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Note: This page contains sample records for the topic "latent heat flux" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

ARM - Measurement - Latent heat flux  

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

govMeasurementsLatent heat flux govMeasurementsLatent heat flux ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Latent heat flux The time rate of flow for the specific enthalpy difference between two phases of a substance at the same temperature, typically water. Categories Surface Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments CO2FLX : Carbon Dioxide Flux Measurement Systems ECOR : Eddy Correlation Flux Measurement System EBBR : Energy Balance Bowen Ratio Station

2

Global patterns of landatmosphere fluxes of carbon dioxide, latent heat, and sensible heat derived from eddy covariance,  

E-Print Network [OSTI]

(NEE), latent energy (LE), and sensible heat (H) based on remote sensing indices, climateGlobal patterns of landatmosphere fluxes of carbon dioxide, latent heat, and sensible heat derived

Chen, Jiquan

3

Spatially Distributed CO2, Sensible, and Latent Heat Fluxes Over the  

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

Spatially Distributed CO2, Sensible, and Latent Heat Fluxes Over the Spatially Distributed CO2, Sensible, and Latent Heat Fluxes Over the Southern Great Plains Berry, Joseph Carnegie Inst.of Washington Riley, William Lawrence Berkeley National Laboratory Biraud, Sebastien Lawrence Berkeley National Laboratory Torn, Margaret Lawrence Berkeley National Laboratory Fischer, Marc Lawrence Berkeley National Laboratory Category: Atmospheric State and Surface Vegetation strongly influences the spatial distribution of surface sensible and latent heat fluxes, and also impacts the ecosystem to atmosphere CO2 exchanges. We describe here a methodology to estimate surface energy fluxes and Net Ecosystem Exchange (NEE) of CO2 continuously over the Southern Great Plains, using (1) data from the Atmospheric Radiation Measurement (ARM) program in Oklahoma and Kansas; (2) meteorological forcing data from

4

A. Gershunov R. Roca Coupling of latent heat flux and the greenhouse effect by large-scale  

E-Print Network [OSTI]

A. Gershunov Ã? R. Roca Coupling of latent heat flux and the greenhouse effect by large Abstract Coupled variability of the greenhouse effect (GH) and latent heat flux (LHF) over the tropical of convection) form regions of strong greenhouse effect in tropical convergence zones while subtropical high

5

Latent Heat Flux and Canopy Conductance Based on Penman–Monteith, Priestley–Taylor Equation, and Bouchet’s Complementary Hypothesis  

Science Journals Connector (OSTI)

A novel method is presented to analytically resolve the terrestrial latent heat flux (?E) and conductances (boundary layer gB and surface gS) using net radiation (RN), ground heat flux (G), air temperature (Ta), and relative humidity (RH). This ...

Kaniska Mallick; Andrew Jarvis; Joshua B. Fisher; Kevin P. Tu; Eva Boegh; Dev Niyogi

2013-04-01T23:59:59.000Z

6

Convective heat transfer enhancement of laminar flow of latent functionally thermal fluid in a circular tube with constant heat flux: internal heat source model and its application  

Science Journals Connector (OSTI)

This paper analyzes the convective heat transfer enhancement mechanism of latent heat functionally thermal fluid. By using the proposed internal heat source model, the influence of each factor affecting the heat

Yinping Zhang; Xianxu Hu; Qing Hao; Xin Wang

2003-04-01T23:59:59.000Z

7

Regional CO2 and latent heat surface fluxes in the Southern Great Plains: Measurements, modeling, and scaling  

SciTech Connect (OSTI)

Characterizing net ecosystem exchanges (NEE) of CO{sub 2} and sensible and latent heat fluxes in heterogeneous landscapes is difficult, yet critical given expected changes in climate and land use. We report here a measurement and modeling study designed to improve our understanding of surface to atmosphere gas exchanges under very heterogeneous land cover in the mostly agricultural U.S. Southern Great Plains (SGP). We combined three years of site-level, eddy covariance measurements in several of the dominant land cover types with regional-scale climate data from the distributed Mesonet stations and Next Generation Weather Radar precipitation measurements to calibrate a land surface model of trace gas and energy exchanges (isotope-enabled land surface model (ISOLSM)). Yearly variations in vegetation cover distributions were estimated from Moderate Resolution Imaging Spectroradiometer normalized difference vegetation index and compared to regional and subregional vegetation cover type estimates from the U.S. Department of Agriculture census. We first applied ISOLSM at a 250 m spatial scale to account for vegetation cover type and leaf area variations that occur on hundred meter scales. Because of computational constraints, we developed a subsampling scheme within 10 km 'macrocells' to perform these high-resolution simulations. We estimate that the Atmospheric Radiation Measurement Climate Research Facility SGP region net CO{sub 2} exchange with the local atmosphere was -240, -340, and -270 gC m{sup -2} yr{sup -1} (positive toward the atmosphere) in 2003, 2004, and 2005, respectively, with large seasonal variations. We also performed simulations using two scaling approaches at resolutions of 10, 30, 60, and 90 km. The scaling approach applied in current land surface models led to regional NEE biases of up to 50 and 20% in weekly and annual estimates, respectively. An important factor in causing these biases was the complex leaf area index (LAI) distribution within cover types. Biases in predicted weekly average regional latent heat fluxes were smaller than for NEE, but larger than for either ecosystem respiration or assimilation alone. However, spatial and diurnal variations of hundreds of W m{sup -2} in latent heat fluxes were common. We conclude that, in this heterogeneous system, characterizing vegetation cover type and LAI at the scale of spatial variation are necessary for accurate estimates of bottom-up, regional NEE and surface energy fluxes.

Riley, W. J.; Biraud, S.C.; Torn, M.S.; Fischer, M.L.; Billesbach, D.P.; Berry, J.A.

2009-08-15T23:59:59.000Z

8

Latent heat of nuclear matter  

E-Print Network [OSTI]

We study the latent heat of the liquid-gas phase transition in symmetric nuclear matter using self-consistent mean-field calculations with a few Skyrme forces. The temperature dependence of the latent heat is rather independent of the mean-field parametrization and can be characterized by a few parameters. At low temperatures, the latent heat tends to the saturation energy. Near the critical point, the latent heat goes to zero with a well-determined mean-field critical exponent. A maximum value of the latent heat in the range l ~ 25-30 MeV is found at intermediate temperatures, which might have experimental relevance. All these features can be explained from very basic principles.

Arianna Carbone; Artur Polls; Arnau Rios; Isaac Vidaña

2010-12-10T23:59:59.000Z

9

Optical heat flux gauge  

DOE Patents [OSTI]

A heat flux gauge comprising first and second thermographic phosphor layers separated by a layer of a thermal insulator. The gauge may be mounted on a surface with the first thermographic phosphor in contact with the surface. A light source is directed at the gauge, causing the phosphors to luminesce. The luminescence produced by the phosphors is collected and its spectra analyzed in order to determine the heat flux on the surface. First and second phosphor layers must be different materials to assure that the spectral lines collected will be distinguishable.

Noel, Bruce W. (Espanola, NM); Borella, Henry M. (Santa Barbara, CA); Cates, Michael R. (Oak Ridge, TN); Turley, W. Dale (Santa Barbara, CA); MaCarthur, Charles D. (Clayton, OH); Cala, Gregory C. (Dayton, OH)

1991-01-01T23:59:59.000Z

10

Optical heat flux gauge  

DOE Patents [OSTI]

A heat flux gauge comprising first and second thermographic phosphor layers separated by a layer of a thermal insulator wherein each thermographic layer comprises a plurality of respective thermographic phosphors. The gauge may be mounted on a surface with the first thermographic phosphor in contact with the surface. A light source is directed at the gauge, causing the phosphors to luminesce. The luminescence produced by the phosphors is collected and its spectra analyzed in order to determine the heat flux on the surface. First and second phosphor layers must be different materials to assure that the spectral lines collected will be distinguishable.

Noel, Bruce W. (Espanola, NM); Borella, Henry M. (Santa Barbara, CA); Cates, Michael R. (Oak Ridge, TN); Turley, W. Dale (Santa Barbara, CA); MacArthur, Charles D. (Clayton, OH); Cala, Gregory C. (Dayton, OH)

1991-01-01T23:59:59.000Z

11

Optical heat flux gauge  

DOE Patents [OSTI]

A heat flux gauge comprising first and second thermographic phosphor layers separated by a layer of a thermal insulator, wherein each thermographic layer comprises a plurality of respective thermographic sensors in a juxtaposed relationship with respect to each other. The gauge may be mounted on a surface with the first thermographic phosphor in contact with the surface. A light source is directed at the gauge, causing the phosphors to luminesce. The luminescence produced by the phosphors is collected and its spectra analyzed in order to determine the heat flux on the surface. First and second phosphor layers must be different materials to assure that the spectral lines collected will be distinguishable.

Noel, Bruce W. (Espanola, NM); Borella, Henry M. (Santa Barbara, CA); Cates, Michael R. (Oak Ridge, TN); Turley, W. Dale (Santa Barbara, CA); MacArthur, Charles D. (Clayton, OH); Cala, Gregory C. (Dayton, OH)

1991-01-01T23:59:59.000Z

12

Experimental Research on Solar Assisted Heat Pump Heating System with Latent Heat Storage  

E-Print Network [OSTI]

-reaching meaning of solving energy and environment problems if new type energy conservation and environment protection heating system ? solar assisted ground-source heat pump (SAGHP) heating system with a latent heat storage tank will be practical... was established at the laboratory of construction energy conservation in Harbin Institute of Technology (HIT) in 2004. It added a latent heat storage tank in original SAGHP system. The schematic diagram of the system is shown in Figure 1. The experimental...

Han, Z.; Zheng, M.; Liu, W.; Wang, F.

2006-01-01T23:59:59.000Z

13

TURBULENT HEAT FLUXES ABOVE A SUBURBAN RESERVOIR – A CASE STUDY FROM GERMANY  

Science Journals Connector (OSTI)

With the objective of quantifying turbulent sensible (QH) and latent (QE) heat fluxes above a suburban reservoir, a micro-meteorological turbulence measurement campaign using the eddy-covariance technique was carried out between June and November ...

Anja Goldbach; Wilhelm Kuttler

14

ARM - Measurement - Sensible heat flux  

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

govMeasurementsSensible heat flux govMeasurementsSensible heat flux ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Sensible heat flux The time rate of flow for the energy transferred from a warm or hot surface to whatever is touching it, typically air. Categories Surface Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments CO2FLX : Carbon Dioxide Flux Measurement Systems ECOR : Eddy Correlation Flux Measurement System EBBR : Energy Balance Bowen Ratio Station

15

ARM - Measurement - Soil heat flux  

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

heat flux heat flux ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Soil heat flux A quantity measured according to the formula B = {lambda}(dT/dz), where {lambda} is the conductivity of the soil that the heat is moving through. Categories Surface Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments CO2FLX : Carbon Dioxide Flux Measurement Systems EBBR : Energy Balance Bowen Ratio Station SEBS : Surface Energy Balance System External Instruments

16

Photovoltaic roof heat flux  

E-Print Network [OSTI]

Effect of building integrated photovoltaics on microclimateof a building's integrated-photovoltaics on heating a n dgaps for building- integrated photovoltaics, Solar Energy

Samady, Mezhgan Frishta

2011-01-01T23:59:59.000Z

17

The Effects of Latent Heating on The Extratropical Transition of Typhoon Sinlaku  

E-Print Network [OSTI]

The Effects of Latent Heating on The Extratropical Transition of Typhoon Sinlaku Dr. Jenni Evans and completion to latent heating from the storm and surrounding area. Two sets of simulations using the Weather Research and Forecasting (WRF) model are examined to clarify the role of latent heating during ET

Bjørnstad, Ottar Nordal

18

Technical Sessions Measurements of Surface Heat Flux Over Contrasting Surfaces  

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

Measurements of Surface Heat Flux Measurements of Surface Heat Flux Over Contrasting Surfaces R. L. Coulter J. D. Shannon T. J. Martin Argonne National Laboratory Argonne, IL 60439 In a multilaboratory field study held near Boardman in northeastern Oregon in June 1991 and described in greater detail elsewhere (Doran et al. 1991), various properties of the surface and lower atmospheric boundary layer over heavily irrigated cropland and adjacent desert steppe were investigated. The locale was selected because its disparate characteristics over various spatial scales stress the ability of general circulation models (GCMs) to describe lower boundary conditions, particularly across the discontinuity between desert (in which turbulent flux of heat must be primarily as sensible heat) and large irrigated tracts (in which turbulent flux of latent heat should be the larger term).

19

Heat flux limiting sleeves  

DOE Patents [OSTI]

A heat limiting tubular sleeve extending over only a portion of a tube having a generally uniform outside diameter, the sleeve being open on both ends, having one end thereof larger in diameter than the other end thereof and having a wall thickness which decreases in the same direction as the diameter of the sleeve decreases so that the heat transfer through the sleeve and tube is less adjacent the large diameter end of the sleeve than adjacent the other end thereof.

Harris, William G. (Tampa, FL)

1985-01-01T23:59:59.000Z

20

Heat flux solarimeter  

SciTech Connect (OSTI)

The solarimeter presented in this work is easy to assemble. It is calibrated and its performance is validated by means of Hottel's method. Finally, the curves obtained with this solarimeter are compared to the ones obtained with a commercial solarimeter. This device is based on the evaluation of the heat flow in a metal rod. In consequence, measurements are not affected by ambient temperature variations. On the other hand, there is a linear relationship between the temperatures measured at the rod ends and the incident radiation, as can be concluded both from the theory of its operation and the calibration lines obtained. The results obtained from the global irradiance measurements in the area of Los Polvorines (Buenos Aires Province), together with a preliminary evaluation of the solarimeter's response time, are presented in this work. (author)

Sartarelli, A.; Vera, S.; Cyrulies, E. [Instituto de Desarrollo Humano, Univ. Nac. de Gral. Sarmiento (IDH, UNGS), Los Polvorines (Argentina); Echarri, R. [Instituto de Desarrollo Humano, Univ. Nac. de Gral. Sarmiento (IDH, UNGS), Los Polvorines (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Samson, I. [INTEC (Instituto Tecnologico Santo Domingo), Santo Domingo (Dominican Republic)

2010-12-15T23:59:59.000Z

Note: This page contains sample records for the topic "latent heat flux" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Isentropic Slopes, Downgradient Eddy Fluxes, and the Extratropical Atmospheric Circulation Response to Tropical Tropospheric Heating  

E-Print Network [OSTI]

to Tropical Tropospheric Heating AMY H. BUTLER NOAA/NWS/NCEP/Climate Prediction Center, Camp Springs, Maryland of the midlatitude jets and their associated eddy fluxes of heat and potential vorticity (PV). Experiments run latent heating and thus locally enhanced warming in the tropical troposphere. Here the authors provide

22

High Heat Flux Thermoelectric Module Using Standard Bulk Material...  

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

Heat Flux Thermoelectric Module Using Standard Bulk Material High Heat Flux Thermoelectric Module Using Standard Bulk Material Presents high heat flux thermoelectric module design...

23

An investigation into the thermal properties of selected sensible and latent heat storage materials  

E-Print Network [OSTI]

in the latent heat of fusion. Considerable work has been done in analyzing latent heat storage systems. Telkes and Raymond [lj did early work with a sodium sulfate system using sealed drums. iVore recent experimental work was conducted with other salt...

Wood, Stanley Clayton

1982-01-01T23:59:59.000Z

24

Heat Capacity and Latent Heat The objective of this laboratory is for you to explore the heat capacity of materials due to atomic  

E-Print Network [OSTI]

Heat Capacity and Latent Heat Objective The objective of this laboratory is for you to explore the heat capacity of materials due to atomic vibrations and the latent heat of phase, dataacquisition software, plotting and analysis software Introduction Knowledge of the heat capacity

Braun, Paul

25

Project Profile: Hybrid Organic Silicone HTF Utilizing Endothermic Chemical Reactions for Latent Heat Storage  

Broader source: Energy.gov [DOE]

Los Alamos National Laboratory, under an ARRA CSP Award, is developing a thermally stable, working heat transfer fluid (HTF) that is integrated with chemical reactions as a methodology to store large amounts of latent heat.

26

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

SciTech Connect (OSTI)

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.

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

2014-01-02T23:59:59.000Z

27

ARM Energy Balance Bowen Ratio (EBBR) station: surf. heat flux and related data, 30-min  

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

The Energy Balance Bowen Ratio (EBBR) system produces 30-min estimates of the vertical fluxes of sensible and latent heat at the local surface. Flux estimates are calculated from observations of net radiation, soil surface heat flux, and the vertical gradients of temperature and relative humidity. Meteorological data collected by the EBBR are used to calculate bulk aerodynamic fluxes, which are used in the Bulk Aerodynamic Technique (BA) EBBR value-added product (VAP) to replace sunrise and sunset spikes in the flux data. A unique aspect of the system is the automatic exchange mechanism (AEM), which helps to reduce errors from instrument offset drift.

Cook, David

28

Latent heating contribution from precipitation systems with different sizes, depths and intensities in the tropics  

Science Journals Connector (OSTI)

Latent Heating (LH) from precipitation systems with different sizes, depths and convective intensities are quantified with 15 years of LH retrievals from Version 7 Precipitation Radar (PR) products of the Tropical Rainfall Measuring Mission (TRMM)...

Chuntao Liu; Shoichi Shige; Yukari N. Takayabu; Edward Zipser

29

A model for the latent heat of melting in free standing metal nanoparticles  

SciTech Connect (OSTI)

Nanoparticles of many metals are known to exhibit scale dependent latent heats of melting. Analytical models for this phenomenon have so far failed to completely capture the observed phenomena. Here we present a thermodynamic analysis for the melting of metal nanoparticles in terms of their internal energy and a scale dependent surface tension proposed by Tolman. The resulting model predicts the scale dependence of the latent heat of melting and is confirmed using published data for tin and aluminum.

Shin, Jeong-Heon; Deinert, Mark R., E-mail: mdeinert@mail.utexas.edu [Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78715 (United States)

2014-04-28T23:59:59.000Z

30

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

SciTech Connect (OSTI)

Four types of heat flux gages (Gardon, Schmidt-Boelter, Directional Flame Temperature, and High Temperature Heat Flux Sensor) were assessed and compared under flux conditions ranging between 100-1000 kW/m2, such as those seen in hydrocarbon fire or propellant fire conditions. Short duration step and pulse boundary conditions were imposed using a six-panel cylindrical array of high-temperature tungsten lamps. Overall, agreement between all gages was acceptable for the pulse tests and also for the step tests. However, repeated tests with the HTHFS with relatively long durations at temperatures approaching 1000%C2%B0C showed a substantial decrease (10-25%) in heat flux subsequent to the initial test, likely due to the mounting technique. New HTHFS gages have been ordered to allow additional tests to determine the cause of the flux reduction.

Blanchat, Thomas K.; Hanks, Charles R.

2013-04-01T23:59:59.000Z

31

Longitudinal variation of tides in the MLT region: 2. Relative effects of solar radiative and latent heating  

E-Print Network [OSTI]

of solar radiative and latent heating Xiaoli Zhang,1 Jeffrey M. Forbes,1 and Maura E. Hagan2 Received 11 study examines the relative importance of radiative heating and latent heating in accounting (GSWM) and new tidal heating rates derived from International Satellite Cloud Climatology Project (ISCCP

Forbes, Jeffrey

32

Critical heat flux test apparatus  

DOE Patents [OSTI]

An apparatus for testing, in situ, highly irradiated specimens at high temperature transients is provided. A specimen, which has a thermocouple device attached thereto, is manipulated into test position in a sealed quartz heating tube by a robot. An induction coil around a heating portion of the tube is powered by a radio frequency generator to heat the specimen. Sensors are connected to monitor the temperatures of the specimen and the induction coil. A quench chamber is located below the heating portion to permit rapid cooling of the specimen which is moved into this quench chamber once it is heated to a critical temperature. A vacuum pump is connected to the apparatus to collect any released fission gases which are analyzed at a remote location.

Welsh, Robert E. (West Mifflin, PA); Doman, Marvin J. (McKeesport, PA); Wilson, Edward C. (West Mifflin, PA)

1992-01-01T23:59:59.000Z

33

Spatial and Temporal Distribution of Latent Heating in the South Asian Monsoon Region  

Science Journals Connector (OSTI)

Information from the Tropical Rainfall Measuring Mission (TRMM) level 3 monthly 0.5° × 0.5° Convective and Stratiform Heating (CSH) product and TRMM Microwave Imager (TMI) 2A12 datasets is used to examine the four-dimensional latent heating (LH) ...

Manuel D. Zuluaga; Carlos D. Hoyos; Peter J. Webster

2010-04-01T23:59:59.000Z

34

Vacuum energy and the latent heat of AdS-Kerr black holes  

E-Print Network [OSTI]

Phase transitions for rotating asymptotically anti-de Sitter black holes in four dimensions are described in the $P-T$ plane, in terms of the Hawking temperature and the pressure provided by the cosmological constant. The difference between constant angular momentum and constant angular velocity is highlighted, the former has a second order phase transition while the latter does not. If the angular momentum is fixed there a line of first order phase transitions terminating at a critical point with a second order phase transition and vanishing latent heat, while if the angular velocity is fixed there is a line of first order phase transitions terminating at a critical point with infinite latent heat. For constant angular velocity the analytic form of the phase boundary is determined, latent heats derived and the Clapeyron equation verified.

Brian P. Dolan

2014-07-15T23:59:59.000Z

35

Effects of urban land cover modifications in a mesoscale meteorological model on surface temperature and heat fluxes in the Phoenix metropolitan area.  

E-Print Network [OSTI]

and latent heat fluxes and therefore the ground temperature, Tg. Evaporation, E, for each grid cell temperature and heat fluxes in the Phoenix metropolitan area. S. Grossman-Clarke1, J.A. Zehnder2, and W) satellite images [2]. The data were upscaled to a 30-second grid and used to augment and correct

Hall, Sharon J.

36

High temperature latent heat thermal energy storage: Phase change materials, design considerations and performance enhancement techniques  

Science Journals Connector (OSTI)

Abstract A very common problem in solar power generation plants and various other industrial processes is the existing gap between the period of thermal energy availability and its period of usage. This situation creates the need for an effective method by which excess heat can be stored for later use. Latent heat thermal energy storage is one of the most efficient ways of storing thermal energy through which the disparity between energy production or availability and consumption can be corrected, thus avoiding wastage and increasing the process efficiency. This paper reviews a series of phase change materials, mainly inorganic salt compositions and metallic alloys, which could potentially be used as storage media in a high temperature (above 300 °C) latent heat storage system, seeking to serve the reader as a comprehensive thermophysical properties database to facilitate the material selection task for high temperature applications. Widespread utilization of latent heat storage systems has been held back by the poor thermal conductivity and some other inherent drawbacks of the use of PCMs; this paper reviews several heat transfer and performance enhancement techniques proposed in the literature and discusses a number of design considerations that must be taken into account aiming to provide a broad overview for the design of high temperature latent heat based thermal energy storage systems.

Bruno Cárdenas; Noel León

2013-01-01T23:59:59.000Z

37

Latent heat fluxes through nano-engineered porous materials  

E-Print Network [OSTI]

Micro- and nano-scale truss architectures provide mechanical strength, light weight, and breatheability in polymer barriers. Liquid evaporation and transport of resulting vapor through truss voids (pores) cools surfaces ...

Traum, Matthew J. (Matthew Jason), 1977-

2007-01-01T23:59:59.000Z

38

Heat flux dynamics in dissipative cascaded systems  

E-Print Network [OSTI]

We study the dynamics of heat flux in the thermalization process of a pair of identical quantum system that interact dissipatively with a reservoir in a {\\it cascaded} fashion. Despite the open dynamics of the bipartite system S is globally Lindbladian, one of the subsystems "sees" the reservoir in a state modified by the interaction with the other subsystem and hence it undergoes a non-Markovian dynamics. As a consequence, the heat flow exhibits a non-exponential time behaviour which can greatly deviate from the case where each party is independently coupled to the reservoir. We investigate both thermal and correlated initial states of $S$ and show that the presence of correlations at the beginning can considerably affect the heat flux rate. We carry out our study in two paradigmatic cases -- a pair of harmonic oscillators with a reservoir of bosonic modes and two qubits with a reservoir of fermionic modes -- and compare the corresponding behaviours. In the case of qubits and for initial thermal states, we find that the trace distance discord is at any time interpretable as the correlated contribution to the total heat flux.

Salvatore Lorenzo; Alessandro Farace; Francesco Ciccarello; G. Massimo Palma; Vittorio Giovannetti

2014-12-19T23:59:59.000Z

39

Quarterly Journal of the Royal Meteorological Society Q. J. R. Meteorol. Soc. 140: 139150, January 2014 A The role of latent heating in warm frontogenesis  

E-Print Network [OSTI]

2014 A The role of latent heating in warm frontogenesis Adele L. Igel* and Susan C. van den Heever.igel@colostate.edu The role of latent heating from individual cloud processes associated with one part of a springtime droplet nucleation are the largest sources of latent heat along the frontal surface and together produce

Collett Jr., Jeffrey L.

40

Latent Heat or Phase Change Thermal Energy Storage  

Science Journals Connector (OSTI)

It has been explained in sections 1.6 and 1.6.2 how phase change materials (PCM) have considerably higher thermal energy storage densities compared to sensible heat storage materials and are able to absorb or rel...

H. P. Garg; S. C. Mullick; A. K. Bhargava

1985-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "latent heat flux" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Surface heat fluxes in the Western Equatorial Pacific Ocean  

Science Journals Connector (OSTI)

Estimates of the components of the surface heat flux in the Western Equatorial Pacific Ocean are presented for a 22-day period, ... found that the net heat flux into the ocean over the 22-day period is not...

N. C. Wells

1995-10-01T23:59:59.000Z

42

Nanofluid \\{PCMs\\} for thermal energy storage: Latent heat reduction mechanisms and a numerical study of effective thermal storage performance  

Science Journals Connector (OSTI)

Abstract The latent heat of fusion of paraffin-based nanofluids has been examined to investigate the use of enhanced phase change materials (PCMs) for thermal energy storage (TES) applications. The nanofluid approach has often been exploited to enhance thermal conductivity of PCMs, but the effects of particle addition on other thermal properties affecting TES are relatively ignored. An experimental study of paraffin-based nanofluids containing various particle sizes of multi-walled carbon nanotubes has been conducted to investigate the effect of nanoparticles on latent heat of fusion. Results demonstrated that the magnitude of nanofluid latent heat reduction increases for smaller diameter particles in suspension. Three possible mechanisms – interfacial liquid layering, Brownian motion, and particle clustering – were examined to explain further reduction in latent heat, through the weakening of molecular bond structures. Although additional research is required to explore detailed mechanisms, experimental evidence suggests that interfacial liquid layering and Brownian motion cannot explain the degree of latent heat reduction observed. A finite element model is also presented as a method of quantifying nanofluid PCM energy storage performance. Thermal properties based on modified effective medium theory and an empirical relation for latent heat of fusion were applied as model parameters to determine energy stored and extracted over a given period of time. The model results show that while micro-scale particle inclusions exhibit some performance enhancement, nanoparticles in \\{PCMs\\} provide no significant improvement in TES performance. With smaller particles, the enhancement in thermal conductivity is not significant enough to overcome the reduction in latent heat of fusion, and less energy is stored over the PCM charge period. Therefore, the nanofluid approach may not be justifiable for energy storage applications. However, since the model parameters are dependent on the material properties of the system observed, storage performance may vary for differing nanofluid materials.

Aitor Zabalegui; Dhananjay Lokapur; Hohyun Lee

2014-01-01T23:59:59.000Z

43

Micro gas turbine cogeneration system with latent heat storage at the University: Part III: Temperature control schedule  

Science Journals Connector (OSTI)

Abstract The latent heat storage system is a novel heat storage system. At the University under service conditions, it was demonstrated with a micro gas turbine (MGT) cogeneration system (CGS). Expanding the latent heat storage system into new applications is expected to save energy economically with high density energy storage and reduce exhaust emissions and reduce operational costs. This is the first demonstration of using a latent heat storage system with CGS under service condition and its characteristics are very important. In Part I, a fixed operating schedule of the system was planned and demonstrated at the University. The charge/discharge cycles of the latent heat storage system were repeated for 407 times. The energy flow test of the system shows the importance of the heat release source and total system design. In Part II, an irregular charge case of the latent heat storage system was discussed when the prime mover of the system was operated at a part load and thermal priority mode. A highly sophisticated system design that solves these problems was necessary for extending the applications of the latent heat storage system. In Part III, a temperature control schedule of the system was demonstrated during winter mornings using a new programmable logic controller (PLC). Using a fixed schedule, the MGT-CGS with latent heat storage reduced the CO2 emission when the energy utilization factor was above 50%. The temperature control schedule was considered to be better than the fixed schedule, both in terms of the operational efficiency of the overall system and CO2 reduction. The temperature control schedule was executed using an empirical formula for the temperature rise in a classroom. The restriction on the operation time by the contract with the gas supplier and the low heating capacity of the CGS affected the heating time and temperature rise. The temperature rise in the classroom was almost proportional to the integrated temperature difference across the hot water header of the heating system. On cold days, the rate of temperature rise produced by the CGS was very slow, therefore, additional heat supplied by the original boiler was used to increase the temperature rise. If larger latent heat storage systems will be developed in future, it will be expected that the temperature of the classrooms are kept more comfortable with less energy consumptions and lower CO2 emission.

Osamu Kurata; Norihiko Iki; Takayuki Matsunuma; Tetsuhiko Maeda; Satoshi Hirano; Katsuhiko Kadoguchi; Hiromi Takeuchi; Hiro Yoshida

2014-01-01T23:59:59.000Z

44

High Heat Flux Thermoelectric Module Using Standard Bulk Material  

Broader source: Energy.gov [DOE]

Presents high heat flux thermoelectric module design for cooling using a novel V-shaped shunt configuration with bulk TE elements achieving high area packing fractions

45

Transient critical heat flux and blowdown heat-transfer studies  

SciTech Connect (OSTI)

Objective of this study is to give a best-estimate prediction of transient critical heat flux (CHF) during reactor transients and hypothetical accidents. To accomplish this task, a predictional method has been developed. Basically it involves the thermal-hydraulic calculation of the heated core with boundary conditions supplied from experimental measurements. CHF predictions were based on the instantaneous ''local-conditions'' hypothesis, and eight correlations (consisting of round-tube, rod-bundle, and transient correlations) were tested against most recent blowdown heat-transfer test data obtained in major US facilities. The prediction results are summarized in a table in which both CISE and Biasi correlations are found to be capable of predicting the early CHF of approx. 1 s. The Griffith-Zuber correlation is credited for its prediction of the delay CHF that occurs in a more tranquil state with slowly decaying mass velocity. In many instances, the early CHF can be well correlated by the x = 1.0 criterion; this is certainly indicative of an annular-flow dryout-type crisis. The delay CHF occurred at near or above 80% void fraction, and the success of the modified Zuber pool-boiling correlation suggests that this CHF is caused by flooding and pool-boiling type hydrodynamic crisis.

Leung, J.C.

1980-05-01T23:59:59.000Z

46

Tracking heat flux sensors for concentrating solar applications  

DOE Patents [OSTI]

Innovative tracking heat flux sensors located at or near the solar collector's focus for centering the concentrated image on a receiver assembly. With flux sensors mounted near a receiver's aperture, the flux gradient near the focus of a dish or trough collector can be used to precisely position the focused solar flux on the receiver. The heat flux sensors comprise two closely-coupled thermocouple junctions with opposing electrical polarity that are separated by a thermal resistor. This arrangement creates an electrical signal proportional to heat flux intensity, and largely independent of temperature. The sensors are thermally grounded to allow a temperature difference to develop across the thermal resistor, and are cooled by a heat sink to maintain an acceptable operating temperature.

Andraka, Charles E; Diver, Jr., Richard B

2013-06-11T23:59:59.000Z

47

High flux heat transfer in a target environment  

E-Print Network [OSTI]

High flux heat transfer in a target environment T. Davenne High Power Targets Group Rutherford Valid for: Consider turbulent heat transfer in a 1.5mm diameter pipe ­ Dittus Boelter correlation Achenbach correlation for heat transfer in a packed bed of spheres Max power density for a sphere

McDonald, Kirk

48

The Influence of Moisture Content on the Evaluation of Latent Heat of Molten Salts used for Thermal Energy Storage Applications  

Science Journals Connector (OSTI)

Abstract Precise measurements of the thermo-physical properties are essential for the process design of thermal energy storage systems. This paper is concerned with the measurement of heat of fusion of molten salts, which plays a key role in determining the storage capacity of latent heat based thermal energy storage units. The focus of the work is on the effect of moisture content of molten salts on latent heat measurements using a differential scanning calorimetry. The results reveal that, the change in the mass of the samples investigated is due to moisture content, and hence, this leads to a reduction in the value of the heat of fusion of the phase change material. For instance, the heat of fusion for one of the wet samples (containing moisture) was determined to be 314.29J/g. However, the calculated heat of fusion for the same sample without moisture is found to be 350.029J/g. This is associated with the methodology of the DSC analysis, which does not consider the mass of the moisture in the sample. It is found that, the deviation in the heat of fusion due to the effect of the moisture content in the investigated samples is proportional to the amount of moisture in the original sample. Therefore, it is imperative to consider the effect of the moisture content on the evaluation of the latent heat of molten salts. In order to obtain reliable findings, either the samples should be dried and then weighed promptly, or weighed after the test and then re-evaluate the latent heat using the new weight.

Salama Omran; Peter Heggs; Yulong Ding

2014-01-01T23:59:59.000Z

49

Thermal response of a flat heat pipe sandwich structure to a localized heat flux  

E-Print Network [OSTI]

metal foam wick and distilled water as the working fluid. Heat was applied via a propane torch and radiative heat transfer. A novel method was developed to estimate experimentally, the heat flux distribution rights reserved. Keywords: Flat heat pipe; Thermal spreader; Heat transfer; Evaporator; Condenser 1

Wadley, Haydn

50

MERLOT: a model for flow and heat transfer through porous media for high heat flux applications  

E-Print Network [OSTI]

MERLOT: a model for flow and heat transfer through porous media for high heat flux applications A Abstract Fusion power plant studies have found helium to be an attractive coolant based on its safety tend to provide modest heat transfer performance due to their inherently low heat capacity and heat

Raffray, A. René

51

Divertor Heat Flux Mitigation in the National Spherical Torus Experiment  

SciTech Connect (OSTI)

Steady-state handling of divertor heat flux is a critical issue for both ITER and spherical torus-based devices with compact high power density divertors. Significant reduction of heat flux to the divertor plate has been achieved simultaneously with favorable core and pedestal confinement and stability properties in a highly-shaped lower single null configuration in the National Spherical Torus Experiment (NSTX) [M. Ono et al., Nucl. Fusion 40, 557 2000] using high magnetic flux expansion at the divertor strike point and the radiative divertor technique. A partial detachment of the outer strike point was achieved with divertor deuterium injection leading to peak flux reduction from 4-6 MW m{sup -2} to 0.5-2 MW m{sup -2} in small-ELM 0.8-1.0 MA, 4-6 MW neutral beam injection-heated H-mode discharges. A self-consistent picture of outer strike point partial detachment was evident from divertor heat flux profiles and recombination, particle flux and neutral pressure measurements. Analytic scrape-off layer parallel transport models were used for interpretation of NSTX detachment experiments. The modeling showed that the observed peak heat flux reduction and detachment are possible with high radiated power and momentum loss fractions, achievable with divertor gas injection, and nearly impossible to achieve with main electron density, divertor neutral density or recombination increases alone.

Soukhanovskii, V A; Maingi, R; Gates, D A; Menard, J E; Paul, S F; Raman, R; Roquemore, A L; Bell, M G; Bell, R E; Boedo, J A; Bush, C E; Kaita, R; Kugel, H W; LeBlanc, B P; Mueller, D

2008-08-04T23:59:59.000Z

52

Development of dual temperature ammines for heat pump latent heat storage application. Final report  

SciTech Connect (OSTI)

Ammoniated Complex Compounds can be used as working fluids in space heating and cooling heat pumps and storage systems. This report describes the theoretical and experimental development of complex compound working fluids for a heat pump-storage system. A computerized data base was developed for the preliminary selection of candidate working fluids. The selected substances were experimentally investigated. Several concepts using two ammoniated complex compounds or one complex compound and the plain ligand were developed. A subscale prototype was built using the NaBr-n NH/sub 3/ complex and NH/sub 3/ as the ligand. Two heat exchanger designs were tested and compared in terms of optimum reaction rates. A computer simulation was written to predict the performance of a complex compound heat pump-storage system. The results were compared with a simulation of a conventional R22 heat pump cycle. The influence of additives in the NaBr-n NH/sub 3/ complex was investigated with respect to the adsorption and desprption rates.

Rockenfeller, U.

1986-03-01T23:59:59.000Z

53

Latent Heat Based High Temperature Solar Thermal Energy Storage for Power Generation  

Science Journals Connector (OSTI)

Abstract The design of a phase change material based high temperature solar thermal energy storage device is presented. Said unit will be used as an energy reserve for a 1 kWe domestic CCHP system using a Stirling engine to produce electric power. The thermal energy storage is conducted by means of the exploitation of the latent heat of fusion of the material contained inside the tank. This method was chosen because a great energy density is obtained and, at the same time, it is possible to extract the stored energy with very small variations on the temperature, which is a favorable feature for its intended purpose. The selection of the phase change material is discussed and the design of the different components of the proposed storage model is described. It is analyzed, as well, the insulating solution applied that minimizes heat losses. Finally, a comparison between experimental results of the tests performed on the first built to scale prototype and the data obtained from computer simulations is shown.

Bruno Cárdenas; Noel León

2014-01-01T23:59:59.000Z

54

Heat Conduction with Flux Condition on a Free Patch  

SciTech Connect (OSTI)

A new free boundary or free patch problem for the heat equation is presented. In the problem a nonlinear heat flux condition is prescribed on a free portion of the boundary, the patch, the position of which depends on the solution. The existence of a weak solution is established using the theory of set-valued pseudo monotone operators.

