We show that this experimental setup is capable to reproduce known gas production rates of pure hexagonal water ice. The reduction of the gas production rate due to an additional dust layer on top of the ice surface was measured and compared with the results of another experimental setup in which the gas diffusion through dust layers at room temperature was investigated. We found that the relative permeability of the dust layer is inversely proportional to its thickn...

  19. SIZE AND TEMPERATURE DEPENDENCE IN THE FAR-IR SPECTRA OF WATER ICE PARTICLES

    SciTech Connect (OSTI)

    Medcraft, Chris; McNaughton, Don; Thompson, Chris D. [School of Chemistry, Monash University, Wellington Road, Clayton, Victoria 3800 (Australia); Appadoo, Dominique [Australian Synchrotron, Blackburn Road, Clayton, Victoria 3168 (Australia); Bauerecker, Sigurd [Institut fuer Physikalische und Theoretische Chemie, Technische Universitaet Braunschweig, Hans-Sommer-Strasse 10, D-38106 Braunschweig (Germany); Robertson, Evan G., E-mail: E.Robertson@latrobe.edu.au [Department of Chemistry and La Trobe Institute of Molecular Sciences, La Trobe University, Bundoora, Victoria 3086 (Australia)

    2012-10-10

    Spectra of water-ice aerosol particles have been measured in the far-IR region using synchrotron radiation. The particles in the nanoscale size regime of 1-100 nm were formed by rapid collisional cooling at temperatures ranging from 4 to 190 K. The spectra show the characteristic bands centered near 44 {mu}m (230 cm{sup -1}) and 62 {mu}m (160 cm{sup -1}) associated with the intermolecular lattice modes of crystalline ice at all temperatures, in contrast to previous studies of thin films formed by vapor deposition where amorphous ice is generated below 140 K. The bands shift to higher wavenumber values as the temperature is reduced, consistent with the trend seen in earlier studies, but in our experiments the actual peak positions in the aerosol particle spectra are consistently higher by ca. 4 cm{sup -1}. This finding has implications for the potential use of these spectral features as a temperature probe. The particle sizes are small enough for their spectra to be free of scattering effects, and therefore provide a means to assess imaginary refractive index values obtained through Kramers-Kronig analyses of thin film spectra.

  20. 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

  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)

    2014-04-28

    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. Simulation of Ultra High Energy Neutrino Interactions in Ice and Water

    E-Print Network [OSTI]

    S. Bevan; S. Danaher; J. Perkin; S. Ralph; C. Rhodes; L. Thompson; T. Sloan; D. Waters

    2007-04-08

    The CORSIKA program, usually used to simulate extensive cosmic ray air showers, has been adapted to work in a water or ice medium. The adapted CORSIKA code was used to simulate hadronic showers produced by neutrino interactions. The simulated showers have been used to study the spatial distribution of the deposited energy in the showers. This allows a more precise determination of the acoustic signals produced by ultra high energy neutrinos than has been possible previously. The properties of the acoustic signals generated by such showers are described.

  3. Water-hydroxyl phases on an open metal surface: breaking the ice rules Matthew Forster,a

    E-Print Network [OSTI]

    Alavi, Ali

    Water-hydroxyl phases on an open metal surface: breaking the ice rules Matthew Forster,a Rasmitath July 2011 DOI: 10.1039/c1sc00355k Hydroxyl is a key reaction intermediate in many surface catalyzed redox reactions, yet establishing the phase diagram for water/hydroxyl adsorption on metal

  4. Final Scientific/Technical Report. A closed path methane and water vapor gas analyzer

    SciTech Connect (OSTI)

    Liukang, Xu; Dayle, McDermitt; Tyler, Anderson; Brad, Riensche; Anatoly, Komissarov; Julie, Howe

    2012-05-01

    Robust, economical, low-power and reliable closed-path methane (CH4), carbon dioxide (CO2), and water vapor (H2O) analyzers suitable for long-term measurements are not readily available commercially. Such analyzers are essential for quantifying the amount of CH4 and CO2 released from various ecosystems (wetlands, rice paddies, forests, etc.) and other surface contexts (e.g. landfills, animal husbandry lots, etc.), and for understanding the dynamics of the atmospheric CH4 and CO2 budget and their impact on climate change and global warming. The purpose of this project is to develop a closed-path methane, carbon dioxide gas and water vapor analyzer capable of long-term measurements in remote areas for global climate change and environmental research. The analyzer will be capable of being deployed over a wide range of ecosystems to understand methane and carbon dioxide exchange between the atmosphere and the surface. Measurements of methane and carbon dioxide exchange need to be made all year-round with limited maintenance requirements. During this Phase II effort, we successfully completed the design of the electronics, optical bench, trace gas detection method and mechanical infrastructure. We are using the technologies of two vertical cavity surface emitting lasers, a multiple-pass Herriott optical cell, wavelength modulation spectroscopy and direct absorption to measure methane, carbon dioxide, and water vapor. We also have designed the instrument application software, Field Programmable Gate Array (FPGA), along with partial completion of the embedded software. The optical bench has been tested in a lab setting with very good results. Major sources of optical noise have been identified and through design, the optical noise floor is approaching -60dB. Both laser modules can be temperature controlled to help maximize the stability of the analyzer. Additionally, a piezo electric transducer has been utilized to randomize the noise introduced from potential etalons. It is expected that all original specifications contained within the initial proposal will be met. We are currently in the beginning stages of assembling the first generation prototypes and finalizing the remaining design elements. The first prototypes will initially be tested in our environmental calibration chamber in which specific gas concentrations, temperature and humidity levels can be controlled. Once operation in this controlled setting is verified, the prototypes will be deployed at LI-COR�¢����s Experimental Research Station (LERS). Deployment at the LERS site will test the instrument�¢����s robustness in a real-world situation.

  5. Retrieval of Moisture from Simulated GPS Slant-Path Water Vapor Observations Using 3DVAR with Anisotropic Recursive Filters

    E-Print Network [OSTI]

    Xue, Ming

    Retrieval of Moisture from Simulated GPS Slant-Path Water Vapor Observations Using 3DVAR with Anisotropic Recursive Filters HAIXIA LIU AND MING XUE Center for Analysis and Prediction of Storms, and School) ABSTRACT Anisotropic recursive filters are implemented within a three-dimensional variational data

  6. Spreading of crude petroleum in brash ice; Effects of oil`s physical properties and water current

    SciTech Connect (OSTI)

    Sayed, M.; Kotlyar, L.S.; Sparks, B.D.

    1994-12-31

    Experiments were conducted in a refrigerated, circulating current flume to examine crude oil spreading in brash ice. Amauligak, Hibernia and Norman Wells crudes were tested. Measurements of the physical properties of the oils were also conducted, including: surface and interfacial tensions as well as viscosities. Spreading coefficients were calculated from measured surface and interfacial tensions. Results were obtained for original and weathered oils. For the spreading tests, spill volumes up to 3 liters and water currents up to 0.55 m/s were used. Tests were done using both fresh water ice and saline ice. Slick dimensions were measured, and modes of oil spreading were observed. Slick dimensions depended on oil type, but were not influenced by water current. Oils of high spreading coefficient and low viscosity spread over larger areas than those with low spreading coefficient and high viscosity.

  7. Water in Low-Mass Star-Forming Regions with Herschel: The Link Between Water Gas and Ice in Protostellar Envelopes

    E-Print Network [OSTI]

    Schmalzl, M; Walsh, C; Albertsson, T; van Dishoeck, E F; Kristensen, L E; Mottram, J C

    2014-01-01

    Aims: Our aim is to determine the critical parameters in water chemistry and the contribution of water to the oxygen budget by observing and modelling water gas and ice for a sample of eleven low-mass protostars, for which both forms of water have been observed. Methods: A simplified chemistry network, which is benchmarked against more sophisticated chemical networks, is developed that includes the necessary ingredients to determine the water vapour and ice abundance profiles in the cold, outer envelope in which the temperature increases towards the protostar. Comparing the results from this chemical network to observations of water emission lines and previously published water ice column densities, allows us to probe the influence of various agents (e.g., FUV field, initial abundances, timescales, and kinematics). Results: The observed water ice abundances with respect to hydrogen nuclei in our sample are 30-80ppm, and therefore contain only 10-30% of the volatile oxygen budget of 320ppm. The keys to reprodu...

  8. Nuclear quantum effects in water

    E-Print Network [OSTI]

    Joseph A. Morrone; Roberto Car

    2008-03-25

    In this work, a path integral Car-Parrinello molecular dynamics simulation of liquid water is performed. It is found that the inclusion of nuclear quantum effects systematically improves the agreement of first principles simulations of liquid water with experiment. In addition, the proton momentum distribution is computed utilizing a recently developed open path integral molecular dynamics methodology. It is shown that these results are in good agreement with neutron Compton scattering data for liquid water and ice.

  9. Real-time Non-contact Millimeter Wave Characterization of Water-Freezing and Ice-Melting Dynamics

    E-Print Network [OSTI]

    Woskov, Paul P.

    We applied millimeter wave radiometry for the first time to monitor water-freezing and ice-melting dynamics in real-time non-contact. The measurements were completed at a frequency of 137 GHz. Small amounts (about 2 mL) ...

  10. Ice Concentration Retrieval in Stratiform Mixed-phase Clouds Using Cloud Radar Reflectivity Measurements and 1D Ice Growth Model Simulations

    SciTech Connect (OSTI)

    Zhang, Damao; Wang, Zhien; Heymsfield, Andrew J.; Fan, Jiwen; Luo, Tao

    2014-10-01

    Measurement of ice number concentration in clouds is important but still challenging. Stratiform mixed-phase clouds (SMCs) provide a simple scenario for retrieving ice number concentration from remote sensing measurements. The simple ice generation and growth pattern in SMCs offers opportunities to use cloud radar reflectivity (Ze) measurements and other cloud properties to infer ice number concentration quantitatively. To understand the strong temperature dependency of ice habit and growth rate quantitatively, we develop a 1-D ice growth model to calculate the ice diffusional growth along its falling trajectory in SMCs. The radar reflectivity and fall velocity profiles of ice crystals calculated from the 1-D ice growth model are evaluated with the Atmospheric Radiation Measurements (ARM) Climate Research Facility (ACRF) ground-based high vertical resolution radar measurements. Combining Ze measurements and 1-D ice growth model simulations, we develop a method to retrieve the ice number concentrations in SMCs at given cloud top temperature (CTT) and liquid water path (LWP). The retrieved ice concentrations in SMCs are evaluated with in situ measurements and with a three-dimensional cloud-resolving model simulation with a bin microphysical scheme. These comparisons show that the retrieved ice number concentrations are within an uncertainty of a factor of 2, statistically.

  11. The irradiation of water ice by C$^+$ ions in the cosmic environment

    E-Print Network [OSTI]

    McBride, E J; Kohanoff, J J

    2014-01-01

    We present a first principles molecular dynamics (FPMD) study of the interaction of low energy, positively charged, carbon (C+) projectiles with amorphous solid water clusters at 30 K. Reactions involving the carbon ion at an initial energy of 11 eV and 1.7 eV with 30-molecule clusters have been investigated. Simulations indicate that the neutral isoformyl radical, COH, and carbon monoxide, CO, are the dominant products of these reactions. All these reactions are accompanied by the transfer of a proton from the reacting water molecule to the ice, where it forms a hydronium ion. We find that COH is formed either via a direct, "knock-out", mechanism following the impact of the C+ projectile upon a water molecule or by creation of a COH_2^+ intermediate. The direct mechanism is more prominent at higher energies. CO is generally produced following the dissociation of COH. More frequent production of the formyl radical, HCO, is observed here than in gas phase calculations. A less commonly occurring product is the ...

  12. 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

    2007-05-26

    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).

  13. On the water delivery to terrestrial embryos by ice pebble accretion

    E-Print Network [OSTI]

    Sato, Takao; Ida, Shigeru

    2015-01-01

    Standard accretion disk models suggest that the snow line in the solar nebula migrated interior to the Earth's orbit in a late stage of nebula evolution. In this late stage, a significant amount of ice could have been delivered to 1 AU from outer regions in the form of mm to dm-sized "pebbles." This raises the question why the present Earth is so depleted of water (with the ocean mass being as small as 0.023% of the Earth mass). Here we quantify the amount of icy pebbles accreted by terrestrial embryos after the migration of the snow line assuming that no mechanism halts the pebble flow in outer disk regions. We use a simplified version of the coagulation equation to calculate the formation and radial inward drift of icy pebbles in a protoplanetary disk. The pebble accretion cross section of an embryo is calculated using analytic expressions presented by recent studies. We find that the final mass and water content of terrestrial embryos strongly depends on the radial extent of the gas disk, the strength of d...

  14. Reconstructing the history of water ice formation from HDO/H2O and D2O/HDO ratios in protostellar cores

    E-Print Network [OSTI]

    Furuya, K; Aikawa, Y

    2015-01-01

    Recent interferometer observations have found that the D2O/HDO abundance ratio is higher than that of HDO/H2O by about one order of magnitude in the vicinity of low-mass protostar NGC 1333-IRAS 2A, where water ice has sublimated. Previous laboratory and theoretical studies show that the D2O/HDO ice ratio should be lower than the HDO/H2O ice ratio, if HDO and D2O ices are formed simultaneously with H2O ice. In this work, we propose that the observed feature, D2O/HDO > HDO/H2O, is a natural consequence of chemical evolution in the early cold stages of low-mass star formation: 1) majority of oxygen is locked up in water ice and other molecules in molecular clouds, where water deuteration is not efficient, and 2) water ice formation continues with much reduced efficiency in cold prestellar/protostellar cores, where deuteration processes are highly enhanced due to the drop of the ortho-para ratio of H2, the weaker UV radiation field, etc. Using a simple analytical model and gas-ice astrochemical simulations tracin...

  15. Solar Water Heater Roadmap Leads Path to Market Expansion (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2012-09-01

    Innovative strategy to reduce installed cost of solar water heater systems can rival conventional natural gas water heaters in the marketplace.

  16. A NEW SOURCE OF CO{sub 2} IN THE UNIVERSE: A PHOTOACTIVATED ELEY-RIDEAL SURFACE REACTION ON WATER ICES

    SciTech Connect (OSTI)

    Yuan, Chunqing; Cooke, Ilsa R.; Yates, John T. Jr.

    2014-08-20

    CO{sub 2} is one of the most abundant components of ices in the interstellar medium; however, its formation mechanism has not been clearly identified. Here we report an experimental observation of an Eley-Rideal-type reaction on a water ice surface, where CO gas molecules react by direct collisions with surface OH radicals, made by photodissociation of H{sub 2}O molecules, to produce CO{sub 2} ice on the surface. The discovery of this source of CO{sub 2} provides a new mechanism to explain the high relative abundance of CO{sub 2} ice in space.

  17. Mass hierarchy discrimination with atmospheric neutrinos in large volume ice/water Cherenkov detectors

    E-Print Network [OSTI]

    D. Franco; C. Jollet; A. Kouchner; V. Kulikovskiy; A. Meregaglia; S. Perasso; T. Pradier; A. Tonazzo; V. Van Elewyck

    2013-03-14

    Large mass ice/water Cherenkov experiments, optimized to detect low energy (1-20 GeV) atmospheric neutrinos, have the potential to discriminate between normal and inverted neutrino mass hierarchies. The sensitivity depends on several model and detector parameters, such as the neutrino flux profile and normalization, the Earth density profile, the oscillation parameter uncertainties, and the detector effective mass and resolution. A proper evaluation of the mass hierarchy discrimination power requires a robust statistical approach. In this work, the Toy Monte Carlo, based on an extended unbinned likelihood ratio test statistic, was used. The effect of each model and detector parameter, as well as the required detector exposure, was then studied. While uncertainties on the Earth density and atmospheric neutrino flux profiles were found to have a minor impact on the mass hierarchy discrimination, the flux normalization, as well as some of the oscillation parameter (\\Delta m^2_{31}, \\theta_{13}, \\theta_{23}, and \\delta_{CP}) uncertainties and correlations resulted critical. Finally, the minimum required detector exposure, the optimization of the low energy threshold, and the detector resolutions were also investigated.

  18. Investigating ice nucleation in cirrus clouds with an aerosol-enabled Multiscale Modeling Framework

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

    Zhang, Chengzhu; Wang, Minghuai; Morrison, H.; Somerville, Richard C.; Zhang, Kai; Liu, Xiaohong; Li, J-L F.

    2014-11-06

    In this study, an aerosol-dependent ice nucleation scheme [Liu and Penner, 2005] has been implemented in an aerosol-enabled multi-scale modeling framework (PNNL MMF) to study ice formation in upper troposphere cirrus clouds through both homogeneous and heterogeneous nucleation. The MMF model represents cloud scale processes by embedding a cloud-resolving model (CRM) within each vertical column of a GCM grid. By explicitly linking ice nucleation to aerosol number concentration, CRM-scale temperature, relative humidity and vertical velocity, the new MMF model simulates the persistent high ice supersaturation and low ice number concentration (10 to 100/L) at cirrus temperatures. The low ice numbermore »is attributed to the dominance of heterogeneous nucleation in ice formation. The new model simulates the observed shift of the ice supersaturation PDF towards higher values at low temperatures following homogeneous nucleation threshold. The MMF models predict a higher frequency of midlatitude supersaturation in the Southern hemisphere and winter hemisphere, which is consistent with previous satellite and in-situ observations. It is shown that compared to a conventional GCM, the MMF is a more powerful model to emulate parameters that evolve over short time scales such as supersaturation. Sensitivity tests suggest that the simulated global distribution of ice clouds is sensitive to the ice nucleation schemes and the distribution of sulfate and dust aerosols. Simulations are also performed to test empirical parameters related to auto-conversion of ice crystals to snow. Results show that with a value of 250 ?m for the critical diameter, Dcs, that distinguishes ice crystals from snow, the model can produce good agreement to the satellite retrieved products in terms of cloud ice water path and ice water content, while the total ice water is not sensitive to the specification of Dcs value.« less

  19. Investigating ice nucleation in cirrus clouds with an aerosol-enabled Multiscale Modeling Framework

    SciTech Connect (OSTI)

    Zhang, Chengzhu; Wang, Minghuai; Morrison, H.; Somerville, Richard C.; Zhang, Kai; Liu, Xiaohong; Li, J-L F.

    2014-12-01

    In this study, an aerosol-dependent ice nucleation scheme [Liu and Penner, 2005] has been implemented in an aerosol-enabled multi-scale modeling framework (PNNL MMF) to study ice formation in upper troposphere cirrus clouds through both homogeneous and heterogeneous nucleation. The MMF model represents cloud scale processes by embedding a cloud-resolving model (CRM) within each vertical column of a GCM grid. By explicitly linking ice nucleation to aerosol number concentration, CRM-scale temperature, relative humidity and vertical velocity, the new MMF model simulates the persistent high ice supersaturation and low ice number concentration (10 to 100/L) at cirrus temperatures. The low ice number is attributed to the dominance of heterogeneous nucleation in ice formation. The new model simulates the observed shift of the ice supersaturation PDF towards higher values at low temperatures following homogeneous nucleation threshold. The MMF models predict a higher frequency of midlatitude supersaturation in the Southern hemisphere and winter hemisphere, which is consistent with previous satellite and in-situ observations. It is shown that compared to a conventional GCM, the MMF is a more powerful model to emulate parameters that evolve over short time scales such as supersaturation. Sensitivity tests suggest that the simulated global distribution of ice clouds is sensitive to the ice nucleation schemes and the distribution of sulfate and dust aerosols. Simulations are also performed to test empirical parameters related to auto-conversion of ice crystals to snow. Results show that with a value of 250 ?m for the critical diameter, Dcs, that distinguishes ice crystals from snow, the model can produce good agreement to the satellite retrieved products in terms of cloud ice water path and ice water content, while the total ice water is not sensitive to the specification of Dcs value.

  20. Quarterly Journal of the Royal Meteorological Society Q. J. R. Meteorol. Soc. 00: 110 (2011) Parametrizing the horizontal inhomogeneity of ice water

    E-Print Network [OSTI]

    Hogan, Robin

    2011-01-01

    ) Parametrizing the horizontal inhomogeneity of ice water content using CloudSat data products Peter G. Hilla quantities in the presence of a cloud it is necessary to know not only the mean water content, but also the distribution of this water content. This article describes a study of the in-cloud horizontal inhomogeneity

  1. Ice and water droplets on graphite: A comparison of quantum and classical simulations Rafael Ramrez, Jayant K. Singh, Florian Mller-Plathe, and Michael C. Bhm

    E-Print Network [OSTI]

    Singh, Jayant K.

    to reproduce the macroscopic contact angle of water droplets on graphite. Several energetic and structural compared with the values of ice Ih and liquid water as a function of temperature. The droplet kinetic properties of water droplets with sizes between 102 and 103 molecules were analyzed in a temperature interval

  2. Determination of Large-Scale Cloud Ice Water Concentration by Combining Surface Radar and Satellite Data in Support of ARM SCM Activities

    SciTech Connect (OSTI)

    Liu, Guosheng

    2013-03-15

    Single-column modeling (SCM) is one of the key elements of Atmospheric Radiation Measurement (ARM) research initiatives for the development and testing of various physical parameterizations to be used in general circulation models (GCMs). The data required for use with an SCM include observed vertical profiles of temperature, water vapor, and condensed water, as well as the large-scale vertical motion and tendencies of temperature, water vapor, and condensed water due to horizontal advection. Surface-based measurements operated at ARM sites and upper-air sounding networks supply most of the required variables for model inputs, but do not provide the horizontal advection term of condensed water. Since surface cloud radar and microwave radiometer observations at ARM sites are single-point measurements, they can provide the amount of condensed water at the location of observation sites, but not a horizontal distribution of condensed water contents. Consequently, observational data for the large-scale advection tendencies of condensed water have not been available to the ARM cloud modeling community based on surface observations alone. This lack of advection data of water condensate could cause large uncertainties in SCM simulations. Additionally, to evaluate GCMsâ�� cloud physical parameterization, we need to compare GCM results with observed cloud water amounts over a scale that is large enough to be comparable to what a GCM grid represents. To this end, the point-measurements at ARM surface sites are again not adequate. Therefore, cloud water observations over a large area are needed. The main goal of this project is to retrieve ice water contents over an area of 10 x 10 deg. surrounding the ARM sites by combining surface and satellite observations. Built on the progress made during previous ARM research, we have conducted the retrievals of 3-dimensional ice water content by combining surface radar/radiometer and satellite measurements, and have produced 3-D cloud ice water contents in support of cloud modeling activities. The approach of the study is to expand a (surface) point measurement to an (satellite) area measurement. That is, the study takes the advantage of the high quality cloud measurements (particularly cloud radar and microwave radiometer measurements) at the point of the ARM sites. We use the cloud ice water characteristics derived from the point measurement to guide/constrain a satellite retrieval algorithm, then use the satellite algorithm to derive the 3-D cloud ice water distributions within an 10�° (latitude) x 10�° (longitude) area. During the research period, we have developed, validated and improved our cloud ice water retrievals, and have produced and archived at ARM website as a PI-product of the 3-D cloud ice water contents using combined satellite high-frequency microwave and surface radar observations for SGP March 2000 IOP and TWP-ICE 2006 IOP over 10 deg. x 10 deg. area centered at ARM SGP central facility and Darwin sites. We have also worked on validation of the 3-D ice water product by CloudSat data, synergy with visible/infrared cloud ice water retrievals for better results at low ice water conditions, and created a long-term (several years) of ice water climatology in 10 x 10 deg. area of ARM SGP and TWP sites and then compared it with GCMs.

  3. Ice electrode electrolytic cell

    DOE Patents [OSTI]

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

    1993-04-06

    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.

  4. 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)

    1993-01-01

    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.

  5. The quantum nature of the OH stretching mode in ice and water probed by neutron scattering experiments

    SciTech Connect (OSTI)

    Senesi, Roberto; Flammini, Davide; Kolesnikov, Alexander I; Murray, Eamonn D.; Galli, Giulia; Andreani, Carla

    2013-01-01

    The OH stretching vibrational spectrum of water was measured in a wide range of temperatures across the triple point, 269 K < T < 296 K, using Inelastic Neutron Scattering (INS). The hydrogen projected density of states and the proton mean kinetic energy, _OH, were determined for the first time within the framework of a harmonic description of the proton dynamics. We found that in the liquid the value of _OH is nearly constant as a function of T, indicating that quantum effects on the OH stretching frequency are weakly dependent on temperature. In the case of ice, ab initio electronic structure calculations, using non-local van der Waals functionals, provided _OH values in agreement with INS experiments. We also found that the ratio of the stretching (_OH) to the total (_exp) kinetic energy, obtained from the present measurements, increases in going from ice, where hydrogen bonding is the strongest, to the liquid at ambient conditions and then to the vapour phase, where hydrogen bonding is the weakest. The same ratio was also derived from the combination of previous deep inelastic neutron scattering data, which does not rely upon the harmonic approximation, and the present measurements. We found that the ratio of stretching to the total kinetic energy shows a minimum in the metastable liquid phase. This finding suggests that the strength of intermolecular interactions increases in the supercooled phase, with respect to that in ice, contrary to the accepted view that supercooled water exhibits weaker hydrogen bonding than ice.

  6. Arctic ice islands

    SciTech Connect (OSTI)

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

    1988-01-01

    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.

  7. Ice, Snow and Water: impacts of climate change on California and Himalayan Asia

    E-Print Network [OSTI]

    Fenner, R. A.

    2009-01-01

    of Climate Change on Water, Biodiversity and Livelihoods”Dallas 5. The United Nations World Water Development Report3 (2009) “Water in a Changing World” Unesco Publishing (

  8. A parameterisation of single and multiple muons in the deep water or ice

    E-Print Network [OSTI]

    Annarita Margiotta

    2006-02-01

    A new parameterisation of atmospheric muons deep underwater (or ice) is presented. It takes into account the simultaneous arrival of muons in bundle giving the multiplicity of the events and the muon energy spectrum as a function of their lateral distribution in a shower.

  9. Frequency dependent seismic reflection analysis: a path to new direct hydrocarbon indicators for deep water reservoirs 

    E-Print Network [OSTI]

    Yoo, Seung Chul

    2009-06-02

    ://maps.google.com/). . . . . . . . . . . . . . . . . . . . . . . . . 46 4.2 Before and after the radon demultiple of two CMP gathers near target reservoirs. (a) and (b): before and after at the first CMP. (c) and (d): before and after at the second CMP. Free surface multiples interfere with relatively weaker primaries... the Ursa (deep water, GOM) field data set to preserve amplitude and frequency information. We use move-out based method for demultiple (radon method) and prestack time migration equivalent process (NMO + DMO + FK migration) for imaging. We implement a...

  10. Results and prospects of deep under-ground, under-water and under-ice experiments

    E-Print Network [OSTI]

    Zornoza, J D

    2014-01-01

    Astroparticle experiments have provided a long list of achievements both for particle physics and astrophysics. Many of these experiments require to be protected from the background produced by cosmic rays in the atmosphere. The main options for such protection are to build detectors deep under ground (mines, tunnels) or in the deep sea or antarctic ice. In this proceeding we review the main results shown in the RICAP 2013 conference related with these kind of experiments and the prospects for the future.

  11. Now, Ze assumes |K|2 for water. But what about when we are looking at ice (Smith, 1984, J. Climate and Applied Met., 23, 1258-1260)?

    E-Print Network [OSTI]

    Rutledge, Steven

    for the particle to appear as a large water drop. #12;Rain-Snow lines- with an advertisement for dual-Pol! ZDRZeNow, Ze assumes |K|2 for water. But what about when we are looking at ice (Smith, 1984, J. Climate and Applied Met., 23, 1258-1260)? For water drops in the Rayleigh regime Z = Ze. Ze applies for Mie regime

  12. Biogeochemistry in Sea Ice: CICE model developments

    SciTech Connect (OSTI)

    Jeffery, Nicole; Hunke, Elizabeth; Elliott, Scott; Turner, Adrian

    2012-06-18

    Polar primary production unfolds in a dynamic sea ice environment, and the interactions of sea ice with ocean support and mediate this production. In spring, for example, fresh melt water contributes to the shoaling of the mixed layer enhancing ice edge blooms. In contrast, sea ice formation in the fall reduces light penetration to the upper ocean slowing primary production in marine waters. Polar biogeochemical modeling studies typically consider these types of ice-ocean interactions. However, sea ice itself is a biogeochemically active medium, contributing a significant and, possibly, essential source of primary production to polar regions in early spring and fall. Here we present numerical simulations using the Los Alamos Sea Ice Model (CICE) with prognostic salinity and sea ice biogeochemistry. This study investigates the relationship between sea ice multiphase physics and sea ice productivity. Of particular emphasis are the processes of gravity drainage, melt water flushing, and snow loading. During sea ice formation, desalination by gravity drainage facilitates nutrient exchange between ocean and ice maintaining ice algal blooms in early spring. Melt water flushing releases ice algae and nutrients to underlying waters limiting ice production. Finally, snow loading, particularly in the Southern Ocean, forces sea ice below the ocean surface driving an upward flow of nutrient rich water into the ice to the benefit of interior and freeboard communities. Incorporating ice microphysics in CICE has given us an important tool for assessing the importance of these processes for polar algal production at global scales.

  13. EVOLUTION OF SNOW LINE IN OPTICALLY THICK PROTOPLANETARY DISKS: EFFECTS OF WATER ICE OPACITY AND DUST GRAIN SIZE

    SciTech Connect (OSTI)

    Oka, Akinori; Nakamoto, Taishi; Ida, Shigeru, E-mail: akinorioka1@gmail.com, E-mail: nakamoto@geo.titech.ac.jp [Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Tokyo (Japan)

    2011-09-10

    Evolution of a snow line in an optically thick protoplanetary disk is investigated with numerical simulations. The ice-condensing region in the disk is obtained by calculating the temperature and the density with the 1+1D approach. The snow line migrates as the mass accretion rate ( M-dot ) in the disk decreases with time. Calculations are carried out from an early phase with high disk accretion rates ( M-dot {approx}10{sup -7} M{sub sun} yr{sup -1}) to a later phase with low disk accretion rates ( M-dot {approx}10{sup -12} M{sub sun} yr{sup -1}) using the same numerical method. It is found that the snow line moves inward for M-dot {approx}>10{sup -10} M{sub sun} yr{sup -1}, while it gradually moves outward in the later evolution phase with M-dot {approx}<10{sup -10} M{sub sun} yr{sup -1}. In addition to the silicate opacity, the ice opacity is taken into consideration. In the inward migration phase, the additional ice opacity increases the distance of the snow line from the central star by a factor of 1.3 for dust grains {approx}< 10 {mu}m in size and of 1.6 for {approx}> 100 {mu}m. It is inevitable that the snow line comes inside Earth's orbit in the course of the disk evolution if the viscosity parameter {alpha} is in the range 0.001-0.1, the dust-to-gas mass ratio is higher than a tenth of the solar abundance value, and the dust grains are smaller than 1 mm. The formation of water-devoid planetesimals in the terrestrial planet region seems to be difficult throughout the disk evolution, which imposes a new challenge to planet formation theory.

  14. Cloud fraction, liquid and ice water contents derived from long-term radar, lidar, and microwave radiometer data are systematically compared to models to quantify and

    E-Print Network [OSTI]

    Hogan, Robin

    Cloud fraction, liquid and ice water contents derived from long-term radar, lidar, and microwave a systematic evaluation of clouds in forecast models. Clouds and their associated microphysical processes for end users of weather forecasts, who may be interested not only in cloud cover, but in other variables

  15. Ice thickness measurements by Raman scattering

    E-Print Network [OSTI]

    Pershin, Sergey M; Klinkov, Vladimir K; Yulmetov, Renat N; Bunkin, Alexey F

    2014-01-01

    A compact Raman LIDAR system with a spectrograph was used for express ice thickness measurements. The difference between the Raman spectra of ice and liquid water is employed to locate the ice-water interface while elastic scattering was used for air-ice surface detection. This approach yields an error of only 2 mm for an 80-mm-thick ice sample, indicating that it is promising express noncontact thickness measurements technique in field experiments.

  16. Eos, Vol. 91, No. 29, 20 July 2010 Water and wet sediments under ice sheets

    E-Print Network [OSTI]

    Priscu, John C.

