National Library of Energy BETA

Sample records for atmospheric boundary layer

  1. Interaction between surface and atmosphere in a convective boundary layer /

    E-Print Network [OSTI]

    Garai, Anirban

    2013-01-01

    of cold fluid constitute most of the heat transport andevent cold air descends to the ground, heat transport fromcold air during sweep events. The convective boundary layer has a great influence on moisture transport,

  2. A time-varying subsidence parameterization for the atmospheric boundary layer

    E-Print Network [OSTI]

    Flagg, David D. (David Douglas)

    2005-01-01

    This study examines the effect of a time-varying parameterization for subsidence in the atmospheric boundary layer (ABL) on a one-dimensional coupled land-atmosphere model. Measurements of large-scale divergence in the ABL ...

  3. A 3 km atmospheric boundary layer on Titan indicated by dune spacing and Huygens data

    E-Print Network [OSTI]

    Claudin, Philippe

    Note A 3 km atmospheric boundary layer on Titan indicated by dune spacing and Huygens data Ralph D a b s t r a c t Some 20% of Titan's surface is covered in large linear dunes that resemble parameter limiting the growth of giant dunes, namely the boundary layer thickness (Andreotti et al., 2009

  4. ARM - Field Campaign - Lower Atmospheric Boundary Layer Experiment

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

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  5. Modeling the Atmospheric Boundary Layer Wind Response to Mesoscale Sea Surface Temperature

    E-Print Network [OSTI]

    Kurapov, Alexander

    Modeling the Atmospheric Boundary Layer Wind Response to Mesoscale Sea Surface Temperature The wind speed response to mesoscale SST variability is investigated over the Agulhas Return Current region-Atmosphere Mesoscale Prediction System (COAMPS) atmospheric models. The SST-induced wind response is assessed from

  6. Modeling the Atmospheric Boundary Layer Wind Response to Mesoscale Sea Surface Temperature Perturbations

    E-Print Network [OSTI]

    Kurapov, Alexander

    Modeling the Atmospheric Boundary Layer Wind Response to Mesoscale Sea Surface Temperature received 25 October 2013, in final form 24 July 2014) ABSTRACT The wind speed response to mesoscale SST Research and Forecasting (WRF) Model and the U.S. Navy Coupled Ocean­Atmosphere Mesoscale Prediction System

  7. Wave-driven wind jets in the marine atmospheric boundary layer

    E-Print Network [OSTI]

    Reading, University of

    Wave-driven wind jets in the marine atmospheric boundary layer Kirsty E. Hanley Stephen E. Belcher;Abstract The interaction between ocean surface waves and the overlying wind leads to a transfer of momentum can also be transferred upwards when long wavelength waves, characteristic of re- motely generated

  8. Wind Energy-Related Atmospheric Boundary Layer Large-Eddy Simulation Using OpenFOAM: Preprint

    SciTech Connect (OSTI)

    Churchfield, M.J.; Vijayakumar, G.; Brasseur, J.G.; Moriarty, P.J.

    2010-08-01

    This paper develops and evaluates the performance of a large-eddy simulation (LES) solver in computing the atmospheric boundary layer (ABL) over flat terrain under a variety of stability conditions, ranging from shear driven (neutral stratification) to moderately convective (unstable stratification).

  9. THE SIMULATION OF FINE SCALE NOCTURNAL BOUNDARY LAYER MOTIONS WITH A MESO-SCALE ATMOSPHERIC MODEL

    SciTech Connect (OSTI)

    Werth, D.; Kurzeja, R.; Parker, M.

    2009-04-02

    A field project over the Atmospheric Radiation Measurement-Clouds and Radiation Testbed (ARM-CART) site during a period of several nights in September, 2007 was conducted to explore the evolution of the low-level jet (LLJ). Data was collected from a tower and a sodar and analyzed for turbulent behavior. To study the full range of nocturnal boundary layer (NBL) behavior, the Regional Atmospheric Modeling System (RAMS) was used to simulate the ARM-CART NBL field experiment and validated against the data collected from the site. This model was run at high resolution, and is ideal for calculating the interactions among the various motions within the boundary layer and their influence on the surface. The model reproduces adequately the synoptic situation and the formation and dissolution cycles of the low-level jet, although it suffers from insufficient cloud production and excessive nocturnal cooling. The authors suggest that observed heat flux data may further improve the realism of the simulations both in the cloud formation and in the jet characteristics. In a higher resolution simulation, the NBL experiences motion on a range of timescales as revealed by a wavelet analysis, and these are affected by the presence of the LLJ. The model can therefore be used to provide information on activity throughout the depth of the NBL.

  10. Wake Turbulence of Two NREL 5-MW Wind Turbines Immersed in a Neutral Atmospheric Boundary-Layer Flow

    E-Print Network [OSTI]

    Bashioum, Jessica L; Schmitz, Sven; Duque, Earl P N

    2013-01-01

    The fluid dynamics video considers an array of two NREL 5-MW turbines separated by seven rotor diameters in a neutral atmospheric boundary layer (ABL). The neutral atmospheric boundary-layer flow data were obtained from a precursor ABL simulation using a Large-Eddy Simulation (LES) framework within OpenFOAM. The mean wind speed at hub height is 8m/s, and the surface roughness is 0.2m. The actuator line method (ALM) is used to model the wind turbine blades by means of body forces added to the momentum equation. The fluid dynamics video shows the root and tip vortices emanating from the blades from various viewpoints. The vortices become unstable and break down into large-scale turbulent structures. As the wakes of the wind turbines advect further downstream, smaller-scale turbulence is generated. It is apparent that vortices generated by the blades of the downstream wind turbine break down faster due to increased turbulence levels generated by the wake of the upstream wind turbine.

  11. Ice at the Interface: Atmosphere-Ice-Ocean Boundary Layer Processes and Their Role in Polar Change---Workshop Report

    SciTech Connect (OSTI)

    Hunke, Elizabeth C. [Los Alamos National Laboratory

    2012-07-23

    The atmosphere-ocean boundary layer in which sea ice resides includes many complex processes that require a more realistic treatment in GCMs, particularly as models move toward full earth system descriptions. The primary purpose of the workshop was to define and discuss such coupled processes from observational and modeling points of view, including insight from both the Arctic and Antarctic systems. The workshop met each of its overarching goals, including fostering collaboration among experimentalists, theorists and modelers, proposing modeling strategies, and ascertaining data availability and needs. Several scientific themes emerged from the workshop, such as the importance of episodic or extreme events, precipitation, stratification above and below the ice, and the marginal ice zone, whose seasonal Arctic migrations now traverse more territory than in the past.

  12. Immersed Boundary Methods for High-Resolution Simulation of Atmospheric Boundary-Layer Flow Over Complex Terrain

    E-Print Network [OSTI]

    Chow, Fotini Katopodes

    models, such as the Weather Research and Forecasting (WRF) model, are in- creasingly used for high facilitates explicit resolution of complex terrain, even urban terrain, in the WRF mesoscale model. First gradient boundary conditions. Specified diurnal heating in a valley, producing anabatic winds, is used

  13. Giant aeolian dune size determined by the average depth of the atmospheric boundary layer

    E-Print Network [OSTI]

    Tlemcen, Algeria. 3 Nicholas School of the Environment and Earth Sciences, Center for Nonlinear be related to statistically averaged quantities. The detailed modelling of the atmospheric processes is very

  14. Large-eddy Simulation of the Nighttime Stable Atmospheric Boundary Layer

    E-Print Network [OSTI]

    Zhou, Bowen

    2012-01-01

    At nighttime, wind turbines extract more energy from thewind energy applications, MO similarity must be used with caution under strong stability conditions for predicting wind at turbineWind Energy 2 Abstract The near-surface structure of atmospheric turbulence affects the design and operation of wind turbines

  15. Extended self-similarity of atmospheric boundary layer wind fields in mesoscale regime: Is it real?

    E-Print Network [OSTI]

    Kiliyanpilakkil, V P

    2015-01-01

    In this letter, we study the scaling properties of multi-year observed and atmospheric model-generated wind time series. We have found that the extended self-similarity holds for the observed series, and remarkably, the scaling exponents corresponding to the meoscale range closely match the well-accepted inertial-range turbulence values. However, the scaling results from the simulated time series are significantly different.

  16. Wind Energy and the Turbulent Nature of the Atmospheric Boundary Layer

    E-Print Network [OSTI]

    Wächter, Matthias; Hölling, Michael; Morales, Allan; Milan, Patrick; Mücke, Tanja; Peinke, Joachim; Reinke, Nico; Rinn, Philip

    2012-01-01

    The challenge of developing a sustainable and renewable energy supply within the next decades requires collaborative efforts as well as new concepts in the fields of science and engineering. Here we give an overview on the impact of small-scale properties of atmospheric turbulence on the wind energy conversion process. Special emphasis is given to the noisy and intermittent structure of turbulence and its outcome for wind energy conversion and utilization. Experimental, theoretical, analytical, and numerical concepts and methods are presented. In particular we report on new aspects resulting from the combination of basic research, especially in the field of turbulence and complex stochastic systems, with engineering applications.

  17. Geography 104 Boundary Layer Climates

    E-Print Network [OSTI]

    Geography 104 Boundary Layer Climates Assignment #5 Question 1: The Urban Heat Island The following briefly how the use of giant windmills or fans can be effective in preventing frost in an orchard. Refer

  18. Soil moisture in complex terrain: quantifying effects on atmospheric boundary layer flow and providing improved surface boundary conditions for mesoscale models

    E-Print Network [OSTI]

    Daniels, Megan Hanako

    2010-01-01

    groundwater, land-surface, and mesoscale atmospheric model-and modification of mesoscale circulations. , Mon. Wea.J. Davis, The effects of mesoscale surface heterogeneity on

  19. Ozone Chemistry in the High-Latitude Boundary Layer

    E-Print Network [OSTI]

    Toohey, Darin W.

    Ozone Chemistry in the High-Latitude Boundary Layer Linnea Avallone Department of Atmospheric layer ozone loss phenomenon · In situ observations of BrO at Arctic sites · Preliminary results from Antarctic experiments in 2002 and 2004 #12;Brief History · Springtime ozone loss observed at many sites

  20. Boundary Layer Cloud Turbulence Characteristics

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

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  1. Planetary Boundary Layer from AERI and MPL

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

    Sawyer, Virginia

    The distribution and transport of aerosol emitted to the lower troposphere is governed by the height of the planetary boundary layer (PBL), which limits the dilution of pollutants and influences boundary-layer convection. Because radiative heating and cooling of the surface strongly affect the PBL top height, it follows diurnal and seasonal cycles and may vary by hundreds of meters over a 24-hour period. The cap the PBL imposes on low-level aerosol transport makes aerosol concentration an effective proxy for PBL height: the top of the PBL is marked by a rapid transition from polluted, well-mixed boundary-layer air to the cleaner, more stratified free troposphere. Micropulse lidar (MPL) can provide much higher temporal resolution than radiosonde and better vertical resolution than infrared spectrometer (AERI), but PBL heights from all three instruments at the ARM SGP site are compared to one another for validation. If there is agreement among them, the higher-resolution remote sensing-derived PBL heights can accurately fill in the gaps left by the low frequency of radiosonde launches, and thus improve model parameterizations and our understanding of boundary-layer processes.

  2. Planetary Boundary Layer from AERI and MPL

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

    Sawyer, Virginia

    2014-02-13

    The distribution and transport of aerosol emitted to the lower troposphere is governed by the height of the planetary boundary layer (PBL), which limits the dilution of pollutants and influences boundary-layer convection. Because radiative heating and cooling of the surface strongly affect the PBL top height, it follows diurnal and seasonal cycles and may vary by hundreds of meters over a 24-hour period. The cap the PBL imposes on low-level aerosol transport makes aerosol concentration an effective proxy for PBL height: the top of the PBL is marked by a rapid transition from polluted, well-mixed boundary-layer air to the cleaner, more stratified free troposphere. Micropulse lidar (MPL) can provide much higher temporal resolution than radiosonde and better vertical resolution than infrared spectrometer (AERI), but PBL heights from all three instruments at the ARM SGP site are compared to one another for validation. If there is agreement among them, the higher-resolution remote sensing-derived PBL heights can accurately fill in the gaps left by the low frequency of radiosonde launches, and thus improve model parameterizations and our understanding of boundary-layer processes.

  3. Thick diffusion limit boundary layer test problems

    SciTech Connect (OSTI)

    Bailey, T. S.; Warsa, J. S.; Chang, J. H.; Adams, M. L.

    2013-07-01

    We develop two simple test problems that quantify the behavior of computational transport solutions in the presence of boundary layers that are not resolved by the spatial grid. In particular we study the quantitative effects of 'contamination' terms that, according to previous asymptotic analyses, may have a detrimental effect on the solutions obtained by both discontinuous finite element (DFEM) and characteristic-method (CM) spatial discretizations, at least for boundary layers caused by azimuthally asymmetric incident intensities. Few numerical results have illustrated the effects of this contamination, and none have quantified it to our knowledge. Our test problems use leading-order analytic solutions that should be equal to zero in the problem interior, which means the observed interior solution is the error introduced by the contamination terms. Results from DFEM solutions demonstrate that the contamination terms can cause error propagation into the problem interior for both orthogonal and non-orthogonal grids, and that this error is much worse for non-orthogonal grids. This behavior is consistent with the predictions of previous analyses. We conclude that these boundary layer test problems and their variants are useful tools for the study of errors that are introduced by unresolved boundary layers in diffusive transport problems. (authors)

  4. Laminar boundary layers in convective heat transport

    E-Print Network [OSTI]

    Christian Seis

    2012-12-12

    We study Rayleigh-Benard convection in the high-Rayleigh-number and high-Prandtl-number regime, i.e., we consider a fluid in a container that is exposed to strong heating of the bottom and cooling of the top plate in the absence of inertia effects. While the dynamics in the bulk are characterized by a chaotic convective heat flow, the boundary layers at the horizontal container plates are essentially conducting and thus the fluid is motionless. Consequently, the average temperature exhibits a linear profile in the boundary layers. In this article, we rigorously investigate the average temperature and oscillations in the boundary layer via local bounds on the temperature field. Moreover, we deduce that the temperature profile is indeed essentially linear close to the horizontal container plates. Our results are uniform in the system parameters (e.g. the Rayleigh number) up to logarithmic correction terms. An important tool in our analysis is a new Hardy-type estimate for the convecting velocity field, which can be used to control the fluid motion in the layer. The bounds on the temperature field are derived with the help of local maximal regularity estimates for convection-diffusion equations.

  5. Laminar boundary layers in convective heat transport

    E-Print Network [OSTI]

    Seis, Christian

    2012-01-01

    We study Rayleigh-Benard convection in the high-Rayleigh-number and high-Prandtl-number regime, i.e., we consider a fluid in a container that is exposed to strong heating of the bottom and cooling of the top plate in the absence of inertia effects. While the dynamics in the bulk are characterized by a chaotic convective heat flow, the boundary layers at the horizontal container plates are essentially conducting and thus the fluid is motionless. Consequently, the average temperature exhibits a linear profile in the boundary layers. In this article, we rigorously investigate the average temperature and oscillations in the boundary layer via local bounds on the temperature field. Moreover, we deduce that the temperature profile is indeed essentially linear close to the horizontal container plates. Our results are uniform in the system parameters (e.g. the Rayleigh number) up to logarithmic correction terms. An important tool in our analysis is a new Hardy-type estimate for the convecting velocity field, which ca...

  6. Coupled wake boundary layer model of wind-farms

    E-Print Network [OSTI]

    Stevens, Richard J A M; Meneveau, Charles

    2014-01-01

    We present and test a coupled wake boundary layer (CWBL) model that describes the distribution of the power output in a wind-farm. The model couples the traditional, industry-standard wake expansion/superposition approach with a top-down model for the overall wind-farm boundary layer structure. The wake expansion/superposition model captures the effect of turbine positioning, while the top-down portion adds the interaction between the wind-turbine wakes and the atmospheric boundary layer. Each portion of the model requires specification of a parameter that is not known a-priori. For the wake model the wake expansion coefficient is required, while the top-down model requires an effective span-wise turbine spacing within which the model's momentum balance is relevant. The wake expansion coefficient is obtained by matching the predicted mean velocity at the turbine from both approaches, while the effective span-wise turbine spacing depends on turbine positioning and thus can be determined from the wake expansion...

  7. SUPERSONIC SHEAR INSTABILITIES IN ASTROPHYSICAL BOUNDARY LAYERS

    SciTech Connect (OSTI)

    Belyaev, Mikhail A.; Rafikov, Roman R., E-mail: rrr@astro.princeton.edu [Department of Astrophysical Sciences, Princeton University, Ivy Lane, Princeton, NJ 08540 (United States)

    2012-06-20

    Disk accretion onto weakly magnetized astrophysical objects often proceeds via a boundary layer (BL) that forms near the object's surface, in which the rotation speed of the accreted gas changes rapidly. Here, we study the initial stages of formation for such a BL around a white dwarf or a young star by examining the hydrodynamical shear instabilities that may initiate mixing and momentum transport between the two fluids of different densities moving supersonically with respect to each other. We find that an initially laminar BL is unstable to two different kinds of instabilities. One is an instability of a supersonic vortex sheet (implying a discontinuous initial profile of the angular speed of the gas) in the presence of gravity, which we find to have a growth rate of order (but less than) the orbital frequency. The other is a sonic instability of a finite width, supersonic shear layer, which is similar to the Papaloizou-Pringle instability. It has a growth rate proportional to the shear inside the transition layer, which is of order the orbital frequency times the ratio of stellar radius to the BL thickness. For a BL that is thin compared to the radius of the star, the shear rate is much larger than the orbital frequency. Thus, we conclude that sonic instabilities play a dominant role in the initial stages of nonmagnetic BL formation and give rise to very fast mixing between disk gas and stellar fluid in the supersonic regime.

  8. LARGE EDDY SIMULATION OF TURBULENT BOUNDARY LAYERS OVER ROUGH BEDS

    E-Print Network [OSTI]

    Pawlak, Geno

    that determines the response of the boundary layer is not clear. One method to characterize the irregular nature with different spectral slopes using 2D 10 % loading square waves as basis functions. These square waves can) is then used to simulate the turbulent boundary layer over the rough beds. The LES solver is first validated

  9. Aero-Optical Effects of Supersonic Boundary Layers Stanislav Gordeyev

    E-Print Network [OSTI]

    Gordeyev, Stanislav

    Aero-Optical Effects of Supersonic Boundary Layers Stanislav Gordeyev and Eric Jumper University, Colorado 80840 DOI: 10.2514/1.J051266 Aero-optical measurements of a zero-pressure-gradient, supersonic to describe aero-optical effects of both the subsonic and the supersonic boundary layers. Finally, this new

  10. Elements of comparison between Martian and terrestrial mesoscale meteorological phenomena: Katabatic winds and boundary layer convection

    E-Print Network [OSTI]

    Spiga, Aymeric

    Elements of comparison between Martian and terrestrial mesoscale meteorological phenomena Keywords: Mesoscale meteorology Katabatic winds Boundary layer convection Comparative planetology a b s t r a c t Terrestrial and Martian atmospheres are both characterised by a large variety of mesoscale

  11. Comparison of marine boundary layer cloud properties from CERES-MODIS Edition 4 and DOE ARM

    E-Print Network [OSTI]

    Dong, Xiquan

    Comparison of marine boundary layer cloud properties from CERES-MODIS Edition 4 and DOE ARM AMF are compared with observations taken at the Department of Energy Atmospheric Radiation Measurement (ARM) Mobile from ARM ground-based observations were averaged over a 1h interval centered at the satellite overpass

  12. Examining A Hypersonic Turbulent Boundary Layer at Low Reynolds Number 

    E-Print Network [OSTI]

    Semper, Michael Thomas

    2013-05-15

    The purpose of the current study was to answer several questions related to hypersonic, low Reynolds number, turbulent boundary layers, of which available data related to turbulence quantities is scarce. To that end, a ...

  13. Performance of a boundary layer ingesting propulsion system

    E-Print Network [OSTI]

    Plas, Angélique (Angélique Pascale)

    2006-01-01

    This thesis presents an assessment of the aerodynamic performance of an aircraft propulsion system, with embedded engines, in the presence of aircraft fuselage boundary layer ingestion (BLI). The emphasis is on defining ...

  14. Analysis of civil aircraft propulsors with boundary layer ingestion

    E-Print Network [OSTI]

    Hall, David Kenneth

    2015-01-01

    This thesis describes (i) guidelines for propulsor sizing, and (ii) strategies for fan turbomachinery conceptual design, for a boundary layer ingesting (BLI) propulsion system for advanced civil transport aircraft. For the ...

  15. Distributed Roughness Receptivity in a Flat Plate Boundary Layer 

    E-Print Network [OSTI]

    Kuester, Matthew Scott

    2014-04-18

    the incoming boundary layer. This dissertation describes an experiment specifically designed to study the shielding effect. Three roughness configurations, a deterministic distributed roughness patch, a slanted rectangle, and the combination of the two, were...

  16. Stability of High-Speed, Three-Dimensional Boundary Layers 

    E-Print Network [OSTI]

    Craig, Stuart A

    2015-04-02

    Boundary-layer experiments are performed in the low-disturbance, Mach 6 Quiet Tunnel (M6QT) at Texas A&M University. The experiments are focused specifically on investigating the physics of two three-dimensional phenomena in hypersonic boundary...

  17. Boundary-layer control by electric fields A feasibility study

    E-Print Network [OSTI]

    Mendes, R V

    1998-01-01

    A problem of great concern in aviation and submarine propulsion is the control of the boundary layer and, in particular, the methods to extend the laminar region as a means to decrease noise and fuel consumption. In this paper we study the flow of air along an airfoil when a layer of ionized gas and a longitudinal electric field are created in the boundary layer region. By deriving scaling solutions and more accurate numerical solutions we discuss the possibility of achieving significant boundary layer control for realistic physical parameters. Practical design formulas and criteria are obtained. We also discuss the perspectives for active control of the laminar-to-turbulent transition fluctuations by electromagnetic field modulation.

  18. Lidar Investigation of Tropical Nocturnal Boundary Layer Aerosols and Cloud Macrophysics

    SciTech Connect (OSTI)

    Manoj, M. G.; Devara, PC S.; Taraphdar, Sourav

    2013-10-01

    Observational evidence of two-way association between nocturnal boundary layer aerosols and cloud macrophysical properties under different meteorological conditions is reported in this paper. The study has been conducted during 2008-09 employing a high space-time resolution polarimetric micro-pulse lidar over a tropical urban station in India. Firstly, the study highlights the crucial role of boundary layer aerosols and background meteorology on the formation and structure of low-level stratiform clouds in the backdrop of different atmospheric stability conditions. Turbulent mixing induced by the wind shear at the station, which is associated with a complex terrain, is found to play a pivotal role in the formation and structural evolution of nocturnal boundary layer clouds. Secondly, it is shown that the trapping of energy in the form of outgoing terrestrial radiation by the overlying low-level clouds can enhance the aerosol mixing height associated with the nocturnal boundary layer. To substantiate this, the long-wave heating associated with cloud capping has been quantitatively estimated in an indirect way by employing an Advanced Research Weather Research and Forecasting (WRF-ARW) model version 2.2 developed by National Center for Atmospheric Research (NCAR), Colorado, USA, and supplementary data sets; and differentiated against other heating mechanisms. The present investigation as well establishes the potential of lidar remote-sensing technique in exploring some of the intriguing aspects of the cloud-environment relationship.

  19. Stratified Flow over Topography: Wave Generation and Boundary Layer Separation

    E-Print Network [OSTI]

    Sutherland, Bruce

    Stratified Flow over Topography: Wave Generation and Boundary Layer Separation B. R. Sutherland topography. We have chosen to use periodic, finite­amplitude hills which are representative of the Earth upon internal waves generated by flow over rough topography. 1 Introduction Internal waves propagate

  20. Stratified Flow over Topography: Wave Generation and Boundary Layer Separation

    E-Print Network [OSTI]

    Sutherland, Bruce

    Stratified Flow over Topography: Wave Generation and Boundary Layer Separation B. R. Sutherland Abstract We have performed laboratory experiments to study wave generation over and in the lee of model upon internal waves generated by flow over rough topography. 1 Introduction Internal waves propagate

  1. Carbon transport in the bottom boundary layer. Final report

    SciTech Connect (OSTI)

    Agrawal, Y.C.

    1998-10-05

    This report summarizes the activities and findings from a field experiment devised to estimate the rates and mechanisms of transport of carbon across the continental shelves. The specific site chosen for the experiment was the mid-Atlantic Bight, a region off the North Carolina coast. The experiment involved a large contingent of scientists from many institutions. The specific component of the program was the transport of carbon in the bottom boundary layer. The postulate mechanisms of transport of carbon in the bottom boundary layer are: resuspension and advection, downward deposition, and accumulation. The high turbulence levels in the bottom boundary layer require the understanding of the coupling between turbulence and bottom sediments. The specific issues addressed in the work reported here were: (a) What is the sediment response to forcing by currents and waves? (b) What is the turbulence climate in the bottom boundary layer at this site? and (c) What is the rate at which settling leads to carbon sequestering in bottom sediments at offshore sites?

  2. ORIGINAL PAPER Mechanical filtering by the boundary layer and fluidstructure

    E-Print Network [OSTI]

    McHenry, Matt

    ORIGINAL PAPER Mechanical filtering by the boundary layer and fluid­structure interaction force coefficient for fluid c speed of sound in water C integration constant Em Young's modulus moment of area k viscous drag coefficient L hydrodynamic force coefficient M bending moment N number

  3. Mass exchange in the stable boundary layer by coherent structures

    E-Print Network [OSTI]

    Leclerc, Monique Y.

    ) and a dense array of wind sensors to observe an indirect representation of roll vortices and plumes over the surface appears to pump energy near the surface thereby supporting the development of coherent structures gaseous exchange 1. Introduction Mass and energy exchange in the stable boundary layer remains poorly

  4. Large-Scale Streamwise Turbulent Structures in Hypersonic Boundary Layers 

    E-Print Network [OSTI]

    English, Benjamin L.

    2013-04-22

    Prior research in the field of boundary layer turbulence has identified streamwise-elongated large-scale turbulence structures in both low speed compressible and high speed (M=2.0) flow. No experimental work has been done in any flow of M> or =3...

  5. Edge Plasma Boundary Layer Generated By Kink Modes in Tokamaks

    SciTech Connect (OSTI)

    L.E. Zakharov

    2010-11-22

    This paper describes the structure of the electric current generated by external kink modes at the plasma edge using the ideally conducting plasma model. It is found that the edge current layer is created by both wall touching and free boundary kink modes. Near marginal stability, the total edge current has a universal expression as a result of partial compensation of the ?-functional surface current by the bulk current at the edge. The resolution of an apparent paradox with the pressure balance across the plasma boundary in the presence of the surface currents is provided.

  6. Polymer Effects on Heat Transport in Laminar Boundary Layer Flow

    E-Print Network [OSTI]

    Roberto Benzi; Emily S. C. Ching; Vivien W. S. Chu

    2011-04-27

    We consider a laminar Blasius boundary-layer flow above a slightly heated horizontal plate and study the effect of polymer additives on the heat transport. We show that the action of the polymers can be understood as a space-dependent effective viscosity that first increases from the zero-shear value then decreases exponentially back to the zero-shear value as one moves away from the boundary. We find that with such an effective viscosity, both the horizontal and vertical velocities near the plate are decreased thus leading to an increase in the friction drag and a decrease in the heat transport in the flow.

  7. Improving Subtropical Boundary Layer Cloudiness in the 2011 NCEP GFS

    SciTech Connect (OSTI)

    Fletcher, J. K.; Bretherton, Christopher S.; Xiao, Heng; Sun, Ruiyu N.; Han, J.

    2014-09-23

    The current operational version of National Centers for Environmental Prediction (NCEP) Global Forecasting System (GFS) shows significant low cloud bias. These biases also appear in the Coupled Forecast System (CFS), which is developed from the GFS. These low cloud biases degrade seasonal and longer climate forecasts, particularly of short-wave cloud radiative forcing, and affect predicted sea surface temperature. Reducing this bias in the GFS will aid the development of future CFS versions and contributes to NCEP's goal of unified weather and climate modelling. Changes are made to the shallow convection and planetary boundary layer parameterisations to make them more consistent with current knowledge of these processes and to reduce the low cloud bias. These changes are tested in a single-column version of GFS and in global simulations with GFS coupled to a dynamical ocean model. In the single-column model, we focus on changing parameters that set the following: the strength of shallow cumulus lateral entrainment, the conversion of updraught liquid water to precipitation and grid-scale condensate, shallow cumulus cloud top, and the effect of shallow convection in stratocumulus environments. Results show that these changes improve the single-column simulations when compared to large eddy simulations, in particular through decreasing the precipitation efficiency of boundary layer clouds. These changes, combined with a few other model improvements, also reduce boundary layer cloud and albedo biases in global coupled simulations.

  8. An Examination of Configurations for Using Infrared to Measure Boundary Layer Transition 

    E-Print Network [OSTI]

    Freels, Justin Reed

    2012-10-19

    Infrared transition location estimates can be fast and useful measurements in wind tunnel and flight tests. Because turbulent boundary layers have a much higher rate of convective heat transfer than laminar boundary layers, a difference in surface...

  9. Wind profile above the surface boundary layer S.-E. Gryning (1), E. Batchvarova (2) and B. Brmmer (3)

    E-Print Network [OSTI]

    Wind profile above the surface boundary layer S.-E. Gryning (1), E. Batchvarova (2) and B. Brümmer in predictions of the wind profile in the lowest hundreds me- ters of the atmosphere, being connected to the general increase in height of structures such as bridges, high houses and wind turbines. The hub height

  10. Boundary-Layer Meteorol (2014) 150:107130 DOI 10.1007/s10546-013-9864-4

    E-Print Network [OSTI]

    Xue, Ming

    2014-01-01

    Processes in Nocturnal Atmospheric Boundary Layer on Urban Ozone Concentrations Petra M. Klein · Xiao ozone. The prevalence of southerly winds and LLJs in the U.S. Southern Great Plains during summer makes on urban air quality. Ozone (O3) and nitrogen oxide concentrations measured at regulatory monitoring sites

  11. THE URBAN BOUNDARY-LAYER FIELD CAMPAIGN IN MARSEILLE (UBL/CLU-ESCOMPTE): SET-UP AND FIRST RESULTS

    E-Print Network [OSTI]

    ) Abstract. The UBL/CLU (urban boundary layer/couche limite urbaine) observation and modelling campaign to the heat and moisture exchanges between the urban canopy and the atmosphere during periods of low wind mapping of urban land cover, land-use and aerodynamic parameters used in UBL models, and (iv) testing

  12. Response of the bottom boundary layer over a sloping shelf to variations in alongshore wind

    E-Print Network [OSTI]

    to a great extent by flows in the surface and bottom boundary layers (BBL). Wind forcing generates crossResponse of the bottom boundary layer over a sloping shelf to variations in alongshore wind A boundary layer over a sloping shelf to variations in alongshore wind, J. Geophys. Res., 110, C10S09, doi:10

  13. Thermographic analysis of turbulent non-isothermal water boundary layer

    E-Print Network [OSTI]

    Znamenskaya, Irina A

    2015-01-01

    The paper is devoted to the investigation of the turbulent water boundary layer in the jet mixing flows using high-speed infrared (IR) thermography. Two turbulent mixing processes were studied: a submerged water jet impinging on a flat surface and two intersecting jets in a round disc-shaped vessel. An infrared camera (FLIR Systems SC7700) was focused on the window transparent for IR radiation; it provided high-speed recordings of heat fluxes from a thin water layer close to the window. Temperature versus time curves at different points of water boundary layer near the wall surface were acquired using the IR camera with the recording frequency of 100 Hz. The time of recording varied from 3 till 20 min. The power spectra for the temperature fluctuations at different points on the hot-cold water mixing zone were calculated using the Fast Fourier Transform algorithm. The obtained spectral behavior was compared to the Kolmogorov "-5/3 spectrum" (a direct energy cascade) and the dual-cascade scenario predicted for...

  14. Aerodynamic Models for Hurricanes III. Modeling hurricane boundary layer

    E-Print Network [OSTI]

    Leonov, Arkady I

    2008-01-01

    The third paper of the series (see previous ones in Refs.[1-2]) discusses basic physicalprocesses in the (quasi-) steady hurricane boundary layer (HBL), develops an approximate airflow model, establishes the HBL structure, and presents integral balance relations for dynamic and thermodynamic variables in HBL. Models of evaporation and condensation are developed, where the condensation is treated similarly to the slow combustion theory. A turbulent approximation for the lower sub-layer of HBL is applied to the sea-air interaction to establish the observed increase in angular momentum in the outer region of HBL.A closed set of balance relations has been obtained. Simple analytical solution of the set yields expressions for the basic dynamic variables - maximal tangential and radial velocities in hurricane, maximal vertical speed in eye wall, the affinity speed of hurricane travel, and the maximal temperature increase after condensation. Estimated values of the variables seem to be realistic. An attempt is also ...

  15. Heat transport by laminar boundary layer flow with polymers

    E-Print Network [OSTI]

    Roberto Benzi; Emily S. C. Ching.; Vivien W. S. Chu

    2011-04-23

    Motivated by recent experimental observations, we consider a steady-state Prandtl-Blasius boundary layer flow with polymers above a slightly heated horizontal plate and study how the heat transport might be affected by the polymers. We discuss how a set of equations can be derived for the problem and how these equations can be solved numerically by an iterative scheme. By carrying out such a scheme, we find that the effect of the polymers is equivalent to producing a space-dependent effective viscosity that first increases from the zero-shear value at the plate then decreases rapidly back to the zero-shear value far from the plate. We further show that such an effective viscosity leads to an enhancement in the drag, which in turn leads to a reduction in heat transport.

  16. Further development and testing of a second-order bulk boundary layer model. Master's thesis

    SciTech Connect (OSTI)

    Krasner, R.D.

    1993-05-03

    A one-layer bulk boundary layer model is developed. The model predicts the mixed layer values of the potential temperature, mixing ratio, and u- and v-momentum. The model also predicts the depth of the boundary layer and the vertically integrated turbulence kinetic energy (TKE). The TKE is determined using a second-order closure that relates the rate of dissipation to the TKE. The fractional area covered by rising motion sigma and the entrainment rate (E) are diagnostically determined. The model is used to study the clear convective boundary layer (CBL) using data from the Wangara, Australia boundary layer experiment. The Wangara data is also used as an observation base to validate model results. A further study is accomplished by simulating the planetary boundary layer (PBL) over an ocean surface. This study is designed to find the steady-state solutions of the prognostic variable.

  17. Primary, secondary instabilities and control of the rotating-disk boundary layer

    E-Print Network [OSTI]

    ;Typical 3D boundary layers rotating disk swept wing Common features: · crossflow component near the wall · inflection point · strong inviscid instability · secondary instabilities ; growth and saturation of crossflow

  18. Wave mediated angular momentum transport in astrophysical boundary layers

    E-Print Network [OSTI]

    Hertfelder, Marius

    2015-01-01

    Context. Disk accretion onto weakly magnetized stars leads to the formation of a boundary layer (BL) where the gas loses its excess kinetic energy and settles onto the star. There are still many open questions concerning the BL, for instance the transport of angular momentum (AM) or the vertical structure. Aims. It is the aim of this work to investigate the AM transport in the BL where the magneto-rotational instability (MRI) is not operating owing to the increasing angular velocity $\\Omega(r)$ with radius. We will therefore search for an appropriate mechanism and examine its efficiency and implications. Methods. We perform 2D numerical hydrodynamical simulations in a cylindrical coordinate system $(r, \\varphi)$ for a thin, vertically inte- grated accretion disk around a young star. We employ a realistic equation of state and include both cooling from the disk surfaces and radiation transport in radial and azimuthal direction. The viscosity in the disk is treated by the {\\alpha}-model; in the BL there is no v...

  19. Boundary Layer Energy Transport and Cumulus Development over a Heated Mountain: An Observational Study

    E-Print Network [OSTI]

    Geerts, Bart

    Boundary Layer Energy Transport and Cumulus Development over a Heated Mountain: An Observational an isolated, heated mountain are presented. The data were collected around the Santa Catalina Mountains congestus to cumulonimbus development over the mountain. Flights in the boundary layer around the mountain

  20. Coupled Mesoscale-Large-Eddy Modeling of Realistic Stable Boundary Layer Turbulence

    E-Print Network [OSTI]

    Wang, Yao; Manuel, Lance

    2013-01-01

    Site-specific flow and turbulence information are needed for various practical applications, ranging from aerodynamic/aeroelastic modeling for wind turbine design to optical diffraction calculations. Even though highly desirable, collecting on-site meteorological measurements can be an expensive, time-consuming, and sometimes a challenging task. In this work, we propose a coupled mesoscale-large-eddy modeling framework to synthetically generate site-specific flow and turbulence data. The workhorses behind our framework are a state-of-the-art, open-source atmospheric model called the Weather Research and Forecasting (WRF) model and a tuning-free large-eddy simulation (LES) model. Using this coupled framework, we simulate a nighttime stable boundary layer (SBL) case from the well-known CASES-99 field campaign. One of the unique aspects of this work is the usage of a diverse range of observations for characterization and validation. The coupled models reproduce certain characteristics of observed low-level jets....

  1. Turbulent flow over a house in a simulated hurricane boundary layer

    E-Print Network [OSTI]

    Taylor, Zachary; Gurka, Roi; Kopp, Gregory

    2009-01-01

    Every year hurricanes and other extreme wind storms cause billions of dollars in damage worldwide. For residential construction, such failures are usually associated with roofs, which see the largest aerodynamic loading. However, determining aerodynamic loads on different portions of North American houses is complicated by the lack of clear load paths and non-linear load sharing in wood frame roofs. This problem of fluid-structure interaction requires both wind tunnel testing and full-scale structural testing. A series of wind tunnel tests have been performed on a house in a simulated atmospheric boundary layer (ABL), with the resulting wind-induced pressures applied to the full-scale structure. The ABL was simulated for flow over open country terrain where both velocity and turbulence intensity profiles, as well as spectra, were matched with available full scale measurements for this type of terrain. The first set of measurements was 600 simultaneous surface pressure measurements over the entire house. A key...

  2. Mesoscale coupled ocean-atmosphere feedbacks in boundary current systems

    E-Print Network [OSTI]

    Putrasahan, Dian Ariyani

    2012-01-01

    productive oceanic eastern boundary current, providing anCurrent System and the Kuroshio Extension uses OFES products for their oceanic

  3. ARM - Field Campaign - 2013 Lower Atmospheric Boundary Layer Experiment

    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 Anode Design to Improve4AJ01) (See22, 2012 [DataJulyMarch 27,5 Southern2

  4. Clouds, aerosol, and precipitation in the Marine Boundary Layer: An ARM mobile facility deployment

    SciTech Connect (OSTI)

    Wood, Robert; Luke, Ed; Wyant, Matthew; Bretherton, Christopher S.; Remillard, Jasmine; Kollias, Pavlos; Fletcher, Jennifer; Stemmler, Jayson; deSzoeke, S.; Yuter, Sandra; Miller, Matthew; Mechem, David; Tselioudis, George; Chiu, Christine; Mann, Julia; O Connor, Ewan; Hogan, Robin; Dong, Xiquan; Miller, Mark; Ghate, Virendra; Jefferson, Anne; Min, Qilong; Minnis, Patrick; Palinkonda, Rabindra; Albrecht, Bruce; Hannay, Cecile; Lin, Yanluan

    2014-04-27

    The Clouds, Aerosol, and Precipitation in the Marine Boundary Layer (CAP-MBL) deployment at Graciosa Island in the Azores generated a 21-month (April 2009-December 2010) comprehensive dataset documenting clouds, aerosols, and precipitation using the Atmospheric Radiation Measurement Program (ARM) Mobile Facility (AMF). The scientific aim of the deployment is to gain improved understanding of the interactions of clouds, aerosols, and precipitation in the marine boundary layer. Graciosa Island straddles the boundary between the subtropics and midlatitudes in the Northeast Atlantic Ocean and consequently experiences a great diversity of meteorological and cloudiness conditions. Low clouds are the dominant cloud type, with stratocumulus and cumulus occurring regularly. Approximately half of all clouds contained precipitation detectable as radar echoes below the cloud base. Radar and satellite observations show that clouds with tops from 1-11 km contribute more or less equally to surface-measured precipitation at Graciosa. A wide range of aerosol conditions was sampled during the deployment consistent with the diversity of sources as indicated by back-trajectory analysis. Preliminary findings suggest important two-way interactions between aerosols and clouds at Graciosa, with aerosols affecting light precipitation and cloud radiative properties while being controlled in part by precipitation scavenging.The data from Graciosa are being compared with short-range forecasts made with a variety of models. A pilot analysis with two climate and two weather forecast models shows that they reproduce the observed time-varying vertical structure of lower-tropospheric cloud fairly well but the cloud-nucleating aerosol concentrations less well. The Graciosa site has been chosen to be a permanent fixed ARM site that became operational in October 2013.