Kuttler, Kenneth L. [Department of Mathematics, Brigham Young University, Provo, UT 84602 (United States)], E-mail: klkuttler@math.byu.edu; Shillor, Meir [Department of Mathematics and Statistics, Oakland University, Rochester, MI 48309 (United States)], E-mail: shillor@oakland.edu

2004-08-15T23:59:59.000Z

55

Energy partition and conversion of solar and thermal radiation into sensible and latent heat in a greenhouse under arid conditions  

Science Journals Connector (OSTI)

For a greenhouse thermal analysis, it is essential to know the energy partition and the amount of solar and thermal radiation converted into sensible and latent heat in the greenhouse. Factors that are frequently needed are: efficiency of utilization of incident solar radiation (?), and sensible and latent heat factors (? and ?). Previous studies considered these factors as constant parameters. However, they depend on the environmental conditions inside and outside the greenhouse, plants and soil characteristics, and structure, orientation and location of the greenhouse. Moreover, these factors have not yet been evaluated under the arid climatic conditions of the Arabian Peninsula. In this study, simple energy balance equations were applied to investigate ?, ? and ?; energy partitioning among the greenhouse components; and conversion of solar and thermal radiation into sensible and latent heat. For this study, we used an evaporatively cooled, planted greenhouse with a floor area of 48 m2. The parameters required for the analysis were measured on a sunny, hot summer day. The results showed that value of ? was almost constant (?0.75); whereas the values of ? and ? strongly depended on the net radiation over the canopy (Rna); and could be represented by exponential decay functions of Rna. At a plant density corresponding to a leaf area index (LAI) of 3 and an integrated incident solar energy of 27.7 MJ m?2 d?1, the solar and thermal radiation utilized by the greenhouse components were 20.7 MJ m?2 d?1 and 3.74 MJ m?2 d?1, respectively. About 71% of the utilized radiation was converted to sensible heat and 29% was converted to latent heat absorbed by the inside air. Contributions of the floor, cover and plant surfaces on the sensible heat of the inside air were 38.6%, 48.2% and 13.2%, respectively.

I.M. Al-Helal; A.M. Abdel-Ghany

2011-01-01T23:59:59.000Z

56

QUANTIFICATION OF HEAT FLUX FROM A REACTING THERMITE SPRAY  

SciTech Connect (OSTI)

Characterizing the combustion behaviors of energetic materials requires diagnostic tools that are often not readily or commercially available. For example, a jet of thermite spray provides a high temperature and pressure reaction that can also be highly corrosive and promote undesirable conditions for the survivability of any sensor. Developing a diagnostic to quantify heat flux from a thermite spray is the objective of this study. Quick response sensors such as thin film heat flux sensors can not survive the harsh conditions of the spray, but more rugged sensors lack the response time for the resolution desired. A sensor that will allow for adequate response time while surviving the entire test duration was constructed. The sensor outputs interior temperatures of the probes at known locations and utilizes an inverse heat conduction code to calculate heat flux values. The details of this device are discussed and illustrated. Temperature and heat flux measurements of various thermite spray conditions are reported. Results indicate that this newly developed energetic material heat flux sensor provides quantitative data with good repeatability.

Eric Nixon; Michelle Pantoya

2009-07-01T23:59:59.000Z

57

Analysis of selected surface characteristics and latent heat storage for passive solar space heating  

SciTech Connect (OSTI)

Results are presented of an analysis of the value of various technical improvements in the solar collector and thermal storage subsystems of passive solar residential, agricultural, and industrial systems for two regions of the country. The evaluated improvements are: decreased emissivity and increased absorptivity of absorbing surfaces, decreased reflectivity, and decreased emissivity of glazing surface, and the substitution of sensible heat storage media with phase change materials. The value of each improvement is estimated by the additional energy savings resulting from the improvement.

Fthenakis, V.; Leigh, R.

1981-12-01T23:59:59.000Z

58

Coupled flow and heat transfer in viscoelastic fluid with Cattaneo–Christov heat flux model  

Science Journals Connector (OSTI)

Abstract This letter presents a research for coupled flow and heat transfer of an upper-convected Maxwell fluid above a stretching plate with velocity slip boundary. Unlike most classical works, the new heat flux model, which is recently proposed by Christov, is employed. Analytical solutions are obtained by using the homotopy analysis method (HAM). The effects of elasticity number, slip coefficient, the relaxation time of the heat flux and the Prandtl number on velocity and temperature fields are analyzed. A comparison of Fourier’s Law and the Cattaneo–Christov heat flux model is also presented.

Shihao Han; Liancun Zheng; Chunrui Li; Xinxin Zhang

2014-01-01T23:59:59.000Z

59

Downstream Heat Flux Profile vs. Midplane T Profile in Tokamaks  

SciTech Connect (OSTI)

The relationship between the midplane scrape-off-layer electron temperature profile and the parallel heat flux profile at the divertor in tokamaks is investigated. A model is applied which takes into account anisotropic thermal diffusion, in a rectilinear geometry with constant density. Eigenmode analysis is applied to the simplified problem with constant thermal diffusivities. A self-similar nonlinear solution is found for the more realistic problem with anisotropically temperature-dependent thermal diffusivities. Numerical solutions are developed for both cases, with spatially dependent heat flux emerging from the plasma. For both constant and temperature-dependent thermal diffusivities it is found that, below about one-half of its peak, the heat flux profile shape at the divertor, compared with the midplane temperature profile shape, is robustly described by the simplest two-point model. However the physical processes are not those assumed in the simplest two-point model, nor is the numerical coefficient relating q||div to Tmp ?||mp/L|| as predicted. For realistic parameters the peak in the heat flux, moreover, can be reduced by a factor of two or more from the two-point model scaling which fits the remaining profile. For temperature profiles in the SOL region above the x-point set by marginal stability, the heat flux profile to the divertor can be largely decoupled from the prediction of the two-point model. These results suggest caveats for data interpretation, and possibly favorable outcomes for divertor configurations with extended field lines.

Robert J. Goldston

2009-08-20T23:59:59.000Z

60

Carbon, water, and heat flux responses to experimental burning and drought  

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

Carbon, water, and heat flux responses to experimental burning and drought Carbon, water, and heat flux responses to experimental burning and drought in a tallgrass prairie Title Carbon, water, and heat flux responses to experimental burning and drought in a tallgrass prairie Publication Type Journal Article Year of Publication 2012 Authors Fischer, Marc L., Margaret S. Torn, David P. Billesbach, Geoffrey Doyle, Brian Northup, and Sebastien C. Biraud Journal Agricultural and Forest Meteorology Volume 166-167 Pagination 169-174 Keywords Carbon exchange, eddy covariance, Fire, Grassland, Prairie, Water stress Abstract Drought and fire are common disturbances to grassland ecosystems. We report two years of eddy covariance ecosystem-atmosphere fluxes and biometric variables measured in nearby burned and unburned pastures in the US Southern Great Plains. Over the course of the experiment, annual precipitation (∼600 mm yr-1) was lower than the long term mean (∼860 mm yr-1). Soil moisture decreased from productive conditions in March 2005 dry, unproductive conditions during the growing season starting in March 2006. Just prior to the burn in early March 2005, burned and unburned pastures contained 520 ± 60 and 360 ± 40 g C m-2 of total above ground biomass (AGB) and litter, respectively. The fire removed approximately 200 g C m-2 of litter and biomass. In the 2005 growing season following the burn, maximum green AGB was 450 ± 60 and 270 ± 40 g C m-2, with corresponding cumulative annual net ecosystem carbon exchange (NEE) of -330 and -150 g C m-2 for the burned and unburned pastures, respectively. In contrast to NEE, cumulative mean sensible heat and water fluxes were approximately equal in both pastures during the growing season, suggesting either an increase in water use efficiency or a decrease in evaporation in the burned relative to the unburned pasture. In the 2006 growing season, dry conditions decreased carbon uptake and latent heat, and increased sensible heat fluxes. Peak AGB was reduced to 210 ± 30 g C m-2 and 140 ± 30 g C m-2 in the burned and unburned pastures, respectively, while NEE was near zero. These results suggest that the lack of precipitation was responsible for most of the interannual variation in carbon exchange for these un-irrigated prairie pastures.

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61

Sensitivity of Radiative Fluxes and Heating Rates to Cloud Microphysics  

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

Sensitivity of Radiative Fluxes and Heating Sensitivity of Radiative Fluxes and Heating Rates to Cloud Microphysics S. F. Iacobellis and R. C. J. Somerville Scripps Institution of Oceanography University of California, San Diego La Jolla, California G. M. McFarquhar University of Illinois at Urbana-Champaign Urbana, Illinois D. L. Mitchell Desert Research Institute Reno, Nevada Introduction A single-column model (SCM) is used to examine the sensitivity of basic quantities such as atmospheric radiative heating rates and surface and top of atmosphere (TOA) radiative fluxes to various parameter- izations of clouds and cloud microphysics. The SCM was run at the Atmospheric Radiation Measurement (ARM) Program's Southern Great Plains (SGP), Tropical Western Pacific (TWP), and North Slope of Alaska (NSA) sites using forcing data derived from forecast products. The forecast

62

Remote high-temperature insulatorless heat-flux gauge  

DOE Patents [OSTI]

A remote optical heat-flux gauge for use in extremely high temperature environments is described. This application is possible because of the use of thermographic phosphors as the sensing media, and the omission of the need for an intervening layer of insulator between phosphor layers. The gauge has no electrical leads, but is interrogated with ultraviolet or laser light. The luminescence emitted by the two phosphor layers, which is indicative of the temperature of the layers, is collected and analyzed in order to determine the heat flux incident on the surface being investigated. The two layers of thermographic phosphor must be of different materials to assure that the spectral lines collected will be distinguishable. Spatial heat-flux measurements can be made by scanning the light across the surface of the gauge. 3 figures.

Noel, B.W.

1993-12-28T23:59:59.000Z

63

Remote high-temperature insulatorless heat-flux gauge  

DOE Patents [OSTI]

A remote optical heat-flux gauge for use in extremely high temperature environments is described. This application is possible because of the use of thermographic phosphors as the sensing media, and the omission of the need for an intervening layer of insulator between phosphor layers. The gauge has no electrical leads, but is interrogated with ultraviolet or laser light. The luminescence emitted by the two phosphor layers, which is indicative of the temperature of the layers, is collected and analyzed in order to determine the heat flux incident on the surface being investigated. The two layers of thermographic phosphor must be of different materials to assure that the spectral lines collected will be distinguishable. Spatial heat-flux measurements can be made by scanning the light across the surface of the gauge.

Noel, Bruce W. (Espanola, NM)

1993-01-01T23:59:59.000Z

64

Micro and nanostructured surfaces for enhanced phase change heat transfer  

E-Print Network [OSTI]

Two-phase microchannel heat sinks are of significant interest for thermal management applications, where the latent heat of vaporization offers an efficient method to dissipate large heat fluxes in a compact device. However, ...

Chu, Kuang-Han, Ph. D. Massachusetts Institute of Technology

2013-01-01T23:59:59.000Z

65

Sea surface exchanges of momentum, heat, and freshwater determined by satellite remote sensing  

E-Print Network [OSTI]

1 Sea surface exchanges of momentum, heat, and freshwater determined by satellite remote sensing Freshwater flux Latent heat flux Longwave radiation Satellite remote sensing Sea surface flux estimation Sensible heat flux Shortwave radiation Surface wind fields 2 #12;Sea surface exchanges of momentum, heat

Yu, Lisan

66

Long-Term Evolution of Anthropogenic Heat Fluxes into a Subsurface Urban Heat Island  

Science Journals Connector (OSTI)

In this study, we develop an analytical heat flux model to investigate possible drivers such as increased ground surface temperatures (GSTs) at artificial surfaces and heat losses from basements of buildings, sewage systems, subsurface district heating networks, and reinjection of thermal wastewater. ... Although only 41 of the original wells in 1977 could be used for measurements in 2011, both measurement campaigns yield representative regional GWT distributions because of the homogeneous distribution of the wells within the study area (Figure 1). ...

Kathrin Menberg; Philipp Blum; Axel Schaffitel; Peter Bayer

2013-07-29T23:59:59.000Z

67

Method of fission heat flux determination from experimental data  

DOE Patents [OSTI]

A method is provided for determining the fission heat flux of a prime specimen inserted into a specimen of a test reactor. A pair of thermocouple test specimens are positioned at the same level in the holder and a determination is made of various experimental data including the temperature of the thermocouple test specimens, the temperature of bulk water channels located in the test holder, the gamma scan count ratios for the thermocouple test specimens and the prime specimen, and the thicknesses of the outer clads, the fuel fillers, and the backclad of the thermocouple test specimen. Using this experimental data, the absolute value of the fission heat flux for the thermocouple test specimens and prime specimen can be calculated.

Paxton, Frank A. (Schenectady, NY)

1999-01-01T23:59:59.000Z

68

The Effect of Diurnal Sea Surface Temperature Warming on Climatological Air–Sea Fluxes  

E-Print Network [OSTI]

Diurnal sea surface warming affects the fluxes of latent heat, sensible heat, and upwelling longwave radiation. Diurnal warming most typically reaches maximum values of 3°C, although very localized events may reach 7°–8°C. ...

Clayson, Carol Anne

69

Sensitivity of Cenozoic Antarctic ice sheet variations to geothermal heat flux  

E-Print Network [OSTI]

Sensitivity of Cenozoic Antarctic ice sheet variations to geothermal heat flux David Pollard a sheet to geothermal heat flux is investigated, using a coupled climate­ice sheet model with various prescribed values and patterns of geothermal heat flux. The sudden growth of major ice across the Eocene

70

Mean and Variability of Air-Sea Heat Fluxes in the Indian Ocean  

E-Print Network [OSTI]

-sea heat Fluxes) Project: blended product planned activity: daily, 1º-grid, mid 1950's ­ present currently available: daily, 1º-grid, 1988-2003 #12;OAFlux (Objectively Analyzed Air-sea Heat Fluxes) For the GlobalMean and Variability of Air-Sea Heat Fluxes in the Indian Ocean Lisan Yu Woods Hole Oceanographic

Yu, Lisan

71

Investigation of Latent-Heat Storage Systems for Green Building Applications  

Science Journals Connector (OSTI)

In green building applications, highest energy demands are needed for air conditioning to ... heat storage systems during the usage of solar energy and ground-sourced heat pump systems for ... period, analyses sh...

Devrim Aydin; Zafer Utlu; Olcay Kincay

2014-01-01T23:59:59.000Z

72

Scaling and profiles of heat flux during partial detachment in DIII-D  

SciTech Connect (OSTI)

The authors examine the scaling of the peak divertor heat flux and total divertor plate power in partially detached divertor (PDD) discharges in DIII-D, as a function of input power and radiated power. The peak divertor heat flux in the attached plasma increases linearly with input power, but saturates in the detached cases. The total divertor plate power remains linear with input power in both the attached and detached plasmas. This is consistent with the fact that the heat flux peak is reduced from the attached case but other areas receive increased radiant heating from the detached plasma. The divertor plate radiant heating is linear with input power because the total radiated power from the entire plasma is a linear function of input power in both attached and detached plasma. In the private flux region, radiated heat flux absorbed on the target plate calculated from bolometer data is enough to account for the measured plate heating. Approximately half of the overall plate heating power in detached plasma is due to absorbed radiation. By mapping the divertor heat flux before and during the PDD to flux coordinates, and comparing with a flux mapping of inserted bolometer and tangential TV data, they have verified that the radiated power is emitted from the same flux surfaces on which heat flux is reduced.

Lasnier, C.J.; Hill, D.N.; Allen, S.L.; Fenstermacher, M.E.; Porter, G.D. [Lawrence Livermore National Lab., CA (United States); Leonard, A.W.; Petrie, T.W. [General Atomics, San Diego, CA (United States); Watkins, J.G. [Sandia National Labs., Albuquerque, NM (United States)

1998-08-01T23:59:59.000Z

73

Estimation of turbulent surface heat fluxes using sequences of remotely sensed land surface temperature  

E-Print Network [OSTI]

Fluxes of heat and moisture at the land-surface play a significant role in the climate system. These fluxes interact with the overlying atmosphere and influence the characteristics of the planetary boundary layer (e.g. ...

Bateni, Sayed Mohyeddin

2011-01-01T23:59:59.000Z

74

Quantitative method for measuring heat flux emitted from a cryogenic object  

DOE Patents [OSTI]

The present invention is a quantitative method for measuring the total heat flux, and of deriving the total power dissipation, of a heat-fluxing object which includes the steps of placing an electrical noise-emitting heat-fluxing object in a liquid helium bath and measuring the superfluid transition temperature of the bath. The temperature of the liquid helium bath is thereafter reduced until some measurable parameter, such as the electrical noise, exhibited by the heat-fluxing object or a temperature-dependent resistive thin film in intimate contact with the heat-fluxing object, becomes greatly reduced. The temperature of the liquid helum bath is measured at this point. The difference between the superfluid transition temperature of the liquid helium bath surrounding the heat-fluxing object, and the temperature of the liquid helium bath when the electrical noise emitted by the heat-fluxing object becomes greatly reduced, is determined. The total heat flux from the heat-fluxing object is determined as a function of this difference between these temperatures. In certain applications, the technique can be used to optimize thermal design parameters of cryogenic electronics, for example, Josephson junction and infrared sensing devices.

Duncan, R.V.

1993-03-16T23:59:59.000Z

75

Quantitative method for measuring heat flux emitted from a cryogenic object  

DOE Patents [OSTI]

The present invention is a quantitative method for measuring the total heat flux, and of deriving the total power dissipation, of a heat-fluxing object which includes the steps of placing an electrical noise-emitting heat-fluxing object in a liquid helium bath and measuring the superfluid transition temperature of the bath. The temperature of the liquid helium bath is thereafter reduced until some measurable parameter, such as the electrical noise, exhibited by the heat-fluxing object or a temperature-dependent resistive thin film in intimate contact with the heat-fluxing object, becomes greatly reduced. The temperature of the liquid helum bath is measured at this point. The difference between the superfluid transition temperature of the liquid helium bath surrounding the heat-fluxing object, and the temperature of the liquid helium bath when the electrical noise emitted by the heat-fluxing object becomes greatly reduced, is determined. The total heat flux from the heat-fluxing object is determined as a function of this difference between these temperatures. In certain applications, the technique can be used to optimize thermal design parameters of cryogenic electronics, for example, Josephson junction and infra-red sensing devices.

Duncan, Robert V. (Tijeras, NM)

1993-01-01T23:59:59.000Z

76

Experimental investigation and model validation of the heat flux profile in a 300 MW CFB boiler  

Science Journals Connector (OSTI)

Abstract In this paper, systematic experimental investigation on the heat flux distribution inside the furnace of a 300 MW CFB boiler was presented. Detailed experimental setup and measurement techniques were presented and a finite element method approach was applied to determine the heat flux. The heat flux profile on the rear wall along the horizontal direction shows a significant imbalance at different boiler loads. As a result of the non-uniform layout of the heating surfaces, which is the essential reason, as well as the imbalance and deviation of the temperature field, solid suspension density and solid flow rate, the central section of the furnace possesses higher heat flux distribution compared to the side sections. The heat flux is also found to increase with the increasing boiler load and decrease as the height increases. Heat flux near the roof, where the solid suspension density is rather small, is found to decrease remarkably revealing less heat absorption in this area. In addition, an empirical model of heat transfer coefficient is revised using the average data at different boiler loads. A mechanism heat transfer model based on the membrane water-wall configuration is proposed and validated with the heat flux profile obtained from the measurement. The model provides good accuracy for correlating 85% of the data within ± 10%.

Ruiqing Zhang; Hairui Yang; Nan Hu; Junfu Lu; Yuxin Wu

2013-01-01T23:59:59.000Z

77

Numerical Simulation of a Latent Heat Storage System of a Solar-Aided Ground Source Heat Pump  

E-Print Network [OSTI]

In this study, the rectangular phase change storage tank (PCST) linked to a solar-aided ground source heat pump (SAGSHP) system is investigated experimentally and theoretically. The container of the phase change material (PCM) is the controlling...

Wang, F.; Zheng, M.; Li, Z.; Lei, B.

2006-01-01T23:59:59.000Z

78

Conceptual design selection and development of a latent-heat thermal-energy-storage subsystem for a saturated-steam solar receiver and load  

SciTech Connect (OSTI)

The following latent heat storage concepts are described and evaluated in comparison with each other and with an oil/rock sensible heat storage system: (1) passive tube intensive (shell-and-tube heat exchanger) with and without heat transfer enhanced by fins; (2) phase change material cans (or chubbs) with a biphenyl intermediate heat transfer fluid; (3) phase change material macroencapsulation in a containment tank full of tubes; (4) microencapsulation in a porous carrier; (5) direct contact heat exchange; and (6) systems using mechanical scrapers for removing solidified phase change material from container surfaces. A tube intensive system with heat transfer enhancement was selected, and the conceptual design and cost/performance estimates are given for it. A commercial scale unit is assessed, and design changes and corresponding costs are presented that would be required to make the system meet changed requirements. (LEW)

Not Available

1981-02-01T23:59:59.000Z

79

Influence of circumferential solar heat flux distribution on the heat transfer coefficients of linear Fresnel collector absorber tubes  

Science Journals Connector (OSTI)

Abstract The absorber tubes of solar thermal collectors have enormous influence on the performance of the solar collector systems. In this numerical study, the influence of circumferential uniform and non-uniform solar heat flux distributions on the internal and overall heat transfer coefficients of the absorber tubes of a linear Fresnel solar collector was investigated. A 3D steady-state numerical simulation was implemented based on ANSYS Fluent code version 14. The non-uniform solar heat flux distribution was modelled as a sinusoidal function of the concentrated solar heat flux incident on the circumference of the absorber tube. The k–? model was employed to simulate the turbulent flow of the heat transfer fluid through the absorber tube. The tube-wall heat conduction and the convective and irradiative heat losses to the surroundings were also considered in the model. The average internal and overall heat transfer coefficients were determined for the sinusoidal circumferential non-uniform heat flux distribution span of 160°, 180°, 200° and 240°, and the 360° span of circumferential uniform heat flux for 10 m long absorber tubes of different inner diameters and wall thicknesses with thermal conductivity of 16.27 W/mK between the Reynolds number range of 4000 and 210,000 based on the inlet temperature. The results showed that the average internal heat transfer coefficients for the 360° span of circumferential uniform heat flux with different concentration ratios on absorber tubes of the same inner diameters, wall thicknesses and thermal conductivity were approximately the same, but the average overall heat transfer coefficient increased with the increase in the concentration ratios of the uniform heat flux incident on the tubes. Also, the average internal heat transfer coefficient for the absorber tube with a 360° span of uniform heat flux was approximately the same as that of the absorber tubes with the sinusoidal circumferential non-uniform heat flux span of 160°, 180°, 200° and 240° for the heat flux of the same concentration ratio, but the average overall heat transfer coefficient for the uniform heat flux case was higher than that of the non-uniform flux distributions. The average axial local internal heat transfer coefficient for the 360° span of uniform heat flux distribution on a 10 m long absorber tube was slightly higher than that of the 160°, 200° and 240° span of non-uniform flux distributions at the Reynolds number of 4 000. The average internal and overall heat transfer coefficients for four absorber tubes of different inner diameters and wall thicknesses and thermal conductivity of 16.27 W/mK with 200° span of circumferential non-uniform flux were found to increase with the decrease in the inner-wall diameter of the absorber tubes. The numerical results showed good agreement with the Nusselt number experimental correlations for fully developed turbulent flow available in the literature.

Izuchukwu F. Okafor; Jaco Dirker; Josua P. Meyer

2014-01-01T23:59:59.000Z

80

Divertor heat flux reduction by D sub 2 injection in DIII-D  

SciTech Connect (OSTI)

D{sub 2} gas injected into ELMing H-mode discharges in DIII-D reduced total integrated heat flux to the divertor by {approximately}2{times} and peak heat flux by {approximately}5{times}, with only modest degradation to plasma stored energy. Steady gas injection without particle pumping results in eventual degradation in stored energy. The initial reduction in peak heat flux at the divertor tiles may be primarily due to the increase in radiated power from the X-point/divertor region. The eventual formation of a high density region near the X-point appears to play a role in momentum (and energy) transfer from the flux surfaces near the outboard strike point to flux surfaces farther out into the scrapeoff. This may also contribute to further reduction in peak heat flux.

Petrie, T.W.; Groebner, R.J.; Leonard, A.W.; Lippmann, S.I.; Mahdavi, A.M.; West, W.P. (General Atomics, San Diego, CA (United States)); Buchenauer, D.; Campbell, R.B. (Sandia National Labs., Livermore, CA (United States)); Hill, D.N.; Allen, S.L.; Futch, A.H.; Resink, M.E. (Lawrence Livermore National Lab., CA (United States)); Klepper, C.C. (Oak Ridge National Lab., TN (United States))

1992-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "latent heat flux" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Divertor heat flux reduction by D{sub 2} injection in DIII-D  

SciTech Connect (OSTI)

D{sub 2} gas injected into ELMing H-mode discharges in DIII-D reduced total integrated heat flux to the divertor by {approximately}2{times} and peak heat flux by {approximately}5{times}, with only modest degradation to plasma stored energy. Steady gas injection without particle pumping results in eventual degradation in stored energy. The initial reduction in peak heat flux at the divertor tiles may be primarily due to the increase in radiated power from the X-point/divertor region. The eventual formation of a high density region near the X-point appears to play a role in momentum (and energy) transfer from the flux surfaces near the outboard strike point to flux surfaces farther out into the scrapeoff. This may also contribute to further reduction in peak heat flux.

Petrie, T.W.; Groebner, R.J.; Leonard, A.W.; Lippmann, S.I.; Mahdavi, A.M.; West, W.P. [General Atomics, San Diego, CA (United States); Buchenauer, D.; Campbell, R.B. [Sandia National Labs., Livermore, CA (United States); Hill, D.N.; Allen, S.L.; Futch, A.H.; Resink, M.E. [Lawrence Livermore National Lab., CA (United States); Klepper, C.C. [Oak Ridge National Lab., TN (United States)

1992-05-01T23:59:59.000Z

82

Measured and Parameterized Energy Fluxes Estimated for Atlantic Transects of R/V Polarstern  

Science Journals Connector (OSTI)

Sensible and latent heat fluxes were estimated from turbulence measurements gathered during several Atlantic Ocean transects of the research vessel (R/V) Polarstern. The inertial dissipation method was used to analyze the data. Resulting bulk ...

Karl Bumke; Michael Schlundt; John Kalisch; Andreas Macke; Henry Kleta

2014-02-01T23:59:59.000Z

83

Solar passive ceiling system. Final report. [Passive solar heating system with venetian blind reflectors and latent heat storage in ceiling  

SciTech Connect (OSTI)

The construction of a 1200 square foot building, with full basement, built to be used as a branch library in a rural area is described. The primary heating source is a passive solar system consisting of a south facing window system. The system consists of: a set of windows located in the south facing wall only, composed of double glazed units; a set of reflectors mounted in each window which reflects sunlight up to the ceiling (the reflectors are similar to venetian blinds); a storage area in the ceiling which absorbs the heat from the reflected sunlight and stores it in foil salt pouches laid in the ceiling; and an automated curtain which automatically covers and uncovers the south facing window system. The system is totally passive and uses no blowers, pumps or other active types of heat distribution equipment. The building contains a basement which is normally not heated, and the north facing wall is bermed four feet high around the north side.

Schneider, A.R.

1980-01-01T23:59:59.000Z

84

Third law of thermodynamics in the presence of a heat flux  

Science Journals Connector (OSTI)

Following a maximum entropy formalism, we study a one-dimensional crystal under a heat flux. We obtain the phonon distribution function and evaluate the nonequilibrium temperature, the specific heat, and the entropy as functions of the internal energy and the heat flux, in both the quantum and the classical limits. Some analogies between the behavior of equilibrium systems at low absolute temperature and nonequilibrium steady states under high values of the heat flux are shown, which point to a possible generalization of the third law in nonequilibrium situations.

J. Camacho

1995-01-01T23:59:59.000Z

85

Convective currents in nucleate pool boiling and their effects on the heat flux from varying diameter flat plate heating elements  

E-Print Network [OSTI]

investigation was conducred to amine the effects of convection currents in nucleate oool boil ing and to determine the changes in critical heat flux caused by varying the diameter of horizontal flat olate heating surfaces. Freon 113 (Trichlorotrifluoroethane... by high energy costs and thc need to economize in industrial heat transfer applications . I'nucleate boiling is a very efficient neans of heat transfer because of the large sur ace areas involved in vaporization of the bulk fluid. as bubbles form...

Morford, Peter Stephen

1980-01-01T23:59:59.000Z

86

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

SciTech Connect (OSTI)

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

Ruggles, A.E.

1990-10-12T23:59:59.000Z

87

Temperature, thermal-conductivity, and heat-flux data,Raft River area,  

Open Energy Info (EERE)

Temperature, thermal-conductivity, and heat-flux data,Raft River area, Temperature, thermal-conductivity, and heat-flux data,Raft River area, Cassia County, Idaho (1974-1976) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Report: Temperature, thermal-conductivity, and heat-flux data,Raft River area, Cassia County, Idaho (1974-1976) Details Activities (1) Areas (1) Regions (0) Abstract: Basin and Range Province; Cassia County Idaho; economic geology; exploration; geophysical surveys; geothermal energy; heat flow; heat flux; Idaho; North America; Raft River basin; south-central Idaho; surveys; temperature; thermal conductivity; United States; USGS Author(s): Urban, T.C.; Diment, W.H.; Nathenson, M.; Smith, E.P.; Ziagos, J.P.; Shaeffer, M.H. Published: Open-File Report - U. S. Geological Survey, 1/1/1986 Document Number: Unavailable

88

Heat flux characteristics in an atmospheric double arc argon plasma jet  

SciTech Connect (OSTI)

In this study, the axial evolution of heat flux excited by a double arc argon plasma jet impinging on a flat plate is determined, while the nonstationary behavior of the heat flux is investigated by combined means of the fast Fourier transform, Wigner distribution, and short-time Fourier transform. Two frequency groups (<1 and 2-10 kHz) are identified in both the Fourier spectrum and the time-frequency distributions, which suggest that the nature of fluctuations in the heat flux is strongly associated with the dynamic behavior of the plasma arc and the engulfment of ambient air into different plasma jet regions.

Tu Xin; Yu Liang; Yan Jianhua; Cen Kefa [Zhejiang University, Hangzhou 310027 (China); Cheron, Bruno [UMR 6614 CNRS CORIA, Saint Etienne du Rouvray 76801 (France)

2008-10-13T23:59:59.000Z

89

Designing, testing, and analyzing coupled, flux transformer heat  

E-Print Network [OSTI]

of identical effective length, this research shows that sufficient heat can be transferred across the system to work effectively in situations where the single heat pie will fail to operate. The thermal resistance in the condenser and evaporator sections need...

Renzi, Kimberly Irene

1998-01-01T23:59:59.000Z

90

Heat transfer to non-Newtonian power-law fluid past a continuously moving porous flat plate with heat flux  

Science Journals Connector (OSTI)

The analysis of heat transfer to the non-Newtonian power-law fluid flow past a continuously moving flat porous plate in presence of suction/injection with heat flux has been presented. We have obtained...n...=1 a...

B. P. Jadhav; B. B. Waghmode

1990-01-01T23:59:59.000Z

91

Surface energy budget over the South Pole and turbulent heat fluxes as a function of an empirical bulk Richardson number  

E-Print Network [OSTI]

Surface energy budget over the South Pole and turbulent heat fluxes as a function of an empirical in the monthly mean surface energy budget and to investigate the behavior of turbulent heat fluxes under stable and one as the residual of the surface energy budget (i.e., subsurface heat fluxes minus net radiation

Walden, Von P.

92

Heat fluxes at the Earth's surface and coremantle boundary since Pangea formation and their implications for the geomagnetic superchrons  

E-Print Network [OSTI]

Heat fluxes at the Earth's surface and core­mantle boundary since Pangea formation Editor: Y. Ricard Keywords: mantle convection heat flux supercontinent Pangea magnetic polarity reversals The Earth's surface and core­mantle boundary (CMB) heat fluxes are controlled by mantle convection and have

Zhong, Shijie

93

Estimating air-sea fluxes of heat, freshwater, and momentum through global ocean data assimilation  

E-Print Network [OSTI]

Estimating air-sea fluxes of heat, freshwater, and momentum through global ocean data assimilation of surface flux adjustments made to the initial NCEP re-analysis-1 products. During the state estimation the boundary current regions, they are consistent with known large-scale deficiencies in the NCEP products

94

Saturation levels of heat-flux- and fast-electron-driven ion-acoustic-wave turbulence  

Science Journals Connector (OSTI)

Saturation levels of ion-acoustic-wave turbulence driven by a heat-flux and a suprathermal electron current have been calculated on the basis of perturbed-orbit theory. The levels are found to be lower than those commonly estimated from simple trapping arguments and too low to explain the thermal-flux inhibition observed in many laser-plasma experiments.

H. C. Barr and T. J. M. Boyd

1981-10-01T23:59:59.000Z

95

Effect of rolling motion on critical heat flux for subcooled flow boiling in vertical tube  

SciTech Connect (OSTI)

This paper presents defining characteristics of the critical heat flux (CHF) for the boiling of R-134a in vertical tube operation under rolling motion in marine reactor. It is important to predict CHF of marine reactor having the rolling motion in order to increase the safety of the reactor. Marine Reactor Moving Simulator (MARMS) tests are conducted to measure the critical heat flux using R-134a flowing upward in a uniformly heated vertical tube under rolling motion. MARMS was rotated by motor and mechanical power transmission gear. The CHF tests were performed in a 9.5 mm I.D. test section with heated length of 1 m. Mass fluxes range from 285 to 1300 kg m{sup -2}s{sup -1}, inlet subcooling from 3 to 38 deg. C and outlet pressures from 13 to 24 bar. Amplitudes of rolling range from 15 to 40 degrees and periods from 6 to 12 sec. To convert the test conditions of CHF test using R-134a in water, Katto's fluid-to-fluid modeling was used in present investigation. A CHF correlation is presented which accounts for the effects of pressure, mass flux, inlet subcooling and rolling angle over all conditions tested. Unlike existing transient CHF experiments, CHF ratio of certain mass flux and pressure are different in rolling motion. For the mass fluxes below 500 kg m{sup -2}s{sup -1} at 13, 16 (region of relative low mass flux), CHF ratio was decreased but was increased above that mass flux (region of relative high mass flux). Moreover, CHF tend to enhance in entire mass flux at 24 bar. (authors)

Hwang, J. S.; Park, I. U.; Park, M. Y.; Park, G. C. [Dept. of Energy Systems Engineering, Seoul National Univ., 599 Gwanak-Ro, Gwanak-Gu, Seoul, 151-744 (Korea, Republic of)

2012-07-01T23:59:59.000Z

96

Saturated critical heat flux in a multi-microchannel heat sink fed by a split flow system  

SciTech Connect (OSTI)

An extensive experimental campaign has been carried out for the measurement of saturated critical heat flux in a multi-microchannel copper heat sink. The heat sink was formed by 29 parallel channels that were 199 {mu}m wide and 756 {mu}m deep. In order to increase the critical heat flux and reduce the two-phase pressure drop, a split flow system was implemented with one central inlet at the middle of the channels and two outlets at either end. The base critical heat flux was measured using three HFC Refrigerants (R134a, R236fa and R245fa) for mass fluxes ranging from 250 to 1500 kg/m{sup 2} s, inlet subcoolings from -25 to -5 K and saturation temperatures from 20 to 50 C. The parametric effects of mass velocity, saturation temperature and inlet subcooling were investigated. The analysis showed that significantly higher CHF was obtainable with the split flow system (one inlet-two outlets) compared to the single inlet-single outlet system, providing also a much lower pressure drop. Notably several existing predictive methods matched the experimental data quite well and quantitatively predicted the benefit of higher CHF of the split flow. (author)

Mauro, A.W.; Toto, D. [Department of Energetics, Applied Thermofluidynamics and Air Conditioning Systems, FEDERICO II University, p.le Tecchio 80, 80125 Napoli (Italy); Thome, J.R. [Laboratory of Heat and Mass Transfer (LTCM), Faculty of Engineering (STI), Ecole Polytechnique Federale de Lausanne (EPFL), Station 9, Lausanne CH-1015 (Switzerland); Vanoli, G.P. [Engineering Department, Sannio University, Corso Garibaldi 107, Palazzo dell'Aquila Bosco Lucarelli, 82100 Benevento (Italy)

2010-01-15T23:59:59.000Z

97

Standard Test Method for Measuring Heat Flux Using Flush-Mounted Insert Temperature-Gradient Gages  

E-Print Network [OSTI]

1.1 This test method describes the measurement of the net heat flux normal to a surface using gages inserted flush with the surface. The geometry is the same as heat-flux gages covered by Test Method E 511, but the measurement principle is different. The gages covered by this standard all use a measurement of the temperature gradient normal to the surface to determine the heat that is exchanged to or from the surface. Although in a majority of cases the net heat flux is to the surface, the gages operate by the same principles for heat transfer in either direction. 1.2 This general test method is quite broad in its field of application, size and construction. Two different gage types that are commercially available are described in detail in later sections as examples. A summary of common heat-flux gages is given by Diller (1). Applications include both radiation and convection heat transfer. The gages used for aerospace applications are generally small (0.155 to 1.27 cm diameter), have a fast time response ...

American Society for Testing and Materials. Philadelphia

2009-01-01T23:59:59.000Z

98

High heat flux testing capabilities at Sandia National Laboratories - New Mexico  

SciTech Connect (OSTI)

High heat flux testing for the United States fusion power program is the primary mission of the Plasma Materials Test Facility (PMTF) located at Sandia National Laboratories - New Mexico. This facility, which is owned by the United States Department of Energy, has been in operation for over 17 years and has provided much of the high heat flux data used in the design and evaluation of plasma facing components for many of the world`s magnetic fusion, tokamak experiments. In addition to domestic tokamaks such as Tokamak Fusion Test Reactor (TFTR) at Princeton and the DIII-D tokamak at General Atomics, components for international experiments like TEXTOR, Tore-Supra, and JET also have been tested at the PMTF. High heat flux testing spans a wide spectrum including thermal shock tests on passively cooled materials, thermal response and thermal fatigue tests on actively cooled components, critical heat flux-burnout tests, braze reliability tests and safety related tests. The objective of this article is to provide a brief overview of the high heat flux testing capabilities at the PMTF and describe a few of the experiments performed over the last year.

Youchison, D.L.; McDonald, J.M.; Wold, L.S.

1994-12-31T23:59:59.000Z

99

Two-Layer Baroclinic Eddy Heat Fluxes: Zonal Flows and Energy Balance ANDREW F. THOMPSON AND WILLIAM R. YOUNG  

E-Print Network [OSTI]

Two-Layer Baroclinic Eddy Heat Fluxes: Zonal Flows and Energy Balance ANDREW F. THOMPSON of these drag- less heat-flux parameterizations relies on the ability of to direct energy into zonal flows, California (Manuscript received 27 September 2006, in final form 13 December 2006) ABSTRACT The eddy heat

Young, William R.

100

Critical heat flux (CHF) phenomenon on a downward facing curved surface  

SciTech Connect (OSTI)

This report describes a theoretical and experimental study of the boundary layer boiling and critical heat flux phenomena on a downward facing curved heating surface, including both hemispherical and toroidal surfaces. A subscale boundary layer boiling (SBLB) test facility was developed to measure the spatial variation of the critical heat flux and observe the underlying mechanisms. Transient quenching and steady-state boiling experiments were performed in the SBLB facility under both saturated and subcooled conditions to obtain a complete database on the critical heat flux. To complement the experimental effort, an advanced hydrodynamic CHF model was developed from the conservation laws along with sound physical arguments. The model provides a clear physical explanation for the spatial variation of the CHF observed in the SBLB experiments and for the weak dependence of the CHF data on the physical size of the vessel. Based upon the CHF model, a scaling law was established for estimating the local critical heat flux on the outer surface of a heated hemispherical vessel that is fully submerged in water. The scaling law, which compares favorably with all the available local CHF data obtained for various vessel sizes, can be used to predict the local CHF limits on large commercial-size vessels. This technical information represents one of the essential elements that is needed in assessing the efficacy of external cooling of core melt by cavity flooding as a severe accident management strategy. 83 figs., 3 tabs.