    Research Drilling (WISSARD) project (http://www .wissard.org). Begun in 2009, WISSARD will assess how water diversity within glacial environments. Exact selection of drill sites will be based on safety considerations and accessibility as determined through radar, seismic, and satellite data. Surface geophysical surveys will also

  17. In Situ Imaging of Liquid Water and Ice Formation in an Operating PEFC during Cold Start

    E-Print Network [OSTI]

    . Cold-start capability and survivability of polymer electrolyte fuel cells PEFCs in a subzero is insufficient to contain all of the accumulated water before the cell operating temperature rises above freezing to freeze/ thaw cycling between -40 and 80°C. St-Pierre et al.5 found that if a cell was purged with dry gas

  18. Covered Product Category: Water-Cooled Ice Machines | 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:FinancingPetroleum Based| Department of Energy Whole-Home Gas Tankless WaterEnergy

  19. Sensitivity of CAM5-Simulated Arctic Clouds and Radiation to Ice Nucleation Parameterization

    SciTech Connect (OSTI)

    Xie, Shaocheng; Liu, Xiaohong; Zhao, Chuanfeng; Zhang, Yuying

    2013-08-01

    Sensitivity of Arctic clouds and radiation in the Community Atmospheric Model version 5 to the ice nucleation process is examined by testing a new physically based ice nucleation scheme that links the variation of ice nuclei (IN) number concentration to aerosol properties. The default scheme parameterizes the IN concentration simply as a function of ice supersaturation. The new scheme leads to a significant reduction in simulated IN number concentrations at all latitudes while changes in cloud amount and cloud properties are mainly seen in high latitudes and middle latitude storm tracks. In the Arctic, there is a considerable increase in mid-level clouds and a decrease in low clouds, which result from the complex interaction among the cloud macrophysics, microphysics, and the large-scale environment. The smaller IN concentrations result in an increase in liquid water path and a decrease in ice water path due to the slow-down of the Bergeron-Findeisen process in mixed-phase clouds. Overall, there is an increase in the optical depth of Arctic clouds, which leads to a stronger cloud radiative forcing (net cooling) at the top of the atmosphere. The comparison with satellite data shows that the new scheme slightly improves low cloud simulations over most of the Arctic, but produces too many mid-level clouds. Considerable improvements are seen in the simulated low clouds and their properties when compared to Arctic ground-based measurements. Issues with the observations and the model-observation comparison in the Arctic region are discussed.

  20. Flight Path 30L - About ICE House

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HABFES OctoberEvanServices »First ObservationFast ThisAboutR -L The

  1. Flight Path 30L - ICE House

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HABFES OctoberEvanServices »First ObservationFast ThisAboutR -L

  2. Flight Path 30L - ICE House

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HABFES OctoberEvanServices »First ObservationFast ThisAboutR

  3. Flight Path 30R - About ICE II

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HABFES OctoberEvanServices »First ObservationFast ThisAboutR° flight

  4. Flight Path 30R - About ICE II

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HABFES OctoberEvanServices »First ObservationFast ThisAboutR° flightº

  5. Flight Path 30R - ICE II

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

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  6. Flight Path 30R - ICE II

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HABFES OctoberEvanServices »First ObservationFast

  7. Flight Path 30L - ICE House

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory ofDid you not find whatGasEnergyfeature photoTheory ChalkboardFiberFindFindLRL

  8. Flight Path 30R | ICE II

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory ofDid you not find whatGasEnergyfeature photoTheory

  9. A study of the influence of isotopic substitution on the melting point and temperature of maximum density of water by means of path integral simulations of rigid models

    E-Print Network [OSTI]

    McBride, Carl; Noya, Eva G; Vega, Carlos; 10.1039/C2CP42393F

    2012-01-01

    The melting point of ice Ih, as well as the temperature of maximum density (TMD) in the liquid phase, has been computed using the path integral Monte Carlo method. Two new models are introduced; TIP4PQ_D2O and TIP4PQ_T2O which are specifically designed to study D2O and T2O respectively. We have also used these models to study the "competing quantum effects" proposal of Habershon, Markland and Manolopoulos; the TIP4PQ/2005, TIP4PQ/2005 (D2O) and TIP4PQ/2005 (T2O) models are able to study the isotopic substitution of hydrogen for deuterium or tritium whilst constraining the geometry, while the TIP4PQ_D2O and TIP4PQ_T2O models, where the O-H bond lengths are progressively shortened, permit the study of the influence of geometry (and thus dipole moment) on the isotopic effects. For TIP4PQ_D2O - TIP4PQ/2005 we found a melting point shift of 4.9 K (experimentally the value is 3.68K) and a TMD shift of 6K (experimentally 7.2K). For TIP4PQ_T2O - TIP4PQ/2005 we found a melting point shift of 5.2 K (experimentally the ...

  10. Conditions for water ice lines and Mars-mass exomoons around accreting super-Jovian planets at 1 - 20 AU from Sun-like stars

    E-Print Network [OSTI]

    Heller, René

    2015-01-01

    Exomoon detections might be feasible with NASA's Kepler or ESA's upcoming PLATO mission or the ground-based E-ELT. To use observational resources most efficiently we need to know where the largest, most easily detected moons can form. We explore the possibility of large exomoons by following the movement of water (H2O) ice lines in the accretion disks around young super-Jovian planets. We want to know how different heating sources in those disks affect the H2O ice lines. We simulate 2D rotationally symmetric accretion disks in hydrostatic equilibrium around super-Jovian exoplanets. The energy terms in our semi-analytical model -- (1) viscous heating, (2) planetary illumination, (3) accretional heating, and (4) stellar illumination -- are fed by precomputed planet evolution tracks. We consider planets accreting 1 to 12 Jupiter masses at distances between 1 and 20 AU to a Sun-like star. Accretion disks around Jupiter-mass planets closer than ~4.5 AU to Sun-like stars do not feature H2O ice lines, but the most m...

  11. Intercomparison of Large-eddy Simulations of Arctic Mixed-phase Clouds: Importance of Ice Size Distribution Assumptions

    SciTech Connect (OSTI)

    Ovchinnikov, Mikhail; Ackerman, Andrew; Avramov, Alex; Cheng, Anning; Fan, Jiwen; Fridlind, Ann; Ghan, Steven J.; Harrington, Jerry Y.; Hoose, Corinna; Korolev, Alexei; McFarquhar, Greg; Morrison, H.; Paukert, Marco; Savre, Julien; Shipway, Ben; Shupe, Matthew D.; Solomon, Amy; Sulia, Kara

    2014-03-14

    Large-eddy simulations of mixed-phase Arctic clouds by 11 different models are analyzed with the goal of improving understanding and model representation of processes controlling the evolution of these clouds. In a case based on observations from the Indirect and Semi-Direct Aerosol Campaign (ISDAC), it is found that ice number concentration, Ni, exerts significant influence on the cloud structure. Increasing Ni leads to a substantial reduction in liquid water path (LWP) and potential cloud dissipation, in agreement with earlier studies. By comparing simulations with the same microphysics coupled to different dynamical cores as well as the same dynamics coupled to different microphysics schemes, it is found that the ice water path (IWP) is mainly controlled by ice microphysics, while the inter-model differences in LWP are largely driven by physics and numerics of the dynamical cores. In contrast to previous intercomparisons, all models here use the same ice particle properties (i.e., mass-size, mass-fall speed, and mass-capacitance relationships) and a common radiation parameterization. The constrained setup exposes the importance of ice particle size distributions (PSD) in influencing cloud evolution. A clear separation in LWP and IWP predicted by models with bin and bulk microphysical treatments is documented and attributed primarily to the assumed shape of ice PSD used in bulk schemes. Compared to the bin schemes that explicitly predict the PSD, schemes assuming exponential ice PSD underestimate ice growth by vapor deposition and overestimate mass-weighted fall speed leading to an underprediction of IWP by a factor of two in the considered case.

  12. Interstellar Ices

    E-Print Network [OSTI]

    Boogert, A C A

    2003-01-01

    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...

  13. Application of an online-coupled regional climate model, WRF-CAM5, over East Asia for examination of ice nucleation schemes. Part II. Sensitivity to heterogeneous ice nucleation parameterizations and dust emissions

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

    Zhang, Yang; Chen, Ying; Fan, Jiwen; Leung, Lai -Yung

    2015-09-14

    Aerosol particles can affect cloud microphysical properties by serving as ice nuclei (IN). Large uncertainties exist in the ice nucleation parameterizations (INPs) used in current climate models. In this Part II paper, to examine the sensitivity of the model predictions to different heterogeneous INPs, WRF-CAM5 simulation using the INP of Niemand et al. (N12) [1] is conducted over East Asia for two full years, 2006 and 2011, and compared with simulation using the INP of Meyers et al. (M92) [2], which is the original INP used in CAM5. M92 calculates the nucleated ice particle concentration as a function of icemore »supersaturation, while N12 represents the nucleated ice particle concentration as a function of temperature and the number concentrations and surface areas of dust particles. Compared to M92, the WRF-CAM5 simulation with N12 produces significantly higher nucleated ice crystal number concentrations (ICNCs) in the northern domain where dust sources are located, leading to significantly higher cloud ice number and mass concentrations and ice water path, but the opposite is true in the southern domain where temperatures and moistures play a more important role in ice formation. Overall, the simulation with N12 gives lower downward shortwave radiation but higher downward longwave radiation, cloud liquid water path, cloud droplet number concentrations, and cloud optical depth. The increase in cloud optical depth and the decrease in downward solar flux result in a stronger shortwave and longwave cloud forcing, and decreases temperature at 2-m and precipitation. Changes in temperature and radiation lower surface concentrations of OH, O?, SO?²?, and PM2.5, but increase surface concentrations of CO, NO?, and SO? over most of the domain. By acting as cloud condensation nuclei (CCN) and IN, dust particles have different impacts on cloud water and ice number concentrations, radiation, and temperature at 2-m and precipitation depending on whether the dominant role of dust is CCN or IN. These results indicate the importance of the heterogeneous ice nucleation treatments and dust emissions in accurately simulating regional climate and air quality.« less

  14. Glacial conditions that contribute to the regeneration of Fountain Glacier proglacial icing, Bylot Island, Canada

    E-Print Network [OSTI]

    Moorman, Brian

    Glacial conditions that contribute to the regeneration of Fountain Glacier proglacial icing, Bylot icings are one of the most common forms of extrusive ice found in the Canadian Arctic. However, the icing. Its regeneration depends on the availability of subglacial water and on the balance between ice

  15. ARM - Measurement - Liquid 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Comments?govInstrumentsnoaacrnBarrow, Alaska Outreach Home Roomparticlecontent ARM Data Discovery Browse Datapath

  16. Hidden force floating ice

    E-Print Network [OSTI]

    Chang Q. Sun

    2015-01-17

    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.

  17. Intercomparison of the Cloud Water Phase among Global Climate Models

    SciTech Connect (OSTI)

    Komurcu, Muge; Storelvmo, Trude; Tan, Ivy; Lohmann, U.; Yun, Yuxing; Penner, Joyce E.; Wang, Yong; Liu, Xiaohong; Takemura, T.

    2014-03-27

    Mixed-phase clouds (clouds that consist of both cloud droplets and ice crystals) are frequently present in the Earth’s atmosphere and influence the Earth’s energy budget through their radiative properties, which are highly dependent on the cloud water phase. In this study, the phase partitioning of cloud water is compared among six global climate models (GCMs) and with Cloud and Aerosol Lidar with Orthogonal Polarization retrievals. It is found that the GCMs predict vastly different distributions of cloud phase for a given temperature, and none of them are capable of reproducing the spatial distribution or magnitude of the observed phase partitioning. While some GCMs produced liquid water paths comparable to satellite observations, they all failed to preserve sufficient liquid water at mixed-phase cloud temperatures. Our results suggest that validating GCMs using only the vertically integrated water contents could lead to amplified differences in cloud radiative feedback. The sensitivity of the simulated cloud phase in GCMs to the choice of heterogeneous ice nucleation parameterization is also investigated. The response to a change in ice nucleation is quite different for each GCM, and the implementation of the same ice nucleation parameterization in all models does not reduce the spread in simulated phase among GCMs. The results suggest that processes subsequent to ice nucleation are at least as important in determining phase and should be the focus of future studies aimed at understanding and reducing differences among the models.

  18. Method of forming calthrate ice

    DOE Patents [OSTI]

    Hino, T.; Gorski, A.J.

    1985-09-30

    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.

  19. Method of forming clathrate ice

    DOE Patents [OSTI]

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

    1987-01-01

    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.

  20. Path Coupling and Aggregate Path Coupling

    E-Print Network [OSTI]

    Kovchegov, Yevgeniy

    2015-01-01

    In this survey paper, we describe and characterize an extension to the classical path coupling method applied statistical mechanical models, referred to as aggregate path coupling. In conjunction with large deviations estimates, we use this aggregate path coupling method to prove rapid mixing of Glauber dynamics for a large class of statistical mechanical models, including models that exhibit discontinuous phase transitions which have traditionally been more difficult to analyze rigorously. The parameter region for rapid mixing for the generalized Curie-Weiss-Potts model is derived as a new application of the aggregate path coupling method.

  1. Path Coupling and Aggregate Path Coupling

    E-Print Network [OSTI]

    Yevgeniy Kovchegov; Peter T. Otto

    2015-01-13

    In this survey paper, we describe and characterize an extension to the classical path coupling method applied statistical mechanical models, referred to as aggregate path coupling. In conjunction with large deviations estimates, we use this aggregate path coupling method to prove rapid mixing of Glauber dynamics for a large class of statistical mechanical models, including models that exhibit discontinuous phase transitions which have traditionally been more difficult to analyze rigorously. The parameter region for rapid mixing for the generalized Curie-Weiss-Potts model is derived as a new application of the aggregate path coupling method.

  2. A parameterisation of the flux and energy spectrum of single and multiple muons in deep water/ice

    E-Print Network [OSTI]

    M. Bazzotti; S. Biagi; G. Carminati; S. Cecchini; T. Chiarusi; G. Giacomelli; A. Margiotta; M. Sioli; M. Spurio

    2009-10-22

    In this paper parametric formulas are presented to evaluate the flux of atmospheric muons in the range of vertical depth between 1.5 to 5 km of water equivalent (km w.e.) and up to 85^o for the zenith angle. We take into account their arrival in bundles with different muon multiplicities. The energy of muons inside bundles is then computed considering the muon distance from the bundle axis. This parameterisation relies on a full Monte Carlo simulation of primary Cosmic Ray (CR) interactions, shower propagation in the atmosphere and muon transport in deep water [1]. The primary CR flux and interaction models, in the range in which they can produce muons which may reach 1.5 km w.e., suffer from large experimental uncertainties. We used a primary CR flux and an interaction model able to correctly reproduce the flux, the multiplicity distribution, the spatial distance between muons as measured by the underground MACRO experiment.

  3. Passive ice freezing-releasing heat pipe

    DOE Patents [OSTI]

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

    1982-01-01

    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.

  4. Ice Cover on the Great Lakes NATIONALOCEANIC

    E-Print Network [OSTI]

    : In the shallow waters where whitefish spawn, ice cover protects their eggs from destructive wind and wave action://coastwatch.glerl.noaa.gov/glsea/cur/glsea_cur.png #12;GLERL Research Forecast capability The capability to forecast and predict ice cover is important for recreational safety and rescue efforts as well as for navigation, weather forecasting, adapting to lake level

  5. FULLY SAMPLED MAPS OF ICES AND SILICATES IN FRONT OF CEPHEUS A EAST WITH THE SPITZER SPACE TELESCOPE1

    E-Print Network [OSTI]

    Gerakines, Perry

    are relatively constant over the mapped region exhibiting both ice absorptions. The fraction of CO2 ice are invoked. The routine detection of solid CO2, with a fraction relative to water ice between 9% and 37 report the first fully sampled maps of the distribution of interstellar CO2 ices, H2O ices, and total

  6. Weakening of ice by magnesium perchlorate hydrate

    E-Print Network [OSTI]

    Lenferink, Hendrik J., 1985-

    2012-01-01

    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 ...

  7. The universal path integral

    E-Print Network [OSTI]

    Seth Lloyd; Olaf Dreyer

    2013-02-12

    Path integrals represent a powerful route to quantization: they calculate probabilities by summing over classical configurations of variables such as fields, assigning each configuration a phase equal to the action of that configuration. This paper defines a universal path integral, which sums over all computable structures. This path integral contains as sub-integrals all possible computable path integrals, including those of field theory, the standard model of elementary particles, discrete models of quantum gravity, string theory, etc. The universal path integral possesses a well-defined measure that guarantees its finiteness, together with a method for extracting probabilities for observable quantities. The universal path integral supports a quantum theory of the universe in which the world that we see around us arises out of the interference between all computable structures.

  8. Community Ice Sheet Model (CISM2) Development and Marine Ice...

    Office of Scientific and Technical Information (OSTI)

    Conference: Community Ice Sheet Model (CISM2) Development and Marine Ice Sheet Simulations Citation Details In-Document Search Title: Community Ice Sheet Model (CISM2) Development...

  9. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Comments?govInstrumentsnoaacrnBarrow, Alaska Outreach Home Roomparticle sizefraction ARMGeometrytypes

  10. Molecular simulations of heterogeneous ice nucleation. I. Controlling ice nucleation through surface hydrophilicity

    E-Print Network [OSTI]

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

    2015-05-29

    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 physicochemical properties of a material's surface affect its ability to form ice has remained elusive. Here, we use molecular dynamics simulations to directly probe heterogeneous ice nucleation at a 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.

  11. Evidence that ice forms primarily in supercooled liquid clouds at temperatures > -27C2 C. D. Westbrook and A. J. Illingworth3

    E-Print Network [OSTI]

    Reading, University of

    layer of supercooled liquid water droplets at the25 top of ice-phase clouds has been observed in several cases (Rauber and Tokay 1991), but the26 fraction of ice clouds which have liquid water at the top has case where the air35 was supersaturated with respect to ice but below liquid water saturation: ice

  12. Fluid Migration During Ice/Rock Planetesimal Differentiation 

    E-Print Network [OSTI]

    Raney, Robert 1987-

    2012-12-12

    fast melt water can segregate from the core of an ice-rich planetesimal. To answer this question we treat the core as two phase flow problem: a compacting viscous “solid” (ice/rock mixture) and a segregating liquid (melt water). The model developed...

  13. Ethanol adsorbed on ice: A first-principles study C. Thierfelder*

    E-Print Network [OSTI]

    Schmidt, Wolf Gero

    Ethanol adsorbed on ice: A first-principles study C. Thierfelder* Centre of Theoretical Chemistry of ethanol molecules on the ice Ih basal plane. Apart from smooth surfaces, also substrate models simulation for ethanol adsorbed on ice using the TIP4P potential16 for the water-water interaction. Recent

  14. Widespread Excess Ice in Arcadia Planitia, Mars

    E-Print Network [OSTI]

    Bramson, Ali M; Putzig, Nathaniel E; Sutton, Sarah; Plaut, Jeffrey J; Brothers, T Charles; Holt, John W

    2015-01-01

    The distribution of subsurface water ice on Mars is a key constraint on past climate, while the volumetric concentration of buried ice (pore-filling versus excess) provides information about the process that led to its deposition. We investigate the subsurface of Arcadia Planitia by measuring the depth of terraces in simple impact craters and mapping a widespread subsurface reflection in radar sounding data. Assuming that the contrast in material strengths responsible for the terracing is the same dielectric interface that causes the radar reflection, we can combine these data to estimate the dielectric constant of the overlying material. We compare these results to a three-component dielectric mixing model to constrain composition. Our results indicate a widespread, decameters-thick layer that is excess water ice ~10^4 km^3 in volume. The accumulation and long-term preservation of this ice is a challenge for current Martian climate models.

  15. Displaced path integral formulation for the momentum distribution of quantum particles

    E-Print Network [OSTI]

    Lin Lin; Joseph Morrone; Roberto Car; Michele Parrinello

    2010-06-05

    The proton momentum distribution, accessible by deep inelastic neutron scattering, is a very sensitive probe of the potential of mean force experienced by the protons in hydrogen-bonded systems. In this work we introduce a novel estimator for the end to end distribution of the Feynman paths, i.e. the Fourier transform of the momentum distribution. In this formulation, free particle and environmental contributions factorize. Moreover, the environmental contribution has a natural analogy to a free energy surface in statistical mechanics, facilitating the interpretation of experiments. The new formulation is not only conceptually but also computationally advantageous. We illustrate the method with applications to an empirical water model, ab-initio ice, and one dimensional model systems.

  16. Communication: On the stability of ice 0, ice i, and I{sub h}

    SciTech Connect (OSTI)

    Quigley, D.; Alfè, D.; Slater, B.

    2014-10-28

    Using ab initio methods, we examine the stability of ice 0, a recently proposed tetragonal form of ice implicated in the homogeneous freezing of water [J. Russo, F. Romano, and H. Tanaka, Nat. Mater. 13, 670 (2014)]. Vibrational frequencies are computed across the complete Brillouin Zone using Density Functional Theory (DFT), to confirm mechanical stability and quantify the free energy of ice 0 relative to ice I{sub h}. The robustness of this result is tested via dispersion corrected semi-local and hybrid DFT, and Quantum Monte-Carlo calculation of lattice energies. Results indicate that popular molecular models only slightly overestimate the stability of ice zero. In addition, we study all possible realisations of proton disorder within the ice zero unit cell, and identify the ground state as ferroelectric. Comparisons are made to other low density metastable forms of ice, suggesting that the ice i structure [C. J. Fennel and J. D. Gezelter, J. Chem. Theory Comput. 1, 662 (2005)] may be equally relevant to ice formation.

  17. Using Temporal Information in an Automated Classification of Summer, Marginal Ice Zone Imagery*

    E-Print Network [OSTI]

    Kansas, University of

    * Donna Haverkamp and Costas Tsatsoulis Department of Electrical Engineering and Computer Science- analyzed temperature records and regional statistics in order to achieve an automated ice's ice/water concentrations and melt state with temperature and wind data, a current interpretation

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

    E-Print Network [OSTI]

    Christner, Brent C.

    polycarbonate membranes, and secondary electron images were collected at Â500 magnification using a scanning conductivity suggest that the ice comprises lake water which has refrozen to the underside of the ice sheet

  19. A Smoothed Particle Hydrodynamics Model for Ice Sheet and Ice Shelf Dynamics

    SciTech Connect (OSTI)

    Pan, Wenxiao; Tartakovsky, Alexandre M.; Monaghan, Joseph J.

    2012-02-08

    Mathematical modeling of ice sheets is complicated by the non-linearity of the governing equations and boundary conditions. Standard grid-based methods require complex front tracking techniques and have limited capability to handle large material deformations and abrupt changes in bottom topography. As a consequence, numerical methods are usually restricted to shallow ice sheet and ice shelf approximations. We propose a new smoothed particle hydrodynamics (SPH) model for coupled ice sheet and ice shelf dynamics. SPH is a fully Lagrangian particle method. It is highly scalable and its Lagrangian nature and meshless discretization are well suited to the simulation of free surface flows, large material deformation, and material fragmentation. In this paper SPH is used to study ice sheet/ice shelf behavior, and the dynamics of the grounding line. The steady state position of the grounding line obtained from the SPH simulations is in good agreement with laboratory observations for a wide range of simulated bedrock slopes, and density ratios similar to those of ice and sea water. The numerical accuracy of the SPH algorithm is further verified by simulating the plane shear flow of two immiscible fluids and the propagation of a highly viscous blob of fluid along a horizontal surface. In the experiment, the ice was represented with a viscous newtonian fluid. For consistency, in the described SPH model the ice is also modeled as a viscous newtonian fluid. Typically, ice sheets are modeled as a non-Newtonian fluid, accounting for the changes in the mechanical properties of ice. Implementation of a non-Newtonian rheology in the SPH model is the subject of our ongoing research.

  20. Smoothed particle hydrodynamics Non-Newtonian model for ice-sheet and ice-shelf dynamics

    SciTech Connect (OSTI)

    Pan, Wenxiao; Tartakovsky, Alexandre M.; Monaghan, Joseph J.

    2013-06-01

    Mathematical modeling of ice sheets is complicated by the non-linearity of the governing equations and boundary conditions. Standard grid-based methods require complex front tracking techniques and have limited capability to handle large material deformations and abrupt changes in bottom topography. As a consequence, numerical methods are usually restricted to shallow ice sheet and ice shelf approximations. We propose a new smoothed particle hydrodynamics (SPH) non-Newtonian model for coupled ice sheet and ice shelf dynamics. SPH, a fully Lagrangian particle method, is highly scalable and its Lagrangian nature and meshless discretization are well suited to the simulation of free surface ?ows, large material deformation, and material fragmentation. In this paper, SPH is used to study 3D ice sheet/ice shelf behavior, and the dynamics of the grounding line. The steady state position of the grounding line obtained from SPH simulations is in good agreement with laboratory observations for a wide range of simulated bedrock slopes, and density ratios, similar to those of ice and sea water. The numerical accuracy of the SPH algorithm is veri?ed by simulating Poiseuille ?ow, plane shear ?ow with free surface and the propagation of a blob of ice along a horizontal surface. In the laboratory experiment, the ice was represented with a viscous Newtonian ?uid. In the present work, however, the ice is modeled as both viscous Newtonian ?uid and non-Newtonian ?uid, such that the e?ect of non-Newtonian rheology on the dynamics of grounding line was examined. The non-Newtonian constitutive relation is prescribed to be Glen’s law for the creep of polycrystalline ice. A V-shaped bedrock ramp is further introduced to model the real geometry of bedrock slope.

  1. Tortuous path chemical preconcentrator

    DOE Patents [OSTI]

    Manginell, Ronald P. (Albuquerque, NM); Lewis, Patrick R. (Albuquerque, NM); Adkins, Douglas R. (Albuquerque, NM); Wheeler, David R. (Albuquerque, NM); Simonson, Robert J. (Cedar Crest, NM)

    2010-09-21

    A non-planar, tortuous path chemical preconcentrator has a high internal surface area having a heatable sorptive coating that can be used to selectively collect and concentrate one or more chemical species of interest from a fluid stream that can be rapidly released as a concentrated plug into an analytical or microanalytical chain for separation and detection. The non-planar chemical preconcentrator comprises a sorptive support structure having a tortuous flow path. The tortuosity provides repeated twists, turns, and bends to the flow, thereby increasing the interfacial contact between sample fluid stream and the sorptive material. The tortuous path also provides more opportunities for desorption and readsorption of volatile species. Further, the thermal efficiency of the tortuous path chemical preconcentrator is comparable or superior to the prior non-planar chemical preconcentrator. Finally, the tortuosity can be varied in different directions to optimize flow rates during the adsorption and desorption phases of operation of the preconcentrator.

  2. Ising model for melt ponds on Arctic sea ice

    E-Print Network [OSTI]

    Ma, Y -P; Golden, K M

    2014-01-01

    The albedo of melting Arctic sea ice, a key parameter in climate modeling, is determined by pools of water on the ice surface. Recent observations show an onset of pond complexity at a critical area of about 100 square meters, attended by a transition in pond fractal dimension. To explain this behavior and provide a statistical physics approach to sea ice modeling, we introduce a two dimensional Ising model for pond evolution which incorporates ice-albedo feedback and the underlying thermodynamics. The binary magnetic spin variables in the Ising model correspond to the presence of melt water or ice on the sea ice surface. The model exhibits a second-order phase transition from isolated to clustered melt ponds, with the evolution of pond complexity in the clustered phase consistent with the observations.

  3. Microphysical Consequences of the Spatial Distribution of Ice Nucleation in Mixed-Phase Stratiform Clouds

    SciTech Connect (OSTI)

    Yang, Fan; Ovchinnikov, Mikhail; Shaw, Raymond A.

    2014-07-28

    Mixed-phase stratiform clouds can persist even with steady ice precipitation fluxes, and the origin and microphysical properties of the ice crystals are of interest. Vapor deposition growth and sedimentation of ice particles along with a uniform volume source of ice nucleation, leads to a power law relation between ice water content wi and ice number concentration ni with exponent 2.5. The result is independent of assumptions about the vertical velocity structure of the cloud and is therefore more general than the related expression of Yang et al. [2013]. The sensitivity of the wi-ni relationship to the spatial distribution of ice nucleation is confirmed by Lagrangian tracking and ice growth with cloud-volume, cloud-top, and cloud-base sources of ice particles through a time-dependent cloud field. Based on observed wi and ni from ISDAC, a lower bound of 0.006 m^3/s is obtained for the ice crystal formation rate.

  4. Minimalist Model of Ice Microphysics in Mixed-phase Stratiform Clouds

    SciTech Connect (OSTI)

    Yang, F.; Ovchinnikov, Mikhail; Shaw, Raymond A.

    2013-07-28

    The question of whether persistent ice crystal precipitation from super cooled layer clouds can be explained by time-dependent, stochastic ice nucleation is explored using an approximate, analytical model, and a large-eddy simulation (LES) cloud model. The updraft velocity in the cloud defines an accumulation zone, where small ice particles cannot fall out until they are large enough, which will increase the residence time of ice particles in the cloud. Ice particles reach a quasi-steady state between growth by vapor deposition and fall speed at cloud base. The analytical model predicts that ice water content (wi) has a 2.5 power law relationship with ice number concentration ni. wi and ni from a LES cloud model with stochastic ice nucleation also confirm the 2.5 power law relationship. The prefactor of the power law is proportional to the ice nucleation rate, and therefore provides a quantitative link to observations of ice microphysical properties.

  5. Structural and dynamical properties of nanoconfined supercooled water

    E-Print Network [OSTI]

    Oriol Vilanova; Giancarlo Franzese

    2011-02-14

    Bulk water presents a large number of crystalline and amorphous ices. Hydrophobic nanoconfinement is known to affect the tendency of water to form ice and to reduce the melting temperature. However, a systematic study of the ice phases in nanoconfinement is hampered by the computational cost of simulations at very low temperatures. Here we develop a coarse-grained model for a water monolayer in hydrophobic nanoconfinement and study the formation of ice by Mote Carlo simulations. We find two ice phases: low-density-crystal ice at low pressure and high-density hexatic ice at high pressure, an intermediate phase between liquid and high-density-crystal ice.

  6. Spreading of oil spilled under ice

    SciTech Connect (OSTI)

    Yapa, P.D.; Chowdhury, T. )

    1990-12-01

    A new set of equations is presented to describe the process of oil spreading under ice in clam waters. These equations consider the gravity (buoyancy)-inertia phase, the gravity (buoyancy)-viscous phase, and the termination of spreading during the buoyancy-surface-tension phase. The derivation considers both the constant discharge mode and the constant volume mode. Therefore, a complete description of the spreading phenomena from the time of initial spill to the termination of spreading is presented. Laboratory experiments were conducted using both real ice covers in a cold room and artificial ice covers. The experiments included different ice-cover roughnesses from smooth to rough, oils of different viscosities, and a variety of discharge conditions. The experimental data show close agreement with the theory. These equations can be used during cleanup or environmental impact assessment to estimate the area of an oil slick with respect to time.

  7. Counting paths in digraphs

    SciTech Connect (OSTI)

    Sullivan, Blair D; Seymour, Dr. Paul Douglas

    2010-01-01

    Say a digraph is k-free if it has no directed cycles of length at most k, for k {element_of} Z{sup +}. Thomasse conjectured that the number of induced 3-vertex directed paths in a simple 2-free digraph on n vertices is at most (n-1)n(n+1)/15. We present an unpublished result of Bondy proving there are at most 2n{sup 3}/25 such paths, and prove that for the class of circular interval digraphs, an upper bound of n{sup 3}/16 holds. We also study the problem of bounding the number of (non-induced) 4-vertex paths in 3-free digraphs. We show an upper bound of 4n{sup 4}/75 using Bondy's result for Thomasse's conjecture.

  8. Integrated navigation for AUV operations under ice shelves

    E-Print Network [OSTI]

    Griffiths, Gwyn

    2000 Heat Wipes Out Giant Antarctic Ice Shelf The Independent, 31 January 2000 Catastrophic Melting VI Pine Island Bay #12;The (virtual) mission ... #12;The first mission- March 2003: Pine Island Bay NASA 30 km Sea Ice Pine Island Glacier Open Water 9 February 2003 #12;The Pine Island Bay Glacier

  9. Passive ice freezing-releasing heat pipe. [Patent application

    DOE Patents [OSTI]

    Gorski, A.J.; Schertz, W.W.

    1980-09-29

    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.

  10. UV Irradiation of Polycyclic Aromatic Hydrocarbons in Ices

    E-Print Network [OSTI]

    UV Irradiation of Polycyclic Aromatic Hydrocarbons in Ices: Production of Alcohols, Quinones. Clemett,3 Richard N. Zare3 Polycyclic aromatic hydrocarbons (PAHs) in water ice were exposed to ultra, and ethers, and reduced, producing partially hydrogenated aromatic hydrocarbons, molecules that account

  11. Ice formation on nitric acid coated dust particles: Laboratory and modeling studies

    SciTech Connect (OSTI)

    Kulkarni, Gourihar R.; Zhang, Kai; Zhao, Chun; Nandasiri, Manjula I.; Shutthanandan, V.; Liu, Xiaohong; Fast, Jerome D.; Berg, Larry K.