  5. Clouds, aerosol, and precipitation in the Marine Boundary Layer: An ARM mobile facility deployment

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

    Wood, Robert; Luke, Ed; Wyant, Matthew; Bretherton, Christopher S.; Remillard, Jasmine; Kollias, Pavlos; Fletcher, Jennifer; Stemmler, Jayson; deSzoeke, S.; Yuter, Sandra; et al

    2014-04-27

    The Clouds, Aerosol, and Precipitation in the Marine Boundary Layer (CAP-MBL) deployment at Graciosa Island in the Azores generated a 21-month (April 2009-December 2010) comprehensive dataset documenting clouds, aerosols, and precipitation using the Atmospheric Radiation Measurement Program (ARM) Mobile Facility (AMF). The scientific aim of the deployment is to gain improved understanding of the interactions of clouds, aerosols, and precipitation in the marine boundary layer. Graciosa Island straddles the boundary between the subtropics and midlatitudes in the Northeast Atlantic Ocean and consequently experiences a great diversity of meteorological and cloudiness conditions. Low clouds are the dominant cloud type, with stratocumulusmore »and cumulus occurring regularly. Approximately half of all clouds contained precipitation detectable as radar echoes below the cloud base. Radar and satellite observations show that clouds with tops from 1-11 km contribute more or less equally to surface-measured precipitation at Graciosa. A wide range of aerosol conditions was sampled during the deployment consistent with the diversity of sources as indicated by back-trajectory analysis. Preliminary findings suggest important two-way interactions between aerosols and clouds at Graciosa, with aerosols affecting light precipitation and cloud radiative properties while being controlled in part by precipitation scavenging.The data from Graciosa are being compared with short-range forecasts made with a variety of models. A pilot analysis with two climate and two weather forecast models shows that they reproduce the observed time-varying vertical structure of lower-tropospheric cloud fairly well but the cloud-nucleating aerosol concentrations less well. The Graciosa site has been chosen to be a permanent fixed ARM site that became operational in October 2013.« less

  6. DIFFUSION OF A CHEMICAL SPECIES THROUGH A VISCOUS BOUNDARY LAYER

    E-Print Network [OSTI]

    Keller, J.

    2011-01-01

    2.3 Evaluation of a Coal Gasification Atmosphere. . -iv-a highly cor- rosive coal gasification mixture. It is shown2.3 Evaluation of a Coal Gasification Atmosphere The purpose

  7. Mesoscale coupled ocean-atmosphere feedbacks in boundary current systems

    E-Print Network [OSTI]

    Putrasahan, Dian Ariyani

    2012-01-01

    Isolating Mesoscale Coupled Ocean-Atmosphere in the KuroshioSST coupler . . . . Chapter 3 Mesoscale Ocean-Atmosphere4.2 Impact of Mesoscale SST on Precipitation Chapter 4 vi

  8. Active Control of Instabilities in Laminar BoundaryLayer Flow --Part II: Use of Sensors and Spectral Controller

    E-Print Network [OSTI]

    Erlebacher, Gordon

    Active Control of Instabilities in Laminar Boundary­Layer Flow -- Part II: Use of Sensors growth and stabilize the instabilities within the laminar boundary layer. This scenario is shown in Fig

  9. Effect of unsteady wake passing frequency on boundary layer transition on the concave surface of a curved plate 

    E-Print Network [OSTI]

    Read, Robert Kevin

    1997-01-01

    The unsteady boundary layer behavior on the concave surface of a curved plate is investigated. Detailed experimental investigations are carried out to study the effect of unsteady wakes on the boundary layer transition under varying wake passing...

  10. Marine boundary layer structure as observed by space-based Lidar

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

    Luo, T.; Wang, Z.; Zhang, D.

    2015-12-03

    The marine boundary layer (MBL) structure is important to the exchange of heat, momentum, and moisture between oceans and the low atmosphere and to the marine low cloud processes. This paper explores MBL structure over the eastern Pacific region with a new 4 year satellite-based dataset. The MBL aerosol lidar backscattering from the CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) was used to identify the MBL top (BLH) and the mixing layer height (MLH). Results showed that MBL is generally decoupled with MLH / BLH ratio ranging from ? 0.5 to ? 0.8 and the MBL decoupling magnitude ismore »mainly controlled by estimated inversion strength (EIS) that affects the cloud top entrainment process. The systematic differences between drizzling and non-drizzling stratocumulus tops, which may relate to the meso-scale circulations or gravity wave in MBL, also show dependence on EIS. Further analysis indicated that the MBL shows similar decoupled structure for clear sky and cumulus cloud-topped conditions, but is better mixed under stratiform cloud breakup and overcast conditions.« less

  11. Transforming the representation of the boundary layer and low clouds for high-resolution regional climate modeling: Final report

    SciTech Connect (OSTI)

    Huang, Hsin-Yuan; Hall, Alex

    2013-07-24

    Stratocumulus and shallow cumulus clouds in subtropical oceanic regions (e.g., Southeast Pacific) cover thousands of square kilometers and play a key role in regulating global climate (e.g., Klein and Hartmann, 1993). Numerical modeling is an essential tool to study these clouds in regional and global systems, but the current generation of climate and weather models has difficulties in representing them in a realistic way (e.g., Siebesma et al., 2004; Stevens et al., 2007; Teixeira et al., 2011). While numerical models resolve the large-scale flow, subgrid-scale parameterizations are needed to estimate small-scale properties (e.g. boundary layer turbulence and convection, clouds, radiation), which have significant influence on the resolved scale due to the complex nonlinear nature of the atmosphere. To represent the contribution of these fine-scale processes to the resolved scale, climate models use various parameterizations, which are the main pieces in the model that contribute to the low clouds dynamics and therefore are the major sources of errors or approximations in their representation. In this project, we aim to 1) improve our understanding of the physical processes in thermal circulation and cloud formation, 2) examine the performance and sensitivity of various parameterizations in the regional weather model (Weather Research and Forecasting model; WRF), and 3) develop, implement, and evaluate the advanced boundary layer parameterization in the regional model to better represent stratocumulus, shallow cumulus, and their transition. Thus, this project includes three major corresponding studies. We find that the mean diurnal cycle is sensitive to model domain in ways that reveal the existence of different contributions originating from the Southeast Pacific land-masses. The experiments suggest that diurnal variations in circulations and thermal structures over this region are influenced by convection over the Peruvian sector of the Andes cordillera, while the mostly dry mountain-breeze circulations force an additional component that results in semi-diurnal variations near the coast. A series of numerical tests, however, reveal sensitivity of the simulations to the choice of vertical grid, limiting the possibility of solid quantitative statements on the amplitudes and phases of the diurnal and semidiurnal components across the domain. According to our experiments, the Mellor-Yamada-Nakanishi-Niino (MYNN) boundary layer scheme and the WSM6 microphysics scheme is the combination of schemes that performs best. For that combination, mean cloud cover, liquid water path, and cloud depth are fairly wellsimulated, while mean cloud top height remains too low in comparison to observations. Both microphysics and boundary layer schemes contribute to the spread in liquid water path and cloud depth, although the microphysics contribution is slightly more prominent. Boundary layer schemes are the primary contributors to cloud top height, degree of adiabaticity, and cloud cover. Cloud top height is closely related to surface fluxes and boundary layer structure. Thus, our study infers that an appropriate tuning of cloud top height would likely improve the low-cloud representation in the model. Finally, we show that entrainment governs the degree of adiabaticity, while boundary layer decoupling is a control on cloud cover. In the intercomparison study using WRF single-column model experiments, most parameterizations show a poor agreement of the vertical boundary layer structure when compared with large-eddy simulation models. We also implement a new Total-Energy/Mass- Flux boundary layer scheme into the WRF model and evaluate its ability to simulate both stratocumulus and shallow cumulus clouds. Result comparisons against large-eddy simulation show that this advanced parameterization based on the new Eddy-Diffusivity/Mass-Flux approach provides a better performance than other boundary layer parameterizations.

  12. The interaction between the post-perovskite phase change and a thermo-chemical boundary layer near the coremantle boundary

    E-Print Network [OSTI]

    Tackley, Paul J.

    The interaction between the post-perovskite phase change and a thermo-chemical boundary layer near convection with the newly-discovered post-perovskite (PPV) phase change are used to characterize its depth. The strongly exothermic nature of the post-perovskite phase change induces an anti

  13. Stratification Prediction and Bottom Boundary Layer Dynamics over the Texas-Louisiana Continental Shelf 

    E-Print Network [OSTI]

    Zhang, Wenxia

    2015-03-02

    and hypoxia formation. In this research, Both observations and numerical models are used to study models' ability of reproducing observed stratification and bottom boundary layer dynamics over the Texas-Louisiana shelf. Simulated vertical stratification...

  14. Analysis and interpretation of tidal currents in the coastal boundary layer

    E-Print Network [OSTI]

    May, Paul Wesley, 1950-

    1979-01-01

    Concern with the impact of human activities on the coastal region of the world's oceans has elicited interest in the so-called "coastal boundary layer"-that band of water adjacent to the coast where ocean currents adjust ...

  15. Design of a model propulsor for a boundary layer ingesting aircraft

    E-Print Network [OSTI]

    Grasch, Adam D. (Adam Davis)

    2013-01-01

    This thesis presents contributions to the analysis and design of propulsion simulators for 1:11 and 1:4 scale model wind tunnel investigations of an advanced civil transport aircraft with boundary layer ingestion (BLI). ...

  16. Turbulent combined wave-current boundary layer model for application in coastal waters

    E-Print Network [OSTI]

    Humbyrd, Chelsea Joy

    2012-01-01

    Accurately predicting transport processes, including sediment transport, in the coastal environment is impossible without correct current velocity and shear stress information. A combined wave-current boundary layer theory ...

  17. The hydrodynamic stability of crossflow vortices in the Bdewadt boundary layer

    E-Print Network [OSTI]

    The hydrodynamic stability of crossflow vortices in the Bödewadt boundary layer N. A. Culverhouse the critical Reynolds number. extends the laminar flow region. decreasing the magnitude of the crossflow

  18. Nonlinear equilibration of baroclinic eddies : the role of boundary layer processes and seasonal forcing

    E-Print Network [OSTI]

    Zhang, Yang, Ph. D. Massachusetts Institute of Technology

    2009-01-01

    In this thesis, the influence of boundary layer processes and seasonal forcing on baroclinic eddy equilibration is studied to understand how the baroclinic adjustment is modified when taking into account these two factors. ...

  19. Spectral properties of parabolic layer potentials and transmission boundary problems in nonsmooth domains

    E-Print Network [OSTI]

    Mitrea, Marius

    Spectral properties of parabolic layer potentials and transmission boundary problems in nonsmooth, and is a Lipschitz domain. Applications to transmission boundary value problems are also presented. 1 Introduction. While, in principle, this seems flexible enough a program to be worth pursuing in the case of the heat

  20. Spectral properties of parabolic layer potentials and transmission boundary problems in nonsmooth domains #

    E-Print Network [OSTI]

    Mitrea, Marius

    Spectral properties of parabolic layer potentials and transmission boundary problems in nonsmooth# is a Lipschitz domain. Applications to transmission boundary value problems are also presented. 1 Introduction of the heat operator, the algebra associated with the problem at hand is di#erent. In particular

  1. Spectral properties of parabolic layer potentials and transmission boundary problems in nonsmooth domains

    E-Print Network [OSTI]

    Hofmann, Steve

    Spectral properties of parabolic layer potentials and transmission boundary problems in nonsmooth potential operator, and is a Lipschitz domain. Applications to transmission boundary value problems in the case of the heat operator, the algebra associated with the problem at hand is di#11;erent

  2. Turbulence Structure and Wall Signature in Hypersonic Turbulent Boundary Layer

    E-Print Network [OSTI]

    Martín, Pino

    layers have been mostly studied in the subsonic flow regime (for example, Tomkins and Adrian;7 del ´Alamo and Jim´enez;8 Ganapathisubramani, Longmire and Marusic;9 del ´Alamo et al.;10 del ´Alamo et al.;11 Guala

  3. Turbulence Structure and Wall Signature in Hypersonic Boundary Layer

    E-Print Network [OSTI]

    Martín, Pino

    layers have been mostly studied in the subsonic flow regime (for example, Tomkins and Adrian;7 del ´Alamo and Jim´enez;8 Ganapathisubramani, Longmire and Marusic;9 del ´Alamo et al.;10 del ´Alamo et al.;11 Guala

  4. Boundary-Layer Meteorology An International Journal of Physical,

    E-Print Network [OSTI]

    Lebedev, Vladimir

    atmosphere is of great importance for a variety of disciplines, from meteorology and urban planning to botany is highly anisotropic and inhomogeneous, since both the mean wind velocity and the turbulent diffusivity transport in a turbulent environment we adopt a standard model of turbulent diffusion, which is based

  5. ARM - Field Campaign - Boundary Layer CO2 Using CW Lidar

    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 Anode Design to Improve4AJ01) (See22, 2012IIIAtlanticMarine BoundarygovCampaignsBoundary

  6. Combustion-turbulence interaction in the turbulent boundary layer over a hot surface

    SciTech Connect (OSTI)

    Ng, T.T.; Cheng, R.K.; Robben, F.; Talbot, L.

    1982-01-01

    The turbulence-combustion interaction in a reacting turbulent boundary layer over a heated flat plate was studied. Ethylene/air mixture with equivalence ratio of 0.35 was used. The free stream velocity was 10.5 m/s and the wall temperature was 1250/sup 0/K. Combustion structures visualization was provided by high-speed schlieren photographs. Fluid density statistics were deduced from Rayleigh scattering intensity measurements. A single-component laser Doppler velocimetry system was used to obtain mean and root-mean-square velocity distributions, the Reynolds stress, the streamwise and the cross-stream turbulent kinetic energy diffusion, and the production of turbulent kinetic energy by Reynolds stress. The combustion process was dominated by large-scale turbulent structures of the boundary layer. Combustion causes expansion of the boundary layer. No overall self-similarity is observed in either the velocity or the density profiles. Velocity fluctuations were increased in part of the boundary layer and the Reynolds stress was reduced. The turbulent kinetic energy diffusion pattern was changed significantly and a modification of the boundary layer assumption will be needed when dealing with this problem analytically. 11 figures, 1 table.

  7. Sensitivity of a global climate model to the critical Richardson number in the boundary layer parameterization

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

    Zhang, Ning; Liu, Yangang; Gao, Zhiqiu; Li, Dan

    2015-04-27

    The critical bulk Richardson number (Ricr) is an important parameter in planetary boundary layer (PBL) parameterization schemes used in many climate models. This paper examines the sensitivity of a Global Climate Model, the Beijing Climate Center Atmospheric General Circulation Model, BCC_AGCM to Ricr. The results show that the simulated global average of PBL height increases nearly linearly with Ricr, with a change of about 114 m for a change of 0.5 in Ricr. The surface sensible (latent) heat flux decreases (increases) as Ricr increases. The influence of Ricr on surface air temperature and specific humidity is not significant. The increasingmore »Ricr may affect the location of the Westerly Belt in the Southern Hemisphere. Further diagnosis reveals that changes in Ricr affect stratiform and convective precipitations differently. Increasing Ricr leads to an increase in the stratiform precipitation but a decrease in the convective precipitation. Significant changes of convective precipitation occur over the inter-tropical convergence zone, while changes of stratiform precipitation mostly appear over arid land such as North Africa and Middle East.« less

  8. RACORO continental boundary layer cloud investigations. 3. Separation of parameterization biases in single-column model CAM5 simulations of shallow cumulus

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

    Lin, Wuyin; Liu, Yangang; Vogelmann, Andrew M.; Fridlind, Ann; Endo, Satoshi; Song, Hua; Feng, Sha; Toto, Tami; Li, Zhijin; Zhang, Minghua

    2015-06-19

    Climatically important low-level clouds are commonly misrepresented in climate models. The FAst-physics System TEstbed and Research (FASTER) project has constructed case studies from the Atmospheric Radiation Measurement (ARM) Climate Research Facility's Southern Great Plain site during the RACORO aircraft campaign to facilitate research on model representation of boundary-layer clouds. This paper focuses on using the single-column Community Atmosphere Model version 5 (SCAM5) simulations of a multi-day continental shallow cumulus case to identify specific parameterization causes of low-cloud biases. Consistent model biases among the simulations driven by a set of alternative forcings suggest that uncertainty in the forcing plays only amore »relatively minor role. In-depth analysis reveals that the model's shallow cumulus convection scheme tends to significantly under-produce clouds during the times when shallow cumuli exist in the observations, while the deep convective and stratiform cloud schemes significantly over-produce low-level clouds throughout the day. The links between model biases and the underlying assumptions of the shallow cumulus scheme are further diagnosed with the aid of large-eddy simulations and aircraft measurements, and by suppressing the triggering of the deep convection scheme. It is found that the weak boundary layer turbulence simulated is directly responsible for the weak cumulus activity and the simulated boundary layer stratiform clouds. Increased vertical and temporal resolutions are shown to lead to stronger boundary layer turbulence and reduction of low-cloud biases.« less

  9. RACORO continental boundary layer cloud investigations. Part I: Case study development and ensemble large-scale forcings

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

    Vogelmann, Andrew M.; Fridlind, Ann M.; Toto, Tami; Endo, Satoshi; Lin, Wuyin; Wang, Jian; Feng, Sha; Zhang, Yunyan; Turner, David D.; Liu, Yangang; et al

    2015-06-19

    Observation-based modeling case studies of continental boundary layer clouds have been developed to study cloudy boundary layers, aerosol influences upon them, and their representation in cloud- and global-scale models. Three 60-hour case study periods span the temporal evolution of cumulus, stratiform, and drizzling boundary layer cloud systems, representing mixed and transitional states rather than idealized or canonical cases. Based on in-situ measurements from the RACORO field campaign and remote-sensing observations, the cases are designed with a modular configuration to simplify use in large-eddy simulations (LES) and single-column models. Aircraft measurements of aerosol number size distribution are fit to lognormal functionsmore »for concise representation in models. Values of the aerosol hygroscopicity parameter, ?, are derived from observations to be ~0.10, which are lower than the 0.3 typical over continents and suggestive of a large aerosol organic fraction. Ensemble large-scale forcing datasets are derived from the ARM variational analysis, ECMWF forecasts, and a multi-scale data assimilation system. The forcings are assessed through comparison of measured bulk atmospheric and cloud properties to those computed in 'trial' large-eddy simulations, where more efficient run times are enabled through modest reductions in grid resolution and domain size compared to the full-sized LES grid. Simulations capture many of the general features observed, but the state-of-the-art forcings were limited at representing details of cloud onset, and tight gradients and high-resolution transients of importance. Methods for improving the initial conditions and forcings are discussed. The cases developed are available to the general modeling community for studying continental boundary clouds.« less

  10. Temporal variability of the trade wind inversion: Measured with a boundary layer vertical profiler. Master's thesis

    SciTech Connect (OSTI)

    Grindinger, C.M.

    1992-05-01

    This study uses Hawaiian Rainband Project (HaRP) data, from the summer of 1991, to show a boundary layer wind profiler can be used to measure the trade wind inversion. An algorithm has been developed for the profiler that objectively measures the depth of the moist oceanic boundary layer. The Hilo inversion, measured by radiosonde, is highly correlated with the moist oceanic boundary layer measured by the profiler at Paradise Park. The inversion height on windward Hawaii is typically 2253 + or - 514 m. The inversion height varies not only on a daily basis, but on less than an hourly basis. It has a diurnal, as well as a three to four day cycle. There appears to be no consistent relationship between inversion height and precipitation. Currently, this profiler is capable of making high frequency (12 minute) measurements of the inversion base variation, as well as other features.

  11. Active Control of Instabilities in Laminar BoundaryLayer Flow--Part I: An Overview

    E-Print Network [OSTI]

    Erlebacher, Gordon

    Active Control of Instabilities in Laminar Boundary­Layer Flow-- Part I: An Overview Ronald D laminar flow in a region of the flow in which the natural instabilities, if left unattended, lead have been restricted to maintaining laminar flow through use of a technique termed ``wave cancellation

  12. Sensitivity of Swept-Wing, Boundary-Layer Transition to Spanwise-Periodic Discrete Roughness Elements 

    E-Print Network [OSTI]

    West, David Edward

    2014-12-12

    ) was unexpectedly farther aft than the polished. Transport unit Reynolds numbers were achieved using a Cessna O-2A Skymaster. Infrared thermography, coupled with a post-processing code, was used to globally extract a quantitative boundary-layer transition location...

  13. DNS of a Mach 4 Boundary Layer with Chemical Reactions M. Pino Martin

    E-Print Network [OSTI]

    Martín, Pino

    DNS of a Mach 4 Boundary Layer with Chemical Reactions M. Pino Mart´in Graham V. Candler Aerospace understanding of the interaction between turbulent motion and chemical reactions in hypersonic flows is limited to perform a fundamental study of isotropic turbulence interacting with finite-rate chemical reactions

  14. Effect of Finite-rate Chemical Reactions on Turbulence in Hypersonic Turbulent Boundary Layers

    E-Print Network [OSTI]

    Martín, Pino

    Effect of Finite-rate Chemical Reactions on Turbulence in Hypersonic Turbulent Boundary Layers Lian reaction. The influence of chemical reactions on temperature fluctuation variance, Reynolds stresses that the recombination reaction enhances turbulence, while the dissociation reaction damps turbulence. Chemical reactions

  15. Recent Measurements of Aero-Optical Effects Caused by Subsonic Boundary Layers

    E-Print Network [OSTI]

    Gordeyev, Stanislav

    Recent Measurements of Aero-Optical Effects Caused by Subsonic Boundary Layers Adam E. Smith Dame, Notre Dame, IN, USA 46545 ABSTRACT Results of recent experimental measurements of aero aperture sizes on levels of aero-optical aberrations and detailed statistical analysis of spatial

  16. Aero-optical measurements in a subsonic, turbulent boundary layer with non-adiabatic walls

    E-Print Network [OSTI]

    Gordeyev, Stanislav

    Aero-optical measurements in a subsonic, turbulent boundary layer with non-adiabatic walls to IP: 129.74.64.123 On: Wed, 29 Apr 2015 14:08:38 #12;PHYSICS OF FLUIDS 27, 045110 (2015) Aero online 29 April 2015) This paper presents experimental studies of aero-optical distortions due

  17. Numerical Simulations of the Wave Bottom Boundary Layer over Sand Ripples

    E-Print Network [OSTI]

    Slinn, Donald

    Numerical Simulations of the Wave Bottom Boundary Layer over Sand Ripples by Thomas Pierro A Thesis over sand ripples, and to compare the results with flows over a smooth bed to determine how wave energy energy dissipation rates are quantified and a better understanding of oscillatory flow over sand ripples

  18. American Institute of Aeronautics and Astronautics Shock/Boundary Layer Interaction Effects of Transverse

    E-Print Network [OSTI]

    Texas at Arlington, University of

    of Transverse Jets in Crossflow over a Body of Revolution Dean A. Dickmann* Lockheed Martin Missiles and Fire 76019 Shock/boundary layer interaction present in transverse jets in supersonic crossflow alteres suggested a transverse jet in crossflow can be represented by a solid body of given length and shape

  19. A Simple Parameterization Coupling the Convective Daytime Boundary Layer and Fair-Weather Cumuli

    SciTech Connect (OSTI)

    Berg, Larry K.; Stull, Roland B.

    2005-06-15

    A new parameterization for boundary-layer cumulus clouds, called the Cumulus Potential (CuP) scheme is introduced. This scheme uses Joint Probability Density Functions (JPDFs) of virtual potential temperature and water-vapor mixing ratio, as well as the mean vertical profiles of virtual potential temperature to predict the amount and size distribution of boundary-layer cloud cover. This model considers the diversity of air parcels over a heterogeneous surface, and recognizes that some parcels rise above their lifting condensation level to become cumulus, while other parcels might rise as non-cloud updrafts. This model has several unique features: (1) cloud cover is determined from the boundary-layer JPDF of virtual potential temperature vs. water-vapor mixing ratio , (2) clear and cloudy thermals are allowed to coexist at the same altitude, and (3) a range of cloud-base heights, cloud-top heights, and cloud thicknesses are predicted within any one cloud field, as observed. Using data from Boundary Layer Experiment 1996, and a model intercomparsion study using Large Eddy Simulation (LES) based on BOMEX, it is shown that the CuP model does a good job predicting cloud-base height and cloud-top height. The model also shows promise in predicting cloud cover, and is found to give better cloud-cover estimates than three other cumulus parameterizations: one based on relative humidity, a statistical scheme based on the saturation deficit, and a slab model.

  20. Local and Bi-Global Stability Analysis of a Plasma Actuated Boundary Layer

    E-Print Network [OSTI]

    Roy, Subrata

    velocities ¯p Mean pressure ~u, ~v, ~w Disturbance flow velocities ~p Disturbance pressure u , v , w Complex disturbance flow velocities p Complex disturbance pressure u Freestream velocity up Induced velocity Complex spatial frequency in x Complex spatial frequency in z Complex temporal frequency 99% Boundary layer

  1. Large Eddy Simulation of Stable Boundary Layer Turbulent Processes in Complex Terrain

    SciTech Connect (OSTI)

    Eric D. Skyllingstad

    2005-01-26

    Research was performed using a turbulence boundary layer model to study the behavior of cold, dense flows in regions of complex terrain. Results show that flows develop a balance between turbulent entrainment of warm ambient air and dense, cold air created by surface cooling. Flow depth and strength is a function of downslope distance, slope angle and angle changes, and the ambient air temperature.

  2. Small Scale Processes and Entrainment in a Stratocumulus Marine Boundary Layer

    E-Print Network [OSTI]

    Bell, John B.

    Small Scale Processes and Entrainment in a Stratocumulus Marine Boundary Layer David E. Stevens of entrainment into the tops of marine stratus in a moist generalization of the 1995 GCSS (GEWEX Cloud System of entrainment rate and discuss how these predictions relate to the structure of the numerical solutions. 1 #12

  3. HIGH-ORDER FINITE VOLUME SCHEMES FOR LAYERED ATMOSPHERIC MODELS

    E-Print Network [OSTI]

    of use of layered models are: air pollution models (see for example the early study in [1]), moisture

  4. DNS of laminar-turbulent boundary layer transition induced by solid obstacles

    E-Print Network [OSTI]

    Orlandi, Paolo; Bernardini, Matteo

    2015-01-01

    Results of numerical simulations obtained by a staggered finite difference scheme together with an efficient immersed boundary method are presented to understand the effects of the shape of three-dimensional obstacles on the transition of a boundary layer from a laminar to a turbulent regime. Fully resolved Direct Numerical Simulations (DNS), highlight that the closer to the obstacle the symmetry is disrupted the smaller is the transitional Reynolds number. It has been also found that the transition can not be related to the critical roughness Reynolds number used in the past. The simulations highlight the differences between wake and inflectional instabilities, proving that two-dimensional tripping devices are more efficient in promoting the transition. Simulations at high Reynolds number demonstrate that the reproduction of a real experiment with a solid obstacle at the inlet is an efficient tool to generate numerical data bases for understanding the physics of boundary layers. The quality of the numerical ...

  5. Clouds, Precipitation, and Marine Boundary Layer Structure during the MAGIC Field Campaign

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

    Zhou, Xiaoli; Kollias, Pavlos; Lewis, Ernie R.

    2015-03-01

    The recent ship-based MAGIC (Marine ARM GCSS Pacific Cross-Section Intercomparison (GPCI) Investigation of Clouds) field campaign with the marine-capable Second ARM Mobile Facility (AMF2) deployed on the Horizon Lines cargo container M/V Spirit provided nearly 200 days of intraseasonal high-resolution observations of clouds, precipitation, and marine boundary layer (MBL) structure on multiple legs between Los Angeles, California, and Honolulu, Hawaii. During the deployment, MBL clouds exhibited a much higher frequency of occurrence than other cloud types and occurred more often in the warm season than in the cold season. MBL clouds demonstrated a propensity to produce precipitation, which often evaporatedmore »before reaching the ocean surface. The formation of stratocumulus is strongly correlated to a shallow MBL with a strong inversion and a weak transition, while cumulus formation is associated with a much weaker inversion and stronger transition. The estimated inversion strength is shown to depend seasonally on the potential temperature at 700 hPa. The location of the commencement of systematic MBL decoupling always occurred eastward of the locations of cloud breakup, and the systematic decoupling showed a strong moisture stratification. The entrainment of the dry warm air above the inversion appears to be the dominant factor triggering the systematic decoupling, while surface latent heat flux, precipitation, and diurnal circulation did not play major roles. MBL clouds broke up over a short spatial region due to the changes in the synoptic conditions, implying that in real atmospheric conditions the MBL clouds do not have enough time to evolve as in the idealized models. (auth)« less

  6. Clouds, Precipitation, and Marine Boundary Layer Structure during the MAGIC Field Campaign

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

    Zhou, Xiaoli [McGill Univ., Montreal, Quebec (Canada); Dept. of Atmospheric and Oceanic Sciences; Kollias, Pavlos [McGill Univ., Montreal, Quebec (Canada); Dept. of Atmospheric and Oceanic Sciences; Lewis, Ernie R. [Brookhaven National Lab., Upton, NY (United States). Biological, Environmental, and Climate Sciences Dept.

    2015-03-01

    The recent ship-based MAGIC (Marine ARM GCSS Pacific Cross-Section Intercomparison (GPCI) Investigation of Clouds) field campaign with the marine-capable Second ARM Mobile Facility (AMF2) deployed on the Horizon Lines cargo container M/V Spirit provided nearly 200 days of intraseasonal high-resolution observations of clouds, precipitation, and marine boundary layer (MBL) structure on multiple legs between Los Angeles, California, and Honolulu, Hawaii. During the deployment, MBL clouds exhibited a much higher frequency of occurrence than other cloud types and occurred more often in the warm season than in the cold season. MBL clouds demonstrated a propensity to produce precipitation, which often evaporated before reaching the ocean surface. The formation of stratocumulus is strongly correlated to a shallow MBL with a strong inversion and a weak transition, while cumulus formation is associated with a much weaker inversion and stronger transition. The estimated inversion strength is shown to depend seasonally on the potential temperature at 700 hPa. The location of the commencement of systematic MBL decoupling always occurred eastward of the locations of cloud breakup, and the systematic decoupling showed a strong moisture stratification. The entrainment of the dry warm air above the inversion appears to be the dominant factor triggering the systematic decoupling, while surface latent heat flux, precipitation, and diurnal circulation did not play major roles. MBL clouds broke up over a short spatial region due to the changes in the synoptic conditions, implying that in real atmospheric conditions the MBL clouds do not have enough time to evolve as in the idealized models. (auth)

  7. Prospects for Simulating Macromolecular Surfactant Chemistry at the Ocean-Atmosphere Boundary

    SciTech Connect (OSTI)

    Elliott, S.; Burrows, Susannah M.; Deal, C.; Liu, Xiaohong; Long, M.; Ogunro, O.; Russell, Lynn M.; Wingenter, O.

    2014-05-01

    Biogenic lipids and polymers are surveyed for their ability to adsorb at the water-air interfaces associated with bubbles, marine microlayers and particles in the overlying boundary layer. Representative ocean biogeochemical regimes are defined in order to estimate local concentrations for the major macromolecular classes. Surfactant equilibria and maximum excess are then derived based on a network of model compounds. Relative local coverage and upward mass transport follow directly, and specific chemical structures can be placed into regional rank order. Lipids and denatured protein-like polymers dominate at the selected locations. The assigned monolayer phase states are variable, whether assessed along bubbles or at the atmospheric spray droplet perimeter. Since oceanic film compositions prove to be irregular, effects on gas and organic transfer are expected to exhibit geographic dependence as well. Moreover, the core arguments extend across the sea-air interface into aerosol-cloud systems. Fundamental nascent chemical properties including mass to carbon ratio and density depend strongly on the geochemical state of source waters. High surface pressures may suppress the Kelvin effect, and marine organic hygroscopicities are almost entirely unconstrained. While bubble adsorption provides a well-known means for transporting lipidic or proteinaceous material into sea spray, the same cannot be said of polysaccharides. Carbohydrates tend to be strongly hydrophilic so that their excess carbon mass is low despite stacked polymeric geometries. Since sugars are abundant in the marine aerosol, gel-based mechanisms may be required to achieve uplift. Uncertainties in the surfactant logic distill to a global scale dearth of information regarding two dimensional kinetics and equilibria. Nonetheless simulations are recommended, to initiate the process of systems level quantification.

  8. Joint retrievals of cloud and drizzle in marine boundary layer clouds using ground-based radar, lidar and zenith radiances

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

    Fielding, M. D.; Chiu, J. C.; Hogan, R. J.; Feingold, G.; Eloranta, E.; O'Connor, E. J.; Cadeddu, M. P.

    2015-07-02

    Active remote sensing of marine boundary-layer clouds is challenging as drizzle drops often dominate the observed radar reflectivity. We present a new method to simultaneously retrieve cloud and drizzle vertical profiles in drizzling boundary-layer clouds using surface-based observations of radar reflectivity, lidar attenuated backscatter, and zenith radiances under conditions when precipitation does not reach the surface. Specifically, the vertical structure of droplet size and water content of both cloud and drizzle is characterised throughout the cloud. An ensemble optimal estimation approach provides full error statistics given the uncertainty in the observations. To evaluate the new method, we first perform retrievalsmore »using synthetic measurements from large-eddy simulation snapshots of cumulus under stratocumulus, where cloud water path is retrieved with an error of 31 g m-2. The method also performs well in non-drizzling clouds where no assumption of the cloud profile is required. We then apply the method to observations of marine stratocumulus obtained during the Atmospheric Radiation Measurement MAGIC deployment in the Northeast Pacific. Here, retrieved cloud water path agrees well with independent three-channel microwave radiometer retrievals, with a root mean square difference of 10–20 g m-2.« less

  9. Joint retrievals of cloud and drizzle in marine boundary layer clouds using ground-based radar, lidar and zenith radiances

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

    Fielding, M. D.; Chiu, J. C.; Hogan, R. J.; Feingold, G.; Eloranta, E.; O'Connor, E. J.; Cadeddu, M. P.

    2015-02-16

    Active remote sensing of marine boundary-layer clouds is challenging as drizzle drops often dominate the observed radar reflectivity. We present a new method to simultaneously retrieve cloud and drizzle vertical profiles in drizzling boundary-layer cloud using surface-based observations of radar reflectivity, lidar attenuated backscatter, and zenith radiances. Specifically, the vertical structure of droplet size and water content of both cloud and drizzle is characterised throughout the cloud. An ensemble optimal estimation approach provides full error statistics given the uncertainty in the observations. To evaluate the new method, we first perform retrievals using synthetic measurements from large-eddy simulation snapshots of cumulusmore »under stratocumulus, where cloud water path is retrieved with an error of 31 g m?2. The method also performs well in non-drizzling clouds where no assumption of the cloud profile is required. We then apply the method to observations of marine stratocumulus obtained during the Atmospheric Radiation Measurement MAGIC deployment in the northeast Pacific. Here, retrieved cloud water path agrees well with independent 3-channel microwave radiometer retrievals, with a root mean square difference of 10–20 g m?2.« less

  10. Resuspension of Small Particles from Multilayer Deposits in Turbulent Boundary Layers

    E-Print Network [OSTI]

    F. Zhang; M. Reeks; M. Kissane; R. J. Perkins

    2012-06-09

    We present a hybrid stochastic model for the resuspension of micron-size particles from multilayer deposits in a fully-developed turbulent boundary layer. The rate of removal of particles from any given layer depends upon the rate of removal of particles from the layer above which acts as a source of uncovering and exposure of particles to the resuspending flow. The primary resuspension rate constant for an individual particle within a layer is based on the Rock'n'Roll (R'n'R) model using non-Gaussian statistics for the aerodynamic forces acting on the particles (Zhang et al., 2012). The coupled layer equations that describe multilayer resuspension of all the particles in each layer are based on the generic lattice model of Friess & Yadigaroglu (2001) which is extended here to include the influence of layer coverage and particle size distribution. We consider the influence of layer thickness on the resuspension along with the spread of adhesion within layers, and the statistics of non-Gaussian versus Gaussian removal forces including their timescale. Unlike its weak influence on long-term resuspension rates for monolayers, this timescale plays a crucial and influential role in multilayer resuspension. Finally we compare model predictions with those of a large-scale and a mesoscale resuspension test, STORM (Castelo et al., 1999) and BISE (Alloul-Marmor, 2002).

  11. Eddy-resolving Lidar Measurements and Numerical Simulations of the Convective Internal Boundary Layer

    E-Print Network [OSTI]

    Eloranta, Edwin W.

    in speed. The vertical gradient of wind-speed decreases offshore because of strong vertical mixing caused Layer Shane D. Mayor, Gregory J. Tripoli, and Edwin W. Eloranta Department of Atmospheric and Oceanic 10 January 1998, 14:16-14:57 UT divergence(s-1) Distance east of VIL (offshore distance) km 0 1 2 3 4

  12. Many-body microhydrodynamics of colloidal particles with active boundary layers

    E-Print Network [OSTI]

    Rajesh Singh; Somdeb Ghose; R. Adhikari

    2015-07-13

    Colloidal particles with active boundary layers - regions surrounding the particles where nonequilibrium processes produce large velocity gradients - are common in many physical, chemical and biological contexts. The velocity or stress at the edge of the boundary layer determines the exterior fluid flow and, hence, the many-body interparticle hydrodynamic interaction. Here, we present a method to compute the many-body hydrodynamic interaction between $N$ spherical active particles induced by their exterior microhydrodynamic flow. First, we use a boundary integral representation of the Stokes equation to eliminate bulk fluid degrees of freedom. Then, we expand the boundary velocities and tractions of the integral representation in an infinite-dimensional basis of tensorial spherical harmonics and, on enforcing boundary conditions in a weak sense on the surface of each particle, obtain a system of linear algebraic equations for the unknown expansion coefficients. The truncation of the infinite series, fixed by the degree of accuracy required, yields a finite linear system that can be solved accurately and efficiently by iterative methods. The solution linearly relates the unknown rigid body motion to the known values of the expansion coefficients, motivating the introduction of propulsion matrices. These matrices completely characterize hydrodynamic interactions in active suspensions just as mobility matrices completely characterize hydrodynamic interactions in passive suspensions. The reduction in the dimensionality of the problem, from a three-dimensional partial differential equation to a two-dimensional integral equation, allows for dynamic simulations of hundreds of thousands of active particles on multi-core computational architectures.