Cheung, F.B.; Haddad, K.H.; Liu, Y.C. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Mechanical Engineering

1997-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "latent heat flux" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Theoretical and experimental estimation of limiting input heat flux for thermoelectric power generators with passive cooling  

Science Journals Connector (OSTI)

Abstract This paper focuses on theoretical and experimental analysis used to establish the limiting heat flux for passively cooled thermoelectric generators (TEG). 2 commercially available TEG’s further referred as type A and type B with different allowable hot side temperatures (150 °C and 250 °C respectively) were investigated in this research. The thermal resistance of TEG was experimentally verified against the manufacturer’s specifications and used for theoretical analysis in this paper. A theoretical model is presented to determine the maximum theoretical heat flux capacity of both the TEG’s. The conventional methods are used for cooling of TEG’s and actual limiting heat flux is experimentally established for various cold end cooling configurations namely bare plate, finned block and heat pipe with finned condenser. Experiments were performed on an indoor setup and outdoor setup to validate the results from the theoretical model. The outdoor test setup consist of a fresnel lens solar concentrator with manual two axis solar tracking system for varying the heat flux, whereas the indoor setup uses electric heating elements to vary the heat flux and a low speed wind tunnel blows the ambient air past the device to simulate the outdoor breezes. It was observed that bare plate cooling can achieve a maximum heat flux of 18,125 W/m2 for type A and 31,195 W/m2 for type B at ambient wind speed of 5 m/s while maintaining respective allowable temperature over the hot side of TEG’s. Fin geometry was optimised for the finned block cooling by using the fin length and fin gap optimisation model presented in this paper. It was observed that an optimum finned block cooling arrangement can reach a maximum heat flux of 26,067 W/m2 for type A and 52,251 W/m2 for type B TEG at ambient wind speed of 5 m/s of ambient wind speed. The heat pipe with finned condenser used for cooling can reach 40,375 W/m2 for type A TEG and 76,781 W/m2 for type B TEG.

Ashwin Date; Abhijit Date; Chris Dixon; Randeep Singh; Aliakbar Akbarzadeh

2015-01-01T23:59:59.000Z

102

Transport of radial heat flux and second sound in fusion plasmas  

SciTech Connect (OSTI)

Simple flux-gradient relations that involve time delay and radial coupling are discussed. Such a formulation leads to a rather simple description of avalanches and may explain breaking of gyroBohm transport scaling. The generalization of the flux-gradient relation (i.e., constitutive relation), which involve both time delay and spatial coupling, is derived from drift-kinetic equation, leading to kinetic definitions of constitutive elements such as the flux of radial heat flux. This allows numerical simulations to compute these cubic quantities directly. The formulation introduced here can be viewed as an extension of turbulence spreading to include the effect of spreading of cross-phase as well as turbulence intensity, combined in such a way to give the flux. The link between turbulence spreading and entropy production is highlighted. An extension of this formulation to general quasi-linear theory for the distribution function in the phase space of radial position and parallel velocity is also discussed.

Guercan, Oe. D.; Berionni, V.; Hennequin, P.; Morel, P.; Vermare, L. [Laboratoire de Physique des Plasmas, Ecole Polytechnique, CNRS, 91128 Palaiseau Cedex (France); Diamond, P. H. [WCI Center for Fusion Theory, NFRI, Daejeon (Korea, Republic of); CMTFO and CASS, UCSD, California 92093 (United States); Garbet, X.; Dif-Pradalier, G. [CEA, IRFM, F-13108 Saint Paul Lez Durance (France); Kosuga, Y. [WCI Center for Fusion Theory, NFRI, Daejeon (Korea, Republic of)

2013-02-15T23:59:59.000Z

103

Spatial distribution of heat flux and fluctuations in turbulent Rayleigh-Bénard convection  

Science Journals Connector (OSTI)

We numerically investigate the radial dependence of the velocity and temperature fluctuations and of the time-averaged heat flux j¯(r) in a cylindrical Rayleigh-Bénard cell with aspect ratio ?=1 for Rayleigh numbers Ra between 2×106 and 2×109 at a fixed Prandtl number Pr=5.2. The numerical results reveal that the heat flux close to the sidewall is larger than in the center and that, just as the global heat transport, it has an effective power law dependence on the Rayleigh number, j¯(r)?Ra?j(r). The scaling exponent ?j(r) decreases monotonically from 0.43 near the axis (r?0) to 0.29 close to the sidewalls (r?D/2). The effective exponents near the axis and the sidewall agree well with the measurements of Shang et al. [Phys. Rev. Lett. 100, 244503 (2008)] and the predictions of Grossmann and Lohse [Phys. Fluids 16, 1070 (2004)]. Extrapolating our results to large Rayleigh number would imply a crossover at Ra?1015, where the heat flux near the axis would begin to dominate. In addition, we find that the local heat flux is more than twice as high at the location where warm or cold plumes go up or down than in plume depleted regions.

Rajaram Lakkaraju; Richard J. A. M. Stevens; Roberto Verzicco; Siegfried Grossmann; Andrea Prosperetti; Chao Sun; Detlef Lohse

2012-11-26T23:59:59.000Z

104

New charged shear-free relativistic models with heat flux  

E-Print Network [OSTI]

We study shear-free spherically symmetric relativistic gravitating fluids with heat flow and electric charge. The solution to the Einstein-Maxwell system is governed by the generalised pressure isotropy condition which contains a contribution from the electric field. This condition is a highly nonlinear partial differential equation. We analyse this master equation using Lie's group theoretic approach. The Lie symmetry generators that leave the equation invariant are found. The first generator is independent of the electromagnetic field. The second generator depends critically on the form of the charge, which is determined explicitly in general. We provide exact solutions to the gravitational potentials using the symmetries admitted by the equation. Our new exact solutions contain earlier results without charge. We show that other charged solutions, related to the Lie symmetries, may be generated using the algorithm of Deng. This leads to new classes of charged Deng models which are generalisations of conformally flat metrics.

Y. Nyonyi; S. D. Maharaj; K. S. Govinder

2014-12-21T23:59:59.000Z

105

New charged shear-free relativistic models with heat flux  

E-Print Network [OSTI]

We study shear-free spherically symmetric relativistic gravitating fluids with heat flow and electric charge. The solution to the Einstein-Maxwell system is governed by the generalised pressure isotropy condition which contains a contribution from the electric field. This condition is a highly nonlinear partial differential equation. We analyse this master equation using Lie's group theoretic approach. The Lie symmetry generators that leave the equation invariant are found. The first generator is independent of the electromagnetic field. The second generator depends critically on the form of the charge, which is determined explicitly in general. We provide exact solutions to the gravitational potentials using the symmetries admitted by the equation. Our new exact solutions contain earlier results without charge. We show that other charged solutions, related to the Lie symmetries, may be generated using the algorithm of Deng. This leads to new classes of charged Deng models which are generalisations of conform...

Nyonyi, Y; Govinder, K S

2014-01-01T23:59:59.000Z

106

Carbon Dioxide Flux Measurement Systems (CO2Flux) Handbook  

SciTech Connect (OSTI)

The Southern Great Plains (SGP) carbon dioxide flux (CO2 flux) measurement systems provide half-hour average fluxes of CO2, H2O (latent heat), and sensible heat. The fluxes are obtained by the eddy covariance technique, which computes the flux as the mean product of the vertical wind component with CO2 and H2O densities, or estimated virtual temperature. A three-dimensional sonic anemometer is used to obtain the orthogonal wind components and the virtual (sonic) temperature. An infrared gas analyzer is used to obtain the CO2 and H2O densities. A separate sub-system also collects half-hour average measures of meteorological and soil variables from separate 4-m towers.

Fischer, M

2005-01-01T23:59:59.000Z

107

Heat transfer to impacting drops and post critical heat flux dispersed flow  

E-Print Network [OSTI]

Heat transfer to drops impacting on a hot surface is examined in context of dispersions of flowing, boiling fluids. The liquid contribution to heat transfer from a hot tube to a two-phase dispersion is formulated in terms ...

Kendall, Gail E.

1978-01-01T23:59:59.000Z

108

The deterioration in heat transfer to fluids at supercritical pressure and high heat fluxes  

E-Print Network [OSTI]

At slightly supercritical pressure and in the neighborhood of the pseudo-critical temperature (defined as the temperature corresponding to the peak in specific heat at the operating pressure), the heat transfer coefficient ...

Shiralkar, B. S.

1968-01-01T23:59:59.000Z

109

The Total Meridional Heat Flux and Its Oceanic and Atmospheric Partition CARL WUNSCH  

E-Print Network [OSTI]

model residual is done to permit calculation of a preliminary uncertainty estimate for the atmospheric the oceanic flux drops rapidly, but does not actually vanish until the oceanic surface area goes to zero The partitioning and fluctuations in the net poleward transport of heat (energy, actually enthalpy; see War- ren

Wunsch, Carl

110

First-wall heat-flux measurements during ELMing H-mode plasma  

SciTech Connect (OSTI)

In this report we present measurements of the diverter heat flux in DIII-D for ELMing H-mode and radiative diverter conditions. In previous work we have examined heat flux profiles in lower single-null diverted plasmas and measured the scaling of the peak heat flux with plasma current and beam power. One problem with those results was our lack of good power accounting. This situation has been improved to better than 80--90% accountability with the installation of new bolometer arrays, and the operation of the entire complement of 5 Infrared (IR) TV cameras using the DAPS (Digitizing Automated Processing System) video processing system for rapid inter-shot data analysis. We also have expanded the scope of our measurements to include a wider variety of plasma shapes (e.g., double-null diverters (DND), long and short single-null diverters (SND), and inside-limited plasmas), as well as more diverse discharge conditions. Double-null discharges are of particular interest because that shape has proven to yield the highest confinement (VH-mode) and beta of all DIII-D plasmas, so any future diverter modifications for DIII-D will have to support DND operation. In addition, the proposed TPX tokamak is being designed for double-null operation, and information on the magnitude and distribution of diverter heat flux is needed to support the engineering effort on that project. So far, we have measured the DND power sharing at the target plates and made preliminary tests of heat flux reduction by gas injection.

Lasnier, C.J.; Allen, S.L.; Hill, D.N. [Lawrence Livermore National Lab., CA (United States); Leonard, A.W.; Petrie, T.W. [General Atomics, San Diego, CA (United States)

1994-01-28T23:59:59.000Z

111

Inverse natural convection problem of estimating wall heat flux using a moving sensor  

SciTech Connect (OSTI)

Inverse heat transfer problems have many applications in various branch of science and engineering. Here, the inverse problem of determining heat flux at the bottom wall of a two-dimensional cavity from temperature measurement in the domain is considered. The Boussinesq equation is used to model the natural convection induced by the wall heat flux. The inverse natural convection problem is posed as a minimization problem of the performance function, which is the sum of square residuals between calculated and observed temperature, by means of a conjugate gradient method. Instead of employing several fixed sensors, a single sensor is used which is moving at a given frequency over the bottom wall. The present method solves the inverse natural convection problem accurately without a priori information about the unknown function to be estimated.

Park, H.M.; Chung, O.Y.

1999-11-01T23:59:59.000Z

112

Effect of ocean surface currents on wind stress, heat flux, and wind power input to the ocean  

E-Print Network [OSTI]

Effect of ocean surface currents on wind stress, heat flux, and wind power input to the ocean, J. T., and L. Thompson (2006), Effect of ocean surface currents on wind stress, heat flux, and wind power input to the ocean, Geophys. Res. Lett., 33, L09604, doi:10.1029/2006GL025784. 1. Introduction [2

Thompson, LuAnne

113

Relationship between heat transfer intensity and absolute vorticity flux intensity in flat tube bank fin channels with Vortex Generators  

Science Journals Connector (OSTI)

The heat transfer enhancement can be achieved through the secondary flow. It is found that absolute vorticity flux along the main flow can describe the secondary flow intensity and correspond to the heat transfer enhancement averaged in span wise direction. Investigations to verify this phenomenon are reported. The results show that there has a similar distribution for absolute vorticity flux in the main flow direction compared with that for span averaged Nusselt number. The conformance of Nusselt number and absolute vorticity flux shows that absolute vorticity flux can reflect the intensity of heat transfer produced by the secondary flow.

Ke-Wei Song; Liang-Bi Wang

2008-01-01T23:59:59.000Z

114

Analysis of a multi-machine database on divertor heat flux  

SciTech Connect (OSTI)

A coordinated effort to measure divertor heat flux characteristics in fully attached, similarly shaped H-mode plasmas on C-Mod, DIII-D, and NSTX was carried out in 2010 in order to construct a predictive scaling relation applicable to next step devices including ITER, FNSF, and DEMO. Few published scaling laws are available and those that have been published were obtained under widely varying conditions and divertor geometries, leading to conflicting predictions for this critically important quantity. This study was designed to overcome these deficiencies. Analysis of the combined data set reveals that the primary dependence of the parallel heat flux width is robustly inverse with I-p, which all three tokamaks independently demonstrate. An improved Thomson scattering system on DIII-D has yielded very accurate scrape off layer (SOL) profile measurements from which tests of parallel transport models have been made. It is found that a flux-limited model agrees best with the data at all collisionalities, while a Spitzer resistivity model agrees at higher collisionality where it is more valid. The SOL profile measurements and divertor heat flux scaling are consistent with a heuristic drift based model as well as a critical gradient model.

Makowski, M. A. [Lawrence Livermore National Laboratory (LLNL); Elder, J. D. [University of Toronto, Toronto, ON, Canada; Gray, Travis K [ORNL; LaBombard, Brian [Massachusetts Institute of Technology (MIT); Lasnier, C. J. [Lawrence Livermore National Laboratory (LLNL); Leonard, A. W. [General Atomics; Maingi, Rajesh [ORNL; Osborne, T. H. [General Atomics; Stangeby, P. C. [University of Toronto Institute for Aerospace Studies; Terry, J. L. [MIT Plasma Science & Fusion Center, Cambridge, MA 02139 USA; Watkins, J. G. [Sandia National Laboratories (SNL)

2012-01-01T23:59:59.000Z

115

Heat Flux Analysis of a Reacting Thermite Spray Impingent on a Substrate  

SciTech Connect (OSTI)

Spray combustion from a thermite reaction is a new area of research relevant to localized energy generation applications, such as welding or cutting. In this study, we characterized the heat flux of combustion spray impinging on a target from a nozzle for three thermite mixtures. The reactions studied include aluminum (Al) with iron oxide (Fe2O3), Al with copper oxide (CuO), and Al with molybdenum oxide (MoO3). Several standoff distances (i.e., distance from the nozzle exit to the target) were analyzed. A fast response heat flux sensor was engineered for this purpose and is discussed in detail. Results correlated substrate damage to a threshold heat flux of 4550 W/cm2 for a fixed-nozzle configuration. Also, higher gas-generating thermites were shown to produce a widely dispersed spray and be less effective at imparting kinetic energy damage to a target. These results provide an understanding of the role of thermal and physical properties (i.e., such as heat of combustion, gas generation, and particle size) on thermite spray combustion performance measured by damaging a target substrate.

Eric S. Collins; Michelle L. Pantoya; Michael A. Daniels; Daniel J. Prentice; Eric D. Steffler; Steven P. D'Arche

2012-03-01T23:59:59.000Z

116

Ultrahigh heat flux plasma-facing components for magnetic fusion energy  

SciTech Connect (OSTI)

Sandia and Ultramet partnered to design and test refractory metal plasma-facing components and heat exchangers for advanced, high-temperature power conversion systems. These devices consisted of high-temperature helium-to-helium and lithium-to-helium heat exchangers that operate with high efficiency due to the porous foam inserts used in the gas stream, which promote turbulence and provide extended surface area for enhanced convection. Single- and multi-channel helium panels and the Li-He heat exchanger were fabricated from either pure molybdenum, TZM, or tungsten. The design was carried out through an Ultramet subcontractor. The flow path was carefully tailored to minimize the pressure drop while maximizing the heat transfer. The single- and multi-channel helium panels were tested at Sandia's PMTF using an electron beam system and the closed helium flow loop. In 2006, a single-channel tungsten tube was successfully tested to an average heat flux of 14 MW/m{sup 2} with a localized peak of 22 MW/m{sup 2} along the axial centerline at the outer radius. Under this CRADA, multiple square-channel molybdenum components were successfully tested to heat flux levels approaching 8.5 MW/m{sup 2}. The three multi-channel prototypes experienced mechanical failure due to issues related to the design of the large unsupported span of the heated faceplates in combination with prototype material and braze selection. The Li-He heat exchanger was both designed and partially tested at the PMTF for helium and lithium flow.

Youchison, D. L.

2012-03-01T23:59:59.000Z

117

Interactions Between the Daytime Mixed Layer and the Surface: Oklahoma Mesonet and EBBR Heat Fluxes  

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

Interactions Between the Daytime Mixed Layer Interactions Between the Daytime Mixed Layer and the Surface: Oklahoma Mesonet and EBBR Heat Fluxes R. L. Coulter Argonne National Laboratory Argonne, Illinois Introduction Surface layer estimates of surface sensible heat flux have been made at 10 - 14 locations within the Central Facility (CF) of the Southern Great Plains (SGP) Atmospheric Radiation Measurement (ARM) Program site by using energy balance Bowen ratio (EBBR) stations located mostly in uncultivated areas. The advent of the Oklahoma Mesonet (OKM) with approximately 50 stations within the boundaries of the Cloud and Radiation Testbed (CART) site that measure a variety of meteorological parameters leads to the possibility of using the OKM to provide additional estimates of surface energy budget to augment

118

Further considerations of critical heat flux in saturated pool boiling during power transients  

SciTech Connect (OSTI)

In this paper, we further evaluate our previously postulated transient CHF model. First, we verify the steady-state CHF model on which the transient model is based by using recent macrolayer-thickness data. We also include the effect of thermal storage in the heater that we previously neglected. The use of a simplified approach in the prediction of the instantaneous surface heat flux for given pwoer generation rates considerably improves the predictive capability of the transient critical heat-flux (CHF) model. Finally, we discuss the statistical vapor mass behavior during transient boiling and its effect on the transient CHF model. We show that the data scatter within a small range may be partially explained through such an approach.

Pasamehmetoglu, K.O.; Nelson, R.A.

1988-01-01T23:59:59.000Z

119

Parallel heat flux and flow acceleration in open field line plasmas with magnetic trapping  

SciTech Connect (OSTI)

The magnetic field strength modulation in a tokamak scrape-off layer (SOL) provides both flux expansion next to the divertor plates and magnetic trapping in a large portion of the SOL. Previously, we have focused on a flux expander with long mean-free-path, motivated by the high temperature and low density edge anticipated for an absorbing boundary enabled by liquid lithium surfaces. Here, the effects of magnetic trapping and a marginal collisionality on parallel heat flux and parallel flow acceleration are examined. The various transport mechanisms are captured by kinetic simulations in a simple but representative mirror-expander geometry. The observed parallel flow acceleration is interpreted and elucidated with a modified Chew-Goldberger-Low model that retains temperature anisotropy and finite collisionality.

Guo, Zehua; Tang, Xian-Zhu; McDevitt, Chris [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2014-10-15T23:59:59.000Z

120

Elementary Heating Events - Magnetic Interactions Between Two Flux Sources. III Energy Considerations  

E-Print Network [OSTI]

The magnetic field plays a crucial role in heating the solar corona, but the exact energy release mechanism(s) is(are) still unknown. Here, we investigate in detail, the process of magnetic energy release in a situation where two initially independent flux systems are forced into each other. Work done by the foot point motions goes in to building a current sheet in which magnetic reconnection takes place. The scaling relations of the energy input and output are determined as functions of the driving velocity and the strength of fluxes in the independent flux systems. In particular, it is found that the energy injected into the system is proportional to the distance travelled not the rate of travel. Similarly, the rate of Joule dissipation is related to the distance travelled. Hence, rapidly driven foot points lead to bright, intense, but short-lived events, whilst slowly driven foot points produce weaker, but longer-lived brightenings. Integrated over the lifetime of the events both would produce the same heating if all other factors were the same. A strong overlying field has the affect of creating compact flux lobes from the sources. These appear to lead to a more rapid injection of energy, as well as a more rapid release of energy. Thus, the stronger the overlying field the more compact and more intense the heating. This means observers must know the rate of movement of the magnetic fragments involved in an events, as well as determine the strength and orientation of the surrounding field to be able to predict anything about the energy dissipated.

K. Galsgaard; C. E. Parnell

2005-04-28T23:59:59.000Z

Note: This page contains sample records for the topic "latent heat flux" from the National Library of EnergyBeta (NLEBeta).
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121

Commissioning of the Korean High Heat Flux Test Facility by Using Electron Beam System for Plasma Facing Components  

Science Journals Connector (OSTI)

Divertor and High-Heat-Flux Components / Proceedings of the Twentieth Topical Meeting on the Technology of Fusion Energy (TOFE-2012) (Part 1), Nashville, Tennessee, August 27-31, 2012

Suk-Kwon Kim; Eo Hwak Lee; Jae-Sung Yoon; Dong Won Lee; Duck-Hoi Kim; Seungyon Cho

122

OPTIMIZATION AND DESIGN GUIDELINES FOR HIGH FLUX MICRO-CHANNEL HEAT SINKS FOR LIQUID AND GASEOUS SINGLE-PHASE FLOW  

E-Print Network [OSTI]

orders of magnitude, especially for high heat flux devices. Using water and air as coolants, designs with the optimization tool are generalized and optimum configurations are illustrated on design charts. Physical trends

Müller, Norbert

123

Investigation of downward facing critical heat flux with water-based nanofluids for In-Vessel Retention applications  

E-Print Network [OSTI]

In-Vessel Retention ("IVR") is a severe accident management strategy that is power limiting to the Westinghouse AP1000 due to critical heat flux ("CHF") at the outer surface of the reactor vessel. Increasing the CHF level ...

DeWitt, Gregory L

2011-01-01T23:59:59.000Z

124

Critical Heat Flux -CHF in Liquid Metal in Presence of a Magnetic Field with Particular Reference to Fusion Reactor Project  

Science Journals Connector (OSTI)

Knowledge of the critical heat flux q??crit is a cornerstone of reactor design fission, but as will demonstrate also in fusion reactors. This quantity cannot be deduced directly,...

F. J. Arias

2010-04-01T23:59:59.000Z

125

On the heat flux vector for flowing granular materials--Part I: effective thermal conductivity and background  

SciTech Connect (OSTI)

Heat transfer plays a major role in the processing of many particulate materials. The heat flux vector is commonly modelled by the Fourier’s law of heat conduction and for complex materials such as nonlinear fluids, porous media, or granular materials, the coeffcient of thermal conductivity is generalized by assuming that it would depend on a host of material and kinematical parameters such as temperature, shear rate, porosity or concentration, etc. In Part I, we will give a brief review of the basic equations of thermodynamics and heat transfer to indicate the importance of the modelling of the heat flux vector. We will also discuss the concept of effective thermal conductivity (ETC) in granular and porous media. In Part II, we propose and subsequently derive a properly frame-invariant constitutive relationship for the heat flux vector for a (single phase) flowing granular medium. Standard methods in continuum mechanics such as representation theorems and homogenization techniques are used. It is shown that the heat flux vector in addition to being proportional to the temperature gradient (the Fourier’s law), could also depend on the gradient of density (or volume fraction), and D (the symmetric part of the velocity gradient) in an appropriate manner. The emphasis in this paper is on the idea that for complex non-linear materials it is the heat flux vector which should be studied; obtaining or proposing generalized form of the thermal conductivity is not always appropriate or suffcient.

Massoudi, Mehrdad

2006-09-10T23:59:59.000Z

126

Numerical simulation of natural convection of latent heat phase-change-material microcapsulate slurry packed in a horizontal rectangular enclosure heated from below and cooled from above  

Science Journals Connector (OSTI)

A two-dimensional numerical simulation of natural convection in a rectangular enclosure heated from below and cooled from above has been conducted with non-Newtonian phase-change-material (PCM) microcapsulate slu...

Hideo Inaba; Yanlai Zhang; Akihiko Horibe; Naoto Haruki

2007-03-01T23:59:59.000Z

127

Subsurface Temperature, Moisture, Thermal Conductivity and Heat Flux, Barrow, Area A, B, C, D  

SciTech Connect (OSTI)

Subsurface temperature data are being collected along a transect from the center of the polygon through the trough (and to the center of the adjacent polygon for Area D). Each transect has five 1.5m vertical array thermistor probes with 16 thermistors each. This dataset also includes soil pits that have been instrumented for temperature, water content, thermal conductivity, and heat flux at the permafrost table. Area C has a shallow borehole of 2.5 meters depth is instrumented in the center of the polygon.

Cable, William; Romanovsky, Vladimir

2014-03-31T23:59:59.000Z

128

Subsurface Temperature, Moisture, Thermal Conductivity and Heat Flux, Barrow, Area A, B, C, D  

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

Subsurface temperature data are being collected along a transect from the center of the polygon through the trough (and to the center of the adjacent polygon for Area D). Each transect has five 1.5m vertical array thermistor probes with 16 thermistors each. This dataset also includes soil pits that have been instrumented for temperature, water content, thermal conductivity, and heat flux at the permafrost table. Area C has a shallow borehole of 2.5 meters depth is instrumented in the center of the polygon.

Cable, William; Romanovsky, Vladimir

129

Group solution for unsteady free-convection flow from a vertical moving plate subjected to constant heat flux  

Science Journals Connector (OSTI)

The problem of heat and mass transfer in an unsteady free-convection flow over a continuous moving vertical sheet in an ambient fluid is investigated for constant heat flux using the group theoretical method. The nonlinear coupled partial differential ... Keywords: 22E05, 35Q53, 54H15, Free convective flow, Group theoretic method, Prandtl number, Thermal boundary layer

M. Kassem

2006-03-01T23:59:59.000Z

130

Anisotropic dissipative effects on the buoyancy instability with background heat flux  

SciTech Connect (OSTI)

The linear buoyancy instability in magnetized plasmas is investigated in the presence of anisotropic resistivity and viscosity by taking into account the background heat flux. The magnetic field is assumed to be homogeneous and has both horizontal and vertical components. The heat is primarily transported along the magnetic force lines when the gyro radius is much less than the mean collision free path. The Hall term is examined first and shows a damping effect on the magnetothermal instability. The heat-flux-driven buoyancy instability (HBI) is then investigated by taking into account the parallel resistivity (PR), cross-field resistivity (CR), and the anisotropic viscosity. The general dispersion relation (DR) is derived and discussed in several special cases. We show that only the CR and viscosity exert effects on the DR in the first case. The critical condition for the occurrence of HBI is modified by the CR coupled with the viscosity and the value of the instability growth rate is diminished by them. The effects due to the PR (resp. viscosity) on the HBI are examined next. The PR (resp. viscosity) is shown to alter not only the growth rate but also the instability criterion. There exists an unstable mode when the temperature decreases in the direction of gravity while this case is proven to be magnetothermally stable in the ideal magnetohydrodynamic limit. A new unstable mode is solely induced by the presence of PR (resp. viscosity). When the PR and CR are both taken into account, the resistivity is shown to induce a damping mode rather than an instability. Finally, considering the PR and viscosity simultaneously, it is found that a new unstable mode is excited when the PR is not equal to the viscosity, or else, dissipation effects do not alter the instability criterion and just cut down the growth rate.

Ren Haijun; Wu Zhengwei [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong); CAS Key Laboratory of Basic Plasma Physics, University of Science and Technology of China, Hefei 230026 (China); Cao Jintao [CAS Key Laboratory of Basic Plasma Physics, University of Science and Technology of China, Hefei 230026 (China); Chu, Paul K. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong)

2011-03-15T23:59:59.000Z

131

Flux  

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

5000 5000 6000 7000 8000 Wavelength (Angstroms) Flux (in arbitrary units) SN 1990N SN 1989B SN 1993O SN 1981B SN 1994D SN 1997ap Iron Peak Blends Ca II Si II & Co II Fe II & III Day -7 Day -5 Day -4 Day -2 ± 2 Day 0 Day +2 * -50 0 50 100 150 Observed days from peak Observed I magnitude 27 26 25 24 23 Observed R magnitude 27 26 25 24 Observed I magnitude 27 26 25 24 23 R band Ground-based I band HST I band (b) (c) (a) Pre-SN observation 3.5 4.0 4.5 5.0 5.5 log(cz) 14 16 18 20 22 24 26 effective m B 0.02 0.05 0.1 0.2 0.5 1.0 redshift z Hamuy et al (A.J. 1996) Supernova Cosmology Project 6 8 % 9 0 % 0.5 1.0 1.5 2.0 2.5 3.0 ! M Age < 9.6 Gyr (H = 50 km s -1 Mpc -1 ) No Big Bang 0.0 0.5 1.0 1.5 2.0 2.5 3.0 -3 -2 -1 0 1 2 3 -3 -2 -1 0 1 2 3 ! " z ~ 0 . 4 z = 0 . 8 3 6 8 % 9 0 % 0.5 1.0 1.5 2.0 2.5 3.0 ! M Age < 9.6 Gyr (H=50 km/s/Mpc)

132

The Surface Energy Balance System (SEBS) for estimation of turbulent heat fluxes Hydrology and Earth System Sciences, 6(1), 8599 (2002) EGS  

E-Print Network [OSTI]

, turbulent heat flux, evaporation, remote sensing Introduction The estimation of atmospheric turbulent fluxes because of the heterogeneity of land surfaces and the dynamic nature of heat transfer processes. Remote be represented by point measurements only. Methods using remote sensing information to estimate heat exchange

Paris-Sud XI, Université de

133

Facility for high-heat flux testing of irradiated fusion materials and components using infrared plasma arc lamps  

Science Journals Connector (OSTI)

A new high-heat flux testing (HHFT) facility using water-wall stabilized high-power high-pressure argon plasma arc lamps (PALs) has been developed for fusion applications. It can accommodate irradiated plasma facing component materials and sub-size mock-up divertor components. Two PALs currently available at Oak Ridge National Laboratory can provide maximum incident heat fluxes of 4.2 and 27 MW m?2, which are prototypic of fusion steady state heat flux conditions, over a heated area of 9 ? 12 and 1 ? 10 cm2, respectively. The use of PAL permits the heat source to be environmentally separated from the components of the test chamber, simplifying the design to accommodate safe testing of low-level irradiated articles and materials under high-heat flux. Issues related to the operation and temperature measurements during testing of tungsten samples are presented and discussed. The relative advantages and disadvantages of this photon-based HHFT facility are compared to existing e-beam and particle beam facilities used for similar purposes.

Adrian S Sabau; Evan K Ohriner; Jim Kiggans; David C Harper; Lance L Snead; Charles R Schaich

2014-01-01T23:59:59.000Z

134

Modification of divertor heat and article flux profiles with applied 3D fields in NSTX H-mode plasmas  

SciTech Connect (OSTI)

Externally imposed non-axisymmetric magnetic perurbations are observed to alter divertor heat and particle flux profiles in the National Spherical Torus Experiment (NSTX). The divertor profiles are foud to have a modust level of multiple local peaks, characteristic of strike poimt splitting or the "magnetis lob" structure, even before the application of the 3D fields in some (but not all) NSTX discharges. This is thought to be due to the intrinsic error fields. The applied 3D fields augmented the intrinsic strike point splitting, making the ampliture of local peaks, and valleys larger in the divertor profile and striations at the divertor surface brighter. The measured heat flux profile shows that the radial location and spacing of the strations are qualitativel consistent witth a vacuum field tracing calcultion. 3D field application did not change the peak divertor heat and particle fluxes at the toroidal location of measurement. Spatial characteristics of the observed patterns are also reported in the paper.

Ahn, Joon-Wook [Oak Ridge National Laboratory (ORNL); Canik, John [ORNL; Soukhanovskii, V. A. [Lawrence Livermore National Laboratory (LLNL); Maingi, Rajesh [ORNL; Battaglia, D. J. [Oak Ridge National Laboratory (ORNL)

2010-04-01T23:59:59.000Z

135

Investigating the use of nanofluids to improve high heat flux cooling systems  

E-Print Network [OSTI]

The thermal performance of high heat flux components in a fusion reactor could be enhanced significantly by the use of nanofluid coolants, suspensions of a liquid with low concentrations of solid nanoparticles. However, before they are considered viable for fusion, the long-term behaviour of nanofluids must be investigated. This paper reports an experiment which is being prepared to provide data on nanofluid stability, settling and erosion in a HyperVapotron device. Procedures are demonstrated for nanofluid synthesis and quality assessment, and the fluid sample analysis methods are described. The end results from this long-running experiment are expected to allow an initial assessment of the suitability of nanofluids as coolants in a fusion reactor.

Barrett, T R; Flinders, K; Sergis, A; Hardalupas, Y

2013-01-01T23:59:59.000Z

136

Secondary electron emission and the bifurcation of the heat flux to the targets in fusion plasmas  

SciTech Connect (OSTI)

The presence of secondary electron emission (SEE) from plasma facing components in fusion devices can result in a strong localization of the heat flux from plasma to the wall and subsequent wall erosion. Usually, the impact of the SEE is considered assuming the Maxwellian distribution of the electrons coming to the surface. As a result, the SEE coefficient only depends on the temperature of primary electrons. However, the tail of primary electron distribution function in the scrape off layer (SOL) of fusion devices can be far from Maxwellian due to preferential loss of fast electrons. Consequently, it is shown that the SEE coefficient will depend on the wall potential and multiple solutions can be possible corresponding to different regimes of plasma flow to the wall: with and without SEE effects. This effect can cause two-slope electron temperature profiles in the SOL, which are often seen in experiments.

Lee, Wonjae; Krasheninnikov, Sergei I. [University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093 (United States)] [University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093 (United States)

2013-12-15T23:59:59.000Z

137

Oxidation and Volatilization from Tungsten Brush High Heat Flux Armor During High Temperature Steam Exposure  

SciTech Connect (OSTI)

Tungsten brush accommodates thermal stresses and high heat flux in fusion reactor components such as plasma facing surfaces or armor. However, inherently higher surface areas are introduced with the brush design. We have tested a specific design of tungsten brush in steam between 500 and 1100°C. Hydrogen generation and tungsten volatilization rates were determined to address fusion safety issues. The brush prepared from 3.2-mm diameter welding rods had a packing density of 85 percent. We found that both hydrogen generation and tungsten volatilization from brush, fixtured to represent a unit within a larger component, were less than projections based upon the total integrated surface area (TSA). Steam access and the escape of hydrogen and volatile oxide from void spaces within the brush are restricted compared to specimens with more direct diffusion pathways to the test environment. Hydrogen generation rates from restrained specimens based on normal surface area (NSA) remain about five times higher than rates based on total surface areas from specimens with direct steam access. Volatilization rates from restrained specimens based upon normal surface area (NSA) were only 50 percent higher than our historic cumulative maximum flux plot (CMFP) for tungsten. This study has shown that hydrogen generation and tungsten volatilization from brush do not scale according to predictions with previously determined rates, but in fact, with higher packing density could approach those from flat surfaces.

Smolik, Galen Richard; Pawelko, Robert James; Anderl, Robert Andrew; Petti, David Andrew

2000-05-01T23:59:59.000Z

138

Divertor Heat Flux Mitigation in High-Performance H-mode Plasmas in the National Spherical Torus Experiment.  

SciTech Connect (OSTI)

Experiments conducted in high-performance 1.0-1.2 MA 6 MW NBI-heated H-mode plasmas with a high flux expansion radiative divertor in NSTX demonstrate that significant divertor peak heat flux reduction and access to detachment may be facilitated naturally in a highly-shaped spherical torus (ST) configuration. Improved plasma performance with high {beta}{sub p} = 15-25%, a high bootstrap current fraction f{sub BS} = 45-50%, longer plasma pulses, and an H-mode regime with smaller ELMs has been achieved in the lower single null configuration with higher-end elongation 2.2-2.4 and triangularity 0.6-0.8. Divertor peak heat fluxes were reduced from 6-12 MW/m{sup 2} to 0.5-2 MW/m{sup 2} in ELMy H-mode discharges using high magnetic flux expansion and partial detachment of the outer strike point at several D{sub 2} injection rates, while good core confinement and pedestal characteristics were maintained. The partially detached divertor regime was characterized by a 30-60% increase in divertor plasma radiation, a peak heat flux reduction by up to 70%, measured in a 10 cm radial zone, a five-fold increase in divertor neutral pressure, and a significant volume recombination rate increase.

Soukhanovskii, V A; Maingi, R; Gates, D; Menard, J; Paul, S F; Raman, R; Roquemore, A L; Bell, R E; Bush, C; Kaita, R

2008-09-22T23:59:59.000Z

139

Facility for high heat flux testing of irradiated fusion materials and components using infrared plasma arc lamps  

SciTech Connect (OSTI)

A new high-heat flux testing facility using water-wall stabilized high-power high-pressure argon Plasma Arc Lamps (PALs) has been developed for fusion applications. It can handle irradiated plasma facing component materials and mock-up divertor components. Two PALs currently available at ORNL can provide maximum incident heat fluxes of 4.2 and 27 MW/m2 over a heated area of 9x12 and 1x10 cm2, respectively, which are fusion-prototypical steady state heat flux conditions. The facility will be described and the main differences between the photon-based high-heat flux testing facilities, such as PALs, and the e-beam and particle beam facilities more commonly used for fusion HHF testing are discussed. The components of the test chamber were designed to accommodate radiation safety and materials compatibility requirements posed by high-temperature exposure of low levels irradiated tungsten articles. Issues related to the operation and temperature measurements during testing are presented and discussed.

Sabau, Adrian S [ORNL] [ORNL; Ohriner, Evan Keith [ORNL] [ORNL; Kiggans, Jim [ORNL] [ORNL; Harper, David C [ORNL] [ORNL; Snead, Lance Lewis [ORNL] [ORNL; Schaich, Charles Ross [ORNL] [ORNL

2014-01-01T23:59:59.000Z

140

Thermal properties for the thermal-hydraulics analyses of the BR2 maximum nominal heat flux.  

SciTech Connect (OSTI)

This memo describes the assumptions and references used in determining the thermal properties for the various materials used in the BR2 HEU (93% enriched in {sup 235}U) to LEU (19.75% enriched in {sup 235}U) conversion feasibility analysis. More specifically, this memo focuses on the materials contained within the pressure vessel (PV), i.e., the materials that are most relevant to the study of impact of the change of fuel from HEU to LEU. This section is regrouping all of the thermal property tables. Section 2 provides a summary of the thermal properties in form of tables while the following sections present the justification of these values. Section 3 presents a brief background on the approach used to evaluate the thermal properties of the dispersion fuel meat and specific heat capacity. Sections 4 to 7 discuss the material properties for the following materials: (i) aluminum, (ii) dispersion fuel meat (UAlx-Al and U-7Mo-Al), (iii) beryllium, and (iv) stainless steel. Section 8 discusses the impact of irradiation on material properties. Section 9 summarizes the material properties for typical operating temperatures. Appendix A elaborates on how to calculate dispersed phase's volume fraction. Appendix B shows the evolution of the BR2 maximum heat flux with burnup.