    2015-08-16

    Changes in the ice nucleation characteristics of atmospherically relevant mineral dust particles due to nitric acid coating are not well understood. Further, the atmospheric implications of dust coating on ice-cloud properties under different assumptions of primary ice nucleation mechanisms are unknown. We investigated ice nucleation ability of Arizona test dust, illite, K-feldspar and quartz as a function of temperature (-25 to -30°C) and relative humidity with respect to water (75 to 110%). Particles were size selected at 250 nm and transported (bare or coated) to the ice nucleation chamber to determine the fraction of particles nucleating ice at various temperature and water saturation conditions. All dust nucleated ice at water-subsaturated conditions, but the coated particles showed a reduction in their ice nucleation ability compared to bare particles. However, at water-supersaturated conditions, we observed that bare and coated particles had nearly similar ice nucleation characteristics. X-ray diffraction patterns indicated that structural properties of bare dust particles modified after acid treatment. We found that lattice parameters were slightly different, but crystallite sizes of the coated particles were reduced compared to bare particles. Next, single-column model results show that simulated ice crystal number concentrations mostly depends upon fraction of particles that are coated, primary ice nucleation mechanisms, and the competition between ice nucleation mechanisms to nucleate ice. In general, we observed that coating modify the ice-cloud properties and the picture of ice and mixed-phase cloud evolution is complex when different primary ice nucleation mechanisms are competing for fixed water vapor mass.

  12. THE EXTENT OF PLEISTOCENE ICE CAP, GLACIAL DEPOSITS AND GLACIOKARST IN THE ALADAGLAR

    E-Print Network [OSTI]

    Zreda, Marek

    holes, ice caves, glacial melt-water streams, stone circles and girlands represent glacialTHE EXTENT OF PLEISTOCENE ICE CAP, GLACIAL DEPOSITS AND GLACIOKARST IN THE ALADAGLAR MASSIF between 1100 m and 3756 m of altitudes. Many of the glacial landforms, such as moraines and ice

  13. A Computational Study of the Spreading of Oil Underneath a Sheet of Ice Mark Sussman

    E-Print Network [OSTI]

    Sussman, Mark

    A Computational Study of the Spreading of Oil Underneath a Sheet of Ice Mark Sussman Department) The spreading of oil underneath a sheet of ice is computed using an adaptive level set method for incompressible of a body of oil under ice in water. The computational models are used to make further observations

  14. A Computational Study of the Spreading of Oil Underneath a Sheet of Ice

    E-Print Network [OSTI]

    Ferguson, Thomas S.

    A Computational Study of the Spreading of Oil Underneath a Sheet of Ice Mark Sussman Department) Abstract The spreading of oil underneath a sheet of ice is computed using an adaptive level set method the final steady profile of a body of oil under ice in water. The computational models are used to make

  15. An investigation of ice shape prediction methodologies and comparison with experimental data 

    E-Print Network [OSTI]

    Britton, Randall Keith

    1989-01-01

    water content has allowed rime, mixed, and glaze ice shapes on the leading edge of an airfoil to be investigated. To my beloved parents, their 6rst grandson, and his mother ACKNOWLEDGEMENTS I would like to thank the members of my committee, Dr... water droplets. The free air temperature heavily inSuences what type and the extent which ice will accrete. Higher temperatures are usually associated with higher liquid water contents and thus lend themselves to the formation of glaze ice. Conversely...

  16. Global Simulations of Ice nucleation and Ice Supersaturation...

    Office of Scientific and Technical Information (OSTI)

    Article: Global Simulations of Ice nucleation and Ice Supersaturation with an Improved Cloud Scheme in the Community Atmosphere Model Citation Details In-Document Search Title:...

  17. Heterogeneous ice nucleation controlled by the coupling of surface crystallinity and surface hydrophilicity

    E-Print Network [OSTI]

    Bi, Yuanfei; Li, Tianshu

    2015-01-01

    The microscopic mechanisms controlling heterogeneous ice nucleation are complex and remain poorly understood. Although good ice nucleators are generally believed to match ice lattice and to bind water, counter examples are often identified. Here we show, by advanced molecular simulations, that the heterogeneous nucleation of ice on graphitic surface is controlled by the coupling of surface crystallinity and surface hydrophilicity. Molecular level analysis reveals that the crystalline graphitic lattice with an appropriate hydrophilicity may indeed template ice basal plane by forming a strained ice layer, thus significantly enhancing its ice nucleation efficiency. Remarkably, the templating effect is found to transit from within the first contact layer of water to the second as the hydrophilicity increases, yielding an oscillating distinction between the crystalline and amorphous graphitic surfaces in their ice nucleation efficiencies. Our study sheds new light on the long-standing question of what constitutes ...

  18. Autosub missions beneath Polar Ice: Preparation and Experience

    E-Print Network [OSTI]

    Griffiths, Gwyn

    events implemented (up from 1); ordered sequences of events to trigger next mission element added. J and shelf ice. 4 - 12 kHz chirp sub-bottom profiler to obtain the stratigraphy within sediments Water

  19. Hydrological and biogeochemical cycling along the Greenland ice sheet margin

    E-Print Network [OSTI]

    Bhatia, Maya Pilar, 1979-

    2012-01-01

    Global warming has led to a significant increase in Greenland ice sheet (GrIS) melt and runoff since 1990, resulting in escalated export of fresh water and associated sediment to the surrounding North Atlantic and Arctic ...

  20. Prediction of lake ice in the Netherlands

    E-Print Network [OSTI]

    Haak, Hein

    by HARMONIE ·Flake driven by ECMWF ensembles ·Conclusions and Outlook #12;Lake workshop sept 2012 Motivation Operational Observations ECMWF model #12;Lake workshop sept 2012 h D Air Water Ice ·Surface energy ·Radiative fluxes (Qs, Ql, absorbed solar radiation) ·Turbulent fluxes (sensible and latent heat fluxes

  1. A Comparison of TWP-ICE Observational Data with Cloud-Resolving Model Results

    SciTech Connect (OSTI)

    Fridlind, A. M.; Ackerman, Andrew; Chaboureau, Jean-Pierre; Fan, Jiwen; Grabowski, Wojciech W.; Hill, A.; Jones, T. R.; Khaiyer, M. M.; Liu, G.; Minnis, Patrick; Morrison, H.; Nguyen, L.; Park, S.; Petch, Jon C.; Pinty, Jean-Pierre; Schumacher, Courtney; Shipway, Ben; Varble, A. C.; Wu, Xiaoqing; Xie, Shaocheng; Zhang, Minghua

    2012-03-13

    Observations made during the TWP-ICE campaign are used to drive and evaluate thirteen cloud-resolving model simulations with periodic lateral boundary conditions. The simulations employ 2D and 3D dynamics, one- and two-moment microphysics, several variations on large-scale forcing, and the use of observationally derived aerosol properties to prognose droplet numbers. When domain means are averaged over a 6-day active monsoon period, all simulations reproduce observed surface precipitation rate but not its structural distribution. Simulated fractional areas covered by convective and stratiform rain are uncorrelated with one another, and are both variably overpredicted by up to a factor of {approx}2. Stratiform area fractions are strongly anticorrelated with outgoing longwave radiation (OLR) but are negligibly correlated with ice water path (IWP), indicating that ice spatial distribution controls OLR more than mean IWP. Overpredictions of OLR tend to be accompanied by underpredictions of reflected shortwave radiation (RSR). When there are two simulations differing only in microphysics scheme or large-scale forcing, the one with smaller stratiform area tends to exhibit greater OLR and lesser RSR by similar amounts. After {approx}10 days, simulations reach a suppressed monsoon period with a wide range of mean precipitable water vapor, attributable in part to varying overprediction of cloud-modulated radiative flux divergence compared with observationally derived values. Differences across the simulation ensemble arise from multiple sources, including dynamics, microphysics, and radiation treatments. Close agreement of spatial and temporal averages with observations may not be expected, but the wide spreads of predicted stratiform fraction and anticorrelated OLR indicate a need for more rigorous observation-based evaluation of the underlying micro- and macrophysical properties of convective and stratiform structures.

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

    E-Print Network [OSTI]

    by impeding or stopping navigation, interfering with power plants and cooling water intakes, and damaging was virtually free of any significant ice cover in 1998 and, with the exception of portions of January, the same

  3. Probing the Interiors of the Ice Giants: Shock Compression of Water to 700 GPa and 3.8 g/cm³

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

    Knudson, M. D.; Desjarlais, M. P.; Lemke, R. W.; Mattsson, T. R.; French, M.; Nettelmann, N.; Redmer, R.

    2012-02-27

    Recently, there has been a tremendous increase in the number of identified extrasolar planetary systems. Our understanding of their formation is tied to exoplanet internal structure models, which rely upon equations of state of light elements and compounds such as water. Here, we present shock compression data for water with unprecedented accuracy that show that water equations of state commonly used in planetary modeling significantly overestimate the compressibility at conditions relevant to planetary interiors. Furthermore, we show that its behavior at these conditions, including reflectivity and isentropic response, is well-described by a recent first-principles based equation of state. These findingsmore »advocate that this water model be used as the standard for modeling Neptune, Uranus, and “hot Neptune” exoplanets and should improve our understanding of these types of planets.« less

  4. Probing the Interiors of the Ice Giants: Shock Compression of Water to 700 GPa and 3.8 g/cm³

    SciTech Connect (OSTI)

    Knudson, M. D.; Desjarlais, M. P.; Lemke, R. W.; Mattsson, T. R.; French, M.; Nettelmann, N.; Redmer, R.

    2012-02-27

    Recently, there has been a tremendous increase in the number of identified extrasolar planetary systems. Our understanding of their formation is tied to exoplanet internal structure models, which rely upon equations of state of light elements and compounds such as water. Here, we present shock compression data for water with unprecedented accuracy that show that water equations of state commonly used in planetary modeling significantly overestimate the compressibility at conditions relevant to planetary interiors. Furthermore, we show that its behavior at these conditions, including reflectivity and isentropic response, is well-described by a recent first-principles based equation of state. These findings advocate that this water model be used as the standard for modeling Neptune, Uranus, and “hot Neptune” exoplanets and should improve our understanding of these types of planets.

  5. Path Integral for Quantum Operations

    E-Print Network [OSTI]

    Vasily E. Tarasov

    2007-06-14

    In this paper we consider a phase space path integral for general time-dependent quantum operations, not necessarily unitary. We obtain the path integral for a completely positive quantum operation satisfied Lindblad equation (quantum Markovian master equation). We consider the path integral for quantum operation with a simple infinitesimal generator.

  6. Energy conservation in ice skating rinks

    SciTech Connect (OSTI)

    Dietrich, B.K.; McAvoy, T.J.

    1980-01-01

    An economic and energy analysis of ice rinks was made to examine the areas in which energy could be profitably conserved. The areas where new equipment could make a major reduction in energy use are: the use of waste heat for space heating, the installation of a low emissivity false ceiling to reduce radiant heat, the use of a load cycling controller to reduce refrigeration costs, and the installation of more efficient lighting systems. Changes in rink operating procedure that could cut energy use are: higher refrigerant temperatures, thinner ice, the use of colder resurfacing water, turning the compressors and pumps off at night, and reducing ventilation.

  7. Arctic Sea ice model sensitivities.

    SciTech Connect (OSTI)

    Peterson, Kara J.; Bochev, Pavel Blagoveston; Paskaleva, Biliana Stefanova

    2010-12-01

    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 state to internal model parameters. A new sea ice model that holds some promise for improving 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 this MPM sea ice code and compare it with the Los Alamos National Laboratory CICE 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.

  8. Flight Path 12

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HABFES OctoberEvanServices »First ObservationFast This flight path is

  9. Flight Path 12

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HABFES OctoberEvanServices »First ObservationFast This flight path

  10. Flight Path 5

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory ofDid you not find whatGasEnergyfeature photoTheory05 Target 1 Flight Path 05

  11. Flight Path Target 2

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory ofDid you not find whatGasEnergyfeature photoTheory05 Target 1 Flight Path90L2

  12. Field demonstration of the ICE 250{trademark} Cleaning System

    SciTech Connect (OSTI)

    Johnston, J.L.; Jackson, L.M.

    1999-10-05

    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.

  13. Open Quantum to classical phases transition in the stochastic hydrodynamic analogy: the explanation of the Lindemann relation and the analogies between the maximum of density at He lambda point and that one at water-ice phase transition

    E-Print Network [OSTI]

    Piero Chiarelli

    2013-05-20

    In the present paper the gas, liquid and solid phases made of structureless particles, are visited to the light of the quantum stochastic hydrodynamic analogy (SQHA). The SQHA shows that the open quantum mechanical behavior is maintained on a distance shorter than the theory-defined quantum correlation length (lc). When, the physical length of the problem is larger than lc, the model shows that the quantum (potential) interactions may have a finite range of interaction maintaining the non-local behavior on a finite distance quantum non-locality length lq. The present work shows that when the mean molecular distance is larger than the quantum non-locality length we have a classical phases (gas and van der Waals liquids) while when the mean molecular distance becomes smaller than lq or than lc we have phases such as the solid crystal or the superfluid one, respectively, that show quantum characteristics. The model agrees with Lindemann empirical law (and explains it), for the mean square deviation of atom from the equilibrium position at melting point of crystal, and shows a connection between the maximum density at the He lambda point and that one near the water-ice solidification point.

  14. Ice Bear® Storage Module | Department of Energy

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

    Ice Bear Storage Module Ice Bear Storage Module Thermal Energy Storage for Light Commercial Refrigerant-Based Air Conditioning Units The Ice Bear storage technology was...

  15. Storage of Dressed Chinook Salmon, Oncorhynchus tshawytscha, in Refrigerated Freshwater, Diluted Seawater, Seawater, and in Ice

    E-Print Network [OSTI]

    Storage of Dressed Chinook Salmon, Oncorhynchus tshawytscha, in Refrigerated Freshwater, Diluted during storage. Iced storage offers several advantages over the water chilling systems, including little by 25 per- cent within four days after transfer to ice, and weight gained during water storage was lost

  16. An icing physics study by using lifetime-based molecular tagging thermometry technique

    E-Print Network [OSTI]

    Hu, Hui

    of water droplets Solidification process Micro scale heat transfer Wind turbine icing a b s t r a c to produce 20% of its total power from wind by 2030. According to American Wind Energy Association (AWEA within small icing water droplets in order to elucidate underlying physics to improve our under- standing

  17. THE STRUCTURE OF SURFACE H{sub 2}O LAYERS OF ICE-COVERED PLANETS WITH HIGH-PRESSURE ICE

    SciTech Connect (OSTI)

    Ueta, S.; Sasaki, T. E-mail: takanori@geo.titech.ac.jp

    2013-10-01

    Many extrasolar (bound) terrestrial planets and free-floating (unbound) planets have been discovered. While the existence of bound and unbound terrestrial planets with liquid water is an important question, of particular importance is the question of these planets' habitability. Even for a globally ice-covered planet, geothermal heat from the planetary interior may melt the interior ice, creating an internal ocean covered by an ice shell. In this paper, we discuss the conditions that terrestrial planets must satisfy for such an internal ocean to exist on the timescale of planetary evolution. The question is addressed in terms of planetary mass, distance from a central star, water abundance, and abundance of radiogenic heat sources. In addition, we investigate the structure of the surface H{sub 2}O layers of ice-covered planets by considering the effects of ice under high pressure (high-pressure ice). As a fiducial case, a 1 M{sub ?} planet at 1 AU from its central star and with 0.6-25 times the H{sub 2}O mass of the Earth could have an internal ocean. We find that high-pressure ice layers may appear between the internal ocean and the rock portion on a planet with an H{sub 2}O mass over 25 times that of the Earth. The planetary mass and abundance of surface water strongly restrict the conditions under which an extrasolar terrestrial planet may have an internal ocean with no high-pressure ice under the ocean. Such high-pressure ice layers underlying the internal ocean are likely to affect the habitability of the planet.

  18. PET 424304 2015 Exercises 1+2 of 4 16 Jan + 30 Jan 2015 1. 1kg ice at 263 K 1 kg water at 293 K. Heat Q at T = T is supplied by the surroundings.

    E-Print Network [OSTI]

    Zevenhoven, Ron

    ,340] = 293·[(-21,99 ­ 5,339) + (149,13 ­ 65,13)·0,34)] = 361 (W/s)/mol ice The same result is found via lost,340·5141 = 1750 W/mol ice xout/H2O = 491,8 + 0,340·2612 = 1381 W/mol ice EX = 1381 / 1750 = 0/mol for ex4 PET 424304 2015 Exercises 1+2 of 4 16 Jan + 30 Jan 2015 3. Wmin = Ex°separation = 0,79·Ex°N2

  19. Electronic structure effects in liquid water studied by photoelectron spectroscopy and density functional theory

    E-Print Network [OSTI]

    Nordlund, Dennis

    2008-01-01

    Structure Effects in Liquid Water studied by Photoelectronphotoelectron emission spectra of liquid water in comparisonwith gas-phase water, ice close to the melting point, low

  20. 221A Lecture Notes Path Integral

    E-Print Network [OSTI]

    Murayama, Hitoshi

    221A Lecture Notes Path Integral 1 Feynman's Path Integral Formulation Feynman's formulation to reach a position xf at time tf , you integrate over all possible paths connecting the points with a weight factor given by the classical action for each path. Hence the name path integral. This is it. Note

  1. Impact of Solvent on Photocatalytic Mechanisms: Reactions of Photodesorption Products with Ice Overlayers on the TiO2(110) Surface

    SciTech Connect (OSTI)

    Shen, Mingmin; Henderson, Michael A.

    2011-04-07

    The effects of water and methanol ice overlayers on the photodecomposition of acetone on rutile TiO2(110) were evaluated in ultrahigh vacuum (UHV) using photon stimulated desorption (PSD) and temperature programmed desorption (TPD). In the absence of ice overlayers, acetone photodecomposed on TiO2(110) at 95 K by ejection of a methyl radical into the gas phase and formation of acetate on the surface. With ice overlayers, the methyl radicals are trapped at the interface between TiO2(110) and the ice. When water ice was present, these trapped methyl radicals reacted either with each other to form ethane or with other molecules in the ice (e.g., water or displaced acetone) to form methane (CH4), ethane (CH3CH3) and other products (e.g., methanol), with all of these products trapped in the ice. The new products were free to revisit the surface or depart during desorption of the ice. When methanol ice was present, methane formation came about only from reaction of trapped methyl radicals with the methanol ice. Methane and ethane slowly leaked through methanol ice overlayers into vacuum at 95 K, but not through water ice overlayers. Different degrees of site competition between water and acetone, and between methanol and acetone led to different hydrogen abstraction pathways in the two ices. These results provide new insights into product formation routes and solution-phase radical formation mechanisms that are important in heterogeneous photocatalysis.

  2. Sensor development and calibration for acoustic neutrino detection in ice

    E-Print Network [OSTI]

    Karg, Timo; Laihem, Karim; Semburg, Benjamin; Tosi, Delia

    2009-01-01

    A promising approach to measure the expected low flux of cosmic neutrinos at the highest energies (E > 1 EeV) is acoustic detection. There are different in-situ test installations worldwide in water and ice to measure the acoustic properties of the medium with regard to the feasibility of acoustic neutrino detection. The parameters of interest include attenuation length, sound speed profile, background noise level and transient backgrounds. The South Pole Acoustic Test Setup (SPATS) has been deployed in the upper 500 m of drill holes for the IceCube neutrino observatory at the geographic South Pole. In-situ calibration of sensors under the combined influence of low temperature, high ambient pressure, and ice-sensor acoustic coupling is difficult. We discuss laboratory calibrations in water and ice. Two new laboratory facilities, the Aachen Acoustic Laboratory (AAL) and the Wuppertal Water Tank Test Facility, have been set up. They offer large volumes of bubble free ice (3 m^3) and water (11 m^3) for the devel...

  3. Hydrogen Education Curriculum Path at Michigan Technological...

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

    Curriculum Path at Michigan Technological University Hydrogen Education Curriculum Path at Michigan Technological University 2009 DOE Hydrogen Program and Vehicle Technologies...

  4. COMPUTER SCIENCE: MISCONCEPTIONS, CAREER PATHS

    E-Print Network [OSTI]

    Hristidis, Vagelis

    COMPUTER SCIENCE: MISCONCEPTIONS, CAREER PATHS AND RESEARCH CHALLENGES School of Computing Undergraduate Student) #12;Computer Science Misconceptions Intro to Computer Science - Florida International University 2 Some preconceived ideas & stereotypes about Computer Science (CS) are quite common

  5. Collaborative Authoring of Walden's Paths 

    E-Print Network [OSTI]

    Li, Yuanling

    2012-10-19

    The World Wide Web contains rich collections of digital materials that can be used in education and learning settings. The collaborative authoring prototype of Walden's Paths targets two groups of users: educators and ...

  6. Water Emissions from Fuel Cell Vehicles

    Broader source: Energy.gov [DOE]

    Hydrogen fuel cell vehicles (FCVs) emit approximately the same amount of water per mile as vehicles using gasoline-powered internal combustion engines (ICEs).

  7. Thermal desorption of CH4 retained in CO2 ice

    E-Print Network [OSTI]

    Luna, R; Domingo, M; Satorre, M A

    2008-01-01

    CO2 ices are known to exist in different astrophysical environments. In spite of this, its physical properties (structure, density, refractive index) have not been as widely studied as those of water ice. It would be of great value to study the adsorption properties of this ice in conditions related to astrophysical environments. In this paper, we explore the possibility that CO2 traps relevant molecules in astrophysical environments at temperatures higher than expected from their characteristic sublimation point. To fulfil this aim we have carried out desorption experiments under High Vacuum conditions based on a Quartz Crystal Microbalance and additionally monitored with a Quadrupole Mass Spectrometer. From our results, the presence of CH4 in the solid phase above the sublimation temperature in some astrophysical scenarios could be explained by the presence of several retaining mechanisms related to the structure of CO2 ice.

  8. Thermal desorption of CH4 retained in CO2 ice

    E-Print Network [OSTI]

    R. Luna; C. Millan; M. Domingo; M. A. Satorre

    2008-01-21

    CO2 ices are known to exist in different astrophysical environments. In spite of this, its physical properties (structure, density, refractive index) have not been as widely studied as those of water ice. It would be of great value to study the adsorption properties of this ice in conditions related to astrophysical environments. In this paper, we explore the possibility that CO2 traps relevant molecules in astrophysical environments at temperatures higher than expected from their characteristic sublimation point. To fulfil this aim we have carried out desorption experiments under High Vacuum conditions based on a Quartz Crystal Microbalance and additionally monitored with a Quadrupole Mass Spectrometer. From our results, the presence of CH4 in the solid phase above the sublimation temperature in some astrophysical scenarios could be explained by the presence of several retaining mechanisms related to the structure of CO2 ice.

  9. Water and Solute Flow in a Highly-Structured Soil 

    E-Print Network [OSTI]

    Hallmark, C. Tom; Wilding, Larry P.; McInnes, Kevin J.; Heuvelman, Willem J.

    1993-01-01

    to groundwater may be related to the degree of flow path channelization (convergence or divergence of water flow paths). This project was designed to test the feasibility of measuring the degree of channelization as water percolates through structured soils. A...

  10. No Confinement Needed: Observation of a Metastable Hydrophobic Wetting Two-Layer Ice on Graphene

    SciTech Connect (OSTI)

    Kimmel, Gregory A.; Matthiesen, Jesper; Baer, Marcel; Mundy, Christopher J.; Petrik, Nikolay G.; Smith, R. Scott; Dohnalek, Zdenek; Kay, Bruce D.

    2009-09-09

    The structure of water at interfaces is crucial for processes ranging from photocatalysis to protein folding. Here, we investigate the structure and lattice dynamics of two-layer crystalline ice films grown on a hydrophobic substrate - graphene on Pt(111) - with low energy electron diffraction, reflection-absorption infrared spectroscopy, rare-gas adsorption/desorption, and ab-initio molecular dynamics. Unlike hexagonal ice, which consists of stacks of puckered hexagonal "bilayers", this new ice polymorph consists of two flat hexagonal sheets of water molecules in which the hexagons in each sheet are stacked directly on top of each other. Such two-layer ices have been predicted for water confined between hydrophobic slits, but not previously observed. Our results show that the two-layer ice forms even at zero pressure at a single hydrophobic interface by maximizing the number of hydrogen bonds at the expense of adopting a non-tetrahedral geometry with weakened bonds.

  11. Thermodynamic analysis and experimental study of the effect of atmospheric pressure on the ice point

    SciTech Connect (OSTI)

    Harvey, A. H. [Thermophysical Properties Division National Institute of Standards and Technology, Boulder, Colorado (United States)] [Thermophysical Properties Division National Institute of Standards and Technology, Boulder, Colorado (United States); McLinden, M. O. [Thermophysical Properties Division, National Institute of Standards and Technology, Boulder, Colorado (United States)] [Thermophysical Properties Division, National Institute of Standards and Technology, Boulder, Colorado (United States); Tew, W. L. [Sensor Science Division National Institute of Standards and Technology, Gaithersburg, Maryland (United States)] [Sensor Science Division National Institute of Standards and Technology, Gaithersburg, Maryland (United States)

    2013-09-11

    We present a detailed thermodynamic analysis of the temperature of the ice point as a function of atmospheric pressure. This analysis makes use of accurate international standards for the properties of water and ice, and of available high-accuracy data for the Henry's constants of atmospheric gases in liquid water. The result is an ice point of 273.150 019(5) K at standard atmospheric pressure, with higher ice-point temperatures (varying nearly linearly with pressure) at lower pressures. The effect of varying ambient CO{sub 2} concentration is analyzed and found to be significant in comparison to other uncertainties in the model. The thermodynamic analysis is compared with experimental measurements of the temperature difference between the ice point and the triple point of water performed at elevations ranging from 145 m to 4302 m, with atmospheric pressures from 101 kPa to 60 kPa.

  12. Atom addition reactions in interstellar ice analogues

    E-Print Network [OSTI]

    Linnartz, Harold; Fedoseev, Gleb

    2015-01-01

    This review paper summarizes the state-of-the-art in laboratory based interstellar ice chemistry. The focus is on atom addition reactions, illustrating how water, carbon dioxide and methanol can form in the solid state at astronomically relevant temperatures, and also the formation of more complex species such as hydroxylamine, an important prebiotic molecule, and glycolaldehyde, the smallest sugar, is discussed. These reactions are particularly relevant during the dark ages of star and planet formation, i.e., when the role of UV light is restricted. A quantitative characterization of such processes is only possible through dedicated laboratory studies, i.e., under full control of a large set of parameters such as temperature, atom-flux, and ice morphology. The resulting numbers, physical and chemical constants, e.g., barrier heights, reaction rates and branching ratios, provide information on the molecular processes at work and are needed as input for astrochemical models, in order to bridge the timescales t...

  13. Ice Storm Supercomputer

    ScienceCinema (OSTI)

    None

    2013-05-28

    "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.

  14. Cryoconite Hole Ecosystems in Antarctic Glacier Ice Brent C. Christner, Montana State University, Department of Land

    E-Print Network [OSTI]

    Christner, Brent C.

    released from the melted glacial ice and attached to deposited airborne particulates provide the biological glacial melting. Cryoconite hole ecosystems exist and thrive under the harsh conditions associated, are warmed by the sun, and melt into the ice producing a cylindrical basin of liquid water. Organisms

  15. ICE SHEETS, GLOBAL WARMING, AND ARTICLE 2 OF THE UNFCCC An Editorial Essay

    E-Print Network [OSTI]

    Oppenheimer, Michael

    in area and perhaps in mass since the Last Glacial Maximum (Bindschadler, 1998; Huybrechts, 2002) provides of ice loss by altering the mass balance between precipitation rates on the one hand, and melting and ice site has been tied to the availability of surface melt water, which percolates to and lubricates

  16. A network model for fluid transport through sea ice A. JABINI,1,2

    E-Print Network [OSTI]

    Golden, Kenneth M.

    ice also plays an important role in heat transfer between the ocean and atmosphere (Lytle and Ackley, 1996; Trodahl and others, 2000), and in the input of dense brine and fresh water into the upper ocean oriented brine channels penetrating much of the ice thickness (Cole and Shapiro, 1998). Correspondingly

  17. Constraints on the lake volume required for hydro-fracture through ice sheets

    E-Print Network [OSTI]

    Skemer, Philip

    Constraints on the lake volume required for hydro-fracture through ice sheets M. J. Krawczynski,1 M April 2009; published 16 May 2009. [1] Water-filled cracks are an effective mechanism to drive hydro to rapidly drive hydro-fractures through 1­1.5 km of subfreezing ice. This represents $98% of the meltwater

  18. Origin and Phylogeny of Microbes Living in Permanent Antarctic Lake Ice

    E-Print Network [OSTI]

    Priscu, John C.

    of bacteria and cyanobacteria colonizing sediment particles in the per- manent ice cover of an Antarctic lake in the surrounding region and opportunistically colonize the unusual habitat provided by the sediments suspended worlds [16]. This analogy is particularly relevant to Mars and the Jovian moon Europa, where water ice

  19. Climate Impacts of Ice Nucleation

    SciTech Connect (OSTI)

    Gettelman, A.; Liu, Xiaohong; Barahona, Donifan; Lohmann, U.; Chen, Chih-Chieh

    2012-10-27

    Several different ice nucleation parameterizations in two different General Circulation Models are used to understand the effects of ice nucleation on the mean climate state, and the climate effect of aerosol perturbations to ice clouds. The simulations have different ice microphysical states that are consistent with the spread of observations. These different states occur from different parameterizations of the ice cloud nucleation processes, and feature different balances of homogeneous and heterogeneous nucleation. At reasonable efficiencies, consistent with laboratory measurements and constrained by the global radiative balance, black carbon has a small (-0.06 Wm?2) and not statistically significant climate effect. Indirect effects of anthropogenic aerosols on cirrus clouds occur mostly due to increases in homogeneous nucleation fraction as a consequence of anthropogenic sulfur emissions. The resulting ice indirect effects do not seem strongly dependent on the ice micro-physical balance, but are slightly larger for those states with less homogeneous nucleation in the base state. The total ice AIE is estimated at 0.26±0.09 Wm?2 (1? uncertainty). This represents an offset of 20-30% of the simulated total Aerosol Indirect Effect for ice and liquid clouds.

  20. arXiv:1408.2487v2[physics.ao-ph]22Aug2014 Ising model for melt ponds on Arctic sea ice

    E-Print Network [OSTI]

    Golden, Kenneth M.

    arXiv:1408.2487v2[physics.ao-ph]22Aug2014 Ising model for melt ponds on Arctic sea ice Yi-Ping Ma,1 of water on the ice surface. Recent observations show an onset of pond complexity at a critical area modeling, we introduce a two dimensional Ising model for pond evolution which incorporates ice

  1. Shortest Path Algorithm What is the Shortest Path Problem?

    E-Print Network [OSTI]

    Razak, Saquib

    .getNumberOfVertices(); Entry table[] = new Entry[n]; for(int v = 0; v new Entry(); table;What is the shortest path problem? · In an edge-weighted graph, the weight of an edge measures the cost represent: distance, cost or time. · Such a graph could be used to answer any of the following: ­ What

  2. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Comments? WeDatastreamstps DocumentationAtlanticENAField ParticipantsField Campaign StatisticsPastIce Cores

  3. Drilling deep in South Pole Ice

    E-Print Network [OSTI]

    Karg, Timo

    2014-01-01

    To detect the tiny flux of ultra-high energy neutrinos from active galactic nuclei or from interactions of highest energy cosmic rays with the microwave background photons needs target masses of the order of several hundred cubic kilometers. Clear Antarctic ice has been discussed as a favorable material for hybrid detection of optical, radio and acoustic signals from ultra-high energy neutrino interactions. To apply these technologies at the adequate scale hundreds of holes have to be drilled in the ice down to depths of about 2500 m to deploy the corresponding sensors. To do this on a reasonable time scale is impossible with presently available tools. Remote drilling and deployment schemes have to be developed to make such a detector design reality. After a short discussion of the status of modern hot water drilling we present here a design of an autonomous melting probe, tested 50 years ago to reach a depth of about 1000 m in Greenland ice. A scenario how to build such a probe today with modern technologies...