  13. Global and regional modeling of clouds and aerosols in the marine boundary layer during VOCALS: the VOCA intercomparison

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

    Wyant, M. C.; Bretherton, Christopher S.; Wood, Robert; Carmichael, Gregory; Clarke, A. D.; Fast, Jerome D.; George, R.; Gustafson, William I.; Hannay, Cecile; Lauer, Axel; et al

    2015-01-09

    A diverse collection of models are used to simulate the marine boundary layer in the southeast Pacific region during the period of the October–November 2008 VOCALS REx (VAMOS Ocean Cloud Atmosphere Land Study Regional Experiment) field campaign. Regional models simulate the period continuously in boundary-forced free-running mode, while global forecast models and GCMs (general circulation models) are run in forecast mode. The models are compared to extensive observations along a line at 20° S extending westward from the South American coast. Most of the models simulate cloud and aerosol characteristics and gradients across the region that are recognizably similar tomore »observations, despite the complex interaction of processes involved in the problem, many of which are parameterized or poorly resolved. Some models simulate the regional low cloud cover well, though many models underestimate MBL (marine boundary layer) depth near the coast. Most models qualitatively simulate the observed offshore gradients of SO2, sulfate aerosol, CCN (cloud condensation nuclei) concentration in the MBL as well as differences in concentration between the MBL and the free troposphere. Most models also qualitatively capture the decrease in cloud droplet number away from the coast. However, there are large quantitative intermodel differences in both means and gradients of these quantities. Many models are able to represent episodic offshore increases in cloud droplet number and aerosol concentrations associated with periods of offshore flow. Most models underestimate CCN (at 0.1% supersaturation) in the MBL and free troposphere. The GCMs also have difficulty simulating coastal gradients in CCN and cloud droplet number concentration near the coast. The overall performance of the models demonstrates their potential utility in simulating aerosol–cloud interactions in the MBL, though quantitative estimation of aerosol–cloud interactions and aerosol indirect effects of MBL clouds with these models remains uncertain.« less

  14. Global and regional modeling of clouds and aerosols in the marine boundary layer during VOCALS: the VOCA intercomparison

    SciTech Connect (OSTI)

    Wyant, M. C.; Bretherton, Christopher S.; Wood, Robert; Carmichael, Gregory; Clarke, A. D.; Fast, Jerome D.; George, R.; Gustafson, William I.; Hannay, Cecile; Lauer, Axel; Lin, Yanluan; Morcrette, J. -J.; Mulcahay, Jane; Saide, Pablo; Spak, S. N.; Yang, Qing

    2015-01-01

    A diverse collection of models are used to simulate the marine boundary layer in the southeast Pacific region during the period of the October–November 2008 VOCALS REx (VAMOS Ocean Cloud Atmosphere Land Study Regional Experiment) field campaign. Regional models simulate the period continuously in boundary-forced free-running mode, while global forecast models and GCMs (general circulation models) are run in forecast mode. The models are compared to extensive observations along a line at 20° S extending westward from the South American coast. Most of the models simulate cloud and aerosol characteristics and gradients across the region that are recognizably similar to observations, despite the complex interaction of processes involved in the problem, many of which are parameterized or poorly resolved. Some models simulate the regional low cloud cover well, though many models underestimate MBL (marine boundary layer) depth near the coast. Most models qualitatively simulate the observed offshore gradients of SO2, sulfate aerosol, CCN (cloud condensation nuclei) concentration in the MBL as well as differences in concentration between the MBL and the free troposphere. Most models also qualitatively capture the decrease in cloud droplet number away from the coast. However, there are large quantitative intermodel differences in both means and gradients of these quantities. Many models are able to represent episodic offshore increases in cloud droplet number and aerosol concentrations associated with periods of offshore flow. Most models underestimate CCN (at 0.1% supersaturation) in the MBL and free troposphere. The GCMs also have difficulty simulating coastal gradients in CCN and cloud droplet number concentration near the coast. The overall performance of the models demonstrates their potential utility in simulating aerosol–cloud interactions in the MBL, though quantitative estimation of aerosol–cloud interactions and aerosol indirect effects of MBL clouds with these models remains uncertain.

  15. Using Mesoscale Weather Model Output as Boundary Conditions for Atmospheric Large-Eddy Simulations and Wind-Plant Aerodynamic Simulations (Presentation)

    SciTech Connect (OSTI)

    Churchfield, M. J.; Michalakes, J.; Vanderwende, B.; Lee, S.; Sprague, M. A.; Lundquist, J. K.; Moriarty, P. J.

    2013-10-01

    Wind plant aerodynamics are directly affected by the microscale weather, which is directly influenced by the mesoscale weather. Microscale weather refers to processes that occur within the atmospheric boundary layer with the largest scales being a few hundred meters to a few kilometers depending on the atmospheric stability of the boundary layer. Mesoscale weather refers to large weather patterns, such as weather fronts, with the largest scales being hundreds of kilometers wide. Sometimes microscale simulations that capture mesoscale-driven variations (changes in wind speed and direction over time or across the spatial extent of a wind plant) are important in wind plant analysis. In this paper, we present our preliminary work in coupling a mesoscale weather model with a microscale atmospheric large-eddy simulation model. The coupling is one-way beginning with the weather model and ending with a computational fluid dynamics solver using the weather model in coarse large-eddy simulation mode as an intermediary. We simulate one hour of daytime moderately convective microscale development driven by the mesoscale data, which are applied as initial and boundary conditions to the microscale domain, at a site in Iowa. We analyze the time and distance necessary for the smallest resolvable microscales to develop.

  16. Experimental investigation of sound generation by a protuberance in a laminar boundary layer

    SciTech Connect (OSTI)

    Kobayashi, M.; Asai, M.; Inasawa, A. [Department of Aerospace Engineering, Tokyo Metropolitan University, 6-6 Asahigaoka, Hino, Tokyo 191-0065 (Japan)

    2014-08-15

    Sound radiation from a two-dimensional protuberance glued on the wall in a laminar boundary layer was investigated experimentally at low Mach numbers. When the protuberance was as high as the boundary-layer thickness, a feedback-loop mechanism set in between protuberance-generated sound and Tollmien-Schlichting (T-S) waves generated by the leading-edge receptivity to the upstream-propagating sound. Although occurrence of a separation bubble immediately upstream of the protuberance played important roles in the evolution of instability waves into vortices interacting with the protuberance, the frequency of tonal vortex sound was determined by the selective amplification of T-S waves in the linear instability stage upstream of the separation bubble and was not affected by the instability of the separation bubble.

  17. Viscous boundary layers of radiation-dominated, relativistic jets. I. The two-stream model

    E-Print Network [OSTI]

    Coughlin, Eric R

    2015-01-01

    Using the relativistic equations of radiation hydrodynamics in the viscous limit, we analyze the boundary layers that develop between radiation-dominated jets and their environments. In this paper we present the solution for the self-similar, 2-D, plane-parallel two-stream problem, wherein the jet and the ambient medium are considered to be separate, interacting fluids, and we compare our results to those of previous authors. (In a companion paper we investigate an alternative scenario, known as the free-streaming jet model.) Consistent with past findings, we show that the boundary layer that develops between the jet and its surroundings creates a region of low-density material. These models may be applicable to sources such as super-Eddington tidal disruption events and long gamma-ray bursts.

  18. Viscous boundary layers of radiation-dominated, relativistic jets. II. The free-streaming jet model

    E-Print Network [OSTI]

    Coughlin, Eric R

    2015-01-01

    We analyze the interaction of a radiation-dominated jet and its surroundings using the equations of radiation hydrodynamics in the viscous limit. In a previous paper we considered the two-stream scenario, which treats the jet and its surroundings as distinct media interacting through radiation viscous forces. Here we present an alternative boundary layer model, known as the free-streaming jet model -- where a narrow stream of fluid is injected into a static medium -- and present solutions where the flow is ultrarelativistic and the boundary layer is dominated by radiation. It is shown that these jets entrain material from their surroundings and that their cores have a lower density of scatterers and a harder spectrum of photons, leading to observational consequences for lines of sight that look "down the barrel of the jet." These jetted outflow models may be applicable to the jets produced during long gamma-ray bursts and super-Eddington phases of tidal disruption events.

  19. Including Atmospheric Layers in Vegetation and Urban Offline Surface Schemes VALE RY MASSON AND YANN SEITY

    E-Print Network [OSTI]

    is able to model the 2-m temperature accurately, as well as the 10-m wind, without any use of analyticalIncluding Atmospheric Layers in Vegetation and Urban Offline Surface Schemes VALE´ RY MASSON coupling between atmospheric-model levels and surface-scheme levels, the coupling proposed here remains

  20. Surface heterogeneity impacts on boundary layer dynamics via energy balance partitioning

    E-Print Network [OSTI]

    Brunsell, Nathaniel A.; Mechem, David B.; Anderson, M. C.

    2011-04-11

    vegetation types and phenological patterns be examined for altering the conversion of net radi- ation into turbulent heat fluxes and the potential impacts this may have on boundary layer dynamics. Our results are important for understanding the mechanis- tic... stream_size 62188 stream_content_type text/plain stream_name Brunsell_2011_Surface-heterogeneity-impacts.pdf.txt stream_source_info Brunsell_2011_Surface-heterogeneity-impacts.pdf.txt Content-Encoding UTF-8 Content-Type text...

  1. Quantification of the boundary layer ingestion benet for the D8-series aircraft using a pressure rake system

    E-Print Network [OSTI]

    Lieu, Michael K

    2015-01-01

    This thesis presents the results of experiments carried out at NASA Langley Research Center (LaRC) 14'x22' Subsonic Wind Tunnel to determine the aerodynamic boundary layer ingestion (BLI) benet for the D8 aircraft advanced ...

  2. The effect of periodic unsteady wakes on boundary layer transition and heat transfer on a curved plate 

    E-Print Network [OSTI]

    Wright, Lance Cole

    1996-01-01

    The effect of unsteady periodic wakes on heat transfer and boundary layer transition was investigated on a constant curvature heat transfer curved plate in a subsonic wind tunnel facility. The local heat transfer coefficient ...

  3. The chemistry of OH and HO2 radicals in the boundary layer over the tropical Atlantic Ocean

    E-Print Network [OSTI]

    2010-01-01

    J. M. C. : Peroxy radical chemistry and the control of ozoneImpact of halogen monoxide chemistry upon boundary layer OHL. K. Whalley et al. : Chemistry of OH and HO 2 radicals

  4. An empirical model for the mean-velocity profiles of a turbulent boundary layer under the effects of surface curvature 

    E-Print Network [OSTI]

    Huynh, Long Quang

    1994-01-01

    An empirical model has been developed to predict the mean-velocity profile of a turbulent boundary layer under the influence of surface curvature. The model proposed is able to determine the profiles for both a convex and concave curvature...

  5. Secondary ow and forced convection heat transfer near endwall boundary layer fences in a 90 turning duct

    E-Print Network [OSTI]

    Camci, Cengiz

    ° turning duct Cengiz Camci *, Dean H. Rizzo Turbomachinery Heat Transfer Laboratory, Department with the secondary ¯ow and heat transfer aspects of endwall boundary layer fences in 90° turning ducts. Boundary coolant channel is simulated by a 90° turning duct (ReD 360,000) to study the aerothermal interaction

  6. Accretion Disk Boundary Layers Around Neutron Stars: X-ray Production in Low-Mass X-ray Binaries

    E-Print Network [OSTI]

    Robert Popham; Rashid Sunyaev

    2000-04-03

    We present solutions for the structure of the boundary layer where the accretion disk meets the neutron star, which is expected to be the dominant source of high-energy radiation in low-mass X-ray binaries which contain weakly magnetized accreting neutron stars. We find that the main portion of the boundary layer gas is hot (> ~10^8 K), low in density, radially and vertically extended, and optically thick to scattering but optically thin to absorption. It will produce large X-ray luminosity by Comptonization. Energy is transported inward by viscosity, concentrating the energy dissipation in the dense, optically thick zone close to the stellar surface. We explore the dependence of the boundary layer structure on the mass accretion rate, the rotation rate of the star, the alpha viscosity parameter and the viscosity prescription. Radiation pressure is the dominant source of pressure in the boundary layer; the flux is close to the Eddington limiting flux even for luminosities well below (~0.01 times) L(Edd). At luminosities near L(Edd), the boundary layer expands radially, and has a radial extent larger than one stellar radius. Based on the temperatures and optical depths which characterize the boundary layer, we expect that Comptonization will produce a power-law spectrum at low source luminosities. At high luminosities, a Planckian spectrum will be produced in the dense region where most of the energy is released, and modified by Comptonization as the radiation propagates outward.

  7. Behavior of Turbulent Structures within a Mach 5 Mechanically Distorted Boundary Layer 

    E-Print Network [OSTI]

    Peltier, Scott Jacob

    2013-08-05

    stream_source_info PELTIER-DISSERTATION-2013.pdf.txt stream_content_type text/plain stream_size 560918 Content-Encoding ISO-8859-1 stream_name PELTIER-DISSERTATION-2013.pdf.txt Content-Type text/plain; charset=ISO-8859...-1 BEHAVIOR OF TURBULENT STRUCTURES WITHIN A MACH 5 MECHANICALLY DISTORTED BOUNDARY LAYER A Dissertation by SCOTT JACOB PELTIER Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements...

  8. Numerical modeling of boundary layer flow under shoaling and breaking waves 

    E-Print Network [OSTI]

    Pattipawaej, Olga Catherina

    1998-01-01

    velocities and shear stresses in the bottom boundary layer under breaking waves. The experiment wss conducted in the Precision Wave Tank located in the Ocean Engineering Laboratory at the University of Delaware. The flume was 33 m long, 0. 6 m wide, and 1... modeling of surf zone hydrodynamics. " Rep. No. CACR-95-97, Center for Applied Coastal Research, University Delaware, Newark, Delaware. Cox, D. T. , Kobayashi, N. , and Okayasu, A. (1996). "Bottom shear stress in the surf zone. " J. Geophys. Res. , 101(C...

  9. Boundary layer modeling of reactive flow over a porous surface with angled injection

    SciTech Connect (OSTI)

    Liu, Shiling; Fotache, Catalin G.; Hautman, Donald J.; Ochs, Stuart S. [United Technologies Research Center, MS 129-29, 411 Silver Lane, East Hartford, CT 06108 (United States); Chao, Beei-Huan [Department of Mechanical Engineering, University of Hawaii at Manoa, Honolulu, HI 96822 (United States)

    2008-08-15

    An analytical model was developed to investigate the dynamics of nonpremixed flames in a shear layer established between a mainstream flow of fuel-rich combustion products and a porous surface with an angled injection of air. In the model, a one-step overall chemical reaction was employed, together with boundary layer conservation equations solved using similarity solutions. Parametric studies were performed to understand the effects of equivalence ratio, temperature, and mass flow rate of the fuel and air streams on the flame standoff distance, surface temperature, and heat flux at the surface. The analytical model predictions were compared with computational fluid dynamics results obtained using the FLUENT commercial code for both the laminar and the turbulent flow models. Qualitative agreement in surface temperature was observed. Finally, the flame stability limits predicted by the model were compared with available experimental data and found to agree qualitatively, as well. (author)

  10. Soft repulsive mixtures under gravity: brazil-nut effect, depletion bubbles, boundary layering, nonequilibrium shaking

    E-Print Network [OSTI]

    Tobias Kruppa; Tim Neuhaus; René Messina; Hartmut Löwen

    2011-12-28

    A binary mixture of particles interacting via long-ranged repulsive forces is studied in gravity by computer simulation and theory. The more repulsive A-particles create a depletion zone of less repulsive B-particles around them reminiscent to a bubble. Applying Archimedes' principle effectively to this bubble, an A-particle can be lifted in a fluid background of B-particles. This "depletion bubble" mechanism explains and predicts a brazil-nut effect where the heavier A-particles float on top of the lighter B-particles. It also implies an effective attraction of an A-particle towards a hard container bottom wall which leads to boundary layering of A-particles. Additionally, we have studied a periodic inversion of gravity causing perpetual mutual penetration of the mixture in a slit geometry. In this nonequilibrium case of time-dependent gravity, the boundary layering persists. Our results are based on computer simulations and density functional theory of a two-dimensional binary mixture of colloidal repulsive dipoles. The predicted effects also occur for other long-ranged repulsive interactions and in three spatial dimensions. They are therefore verifiable in settling experiments on dipolar or charged colloidal mixtures as well as in charged granulates and dusty plasmas.

  11. Transitions of cloud-topped marine boundary layers characterized by AIRS, MODIS, and a large eddy simulation model

    SciTech Connect (OSTI)

    Yue, Qing; Kahn, Brian; Xiao, Heng; Schreier, Mathias; Fetzer, E. J.; Teixeira, J.; Suselj, Kay

    2013-08-16

    Cloud top entrainment instability (CTEI) is a hypothesized positive feedback between entrainment mixing and evaporative cooling near the cloud top. Previous theoretical and numerical modeling studies have shown that the persistence or breakup of marine boundary layer (MBL) clouds may be sensitive to the CTEI parameter. Collocated thermodynamic profile and cloud observations obtained from the Atmospheric Infrared Sounder (AIRS) and Moderate Resolution Imaging Spectroradiometer (MODIS) instruments are used to quantify the relationship between the CTEI parameter and the cloud-topped MBL transition from stratocumulus to trade cumulus in the northeastern Pacific Ocean. Results derived from AIRS and MODIS are compared with numerical results from the UCLA large eddy simulation (LES) model for both well-mixed and decoupled MBLs. The satellite and model results both demonstrate a clear correlation between the CTEI parameter and MBL cloud fraction. Despite fundamental differences between LES steady state results and the instantaneous snapshot type of observations from satellites, significant correlations for both the instantaneous pixel-scale observations and the long-term averaged spatial patterns between the CTEI parameter and MBL cloud fraction are found from the satellite observations and are consistent with LES results. This suggests the potential of using AIRS and MODIS to quantify global and temporal characteristics of the cloud-topped MBL transition.

  12. Model of the boundary layer of a vacuum-arc magnetic filter

    SciTech Connect (OSTI)

    Minotti, F.; Giuliani, L.; Grondona, D.; Della Torre, H.; Kelly, H.

    2013-03-21

    A model is developed to describe the electrostatic boundary layer in a positively biased magnetic filter in filtered arcs with low collisionality. The set of equations used includes the electron momentum equation, with an anomalous collision term due to micro-instabilities leading to Bohm diffusion, electron mass conservation, and Poisson equation. Analytical solutions are obtained, valid for the regimes of interest, leading to an explicit expression to determine the electron density current to the filter wall as a function of the potential of the filter and the ratio of electron density at the plasma to that at the filter wall. Using a set of planar and cylindrical probes it is verified experimentally that the mentioned ratio of electron densities remains reasonably constant for different magnetic field values and probe bias, which allows to obtain a closed expression for the current. Comparisons are made with the experimentally determined current collected at different sections of a positively biased straight filter.

  13. Experimental observations on transition to turbulence in confined coaxial jets and other boundary layer flows

    SciTech Connect (OSTI)

    Gore, R.A. (Los Alamos National Lab., NM (USA)); Crowe, C.T. (Washington State Univ., Pullman, WA (USA). Dept. of Mechanical and Materials Engineering); Bejan, A. (Duke Univ., Durham, NC (USA). Dept. of Mechanical Engineering and Materials Science)

    1990-01-01

    Experiments performed demonstrate the transition to turbulent flow of water jets discharging coaxially into a stream confined in a round duct. The critical Reynolds number is shown to be a strong function of velocity ratio. From the flow visualization it is shown that a proportionality between the laminar length of the jet (L) and the wavelength ({lambda}) can be seen in the region of transition to turbulence. The proportionality coincides with similar observations concerning the transition to turbulence in various other flows. A brief argument based on scale analysis is presented for the confined coaxial jet and round plume. The apparent universality of the L/{lambda} {approximately} O(10) scaling law supports the conclusion that the laminar sections of all naturally progressing boundary layer-type flows are geometrically similar. 21 refs., 8 figs.

  14. Pulsed Plasma with Synchronous Boundary Voltage for Rapid Atomic Layer Etching

    SciTech Connect (OSTI)

    Economou, Demetre J.; Donnelly, Vincent M.

    2014-05-13

    Atomic Layer ETching (ALET) of a solid with monolayer precision is a critical requirement for advancing nanoscience and nanotechnology. Current plasma etching techniques do not have the level of control or damage-free nature that is needed for patterning delicate sub-20 nm structures. In addition, conventional ALET, based on pulsed gases with long reactant adsorption and purging steps, is very slow. In this work, novel pulsed plasma methods with synchronous substrate and/or “boundary electrode” bias were developed for highly selective, rapid ALET. Pulsed plasma and tailored bias voltage waveforms provided controlled ion energy and narrow energy spread, which are critical for highly selective and damage-free etching. The broad goal of the project was to investigate the plasma science and engineering that will lead to rapid ALET with monolayer precision. A combined experimental-simulation study was employed to achieve this goal.

  15. Electron distributions observed with Langmuir waves in the plasma sheet boundary layer

    SciTech Connect (OSTI)

    Hwang, Junga [Solar and Space Weather Research Group, Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of); Department of Astronomy and Space Science, University of Science and Technology, Daejeon (Korea, Republic of); Rha, Kicheol [Department of Physics, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Seough, Jungjoon [Solar and Space Weather Research Group, Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of); Yoon, Peter H. [School of Space Research, Kyung Hee University, Yongin-Si, Gyeonggi-Do 446-701 (Korea, Republic of); Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742 (United States)

    2014-09-15

    The present paper investigates the Langmuir turbulence driven by counter-streaming electron beams and its plausible association with observed features in the Earth's plasma sheet boundary layer region. A one-dimensional electrostatic particle-in-cell simulation code is employed in order to simulate broadband electrostatic waves with characteristic frequency in the vicinity of the electron plasma frequency ?/?{sub pe}?1.0. The present simulation confirms that the broadband electrostatic waves may indeed be generated by the counter-streaming electron beams. It is also found that the observed feature associated with low energy electrons, namely quasi-symmetric velocity space plateaus, are replicated according to the present simulation. However, the present investigation only partially succeeds in generating the suprathermal tails such that the origin of observed quasi power-law energetic population formation remains outstanding.

  16. ATMOS 5000: Intro to Atmospheric Science Fall Term 2013

    E-Print Network [OSTI]

    Lin, John Chun-Han

    allows: · Atmospheric boundary layer · Carbon cycle, CO2 · Ozone hole, stratospheric chemistry · Air on the atmospheric controls on the weather (beach volleyball versus a rainy day indoors, skiing on a sunny day

  17. Boundary-Layer Meteorol (2009) 131:441463 DOI 10.1007/s10546-009-9371-9

    E-Print Network [OSTI]

    Gohm, Alexander

    2009-01-01

    Boundary-Layer Meteorol (2009) 131:441­463 DOI 10.1007/s10546-009-9371-9 ARTICLE Air Pollution, Austria, is analysed in order to study mechanisms of air pollution transport in an Alpine valley in the dispersion of air pollutants in mountainous terrain. Dynamically or thermally forced winds may enhance

  18. Distribution of Energy Spectra, Reynolds Stresses, Turbulence Production, and Dissipation in a Tidally Driven Bottom Boundary Layer

    E-Print Network [OSTI]

    Distribution of Energy Spectra, Reynolds Stresses, Turbulence Production, and Dissipation in a Tidally Driven Bottom Boundary Layer L. LUZNIK,* R. GURKA,*, W. A. M. NIMMO SMITH,# W. ZHU,* J. KATZ) site] are examined, covering the accelerating and decelerating phases of a single tidal cycle

  19. Nature of the Mesoscale Boundary Layer Height and Water Vapor Variability Observed 14 June 2002 during the IHOP_2002 Campaign

    E-Print Network [OSTI]

    Nature of the Mesoscale Boundary Layer Height and Water Vapor Variability Observed 14 June 2002, Boulder, Colorado (Manuscript received 4 September 2007, in final form 23 June 2008) ABSTRACT Mesoscale at the mesoscale, with the spatial pattern and the magnitude of the variability changing from day to day. On 14

  20. Evolution and lifetimes of flow topology in a turbulent boundary layer G. E. Elsinga and I. Marusic

    E-Print Network [OSTI]

    Marusic, Ivan

    Evolution and lifetimes of flow topology in a turbulent boundary layer G. E. Elsinga and I. Marusic of Physics. Related Articles Lagrangian evolution of the invariants of the velocity gradient tensor subject to AIP license or copyright; see http://pof.aip.org/about/rights_and_permissions #12;Evolution

  1. Two-equation model computations of high-speed (ma=2.25, 7.2), turbulent boundary layers 

    E-Print Network [OSTI]

    Arasanipalai, Sriram Sharan

    2009-05-15

    of the Boussinesq coefficient (Cu) and turbulenttransport coefficients (sigmak; sigmaE; sigma; sigma*) on the boundary layer ow is examined. Further,the performance of a new model with realizability-based correction to Cu and corresponding modifications to sigma...

  2. Characterizing the Separation and Reattachment of Suction Surface Boundary Layer in Low Pressure Turbine Using Massively Parallel Large Eddy Simulations 

    E-Print Network [OSTI]

    Jagannathan, Shriram

    2012-02-14

    The separation and reattachment of the suction surface boundary layer in a low pressure turbine is characterized using large-eddy simulation at Re=68,000 based on freestream velocity and suction surface length. A high pass filtered Smagorinsky model...

  3. European Journal of Mechanics B/Fluids 25 (2006) 117 Algebraic growth in a Blasius boundary layer

    E-Print Network [OSTI]

    Zuccher, Simone

    2006-01-01

    . 2005 Elsevier SAS. All rights reserved. Keywords: Boundary layer; Stability; Transient growth). 0997-7546/$ ­ see front matter 2005 Elsevier SAS. All rights reserved. doi:10.1016/j.euromechflu.2005 April 2005; accepted 9 July 2005 Available online 1 September 2005 Abstract The three

  4. Impacts of boundary layer mixing on pollutant vertical profiles in the lower troposphere: Implications to satellite remote sensing

    E-Print Network [OSTI]

    Jacob, Daniel J.

    primarily by the extent of parameteriza- tion, several types of PBL mixing scheme have been employed-local scheme Full-mixing Satellite remote sensing a b s t r a c t Mixing in the planetary boundary layer (PBL recently been supplemented with a non-local PBL scheme. This study analyzes the impact of the non

  5. On the Interaction between Marine Boundary Layer Cellular Cloudiness and Surface Heat Fluxes

    SciTech Connect (OSTI)

    Kazil, J.; Feingold, G.; Wang, Hailong; Yamaguchi, T.

    2014-01-02

    The interaction between marine boundary layer cellular cloudiness and surface uxes of sensible and latent heat is investigated. The investigation focuses on the non-precipitating closed-cell state and the precipitating open-cell state at low geostrophic wind speed. The Advanced Research WRF model is used to conduct cloud-system-resolving simulations with interactive surface fluxes of sensible heat, latent heat, and of sea salt aerosol, and with a detailed representation of the interaction between aerosol particles and clouds. The mechanisms responsible for the temporal evolution and spatial distribution of the surface heat fluxes in the closed- and open-cell state are investigated and explained. It is found that the horizontal spatial structure of the closed-cell state determines, by entrainment of dry free tropospheric air, the spatial distribution of surface air temperature and water vapor, and, to a lesser degree, of the surface sensible and latent heat flux. The synchronized dynamics of the the open-cell state drives oscillations in surface air temperature, water vapor, and in the surface fluxes of sensible and latent heat, and of sea salt aerosol. Open-cell cloud formation, cloud optical depth and liquid water path, and cloud and rain water path are identified as good predictors of the spatial distribution of surface air temperature and sensible heat flux, but not of surface water vapor and latent heat flux. It is shown that by enhancing the surface sensible heat flux, the open-cell state creates conditions by which it is maintained. While the open-cell state under consideration is not depleted in aerosol, and is insensitive to variations in sea-salt fluxes, it also enhances the sea-salt flux relative to the closed-cell state. In aerosol-depleted conditions, this enhancement may replenish the aerosol needed for cloud formation, and hence contribute to the perpetuation of the open-cell state as well. Spatial homogenization of the surface fluxes is found to have only a small effect on cloud properties in the investigated cases. This indicates that sub-grid scale spatial variability in the surface flux of sensible and latent heat and of sea salt aerosol may not be required in large scale and global models to describe marine boundary layer cellular cloudiness.

  6. A method for the direct numerical simulation of hypersonic boundary-layer instability with finite-rate chemistry

    SciTech Connect (OSTI)

    Marxen, Olaf, E-mail: olaf.marxen@vki.ac.be [Center for Turbulence Research, Building 500, Stanford University, Stanford, CA 94305-3035 (United States) [Center for Turbulence Research, Building 500, Stanford University, Stanford, CA 94305-3035 (United States); Aeronautics and Aerospace Department, von Karman Institute for Fluid Dynamics, Chaussée de Waterloo, 72, 1640 Rhode-St-Genèse (Belgium); Magin, Thierry E. [Aeronautics and Aerospace Department, von Karman Institute for Fluid Dynamics, Chaussée de Waterloo, 72, 1640 Rhode-St-Genèse (Belgium)] [Aeronautics and Aerospace Department, von Karman Institute for Fluid Dynamics, Chaussée de Waterloo, 72, 1640 Rhode-St-Genèse (Belgium); Shaqfeh, Eric S.G.; Iaccarino, Gianluca [Center for Turbulence Research, Building 500, Stanford University, Stanford, CA 94305-3035 (United States)] [Center for Turbulence Research, Building 500, Stanford University, Stanford, CA 94305-3035 (United States)

    2013-12-15

    A new numerical method is presented here that allows to consider chemically reacting gases during the direct numerical simulation of a hypersonic fluid flow. The method comprises the direct coupling of a solver for the fluid mechanical model and a library providing the physio-chemical model. The numerical method for the fluid mechanical model integrates the compressible Navier–Stokes equations using an explicit time advancement scheme and high-order finite differences. This Navier–Stokes code can be applied to the investigation of laminar-turbulent transition and boundary-layer instability. The numerical method for the physio-chemical model provides thermodynamic and transport properties for different gases as well as chemical production rates, while here we exclusively consider a five species air mixture. The new method is verified for a number of test cases at Mach 10, including the one-dimensional high-temperature flow downstream of a normal shock, a hypersonic chemical reacting boundary layer in local thermodynamic equilibrium and a hypersonic reacting boundary layer with finite-rate chemistry. We are able to confirm that the diffusion flux plays an important role for a high-temperature boundary layer in local thermodynamic equilibrium. Moreover, we demonstrate that the flow for a case previously considered as a benchmark for the investigation of non-equilibrium chemistry can be regarded as frozen. Finally, the new method is applied to investigate the effect of finite-rate chemistry on boundary layer instability by considering the downstream evolution of a small-amplitude wave and comparing results with those obtained for a frozen gas as well as a gas in local thermodynamic equilibrium.

  7. Boundary layers and incompressible Navier-Stokes-Fourier limit of the Boltzmann Equation in Bounded Domain (I)

    E-Print Network [OSTI]

    Ning Jiang; Nader Masmoudi

    2015-10-10

    We establish the incompressible Navier-Stokes-Fourier limit for solutions to the Boltzmann equation with a general cut-off collision kernel in a bounded domain. Appropriately scaled families of DiPerna-Lions-(Mischler) renormalized solutions with Maxwell reflection boundary conditions are shown to have fluctuations that converge as the Knudsen number goes to zero. Every limit point is a weak solution to the Navier-Stokes-Fourier system with different types of boundary conditions depending on the ratio between the accommodation coefficient and the Knudsen number. The main new result of the paper is that this convergence is strong in the case of Dirichlet boundary condition. Indeed, we prove that the acoustic waves are damped immediately, namely they are damped in a boundary layer in time. This damping is due to the presence of viscous and kinetic boundary layers in space. As a consequence, we also justify the first correction to the infinitesimal Maxwellian that one obtains from the Chapman-Enskog expansion with Navier-Stokes scaling. This extends the work of Golse and Saint-Raymond \\cite{Go-Sai04, Go-Sai05} and Levermore and Masmoudi \\cite{LM} to the case of a bounded domain. The case of a bounded domain was considered by Masmoudi and Saint-Raymond \\cite{M-S} for linear Stokes-Fourier limit and Saint-Raymond \\cite{SRM} for Navier-Stokes limit for hard potential kernels. Both \\cite{M-S} and \\cite{SRM} didn't study the damping of the acoustic waves. This paper extends the result of \\cite{M-S} and \\cite{SRM} to the nonlinear case and includes soft potential kernels. More importantly, for the Dirichlet boundary condition, this work strengthens the convergence so as to make the boundary layer visible. This answers an open problem proposed by Ukai \\cite{Ukai}.

  8. RACORO continental boundary layer cloud investigations. 2. Large-eddy simulations of cumulus clouds and evaluation with in-situ and ground-based observations

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

    Endo, Satoshi; Fridlind, Ann M.; Lin, Wuyin; Vogelmann, Andrew M.; Toto, Tami; Ackerman, Andrew S.; McFarquhar, Greg M.; Jackson, Robert C.; Jonsson, Haflidi H.; Liu, Yangang

    2015-06-19

    A 60-hour case study of continental boundary layer cumulus clouds is examined using two large-eddy simulation (LES) models. The case is based on observations obtained during the RACORO Campaign (Routine Atmospheric Radiation Measurement [ARM] Aerial Facility [AAF] Clouds with Low Optical Water Depths [CLOWD] Optical Radiative Observations) at the ARM Climate Research Facility's Southern Great Plains site. The LES models are driven by continuous large-scale and surface forcings, and are constrained by multi-modal and temporally varying aerosol number size distribution profiles derived from aircraft observations. We compare simulated cloud macrophysical and microphysical properties with ground-based remote sensing and aircraft observations.more »The LES simulations capture the observed transitions of the evolving cumulus-topped boundary layers during the three daytime periods, and generally reproduce variations of droplet number concentration with liquid water content (LWC), corresponding to the gradient between the cloud centers and cloud edges at given heights. The observed LWC values fall within the range of simulated values; the observed droplet number concentrations are commonly higher than simulated, but differences remain on par with potential estimation errors in the aircraft measurements. Sensitivity studies examine the influences of bin microphysics versus bulk microphysics, aerosol advection, supersaturation treatment, and aerosol hygroscopicity. Simulated macrophysical cloud properties are found to be insensitive in this non-precipitating case, but microphysical properties are especially sensitive to bulk microphysics supersaturation treatment and aerosol hygroscopicity.« less

  9. Discovery of Drifting High-frequency QPOs in Global Simulations of Magnetic Boundary Layers

    E-Print Network [OSTI]

    M. M. Romanova; A. K. Kulkarni

    2009-06-02

    We report on the numerical discovery of quasi-periodic oscillations (QPOs) associated with accretion through a non-axisymmetric magnetic boundary layer in the unstable regime, when two ordered equatorial streams form and rotate synchronously at approximately the angular velocity of the inner disk The streams hit the star's surface producing hot spots. Rotation of the spots leads to high-frequency QPOs. We performed a number of simulation runs for different magnetospheric sizes from small to tiny, and observed a definite correlation between the inner disk radius and the QPO frequency: the frequency is higher when the magnetosphere is smaller. In the stable regime a small magnetosphere forms and accretion through the usual funnel streams is observed, and the frequency of the star is expected to dominate the lightcurve. We performed exploratory investigations of the case in which the magnetosphere becomes negligibly small and the disk interacts with the star through an equatorial belt. We also performed investigation of somewhat larger magnetospheres where one or two ordered tongues may dominate over other chaotic tongues. In application to millisecond pulsars we obtain QPO frequencies in the range of 350 Hz to 990 Hz for one spot. The frequency associated with rotation of one spot may dominate if spots are not identical or antipodal. If the spots are similar and antipodal then the frequencies are twice as high. We show that variation of the accretion rate leads to drift of the QPO peak.

  10. On the boundary layer structure near a highly permeable porous interface

    E-Print Network [OSTI]

    Dalwadi, Mohit P; Waters, Sarah L; Oliver, James M

    2015-01-01

    The method of matched asymptotic expansions is used to study the canonical problem of steady laminar flow through a narrow two-dimensional channel blocked by a tight-fitting finite-length highly permeable porous obstacle. We investigate the behaviour of the local flow close to the interface between the single-phase and porous regions (governed by the incompressible Navier--Stokes and Darcy flow equations, respectively). We solve for the local flow in the limits of low and high Reynolds number, facilitating an understanding of the nature of the transition from Poiseuille to plug to Poiseuille flow in each of these limits. Significant analytic progress is made in the high-Reynolds-number limit, as we are able to explore in detail the rich boundary layer structure that occurs. We derive general results for the interfacial stress and for the conditions that couple the flow in the regions away from the interface. We consider the three-dimensional generalization to unsteady laminar flow through and around a tight-f...

  11. Technical notes Experiments in Fluids 22 (1997) 351--353 Springer-Verlag 1997 Vortex stretching in a laminar boundary layer flow

    E-Print Network [OSTI]

    Wesfreid, José Eduardo

    1997-01-01

    in a laminar boundary layer flow P. Petitjeans, J. E. Wesfreid, J. C. Attiach Abstract A new technique the effects of stretching on a controlled vorticity sheet coming from a laminar boundary layer flow on a flat. A diffuser keeps the flow laminar with a minimum of perturbation. The key elements of the channel

  12. Global warming and its implications for conservation. 3. How does it work? Part two: atmospheric science and the layer model

    E-Print Network [OSTI]

    Creel, Scott

    Global warming and its implications for conservation. 3. How does it work? Part two: atmospheric warms the surface of the planet as it moves toward an equilibrium of energy fluxes in and out. The layer

  13. Cloud climatology at the Southern Great Plains and the layer structure, drizzle, and atmospheric modes of continental stratus

    E-Print Network [OSTI]

    Cloud climatology at the Southern Great Plains and the layer structure, drizzle, and atmospheric.5 years) cloud observations from the Atmospheric Radiation Measurements (ARM) program Southern Great Plains (SGP) climate research facility in Oklahoma are used to develop detailed cloud climatology. Clouds

  14. Dipole tilt angle effects on the latitude of the cusp and cleft/low-latitude boundary layer

    SciTech Connect (OSTI)

    Newell, P.T.; Meng, C.I. (Johns Hopkins Univ., Laurel, MD (USA))

    1989-06-01

    A large data set of approximately 12,000 Defense Meteorological Satellite Program satellite F7 crossings of the cusp or the cleft (i.e., the dayside magnetospheric boundary layer) over a 3-year period is studied for seasonal dependence in latitudinal position. A carefully tested algorithm is used to distinguish the various dayside particle precipitation regions and boundaries. It is found that in the 1,100-1,300 MLT sector, the cusp proper exhibits about {minus}0.06{degree} magnetic latitude (MLAT) shift for each degree increase in dipole tilt angle. Thus the difference between the average summer and winter cusp positions is close to 4{degree} MLAT, approximately symmetric about equinox. For the cleft (magnetospheric boundary layer) the variation is smaller. For example, in the 0700-0900 MLT sector the cleft equatorward boundary shift is {minus} 0.027{degree} MLAT/1{degree} dipole tilt. These results are in general agreement with the predictions of empirical magnetospheric magnetic field models. Various ground-based and low-altitude observations can be systematically affected by the seasonal latitudinal shift herein documented.

  15. Collaborative Research: ARM observations for the development and evaluation of models and parameterizations of cloudy boundary layers

    SciTech Connect (OSTI)

    Albrecht, Bruce,

    2013-07-12

    This is a collaborative project with Dr. Ping Zhu at Florida International University. It was designed to address key issues regarding the treatment of boundary layer cloud processes in climate models with UM’s research focusing on the analyses of ARM cloud radar observations from MMCR and WACR and FIU’s research focusing on numerical simulations of boundary layer clouds. This project capitalized on recent advancements in the ARM Millimeter Cloud Radar (MMCR) processing and the development of the WACR (at the SGP) to provide high temporal and spatial resolution Doppler cloud radar measurements for characterizing in-cloud turbulence, large-eddy circulations, and high resolution cloud structures of direct relevance to high resolution numerical modeling studies. The principal focus of the observational component of this collaborative study during this funding period was on stratocumulus clouds over the SGP site and fair-weather cumuli over the Nauru site. The statistical descriptions of the vertical velocity structures in continental stratocumulus clouds and in the Nauru shallow cumuli that are part of this study represents the most comprehensive observations of the vertical velocities in boundary layer clouds to date and were done in collaboration with Drs. Virendra Ghate and Pavlos Kollias.

  16. Vehicle cabin cooling system for capturing and exhausting heated boundary layer air from inner surfaces of solar heated windows

    DOE Patents [OSTI]

    Farrington, Robert B. (Golden, CO); Anderson, Ren (Broomfield, CO)

    2001-01-01

    The cabin cooling system includes a cooling duct positioned proximate and above upper edges of one or more windows of a vehicle to exhaust hot air as the air is heated by inner surfaces of the windows and forms thin boundary layers of heated air adjacent the heated windows. The cabin cooling system includes at least one fan to draw the hot air into the cooling duct at a flow rate that captures the hot air in the boundary layer without capturing a significant portion of the cooler cabin interior air and to discharge the hot air at a point outside the vehicle cabin, such as the vehicle trunk. In a preferred embodiment, the cooling duct has a cross-sectional area that gradually increases from a distal point to a proximal point to the fan inlet to develop a substantially uniform pressure drop along the length of the cooling duct. Correspondingly, this cross-sectional configuration develops a uniform suction pressure and uniform flow rate at the upper edge of the window to capture the hot air in the boundary layer adjacent each window.