Dionne, B.; Kim, Y. S.; Hofman, G. L. (Nuclear Engineering Division) [Nuclear Engineering Division

2011-05-23T23:59:59.000Z

Note: This page contains sample records for the topic "latent heat flux" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Next: effect of eddies on the Hadley circulation We talked about ways to incorporate eddy heat fluxes  

E-Print Network [OSTI]

Next: effect of eddies on the Hadley circulation We talked about ways to incorporate eddy heat ¡ An eddy-driven Hadley cell model #12;Effect of eddy fluxes Compare the dry dynamical core model run axisymmetrically versus with eddies ¡ Hadley cell is significantly stronger with eddies ¡ Suggests eddies

Frierson, Dargan

142

Pressure tensor and heat flux vector for inhomogeneous nonequilibrium fluids under the influence of three-body forces  

E-Print Network [OSTI]

Pressure tensor and heat flux vector for inhomogeneous nonequilibrium fluids under the influence of three-body forces Junfang Zhang and B. D. Todd* Centre for Molecular Simulation, Swinburne University of Technology, P.O. Box 218, Hawthorn Victoria 3122, Australia Received 11 September 2003; published 31 March

143

Proceedings of US/Japan workshop, Q219 on high heat flux components and plasma surface interactions for next fusion devices  

SciTech Connect (OSTI)

This report contains the viewgraphs from the proceedings of US/Japan Workshop on High Heat Flux Components and Plasma Surface Interactions for Next Fusion Devices. Some of the general topics covered by this report are: PFC/PSI in tokamak and helical devices; development of high heat flux components; PSIS and plasma facing materials;tritium; and material damage.

Ulrickson, M.A.; Stevens, P.L.; Hino, T.; Hirohata, Y. [eds.] [eds.

1996-12-01T23:59:59.000Z

144

Measurements of net radiation, ground heat flux and surface temperature in an urban canyon  

SciTech Connect (OSTI)

The Joint Urban 2003 (JU2003) field study was conducted in Oklahoma City in July 2003 to collect data to increase our knowledge of dispersion in urban areas. Air motions in and around urban areas are very complicated due to the influence of urban structures on both mechanical and thermal forcing. During JU2003, meteorological instruments were deployed at various locations throughout the urban area to characterize the processes that influence dispersion. Some of the instruments were deployed to characterize urban phenomena, such as boundary layer development. In addition, particular sites were chosen for more concentrated measurements to investigate physical processes in more detail. One such site was an urban street canyon on Park Avenue between Broadway and Robinson Avenues in downtown Oklahoma City. The urban canyon study was designed to examine the processes that control dispersion within, into and out of the urban canyon. Several towers were deployed in the Park Avenue block, with multiple levels on each tower for observing the wind using sonic anemometers. Infrared thermometers, net radiometers and ground heat flux plates were deployed on two of the towers midway in the canyon to study the thermodynamic effects and to estimate the surface energy balance. We present results from the surface energy balance observations.

Gouveia, F J; Leach, M J; Shinn, J H

2003-11-06T23:59:59.000Z

145

NACP Site-Model and Aggregated Flux Data Published  

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

Site-Model and Aggregated Flux Data Published Site-Model and Aggregated Flux Data Published The ORNL DAAC is pleased to announce the release of a data set from the North American Carbon Program (NACP): NACP Site: Terrestrial Biosphere Model and Aggregated Flux Data in Standard Format . Data set prepared by D.M. Ricciuto, K. Schaefer, P.E. Thornton, K. Davis, R.B. Cook, Shishi Liu, R. Anderson, M.A. Arain, I. Baker, J.M. Chen, M. Dietze, R. Grant, C. Izaurralde, A.K. Jain, A.W. King, C. Kucharik, Shuguang Liu, E. Lokupitiya, Y. Luo, C. Peng, B. Poulter, D. Price, W. Riley, A. Sahoo, H. Tian, C. Tonitto, and H. Verbeeck. This data set provides standardized output variables for gross primary productivity (GPP), net ecosystem exchange (NEE), leaf area index (LAI), ecosystem respiration (Re), latent heat flux (LE), and sensible heat flux (H) from 24

146

The role of parallel heat transport in the relation between upstream scrape-off layer widths and target heat flux width in H-mode plasmas of NSTX.  

SciTech Connect (OSTI)

The physics of parallel heat transport was tested in the Scrape-off Layer (SOL) plasma of the National Spherical Torus Experiment (NSTX) [M. Ono, et al., Nucl. Fusion 40, 557 (2000) and S. M. Kaye, et al., Nucl. Fusion 45, S168 (2005)] tokamak by comparing the upstream electron temperature (T{sub e}) and density (n{sub e}) profiles measured by the mid-plane reciprocating probe to the heat flux (q{sub {perpendicular}}) profile at the divertor plate measured by an infrared (IR) camera. It is found that electron conduction explains the near SOL width data reasonably well while the far SOL, which is in the sheath limited regime, requires an ion heat flux profile broader than the electron one to be consistent with the experimental data. The measured plasma parameters indicate that the SOL energy transport should be in the conduction-limited regime for R-R{sub sep} (radial distance from the separatrix location) < 2-3 cm. The SOL energy transport should transition to the sheath-limited regime for R-R{sub sep} > 2-3cm. The T{sub e}, n{sub e}, and q{sub {perpendicular}} profiles are better described by an offset exponential function instead of a simple exponential. The conventional relation between mid plane electron temperature decay length ({lambda}{sub Te}) and target heat flux decay length ({lambda}{sub q}) is {lambda}{sub Te} = 7/2{lambda}{sub q}, whereas the newly-derived relation, assuming offset exponential functional forms, implies {lambda}{sub Te} = (2-2.5){lambda}{sub q}. The measured values of {lambda}{sub Te}/{lambda}{sub q} differ from the new prediction by 25-30%. The measured {lambda}{sub q} values in the far SOL (R-R{sub sep} > 2-3cm) are 9-10cm, while the expected values are 2.7 < {lambda}{sub q} < 4.9 cm (for sheath-limited regime). We propose that the ion heat flux profile is substantially broader than the electron heat flux profile as an explanation for this discrepancy in the far SOL.

Ahn, J W; Boedo, J A; Maingi, R; Soukhanovskii, V A

2009-01-05T23:59:59.000Z

147

An analysis of pavement heat flux to optimize the1 water efficiency of a pavement-watering method2  

E-Print Network [OSTI]

An analysis of pavement heat flux to optimize the1 water efficiency of a pavement-watering method2 Martin HENDEL1,2,3* , Morgane COLOMBERT2 , Youssef DIAB2,4 , Laurent ROYON3 3 1 Paris City Hall, Water.hendel@paris.fr)8 9 Preprint version. Uploaded on May 12th , 2014.10 Abstract: Pavement-watering as a technique

Paris-Sud XI, Université de

148

Critical heat flux predictions based on the BODYFIT-2PE computer code and Columbia University CHF correlation. [PWR; BWR  

SciTech Connect (OSTI)

The BODYFIT-2PE (Boundary-Fitted Coordinate, 2-Phase Flow with Partially Elliptic) computer code has been developed and was employed to simulate the critical heat flux experiment in a General Electric 3 x 3 rod bundle by using a CHF correlation recently developed at Columbia University under EPRI sponsorship. CHF predictions are important in analyzing rod bundle performance in nuclear reactor operation. The results of the BODYFIT calculations compared favorably with the experimental measurements.

Chen, B.C.J.; Chien, T.H.; Sha, W.T.; Kim, J.H.

1983-01-01T23:59:59.000Z

149

Heat transfer and pressure drop data for high heat flux densities to water at high subcritical pressures  

E-Print Network [OSTI]

Local surface ooeffioients of heat t-ansfer, overall pressure drop data and mean friction factor are presented for heat flamms up to 3.52106 BtuAr ft2 for water flowing in a nickel tabe isder the following conditions: mass ...

Rohsenow, Warren M.

1951-01-01T23:59:59.000Z

150

About the conditions of suppression of turbulence effects on the poloidal fluxes in thoroidal plasmas in the presence of RF heating  

E-Print Network [OSTI]

plasmas in the presence of RF heating N. Pometescu University of Craiova, Association EURATOM of the poloidal particle and heat fluxes in the thoroidal plasmas due to electrostatic turbulence in the presence of external Radio Frequency heating. The effects of the electrostatic turbulence contain two terms. One

151

Momentum and heat fluxes in a turbulent air flow over a wet, smooth boundary  

E-Print Network [OSTI]

are negligible in directions other than those normal to the boundary surface. Such equa? tions were first employed by Boussinesq (5* 6). For turbulent flow, he suggested the equatiisns, ? IS ^7/ (momentum flux)/ - U and ^ =. Kh (beat flux) where KM and c... of a pre? cision potentiometer. Continuous, uniform water supply to the test surface was achieved by a distilled water supply system composed of glass bottles and copper tubing arranged to supply water at any required rate without attention from...

Rice, Warren

2013-10-04T23:59:59.000Z

152

Natural convection in high heat flux tanks at the Hanford Waste Site / [by] Mark van der Helm and Mujid S. Kazimi  

E-Print Network [OSTI]

A study was carried out on the potential for natural convection and the effect of natural convection in a High Heat Flux Tank, Tank 241-C-106, at the Hanford Reservation. To determine the existence of natural convection, ...

Van der Helm, Mark Johan, 1972-

1996-01-01T23:59:59.000Z

153

Finite difference analysis of mass transfer effects on flow past an impulsively started infinite vertical plate in dissipative fluid and constant heat flux  

Science Journals Connector (OSTI)

A finite-difference solution to the flow past an impulsively started infinite vertical plate is derived by assuming 1) presence of species concentration like water vapour, CO2 etc. and 2) constant heat flux at th...

J. N. Das; S. N. Ray; Prof. Dr. V. M. Soundalgekar

1995-02-01T23:59:59.000Z

154

Journal of the MeteorologicalSocietyof Japan, Vol.76,No.6, pp.909-923,1998 909 On the Annual Cycle of Latent Heat Fluxes over  

E-Print Network [OSTI]

.g., Weare et al., 1981;Esbensen and Reynolds, 1981;Esbensenand Kushnir, 1981;Reed, 1985; Oberhuber, 1988. (1995), long-term ship records and marine weather reports are generally used in researchcommunitiesto

Hawai'i at Manoa, University of

155

Simulated and observed fluxes of sensible and latent heat and CO2 at the WLEF-TV tower using SiB2.5  

E-Print Network [OSTI]

, water, momentum, and trace gases to the atmosphere. A parameterized representa- tion of these exchanges prediction (NWP) models to forecast weather under extreme climatic conditions such as droughts (Atlas et al

Collett Jr., Jeffrey L.

156

Comparing Simulated and Measured Sensible and Latent Heat Fluxes over Snow under a Pine Canopy to Improve an Energy Balance Snowmelt Model  

Science Journals Connector (OSTI)

During the second year of the NASA Cold Land Processes Experiment (CLPX), an eddy covariance (EC) system was deployed at the Local Scale Observation Site (LSOS) from mid-February to June 2003. The EC system was located beneath a uniform pine ...

D. Marks; A. Winstral; G. Flerchinger; M. Reba; J. Pomeroy; T. Link; K. Elder

2008-12-01T23:59:59.000Z

157

Figure 5. Net radiation of the study area on June 21, 2003 ESTIMATION OF HEAT FLUXES  

E-Print Network [OSTI]

of incoming solar radiation and long-wave radiation emitted from the atmosphere to land surface and from chimneys etc. In addition anthropogenic sensible heat contributes to increased surface temperature. However this influence is sufficiently small compared to the solar radiation under clear skies during

Hall, Sharon J.

158

Multi-scale Control and Enhancement of Reactor Boiling Heat Flux by Reagents and Nanoparticles  

SciTech Connect (OSTI)

The phenomenological characterization of the use of non-invasive and passive techniques to enhance the boiling heat transfer in water has been carried out in this extended study. It provides fundamental enhanced heat transfer data for nucleate boiling and discusses the associated physics with the aim of addressing future and next-generation reactor thermal-hydraulic management. It essentially addresses the hypothesis that in phase-change processes during boiling, the primary mechanisms can be related to the liquid-vapor interfacial tension and surface wetting at the solidliquid interface. These interfacial characteristics can be significantly altered and decoupled by introducing small quantities of additives in water, such as surface-active polymers, surfactants, and nanoparticles. The changes are fundamentally caused at a molecular-scale by the relative bulk molecular dynamics and adsorption-desorption of the additive at the liquid-vapor interface, and its physisorption and electrokinetics at the liquid-solid interface. At the micro-scale, the transient transport mechanisms at the solid-liquid-vapor interface during nucleation and bubblegrowth can be attributed to thin-film spreading, surface-micro-cavity activation, and micro-layer evaporation. Furthermore at the macro-scale, the heat transport is in turn governed by the bubble growth and distribution, macro-layer heat transfer, bubble dynamics (bubble coalescence, collapse, break-up, and translation), and liquid rheology. Some of these behaviors and processes are measured and characterized in this study, the outcomes of which advance the concomitant fundamental physics, as well as provide insights for developing control strategies for the molecular-scale manipulation of interfacial tension and surface wetting in boiling by means of polymeric reagents, surfactants, and other soluble surface-active additives.

R.M. Manglik; A. Athavale; D.S. Kalaikadal; A. Deodhar; U. Verma

2011-09-02T23:59:59.000Z

159

An experimental study of external reactor vessel cooling strategy on the critical heat flux using the graphene oxide nano-fluid  

SciTech Connect (OSTI)

External reactor vessel cooling (ERVC) for in-vessel retention (IVR) of corium as a key severe accident management strategy can be achieved by flooding the reactor cavity during a severe accident. In this accident mitigation strategy, the decay heat removal capability depends on whether the imposed heat flux exceeds critical heat flux (CHF). To provide sufficient cooling for high-power reactors such as APR1400, there have been some R and D efforts to use the reactor vessel with micro-porous coating and nano-fluids boiling-induced coating. The dispersion stability of graphene-oxide nano-fluid in the chemical conditions of flooding water that includes boric acid, lithium hydroxide (LiOH) and tri-sodium phosphate (TSP) was checked in terms of surface charge or zeta potential before the CHF experiments. Results showed that graphene-oxide nano-fluids were very stable under ERVC environment. The critical heat flux (CHF) on the reactor vessel external wall was measured using the small scale two-dimensional slide test section. The radius of the curvature is 0.1 m. The dimension of each part in the facility simulated the APR-1400. The heater was designed to produce the different heat flux. The magnitude of heat flux follows the one of the APR-1400 when the severe accident occurred. All tests were conducted under inlet subcooling 10 K. Graphene-oxide nano-fluids (concentration: 10 -4 V%) enhanced CHF limits up to about 20% at mass flux 50 kg/m{sup 2}s and 100 kg/m{sup 2}s in comparison with the results of the distilled water at same test condition. (authors)

Park, S. D.; Lee, S. W.; Kang, S.; Kim, S. M.; Seo, H.; Bang, I. C. [Ulsan National Inst. of Science and Technology UNIST, 100 Banyeon-ri, Eonyang-eup, Ulju-gun, Ulasn Metropolitan City 689-798 (Korea, Republic of)

2012-07-01T23:59:59.000Z

160

Floating Refrigerant Loop Based on R-134a Refrigerant Cooling of High-Heat Flux Electronics  

SciTech Connect (OSTI)

The Oak Ridge National Laboratory (ORNL) Power Electronics and Electric Machinery Research Center (PEEMRC) have been developing technologies to address the thermal issues associated with hybrid vehicles. Removal of the heat generated from electrical losses in traction motors and their associated power electronics is essential for the reliable operation of motors and power electronics. As part of a larger thermal control project, which includes shrinking inverter size and direct cooling of electronics, ORNL has developed U.S. Patent No. 6,772,603 B2, ''Methods and Apparatus for Thermal Management of Vehicle Systems and Components'' [1], and patent pending, ''Floating Loop System for Cooling Integrated Motors and Inverters Using Hot Liquid Refrigerant'' [2]. The floating-loop system provides a large coefficient of performance (COP) for hybrid-drive component cooling. This loop (based on R-134a) is integrated with a vehicle's existing air-conditioning (AC) condenser, which dissipates waste heat to the ambient air. Because the temperature requirements for cooling of power electronics and electric machines are not as low as that required for passenger compartment air, this adjoining loop can operate on the high-pressure side of the existing AC system. This arrangement also allows the floating loop to run without the need for the compressor and only needs a small pump to move the liquid refrigerant. For the design to be viable, the loop must not adversely affect the existing system. The loop should also provide a high COP, a flat-temperature profile, and low-pressure drop. To date, the floating-loop test prototype has successfully removed 2 kW of heat load in a 9 kW automobile passenger AC system with and without the automotive AC system running. The COP for the tested floating-loop system ranges from 40-45, as compared to a typical AC system COP of about 2-4. The estimated required waste-heat load for future hybrid applications is 5.5 kW and the existing system could be easily scaleable for this larger load.

Lowe, K.T.

2005-10-07T23:59:59.000Z

Note: This page contains sample records for the topic "latent heat flux" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Higher dimensional charged shear-free relativistic models with heat flux  

E-Print Network [OSTI]

We analyse shear-free spherically symmetric relativistic models of gravitating fluids with heat flow and electric charge defined on higher dimensional manifolds. The solution to the Einstein-Maxwell system is governed by the pressure isotropy condition which depends on the spacetime dimension. We study this highly nonlinear partial differential equation using Lie's group theoretic approach. The Lie symmetry generators that leave the equation invariant are determined. We provide exact solutions to the gravitational potentials using the first symmetry admitted by the equation. Our new exact solutions contain the earlier results for the four-dimensional case. Using the other Lie generators, we are able to provide solutions to the gravitational potentials or reduce the order of the master equation to a first order nonlinear differential equation. We derive the temperature transport equation in higher dimensions and find expressions for the causal and Eckart temperatures showing their explicit dependance on the dimension. We analyse a particular solution, obtained via group techniques, to show its physical applicability.

Y. Nyonyi; S. D. Maharaj; K. S. Govinder

2014-05-10T23:59:59.000Z

162

Numerical investigation of edge plasma phenomena in an enhanced D-alpha discharge at Alcator C-Mod: Parallel heat flux and quasi-coherent edge oscillations  

SciTech Connect (OSTI)

Reduced-model scrape-off layer turbulence (SOLT) simulations of an enhanced D-alpha (EDA) H-mode shot observed in the Alcator C-Mod tokamak were conducted to compare with observed variations in the scrape-off-layer (SOL) width of the parallel heat flux profile. In particular, the role of the competition between sheath- and conduction-limited parallel heat fluxes in determining that width was studied for the turbulent SOL plasma that emerged from the simulations. The SOL width decreases with increasing input power and with increasing separatrix temperature in both the experiment and the simulation, consistent with the strong temperature dependence of the parallel heat flux in balance with the perpendicular transport by turbulence and blobs. The particularly strong temperature dependence observed in the case analyzed is attributed to the fact that these simulations produce SOL plasmas which are in the conduction-limited regime for the parallel heat flux. A persistent quasi-coherent (QC) mode dominates the SOLT simulations and bears considerable resemblance to the QC mode observed in C-Mod EDA operation. The SOLT QC mode consists of nonlinearly saturated wave-fronts located just inside the separatrix that are convected poloidally by the mean flow, continuously transporting particles and energy and intermittently emitting blobs into the SOL.

Russell, D. A.; D'Ippolito, D. A.; Myra, J. R. [Lodestar Research Corporation, 2400 Central Ave., P-5, Boulder, Colorado 80301 (United States); LaBombard, B.; Terry, J. L. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, 167 Albany Street, Cambridge, Massachusetts 02138 (United States); Zweben, S. J. [Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08540 (United States)

2012-08-15T23:59:59.000Z

163

Numerical prediction of heat-flux to massive calorimeters engulfed in regulatory fires with the cask analysis fire environment (CAFE) model  

SciTech Connect (OSTI)

Recent observations show that the thermal boundary conditions within large-scale fires are significantly affected by the presence of thermally massive objects. These objects cool the soot and gas near their surfaces, and these effects reduce the incoming radiant heat-flux to values lower than the levels expected from simple {sigma}T{sub fire}{sup 4} models. They also affect the flow and temperature fields in the fire far from their surfaces. The Cask Analysis Fire Environment (CAFE) code has been developed at Sandia National Laboratories to provide an enhanced fire boundary condition for the design of radioactive material packages. CAFE is a set of computer subroutines that use computational fluid mechanics methods to predict convective heat transfer and mixing. It also includes models for fuel and oxygen transport, chemical reaction, and participating-media radiation heat transfer. This code uses two-dimensional computational models so that it has reasonably short turnaround times on standard workstations and is well suited for design and risk studies. In this paper, CAFE is coupled with a commercial finite-element program to model a large cylindrical calorimeter fully engulfed in a pool fire. The time-dependent heat-flux to the calorimeter and the calorimeter surface temperature are determined for several locations around the calorimeter circumference. The variation of heat-flux with location is determined for calorimeters with different diameters and wall thickness, and the observed effects discussed.

KOSKI,JORMAN A.; SUO-ANTITLA,AHTI; KRAMER,M. ALEX; GREINER,MILES

2000-05-11T23:59:59.000Z

164

Experimental results with cryogenically cooled, thin, silicon crystal x-ray monochromators on high-heat-flux beamlines  

SciTech Connect (OSTI)

A novel, silicon crystal monochromator has been designed and tested for use on undulator and focused wiggler beamlines at third-generation synchrotron sources. The crystal utilizes a thin, partially transmitting diffracting element fabricated within a liquid-nitrogen cooled, monolithic block of silicon. This report summarizes the results from performance tests conducted at the European Synchrotron Radiation Facility (ESRF) using a focused wiggler beam and at the Advanced Photon Source (APS) on an undulator beamline. These experiments indicate that a cryogenic crystal can handle the very high power and power density x-ray beams of modem synchrotrons with sub-arcsec thermal broadening of the rocking curve. The peak power density absorbed on the surface of the crystal at the ESRF exceeded go W/mm{sup 2} with an absorbed power of 166 W, this takes into account the spreading of the beam due to the Bragg angle of 11.4{degrees}. At the APS, the peak heat flux incident on the crystal was 1.5 W/mA/mm{sup 2} with a power of 6.1 W/mA for a 2.0 H x 2.5 V mm{sup 2} beam at an undulator gap of 11.1 mm and stored current up to 96 mA.

Rogers, C.S.; Mills, D.M.; Lee, W.K.; Fernandez, P.B.; Graber, T.

1996-08-01T23:59:59.000Z

165

Subantarctic Mode Water formation : air-sea fluxes and cross-frontal exchange  

E-Print Network [OSTI]

remote sensing data. The Kelly latent and sensible heatRemote Sensing Obser- vations (J-OFURO), Kelly, OAFlux, and the Southern Ocean State Estimate (SOSE). The heat

Holte, James

2010-01-01T23:59:59.000Z

166

Latent Heat of Evaporation of Liquid Helium  

Science Journals Connector (OSTI)

... THE letter of Dr. J. Newton Friend in NATURE of December 26, 1936, on this subject raises interest in his equation. I have tested it ...

JOHN SATTERLY

1937-03-13T23:59:59.000Z

167

Validation/Uncertainty Quantification for Large Eddy Simulations of the heat flux in the Tangentially Fired Oxy-Coal Alstom Boiler Simulation Facility  

SciTech Connect (OSTI)

The objective of this task is to produce predictive capability with quantified uncertainty bounds for the heat flux in commercial-scale, tangentially fired, oxy-coal boilers. Validation data came from the Alstom Boiler Simulation Facility (BSF) for tangentially fired, oxy-coal operation. This task brings together experimental data collected under Alstom’s DOE project for measuring oxy-firing performance parameters in the BSF with this University of Utah project for large eddy simulation (LES) and validation/uncertainty quantification (V/UQ). The Utah work includes V/UQ with measurements in the single-burner facility where advanced strategies for O2 injection can be more easily controlled and data more easily obtained. Highlights of the work include: • Simulations of Alstom’s 15 megawatt (MW) BSF, exploring the uncertainty in thermal boundary conditions. A V/UQ analysis showed consistency between experimental results and simulation results, identifying uncertainty bounds on the quantities of interest for this system (Subtask 9.1) • A simulation study of the University of Utah’s oxy-fuel combustor (OFC) focused on heat flux (Subtask 9.2). A V/UQ analysis was used to show consistency between experimental and simulation results. • Measurement of heat flux and temperature with new optical diagnostic techniques and comparison with conventional measurements (Subtask 9.3). Various optical diagnostics systems were created to provide experimental data to the simulation team. The final configuration utilized a mid-wave infrared (MWIR) camera to measure heat flux and temperature, which was synchronized with a high-speed, visible camera to utilize two-color pyrometry to measure temperature and soot concentration. • Collection of heat flux and temperature measurements in the University of Utah’s OFC for use is subtasks 9.2 and 9.3 (Subtask 9.4). Several replicates were carried to better assess the experimental error. Experiments were specifically designed for the generation of high-fidelity data from a turbulent oxy-coal flame for the validation of oxy-coal simulation models. Experiments were also conducted on the OFC to determine heat flux profiles using advanced strategies for O2 injection. This is important when considering retrofit of advanced O2 injection in retrofit configurations.

Smith, P.J.; Eddings, E.G.; Ring, T.; Thornock, J.; Draper, T.; Isaac, B.; Rezeai, D.; Toth, P.; Wu, Y.; Kelly, K.

2014-08-01T23:59:59.000Z

168

Photovoltaic roof heat flux  

E-Print Network [OSTI]

t y (2009). 11. Pacific Gas &Electric, Go Solar California:California Solar Initiative (2008). A consumer's guide toprograms such as the California Solar Initiative (CSI) to

Samady, Mezhgan Frishta

2011-01-01T23:59:59.000Z

169

Photovoltaic roof heat flux  

E-Print Network [OSTI]

d b y t h e a n g l e d solar panel F i g u r e 62: C a l cK l e i s s l , C h a i r Solar panels were mounted w i t hthe optimal angles for solar panels [9], i n this study both

Samady, Mezhgan Frishta

2011-01-01T23:59:59.000Z

170

Advanced Heat Transfer Fluids and Novel Thermal Storage Concepts...  

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

Systems Lehigh University: Novel Thermal Storage Technologies for Concentrating Solar Power Generation Terrafore: Heat Transfer and Latent Heat Storage in Inorganic Molten...

171

An Experimental Study of Upward and Downward Flow of Supercritical Carbon Dioxide in a Straight Pipe Heat Exchanger with Constant Wall Heat Flux  

E-Print Network [OSTI]

An experimental analysis was conducted on a single circular tube heat exchanger using supercritical carbon dioxide as the working fluid. The heat exchanger was operated in two different orientations: vertically upward and downward. The experimental...

Umrigar, Eric Dara

2014-05-01T23:59:59.000Z

172

Optimal heliostat aiming strategy for uniform distribution of heat flux on the receiver of a solar power tower plant  

Science Journals Connector (OSTI)

Abstract Temperature distribution on the receiver surface of a solar power tower plant is of great importance. High temperature gradients may lead to local hot spots and consequently failure of the receiver. The temperature distribution can be controlled by defining several aiming points on the receiver surface and adjusting the heliostats accordingly. In this paper, a new optimization algorithm which works based on the principles of genetic algorithm is developed to find the optimal flux distribution on the receiver surface. The objective is to minimize the standard deviation of the flux density distribution by changing the aiming points of individual heliostats. Flux distribution of each heliostat is found by using the HFLCAL model [1], which is validated against experimental data. The results show that after employing the new algorithm the maximum flux density is reduced by an order of magnitude. The effects of number of aiming points and size of the aiming surface on the flux density distribution are investigated in detail.

Saeb M. Besarati; D. Yogi Goswami; Elias K. Stefanakos

2014-01-01T23:59:59.000Z

173

Dish Stirling Advanced Latent Storage Feasibility  

Science Journals Connector (OSTI)

Abstract Dish-Stirling systems have been demonstrated to provide high-efficiency solar-only electrical generation, holding the world record at 31.25%. This high efficiency results in a system with a high possibility of meeting the DOE SunShot goal of $0.06/kWh. Current dish-Stirling systems do not incorporate thermal storage. For the next generation of non-intermittent and cost-competitive solar power plants, we propose a thermal energy storage system that combines latent (phase-change) energy transport and latent energy storage in order to match the isothermal input requirements of Stirling engines while also maximizing the exergetic efficiency of the entire system. This paper reports on the technical advantages and challenges of dish Stirling with storage, to make a preliminary estimate as to the technical feasibility of such a system. The proposed system with storage incorporates high temperature latent transport and latent storage, providing an exergetic match to the isothermal input of the Stirling cycle. The transport from the receiver to the storage, and from storage to the engine, is accomplished with advanced sodium heat pipes. The storage is in a solid-liquid phase change material (PCM), likely a metallic eutectic to reduce exergy losses in thermal conduction. We model a dish Stirling system at a block level, using a combination of real data from several dish systems with and without heat pipe transport, and determine annual energy production and revenue streams based on Barstow California weather data and Southern California Edison Time of Day pricing. We optimize the system on solar multiple, capacity of storage, and several operational strategies. We find that a storage system using metallic eutectic phase change storage results in a feasible physical embodiment, with mass, volume, and complexity suitable for 25kWe dish Stirling systems. The results indicate a system with 6 hours of storage and a solar multiple of 1.25 provides the optimum impact to LCOE and profit for the range of cases studied. A storage system applied to dish Stirling will leverage the current high performance systems, increasing the value to the utilities and transmission entities. A feasible embodiment has been proposed, which with sufficient development will re-establish dish Stirling as a leading energy option.

C.E. Andraka

2014-01-01T23:59:59.000Z

174

Experimental investigations of uncovered-bundle heat transfer and two-phase mixture-level swell under high-pressure low heat-flux conditions. [PWR  

SciTech Connect (OSTI)

Results are reported from a series of uncovered-bundle heat transfer and mixture-level swell tests. Experimental testing was performed at Oak Ridge National Laboratory in the Thermal Hydraulic Test Facility (THTF). The THTF is an electrically heated bundle test loop configured to produce conditions similar to those in a small-break loss-of-coolant accident. The objective of heat transfer testing was to acquire heat transfer coefficients and fluid conditions in a partially uncovered bundle. Testing was performed in a quasi-steady-state mode with the heated core 30 to 40% uncovered. Linear heat rates varied from 0.32 to 2.22 kW/m.rod (0.1 to 0.68 kW/ft.rod). Under these conditions peak clad temperatures in excess of 1050 K (1430/sup 0/F) were observed, and total heat transfer coefficients ranged from 0.0045 to 0.037 W/cm/sup 2/.K (8 to 65 Btu/h.ft/sup 2/./sup 0/F). Spacer grids were observed to enhance heat transfer at, and downstream of, the grid. Radiation heat transfer was calculated to account for as much as 65% of total heat transfer in low-flow tests.

Anklam, T. M.; Miller, R. J.; White, M. D.

1982-03-01T23:59:59.000Z

175

Heat Flux Calculation and Problem of Flaking of Boron Carbide Coatings on the Faraday Screen of the ICRH Antennas During Tore Supra High Power, Long Pulse Operation  

SciTech Connect (OSTI)

Reliable and repetitive high power and long pulse tokamak operation is strongly dependant of the ability to secure the Plasma Facing Components (PFCs). In Tore Supra, a network of 7 infrared (IR) video cameras is routinely used to prevent PFCs overheating and damage in selected regions. Real time feedback control and offline analysis are essential for basic protection and understanding of abnormal thermal events. One important limitation detected by the IR real time feed-back loop during high power RF operation (injected power of 9.5 MW over 26 s and 12 MW over 10 s have been achieved respectively in 2006 and 2008) is due to the interaction between fast ions which increase the power flux density and flaking of the boron carbide coatings on the Faraday screen box of the ICRH antennas. An IR-based experimental procedure is proposed in order to detect new flakes during plasma operation. The thermal response of the B4C coating is studied with and without flaking during plasma operation. The experimental heat flux deposited by fast ion losses on the Faraday screen is calculated for high (3.8 T) and low magnetic field (2 T) during high RF power operation (with fundamental hydrogen minority and second harmonic ICRH heating schemes respectively). The paper addresses both thermal science issues applied to machine protection and limitation due to fast ions issues during high RF power, long pulse operation. Safety margin to critical heat flux and number of fatigue cycles under heat load are presented in the paper.

Corre, Y. [French Atomic Energy Commission (CEA), Cadarache, St. Paul lez Durance] [French Atomic Energy Commission (CEA), Cadarache, St. Paul lez Durance; Lipa, M. [CEA IRFM, St. Paul-lez-Durance, France] [CEA IRFM, St. Paul-lez-Durance, France; Agarici, G. [Fusion for Energy (F4E), Barcelona, Spain] [Fusion for Energy (F4E), Barcelona, Spain; Basiuk, V. [CEA IRFM, St. Paul-lez-Durance, France] [CEA IRFM, St. Paul-lez-Durance, France; Colas, L. [French Atomic Energy Commission (CEA)] [French Atomic Energy Commission (CEA); Courtois, X. [CEA, St. Paul Les Durance, France] [CEA, St. Paul Les Durance, France; Dumont, R. J. [French Atomic Energy Commission (CEA), Cadarache, St. Paul lez Durance] [French Atomic Energy Commission (CEA), Cadarache, St. Paul lez Durance; Ekedahl, A. [French Atomic Energy Commission (CEA), Institute for Magnetic Fusion Research (IRFM)] [French Atomic Energy Commission (CEA), Institute for Magnetic Fusion Research (IRFM); Gardarein, J. L. [University of Aix, Marseille, France] [University of Aix, Marseille, France; Klepper, C Christopher [ORNL] [ORNL; Martin, V. [French Atomic Energy Commission (CEA), Institute for Magnetic Fusion Research (IRFM)] [French Atomic Energy Commission (CEA), Institute for Magnetic Fusion Research (IRFM); Moncada, V. [CEA, St. Paul Les Durance, France] [CEA, St. Paul Les Durance, France; Portafaix, C. [CEA, St. Paul Les Durance, France] [CEA, St. Paul Les Durance, France; Rigollet, F. [University of Aix, Marseille, France] [University of Aix, Marseille, France; Tawizgant, R. [CEA, St. Paul Les Durance, France] [CEA, St. Paul Les Durance, France; Travere, J. M. [CEA, St. Paul Les Durance, France] [CEA, St. Paul Les Durance, France; Valliez, K. [CEA, St. Paul Les Durance, France] [CEA, St. Paul Les Durance, France

2011-01-01T23:59:59.000Z

176

An Urban Parameterization for a Global Climate Model. Part II: Sensitivity to Input Parameters and the Simulated Urban Heat Island in Offline Simulations  

E-Print Network [OSTI]

of the physical processes controlling energy and water fluxes and 2) the charac- terization of urban morphology and urban materials with respect to aerodynamic, radiative, and heat trans- fer properties (e.g., Terjung and O’Rourke 1980; Arn- field 2000; Masson... by the correlation coefficient), re- sulting in a slight decrease in the RMSE. A decrease in the roof fraction has the opposite effect. The latent heat flux also exhibits relatively small sensitivity to morpho- logical parameters primarily because it is such a small...

Oleson, Keith W.; Bonan, Gordon B.; Feddema, Johannes J.; Vertenstein, M.

2008-01-01T23:59:59.000Z

177

Experimental investigations of two-phase mixture level swell and axial void fraction distribution under high pressure, low heat flux conditions in rod bundle geometry  

SciTech Connect (OSTI)

Experimental data is reported from a series of quasi-steady-state two-phase mixture level swell and void fraction distribution tests. Testing was performed at ORNL in the Thermal Hydraulic Test Facility - a large electrically heated test loop configured to produce conditions similar to those expected in a small break loss of coolant accident. Pressure was varied from 2.7 to 8.2 MPa and linear power ranged from 0.33 to 1.95 kW/m. Mixture swell was observed to vary linearly with the total volumetric vapor generation rate over the power range of primary interest in small break analysis. Void fraction data was fit by a drift-flux model and both the drift-velocity and concentration parameter were observed to decrease with increasing pressure.

Anklam, T.M.; White, M.D.

1981-01-01T23:59:59.000Z

178

Measurement of gas species, temperatures, coal burnout, and wall heat fluxes in a 200 MWe lignite-fired boiler with different overfire air damper openings  

SciTech Connect (OSTI)

Measurements were performed on a 200 MWe, wall-fired, lignite utility boiler. For different overfire air (OFA) damper openings, the gas temperature, gas species concentration, coal burnout, release rates of components (C, H, and N), furnace temperature, and heat flux and boiler efficiency were measured. Cold air experiments for a single burner were conducted in the laboratory. The double-swirl flow pulverized-coal burner has two ring recirculation zones starting in the secondary air region in the burner. As the secondary air flow increases, the axial velocity of air flow increases, the maxima of radial velocity, tangential velocity and turbulence intensity all increase, and the swirl intensity of air flow and the size of recirculation zones increase slightly. In the central region of the burner, as the OFA damper opening widens, the gas temperature and CO concentration increase, while the O{sub 2} concentration, NOx concentration, coal burnout, and release rates of components (C, H, and N) decrease, and coal particles ignite earlier. In the secondary air region of the burner, the O{sub 2} concentration, NOx concentration, coal burnout, and release rates of components (C, H, and N) decrease, and the gas temperature and CO concentration vary slightly. In the sidewall region, the gas temperature, O{sub 2} concentration, and NOx concentration decrease, while the CO concentration increases and the gas temperature varies slightly. The furnace temperature and heat flux in the main burning region decrease appreciably, but increase slightly in the burnout region. The NOx emission decreases from 1203.6 mg/m{sup 3} (6% O{sub 2}) for a damper opening of 0% to 511.7 mg/m{sup 3} (6% O{sub 2}) for a damper opening of 80% and the boiler efficiency decreases from 92.59 to 91.9%. 15 refs., 17 figs., 3 tabs.