  4. Resonant vibrational energy transfer in ice Ih

    SciTech Connect (OSTI)

    Shi, L.; Li, F.; Skinner, J. L.

    2014-06-28

    Fascinating anisotropy decay experiments have recently been performed on H{sub 2}O ice Ih by Timmer and Bakker [R. L. A. Timmer, and H. J. Bakker, J. Phys. Chem. A 114, 4148 (2010)]. The very fast decay (on the order of 100 fs) is indicative of resonant energy transfer between OH stretches on different molecules. Isotope dilution experiments with deuterium show a dramatic dependence on the hydrogen mole fraction, which confirms the energy transfer picture. Timmer and Bakker have interpreted the experiments with a Förster incoherent hopping model, finding that energy transfer within the first solvation shell dominates the relaxation process. We have developed a microscopic theory of vibrational spectroscopy of water and ice, and herein we use this theory to calculate the anisotropy decay in ice as a function of hydrogen mole fraction. We obtain very good agreement with experiment. Interpretation of our results shows that four nearest-neighbor acceptors dominate the energy transfer, and that while the incoherent hopping picture is qualitatively correct, vibrational energy transport is partially coherent on the relevant timescale.

  5. ICE CHEMISTRY IN EMBEDDED YOUNG STELLAR OBJECTS IN THE LARGE MAGELLANIC CLOUD

    SciTech Connect (OSTI)

    Oliveira, J. M.; Van Loon, J. Th. [School of Physical and Geographical Sciences, Lennard-Jones Laboratories, Keele University, Staffordshire ST5 5BG (United Kingdom); Chen, C.-H. R.; Indebetouw, R. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904 (United States); Tielens, A. G. G. M. [Leiden Observatory, P.O. Box 9513, NL-2300 RA Leiden (Netherlands); Sloan, G. C. [Department of Astronomy, Cornell University, Ithaca, NY 14853 (United States); Woods, P. M.; Kemper, F. [Jodrell Bank Centre for Astrophysics, Alan Turing Building, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Gordon, K. D.; Boyer, M. L.; Shiao, B.; Meixner, M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Madden, S. [Service d'Astrophysique, Commissariat a L'Energie Atomique de Saclay, 91191 Gif-sur-Yvette (France); Speck, A. K. [Physics and Astronomy, University of Missouri, Columbia, MO 65211 (United States); Marengo, M. [Department of Physics and Astronomy, Iowa State University, Ames, IA 50010 (United States)

    2009-12-20

    We present spectroscopic observations of a sample of 15 embedded young stellar objects (YSOs) in the Large Magellanic Cloud (LMC). These observations were obtained with the Spitzer Infrared Spectrograph (IRS) as part of the SAGE-Spec Legacy program. We analyze the two prominent ice bands in the IRS spectral range: the bending mode of CO{sub 2} ice at 15.2 mum and the ice band between 5 and 7 mum that includes contributions from the bending mode of water ice at 6 mum among other ice species. The 5-7 mum band is difficult to identify in our LMC sample due to the conspicuous presence of polycyclic aromatic hydrocarbon emission superimposed onto the ice spectra. We identify water ice in the spectra of two sources; the spectrum of one of those sources also exhibits the 6.8 mum ice feature attributed in the literature to ammonium and methanol. We model the CO{sub 2} band in detail, using the combination of laboratory ice profiles available in the literature. We find that a significant fraction (approx>50%) of CO{sub 2} ice is locked in a water-rich component, consistent with what is observed for Galactic sources. The majority of the sources in the LMC also require a pure-CO{sub 2} contribution to the ice profile, evidence of thermal processing. There is a suggestion that CO{sub 2} production might be enhanced in the LMC, but the size of the available sample precludes firmer conclusions. We place our results in the context of the star formation environment in the LMC.

  6. State estimation of the Labrador Sea with a coupled sea ice-ocean adjoint model

    E-Print Network [OSTI]

    Fenty, Ian Gouverneur

    2010-01-01

    Sea ice (SI) and ocean variability in marginal polar and subpolar seas are closely coupled. SI variability in the Labrador Sea is of climatic interest because of its relationship to deep convection/mode water formation, ...

  7. Fuel movement along grain boundaries in ice Steven M. Jepsen a,, Edward E. Adams a,1

    E-Print Network [OSTI]

    Priscu, John C.

    of hydrocarbon-based drilling fluids used to maintain lithostatic pressure in deep ice coring projects to the infiltration pro- cesses of a hydrocarbon fluid. Water veins are believed to be exceptionally large

  8. 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...

  9. Light propagation in the South Pole ice

    SciTech Connect (OSTI)

    Williams, Dawn; Collaboration: IceCube Collaboration

    2014-11-18

    The IceCube Neutrino Observatory is located in the ice near the geographic South Pole. Particle showers from neutrino interactions in the ice produce light which is detected by IceCube modules, and the amount and pattern of deposited light are used to reconstruct the properties of the incident neutrino. Since light is scattered and absorbed by ice between the neutrino interaction vertex and the sensor, IceCube event reconstruction depends on understanding the propagation of light through the ice. This paper presents the current status of modeling light propagation in South Pole ice, including the recent observation of an azimuthal anisotropy in the scattering.

  10. IceCube Project Monthly Report -April 2010 Accomplishments

    E-Print Network [OSTI]

    Saffman, Mark

    Water Drill equipment (http://www.icecube.wisc.edu/disposition/index.php) and the site was circulated to solicit interest in the equipment following the end of IceCube construction. · The training at shorter distances. #12; 2 Cost and Schedule Performance ­ The project is 94.7% complete

  11. GREAT LAKES ICE COVER RaymondA. Asset'

    E-Print Network [OSTI]

    to the early fifteenth centllry. in central Japan. southern Germany,and Switzerland." I National Oceanographic hydropower production and cooling water intakes, and damaging shore structures. Ice cover also impacts, and spring energy exchanges between the lake and the planetary boundary layer. Although observations of shore

  12. 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

  13. Autonomous Ground Vehicle Path Planning for Autocross Tracks: Optimal vs an Efficient Bézier Curve Path

    E-Print Network [OSTI]

    Ash, John Patrick

    2015-01-01

    to Computationally Efficient Method . . . . . Minimizing theTracks: Optimal vs an Efficient B´ ezier Curve Path MASTERproposes a computationally efficient path planning algorithm

  14. Development of an ultrasonic pulse-echo (UPE) technique for aircraft icing studies

    SciTech Connect (OSTI)

    Liu, Yang; Hu, Hui [Department of Aerospace Engineering, Iowa State University, 2271 Howe Hall, Room 1200, Ames, IA 50011 (United States); Chen, Wen-Li [Department of Aerospace Engineering, Iowa State University, 2271 Howe Hall, Room 1200, Ames, IA 50011 (United States); School of Civil Engineering, Harbin Institute of Technology, Harbin, Heilongjiang 150090 (China); Bond, Leonard J. [Department of Aerospace Engineering, Iowa State University, 2271 Howe Hall, Room 1200, Ames, IA 50011 (United States); Center for Nondestructive Evaluation, Iowa State University, 1915 Scholl Road, 151 ASC II, Ames, IA 50011 (United States)

    2014-02-18

    Aircraft operating in some cold weather conditions face the risk of icing. Icing poses a threat to flight safety and its management is expensive. Removing light frost on a clear day from a medium-size business jet can cost $300, heavy wet snow removal can cost $3,000 and removal of accumulated frozen/freezing rain can cost close to $10,000. Understanding conditions that lead to severe icing events is important and challenging. When an aircraft or rotorcraft flies in a cold climate, some of the super cooled droplets impinging on exposed aircraft surfaces may flow along the surface prior to freezing and give various forms and shapes of ice. The runback behavior of a water film on an aircraft affects the morphology of ice accretion and the rate of formation. In this study, we report the recent progress to develop an Ultrasonic Pulse-Echo (UPE) technique to provide real-time thickness distribution measurements of surface water flows driven by boundary layer airflows for aircraft icing studies. A series of initial experimental investigations are conducted in an ice wind tunnel employing an array of ultrasonic transducers placed underneath the surface of a flat plate. The water runback behavior on the plate is evaluated by measuring the thickness profile variation of the water film along the surface by using the UPE technique under various wind speed and flow rate conditions.

  15. PathScale Compliers at NERSC

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

    1-800-66-NERSC, option 3 or 510-486-8611 Home For Users Software Compilers PathScale PathScale Compilers (Fortran, C, C++) Availability The Pathscale...

  16. Experimental investigation of ice slurry flow pressure drop in horizontal tubes

    SciTech Connect (OSTI)

    Grozdek, Marino; Khodabandeh, Rahmatollah; Lundqvist, Per [Royal Institute of Technology, Department of Energy Technology, Division of Applied Thermodynamics and Refrigeration, Brinellvaegen 68, 10044 Stockholm (Sweden)

    2009-01-15

    Pressure drop behaviour of ice slurry based on ethanol-water mixture in circular horizontal tubes has been experimentally investigated. The secondary fluid was prepared by mixing ethyl alcohol and water to obtain initial alcohol concentration of 10.3% (initial freezing temperature -4.4 C). The pressure drop tests were conducted to cover laminar and slightly turbulent flow with ice mass fraction varying from 0% to 30% depending on test conditions. Results from flow tests reveal much higher pressure drop for higher ice concentrations and higher velocities in comparison to the single phase flow. However for ice concentrations of 15% and higher, certain velocity exists at which ice slurry pressure drop is same or even lower than for single phase flow. It seems that higher ice concentration delay flow pattern transition moment (from laminar to turbulent) toward higher velocities. In addition experimental results for pressure drop were compared to the analytical results, based on Poiseulle and Buckingham-Reiner models for laminar flow, Blasius, Darby and Melson, Dodge and Metzner, Steffe and Tomita for turbulent region and general correlation of Kitanovski which is valid for both flow regimes. For laminar flow and low buoyancy numbers Buckingham-Reiner method gives good agreement with experimental results while for turbulent flow best fit is provided with Dodge-Metzner and Tomita methods. Furthermore, for transport purposes it has been shown that ice mass fraction of 20% offers best ratio of ice slurry transport capability and required pumping power. (author)

  17. Neutrino Mean Free Path in Neutron Star

    E-Print Network [OSTI]

    P. T. P. Hutauruk

    2010-07-22

    Have been calculated the differential cross section and mean free path of neutrino of neutrino interaction in dense matter.

  18. Improved Geothermometry Through Multivariate Reaction Path Modeling...

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

    Improved Geothermometry Through Multivariate Reaction Path Modeling and Evaluation of Geomicrobiological Influences on Geochemical Temperature Indicators Improved Geothermometry...

  19. Winter Driving Tips Driving in Ice & Snow

    E-Print Network [OSTI]

    Capogna, Luca

    Winter Driving Tips Driving in Ice & Snow: When you must drive, clear the ice and snow from your in ice and snow, other drivers will be traveling cautiously. Don't disrupt the flow of traffic by driving handle better in ice and snow, but they do not have flawless traction, and skids can occur unexpectedly

  20. Path to High Efficiency Gasoline Engine | Department of Energy

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

    Path to High Efficiency Gasoline Engine Path to High Efficiency Gasoline Engine Path to High Efficiency Gasoline Engine deer10johansson.pdf More Documents & Publications Partially...

  1. WATER-TRAPPED WORLDS

    SciTech Connect (OSTI)

    Menou, Kristen [Department of Astronomy, Columbia University, 550 West 120th Street, New York, NY 10027 (United States)

    2013-09-01

    Although tidally locked habitable planets orbiting nearby M-dwarf stars are among the best astronomical targets to search for extrasolar life, they may also be deficient in volatiles and water. Climate models for this class of planets show atmospheric transport of water from the dayside to the nightside, where it is precipitated as snow and trapped as ice. Since ice only slowly flows back to the dayside upon accumulation, the resulting hydrological cycle can trap a large amount of water in the form of nightside ice. Using ice sheet dynamical and thermodynamical constraints, I illustrate how planets with less than about a quarter the Earth's oceans could trap most of their surface water on the nightside. This would leave their dayside, where habitable conditions are met, potentially dry. The amount and distribution of residual liquid water on the dayside depend on a variety of geophysical factors, including the efficiency of rock weathering at regulating atmospheric CO{sub 2} as dayside ocean basins dry up. Water-trapped worlds with dry daysides may offer similar advantages as land planets for habitability, by contrast with worlds where more abundant water freely flows around the globe.

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

    E-Print Network [OSTI]

    Kirby, Mark Samuel

    1986-01-01

    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; ...

  3. Dynamics of the sea ice edge in Davis Strait M.P. Heide-Jrgensen a,, H. Stern b

    E-Print Network [OSTI]

    Laidre, Kristin L.

    ice concentration and plankton abundance could be detected but the recruitment of the offshore cod strong seasonal changes in sea ice extent and concentration, primarily driven by wind and current Strait. This water mass is transported from the Arctic Ocean through the Canadian high Arctic archi

  4. Flight Path 60R - GEANIE

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory ofDid you not find whatGasEnergyfeature photoTheory05 Target 1 Flight Path

  5. Flight Path 90L - TPC

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory ofDid you not find whatGasEnergyfeature photoTheory05 Target 1 Flight Path90L

  6. Path Profile Guided Partial Dead Code Elimination Using Predication \\Lambda

    E-Print Network [OSTI]

    Gupta, Rajiv

    executed paths by reduc­ ing their critical path lengths. The paper presents a cost­benefit data flow architectures since critical path lengths along frequently executed paths can be reduced through PDE [11, 6, 13 optimization moves in­ structions that are dead along critical paths off the critical paths [19, 22]. Modern

  7. Modeling the impediment of methane ebullition bubbles by seasonal lake ice

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

    Greene, S.; Walter Anthony, K. M.; Archer, D.; Sepulveda-Jauregui, A.; Martinez-Cruz, K.

    2014-12-08

    Microbial methane (CH4) ebullition (bubbling) from anoxic lake sediments comprises a globally significant flux to the atmosphere, but ebullition bubbles in temperate and polar lakes can be trapped by winter ice cover and later released during spring thaw. This "ice-bubble storage" (IBS) constitutes a novel mode of CH4 emission. Before bubbles are encapsulated by downward-growing ice, some of their CH4 dissolves into the lake water, where it may be subject to oxidation. We present field characterization and a model of the annual CH4 cycle in Goldstream Lake, a thermokarst (thaw) lake in interior Alaska. We find that summertime ebullition dominatesmore »annual CH4 emissions to the atmosphere. Eighty percent of CH4 in bubbles trapped by ice dissolves into the lake water column in winter, and about half of that is oxidized. The ice growth rate and the magnitude of the CH4 ebullition flux are important controlling factors of bubble dissolution. Seven percent of annual ebullition CH4 is trapped as IBS and later emitted as ice melts. In a future warmer climate, there will likely be less seasonal ice cover, less IBS, less CH4 dissolution from trapped bubbles, and greater CH4 emissions from northern lakes.« less

  8. Modeling the impediment of methane ebullition bubbles by seasonal lake ice

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

    Greene, S.; Walter Anthony, K. M.; Archer, D.; Sepulveda-Jauregui, A.; Martinez-Cruz, K.

    2014-07-15

    Microbial methane (CH4) ebullition (bubbling) from anoxic lake sediments comprises a globally significant flux to the atmosphere, but ebullition bubbles in temperate and polar lakes can be trapped by winter ice cover and later released during spring thaw. This "ice-bubble storage" (IBS) constitutes a novel mode of CH4 emission. Before bubbles are encapsulated by downward-growing ice, some of their CH4 dissolves into the lake water, where it may be subject to oxidation. We present field characterization and a model of the annual CH4 cycle in Goldstream Lake, a thermokarst (thaw) lake in interior Alaska. We find that summertime ebullition dominatesmore »annual CH4 emissions to the atmosphere. Eighty percent of CH4 in bubbles trapped by ice dissolves into the lake water column in winter, and about half of that is oxidized. The ice growth rate and the magnitude of the CH4 ebullition flux are important controlling factors of bubble dissolution. Seven percent of annual ebullition CH4 is trapped as IBS and later emitted as ice melts. In a future warmer climate, there will likely be less seasonal ice cover, less IBS, less CH4 dissolution from trapped bubbles, and greater CH4 emissions from northern lakes.« less

  9. Laboratory Investigation of Contact Freezing and the Aerosol to Ice Crystal Transformation Process

    SciTech Connect (OSTI)

    Shaw, Raymond A.

    2014-10-28

    This project has been focused on the following objectives: 1. Investigations of the physical processes governing immersion versus contact nucleation, specifically surface-induced crystallization; 2. Development of a quadrupole particle trap with full thermodynamic control over the temperature range 0 to –40 °C and precisely controlled water vapor saturation ratios for continuous, single-particle measurement of the aerosol to ice crystal transformation process for realistic ice nuclei; 3. Understanding the role of ice nucleation in determining the microphysical properties of mixed-phase clouds, within a framework that allows bridging between laboratory and field measurements.

  10. Electrothermal Icing Protection of Aerosurfaces Using Conductive Polymer Nanocomposites

    E-Print Network [OSTI]

    Buschhorn, Samuel T.

    Ice protection systems (IPS) are critical components for many aerospace flight vehicles, including commercial transports and unmanned aerial systems (UAS), and can include anti-icing, de-icing, ice sensing, etc. Here, an ...

  11. 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. L.

    2001-12-27

    averaged over a distance covered by aircraft in 1 s (-130 m).) tt(X, g = -d) = Sice(t: T, x). (6) The value t = - can be interpreted as the time when S ice(t, x) represents the wave energy due to scattering specifically from depth d, as opposed... of the Greenland ice sheet produced by Mark Fahnestock (Department of Meteorology, University of Maryland, College Park) and Ron Kwok (Jet Propulsion Laboratory, California Institute of Technology, Pasa- dena). The helpful suggestions and comments of two...

  12. Pressurized oceans and the eruption of liquid water on Europa and Enceladus

    E-Print Network [OSTI]

    Manga, Michael

    expansion of water as it freezes from the top increases pressure in the water confined below the ice. We the pressure in water trapped below the ice, we present in Figure 1 the results of a straightforward demonPressurized oceans and the eruption of liquid water on Europa and Enceladus M. Manga1 and C

  13. Critical function and success path summary display

    DOE Patents [OSTI]

    Scarola, Kenneth (Windsor, CT); Jamison, David S. (Windsor, CT); Manazir, Richard M. (North Canton, CT); Rescorl, Robert L. (Vernon, CT); Harmon, Daryl L. (Enfield, CT)

    1995-01-01

    The content of and hierarchical access to three levels of display pages containing information on critical function monitoring and success path monitoring.

  14. Personalized PageRank Solution Paths

    E-Print Network [OSTI]

    2015-04-13

    gorithms to estimate the solution path as a function of the sparsity and propose .... see shortly, we actually are describing degree normalized. PageRank values.

  15. Robust constrained shortest path problems under budgeted ...

    E-Print Network [OSTI]

    2014-09-12

    The shortest path problem with capacity constraint is denoted by CSP. Differently from the capacity constraint, time windows must be satisfied at each node ...

  16. Rubber friction on ice and snow surfaces 

    E-Print Network [OSTI]

    Skouvaklis, Gerasimos

    2011-06-28

    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 ...

  17. Thermal Storage with Ice Harvesting Systems 

    E-Print Network [OSTI]

    Knebel, D. E.

    1986-01-01

    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...

  18. The convective desalination of sea ice

    E-Print Network [OSTI]

    Rees Jones, David

    2014-07-01

    in the interstices of an ice matrix. My focus is on one of the processes by which the salt content of sea ice decreases, namely convective desalination, which is also often called gravity drainage by geophysicists. Modelling convective desalination requires...

  19. 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 of interior properties, and habitability. The electrical properties of saline H2O are controlled by the binary

  20. Methodology for Augmenting Existing Paths with Additional Parallel Transects

    SciTech Connect (OSTI)

    Wilson, John E.

    2013-09-30

    Visual Sample Plan (VSP) is sample planning software that is used, among other purposes, to plan transect sampling paths to detect areas that were potentially used for munition training. This module was developed for application on a large site where existing roads and trails were to be used as primary sampling paths. Gap areas between these primary paths needed to found and covered with parallel transect paths. These gap areas represent areas on the site that are more than a specified distance from a primary path. These added parallel paths needed to optionally be connected together into a single path—the shortest path possible. The paths also needed to optionally be attached to existing primary paths, again with the shortest possible path. Finally, the process must be repeatable and predictable so that the same inputs (primary paths, specified distance, and path options) will result in the same set of new paths every time. This methodology was developed to meet those specifications.

  1. Evaluating and Constraining Ice Cloud Parameterizations in CAM5 using Aircraft Measurements from the SPARTICUS Campaign

    SciTech Connect (OSTI)

    Zhang, Kai; Liu, Xiaohong; Wang, Minghuai; Comstock, Jennifer M.; Mitchell, David; Mishra, Subhashree; Mace, Gerald G.

    2013-01-01

    This study uses aircraft measurements of relative humidity and ice crystal size distribution collected in synoptic cirrus during the SPARTICUS (Small PARTicles In CirrUS) field campaign to evaluate and constrain ice cloud parameterizations in the Community Atmosphere Model version 5. The probability density function (PDF) of ice crystal number concentration (Ni) derived from high frequency (1 Hz) measurements features a strong dependence on ambient temperature. As temperature decreases from -35°C to -62°C, the peak in the PDF shifts from 10-20 L-1 to 200-1000 L-1, while the ice crystal number concentration shows a factor of 6-7 increase. Model simulations are performed with two different insitu ice nucleation schemes. One of the schemes can reproduce a clear increase of Ni with decreasing temperature, by using either an observation based ice nuclei spectrum or a classical theory based spectrum with a relatively low (5%-10%) maximum freezing ratio for dust aerosols. The simulation with the other scheme, which assumes a high maximum freezing ratio (100%), shows much weaker temperature dependence of Ni. Simulations are also performed to test empirical parameters related to water vapor deposition and the auto-conversion of ice crystals to snow. Results show that a value between 0.05 and 0.1 for the water vapor deposition coefficient and 250 um for the critical ice crystal size can produce good agreements between model simulation and the SPARTICUS measurements in terms of ice crystal number concentration and effective radius. The climate impact of perturbing these parameters is also discussed.

  2. Ice-lens formation and geometrical supercooling in soils and other colloidal materials

    E-Print Network [OSTI]

    Robert W. Style; Stephen S. L. Peppin; Alan C. F. Cocks; John S. Wettlaufer

    2011-09-09

    We present a new, physically-intuitive model of ice-lens formation and growth during the freezing of soils and other dense, particulate suspensions. Motivated by experimental evidence, we consider the growth of an ice-filled crack in a freezing soil. At low temperatures, ice in the crack exerts large pressures on the crack walls that will eventually cause the crack to split open. We show that the crack will then propagate across the soil to form a new lens. The process is controlled by two factors: the cohesion of the soil, and the geometrical supercooling of the water in the soil; a new concept introduced to measure the energy available to form a new ice lens. When the supercooling exceeds a critical amount (proportional to the cohesive strength of the soil) a new ice lens forms. This condition for ice-lens formation and growth does not appeal to any ad hoc, empirical assumptions, and explains how periodic ice lenses can form with or without the presence of a frozen fringe. The proposed mechanism is in good agreement with experiments, in particular explaining ice-lens pattern formation, and surges in heave rate associated with the growth of new lenses. Importantly for systems with no frozen fringe, ice-lens formation and frost heave can be predicted given only the unfrozen properties of the soil. We use our theory to estimate ice-lens growth temperatures obtaining quantitative agreement with the limited experimental data that is currently available. Finally we suggest experiments that might be performed in order to verify this theory in more detail. The theory is generalizable to complex natural-soil scenarios, and should therefore be useful in the prediction of macroscopic frost heave rates.

  3. Multi-objective stochastic path planning 

    E-Print Network [OSTI]

    Dasgupta, Sumantra

    2009-05-15

    . Provide an O (V.E+C2) heuristic for generating Pareto optimal shortest paths in presence of multiple objectives where C is the upper bound for path length. The complexity can be further reduced to O (V.E) by using graphical read-out of the Pareto frontier...

  4. PARALLEL EVOLUTIONARY ALGORITHMS FOR UAV PATH PLANNING

    E-Print Network [OSTI]

    PARALLEL EVOLUTIONARY ALGORITHMS FOR UAV PATH PLANNING Dong Jia Post-Doctoral Research Associate vehicles (UAVs). Premature convergence prevents evolutionary-based algorithms from reaching global optimal. To overcome this problem, this paper presents a framework of parallel evolutionary algorithms for UAV path

  5. At-Speed Path Delay Test 

    E-Print Network [OSTI]

    Chakraborty, Swati

    2015-04-27

    This research describes an approach to test metastability of flip-flops with help of multiple at-speed capture cycles during delay test. K longest paths per flip-flop test patterns are generated, such that a long path on one clock cycle feeds a long...

  6. Visualization of Ant Pheromone Based Path Following 

    E-Print Network [OSTI]

    Sutherland, Benjamin T.

    2010-07-14

    This thesis develops a simulation and visualization of a path finding algorithm based on ant pheromone paths created in 3D space. The simulation is useful as a demonstration of a heuristic approach to NP-complete problems and as an educational tool...

  7. CALIFORNIA PATH PROGRAM INSTITUTE OF TRANSPORTATION STUDIES

    E-Print Network [OSTI]

    Agogino, Alice M.

    CALIFORNIA PATH PROGRAM INSTITUTE OF TRANSPORTATION STUDIES UNIVERFITY OF CALIFORNIA, BERKELEY,in cooperation with the State of California Business, Transportation, and Housing Agency, Department Agogino, Kai Goebel SatnamAlag University of California,Berkeley CaliforniaPATH Research Report UCB

  8. Medical ice slurry production device

    DOE Patents [OSTI]

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

    2008-06-24

    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.

  9. Critical Review of Path Integral Formulation

    E-Print Network [OSTI]

    Takehisa Fujita

    2008-01-13

    The path integral formulation in quantum mechanics corresponds to the first quantization since it is just to rewrite the quantum mechanical amplitude into many dimensional integrations over discretized coordinates $x_n$. However, the path integral expression cannot be connected to the dynamics of classical mechanics, even though, superficially, there is some similarity between them. Further, the field theory path integral in terms of many dimensional integrations over fields does not correspond to the field quantization. We clarify the essential difference between Feynman's original formulation of path integral in QED and the modern version of the path integral method prevailing in lattice field theory calculations, and show that the former can make a correct second quantization while the latter cannot quantize fields at all and its physical meaning is unknown.

  10. ELECTRON IRRADIATION OF CARBON DISULFIDE-OXYGEN ICES: TOWARD THE FORMATION OF SULFUR-BEARING MOLECULES IN INTERSTELLAR ICES

    SciTech Connect (OSTI)

    Maity, Surajit; Kaiser, Ralf I. [Department of Chemistry, University of Hawai'i at Manoa, Honolulu, HI 96822 (United States)

    2013-08-20

    The formation of sulfur-bearing molecules in interstellar ices was investigated during the irradiation of carbon disulfide (CS{sub 2})-oxygen (O{sub 2}) ices with energetic electrons at 12 K. The irradiation-induced chemical processing of these ices was monitored online and in situ via Fourier transform infrared spectroscopy to probe the newly formed products quantitatively. The sulfur-bearing molecules produced during the irradiation were sulfur dioxide (SO{sub 2}), sulfur trioxide (SO{sub 3}), and carbonyl sulfide (OCS). Formations of carbon dioxide (CO{sub 2}), carbon monoxide (CO), and ozone (O{sub 3}) were observed as well. To fit the temporal evolution of the newly formed products and to elucidate the underlying reaction pathways, kinetic reaction schemes were developed and numerical sets of rate constants were derived. Our studies suggest that carbon disulfide (CS{sub 2}) can be easily transformed to carbonyl sulfide (OCS) via reactions with suprathermal atomic oxygen (O), which can be released from oxygen-containing precursors such as water (H{sub 2}O), carbon dioxide (CO{sub 2}), and/or methanol (CH{sub 3}OH) upon interaction with ionizing radiation. This investigation corroborates that carbonyl sulfide (OCS) and sulfur dioxide (SO{sub 2}) are the dominant sulfur-bearing molecules in interstellar ices.

  11. Arctic sea ice animation (Tom Agnew, Environment Canada) Lecture 12 HAS222d Intro to energy and environment 2009

    E-Print Network [OSTI]

    Arctic sea ice animation (Tom Agnew, Environment Canada) #12;Lecture 12 HAS222d Intro to energy. moisture streamers: (1 Sverdrup...106 m3/sec tranport of water carries 2.2 x 1015 watt thermal energy and environment 2009 slides on water in the atmosphere P.B. Rhines #12;Satellite image of water vapor (not cloud

  12. The measured compositions of Uranus and Neptune from their formation on the CO ice line

    SciTech Connect (OSTI)

    Ali-Dib, Mohamad; Mousis, Olivier; Petit, Jean-Marc

    2014-09-20

    The formation mechanisms of the ice giants Uranus and Neptune, and the origin of their elemental and isotopic compositions, have long been debated. The density of solids in the outer protosolar nebula is too low to explain their formation, and spectroscopic observations show that both planets are highly enriched in carbon, very poor in nitrogen, and the ices from which they originally formed might have had deuterium-to-hydrogen ratios lower than the predicted cometary value, unexplained properties that were observed in no other planets. Here, we show that all these properties can be explained naturally if Uranus and Neptune both formed at the carbon monoxide ice line. Due to the diffusive redistribution of vapors, this outer region of the protosolar nebula intrinsically has enough surface density to form both planets from carbon-rich solids but nitrogen-depleted gas, in abundances consistent with their observed values. Water-rich interiors originating mostly from transformed CO ices reconcile the D/H value of Uranus's and Neptune's building blocks with the cometary value. Finally, our scenario generalizes a well known hypothesis that Jupiter formed on an ice line (water snow line) for the two ice giants, and might be a first step toward generalizing this mechanism for other giant planets.

  13. CO2 hydrate dissociation at low temperatures - formation and annealing of ice Ic

    E-Print Network [OSTI]

    Falenty, Andrzej; Kuhs, Werner F

    2015-01-01

    Dissociation of gas hydrates below 240 K leads to the formation of a metastable form of water ice, so called cubic ice (Ic). Through its defective nature and small particle size the surface film composed of such material is incapable of creating any significant diffusion barrier. Above 160 K, cubic ice gradually transforms to the stable hexagonal (Ih) form on laboratory time scales. The annealing, coupled with a parallel decomposition of gas hydrates, accelerates as temperature rises but already above 190 K the first process prevails, transforming cubic stacking sequences in-to ordinary Ih ice within a few minutes. Remaining stacking faults are removed through very slow isothermal annealing or after heating up above 240 K. The role of the proportion of cubic stacking on the decomposition rate is discussed. A better understanding of the dissociation kinetics at low temperatures is particularly im-portant for the critical evaluation of existing hypotheses that consider clathrates as a potential medium that acti...

  14. Ice Nucleation of Bare and Sulfuric Acid-coated Mineral Dust Particles and Implication for Cloud Properties

    SciTech Connect (OSTI)

    Kulkarni, Gourihar R.; Sanders, Cassandra N.; Zhang, Kai; Liu, Xiaohong; Zhao, Chun

    2014-08-27

    Ice nucleation properties of different dust species coated with soluble material are not well understood. We determined the ice nucleation ability of bare and sulfuric acid coated mineral dust particles as a function of temperature (-25 to -35 deg C) and relative humidity with respect to water (RHw). Five different mineral dust species: Arizona test dust (ATD), illite, montmorillonite, quartz and kaolinite were dry dispersed and size-selected at 150 nm and exposed to sulfuric acid vapors in the coating apparatus. The condensed sulfuric acid soluble mass fraction per particle was estimated from the cloud condensation nuclei activated fraction measurements. The fraction of dust particles nucleating ice at various temperatures and RHw was determined using a compact ice chamber. In water-subsaturated conditions, compared to bare dust particles, we found that only coated ATD particles showed suppression of ice nucleation ability while other four dust species did not showed the effect of coating on the fraction of particles nucleating ice. The results suggest that interactions between the dust surface and sulfuric acid vapor are important, such that interactions may or may not modify the surface via chemical reactions with sulfuric acid. At water-supersaturated conditions we did not observed the effect of coating, i.e. the bare and coated dust particles had similar ice nucleation behavior.