  17. Forecast of surface layer meteorological parameters at Cerro Paranal with a mesoscale atmospherical model

    E-Print Network [OSTI]

    Lascaux, Franck; Fini, Luca

    2015-01-01

    This article aims at proving the feasibility of the forecast of all the most relevant classical atmospherical parameters for astronomical applications (wind speed and direction, temperature) above the ESO ground-base site of Cerro Paranal with a mesoscale atmospherical model called Meso-Nh. In a precedent paper we have preliminarily treated the model performances obtained in reconstructing some key atmospherical parameters in the surface layer 0-30~m studying the bias and the RMSE on a statistical sample of 20 nights. Results were very encouraging and it appeared therefore mandatory to confirm such a good result on a much richer statistical sample. In this paper, the study was extended to a total sample of 129 nights between 2007 and 2011 distributed in different parts of the solar year. This large sample made our analysis more robust and definitive in terms of the model performances and permitted us to confirm the excellent performances of the model. Besides, we present an independent analysis of the model p...

  18. Immersed Boundary Methods for High-Resolution Simulation of Atmospheric Boundary-Layer Flow Over Complex Terrain

    E-Print Network [OSTI]

    Lundquist, Katherine Ann

    2010-01-01

    Wind Energy Association Windpower 2008 Conference, AmericanWind Energy Association Windpower 2006 Conference, American

  19. Immersed Boundary Methods for High-Resolution Simulation of Atmospheric Boundary-Layer Flow Over Complex Terrain

    E-Print Network [OSTI]

    Lundquist, Katherine Ann

    2010-01-01

    wall region, the first off wall grid point should be locatedwall point. If the first off wall grid point is located innoting that the first off wall grid point was located in the

  20. An investigation of the air flow structure over a rooftop in the turbulent atmospheric boundary layer

    E-Print Network [OSTI]

    Hayes, William Joseph

    2010-01-01

    that a large coherent vortex tube is present spanning theof the leading edge. This vortex tube did not, however, spansame apparatus a similar vortex tube is present but due to

  1. Atmospheric dispersion in the arctic: Winter-time boundary-layer measurements

    E-Print Network [OSTI]

    Guenther, A; Lamb, B

    1989-01-01

    0 Hour 12 Hour 13 Hour 14 Crosswind Distance (m) Fig. 11.Gaussian hourly averaged crosswind concentration profilesresults. Non-Gaussian hourly crosswind distributions are not

  2. Modeling passive scalar dispersion in the atmospheric boundary layer with WRF large-eddy simulation

    E-Print Network [OSTI]

    Nottrott, Anders; Kleissl, Jan; Keeling, Ralph

    2014-01-01

    self-similarity only in the crosswind direction. Thoseas the vertical and crosswind dimensions of the plumeObukhov length streamwise, crosswind horizontal and vertical

  3. Observations of marine atmospheric boundary layer transitions across the summer Kuroshio Extension

    E-Print Network [OSTI]

    Xie, Shang-Ping

    , Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan 3 International Pacific Research of Hawaii, Honolulu, HI 5 Faculty of Marine Technology, Tokyo University of Marine Science and Technology-Earth Science and Technology, Yokosuka, Japan 7 Department of Earth and Planetary Science, University of Tokyo

  4. Large-eddy Simulation of the Nighttime Stable Atmospheric Boundary Layer

    E-Print Network [OSTI]

    Zhou, Bowen

    2012-01-01

    and wind turbine micro-siting in complex terrain. ” Journal of Wind Engineering and Industrial Aerodynamics

  5. Buoyancy Effects on the Scaling Characteristics of Atmospheric Boundary Layer Wind Fields in the Mesoscale Range

    E-Print Network [OSTI]

    Kiliyanpilakkil, V P; Ruiz-Columbié, A; Araya, G; Castillo, L; Hirth, B; Burgett, W

    2015-01-01

    We have analyzed long-term wind speed time-series from five field sites up to a height of 300 m from the ground. Structure function-based scaling analysis has revealed that the scaling exponents in the mesoscale regime systematically depend on height. This anomalous behavior is shown to be caused by the buoyancy effects. In the framework of the extended self-similarity, the relative scaling exponents portray quasi-universal behavior.

  6. Large-eddy Simulation of the Nighttime Stable Atmospheric Boundary Layer

    E-Print Network [OSTI]

    Zhou, Bowen

    2012-01-01

    of US winds and wind power at 80 m derived fromMaxima and Problem of Wind Power Assessment. ” Environmentalsiting and operational wind power forecasting. For example,

  7. Large-eddy Simulation of the Nighttime Stable Atmospheric Boundary Layer

    E-Print Network [OSTI]

    Zhou, Bowen

    2012-01-01

    Turbulence/Rotor Interactions. ” Wind Energy 3 (3): 121–134.to complex terrain. ” Wind Energy 14 (2) (March): 225–237.Patterns at Midwest Wind Energy Facilities. ” In Proceedings

  8. THE THERMODYNAMIC EFFECTS OF SUBLIMATING, BLOWING SNOW IN THE ATMOSPHERIC BOUNDARY LAYER

    E-Print Network [OSTI]

    Dery, Stephen

    . Apart from the transport of snow, the thermodynamic impact of sublimat- ing blowing snow in air near process is self- limiting despite ongoing transport of snow by wind, yielding significantly lower values their lengthy winters (Stewart et al., 1995). These storms are often associated with sub-freezing temper- atures

  9. An investigation of the air flow structure over a rooftop in the turbulent atmospheric boundary layer

    E-Print Network [OSTI]

    Hayes, William Joseph

    2010-01-01

    DEMROES data for Wind Direction (left) and Solar Radiation (for wind speed and solar radiation (Figure 15: StandardDirection (left) and Solar Radiation (right).Figure 15).

  10. An investigation of the air flow structure over a rooftop in the turbulent atmospheric boundary layer

    E-Print Network [OSTI]

    Hayes, William Joseph

    2010-01-01

    DEMROES data for Wind Direction (left) and Solar Radiation (DEMROES data for Wind Direction (left) and Solar Radiation (DEMROES data for Wind Direction (left) and Solar Radiation (

  11. Boundary Layer The U.S. Department of Energy's Atmospheric Radiation

    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 OLaura|BilayerBiomimeticBooks Are

  12. DOE/SC-ARM-14-034 Lower Atmospheric Boundary Layer Experiment

    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 HAB Packet HanfordDOE ProjectREMOTE-HANDLED TRU764 The6 User3 ARM4

  13. Harmonic propagation of variability in surface energy balance within a coupled soil-vegetation-atmosphere system

    E-Print Network [OSTI]

    Gentine, P.

    [1] The response of a soil-vegetation-atmosphere continuum model to incoming radiation forcing is investigated in order to gain insights into the coupling of soil and atmospheric boundary layer (ABL) states and fluxes. The ...

  14. Seismic and gravitational studies of melting in the mantle's thermal boundary layers

    E-Print Network [OSTI]

    Van Ark, Emily M

    2007-01-01

    This thesis presents three studies which apply geophysical tools to the task of better understanding mantle melting phenomena at the upper and lower boundaries of the mantle. The first study uses seafloor bathymetry and ...

  15. UNIVERSITY OF CALIFORNIA, SAN DIEGO Numerical Simulations of the Stratified Oceanic Bottom Boundary Layer

    E-Print Network [OSTI]

    Taylor, John R.

    UNIVERSITY OF CALIFORNIA, SAN DIEGO Numerical Simulations of the Stratified Oceanic Bottom Boundary of Philosophy in Mechanical Engineering by John R. Taylor Committee in charge: Sutanu Sarkar, Chair Thomas Simulation of Stably Stratified Open Channel Flow . . . . . 6 1. Introduction

  16. Characterization of the Influence of a Favorable Pressure Gradient on the Basic Structure of a Mach 5.0 High Reynolds Number Supersonic Turbulent Boundary Layer 

    E-Print Network [OSTI]

    Tichenor, Nathan R.

    2010-10-12

    High-speed high Reynolds number boundary layer flows with mechanical non-equilibrium effects have numerous practical applications; examples include access-to-space ascent, re-entry and descent, and military hypersonic ...

  17. Combined effects of Reynolds number, turbulence intensity and periodic unsteady wake flow conditions on boundary layer development and heat transfer of a low pressure turbine blade 

    E-Print Network [OSTI]

    Ozturk, Burak

    2009-05-15

    Detailed experimental investigation has been conducted to provide a detailed insight into the heat transfer and aerodynamic behavior of a separation zone that is generated as a result of boundary layer development along ...

  18. On the use of a nascent delta function in radiative-transfer calculations for multi-layer media subject to Fresnel boundary

    E-Print Network [OSTI]

    Siewert, Charles E.

    subject to Fresnel boundary and interface conditions R.D.M. Garcia a,Ã, C.E. Siewert b a Instituto de: Radiative transfer Nascent delta function Fresnel conditions Discrete-ordinates method a b s t r a c in a plane-parallel, multi-layer medium subject to Fresnel boundary and interface conditions. As a result

  19. Synoptic and local influences on boundary layer processes, with an application to California wind power

    E-Print Network [OSTI]

    Mansbach, David K

    2010-01-01

    stations, and other ob- servation and buoy sites used in thePrograms of the National Data Buoy Center. Bulletin of theand Winant, C. , 1995: Buoy observations of the atmosphere

  20. A boundary perturbation method for recovering interface shapes in layered media

    E-Print Network [OSTI]

    Malcolm, Alison E.

    The scattering of linear acoustic radiation by a periodic layered structure is a fundamental model in the geosciences as it closely approximates the propagation of pressure waves in the earth's crust. In this contribution, ...

  1. XMM-Newton observations of the dwarf nova RU Peg in quiescence: Probe of the boundary layer

    E-Print Network [OSTI]

    Balman, S; Sion, E M; Ness, J -U; Schlegel, E; Barrett, P E; Szkody, P

    2011-01-01

    We present an analysis of X-ray and UV data obtained with the XMM-Newton Observatory of the long period dwarf nova RU Peg. RU Peg contains a massive white dwarf, possibly the hottest white dwarf in a dwarf nova, it has a low inclination, thus optimally exposing its X-ray emitting boundary layer, and has an excellent trigonometric parallax distance. We modeled the X-ray data using XSPEC assuming a multi-temperature plasma emission model built from the MEKAL code. We obtained a maximum temperature of 31.7 keV, based on the EPIC MOS1, 2 and pn data, indicating that RU Peg has an X-ray spectrum harder than most dwarf novae, except U Gem. This result is consistent with and indirectly confirms the large mass of the white dwarf in RU Peg. The X-ray luminosity we computed corresponds to a boundary layer luminosity for a mass accretion rate of 2.E-11 Msun/yr (assuming Mwd=1.3Msun), in agreement with an expected quiescent accretion rate. The modeling of the O VIII emission line at 19A as observed by the RGS implies a p...

  2. Turbulent boundary layers interacting with groups of obstacles Project Staff Principal investigator: Dr Costantino Manes

    E-Print Network [OSTI]

    Sóbester, András

    as in the case of atmospheric flows over wind farms or marine turbines in tidal channels. Certainly, with respect and the Environment Related website When wind or water meets an obstacle it is surprising how little is known about the interaction they have. When building a city or planning on positioning wind or tidal turbines it would

  3. Aerosol properties and their influences on marine boundary layer cloud condensation nuclei

    E-Print Network [OSTI]

    Dong, Xiquan

    and early spring months had the highest mean surface wind speed (> 5 m sÀ1 ) and greatest contribution of aerosols found in the atmosphere such as mineral dust, urban/industrial pollution, biomass burning, and sea by using observations and model simulations [Rosenfeld et al., 2008; Li et al., 2011; Feingold et al., 2006

  4. Cumulant expansions for atmospheric flows

    E-Print Network [OSTI]

    Ait-Chaalal, Farid; Meyer, Bettina; Marston, J B

    2015-01-01

    The equations governing atmospheric flows are nonlinear, and consequently the hierarchy of cumulant equations is not closed. But because atmospheric flows are inhomogeneous and anisotropic, the nonlinearity may manifests itself only weakly through interactions of mean fields with disturbances such as thermals or eddies. In such situations, truncations of the hierarchy of cumulant equations hold promise as a closure strategy. We review how truncations at second order can be used to model and elucidate the dynamics of turbulent atmospheric flows. Two examples are considered. First, we study the growth of a dry convective boundary layer, which is heated from below, leading to turbulent upward energy transport and growth of the boundary layer. We demonstrate that a quasilinear truncation of the equations of motion, in which interactions of disturbances among each other are neglected but interactions with mean fields are taken into account, can successfully capture the growth of the convective boundary layer. Seco...

  5. 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

  6. Confinement of the Sun's interior magnetic field: some exact boundary-layer solutions

    E-Print Network [OSTI]

    T. S. Wood; M. E. McIntyre

    2007-09-10

    High-latitude laminar confinement of the Sun's interior magnetic field is shown to be possible, as originally proposed by Gough and McIntyre (1998) but contrary to a recent claim by Brun and Zahn (A&A 2006). Mean downwelling as weak as 2x10^-6cm/s -- gyroscopically pumped by turbulent stresses in the overlying convection zone and/or tachocline -- can hold the field in advective-diffusive balance within a confinement layer of thickness scale ~ 1.5Mm ~ 0.002 x (solar radius) while transmitting a retrograde torque to the Ferraro-constrained interior. The confinement layer sits at the base of the high-latitude tachocline, near the top of the radiative envelope and just above the `tachopause' marking the top of the helium settling layer. A family of exact, laminar, frictionless, axisymmetric confinement-layer solutions is obtained for uniform downwelling in the limit of strong rotation and stratification. A scale analysis shows that the flow is dynamically stable and the assumption of laminar flow realistic. The solution remains valid for downwelling values of the order of 10^-5cm/s but not much larger. This suggests that the confinement layer may be unable to accept a much larger mass throughput. Such a restriction would imply an upper limit on possible internal field strengths, perhaps of the order of hundreds of gauss, and would have implications also for ventilation and lithium burning. The solutions have interesting chirality properties not mentioned in the paper owing to space restrictions, but described at http://www.atmos-dynamics.damtp.cam.ac.uk/people/mem/papers/SQBO/solarfigure.html

  7. Behavior of buoyant moist plumes in turbulent atmospheres

    E-Print Network [OSTI]

    Hamza, Redouane

    1981-01-01

    A widely applicable computational model of buoyant moist plumes in turbulent atmospheres has been constructed. To achieve this a one dimensional Planetary Boundary Layer (P.B.L.) model has been developed to account for ...

  8. Friction and Diapycnal Mixing at a Slope: Boundary Control of Potential Vorticity

    E-Print Network [OSTI]

    Benthuysen, Jessica

    Although atmospheric forcing by wind stress or buoyancy flux is known to change the ocean’s potential vorticity (PV) at the surface, less is understood about PV modification in the bottom boundary layer. The adjustment of ...

  9. Boundary Layer Structure in the Inn Valley during High Air Pollution (INNAP) Institute of Meteorology and Geophysics (IMGI), University of Innsbruck, Austria

    E-Print Network [OSTI]

    Gohm, Alexander

    Boundary Layer Structure in the Inn Valley during High Air Pollution (INNAP) 1 Institute sources, may be affected by air pollution since slope winds are able to transport pollutants even above project INNAP. DISCUSSION AND CONCLUSIONS In general, the three-dimensional distribution of air

  10. Marine biogenic and anthropogenic contributions to non-sea-salt sulfate in the marine boundary layer over the North Atlantic Ocean

    E-Print Network [OSTI]

    Prospero, Joseph M.

    Experiment (AEROCE), daily aerosol samples were collected in the marine boundary layer at Barbados, West at Bermuda and Barbados, the marine nss SO4 2À /MSA mass ratios (19.6 ± 2.1 and 18.8 ± 2.2) were consistent sources dominate. Intermediate values occurred at Barbados (18,000) and Izan~a (24,000) where both

  11. Clouds, Aerosol, and Precipitation in the Marine Boundary Layer: Analysis of Results from the ARM Mobile Facility Deployment to the Azores (2009/2010)

    SciTech Connect (OSTI)

    Wood, Robert

    2013-05-31

    The project focuses upon dataset analysis and synthesis of datasets from the AMF deployment entitled “Clouds, Aerosols, and Precipitation in the Marine Boundary Layer (CAP?MBL)” at Graciosa Island in the Azores. Wood is serving a PI for this AMF deployment.

  12. Ellipsometry characterization of polycrystalline ZnO layers with the modeling of carrier concentration gradient: Effects of grain boundary, humidity, and surface texture

    SciTech Connect (OSTI)

    Sago, Keisuke; Fujiwara, Hiroyuki; Kuramochi, Hideto; Iigusa, Hitoshi; Utsumi, Kentaro

    2014-04-07

    Spectroscopic ellipsometry (SE) has been applied to study the effects of grain boundary, humidity, and surface texture on the carrier transport properties of Al-doped ZnO layers fabricated by dc and rf magnetron sputtering. In the SE analysis, the variation in the free carrier absorption toward the growth direction, induced by the ZnO grain growth on foreign substrates, has been modeled explicitly by adopting a multilayer model in which the optical carrier concentration (N{sub opt}) varies continuously with a constant optical mobility (?{sub opt}). The effect of the grain boundary has been studied by comparing ?{sub opt} with Hall mobility (?{sub Hall}). The change in ?{sub Hall}/?{sub opt} indicates a sharp structural transition of the ZnO polycrystalline layer at a thickness of d???500?nm, which correlates very well with the structure confirmed by transmission electron microscopy. In particular, below the transition thickness, the formation of the high density grain boundary leads to the reduction in the ?{sub Hall}/?{sub opt} ratio as well as N{sub opt}. As a result, we find that the thickness dependence of the carrier transport properties is almost completely governed by the grain boundary formation. On the other hand, when the ZnO layer is exposed to wet air at 85?°C, ?{sub Hall} reduces drastically with a minor variation of ?{sub opt} due to the enhanced grain boundary scattering. We have also characterized textured ZnO:Al layers prepared by HCl wet etching by SE. The analysis revealed that the near-surface carrier concentration increases slightly after the etching. We demonstrate that the SE technique can be applied to distinguish various rough textured structures (size???1??m) of the ZnO layers prepared by the HCl etching.

  13. Use of a Seeing Monitor to Determine the Velocities of Turbulent Atmospheric Layers

    E-Print Network [OSTI]

    Meisner, Jeff

    with ground based interferometers and adaptive optics systems, as well as in statistical studies of seeing- tical astronomical images well beyond the di#11;raction limit of the telescopes. An adaptive optics;erential atmospheric delay a#11;ecting the light received at separated points. In all such ground

  14. A meta-analysis of water vapor deuterium-excess in the midlatitude atmospheric surface layer

    E-Print Network [OSTI]

    Minnesota, University of

    are in natural ecosystems, a forest (Borden Forest, Ontario, Canada) and a grassland (Duolun, China). We found.1029/2011GB004246. 1. Introduction [2] Water vapor is the most important atmospheric greenhouse gas and temporal variability in the isotopic composition of water in the air and also on the land surface (i

  15. Mars Exploration Rover (MER) Panoramic Camera (Pancam) Twilight Image Analysis for Determination of Planetary Boundary Layer and Dust Particle Size Parameters 

    E-Print Network [OSTI]

    Grounds, Stephanie Beth

    2012-02-14

    Thermal Emission Spectrometer (Mini- TES) thermal infrared spectra (Smith et al., 2006). MER-based Mini-TES spectra have been used in the determination of generalized boundary layer parameters for Martian GCMs. Mini-TES spectra were collected in both... superadiabatic layer found near the surface (Smith et al., 2006). Mini-TES observations were used to observe general timescales, duration times, and overall intensities of multiple local- and regional-scale dust storms, and upward-looking Mini-TES research can...

  16. Implementation of the Immersed Boundary Method in the Weather Research and Forecasting model

    SciTech Connect (OSTI)

    Lundquist, K A

    2006-12-07

    Accurate simulations of atmospheric boundary layer flow are vital for predicting dispersion of contaminant releases, particularly in densely populated urban regions where first responders must react within minutes and the consequences of forecast errors are potentially disastrous. Current mesoscale models do not account for urban effects, and conversely urban scale models do not account for mesoscale weather features or atmospheric physics. The ultimate goal of this research is to develop and implement an immersed boundary method (IBM) along with a surface roughness parameterization into the mesoscale Weather Research and Forecasting (WRF) model. IBM will be used in WRF to represent the complex boundary conditions imposed by urban landscapes, while still including forcing from regional weather patterns and atmospheric physics. This document details preliminary results of this research, including the details of three distinct implementations of the immersed boundary method. Results for the three methods are presented for the case of a rotation influenced neutral atmospheric boundary layer over flat terrain.

  17. XMM-NEWTON OBSERVATIONS OF THE DWARF NOVA RU Peg IN QUIESCENCE: PROBE OF THE BOUNDARY LAYER

    SciTech Connect (OSTI)

    Balman, Soelen [Department of Physics, Middle East Technical University, Ankara (Turkey); Godon, Patrick; Sion, Edward M. [Department of Astronomy and Astrophysics, Villanova University, Villanova, PA 19085 (United States); Ness, Jan-Uwe [XMM-Newton Science Operations Centre, European Space Agency (ESA/ESAC), E-28691 Villanueva de la Canada, Madrid (Spain); Schlegel, Eric [Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX 78249 (United States); Barrett, Paul E. [United States Naval Observatory, Washington, DC 20392 (United States); Szkody, Paula, E-mail: solen@astroa.physics.metu.edu.tr, E-mail: patrick.godon@villanova.edu, E-mail: edward.sion@villanova.edu, E-mail: juness@sciops.esa.int, E-mail: eric.schlegel@utsa.edu, E-mail: barrett.paul@usno.navy.mil, E-mail: szkody@astro.washington.edu [Astronomy Department, University of Seattle, Seattle, WA 98195 (United States)

    2011-11-10

    We present an analysis of X-ray and UV data obtained with the XMM-Newton Observatory of the long-period dwarf nova RU Peg. RU Peg contains a massive white dwarf (WD), possibly the hottest WD in a dwarf nova (DN), it has a low inclination, thus optimally exposing its X-ray emitting boundary layer (BL), and has an excellent trigonometric parallax distance. We modeled the X-ray data using XSPEC assuming a multi-temperature plasma emission model built from the MEKAL code (i.e., CEVMKL). We obtained a maximum temperature of 31.7 keV, based on the European Photon Imaging Camera MOS1, 2 and pn data, indicating that RU Peg has an X-ray spectrum harder than most DNe, except U Gem. This result is consistent with and indirectly confirms the large mass of the WD in RU Peg. The X-ray luminosity we computed corresponds to a BL luminosity for a mass accretion rate of 2 Multiplication-Sign 10{sup -11} M{sub sun} yr{sup -1} (assuming M{sub wd} = 1.3 M{sub sun}), in agreement with the expected quiescent accretion rate. The modeling of the O VIII emission line at 19 A as observed by the Reflection Grating Spectrometer implies a projected stellar rotational velocity v{sub rot}sin i = 695 km s{sup -1}, i.e., the line is emitted from material rotating at {approx}936-1245 km s{sup -1} (i {approx} 34 Degree-Sign -48 Degree-Sign) or about 1/6 of the Keplerian speed; this velocity is much larger than the rotation speed of the WD inferred from the Far Ultraviolet Spectroscopic Explorer spectrum. Cross-correletion analysis yielded an undelayed (time lag {approx} 0) component and a delayed component of 116 {+-} 17 s where the X-ray variations/fluctuations lagged the UV variations. This indicates that the UV fluctuations in the inner disk are propagated into the X-ray emitting region in about 116 s. The undelayed component may be related to irradiation effects.

  18. The chemistry of OH and HO2 radicals in the boundary layer over the tropical Atlantic Ocean

    E-Print Network [OSTI]

    2010-01-01

    fore passing near to the Canary Islands on its way to Capepassing close to the Canary Islands before approaching CapePolarstern north of the Canary Islands. Significant boundary

  19. Contributions of the wall boundary layer to the formation of the counter-rotating vortex pair in transverse jets

    E-Print Network [OSTI]

    Schlegel, Fabrice

    Using high-resolution 3-D vortex simulations, this study seeks a mechanistic understanding of vorticity dynamics in transverse jets at a finite Reynolds number. A full no-slip boundary condition, rigorously formulated in ...

  20. Existence and stability of noncharacteristic boundary-layers for the compressible Navier-Stokes and viscous MHD equations

    E-Print Network [OSTI]

    Métivier, Guy

    @cmi.univ-mrs.fr. Universit´e de Bordeaux; IMB; metivier@math.u-bordeaux.fr. University of North Carolina; williams spectral stability condition on layer profiles that is expressible in terms of an Evans function (uniform above, we carry out energy estimates showing that constant (and thus small-amplitude) layers always

  1. Large eddy simulation of atmospheric boundary layer flow in urban terrain : implications for transport of pollution and heat

    E-Print Network [OSTI]

    Sun, Long

    2011-01-01

    such as the urban heat island and increase in urban energyloads and the urban heat island-the effects of albedo,modeling of urban heat islands. Final report prepared by

  2. Isolating Effects of Water Table Dynamics, Terrain, and Soil Moisture Heterogeneity on the Atmospheric Boundary Layer Using Coupled Models

    E-Print Network [OSTI]

    Rihani, Jehan

    2010-01-01

    yearly averages of water and energy balance components forthe transfer of water and energy between the loweryearly averages of water and energy balance components for

  3. Experimental development of the predictive relations for the eddy exchange coefficients for momentum and heat in the atmospheric boundary layer 

    E-Print Network [OSTI]

    Jensen, Paul Alfred

    1972-01-01

    . 3 &ii. t' i' 1i~:. . ;at of: t'ai. , : -. . '. ; r. ;. ;. r, ': i r:;. - ~ leer-. . - . :. . . , , . ;: o i r ". pc i' FC:"1;', );, 1')7p EXPERIYENT'L Dj. 'VELOPkjENT OF THE PRFDICTZFF. RETATIONS 1'OR T13E Fl)DY E1CH'NGF CO1'FFZCZENTS I'OR 3j... m~. 'rir g scheme 44 V. TROCRSSINO i!RAN Dz&T4 VI. ANAIULSIS I'ROCRDURL 49 51 VII. RDDT ILXCDWCR CO. II'ICIRNl ICR NONRNTI!N (i) Sel ec L" on og for'ms occ Z m (Li ) Besu l ls (i'i) Discusscon 60 v2 p, p rf I I, "7)i r', ?'. 'XCIIAir...

  4. Large eddy simulation of atmospheric boundary layer flow in urban terrain : implications for transport of pollution and heat

    E-Print Network [OSTI]

    Sun, Long

    2011-01-01

    loads and the urban heat island-the effects of albedo,modeling of urban heat islands. Final report prepared byeffects such as the urban heat island and increase in urban

  5. A Large-Eddy Simulation Study of the Influence of Subsidence on the Stably Stratified Atmospheric Boundary Layer

    E-Print Network [OSTI]

    Mirocha, Jeffrey D.; Kosovi?, Branko

    2010-01-01

    Study of the In?uence of Subsidence on the Stably Strati?eduence of the large-scale subsidence rate, S, on the stablydepth and temperature. Subsidence reduces the magnitudes of

  6. High-Resolution Satellite Measurements of the Atmospheric Boundary Layer Response to SST Variations along the Agulhas Return Current

    E-Print Network [OSTI]

    Kurapov, Alexander

    -scale perturbations in the wind stress curl and divergence fields that are linearly related to the crosswind

  7. Large eddy simulation of atmospheric boundary layer flow in urban terrain : implications for transport of pollution and heat

    E-Print Network [OSTI]

    Sun, Long

    2011-01-01

    pollution. In this research numerical methods are used to investigate some basic turbulent and thermal

  8. Isolating Effects of Water Table Dynamics, Terrain, and Soil Moisture Heterogeneity on the Atmospheric Boundary Layer Using Coupled Models

    E-Print Network [OSTI]

    Rihani, Jehan

    2010-01-01

    for simulating surface water–groundwater interactions”,Advances in Water Resources, doi: 10.1016/j.hydraulic properties”, Water Resources Research, 43, W07445,

  9. Large eddy simulation of atmospheric boundary layer flow in urban terrain : implications for transport of pollution and heat

    E-Print Network [OSTI]

    Sun, Long

    2011-01-01

    loads and the urban heat island-the effects of albedo,modeling of urban heat islands. Final report prepared byespecially the urban heat island (UHI) and urban air

  10. Large eddy simulation of atmospheric boundary layer flow in urban terrain : implications for transport of pollution and heat

    E-Print Network [OSTI]

    Sun, Long

    2011-01-01

    losses of a flat-plate collector, Solar Energy 35, 15–19.from outer cover of solar collectors, Renew. Energ. 10 (4)

  11. Large eddy simulation of atmospheric boundary layer flow in urban terrain : implications for transport of pollution and heat

    E-Print Network [OSTI]

    Sun, Long

    2011-01-01

    Hernandez, Matthew Lave and Neda Yaghoobian. Especiallyto me in my dissertation review, Neda Yaghoobian and Anthony

  12. Large eddy simulation of atmospheric boundary layer flow in urban terrain : implications for transport of pollution and heat

    E-Print Network [OSTI]

    Sun, Long

    2011-01-01

    downwind of the hill shows small wind speeds (Fig. 4.4a).downwind of the hill shows small wind speeds (Fig.4.4a). For

  13. Quantifying chaos in the atmosphere Richard Washington

    E-Print Network [OSTI]

    Washington, Richard

    , Mansfield Road, Oxford OX1 3TB, UK Abstract: The atmosphere is known to be forced by a variety of energy sources, including radiation and heat fluxes emanating from the boundary layer associated with sea as the competing champions controlling process in the physical world. With or without Einstein, there can

  14. A Comparison of Atmospheric Reanalysis Surface Products over the Ocean and Implications for Uncertainties in Air–Sea Boundary Forcing

    E-Print Network [OSTI]

    Chaudhuri, Ayan H.

    This paper investigates the uncertainties related to atmospheric fields from reanalysis products used in forcing ocean models. Four reanalysis products, namely from 1) the interim ECMWF Re-Analysis (ERA-Interim), 2) version ...

  15. Improved heterojunction quality in Cu2O-based solar cells through the optimization of atmospheric pressure spatial atomic layer deposited Zn1-xMgxO

    E-Print Network [OSTI]

    Ievskaya, Yulia; Hoye, Robert L. Z.; Sadhanala, Aditya; Musselman, Kevin P.; MacManus-Driscoll, Judith L.

    2015-01-01

    Atmospheric pressure spatial atomic layer deposition (AP-SALD) was used to deposit n-type ZnO and Zn1-xMgxO thin films onto p-type thermally oxidized Cu2O substrates outside vacuum at low temperature. The performance of photovoltaic devices...

  16. Soil moisture in complex terrain: quantifying effects on atmospheric boundary layer flow and providing improved surface boundary conditions for mesoscale models

    E-Print Network [OSTI]

    Daniels, Megan Hanako

    2010-01-01

    74 ii Soil Moisture Sensors: Decagon ECH2O Capacitance133 A.10 Soil types corresponding to each75 Soil Moisture and Temperature Probe

  17. On Techniques to Characterize and Correlate Grain Size, Grain Boundary Orientation and the Strength of the SiC Layer of TRISO Coated Particles: A Preliminary Study

    SciTech Connect (OSTI)

    I.J.van Rooyen; J.L. Dunzik Gougar; T. Trowbridge; Philip M van Rooyen

    2012-10-01

    The mechanical properties of the silicon carbide (SiC) layer of the TRi-ISOtropic (TRISO) coated particle (CP) for high temperature gas reactors (HTGR) are performance parameters that have not yet been standardized by the international HTR community. Presented in this paper are the results of characterizing coated particles to reveal the effect of annealing temperature (1000 to 2100°C) on the strength and grain size of unirradiated coated particles. This work was further expanded to include possible relationships between the grain size and strength values. The comparative results of two strength measurement techniques and grain size measured by the Lineal intercept method are included. Preliminary grain boundary characterization results determined by electron backscatter diffraction (EBSD) are included. These results are also important for future fission product transport studies, as grain boundary diffusion is identified as a possible mechanism by which 110mAg, one of the fission activation products, might be released through intact SiC layers. Temperature is a parameter known to influence the grain size of SiC and therefore it is important to investigate the effect of high temperature annealing on the SiC grain size. Recommendations and future work will also be briefly discussed.

  18. Boundary Layer Aerosol Chemistry during TexAQS/GoMACCS 2006: Insights into Aerosol Sources and Transformation Processes

    E-Print Network [OSTI]

    atmosphere and thus have a substantial impact on the radiative energy balance over the Gulf of Mexico3,4 , S.C. Tucker3,4 , W.A. Brewer3 , and A. Stohl5 1 Pacific Marine Environmental Laboratory, NOAA of Washington, Seattle, Washington, USA 3 Cooperative Institute for Research in the Environmental Sciences

  19. Reply to Comments on ``Seasonal Variation of the Physical Properties of Marine Boundary Layer Clouds off the California Coast''

    E-Print Network [OSTI]

    Clouds off the California Coast'' WUYIN LIN* AND MINGHUA ZHANG School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, New York NORMAN G. LOEB NASA Langley Research Center, Hampton the Moderate Resolution Imaging Spectroradi- ometer­Clouds and the Earth's Radiant Energy System (MODIS

  20. Boundary-Layer Meteorol (2009) 132:129149 DOI 10.1007/s10546-009-9380-8

    E-Print Network [OSTI]

    Porté-Agel, Fernando

    2009-01-01

    is related to the power loss from the wind turbine; and (b) the turbulence levels, which may affect flow velocity deficit is essential to optimizing the design (turbine siting) of wind farms. UBoundary-Layer Meteorol (2009) 132:129­149 DOI 10.1007/s10546-009-9380-8 ARTICLE A Wind

  1. The dissipation of trapped lee waves. Part II: The relative importance of the1 boundary layer and the stratosphere2

    E-Print Network [OSTI]

    Frierson, Dargan

    , including the roughness of the un-36 derlying surface, the efficiency with which wave energy can leak upward studied in isolation, their relative impor- tance has not been previously assessed. Here we conduct waves in the two-layer case do not leak much energy upwards is that the resonant wavelength is greatly

  2. The dissipation of trapped lee waves. Part II: The relative importance of the1 boundary layer and the stratosphere2

    E-Print Network [OSTI]

    Blossey, Peter

    , including the roughness of the un-35 derlying surface, the efficiency with which wave energy can leak upward each of these decay mechanisms has been studied in isolation, their relative impor- tance has not been that trapped waves in the two-layer case do not leak much energy upwards is that the resonant wavelength

  3. Interface boundary conditions for dynamic magnetization and spin wave dynamics in a ferromagnetic layer with the interface Dzyaloshinskii-Moriya interaction

    SciTech Connect (OSTI)

    Kostylev, M.

    2014-06-21

    In this work, we derive the interface exchange boundary conditions for the classical linear dynamics of magnetization in ferromagnetic layers with the interface Dzyaloshinskii-Moriya interaction (IDMI). We show that IDMI leads to pinning of dynamic magnetization at the interface. An unusual peculiarity of the IDMI-based pinning is that its scales as the spin-wave wave number. We incorporate these boundary conditions into an existing numerical model for the dynamics of the Damon-Eshbach spin wave in ferromagnetic films. IDMI affects the dispersion and the frequency non-reciprocity of the travelling Damon-Eshbach spin wave. For a broad range of film thicknesses L and wave numbers, the results of the numerical simulations of the spin wave dispersion are in a good agreement with a simple analytical expression, which shows that the contribution of IDMI to the dispersion scales as 1/L, similarly to the effect of other types of interfacial anisotropy. Suggestions to experimentalists how to detect the presence of IDMI in a spin wave experiment are given.

  4. Journal of Atmospheric Chemistry (2006) 53: 1342 DOI: 10.1007/s10874-006-0948-0 C Springer 2006

    E-Print Network [OSTI]

    Jacobson, Mark

    2006-01-01

    Journal of Atmospheric Chemistry (2006) 53: 13­42 DOI: 10.1007/s10874-006-0948-0 C Springer 2006. Introduction Convective clouds impact tropospheric chemistry through transport and transfor- mation of trace and Dana, 1979). They also transport and mix trace species between the atmospheric boundary layer

  5. Atmospheric and Wake Turbulence Impacts on Wind Turbine Fatigue Loading: Preprint

    SciTech Connect (OSTI)

    Lee, S.; Churchfield, M.; Moriarty, P.; Jonkman, J.; Michalakes, J.

    2011-12-01

    Large-eddy simulations of atmospheric boundary layers under various stability and surface roughness conditions are performed to investigate the turbulence impact on wind turbines. In particular, the aeroelastic responses of the turbines are studied to characterize the fatigue loading of the turbulence present in the boundary layer and in the wake of the turbines. Two utility-scale 5 MW turbines that are separated by seven rotor diameters are placed in a 3 km by 3 km by 1 km domain. They are subjected to atmospheric turbulent boundary layer flow and data is collected on the structural response of the turbine components. The surface roughness was found to increase the fatigue loads while the atmospheric instability had a small influence. Furthermore, the downstream turbines yielded higher fatigue loads indicating that the turbulent wakes generated from the upstream turbines have significant impact.

  6. Boundary layer methods in Biomecanics

    E-Print Network [OSTI]

    Lagrée, Pierre-Yves

    x u+v r u = - p x + 2 x2 u+ rr r u rX v t +u x v+v r v = - p r + 2 x2 v+ rr r v r X RNS/P #12;u = - p r + 2 x2 v+ rr r v r X XXXX RNS/P #12;RNS/P u x + rv rr = 0 X u t +u x u+v r u = - p x + rr r u r 0 = - p r #12;RNS/P u x + rv rr = 0 X u t +u x u+v r u = - p x + rr r u r 0 = - p r 1 R2 #12

  7. Effect of annealing atmosphere on the structure and luminescence of Sn-implanted SiO{sub 2} layers

    SciTech Connect (OSTI)

    Lopes, J.M.J.; Zawislak, F.C.; Fichtner, P.F.P.; Lovey, F.C.; Condo, A.M. [Instituto de Fisica - UFRGS, Cx. Postal 15051, 91501-970 Porto Alegre (Brazil); Departamento de Metalurgia, Escola de Engenharia - UFRGS, Porto Alegre (Brazil); Centro Atomico Bariloche, 8400 S.C. Bariloche (Argentina)

    2005-01-10

    Sn nanoclusters are synthesized in 180 nm SiO{sub 2} layers after ion implantation and heat treatment. Annealings in N{sub 2} ambient at high temperatures (T{>=}700 deg. C) lead to the formation of Sn nanoclusters of different sizes in metallic and in oxidized phases. High-resolution transmission electron microscopy (TEM) analyses revealed that the formed larger nanoparticles are composed by a Sn metallic core and a SnO{sub x} shell. The corresponding blue-violet photoluminescence (PL) presents low intensity. However, for heat treatments in vacuum, the PL intensity is increased by a factor of 5 and the TEM data show a homogeneous size distribution of Sn nanoclusters. The low intensity of PL for the N{sub 2} annealed samples is associated with Sn oxidation.

  8. Proceedings of the 51st Anniversary Conference of KSME PHYSICAL MODELING OF ATMOSPHERIC FLOW

    E-Print Network [OSTI]

    White, Bruce

    a model house in a small wind tunnel to measure wind pressure against the model. Since then, many attempts over tall buildings. The temperature differences within the atmospheric boundary layer affect both wind is discussed with special emphasis on wind-tunnel simulation techniques. The governing equations of motion

  9. Heat transport and weakening of atmospheric stability induced by mesoscale flows

    E-Print Network [OSTI]

    Pielke, Roger A.