Jianping Jing; Zhengqi Li; Guangkui Liu; Zhichao Chen; Chunlong Liu [Harbin Institute of Technology, Harbin (China). School of Energy Science and Engineering

2009-07-15T23:59:59.000Z

179

Analytic theory of L{yields}H transition, barrier structure, and hysteresis for a simple model of coupled particle and heat fluxes  

SciTech Connect (OSTI)

The two-field (pressure/density) model for the L{yields}H transition is extended and analyzed qualitatively. In its original form the model is ambiguous as to the location of the transition within the range of bistability of particle and thermal fluxes. Here, the model is regularized by including (i) hyperdiffusion, (ii) time dependence, and (iii) curvature of the pressure profile. The regularizations (i)-(ii) agree and indicate that the Maxwell rule for the forward and back transition applies, as opposed to the maximum flux forward and minimum flux backward transition rules (which yields hysteresis) as suggested previously. Regarding (i)-(ii), simple models suggest that for a pressure gradient driven electric field shear bifurcation, the basic scale of the pedestal is inexorably tied to the particle fueling depth, which normally is the neutral penetration depth. There is no hysteresis predicted by the local model of transport suppression. However, the effect of pressure profile curvature (iii) changes these results substantially. When it dominates, the curvature effect reduces the transition threshold to the lower end of the range of heating power, which falls within the phase coexistence region for both forward and back transitions. This softens the transition threshold requirements. In this limit, the model with pressure curvature also predicts transitions which occur in regimes of flat density and driven exclusively by the temperature gradient. This allows the pedestal to extend beyond the fueling depth, and also allows some decoupling of density and pressure profiles. In a parameter range where the pressure curvature is less important the transition occurs somewhere between the above two limits.

Malkov, M. A.; Diamond, P. H. [Center for Astrophysics and Space Sciences and Department of Physics, University of California, San Diego, La Jolla, California 92093 (United States)

2008-12-15T23:59:59.000Z

180

Minimum entropy generation due to heat transfer and fluid friction in a parabolic trough receiver with non-uniform heat flux at different rim angles and concentration ratios  

Science Journals Connector (OSTI)

Abstract In this paper, Monte Carlo ray-tracing and computational fluid dynamics are used to numerically investigate the minimum entropy generation due to heat transfer and fluid friction in a parabolic trough receiver. The analysis was carried out for rim angles in the range 40°–120°, concentration ratios in the range 57–143, Reynolds numbers in the range 1.02 × 104–1.36 × 106 and fluid temperatures in the range 350–650 K. Results show existence of an optimal Reynolds number at any given combination of fluid temperature, concentration ratio and rim angle for which the total entropy generation is a minimum. The total entropy generation was found to increase as the rim angle reduced, concentration ratio increased and fluid temperature reduced. The high entropy generation rates at low rim angles are mainly due to high peak temperatures in the absorber tube at these low rim angles.

Aggrey Mwesigye; Tunde Bello-Ochende; Josua P. Meyer

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "latent heat flux" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Proceedings of 1999 U.S./Japan Workshop (99FT-05) On High Heat Flux Components and Plasma Surface Interactions for Next Fusion Devices  

SciTech Connect (OSTI)

The 1999 US-Japan Workshop on High Heat Flux Components and Plasma Surface Interactions in Next Step Fusion Devices was held at the St. Francis Hotel in Santa Fe, New Mexico, on November 1-4, 1999. There were 42 presentations as well as discussion on technical issues and planning for future collaborations. The participants included 22 researchers from Japan and the United States as well as seven researchers from Europe and Russia. There have been important changes in the programs in both the US and Japan in the areas of plasma surface interactions and plasma facing components. The US has moved away from a strong focus on the ITER Project and has introduced new programs on use of liquid surfaces for plasma facing components, and operation of NSTX has begun. In Japan, the Large Helical Device began operation. This is the first large world-class confinement device operating in a magnetic configuration different than a tokamak. In selecting the presentations for this workshop, the organizers sought a balance between research in laboratory facilities or confinement devices related to plasma surface interactions and experimental research in the development of plasma facing components. In discussions about the workshop itself, the participants affirmed their preference for a setting where ''work-in-progress'' could be informally presented and discussed.

NYGREN,RICHARD E.; STAVROS,DIANA T.

2000-06-01T23:59:59.000Z

182

Steady response to heating: Gaussian heat source  

E-Print Network [OSTI]

+ prescribed latent heating => "Matsuno-Gill model" Moisture equation for precipitation term ¡ Can make. of Equatorial Waves Filter out "background spectrum": ¡ Can see all different wave types! Especially Kelvin #12;Equatorial Waves Alternative theory for wave speed: ¡ Higher vertical mode structure causes phase

Frierson, Dargan

183

Sensitivity of Surface Flux Simulations to Hydrologic Parameters Based on an Uncertainty Quantification Framework Applied to the Community Land Model  

SciTech Connect (OSTI)

Uncertainties in hydrologic parameters could have significant impacts on the simulated water and energy fluxes and land surface states, which will in turn affect atmospheric processes and the carbon cycle. Quantifying such uncertainties is an important step toward better understanding and quantification of uncertainty of integrated earth system models. In this paper, we introduce an uncertainty quantification (UQ) framework to analyze sensitivity of simulated surface fluxes to selected hydrologic parameters in the Community Land Model (CLM4) through forward modeling. Thirteen flux tower footprints spanning a wide range of climate and site conditions were selected to perform sensitivity analyses by perturbing the parameters identified. In the UQ framework, prior information about the parameters was used to quantify the input uncertainty using the Minimum-Relative-Entropy approach. The quasi-Monte Carlo approach was applied to generate samples of parameters on the basis of the prior pdfs. Simulations corresponding to sampled parameter sets were used to generate response curves and response surfaces and statistical tests were used to rank the significance of the parameters for output responses including latent (LH) and sensible heat (SH) fluxes. Overall, the CLM4 simulated LH and SH show the largest sensitivity to subsurface runoff generation parameters. However, study sites with deep root vegetation are also affected by surface runoff parameters, while sites with shallow root zones are also sensitive to the vadose zone soil water parameters. Generally, sites with finer soil texture and shallower rooting systems tend to have larger sensitivity of outputs to the parameters. Our results suggest the necessity of and possible ways for parameter inversion/calibration using available measurements of latent/sensible heat fluxes to obtain the optimal parameter set for CLM4. This study also provided guidance on reduction of parameter set dimensionality and parameter calibration framework design for CLM4 and other land surface models under different hydrologic and climatic regimes.

Hou, Zhangshuan; Huang, Maoyi; Leung, Lai-Yung R.; Lin, Guang; Ricciuto, Daniel M.

2012-08-10T23:59:59.000Z

184

Modeling driving decisions with latent plans  

E-Print Network [OSTI]

Driving is a complex task that includes a series of interdependent decisions. In many situations, these decisions are based on a specific plan. The plan is however unobserved or latent and only the manifestations of the ...

Choudhury, Charisma Farheen, 1978-

2007-01-01T23:59:59.000Z

185

Intercomparison of Sensible Heat Flux from Large Aperture Scintillometer and Eddy Covariance Methods: Field Experiment over a Homogeneous Semi-arid Region  

E-Print Network [OSTI]

of satellite remote sensing sensible heat-?ux estimates dueremote sensing algorithms. A typical approach identi?es spectral bands particularly sensitive to surface heat ?

Zeweldi, Dawit A.; Gebremichael, Mekonnen; Wang, Junming; Sammis, Theodore; Kleissl, Jan; Miller, David

2010-01-01T23:59:59.000Z

186

Waste Heat Management Options: Industrial Process Heating Systems  

Broader source: Energy.gov (indexed) [DOE]

Heat Management Options Heat Management Options Industrial Process Heating Systems By Dr. Arvind C. Thekdi E-mail: athekdi@e3minc.com E3M, Inc. August 20, 2009 2 Source of Waste Heat in Industries * Steam Generation * Fluid Heating * Calcining * Drying * Heat Treating * Metal Heating * Metal and Non-metal Melting * Smelting, agglomeration etc. * Curing and Forming * Other Heating Waste heat is everywhere! Arvind Thekdi, E3M Inc Arvind Thekdi, E3M Inc 3 Waste Heat Sources from Process Heating Equipment * Hot gases - combustion products - Temperature from 300 deg. F. to 3000 deg.F. * Radiation-Convection heat loss - From temperature source of 500 deg. F. to 2500 deg. F. * Sensible-latent heat in heated product - From temperature 400 deg. F. to 2200 deg. F. * Cooling water or other liquids - Temperature from 100 deg. F. to 180 deg. F.

187

An experimental study on heat transfer from a horizontal heated circular cylinder enhanced by water spray.  

E-Print Network [OSTI]

??A series of experiments were conducted to investigate the heat transfer which occurs with a heated, constant heat flux, horizontal, single circular cylinder is exposed… (more)

Chau, Man Hei

2009-01-01T23:59:59.000Z

188

Consistent and efficient reconstruction of latent tree models  

E-Print Network [OSTI]

We study the problem of learning a latent tree graphical model where samples are available only from a subset of variables. We propose two consistent and computationally efficient algorithms for learning minimal latent ...

Choi, Myung Jin

189

LABORATORY I: CONSERVATION OF ENERGY AND HEAT  

E-Print Network [OSTI]

Lab I - 1 LABORATORY I: CONSERVATION OF ENERGY AND HEAT In 1101 labs, you used conservation are in thermal equilibrium · Use the latent heat to determine the internal energy change of a system during conservation of energy, you can then determine the metal's specific heat. However, you know that some energy

Minnesota, University of

190

A model of heat and moisture transfer through clothing integrated with the UC Berkeley comfort model  

E-Print Network [OSTI]

E, Zhang H, Huizenga C. Heat and moisture transfer throughMG, Wang XX, et al. Apparent latent heat of evaporation fromclothing: attenuation and "heat pipe" effects. J Appl

Fu, Ming; Yu, Tiefeng; Zhang, Hui; Arens, Edward; Weng, Wenguo; Yuan, Hongyong

2014-01-01T23:59:59.000Z

191

Horizontal internal-tide fluxes support elevated phytoplankton productivity over the inner continental shelf  

E-Print Network [OSTI]

The semidiurnal internal-tide energy flux was onshore over1 Cross-shelf internal-tide energy (J e ), heat (J q ),coherent with the internal-tide energy flux and heat flux (

Lucas, Andrew

2014-01-01T23:59:59.000Z

192

AIAA Journal of Thermophysics and Heat Transfer Vol. 13(1), pp. 126-133, 1999  

E-Print Network [OSTI]

= specific heat, W kg-1 k-1 h = heat transfer coefficient of evaporator, W m-2 K-1 hfg = latent heat of fluid1 AIAA Journal of Thermophysics and Heat Transfer Vol. 13(1), pp. 126-133, 1999 Evaporative Heat Transfer in a Capillary Structure Heated by a Grooved Block Q. Liao* and T. S. Zhao The Hong Kong

Zhao, Tianshou

193

Effect of Hyperthermia (45°C) on Calcium Flux in Chinese Hamster Ovary HA-1 Fibroblasts and Its Potential Role in Cytotoxicity and Heat Resistance  

Science Journals Connector (OSTI)

...little further increase (Fig. IB). These effects displayed a similar dose-effect relation ship to the heat-induced increase in 45Ca2'f...general membrane integrity, we investigated the effect of hyperthermia on externally bound Ca2+ as...

Mary Ann Stevenson; Stuart K. Calderwood; and George M. Hahn

1987-07-15T23:59:59.000Z

194

Analysis of the behavior of an experimental absorption heat transformer for water purification for different mass flux rates in the generator  

Science Journals Connector (OSTI)

In the present study, first and second laws of thermodynamics have been used to analyse the performance of an experimental absorption heat transformer for water purification. Irreversibilities, coefficients of performance (COP) and exergy coefficients of performance (ECOP) were determined as function of the mass flow of hot water supplied to the generator and as function of the overall thermal specific energy consumption (OSTEC) parameter defined in this paper. The results showed that the system irreversibilities increase meanwhile the coefficients of performance and the exergy coefficient of performance decrease with an increment of the mass flow of hot water supplied to the generator. Also it was shown that the system performance is better when the production of purified water increases due to the increment of the heat recycled to the generator and evaporator.

Armando Huicochea; Wilfrido Rivera; Hiram Martínez; Javier Siqueiros; Erasmo Cadenas

2013-01-01T23:59:59.000Z

195

Rank/sparsity minimization and latent variable graphical model selection  

E-Print Network [OSTI]

Rank/sparsity minimization and latent variable graphical model selection Pablo A. Parrilo · Complication: latent variables · Rank/sparsity decomposition, and generalizations · Convex optimization cond. on other vars. 1 3 2 4 Sparse Low-rank Concentration matrix #12;Proposal for modeling · Decompose

Parrilo, Pablo A.

196

The effect of post-fire stand age on the boreal forest energy balance  

E-Print Network [OSTI]

solar radiation (S), albedo, sensible heat flux density (H), and latent heat flux density (LE), above the vegetation canopy from towers,

2006-01-01T23:59:59.000Z

197

Solar heating system  

DOE Patents [OSTI]

An improved solar heating system in which the incident radiation of the sun is absorbed on collector panels, transferred to a storage unit and then distributed as heat for a building and the like. The improvement is obtained by utilizing a storage unit comprising separate compartments containing an array of materials having different melting points ranging from 75.degree. to 180.degree. F. The materials in the storage system are melted in accordance with the amount of heat absorbed from the sun and then transferred to the storage system. An efficient low volume storage system is provided by utilizing the latent heat of fusion of the materials as they change states in storing and releasing heat for distribution.

Schreyer, James M. (Oak Ridge, TN); Dorsey, George F. (Concord, TN)

1982-01-01T23:59:59.000Z

198

Gas Flux Sampling At Long Valley Caldera Geothermal Area (Lewicki...  

Open Energy Info (EERE)

Flux Sampling Activity Date - 2008 Usefulness useful DOE-funding Unknown Notes "CO2 and heat fluxes were measured over a six-week period (09082006 to 10242006) by the eddy...

199

Laser interrogation of latent vehicle registration number  

SciTech Connect (OSTI)

A recent investigation involved automobile registration numbers as important evidentiary specimens. In California, as in most states, small, thin metallic decals are issued to owners of vehicles each year as the registration is renewed. The decals are applied directly to the license plate of the vehicle and typically on top of the previous year`s expired decal. To afford some degree of security, the individual registration decals have been designed to tear easily; they cannot be separated from each other, but can be carefully removed intact from the metal license plate by using a razor blade. In September 1993, the City of Livermore Police Department obtained a blue 1993 California decal that had been placed over an orange 1992 decal. The two decals were being investigated as possible evidence in a case involving vehicle registration fraud. To confirm the suspicion and implicate a suspect, the department needed to known the registration number on the bottom (completely covered) 1992 decal. The authors attempted to use intense and directed light to interrogate the colored stickers. Optical illumination using a filtered white-light source partially identified the latent number. However, the most successful technique used a tunable dye laser pumped by a pulsed Nd:YAG laser. By selectively tuning the wavelength and intensity of the dye laser, backlit illumination of the decals permitted visualization of the underlying registration number through the surface of the top sticker. With optimally-tuned wavelength and intensity, 100% accuracy was obtained in identifying the sequence of latent characters. The advantage of optical techniques is their completely nondestructive nature, thus preserving the evidence for further interrogation or courtroom presentation.

Russo, R.E. [Lawrence Berkeley Lab., CA (United States). Energy and Environment Div.]|[Lawrence Livermore National Lab., CA (United States). Forensic Science Center; Pelkey, G.E. [City of Livermore Police Dept., CA (United States); Grant, P.; Whipple, R.E.; Andresen, B.D. [Lawrence Livermore National Lab., CA (United States). Forensic Science Center

1994-09-01T23:59:59.000Z

200

Flow and heat transfer in porous micro heat sink for thermal management of high power LEDs  

Science Journals Connector (OSTI)

A novel porous micro heat sink system is presented for thermal management of high power LEDs, which has high heat transport capability. The operational principle and heat transfer characteristics of porous micro heat sink are analyzed. Numerical model ... Keywords: Heat dissipation, High heat flux, High power LEDs, Porous media, Porous micro heat sink

Z. M. Wan; J. Liu; K. L. Su; X. H. Hu; S. S. M

2011-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "latent heat flux" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Boundary mixing and nutrient fluxes in Mono Lake, California  

Science Journals Connector (OSTI)

we inferred that most heat flux occurred due to boundary mixing at the base of the pycnocline ..... squares fit of the power spectral densities of the temperature-.

1999-05-20T23:59:59.000Z

202

Cloud Processes: Insights over a Decade into the Links between  

E-Print Network [OSTI]

Cloud Resolving Models Satellite and radar data Field Campaigns Radar Simulators (image: C. McGee) Grid Diffuse Sensible heat flux Latent heat flux Latent heat flux Aerosol direct effects Incoming solar radiation Direct Diffuse Sensible heat flux SiB RAMS CO2 Fluxes: Photosynthesis Respiration CO2 Radiative

Collett Jr., Jeffrey L.

203

3, 681705, 2006 Measurement and  

E-Print Network [OSTI]

and latent heat flux over the heterogeneous surface. Since 1970s, remote sensing technology has brought superiority to estimate areal sensible and latent heat flux over heterogenrous surface. For remote sensing temperature retrieved from remote sensing data and air temperature. Then latent heat flux can be calculated

Boyer, Edmond

204

Exergy analysis of a latent storage system combined solar selective coating with nickel nano-particles  

Science Journals Connector (OSTI)

Exergy analysis of a latent heat storage system with phase change materials (PCMs) for a flat-plate was investigated. A selectively absorbing surface consists of nickel nano-particles was electrochemically prepared for solar collecting. The eutectic mixture formamide-sodium acetate trihydrate was used as phase change material (PCM), with a melting temperature of 40.5°C and heat of fusion of 255 kJ/kg. Exergy analysis, which is based on the second law of thermodynamics were introduced to evaluate efficiency of the system during the charging period. It was observed that the average energy and exergy efficiency of the system was 29.0% and 78.3%, respectively.

Hao Liang; Qichang Yang

2013-01-01T23:59:59.000Z

205

Project Profile: Heat Transfer and Latent Heat Storage in Inorganic Molten Salts for CSP Plants  

Broader source: Energy.gov [DOE]

Terrafore, under the Thermal Storage FOA, is developing an economically feasible thermal energy storage (TES) system based on phase change materials (PCMs), for CSP plants.

206

Transient-heat-transfer and stress analysis of a thermal-storage solar cooker module  

E-Print Network [OSTI]

This paper details the analysis carried out in Solidworks to determine the best material and configuration of a thermal-storage solar cooker module.The thermal-storage solar cooker utilizes the high-latent-heat lithium ...

Zengeni, Hazel C

2014-01-01T23:59:59.000Z

207

Plume heat flow is much lower than CMB heat flow Eric Mittelstaedt a,*, Paul J. Tackley a,b  

E-Print Network [OSTI]

to follow a power-law size distribution, estimated a plume heat flux as high as 35% of surface heat fluxPlume heat flow is much lower than CMB heat flow Eric Mittelstaedt a,*, Paul J. Tackley a, of the heat conducted across the CMB. Here this assumption is explored using numerical convection models

Tackley, Paul J.

208

Heat fluxes in Tampa Bay, Florida.  

E-Print Network [OSTI]

??The Meyers et al. (2007) Tampa Bay Model produces water level and three-dimensional current and salinity fields for Tampa Bay. It is capable of computing… (more)

Sopkin, Kristin L

2008-01-01T23:59:59.000Z

209

E-Print Network 3.0 - atmosphere ocean heat Sample Search Results  

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

of ACC oceanic... heat flux Total heat flux at 900 m: 4.7 to 7.5 kWm2. Implies 0.3 PW heat loss to atmosphere south... 12;Mechanisms: ... Source: Gille, Sarah T. - Scripps...

210

Fast flux locked loop  

DOE Patents [OSTI]

A flux locked loop for providing an electrical feedback signal, the flux locked loop employing radio-frequency components and technology to extend the flux modulation frequency and tracking loop bandwidth. The flux locked loop of the present invention has particularly useful application in read-out electronics for DC SQUID magnetic measurement systems, in which case the electrical signal output by the flux locked loop represents an unknown magnetic flux applied to the DC SQUID.

Ganther, Jr., Kenneth R. (Olathe, KS); Snapp, Lowell D. (Independence, MO)

2002-09-10T23:59:59.000Z

211

Inr J Heat Mass Transfer. Vol. 39. No. 15, pp. 3165-3173, 1996 Copyright 0 1996 Elsevier Science Ltd  

E-Print Network [OSTI]

is described by a temperature transforming model coupled to the heat transfer from the transfer fluid. The heat the heat transfer in thermal energy storage systems when a fluid with a low thermal conductivity is used space around the tube, while the transfer fluid flows within the tube. This type of latent heat storage

Zhang, Yuwen

212

Cost and performance analysis of concentrating solar power systems with integrated latent thermal energy storage  

Science Journals Connector (OSTI)

Abstract Integrating TES (thermal energy storage) in a CSP (concentrating solar power) plant allows for continuous operation even during times when solar irradiation is not available, thus providing a reliable output to the grid. In the present study, the cost and performance models of an EPCM-TES (encapsulated phase change material thermal energy storage) system and HP-TES (latent thermal storage system with embedded heat pipes) are integrated with a CSP power tower system model utilizing Rankine and s-CO2 (supercritical carbon-dioxide) power conversion cycles, to investigate the dynamic TES-integrated plant performance. The influence of design parameters of the storage system on the performance of a 200 MWe capacity power tower CSP plant is studied to establish design envelopes that satisfy the U.S. Department of Energy SunShot Initiative requirements, which include a round-trip annualized exergetic efficiency greater than 95%, storage cost less than $15/kWht and LCE (levelized cost of electricity) less than 6 ¢/kWh. From the design windows, optimum designs of the storage system based on minimum LCE, maximum exergetic efficiency, and maximum capacity factor are reported and compared with the results of two-tank molten salt storage system. Overall, the study presents the first effort to construct and analyze LTES (latent thermal energy storage) integrated CSP plant performance that can help assess the impact, cost and performance of LTES systems on power generation from molten salt power tower CSP plant.

K. Nithyanandam; R. Pitchumani

2014-01-01T23:59:59.000Z

213

Proceedings of HT'03 2003 Summer Heat Transfer Conference  

E-Print Network [OSTI]

Proceedings of HT'03 2003 Summer Heat Transfer Conference July 21­23, 2003, Las Vegas, Nevada, USA HT2003-47016 A NEW TECHNIQUE FOR HEAT FLUX DETERMINATION D.G. Walker Department of Mechanical@vt.edu ABSTRACT A new method for estimating heat fluxes from heating rate measurements and an approach to measure

Walker, D. Greg

214

Pulse flux measuring device  

DOE Patents [OSTI]

A device for measuring particle flux comprises first and second photodiode detectors for receiving flux from a source and first and second outputs for producing first and second signals representing the flux incident to the detectors. The device is capable of reducing the first output signal by a portion of the second output signal, thereby enhancing the accuracy of the device. Devices in accordance with the invention may measure distinct components of flux from a single source or fluxes from several sources.

Riggan, William C. (Albuquerque, NM)

1985-01-01T23:59:59.000Z

215

A critical evaluation of the upper ocean heat budget in the Climate Forecast System Reanalysis data for the south central equatorial Pacific  

SciTech Connect (OSTI)

Coupled ocean-atmospheric models suffer from the common bias of a spurious rain belt south of the central equatorial Pacific throughout the year. Observational constraints on key processes responsible for this bias are scarce. The recently available reanalysis from a coupled model system for the National Centers for Environmental Prediction (NCEP) Climate Forecast System Reanalysis (CFSR) data is a potential benchmark for climate models in this region. Its suitability for model evaluation and validation, however, needs to be established. This paper examines the mixed layer heat budget and the ocean surface currents - key factors for the sea surface temperature control in the double Inter-Tropical Convergence Zone in the central Pacific - from 5{sup o}S to 10{sup o}S and 170{sup o}E to 150{sup o}W. Two independent approaches are used. The first approach is through comparison of CFSR data with collocated station observations from field experiments; the second is through the residual analysis of the heat budget of the mixed layer. We show that the CFSR overestimates the net surface flux in this region by 23 W m{sup -2}. The overestimated net surface flux is mainly due to an even larger overestimation of shortwave radiation by 44 W m{sup -2}, which is compensated by a surface latent heat flux overestimated by 14 W m{sup -2}. However, the quality of surface currents and the associated oceanic heat transport in CFSR are not compromised by the surface flux biases, and they agree with the best available estimates. The uncertainties of the observational data from field experiments are also briefly discussed in the present study.

Liu H.; Lin W.; Liu, X.; Zhang, M.

2011-08-26T23:59:59.000Z

216

World IMACS / MODSIM Congress, Cairns, Australia 13-17 July 2009 http://mssanz.org.au/modsim09  

E-Print Network [OSTI]

. Keywords: Land surface models, evapotranspiration, latent heat flux, satellite remote sensing Comparison of latent heat flux estimates over Australia Matthew F. McCabe1 , Yi Y. Liu1 , Raghuveer Vinukollu from such data do not contribute to model assessment and calibration. This study compares latent heat

Evans, Jason

217

Simplified numerical description of latent storage characteristics for phase change wallboard  

SciTech Connect (OSTI)

Cooling of residential California buildings contributes significantly to electrical consumption and peak power demand. Thermal mass can be utilized to reduce the peak-power demand, down-size the cooling systems and/or switch to low-energy cooling sources. Large thermal storage devices have been used in the past to overcome the short-comings of alternative cooling sources or to avoid high demand charges. With the advent of phase change material (PCM) implemented in gypsum board, plaster or other wall-covering material, thermal storage can be part of the building structure even for light-weight buildings. PCMs have two important advantages as storage media: they can offer an order-of-magnitude increase in thermal storage capacity and their discharge is almost isothermal. This allows to store large amounts of energy without significantly changing the temperature of the sheathing. As heat storage takes place in the building part where the loads occur, rather than externally (e.g., ice or chilled water storage), additional transport energy is not needed. To numerically evaluate the latent storage performance of treated wallboard, RADCOOL, a thermal building simulation model based on the finite difference approach, will be used. RADCOOL has been developed in the SPARK environment in order to be compatible with the new family of simulation tools being developed at Lawrence Berkeley Laboratory. As logical statements are difficult to use in SPARK, a continuous function for the specific heat and the enthalpy had to be found. This report covers the development of a simplified description of latent storage characteristics for wallboard treated with phase change material.

Feustel, H.E.

1995-05-01T23:59:59.000Z

218

Waste-heat recovery in batch processes using heat storage  

SciTech Connect (OSTI)

The waste-heat recovery in batch processes has been studied using the pinch-point method. The aim of the work has been to investigate theoretical and practical approaches to the design of heat-exchanger networks, including heat storage, for waste-heat recovery in batch processes. The study is limited to the incorporation of energy-storage systems based on fixed-temperature variable-mass stores. The background for preferring this to the alternatives (variable-temperature fixed-mass and constant-mass constant-temperature (latent-heat) stores) is given. It is shown that the maximum energy-saving targets as calculated by the pinch-point method (time average model, TAM) can be achieved by locating energy stores at either end of each process stream. This theoretically large number of heat-storage tanks (twice the number of process streams) can be reduced to just a few tanks. A simple procedure for determining a number of heat-storage tanks sufficient to achieve the maximum energy-saving targets as calculated by the pinch-point method is described. This procedure relies on combinatorial considerations, and could therefore be labeled the combinatorial method for incorporation of heat storage in heat-exchanger networks. Qualitative arguments justifying the procedure are presented. For simple systems, waste-heat recovery systems with only three heat-storage temperatures (a hot storage, a cold storage, and a heat store at the pinch temperature) often can achieve the maximum energy-saving targets. Through case studies, six of which are presented, it is found that a theoretically large number of heat-storage tanks (twice the number of process streams) can be reduced to just a few tanks. The description of these six cases is intended to be sufficiently detailed to serve as benchmark cases for development of alternative methods.

Stoltze, S.; Mikkelsen, J.; Lorentzen, B.; Petersen, P.M.; Qvale, B. [Technical Univ. of Denmark, Lyngby (Denmark). Lab. for Energetics

1995-06-01T23:59:59.000Z

219

On meridional transports of heat and freshwater in the pacific ocean  

Science Journals Connector (OSTI)

For the Pacific Ocean estimates of meridional heat and freshwater transport ... to multi-annual mean conditions. Concerning the Pacific heat transport, a southward directed flux across...

Prof. Dr. S. Hastenrath

1984-01-01T23:59:59.000Z

220

Metrological tool for the characterization of flame fronts based on the coupling of heat  

E-Print Network [OSTI]

° flame inclination angle due to wind [ ]th i W theoretical radiative heat flux received by the ith target

Boyer, Edmond

Note: This page contains sample records for the topic "latent heat flux" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Are ghost surfaces and quadratic-flux-minimizing surfaces the same?  

E-Print Network [OSTI]

12 2 2 10 || parallel diffusion dominates perpendicular diffusio solved numerically on grid 2 2 heat, 1 Nov 2009, Atlanta, GA, USA ( ) -10 || ||heat transport is anisotropic: 0 with / =10 if nested flux

Hudson, Stuart

222

Regional climate effects of irrigation and urbanization in the western united states: a model intercomparison  

E-Print Network [OSTI]

In the two northern grid cells, sensible heat flux decreasedthe two southern grid cells sensible heat flux increased andgrid cells that were irrigated in Figure 5. January and August latent heat

2006-01-01T23:59:59.000Z

223

Atmospheric Neutrino Fluxes  

E-Print Network [OSTI]

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

Thomas K. Gaisser

2005-02-18T23:59:59.000Z

224

Spheromak reactor with poloidal flux-amplifying transformer  

DOE Patents [OSTI]

An inductive transformer in the form of a solenoidal coils aligned along the major axis of a flux core induces poloidal flux along the flux core's axis. The current in the solenoidal coil is then reversed resulting in a poloidal flux swing and the conversion of a portion of the poloidal flux to a toroidal flux in generating a spheromak plasma wherein equilibrium approaches a force-free, minimum Taylor state during plasma formation, independent of the initial conditions or details of the formation. The spheromak plasma is sustained with the Taylor state maintained by oscillating the currents in the poloidal and toroidal field coils within the plasma-forming flux core. The poloidal flux transformer may be used either as an amplifier stage in a moving plasma reactor scenario for initial production of a spheromak plasma or as a method for sustaining a stationary plasma and further heating it. The solenoidal coil embodiment of the poloidal flux transformer can alternately be used in combination with a center conductive cylinder aligned along the length and outside of the solenoidal coil. This poloidal flux-amplifying inductive transformer approach allows for a relaxation of demanding current carrying requirements on the spheromak reactor's flux core, reduces plasma contamination arising from high voltage electrode discharge, and improves the efficiency of poloidal flux injection.

Furth, Harold P. (Princeton, NJ); Janos, Alan C. (East Windsor, NJ); Uyama, Tadao (Osaka, JP); Yamada, Masaaki (Lawrenceville, NJ)

1987-01-01T23:59:59.000Z

225

Enhanced heat transfer for thermionic power modules  

SciTech Connect (OSTI)

The thermionic power module is capable of operating at very high heat fluxes, which in turn serve to reduce capital costs. The most efficient operation also requires uniform heat fluxes. The development of enhanced heat transfer systems is required to meet the demand for high heat fluxes (>20 w/cm/sup 2/) at high temperatures (>1500K) which advanced thermionic power modules place upon combustion systems. Energy transfer from the hot combustion gases may take place by convection, radiation, or a combination of radiation and convection. Enhanced convective heat transfer with a jet impingement system has been demonstrated in a thermionic converter. The recently-developed cellular ceramic radiative heat transfer system has also been applied to a thermionic converter. By comparing the jet impingement and cellular ceramic radiative heat transfer systems, an appropriate system may be selected for utilization in advanced thermionic power modules. Results are reported.

Johnson, D.C.

1981-07-01T23:59:59.000Z

226

Plasma momentum meter for momentum flux measurements  

DOE Patents [OSTI]

Invention comprises an instrument in which momentum flux onto a biasable target plate is transferred via a suspended quartz tube onto a sensitive force transducer--a capacitance-type pressure gauge. The transducer is protected from thermal damage, arcing and sputtering, and materials used in the target and pendulum are electrically insulating, rigid even at elevated temperatures, and have low thermal conductivity. The instrument enables measurement of small forces (10.sup.-5 to 10.sup.3 N) accompanied by high heat fluxes which are transmitted by energetic particles with 10's of eV of kinetic energy in a intense magnetic field and pulsed plasma environment.

Zonca, Fulvio (Rome, IT); Cohen, Samuel A. (Hopewell, NJ); Bennett, Timothy (Princeton, NJ); Timberlake, John R. (Allentown, NJ)

1993-01-01T23:59:59.000Z

227

Heat Content Changes in the Pacific Ocean  

E-Print Network [OSTI]

Heat Content Changes in the Pacific Ocean The Acoustic Thermometry of Ocean Cli- mate (ATOC assimilating ocean observations and changes expected from surface heat fluxes as measured by the daily National are a result of advection of heat by ocean currents. We calculate that the most likely cause of the discrepancy

Frandsen, Jannette B.

228

The Phylogenetic Indian Buffet Process: A Non-Exchangeable Nonparametric Prior for Latent Features  

E-Print Network [OSTI]

The Phylogenetic Indian Buffet Process: A Non-Exchangeable Nonparametric Prior for Latent Features- exchangeable prior for a class of nonparametric latent feature models. Our point of departure is the In- dian. In this stochastic process--the Phylogenetic Indian Buffet Process (pIBP)--the probability that a diner chooses

Jordan, Michael I.

229

Bayesian latent variable modelling in studies of air pollution and health  

E-Print Network [OSTI]

Bayesian latent variable modelling in studies of air pollution and health Duncan Lee, Gavin://www.bath.ac.uk/math-sci/BICS #12;Bayesian latent variable modelling in studies of air pollution and health. Duncan Lee (1), Gavin to the approach adopted for modelling the trend and correlation. KEYWORDS: Air pollution and health; Bayesian

Burton, Geoffrey R.

230

Rank-r latent models for cross-covariance Jacob A. Wegelin  

E-Print Network [OSTI]

Rank-r latent models for cross-covariance Jacob A. Wegelin Thomas S. Richardson University of Gaussian rank-r latent models for cross-covariance. We show by construction that any variance-covariance matrix for the ob- served variables induced by rank-r reduced-rank regression can be induced by a rank

Washington at Seattle, University of

231

Atmospheric State, Cloud Microphysics and Radiative Flux  

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

Atmospheric thermodynamics, cloud properties, radiative fluxes and radiative heating rates for the ARM Southern Great Plains (SGP) site. The data represent a characterization of the physical state of the atmospheric column compiled on a five-minute temporal and 90m vertical grid. Sources for this information include raw measurements, cloud property and radiative retrievals, retrievals and derived variables from other third-party sources, and radiative calculations using the derived quantities.

Mace, Gerald

232

Phase Change Characteristics of a Nanoemulsion as a Latent Heat Storage Material  

Science Journals Connector (OSTI)

The primary objective of this study was to investigate the fundamental phase change characteristics of a nanoemulsion using differential scanning ... point than water, was utilized as the phase change material fo...

Koji Fumoto; Noriaki Sato; Masahiro Kawaji…

2014-10-01T23:59:59.000Z

233

Novel Latent Heat Storage Devices for Thermal Management of Electric Vehicle Battery Systems  

Science Journals Connector (OSTI)

A major aspect for safe and efficient operation of battery electric vehicles (BEV) is the thermal management of their battery systems. As temperature uniformity and level highly ... performance and the lifetime, ...

Ch. Huber; A. Jossen; R. Kuhn

2014-01-01T23:59:59.000Z

234

Characteristics of Precipitation, Cloud, and Latent Heating Associated with the Madden–Julian Oscillation  

Science Journals Connector (OSTI)

This study investigates the evolution of cloud and rainfall structures associated with Madden–Julian oscillation (MJO) using Tropical Rainfall Measuring Mission (TRMM) data. Two complementary indices are used to define MJO phases. Joint ...

K-M. Lau; H-T. Wu

2010-02-01T23:59:59.000Z

235

A Modeling Study of Irrigation Effects on Surface Fluxes and Land-Air-Cloud Interactions in the Southern Great Plains  

SciTech Connect (OSTI)

In this study, the authors incorporate an operational-like irrigation scheme into the Noah land surface model as part of the Weather Research and Forecasting Model (WRF). A series of simulations, with and without irrigation, is conducted over the Southern Great Plains (SGP) for an extremely dry (2006) and wet (2007) year. The results show that including irrigation reduces model bias in soil moisture and surface latent heat (LH) and sensible heat (SH) fluxes, especially during a dry year. Irrigation adds additional water to the surface, leading to changes in the planetary boundary layer. The increase in soil moisture leads to increases in the surface evapotranspiration and near-surface specific humidity but decreases in the SH and surface temperature. Those changes are local and occur during daytime. There is an irrigation-induced decrease in both the lifting condensation level (ZLCL) and mixed-layer depth. The decrease in ZLCL is larger than the decrease in mixed-layer depth, suggesting an increasing probability of shallow clouds. The simulated changes in precipitation induced by irrigation are highly variable in space, and the average precipitation over the SGP region only slightly increases. A high correlation is found among soil moisture, SH, and ZLCL. Larger values of soil moisture in the irrigated simulation due to irrigation in late spring and summer persist into the early fall, suggesting that irrigation-induced soil memory could last a few weeks to months. The results demonstrate the importance of irrigation parameterization for climate studies and improve the process-level understanding on the role of human activity in modulating land–air–cloud interactions.

Qian, Yun; Huang, Maoyi; Yang, Ben; Berg, Larry K.

2013-06-13T23:59:59.000Z

236

Latent Class Models in action: Bridging social capital & Internet usage  

Science Journals Connector (OSTI)

Abstract This paper explores how Latent Class Models (LCM) can be applied in social research, when the basic assumptions of regression models cannot be validated. We examine the usefulness of this method with data collected from a study on the relationship between bridging social capital and the Internet. Social capital is defined here as the resources that are potentially available in one’s social ties. Bridging is a dimension of social capital, usually related to weak ties (acquaintances), and a source of instrumental resources such as information. The study surveyed a stratified random sample of 417 inhabitants of Lisbon, Portugal. We used LCM to create the variable bridging social capital, but also to estimate the relationship between bridging social capital and Internet usage when we encountered convergence problems with the logistic regression analysis. We conclude by showing a positive relationship between bridging and Internet usage, and by discussing the potential of LCM for social science research.

Barbara Barbosa Neves; Jaime R.S. Fonseca

2015-01-01T23:59:59.000Z

237

Formation of a flux core spheromak  

Science Journals Connector (OSTI)

An alternate design for compact tori specifically of the spheromak type is studied. In this design the ‘‘flux core spheromak’’ [Nucl. Fusion 29 219 (1989)] the externally imposed bias field links the confinement region of closed flux surfaces. The advantages of this configuration are: (i) it enjoys greater stability to magnetohydrodynamic (MHD) modes particularly the tilt and shift; (ii) it has a poloidal divertor and an amount of poloidal flux separating the closed flux surface region from the walls; and (iii) it might be sustained by helicity injection. Results are presented showing the dependence of the geometry on the distribution of bias flux on the conducting walls and showing the optimization of the 2?D formation scheme to minimize the contact of the plasma with coils electrodes and walls. This last topic involves taking advantage of current sheet formation and subsequent tearing as in formation of the MS spheromak [Phys. Fluids 28 3154 (1985)]. The parameters which can be varied to produce this favorable formation scheme via tearing rather than a formation that proceeds off the reversal coils are explored. In addition it is found that there is strong viscous heating of the ions in this early reconnection phase.