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

    E-Print Network [OSTI]

    2013-01-01

    Surface configuration, ice thick- ness, volume and bedrockconstruction of the ice thick- ness grids. between flightof the physical ice thick- ness, rather than an “ice-

  16. Path Integral Representations on the Complex Sphere

    E-Print Network [OSTI]

    Christian Grosche

    2007-10-23

    In this paper we discuss the path integral representations for the coordinate systems on the complex sphere S3C. The Schroedinger equation, respectively the path integral, separates in exactly 21 orthogonal coordinate systems. We enumerate these coordinate systems and we are able to present the path integral representations explicitly in the majority of the cases. In each solution the expansion into the wave-functions is stated. Also, the kernel and the corresponding Green function can be stated in closed form in terms of the invariant distance on the sphere, respectively on the hyperboloid.

  17. FACT SHEET: The Path Forward on Nuclear Waste Disposal | Department...

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

    FACT SHEET: The Path Forward on Nuclear Waste Disposal FACT SHEET: The Path Forward on Nuclear Waste Disposal FACT SHEET: The Path Forward on Nuclear Waste Disposal More Documents...

  18. Automatic Beam Path Analysis of Laser Wakefield Particle Acceleration Data

    E-Print Network [OSTI]

    Rubel, Oliver

    2010-01-01

    A. Hakim, R¨ bel et al. Automatic Beam Path Analysis of399, 1976. R¨ bel et al. Automatic Beam Path Analysis ofAutomatic Beam Path Analysis of Laser Wake?eld Particle

  19. Laboratory investigations of irradiated acetonitrile-containing ices on an interstellar dust analog

    SciTech Connect (OSTI)

    Abdulgalil, Ali G. M.; Marchione, Demian; Rosu-Finsen, Alexander; Collings, Mark P.; McCoustra, Martin R. S.

    2012-07-15

    Reflection-absorption infrared spectroscopy is used to study the impact of low-energy electron irradiation of acetonitrile-containing ices, under conditions close to those in the dense star-forming regions in the interstellar medium. Both the incident electron energy and the surface coverage were varied. The experiments reveal that solid acetonitrile is desorbed from its ultrathin solid films with a cross section of the order of 10{sup -17} cm{sup 2}. Evidence is presented for a significantly larger desorption cross section for acetonitrile molecules at the water-ice interface, similar to that previously observed for the benzene-water system.

  20. Modeling the Alaskan Continental Shelf waters. Final report

    SciTech Connect (OSTI)

    Liu, S.K.; Leendertse, J.J.

    1987-10-01

    This report describes a three-dimensional ocean circulation model and two dimensional stochastic weather model used to calculate hypothetical oil-spill trajectories over the Alaskan Outer Continental Shelf (OCS) areas. Special consideration is given to the movement of sea ice in areas characterized by the presence of seasonal ice, and to ice/water interaction under different current and wind conditions. Spreading, dispersion, and weathering of crude oil, and probable landfalls of trajectories are calculated under hypothetical scenarios of oil spills from tanker accidents and well blow-outs. The report also provides comparisons between simulated data on water and sea ice motion with available field observations.

  1. Hydrogen ICE Vehicle Testing Activities

    SciTech Connect (OSTI)

    J. Francfort; D. Karner

    2006-04-01

    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.

  2. Water in protoplanetary disks: Deuteration and turbulent mixing

    SciTech Connect (OSTI)

    Furuya, Kenji; Aikawa, Yuri; Nomura, Hideko; Hersant, Franck; Wakelam, Valentine

    2013-12-10

    We investigate water and deuterated water chemistry in turbulent protoplanetary disks. Chemical rate equations are solved with the diffusion term, mimicking turbulent mixing in a vertical direction. Water near the midplane is transported to the disk atmosphere by turbulence and is destroyed by photoreactions to produce atomic oxygen, while the atomic oxygen is transported to the midplane and reforms water and/or other molecules. We find that this cycle significantly decreases column densities of water ice at r ? 30 AU, where dust temperatures are too high to reform water ice effectively. The radial extent of such region depends on the desorption energy of atomic hydrogen. Our model indicates that water ice could be deficient even outside the sublimation radius. Outside this radius, the cycle decreases the deuterium-to-hydrogen (D/H) ratio of water ice from ?2 × 10{sup –2}, which is set by the collapsing core model, to 10{sup –4}-10{sup –2} in 10{sup 6} yr, without significantly decreasing the water ice column density. The resultant D/H ratios depend on the strength of mixing and the radial distance from the central star. Our finding suggests that the D/H ratio of cometary water (?10{sup –4}) could be established (i.e., cometary water could be formed) in the solar nebula, even if the D/H ratio of water ice delivered to the disk was very high (?10{sup –2}).

  3. Molecular interactions with ice: Molecular embedding, adsorption, detection, and release

    SciTech Connect (OSTI)

    Gibson, K. D.; Langlois, Grant G.; Li, Wenxin; Sibener, S. J.; Killelea, Daniel R.

    2014-11-14

    The interaction of atomic and molecular species with water and ice is of fundamental importance for chemistry. In a previous series of publications, we demonstrated that translational energy activates the embedding of Xe and Kr atoms in the near surface region of ice surfaces. In this paper, we show that inert molecular species may be absorbed in a similar fashion. We also revisit Xe embedding, and further probe the nature of the absorption into the selvedge. CF{sub 4} molecules with high translational energies (?3 eV) were observed to embed in amorphous solid water. Just as with Xe, the initial adsorption rate is strongly activated by translational energy, but the CF{sub 4} embedding probability is much less than for Xe. In addition, a larger molecule, SF{sub 6}, did not embed at the same translational energies that both CF{sub 4} and Xe embedded. The embedding rate for a given energy thus goes in the order Xe > CF{sub 4} > SF{sub 6}. We do not have as much data for Kr, but it appears to have a rate that is between that of Xe and CF{sub 4}. Tentatively, this order suggests that for Xe and CF{sub 4}, which have similar van der Waals radii, the momentum is the key factor in determining whether the incident atom or molecule can penetrate deeply enough below the surface to embed. The more massive SF{sub 6} molecule also has a larger van der Waals radius, which appears to prevent it from stably embedding in the selvedge. We also determined that the maximum depth of embedding is less than the equivalent of four layers of hexagonal ice, while some of the atoms just below the ice surface can escape before ice desorption begins. These results show that energetic ballistic embedding in ice is a general phenomenon, and represents a significant new channel by which incident species can be trapped under conditions where they would otherwise not be bound stably as surface adsorbates. These findings have implications for many fields including environmental science, trace gas collection and release, and the chemical composition of astrophysical icy bodies in space.

  4. Commercial Light Water Production of Tritium: Update and Path Forward

    Broader source: Energy.gov [DOE]

    Presentation from the 32nd Tritium Focus Group Meeting held in Germantown, Maryland on April 23-25, 2013.

  5. Linear water waves with vorticity: rotational features and particle paths

    E-Print Network [OSTI]

    Mats Ehrnstrom; Gabriele Villari

    2007-12-04

    Steady linear gravity waves of small amplitude travelling on a current of constant vorticity are found. For negative vorticity we show the appearance of internal waves and vortices, wherein the particle trajectories are not any more closed ellipses. For positive vorticity the situation resembles that of Stokes waves, but for large vorticity the trajectories are affected.

  6. An Evaluation of MWR Retrievals of Liquid 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L O O D S TAPropaneand LosAmesAmped Up!Energy Preserving

  7. ARM - Publications: Science Team Meeting Documents: Liquid 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better AnodeThe Influence of Clouds, Aerosols,Comparisonat the ARMCarloDerivingimpact ofestimates

  8. Graphene-based battery electrodes having continuous flow paths...

    Office of Scientific and Technical Information (OSTI)

    Graphene-based battery electrodes having continuous flow paths Citation Details In-Document Search Title: Graphene-based battery electrodes having continuous flow paths Some...

  9. A CONSTRUCTION OF THE ROUGH PATH ABOVE FRACTIONAL ...

    E-Print Network [OSTI]

    2013-03-05

    Appl. 120 (2010) 1444–1472], where the construction of a rough path over B was first introduced. 1. Introduction. Rough paths analysis is a theory introduced by ...

  10. The Path to Transforming Knowledge into Energy Projects: DOE...

    Office of Environmental Management (EM)

    The Path to Transforming Knowledge into Energy Projects: DOE Tribal Renewable Energy Webinar Series 2015 The Path to Transforming Knowledge into Energy Projects: DOE Tribal...

  11. REGULAR PATHS IN SPARQL: QUERYING THE NCI THESAURUS

    E-Print Network [OSTI]

    Washington at Seattle, University of

    REGULAR PATHS IN SPARQL: QUERYING THE NCI THESAURUS University of Washington Structural Informatics path enhancements Examples NCI Thesaurus Widely used Exhibits common OWL representational patterns

  12. Shortest Paths, Network Design and Associated Polyhedra

    E-Print Network [OSTI]

    Magnanti, Thomas L.

    We study a specialized version of network design problems that arise in telecommunication, transportation and other industries. The problem, a generalization of the shortest path problem, is defined on an undirected network ...

  13. FAFCO Ice Storage test report

    SciTech Connect (OSTI)

    Stovall, T.K.

    1993-11-01

    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.

  14. Local Investigation of Femtosecond Laser Induced Dynamics of Water Nanoclusters on Cu(111) Michael Mehlhorn,1

    E-Print Network [OSTI]

    Alavi, Ali

    .37.Ef, 68.43.Bc, 82.30.Rs, 82.53.St There is broad interest in supported water-ice and the mechanims

  15. Further observations of a decreasing atmospheric CO2 uptake capacity in the Canada Basin (Arctic Ocean) due to sea ice loss

    E-Print Network [OSTI]

    Boyer, Edmond

    decayed ice cover, we found surprisingly high pCO2sw (~290­320 matm), considering that surface waterFurther observations of a decreasing atmospheric CO2 uptake capacity in the Canada Basin (Arctic as an atmospheric CO2 sink under the summertime ice-free conditions expected in the near future. Beneath a heavily

  16. Steam Path Audits on Industrial Steam Turbines 

    E-Print Network [OSTI]

    Mitchell, D. R.

    1992-01-01

    on Industrial steam Turbines DOUGLAS R. MITCHELL. ENGINEER. ENCOTECH, INC., SCHENECTADY, NEW YORK ABSTRACT The electric utility industry has benefitted from steam path audits on steam turbines for several years. Benefits include the ability to identify... areas of performance degradation during a turbine outage. Repair priorities can then be set in accordance with quantitative results from the steam path audit. As a result of optimized repair decisions, turbine efficiency increases, emissions...

  17. Geol 795 Paleoceanography Ice Sheet Dynamics and Climate Change

    E-Print Network [OSTI]

    Barranco, Joseph

    Geol 795 ­ Paleoceanography Ice Sheet Dynamics and Climate Change Class Meetings: Tuesday 9 of articles related ice sheet dynamics and the role of ice sheets in past, present, and future climate change ice sheet dynamics and the role of ice sheets in climate change. We will discuss effective ways

  18. Ices in the edge-on disk CRBR 2422.8-3423: Spitzer spectroscopy and Monte Carlo radiative transfer modeling

    E-Print Network [OSTI]

    Klaus M. Pontoppidan; Cornelis P. Dullemond; Ewine F. van Dishoeck; Geoffrey A. Blake; Adwin C. A. Boogert; Neal J. Evans II; Jacqueline E. Kessler-Silacci; Fred Lahuis

    2004-11-13

    We present 5.2-37.2 micron spectroscopy of the edge-on circumstellar disk CRBR 2422.8-3423 obtained using the InfraRed Spectrograph (IRS) of the Spitzer Space Telescope. The IRS spectrum is combined with ground-based 3-5 micron spectroscopy to obtain a complete inventory of solid state material present along the line of sight toward the source. We model the object with a 2D axisymmetric (effectively 3D) Monte Carlo radiative transfer code. It is found that the model disk, assuming a standard flaring structure, is too warm to contain the very large observed column density of pure CO ice, but is possibly responsible for up to 50% of the water, CO2 and minor ice species. In particular the 6.85 micron band, tentatively due to NH4+, exhibits a prominent red wing, indicating a significant contribution from warm ice in the disk. It is argued that the pure CO ice is located in the dense core Oph-F in front of the source seen in the submillimeter imaging, with the CO gas in the core highly depleted. The model is used to predict which circumstances are most favourable for direct observations of ices in edge-on circumstellar disks. Ice bands will in general be deepest for inclinations similar to the disk opening angle, i.e. ~70 degrees. Due to the high optical depths of typical disk mid-planes, ice absorption bands will often probe warmer ice located in the upper layers of nearly edge-on disks. The ratios between different ice bands are found to vary by up to an order of magnitude depending on disk inclination due to radiative transfer effects caused by the 2D structure of the disk. Ratios between ice bands of the same species can therefore be used to constrain the location of the ices in a circumstellar disk. [Abstract abridged

  19. IceT users' guide and reference.

    SciTech Connect (OSTI)

    Moreland, Kenneth D.

    2011-01-01

    The Image Composition Engine for Tiles (IceT) is a high-performance sort-last parallel rendering library. In addition to providing accelerated rendering for a standard display, IceT provides the unique ability to generate images for tiled displays. The overall resolution of the display may be several times larger than any viewport that may be rendered by a single machine. This document is an overview of the user interface to IceT.

  20. China Energy and Emissions Paths to 2030

    E-Print Network [OSTI]

    Fridley, David

    2012-01-01

    Waste heat recovery from cooling water: Waste heat can behot strip mill Waste heat recovery from cooling water Coldmills * Waste heat recovery from cooling water * Recovery of

  1. In situ cosmogenic radiocarbon production and 2-D ice flow line modeling for an Antarctic blue ice area

    E-Print Network [OSTI]

    Severinghaus, Jeffrey P.

    In situ cosmogenic radiocarbon production and 2-D ice flow line modeling for an Antarctic blue ice; accepted 12 April 2012; published 24 May 2012. [1] Radiocarbon measurements at ice margin sites and blue and 2-D ice flow line modeling for an Antarctic blue ice area, J. Geophys. Res., 117, F02029, doi:10

  2. BISICLES Captures Details of Retreating Antarctic Ice

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

    software framework, and linked them to the existing Community Ice Sheet Model code (CISM). With AMR, researchers can now model dynamic points of interest at extremely high...

  3. The Next ICE Age | Department of Energy

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

    More Documents & Publications The Next ICE Age Fuel Modification t Facilitate Future Combustion Regimes? Optimization of Advanced Diesel Engine Combustion Strategies...

  4. The Stability of the Greenland Ice Sheet

    E-Print Network [OSTI]

    Biasutti, Michela

    , distribution and seasonality · Solid Earth: · Geothermal heatflux Abrupt Climate Change Studies Symposium 21 Rebound (GIA) GPS stations measure vertical deformation of solid Earth as ice

  5. Mathematics Of Ice To Aid Global Warming Forecasts Mathematics Of Ice To Aid Global Warming Forecasts

    E-Print Network [OSTI]

    Golden, Kenneth M.

    Mathematics Of Ice To Aid Global Warming Forecasts Mathematics Of Ice To Aid Global Warming forecasts of how global warming will affect polar icepacks. See also: Earth & Climate q Global Warming q the effects of climate warming, and its presence greatly reduces solar heating of the polar oceans." "Sea ice

  6. A New Approach for Exploring Ice Sheets and Sub-Ice Geology

    E-Print Network [OSTI]

    Kristoffersen, Yngve

    A New Approach for Exploring Ice Sheets and Sub-Ice Geology Active seismic measurements were geology driven by ice flow [Smith et al., 2007] and the long record of seismic exploration of subglacial sur- veys because of the considerable logistical effort necessary for seismic data acquisition

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

    E-Print Network [OSTI]

    (look-up table) for different ice types. The library is used in the computer classifica- tion (freshwater) ice types using the Jet Propulsion Laboratory C-band scatterometer, together with surface data set, composed of over 20 variations of different ice types measured at incident angles from 0

  8. Ice Surface Entropy Induction by Humidity or How Humidity Prompts Freezing

    E-Print Network [OSTI]

    Jose Luis Perez-Diaz; Marco Antonio Alvarez-Valenzuela; Juan Sanchez-Garcia-Casarrubios; Sergio Jimenez-Lopez

    2015-09-22

    In this work we measured Surface Energy and Freezing Temperature of supercooled water droplets in air. We find that freezing of water droplets is triggered at the water-air interface and that freezing progresses faster on the surface than in the bulk. The Freezing Point of water droplets is strongly depressed by dryness in air and how humidity triggers freezing. Additionally it is shown to be a Surface phenomenon related to a transfer of Entropy from water vapour to the surface of ice.

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

    E-Print Network [OSTI]

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

    2004-01-01

    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...

  10. LABORATORY STUDIES ON THE FORMATION OF FORMIC ACID (HCOOH) IN INTERSTELLAR AND COMETARY ICES

    SciTech Connect (OSTI)

    Bennett, Chris J.; Kim, Yong Seol; Kaiser, Ralf I.; Hama, Tetsuya; Kawasaki, Masahiro

    2011-01-20

    Mixtures of water (H{sub 2}O) and carbon monoxide (CO) ices were irradiated at 10 K with energetic electrons to simulate the energy transfer processes that occur in the track of galactic cosmic-ray particles penetrating interstellar ices. We identified formic acid (HCOOH) through new absorption bands in the infrared spectra at 1690 and 1224 cm{sup -1} (5.92 and 8.17 {mu}m, respectively). During the subsequent warm-up of the irradiated samples, formic acid is evident from the mass spectrometer signal at the mass-to-charge ratio, m/z = 46 (HCOOH{sup +}) as the ice sublimates. The detection of formic acid was confirmed using isotopically labeled water-d2 with carbon monoxide, leading to formic acid-d2 (DCOOD). The temporal fits of the reactants, reaction intermediates, and products elucidate two reaction pathways to formic acid in carbon monoxide-water ices. The reaction is induced by unimolecular decomposition of water forming atomic hydrogen (H) and the hydroxyl radical (OH). The dominating pathway to formic acid (HCOOH) was found to involve addition of suprathermal hydrogen atoms to carbon monoxide forming the formyl radical (HCO); the latter recombined with neighboring hydroxyl radicals to yield formic acid (HCOOH). To a lesser extent, hydroxyl radicals react with carbon monoxide to yield the hydroxyformyl radical (HOCO), which recombined with atomic hydrogen to produce formic acid. Similar processes are expected to produce formic acid within interstellar ices, cometary ices, and icy satellites, thus providing alternative processes for the generation of formic acid whose abundance in hot cores such as Sgr-B2 cannot be accounted for solely by gas-phase chemistry.

  11. SIGNAL-PATH LEVEL ASSIGNMENT FOR DUAL-Vt TECHNIQUE

    E-Print Network [OSTI]

    Wang, Yu

    be assigned to some of the transistors in the non-critical paths and a lower Vt is assigned to other to get the critical paths and non-critical paths of the circuit much faster and with more accuracy. The gates in the critical paths will remain unchanged to maintain the performance; and the gates in the non-critical

  12. An Efficient Computation of Statistically Critical Sequential Paths Under Retiming

    E-Print Network [OSTI]

    Lim, Sung Kyu

    An Efficient Computation of Statistically Critical Sequential Paths Under Retiming Mongkol the statistically critical paths under retiming, which are the paths with a high probability of becoming timing- critical after retiming. SRTA enables the designers to perform circuit optimization on these paths

  13. A direct evidence of vibrationally delocalized response at ice surface

    SciTech Connect (OSTI)

    Ishiyama, Tatsuya; Morita, Akihiro

    2014-11-14

    Surface-specific vibrational spectroscopic responses at isotope diluted ice and amorphous ice are investigated by molecular dynamics (MD) simulations combined with quantum mechanics/molecular mechanics calculations. The intense response specific to the ordinary crystal ice surface is predicted to be significantly suppressed in the isotopically diluted and amorphous ices, demonstrating the vibrational delocalization at the ordinary ice surface. The collective vibration at the ice surface is also analyzed with varying temperature by the MD simulation.

  14. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Comments?govInstrumentsnoaacrnBarrow, AlaskaManus Site-Inactive TWP Related Links Facilities andTWP-ICE Maps

  15. IceCube at NERSC

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation CurrentHenry Bellamy, Ph.D.FoodHydropower,Principal InvestigatorsIceCube at

  16. Results from IceCube/IceTop Ooty, 17/12/12 Tom Gaisser for the IceCube Collab. 1

    E-Print Network [OSTI]

    Gaisser, Thomas K.

    , 17/12/12 Tom Gaisser for the IceCube Collab. 3 #12;Mumbai, 11/12/12 Tom;Mumbai, 11/12/12 Tom Gaisser for the IceCube Collab. 5 DetecMng neutrinos in H of interac,ons IceTop #12;Mumbai, 11/12/12 Tom Gaisser for the IceCube Collab. 6

  17. Radar attenuation and temperature within the Greenland Ice Sheet

    E-Print Network [OSTI]

    2015-01-01

    on obliquely propagating radio waves, IEEE Trans. Geosci.dielectric attenuation of radio waves through ice is alsoattenuation of radio waves through ice is also temperature

  18. ICR-ICE Standard Operating Procedures (Update Sept 2013) | Department...

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

    ICR-ICE Standard Operating Procedures (Update Sept 2013) ICR-ICE Standard Operating Procedures (Update Sept 2013) ICRICE SOPSep 2013Final.pdf More Documents & Publications...

  19. Rapid development of an ice sheet climate application using the...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Rapid development of an ice sheet climate application using the components-based approach Citation Details In-Document Search Title: Rapid development of an ice...

  20. 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...

  1. Cosmic-ray results from IceCube/ Mumbai, 12/12/12 Tom Gaisser for the IceCube Collab. 1

    E-Print Network [OSTI]

    Gaisser, Thomas K.

    Cosmic-ray results from IceCube/ IceTop Mumbai, 12/12/12 Tom Gaisser for the IceCube Collab. 1 #12;Mumbai, 12/12/12 Tom Gaisser for the IceCube Collab. 2 events ­ IceTop/deep IceCube Mumbai, 12/12/12 Tom Gaisser for the IceCube Collab

  2. Improvements in Shortwave Bulk Scattering and Absorption Models for the Remote Sensing of Ice Clouds

    E-Print Network [OSTI]

    Baum, Bryan A.

    ) sensor, hyperspectral IR mea- surements from the Atmospheric Infrared Sounder (AIRS; Aumann et al. 2003 water content in the microphysical data spans six orders of magnitude. For evaluation, a library of ice suite of spaceborne sensors that compose the National Aero- nautics and Space Administration (NASA

  3. Some Thoughts on the Freezing and Melting of Sea Ice and Their Effects on the Ocean

    E-Print Network [OSTI]

    Washington at Seattle, University of

    Some Thoughts on the Freezing and Melting of Sea Ice and Their Effects on the Ocean K. Aagaard. The high-latitude freezing and melting cycle can variously result in haline con- vection, freshwater of this process is that water distilled at the surface of the Arctic Ocean by freezing ends up at mid

  4. Toward ice formation closure in Arctic mixedphase boundary layer clouds during ISDAC

    E-Print Network [OSTI]

    above water saturation) and another in which initial IN concentrations were vertically uniform. A key aspect of the latter was an IN reservoir under the wellmixed cloud layer: as the simulations progressed, the reservoir IN slowly mixed upward, helping to maintain ice concentrations close to those observed. Given

  5. The Ross Sea Response to Evolving Ocean-Ice Interactions in a Changing Climate 

    E-Print Network [OSTI]

    Wiederwohl, Christina 1980-

    2012-12-03

    decade (1994–2007) mostly (50%) from larger melt water inputs from the Pine Island (17.7 km^3 per decade) and Dotson (14.8 km^3 per decade) glaciers. Two decades of steady (1978-2000) strengthening of sea ice productivity (200 km^3 per decade) within...

  6. An update on modeling land-ice/ocean interactions in CESM

    SciTech Connect (OSTI)

    Asay-davis, Xylar

    2011-01-24

    This talk is an update on ongoing land-ice/ocean coupling work within the Community Earth System Model (CESM). The coupling method is designed to allow simulation of a fully dynamic ice/ocean interface, while requiring minimal modification to the existing ocean model (the Parallel Ocean Program, POP). The method makes use of an immersed boundary method (IBM) to represent the geometry of the ice-ocean interface without requiring that the computational grid be modified in time. We show many of the remaining development challenges that need to be addressed in order to perform global, century long climate runs with fully coupled ocean and ice sheet models. These challenges include moving to a new grid where the computational pole is no longer at the true south pole and several changes to the coupler (the software tool used to communicate between model components) to allow the boundary between land and ocean to vary in time. We discuss benefits for ice/ocean coupling that would be gained from longer-term ocean model development to allow for natural salt fluxes (which conserve both water and salt mass, rather than water volume).

  7. Ice formation in PEM fuel cells operated isothermally at sub-freezing temperatures

    SciTech Connect (OSTI)

    Mukundan, Rangachary; Luhan, Roger W; Davey, John R; Spendelow, Jacob S; Borup, Rodney L; Hussey, Daniel S; Jacobson, David L; Arif, Muhammad

    2009-01-01

    The effect of MEA and GDL structure and composition on the performance of single-PEM fuel cells operated isothermally at subfreezing temperatures is presented. The cell performance and durability are not only dependent on the MEA/GDL materials used but also on their interfaces. When a cell is operated isothermally at sub-freezing temperatures in constant current mode, the water formation due to the current density initially hydrates the membrane/ionomer and then forms ice in the catalyst layer/GDL. An increase in high frequency resistance was also observed in certain MEAs where there is a possibility of ice formation between the catalyst layer and GDL leading to a loss in contact area. The total water/ice holding capacity for any MEA was lower at lower temperatures and higher current densities. The durability of MEAs subjected to multiple isothermal starts was better for LANL prepared MEAs as compared to commercial MEAs, and cloth GDLs when compared to paper GDLs. The ice formation was monitored using high-resolution neutron radiography and was found to be concentrated near the cathode catalyst layer. However, there was significant ice formation in the GDLs especially at the higher temperature ({approx} -10 C) and lower current density (0.02 A/cm{sup 2}) operations. These results are consistent with the longer-term durability observations that show more severe degradation at the lower temperatures.

  8. Enhancing the resolution of sea ice in long-term global ocean general circulation model (gcm) integrations 

    E-Print Network [OSTI]

    Kim, Joong Tae

    2007-09-17

    Open water in sea ice, such as leads and polynyas, plays a crucial role in determining the formation of deep- and bottom-water, as well as their long-term global properties and circulation. Ocean general circulation models (GCMs) designed...

  9. Infrared characterization of amorphous and polycrystalline D2O ice on controlled wettability self-assembled alkanethiolate monolayers

    E-Print Network [OSTI]

    Parikh, Atul N.

    °, where is the static contact angle with water. Dosing of D2O and infrared measurements were carried out at selected sample temperatures between 82 and 150 K. Experimental spectra of ice overlayers recorded below the interactions of water with a large set of SAMs of single and mixed chemical function- alities.

  10. Feynman's path integral and mutually unbiased bases

    E-Print Network [OSTI]

    J Tolar; G Chadzitaskos

    2009-08-05

    Our previous work on quantum mechanics in Hilbert spaces of finite dimensions N is applied to elucidate the deep meaning of Feynman's path integral pointed out by G. Svetlichny. He speculated that the secret of the Feynman path integral may lie in the property of mutual unbiasedness of temporally proximal bases. We confirm the corresponding property of the short-time propagator by using a specially devised N x N -approximation of quantum mechanics in L^2(R) applied to our finite-dimensional analogue of a free quantum particle.

  11. 1 Introduction The shortest augmenting path flow algorithm repeatedly finds a shortest augmenting path (A-path) in the residual

    E-Print Network [OSTI]

    California at Davis, University of

    -path, success if hits t, fail if backup to s last Advance(s); // move forward from s till get stuck at last in Gf . Advance(v) // moves towards t till gets stuck, or hits t cv v; // cv represents the current While (last = s, t) // stuck partway, so backup { v pred(last); relabel(last); // can't move forward

  12. Critical Mechanisms for the Formation of Extreme Arctic Sea-Ice Extent in the Summers of 2007 and 1996

    SciTech Connect (OSTI)

    Dong, Xiquan; Zib, Benjamin J.; Xi, Baike; Stanfield, Ryan; Deng, Yi; Zhang, Xiangdong; Lin, B.; Long, Charles N.

    2014-07-29

    A warming Arctic climate is undergoing significant e 21 nvironmental change, most evidenced by the reduction of Arctic sea-ice extent during the summer. In this study, we examine two extreme anomalies of September sea-ice extent in 2007 and 1996, and investigate the impacts of cloud fraction (CF), atmospheric precipitable water vapor (PWV), downwelling longwave flux (DLF), surface air temperature (SAT), pressure and winds on the sea-ice variation in 2007 and 1996 using both satellite-derived sea-ice products and MERRA reanalysis. The area of the Laptev, East Siberian and West Chukchi seas (70-90oN, 90-180oE) has experienced the largest variation in sea-ice extent from year-to-year and defined here as the Area Of Focus (AOF). The record low September sea-ice extent in 2007 was associated with positive anomalies 30 of CF, PWV, DLF, and SAT over the AOF. Persistent anti-cyclone positioned over the Beaufort Sea coupled with low pressure over Eurasia induced easterly zonal and southerly meridional winds. In contrast, negative CF, PWV, DLF and SAT anomalies, as well as opposite wind patterns to those in 2007, characterized the 1996 high September sea-ice extent. Through this study, we hypothesize the following positive feedbacks of clouds, water vapor, radiation and atmospheric variables on the sea-ice retreat during the summer 2007. The record low sea-ice extent during the summer 2007 is initially triggered by the atmospheric circulation anomaly. The southerly winds across the Chukchi and East Siberian seas transport warm, moist air from the north Pacific, which is not only enhancing sea-ice melt across the AOF, but also increasing clouds. The positive cloud feedback results in higher SAT and more sea-ice melt. Therefore, 40 more water vapor could be evaporated from open seas and higher SAT to form more clouds, which will enhance positive cloud feedback. This enhanced positive cloud feedback will then further increase SAT and accelerate the sea-ice retreat during the summer 2007.

  13. Aircraft Measurements of Cloud Liquid Water Content using the Forward

    E-Print Network [OSTI]

    Delene, David J.

    Aircraft Measurements of Cloud Liquid Water Content using the Forward Scattering Spectrometer Probe Water Content? Basic Cloud Parameter (MPACE) Icing Studies (WISP04, Sikorsky) Comparison with Remote Sensing Measurements (THORpex, IOP1) #12;Liquid Water Content Calculation The amount of liquid water

  14. Access Paths Multi-dimensional Index Structures

    E-Print Network [OSTI]

    Mannheim, Universität

    for result TID-lists) · high cost for intersection if one of the indexes deliverse many results · But') · index.find_key(`ZH1984') · Discussion: · cost equivalent to the cost of a one-dimensional access! KeyAccess Paths Multi-dimensional Index Structures 1Freitag, 4. Juni 2010 #12;September 27, 2007

  15. Clearance Based Path Optimization for Motion Planning

    E-Print Network [OSTI]

    Utrecht, Universiteit

    Abstract Many motion planning techniques, like the probabilistic roadmap method (PRM), gen­ erate low] and humanoid robot planning [13]. A commonly used technique for planning paths is the Probabilistic Roadmap.1 Probabilistic Roadmap Method The probabilistic roadmap method consists of two phases: a construction and a query

  16. The Path to Disaster The Deepwater Horizon

    E-Print Network [OSTI]

    Pym, David J.

    was not disconnected · The escaping gas ignited · 11 dead · The drilling rig Deepwater Horizon sank after 2 days #1221/08/2013 1 The Path to Disaster The Deepwater Horizon BP's disaster in the Gulf of Mexico Industrial Psychology Research Centre 14th August, 2013 Transocean Deepwater Horizon #12;21/08/2013 2

  17. Protecting BGP from Invalid Paths Josh Karlin

    E-Print Network [OSTI]

    New Mexico, University of

    Protecting BGP from Invalid Paths Josh Karlin University of New Mexico karlinjf@cs.unm.edu Stephanie Forrest University of New Mexico Santa Fe Institute forrest@cs.unm.edu Jennifer Rexford Princeton University jrex@cs.princeton.edu ABSTRACT The Internet's interdomain routing protocol, BGP, is vul- nerable

  18. Clearance Based Path Optimization for Motion Planning

    E-Print Network [OSTI]

    Utrecht, Universiteit

    Abstract Many motion planning techniques, like the probabilistic roadmap method (PRM), gen- erate low] and humanoid robot planning [13]. A commonly used technique for planning paths is the Probabilistic Roadmap. 1.1 Probabilistic Roadmap Method The probabilistic roadmap method consists of two phases

  19. Folded-path optical analysis gas cell

    DOE Patents [OSTI]

    Carangelo, R.M.; Wright, D.D.