    Heat transport and weakening of atmospheric stability induced by mesoscale flows G. A. Dalu boundary layer (CBL) is transported upward into the midtroposphere by mesoscale flows, and how the air, and diffusion, associated with the mesoscale flow, is more clearly shown when the forcing is periodic in time

  10. Atmospheric science and power production

    SciTech Connect (OSTI)

    Randerson, D.

    1984-07-01

    This is the third in a series of scientific publications sponsored by the US Atomic Energy Commission and the two later organizations, the US Energy Research and Development Adminstration, and the US Department of Energy. The first book, Meteorology and Atomic Energy, was published in 1955; the second, in 1968. The present volume is designed to update and to expand upon many of the important concepts presented previously. However, the present edition draws heavily on recent contributions made by atmospheric science to the analysis of air quality and on results originating from research conducted and completed in the 1970s. Special emphasis is placed on how atmospheric science can contribute to solving problems relating to the fate of combustion products released into the atmosphere. The framework of this book is built around the concept of air-quality modeling. Fundamentals are addressed first to equip the reader with basic background information and to focus on available meteorological instrumentation and to emphasize the importance of data management procedures. Atmospheric physics and field experiments are described in detail to provide an overview of atmospheric boundary layer processes, of how air flows around obstacles, and of the mechanism of plume rise. Atmospheric chemistry and removal processes are also detailed to provide fundamental knowledge on how gases and particulate matter can be transformed while in the atmosphere and how they can be removed from the atmosphere. The book closes with a review of how air-quality models are being applied to solve a wide variety of problems. Separate analytics have been prepared for each chapter.

  11. Journal of Atmospheric and Solar-Terrestrial Physics 69 (2007) 191211 The magnetosphereionosphere system from the perspective of

    E-Print Network [OSTI]

    Lotko, William

    2007-01-01

    Journal of Atmospheric and Solar-Terrestrial Physics 69 (2007) 191­211 The magnetosphere and plasmasheet boundary layer and in downward-current ``pressure cookers.'' Observational evidence indicating. The impacts of an O+ -enriched plasma on solar wind­magnetosphere­ionosphere coupling are considered at both

  12. Pacific Northwest Laboratory annual report for 1984 to the DOE Office of Energy Research. Part 3. Atmospheric sciences

    SciTech Connect (OSTI)

    Elderkin, C.E.

    1985-02-01

    The goals of atmospheric research at Pacific Northwest Laboratory (PNL) are to assess, describe, and predict the nature and fate of atmospheric contaminants and to study the impacts of contaminants on local, regional, and global climates. The contaminants being investigated are those resulting from the development and use of conventional resources (coal, gas, oil, and nuclear power) as well as alternative energy sources. The description of the research is organized into 3 sections: (1) Atmospheric Studies in Complex Terrain (ASCOT); (2) Boundary Layer Meteorology; and (3) Dispersion, Deposition, and Resuspension of Atmospheric Contaminants. Separate analytics have been done for each of the sections and are indexed and contained in the EDB. (MDF)

  13. ChEAS Data: The Chequamegon Ecosystem Atmosphere Study

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

    Davis, Kenneth J. [Penn State

    The Chequamegon Ecosystem-Atmosphere Study (ChEAS) is a multi-organizational research effort studying biosphere/atmosphere interactions within a northern mixed forest in Northern Wisconsin. A primary goal is to understand the processes controlling forest-atmosphere exchange of carbon dioxide and the response of these processes to climate change. Another primary goal is to bridge the gap between canopy-scale flux measurements and the global CO2 flask sampling network. The ChEAS flux towers participate in AmeriFlux, and the region is an EOS-validation site. The WLEF tower is a NOAA-CMDL CO2 sampling site. ChEAS sites are primarily located within or near the Chequamegon-Nicolet National Forest in northern Wisconsin, with one site in the Ottawa National Forest in the upper peninsula of Michigan. Current studies observe forest/atmosphere exchange of carbon dioxide at canopy and regional scales, forest floor respiration, photosynthesis and transpiration at the leaf level and use models to scale to canopy and regional levels. EOS-validation studies quantitatively assess the land cover of the area using remote sensing and conduct extensive ground truthing of new remote sensing data (i.e. ASTER and MODIS). Atmospheric remote sensing work is aimed at understanding atmospheric boundary layer dynamics, the role of entrainment in regulating the carbon dioxide mixing ratio profiles through the lower troposphere, and feedback between boundary layer dynamics and vegetation (especially via the hydrologic cycle). Airborne studies have included include balloon, kite and aircraft observations of the CO2 profile in the troposphere.

  14. Estimation of atmospheric deposition velocities and fluxes from weather and ambient pollutant concentration conditions. Part 1: Application of a multi-layer dry deposition model to measurements at a north central Florida site

    SciTech Connect (OSTI)

    Park, J.K. [Inje Univ., Kimhae (Korea, Republic of). Dept. of Environmental Sciences; Allen, E.R. [Univ. of Florida, Gainesville, FL (United States). Dept. of Environmental Engineering Sciences

    1997-12-31

    The harmful effects of dry acid deposition on terrestrial ecosystems could be as significant as those from wet acid deposition. Dry deposition involves removal of air pollutants to surfaces by sedimentation, impaction, interception and diffusion. Dry deposition velocities and fluxes of air pollutants, such as SO{sub 2}(g), O{sub 3}(g), HNO{sub 3}(g), submicron particulates, NO{sub 3}{sup {minus}}(s), and SO{sub 4}{sup 2{minus}}(s), have been estimated according to local meteorological elements in the boundary layer. The model that was used for these calculations is the multiple layer resistance model developed by Hicks. It consists of multiple layered resistances including an aerodynamic resistance, a boundary layer resistance, and a surface resistance. Meteorological data were recorded on an hourly basis from July, 1990 to June, 1991 at the Austin Cary forest site, near Gainesville FL. Weekly integrated samples of ambient dry deposition species were collected at the site using triple filter packs and chemically analyzed. For the study period at this site annual average dry deposition velocities were estimated to be : 0.87--0.07 [cm/s] for SO{sub 2}(g), 0.65--0.11 [cm/s] for O{sub 3}(g), 1.20--0.14 [cm/s] for HNO{sub 3}(g), 0.0045--0.0006 [cm/s] for submicron particulates, and 0.089--0.014 [cm/s] for NO{sub 3}{sup {minus}}(s) and SO{sub 4}{sup 2{minus}}(s). Trends observed in daily mean deposition velocities are largely seasonal, indicated by larger deposition velocities for the summer season and smaller deposition velocities for the winter season. Note that the summer season at this southern US site extends from April through October (7 months) and the winter season extends from December through February. Monthly and weekly averaged values for deposition velocities do not show large differences over the year but do show a tendency for increased deposition velocities in summer and decreased values in winter.

  15. RACORO continental boundary layer cloud investigations. Part...

    Office of Scientific and Technical Information (OSTI)

    + Show Author Affiliations Brookhaven National Lab. (BNL), Upton, NY (United States) NASA Goddard Inst. for Space Studies (GISS), New York, NY (United States) UCLA Joint...

  16. GEOGRAPHY 104: BOUNDARY LAYER CLIMATES Assignment #2

    E-Print Network [OSTI]

    at equinox at the two different locations given below for the local apparent times 6:00 a.m., 9:00a.m., 12

  17. Boundary Layer Analysis of Membraneless Electrochemical Cells

    E-Print Network [OSTI]

    Braff, William

    A mathematical theory is presented for the charging and discharging behavior of membraneless electrochemical cells that rely on slow diffusion in laminar flow to separate the half reactions. Ion transport is described by ...

  18. Boundary layer flows in large vessels

    E-Print Network [OSTI]

    Lagrée, Pierre-Yves

    x u+v r u = - p x + 2 x2 u+ rr r u rX v t +u x v+v r v = - p r + 2 x2 v+ rr r v r X RNS/P #12;u = - p r + 2 x2 v+ rr r v r X XXXX RNS/P #12;RNS/P u x + rv rr = 0 X u t +u x u+v r u = - p x + rr r u r 0 = - p r #12;RNS/P u x + rv rr = 0 X u t +u x u+v r u = - p x + rr r u r 0 = - p r 1 R2 #12

  19. ARM - Field Campaign - Boundary Layer Cloud IOP

    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 Anode Design to Improve4AJ01) (See22, 2012IIIAtlanticMarine

  20. ARM - Measurement - Planetary boundary layer height

    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 Roomparticlecontentnumber concentration

  1. Boundary Layer Lubrication Mechanisms | 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 Fuels Researchof Energy|Make6,Energy1 DOE Hydrogen and Fuel Cells

  2. Boundary Layer Lubrication Mechanisms | 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 Fuels Researchof Energy|Make6,Energy1 DOE Hydrogen and Fuel Cells0

  3. Boundary Layer Lubrication | 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 Fuels Researchof Energy|Make6,Energy1 DOE Hydrogen and Fuel

  4. Atmospheric Environment ] (

    E-Print Network [OSTI]

    Raman, Sethu

    that the influence of the urban region on wind patterns and atmospheric stability could be studied. HeightAtmospheric Environment ] (

  5. A New Photochemistry Code for Terrestrial Exoplanet Atmospheres

    E-Print Network [OSTI]

    Johnson, Robert E.

    A New Photochemistry Code for Terrestrial Exoplanet Atmospheres Renyu Hu, Sara Seager Massachusetts-transport equation for 111 molecules and aerosols · Eddy diffusion · Chemical kinetics · Photolysis · Boundary

  6. HYPERsensarium : an archive of atmospheric conditions

    E-Print Network [OSTI]

    Shaw, Kelly E. (Kelly Evelyn)

    2013-01-01

    HYPERsensarium proposes a tangible interface of atmospheres for public experience through an archive of historical and projected weathers. While architecture's purpose has long been to act as the technical boundary between ...

  7. Humidity variations in the atmospheric surface layer 

    E-Print Network [OSTI]

    Humphrey, Scott Richard

    1985-01-01

    downwind and crosswind components, based on a one hour average wind direction . In addi t1on, the relative humi- d1ty data were converted into specific hum1dity, q, in units of g(Kg). Next, the data were filtered so as to remove trends and long period...

  8. Finite element analysis of shells with layers

    E-Print Network [OSTI]

    Hiller, Jean-François, 1974-

    2002-01-01

    It is well established that thin shell structures frequently feature narrow bands of strain concentration and localized displacement irregularities referred to as boundary and internal layers. It is crucial to capture these ...

  9. APIVT-Grown Silicon Thin Layers and PV Devices: Preprint

    SciTech Connect (OSTI)

    Wang, T. H.; Ciszek, T. F.; Page, M. R.; Bauer, R. E.; Wang, Q.; Landry, M. D.

    2002-05-01

    Large-grained (5-20 ..mu..m) polycrystalline silicon layers have been grown at intermediate temperatures of 750-950C directly on foreign substrates without a seeding layer by iodine vapor transport at atmospheric pressure with rates as high as 3 mm/min. A model is constructed to explain the atypical temperature dependence of growth rate. We have also used this technique to grow high-quality epitaxial layers on heavily doped CZ-Si and on upgraded MG-Si substrates. Possible solar cell structures of thin-layer polycrystalline silicon on foreign substrates with light trapping have been examined, compared, and optimized by two-dimensional device simulations. The effects of grain boundary re-combination on device performance are presented for two grain sizes of 2 and 20 mm. We found that 104 cm/s recombination velocity is adequate for 20-m m grain-sized thin silicon, whereas a very low recombination velocity of 103 cm/s must be accomplished in order to achieve reasonable performance for a 2- mm grain-sized polycrystalline silicon device.

  10. Observations of Exoplanet Atmospheres

    E-Print Network [OSTI]

    Crossfield, Ian J M

    2015-01-01

    Detailed characterization of an extrasolar planet's atmosphere provides the best hope for distinguishing the makeup of its outer layers, and the only hope for understanding the interplay between initial composition, chemistry, dynamics & circulation, and disequilibrium processes. In recent years, some areas have seen rapid progress while developments in others have come more slowly and/or have been hotly contested. This article gives an observer's perspective on the current understanding of extrasolar planet atmospheres prior to the considerable advances expected from the next generation of observing facilities. Atmospheric processes of both transiting and directly-imaged planets are discussed, including molecular and atomic abundances, cloud properties, thermal structure, and planetary energy budgets. In the future we can expect a continuing and accelerating stream of new discoveries, which will fuel the ongoing exoplanet revolution for many years to come.

  11. Atmospheric Neutrinos

    E-Print Network [OSTI]

    Thomas K. Gaisser

    2006-12-11

    This paper is a brief overview of the theory and experimental data of atmospheric neutrino production at the fiftieth anniversary of the experimental discovery of neutrinos.

  12. Optimized capping layers for EUV multilayers

    DOE Patents [OSTI]

    Bajt, Sasa (Livermore, CA); Folta, James A. (Livermore, CA); Spiller, Eberhard A. (Livermore, CA)

    2004-08-24

    A new capping multilayer structure for EUV-reflective Mo/Si multilayers consists of two layers: A top layer that protects the multilayer structure from the environment and a bottom layer that acts as a diffusion barrier between the top layer and the structure beneath. One embodiment combines a first layer of Ru with a second layer of B.sub.4 C. Another embodiment combines a first layer of Ru with a second layer of Mo. These embodiments have the additional advantage that the reflectivity is also enhanced. Ru has the best oxidation resistance of all materials investigated so far. B.sub.4 C is an excellent barrier against silicide formation while the silicide layer formed at the Si boundary is well controlled.

  13. The middle Martian atmosphere

    SciTech Connect (OSTI)

    Jaquin, R.F.

    1989-01-01

    Profiles of scattered light above the planetary limb from 116 Viking Orbiter images are used to constrain the temporal and spatial behavior of aerosols suspended in the Martian atmosphere. The data cover a wide range of seasons, locations, and viewing geometry, providing information about the aerosol optical properties and vertical distribution. The typical atmospheric column contains one or more discrete, optically thin, ice-like haze layers between 30 and 90 km elevation whose composition is inferred to be water ice. Below the detached hazes, a continuous haze, interpreted to have a large dust component, extends from as much as 50 km to the surface. The haze distribution exhibits an annual variation that reflects a seasonally driven circulation in the middle atmosphere. The potential role of stationary gravity waves in modifying the middle atmosphere circulation is explored using a linear theory applied to a realistic Martian environment. Martian topography derived from radar observations is decomposed into Fourier harmonics and used to linearly superpose gravity waves arising from each component. The larger amplitude topography on Mars combined with the absence of extended regions of smooth topography like oceans generates larger wave amplitudes than on the Earth. The circulation of the middle atmosphere is examined using a two-dimensional, linearized, axisymmetric model successfully employed in the study of the terrestrial mesosphere. Illustrations of temperature and wind speeds are presented for the southern summer solstice and southern spring equinox.

  14. Vortex rings impinging on permeable boundaries

    E-Print Network [OSTI]

    Mujal-Colilles, Anna; Dalziel, Stuart B.; Bateman, Allen

    2015-01-17

    of the boundary layer inside 548 the porous media or the flux exchange between the downstream and upstream sides of the 549 grid. 550 Recalling that one of the main differences between our experiments and the thin grid 551 research already published...

  15. Development of an Immersed Boundary Method to Resolve Complex Terrain in the Weather Research and Forecasting Model

    SciTech Connect (OSTI)

    Lunquist, K A; Chow, F K; Lundquist, J K; Mirocha, J D

    2007-09-04

    Flow and dispersion processes in urban areas are profoundly influenced by the presence of buildings which divert mean flow, affect surface heating and cooling, and alter the structure of turbulence in the lower atmosphere. Accurate prediction of velocity, temperature, and turbulent kinetic energy fields are necessary for determining the transport and dispersion of scalars. Correct predictions of scalar concentrations are vital in densely populated urban areas where they are used to aid in emergency response planning for accidental or intentional releases of hazardous substances. Traditionally, urban flow simulations have been performed by computational fluid dynamics (CFD) codes which can accommodate the geometric complexity inherent to urban landscapes. In these types of models the grid is aligned with the solid boundaries, and the boundary conditions are applied to the computational nodes coincident with the surface. If the CFD code uses a structured curvilinear mesh, then time-consuming manual manipulation is needed to ensure that the mesh conforms to the solid boundaries while minimizing skewness. If the CFD code uses an unstructured grid, then the solver cannot be optimized for the underlying data structure which takes an irregular form. Unstructured solvers are therefore often slower and more memory intensive than their structured counterparts. Additionally, urban-scale CFD models are often forced at lateral boundaries with idealized flow, neglecting dynamic forcing due to synoptic scale weather patterns. These CFD codes solve the incompressible Navier-Stokes equations and include limited options for representing atmospheric processes such as surface fluxes and moisture. Traditional CFD codes therefore posses several drawbacks, due to the expense of either creating the grid or solving the resulting algebraic system of equations, and due to the idealized boundary conditions and the lack of full atmospheric physics. Meso-scale atmospheric boundary layer simulations, on the other hand, are performed by numerical weather prediction (NWP) codes, which cannot handle the geometry of the urban landscape, but do provide a more complete representation of atmospheric physics. NWP codes typically use structured grids with terrain-following vertical coordinates, include a full suite of atmospheric physics parameterizations, and allow for dynamic synoptic scale lateral forcing through grid nesting. Terrain following grids are unsuitable for urban terrain, as steep terrain gradients cause extreme distortion of the computational cells. In this work, we introduce and develop an immersed boundary method (IBM) to allow the favorable properties of a numerical weather prediction code to be combined with the ability to handle complex terrain. IBM uses a non-conforming structured grid, and allows solid boundaries to pass through the computational cells. As the terrain passes through the mesh in an arbitrary manner, the main goal of the IBM is to apply the boundary condition on the interior of the domain as accurately as possible. With the implementation of the IBM, numerical weather prediction codes can be used to explicitly resolve urban terrain. Heterogeneous urban domains using the IBM can be nested into larger mesoscale domains using a terrain-following coordinate. The larger mesoscale domain provides lateral boundary conditions to the urban domain with the correct forcing, allowing seamless integration between mesoscale and urban scale models. Further discussion of the scope of this project is given by Lundquist et al. [2007]. The current paper describes the implementation of an IBM into the Weather Research and Forecasting (WRF) model, which is an open source numerical weather prediction code. The WRF model solves the non-hydrostatic compressible Navier-Stokes equations, and employs an isobaric terrain-following vertical coordinate. Many types of IB methods have been developed by researchers; a comprehensive review can be found in Mittal and Iaccarino [2005]. To the authors knowledge, this is the first IBM approach that is able to

  16. GCM simulations of Titan's middle and lower atmosphere and comparison to observations

    E-Print Network [OSTI]

    Lora, Juan M; Russell, Joellen L

    2014-01-01

    Simulation results are presented from a new general circulation model (GCM) of Titan, the Titan Atmospheric Model (TAM), which couples the Flexible Modeling System (FMS) spectral dynamical core to a suite of external/sub-grid-scale physics. These include a new non-gray radiative transfer module that takes advantage of recent data from Cassini-Huygens, large-scale condensation and quasi-equilibrium moist convection schemes, a surface model with "bucket" hydrology, and boundary layer turbulent diffusion. The model produces a realistic temperature structure from the surface to the lower mesosphere, including a stratopause, as well as satisfactory superrotation. The latter is shown to depend on the dynamical core's ability to build up angular momentum from surface torques. Simulated latitudinal temperature contrasts are adequate, compared to observations, and polar temperature anomalies agree with observations. In the lower atmosphere, the insolation distribution is shown to strongly impact turbulent fluxes, and ...

  17. Testing outer boundary treatments for the Einstein equations

    E-Print Network [OSTI]

    Oliver Rinne; Lee Lindblom; Mark A. Scheel

    2007-07-25

    Various methods of treating outer boundaries in numerical relativity are compared using a simple test problem: a Schwarzschild black hole with an outgoing gravitational wave perturbation. Numerical solutions computed using different boundary treatments are compared to a `reference' numerical solution obtained by placing the outer boundary at a very large radius. For each boundary treatment, the full solutions including constraint violations and extracted gravitational waves are compared to those of the reference solution, thereby assessing the reflections caused by the artificial boundary. These tests use a first-order generalized harmonic formulation of the Einstein equations. Constraint-preserving boundary conditions for this system are reviewed, and an improved boundary condition on the gauge degrees of freedom is presented. Alternate boundary conditions evaluated here include freezing the incoming characteristic fields, Sommerfeld boundary conditions, and the constraint-preserving boundary conditions of Kreiss and Winicour. Rather different approaches to boundary treatments, such as sponge layers and spatial compactification, are also tested. Overall the best treatment found here combines boundary conditions that preserve the constraints, freeze the Newman-Penrose scalar Psi_0, and control gauge reflections.

  18. An Embedded Boundary Integral Solver for the Unsteady Incompressible Navier-Stokes Equations1

    E-Print Network [OSTI]

    Zorin, Denis

    An Embedded Boundary Integral Solver for the Unsteady Incompressible Navier-Stokes Equations1-Stokes operator discretization is done using boundary integrals and structured-grid finite elements. We use a two is formulated as a double-layer boundary integral equation. Domain integrals are computed via finite elements

  19. Matched interface and boundary (MIB) method for elliptic problems with sharp-edged interfaces

    E-Print Network [OSTI]

    Zhou, Yongcheng

    Matched interface and boundary (MIB) method for elliptic problems with sharp-edged interfaces with sharp-edged interfaces, thin-layered interfaces and interfaces that intersect with geometric boundary. This work generalizes the matched interface and boundary (MIB) method previously designed for solving

  20. Spectral behavior of the coupled land-atmosphere system

    E-Print Network [OSTI]

    Gentine, Pierre

    2010-01-01

    The main objective of this thesis is to understand the daily cycle of the energy coupling between the land and the atmosphere in response to a forcing of incoming radiation at their common boundary, the land surface. This ...

  1. Pacific Northwest Laboratory annual report for 1993 to the DOE Office of Energy Research. Part 3: Atmospheric and climate research

    SciTech Connect (OSTI)

    Not Available

    1994-05-01

    The US Department of Energy`s (DOE`s) Office of Health and Environmental Research (OHER) atmospheric sciences and carbon dioxide research programs provide the DOE with scientifically defensible information on the local, regional, and global distributions of energy-related pollutants and their effects on climate. PNL has had a long history of technical leadership in the atmospheric sciences research programs within OHER. Within the Environmental Sciences Division of OHER, the Atmospheric Chemistry Program continues DOE`s long-term commitment to understanding the local, regional, and global effects of energy-related air pollutants. Research through direct measurement, numerical modeling, and analytical studies in the Atmospheric Chemistry Program emphasizes the long-range transport, chemical transformation, and removal of emitted pollutants, photochemically produced oxidant species, nitrogen-reservoir species, and aerosols. The atmospheric studies in Complex Terrain Program applies basic research on atmospheric boundary layer structure and evolution over inhomogeneous terrain to DOE`s site-specific and generic mission needs in site safety, air quality, and climate change. Research at PNL provides basic scientific underpinnings to DOE`s program of global climate research. Research projects within the core carbon dioxide and ocean research programs are now integrated with those in the Atmospheric Radiation Measurements, the Computer Hardware, Advanced Mathematics and Model Physics, and Quantitative Links program to form DOE`s contribution to the US Global Change Research Program. The description of ongoing atmospheric and climate research at PNL is organized in two broad research areas: atmospheric research; and climate research. This report describes the progress in fiscal year 1993 in each of these areas. Individual papers have been processed separately for inclusion in the appropriate data bases.

  2. Layer inflow into precipitating convection over the western tropical Pacific

    E-Print Network [OSTI]

    Mechem, David B.; Houze, Robert A. Jr.; Chen, Shuyi S.

    2002-07-01

    A conceptual model of tropical convection frequently used in convective parametrization schemes is that of a parcel process in which boundary-layer air, characterized by high equivalent potential temperature, ascends to ...

  3. Boundaries and Topological Algorithms

    E-Print Network [OSTI]

    Fleck, Margaret Morrison

    1988-09-01

    This thesis develops a model for the topological structure of situations. In this model, the topological structure of space is altered by the presence or absence of boundaries, such as those at the edges of objects. ...

  4. The effect of tangential blowing on boundary-layer profiles 

    E-Print Network [OSTI]

    Olson, Milford Eugene

    1967-01-01

    . 2065 Blowing Rate Sys&ho 1 " hw (in. H20) Pf (p ~ s i) (Slot width-0. 033 inches) Cl C C 3. 1 7. 5 9. 7 14. 980 15. 5l 0 15. 820 534 534 534 . 2935 . 4670 . 5370 (Slot wi. dth-0. 0415 inches) Dl D2 D 5. 0 11. 5 15. 9 15. 040...; Blowing Rate Symbols B) B2 B 3 Cl C 2 C 3 D V (fps) J 163 246 2 75 163 246 275 163 Bjowing Rale (ft /sec) . 3 0. 0418 0. 0630 0. 0705 0. 1061 0. 1600 0. 1790 0. 1333 D D 3 246 275 0. 2013 0. 2250 A theory which expressed a...

  5. Boundary layer ingesting inlet design for a silent aircraft

    E-Print Network [OSTI]

    Freuler, Patrick N., 1980-

    2005-01-01

    (cont.) common nacelle, L/D ratios between 2.5 and 3.0, fan face to throat area ratios above 1.06, and offsets lower than 11%. Curvature ahead of the inlet should be avoided as well as bifurcations inside the duct. Inlet ...

  6. Chambry, France, 4 8 June 2007 On boundary layer processes

    E-Print Network [OSTI]

    Gohm, Alexander

    distribution of air pollutants in an Alpine valley Alexander Gohm* F. Harnisch, R. Schnitzhofer, A. Hansel, A University of Innsbruck #12;2Spatial distribution of air pollutants in an Alpine valley Motivation: High air: Preliminary analysis of two different air pollution cases #12;3Spatial distribution of air pollutants

  7. RACORO continental boundary layer cloud investigations. 2. Large...

    Office of Scientific and Technical Information (OSTI)

    + Show Author Affiliations Brookhaven National Lab. (BNL), Upton, NY (United States) NASA Goddard Inst. for Space Studies (GISS), New York, NY (United States) Univ. of Illinois,...

  8. Numerical simulations of the stratified oceanic bottom boundary layer

    E-Print Network [OSTI]

    Taylor, John R.

    2008-01-01

    · x ? ?t)], the kinetic and potential energy dissipation canuid that releases potential energy to kinetic energy. Komoriturbulent kinetic energy to the potential energy de?cit

  9. Thermal boundary layer development in dispersed flow film boiling

    E-Print Network [OSTI]

    Hull, Lawrence M.

    1982-01-01

    Dispersed flow film boiling consists of a dispersion of droplets which are carried over a very hot surface by their vapor. This process occurs in cryogenic equipment and wet steam turbines. It is also of interest in the ...

  10. Experimental and theoretical study of turbulent oscillatory boundary layers

    E-Print Network [OSTI]

    Yuan, Jing, Ph. D. Massachusetts Institute of Technology

    2013-01-01

    Sediment transport is of crucial importance to engineering projects in coastal regions, so it is of primary interest in coastal engineering. The driving forces for sediment transport are mostly determined by the hydrodynamics ...

  11. IMPACT OF BOUNDARY-LAYER CUTTING ON FREE-SURFACE

    E-Print Network [OSTI]

    ;5 Flow Loop A Pump H 400 gal tank B Bypass line I Butterfly valve C Flow meter J 700 gal tank D Pressure) "Standard design" · Contracting nozzle Contraction ratio = 3x y z HC PP FS 3.9 cm 3.0 cm 14.7 cm #12 of inclination, = 6.5° · Samples acquired over 0.5 ­ 1 hr · Collected mass used to calculate: Mass flux, G [kg

  12. A Note on the Intermediate Region in Turbulent Boundary Layers

    E-Print Network [OSTI]

    G. I. Barenblatt; A. J. Chorin; V. M. Prostokishin

    2000-02-16

    We demonstrate that the processing of the experimental data for the average velocity profiles obtained by J. M. \\"Osterlund (www.mesh.kth.se/$\\sim$jens/zpg/) presented in [1] was incorrect. Properly processed these data lead to the opposite conclusion: they confirm the Reynolds-number-dependent scaling law and disprove the conclusion that the flow in the intermediate (`overlap') region is Reynolds-number-independent.

  13. RACORO continental boundary layer cloud investigations. 3. Separation...

    Office of Scientific and Technical Information (OSTI)

    shallow cumulus Climatically important low-level clouds are commonly misrepresented in climate models. The FAst-physics System TEstbed and Research (FASTER) project has constructed...

  14. Numerical simulations of the stratified oceanic bottom boundary layer

    E-Print Network [OSTI]

    Taylor, John R.

    2008-01-01

    found that only 6% of the wave energy was re?ected back fromfound that the internal wave energy spec- trum in the outerenergy to the internal wave energy ?ux, and it was found

  15. DIFFUSION OF A CHEMICAL SPECIES THROUGH A VISCOUS BOUNDARY LAYER

    E-Print Network [OSTI]

    Keller, J.

    2011-01-01

    use an operating coal gasifier will be discussed. ofof the products of the gasifier with H S removed, then theconditions existing in coal gasifiers the con- centration

  16. BOUNDARY LAYER CONTROL IN PIPES THROUGH STRONG INJECTION

    E-Print Network [OSTI]

    Yeung, William Chor Chun

    2014-01-01

    the environment in a gasifier contains hydrogen, water,compo- nents of the gasifier must be corrosion resistant atis used in existing coal gasifiers. Since hydrogen sulfide

  17. Linear Stability Analysis of a Boundary Layer with Plasma Actuators

    E-Print Network [OSTI]

    Roy, Subrata

    in the ith direction p Pressure ¯ui Mean flow velocity in the ith direction ¯p Mean pressure ~ui Disturbance flow velocity in the ith direction ~p Disturbance pressure ui Complex 1D disturbance flow velocity Complex spatial frequency in x1 Complex spatial frequency in x3 Complex temporal frequency cp Complex

  18. Small-Scale Forcing of a Turbulent Boundary Layer

    E-Print Network [OSTI]

    Lorkowski, Thomas

    In order to understand the effect of small scale forcing on turbulent flows and its implications on control, an experimental investigation is made into the forcing of the inertial scales in the wall region of a turbulent ...

  19. Multidimensional Longwave Forcing of Boundary Layer Cloud Systems

    E-Print Network [OSTI]

    Mechem, David B.; Kogan, Yefim L.; Ovtchinnikov, Mikhail; Davis, Anthony B.; Evans, K. Franklin; Ellingson, Robert G.

    2008-12-01

    The importance of multidimensional (MD) longwave radiative effects on cloud dynamics is evaluated in an eddy-resolving model (ERM)—the two-dimensional analog to large-eddy simulation (LES)—framework employing multidimensional radiative transfer...

  20. Numerical simulations of the stratified oceanic bottom boundary layer

    E-Print Network [OSTI]

    Taylor, John R.

    2008-01-01

    approximation that the mean wave energy and the backgroundfound that only 6% of the wave energy was re?ected back fromfound that the internal wave energy spec- trum in the outer

  1. Supersonic turbulent boundary layers with periodic mechanical non-equilibrium 

    E-Print Network [OSTI]

    Ekoto, Isaac Wesley

    2007-04-25

    is essential. Turbulence reduction has applications for reentry vehicles. On their undersurface they have a heat shield that is composed of uniformly shaped materials (e.g. tiles, ablative materiel, etc.). Shape selection that can reduce turbulent heat... of the literature reveals roughness elements with sharp leading edges have not been explored. Much could be revealed by an investigation into a these type of roughness elements. The thought is that the blunt shaped roughness elements used in the past (e.g. square...

  2. A dual mass flux framework for boundary layer convection

    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 Anode Design to Improve Lithium-Ion Batteries PrintA New SolarAComplexA dual mass flux

  3. ARM - PI Product - Planetary Boundary Layer from AERI and MPL

    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 OutreachCalendar NSAProductsMerged and corrected 915Dust

  4. RACORO continental boundary layer cloud investigations. 2. Large-eddy

    Office of Scientific and Technical Information (OSTI)

    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 NaturalDukeWakefieldSulfateSciTech ConnectSpeedingConnect Pulse energy(Conference) | SciTechQuirkssimulations of

  5. RACORO continental boundary layer cloud investigations. 3. Separation of

    Office of Scientific and Technical Information (OSTI)

    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 NaturalDukeWakefieldSulfateSciTech ConnectSpeedingConnect Pulse energy(Conference) | SciTechQuirkssimulations

  6. RACORO continental boundary layer cloud investigations. Part I: Case study

    Office of Scientific and Technical Information (OSTI)

    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 NaturalDukeWakefieldSulfateSciTech ConnectSpeedingConnect Pulse energy(Conference) |

  7. Vertical Velocities in Continental Boundary Layer Stratocumulus Clouds

    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 AdministrationRobust,Field-effectWorking WithTelecentricN A County roadFeet) Deliveries DennisVertical

  8. Mesoscale coupled ocean-atmosphere feedbacks in boundary current systems

    E-Print Network [OSTI]

    Putrasahan, Dian Ariyani

    2012-01-01

    N/m 2 per 10000km) against crosswind SST gradients ( ? C peroverlaid with contours crosswind SST gradients ( ? C perpositive (negative) crosswind SST gradients at 0.4 ? C per

  9. Mesoscale coupled ocean-atmosphere feedbacks in boundary current systems

    E-Print Network [OSTI]

    Putrasahan, Dian Ariyani

    2012-01-01

    a shifted maximum wind stress offshore when compare to Fig.strengthening winds while extending offshore. A seasonalthe shift of wind stress peak offshore (Fig. 3.30) changes

  10. Mesoscale coupled ocean-atmosphere feedbacks in boundary current systems

    E-Print Network [OSTI]

    Putrasahan, Dian Ariyani

    2012-01-01

    to about 600km offshore, beyond which wind stress curla shifted maximum wind stress offshore when compare to Fig.strengthening winds while extending offshore. A seasonal

  11. Field measurement of the fate of atmospheric H? in a forest environment : from canopy to soil

    E-Print Network [OSTI]

    Meredith, Laura Kelsey, 1982-

    2013-01-01

    Atmospheric hydrogen (H? ), an indirect greenhouse gas, plays a notable role in the chemistry of the atmosphere and ozone layer. Current anthropogenic emissions of H? are substantial and may increase with its widespread ...

  12. Transport Layer Cornell University

    E-Print Network [OSTI]

    Low, Steven H.

    Transport Layer Ao Tang Cornell University Ithaca, NY 14853 Lachlan L. H. Andrew California. Low California Institute of Technology Pasadena, CA 91125 I. INTRODUCTION The Internet has evolved of the physical layer, the link layer, the network layer, the transport layer and the application layer1 . See

  13. Atmospheric Stability Impacts on Power Curves of Tall Wind Turbines - An Analysis of a West Coast North American Wind Farm

    SciTech Connect (OSTI)

    Wharton, S; Lundquist, J K

    2010-02-22

    Tall wind turbines, with hub heights at 80 m or above, can extract large amounts of energy from the atmosphere because they are likely to encounter higher wind speeds, but they face challenges given the complex nature of wind flow and turbulence at these heights in the boundary layer. Depending on whether the boundary layer is stable, neutral, or convective, the mean wind speed, direction, and turbulence properties may vary greatly across the tall turbine swept area (40 to 120 m AGL). This variability can cause tall turbines to produce difference amounts of power during time periods with identical hub height wind speeds. Using meteorological and power generation data from a West Coast North American wind farm over a one-year period, our study synthesizes standard wind park observations, such as wind speed from turbine nacelles and sparse meteorological tower observations, with high-resolution profiles of wind speed and turbulence from a remote sensing platform, to quantify the impact of atmospheric stability on power output. We first compare approaches to defining atmospheric stability. The standard, limited, wind farm operations enable the calculation only of a wind shear exponent ({alpha}) or turbulence intensity (I{sub U}) from cup anemometers, while the presence at this wind farm of a SODAR enables the direct observation of turbulent kinetic energy (TKE) throughout the turbine rotor disk. Additionally, a nearby research meteorological station provided observations of the Obukhov length, L, a direct measure of atmospheric stability. In general, the stability parameters {alpha}, I{sub U}, and TKE are in high agreement with the more physically-robust L, with TKE exhibiting the best agreement with L. Using these metrics, data periods are segregated by stability class to investigate power performance dependencies. Power output at this wind farm is highly correlated with atmospheric stability during the spring and summer months, while atmospheric stability exerts little impact on power output during the winter and autumn periods. During the spring and summer seasons, power output for a given wind speed was significantly higher during stable conditions and significantly lower during strongly convective conditions: power output differences approached 20% between stable and convective regimes. The dependency of stability on power output was apparent only when both turbulence and the shape of the wind speed profile were considered. Turbulence is one of the mechanisms by which atmospheric stability affects a turbine's power curve at this particular site, and measurements of turbulence can yield actionable insights into wind turbine behavior.

  14. Water Vapor Turbulence Profiles in Stationary Continental Convective Mixed Layers

    SciTech Connect (OSTI)

    Turner, D. D.; Wulfmeyer, Volker; Berg, Larry K.; Schween, Jan

    2014-10-08

    The U.S. Department of Energy Atmospheric Radiation Measurement (ARM) program’s Raman lidar at the ARM Southern Great Plains (SGP) site in north-central Oklahoma has collected water vapor mixing ratio (q) profile data more than 90% of the time since October 2004. Three hundred (300) cases were identified where the convective boundary layer was quasi-stationary and well-mixed for a 2-hour period, and q mean, variance, third order moment, and skewness profiles were derived from the 10-s, 75-m resolution data. These cases span the entire calendar year, and demonstrate that the q variance profiles at the mixed layer (ML) top changes seasonally, but is more related to the gradient of q across the interfacial layer. The q variance at the top of the ML shows only weak correlations (r < 0.3) with sensible heat flux, Deardorff convective velocity scale, and turbulence kinetic energy measured at the surface. The median q skewness profile is most negative at 0.85 zi, zero at approximately zi, and positive above zi, where zi is the depth of the convective ML. The spread in the q skewness profiles is smallest between 0.95 zi and zi. The q skewness at altitudes between 0.6 zi and 1.2 zi is correlated with the magnitude of the q variance at zi, with increasingly negative values of skewness observed lower down in the ML as the variance at zi increases, suggesting that in cases with larger variance at zi there is deeper penetration of the warm, dry free tropospheric air into the ML.

  15. Review Article Layer-specific anatomical, physiological and functional MRI

    E-Print Network [OSTI]

    Duong, Timothy Q.

    ­3). Starting from the vitreous boundary, they include the ganglion cell layer (GCL), inner plexiform layer (IPL: the retinal and choroidal circulations (1,4,5). Retinal vessels exist in the GCL, INL, IPL and OPL. Choroidal the choroid, has been reported to be $217 mm (2,3) and the choroidal thickness, which is less well documented

  16. Boundary Plasma Turbulence Simulations for Tokamaks

    SciTech Connect (OSTI)

    Xu, X; Umansky, M; Dudson, B; Snyder, P

    2008-05-15

    The boundary plasma turbulence code BOUT models tokamak boundary-plasma turbulence in a realistic divertor geometry using modified Braginskii equations for plasma vorticity, density (ni), electron and ion temperature (T{sub e}; T{sub i}) and parallel momenta. The BOUT code solves for the plasma fluid equations in a three dimensional (3D) toroidal segment (or a toroidal wedge), including the region somewhat inside the separatrix and extending into the scrape-off layer; the private flux region is also included. In this paper, a description is given of the sophisticated physical models, innovative numerical algorithms, and modern software design used to simulate edge-plasmas in magnetic fusion energy devices. The BOUT code's unique capabilities and functionality are exemplified via simulations of the impact of plasma density on tokamak edge turbulence and blob dynamics.

  17. Energy transport, overshoot, and mixing in the atmospheres of very cool stars

    E-Print Network [OSTI]

    H. -G. Ludwig

    2002-08-30

    We constructed hydrodynamical model atmospheres for mid M-type main-, as well as pre-main-sequence objects. Despite the complex chemistry encountered in such cool atmospheres a reasonably accurate representation of the radiative transfer is possible. The detailed treatment of the interplay between radiation and convection in the hydrodynamical models allows to study processes usually not accessible within the framework conventional model atmospheres. In particular, we determined the efficiency of the convective energy transport, and the efficiency of mixing by convective overshoot. The convective transport efficiency expressed in terms of an equivalent mixing-length parameter amounts to values around ~2 in the optically thick, and ~2.8 in the optically thin regime. The thermal structure of the formally convectively stable layers is little affected by convective overshoot and wave heating, i.e. stays close to radiative equilibrium. Mixing by convective overshoot shows an exponential decline with geometrical distance from the Schwarzschild stability boundary. The scale height of the decline varies with gravitational acceleration roughly as g^(-1/2), with 0.5 pressure scale heights at log(g)=5.0.