John M. Finn; Parvez N. Guzdar

1991-01-01T23:59:59.000Z

238

Development of a fuel-rod simulator and small-diameter thermocouples for high-temperature, high-heat-flux tests in the Gas-Cooled Fast Reactor Core Flow Test Loop  

SciTech Connect (OSTI)

The Core Flow Test Loop was constructed to perform many of the safety, core design, and mechanical interaction tests in support of the Gas-Cooled Fast Reactor (GCFR) using electrically heated fuel rod simulators (FRSs). Operation includes many off-normal or postulated accident sequences including transient, high-power, and high-temperature operation. The FRS was developed to survive: (1) hundreds of hours of operation at 200 W/cm/sup 2/, 1000/sup 0/C cladding temperature, and (2) 40 h at 40 W/cm/sup 2/, 1200/sup 0/C cladding temperature. Six 0.5-mm type K sheathed thermocouples were placed inside the FRS cladding to measure steady-state and transient temperatures through clad melting at 1370/sup 0/C.

McCulloch, R.W.; MacPherson, R.E.

1983-03-01T23:59:59.000Z

239

EXPERIMENTAL INVESTIGATION OF BOILING HEAT CONVECTION IN A FRACTURE  

E-Print Network [OSTI]

EXPERIMENTAL INVESTIGATION OF BOILING HEAT CONVECTION IN A FRACTURE A REPORT SUBMITTED between heat conduction and heat convection with boiling flow in a rock fracture. An experimental coefficient. This coefficient is the proportionality factor between the heat flux to a fracture surface

Stanford University

240

Solar Magnetic Flux Ropes  

E-Print Network [OSTI]

The most probable initial magnetic configuration of a CME is a flux rope consisting of twisted field lines which fill the whole volume of a dark coronal cavity. The flux ropes can be in stable equilibrium in the coronal magnetic field for weeks and even months, but suddenly they loose their stability and erupt with high speed. Their transition to the unstable phase depends on the parameters of the flux rope (i.e., total electric current, twist, mass loading etc.), as well as on the properties of the ambient coronal magnetic field. One of the major governing factors is the vertical gradient of the coronal magnetic field which is estimated as decay index (n). Cold dense prominence material can be collected in the lower parts of the helical flux tubes. Filaments are therefore good tracers of the flux ropes in the corona, which become visible long before the beginning of the eruption. The perspectives of the filament eruptions and following CMEs can be estimated by the comparison of observed filament heights with...

Filippov, Boris; Srivastava, Abhishek K; Uddin, Wahab

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "latent heat flux" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

DOE/SC-ARM-12-020 MAGIC: Marine ARM GPCI Investigation of Clouds  

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

essential to have complementary observations from the surface, both in situ as well as remote sensed, such as surface fluxes (radiation, latent and sensible heat); cloud...

242

Posters Comparison Between General Circulation Model Simulation...  

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

triangulation interpolation. For the GCM simulation, the monthly mean surface latent heat flux is sampled at the grid points closest to the buoy sites, then interpolated the...

243

Changes in the Land Surface Energy Budget in Eastern China over the Past Three Decades: Contributions of Land-Cover Change and Climate Change  

Science Journals Connector (OSTI)

Sensible heat flux (H), latent heat flux (LE), and net radiation (NR) are important surface energy components that directly influence climate systems. In this study, the changes in the surface energy and their contributions from global climate ...

J. W. Yan; J. Y. Liu; B. Z. Chen; M. Feng; S. F. Fang; G. Xu; H. F. Zhang; M. L. Che; W. Liang; Y. F. Hu; W. H. Kuang; H. M. Wang

2014-12-01T23:59:59.000Z

244

Section 69  

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

few tenths of a degree cooler than the temperature a few millimeters below it because of heat loss by sensible and latent heat fluxes as well as outgoing longwave radiative fluxes...

245

NOVEMBER 1997 2847L O F G R E N Simulated Effects of Idealized Laurentian Great Lakes on  

E-Print Network [OSTI]

cycle of latent and sensible heat flux. Very high upward sensible heat flux occurs over these idealized noted remote effects of the Great Lakes in the form of different precipitation patterns over

246

Geothermal Heat Pumps- Heating Mode  

Broader source: Energy.gov [DOE]

In winter, fluid passing through this vertical, closed loop system is warmed by the heat of the earth; this heat is then transferred to the building.

247

Latent class analysis of new self-report measures of physical and sexual abuse  

E-Print Network [OSTI]

Latent class analysis (LCA) will be used to meet this goalLanza, Flaherty & Collins, 2003). LCA capitalizes on the3) physical and sexual abuse. LCA will be used to identify

Nooner, Kate Brody

2007-01-01T23:59:59.000Z

248

Acoustic emission from magnetic flux tubes in the solar network  

E-Print Network [OSTI]

We present the results of three-dimensional numerical simulations to investigate the excitation of waves in the magnetic network of the Sun due to footpoint motions of a magnetic flux tube. We consider motions that typically mimic granular buffeting and vortex flows and implement them as driving motions at the base of the flux tube. The driving motions generates various MHD modes within the flux tube and acoustic waves in the ambient medium. The response of the upper atmosphere to the underlying photospheric motion and the role of the flux tube in channeling the waves is investigated. We compute the acoustic energy flux in the various wave modes across different boundary layers defined by the plasma and magnetic field parameters and examine the observational implications for chromospheric and coronal heating.

Vigeesh, G

2013-01-01T23:59:59.000Z

249

A Reduced-Order Model of a Chevron Plate Heat Exchanger for Rapid Thermal Management by Using Thermo-Chemical Energy Storage  

E-Print Network [OSTI]

The heat flux demands for electronics cooling applications are quickly approaching the limits of conventional thermal management systems. To meet the demand of next generation electronics, a means for rejecting high heat fluxes at low temperatures...

Niedbalski, Nicholas

2012-10-19T23:59:59.000Z

250

Anisotropic Heat and Water Transport in a PEFC Cathode Gas Diffusion Layer  

E-Print Network [OSTI]

PEFCs , owing to their high en- ergy efficiency, low emission, and low noise, are widely considered. In addition, the latent heat effects due to condensation/evaporation of water on the temperature and water ohmic losses. Along with water man- agement, thermal management is also a key to high performance

251

Design of a flux buffer based on the flux shuttle  

SciTech Connect (OSTI)

This paper discusses the design considerations for a flux buffer based on the flux-shuttle concept. Particular attention is given to the issues of flux popping, stability of operation and saturation levels for a large input. Modulation techniques used in order to minimize 1/f noise, in addition to offsets are also analyzed. Advantages over conventional approaches using a SQUID for a flux buffer are discussed. Results of computer simulations are presented.

Gershenson, M. (Naval Coastal Systems Lab., Panama City, FL (United States))

1991-03-01T23:59:59.000Z

252

Modulation of near-field heat transfer between two gratings  

E-Print Network [OSTI]

We present a theoretical study of near-field heat transfer between two uniaxial anisotropic planar structures. We investigate how the distance and relative orientation (with respect to their optical axes) between the objects affect the heat flux. In particular, we show that by changing the angle between the optical axes it is possible in certain cases to modulate the net heat flux up to 90% at room temperature, and discuss possible applications of such a strong effect.

Svend-Age Biehs; Felipe S. S. Rosa; Philippe Ben-Abdallah

2011-05-18T23:59:59.000Z

253

The Effect of Inaccuracies in Weather-Ship Data on Bulk-Derived Estimates of Flux, Stability and Sea-Surface Roughness  

Science Journals Connector (OSTI)

An analytical error analysis (or sensitivity study) is performed for the momentum, heat, and humidity flux estimates made from weather-ship observations by using the bulk flux method. Bulk-derived stability and roughness errors are also examined. ...

Theodore V. Blanc

1986-03-01T23:59:59.000Z

254

High flux compact neutron generators  

E-Print Network [OSTI]

High Flux Compact Neutron Generators ‡ J. Reijonen §,1 , T-Compact high flux neutron generators are developed at thevoltage feed through of the generator is shown in Fig. 4.

Reijonen, J.; Lou, T.-P.; Tolmachoff, B.; Leung, K.-N.; Verbeke, J.; Vujic, J.

2001-01-01T23:59:59.000Z

255

Flux, Volume 1, Issue 1  

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

&24; Table of Contents flux a publication of the national high magnetic field laboratory PG. 3 ... What is Flux? An introduction to our new publication. PG. 4 ... How Magnet...

256

ASME Journal of Heat Transfer Vol. 121(3), pp.646-652, 1999  

E-Print Network [OSTI]

#12;3 Introduction Buoyancy-induced convective fluid flow with and without phase change heat transfer1 ASME Journal of Heat Transfer Vol. 121(3), pp.646-652, 1999 Variations of Buoyancy-Induced Mass-change heat transfer in a vertical porous tube heated at a constant heat flux. Experiments were carried out

Zhao, Tianshou

257

Thermosolutal convection from a discrete heat and solute source in a vertical porous annulus  

E-Print Network [OSTI]

on the fluid flow and heat and mass transfer rates. The porous annulus is subject to heat and mass fluxes from, buoyancy ratio and radius ratio are investigated on the flow patterns, and heat and mass transfer rates and the rates of heat and mass transfer strongly depend on the location of the heat and solute source. Further

Lopez, John M.

258

Susanville District Heating District Heating Low Temperature...  

Open Energy Info (EERE)

Susanville District Heating District Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Susanville District Heating District Heating Low Temperature...

259

Mixed Layer Lateral Eddy Fluxes Mediated by Air-Sea Interaction  

E-Print Network [OSTI]

The modulation of air–sea heat fluxes by geostrophic eddies due to the stirring of temperature at the sea surface is discussed and quantified. It is argued that the damping of eddy temperature variance by such air–sea ...

Shuckburgh, Emily

260

RECENT ADVANCES IN HEAT TRANSFER TO HELIUM 1  

E-Print Network [OSTI]

509 RECENT ADVANCES IN HEAT TRANSFER TO HELIUM 1 C. JOHANNES Service de Recherches Appliquées, L boiling, forced convection heat transfer. Relations between critical nucleate flux and some parameters confronted with the problem of calculating the heat transfer from the helium to the superconducting material

Paris-Sud XI, Université de

Note: This page contains sample records for the topic "latent heat flux" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

The Heat Budget of a Body of Water of Varying Volume  

Science Journals Connector (OSTI)

internal energy of the system is equal to the net flux of heat ... The internal energy is represented by the temperature .... unit time. The conversion factor is the.

1999-12-07T23:59:59.000Z

262

A Novel approach to magnetic nanoparticles for the development of latent fingerprints  

Science Journals Connector (OSTI)

Abstract Majority of crime scenes do contain fingerprints as physical evidence. The uniqueness of fingerprints makes them more valuable in the court of law. As fingerprint identification is a perfect science many efforts have been made to make it more precise. The most important factor in fingerprint science is the development of prints. The traditional powder methods are routinely used all over the world. Here in this study an effort is made to develop latent fingerprints by means of magnetic nanoparticles. Magnetic nanoparticles are easy to synthesize and need no more processing. Magnetic nanoparticles carry good properties used in different fields. By using magnetic nanoparticles latent prints can be developed easily and the prints last for long in different environmental conditions. Due to this uniqueness of magnetic nanoparticles old fingerprints can also be developed. The piece of work presented here shows the affinity of magnetic nanoparticles towards the latent fingerprints.

A.K. Kavad (Ahir); Y.D. Karande

2014-01-01T23:59:59.000Z

263

Boosted Fast Flux Loop Final Report  

SciTech Connect (OSTI)

The Boosted Fast Flux Loop (BFFL) project was initiated to determine basic feasibility of designing, constructing, and installing in a host irradiation facility, an experimental vehicle that can replicate with reasonable fidelity the fast-flux test environment needed for fuels and materials irradiation testing for advanced reactor concepts. Originally called the Gas Test Loop (GTL) project, the activity included (1) determination of requirements that must be met for the GTL to be responsive to potential users, (2) a survey of nuclear facilities that may successfully host the GTL, (3) conceptualizing designs for hardware that can support the needed environments for neutron flux intensity and energy spectrum, atmosphere, flow, etc. needed by the experimenters, and (4) examining other aspects of such a system, such as waste generation and disposal, environmental concerns, needs for additional infrastructure, and requirements for interfacing with the host facility. A revised project plan included requesting an interim decision, termed CD-1A, that had objectives of' establishing the site for the project at the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL), deferring the CD 1 application, and authorizing a research program that would resolve the most pressing technical questions regarding GTL feasibility, including issues relating to the use of booster fuel in the ATR. Major research tasks were (1) hydraulic testing to establish flow conditions through the booster fuel, (2) mini-plate irradiation tests and post-irradiation examination to alleviate concerns over corrosion at the high heat fluxes planned, (3) development and demonstration of booster fuel fabrication techniques, and (4) a review of the impact of the GTL on the ATR safety basis. A revised cooling concept for the apparatus was conceptualized, which resulted in renaming the project to the BFFL. Before the subsequent CD-1 approval request could be made, a decision was made in April 2006 that further funding for the project would be suspended. Remaining funds have been used to prepare and irradiate mini-plates of the proposed booster fuel. The current baseline design is for a set of three test positions inside an in-pile tube with a thermal neutron absorber and heat sink made of aluminum mixed with hafnium. Operating the ATR at power levels needed to achieve the required fast flux will result in an estimated increase in ATR fuel consumption between 15 and 20% above present rates and a reduction in the time between fuel replacements. Preliminary safety analyses conducted have indicted safe operation of the ATR with the GTL under normal, abnormal, and postulated accident conditions. More comprehensive analyses are needed.

Boosted Fast Flux Loop Project Staff

2009-09-01T23:59:59.000Z

264

Independent Control of Sensible and Latent Cooling in Small Buildings  

E-Print Network [OSTI]

util impact. INTRODUCTION Dehumidification has become an increasingly large fraction of the total cooling load in many new buildings, as heat gains through the envelope have been reduced but internal moisture generation and the need... to be coincident with maximum air-conditioning loads. The possibility was suggested that by independently controlling temperature and humidity ways might be found to ameliorate the peak electrical loads imposed on utilities by the residential and small...

Andrews, J.; Lamontagne, J.; Piraino, M.

1989-01-01T23:59:59.000Z

265

ARM - Measurement - Radiative heating rate  

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

govMeasurementsRadiative heating rate govMeasurementsRadiative heating rate ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Radiative heating rate The heating rate due to the divergence of long and shortwave radiative flux. Categories Radiometric, Atmospheric State Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. External Instruments MOLTS : Model Output Location Time Series Datastreams MOLTS : Model Output Location Time Series Datastreams MOLTSEDASSNDCLASS1 : Model Output Loc. Time Ser. (MOLTS): EDAS

266

Heat Transfer Coefficient Distribution in the Furnace of a 300MWe CFB Boiler  

Science Journals Connector (OSTI)

Properly understanding and calculating the distributions of heat flux and heat transfer coefficient (?) in the furnace is important in designing a circulating fluidized bed (CFB) boiler, especially with supercrit...

P. Zhang; J. F. Lu; H. R. Yang; J. S. Zhang…

2010-01-01T23:59:59.000Z

267

Six-Week Time Series Of Eddy Covariance Co2 Flux At Mammoth Mountain,  

Open Energy Info (EERE)

Six-Week Time Series Of Eddy Covariance Co2 Flux At Mammoth Mountain, Six-Week Time Series Of Eddy Covariance Co2 Flux At Mammoth Mountain, California- Performance Evaluation And Role Of Meteorological Forcing Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Six-Week Time Series Of Eddy Covariance Co2 Flux At Mammoth Mountain, California- Performance Evaluation And Role Of Meteorological Forcing Details Activities (1) Areas (1) Regions (0) Abstract: CO2 and heat fluxes were measured over a six-week period (09/08/2006 to 10/24/2006) by the eddy covariance (EC) technique at the Horseshoe Lake tree kill (HLTK), Mammoth Mountain, CA, a site with complex terrain and high, spatially heterogeneous CO2 emission rates. EC CO2 fluxes ranged from 218 to 3500 g m- 2 d- 1 (mean = 1346 g m- 2 d- 1). Using footprint modeling, EC CO2 fluxes were compared to CO2 fluxes measured by

268

Physics of String Flux Compactifications  

E-Print Network [OSTI]

We provide a qualitative review of flux compactifications of string theory, focusing on broad physical implications and statistical methods of analysis.

Frederik Denef; Michael R. Douglas; Shamit Kachru

2007-01-06T23:59:59.000Z

269

Small break LOCA analysis of the ONRL high flux isotope reactor  

SciTech Connect (OSTI)

A digital simulation program, HFIRSYS, was developed using MMS to analyze small break loss of coolant events in the ORNL High Flux Isotope Reactor. The code evaluates the response of the primary reactor system including automatic controls actions resulting from breaks in auxiliary piping connected to the primary. The primary output of the code is the margin to the onset of nucleate boiling expressed as a ratio of heat flux which would cause boiling to the current hot channel heat flux. A description of the model, validation results and a sample transient are presented.

Wilson, T.L. Jr.; Cook, D.H.; Sozer, A.

1988-01-01T23:59:59.000Z

270

Heat Stroke  

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

stress, from exertion or hot environments, places stress, from exertion or hot environments, places workers at risk for illnesses such as heat stroke, heat exhaustion, or heat cramps. Heat Stroke A condition that occurs when the body becomes unable to control its temperature, and can cause death or permanent disability. Symptoms â–  High body temperature â–  Confusion â–  Loss of coordination â–  Hot, dry skin or profuse sweating â–  Throbbing headache â–  Seizures, coma First Aid â–  Request immediate medical assistance. â–  Move the worker to a cool, shaded area. â–  Remove excess clothing and apply cool water to their body. Heat Exhaustion The body's response to an excessive loss of water and salt, usually through sweating. Symptoms â–  Rapid heart beat â–  Heavy sweating â–  Extreme weakness or fatigue â– 

271

Materials Compatibility and Aging for Flux and Cleaner Combinations.  

SciTech Connect (OSTI)

A materials study of high reliability electronics cleaning is presented here. In Phase 1, mixed type substrates underwent a condensed contaminants application to view a worst- case scenario for unremoved flux with cleaning agent residue for parts in a silicone oil filled environment. In Phase 2, fluxes applied to copper coupons and to printed wiring boards underwent gentle cleaning then accelerated aging in air at 65% humidity and 30 O C. Both sets were aged for 4 weeks. Contaminants were no-clean (ORL0), water soluble (ORH1 liquid and ORH0 paste), and rosin (RMA; ROL0) fluxes. Defluxing agents were water, solvents, and engineered aqueous defluxers. In the first phase, coupons had flux applied and heated, then were placed in vials of oil with a small amount of cleaning agent and additional coupons. In the second phase, pairs of copper coupons and PWB were hand soldered by application of each flux, using tin-lead solder in a strip across the coupon or a set of test components on the PWB. One of each pair was cleaned in each cleaning agent, the first with a typical clean, and the second with a brief clean. Ionic contamination residue was measured before accelerated aging. After aging, substrates were removed and a visual record of coupon damage made, from which a subjective rank was applied for comparison between the various flux and defluxer combinations; more corrosion equated to higher rank. The ORH1 water soluble flux resulted in the highest ranking in both phases, the RMA flux the least. For the first phase, in which flux and defluxer remained on coupons, the aqueous defluxers led to worse corrosion. The vapor phase cleaning agents resulted in the highest ranking in the second phase, in which there was no physical cleaning. Further study of cleaning and rinsing parameters will be required.

Archuleta, Kim; Piatt, Rochelle

2015-01-01T23:59:59.000Z

272

Numerical Simulations of Bubble Dynamics and Heat Transfer in Pool Boiling--Including the Effects of Conjugate Conduction, Level of Gravity, and Noncondensable Gas Dissolved in the Liquid  

E-Print Network [OSTI]

flow boiling. ” Journal of heat transfer, 124(4), 4. Basu,Dhir, V. K. (2005). “Wall heat flux partitioning duringdevelopment. ” Journal of Heat Transfer, 127(2), 5. Carey

Aktinol, Eduardo

2014-01-01T23:59:59.000Z

273

Heat Transfer -1 A satellite in space orbits the sun. The satellite can be approximated as a flat plate with  

E-Print Network [OSTI]

Heat Transfer - 1 A satellite in space orbits the sun. The satellite can be approximated as a flat plate with dimensions and properties given below. (a) Calculate the solar heat flux (W/m2 is at a distance where the solar heat flux (as defined above) is 500 W/m2 , and the flat plate is oriented

Virginia Tech

274

Geographical Coincidence of High Heat Flow, High Seismicity, and Upwelling, with Hydrocarbon Deposits, Phosphorites, Evaporites, and Uranium Ores  

Science Journals Connector (OSTI)

...sea and seismicity and geothermal heat flux. We suggest...upwelling caused by the geothermal heat (2), which brings...sedimentary rocks. High geothermal heat fluxes correlate...Lawrence River, as well as a fourth line along...Arizona, Montana, New Mexico, and Utah. Lignites...

L. M. Libby; W. F. Libby

1974-01-01T23:59:59.000Z

275

New Findings from Terrorism Data: Dirichlet Process Random Effects Models for Latent Groups  

E-Print Network [OSTI]

New Findings from Terrorism Data: Dirichlet Process Random Effects Models for Latent Groups Minjung such a model can best be implemented, and then we use the model to analyze terrorism data. We seeG99. Keywords and phrases: terrorists, empirical studies of terrorism, logistic regression, gen

Casella, George

276

New Findings from Terrorism Data: Dirichlet Process Random Effects Models for Latent Groups  

E-Print Network [OSTI]

New Findings from Terrorism Data: Dirichlet Process Random Effects Models for Latent Groups Minjung, and then we use the model to analyze terrorism data. We see that the richer Dirichlet process random effects, empirical studies of terrorism, logistic regression, gen- eralized linear mixed models, hierarchical models

Gill, Jeff

277

BUILDING BLOCKS FOR HIERARCHICAL LATENT VARIABLE MODELS Harri Valpola, Tapani Raiko and Juha Karhunen  

E-Print Network [OSTI]

BUILDING BLOCKS FOR HIERARCHICAL LATENT VARIABLE MODELS Harri Valpola, Tapani Raiko and Juha, Espoo, Finland E­mail: {Harri.Valpola, Tapani.Raiko, Juha.Karhunen}@hut.fi URL: http; and the approximation of the true posterior p(#18; j X) by q(#18;). The cost function C used in ensemble learning is C

Karhunen, Juha

278

UN MODLE VARIABLES LATENTES POUR LE TRAITEMENT DE DONNES HYBRIDES ISSUES DE COMPARAISONS  

E-Print Network [OSTI]

integrating both a hierarchical regression model of biases and a structural equation model of the answers : hierarchical model, latent variables, structural equations, shared variables, experts knowledge, uncertainty 1 sont précisément définis dans un guide international, le VIM (2007). Des normes proposent des méthodes

Paris-Sud XI, Université de

279

Latent-to-full palmprint comparison based on radial triangulation under forensic conditions  

E-Print Network [OSTI]

Latent-to-full palmprint comparison based on radial triangulation under forensic conditions Ruifang In forensic applications the evidential value of palmprints is obvious according to surveys of law enforcement. Consequently, developing forensic automatic palmprint identification technology is an urgent and challenging

Autonoma de Madrid, Universidad

280

The Solar Wind Energy Flux  

Science Journals Connector (OSTI)

The solar-wind energy flux measured near the Ecliptic is known...Helios, Ulysses, and Wind...covering a large range of latitudes and time, we show that the solar-wind energy flux is independent of the solar-wind....

G. Le Chat; K. Issautier; N. Meyer-Vernet

2012-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "latent heat flux" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Heat Transfer to the Structure during the Fire   

E-Print Network [OSTI]

The post-flashover Fire Test One of a furnished room in Dalmarnock provides a wealth of information including measurements in both the gas phase and on compartment boundaries (Chapter 3). Total heat fluxes at a number ...

Jowsey, Allan; Torero, Jose L; Lane, Barbara

2007-11-14T23:59:59.000Z

282

Influence of Infrared Radiation on Attic Heat Transfer  

E-Print Network [OSTI]

roof temperatures. It was found that a radiant barrier such as aluminum foil can reduce the heat flux significantly. Experimental results were compared to a Three-Region approximate solution developed at Oak Ridge National Laboratories (ORNL). The model...

Katipamula, S.; Turner, W. D.; Murphy, W. E.; O'Neal, D. L.

1985-01-01T23:59:59.000Z

283

Heat collector  

DOE Patents [OSTI]

A heat collector and method suitable for efficiently and cheaply collecting solar and other thermal energy are provided. The collector employs a heat pipe in a gravity-assist mode and is not evacuated. The collector has many advantages, some of which include ease of assembly, reduced structural stresses on the heat pipe enclosure, and a low total materials cost requirement. Natural convective forces drive the collector, which after startup operates entirely passively due in part to differences in molecular weights of gaseous components within the collector.

Merrigan, Michael A. (Santa Cruz, NM)

1984-01-01T23:59:59.000Z

284

Heat collector  

DOE Patents [OSTI]

A heat collector and method suitable for efficiently and cheaply collecting solar and other thermal energy are provided. The collector employs a heat pipe in a gravity-assist mode and is not evacuated. The collector has many advantages, some of which include ease of assembly, reduced structural stresses on the heat pipe enclosure, and a low total materials cost requirement. Natural convective forces drive the collector, which after startup operates entirely passively due in part to differences in molecular weights of gaseous components within the collector.

Merrigan, M.A.

1981-06-29T23:59:59.000Z

285

45 (2008-5) Adjoint-Based Shape Optimization of a Heat-Exchanger Passage  

E-Print Network [OSTI]

conduction is employed. The cost function is defined as a sum of pressure loss and heat transfer, Distribution of non-dimensional heat flux : (c) Initial shape, (d) 6th shape, (e) Cross section of the bottomF244 45 (2008-5) - 623 - Adjoint-Based Shape Optimization of a Heat-Exchanger Passage with Heat

Kasagi, Nobuhide

286

~) Pergamon Int. J. Heat Mass Transfer. Vol. 39, No. 13, pp. 2653-2662, 1996  

E-Print Network [OSTI]

in the grinding process is presented in this paper. Heat transfer models for the abrasive grain, fluid. Lavine and Jen [4, 5] presented a model to simulate the heat transfer to the workpiece, wheel, and fluid or the convection heat transfer coefficient of the grinding fluid. They assumed that the heat flux into the work

Zhang, Yuwen

287

NUMERICAL SIMULATION OF POOL BOILING FOR STEADY STATE AND TRANSIENT HEATING  

E-Print Network [OSTI]

1 NUMERICAL SIMULATION OF POOL BOILING FOR STEADY STATE AND TRANSIENT HEATING Ying He, Masahiro role in nucleate and transition boiling heat transfer at high heat flux. Many experiments have been in the numerical simulation of boiling heat transfer. In this study, based on the macrolayer evaporation model

Maruyama, Shigeo

288

ION CYCLOTRON RESONANCE HEATING IN A TOROIDAL OCTUPOLE J. C. Sprott and J. D. Barter  

E-Print Network [OSTI]

ION CYCLOTRON RESONANCE HEATING IN A TOROIDAL OCTUPOLE J. C. Sprott and J. D. Barter May 1976 at the ion cyclotron frequency (2.6 MHz) has been used to heat the ions from for a high neutral re flux are observed to accompany the heating. Ion cyclotron resonance heating

Sprott, Julien Clinton

289

Condensation heat transfer in square, triangular, and semi-circular mini-channels Melanie Derby a  

E-Print Network [OSTI]

Condensation heat transfer in square, triangular, and semi-circular mini-channels Melanie Derby: Condensation Heat transfer Minichannel Channel shape Correlation a b s t r a c t Condensation heat transfer significant effects on the condensation process, even at lower mass fluxes, while saturation pressure, heat

Peles, Yoav

290

A refrigerator-heat-pump desalination scheme for fresh-water and salt recovery  

Science Journals Connector (OSTI)

This study concerns a refrigerator-heat-pump desalination scheme (RHPDS), which allows energy-efficient recovery of fresh water and salt from the sea. In this scheme, a salt-water chamber is continuously refilled with sea water via atmospheric pressure. Sea water is evaporated into a vacuum chamber and the water vapor is condensed on top of a fresh-water chamber. A refrigerator-heat-pump circuit maintains the two water chambers at suitably different operating temperatures and allows efficient recovery of the latent heat of condensation. The scheme is analyzed with special consideration to potential exploitation of renewable energy sources such as solar and wind energy.

M. Reali

1984-01-01T23:59:59.000Z

291

Heat transfer characteristics of laminar methane/air flame impinging normal to a cylindrical surface  

SciTech Connect (OSTI)

An experimental study has been conducted to determine the heat transfer characteristics of methane/air laminar flames impinging normal to a cylindrical surface. Effects of variations in the values of Reynolds number (Re = 600-1300), equivalence ratio ({phi} = 0.8-1.3), dimensionless separation distance (H/d = 1-5), and burner diameter to cylinder diameter ratio (d/D = 0.0538-0.1076) have been investigated. Three important configurations, viz., flame inner reaction zone far away, just touching and intercepted by the impingement surface, were examined in detail. High stagnation point heat fluxes were obtained when tip of the flame inner reaction zone just touched the target surface. Stagnation point heat fluxes were either zero or negative when the inner reaction zone was intercepted by the impingement surface. An off-stagnation peak in heat flux was obtained at moderate separation distances above the flame tip. Both stagnation point and peak heat fluxes increased with Re when the inner reaction zone length was less than the separation distance. Heat fluxes in the wall-jet region were high at high Re. Maximum heat fluxes were obtained for initially fuel-rich mixture conditions due to entrainment of the surrounding air. Smaller burner diameters produced high heat flux at the stagnation region for fixed Reynolds number and opposite trends were seen in the wall-jet region. A secondary rise in stagnation point heat flux was obtained at larger separation distances. This secondary rise in heat flux was quite significant for larger burner diameters and at low flow rates. Correlations were developed for stagnation point heat flux. Results were also compared with flat plate under identical operating conditions. (author)

Chander, Subhash; Ray, Anjan [Department of Mechanical Engineering, Indian Institute of Technology, Delhi, New Delhi 110 016 (India)

2007-11-15T23:59:59.000Z

292

ARM - PI Product - Atmospheric State, Cloud Microphysics & Radiative Flux  

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

ProductsAtmospheric State, Cloud Microphysics & ProductsAtmospheric State, Cloud Microphysics & Radiative Flux Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send PI Product : Atmospheric State, Cloud Microphysics & Radiative Flux 1997.01.01 - 2010.12.31 Site(s) NSA SGP TWP General Description This data product contains atmospheric thermodynamics, cloud properties, radiative fluxes and radiative heating rates. The data represent a characterization of the physical state of the atmospheric column compiled on a five-minute temporal and 90m vertical grid. Sources for this information include raw measurements, cloud property and radiative retrievals, retrievals and derived variables from other third-party sources, and radiative calculations using the derived quantities.

293

The Sensitivity of Radiative Fluxes to Parameterized Cloud Microphysics  

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

Sensitivity of Radiative Fluxes to Sensitivity of Radiative Fluxes to Parameterized Cloud Microphysics S. F. Iacobellis and R. C. J. Somerville Scripps Institution of Oceanography University of California San Diego, California G. M. McFarquhar University of Illinois at Urbana-Champaign Urbana, Illinois D. L. Mitchell Desert Research Institute Las Vegas, Nevada Introduction We have used a single-column model (SCM) to examine the sensitivity of fundamental quantities such as atmospheric radiative heating rates and surface and top of atmosphere (TOA) radiative fluxes to various parameterizations of clouds and cloud microphysics. When an SCM, which consists of one isolated column of a global atmospheric model, is forced with observational estimates of horizontal advection terms, the parameterizations within the SCM produce time-dependent fields which can be

294

SHOCKS AND THERMAL CONDUCTION FRONTS IN RETRACTING RECONNECTED FLUX TUBES  

SciTech Connect (OSTI)

We present a model for plasma heating produced by time-dependent, spatially localized reconnection within a flare current sheet separating skewed magnetic fields. The reconnection creates flux tubes of new connectivity which subsequently retract at Alfvenic speeds from the reconnection site. Heating occurs in gas-dynamic shocks (GDSs) which develop inside these tubes. Here we present generalized thin flux tube equations for the dynamics of reconnected flux tubes, including pressure-driven parallel dynamics as well as temperature-dependent, anisotropic viscosity and thermal conductivity. The evolution of tubes embedded in a uniform, skewed magnetic field, following reconnection in a patch, is studied through numerical solutions of these equations, for solar coronal conditions. Even though viscosity and thermal conductivity are negligible in the quiet solar corona, the strong GDSs generated by compressing plasma inside reconnected flux tubes generate large velocity and temperature gradients along the tube, rendering the diffusive processes dominant. They determine the thickness of the shock that evolves up to a steady state value, although this condition may not be reached in the short times involved in a flare. For realistic solar coronal parameters, this steady state shock thickness might be as long as the entire flux tube. For strong shocks at low Prandtl numbers, typical of the solar corona, the GDS consists of an isothermal sub-shock where all the compression and cooling occur, preceded by a thermal front where the temperature increases and most of the heating occurs. We estimate the length of each of these sub-regions and the speed of their propagation.

Guidoni, S. E.; Longcope, D. W., E-mail: guidoni@physics.montana.ed [Department of Physics, Montana State University, Bozeman, MT 59717-3840 (United States)

2010-08-01T23:59:59.000Z

295

Solar wind energy and momentum from the emergence of new small?scale flux  

Science Journals Connector (OSTI)

Recent Hinode observations have shown the remarkably rapid reconfiguration of the Sun’s small?scale magnetic flux. On the size?scale of granules solar magnetic flux is reconfigured over only 10 minutes. On the larger scales of supergranules magnetic flux is continually and rapidly reconfigured over about a day. We discuss how the reconfiguration processes observed by Hinode TRACE and SOHO may be related. The emergence of new magnetic flux continually drives reconnection between smaller emerging loops and overlying closed or open fields. Ultimately the energy and momentum from this emerging flux is converted into kinetic energy to drive the solar wind and thermal conductive and radiative energy in closed loops. Thus we describe the relationship between emerging small?scale magnetic flux and the momentum and energy that drives the solar wind and heats the corona.

N. A. Schwadron

2007-01-01T23:59:59.000Z

296

ARM - Measurement - Soil moisture flux  

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

moisture flux moisture flux ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Soil moisture flux A quantity measured according to the formula B = {lambda}(dq/dz), where {lambda} is the conductivity of the soil that the moisture is moving through. Categories Surface Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments CO2FLX : Carbon Dioxide Flux Measurement Systems External Instruments ECMWFDIAG : European Centre for Medium Range Weather Forecasts

297

Flux, Vol. 1, Issue 2  

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

&24; flux a publication of the national high magnetic field laboratory Introduction &24; In a weak economy, U.S. research funding tends to become more heavily weighted toward applied...

298

Heating System Specification Specification of Heating System  

E-Print Network [OSTI]

Appendix A Heating System Specification /* Specification of Heating System (loosely based */ requestHeat : Room ­? bool; 306 #12; APPENDIX A. HEATING SYSTEM SPECIFICATION 307 /* user inputs */ livingPattern : Room ­? behaviour; setTemp : Room ­? num; heatSwitchOn, heatSwitchOff, userReset : simple

Day, Nancy

299

AOSC 621AOSC 621 Radiative Heating/CoolingRadiative Heating/Cooling  

E-Print Network [OSTI]

? Why drop off near sfc? 4 #12;Net flux Net flux: F = F+ - F- 1 2 F-(1) F+(1) F-(2) F+(2) Net energy at the top of the atmosphere is zero. Then we can write 1' ' )',( )'()0,()( 0 * dz dz zzdT zBzTBzF z z F F · The heating rate at z is defined as follows: )( )( d zdF zH net four termsofconsistwilland dz A

Li, Zhanqing

300

Plasmoids as magnetic flux ropes  

SciTech Connect (OSTI)

Observational constraints on the magnetic topology and orientation of plasmoids is examined using a magnetic field model. The authors develop a magnetic flux rope model to examine whether principal axis analysis (PAA) of magnetometer signatures from a single satellite pass is sufficient to determine the magnetic topology of plasmoids and if plasmoid observations are best explained by the flux rope, closed loop, or large-amplitude wave picture. Satellite data are simulated by extracting the magnetic field along a path through the model of a magnetic flux rope. They then examine the results using PAA. They find that the principal axis directions (and therefore the interpretation of structure orientation) is highly dependent on several parameters including the satellite trajectory through the structure. Because of this they conclude that PAA of magnetometer data from a single satellite pass is insufficient to differentiate between magnetic closed loop and flux rope models. They also compare the model results to ISEE 3 magnetometer data of plasmoid events in various coordinate frames including principal axis and geocentric solar magnetospheric. They find that previously identified plasmoid events that have been explained as closed loop structures can also be modeled as flux ropes. They also searched the literature for previously reported flux rope and closed loop plasmoid events to examine if these structures had any similarities and/or differences. The results of the modeling efforts and examination of both flux rope and plasmoid events lead them to favor the flux rope model of plasmoid formation, as it is better able to unify the observations of various magnetic structures observed by ISEE 3.

Moldwin, M.B.; Hughes, W.J. (Boston Univ., MA (United States))

1991-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "latent heat flux" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Precipitation Banding in Idealized Baroclinic Waves  

Science Journals Connector (OSTI)

Moist idealized baroclinic-wave simulations show the development of precipitation bands from a zonally uniform initial midlatitude jet. For a frictionless lower boundary, and with no latent-heat release or surface heat and moisture fluxes, warm ...

Jesse Norris; Geraint Vaughan; David M. Schultz

2014-09-01T23:59:59.000Z

302

Gas Flux Sampling | Open Energy Information  

Open Energy Info (EERE)

Gas Flux Sampling Gas Flux Sampling Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Gas Flux Sampling Details Activities (26) Areas (20) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Field Techniques Exploration Sub Group: Field Sampling Parent Exploration Technique: Gas Sampling Information Provided by Technique Lithology: Stratigraphic/Structural: High flux can be indicative of conduits for fluid flow. Hydrological: Thermal: Anomalous flux is associated with active hydrothermal activity. Dictionary.png Gas Flux Sampling: Gas flux sampling measures the flow of volatile gas emissions from a specific location and compares it to average background emissions. Anomalously high gas flux can be an indication of hydrothermal activity.

303

Heat Transfer Enhancement: Second Generation Technology  

E-Print Network [OSTI]

stant temperature difference or one-ninth the temp erature difference at a constant heat flux compared to plain tubes. 7.5 frn/em lin tube Atter flanening ltn tips Some manufacturers also employ tube-side en hancement for water flowing...

Bergles, A. E.; Webb, R. L.