    1995-08-08

    A folded-path gas cell employs an elliptical concave mirror in confronting relationship to two substantially spherical concave mirrors. At least one of the spherical mirrors, and usually both, are formed with an added cylindrical component to increase orthogonal foci coincidence and thereby to increase the radiation energy throughput characteristic of the cell. 10 figs.

  20. Folded-path optical analysis gas cell

    DOE Patents [OSTI]

    Carangelo, Robert M. (Glastonbury, CT); Wright, David D. (Vershire, VT)

    1995-01-01

    A folded-path gas cell employs an elliptical concave mirror in confronting relationship to two substantially spherical concave mirrors. At least one of the spherical mirrors, and usually both, are formed with an added cylindrical component to increase orthogonal focii coincidence and thereby to increase the radiation energy throughput characteristic of the cell.

  1. Ice Thermal Storage Systems for Nuclear Power Plant Supplemental Cooling and Peak Power Shifting

    SciTech Connect (OSTI)

    Haihua Zhao; Hongbin Zhang; Phil Sharpe; Blaise Hamanaka; Wei Yan; WoonSeong Jeong

    2013-03-01

    Availability of cooling water has been one of the major issues for the nuclear power plant site selection. Cooling water issues have frequently disrupted the normal operation at some nuclear power plants during heat waves and long draught. One potential solution is to use ice thermal storage (ITS) systems that reduce cooling water requirements and boost the plant’s thermal efficiency in hot hours. ITS uses cheap off-peak electricity to make ice and uses the ice for supplemental cooling during peak demand time. ITS also provides a way to shift a large amount of electricity from off peak time to peak time. For once-through cooling plants near a limited water body, adding ITS can bring significant economic benefits and avoid forced derating and shutdown during extremely hot weather. For the new plants using dry cooling towers, adding the ITS systems can effectively reduce the efficiency loss during hot weather so that new plants could be considered in regions lack of cooling water. This paper will review light water reactor cooling issues and present the feasibility study results.

  2. A Study of the Occurrence of Supercooling of Water

    E-Print Network [OSTI]

    K. -C. Tan; W. Ho; J. I. Katz; S. -J. Feng

    2014-12-30

    Water supercooling has received considerable research attention. The parameters influencing supercooling include the initial temperature of the water and the temperature of the chilling medium. In this study, we investigated an additional parameter, the type of chilling medium. We correlated the occurrence of supercooling with the minimum temperature anywhere in the water. If the minimum temperature is higher, ice nucleation is unlikely and supercooling will take place. Besides distilled water, we also investigated supercooling of water found in nature, and found that impurities in such water do not facilitate ice nucleation.

  3. Radiostratigraphy and age structure of the Greenland Ice Sheet

    E-Print Network [OSTI]

    2015-01-01

    is 3.15, equivalent to a radio-wave velocity in ice of 168.9to be vertical) that a radio wave travels through ice during?t is where v ice is the radio-wave velocity in ice, ?z ¼ v

  4. Remote sensing of seawater and drifting ice in Svalbard fjords by compact Raman LIDAR

    E-Print Network [OSTI]

    Bunkin, Alexey F; Lednev, Vasily N; Lushnikov, Dmitry L; Marchenko, Aleksey V; Morozov, Eugene G; Pershin, Sergey M; Yulmetov, Renat N

    2013-01-01

    A compact Raman LIDAR system for remote sensing of sea and drifting ice was developed at the Wave Research Center at the Prokhorov General Physics Institute of the RAS. The developed system is based on a diode pumped solid state YVO4:Nd laser combined with compact spectrograph equipped with gated detector. The system exhibits high sensitivity and can be used for mapping or depth profiling of different parameters within many oceanographic problems. Light weight (~20 kg) and low power consumption (300 W) make possible to install the device on any vehicle including unmanned aircraft or submarine system. The Raman LIDAR presented was used for Svalbard fjords study and analysis of different influence of the open sea and glaciers on the water properties. Temperature, phytoplankton, and dissolved organic matter distributions in the seawater were studied in the Ice Fjord, Van Mijen Fjord and Rinders Fjord. Drifting ice and seawater in the Rinders Fjord were characterized by the Raman spectroscopy and fluorescence. It...

  5. Hurricane jeanne Preliminary Water Levels Report

    E-Print Network [OSTI]

    Hurricane jeanne Preliminary Water Levels Report Tide Gauges within the Path of Hurricane Jeanne-OPS Hurricane JEANNE Preliminary Report #12;SUMMARY CO-OPS Tide Gauge Data for Hurricane Jeanne NOAA's Center://tidesonline.nos.noaa.gov). Storm surge is the observed water level minus the predicted water level referred to MLLW. Hurricane

  6. 1 Introduction The shortest augmenting path flow algorithm repeatedly finds a shortest augmenting path (A-path) in the residual

    E-Print Network [OSTI]

    California at Davis, University of

    -path, success if hits t, fail if backup to s last Advance(s); // move forward from s till get stuck at last of u in Gf . Advance(v) //moves towards t till gets stuck, or hits t cv v; // cv records the current While (last = s, t) // stuck partway, so backup { v pred(last); relabel(last); // can't move forward

  7. Do blue-ice moraines in the Heritage Range show the West Antarctic ice sheet survived the last interglacial?

    E-Print Network [OSTI]

    Do blue-ice moraines in the Heritage Range show the West Antarctic ice sheet survived the last in revised form 10 January 2011 Accepted 28 January 2011 Available online xxxx Keywords: Blue-ice moraine cosmogenic isotope data on blue-ice moraines in the Heritage Range, West Antarctica. The age of the moraines

  8. 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

  9. Processes driving sea ice variability in the Bering Sea in an eddying ocean/sea ice model: Mean seasonal cycle

    E-Print Network [OSTI]

    Eisenman, Ian

    the southern ice edge, especially on the western side. The sea ice force balance analysis shows that sea ice air from northerly winds and ice motion away from the coast. South of St Lawrence Island, winds drive is important both climatically and economically. Understanding the processes that control the temporal

  10. Experimental and numerical investigation of phonon mean free path distribution

    E-Print Network [OSTI]

    Zeng, Lingping

    2013-01-01

    Knowledge of phonon mean free path (MFP) distribution is critically important to engineering size effects. Phenomenological models of phonon relaxation times can give us some sense about the mean free path distribution, ...

  11. Working with Utilities: Effective Paths for Tribal Governments...

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

    Working with Utilities: Effective Paths for Tribal Governments Webinar Working with Utilities: Effective Paths for Tribal Governments Webinar September 30, 2015 11:00AM to 12:30PM...

  12. A Surprising Path for Proton Transfer Without Hydrogen Bonds

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

    A Surprising Path for Proton Transfer Without Hydrogen Bonds A Surprising Path for Proton Transfer Without Hydrogen Bonds Print Wednesday, 25 July 2012 00:00 Hydrogen bonds are...

  13. A Potential Path to Emissions-Free Fossil Energy | Department...

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

    A Potential Path to Emissions-Free Fossil Energy A Potential Path to Emissions-Free Fossil Energy August 20, 2013 - 10:00am Addthis The National Energy Technology Laboratory's...

  14. Surface-adaptive and Collision-avoiding Path Planning

    E-Print Network [OSTI]

    Morik, Katharina

    that a desired workpiece is generated by remov- ing material form the stock. The tool is moved by a milling machine which is computer-controlled. The task of automatic path planning is to find a suitable path

  15. The Path a Proton Takes Through a Fuel Cell Membrane

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

    The Path a Proton Takes Through a Fuel Cell Membrane The Path a Proton Takes Through a Fuel Cell Membrane October 11, 2012 Linda Vu, lvu@lbl.gov, +1 510 495 2402 Ram.jpg The cover...

  16. MOF Coating a Promising Path to White LEDs

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

    MOF Coating a Promising Path to White LEDs MOF Coating a Promising Path to White LEDs Print Friday, 27 February 2015 17:11 Hu et al. designed a new yellow phosphor with high...

  17. Largest Ice-Bank Promotes Load Management 

    E-Print Network [OSTI]

    Brarmann, G. L.

    1983-01-01

    conservation measures were incorporated in the design of the new research facility, the ice-bank system has been the most cost-effective of the load management projects at Union Oil....

  18. Glaciers and Ice Sheets Mapping Orbiter concept

    E-Print Network [OSTI]

    Jezek, Kenneth; Rodriguez, Ernesto; Gogineni, Sivaprasad; Freeman, Anthony; Curlander, John; Paden, John D.; Allen, Christopher Thomas

    2006-05-13

    We describe a concept for a spaceborne radar system designed to measure the surface and basal topography of terrestrial ice sheets and to determine the physical properties of the glacier bed. Our primary objective is to ...

  19. Recent vs from IceCube

    E-Print Network [OSTI]

    Klein, Spencer R.; IceCube Collaboration

    2008-01-01

    in the Sun and the Earth, look for low-energy (10 MeV)Sun. IceTop has made a preliminary measurement of the cosmic-ray energy

  20. WATER TRAPPING ON TIDALLY LOCKED TERRESTRIAL PLANETS REQUIRES SPECIAL CONDITIONS

    SciTech Connect (OSTI)

    Yang, Jun; Abbot, Dorian S.; Liu, Yonggang; Hu, Yongyun

    2014-12-01

    Surface liquid water is essential for standard planetary habitability. Calculations of atmospheric circulation on tidally locked planets around M stars suggest that this peculiar orbital configuration lends itself to the trapping of large amounts of water in kilometers-thick ice on the night side, potentially removing all liquid water from the day side where photosynthesis is possible. We study this problem using a global climate model including coupled atmosphere, ocean, land, and sea ice components as well as a continental ice sheet model driven by the climate model output. For a waterworld, we find that surface winds transport sea ice toward the day side and the ocean carries heat toward the night side. As a result, nightside sea ice remains O(10 m) thick and nightside water trapping is insignificant. If a planet has large continents on its night side, they can grow ice sheets O(1000 m) thick if the geothermal heat flux is similar to Earth's or smaller. Planets with a water complement similar to Earth's would therefore experience a large decrease in sea level when plate tectonics drives their continents onto the night side, but would not experience complete dayside dessiccation. Only planets with a geothermal heat flux lower than Earth's, much of their surface covered by continents, and a surface water reservoir O(10%) of Earth's would be susceptible to complete water trapping.

  1. Asynchronous ice lobe retreat and glacial Lake Bascom: Deglaciation of the Hoosic and Vermont valleys, southwestern Vermont

    SciTech Connect (OSTI)

    Small, E.; Desimone, D. (Williams Coll., Williamstown, MA (United States). Dept. of Geology)

    1993-03-01

    Deglaciation of the Hoosic River drainage basin in southwestern Vermont was more complex than previously described. Detailed surficial mapping, stratigraphic relationships, and terrace levels/delta elevations reveal new details in the chronology of glacial Lake Bascom: (1) a pre-Wisconsinan proglacial lake was present in a similar position to Lake Bascom as ice advanced: (2) the northern margin of 275m (900 ft) glacial Lake Bascom extended 10 km up the Vermont Valley; (3) the 215m (705 ft) Bascom level was stable and long lived; (4) intermediate water planes existed between 215m and 190m (625 ft) levels; and (5) a separate ice tongue existed in Shaftsbury Hollow damming a small glacial lake, here named glacial Lake Emmons. This information is used to correlate ice margins to different lake levels. Distance of ice margin retreat during a lake level can be measured. Lake levels are then used as control points on a Lake Bascom relative time line to compare rate of retreat of different ice tongues. Correlation of ice margins to Bascom levels indicates ice retreat was asynchronous between nearby tongues in southwestern Vermont. The Vermont Valley ice tongue retreated between two and four times faster than the Hoosic Valley tongue during the Bascom 275m level. Rate of retreat of the Vermont Valley tongue slowed to one-half of the Hoosic tongue during the 215m--190m lake levels. Factors responsible for varying rates of retreat are subglacial bedrock gradient, proximity to the Hudson-Champlain lobe, and the presence of absence of a calving margins. Asynchronous retreat produced splayed ice margins in southwestern Vermont. Findings from this study do not support the model of parallel, synchronous retreat proposed by many workers for this region.

  2. Aerosol Effects on Cirrus through Ice Nucleation in the Community Atmosphere Model CAM5 with a Statistical Cirrus Scheme

    SciTech Connect (OSTI)

    Wang, Minghuai; Liu, Xiaohong; Zhang, Kai; Comstock, Jennifer M.

    2014-09-01

    A statistical cirrus cloud scheme that tracks ice saturation ratio in the clear-sky and cloudy portion of a grid box separately has been implemented into NCAR CAM5 to provide a consistent treatment of ice nucleation and cloud formation. Simulated ice supersaturation and ice crystal number concentrations strongly depend on the number concentrations of heterogeneous ice nuclei (IN), subgrid temperature formulas and the number concentration of sulfate particles participating in homogeneous freezing, while simulated ice water content is insensitive to these perturbations. 1% to 10% dust particles serving as heterogeneous IN is 20 found to produce ice supersaturaiton in better agreement with observations. Introducing a subgrid temperature perturbation based on long-term aircraft observations of meso-scale motion produces a better hemispheric contrast in ice supersaturation compared to observations. Heterogeneous IN from dust particles significantly alter the net radiative fluxes at the top of atmosphere (TOA) (-0.24 to -1.59 W m-2) with a significant clear-sky longwave component (0.01 to -0.55 W m-2). Different cirrus treatments significantly perturb the net TOA anthropogenic aerosol forcing from -1.21 W m-2 to -1.54 W m-2, with a standard deviation of 0.10 W m-2. Aerosol effects on cirrus clouds exert an even larger impact on the atmospheric component of the radiative fluxes (two or three times the changes in the TOA radiative fluxes) and therefore on the hydrology cycle through the fast atmosphere response. This points to the urgent need to quantify aerosol effects on cirrus clouds through ice nucleation and how these further affect the hydrological cycle.

  3. Development of a Mobile Ice Nucleus Counter

    SciTech Connect (OSTI)

    Kok, Gregory; Kulkarni, Gourihar

    2014-07-10

    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.

  4. Software-based tool path evaluation for environmental sustainability

    E-Print Network [OSTI]

    KONG, DAEYOUNG; Seungchoun Choi; Yusuke Yasui; Sushrut Pavanaskar; Dornfeld, David; Wright, Paul

    2011-01-01

    productivity, while the sustainability and energy ef?ciencyof sustainability of a tool path (i.e. energy consumption

  5. FESAC Development Path Meeting Draft Agenda

    E-Print Network [OSTI]

    Facility (ST, Tokamak, GDT) - M. Peng 10:50 - 11:10 Discussion 11:10 - 11:45 3) First dry wall for IFE for Demo? MFE timing issues (licensing of CTF) Interaction with IFE ETF to Demo transition? (licensing in the IFE path - Wayne Meier HIF liquid walls Z pinches Dry walls 2:30 - 2:50 Discussion 2:50 - 3:00 Break 3

  6. Saving the Coherent State Path Integral

    E-Print Network [OSTI]

    Yariv Yanay; Erich J. Mueller

    2013-03-19

    By returning to the underlying discrete time formalism, we relate spurious results in coherent state path integral calculations to the high frequency structure of their propagators. We show how to modify the standard expressions for thermodynamic quantities to yield correct results. These expressions are relevant to a broad range of physical problems, from the thermodynamics of Bose lattice gases to the dynamics of spin systems.

  7. Free Energy Changes, Fluctuations, and Path Probabilities

    E-Print Network [OSTI]

    William G. Hoover; Carol G. Hoover

    2011-04-20

    We illustrate some of the static and dynamic relations discovered by Cohen, Crooks, Evans, Jarzynski, Kirkwood, Morriss, Searles, and Zwanzig. These relations link nonequilibrium processes to equilibrium isothermal free energy changes and to dynamical path probabilities. We include ideas suggested by Dellago, Geissler, Oberhofer, and Schoell-Paschinger. Our treatment is intended to be pedagogical, for use in an updated version of our book: Time Reversibility, Computer Simulation, and Chaos. Comments are very welcome.

  8. The lattice path operad Clemens Berger (Nice)

    E-Print Network [OSTI]

    Berger, Clemens

    -operads. Let (X, ) be a based topological space and (Sn, ) be the n-sphere. Then nX = Top(Sn, X) is an algebra operad O in E. Let EOu. Then HomOu(, X) is a CoendO()-algebra. 6 #12;E = Top or E = Ch(Z) contains SetsThe lattice path operad Clemens Berger (Nice) Third Arolla Conference on Algebraic Topology August

  9. Nanocluster building blocks of artificial square spin ice: Stray-field studies of thermal dynamics

    SciTech Connect (OSTI)

    Pohlit, Merlin Porrati, Fabrizio; Huth, Michael; Müller, Jens

    2015-05-07

    We present measurements of the thermal dynamics of a Co-based single building block of an artificial square spin ice fabricated by focused electron-beam-induced deposition. We employ micro-Hall magnetometry, an ultra-sensitive tool to study the stray field emanating from magnetic nanostructures, as a new technique to access the dynamical properties during the magnetization reversal of the spin-ice nanocluster. The obtained hysteresis loop exhibits distinct steps, displaying a reduction of their “coercive field” with increasing temperature. Therefore, thermally unstable states could be repetitively prepared by relatively simple temperature and field protocols allowing one to investigate the statistics of their switching behavior within experimentally accessible timescales. For a selected switching event, we find a strong reduction of the so-prepared states' “survival time” with increasing temperature and magnetic field. Besides the possibility to control the lifetime of selected switching events at will, we find evidence for a more complex behavior caused by the special spin ice arrangement of the macrospins, i.e., that the magnetic reversal statistically follows distinct “paths” most likely driven by thermal perturbation.

  10. IceCube: Performance, Status, and Future

    E-Print Network [OSTI]

    Carsten Rott; for the IceCube Collaboration

    2006-11-28

    High-energy neutrinos are uniquely suited to study a large variety of physics as they traverse the universe almost untouched, in contrast to conventional astronomical messengers like photons or cosmic rays which are limited by interactions with radiation and matter at high energies or deflected by ambient magnetic fields. Located at the South Pole, IceCube combined with its predecessor AMANDA comprise the world's largest neutrino telescope. IceCube currently consists of nine strings, each containing 60 digital optical modules, deployed at depths of 1.5 to 2.5km in the ice and an array of 16 surface air-shower stations. IceCube is expected to be completed in early 2011 at which time it will instrument a volume of one km^3 below the IceTop air-shower array covering an area of one km^2. The current IceCube detector performance is described and an outlook given into the large variety of physics that it can address, with an emphasis on the search for ultra-high-energy neutrinos which may shed light on the origins of the highest energy cosmic rays.

  11. IceCube: Performance, Status, and Future

    E-Print Network [OSTI]

    Rott, C

    2006-01-01

    High-energy neutrinos are uniquely suited to study a large variety of physics as they traverse the universe almost untouched, in contrast to conventional astronomical messengers like photons or cosmic rays which are limited by interactions with radiation and matter at high energies or deflected by ambient magnetic fields. Located at the South Pole, IceCube combined with its predecessor AMANDA comprise the world's largest neutrino telescope. IceCube currently consists of nine strings, each containing 60 digital optical modules, deployed at depths of 1.5 to 2.5km in the ice and an array of 16 surface air-shower stations. IceCube is expected to be completed in early 2011 at which time it will instrument a volume of one km^3 below the IceTop air-shower array covering an area of one km^2. The current IceCube detector performance is described and an outlook given into the large variety of physics that it can address, with an emphasis on the search for ultra-high-energy neutrinos which may shed light on the origins ...

  12. Ice chemistry in starless molecular cores

    E-Print Network [OSTI]

    Kalvans, Juris

    2015-01-01

    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...

  13. Microwave and Millimeter-Wave Radiometric Studies of Temperature, Water Vapor and Clouds

    SciTech Connect (OSTI)

    Westwater, Edgeworth

    2011-05-06

    The importance of accurate measurements of column amounts of water vapor and cloud liquid has been well documented by scientists within the Atmospheric Radiation Measurement (ARM) Program. At the North Slope of Alaska (NSA), both microwave radiometers (MWR) and the MWRProfiler (MWRP), been used operationally by ARM for passive retrievals of the quantities: Precipitable Water Vapor (PWV) and Liquid Water Path (LWP). However, it has been convincingly shown that these instruments are inadequate to measure low amounts of PWV and LWP. In the case of water vapor, this is especially important during the Arctic winter, when PWV is frequently less than 2 mm. For low amounts of LWP (< 50 g/m{sup 2}), the MWR and MWRP retrievals have an accuracy that is also not acceptable. To address some of these needs, in March-April 2004, NOAA and ARM conducted the NSA Arctic Winter Radiometric Experiment - Water Vapor Intensive Operational Period at the ARM NSA/Adjacent Arctic Ocean (NSA/AAO) site. After this experiment, the radiometer group at NOAA moved to the Center for Environmental Technology (CET) of the Department of Electrical and Computer Engineering of the University of Colorado at Boulder. During this 2004 experiment, a total of 220 radiosondes were launched, and radiometric data from 22.235 to 380 GHz were obtained. Primary instruments included the ARM MWR and MWRP, a Global Positioning System (GPS), as well as the CET Ground-based Scanning Radiometer (GSR). We have analyzed data from these instruments to answer several questions of importance to ARM, including: (a) techniques for improved water vapor measurements; (b) improved calibration techniques during cloudy conditions; (c) the spectral response of radiometers to a variety of conditions: clear, liquid, ice, and mixed phase clouds; and (d) forward modeling of microwave and millimeter wave brightness temperatures from 22 to 380 GHz. Many of these results have been published in the open literature. During the third year of this contract, we participated in another ARM-sponsored experiment at the NSA during February-March 2007. This experiment is called the Radiative Heating in Underexplored Bands Campaign (RHUBC) and the GSR was operated successfully for the duration of the campaign. One of the principal goals of the experiment was to provide retrievals of water vapor during PWV amounts less than 2 mm and to compare GSR data with ARM radiometers and radiosondes. A secondary goal was to compare the radiometric response of the microwave and millimeter wavelength radiometers to water and ice clouds. In this final report, we will include the separate progress reports for each of the three years of the project and follow with a section on major accomplishments of the project.

  14. "Multi-machine" Strategy: The Other Path of the FESAC

    E-Print Network [OSTI]

    "Multi-machine" Strategy: The Other Path of the FESAC Burning Plasma Strategy Gerald Navratil Difference ITER Development Path FIRE Development Path `Single Machine Strategy' `Multi-machine Strategy Machine Strategy' `Multi-machine Strategy' `One Step to DEMO' Modular Strategy `Penultimate Step to DEMO

  15. United States Department of Critical Path Method AppliedAgriculture

    E-Print Network [OSTI]

    Forest and Range Experiment Station PO. Box 245, Berkeley, California 94701 August 1986 #12;Critical Path interrelated activities. One approach that has been widely used is the critical path method, in which a network of thousands of activities, such as major construction and engineering projects. In the 1950's, a critical path

  16. Modeling the Global Critical Path in Concurrent Systems

    E-Print Network [OSTI]

    Modeling the Global Critical Path in Concurrent Systems Girish Venkataramani Tiberiu Chelcea Mihai Molecular Electronics, under contract number CCR0205523. #12;Keywords: Performance modeling, critical path analysis, high-level synthesis #12;Abstract We show how the global critical path can be used as a practical

  17. Computing Along the Critical Path Dean M. Tullsen Brad Calder

    E-Print Network [OSTI]

    Sair, Suleyman

    Computing Along the Critical Path Dean M. Tullsen Brad Calder Department of Computer Science dependencies that constrain execution speed constitute the critical path of execution. To optimize the performance of the processor, we either have to reduce the critical path or execute it more efficiently

  18. Capturing Post-Silicon Variations using a Representative Critical Path

    E-Print Network [OSTI]

    Sapatnekar, Sachin

    1 Capturing Post-Silicon Variations using a Representative Critical Path Qunzeng Liu and Sachin S on measurements on a replica of the nominal critical path, whose variations are intended to reflect those of the entire circuit after manufacturing. For realistic circuits, where the number of critical paths can

  19. Multipath channels Path timing critical (versus amplitude information)

    E-Print Network [OSTI]

    Southern California, University of

    1 · Multipath channels · Path timing critical (versus amplitude information) ­ Certain modulations: PPM ­ Location/Ranging · Model ­ Delay spread ­ L paths (M choose L possible profiles) ­ Independent path amplitudes ­ Block constant channel ­ AW GN 0 100 200 300 400 500 600 -0.02 0 0.02 The Channel

  20. Reconstructing Critical Paths from Execution Traces Martijn Hendriks

    E-Print Network [OSTI]

    Vaandrager, Frits

    Reconstructing Critical Paths from Execution Traces Martijn Hendriks Embedded Systems Institute of constructing critical paths from incomplete information. In general, a directed acyclic graph of tasks with their execution times (i.e., a task graph) is necessary to extract critical paths. We assume, however, that only

  1. Accurate Critical Path Analysis via Random Trace Construction

    E-Print Network [OSTI]

    Zilles, Craig

    Accurate Critical Path Analysis via Random Trace Construction Pierre Salverda Charles Tucker Craig to their profiled behavior. We demonstrate our technique in the context of critical path analysis, showing it can achieve the same accuracy as a hardware critical path predictor, but with lower hardware requirements. Key

  2. Robot Path Planning in Uncertain Environments: A Language-Measure-

    E-Print Network [OSTI]

    Ray, Asok

    Robot Path Planning in Uncertain Environments: A Language-Measure- Theoretic Approach Devesh K. Jha the problem of goal-directed robot path planning in the presence of uncertainties that are induced by bounded, probabilistic finite state automata 1 Motivation and Introduction In general, path planning of robots (e

  3. Automatic Construction of High Quality Roadmaps for Path Planning

    E-Print Network [OSTI]

    Utrecht, Universiteit

    Automatic Construction of High Quality Roadmaps for Path Planning D.Nieuwenhuisen A.Kamphuis M-CS-2004-068 www.cs.uu.nl #12;Automatic Construction of High Quality Roadmaps for Path Planning D on a technique from robotics, that computes a roadmap of smooth, collision-free, high-quality paths. This roadmap

  4. UNIVERSITY OF CALIFORNIA, SAN DIEGO Critical-Path Aware Processor Architectures

    E-Print Network [OSTI]

    Sair, Suleyman

    UNIVERSITY OF CALIFORNIA, SAN DIEGO Critical-Path Aware Processor Architectures A dissertation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 C. Multithreading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 III Critical Path Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 A. General Critical-Path Analysis

  5. Quantum Mechanical Single Molecule Partition Function from Path Integral Monte Carlo Simulations

    E-Print Network [OSTI]

    Chempath, Shaji; Bell, Alexis T.; Predescu, Cristian

    2008-01-01

    calculated from path integral Monte Carlo(PIMC) and harmoniccalculated from path integral Monte Carlo (PIMC) andFunction from Path Integral Monte Carlo Simulations Shaji

  6. A path integral approach to data assimilation in stochastic nonlinear systems

    E-Print Network [OSTI]

    Quinn, John C.

    2010-01-01

    Values as Path Integrals . . . . . . . . . . .2.3Carlo Evaluation of Path Integrals . . . . . . . . . . . 3.1Sampling . . . . . . . . . . 3.2 Path Integral Monte Carlo

  7. A Path-Integral Approach to Bayesian Inference for Inverse Problems Using the Semiclassical Approximation

    E-Print Network [OSTI]

    Chang, JC; Savage, VM; Chou, T

    2014-01-01

    CC, Buice MA (2010) Path integral methods for stochastic di?2012) Quantum mechanics and path integrals: Emended edition.15. Graham R (1977) Path integral formulation of general di?

  8. Technology demonstration of Ka-band digitally-beamformed radar for ice topography mapping

    E-Print Network [OSTI]

    Sadowy, G; Heavey, B; Moller, D; Rignot, E; Zawadzki, M; Rengarajan, S

    2007-01-01

    Beamformed Radar for Ice Topography Mapping Gregory Sadowy,Glacier and Land Ice Surface Topography Interferometer) is aGLISTIN will collect ice topography measurements over a wide

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

    E-Print Network [OSTI]

    Zhang, Jinlun

    of the actual fields. The simulated ice thickness can then be used to determine the major modes of variability of the ice thickness and the physical processes that are important in their formation. The simulations from concentration measured by satellites is subject to errors (Kwok 2002), particularly during the summer when

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

    E-Print Network [OSTI]

    Papalambros, Panos

    , marketing, and psychology. Quantitative models from these disciplines can be integrated into a design for teaching product design and for designing products taking into account market and policy environments alongICED'09/148 INTERNATIONAL CONFERENCE ON ENGINEERING DESIGN, ICED'09 24 - 27 AUGUST 2009, STANFORD

  11. Water in Protoplanetary Disks: Deuteration and Turbulent Mixing

    E-Print Network [OSTI]

    Furuya, Kenji; Nomura, Hideko; Hersant, Franck; Wakelam, Valentine

    2013-01-01

    We investigate water and deuterated water chemistry in turbulent protoplanetary disks. Chemical rate equations are solved with the diffusion term, mimicking turbulent mixing in vertical direction. Water near the midplane is transported to the disk atmosphere by turbulence and destroyed by photoreactions to produce atomic oxygen, while the atomic oxygen is transported to the midplane and reforms water and/or other molecules. We find that this cycle significantly decreases column densities of water ice at r < 30 AU, where dust temperatures are too high to reform water ice effectively. The radial extent of such region depends on the desorption energy of atomic hydrogen. Our model indicates that water ice could be deficient even outside the sublimation radius. Outside this radius, the cycle decreases the D/H ratio of water ice from 2x10^-2, which is set by the collapsing core model, to 10^-4-10^-2 in 10^6 yr, without significantly decreasing the water ice column density. The resultant D/H ratios depend on the ...

  12. A Comprehensive Parameterization of Heterogeneous Ice Nucleation of Dust Surrogate: Laboratory Study with Hematite Particles and Its Application to Atmospheric Models

    SciTech Connect (OSTI)

    Hiranuma, Naruki; Paukert, Marco; Steinke, Isabelle; Zhang, Kai; Kulkarni, Gourihar R.; Hoose, Corinna; Schnaiter, Martin; Saathoff, Harald; Mohler, Ottmar

    2014-12-10

    A new heterogeneous ice nucleation parameterization that covers a wide temperature range (-36 ?C to -78 ?C) is presented. Developing and testing such an ice nucleation parameterization, which is constrained through identical experimental conditions, is critical in order to accurately simulate the ice nucleation processes in cirrus clouds. The surface-scaled ice nucleation efficiencies of hematite particles, inferred by ns, were derived from AIDA (Aerosol Interaction and Dynamics in the Atmosphere) cloud chamber measurements under water subsaturated conditions that were realized by continuously changing temperature (T) and relative humidity with respect to ice (RHice) in the chamber. Our measurements showed several different pathways to nucleate ice depending on T and RHice conditions. For instance, almost independent freezing was observed at -60 ?C < T < -50 ?C, where RHice explicitly controlled ice nucleation efficiency, while both T and RHice played roles in other two T regimes: -78 ?C < T < -60 ?C and -50 ?C < T < -36 ?C. More specifically, observations at T colder than -60 ?C revealed that higher RHice was necessary to maintain constant ns, whereas T may have played a significant role in ice nucleation at T warmer than -50 ?C. We implemented new ns parameterizations into two cloud models to investigate its sensitivity and compare with the existing ice nucleation schemes towards simulating cirrus cloud properties. Our results show that the new AIDA-based parameterizations lead to an order of magnitude higher ice crystal concentrations and inhibition of homogeneous nucleation in colder temperature regions. Our cloud simulation results suggest that atmospheric dust particles that form ice nuclei at lower temperatures, below -36 ?C, can potentially have stronger influence on cloud properties such as cloud longevity and initiation when compared to previous parameterizations.