  18. Preprint of the paper "A General Formulation based on the Boundary Element Method for the Analysis

    E-Print Network [OSTI]

    Colominas, Ignasi

    cost) to the analysis of large grounding systems in electrical substations. In this paper we present a new Boundary Element formulation for substation grounding systems embedded in layered soils of the substation site. Obviously, from a technical (and

  19. DOE Workshop; Pan-Gass Conference on the Representation of Atmospheric Processes in Weather and Climate Models

    SciTech Connect (OSTI)

    Morrison, PI Hugh

    2012-09-21

    This is the first meeting of the whole new GEWEX (Global Energy and Water Cycle Experiment) Atmospheric System Study (GASS) project that has been formed from the merger of the GEWEX Cloud System Study (GCSS) Project and the GEWEX Atmospheric Boundary Layer Studies (GABLS). As such, this meeting will play a major role in energizing GEWEX work in the area of atmospheric parameterizations of clouds, convection, stable boundary layers, and aerosol-cloud interactions for the numerical models used for weather and climate projections at both global and regional scales. The representation of these processes in models is crucial to GEWEX goals of improved prediction of the energy and water cycles at both weather and climate timescales. This proposal seeks funds to be used to cover incidental and travel expenses for U.S.-based graduate students and early career scientists (i.e., within 5 years of receiving their highest degree). We anticipate using DOE funding to support 5-10 people. We will advertise the availability of these funds by providing a box to check for interested participants on the online workshop registration form. We will also send a note to our participants' mailing lists reminding them that the funds are available and asking senior scientists to encourage their more junior colleagues to participate. All meeting participants are encouraged to submit abstracts for oral or poster presentations. The science organizing committee (see below) will base funding decisions on the relevance and quality of these abstracts, with preference given to under-represented populations (especially women and minorities) and to early career scientists being actively mentored at the meeting (e.g. students or postdocs attending the meeting with their advisor).

  20. Building biomedical materials layer-by-layer

    E-Print Network [OSTI]

    Hammond, Paula T.

    In this materials perspective, the promise of water based layer-by-layer (LbL) assembly as a means of generating drug-releasing surfaces for biomedical applications, from small molecule therapeutics to biologic drugs and ...

  1. JournalofGeophysicalResearch: Atmospheres RESEARCH ARTICLE

    E-Print Network [OSTI]

    Raible, Christoph C.

    MAR 2015 The influence of absorbed solar radiation by Saharan dust on hurricane genesis Sebastian, Bern, Switzerland Abstract To date, the radiative impact of dust and the Saharan air layer (SAL the atmosphere due to absorption of solar radiation but thus shifts convection to regions more conducive

  2. Gas-surface interaction and boundary conditions for the Boltzmann equation

    E-Print Network [OSTI]

    Mieussens, Luc

    Gas-surface interaction and boundary conditions for the Boltzmann equation St´ephane Brull, Pierre Equation. The interaction between the wall atoms and the gas molecules within a thin surface layer of the gas in the bulk flow. Boundary conditions are formally derived from this model by using classical

  3. Combined influence of atmospheric physics and soil hydrology on the simulated meteorology at the SIRTA atmospheric

    E-Print Network [OSTI]

    Hourdin, Chez Frédéric

    for This paper is a contribution to the special issue on the IPSL and CNRM global climate and Earth System Models it to evaluate the standard and new parametrizations of boundary layer/convection/clouds in the Earth System Model (ESM) of Institut Pierre Simon Laplace (IPSL), which differentiate the IPSL-CM5A and IPSL- CM5B

  4. 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

  5. A Simple Multi-Directional Absorbing Layer Method to Simulate Elastic Wave Propagation in Unbounded Domains

    E-Print Network [OSTI]

    Semblat, Jean-François; Gandomzadeh, Ali

    2010-01-01

    The numerical analysis of elastic wave propagation in unbounded media may be difficult due to spurious waves reflected at the model artificial boundaries. This point is critical for the analysis of wave propagation in heterogeneous or layered solids. Various techniques such as Absorbing Boundary Conditions, infinite elements or Absorbing Boundary Layers (e.g. Perfectly Matched Layers) lead to an important reduction of such spurious reflections. In this paper, a simple absorbing layer method is proposed: it is based on a Rayleigh/Caughey damping formulation which is often already available in existing Finite Element softwares. The principle of the Caughey Absorbing Layer Method is first presented (including a rheological interpretation). The efficiency of the method is then shown through 1D Finite Element simulations considering homogeneous and heterogeneous damping in the absorbing layer. 2D models are considered afterwards to assess the efficiency of the absorbing layer method for various wave types and inci...

  6. Improved detection of atmospheric turbulence with SLODAR

    E-Print Network [OSTI]

    Michael Goodwin; Charles Jenkins; Andrew Lambert

    2007-06-19

    We discuss several improvements in the detection of atmospheric turbulence using SLOpe Detection And Ranging (SLODAR). Frequently, SLODAR observations have shown strong ground-layer turbulence, which is beneficial to adaptive optics. We show that current methods which neglect atmospheric propagation effects can underestimate the strength of high altitude turbulence by up to ~ 30%. We show that mirror and dome seeing turbulence can be a significant fraction of measured ground-layer turbulence, some cases up to ~ 50%. We also demonstrate a novel technique to improve the nominal height resolution, by a factor of 3, called Generalized SLODAR. This can be applied when sampling high-altitude turbulence, where the nominal height resolution is the poorest, or for resolving details in the important ground-layer.

  7. Brunnian Braids Boundary Brunnian Braids Main Results Boundary Brunnian braids, mirror reflection

    E-Print Network [OSTI]

    Wu, Jie

    Brunnian Braids Boundary Brunnian Braids Main Results Boundary Brunnian braids, mirror reflection December 17, 2007 #12;Brunnian Braids Boundary Brunnian Braids Main Results Boundary Brunnian braids, mirror reflection and the homotopy groups Brunnian Braids Boundary Brunnian Braids Main Results #12

  8. Gradient zone boundary control in salt gradient solar ponds

    DOE Patents [OSTI]

    Hull, John R. (Downers Grove, IL)

    1984-01-01

    A method and apparatus for suppressing zone boundary migration in a salt gradient solar pond includes extending perforated membranes across the pond at the boundaries, between the convective and non-convective zones, the perforations being small enough in size to prevent individual turbulence disturbances from penetrating the hole, but being large enough to allow easy molecular diffusion of salt thereby preventing the formation of convective zones in the gradient layer. The total area of the perforations is a sizable fraction of the membrane area to allow sufficient salt diffusion while preventing turbulent entrainment into the gradient zone.

  9. A moist aquaplanet variant of the Held–Suarez test for atmospheric model dynamical cores

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

    Thatcher, D. R.; Jablonowski, C.

    2015-09-29

    A moist idealized test case (MITC) for atmospheric model dynamical cores is presented. The MITC is based on the Held–Suarez (HS) test that was developed for dry simulations on a flat Earth and replaces the full physical parameterization package with a Newtonian temperature relaxation and Rayleigh damping of the low-level winds. This new variant of the HS test includes moisture and thereby sheds light on the non-linear dynamics-physics moisture feedbacks without the complexity of full physics parameterization packages. In particular, it adds simplified moist processes to the HS forcing to model large-scale condensation, boundary layer mixing, and the exchange ofmore »latent and sensible heat between the atmospheric surface and an ocean-covered planet. Using a variety of dynamical cores of NCAR's Community Atmosphere Model (CAM), this paper demonstrates that the inclusion of the moist idealized physics package leads to climatic states that closely resemble aquaplanet simulations with complex physical parameterizations. This establishes that the MITC approach generates reasonable atmospheric circulations and can be used for a broad range of scientific investigations. This paper provides examples of two application areas. First, the test case reveals the characteristics of the physics-dynamics coupling technique and reproduces coupling issues seen in full-physics simulations. In particular, it is shown that sudden adjustments of the prognostic fields due to moist physics tendencies can trigger undesirable large-scale gravity waves, which can be remedied by a more gradual application of the physical forcing. Second, the moist idealized test case can be used to intercompare dynamical cores. These examples demonstrate the versatility of the MITC approach and suggestions are made for further application areas. The new moist variant of the HS test can be considered a test case of intermediate complexity.« less

  10. Atmospheric Transport of Radionuclides

    SciTech Connect (OSTI)

    Crawford, T.V.

    2003-03-03

    The purpose of atmospheric transport and diffusion calculations is to provide estimates of concentration and surface deposition from routine and accidental releases of pollutants to the atmosphere. This paper discusses this topic.

  11. Photovoltaic devices comprising zinc stannate buffer layer and method for making

    DOE Patents [OSTI]

    Wu, Xuanzhi (Golden, CO); Sheldon, Peter (Lakewood, CO); Coutts, Timothy J. (Lakewood, CO)

    2001-01-01

    A photovoltaic device has a buffer layer zinc stannate Zn.sub.2 SnO.sub.4 disposed between the semiconductor junction structure and the transparent conducting oxide (TCO) layer to prevent formation of localized junctions with the TCO through a thin window semiconductor layer, to prevent shunting through etched grain boundaries of semiconductors, and to relieve stresses and improve adhesion between these layers.

  12. Boundary Degeneracy of Topological Order

    E-Print Network [OSTI]

    Juven Wang; Xiao-Gang Wen

    2015-01-15

    We introduce the concept of boundary degeneracy of topologically ordered states on a compact orientable spatial manifold with boundaries, and emphasize that the boundary degeneracy provides richer information than the bulk degeneracy. Beyond the bulk-edge correspondence, we find the ground state degeneracy of the fully gapped edge modes depends on boundary gapping conditions. By associating different types of boundary gapping conditions as different ways of particle or quasiparticle condensations on the boundary, we develop an analytic theory of gapped boundaries. By Chern-Simons theory, this allows us to derive the ground state degeneracy formula in terms of boundary gapping conditions, which encodes more than the fusion algebra of fractionalized quasiparticles. We apply our theory to Kitaev's toric code and Levin-Wen string-net models. We predict that the $Z_2$ toric code and $Z_2$ double-semion model (more generally, the $Z_k$ gauge theory and the $U(1)_k \\times U(1)_{-k}$ non-chiral fractional quantum Hall state at even integer $k$) can be numerically and experimentally distinguished, by measuring their boundary degeneracy on an annulus or a cylinder.

  13. CORIOLIS EFFECTS IN MESOSCALE SHALLOW LAYER FLOWS J. C. R. Hunt

    E-Print Network [OSTI]

    Hunt, Julian

    CORIOLIS EFFECTS IN MESOSCALE SHALLOW LAYER FLOWS J. C. R. Hunt ¢¡ £ ,A. Orr , D. Cresswell layer or inversion layer, is developed for idealised and steady, but typical, mesoscale atmospheric estimates for a wide range of perturbed mesoscale flows, especially where the surface conditions change

  14. Atmospheric chemistry and global change

    E-Print Network [OSTI]

    Prather, MJ

    1999-01-01

    and particles. Thus Atmospheric Chemistry and Global Changethe future of atmospheric chemistry. BROWSINGS Tornadothe complexity of atmospheric chemistry well, but trips a

  15. The effect of atmospheric corona treatment on AA1050 aluminium M. Jariyaboon a,1

    E-Print Network [OSTI]

    Dunin-Borkowski, Rafal E.

    , 5, and 15 min) in atmospheric air. A 200 nm oxide layer was generated on AA1050 after the 15 min air of a thin oxide layer on alumin- ium alloy surfaces similar to conversion coatings. A significant reduction. The thickness of oxide layer was found to be around 150­300 nm after 20 min of the treatment. However

  16. VALDRIFT 1.0: A valley atmospheric dispersion model with deposition

    SciTech Connect (OSTI)

    Allwine, K.J.; Bian, X.; Whiteman, C.D.

    1995-05-01

    VALDRIFT version 1.0 is an atmospheric transport and diffusion model for use in well-defined mountain valleys. It is designed to determine the extent of ddft from aedal pesticide spraying activities, but can also be applied to estimate the transport and diffusion of various air pollutants in valleys. The model is phenomenological -- that is, the dominant meteorological processes goveming the behavior of the valley atmosphere are formulated explicitly in the model, albeit in a highly parameterized fashion. The key meteorological processes treated are: (1) nonsteady and nonhomogeneous along-valley winds and turbulent diffusivities, (2) convective boundary layer growth, (3) inversion descent, (4) noctumal temperature inversion breakup, and (5) subsidence. The model is applicable under relatively cloud-free, undisturbed synoptic conditions and is configured to operate through one diumal cycle for a single valley. The inputs required are the valley topographical characteristics, pesticide release rate as a function of time and space, along-valley wind speed as a function of time and space, temperature inversion characteristics at sunrise, and sensible heat flux as a function of time following sunrise. Default values are provided for certain inputs in the absence of detailed observations. The outputs are three-dimensional air concentration and ground-level deposition fields as a function of time.

  17. A New Ensemble of Perturbed-Input-Parameter Simulations by the Community Atmosphere Model

    SciTech Connect (OSTI)

    Covey, C; Brandon, S; Bremer, P T; Domyancis, D; Garaizar, X; Johannesson, G; Klein, R; Klein, S A; Lucas, D D; Tannahill, J; Zhang, Y

    2011-10-27

    Uncertainty quantification (UQ) is a fundamental challenge in the numerical simulation of Earth's weather and climate, and other complex systems. It entails much more than attaching defensible error bars to predictions: in particular it includes assessing low-probability but high-consequence events. To achieve these goals with models containing a large number of uncertain input parameters, structural uncertainties, etc., raw computational power is needed. An automated, self-adapting search of the possible model configurations is also useful. Our UQ initiative at the Lawrence Livermore National Laboratory has produced the most extensive set to date of simulations from the US Community Atmosphere Model. We are examining output from about 3,000 twelve-year climate simulations generated with a specialized UQ software framework, and assessing the model's accuracy as a function of 21 to 28 uncertain input parameter values. Most of the input parameters we vary are related to the boundary layer, clouds, and other sub-grid scale processes. Our simulations prescribe surface boundary conditions (sea surface temperatures and sea ice amounts) to match recent observations. Fully searching this 21+ dimensional space is impossible, but sensitivity and ranking algorithms can identify input parameters having relatively little effect on a variety of output fields, either individually or in nonlinear combination. Bayesian statistical constraints, employing a variety of climate observations as metrics, also seem promising. Observational constraints will be important in the next step of our project, which will compute sea surface temperatures and sea ice interactively, and will study climate change due to increasing atmospheric carbon dioxide.

  18. An interfacial transport theory for electro-chemical phenomena with emphasis on electric double layers 

    E-Print Network [OSTI]

    Ambati, Muralidhar S

    2002-01-01

    -dimensional theory in which the effects of the double layer are included as boundary conditions for the volume equations. Example solutions are provided for electroosmosis, including electro-Poiseuille flow and electro-Couette flow....

  19. Photonic layered media

    DOE Patents [OSTI]

    Fleming, James G. (Albuquerque, NM); Lin, Shawn-Yu (Albuquerque, NM)

    2002-01-01

    A new class of structured dielectric media which exhibit significant photonic bandstructure has been invented. The new structures, called photonic layered media, are easy to fabricate using existing layer-by-layer growth techniques, and offer the ability to significantly extend our practical ability to tailor the properties of such optical materials.

  20. Scintillator reflective layer coextrusion

    DOE Patents [OSTI]

    Yun, Jae-Chul (Naperville, IL); Para, Adam (St. Charles, IL)

    2001-01-01

    A polymeric scintillator has a reflective layer adhered to the exterior surface thereof. The reflective layer comprises a reflective pigment and an adhesive binder. The adhesive binder includes polymeric material from which the scintillator is formed. A method of forming the polymeric scintillator having a reflective layer adhered to the exterior surface thereof is also provided. The method includes the steps of (a) extruding an inner core member from a first amount of polymeric scintillator material, and (b) coextruding an outer reflective layer on the exterior surface of the inner core member. The outer reflective layer comprises a reflective pigment and a second amount of the polymeric scintillator material.

  1. Vacuum Structure and Boundary Renormalization Group

    E-Print Network [OSTI]

    M. Asorey; J. M. Munoz-Castaneda

    2007-12-28

    The vacuum structure is probed by boundary conditions. The behaviour of thermodynamical quantities like free energy, boundary entropy and entanglement entropy under the boundary renormalization group flow are analysed in 2D conformal field theories. The results show that whereas vacuum energy and boundary entropy turn out to be very sensitive to boundary conditions, the vacuum entanglement entropy is independent of boundary properties when the boundary of the entanglement domain does not overlap the boundary of the physical space. In all cases the second law of thermodynamics holds along the boundary renormalization group flow.

  2. Bifurcations from steady sliding to stick slip in boundary lubrication A. A. Batista and J. M. Carlson

    E-Print Network [OSTI]

    Carlson, Jean

    Bifurcations from steady sliding to stick slip in boundary lubrication A. A. Batista and J. M in models for boundary lubrication introduced in J. M. Carlson and A. A. Batista, Phys. Rev. E 53, 4153 1996 distinguishing features associated with surfaces separated by a few molecular layers of lubricant. Here we find

  3. Synergistic Effects of Turbine Wakes and Atmospheric Stability on Power Production at an Onshore Wind Farm

    SciTech Connect (OSTI)

    Wharton, S; Lundquist, J K; Marjanovic, N

    2012-01-25

    This report examines the complex interactions between atmospheric stability and turbine-induced wakes on downwind turbine wind speed and power production at a West Coast North American multi-MW wind farm. Wakes are generated when the upwind flow field is distorted by the mechanical movement of the wind turbine blades. This has two consequences for downwind turbines: (1) the downwind turbine encounters wind flows with reduced velocity and (2) the downwind turbine encounters increased turbulence across multiple length scales via mechanical turbulence production by the upwind turbine. This increase in turbulence on top of ambient levels may increase aerodynamic fatigue loads on the blades and reduce the lifetime of turbine component parts. Furthermore, ambient atmospheric conditions, including atmospheric stability, i.e., thermal stratification in the lower boundary layer, play an important role in wake dissipation. Higher levels of ambient turbulence (i.e., a convective or unstable boundary layer) lead to higher turbulent mixing in the wake and a faster recovery in the velocity flow field downwind of a turbine. Lower levels of ambient turbulence, as in a stable boundary layer, will lead to more persistent wakes. The wake of a wind turbine can be divided into two regions: the near wake and far wake, as illustrated in Figure 1. The near wake is formed when the turbine structure alters the shape of the flow field and usually persists one rotor diameter (D) downstream. The difference between the air inside and outside of the near wake results in a shear layer. This shear layer thickens as it moves downstream and forms turbulent eddies of multiple length scales. As the wake travels downstream, it expands depending on the level of ambient turbulence and meanders (i.e., travels in non-uniform path). Schepers estimates that the wake is fully expanded at a distance of 2.25 D and the far wake region begins at 2-5 D downstream. The actual distance traveled before the wake recovers to its inflow velocity is dependent on the amount ambient turbulence, the amount of wind shear, and topographical and structural effects. The maximum velocity deficit is estimated to occur at 1-2 D but can be longer under low levels of ambient turbulence. Our understanding of turbine wakes comes from wind tunnel experiments, field experiments, numerical simulations, and from studies utilizing both experimental and modeling methods. It is well documented that downwind turbines in multi-Megawatt wind farms often produce less power than upwind turbine rows. These wake-induced power losses have been estimated from 5% to up to 40% depending on the turbine operating settings (e.g., thrust coefficient), number of turbine rows, turbine size (e.g., rotor diameter and hub-height), wind farm terrain, and atmospheric flow conditions (e.g., ambient wind speed, turbulence, and atmospheric stability). Early work by Elliott and Cadogan suggested that power data for different turbulent conditions be segregated to distinguish the effects of turbulence on wind farm power production. This may be especially important for downwind turbines within wind farms, as chaotic and turbulent wake flows increase stress on downstream turbines. Impacts of stability on turbine wakes and power production have been examined for a flat terrain, moderate size (43 turbines) wind farm in Minnesota and for an offshore, 80 turbine wind farm off the coast of Denmark. Conzemius found it difficult to distinguish wakes (i.e., downwind velocity deficits) when the atmosphere was convective as large amounts of scatter were present in the turbine nacelle wind speed data. This suggested that high levels of turbulence broke-up the wake via large buoyancy effects, which are generally on the order of 1 km in size. On the other hand, they found pronounced wake effects when the atmosphere was very stable and turbulence was either suppressed or the length scale was reduced as turbulence in this case was mechanically produced (i.e., friction forces). This led to larger reductions at downwind turbines and maximum ve

  4. Atmospheric Neutrino Fluxes

    E-Print Network [OSTI]

    Thomas K. Gaisser

    2005-02-18

    Starting with an historical review, I summarize the status of calculations of the flux of atmospheric neutrinos and how they compare to measurements.

  5. Layered plasma polymer composite membranes

    DOE Patents [OSTI]

    Babcock, W.C.

    1994-10-11

    Layered plasma polymer composite fluid separation membranes are disclosed, which comprise alternating selective and permeable layers for a total of at least 2n layers, where n is [>=]2 and is the number of selective layers. 2 figs.

  6. Atmospheric Science The Earth's atmosphere, a layered sphere of gas extending

    E-Print Network [OSTI]

    Mojzsis, Stephen J.

    observations and modeling. Measuring the radiative effects of aerosols from urban pollution and forest fires sandstorms and volcanoes · Sea spray from the oceans · Smoke from agricultural burning and forest fires

  7. Oceanography and Atmospheric Sciences

    E-Print Network [OSTI]

    Kurapov, Alexander

    Oceanography and Atmospheric Sciences 1959­2009 WayneBurt. #12;Oceanography and Atmospheric in Oceanography (TENOC). Wayne Burt immediately responds with proposal to President Strand of Oregon State College to start a graduate Department of Oceanography. 1959 Oregon State Board of Higher Education approves

  8. NOTES AND CORRESPONDENCE An Analytic Longwave Radiation Formula for Liquid Layer Clouds

    E-Print Network [OSTI]

    NOTES AND CORRESPONDENCE An Analytic Longwave Radiation Formula for Liquid Layer Clouds VINCENT E of boundary layer clouds have used a convenient but idealized longwave radiation formula for clouds in their large-eddy simulations (LESs). Under what conditions is this formula justified? Can it be extended

  9. Dynamics of thermochemical plumes: 1. Plume formation and entrainment of a dense layer

    E-Print Network [OSTI]

    van Keken, Peter

    Dynamics of thermochemical plumes: 1. Plume formation and entrainment of a dense layer Shu investigate the formation of plumes from a thermochemical boundary layer and the entrainment of the dense three factors influence the nature of plume formation and entrainment of dense material. The complexity

  10. Fiscal year 1998 summary report of the NOAA Atmospheric Sciences Modeling Division to the U.S. Environmental Protection Agency. Technical memo

    SciTech Connect (OSTI)

    Poole-Kober, E.M.; Viebrock, H.J.

    1999-06-01

    During Fiscal Year 1998, the Atmospheric Sciences Modeling Division provided meteorological and modeling assistance to the US Environmental Protection Agency. Among the significant research studies and results were the following: publication and distribution of Models-3/Community Mutliscale Air Quality system; estimation of the nitrogen deposition to Chesapeake Bay, continued evaluation and application of air quality models for mercury, dioxin, and heavy metals, continued conduct of deposition velocity field studies over various major categories of land-use; conduct of the Ozark Isoprene Experiment to investigate biogenic isoprene emissions; analysis and modeling of dust resuspension data; continued study of buoyant puff dispersion in the convective boundary layer; and development of a standard practice for an objective statistical procedure for comparing air quality model outputs with field data.

  11. Multiple density layered insulator

    DOE Patents [OSTI]

    Alger, Terry W. (Tracy, CA)

    1994-01-01

    A multiple density layered insulator for use with a laser is disclosed wh provides at least two different insulation materials for a laser discharge tube, where the two insulation materials have different thermoconductivities. The multiple layer insulation materials provide for improved thermoconductivity capability for improved laser operation.

  12. Long-Term Passivation of Strongly Interacting Metals with Single-Layer Graphene

    E-Print Network [OSTI]

    Weatherup, Robert S.; D'Arsié, Lorenzo; Cabrero-Vilatela, Andrea; Caneva, Sabina; Blume, Raoul; Robertson, John; Schlögl, Robert; Hofmann, Stephan

    2015-10-24

    The long-term (>18 months) protection of Ni surfaces against oxidation under atmospheric conditions is demonstrated by coverage with single-layer graphene, formed by chemical vapor deposition. In situ, depth-resolved X-ray photoelectron spectroscopy...

  13. Ensemble Atmospheric Dispersion Modeling

    SciTech Connect (OSTI)

    Addis, R.P.

    2002-06-24

    Prognostic atmospheric dispersion models are used to generate consequence assessments, which assist decision-makers in the event of a release from a nuclear facility. Differences in the forecast wind fields generated by various meteorological agencies, differences in the transport and diffusion models, as well as differences in the way these models treat the release source term, result in differences in the resulting plumes. Even dispersion models using the same wind fields may produce substantially different plumes. This talk will address how ensemble techniques may be used to enable atmospheric modelers to provide decision-makers with a more realistic understanding of how both the atmosphere and the models behave.

  14. Extreme hydrodynamic atmospheric loss near the critical thermal escape regime

    E-Print Network [OSTI]

    Erkaev, N V; Odert, P; Kulikov, Yu N; Kislyakova, K G

    2015-01-01

    By considering martian-like planetary embryos inside the habitable zone of solar-like stars we study the behavior of the hydrodynamic atmospheric escape of hydrogen for small values of the Jeans escape parameter $\\beta thermal energy. Our study is based on a 1-D hydrodynamic upper atmosphere model that calculates the volume heating rate in a hydrogen dominated thermosphere due to the absorption of the stellar soft X-ray and extreme ultraviolet (XUV) flux. We find that when the $\\beta$ value near the mesopause/homopause level exceeds a critical value of $\\sim$2.5, there exists a steady hydrodynamic solution with a smooth transition from subsonic to supersonic flow. For a fixed XUV flux, the escape rate of the upper atmosphere is an increasing function of the temperature at the lower boundary. Our model results indicate a crucial enhancement of the atmospheric escape rate, when the Jeans escape parameter $\\beta$ decr...

  15. Strategic Environmental Research and Development Program: Atmospheric Remote Sensing and Assessment Program -- Final Report. Part 1: The lower atmosphere

    SciTech Connect (OSTI)

    Tooman, T.P.

    1997-01-01

    This report documents work done between FY91 and FY95 for the lower atmospheric portion of the joint Department of Defense (DoD) and Department of Energy (DOE) Atmospheric Remote Sensing and Assessment Program (ARSAP) within the Strategic Environmental Research and Development Program (SERDP). The work focused on (1) developing new measurement capabilities and (2) measuring atmospheric heating in a well-defined layer and then relating it to cloud properties an water vapor content. Seven new instruments were develop3ed for use with Unmanned Aerospace Vehicles (UAVs) as the host platform for flux, radiance, cloud, and water vapor measurements. Four major field campaigns were undertaken to use these new as well as existing instruments to make critically needed atmospheric measurements. Scientific results include the profiling of clear sky fluxes from near surface to 14 km and the strong indication of cloudy atmosphere absorption of solar radiation considerably greater than predicted by extant models.

  16. Toxicity of atmospheric aerosols on marine phytoplankton

    E-Print Network [OSTI]

    2009-01-01

    address: Center for Atmospheric Chemistry Study, Departmenttween phytoplankton, atmospheric chemistry, and climate areno. 12 ? 4601– 4605 CHEMISTRY Atmospheric aerosol deposition

  17. Energy transport, overshoot, and mixing in the atmospheres of M-type main- and pre-main-sequence objects

    E-Print Network [OSTI]

    H. -G. Ludwig; F. Allard; P. H. Hauschildt

    2006-08-12

    We constructed hydrodynamical model atmospheres for mid M-type main-, as well as pre-main-sequence (PMS) objects. Despite the complex chemistry encountered in these cool atmospheres a reasonably accurate representation of the radiative transfer is possible, even in the context of time-dependent and three-dimensional models. The models provide detailed information about the morphology of M-type granulation and statistical properties of the convective surface flows. In particular, we determined the efficiency of the convective energy transport, and the efficiency of mixing by convective overshoot. The convective transport efficiency was expressed in terms of an equivalent mixing-length parameter alpha in the formulation of mixing-length theory (MLT) given by Mihalas (1978). Alpha amounts to values around 2 for matching the entropy of the deep, adiabatically stratified regions of the convective envelope, and lies between 2.5 and 3.0 for matching the thermal structure of the deep photosphere. For current spectral analysis of PMS objects this implies that MLT models based on alpha=2.0 overestimate the effective temperature by 100 K and surface gravities by 0.25 dex. The average thermal structure of the formally convectively stable layers is little affected by convective overshoot and wave heating, i.e., stays close to radiative equilibrium conditions. Our models suggest that the rate of mixing by convective overshoot declines exponentially with geometrical distance to the Schwarzschild stability boundary. It increases at given effective temperature with decreasing gravitational acceleration.

  18. Computer Modeling of Transport of Oxidizing Species in Grain Boundaries during Zirconium Corrosion

    SciTech Connect (OSTI)

    Xian-Ming Bai; Yongfeng Zhang; Michael R. Tonks

    2014-06-01

    Zirconium (Zr) based alloys are widely used as the cladding materials in light-water reactors. The water-side corrosion of these alloys degrades their structural integrity and poses serious safety concerns. During the Zr corrosion process, a thin Zr oxide (ZrO2) layer forms on the alloy surface and serves as a barrier layer for further corrosion. The majority of the oxide has the monoclinic phase. At the transition region between the oxide and the metal, the oxide contains a thin layer of stabilized tetragonal phase. It is found that the texture of the tetragonal layer determines the protectiveness of the oxide for corrosion. The transport of oxidizing species, such as anion defects, cation defects, and electron through the tetragonal oxide layer could be the rate limiting step of the corrosion. The defect diffusion can be affected by the growing stresses and microstructures such as grain boundaries and dislocations. In this work molecular dynamics simulations are used to investigate the anion and cation diffusion in bulk and at grain boundaries in tetragonal ZrO2. The results show that defect diffusion at grain boundaries is complex and the behavior strongly depends on the grain boundary type. For most of the grain boundaries studied the defect diffusion are much slower than in the bulk, implying that grain boundaries may not be fast defect transport paths during corrosion. The connection between the modeling results and published experimental work will also be discussed. This work is funded by the Laboratory Directed Research and Development (LDRD) program at Idaho National Laboratory.

  19. Atmospheric optical calibration system

    DOE Patents [OSTI]

    Hulstrom, Roland L. (Bloomfield, CO); Cannon, Theodore W. (Golden, CO)

    1988-01-01

    An atmospheric optical calibration system is provided to compare actual atmospheric optical conditions to standard atmospheric optical conditions on the basis of aerosol optical depth, relative air mass, and diffuse horizontal skylight to global horizontal photon flux ratio. An indicator can show the extent to which the actual conditions vary from standard conditions. Aerosol scattering and absorption properties, diffuse horizontal skylight to global horizontal photon flux ratio, and precipitable water vapor determined on a real-time basis for optical and pressure measurements are also used to generate a computer spectral model and for correcting actual performance response of a photovoltaic device to standard atmospheric optical condition response on a real-time basis as the device is being tested in actual outdoor conditions.

  20. Atmospheric optical calibration system

    DOE Patents [OSTI]

    Hulstrom, R.L.; Cannon, T.W.

    1988-10-25

    An atmospheric optical calibration system is provided to compare actual atmospheric optical conditions to standard atmospheric optical conditions on the basis of aerosol optical depth, relative air mass, and diffuse horizontal skylight to global horizontal photon flux ratio. An indicator can show the extent to which the actual conditions vary from standard conditions. Aerosol scattering and absorption properties, diffuse horizontal skylight to global horizontal photon flux ratio, and precipitable water vapor determined on a real-time basis for optical and pressure measurements are also used to generate a computer spectral model and for correcting actual performance response of a photovoltaic device to standard atmospheric optical condition response on a real-time basis as the device is being tested in actual outdoor conditions. 7 figs.

  1. Autumn 2014 Atmospheric Circulation

    E-Print Network [OSTI]

    Doty, Sharon Lafferty

    to perform atmospheric chemistry measurements in this remote region of ubiquitous oil and gas drilling 30 days they raised $12,000, enough to support Maria's travel to Utah and to cover the costs

  2. Measurements of grain boundary properties in nanocrystalline ceramics

    SciTech Connect (OSTI)

    Chiang, Y.M.; Smyth, I.P.; Terwilliger, C.D. (Massachusetts Inst. of Tech., Cambridge, MA (USA). Dept. of Materials Science and Engineering); Petuskey, W.T. (Arizona State Univ., Tempe, AZ (USA). Dept. of Chemistry); Eastman, J.A. (Argonne National Lab., IL (USA))

    1990-11-01

    The advent of nanocrystalline ceramics prepared by a variety of solution-chemical and vapor deposition methods offers a unique opportunity for the determination grain boundary properties by bulk'' thermodynamic methods. In this paper we discuss results from two types of measurements on model nanocrystalline ceramics. The first is a solution thermodynamic measurement of the activity of nanocrystalline SiC in polycarbosilane-derived silicon carbide fibers (Nicalon). Structural studies have shown that Nicalon consists of well-ordered cubic ({beta} or 3C polytype) SiC grains separated by a very thin grain boundary layer (<1 nm thick) containing the oxygen. The physical properties and chemical reactivity of these fibers are distinctly different from that of bulk silicon carbide. Direct measurement of the alloy composition and analysis of the microstructure has allowed the dissolution reaction to be identified and a lower limit for the SiC activity in the nanocrystalline form to be determined. A second method of measuring grain boundary properties we have investigated for nanocrystalline Si and TiO{sub 2} is high temperature calorimetry. In appropriate samples the grain boundary enthalpy can be measured through the heat evolved during grain growth. Preliminary results on nanocrystalline Si prepared by the recrystallization of amorphous evaporated films and on TiO{sub 2} condensed from the vapor phase are discussed. 29 refs., 3 figs., 1 tab.

  3. Atmospheric Neutrino Oscillations for Earth Tomography

    E-Print Network [OSTI]

    Winter, Walter

    2015-01-01

    Modern proposed atmospheric neutrino oscillation experiments, such as PINGU in the Antarctic ice or or ORCA in Mediterranean sea water, aim for precision measurements of the oscillation parameters including the ordering of the neutrino masses. They can, however, go far beyond that: Since neutrino oscillations are affected by the coherent forward scattering with matter, neutrinos can provide a new view on the interior of the earth. We show that the proposed atmospheric oscillation experiments can robustly measure the lower mantle density of the earth with a precision at the level of 4-5 percent, including the uncertainties of the oscillation parameters and correlations among different density layers. While the earth's core is, in principle, accessible by the angular resolution, new technology would be required to extract degeneracy-free information.

  4. Boundary Behavior of the GinzburgLandau Order Parameter in the Surface Superconductivity Regime

    E-Print Network [OSTI]

    Recanati, Catherine

    Boundary Behavior of the Ginzburg­Landau Order Parameter in the Surface Superconductivity Regime M­Landau theory for a type­II superconductor in an applied magnetic field varying between the second and third of this energy expansion, which allows us to prove the desired uniformity of the surface superconductivity layer

  5. Boundary lubrication with a glassy interface Anal Lematre1,2

    E-Print Network [OSTI]

    Carlson, Jean

    Boundary lubrication with a glassy interface Anaël Lemaître1,2 and Jean Carlson1 1 Department lubrication. The model is based on a generalization of the shear transformation zone (STZ) theory, in which mea- surements on a microscopically thin layer of lubricant, sepa- rating atomically smooth (typically

  6. Wavelet analysis study of microbubble drag reduction in a boundary channel flow 

    E-Print Network [OSTI]

    Zhen, Ling

    2006-04-12

    components in streamwise-near-wall normal plane of a turbulent channel flow at Reynolds number of 5128 based on the half height of the channel were measured. The influence of the presence of microbubbles in the boundary layer was assessed and compared...

  7. Air Resources Laboratory The Air Resources Laboratory (ARL) is a research laboratory within the National Oceanic and Atmospheric Administration

    E-Print Network [OSTI]

    the National Oceanic and Atmospheric Administration (NOAA). ARL is headquartered at the NOAA Center for Weather in order to improve the Nation's ability to protect human and ecosystem health. What We Do ARL conducts research and development in the fields of atmospheric dispersion, air quality, climate change, and boundary

  8. Layered electrode for electrochemical cells

    DOE Patents [OSTI]

    Swathirajan, Swathy (West Bloomfield, MI); Mikhail, Youssef M. (Sterling Heights, MI)

    2001-01-01

    There is provided an electrode structure comprising a current collector sheet and first and second layers of electrode material. Together, the layers improve catalyst utilization and water management.

  9. 13, 1479714822, 2013 Atmospheric waves

    E-Print Network [OSTI]

    Lovejoy, Shaun

    .5194/acpd-13-14797-2013 © Author(s) 2013. CC Attribution 3.0 License. Sciences ss Atmospheric Chemistry and Physics OpenAccess Atmospheric Chemistry and Physics OpenAccess Discussions Atmospheric Measurement s Discussions This discussion paper is/has been under review for the journal Atmospheric Chemistry and Physics

  10. Irradiation Assisted Grain Boundary Segregation in Steels

    SciTech Connect (OSTI)

    Lu, Zheng; Faulkner, Roy G.

    2008-07-01

    The understanding of radiation-induced grain boundary segregation (RIS) has considerably improved over the past decade. New models have been introduced and much effort has been devoted to obtaining comprehensive information on segregation from the literature. Analytical techniques have also improved so that chemical analysis of layers 1 nm thick is almost routine. This invited paper will review the major methods used currently for RIS prediction: namely, Rate Theory, Inverse Kirkendall, and Solute Drag approaches. A summary is made of the available data on phosphorus RIS in reactor pressure vessel (RPV) steels. This will be discussed in the light of the predictions of the various models in an effort to show which models are the most reliable and easy to use for forecasting P segregation behaviour in steels. A consequence of RIS in RPV steels is a radiation induced shift in the ductile to brittle transition temperature (DBTT). It will be shown how it is possible to relate radiation-induced P segregation levels to DBTT shift. Examples of this exercise will be given for RPV steels and for ferritic steels being considered for first wall fusion applications. Cr RIS in high alloy stainless steels and associated irradiation-assisted stress corrosion cracking (IASCC) will be briefly discussed. (authors)

  11. Atmospheric measurements of carbonyl sulfide, dimethyl sulfide, and carbon disulfide using the electron capture sulfur detector

    SciTech Connect (OSTI)

    Johnson, J.E.; Bates, T.S. [NOAA, Seattle, WA (United States)

    1993-12-01

    Measurements of atmospheric dimethyl sulfide (DMS), carbonyl sulfide (COS), and carbon disulfide (CS2) were conducted over the Atlantic Ocean on board the NASA Electra aircraft during the Chemical Instrumentation Test and Evaluation (CITE 3) project using the electron capture sulfur detector (ECD-S). The system employed cryogenic preconcentration of air samples, gas chromatographic separation, catalytic fluorination, and electron capture detection. Samples collected for DMS analysis were scrubbed of oxidants with NaOH impregnated glass fiber filters to preconcentration. The detection limits (DL) of the system for COS, DMS, and CS2 were 5, 5, and 2 ppt, respectively. COS concentrations ranged from 404 to 603 ppt with a mean of 489 ppt for measurements over the North Atlantic Ocean (31 deg N to 41 deg N), and from 395 to 437 ppt with a mean of 419 ppt for measurements over the Tropical Atlantic Ocean (11 deg S to 2 deg N). DMS concentrations in the lower marine boundary layer, below 600-m altitude, ranged from below DL to 150 ppt from flights over the North Atlantic, and from 9 to 104 ppt over the Tropical Atlantic. CS2 concentrations ranged from below DL to 29 ppt over the North Atlantic. Almost all CS2 measurements over the Tropical Atlantic were below DL.