1984-01-01T23:59:59.000Z

304

Final Report: Latent Expression of Genetic Damage in Human Lung Cells  

SciTech Connect (OSTI)

This project was aimed at furthering understanding of the latent effects of ionizing radiation. The underlying premise was that such latent (i.e., delayed) effects stemmed from radiation-induced genetic instability. As model system to investigate certain aspects of genomic instability, they proposed to look at chromosomal instability involving quasi-targeted radiation-induced breakpoints in the vicinity of the HPRT gene in EJ30 human epithelial cells. Using whole chromosome painting of the X chromosome, the authors were able to show that about 15% of randomly selected 6-thioguanine resistant (6TG{prime}) mutants involved translocations in the terminal portion of Xq. Subsequent analysis, using human genomic YAC probes confirmed that all the translocations were either within (or near Xq26.1), the cytogenetic location of HPRT, whereas none were found elsewhere involving the X chromosome.

Cornforth, Michael N.

1999-02-28T23:59:59.000Z

305

Identifying Latent Classes of Adults at Risk for Skin Cancer Based on Constitutional Risk and Sun Protection Behavior  

Science Journals Connector (OSTI)

...these habits were greater for those with higher...skin cancer. The classes seemed to represent...numbers indicating greater risk in the class (Tables 1 and 2...higher risk reported greater sun protection practices. Latent Class Validation The LCA...

Alana D. Steffen; Karen Glanz; and Lynne R. Wilkens

2007-07-01T23:59:59.000Z

306

Model Specification Searches in Latent Growth Modeling: A Monte Carlo Study  

E-Print Network [OSTI]

that the error covariance structure is over parameterized (Everitt, 1998). More recently developed approaches for analyzing longitudinal data include multilevel modeling (MLM) and latent growth modeling (LGM). Although these two approaches were developed... of the commercially developed structural equation modeling (SEM) programs, such as LISREL, EQS, and Mplus, have included a multilevel analysis routine. In brief, MLM (Goldstein, 1995; Hox, 2002; Raudenbush & Bryk, 2002) analyzes longitudinal data with an univariate...

Kim, Min Jung

2012-07-16T23:59:59.000Z

307

December 31, 2003 Contents of NARR output AWIPS GRIB files  

E-Print Network [OSTI]

] * Sensible heat flux [W/m^2] * Latent heat flux [W/m^2] * Exchange coefficient [(kg/m^3)(m/s)] * Vegetation [%] * Ground Heat Flux [W/m^2] * Canopy conductance [m/s] * Temperature parameter in canopy conductance] Planetary boundary layer height [m] Pressure [Pa] * Pressure (nearest grid point) [Pa] * Temp. [K

308

Dt2boool2> Nora Heat Transfer Correlations  

E-Print Network [OSTI]

Dt2boool2> Nora Heat Transfer Correlations in Nuclear Reactor Safety Calculations VW CORRELATIONS IN NUCLEAR REACTOR SAFETY CALCULATIONS SAK-5 H. Abel-Larsen, Ris� A. J. T. J. A. K. Olsen.1. Critical heat flux 103 B4.2. Transition boiling 109 APPENDIX C. DISPERSED FLOW 129 CI. Droplet generation

309

High-Latitude Ocean and Sea Ice Surface Fluxes: Challenges for Climate Research Mark A. Bourassa1  

E-Print Network [OSTI]

, the Wilkins Ice Shelf collapsed equally quickly (Scambos et al. 2009). Ocean heat content is rising rapidlyHigh-Latitude Ocean and Sea Ice Surface Fluxes: Challenges for Climate Research Mark A. Bourassa1 conditions for the measurement and estimation of air­sea and ice fluxes, limiting understanding of related

Gille, Sarah T.

310

High-Latitude Ocean and Sea Ice Surface Fluxes: Challenges for Climate Research1 Mark A. Bourassa1  

E-Print Network [OSTI]

), and in 2008, the Wilkins Ice Shelf51 collapsed equally quickly (Scambos et al. 2009). Ocean heat content1 High-Latitude Ocean and Sea Ice Surface Fluxes: Challenges for Climate Research1 2 Mark A conditions for the measurement and estimation of air­27 sea and ice fluxes, limiting understanding of related

Gille, Sarah T.

311

High-Latitude Ocean and Sea Ice Surface Fluxes: Challenges for Climate Research1 Mark A. Bourassa1  

E-Print Network [OSTI]

), and in 2008, the Wilkins Ice Shelf51 collapsed equally quickly (Scambos et al. 2009). Ocean heat content1 High-Latitude Ocean and Sea Ice Surface Fluxes: Challenges for Climate Research1 2 Mark A-latitude surface fluxes will require close collaboration among meteorologists,33 oceanographers, ice physicists

Gille, Sarah T.

312

Micro loop heat pipe evaporator coherent pore structures  

E-Print Network [OSTI]

and 5360 K for water, Pv is vapor pressure, sigma is surface tension, Rc is the radius of curvature, Psat(Tl) is water saturation pressure at liquid temperature for flat interface, A is Hamaker constant, delta is liquid film thickness, )vib... is the vibrational partion function, w s pore wall temperature, hfg is water latent heat of vaporization, kl is liquid conductivity. The FPEM was developed by Ward1 and applied by Oinuma2 in order to eliminate the need for empirical constants required by Kinetic...

Alexseev, Alexandre Viktorovich

2005-02-17T23:59:59.000Z

313

Thermality of the Hawking flux  

E-Print Network [OSTI]

Is the Hawking flux "thermal"? Unfortunately, the answer to this seemingly innocent question depends on a number of often unstated, but quite crucial, technical assumptions built into modern (mis-)interpretations of the word "thermal". The original 1850's notions of thermality --- based on classical thermodynamic reasoning applied to idealized "black bodies" or "lamp black surfaces" --- when supplemented by specific basic quantum ideas from the early 1900's, immediately led to the notion of the black-body spectrum, (the Planck-shaped spectrum), but "without" any specific assumptions or conclusions regarding correlations between the quanta. Many (not all) modern authors (often implicitly and unintentionally) add an extra, and quite unnecessary, assumption that there are no correlations in the black-body radiation; but such usage is profoundly ahistorical and dangerously misleading. Specifically, the Hawking flux from an evaporating black hole, (just like the radiation flux from a leaky furnace or a burning lump of coal), is only "approximately" Planck-shaped over a bounded frequency range. Standard physics (phase space and adiabaticity effects) explicitly bound the frequency range over which the Hawking flux is "approximately" Planck-shaped from both above and below --- the Hawking flux is certainly not exactly Planckian, and there is no compelling physics reason to assume the Hawking photons are uncorrelated.

Matt Visser

2014-09-27T23:59:59.000Z

314

Improving Air Conditioner and Heat Pump Modeling  

Broader source: Energy.gov (indexed) [DOE]

Improving Air-Conditioner Improving Air-Conditioner and Heat Pump Modeling Building America Stakeholders Meeting Jon Winkler March 2, 2012 2 * How do you recommend the most cost-effective A/C? Simple Question 3 Solution Whole-House Simulation Tool A/C Information * SEER 13 * SEER 14 * SEER 15 * SEER 16 * SEER 17 * SEER 18 * SEER 21 Annualized Cooling Cost (Energy + Equipment) 4 Background * Power, capacity and SHR vary with: o Outdoor temperature o Entering wetbulb o Air mass flow rate o Part load ratio Power Sensible Capacity Latent Capacity * How to accurately and easily model A/C performance? 5 Background: Model Development * A/C modeling utilizes two types of input o Rated values (capacity, efficiency, etc.) o Performance curves Capacity 1 / Efficiency 6 Background: Manufacturer's Data

315

Triaxial thermopile array geo-heat-flow sensor  

DOE Patents [OSTI]

A triaxial thermopile array geothermal heat flow sensor is designed to measure heat flow in three dimensions in a reconstituted or unperturbed subsurface regime. Heat flow can be measured in conductive or permeable convective media. The sensor may be encased in protective pvc tubing and includes a plurality of thermistors and an array of heat flow transducers produce voltage proportional to heat flux along the subsurface regime and permit direct measurement of heat flow in the subsurface regime. The presence of the thermistor array permits a comparison to be made between the heat flow estimates obtained from the transducers and heat flow calculated using temperature differences and Fourier's Law. The device is extremely sensitive with an accuracy of less than 0.1 Heat Flow Units (HFU) and may be used for long term readings. 6 figs.

Carrigan, C.R.; Hardee, H.C.; Reynolds, G.D.; Steinfort, T.D.

1990-01-01T23:59:59.000Z

316

Triaxial thermopile array geo-heat-flow sensor  

DOE Patents [OSTI]

A triaxial thermopile array geothermal heat flow sensor is designed to measure heat flow in three dimensions in a reconstituted or unperturbed subsurface regime. Heat flow can be measured in conductive or permeable convective media. The sensor may be encased in protective pvc tubing and includes a plurality of thermistors and an array of heat flow transducers arranged in a vertical string. The transducers produce voltage proportional to heat flux along the subsurface regime and permit direct measurement of heat flow in the subsurface regime. The presence of the thermistor array permits a comparison to be made between the heat flow estimates obtained from the transducers and heat flow calculated using temperature differences and Fourier's Law. The device is extremely sensitive with an accuracy of less than 0.1 Heat Flow Units (HFU) and may be used for long term readings.

Carrigan, Charles R. (Tracy, CA); Hardee, Harry C. (Albuquerque, NM); Reynolds, Gerald D. (Tijeras, NM); Steinfort, Terry D. (Tijeras, NM)

1992-01-01T23:59:59.000Z

317

Including radiative heat transfer and reaction quenching in modeling a Claus plant waste heat boiler  

SciTech Connect (OSTI)

Due to increasingly stringent sulfur emission regulations, improvements are necessary in the modified Claus process. A recently proposed model by Nasato et al. for the Claus plant waste heat boiler (WHB) is improved by including radiative heat transfer, which yields significant changes in the predicted heat flux and the temperature profile along the WHB tube, leading to a faster quenching of chemical reactions. For the WHB considered, radiation accounts for approximately 20% of the heat transferred by convection alone. More importantly, operating the WHB at a higher gas mass flux is shown to enhance reaction quenching, resulting in a doubling of the predicted hydrogen flow rate. This increase in hydrogen flow rate is sufficient to completely meet the hydrogen requirement of the H[sub 2]S recovery process considered, which would eliminate the need for a hydrogen plant.

Karan, K.; Mehrotra, A.K.; Behie, L.A. (Univ. of Calgary, Alberta (Canada). Dept. of Chemical and Petroleum Engineering)

1994-11-01T23:59:59.000Z

318

Finite ballooning angle effects on ion temperature gradient driven mode in gyrokinetic flux tube simulations  

SciTech Connect (OSTI)

This paper presents effects of finite ballooning angles on linear ion temperature gradient (ITG) driven mode and associated heat and momentum flux in Gyrokinetic flux tube simulation GENE. It is found that zero ballooning angle is not always the one at which the linear growth rate is maximum. The ITG mode acquires a short wavelength (SW) branch (k{sub ?}?{sub i}?>?1) when growth rates maximized over all ballooning angles are considered. However, the SW branch disappears on reducing temperature gradient showing characteristics of zero ballooning angle SWITG in case of extremely high temperature gradient. Associated heat flux is even with respect to ballooning angle and maximizes at nonzero ballooning angle while the parallel momentum flux is odd with respect to the ballooning angle.

Singh, Rameswar, E-mail: rameswar.singh@lpp.polytechnique.fr [Institute for Plasma Research, Bhat Gandhinagar, Gujarat 2382 428 (India) [Institute for Plasma Research, Bhat Gandhinagar, Gujarat 2382 428 (India); Laboratoire de Physique des Plasmas, Ecole Polytechnique, Route de Saclay, 91128 Palaiseau Cedex (France); Brunner, S. [CRPP, Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne (Switzerland)] [CRPP, Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne (Switzerland); Ganesh, R. [Institute for Plasma Research, Bhat Gandhinagar, Gujarat 2382 428 (India)] [Institute for Plasma Research, Bhat Gandhinagar, Gujarat 2382 428 (India); Jenko, F. [Max-Planck-Institut fur Plasmaphysik, EURATOM Association, D-85748 Garching (Germany)] [Max-Planck-Institut fur Plasmaphysik, EURATOM Association, D-85748 Garching (Germany)

2014-03-15T23:59:59.000Z

319

Characterisation of local ICRF heat loads on the JET ILW  

E-Print Network [OSTI]

When using Ion Cyclotron Range of Frequency (ICRF) heating, enhanced heat-fluxes are commonly observed on some plasma facing components close to the antennas. Experiments have recently been carried out on JET with the new ITER-Like-Wall (ILW) to characterize the heat flux to the JET ICRF antennas. Using Infra-Red thermography and thermal models of the tiles, heat-fluxes were evaluated from the surface temperature increase during the RF phase of L-mode plasmas. The maximum observed heat-flux intensity was ~ 4.5 MW/m2 when operating with -{\\pi}/2 current drive strap phasing at power level of 2MW per antenna and with a 4 cm distance between the plasma and the outer limiters. Heat-fluxes are reduced when using dipole strap phasing. The fraction of ICRF power deposited on the antenna limiters or septa was in the range 2-10% for dipole phasing and 10-20% with +/-{\\pi}/2 phasing.

Jacquet, P; Colas, L; Arnoux, G; Bobkov, V; Corre, Y; Devaux, S; Gardarein, J-L; Gauthier, E; Graham, M; Lerche, E; Mayoral, M-L; Monakhov, I; Rimini, F; Sirinelli, A; Van Eester, D; contributors, JET EFDA

2013-01-01T23:59:59.000Z

320

The development of a latent heat thermal energy storage system using a phase change material for solar energy application.  

E-Print Network [OSTI]

??This investigation forms part of an attempt to provide an alternative to conventional power generation technologies that use fossil fuels which have impact on global… (more)

Zulu, Njabulo Mziwandile.

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "latent heat flux" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Investigation of the stability of paraffin-exfoliated graphite nanoplatelet composites for latent heat thermal storage systems  

SciTech Connect (OSTI)

Organic materials, such as paraffin wax, are sought as stable and environmentally friendly phase change materials (PCM) for thermal energy storage, but they suffer from low thermal conductivity which limits the rate at which thermal energy flows into and out of the material. A common method to improve the PCM thermal behavior is through loading with high thermal conductivity particulate fillers. However, the stability of these composites in the molten state is a concern as settling of the fillers will change the effective thermal conductivity. In this work, we investigate the stability of wax loaded with exfoliated graphite nanoplatelets either of 1 m (xGnP-1) or 15 m (xGnP-15) diameter. The effect of dispersants, oxidation of the wax, viscosity of the wax, mixing time, and hydrocarbon chain length on stability is reported. It was found that the addition of octadecylphosphonic acid (ODPA) is an effective dispersant for xGnP in paraffin and microcrystalline wax. In addition, mixing time, viscosity, and oxidation of the wax influence stability in the molten state. Overall, it was found that a mixing time of 24 hours for xGnP-15 along with ODPA mixed in a high viscosity, oxidized microcrystalline wax results in composite PCM systems with the greatest stability determined at 80 C in the molten state.

Abdelaziz, Omar [ORNL; Mallow, Anne [Georgia Institute of Technology; Graham, Samuel [Georgia Institute of Technology; Kalaitzidou, Kyriaki [Georgia Institute of Technology

2012-01-01T23:59:59.000Z

322

Geothermal district heating systems  

SciTech Connect (OSTI)

Ten district heating demonstration projects and their present status are described. The projects are Klamath County YMCA, Susanville District Heating, Klamath Falls District Heating, Reno Salem Plaza Condominium, El Centro Community Center Heating/Cooling, Haakon School and Business District Heating, St. Mary's Hospital, Diamond Ring Ranch, Pagosa Springs District Heating, and Boise District Heating.

Budney, G.S.; Childs, F.

1982-01-01T23:59:59.000Z

323

High flux solar energy transformation  

DOE Patents [OSTI]

Disclosed are multi-stage systems for high flux transformation of solar energy allowing for uniform solar intensification by a factor of 60,000 suns or more. Preferred systems employ a focusing mirror as a primary concentrative device and a non-imaging concentrator as a secondary concentrative device with concentrative capacities of primary and secondary stages selected to provide for net solar flux intensification of greater than 2000 over 95 percent of the concentration area. Systems of the invention are readily applied as energy sources for laser pumping and in other photothermal energy utilization processes.

Winston, Roland (Chicago, IL); Gleckman, Philip L. (Chicago, IL); O'Gallagher, Joseph J. (Flossmoor, IL)

1991-04-09T23:59:59.000Z

324

Beta ray flux measuring device  

DOE Patents [OSTI]

A beta ray flux measuring device in an activated member in-core instrumentation system for pressurized water reactors. The device includes collector rings positioned about an axis in the reactor's pressure boundary. Activated members such as hydroballs are positioned within respective ones of the collector rings. A response characteristic such as the current from or charge on a collector ring indicates the beta ray flux from the corresponding hydroball and is therefore a measure of the relative nuclear power level in the region of the reactor core corresponding to the specific exposed hydroball within the collector ring.

Impink, Jr., Albert J. (Murrysville, PA); Goldstein, Norman P. (Murrysville, PA)

1990-01-01T23:59:59.000Z

325

Berry-Phase-Induced Heat Pumping and Its Impact on the Fluctuation Theorem Jie Ren (),1,2,* Peter Hanggi,2,3,  

E-Print Network [OSTI]

Berry-Phase-Induced Heat Pumping and Its Impact on the Fluctuation Theorem Jie Ren (),1,2,* Peter heat baths. We demonstrate that the pumped heat typically exhibits a Berry-phase effect in providing-dependent manipulations various molecular heat pumps have been proposed to efficiently control heat flux against thermal

Li, Baowen

326

Water and Space Heating Heat Pumps  

E-Print Network [OSTI]

This paper discusses the design and operation of the Trane Weathertron III Heat Pump Water Heating System and includes a comparison of features and performance to other domestic water heating systems. Domestic water is generally provided through...

Kessler, A. F.

1985-01-01T23:59:59.000Z

327

The Open Magnetic Flux of the Sun. I. Transport by Reconnections with Coronal Loops  

Science Journals Connector (OSTI)

The magnetic field of the Sun includes a component that opens into and creates the heliospheric magnetic field, the so-called open magnetic flux of the Sun. Open flux is transported along the solar surface by random convective motions in the photosphere and also by reconnection with coronal loops and the subsequent displacement of the open field lines. A model is developed to describe the interactions through reconnection of open magnetic field lines and smaller coronal loops on the quiet Sun. The displacement of open field lines by reconnection with such loops can be described as a diffusive process, and the model yields the appropriate diffusion coefficient. The model also relates the total diffusive transport of open flux, as a result of reconnection with loops and random convective motions, to a basic solar parameter, the rate of emergence of magnetic flux per unit surface area. This in turn provides an explanation for the formation of coronal holes: accumulations of open flux. The diffusion process will tend to accumulate open flux into regions where the rate of emergence of new magnetic flux is a local minimum. It is also shown that the parameters used in this model are consistent with and can interrelate a variety of different observations. This work serves as the basis for subsequent papers in which the distribution of open magnetic flux on the Sun and its evolution during the solar cycle is determined, and the transport of open magnetic flux is related to the heating and acceleration of the solar wind.

L. A. Fisk

2005-01-01T23:59:59.000Z

328

2, 10671085, 2005 Flux measurements  

E-Print Network [OSTI]

0.50 m. The study site consisted of grass (10% of area), bean5 (15%), corn (15%) and rice (60 in the components of the surface energy balance and in CO2 flux. Results show that the pattern of energy parti- tion suddenly increased after thunderstorm events. We examined the energy budget closure and found

Paris-Sud XI, Université de

329

Superconducting flux flow digital circuits  

DOE Patents [OSTI]

A NOR/inverter logic gate circuit and a flip flop circuit implemented with superconducting flux flow transistors (SFFTs) are disclosed. Both circuits comprise two SFFTs with feedback lines. They have extremely low power dissipation, very high switching speeds, and the ability to interface between Josephson junction superconductor circuits and conventional microelectronics. 8 figs.

Hietala, V.M.; Martens, J.S.; Zipperian, T.E.

1995-02-14T23:59:59.000Z

330

Superconducting flux flow digital circuits  

DOE Patents [OSTI]

A NOR/inverter logic gate circuit and a flip flop circuit implemented with superconducting flux flow transistors (SFFTs). Both circuits comprise two SFFTs with feedback lines. They have extremely low power dissipation, very high switching speeds, and the ability to interface between Josephson junction superconductor circuits and conventional microelectronics.

Hietala, Vincent M. (Placitas, NM); Martens, Jon S. (Sunnyvale, CA); Zipperian, Thomas E. (Albuquerque, NM)

1995-01-01T23:59:59.000Z

331

Anthropogenic and Biogenic Carbon Dioxide Fluxes From Typical Land Uses in Houston, Texas  

E-Print Network [OSTI]

photosynthetically active radiation (PAR) sensor (Apogee) to measure incoming solar radiation, a heat flux plate sensor installed on a nearby shingle roof, and a rain gauge. Raw 3-D wind data and data from the gas analyzers were recorded in binary format on a CR... photosynthetically active radiation (PAR) sensor (Apogee) to measure incoming solar radiation, a heat flux plate sensor installed on a nearby shingle roof, and a rain gauge. Raw 3-D wind data and data from the gas analyzers were recorded in binary format on a CR...

Werner, Nicholas D

2013-04-29T23:59:59.000Z

332

Determining Reactor Flux from Xenon-136 and Cesium-135 in Spent Fuel  

E-Print Network [OSTI]

The ability to infer the reactor flux from spent fuel or seized fissile material would enhance the tools of nuclear forensics and nuclear nonproliferation significantly. We show that reactor flux can be inferred from the ratios of xenon-136 to xenon-134 and cesium-135 to cesium-137. If the average flux of a reactor is known, the flux inferred from measurements of spent fuel could help determine whether that spent fuel was loaded as a blanket or close to the mid-plane of the reactor. The cesium ratio also provides information on reactor shutdowns during the irradiation of fuel, which could prove valuable for identifying the reactor in question through comparisons with satellite reactor heat monitoring data. We derive analytic expressions for these correlations and compare them to experimental data and to detailed reactor burn simulations. The enrichment of the original uranium fuel affects the correlations by up to 3 percent, but only at high flux.

A. C. Hayes; Gerard Jungman

2012-05-30T23:59:59.000Z

333

Heat transfer and heat exchangers reference handbook  

SciTech Connect (OSTI)

The purpose of this handbook is to provide Rocky Flats personnel with an understanding of the basic concepts of heat transfer and the operation of heat exchangers.

Not Available

1991-01-15T23:59:59.000Z

334

Heating systems for heating subsurface formations  

DOE Patents [OSTI]

Methods and systems for heating a subsurface formation are described herein. A heating system for a subsurface formation includes a sealed conduit positioned in an opening in the formation and a heat source. The sealed conduit includes a heat transfer fluid. The heat source provides heat to a portion of the sealed conduit to change phase of the heat transfer fluid from a liquid to a vapor. The vapor in the sealed conduit rises in the sealed conduit, condenses to transfer heat to the formation and returns to the conduit portion as a liquid.

Nguyen, Scott Vinh (Houston, TX); Vinegar, Harold J. (Bellaire, TX)

2011-04-26T23:59:59.000Z

335

Operation of the ORNL High Particle Flux Helicon Plasma Source  

SciTech Connect (OSTI)

A high power, high particle flux rf-based helicon plasma source has been constructed at ORNL and operated at power levels up to 30 kW. High-density hydrogen and helium plasmas have been produced. The source has been designed as the basis for a linear plasma materials interaction (PMI) test facility that will generate particle fluxes {Gamma}{sub p}10{sup 23} m{sup -3} s{sup -1}, and utilize additional ion and electron cyclotron heating to produce high parallel (to the magnetic field) heat fluxes of {approx}10 MW/m{sup 2}. An rf-based source for PMI research is of interest because high plasma densities are generated with no internal electrodes, allowing true steady state operation with minimal impurity generation. The ORNL helicon source has a diameter of 15 cm and to-date has operated at a frequency f = 13.56 MHz, with magnetic field strength |B| in the antenna region up to {approx}0.15 T. Maximum densities of 3x10{sup 19} m{sup -3} in He and 2.5x10{sup 19} m{sup -3} in H have been achieved. Radial density profiles have been seen to be dependent on the axial |B| profile.

Goulding, R. H.; Biewer, T. M.; Caughman, J. B. O.; Chen, G. C.; Owen, L. W.; Sparks, D. O. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6169 (United States)

2011-12-23T23:59:59.000Z

336

Operation of the ORNL High Particle Flux Helicon Plasma Source  

SciTech Connect (OSTI)

A high power, high particle flux rf-based helicon plasma source has been constructed at ORNL and operated at power levels up to 30 kW. High-density hydrogen and helium plasmas have been produced. The source has been designed as the basis for a linear plasma materials interaction (PMI) test facility that will generate particle fluxes Gamma(p) > 10(23) M-3 s(-1), and utilize additional ion and electron cyclotron heating to produce high parallel (to the magnetic field) heat fluxes of similar to 10 MW/m(2). An rf-based source for PMI research is of interest because high plasma densities are generated with no internal electrodes, allowing true steady state operation with minimal impurity generation. The ORNL helicon source has a diameter of 15 cm and to-date has operated at a frequency f = 13.56 MHz, with magnetic field strength vertical bar B vertical bar in the antenna region up to similar to 0.15 T. Maximum densities of 3 x 10(19) M-3 in He and 2.5 x 10(19) m(-3) in H have been achieved. Radial density profiles have been seen to be dependent on the axial vertical bar B vertical bar profile.

Goulding, Richard Howell [ORNL; Biewer, Theodore M [ORNL; Caughman, John B [ORNL; Chen, Guangye [ORNL; Owen, Larry W [ORNL; Sparks, Dennis O [ORNL

2011-01-01T23:59:59.000Z

337

Heat exchanger  

DOE Patents [OSTI]

A heat exchanger comparising a shell attached at its open end to one side of a tube sheet and a detachable head connected to the other side of said tube sheet. The head is divided into a first and second chamber in fluid communication with a nozzle inlet and nozzle outlet, respectively, formed in said tube sheet. A tube bundle is mounted within said shell and is provided with inlets and outlets formed in said tube sheet in communication with said first and second chambers, respectively.

Brackenbury, Phillip J. (Richland, WA)

1986-01-01T23:59:59.000Z

338

Heat exchanger  

DOE Patents [OSTI]

A heat exchanger comparising a shell attached at its open end to one side of a tube sheet and a detachable head connected to the other side of said tube sheet. The head is divided into a first and second chamber in fluid communication with a nozzle inlet and nozzle outlet, respectively, formed in said tube sheet. A tube bundle is mounted within said shell and is provided with inlets and outlets formed in said tube sheet in communication with said first and second chambers, respectively.

Brackenbury, P.J.

1983-12-08T23:59:59.000Z

339

Identifying the top of the tropical tropopause layer from vertical mass flux analysis and CALIPSO lidar cloud observations  

E-Print Network [OSTI]

defined as the level of zero net radiative heating, which occurs near 14.5­15 km [e.g., Folkins et al layer (TTL) by analyzing the vertical mass flux profile based on radiative transfer calculations will rise into the stratosphere. Thus convection has to transport air at least to the zero radiative heating

Hochberg, Michael

340

J1.15 PARAMETERIZING THE TURBULENT SURFACE FLUXES OVER SUMMER SEA ICE Edgar L Andreas1*  

E-Print Network [OSTI]

of the surface heat budget for that year at several sites around the SHEBA ice camp (Andreas et al. 1999; Persson1 of 9 J1.15 PARAMETERIZING THE TURBULENT SURFACE FLUXES OVER SUMMER SEA ICE Edgar L Andreas1* , P to study the Surface Heat Budget of the Arctic Ocean (SHEBA) lasted for a year (Uttal et al. 2002). Our

Persson, Ola

Note: This page contains sample records for the topic "latent heat flux" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Submitted to the Astrophysical Journal Emission measure distribution in loops impulsively heated at the  

E-Print Network [OSTI]

Submitted to the Astrophysical Journal Emission measure distribution in loops impulsively heated balance under the e#ects of steady heating, heat flux and radiative losses, with the magnetic field only by the evidence of sharply peaked emission measure distributions in active stars, and by the claims of isothermal

342

7th World Conference on Experimental Heat Transfer, Fluid Mechanics and Thermodynamics  

E-Print Network [OSTI]

i #12;ExHFT-7 7th World Conference on Experimental Heat Transfer, Fluid Mechanics Conference on Experimental Heat Transfer, Fluid Mechanics and Thermodynamics 28 June ­ 03 July 2009, Krakow environment of high surface and volumetric heating, intense radiation fluxes, strong 3-component magnetic

Abdou, Mohamed

343

Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow  

E-Print Network [OSTI]

Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow S in a rotor-stator cavity subjected to a superimposed throughflow with heat transfer. Nu- merical predictions field from the heat transfer process. The turbulent flux is approximated by a gradient hypothesis

Boyer, Edmond

344

Measurements of Film Flow Rate in Heated Tubes with Various Axial Power Distributions  

E-Print Network [OSTI]

Measurements of Film Flow Rate in Heated Tubes with Various Axial Power Distributions by Carl, Measurements of Film Flow Rate in Heated Tubes with Various Axial Power Distributions KTH Nuclear Reactor power is limited by a phenomenon called critical heat flux (CHF). It appears as a sudden detoriation

Haviland, David

345

Quantum Fusion of Domain Walls with Fluxes  

E-Print Network [OSTI]

We study how fluxes on the domain wall world volume modify quantum fusion of two distant parallel domain walls into a composite wall. The elementary wall fluxes can be separated into parallel and antiparallel components. The parallel component affects neither the binding energy nor the process of quantum merger. The antiparallel fluxes, instead, increase the binding energy and, against naive expectations, suppress quantum fusion. In the small flux limit we explicitly find the bounce solution and the fusion rate as a function of the flux. We argue that at large (antiparallel) fluxes there exists a critical value of the flux (versus the difference in the wall tensions), which switches off quantum fusion altogether. This phenomenon of flux-related wall stabilization is rather peculiar: it is unrelated to any conserved quantity. Our consideration of the flux-related all stabilization is based on substantiated arguments that fall short of complete proof.

S. Bolognesi; M. Shifman; M. B. Voloshin

2009-07-20T23:59:59.000Z

346

Heat conduction in relativistic neutral gases revisited  

E-Print Network [OSTI]

The kinetic theory of dilute gases to first order in the gradients yields linear relations between forces and fluxes. The heat flux for the relativistic gas has been shown to be related not only to the temperature gradient but also to the density gradient in the representation where number density, temperature and hydrodynamic velocity are the independent state variables. In this work we show the calculation of the corresponding transport coefficients from the full Boltzmann equation and compare the magnitude of the relativistic correction.

A. L. Garcia-Perciante; A. R. Mendez

2010-09-30T23:59:59.000Z

347

Relating magnetic reconnection to coronal heating  

E-Print Network [OSTI]

It is clear that the solar corona is begin heated and that coronal magnetic fields undergo reconnection all the time. Here we attempt to show that these two facts are in fact related - i.e. coronal reconnection generates heat. This attempt must address the fact that topological change of field lines does not automatically generate heat. We present one case of flux emergence where we have measured the rate of coronal magnetic reconnection and the rate of energy dissipation in the corona. The ratio of these two, $P/\\dot{\\Phi}$, is a current comparable to the amount of current expected to flow along the boundary separating the emerged flux from the pre-existing flux overlying it. We can generalize this relation to the overall corona in quiet Sun or in active regions. Doing so yields estimates for the contribution to corona heating from magnetic reconnection. These estimated rates are comparable to the amount required to maintain the corona at its observed temperature.

Longcope, Dana W

2015-01-01T23:59:59.000Z

348

Quantification of latent travel demand on new urban facilities in the state of Texas  

E-Print Network [OSTI]

for the degree of MASTER OF SCIENCE May 1989 Major Subject: Civil Engineering DUANTIFICATION OF LATENT TRAVEL DEMAND ON NEW URBAN FACILITIES IN THE STATE OF TEXAS A Thesis by RUSSELL HAROLD HENK Approved as to style and content by: eilon J an (C 'r 6f... 287 to FM 157) Radial I-20S (1-35 to US 287) Circumferential I-30W (1-20 to SH 183) Radial I-820W ( 1-20 to SH 199) Circumferential SH 121 (1-35 to 1-820) Radi al Table 6 Houston Study Sites-Facility Types Site Number Study Site I-610N (US 59...

Henk, Russell H

1989-01-01T23:59:59.000Z

349

Stochastic volatility models with persistent latent factors: theory and its applications to asset prices  

E-Print Network [OSTI]

consider the nonlinear nonstationary state-space model given by yt = radicalbig f(xt,?) ut, xt+1 = ?xt +vt+1,(2.1) where I make the following assumptions: Assumption 1: The volatility function is given by (2.2) f(xt,?) = µ+ ?1+exp(??(x t ??)) , where ? = (µ.... Assumption 2: (xt) is a scalar latent volatility factor and |?| ? 1, I describe the volatility factor, (xt) explicitly in the transition equation because I am interested in the linkage between it and macro economic fundamentals. I assume that this volatility...

Lee, Hyoung Il

2008-10-10T23:59:59.000Z

350

Segmented heat exchanger  

DOE Patents [OSTI]

A segmented heat exchanger system for transferring heat energy from an exhaust fluid to a working fluid. The heat exchanger system may include a first heat exchanger for receiving incoming working fluid and the exhaust fluid. The working fluid and exhaust fluid may travel through at least a portion of the first heat exchanger in a parallel flow configuration. In addition, the heat exchanger system may include a second heat exchanger for receiving working fluid from the first heat exchanger and exhaust fluid from a third heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the second heat exchanger in a counter flow configuration. Furthermore, the heat exchanger system may include a third heat exchanger for receiving working fluid from the second heat exchanger and exhaust fluid from the first heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the third heat exchanger in a parallel flow configuration.

Baldwin, Darryl Dean (Lafayette, IN); Willi, Martin Leo (Dunlap, IL); Fiveland, Scott Byron (Metamara, IL); Timmons, Kristine Ann (Chillicothe, IL)

2010-12-14T23:59:59.000Z

351

Posters Surface Flux Intercomparison Between the MM5 Model  

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

Posters Surface Flux Intercomparison Between the MM5 Model and Observations During the Storm-Scale Observations Regional Measurement Program-Fronts Experiment Systems Test 1992 J. Dudhia and S. P. Oncley Mesoscale and Microscale Meteorology Division Atmospheric Technology Division National Center for Atmospheric Research Boulder, Colorado Introduction Mesoscale model 5 (MM5) is being used as a data assimilation tool for the Atmospheric Radiation Measurement (ARM) Program. There is a need to verify that the model physics is consistent with observations under a range of conditions. Surface fluxes of heat, moisture, and momentum are a particular area of uncertainty in the model owing to their dependence on surface properties, some of which are time-dependent. The National Center for Atmospheric Research (NCAR)

352

Enhancement of pool boiling heat transfer with electrohydrodynamics and its fundamental study  

E-Print Network [OSTI]

, and 10kV. To conduct this study, an existing low pressure pool boiling apparatus was modified and another high pressure apparatus was designed and built. The fluids were tested on the smooth tube at operating temperatures of 4'C and 20'C, and 19 fins... TWl Tvvo Heat flux of EHD enhancement of boiling (W/m ) Total heat flux with EHD at 10kV (W/m ) Total heat flux with no EHD (W/m ) Minimum cavity mouth radius (m) Rayleigh number Fluid temperature ('C) Pool Saturation temperature ('C) Tube...

Raghupathi, Sri Laxmi Priya

2012-06-07T23:59:59.000Z

353

Solar Glare and Flux Mapping  

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

SGFMT Home SGFMT Home Register Glare Analysis Solar Glare Hazard Analysis SGHAT 1.0 (old) Empirical Glare Analysis Analytical Glare Analysis PHLUX Mapping Reflectivity Calculator References Contact Us Solar Glare and Flux Mapping Tools Measurement of reflected solar irradiance is receiving significant attention by industry, military, and government agencies to assess potential impacts of glint and glare from growing numbers of solar power installations around the world. In addition, characterization of the incident solar flux distribution on central receivers for concentrating solar power applications is important to monitor and maintain system performance. This website contains tools to evaluate solar glare and receiver irradiance. Register to access the tools Solar Glare Hazard Analysis Tool

354

HEATING 7. 1 user's manual  

SciTech Connect (OSTI)

HEATING is a FORTRAN program designed to solve steady-state and/or transient heat conduction problems in one-, two-, or three- dimensional Cartesian, cylindrical, or spherical coordinates. A model may include multiple materials, and the thermal conductivity, density, and specific heat of each material may be both time- and temperature-dependent. The thermal conductivity may be anisotropic. Materials may undergo change of phase. Thermal properties of materials may be input or may be extracted from a material properties library. Heating generation rates may be dependent on time, temperature, and position, and boundary temperatures may be time- and position-dependent. The boundary conditions, which may be surface-to-boundary or surface-to-surface, may be specified temperatures or any combination of prescribed heat flux, forced convection, natural convection, and radiation. The boundary condition parameters may be time- and/or temperature-dependent. General graybody radiation problems may be modeled with user-defined factors for radiant exchange. The mesh spacing may be variable along each axis. HEATING is variably dimensioned and utilizes free-form input. Three steady-state solution techniques are available: point-successive-overrelaxation iterative method with extrapolation, direct-solution (for one-dimensional or two-dimensional problems), and conjugate gradient. Transient problems may be solved using one of several finite-difference schemes: Crank-Nicolson implicit, Classical Implicit Procedure (CIP), Classical Explicit Procedure (CEP), or Levy explicit method (which for some circumstances allows a time step greater than the CEP stability criterion). The solution of the system of equations arising from the implicit techniques is accomplished by point-successive-overrelaxation iteration and includes procedures to estimate the optimum acceleration parameter.

Childs, K.W.

1991-07-01T23:59:59.000Z

355

HEATING AND COOLING PROTOSTELLAR DISKS  

SciTech Connect (OSTI)

We examine heating and cooling in protostellar disks using three-dimensional radiation-MHD calculations of a patch of the Solar nebula at 1 AU, employing the shearing-box and flux-limited radiation diffusion approximations. The disk atmosphere is ionized by stellar X-rays, well coupled to magnetic fields, and sustains a turbulent accretion flow driven by magnetorotational instability, while the interior is resistive and magnetically dead. The turbulent layers are heated by absorbing the light from the central star and by dissipating the magnetic fields. They are optically thin to their own radiation and cool inefficiently. The optically thick interior in contrast is heated only weakly, by re-emission from the atmosphere. The interior is colder than a classical viscous model and isothermal. The magnetic fields support an extended atmosphere that absorbs the starlight 1.5 times higher than the hydrostatic viscous model. The disk thickness thus measures not the internal temperature, but the magnetic field strength. Fluctuations in the fields move the starlight-absorbing surface up and down. The height ranges between 13% and 24% of the radius over timescales of several orbits, with implications for infrared variability. The fields are buoyant, so the accretion heating occurs higher in the atmosphere than the stresses. The heating is localized around current sheets, caused by magnetorotational instability at lower elevations and by Parker instability at higher elevations. Gas in the sheets is heated above the stellar irradiation temperature, even though accretion is much less than irradiation power when volume averaged. The hot optically thin current sheets might be detectable through their line emission.