  13. Application of an online-coupled regional climate model, WRF-CAM5, over East Asia for examination of ice nucleation schemes: Part I. Comprehensive model evaluation and trend analysis for 2006 and 2011

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

    Chen, Ying; Zhang, Yang; Fan, Jiwen; Leung, Lai -Yung; Zhang, Qiang; He, Kebin

    2015-08-18

    Online-coupled climate and chemistry models are necessary to realistically represent the interactions between climate variables and chemical species and accurately simulate aerosol direct and indirect effects on cloud, precipitation, and radiation. In this Part I of a two-part paper, simulations from the Weather Research and Forecasting model coupled with the physics package of Community Atmosphere Model (WRF-CAM5) are conducted with the default heterogeneous ice nucleation parameterization over East Asia for two full years: 2006 and 2011. A comprehensive model evaluation is performed using satellite and surface observations. The model shows an overall acceptable performance for major meteorological variables at themore »surface and in the boundary layer, as well as column variables (e.g., precipitation, cloud fraction, precipitating water vapor, downward longwave and shortwave radiation). Moderate to large biases exist for cloud condensation nuclei over oceanic areas, cloud variables (e.g., cloud droplet number concentration, cloud liquid and ice water paths, cloud optical depth, longwave and shortwave cloud forcing). These biases indicate a need to improve the model treatments for cloud processes, especially cloud droplets and ice nucleation, as well as to reduce uncertainty in the satellite retrievals. The model simulates well the column abundances of chemical species except for column SO2 but relatively poor for surface concentrations of several species such as CO, NO2, SO2, PM2.5, and PM10. Several reasons could contribute to the underestimation of major chemical species in East Asia including underestimations of anthropogenic emissions and natural dust emissions, uncertainties in the spatial and vertical distributions of the anthropogenic emissions, as well as biases in meteorological, radiative, and cloud predictions. Despite moderate to large biases in the chemical predictions, the model performance is generally consistent with or even better than that reported for East Asia with only a few exceptions. The model generally reproduces the observed seasonal variations and the difference between 2006 and 2011 for most variables or chemical species. Overall, these results demonstrate promising skills of WRF-CAM5 for long-term simulations at a regional scale and suggest several areas of potential improvements.« less

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

    E-Print Network [OSTI]

    Ferrantelli, Andrea

    2015-01-01

    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.

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

    E-Print Network [OSTI]

    Andrea Ferrantelli; Klaus Viljanen

    2015-06-30

    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.

  16. A three-phase free boundary problem with melting ice and dissolving gas

    E-Print Network [OSTI]

    Maurizio Ceseri; John M. Stockie

    2014-11-05

    We develop a mathematical model for a three-phase free boundary problem in one dimension that involves the interactions between gas, water and ice. The dynamics are driven by melting of the ice layer, while the pressurized gas also dissolves within the meltwater. The model incorporates a Stefan condition at the water-ice interface along with Henry's law for dissolution of gas at the gas-water interface. We employ a quasi-steady approximation for the phase temperatures and then derive a series solution for the interface positions. A non-standard feature of the model is an integral free boundary condition that arises from mass conservation owing to changes in gas density at the gas-water interface, which makes the problem non-self-adjoint. We derive a two-scale asymptotic series solution for the dissolved gas concentration, which because of the non-self-adjointness gives rise to a Fourier series expansion in eigenfunctions that do not satisfy the usual orthogonality conditions. Numerical simulations of the original governing equations are used to validate the series approximations.

  17. Improved initial guess for minimum energy path calculations

    SciTech Connect (OSTI)

    Smidstrup, Søren; Pedersen, Andreas; Stokbro, Kurt

    2014-06-07

    A method is presented for generating a good initial guess of a transition path between given initial and final states of a system without evaluation of the energy. An objective function surface is constructed using an interpolation of pairwise distances at each discretization point along the path and the nudged elastic band method then used to find an optimal path on this image dependent pair potential (IDPP) surface. This provides an initial path for the more computationally intensive calculations of a minimum energy path on an energy surface obtained, for example, by ab initio or density functional theory. The optimal path on the IDPP surface is significantly closer to a minimum energy path than a linear interpolation of the Cartesian coordinates and, therefore, reduces the number of iterations needed to reach convergence and averts divergence in the electronic structure calculations when atoms are brought too close to each other in the initial path. The method is illustrated with three examples: (1) rotation of a methyl group in an ethane molecule, (2) an exchange of atoms in an island on a crystal surface, and (3) an exchange of two Si-atoms in amorphous silicon. In all three cases, the computational effort in finding the minimum energy path with DFT was reduced by a factor ranging from 50% to an order of magnitude by using an IDPP path as the initial path. The time required for parallel computations was reduced even more because of load imbalance when linear interpolation of Cartesian coordinates was used.

  18. New age water chillers with water as refrigerant

    E-Print Network [OSTI]

    Kühnl-Kinel, J

    1998-01-01

    Vacuum-process technology producing chilled water needs no refrigerant of the conventional kind, but water from the process itself is used to generate cooling. This eye-catching novelty incorporates many of the considerations about the future of refrigerants: "ozone friendly", no extra demands for safety measures or for skilful operators, no special requirements concerning the installation's components, lower maintenance costs since leakages can be accommodated from the system. Vacuum-process technology may be used not only for production of chilled water but also for Binary Ice - pumpable suspension of minute ice crystals in an aqueous solution. This means that all the advantages related to a latent heat system may become available.

  19. THE INTERIOR DYNAMICS OF WATER PLANETS

    SciTech Connect (OSTI)

    Fu, Roger; O'Connell, Richard J.; Sasselov, Dimitar D. E-mail: richard_oconnell@harvard.ed

    2010-01-10

    The ever-expanding catalog of detected super-Earths calls for theoretical studies of their properties in the case of a substantial water layer. This work considers such water planets with a range of masses and water mass fractions (2-5 M{sub Earth}, 0.02%-50% H{sub 2}O). First, we model the thermal and dynamical structure of the near-surface for icy and oceanic surfaces, finding separate regimes where the planet is expected to maintain a subsurface liquid ocean and where it is expected to exhibit ice tectonics. Newly discovered exoplanets may be placed into one of these regimes given estimates of surface temperature, heat flux, and gravity. Second, we construct a parameterized convection model for the underlying ice mantle of higher ice phases, finding that materials released from the silicate-iron core should traverse the ice mantle on the timescale of 0.1 to 100 megayears. We present the dependence of the overturn times of the ice mantle and the planetary radius on total mass and water mass fraction. Finally, we discuss the implications of these internal processes on atmospheric observables.

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

    SciTech Connect (OSTI)

    Barry, Roger G.

    2007-12-19

    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.

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

    ScienceCinema (OSTI)

    Barry, Roger G.

    2009-09-01

    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.

  2. Characterizing the Groundwater-Surface Water Interactions in Different Subsurface Geologic Environments Using Geochemical and Isotopic Analyses

    E-Print Network [OSTI]

    Long, Molly

    2014-12-31

    -surface water interactions. Knowledge of the influence these factors have on surface water connections with groundwater will help determine possible recharge and contaminant flow paths affecting future water supply wells installed in similar alluvial...

  3. Turbid water Clear water

    E-Print Network [OSTI]

    Jaffe, Jules

    Turbid water Clear water pixel position cameraresponsecameraresponse pixel position ABSTRACT: A new underwater laser scanning system, providing microbathymetric information in coastal waters is described the backscatter component resulting in enhanced performance in turbid waters. The system is expected to provide

  4. Two formation paths for cluster dwarf galaxies?

    E-Print Network [OSTI]

    Bianca M. Poggianti; Nobunari Kashikawa; Terry Bridges; Bahram Mobasher; Yutaka Komiyama; Dave Carter; Sadanori Okamura; Masafumi Yagi

    2003-10-15

    A surprising result of our recent spectroscopic survey of galaxies in the Coma cluster has been the discovery of a possible bimodal distribution in the metallicities of faint galaxies at $M_B>-17$. We identified a group of dwarfs with luminosity-weighted metallicities around solar and a group with [M/H] around -1.5. A metallicity bimodality among galaxies of similar luminosities is unexpected and suggests that faint cluster galaxies could be an heterogeneous population that formed through more than one evolutionary path, possibly as a consequence of the cluster environment.

  5. Path integral quantization of generalized quantum electrodynamics

    SciTech Connect (OSTI)

    Bufalo, R.; Pimentel, B. M.; Zambrano, G. E. R.

    2011-02-15

    In this paper, a complete covariant quantization of generalized electrodynamics is shown through the path integral approach. To this goal, we first studied the Hamiltonian structure of the system following Dirac's methodology and, then, we followed the Faddeev-Senjanovic procedure to obtain the transition amplitude. The complete propagators (Schwinger-Dyson-Fradkin equations) of the correct gauge fixation and the generalized Ward-Fradkin-Takahashi identities are also obtained. Afterwards, an explicit calculation of one-loop approximations of all Green's functions and a discussion about the obtained results are presented.

  6. ClearPath | 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTIONRobertsdale, Alabama (Utility Company) Jump to:New York:ClayBurnVitaCleanstarClearPath Jump to:

  7. EnerPath | 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX ECoopButtePowerEdisto Electric Coop, Inc JumpElko, Nevada:Geothermal7)EnerPath Jump to:

  8. The Flight Paths for Biojet Fuel

    Gasoline and Diesel Fuel Update (EIA)

    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 Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustments (Billion Cubic Feet) Wyoming963 1.969 1.979 1.988Prices,Flight Paths for Biojet Fuel Tony Radich

  9. Looking for the rainbow on exoplanets covered by liquid and icy water clouds

    E-Print Network [OSTI]

    Karalidi, T; Hovenier, J W

    2012-01-01

    Looking for the primary rainbow in starlight that is reflected by exoplanets appears to be a promising method to search for liquid water clouds in exoplanetary atmospheres. Ice water clouds, that consist of water crystals instead of water droplets, could potentially mask the rainbow feature in the planetary signal by covering liquid water clouds. Here, we investigate the strength of the rainbow feature for exoplanets that have liquid and icy water clouds in their atmosphere, and calculate the rainbow feature for a realistic cloud coverage of Earth. We calculate flux and polarization signals of starlight that is reflected by horizontally and vertically inhomogeneous Earth--like exoplanets, covered by patchy clouds consisting of liquid water droplets or water ice crystals. The planetary surfaces are black. On a planet with a significant coverage of liquid water clouds only, the total flux signal shows a weak rainbow feature. Any coverage of the liquid water clouds by ice clouds, however, dampens the rainbow fea...

  10. Fast Numerical Method for Growth and Retreat of Subsurface Ice on Mars Norbert Schorghofer

    E-Print Network [OSTI]

    Schörghofer, Norbert

    ice, retreat of pore ice, retreat of an ice sheet, and retreat of pore ice due to geothermal heating is the vertical spatial resolution and D the diffusion coefficient. The vertical grid spacing needs to be finer

  11. Ocean-ice/oil-weathering computer program user's manual. Final report

    SciTech Connect (OSTI)

    Kirstein, B.E.; Redding, R.T.

    1987-10-01

    The ocean-ice/oil-weathering code is written in FORTRAN as a series of stand-alone subroutines that can easily be installed on most any computer. All of the trial-and-error routines, integration routines, and other special routines are written in the code so that nothing more than the normal system functions such as EXP are required. The code is user-interactive and requests input by prompting questions with suggested input. Therefore, the user can actually learn about the nature of crude oil and oil weathering by using this code. The ocean-ice oil-weathering model considers the following weathering processes: evaporation; dispersion (oil into water); moussee (water into oil); and spreading; These processes are used to predict the mass balance and composition of oil remaining in the slick as a function of time and environmental parameters.

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

    SciTech Connect (OSTI)

    Bezacier, Lucile; Hanfland, Michael; Journaux, Baptiste; Perrillat, Jean-Philippe; Cardon, Hervé; Daniel, Isabelle

    2014-09-14

    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.

  13. Path Planning Algorithm for Extinguishing Forest Fires

    E-Print Network [OSTI]

    Kumar, M P Sivaram

    2012-01-01

    One of the major impacts of climatic changes is due to destroying of forest. Destroying of forest takes place in many ways but the majority of the forest is destroyed due to wild forest fires. In this paper we have presented a path planning algorithm for extinguishing fires which uses Wireless Sensor and Actor Networks (WSANs) for detecting fires. Since most of the works on forest fires are based on Wireless Sensor Networks (WSNs) and a collection of work has been done on coverage, message transmission, deployment of nodes, battery power depletion of sensor nodes in WSNs we focused our work in path planning approach of the Actor to move to the target area where the fire has occurred and extinguish it. An incremental approach is presented in order to determine the successive moves of the Actor to extinguish fire in an environment with and without obstacles. This is done by comparing the moves determined with target location readings obtained using sensors until the Actor reaches the target area to extinguish f...

  14. Did changes in the Subpolar North Atlantic trigger the recent mass loss from the Greenland Ice Sheet?

    E-Print Network [OSTI]

    Straneo, Fiamma

    . The loss was not so much a result of increased surface melt but, rather, of ice loss due to the widespread; Holland et al. 2008]. Specifically, increased melting due, for example, to warming ocean waters can speed that STW penetrate inside Greenland's glacial fjords is limited to a handful of summer profiles from

  15. Melting of the Patagonian Ice Sheet and deglacial perturbations of the nitrogen cycle in the eastern South Pacific

    E-Print Network [OSTI]

    Cattin, Rodolphe

    Melting of the Patagonian Ice Sheet and deglacial perturbations of the nitrogen cycle; published 18 February 2006. [1] We report the last glacial-interglacial transition of marine denitrification denitrification changes are in close agreement with the fresh-water pulses that resulted from the melting

  16. Synchrotron X-ray Diffraction Investigation of the Anomalous Behavior of Ice During Freezing of Aqueous Systems

    E-Print Network [OSTI]

    Elliott, James

    Synchrotron X-ray Diffraction Investigation of the Anomalous Behavior of Ice During Freezing be used to quantify stresses during freezing, which could improve our understanding of the role of water, such as freeze-induced destabilization of biological systems, and laboratory or industrial practices

  17. A reconciled estimate of ice-sheet mass balance

    E-Print Network [OSTI]

    2012-01-01

    Estimate of Ice-Sheet Mass Balance Andrew Shepherd, 1 * Erikand models of surface mass balance and glacial isostaticThis Ice Sheet Mass Balance Exercise (IMBIE) was facilitated

  18. Optimization of Ice Thermal Storage Systems Design for HVAC Systems 

    E-Print Network [OSTI]

    Nassif, N.; Hall, C.; Freelnad, D.

    2013-01-01

    energy cost. A tool for optimal ice storage design is developed, considering the charging and discharge times and optimal sizing of ice thermal storage system. Detailed simulation studies using real office building located near Orlando, FL including...

  19. Searching for Cosmic Accelerators via IceCube

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

    Searching for Cosmic Accelerators via IceCube Searching for Cosmic Accelerators via IceCube Berkeley Lab Researchers Part of an International Hunt November 21, 2013 Lynn Yarris,...

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

    E-Print Network [OSTI]

    Froyd, Karl D.

    2013-01-01

    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 ...

  1. Three Different Behaviors of Liquid Water Path of Water Clouds in Aerosol-Cloud Interactions

    E-Print Network [OSTI]

    Han, Quingyuan

    third of the cases, a minus one third (-1/3) power law relation between effective droplet radius droplet size and enhance evaporation just below cloud base, which decouples the cloud from the boundary explanation for the observed decrease of the diurnal temperature cycle (Hansen et al., 1997). Significant

  2. Towards a realistic parsing of the Feynman path integral

    E-Print Network [OSTI]

    K. B. Wharton

    2015-11-29

    The Feynman path integral does not allow a "one real path" interpretation, because amplitudes contribute to probabilities in a non-separable manner. The opposite extreme, "all paths happen", is not a useful or informative account. In this paper it is shown that an intermediate parsing of the path integral, into realistic non-interfering possibilities, is always available. Each realistic possibility formally corresponds to numerous particle paths, but is arguably best interpreted as a spacetime-valued field. Notably, one actual field history can always be said to occur, although it will generally not have an extremized action. The most obvious concerns with this approach are addressed, indicating necessary follow-up research. But without obvious showstoppers, it seems plausible that the path integral might be reinterpreted to explain quantum phenomena in terms of Lorentz covariant field histories.

  3. Path Integral and Effective Hamiltonian in Loop Quantum Cosmology

    E-Print Network [OSTI]

    Haiyun Huang; Yongge Ma; Li Qin

    2011-06-27

    We study the path integral formulation of Friedmann universe filled with a massless scalar field in loop quantum cosmology. All the isotropic models of $k=0,+1,-1$ are considered. To construct the path integrals in the timeless framework, a multiple group-averaging approach is proposed. Meanwhile, since the transition amplitude in the deparameterized framework can be expressed in terms of group-averaging, the path integrals can be formulated for both deparameterized and timeless frameworks. Their relation is clarified. It turns out that the effective Hamiltonian derived from the path integral in deparameterized framework is equivalent to the effective Hamiltonian constraint derived from the path integral in timeless framework, since they lead to same equations of motion. Moreover, the effective Hamiltonian constraints of above models derived in canonical theory are confirmed by the path integral formulation.

  4. Operation and Control of Full Ice-storage System 

    E-Print Network [OSTI]

    Liu, Q.; Liu, Y.

    2006-01-01

    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...

  5. Ice Simulation Using GPGPU Shadi Alawneh and Dennis Peters

    E-Print Network [OSTI]

    Peters, Dennis

    is to increase the understanding of interactions between ice and steel structures such as ships and oil rigsIce 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

  6. Hyper-Real-Time Ice Simulation and Modeling Using GPGPU

    E-Print Network [OSTI]

    Peters, Dennis

    Hyper-Real-Time Ice Simulation and Modeling Using GPGPU By c Shadi Alawneh, B. Eng., M. Eng's, Newfoundland Title: Hyper-Real-Time Ice Simulation and Modeling Using GPGPU Author: Shadi Alawneh, B. Eng operating in pack ice is a computationally in- tensive process to which General Purpose Computing

  7. Introduction Microorganisms in sea ice function ecologically in the

    E-Print Network [OSTI]

    Stewart, Frank

    where pelagic and sea ice habitats are intrinsically coupled (Laws 1985, Garrison 1991, Eicken 1992, Knox 1994, Garrison & Mathot 1996, Arrigo et al. 1997, Brierley & Thomas 2002). For instance, sea ice algae - primarily diatoms and phototrophic flagellates (e.g. Garrison 1991) - are inocula for ice

  8. Remote Sensing of WaterRemote Sensing of WaterRemote Sensing of Water One of the most pressing resource issues facing humanity in the 21st

    E-Print Network [OSTI]

    moderate to high shortages in water supply. The outlook is particularly bleak for developing countries resulting from the downwelling solar (Esun) and sky (Esky) radiation. This is unwanted path radiance

  9. 29April2011JohnLearnedatIceCubeDedication1 IceCube Dedication Symposium, Madison, Wisconsin

    E-Print Network [OSTI]

    Learned, John

    29April2011JohnLearnedatIceCubeDedication1 IceCube Dedication Symposium, Madison, Wisconsin 29 of Neutrino Studies #12;"Talking to the neighbors" 29April2011JohnLearnedatIceCubeDedication2 "A modest://www.economist.com/PrinterFriendly.cfm?story_id=18526871 Not what this talk is about.... SETI with Neutrinos #12;29April2011JohnLearnedatIceCubeDedication3

  10. Navigating Roadblocks on the Path to Advanced Biofuels Deployment

    Broader source: Energy.gov [DOE]

    Breakout Session 2: Frontiers and Horizons Session 2–C: Navigating Roadblocks on the Path to Advanced Biofuels Deployment Andrew Held, Senior Director of Feedstock Development, Virent, Inc.

  11. Reduction of Emission Variance by Intelligent Air Path Control

    Broader source: Energy.gov [DOE]

    This poster describes an air path control concept, which minimizes NOx and PM emission variance while having the ability to run reliably with many different sensor configurations.

  12. ORNL thermomagnetic processing method provides path to new materials...

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

    thermomagnetic processing method provides path to new materials The high magnetic field environments are provided by fully recondensing commercial prototype superconducting magnet...

  13. DOE EM Landfill Workshop and Path Forward - July 2009

    Office of Environmental Management (EM)

    Teleconference: 2. DOE EM Landfill Workshop & Path Forward Office of Groundwater and Soil Remediation US Department of Energy July 2009 Slides prepared by CRESP DOE EM Landfill...

  14. Office of River Protection's (ORP) Path to Reinvigorating Technology...

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

    Development Presentation from the 2015 DOE National Cleanup Workshop by Kevin Smith, Manager, Office of River Protection. ORP's Path to Reinvigorating Technology...

  15. Community-Based Forest (Natural) Resource Management: A Path...

    Open Energy Info (EERE)

    Community-Based Forest (Natural) Resource Management: A Path to Sustainable Environment and Development Jump to: navigation, search Name Community-Based Forest (Natural) Resource...

  16. Minimal paths between communities induced by geographical networks

    E-Print Network [OSTI]

    de Arruda, Henrique Ferraz; Costa, Luciano da Fontoura

    2015-01-01

    In this work we investigate the betweenness centrality in geographical networks and its relationship with network communities. We show that nodes with large betweenness define what we call characteristic betweenness paths in both modeled and real-world geographical networks. We define a geographical network model that possess a simple topology while still being able to present such betweenness paths. Using this model, we show that such paths represent pathways between entry and exit points of highly connected regions, or communities, of geographical networks. By defining a new network, containing information about community adjacencies in the original network, we describe a means to characterize the mesoscale connectivity provided by such characteristic betweenness paths.

  17. Identification of MHF Fracture Planes and Flow Paths- a Correlation...

    Open Energy Info (EERE)

    creation of flow paths through the rock between two wellbores. To date, circulation systems have only been created by drilling one wellbore, hydraulically fracturing the well...

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

    E-Print Network [OSTI]

    Stearns, Leigh; Jezek, Kenneth C.; van der Veen, Cornelis J.

    2005-01-05

    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) ...

  19. 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, Cornelis J.

    2005-01-01

    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) ...

  20. 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.

    2001-10-01

    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...

  1. A Development Path for the Stabilized Spheromak

    SciTech Connect (OSTI)

    Fowler, T K

    2007-07-13

    In Refs. [1] - [3], I suggest a concerted computational effort to study profile control of spheromaks, in anticipation that it is timely to incorporate the q < 1 regime of RFP's and spheromaks into an integrated advanced toroidal confinement program, together with improvements in tokamaks and stellarators now being pursued. For profile control of spheromaks by neutral beam injection, with care to avoid super-Alfvenic beam instability the main issue is excitation of tearing modes that can be studied using the NIMROD code already calibrated to MST and SSPX. In this note, I show that profile control on spheromaks could be demonstrated in a device the size of SSPX, leading ultimately to a very compact ignition facility, and possibly modular fusion reactors with a shorter development path.

  2. Hot gas path component cooling system

    DOE Patents [OSTI]

    Lacy, Benjamin Paul; Bunker, Ronald Scott; Itzel, Gary Michael

    2014-02-18

    A cooling system for a hot gas path component is disclosed. The cooling system may include a component layer and a cover layer. The component layer may include a first inner surface and a second outer surface. The second outer surface may define a plurality of channels. The component layer may further define a plurality of passages extending generally between the first inner surface and the second outer surface. Each of the plurality of channels may be fluidly connected to at least one of the plurality of passages. The cover layer may be situated adjacent the second outer surface of the component layer. The plurality of passages may be configured to flow a cooling medium to the plurality of channels and provide impingement cooling to the cover layer. The plurality of channels may be configured to flow cooling medium therethrough, cooling the cover layer.

  3. Ice-volcano interactions Eyjafjallajkull volcano, Iceland

    E-Print Network [OSTI]

    Berthier, Etienne

    Ice-volcano interactions in Eyjafjallajökull volcano, Iceland Eyjólfur Magnússon1, Magnús Tumi Sciences, University of Iceland, Reykjavík, Iceland 2. Institute of Earth Sciences, University of Iceland, Reykjavík, Iceland 3. Icelandic Coast Guard SPIRIT workshop 29&30 April 2010, Toulouse Picture by Eyjólfur

  4. 4, 709732, 2007 Ice-shelf ocean

    E-Print Network [OSTI]

    Boyer, Edmond

    and out over the continental slope10 into deep water. Glacial melt water is concentrated in a 200 m thick in the water mass transformations that take place there. The source water is Warm Deep Water (WDW), derived from Circumpolar Deep Water, an old, salty and relatively warm wa- ter mass. Around Antarctica

  5. Hanford spent nuclear fuel project recommended path forward, volume III: Alternatives and path forward evaluation supporting documentation

    SciTech Connect (OSTI)

    Fulton, J.C.

    1994-10-01

    Volume I of the Hanford Spent Nuclear Fuel Project - Recommended Path Forward constitutes an aggressive series of projects to construct and operate systems and facilities to safely retrieve, package, transport, process, and store K Basins fuel and sludge. Volume II provided a comparative evaluation of four Alternatives for the Path Forward and an evaluation for the Recommended Path Forward. Although Volume II contained extensive appendices, six supporting documents have been compiled in Volume III to provide additional background for Volume II.

  6. Effects of Frozen Soil on Snowmelt Runoff and Soil Water Storage at a Continental Scale

    E-Print Network [OSTI]

    Yang, Zong-Liang

    Effects of Frozen Soil on Snowmelt Runoff and Soil Water Storage at a Continental Scale GUO-YUE NIU) ABSTRACT The presence of ice in soil dramatically alters soil hydrologic and thermal properties. Despite computes soil ice content and its modifications to soil hydrologic and thermal properties. However

  7. Water Resources Water Quality and Water Treatment

    E-Print Network [OSTI]

    Sohoni, Milind

    Water Resources TD 603 Lecture 1: Water Quality and Water Treatment CTARA Indian Institute of Technology, Bombay 2nd November, 2011 #12;OVERVIEW Water Quality WATER TREATMENT PLANTS WATER TREATMENT PLANTS WATER TREATMENT PLANTS WATER TRE OVERVIEW OF THE LECTURE 1. Water Distribution Schemes Hand Pump

  8. Short time proton dynamics in bulk ice and in porous anode solid oxide fuel cell materials

    SciTech Connect (OSTI)

    Basoli, Francesco; Senesi, Roberto; Kolesnikov, Alexander I; Licoccia, Silvia

    2014-01-01

    Oxygen reduction and incorporation into solid electrolytes and the reverse reaction of oxygen evolution play a cru-cial role in Solid Oxide Fuel Cell (SOFC) applications. However a detailed un derstanding of the kinetics of the cor-responding reactions, i.e. on reaction mechanisms, rate limiting steps, reaction paths, electrocatalytic role of materials, is still missing. These include a thorough characterization of the binding potentials experienced by protons in the lattice. We report results of Inelastic Neutron Scattering (INS) measurements of the vibrational state of the protons in Ni- YSZ highly porous composites (75% to 90% ), a ceramic-metal material showing a high electrical conductivity and ther mal stability, which is known to be most effectively used as anodes for solid ox ide fuel cells. The results are compared with INS and Deep Inelastic Neutron Scattering (DINS) experiments on the proton binding states in bulk ice.

  9. On the Accuracy of van der Waals Inclusive Density-Functional Theory Exchange-Correlation Functionals for Ice at Ambient and High Pressures

    E-Print Network [OSTI]

    Biswajit Santra; Ji?í Klimeš; Alexandre Tkatchenko; Dario Alfè; Ben Slater; Angelos Michaelides; Roberto Car; Matthias Scheffler

    2014-08-14

    Density-functional theory (DFT) has been widely used to study water and ice for at least 20 years. However, the reliability of different DFT exchange-correlation (xc) functionals for water remains a matter of considerable debate. This is particularly true in light of the recent development of DFT based methods that account for van der Waals (vdW) dispersion forces. Here, we report a detailed study with several xc functionals (semi-local, hybrid, and vdW inclusive approaches) on ice Ih and six proton ordered phases of ice. Consistent with our previous study [Phys. Rev. Lett. 107, 185701 (2011)] which showed that vdW forces become increasingly important at high pressures, we find here that all vdW inclusive methods considered improve the relative energies and transition pressures of the high-pressure ice phases compared to those obtained with semi-local or hybrid xc functionals. However, we also find that significant discrepancies between experiment and the vdW inclusive approaches remain in the cohesive properties of the various phases, causing certain phases to be absent from the phase diagram. Therefore, room for improvement in the description of water at ambient and high pressures remains and we suggest that because of the stern test the high pressure ice phases pose they should be used in future benchmark studies of simulation methods for water.

  10. Modeling the Fracture of Ice Sheets on Parallel Computers

    SciTech Connect (OSTI)

    Waisman, Haim; Tuminaro, Ray

    2013-10-10

    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. NC machine tool path generation from CSG part

    E-Print Network [OSTI]

    Bobrow, James E.

    NC machine tool path generation from CSG part representations James E Bobrow Recent improvements for machine tool path generation. Current machining algorithms require that any port geometric information modelling system is used. Thispaper presents o method for generating numerically-controlled milling machine

  12. Disjoint BoundaryBoundary Paths in Critical Circular Planar Networks

    E-Print Network [OSTI]

    Morrow, James A.

    Disjoint Boundary­Boundary Paths in Critical Circular Planar Networks Ryan Sturgell December 8 that in a critical circular planar network every interior vertex has three disjoint paths to the boundary. 1, 1998 Abstract This paper explores some properties of critical circular planar net­ works. The main

  13. L1 Regularization Path Algorithm for Generalized Linear Models

    E-Print Network [OSTI]

    Hastie, Trevor

    of the paths; we suggest intuitive and flexible strategies for choosing appropriate values. We demonstrate: ^() = argmin {- log L(y; ) + 1}, (2) where > 0 is the regularization parameter. Logistic regression with L1 the most complex stage possible. By generating the regularization path rather than computing solutions

  14. Path Planning for Permutation-Invariant Multi-Robot Formations

    E-Print Network [OSTI]

    Hutchinson, Seth

    Path Planning for Permutation-Invariant Multi-Robot Formations Stephen Kloder Seth Hutchinson, IL 61801 Email: {kloder, seth}@uiuc.edu Abstract-- In this paper we demonstrate path planning for our-assign roles for each individual robot, rely on local planning and behaviors to build emergent behaviors

  15. Efficient Path Delay Test Generation with Boolean Satisfiability 

    E-Print Network [OSTI]

    Bian, Kun

    2013-12-10

    This dissertation focuses on improving the accuracy and efficiency of path delay test generation using a Boolean satisfiability (SAT) solver. As part of this research, one of the most commonly used SAT solvers, MiniSat, was integrated into the path...

  16. Cost effective path to DEMO University of Washington

    E-Print Network [OSTI]

    1 Cost effective path to DEMO By Tom Jarboe University of Washington To Fusion Power Associates December 14, 2011 #12;2 Outline · Maximizing the development-cost benefit from ITER knowledge · Getting on cost effective path · Requirements of smaller scale experiment · Cost problems are helped

  17. Efficient Static Analysis with Path Pruning using Coverage Data

    E-Print Network [OSTI]

    Jalote, Pankaj

    Efficient Static Analysis with Path Pruning using Coverage Data Vipindeep V, Pankaj Jalote,jalote}@cse.iitk.ac.in ABSTRACT Soundness and completeness are two primary concerns of a static analysis tool for finding defects in software. Exhaus- tive static analysis of the program through all paths is not always possible, especially

  18. Finding Chemical Reaction Paths with a Multilevel Preconditioning Seyit Kale,,

    E-Print Network [OSTI]

    Dinner, Aaron

    Finding Chemical Reaction Paths with a Multilevel Preconditioning Protocol Seyit Kale,, Olaseni for chemical reactions can be computationally costly owing to the level of quantum- chemical theory needed for the reaction path iteratively. These methods have yielded important insights in quantum chemical contexts9

  19. Mechanism of Ligand Exchange Studied Using Transition Path Sampling

    E-Print Network [OSTI]

    Harris, Charles B.

    Mechanism of Ligand Exchange Studied Using Transition Path Sampling Preston T. Snee, Jennifer@socrates.berkeley.edu Abstract: The mechanism of intermolecular ligand exchange has been studied using transition path sampling that there are multiple steps in the reaction mechanism. The first involves partial dissociation of the coordinated

  20. The Reaction Path in Chemistry: Current Approaches and Perspectives

    E-Print Network [OSTI]

    Quapp, Wolfgang

    , Germany UNDERSTANDING CHEMICAL REACTIVITY 16 August 1995 Hardbound 308 pp. ISBN 0-7923-3589-9 The reaction and usage of the reaction path concept; D. Heidrich. From reaction path to reaction mechanism: Fundamental. Second-order methods for the optimization of molecular potential energy surfaces; T. Helgaker et al

  1. Minimizing communication in all-pairs shortest paths Edgar Solomonik

    E-Print Network [OSTI]

    California at Berkeley, University of

    Minimizing communication in all-pairs shortest paths Edgar Solomonik Aydin Buluc James Demmel;Copyright © 2013, by the author(s). All rights reserved. Permission to make digital or hard copies of all, requires prior specific permission. #12;Minimizing communication in all-pairs shortest paths Edgar

  2. Pedestrian Path Prediction with Recursive Bayesian Filters: A Comparative Study

    E-Print Network [OSTI]

    Gavrila, Dariu M.