  12. Hydrostatic Simulation of Earth's Atmospheric Gas Using Multi-particle Collision Dynamics

    E-Print Network [OSTI]

    Pattisahusiwa, Asis; Virid, Sparisoma

    2015-01-01

    Multi-particle collision dynamics (MPCD) is a mesoscopic simulation method to simulate fluid particle-like flows. MPCD has been widely used to simulate various problems in condensed matter. In this study, hydrostatic behavior of gas in the Earth's atmospheric layer is simulated by using MPCD method. The simulation is carried out by assuming the system under ideal state and is affected only by gravitational force. Gas particles are homogeneous and placed in 2D box. Interaction of the particles with the box is applied through implementation of boundary conditions (BC). Periodic BC is applied on the left and the right side, specular reflection on the top side, while bounce-back on the bottom side. Simulation program is executed in Arch Linux and running in notebook with processor Intel i5 @2700 MHz with 10 GB DDR3 RAM. The results show behaviors of the particles obey kinetic theory for ideal gas when gravitational acceleration value is proportional to the particle mass. Density distribution as a function of alti...

  13. Influence of Atmospheric Pressure and Water Table Fluctuations on Gas Phase Flow and Transport of Volatile Organic Compounds (VOCs) in Unsaturated Zones 

    E-Print Network [OSTI]

    You, Kehua

    2013-04-19

    solution in a three-layered unsaturated zone in response to field atmospheric pressure fluctuations at the Hanford site in Richland, Washington... ................................................................................................. 92 4.3 Comparison of gas flow rate calculated by the ML solution with measured flow rates in a three-layered unsaturated zone in response to field atmospheric pressure variations at the Hanford site in Richland...

  14. Where do fossil fuel carbon dioxide emissions from California go? An analysis based on radiocarbon observations and an atmospheric transport model

    SciTech Connect (OSTI)

    Riley, W.J.; Hsueh, D.Y.; Randerson, J.T.; Fischer, M.L.; Hatch, J.G.; Pataki, D.E.; Wang, W.; Goulden, M.L.

    2008-05-01

    Characterizing flow patterns and mixing of fossil fuel-derived CO{sub 2} is important for effectively using atmospheric measurements to constrain emissions inventories. Here we used measurements and a model of atmospheric radiocarbon ({sup 14}C) to investigate the distribution and fluxes of atmospheric fossil fuel CO{sub 2} across the state of California. We sampled {sup 14}C in annual C{sub 3} grasses at 128 sites and used these measurements to test a regional model that simulated anthropogenic and ecosystem CO{sub 2} fluxes, transport in the atmosphere, and the resulting {sup 14}C of annual grasses ({Delta}{sub g}). Average measured {Delta}{sub g} in Los Angeles, San Francisco, the Central Valley, and the North Coast were 27.7 {+-} 20.0, 44.0 {+-} 10.9, 48.7 {+-} 1.9, and 59.9 {+-} 2.5{per_thousand}, respectively, during the 2004-2005 growing season. Model predictions reproduced regional patterns reasonably well, with estimates of 27.6 {+-} 2.4, 39.4 {+-} 3.9, 46.8 {+-} 3.0, and 59.3 {+-} 0.2{per_thousand} for these same regions and corresponding to fossil fuel CO{sub 2} mixing ratios (Cf) of 13.7, 6.1, 4.8, and 0.3 ppm. {Delta}{sub g} spatial heterogeneity in Los Angeles and San Francisco was higher in the measurements than in the predictions, probably from insufficient spatial resolution in the fossil fuel inventories (e.g., freeways are not explicitly included) and transport (e.g., within valleys). We used the model to predict monthly and annual transport patterns of fossil fuel-derived CO{sub 2} within and out of California. Fossil fuel CO{sub 2} emitted in Los Angeles and San Francisco was predicted to move into the Central Valley, raising Cf above that expected from local emissions alone. Annually, about 21, 39, 35, and 5% of fossil fuel emissions leave the California airspace to the north, east, south, and west, respectively, with large seasonal variations in the proportions. Positive correlations between westward fluxes and Santa Ana wind conditions were observed. The southward fluxes over the Pacific Ocean were maintained in a relatively coherent flow within the marine boundary layer, while the eastward fluxes were more vertically dispersed. Our results indicate that state and continental scale atmospheric inversions need to consider areas where concentration measurements are sparse (e.g., over the ocean to the south and west of California), transport within and across the marine boundary layer, and terrestrial boundary layer dynamics. Measurements of {Delta}{sub g} can be very useful in constraining these estimates.

  15. Building BoundariesTM Information for Parents

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    Building BoundariesTM Information for Parents Even very young children can learn some skills of 2 #12;Building BoundariesTM: Information for Parents How to Recognize Warning Signs in Your Child

  16. Boundary learning by optimization with topological constraints

    E-Print Network [OSTI]

    Helmstaedter, Moritz N.

    Recent studies have shown that machine learning can improve the accuracy of detecting object boundaries in images. In the standard approach, a boundary detector is trained by minimizing its pixel-level disagreement with ...

  17. Layered semiconductor neutron detectors

    DOE Patents [OSTI]

    Mao, Samuel S; Perry, Dale L

    2013-12-10

    Room temperature operating solid state hand held neutron detectors integrate one or more relatively thin layers of a high neutron interaction cross-section element or materials with semiconductor detectors. The high neutron interaction cross-section element (e.g., Gd, B or Li) or materials comprising at least one high neutron interaction cross-section element can be in the form of unstructured layers or micro- or nano-structured arrays. Such architecture provides high efficiency neutron detector devices by capturing substantially more carriers produced from high energy .alpha.-particles or .gamma.-photons generated by neutron interaction.

  18. Localization length of nearly periodic layered metamaterials

    E-Print Network [OSTI]

    del Barco, O

    2015-01-01

    We have analyzed numerically the localization length of light $\\xi$ for nearly periodic arrangements of homogeneous stacks (formed exclusively by right-handed materials) and mixed stacks (with alternating right and left-handed metamaterials). Layers with index of refraction $n_1$ and thickness $L_1$ alternate with layers of index of refraction $n_2$ and thickness $L_2$. Positional disorder has been considered by shifting randomly the positions of the layer boundaries with respect to periodic values. For homogeneous stacks, we have shown that the localization length is modulated by the corresponding bands and that $\\xi$ is enhanced at the center of each allowed band. In the limit of long-wavelengths $\\lambda$, the parabolic behavior previously found in purely disordered systems is recovered, whereas for $\\lambda \\ll L_1 + L_2$ a saturation is reached. In the case of nearly periodic mixed stacks with the condition $|n_1 L_1|=|n_2 L_2|$, instead of bands there is a periodic arrangement of Lorenztian resonances, ...

  19. Autumn 2012 Atmospheric Circulation

    E-Print Network [OSTI]

    Doty, Sharon Lafferty

    wind, and accumulated precipitation at a designated city. Forecasts are made over a two-week period Department 1 The UW Atmospheric Sciences spring forecast contest has been an annual tradition there will be a marine push or a convergence zone wrecking their forecast for maximum temperature and precipitation

  20. Laboratory for Atmospheric and

    E-Print Network [OSTI]

    Mojzsis, Stephen J.

    Laboratory for Atmospheric and Space Physics Activity Report 2013 University of Colorado at Boulder from the Naval Research Center and the Air Force Cambridge Research Laboratory (now the Phillips Laboratory), the University of Colorado formed a research group called the Upper Air Laboratory (UAL

  1. Laboratory for Atmospheric and

    E-Print Network [OSTI]

    Mojzsis, Stephen J.

    Laboratory for Atmospheric and Space Physics Activity Report 2012 University of Colorado at Boulder from the Naval Research Center and the Air Force Cambridge Research Laboratory (now the Phillips Laboratory), the University of Colorado formed a research group called the Upper Air Laboratory (UAL

  2. Laboratory for Atmospheric and

    E-Print Network [OSTI]

    Mojzsis, Stephen J.

    Laboratory for Atmospheric and Space Physics Activity Report 2008 University of Colorado at Boulder, Jet Propulsion Laboratory) LASP: A Brief History In 1946-47, a handful of American universities joined Laboratory (now the Phillips Laboratory), the University of Colorado formed a research group called the Upper

  3. Laboratory for Atmospheric and

    E-Print Network [OSTI]

    Mojzsis, Stephen J.

    1 Laboratory for Atmospheric and Space Physics Activity Report 2010 University of Colorado from the Na- val Research Center and the Air Force Cambridge Research Laboratory (now the Phillips Laboratory), the University of Colorado formed a research group called the Upper Air Laboratory (UAL

  4. ATMOSPHERIC CHEMISTRY AND PHYSICS

    E-Print Network [OSTI]

    Brandenburg, Axel

    of electronic formats. Some content that appears in print may not be available in electronic formats. For more information about Wiley products, visit our web site at www.wiley.com. Library of Congress Cataloging components of the atmosphere, nitrogen, oxygen, water, carbon dioxide, and the noble gases. In the late

  5. Validating computed grain boundary energies in fcc metals using the grain boundary character distribution

    E-Print Network [OSTI]

    Rohrer, Gregory S.

    Validating computed grain boundary energies in fcc metals using the grain boundary character. Since the GBCD is inversely related to the grain boundary energy distribution, it offers a useful metric for validating grain boundary energy calculations. Comparisons between the measured GBCD and calculated energies

  6. The Influence of Chemi-ionization and Recombination Processes on Spectral Line Shapes in Stellar Atmospheres

    E-Print Network [OSTI]

    Mihajlov, Anatolij A; Sreckovic, Vladimir A; Dimitrijevic, Milan S

    2011-01-01

    In this work, the chemi-ionization processes in atom- Rydberg atom collisions, as well as the corresponding chemi-recombination processes are considered as factors of influence on the atom exited-state populations in weakly ionized layers of stellar atmospheres. The presented results are related to the photospheres of the Sun and some M red dwarfs as well as weakly ionized layers of DB white dwarfs atmospheres. It has been found that the mentioned chemi ionization/recombination processes dominate over the relevant concurrent electron-atom and electron-ion ionization and recombination process in all parts of considered stellar atmospheres. The obtained results demonstrate the fact that the considered chemi ionization/recombination processes must have a very significant influence on the optical properties of the stellar atmospheres. Thus, it is shown that these processes and their importance for non-local thermodynamic equilibrium (non-LTE) modeling of the solar atmospheres should be investigated further.

  7. Grain boundaries in coated conductors

    E-Print Network [OSTI]

    Weigand, Marcus

    2010-07-06

    ,757 • Bibliography: 5,087 ix Publications and Conference Presentations This thesis led to the following publications: • M. Weigand, S. C. Speller, G. M. Hughes, N. A. Rutter, S. Lozano-Perez, C. R. M. Grovenor and J. H. Durrell: “Individual grain boundary properties... and overall performance of metal-organic deposition coated conductors ”, Phys. Rev. B 81, 174537 (2010) • R. Hühne, J. Eickemeyer, V. S. Sarma, A. Güth, T. Thersleff, J. Freudenberger, O. de Haas, M. Weigand, J. H. Durrell, L. Schultz and B. Holzapfel: “Ap...

  8. Differential atmospheric tritium sampler

    DOE Patents [OSTI]

    Griesbach, O.A.; Stencel, J.R.

    1987-10-02

    An atmospheric tritium sampler is provided which uses a carrier gas comprised of hydrogen gas and a diluting gas, mixed in a nonexplosive concentration. Sample air and carrier gas are drawn into and mixed in a manifold. A regulator meters the carrier gas flow to the manifold. The air sample/carrier gas mixture is pulled through a first moisture trap which adsorbs water from the air sample. The moisture then passes through a combustion chamber where hydrogen gas in the form of H/sub 2/ or HT is combusted into water. The manufactured water is transported by the air stream to a second moisture trap where it is adsorbed. The air is then discharged back into the atmosphere by means of a pump.

  9. Thermal Transitions in Layer-By-Layer Assemblies 

    E-Print Network [OSTI]

    Sung, Choonghyun

    2014-10-13

    Thermal transitions in layer-by-layer (LbL) assemblies were investigated under dry and hydrated conditions. In the dry state, the effects of film thickness and the film deposition method on the glass transition temperature (Tg) were studied...

  10. Layer-by-layer assembly in confined geometries

    E-Print Network [OSTI]

    DeRocher, Jonathan P

    2011-01-01

    The fundamental nature of layer-by-layer (LbL) assembly in confined geometries was investigated for a number of different chemical systems. The first part of this thesis concerns the modification of microfluidic and ...

  11. Ion transport and structure of layer-by-layer assemblies

    E-Print Network [OSTI]

    Lutkenhaus, Jodie Lee

    2007-01-01

    Layer-by-layer (LbL) films of various architectures were examined as potential solid state electrolytes for electrochemical systems (e.g. batteries and fuel cells). The relationship between materials properties and ion ...

  12. Engineering electroresponsive layer-by-layer thin films

    E-Print Network [OSTI]

    Schmidt, Daniel J., Ph. D. Massachusetts Institute of Technology

    2011-01-01

    Electroresponsive layer-by-layer (LbL) polymer films and polymer nanocomposite films were investigated as model systems for electrically triggered drug delivery applications and "mechanomutable" surface coating applications. ...

  13. Atmospheric Chemistry Theodore S. Dibble

    E-Print Network [OSTI]

    Dibble, Theodore

    SYLLABUS FOR Atmospheric Chemistry FCH 511 Fall 2014 Theodore S. Dibble Professor of Chemistry 421 in Required Text Seinfeld, J. H. and Pandis, S. N. Atmospheric Chemistry and Physics: From Air Pollution nineteenth year at ESF, and my seventeenth year teaching FCH 511 (Atmospheric Chemistry). I have done a lot

  14. Ocean Barrier Layers’ Effect on Tropical Cyclone Intensification

    SciTech Connect (OSTI)

    Balaguru, Karthik; Chang, P.; Saravanan, R.; Leung, Lai-Yung R.; Xu, Zhao; Li, M.; Hsieh, J.

    2012-09-04

    Improving a tropical cyclone's forecast and mitigating its destructive potential requires knowledge of various environmental factors that influence the cyclone's path and intensity. Herein, using a combination of observations and model simulations, we systematically demonstrate that tropical cyclone intensification is significantly affected by salinity-induced barrier layers, which are 'quasi-permanent' features in the upper tropical oceans. When tropical cyclones pass over regions with barrier layers, the increased stratification and stability within the layer reduce storm-induced vertical mixing and sea surface temperature cooling. This causes an increase in enthalpy flux from the ocean to the atmosphere and, consequently, an intensification of tropical cyclones. On average, the tropical cyclone intensification rate is nearly 50% higher over regions with barrier layers, compared to regions without. Our finding, which underscores the importance of observing not only the upper-ocean thermal structure but also the salinity structure in deep tropical barrier layer regions, may be a key to more skillful predictions of tropical cyclone intensities through improved ocean state estimates and simulations of barrier layer processes. As the hydrological cycle responds to global warming, any associated changes in the barrier layer distribution must be considered in projecting future tropical cyclone activity.

  15. Arsenic decapping and pre-atomic layer deposition trimethylaluminum passivation of Al2O3/InGaAs(100) interfaces

    E-Print Network [OSTI]

    Kummel, Andrew C.

    Arsenic decapping and pre-atomic layer deposition trimethylaluminum passivation of Al2O3/InGaAs(100 traps in atomic-layer-deposited Al2O3/GaAs (001) metal-oxide- semiconductor capacitors using atmospheric of atomic layer deposition temperature on HfO2/InGaAs metal-oxide-semiconductor interface properties J. Appl

  16. Lifetimes and eigenstates in atmospheric chemistry

    E-Print Network [OSTI]

    Prather, Michael J

    1994-01-01

    Perturbation dynamics in atmospheric chemistry. J. Geophys.isotopic variations in atmospheric chemistry. Geophys. Res.M. et al. 2001 Atmospheric chemistry and greenhouse gases (

  17. Atmospheric chemistry of an Antarctic volcanic plume

    E-Print Network [OSTI]

    2010-01-01

    L. , et al. (2010), Atmospheric chemistry results from theI. , et al. (2006), Atmospheric chemistry of a 33 – 34 hourvolcanic eruptions on atmospheric chemistry, Chem. Geol. ,

  18. Gradient zone-boundary control in salt-gradient solar ponds

    DOE Patents [OSTI]

    Hull, J.R.

    1982-09-29

    A method and apparatus for suppressing zone boundary migration in a salt gradient solar pond includes extending perforated membranes across the pond at the boundaries, between the convective and non-convective zones, the perforations being small enough in size to prevent individual turbulence disturbances from penetrating the hole, but being large enough to allow easy molecular diffusion of salt thereby preventing the formation of convective zones in the gradient layer. The total area of the perforations is a sizeable fraction of the membrane area to allow sufficient salt diffusion while preventing turbulent entrainment into the gradient zone.

  19. Journal of Atmospheric Chemistry 32: 375395, 1999. 1999 Kluwer Academic Publishers. Printed in the Netherlands.

    E-Print Network [OSTI]

    von Glasow, Roland

    Journal of Atmospheric Chemistry 32: 375­395, 1999. © 1999 Kluwer Academic Publishers. Printed in the Netherlands. 375 Iodine Chemistry and its Role in Halogen Activation and Ozone Loss in the Marine Boundary set of reactions treating the gas and aqueous phase chemistry of the most important iodine species

  20. JETS: intense circulations in atmospheres and ocean OC569c Spring 2008

    E-Print Network [OSTI]

    1 JETS: intense circulations in atmospheres and ocean OC569c Spring 2008 Room 211 Ocean Teaching.ocean.washington.edu/research/gfd Outline a look at the extratropical jet stream with synoptic data: transport, energy, vertical structure or veering with height) the Hadley cell and its limited size oceanic jets and boundary currents Why

  1. ARM - Atmospheric Heat Budget

    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.TheoryTuesday, August 10, 20102016Study (CHAPS)Archive CampaignListAtmospheric Heat

  2. ARM - Atmospheric Pressure

    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.TheoryTuesday, August 10, 20102016Study (CHAPS)Archive CampaignListAtmospheric

  3. Atmospheric PSF Interpolation

    Office of Scientific and Technical Information (OSTI)

    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 NaturalDukeWakefield MunicipalTechnical Report:Speeding accessby a contractor ofvarDOE PAGES11 PPPL-Atmospheric PSF

  4. Caged Layer Management. 

    E-Print Network [OSTI]

    Cawley, W. O.; Quisenberry, J. H.; Allen, W. S.

    1966-01-01

    for the earnings to justify the investment. Construct Texas cage houses with special emphasis on layer comfort during the summer heat. But housing must also protect birds against the few severely cold winter days. When constructing a cage house, consider... cost is de- sired, do not confuse wit11 ligl~t or inferior type construction. A study of poultry houses damaged by severe weather indicates most damage results from not securely fastening studs to foundation. Figure 12. Plans for this 24-foot wide...

  5. 4.3 Boundary integral equations

    E-Print Network [OSTI]

    2010-10-18

    62. CHAPTER 4. OBSTACLE SCATTERING. 4.3 Boundary integral equations. We introduce the equivalent sources for the Helmholtz equation and establish ...

  6. Performance Boundaries in Nb3Sn Superconductors

    E-Print Network [OSTI]

    Godeke, Arno

    2006-01-01

    Boundaries in Nb 3 Sn Superconductors – Berkeley, CABoundaries in Nb 3 Sn Superconductors – Berkeley, CABoundaries in Nb 3 Sn Superconductors Arno Godeke Berkeley,

  7. Spatially Resolved Mapping of Electrical Conductivity around Individual Domain (Grain) Boundaries in Graphene

    SciTech Connect (OSTI)

    Li, An-Ping [ORNL; Clark, Kendal W [ORNL; Zhang, Xiaoguang [ORNL; Vlassiouk, Ivan V [ORNL; He, Guowei [Carnegie Mellon University (CMU); Feenstra, Randall [Carnegie Mellon University (CMU)

    2013-01-01

    Graphene films can now be produced on the scale of up to meters. However, all large-scale graphene films contain topological defects that can significantly affect the characteristic transport behaviors of graphene. Here, we spatially map the structures and electronic transport near specific domain and grain boundaries in graphene, and evaluate effects of different types of defect on the electronic conductivity in epitaxial graphene grown on SiC and CVD graphene on Cu subsequently transferred to a SiO2 substrate. We use a combined approach with a multi-probe scanning tunneling potentiometry to investigate both structures and transport at individual grain boundaries and domain boundaries that are defined by coalesced grains, surface steps, and changes in layer thickness. It is found that the substrate step on SiC presents a significant potential barrier for electron transport of epitaxial graphene due to the reduced charge transport from the substrate at the step edges, monolayer-bilayer boundaries exhibit a high resistivity that can change depending on directions of the current across the boundary, and the resistivity of grain boundaries changes with the transition width of the disordered region between two adjacent grains in graphene. The detailed understanding of graphene defects will provide the feedback for controlled engineering of defects in large-scale graphene films.

  8. Metal deposition using seed layers

    DOE Patents [OSTI]

    Feng, Hsein-Ping; Chen, Gang; Bo, Yu; Ren, Zhifeng; Chen, Shuo; Poudel, Bed

    2013-11-12

    Methods of forming a conductive metal layers on substrates are disclosed which employ a seed layer to enhance bonding, especially to smooth, low-roughness or hydrophobic substrates. In one aspect of the invention, the seed layer can be formed by applying nanoparticles onto a surface of the substrate; and the metallization is achieved by electroplating an electrically conducting metal onto the seed layer, whereby the nanoparticles serve as nucleation sites for metal deposition. In another approach, the seed layer can be formed by a self-assembling linker material, such as a sulfur-containing silane material.

  9. Buried oxide layer in silicon

    DOE Patents [OSTI]

    Sadana, Devendra Kumar (Pleasantville, NY); Holland, Orin Wayne (Lenoir, TN)

    2001-01-01

    A process for forming Silicon-On-Insulator is described incorporating the steps of ion implantation of oxygen into a silicon substrate at elevated temperature, ion implanting oxygen at a temperature below 200.degree. C. at a lower dose to form an amorphous silicon layer, and annealing steps to form a mixture of defective single crystal silicon and polycrystalline silicon or polycrystalline silicon alone and then silicon oxide from the amorphous silicon layer to form a continuous silicon oxide layer below the surface of the silicon substrate to provide an isolated superficial layer of silicon. The invention overcomes the problem of buried isolated islands of silicon oxide forming a discontinuous buried oxide layer.

  10. GFD-2 Spring 2004 Syllabus Text: a nearly complete set of text handouts, plus A.E.Gill, Atmosphere-Ocean Dynamics

    E-Print Network [OSTI]

    geography of potential vorticity -lateral circulation: wind-driven ocean gyres and boundary currents -circumpolar ocean currents and the atmospheric westerly winds: stationary Rossby waves with mountains; waveGFD-2 Spring 2004 Syllabus Text: a nearly complete set of text handouts, plus A.E.Gill, Atmosphere-Ocean

  11. Clear sky atmosphere at cm-wavelengths from climatology data

    E-Print Network [OSTI]

    Lew, Bartosz

    2015-01-01

    We utilise ground-based, balloon-born and satellite climatology data to reconstruct site and season-dependent vertical profiles of precipitable water vapour (PWV). We use these profiles to numerically solve radiative transfer through the atmosphere, and derive atmospheric brightness temperature ($T_{\\rm atm}$) and optical depth ($\\tau$) at the centimetre wavelengths. We validate the reconstruction by comparing the model column PWV, with photometric measurements of PWV, performed in the clear sky conditions towards the Sun. Based on the measurements, we devise a selection criteria to filter the climatology data to match the PWV levels to the expectations of the clear sky conditions. We apply the reconstruction to the location of the Polish 32-metre radio telescope, and characterise $T_{\\rm atm}$ and $\\tau$ year-round, at selected frequencies. We also derive the zenith distance dependence for these parameters, and discuss shortcomings of using planar, single-layer, and optically thin atmospheric model approxima...

  12. Environmental Performance Characterization of Atomic Layer Deposition

    E-Print Network [OSTI]

    Yuan, Chris; Dornfeld, David

    2008-01-01

    Rahtu and R. Gordon. “Atomic layer deposition of transitionoxide films grown by atomic layer deposition from iodide andand S. M. George. “Atomic layer deposition of ultrathin and

  13. Surface passivation of c-Si by atmospheric pressure chemical vapor deposition of Al2O3

    E-Print Network [OSTI]

    passivation has to date been mostly deposited by conventional atomic layer deposition (ALD), a technique-effect transistors subjected to on-state bias stress J. Appl. Phys. 111, 084504 (2012) Atomic imaging of atomic layerSurface passivation of c-Si by atmospheric pressure chemical vapor deposition of Al2O3 Lachlan E

  14. Analysis of the Younger Dryas Impact Layer

    SciTech Connect (OSTI)

    Firestone, Richard B.; West, Allen; Revay, Zsolt; Hagstrum, Jonathon T,; Belgya, Thomas; Hee, Shane S. Que; Smith, Alan R.

    2010-02-27

    We have uncovered a thin layer of magnetic grains and microspherules, carbon spherules, and glass-like carbon at nine sites across North America, a site in Belgium, and throughout the rims of 16 Carolina Bays. It is consistent with the ejecta layer from an impact event and has been dated to 12.9 ka BP coinciding with the onset of Younger Dryas (YD) cooling and widespread megafaunal extinctions in North America. At many locations the impact layer is directly below a black mat marking the sudden disappearance of the megafauna and Clovis people. The distribution pattern of the Younger Dryas boundary (YDB) ejecta layer is consistent with an impact near the Great Lakes that deposited terrestrial-like ejecta near the impact site and unusual, titanium-rich projectile-like ejecta further away. High water content associated with the ejecta, up to 28 at. percent hydrogen (H), suggests the impact occurred over the Laurentide Ice Sheet. YDB microspherules and magnetic grains are highly enriched in TiO{sub 2}. Magnetic grains from several sites are enriched in iridium (Ir), up to 117 ppb. The TiO{sub 2}/FeO, K/Th, TiO{sub 2}/Zr, Al{sub 2}O{sub 3}/FeO+MgO, CaO/Al{sub 2}O{sub 3}, REE/ chondrite, FeO/MnO ratios and SiO{sub 2}, Na{sub 2}O, K{sub 2}O, Cr{sub 2}O{sub 3}, Ni, Co, U, Th and other trace element abundances are inconsistent with all terrestrial and extraterrestrial (ET) sources except for KREEP, a lunar igneous rock rich in potassium (K), rare-earth elements (REE), phosphorus (P), and other incompatible elements including U and Th. Normal Fe, Ti, and {sup 238}U/{sup 235}U isotopic abundances were found in the magnetic grains, but {sup 234}U was enriched over equilibrium values by 50 percent in Murray Springs and by 130 percent in Belgium. 40K abundance is enriched by up to 100 percent in YDB sediments and Clovis chert artifacts. Highly vesicular carbon spherules containing nanodiamonds, glass-like carbon, charcoal and soot found in large quantities in the YDB layer are consistent with an impact followed by intense burning. Four holes in the Great Lakes, some deeper than Death Valley, are proposed as possible craters produced by the airburst breakup of a loosely aggregated projectile.

  15. A dominant role of oxygen additive on cold atmospheric-pressure He + O{sub 2} plasmas

    SciTech Connect (OSTI)

    Yang, Aijun; Liu, Dingxin E-mail: xhw@mail.xjtu.edu.cn; Rong, Mingzhe; Wang, Xiaohua E-mail: xhw@mail.xjtu.edu.cn; Kong, Michael G.

    2014-08-15

    We present in this paper how oxygen additive impacts on the cold atmospheric-pressure helium plasmas by means of a one-dimensional fluid model. For the oxygen concentration [O{sub 2}]?>??0.1%, the influence of oxygen on the electron characteristics and the power dissipation becomes important, e.g., the electron density, the electron temperature in sheath, the electron-coupling power, and the sheath width decreasing by 1.6 to 16 folds with a two-log increase in [O{sub 2}] from 0.1% to 10%. Also the discharge mode evolves from the ? mode to the ? mode. The reactive oxygen species are found to peak in the narrow range of [O{sub 2}]?=?0.4%–0.9% in the plasmas, similar to their power-coupling values. This applies to their wall fluxes except for those of O* and O{sub 2}{sup ?}. These two species have very short lifetimes, thus only when generated in boundary layers within several micrometers next to the electrode can contribute to the fluxes. The dominant reactive oxygen species and the corresponding main reactions are schematically presented, and their relations are quantified for selected applications.

  16. Metal precipitation at grain boundaries in silicon: Dependence on grain boundary character and dislocation decoration

    E-Print Network [OSTI]

    Metal precipitation at grain boundaries in silicon: Dependence on grain boundary character are combined to determine the dependence of metal silicide precipitate formation on grain boundary character and microstructure in multicrystalline silicon mc-Si . Metal silicide precipitate decoration is observed to increase

  17. A sharp boundary model for the vertical and kink stability of large aspect-ratio vertically elongated tokamak plasmas

    E-Print Network [OSTI]

    Fitzpatrick, Richard

    elongated tokamak plasmas R. Fitzpatrick Citation: Physics of Plasmas (1994-present) 15, 092502 (2008); doi boundary layer generated by kink modes in tokamaks Phys. Plasmas 18, 062503 (2011); 10.1063/1.3596536 Error-field induced electromagnetic torques in a large aspect-ratio, low- , weakly shaped tokamak plasma Phys

  18. Digestive system and Body Cavities Know the boundaries and contents of each of the divisions of the body

    E-Print Network [OSTI]

    Houde, Peter

    Digestive system and Body Cavities Objectives Know the boundaries and contents of each of the body cavities Know the tissue layers of the digestive tract Know the parts and functions of digestive organs and glands Know where digestive organs and glands are located relative to one another

  19. Aligned fractures modeled as boundary conditions within saturated porous media and induced anisotropy. A finite element approach.

    E-Print Network [OSTI]

    Santos, Juan

    Aligned fractures modeled as boundary conditions within saturated porous media and induced´e M. Carcione, Istituto Nazionale di Oceanografia e di Geofisica Sperimentale, OGS SUMMARY Fractures in a fluid-saturated poroelastic -Biot- medium are very thin, compliant and highly permeable layers. Fracture

  20. Boundary conditions for the subdiffusion equation

    SciTech Connect (OSTI)

    Shkilev, V. P.

    2013-04-15

    The boundary conditions for the subdiffusion equations are formulated using the continuous-time random walk model, as well as several versions of the random walk model on an irregular lattice. It is shown that the boundary conditions for the same equation in different models have different forms, and this difference considerably affects the solutions of this equation.

  1. 2001 TRAFFIC ZONE BOUNDARIES Zone Numbers

    E-Print Network [OSTI]

    Toronto, University of

    2001 TRAFFIC ZONE BOUNDARIES Zone Numbers & Detailed Definitions #12;2001 TRAFFIC ZONE BOUNDARIES of Toronto Joint Program in Transportation January 2003 #12;PREFACE This report presents the 2001 traffic zone numbers by local municipalities in the 2001 TTS survey area. The second part presents detailed

  2. Boundary Behavior of the Ginzburg-Landau Order Parameter in the Surface Superconductivity Regime

    E-Print Network [OSTI]

    M. Correggi; N. Rougerie

    2015-01-27

    We study the 2D Ginzburg-Landau theory for a type-II superconductor in an applied magnetic field varying between the second and third critical value. In this regime the order parameter minimizing the GL energy is concentrated along the boundary of the sample and is well approximated to leading order by a simplified 1D profile in the direction perpendicular to the boundary. Motivated by a conjecture of Xing-Bin Pan, we address the question of whether this approximation can hold uniformly in the boundary region. We prove that this is indeed the case as a corollary of a refined, second order energy expansion including contributions due to the curvature of the sample. Local variations of the GL order parameter are controlled by the second order term of this energy expansion, which allows us to prove the desired uniformity of the surface superconductivity layer.

  3. A Continuous ` \\Gamma oe Vertical Coordinate for a Baroclinic Model of the Atmospheric Circulation

    E-Print Network [OSTI]

    Drake, John B.

    meteorolgoical coordinate system is developed which can support a continuous isentropic­ oe vertical coordinate and boundary layer approximations were addressed by the introduction of a hybrid (patched) model [15]. By use analysis [14, 8]. The effects of heating on the circulation are most clearly seen with the isentropic

  4. AFFILIATIONS: PRENNI, DEMOTT, AND KREIDENWEIS--Department of Atmospheric Science, Colorado State University, Fort Collins,

    E-Print Network [OSTI]

    Harrington, Jerry Y.

    at the surface and also regulate incoming solar radiation in summer. Low-level boundary layer (BL) clouds tend and the Arctic radiation budget may be due to inadequate parameterizations of ice nuclei. T he Arctic near mixedphaseevenatquitelowtemperatures,consisting of liquid water tops that precipitate ice (Pinto 1998). To date, successfully modeling

  5. Environmental boundaries to energy development

    SciTech Connect (OSTI)

    Trivelpiece, A.W.

    1989-01-01

    Public concern about the environment, health and safety consequences of energy technology has been growing steadily for more than two decades in the United States. This concern forms an important boundary condition as the United States seeks to develop a new National Energy Strategy. Furthermore, the international aspects of the energy/environment interface such as acid rain global climate change and stratospheric ozone depletion are very prominent in US thinking. In fact, the energy systems of the world are becoming more closely coupled environmentally and otherwise. Now where is this coupling more important than that between the industrialized and developing world; the choices made by each will have profound effects on the other. The development of energy technologies compatible with both economic growth and improving and sustaining environmental quality represents a major R D challenge to the US and USSR. Decision about adoption of new technology and R D priorities can be improved by better measurements of how energy sources and uses are changing throughout the world and better methods to project the potential consequences of these decisions. Such projection require understanding relative risks of alternating existing and evolving technologies. All of these R D areas, technology improvement energy system monitoring and projection and comparative risk assessment are the topics of this seminar. Progress in each may be enhanced by collaboration and cooperation between our two countries. 7 refs., 27 figs., 5 tabs.

  6. Boundary integral formulation for interfacial cracks in thermodiffusive bimaterials

    E-Print Network [OSTI]

    L. Morini; A. Piccolroaz

    2015-04-29

    An original boundary integral formulation is proposed for the problem of a semi-infinite crack at the interface between two dissimilar elastic materials in the presence of heat flows and mass diffusion. Symmetric and skew-symmetric weight function matrices are used together with a generalized Betti's reciprocity theorem in order to derive a system of integral equations that relate the applied loading, the temperature and mass concentration fields, the heat and mass fluxes on the fracture surfaces and the resulting crack opening. The obtained integral identities can have many relevant applications, such as for the modelling of crack and damage processes at the interface between different components in electrochemical energy devices characterized by multi-layered structures (solid oxide fuel cells and lithium ions batteries).

  7. The effect of reconnection on the structure of the Sun's open-closed-flux boundary

    E-Print Network [OSTI]

    Pontin, D I

    2015-01-01

    Global magnetic field extrapolations are now revealing the huge complexity of the Sun's corona, and in particular the structure of the boundary between open and closed magnetic flux. Moreover, recent developments indicate that magnetic reconnection in the corona likely occurs in highly fragmented current layers, and that this typically leads to a dramatic increase in the topological complexity beyond that of the equilibrium field. In this paper we investigate the consequences of reconnection at the open-closed flux boundary ("interchange reconnection") in a fragmented current layer. We demonstrate that it leads to a situation in which magnetic flux (and therefore plasma) from open and closed field regions is efficiently mixed together. This corresponds to an increase in the length and complexity of the open-closed boundary. Thus, whenever reconnection occurs at a null point or separator of the open-closed boundary, the associated separatrix arc of the so-called "S-web" in the high corona becomes not a single ...

  8. Probing Atmospheric Electric Fields in Thunderstorms through Radio Emission from Cosmic-Ray-Induced Air Showers

    E-Print Network [OSTI]

    Schellart, P; Buitink, S; Corstanje, A; Enriquez, J E; Falcke, H; Hörandel, J R; Nelles, A; Rachen, J P; Rossetto, L; Scholten, O; ter Veen, S; Thoudam, S; Ebert, U; Koehn, C; Rutjes, C; Alexov, A; Anderson, J M; Avruch, I M; Bentum, M J; Bernardi, G; Best, P; Bonafede, A; Breitling, F; Broderick, J W; Brüggen, M; Butcher, H R; Ciardi, B; de Geus, E; de Vos, M; Duscha, S; Eislöffel, J; Fallows, R A; Frieswijk, W; Garrett, M A; Grießmeier, J; Gunst, A W; Heald, G; Hessels, J W T; Hoeft, M; Holties, H A; Juette, E; Kondratiev, V I; Kuniyoshi, M; Kuper, G; Mann, G; McFadden, R; McKay-Bukowski, D; McKean, J P; Mevius, M; Moldon, J; Norden, M J; Orru, E; Paas, H; Pandey-Pommier, M; Pizzo, R; Polatidis, A G; Reich, W; Röttgering, H; Scaife, A M M; Schwarz, D J; Serylak, M; Smirnov, O; Steinmetz, M; Swinbank, J; Tagger, M; Tasse, C; Toribio, M C; van Weeren, R J; Vermeulen, R; Vocks, C; Wise, M W; Wucknitz, O; Zarka, P

    2015-01-01

    We present measurements of radio emission from cosmic ray air showers that took place during thunderstorms. The intensity and polarization patterns of these air showers are radically different from those measured during fair-weather conditions. With the use of a simple two-layer model for the atmospheric electric field, these patterns can be well reproduced by state-of-the-art simulation codes. This in turn provides a novel way to study atmospheric electric fields.

  9. Leakage pathway layer for solar cell

    DOE Patents [OSTI]

    Luan, Andy; Smith, David; Cousins, Peter; Sun, Sheng

    2015-12-01

    Leakage pathway layers for solar cells and methods of forming leakage pathway layers for solar cells are described.

  10. Oxygen-reducing catalyst layer

    DOE Patents [OSTI]

    O'Brien, Dennis P. (Maplewood, MN); Schmoeckel, Alison K. (Stillwater, MN); Vernstrom, George D. (Cottage Grove, MN); Atanasoski, Radoslav (Edina, MN); Wood, Thomas E. (Stillwater, MN); Yang, Ruizhi (Halifax, CA); Easton, E. Bradley (Halifax, CA); Dahn, Jeffrey R. (Hubley, CA); O'Neill, David G. (Lake Elmo, MN)

    2011-03-22

    An oxygen-reducing catalyst layer, and a method of making the oxygen-reducing catalyst layer, where the oxygen-reducing catalyst layer includes a catalytic material film disposed on a substrate with the use of physical vapor deposition and thermal treatment. The catalytic material film includes a transition metal that is substantially free of platinum. At least one of the physical vapor deposition and the thermal treatment is performed in a processing environment comprising a nitrogen-containing gas.

  11. DMS and SO2 measurements in the tropical marine boundary layer

    E-Print Network [OSTI]

    De Bruyn, WJ; Dahl, E; Saltzman, ES

    2006-01-01

    hydrogen sulfide, carbonyl sulfide, dimethyl sulfide andcarbon disulfide, and carbonyl sulfide by isotope dilution

  12. Synoptic and local influences on boundary layer processes, with an application to California wind power

    E-Print Network [OSTI]

    Mansbach, David K

    2010-01-01

    means fall in greater windpower classes than does Palmcontrast, would only fall in windpower classes 1, 3, 2, and

  13. Improving tropical and subtropical boundary layer cloudiness in the NCEP GFS

    E-Print Network [OSTI]

    Bretherton, Chris

    , as well as in the Community Earth System Model (CESM, http://www.cesm.ucar.edu/), using the relative

  14. AN INVESTIGATION INTO THE VIABILITY OF MEMS TECHNOLOGY FOR BOUNDARY LAYER

    E-Print Network [OSTI]

    Davies, Christopher

    and the preliminary design, development, fabrication and testing of appropriate prototype sensors, actuators of those found near the leading edges of aircraft wings, on helicopter rotors and on the fan/compressor blades and ducts within gas turbine engines. Further research is required to develop some of the concepts

  15. Observations of gas phase hydrochloric acid in the polluted marine boundary layer

    E-Print Network [OSTI]

    , California, USA, 2 Chemical Sciences Division, Earth System Research Laboratory, NOAA, Boulder, Colorado, USA Ship-based measurements of gas phase hydrochloric acid (HCl), particulate chloride (p the lifetime of methane [Finlayson-Pitts, 1993; Pszenny et al., 2007; Singh and Kasting, 1988; von Glasow

  16. MEMS Pressure Sensor Array for Aeroacoustic Analysis of the Turbulent Boundary Layer

    E-Print Network [OSTI]

    White, Robert D.