    Pedestrian Path Prediction with Recursive Bayesian Filters: A Comparative Study N. Schneider1 a com- parative study on recursive Bayesian filters for pedestrian path pre- diction at short time/acceleration/turn). These are applied to four typical pedestrian mo- tion types (crossing, stopping, bending in, starting). Position

  3. Pierre.Francois@UCLouvain.be BGP Path visibility

    E-Print Network [OSTI]

    Bonaventure, Olivier

    BGP NHs · Hitless planned maintenance · "Optimal" hot-potato routing · (Churn reduction / convergence the IGP tie-break to clients · Depending on which paths it advertises #12;Churn reduction ??? · Churn reduction for primary paths... · ...with internal churn increase for non-primary ones #12;Churn Reduction

  4. Path to Market for Compact Modular Fusion Power Cores

    E-Print Network [OSTI]

    Precedents? Small number of private fusion companies starting up, filing patents and finding editions Lead author Grounded in DOE program #12;12/13/11 5 Path to market 'next step' Springer Energy Brief: 'Path to Market for Compact Modular Fusion Power' Soliciting wider input from energy, business

  5. Dual Path Instruction Processing Juan L. Aragn1

    E-Print Network [OSTI]

    Acacio, Manuel

    ,joseg}@ditec.um.es 2 Dept. d'Arquitectura de Comp. Universitat Politècnica de Catalunya 08034 Barcelona (Spain) antonio@ac, and renames, but does not execute, instructions from the alternative path for low confidence predicted branches at the same time as the predicted path is being executed. All the stages of the pipeline front

  6. SPECIAL ISSUE PAPER Efficient camera path planning algorithm for human

    E-Print Network [OSTI]

    Chen, Sheng-Wei

    , and a near-optimal path can be obtained. In addition, some COMPUTER ANIMATION AND VIRTUAL WORLDS Comp. AnimSPECIAL ISSUE PAPER Efficient camera path planning algorithm for human motion overview I-Cheng Yeh1 research topic, benefiting many animation applications. Existing optimal-based approaches are generally

  7. Improved Hardness of Approximation for Stackelberg Shortest-Path Pricing

    E-Print Network [OSTI]

    Verbrugge, Clark

    the Stackelberg shortest-path pricing problem, which is defined as follows. Given a graph G with fixed-cost on the predefined fixed costs and our prices, a customer purchases a cheapest s-t-path in G and we receive payment costs, we may assign prices to a subset of the items. Given both fixed costs and prices, a single

  8. NIF: A Path to Fusion Energy

    SciTech Connect (OSTI)

    Moses, E

    2007-06-01

    Fusion energy has long been considered a promising, clean, nearly inexhaustible source of energy. Power production by fusion micro-explosions of inertial confinement fusion (ICF) targets has been a long-term research goal since the invention of the first laser in 1960. The National Ignition Facility (NIF) is poised to take the next important step in the journey by beginning experiments researching ICF ignition. Ignition on NIF will be the culmination of over thirty years of ICF research on high-powered laser systems such as the Nova laser at Lawrence Livermore National Laboratory (LLNL) and the OMEGA laser at the University of Rochester, as well as smaller systems around the world. NIF is a 192-beam Nd-glass laser facility at LLNL that is more than 90% complete. The first cluster of 48 beams is operational in the laser bay, the second cluster is now being commissioned, and the beam path to the target chamber is being installed. The Project will be completed in 2009, and ignition experiments will start in 2010. When completed, NIF will produce up to 1.8 MJ of 0.35-{micro}m light in highly shaped pulses required for ignition. It will have beam stability and control to higher precision than any other laser fusion facility. Experiments using one of the beams of NIF have demonstrated that NIF can meet its beam performance goals. The National Ignition Campaign (NIC) has been established to manage the ignition effort on NIF. NIC has all of the research and development required to execute the ignition plan and to develop NIF into a fully operational facility. NIF will explore the ignition space, including direct drive, 2{omega} ignition, and fast ignition, to optimize target efficiency for developing fusion as an energy source. In addition to efficient target performance, fusion energy requires significant advances in high-repetition-rate lasers and fusion reactor technology. The Mercury laser at LLNL is a high-repetition-rate Nd-glass laser for fusion energy driver development. Mercury uses state-of-the-art technology such as ceramic laser slabs and light diode pumping for improved efficiency and thermal management. Progress in NIF, NIC, Mercury, and the path forward for fusion energy will be presented.

  9. Water Clean Water Clean

    E-Print Network [OSTI]

    Ishida, Yuko

    Keep Our Water Clean Keep Our Water Clean Home and garden pesticides and fertilizers are polluting residues wash into gutters, storm drains, and streams by rain,garden watering,or cleaning up drinking water. Follow these tips to keep our rivers, creeks, and oceans clean. What can you do to protect

  10. Water, water everywhere,

    E-Print Network [OSTI]

    Eberhard, Marc O.

    1 Water, water everywhere, but is it safe to drink? An Inquiry-based unit investigating the journey of your drinking water from source to tap of drinking water will contain different contaminants, based on surrounding land uses (guided inquiry activity

  11. Water Resources Forests & Water

    E-Print Network [OSTI]

    Water Resources Forests & Water More than half of the nation's freshwater supply originates on forestland. Healthy and sustainable forests can help ensure a continuous supply of clean and abundant water. Not only does forestland provide the cleanest water of any land use, it also helps absorb rainfall

  12. Crystal Field Disorder in the Quantum Spin Ice Ground State of Tb2Sn2 xTixO7

    SciTech Connect (OSTI)

    Gaulin, Bruce D.; Zhang, J.; Dahlberg, M. L.; Matthews, Maria J.; Bert, F.; Kermarrec, E.; Fritsch, Katharina; Granroth, Garrett E; Jiramongkolchai, P.; Amato, A.; Baines, C.; Cava, R. J.; Mendels, P.; Schiffer, P

    2015-01-01

    Spin ice physics marries that of hydrogen disorder in water ice, first discussed almost 60 years ago by Pauling, and that of low temperature magnetism on certain networks of connected tetrahedra. Recently the classical spin ice mag- nets Ho2Ti2O7 and Dy2Ti2O7 have shown an emergent artificial magneto- statics , which manifests itself as Coulombic spin correlations and excitations behaving as diffusive magnetic monopoles. The related pyrochlore magnet, Tb2Ti2O7, has been proposed as a quantum variant of spin ice, stabilized by 1 virtual excitations between the crystal field (CF) ground state doublet appro- priate to Tb3+, and its low lying excited state doublet. Isostructural Tb2Sn2O7 displays soft spin ice order, and its Tb3+ ground and excited CF eigenstates are known to differ relative to those of Tb2Ti2O7. We present a comprehensive study of Tb2Sn2 xTixO7 showing a novel, dynamic spin liquid state for all x other than the end members (0, 2). This state is the result of disorder in the low lying Tb3+ CF environments which de-stabilizes the mechanism by which quantum fluctuations contribute to ground state selection in Tb2Sn2 xTixO7.

  13. Ice Thermal Storage Systems for LWR Supplemental Cooling and Peak Power Shifting

    SciTech Connect (OSTI)

    Haihua Zhao; Hongbin Zhang; Phil Sharpe; Blaise Hamanaka; Wei Yan; WoonSeong Jeong

    2010-06-01

    Availability of enough cooling water has been one of the major issues for the nuclear power plant site selection. Cooling water issues have frequently disrupted the normal operation at some nuclear power plants during heat waves and long draught. The issues become more severe due to the new round of nuclear power expansion and global warming. During hot summer days, cooling water leaving a power plant may become too hot to threaten aquatic life so that environmental regulations may force the plant to reduce power output or even temporarily to be shutdown. For new nuclear power plants to be built at areas without enough cooling water, dry cooling can be used to remove waste heat directly into the atmosphere. However, dry cooling will result in much lower thermal efficiency when the weather is hot. One potential solution for the above mentioned issues is to use ice thermal storage systems (ITS) that reduce cooling water requirements and boost the plant’s thermal efficiency in hot hours. ITS uses cheap off-peak electricity to make ice and uses those ice for supplemental cooling during peak demand time. ITS is suitable for supplemental cooling storage due to its very high energy storage density. ITS also provides a way to shift large amount of electricity from off peak time to peak time. Some gas turbine plants already use ITS to increase thermal efficiency during peak hours in summer. ITSs have also been widely used for building cooling to save energy cost. Among three cooling methods for LWR applications: once-through, wet cooling tower, and dry cooling tower, once-through cooling plants near a large water body like an ocean or a large lake and wet cooling plants can maintain the designed turbine backpressure (or condensation temperature) during 99% of the time; therefore, adding ITS to those plants will not generate large benefits. For once-through cooling plants near a limited water body like a river or a small lake, adding ITS can bring significant economic benefits and avoid forced derating and shutdown during extremely hot weather. For the new plants using dry cooling towers, adding the ice thermal storage systems can effectively reduce the efficiency loss and water consumption during hot weather so that new LWRs could be considered in regions without enough cooling water. \\ This paper presents the feasibility study of using ice thermal storage systems for LWR supplemental cooling and peak power shifting. LWR cooling issues and ITS application status will be reviewed. Two ITS application case studies will be presented and compared with alternative options: one for once-through cooling without enough cooling for short time, and the other with dry cooling. Because capital cost, especially the ice storage structure/building cost, is the major cost for ITS, two different cost estimation models are developed: one based on scaling method, and the other based on a preliminary design using Building Information Modeling (BIM), an emerging technology in Architecture/Engineering/Construction, which enables design options, performance analysis and cost estimating in the early design stage.

  14. Shortest Path Set Induced Vertex Ordering and its Application to Distributed Distance Optimal Formation Path Planning and Control on Graphs

    E-Print Network [OSTI]

    LaValle, Steven M.

    Formation Path Planning and Control on Graphs Jingjin Yu Steven M. LaValle Abstract-- For the task of moving formation, it was shown that distance optimal paths can be computed to complete with a tight convergence formation. The ordering leads to a simple distributed scheduling algorithm that assures the same convergence

  15. NGNP Program 2013 Status and Path Forward

    SciTech Connect (OSTI)

    Hans Gougar

    2014-03-01

    High temperature gas-cooled reactor (HTGR) technology can play an important role in the energy future of the United States by extending the use of nuclear energy for non-electricity energy production missions, as well as continuing to provide a considerable base load electric power generation capability. Extending nuclear energy into the industrial and transportation sectors through the coproduction of process heat and electricity provides safe, reliable energy for these sectors in an environmentally responsible manner. The modular HTGR provides a substantial improvement in nuclear plant safety for the protection of the public and the environment, and supports collocation of the HTGRhigh temperature gas-cooled reactor with major industrial facilities. Under U.S. Department of Energy direction since 2006, the Next Generation Nuclear Plant Project at Idaho National Laboratory has been working toward commercializing the HTGR technology. However, a recent decision by the Secretary of Energy to reduce the scope of the Next Generation Nuclear Plant Project to a research and development program, considerable realignment has taken place. This report: (1) summarizes the accomplishments of the Next Generation Nuclear Plant Program from FY2011 through FY2013; (2) lays out the path forward necessary to achieve the ultimate objective of commercializing HTGR technology; and (3) discusses ongoing technical, licensing, and evaluation activities under the realigned Next Generation Nuclear Plant program considered important to preserve the significant investment made by the government to-date and to maintain some progress in meeting the objectives of the Energy Policy Act of 2005 (EPAct2005).

  16. An Electromechanical Which-Path Interferometer

    E-Print Network [OSTI]

    A. D. Armour; M. P. Blencowe

    2001-08-28

    We investigate the possibility of an electromechanical which-path interferometer, in which electrons travelling through an Aharonov-Bohm ring incorporating a quantum dot in one of the arms are dephased by an interaction with the fundamental flexural mode of a radio frequency cantilever. The cantilever is positioned so that its tip lies just above the dot and a bias is applied so that an electric field exists between the dot and the tip. This electric field is modified when an additional electron hops onto the dot, coupling the flexural mode of the cantilever and the microscopic electronic degrees of freedom. We analyze the transmission properties of this system and the dependence of interference fringe visibility on the cantilever-dot coupling and on the mechanical properties of the cantilever. The fringes are progressively destroyed as the interaction with the cantilever is turned up, in part due to dephasing arising from the entanglement of the electron and cantilever states and also due to the thermal smearing that results from fluctuations in the state of the cantilever. When the dwell time of the electron on the dot is comparable to or longer than the cantilever period, we find coherent features in the transmission amplitude. These features are washed out when the cantilever is decohered by its coupling to the environment.

  17. A New Weighted Shortest Path Tree for Convergecast Traffic Routing in WSN

    E-Print Network [OSTI]

    Boyer, Edmond

    , existing SPT approaches aim to construct a tree rooted at the sink such that the cost of the path from any to the basic one. Index Terms--Wireless Sensor Networks (WSN), Shortest Path Tree (SPT), weighted path cost such that the path cost from any node to the sink is minimal. In existing construction algorithms, the cost of a path

  18. Routing Bandwidth Guaranteed Paths with Local Restoration in Label Switched Networks

    E-Print Network [OSTI]

    Li, Li Erran

    information. We first show that joint optimization of primary and backup paths is NP-hard in all cases. We along the primary path, the source node detects path failure and activates the backup path or nodes along primary path fail. In this paper, we address the problem of distributed routing

  19. A method for finding the statically sensitized critical path in VLSI circuits 

    E-Print Network [OSTI]

    Sen, Anindita

    1995-01-01

    The longest sensitizable paths of a circuit are referred to as the critical paths of the circuit. Finding all the critical paths in a circuit is called the critical path problem. There are various methods at present to find the critical path of a...

  20. Should we geoengineer larger ice caps?

    E-Print Network [OSTI]

    Haqq-Misra, Jacob

    2015-01-01

    The climate of Earth is susceptible to catastrophes that could threaten the longevity of human civilization. Geoengineering to reduce incoming solar radiation has been suggested as a way to mediate the warming effects of contemporary climate change, but a geoengineering program for thousands of years could also be used to enlarge the size of the polar ice caps and create a permanently cooler climate. Such a large ice cap state would make Earth less susceptible to climate threats and could allow human civilization to survive further into the future than otherwise possible. Intentionally extending Earth's glacial coverage will require uninterrupted commitment to this program for millenia but would ultimately reach a cooler equilibrium state where geoengineering is no longer needed. Whether or not this program is ever attempted, this concept illustrates the need to identify preference among potential climate states to ensure the long-term success of civilization.

  1. Black carbon aerosols and the third polar ice cap

    SciTech Connect (OSTI)

    Menon, Surabi; Koch, Dorothy; Beig, Gufran; Sahu, Saroj; Fasullo, John; Orlikowski, Daniel

    2010-04-15

    Recent thinning of glaciers over the Himalayas (sometimes referred to as the third polar region) have raised concern on future water supplies since these glaciers supply water to large river systems that support millions of people inhabiting the surrounding areas. Black carbon (BC) aerosols, released from incomplete combustion, have been increasingly implicated as causing large changes in the hydrology and radiative forcing over Asia and its deposition on snow is thought to increase snow melt. In India BC emissions from biofuel combustion is highly prevalent and compared to other regions, BC aerosol amounts are high. Here, we quantify the impact of BC aerosols on snow cover and precipitation from 1990 to 2010 over the Indian subcontinental region using two different BC emission inventories. New estimates indicate that Indian BC emissions from coal and biofuel are large and transport is expected to expand rapidly in coming years. We show that over the Himalayas, from 1990 to 2000, simulated snow/ice cover decreases by {approx}0.9% due to aerosols. The contribution of the enhanced Indian BC to this decline is {approx}36%, similar to that simulated for 2000 to 2010. Spatial patterns of modeled changes in snow cover and precipitation are similar to observations (from 1990 to 2000), and are mainly obtained with the newer BC estimates.

  2. COLD WATER VAPOR IN THE BARNARD 5 MOLECULAR CLOUD

    SciTech Connect (OSTI)

    Wirström, E. S.; Persson, C. M.; Charnley, S. B.; Cordiner, M. A.; Buckle, J. V.; Takakuwa, S.

    2014-06-20

    After more than 30 yr of investigations, the nature of gas-grain interactions at low temperatures remains an unresolved issue in astrochemistry. Water ice is the dominant ice found in cold molecular clouds; however, there is only one region where cold (?10 K) water vapor has been detected—L1544. This study aims to shed light on ice desorption mechanisms under cold cloud conditions by expanding the sample. The clumpy distribution of methanol in dark clouds testifies to transient desorption processes at work—likely to also disrupt water ice mantles. Therefore, the Herschel HIFI instrument was used to search for cold water in a small sample of prominent methanol emission peaks. We report detections of the ground-state transition of o-H{sub 2}O (J = 1{sub 10}-1{sub 01}) at 556.9360 GHz toward two positions in the cold molecular cloud, Barnard 5. The relative abundances of methanol and water gas support a desorption mechanism which disrupts the outer ice mantle layers, rather than causing complete mantle removal.

  3. New England Forests: The Path to Sustainability

    E-Print Network [OSTI]

    Wolfe, Patrick J.

    on forests for the quality and abundance of our region's outstanding drinking water. Forests cool and clean could be more certain that our wood is harvested sustainably and is not contributing to environmental fossil fuels extracted from deep within the earth at great cost to our environment and the climate

  4. Water Levels, Barrow, Alaska, NGEE Areas A, B, C and D for 2012, 2013, 2014, Final Version, 20150324

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

    Anna Liljedahl; Cathy Wilson

    2015-06-08

    Ice wedge polygonal tundra water levels were measured at a total of 45 locations representing polygon centers and troughs during three summers. Early season water levels, which were still affected by ice and snow, are represented by manual measurements only. Continuous (less than hourly) measurements followed through early fall (around mid-Sep). The data set contains inundation depth (cm), absolute water level and local ground surface elevation (masl).

  5. Water Levels, Barrow, Alaska, NGEE Areas A, B, C and D for 2012, 2013, 2014, Final Version, 20150324

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

    Anna Liljedahl; Cathy Wilson

    Ice wedge polygonal tundra water levels were measured at a total of 45 locations representing polygon centers and troughs during three summers. Early season water levels, which were still affected by ice and snow, are represented by manual measurements only. Continuous (less than hourly) measurements followed through early fall (around mid-Sep). The data set contains inundation depth (cm), absolute water level and local ground surface elevation (masl).

  6. Controlling Low-Rate Signal Path Microdischarge for an Ultra-Low-Background Proportional Counter

    SciTech Connect (OSTI)

    Mace, Emily K.; Aalseth, Craig E.; Bonicalzi, Ricco; Day, Anthony R.; Hoppe, Eric W.; Keillor, Martin E.; Myers, Allan W.; Overman, Cory T.; Seifert, Allen

    2013-05-01

    ABSTRACT Pacific Northwest National Laboratory (PNNL) has developed an ultra-low-background proportional counter (ULBPC) made of high purity copper. These detectors are part of an ultra-low-background counting system (ULBCS) in the newly constructed shallow underground laboratory at PNNL (at a depth of ~30 meters water-equivalent). To control backgrounds, the current preamplifier electronics are located outside the ULBCS shielding. Thus the signal from the detector travels through ~1 meter of cable and is potentially susceptible to high voltage microdischarge and other sources of electronic noise. Based on initial successful tests, commercial cables and connectors were used for this critical signal path. Subsequent testing across different batches of commercial cables and connectors, however, showed unwanted (but still low) rates of microdischarge noise. To control this noise source, two approaches were pursued: first, to carefully validate cables, connectors, and other commercial components in this critical signal path, making modifications where necessary; second, to develop a custom low-noise, low-background preamplifier that can be integrated with the ULBPC and thus remove most commercial components from the critical signal path. This integrated preamplifier approach is based on the Amptek A250 low-noise charge-integrating preamplifier module. The initial microdischarge signals observed are presented and characterized according to the suspected source. Each of the approaches for mitigation is described, and the results from both are compared with each other and with the original performance seen with commercial cables and connectors.

  7. 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

    2007-08-24

    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.

  8. IceVeto: Extended PeV neutrino astronomy in the Southern Hemisphere with IceCube

    SciTech Connect (OSTI)

    Auffenberg, Jan; Collaboration: IceCube Collaboration

    2014-11-18

    IceCube, the world's largest high-energy neutrino observatory, built at the South Pole, recently reported evidence of an astrophysical neutrino flux extending to PeV energies in the Southern Hemisphere. This observation raises the question of how the sensitivity in this energy range could be further increased. In the down-going sector, in IceCube's case the Southern Hemisphere, backgrounds from atmospheric muons and neutrinos pose a challenge to the identification of an astrophysical neutrino flux. The IceCube analysis, that led to the evidence for astrophysical neutrinos, is based on an in-ice veto strategy for background rejection. One possibility available to IceCube is the concept of an extended surface detector, IceVeto, which could allow the rejection of a large fraction of atmospheric backgrounds, primarily for muons from cosmic ray (CR) air showers as well as from neutrinos in the same air showers. Building on the experience of IceTop/IceCube, possibly the most cost-effective and sensitive way to build IceVeto is as an extension of the IceTop detector, with simple photomultiplier based detector modules for CR air shower detection. Initial simulations and estimates indicate that such a veto detector will significantly increase the sensitivity to an astrophysical flux of ?{sub ?} induced muon tracks in the Southern Hemisphere compared to current analyses. Here we present the motivation and capabilities based on initial simulations. Conceptual ideas for a simplified surface array will be discussed briefly.

  9. Path integral derivations of novel complex trajectory methods

    E-Print Network [OSTI]

    Jeremy Schiff; Yair Goldfarb; David J. Tannor

    2008-07-30

    Path integral derivations are presented for two recently developed complex trajectory techniques for the propagation of wave packets, Complex WKB and BOMCA. Complex WKB is derived using a standard saddle point approximation of the path integral, but taking into account the hbar dependence of both the amplitude and the phase of the intial wave function, thus giving rise to the need for complex classical trajectories. BOMCA is derived using a modification of the saddle point technique, in which the path integral is approximated by expanding around a near-classical path, chosen so that up to some predetermined order there is no need to add any correction terms to the leading order approximation. Both Complex WKB and BOMCA give the same leading order approximation; in Complex WKB higher accuracy is achieved by adding correction terms, while in BOMCA no additional terms are ever added -higher accuracy is achieved by changing the path along which the original approximation is computed. The path integral derivation of the methods explains the need to incorporate contributions from more than one trajectory, as observed in previous numerical work. On the other hand, it emerges that the methods provide efficient schemes for computing the higher order terms in the asymptotic evaluation of path integrals. The understanding we develop of BOMCA suggests that there should exist near-classical trajectories that give exact quantum dynamical results when used in the computation of the path integral keeping just the leading order term. We also apply our path integral techniques to give a compact derivation of the semiclassical approximation to the coherent state propagator.

  10. 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

  11. Path forward for dosimetry cross sections

    SciTech Connect (OSTI)

    Griffin, P.J. [Sandia National Laboratories, Albuquerque, NM 87185-1146 (United States); Peters, C.D. [Sandia Staffing Alliance, Albuquerque, NM 87110 (United States)

    2011-07-01

    In the 1980's the dosimetry community embraced the need for a high fidelity quantification of uncertainty in nuclear data used for dosimetry applications. This led to the adoption of energy-dependent covariance matrices as the accepted manner of quantifying the uncertainty data. The trend for the dosimetry community to require high fidelity treatment of uncertainty estimates has continued to the current time where requirements on nuclear data are codified in standards such as ASTM E 1018. This paper surveys the current state of the dosimetry cross sections and investigates the quality of the current dosimetry cross section evaluations by examining calculated-to-experimental ratios in neutron benchmark fields. In recent years more nuclear-related technical areas are placing an emphasis on uncertainty quantification. With the availability of model-based cross sections and covariance matrices produced by nuclear data codes, some nuclear-related communities are considering the role these covariance matrices should play. While funding within the dosimetry community for cross section evaluations has been very meager, other areas, such as the solar-related astrophysics community and the US Nuclear Criticality Safety Program, have been supporting research in the area of neutron cross sections. The Cross Section Evaluation Working Group (CSEWG) is responsible for the creation and maintenance of the ENDF/B library which has been the mainstay for the reactor dosimetry community. Given the new trends in cross section evaluations, this paper explores the path forward for the US nuclear reactor dosimetry community and its use of the ENDF/B cross-sections. The major concern is maintenance of the sufficiency and accuracy of the uncertainty estimate when used for dosimetry applications. The two major areas of deficiency in the proposed ENDF/B approach are: 1) the use of unrelated covariance matrices in ENDF/B evaluations and 2) the lack of 'due consideration' of experimental data in the evaluation. (authors)

  12. Final scientific report for DOE award title: Improving the Representation of Ice Sedimentation Rates in Global Climate Models

    SciTech Connect (OSTI)

    Mitchell, David L.

    2013-09-05

    It is well known that cirrus clouds play a major role in regulating the earth’s climate, but the details of how this works are just beginning to be understood. This project targeted the main property of cirrus clouds that influence climate processes; the ice fall speed. That is, this project improves the representation of the mass-weighted ice particle fall velocity, Vm, in climate models, used to predict future climate on global and regional scales. Prior to 2007, the dominant sizes of ice particles in cirrus clouds were poorly understood, making it virtually impossible to predict how cirrus clouds interact with sunlight and thermal radiation. Due to several studies investigating the performance of optical probes used to measure the ice particle size distribution (PSD), as well as the remote sensing results from our last ARM project, it is now well established that the anomalously high concentrations of small ice crystals often reported prior to 2007 were measurement artifacts. Advances in the design and data processing of optical probes have greatly reduced these ice artifacts that resulted from the shattering of ice particles on the probe tips and/or inlet tube, and PSD measurements from one of these improved probes (the 2-dimensional Stereo or 2D-S probe) are utilized in this project to parameterize Vm for climate models. Our original plan in the proposal was to parameterize the ice PSD (in terms of temperature and ice water content) and ice particle mass and projected area (in terms of mass- and area-dimensional power laws or m-D/A-D expressions) since these are the microphysical properties that determine Vm, and then proceed to calculate Vm from these parameterized properties. But the 2D-S probe directly measures ice particle projected area and indirectly estimates ice particle mass for each size bin. It soon became apparent that the original plan would introduce more uncertainty in the Vm calculations than simply using the 2D-S measurements to directly calculate Vm. By calculating Vm directly from the measured PSD, ice particle projected area and estimated mass, more accurate estimates of Vm are obtained. These Vm values were then parameterized for climate models by relating them to (1) sampling temperature and ice water content (IWC) and (2) the effective diameter (De) of the ice PSD. Parameterization (1) is appropriate for climate models having single-moment microphysical schemes whereas (2) is appropriate for double-moment microphysical schemes and yields more accurate Vm estimates. These parameterizations were developed for tropical cirrus clouds, Arctic cirrus, mid-latitude synoptic cirrus and mid-latitude anvil cirrus clouds based on field campaigns in these regions. An important but unexpected result of this research was the discovery of microphysical evidence indicating the mechanisms by which ice crystals are produced in cirrus clouds. This evidence, derived from PSD measurements, indicates that homogeneous freezing ice nucleation dominates in mid-latitude synoptic cirrus clouds, whereas heterogeneous ice nucleation processes dominate in mid-latitude anvil cirrus. Based on these findings, De was parameterized in terms of temperature (T) for conditions dominated by (1) homo- and (2) heterogeneous ice nucleation. From this, an experiment was designed for global climate models (GCMs). The net radiative forcing from cirrus clouds may be affected by the means ice is produced (homo- or heterogeneously), and this net forcing contributes to climate sensitivity (i.e. the change in mean global surface temperature resulting from a doubling of CO2). The objective of this GCM experiment was to determine how a change in ice nucleation mode affects the predicted global radiation balance. In the first simulation (Run 1), the

  13. Path Integral of Bianchi I models in Loop Quantum Cosmology

    E-Print Network [OSTI]

    Xiao Liu; Fei Huang; Jian-Yang Zhu

    2013-02-01

    A path integral formulation of the Bianchi I models containing a massless scalar field in loop quantum cosmology is constructed. Following the strategy used in the homogenous and isotropic case, the calculation is extended to the simplest non-isotropic models according to the $\\bar{\\mu}$ and $\\bar{\\mu}^{\\prime}$ scheme. It is proved from the path integral angle that the quantum dynamic lacks the full invariance with respect to fiducial cell scaling in the $\\bar{\\mu}$ scheme, but it does not in the $\\bar{\\mu}^{\\prime}$ scheme. The investigation affirms the equivalence of the canonical approach and the path integral approach in loop quantum cosmology.

  14. Selecta from a Life-Long Obsession with Path Integrals

    SciTech Connect (OSTI)

    Klauder, John R.

    2008-06-18

    The definition and interpretation of canonical, phase space path integrals has evolved over many years to achieve a form that now admits a correct and rigorous formulation, which is also covariant under canonical coordinate transformations. Such formulations involve coherent state representations, which, in their modern version, were originally introduced as an alternative tool to construct phase space path integrals. Moreover, coherent state representations lead to physical interpretations that are more natural than those afforded by more traditional representations. Suitable continuous time regularization procedures lead to a covariant phase space path integral formulation that greatly clarifies the vague phrase that canonical quantization requires Cartesian coordinates.

  15. Experimental evidence of water formation on interstellar dust grains

    E-Print Network [OSTI]

    Dulieu, F; Fillion, J-H; Matar, E; Momeni, A; Pirronello, V; Lemaire, J L

    2009-01-01

    The synthesis of water is one necessary step in the origin and development of life. It is believed that pristine water is formed and grows on the surface of icy dust grains in dark interstellar clouds. Until now, there has been no experimental evidence whether this scenario is feasible or not. We present here the first experimental evidence of water synthesis under interstellar conditions. After D and O deposition on a water ice substrate (HO) held at 10 K, we observe production of HDO and DO. The water substrate itself has an active role in water formation, which appears to be more complicated than previously thought. Amorphous water ice layers are the matrices where complex organic prebiotic species may be synthesized. This experiment opens up the field of a little explored complex chemistry that could occur on interstellar dust grains, believed to be the site of key processes leading to the molecular diversity and complexity observed in our universe.

  16. Improved Geothermometry Through Multivariate Reaction-path Modeling and Evaluation of Geomicrobiological Influences on Geochemical Temperature Indicators: Final Report

    SciTech Connect (OSTI)

    Mattson, Earl; Smith, Robert; Fujita, Yoshiko; McLing, Travis; Neupane, Ghanashyam; Palmer, Carl; Reed, David; Thompson, Vicki

    2015-03-01

    The project was aimed at demonstrating that the geothermometric predictions can be improved through the application of multi-element reaction path modeling that accounts for lithologic and tectonic settings, while also accounting for biological influences on geochemical temperature indicators. The limited utilization of chemical signatures by individual traditional geothermometer in the development of reservoir temperature estimates may have been constraining their reliability for evaluation of potential geothermal resources. This project, however, was intended to build a geothermometry tool which can integrate multi-component reaction path modeling with process-optimization capability that can be applied to dilute, low-temperature water samples to consistently predict reservoir temperature within ±30 °C. The project was also intended to evaluate the extent to which microbiological processes can modulate the geochemical signals in some thermal waters and influence the geothermometric predictions.

  17. Meltwater effects on flow of Greenland's ice sheet less severe...

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

    Side effects of increasing meltwater less severe than feared Meltwater effects on flow of Greenland's ice sheet less severe for sea level rise than earlier feared, scientists...

  18. Sandia Energy - NASA Award for Marginal Ice Zone Observations...

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

    NASA Award for Marginal Ice Zone Observations and Process Experiment (MIZOPEX) Home Climate Office of Science News News & Events Research & Capabilities Monitoring Analysis...

  19. optimal initial conditions for coupling ice sheet models to earth...

    Office of Scientific and Technical Information (OSTI)

    optimal initial conditions for coupling ice sheet models to earth system models Perego, Mauro Sandia National Laboratories Sandia National Laboratories; Price, Stephen F. Dr...

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

    E-Print Network [OSTI]

    Beem, Lucas H.; Jezek, Ken C.; van der Veen, Cornelis J.

    2010-08-05

    and J.E. Mitchell. 1994. The role of the margins in the dynamics of an active ice stream. J. Glaciol., 40(136), 527–538. Engelhardt, H. 2004a. Ice temperature and high geothermal flux at Siple Dome, West Antarctica, from borehole measurements. J. Glaciol... ratio which varies laterally across the shear margin. Basal drag, ?b, basal velocity, U(b), basal temperature gradient, @T/@z(b), esti- mates of geothermal flux, G, plus knowledge of basal ice properties, density, ?, latent heat of fusion of ice, Li...