    , front-vented, 64 channel (8×8), capacitively sensed pressure sensor array is de- scribed. The array Thickness of air gap Vgap Volume of air gap n Number of holes in the diaphragm ahole Radius of diaphragm vent holes Cc Center­to­center spacing of vent holes Density of air c Speed of sound µ Viscosity

  17. MEMS Pressure Sensor Array for Aeroacoustic Analysis of the Turbulent Boundary Layer

    E-Print Network [OSTI]

    White, Robert D.

    sensed pressure sensor array is de- scribed. The array was fabricated using the MEMSCAP PolyMUMPs R Thickness of diaphragm agap Radius of the gap cavity tgap Thickness of air gap Vgap Volume of air gap n holes Density of air c Speed of sound µ Viscosity of air 1 Density of diaphragm (Polysilicon) E1

  18. Simulating the Transition from Drizzling Marine Stratocumulus to Boundary Layer Cumulus with a Mesoscale Model

    E-Print Network [OSTI]

    Mechem, David B.; Kogan, Yefim L.

    2003-10-01

    variability is analogous to the drizzle-induced cloud breakup produced in large eddy simulation studies. The dynamics of the pure stratocumulus cloud are dictated by the model's subgrid parameterization, while the more convective regime exhibits appreciable...

  19. A case study of boundary layer ventilation by convection and coastal processes

    E-Print Network [OSTI]

    Dacre, Helen

    far and can build up to become a local air pollution problem. In the free troposphere there is no dry wind speeds may greatly expand their range of influence and the local air pollution problem can become 2005 using the UK Met Office Unified Model. Pollution sources are represented by the constant emission

  20. Synoptic and local influences on boundary layer processes, with an application to California wind power

    E-Print Network [OSTI]

    Mansbach, David K

    2010-01-01

    maps showing locations of wind power conversion facilities,of US winds and wind power at 80 m derived fromEvaluation of global wind power. Journal of Geo- physical

  1. An experimental study of boundary-layer transition over a rotating, compliant disk

    E-Print Network [OSTI]

    Thomas, Peter J.

    For over 5 decades the rotating-disk flow has provided the paradigm for the study of laminar-known spiral vortices characterizing the laminar-turbulent transition region which separates the laminar flow. J. Thomas,a) P. W. Carpenter, and A. J. Cooperb) Fluid Dynamics Research Centre, School

  2. Analysis and identification of vortices within a turbulent channel boundary layer flow 

    E-Print Network [OSTI]

    Maroni Veiga, Adrian Gaston

    2006-08-16

    understanding of the drag reduction mechanism is still lacking. Vortices play an important role in turbulence structure. Nevertheless, the identification of vortices is still unclear, not even a universal definition of a vortex is accepted. In the present study...

  3. The Effects of Step Excrescences on Swept-Wing Boundary-Layer Transition 

    E-Print Network [OSTI]

    Duncan, Jr., Glen T.

    2014-08-12

    ................................................................ 61 Fig. 45 Crosswind/asymmetric load limitations (modified from [53]) ............................................... 62 Fig. 46 SWIFTER flare attitude (top) and bank-angle (bottom) limitations during takeoff...

  4. FLOW SEPARATION CHARACTERISATION OF A FORWARD FACING STEP IMMERSED IN A TURBULENT BOUNDARY LAYER

    E-Print Network [OSTI]

    Marusic, Ivan

    seen rapid development in recent times is the wind energy field. Wind generating machines or turbines michael.sherry@eng.monash.edu.au Romain Mathis, Ivan Marusic Walter Basset Aerodynamic Laboratory phenomena are of par- ticular interest in the wind engineering field. One area of wind engineering which has

  5. Understanding the role of organic aerosol in the coastal and remote pacic marine boundary layer

    E-Print Network [OSTI]

    Hawkins, Lelia Nahid

    2010-01-01

    fossil fuel combustion and biomass burning emissions con-fuel combustion and biomass burning emissions provided keyfuel combustion, biogenic, and biomass burning emissions a

  6. Particle Resuspension in Turbulent Boundary Layers and the Influence of Non-Gaussian Removal Forces

    E-Print Network [OSTI]

    Zhang, F; Kissane, M

    2012-01-01

    The work presented is concerned with the way very small micron-size particles attached to a surface are resuspended when exposed to a turbulent flow. Of particular concern is the remobilization of radioactive particles as a consequence of potential nuclear accidents. In this particular case the focus is on small particles, resuspension involving the rocking and rolling of a particle about surface asperities arising from the moments of the fluctuating drag forces acting on the particle close to the surface. In this work the model is significantly improved by using values of both the stream-wise fluid velocity and acceleration close to the wall obtained from Direct Numerical Simulation (DNS) of turbulent channelflow. Using an...

  7. Int. Conference on Boundary and Interior Layers G. Lube, G. Rapin (Eds)

    E-Print Network [OSTI]

    Hartmann, Ralf

    of the compressible Euler equations Ralf Hartmann Institute of Aerodynamics and Flow Technology, German Aerospace Center (DLR), Lilienthalplatz 7, 38108 Braunschweig, Germany, Ralf.Hartmann@dlr.de, and Institute

  8. A High Reynolds Number Turbulent Boundary Layer with Regular `Braille-Type' Roughness

    E-Print Network [OSTI]

    Marusic, Ivan

    high Reynolds number wind-tunnel facility at New Mexico State University (NMSU) was fitted-mail: montyjp@unimelb.edu.au J.J. Allen Department of Mechanical Engineering, New Mexico State University, Las

  9. DNS of a Large-Domain, Mach 3 Turbulent Boundary Layer: Turbulence Structure

    E-Print Network [OSTI]

    Martín, Pino

    & Adrian;9 del ´Alamo & Jim´enez;10 Ganapathisubramani, Longmire & Marusic;11 del ´Alamo et al.;12 del ´Alamo et al.;13 Guala, Hommena & Adrian;14 Hambleton, Hutchins & Marusic;15 Flores et al.;16 Balakumar

  10. Pollution-enhanced reactive chlorine chemistry in the eastern tropical Atlantic boundary layer

    E-Print Network [OSTI]

    2009-01-01

    doi:10.1029/2008GL036666, 2009 Pollution-enhanced reactiveE. S. Saltzman (2009), Pollution-enhanced reactive chlorine5 L08810 LAWLER ET AL. : POLLUTION-ENHANCED CLX IN THE MBL

  11. RACORO LONG-TERM, SYSTEMATIC AIRCRAFT OBSERVATIONS OF BOUNDARY LAYER CLOUDS

    E-Print Network [OSTI]

    ). This type of cloud is common globally, and the Earth's radiative energy balance is particularly sensitive Contract No. DE-AC02- 98CH10886 with the U.S. Department of Energy. The publisher by accepting-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others

  12. Synoptic and local influences on boundary layer processes, with an application to California wind power

    E-Print Network [OSTI]

    Mansbach, David K.

    2010-01-01

    3.4.2 Wind roses . . . . . . . .Figure 5.5: Downscaled wind speed changes and componentin?uences on California’s wind energy resource. Part 1:

  13. Interactions between Soot and CH* in a Laminar Boundary Layer Type Diffusion Flame in Microgravity 

    E-Print Network [OSTI]

    Fuentes, Andres; Legros, Guillaume; Claverie, Alain; Joulain, Pierre; Vantelon, Jean-Pierre; Torero, Jose L

    A three-dimensional laminar non-buoyant diffusion flame was studied with the objective of improving the understanding of the soot production. The flame originated from a porous ethylene burner discharging into a laminar ...

  14. Understanding the role of organic aerosol in the coastal and remote pacic marine boundary layer

    E-Print Network [OSTI]

    Hawkins, Lelia Nahid

    2010-01-01

    Alkane Carboxylic acid Organic hydroxyl Amine Elementalatomic O/C, FTIR organic hydroxyl fraction of OM (by mass),in between (e.g. organic hydroxyl and ketone groups) (Maria

  15. Understanding the role of organic aerosol in the coastal and remote pacic marine boundary layer

    E-Print Network [OSTI]

    Hawkins, Lelia Nahid

    2010-01-01

    acid Organic hydroxyl Amine Elemental Correlations (r) S VCarboxylic acid Organic hydroxyl Amine Organosulfate FTIR O/Group Organic hydroxyl Primary amine Carboxylic acid Alkane

  16. Numerical Investigation of turbulent coupling boundary layer of air-water interaction flow

    E-Print Network [OSTI]

    Liu, Song, S.M. Massachusetts Institute of Technology

    2005-01-01

    Air-water interaction flow between two parallel flat plates, known as Couette flow, is simulated by direct numerical simulation. The two flowing fluids are coupled through continuity of velocity and shear stress condition ...

  17. The effect of periodic-unsteady wakes, curvature, and pressure gradient on boundary-layer transition 

    E-Print Network [OSTI]

    Radke, Robert Edward

    1994-01-01

    periodic-unsteady wakes. In addition, a turbomachinery cascade test facility with periodic-unsteady inlet flow was designed and manufactured for the next generation of research in this area....

  18. Wave boundary layer hydrodynamics and cross-shore sediment transport in the surf zone

    E-Print Network [OSTI]

    González Rodríguez, David, Ph. D. Massachusetts Institute of Technology

    2009-01-01

    Coastal erosion and, more generally, evolution of the beach morphology are major coastal engineering problems. Changes in beach morphology mostly occur in the nearshore region, or surf zone. They are caused by the local ...

  19. American Institute of Aeronautics and Astronautics The Influence of Stable Boundary Layer Flows

    E-Print Network [OSTI]

    Manuel, Lance

    and forecasting of LLJs is needed for robust wind turbine design and for more reliable power generation prediction for wind turbine design. This is surprising since such near-neutral conditions occur in so generated by shear and destroyed by negative buoyancy. Wind shear (both magnitude and direction) under

  20. Field boundary layer characteristics as modified by clams in habitats of varying survival rates

    E-Print Network [OSTI]

    de-spiked - Wave energy removed Flow Direction Buried Clams ADV ADV x y z Mud and Sand Flats: High.K. Delavan*, D.R. Webster *gth900g@mail.gatech.edu, dwebster@ce.gatech.edu Georgia Institute of Technology

  1. Large-Eddy Simulations of Longitudinal Vortices Embedded in a Turbulent Boundary Layer

    E-Print Network [OSTI]

    Mittal, Rajat

    quantity ^ = test-filtered quantity = quantity in wall unit 0 = fluctuation component I. Introduction noise and cavitation in hydraulic pumps. This has motivated recent experiments performed by Kuhl [5] and Ma [6]. They made 3-D laser Doppler anemometer (LDA) [5] and hot-wire [6] measurements of near

  2. Non-linear modulation of a boundary layer induced by vortex generators

    E-Print Network [OSTI]

    Wesfreid, José Eduardo

    - tions,12 in automotive aerodynamics to reduce the drag of a vehicle4 or in chemical industry to increase in various industrial application e.g. in aeronautics, to enhance airplane lift force in near stall situa

  3. CATALYZED COMBUSTION IN A FLAT PLATE BOUNDARY LAYER I. EXPERIMENTAL MEASUREMENTS AND COMPARISON WITH NUMERICAL CALCULATIONS

    E-Print Network [OSTI]

    Robben, R.

    2010-01-01

    l~ Roberts, "Catathermal Combustion: A New Process for Lm'l-significant gas phase combustion is induced by the presenceInternational) on Combustion (to be published), The

  4. CATALYZED COMBUSTION IN A FLAT PLATE BOUNDARY LAYER II. NUMERICAL CALCULATIONS

    E-Print Network [OSTI]

    Schefer, R.

    2010-01-01

    D.G. , Fourteenth Sympo- sium (International) on Combustion,The Combustion Institute, Pittsburgh, 107 (1973). Wilson,Program for Calculation of Combustion Reaction Equilibrium

  5. Boundary-Layer Transition Effects on Aerodynamic Characteristics of AGARD-B Model

    E-Print Network [OSTI]

    Liu, Feng

    of airplanes or airplane components, it is often desirable to simulate a flow that in most respects behaves is an ogive-cylinder with a delta wing designed for calibration of supersonic and transonic wind tunnels

  6. Design of an Instrumentation System for a Boundary Layer Transition Wing Glove Experiment 

    E-Print Network [OSTI]

    Williams, Thomas 1987-

    2012-08-23

    side of the glove. Infrared (IR) thermography has been selected as the primary transition detection tool. A heat transfer analysis has shown that solar radiation will warm the surface of the glove above the adiabatic wall temperature and therefore...

  7. Reactive Halogens in the Marine Boundary Layer (RHaMBLe): the tropical North Atlantic experiments

    E-Print Network [OSTI]

    2010-01-01

    close to or East of the Canary Islands, before arriving atpassing near to the Canary Islands on its way to Cape Verde.passing close to the Canary islands before approaching Cape

  8. Primary crossflow vortices, secondary absolute instabilities and their control in the rotating-disk boundary layer

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Primary crossflow vortices, secondary absolute instabilities and their control in the rotating patterns of crossflow vortices are derived by employing asymptotic techniques. This approach accounts three-dimensional velocity profiles, are subject to inviscid crossflow in- stabilities and rapidly

  9. High-Speed Boundary-Layer Transition : : Study of Stationary Crossflow Using Spectral Analysis

    E-Print Network [OSTI]

    McGuire, Patrick Joseph

    2014-01-01

    Secondary Instability of Crossflow Vortices. J. Fluid Mech.R. & S ARIC , W. S. 1999 Crossflow Stability and TransitionSaturation of Stationary Crossflow Vortices in a Swept-Wing

  10. American Institute of Aeronautics and Astronautics Shock/Boundary Layer Interaction Effects on Transverse

    E-Print Network [OSTI]

    Texas at Arlington, University of

    on Transverse Jets in Crossflow Over a Flat Plate Dean A. Dickmann* Lockheed Martin Missiles and Fire Control crossflow by bifurcating the phase portrait of the separation topology through the addition of saddle points

  11. Solute dispersion in the coastal boundary layer of southern Lake Michigan

    E-Print Network [OSTI]

    of southern Lake Michigan, J. Geophys. Res. Oceans, 118, 1606­1617, doi:10.1002/jgrc.20136. 1. Introduction [2) with turbid waters contributing to increased survival by limiting sunlight penetration, removal of bacteria

  12. Study of turbulence-chemistry interaction in hypersonic turbulent boundary layers

    E-Print Network [OSTI]

    Martín, Pino

    rate, kg/m3 s, or wall-normal velocity, m/s u streamwise velocity, m/s v spanwise velocity, m/mol stoichiometric coefficient, dimensionless k reaction rate coefficient Keq equilibrium constant Ta activation velocity, m/s h specific enthalpy, J/kg Current Address: Research Scientist, National Institute

  13. Surface and bottom boundary layer dynamics on a shallow submarine bank : southern flank of Georges Bank

    E-Print Network [OSTI]

    Werner, Sandra R. (Sandra Regina)

    1999-01-01

    The thesis investigates the circulation at a 76-m deep study site on the southern flank of Georges Bank, a shallow submarine bank located between the deeper Gulf of Maine and the continental slope. Emphasis is placed on ...

  14. NEAR-WALL INFLUENCE OF LARGE-SCALE MOTIONS IN HIGH REYNOLDS NUMBER TURBULENT BOUNDARY LAYERS

    E-Print Network [OSTI]

    Marusic, Ivan

    . Monty, H. Ng, & I. Marusic Department of Mechanical and Manufacturing Engineering, University averages computed based on low and high skin-friction events indicate the presence of a forward-leaning low

  15. CATALYZED COMBUSTION IN A FLAT PLATE BOUNDARY LAYER I. EXPERIMENTAL MEASUREMENTS AND COMPARISON WITH NUMERICAL CALCULATIONS

    E-Print Network [OSTI]

    Robben, R.

    2010-01-01

    combustion process in order to reduce the associated pollution,pollution, Besides this well known example to clean up the exhaust gases from combustion,

  16. Measurement of three-dimensional coherent fluid structure in high Reynolds number turbulent boundary layers

    E-Print Network [OSTI]

    Clark, Thomas Henry

    2012-07-03

    of difference between original and filled-in vectors . . 158 6.22 Restoration of field with 20% missing data . . . . . . . . . . . . . 160 6.23 Restoration of field with 50% missing data . . . . . . . . . . . . . 161 6.24 Median error in restoration of a field... Binary mask used to relate pixel indices in matrix Wij to the reduced pixel indices in Wrs. ?js Binary mask used to relate voxel indices in matrix Wij to the reduced voxel indices in Wrs. ei Error in the ith velocity component. u?iu ? j u? Turbulent...

  17. Numerical Study of Freestream Waves Receptivity and Nonlinear Breakdown in Hypersonic Boundary Layer

    E-Print Network [OSTI]

    Lei, Jia

    2013-01-01

    each fixed-frequency disturbance can be represented by eq. (and LST with the disturbance frequency of 744.5 kHz for theDNS and LST at the disturbance frequency of 744.5 kHz for

  18. Recollimation boundary layers as X-ray sources in young stellar jets

    SciTech Connect (OSTI)

    Günther, Hans Moritz; Li, Zhi-Yun; Schneider, P. C.

    2014-11-01

    Young stars accrete mass from circumstellar disks and, in many cases, the accretion coincides with a phase of massive outflows, which can be highly collimated. Those jets emit predominantly in the optical and IR wavelength range. However, in several cases, X-ray and UV observations reveal a weak but highly energetic component in those jets. X-rays are observed both from stationary regions close to the star and from knots in the jet several hundred AU from the star. In this article, we show semianalytically that a fast stellar wind that is recollimated by the pressure from a slower, more massive disk wind can have the right properties to power stationary X-ray emission. The size of the shocked regions is compatible with observational constraints. Our calculations support a wind-wind interaction scenario for the high-energy emission near the base of young stellar object jets. For the specific case of DG Tau, a stellar wind with a mass-loss rate of 5 × 10{sup –10} M {sub ?} yr{sup –1} and a wind speed of 800 km s{sup –1} reproduces the observed X-ray spectrum. We conclude that a stellar wind recollimation shock is a viable scenario to power stationary X-ray emission close to the jet launching point.

  19. Study of active control of instability in a boundary layer over a flat plate flow 

    E-Print Network [OSTI]

    Oryu, Hiroshi

    2000-01-01

    A feasibility study of utilizing synthetic jet actuators as a mean to mitigate disturbances that can cause instability and turbulent flow is described. Prediction of flow transition via linear stability theory was performed by solving the Orr...

  20. Effect of Strong External Turbulence on a Wall Jet Boundary Layer

    E-Print Network [OSTI]

    Hunt, Julian

    the design of many types of fluid flow machinery and processes. These effects cause changes in heat transfer

  1. GEOGRAPHY 104 BOUNDARY LAYER CLIMATES Assignment #4: Solar Radiation on Angled Surfaces

    E-Print Network [OSTI]

    : You are designing a solar collector for your own residence in Los Angeles: a). Draw 2 diagrams one radiation absorption in all seasons. Where would be the best place to put a solar collector and to what drawn for Part a, indicate how you would adjust your solar collector for obstruction due to the presence

  2. Boundary-Layer Receptivity to Three-Dimensional Roughness Arrays on a Swept-Wing 

    E-Print Network [OSTI]

    Hunt, Lauren Elizabeth

    2012-02-14

    instabilities to occur, which in turn ultimately lead to transition. Computational methods that model the primary and secondary instability growth can accurately model disturbance evolution as long as appropriate initial conditions are supplied. Additionally...

  3. Characterization of Radar Boundary Layer Data Collected During the 2001 Multi-Frequency Radar IOP

    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 BGene Network ShapingDate: M-16-04-04Journal

  4. DOE/SC-ARM/TR-132 Planetary Boundary Layer (PBL) Height Value

    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 HAB Packet HanfordDOE ProjectREMOTE-HANDLED TRU764 The6552-013 ARM4892

  5. Sensitivity of Boundary-layer and Deep Convective Cloud Simulations to

    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 AdministrationRobust,Field-effect Photovoltaics - Energy InnovationOscillation ResultsSystemsVertical

  6. Simulation of Post-Frontal Boundary Layers Observed During the ARM 2000 Cloud IOP

    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 AdministrationRobust,Field-effect Photovoltaics -7541 UnlimitedShift

  7. Posters Triggering of Boundary Layer Cumulus Clouds Over a Heterogeneous Surface

    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 wouldMass mapSpeedingProgram Guidelines This document outlines the majorL.Posters955

  8. Regional Scale Surface CO2 Exchange Estimates Using a Boundary Layer Budget

    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 wouldMassR&D100 Winners * ImpactsandRegarding ConfinementRegional PartnershipsMethod over

  9. Four-Dimensional Data Assimilation Boundary-Layer Observations Over the Southern

    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 likeUniverse (Journal Article)Forthcoming Upgrades to the ARM

  10. Local Correlations and Multi-Fractal Behaviour in Marine Boundary Layer Cloud Dynamics

    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 likeUniverseIMPACTThousand CubicResourcelogo and-E CChinaC L S C O

  11. Space Science : Atmosphere Greenhouse Effect

    E-Print Network [OSTI]

    Johnson, Robert E.

    Space Science : Atmosphere Greenhouse Effect Part-5a Solar + Earth Spectrum IR Absorbers Grey Atmosphere Greenhouse Effect #12;Radiation: Solar and Earth Surface B"(T) Planck Ideal Emission Integrate and it emits Note: heat balance Fvis( = Fout = Te 4 z #12;(simple Greenhouse cont.) 0 1 2 3 4 Ground Space Top

  12. Atmospheric science encompasses meteorology and climatology, as well as fields such as atmospheric chemistry and remote sensing.Atmospheric

    E-Print Network [OSTI]

    chemistry and remote sensing.Atmospheric scientists apply physics, mathematics, and chemistry to understandAtmospheric science encompasses meteorology and climatology, as well as fields such as atmospheric the atmosphere and its interactions with land and sea. One of the goals of atmospheric science is to understand

  13. Method of deforming a biaxially textured buffer layer on a textured metallic substrate and articles therefrom

    DOE Patents [OSTI]

    Lee, Dominic F. (Knoxville, TN); Kroeger, Donald M. (Knoxville, TN); Goyal, Amit (Knoxville, TN)

    2000-01-01

    The present invention provides methods and biaxially textured articles having a deformed epitaxial layer formed therefrom for use with high temperature superconductors, photovoltaic, ferroelectric, or optical devices. A buffer layer is epitaxially deposited onto biaxially-textured substrates and then mechanically deformed. The deformation process minimizes or eliminates grooves, or other irregularities, formed on the buffer layer while maintaining the biaxial texture of the buffer layer. Advantageously, the biaxial texture of the buffer layer is not altered during subsequent heat treatments of the deformed buffer. The present invention provides mechanical densification procedures which can be incorporated into the processing of superconducting films through the powder deposit or precursor approaches without incurring unfavorable high-angle grain boundaries.

  14. An atmospheric pCO2 reconstruction across the Cretaceous-Tertiary boundary from

    E-Print Network [OSTI]

    Royer, Dana

    attribute marked ``green- house'' warming to either volcanic degassing of mantle volatiles (especially CO2 impact. A resultant climatic forcing of 12 W m 2 would have been sufficient to warm the Earth's surface evidence for major climatic warming after the KTB impact and implies that severe and abrupt global warming

  15. Layer-layer competition in multiplex complex networks

    E-Print Network [OSTI]

    Gómez-Gardeñes, Jesús; Gutiérrez, Gerardo; Arenas, Alex; Gómez, Sergio

    2015-01-01

    The coexistence of multiple types of interactions within social, technological and biological networks has moved the focus of the physics of complex systems towards a multiplex description of the interactions between their constituents. This novel approach has unveiled that the multiplex nature of complex systems has strong influence in the emergence of collective states and their critical properties. Here we address an important issue that is intrinsic to the coexistence of multiple means of interactions within a network: their competition. To this aim, we study a two-layer multiplex in which the activity of users can be localized in each of the layer or shared between them, favoring that neighboring nodes within a layer focus their activity on the same layer. This framework mimics the coexistence and competition of multiple communication channels, in a way that the prevalence of a particular communication platform emerges as a result of the localization of users activity in one single interaction layer. Our...

  16. Layer-by-Layer Assembly of Enzymes on Carbon Nanotubes

    SciTech Connect (OSTI)

    Wang, Jun; Liu, Guodong; Lin, Yuehe

    2008-06-01

    The use of Layer-by-layer techniques for immobilizing several types of enzymes, e.g. glucose oxidase (GOx), horse radish oxidases(HRP), and choline oxidase(CHO) on carbon nanotubes and their applications for biosenseing are presented. The enzyme is immobilized on the negatively charged CNT surface by alternatively assembling a cationic polydiallyldimethyl-ammonium chloride (PDDA) layer and a enzyme layer. The sandwich-like layer structure (PDDA/enzyme/PDDA/CNT) formed by electrostatic assembling provides a favorable microenvironment to keep the bioactivity of enzyme and to prevent enzyme molecule leakage. The morphologies and electrocatalytic acitivity of the resulted enzyme film were characterized using TEM and electrochemical techniques, respectively. It was found that these enzyme-based biosensors are very sensitive, selective for detection of biomolecules, e.g. glucose, choline.

  17. Al{sub 2}O{sub 3} multi-density layer structure as a moisture permeation barrier deposited by radio frequency remote plasma atomic layer deposition

    SciTech Connect (OSTI)

    Jung, Hyunsoo [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Samsung Display Co. Ltd., Tangjeong, Chungcheongnam-Do 336-741 (Korea, Republic of); Jeon, Heeyoung [Department of Nano-scale Semiconductor Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Choi, Hagyoung; Ham, Giyul; Shin, Seokyoon [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Jeon, Hyeongtag, E-mail: hjeon@hanyang.ac.kr [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Department of Nano-scale Semiconductor Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2014-02-21

    Al{sub 2}O{sub 3} films deposited by remote plasma atomic layer deposition have been used for thin film encapsulation of organic light emitting diode. In this study, a multi-density layer structure consisting of two Al{sub 2}O{sub 3} layers with different densities are deposited with different deposition conditions of O{sub 2} plasma reactant time. This structure improves moisture permeation barrier characteristics, as confirmed by a water vapor transmission rate (WVTR) test. The lowest WVTR of the multi-density layer structure was 4.7 × 10{sup ?5} gm{sup ?2} day{sup ?1}, which is one order of magnitude less than WVTR for the reference single-density Al{sub 2}O{sub 3} layer. This improvement is attributed to the location mismatch of paths for atmospheric gases, such as O{sub 2} and H{sub 2}O, in the film due to different densities in the layers. This mechanism is analyzed by high resolution transmission electron microscopy, elastic recoil detection, and angle resolved X-ray photoelectron spectroscopy. These results confirmed that the multi-density layer structure exhibits very good characteristics as an encapsulation layer via location mismatch of paths for H{sub 2}O and O{sub 2} between the two layers.

  18. Climatological simulations of ozone and atmospheric aerosols in the Greater Cairo region

    SciTech Connect (OSTI)

    Steiner, A. L.; Tawfik, A. B.; Shalaby, A.; Zakey, A. S.; Abdel Wahab, M. M.; Salah, Z.; Solmon, F.; Sillman, S.; Zaveri, Rahul A.

    2014-04-16

    An integrated chemistry-climate model (RegCM4-CHEM) simulates present-day climate, ozone and tropospheric aerosols over Egypt with a focus on Greater Cairo (GC) region. The densley populated GC region is known for its severe air quality issues driven by high levels of anthropogenic pollution in conjuction with natural sources such as dust and agricultural burning events. We find that current global emission inventories underestimate key pollutants such as nitrogen oxides and anthropogenic aerosol species. In the GC region, average-ground-based NO2 observations of 40-60 ppb are substantially higher than modeled estimates (5-10 ppb), likely due to model grid resolution, improper boundary layer representation, and poor emissions inventories. Observed ozone concentrations range from 35 ppb (winter) to 80 ppb (summer). The model reproduces the seasonal cycle fairly well, but modeled summer ozone is understimated by approximately 15 ppb and exhibits little interannual variability. For aerosols, springtime dust events dominate the seasonal aerosol cycle. The chemistry-climate model captures the springtime peak aerosol optical depth (AOD) of 0.7-1 but is slightly greater than satellite-derived AOD. Observed AOD decreases in the summer and increases again in the fall due to agricultural burning events in the Nile Delta, yet the model underestimates this fall observed AOD peak, as standard emissions inventories underestimate this burning and the resulting aerosol emissions. Our comparison of modeled gas and particulate phase atmospheric chemistry in the GC region indicates that improved emissions inventories of mobile sources and other anthropogenic activities are needed to improve air quality simulations in this region.

  19. New Boundaries for the B-Model

    E-Print Network [OSTI]

    Bergman, Aaron

    2008-01-01

    Witten couples the open topological B-model to a holomorphic vector bundle by adding to the boundary of the worldsheet a Wilson loop for an integrable connection on the bundle. Using the descent procedure for boundary vertex operators in this context, I generalize this construction to write a worldsheet coupling for a graded vector bundle with an integrable superconnection. I then compute the open string vertex operators between two such boundaries. A theorem of J. Block gives that this is equivalent to coupling the B-model to an arbitrary object in the derived category.

  20. DIVISION OF MARINE AND ATMOSPHERIC CHEMISTRY

    E-Print Network [OSTI]

    Shyu, Mei-Ling

    DIVISION OF MARINE AND ATMOSPHERIC CHEMISTRY The missions of the Division of Marine and Atmospheric Chemistry (MAC) are to carry out broadly based research on the chemistry of the atmosphere and marine and stratosphere. Atmospheric Chemistry Research activities in atmospheric chemistry and modeling are diverse

  1. On the Beavers-Joseph-Saffman boundary condition for curved interfaces

    E-Print Network [OSTI]

    Sören Dobberschütz

    2015-04-22

    The appropriate boundary condition between an unconfined incompressible viscous fluid and a porous medium is given by the law of Beavers and Joseph. The latter has been justified both experimentally and mathematically, using the method of periodic homogenisation. However, all results so far deal only with the case of a planar boundary. In this work, we consider the case of a curved, macroscopically periodic boundary. By using a coordinate transformation, we obtain a description of the flow in a domain with a planar boundary, for which we derive the effective behaviour: The effective velocity is continuous in normal direction. Tangential to the interface, a slip occurs. Additionally, a pressure jump occurs. The magnitude of the slip velocity as well as the jump in pressure can be determined with the help of a generalised boundary layer function. The results indicate the validity of a generalised law of Beavers and Joseph, where the geometry of the interface has an influence on the slip and jump constants.

  2. Network layer Connectionless datagram forwarding

    E-Print Network [OSTI]

    (passed down by transport layer) into datagrams Destination host delivers segments up to transport layer by the cold war " If there exists a path, routers will put it in the routing table automatically Forwarding in the original order Physical Link Network Transport Application Physical Link Network Transport Application

  3. Response of a boundless two-layer ocean to atmospheric disturbancesResponse of a boundless two-layer ocean to atmospheric disturbances 

    E-Print Network [OSTI]

    Kajiura, Kinjiro; Kajiura, Kinjiro

    1958-01-01

    for the meeting ? Getting the meeting started ? Giving reports ? Discussing new business ? Amending a motion ? Nominating and electing club officers. Use this information as it best fits your group. Remember that each session is part of the overall club... of Motions (in order of rank) Classification of Motion Second Required Debatable Amendable Vote Required Can Be Reconsidered Privileged Motions 26 Adjourn (when unqualified) Yes No No Majority No 27 Orders of the Day No No No 1 No Incidental Motions...

  4. A FREE BOUNDARY PROBLEM ARISING FROM SEGREGATION ...

    E-Print Network [OSTI]

    2013-06-18

    In this work, we show how to obtain a free boundary problem as the limit of a fully non linear elliptic .... b) to find the solution for a optimal partition problem.

  5. PRE-PRECIPITATION PHENOMENA AT GRAIN BOUNDARIES

    E-Print Network [OSTI]

    Briceno-Valero, J.

    2010-01-01

    13820 DE82 0 1 2 7 9 4 PRE-PRECIPITATION PHENOMENA AT GRAINof any evidence suggesting precipitation has occurred. Theand grain boundary precipitation have shown (1) that there

  6. Process for forming epitaxial perovskite thin film layers using halide precursors

    DOE Patents [OSTI]

    Clem, Paul G. (Albuquerque, NM); Rodriguez, Mark A. (Albuquerque, NM); Voigt, James A. (Corrales, NM); Ashley, Carol S. (Albuquerque, NM)

    2001-01-01

    A process for forming an epitaxial perovskite-phase thin film on a substrate. This thin film can act as a buffer layer between a Ni substrate and a YBa.sub.2 Cu.sub.3 O.sub.7-x superconductor layer. The process utilizes alkali or alkaline metal acetates dissolved in halogenated organic acid along with titanium isopropoxide to dip or spin-coat the substrate which is then heated to about 700.degree. C. in an inert gas atmosphere to form the epitaxial film on the substrate. The YBCO superconductor can then be deposited on the layer formed by this invention.

  7. Suppression of Grain Boundaries in Graphene Growth on Superstructured...

    Office of Scientific and Technical Information (OSTI)

    Suppression of Grain Boundaries in Graphene Growth on Superstructured Mn-Cu(111) Surface Prev Next Title: Suppression of Grain Boundaries in Graphene Growth on...

  8. Heat content asymptotics with transmittal and transmission boundary conditions

    E-Print Network [OSTI]

    Peter Gilkey; Klaus Kirsten

    2002-06-14

    We study the heat content asymptotics on a Riemannian manifold with smoooth boundary defined by Dirichlet, Neumann, transmittal and transmission boundary conditions.

  9. Singular perturbation problem in boundary/fractional combustion

    E-Print Network [OSTI]

    2015-08-18

    reaction-diffusion equation, where the reaction term is of combustion type. ... Free boundary problem, combustion theory, boundary reaction- diffusion, fractional ...

  10. EA-1973: Kootenai River Restoration at Bonners Ferry, Boundary...

    Energy Savers [EERE]

    73: Kootenai River Restoration at Bonners Ferry, Boundary County, Idaho EA-1973: Kootenai River Restoration at Bonners Ferry, Boundary County, Idaho Summary Bonneville Power...

  11. Technoeconomic Boundary Analysis of Biological Pathways to Hydrogen...

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

    Boundary Analysis of Biological Pathways to Hydrogen Production Technoeconomic Boundary Analysis of Biological Pathways to Hydrogen Production Report documenting the biological and...

  12. Behaviour of boundary functions for quantum billiards

    E-Print Network [OSTI]

    A. Bäcker; S. Fürstberger; R. Schubert; F. Steiner

    2002-10-16

    We study the behaviour of the normal derivative of eigenfunctions of the Helmholtz equation inside billiards with Dirichlet boundary condition. These boundary functions are of particular importance because they uniquely determine the eigenfunctions inside the billiard and also other physical quantities of interest. Therefore they form a reduced representation of the quantum system, analogous to the Poincar\\'e section of the classical system. For the normal derivatives we introduce an equivalent to the standard Green function and derive an integral equation on the boundary. Based on this integral equation we compute the first two terms of the mean asymptotic behaviour of the boundary functions for large energies. The first term is universal and independent of the shape of the billiard. The second one is proportional to the curvature of the boundary. The asymptotic behaviour is compared with numerical results for the stadium billiard, different limacon billiards and the circle billiard, and good agreement is found. Furthermore we derive an asymptotic completeness relation for the boundary functions.

  13. ATMOSPHERIC CHEMISTRY - RESPONSE TO HUMAN INFLUENCE

    E-Print Network [OSTI]

    LOGAN, J; PRATHER, M; WOFSY, S; MCELROY, M

    1978-01-01

    Trans. II 70, 253. ATMOSPHERIC CHEMISTRY Clyne, M. A. A. &data for modelling atmospheric chemistry. NBS Technical NoteChem. 80, 2711. ATMOSPHERIC CHEMISTRY Sanadze, G. A. 1963 On

  14. IMPROVED QUASISTEADYSTATEAPPROXIMATION METHODS FOR ATMOSPHERIC CHEMISTRY INTEGRATION #

    E-Print Network [OSTI]

    Jay, Laurent O.

    IMPROVED QUASI­STEADY­STATE­APPROXIMATION METHODS FOR ATMOSPHERIC CHEMISTRY INTEGRATION # L. O. JAY QSSA are presented. Key words. atmospheric chemistry, sti# ordinary di#erential equations, quasi PII. S1064827595283033 1. Introduction. As our scientific understanding of atmospheric chemistry

  15. Stratospheric Temperatures and Water Loss from Moist Greenhouse Atmospheres of Earth-like Planets

    E-Print Network [OSTI]

    Kasting, James F; Kopparapu, Ravi Kumar

    2015-01-01

    A radiative-convective climate model is used to calculate stratospheric temperatures and water vapor concentrations for ozone-free atmospheres warmer than that of modern Earth. Cold, dry stratospheres are predicted at low surface temperatures, in agreement with recent 3-D calculations. However, at surface temperatures above 350 K, the stratosphere warms and water vapor becomes a major upper atmospheric constituent, allowing water to be lost by photodissociation and hydrogen escape. Hence, a 'moist greenhouse' explanation for loss of water from Venus, or some exoplanet receiving a comparable amount of stellar radiation, remains a viable hypothesis. Temperatures in the upper parts of such atmospheres are well below those estimated for a gray atmosphere, and this factor should be taken into account when performing 'inverse' climate calculations to determine habitable zone boundaries using 1-D models.

  16. Global atmospheric chemistry: Integrating over fractional cloud cover

    E-Print Network [OSTI]

    Neu, Jessica L; Prather, Michael J; Penner, Joyce E

    2007-01-01

    trace gases and atmospheric chemistry, in Climate Change2007 Global atmospheric chemistry: Integrating over2007), Global atmospheric chemistry: Integrating over

  17. Infrared Observations of Exoplanet Atmospheres

    E-Print Network [OSTI]

    Crossfield, Ian James Mills

    2012-01-01

    However, atmospheres of cool planets can still be studiedvia outgassing as the planet cools (Rogers & Seager 2010).at low resolution) and the cool, low-mass planet GJ 1214b (

  18. Doctoral Defense "Carbon Dioxide Capture on Elastic Layered Metal-Organic

    E-Print Network [OSTI]

    Kamat, Vineet R.

    Doctoral Defense "Carbon Dioxide Capture on Elastic Layered Metal-Organic Framework Adsorbents Professor, Civil & Environmental Engineering The steady rising level of atmospheric carbon dioxide resulting to the economy that is heavily relied on fossil fuels. Although the transition of the existing carbon

  19. TOWARDS A CLOUD CEILOMETER NETWORK REPORTING MIXING LAYER HEIGHT Wiel M.F. Wauben

    E-Print Network [OSTI]

    Wauben, Wiel

    profiles if the aerosol concentrations are not too low. Since aerosol is well mixed in the atmospheric in the backscatter profile (cf. Wauben et al., 2006). Sometimes, medium and low clouds can also be missed or falsely1 TOWARDS A CLOUD CEILOMETER NETWORK REPORTING MIXING LAYER HEIGHT Wiel M.F. Wauben 1 , Marijn de

  20. OFFLINE EVALUATION OF SIX SURFACE LAYER PARAMETERIZATION SCHEMES AGAINST OBSERVATIONS AT THE ARM SGP SITE

    E-Print Network [OSTI]

    OFFLINE EVALUATION OF SIX SURFACE LAYER PARAMETERIZATION SCHEMES AGAINST OBSERVATIONS AT THE ARM of surface fluxes collected by the DOE (Department of Energy) ARM (Atmospheric Radiation Measurement) program to quantify the uncertainty/discrepancy between the ARM measurements based on the EC (Eddy Correlation