Hirose, S. [Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology, 3173-25 Showamachi, Kanazawa-ku, Yokohama, Kanagawa 236-0001 (Japan); Turner, N. J., E-mail: shirose@jamstec.go.jp, E-mail: neal.turner@jpl.nasa.gov [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

2011-05-10T23:59:59.000Z

356

Thermal neutron flux contours from criticality event  

SciTech Connect (OSTI)

The generation of thermal neutron flux contours from a criticality event is demonstrated for an idealized building with a criticality event in one of the rooms. The MCNP Monte Carlo computer code is used to calculate the thermal neutron flux.

Carter, L.L., Westinghouse Hanford

1996-08-01T23:59:59.000Z

357

High-flux solar photon processes  

SciTech Connect (OSTI)

This study was commissioned by the National Renewable Energy Laboratory (NREL) for the purpose of identifying high-flux photoprocesses that would lead to beneficial national and commercial applications. The specific focus on high-flux photoprocesses is based on the recent development by NREL of solar concentrator technology capable of delivering record flux levels. We examined photolytic and photocatalytic chemical processes as well as photothermal processes in the search for processes where concentrated solar flux would offer a unique advantage. 37 refs.

Lorents, D C; Narang, S; Huestis, D C; Mooney, J L; Mill, T; Song, H K; Ventura, S [SRI International, Menlo Park, CA (United States)

1992-06-01T23:59:59.000Z

358

Relaxation of spheromak configurations with open flux  

Science Journals Connector (OSTI)

The relaxation of several kink unstable equilibria with open flux representative of spheromaks sustained by dc helicity injection is studied by means of three-dimensional resistivemagnetohydrodynamic simulations. No external driving is applied but the initial conditions are chosen to reproduce the current profiles existing in a gun driven spheromak which has a high current density in the open flux region and a low current density in the closed flux region. The growth and nonlinear saturation of various unstable modes the dynamo action which converts toroidal flux into poloidal flux and the evolution of the ? profile ( ? = ? 0 J ? B / B 2 ) are studied. An initial condition is found which results in a dynamo that produces enough poloidal flux to compensate the resistive losses occurred during a characteristic time of the instability. The flux amplification factor around which this case oscillates is consistent with existing experimental data. During the relaxation the central open flux tube develops a helical distortion and the closed flux surfaces are destroyed. After the relaxation event close flux surfaces form again but the final profiles are not fully relaxed and the central open flux tube remains distorted. The effect of the Lundquist number on the evolution and its impact on the required level of fluctuations are evaluated. Finally the dynamics of the system for different current levels in the open flux region is studied.

Pablo Luis García-Martínez; Ricardo Farengo

2009-01-01T23:59:59.000Z

359

Today's Material Gauss' Law and Flux  

E-Print Network [OSTI]

by the contents of the box, the box must contain zero net electric charge. Slide 27-31 #12;Gauss' Law and Flux: · The Concept of Flux · Calculating Electric Flux · Symmetry · Gauss's Law · Using Gauss's Law · Conductors that the box must contain net positive electric charge. Slide 27-29 #12;© 2013 Pearson Education, Inc

Ashlock, Dan

360

Numerical analysis of vapor flow in a micro heat pipe  

E-Print Network [OSTI]

be modeled as a classical blowing and suction problem, i. e. ?(00) = v(00) = o ?(I, p) = v(L0) = 0 ?(x, 0) = ?(x, H) = 0 i(x, 0) = v(x), v(x, H) = -i'(x) 0&x&I. , (2. 6) v(x, 0) = 0, v(x, H) = 0 I. , &x&(L, +L, ) i(x, 0) = -v(x), v(x, H) = v(x) (L, +L... are considerably smoother and appear more reasonable Figure 5. 6 presents the velocity vector which is under q=40W/cm2, H=0. 003m uniform heat flux linear heat flux 0 00 0 O'I 0 02 0. 03 0. 04 0. 05 0 06 x(m) Fig. 5. 2 Heat flux distribution influence...

Liu, Xiaoqin

2012-06-07T23:59:59.000Z

Note: This page contains sample records for the topic "latent heat flux" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Scale and deposits in high-heat-rejection engines  

SciTech Connect (OSTI)

Scaling under conditions very similar to those of a heavy-duty diesel engine cooling system was investigated using a newly designed, versatile test stand. The parameters included flow rate, heat flux, hardness, along with bulk fluid temperatures. The hot surface temperature, a critical parameter, was also measured. Results were interpreted in terms of the conditions in the boundary layer at the hot surface. Critical values of flow rate and heat flux existed for scaling under experimental conditions. A quantitative relationship of scale with heat flux and hardness was observed. Deposits produced from testing of different types of commercial coolants, including phosphate based and nonphosphate bases, were measured and compared with results from simple beaker tests.

Chen, Y.S.; Kershisnik, E.I. [Dober Group, Glenwood, IL (United States); Hudgens, R.D. [Fleetguard, Inc., Cookeville, TN (United States); Corbeels, C.L.; Zehr, R.L. [Cummins Engine Co., Inc., Columbus, IN (United States)

1999-08-01T23:59:59.000Z

362

Neutron imaging of alkali metal heat pipes  

SciTech Connect (OSTI)

High-temperature heat pipes are two-phase, capillary driven heat transfer devices capable of passively providing high thermal fluxes. Such a device using a liquid-metal coolant can be used as a solution for successful thermal management on hypersonic flight vehicles. Imaging of the liquid-metal coolant inside will provide valuable information in characterizing the detailed heat and mass transport. Neutron imaging possesses an inherent advantage from the fact that neutrons penetrate the heat pipe metal walls with very little attenuation, but are significantly attenuated by the liquid metal contained inside. Using the BT-2 beam line at the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland, preliminary efforts have been conducted on a nickel-sodium heat pipe. The contrast between the attenuated beam and the background is calculated to be approximately 3%. This low contrast requires sacrifice in spatial or temporal resolution so efforts have since been concentrated on lithium (Li) which has a substantially larger neutron attenuation cross section. Using the CG-1D beam line at the High Flux Isotope Reactor (HFIR) of Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee, the first neutron images of high-temperature molybdenum (Mo)-Li heat pipes have been achieved. The relatively high neutron cross section of Li allows for the visualization of the Li working fluid inside the heat pipes. The evaporator region of a gravity assisted cylindrical heat pipe prototype 25 cm long was imaged from start-up to steady state operation up to approximately 900 C. In each corner of the square bore inside, the capillary action raises the Li meniscus above the bulk Li pool in the evaporator region. As the operational temperature changes, the meniscus shapes and the bulk meniscus height also changes. Furthermore, a three-dimensional tomographic image is also reconstructed from the total of 128 projection images taken 1.4o apart in which the Li had already cooled and solidified.

Kihm, Ken [University of Tennessee, Knoxville (UTK); Kirchoff, Eric [University of Tennessee, Knoxville (UTK); Golden, Matt [University of Tennessee, Knoxville (UTK); Rosenfeld, J. [Thermacore Inc.; Rawal, S. [Lockheed Martin Space Systems Company; Pratt, D. [United States Air Force Research Laboratory, Wright-Patterson Air Force Base; Bilheux, Hassina Z [ORNL; Walker, Lakeisha MH [ORNL; Voisin, Sophie [ORNL; Hussey, Dan [NIST Center for Neutron Research (NCRN), Gaithersburg, MD

2013-01-01T23:59:59.000Z

363

1832 VOLUME 15J O U R N A L O F C L I M A T E 2002 American Meteorological Society  

E-Print Network [OSTI]

with higher sensible heat fluxes and lower latent heat fluxes in CLM, and the winter warm bias over seasonally regions. Overall, CLM has little impact on precipitation and surface net radiative fluxes. 1. Introduction). For this rea- son, the original bucket-type land surface model (e.g., Manabe 1969) has been replaced by more

Myneni, Ranga B.

364

Floatable solar heat modules  

SciTech Connect (OSTI)

A floating solar heat module for swimming pools comprises a solid surface for conducting heat from the sun's rays to the water and further includes a solid heat storage member for continual heating even during the night. A float is included to maintain the solar heat module on the surface of the pool. The solid heat storage medium is a rolled metal disk which is sandwiched between top and bottom heat conducting plates, the top plate receiving the heat of the sun's rays through a transparent top panel and the bottom plate transferring the heat conducted through the top plate and rolled disk to the water.

Ricks, J.W.

1981-09-29T23:59:59.000Z

365

Gap Filling and Quality Assessment of CO2 and Water Vapour Fluxes above an Urban Area with Radial Basis Function Neural Networks  

Science Journals Connector (OSTI)

Vertical turbulent fluxes of water vapour, carbon dioxide, and sensible heat were measured from 16 August to the 28 September 2006 near the city centre of Münster in north-west Germany. In comparison to result...

A. Schmidt; T. Wrzesinsky; O. Klemm

2008-03-01T23:59:59.000Z

366

Heat conduction: hyperbolic self-similar shock-waves in solids  

E-Print Network [OSTI]

Analytic solutions for cylindrical thermal waves in solid medium is given based on the nonlinear hyperbolic system of heat flux relaxation and energy conservation equations. The Fourier-Cattaneo phenomenological law is generalized where the relaxation time and heat propagation coefficient have a general power law temperature dependence. From such laws one cannot form a second order parabolic or telegraph-type equation. We consider the original non-linear hyperbolic system itself with the self-similar Ansatz for the temperature distribution and for the heat flux. As results continuous and shock-wave solutions are presented. For physical establishment numerous materials with various temperature dependent heat conduction coefficients are mentioned.

Imre Ferenc Barna; Robert Kersner

2012-04-19T23:59:59.000Z

367

The role of trace gas flux networks in biogeosciences  

SciTech Connect (OSTI)

Vast networks of meteorological sensors ring the globe, providing continuous measurements of an array of atmospheric state variables such as temperature, humidity, rainfall, and the concentration of carbon dioxide [New etal., 1999; Tans etal., 1996]. These measurements provide input to weather and climate models and are key to detecting trends in climate, greenhouse gases, and air pollution. Yet to understand how and why these atmospheric state variables vary in time and space, biogeoscientists need to know where, when, and at what rates important gases are flowing between the land and the atmosphere. Tracking trace gas fluxes provides information on plant or microbial metabolism and climate-ecosystem interactions. The existence of trace gas flux networks is a relatively new phenomenon, dating back to research in 1984. The first gas flux measurement networks were regional in scope and were designed to track pollutant gases such as sulfur dioxide, ozone, nitric acid, and nitrogen dioxide. Atmospheric observations and model simulations were used to infer the depositional rates of these hazardous chemicals [Fowler etal., 2009; Meyers etal., 1991]. In the late 1990s, two additional trace gas flux measurement networks emerged. One, the United States Trace Gas Network (TRAGNET), was a short-lived effort that measured trace gas emissions from the soil and plants with chambers distributed throughout the country [Ojima etal., 2000]. The other, FLUXNET, was an international endeavor that brought many regional networks together to measure the fluxes of carbon dioxide, water vapor, and sensible heat exchange with the eddy covariance technique [Baldocchi etal., 2001]. FLUXNET, which remains active today, currently includes more than 400 tower sites, dispersed across most of the world's climatic zones and biomes, with sites in North and South America, Europe, Asia, Africa, and Australia. More recently, several specialized networks have emerged, including networks dedicated to urban areas (Urban Fluxnet), nitrogen compounds in Europe (NitroEurope), and methane (MethaneNet). Technical Aspects of Flux Networks Eddy covariance flux measurements are the preferred method by which biogeoscientists measure trace gas exchange between ecosystems and the atmosphere [Baldocchi, 2003].

Baldocch, Dennis [Department of Environmental Science, Policy and Management, University of California, Berkeley,; Reichstein, Markus [Max Planck Institute for Biogeochemistry; Papale, D. [University of Tuscia; KOTEEN, LAURIE [University of California, Berkeley; VARGAS, RODRIGO [Ensenada Center for Scientific Research and Higher Education (CICESE); Agarwal, D.A [Lawrence Berkeley National Laboratory (LBNL); Cook, Robert B [ORNL

2012-01-01T23:59:59.000Z

368

Heat Pump for High School Heat Recovery  

E-Print Network [OSTI]

ICEBO2006, Shenzhen, China Renewable Energy Resources and a Greener Future Vol.VIII-12-1 Heat Pump for High School Bathroom Heat Recovery Kunrong Huang Hanqing Wang Xiangjiang Zhou Associate professor Professor Professor School...

Huang, K.; Wang, H.; Zhou, X.

2006-01-01T23:59:59.000Z

369

An experimental and theoretical study of radiative and conductive heat transfer in nongray semitransparent media  

E-Print Network [OSTI]

One dimensional temperature profiles and heat fluxes within a slab of molten glass were measured experimentally. The glass slab was contained in a platinum foil lined ceramic tray inside a high temperature furnace. An ...

Eryou, N. Dennis

1969-01-01T23:59:59.000Z

370

Effects of heat and mass transfer on the kinetics of CO oxidation...  

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

KMC simulation. The gas-phase boundary layer domain is described using the grid-based Crank-Nicolson method. At each time step, the heat and mass fluxes between two...

371

Pagosa Springs District Heating District Heating Low Temperature...  

Open Energy Info (EERE)

Pagosa Springs District Heating District Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Pagosa Springs District Heating District Heating Low...

372

Boise City Geothermal District Heating District Heating Low Temperatur...  

Open Energy Info (EERE)

Boise City Geothermal District Heating District Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Boise City Geothermal District Heating District Heating...

373

San Bernardino District Heating District Heating Low Temperature...  

Open Energy Info (EERE)

San Bernardino District Heating District Heating Low Temperature Geothermal Facility Facility San Bernardino District Heating Sector Geothermal energy Type District Heating...

374

Kethcum District Heating District Heating Low Temperature Geothermal...  

Open Energy Info (EERE)

Kethcum District Heating District Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Kethcum District Heating District Heating Low Temperature Geothermal...

375

Philip District Heating District Heating Low Temperature Geothermal...  

Open Energy Info (EERE)

Philip District Heating District Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Philip District Heating District Heating Low Temperature Geothermal...

376

Midland District Heating District Heating Low Temperature Geothermal...  

Open Energy Info (EERE)

Midland District Heating District Heating Low Temperature Geothermal Facility Facility Midland District Heating Sector Geothermal energy Type District Heating Location Midland,...

377

Combined Heat and Power, Waste Heat, and District Energy | Department...  

Broader source: Energy.gov (indexed) [DOE]

Combined Heat and Power, Waste Heat, and District Energy Combined Heat and Power, Waste Heat, and District Energy Presentation-given at the Fall 2011 Federal Utility Partnership...

378

Waste Heat Management Options for Improving Industrial Process Heating Systems  

Broader source: Energy.gov [DOE]

This presentation covers typical sources of waste heat from process heating equipment, characteristics of waste heat streams, and options for recovery including Combined Heat and Power.

379

Guide to Geothermal Heat Pumps  

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

Geothermal Heat Pumps Work Using a heat exchanger, a geothermal heat pump can move heat from one space to another. In summer, the geothermal heat pump extracts heat from a building...

380

A 22-Year Dataset of Surface Longwave Fluxes in the Arctic  

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

22-Year Dataset of Surface Longwave Fluxes 22-Year Dataset of Surface Longwave Fluxes in the Arctic J. Francis and J. Secora Institute of Marine and Coastal Sciences Rutgers University New Brunswick, New Jersey Abstract Downwelling longwave fluxes (DLFs) over the Arctic surface have been generated from 22.5 years of radiances and retrievals from the TIROS (television and infrared observation satellite) operational vertical sounder (TOVS). The flux retrieval algorithm has been validated and improved using surface- based radiation and cloud observations from the Atmospheric Radiation Measurement (ARM) North Slope of Alaska (NSA) site in Barrow, Alaska, and from the Surface Heat Balance of the Arctic (SHEBA) field program (1997-98) in the Beaufort Sea. The DLF product is presented on a 100 x

Note: This page contains sample records for the topic "latent heat flux" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

RADIATIVE HEATING OF THE SOLAR CORONA  

SciTech Connect (OSTI)

We investigate the effect of solar visible and infrared radiation on electrons in the Sun's atmosphere using a Monte Carlo simulation of the wave-particle interaction and conclude that sunlight provides at least 40% and possibly all of the power required to heat the corona, with the exception of dense magnetic flux loops. The simulation uses a radiation waveform comprising 100 frequency components spanning the solar blackbody spectrum. Coronal electrons are heated in a stochastic manner by low coherence solar electromagnetic radiation. The wave 'coherence time' and 'coherence volume' for each component is determined from optical theory. The low coherence of solar radiation allows moving electrons to gain energy from the chaotic wave field which imparts multiple random velocity 'kicks' to these particles causing their velocity distribution to broaden or heat. Monte Carlo simulations of broadband solar radiative heating on ensembles of 1000 electrons show heating at per particle levels of 4.0 x 10{sup -21} to 4.0 x 10{sup -20} W, as compared with non-loop radiative loss rates of {approx}1 x 10{sup -20} W per electron. Since radiative losses comprise nearly all of the power losses in the corona, sunlight alone can explain the elevated temperatures in this region. The volume electron heating rate is proportional to density, and protons are assumed to be heated either by plasma waves or through collisions with electrons.

Moran, Thomas G., E-mail: moran@grace.nascom.nasa.gov [Physics Department, Catholic University of America, 200 Hannan Hall, Washington, DC 20064 (United States) and NASA/GSFC, Code 671, Greenbelt, MD 20771 (United States)

2011-10-20T23:59:59.000Z

382

High flux photon beam monitor  

SciTech Connect (OSTI)

We have designed two photon beam position monitors for use on our x-ray storage ring beam lines. In both designs, a pair of tungsten blades, separated by a pre-determined gap, intercepts a small fraction of the incoming beam. Due to photoemission, an electrical signal is generated which is proportional to the amount of beam intercepted. The thermal load deposited in the blade is transferred by a heat pipe to a heat exchanger outside the vacuum chamber. A prototype monitor with gap adjustment capability was fabricated and tested at a uv beam line. The results show that the generated electrical signal is a good measurement of the photon beam position. In the following sections, design features and test results are discussed.

Mortazavi, P.; Woodle, M.; Rarback, H.; Shu, D.; Howells, M.

1985-01-01T23:59:59.000Z

383

Woven heat exchanger  

DOE Patents [OSTI]

This invention relates to a heat exchanger for waste heat recovery from high temperature industrial exhaust streams. In a woven ceramic heat exchanger using the basic tube-in-shell design, each heat exchanger consisting of tube sheets and tube, is woven separately. Individual heat exchangers are assembled in cross-flow configuration. Each heat exchanger is woven from high temperature ceramic fiber, the warp is continuous from tube to tube sheet providing a smooth transition and unitized construction.

Piscitella, R.R.

1984-07-16T23:59:59.000Z

384

Clustering, fronts, and heat transfer in turbulent suspensions of heavy particles  

E-Print Network [OSTI]

Heavy inertial particles transported by a turbulent flow are shown to concentrate in the regions where an advected passive scalar, such as temperature, displays very strong front-like discontinuities. This novel effect is responsible for extremely high levels of fluctuations for the passive field sampled by the particles that impacts the heat fluxes exchanged between the particles and the surrounding fluid. Instantaneous and averaged heat fluxes are shown to follow strongly intermittent statistics and anomalous scaling laws.

Bec, Jeremie; Krstulovic, Giorgio

2014-01-01T23:59:59.000Z

385

Technical and cost analyses of two different heat storage systems for residential micro-CHP plants  

Science Journals Connector (OSTI)

Abstract The heat storage system represents a key component for micro-cogeneration plants since it permits to store the unused thermal energy during electricity production for a later use. Nevertheless, it also represents a consistent additional cost that has to be taken into account in order to evaluate the profitability of the micro-CHP system with respect to the separate generation. In this paper the results of a technical and of a cost analysis of two different types of thermal energy storage systems for residential micro-CHP plants are presented. Indeed, in the present work hot water thermal energy storage systems and latent heat thermal energy storage systems have been dimensioned for different micro-CHP systems producing electrical and thermal energy for two different buildings situated in Italy. For each analysed micro-CHP system an adequate thermal energy storage capacity is estimated on the basis of the operational logic and of the electric and thermal loads, and the sizing of the cylindrical tank and of the coil heat exchanger relative to both types of thermal energy storage systems is performed. Comparisons in terms of components cost between hot water thermal energy storage systems and latent heat thermal energy storage systems are performed as well.

L. Mongibello; M. Capezzuto; G. Graditi

2014-01-01T23:59:59.000Z

386

Towards Intelligent District Heating.  

E-Print Network [OSTI]

??A district heating system consists of one or more production units supplying energy in the form of heated water through a distribution pipe network to… (more)

Johansson, Christian

2010-01-01T23:59:59.000Z

387

Total Space Heat-  

Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]

Buildings Energy Consumption Survey: Energy End-Use Consumption Tables Total Space Heat- ing Cool- ing Venti- lation Water Heat- ing Light- ing Cook- ing Refrig- eration...

388

ARM - Heat Index Calculations  

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

FAQ Just for Fun Meet our Friends Cool Sites Teachers Teachers' Toolbox Lesson Plans Heat Index Calculations Heat Index is an index that combines air temperature and relative...

389

Category:Gas Flux Sampling | Open Energy Information  

Open Energy Info (EERE)

Gas Flux Sampling page? For detailed information on Gas Flux Sampling as exploration techniques, click here. Category:Gas Flux Sampling Add.png Add a new Gas Flux Sampling...

390

Efficient Heat Storage Materials: Metallic Composites Phase-Change Materials for High-Temperature Thermal Energy Storage  

SciTech Connect (OSTI)

HEATS Project: MIT is developing efficient heat storage materials for use in solar and nuclear power plants. Heat storage materials are critical to the energy storage process. In solar thermal storage systems, heat can be stored in these materials during the day and released at night—when the sun’s not out—to drive a turbine and produce electricity. In nuclear storage systems, heat can be stored in these materials at night and released to produce electricity during daytime peak-demand hours. MIT is designing nanostructured heat storage materials that can store a large amount of heat per unit mass and volume. To do this, MIT is using phase change materials, which absorb a large amount of latent heat to melt from solid to liquid. MIT’s heat storage materials are designed to melt at high temperatures and conduct heat well—this makes them efficient at storing and releasing heat and enhances the overall efficiency of the thermal storage and energy-generation process. MIT’s low-cost heat storage materials also have a long life cycle, which further enhances their efficiency.

None

2011-11-21T23:59:59.000Z

391

The Effects of Great Plains Irrigation on the Surface Energy Balance, Regional Circulation, and Precipitation  

E-Print Network [OSTI]

the net radiation at the surface, channeling that energy into additional latent heat flux, which increases convective available potential energy and provides downstream convective systems with additional energy and moisture. Most noteworthy in this study...

Huber, David B.; Brunsell, Nathaniel A.; Mechem, David B.

2014-05-05T23:59:59.000Z

392

Regional climate effects of irrigation and urbanization in the western united states: a model intercomparison  

E-Print Network [OSTI]

latent heat flux over the Imperial Valley where irrigatedin the Central and Imperial Valleys in RegCM3 (Table 3). Thes Central Valley, Imperial Valley, and southeastern Idaho (

2006-01-01T23:59:59.000Z

393

coulter-99.PDF  

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

area. Presently, a geometrical distribution (1r 2 ) is used to distribute values to each grid element. The critical element in this pass is the calculation of latent heat flux...

394

Metamaterial anisotropic flux concentrators and magnetic arrays  

E-Print Network [OSTI]

A metamaterial magnetic flux concentrator is investigated in detail in combination with a Halbach cylinder of infinite length. A general analytical solution to the field is determined and the magnetic figure of merit is determined for a Halbach cylinder with a flux concentrator. It is shown that an ideal flux concentrator will not change the figure of merit of a given magnet design, while the non-ideal will always lower it. The geometric parameters producing maximum figure of merit, i.e. the most efficient devices, are determined. The force and torque between two concentric Halbach cylinders with flux concentrators is determined and the maximum torque is found. Finally, the effect of non-ideal flux concentrators and the practical use of flux concentrators, as well as demagnetization issues, is discussed.

Bjørk, R; Bahl, C R H

2014-01-01T23:59:59.000Z

395

Numerical investigation of the convection of heat-emitting liquid reactor materials taking stratification into account  

SciTech Connect (OSTI)

Convective heat transfer to a reactor vessel following core destruction is analyzed. Fuel fragment and structural materials are assumed to melt either mix uniformly or stratify. The Navier-Stokes equations were solved numerically with a rectangular coarse difference grid, neglecting the negligibly small contribution of the laminar boundary layer. Calculations for different levels of volume heat release showed that integral heat fluxes at the lateral and top surfaces of the melt are virtually independent of the convective flow scenario. However, the maximum heat flux on the lateral surface is approximately 1.5 times higher for the homogeneous case than for the stratified case. The higher heat flux could result in larger mechanical loads on the reactor vessel, requiring more cooling of the reactor vessel outer surface. 12 refs., 4 figs.

Likhanskii, V.V.; Loboiko, A.I.; Khoruzhii, O.V.

1994-11-01T23:59:59.000Z

396

Heat-pipe gas-combustion system endurance test for Stirling engine. Final report, May 1990-September 1990  

SciTech Connect (OSTI)

Stirling Thermal Motors, Inc., (STM) has been developing a general purpose Heat Pipe Gas Combustion System (HPGC) suitable for use with the STM4-120 Stirling engine. The HPGC consists of a parallel plate recuperative preheater, a finned heat pipe evaporator and a film cooled gas combustor. A principal component of the HPGC is the heat pipe evaporator which collects and distributes the liquid sodium over the heat transfer surfaces. The liquid sodium evaporates and flows to the condensers where it delivers its latent heat. The report presents test results of endurance tests run on a Gas-Fired Stirling Engine (GFSE). Tests on a dynamometer test stand yielded 67 hours of engine operation at power levels over 10 kW (13.5 hp) with 26 hours at power levels above 15 kW (20 hp). Total testing of the engine, including both motoring tests and engine operation, yielded 245 hours of engine run time.

Mahrle, P.

1990-12-01T23:59:59.000Z

397

Evidence for Inhomogeneous Heating in the Solar Wind  

Science Journals Connector (OSTI)

Solar wind observations and magnetohydrodynamic (MHD) simulations are used to probe the nature of turbulence heating. In particular, the electron heat flux, electron temperature, and ion temperature in the solar wind are studied using ACE and Wind data. These heating diagnostics are also compared with MHD simulation estimates of the local dissipation density. Coherent structures, which are sources of inhomogeneity and intermittency in MHD turbulence, are found to be associated with enhancements in every heating-related diagnostic. This supports the hypothesis that significant inhomogeneous heating occurs in the solar wind, connected with current sheets that are dynamically generated by MHD turbulence. Indeed, a subset of these coherent current sheets might be candidates for magnetic reconnection. However, the specific kinetic mechanisms that heat and accelerate particles within these structures require further study.

K. T. Osman; W. H. Matthaeus; A. Greco; S. Servidio

2011-01-01T23:59:59.000Z

398

Heat transfer research on supercritical water flow upward in tube  

SciTech Connect (OSTI)

The experimental research of heat transfer on supercritical water has been carried out on the supercritical water multipurpose test loop with a 7.6 mm upright tube. The experimental data of heat transfer is obtained. The experimental results of thermal-hydraulic parameters on flow and heat transfer of supercritical water show that: Heat transfer enhancement occurs when the fluid temperature reaches pseudo-critical point with low mass flow velocity, and peters out when the mass flow velocity increases. The heat transfer coefficient and Nusselt number decrease with the heat flux or system pressure increases, and increase with the increasing of mass flow velocity. The wall temperature increases when the mass flow velocity decreases or the system pressure increases. (authors)

Li, H. B.; Yang, J. [China Nuclear Power Technology Research Inst., Shenzhen, Guangdong (China); Gu, H. Y.; Zhao, M. [Shanghai Jiao Tong Univ., Shanghai (China); Lu, D. H.; Zhang, J. M.; Wang, F.; Zhang, Y. [China Nuclear Power Technology Research Inst., Shenzhen, Guangdong (China)

2012-07-01T23:59:59.000Z

399

Rotary magnetic heat pump  

DOE Patents [OSTI]

A rotary magnetic heat pump constructed without flow seals or segmented rotor accomplishes recuperation and regeneration by using split flow paths. Heat exchange fluid pumped through heat exchangers and returned to the heat pump splits into two flow components: one flowing counter to the rotor rotation and one flowing with the rotation. 5 figs.

Kirol, L.D.

1987-02-11T23:59:59.000Z

400

Thulium-170 heat source  

SciTech Connect (OSTI)

An isotopic heat source is formed using stacks of thin individual layers of a refractory isotopic fuel, preferably thulium oxide, alternating with layers of a low atomic weight diluent, preferably graphite. The graphite serves several functions: to act as a moderator during neutron irradiation, to minimize bremsstrahlung radiation, and to facilitate heat transfer. The fuel stacks are inserted into a heat block, which is encased in a sealed, insulated and shielded structural container. Heat pipes are inserted in the heat block and contain a working fluid. The heat pipe working fluid transfers heat from the heat block to a heat exchanger for power conversion. Single phase gas pressure controls the flow of the working fluid for maximum heat exchange and to provide passive cooling.

Walter, C.E.; Van Konynenburg, R.; VanSant, J.H.

1990-09-06T23:59:59.000Z

Note: This page contains sample records for the topic "latent heat flux" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Thulium-170 heat source  

DOE Patents [OSTI]

An isotopic heat source is formed using stacks of thin individual layers of a refractory isotopic fuel, preferably thulium oxide, alternating with layers of a low atomic weight diluent, preferably graphite. The graphite serves several functions: to act as a moderator during neutron irradiation, to minimize bremsstrahlung radiation, and to facilitate heat transfer. The fuel stacks are inserted into a heat block, which is encased in a sealed, insulated and shielded structural container. Heat pipes are inserted in the heat block and contain a working fluid. The heat pipe working fluid transfers heat from the heat block to a heat exchanger for power conversion. Single phase gas pressure controls the flow of the working fluid for maximum heat exchange and to provide passive cooling.

Walter, Carl E. (Pleasanton, CA); Van Konynenburg, Richard (Livermore, CA); VanSant, James H. (Tracy, CA)

1992-01-01T23:59:59.000Z

402

Heat Treating Apparatus  

DOE Patents [OSTI]

Apparatus for heat treating a heat treatable material including a housing having an upper opening for receiving a heat treatable material at a first temperature, a lower opening, and a chamber therebetween for heating the heat treatable material to a second temperature higher than the first temperature as the heat treatable material moves through the chamber from the upper to the lower opening. A gas supply assembly is operatively engaged to the housing at the lower opening, and includes a source of gas, a gas delivery assembly for delivering the gas through a plurality of pathways into the housing in countercurrent flow to movement of the heat treatable material, whereby the heat treatable material passes through the lower opening at the second temperature, and a control assembly for controlling conditions within the chamber to enable the heat treatable material to reach the second temperature and pass through the lower opening at the second temperature as a heated material.

De Saro, Robert (Annandale, NJ); Bateman, Willis (Sutton Colfield, GB)

2002-09-10T23:59:59.000Z

403

Anisotropic turbulent model for solar coronal heating  

E-Print Network [OSTI]

Context : We present a self-consistent model of solar coronal heating, originally developed by Heyvaert & Priest (1992), in which we include the dynamical effect of the background magnetic field along a coronal structure by using exact results from wave MHD turbulence (Galtier et al. 2000). Aims : We evaluate the heating rate and the microturbulent velocity for comparison with observations in the quiet corona, active regions and also coronal holes. Methods :The coronal structures are assumed to be in a turbulent state maintained by the slow erratic motions of the magnetic footpoints. A description for the large-scale and the unresolved small-scale dynamics are given separately. From the latter, we compute exactly (or numerically for coronal holes) turbulent viscosites that are finally used in the former to close self-consistently the system and derive the heating flux expression. Results : We show that the heating rate and the turbulent velocity compare favorably with coronal observations. Conclusions : Although the Alfven wave turbulence regime is strongly anisotropic, and could reduce a priori the heating efficiency, it provides an unexpected satisfactory model of coronal heating for both magnetic loops and open magnetic field lines.

B. Bigot; S. Galtier; H. Politano

2007-12-12T23:59:59.000Z

404

Thermoelectric heat exchange element  

DOE Patents [OSTI]

A thermoelectric heat exchange module includes a first substrate including a heat receptive side and a heat donative side and a series of undulatory pleats. The module may also include a thermoelectric material layer having a ZT value of 1.0 or more disposed on at least one of the heat receptive side and the heat donative side, and an electrical contact may be in electrical communication with the thermoelectric material layer.

Callas, James J. (Peoria, IL); Taher, Mahmoud A. (Peoria, IL)

2007-08-14T23:59:59.000Z

405

Heat Integrate Heat Engines in Process Plants  

E-Print Network [OSTI]

and refrigeration systems. In many instances these real heat engines may appear as a complex process consisting of flash vessels, heat exchangers, compressors, furnaces, etc. See Figure 18a, which shows a simplified diagram of a "steam Rankine cycle." How... and rejection profiles of the real machine. For example, the heat acceptance and re jection profiles for the steam Rankine cycle shown in Figure 18a have been drawn on T,H coordinates in Figure 18b. Thus providing we know the heat acceptance and rejection...

Hindmarsh, E.; Boland, D.; Townsend, D. W.

406

The Solar Wind Power from Magnetic Flux  

Science Journals Connector (OSTI)

Observations of the fast, high-latitude solar wind throughout Ulysses' three orbits show that solar wind power correlates remarkably well with the Sun's total open magnetic flux. These observations support a recent model of the solar wind energy and particle sources, where magnetic flux emergence naturally leads to an energy flux proportional to the strength of the large-scale magnetic field. This model has also been shown to be consistent with X-ray observations of the Sun and a variety of other stars over 12 decades of magnetic flux. The observations reported here show that the Sun delivers ~600 kW Wb?1 to power the solar wind, and that this power to magnetic flux relation has been extremely stable over the last 15 years. Thus, the same law that governs energy released in the corona and from other stars also applies to the total energy in the solar wind.

N. A. Schwadron; D. J. McComas

2008-01-01T23:59:59.000Z

407

Ozone heating and the destabilization of traveling waves during summer  

SciTech Connect (OSTI)

The effects of ozone heating on the linear stability of lower stratospheric traveling waves of the summertime, extratropical circulation are examined. Based on coupled equations for the quasigeostrophic potential vorticity and ozone volume mixing ratio, it is shown that the diabatic heating arising from ozone advection can offset the damping due to Newtonian cooling, leading to wave amplification and significant changes in the structure and zonally rectified fluxes of the wave fields in both the lower stratosphere and troposphere. The vertical profile of the zonal mean wind plays a crucial role in determining whether the ozone heating destabilizes eastward and/or westward traveling disturbances.

Nathan, T.R.; Cordero, E.C.; Li, L. [Univ. of California, Davis, CA (United States)] [Univ. of California, Davis, CA (United States)

1994-07-01T23:59:59.000Z

408

Heat transfer system  

DOE Patents [OSTI]

A heat transfer system for a nuclear reactor. Heat transfer is accomplished within a sealed vapor chamber which is substantially evacuated prior to use. A heat transfer medium, which is liquid at the design operating temperatures, transfers heat from tubes interposed in the reactor primary loop to spaced tubes connected to a steam line for power generation purposes. Heat transfer is accomplished by a two-phase liquid-vapor-liquid process as used in heat pipes. Condensible gases are removed from the vapor chamber through a vertical extension in open communication with the chamber interior.

McGuire, Joseph C. (Richland, WA)

1982-01-01T23:59:59.000Z

409

Wound tube heat exchanger  

DOE Patents [OSTI]

What is disclosed is a wound tube heat exchanger in which a plurality of tubes having flattened areas are held contiguous adjacent flattened areas of tubes by a plurality of windings to give a double walled heat exchanger. The plurality of windings serve as a plurality of effective force vectors holding the conduits contiguous heat conducting walls of another conduit and result in highly efficient heat transfer. The resulting heat exchange bundle is economical and can be coiled into the desired shape. Also disclosed are specific embodiments such as the one in which the tubes are expanded against their windings after being coiled to insure highly efficient heat transfer.

Ecker, Amir L. (Duncanville, TX)

1983-01-01T23:59:59.000Z

410

Achieving high flux amplification in a gun-driven, flux-core spheromak  

Science Journals Connector (OSTI)

A new means of operating flux-core spheromaks with possibly increased stability, confinement and pulse length is analysed by a resistive magnetohydrodynamic (MHD) model. High amplification of the bias poloidal flux, required to minimize ohmic losses, is achieved by reducing the bias rapidly in a plasma formed at a lower amplification. The plasma separatrix is predicted to expand and incorporate the removed bias flux maintaining the total poloidal flux within the spheromak's flux-conserving wall. MHD energy on open magnetic field lines is reduced, reducing magnetic fluctuation levels. A means of experimental verification is suggested that may point the way to fusion-relevant spheromaks.

E.B. Hooper; D.N. Hill; H.S. McLean; C.A. Romero-Talamás; R.D. Wood

2007-01-01T23:59:59.000Z

411

Heat Exchangers for Solar Water Heating Systems | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

Heat Exchangers for Solar Water Heating Systems Heat Exchangers for Solar Water Heating Systems Heat Exchangers for Solar Water Heating Systems May 30, 2012 - 3:40pm Addthis Image of a heat exchanger. | Photo from iStockphoto.com Image of a heat exchanger. | Photo from iStockphoto.com Solar water heating systems use heat exchangers to transfer solar energy absorbed in solar collectors to the liquid or air used to heat water or a space. Heat exchangers can be made of steel, copper, bronze, stainless steel, aluminum, or cast iron. Solar heating systems usually use copper, because it is a good thermal conductor and has greater resistance to corrosion. Types of Heat Exchangers Solar water heating systems use three types of heat exchangers: Liquid-to-liquid A liquid-to-liquid heat exchanger uses a heat-transfer fluid that

412

Latent tracks in sapphire induced by 20-MeV fullerene beams  

Science Journals Connector (OSTI)

Single crystals of ?-Al2O3 were irradiated with 20-MeV fullerene beams in a fluence range from 1.0×1010 to 2.2×1011 C60+ cm-2. The cluster electronic stopping power (dE/dx)e was approximately 62 keV nm-1. Two complementary techniques were employed to assess the modifications induced by these irradiations: Rutherford-backscattering spectrometry in channeling geometry (RBS-C) and transmission electron microscopy (TEM). The disorder induced by electronic processes is clearly determined by the RBS-C analysis. A damage cross section Ae of about 2.2×10-12 cm2 has been extracted from the disorder kinetics, which corresponds to a track radius of ?8.5 nm. From lattice-disorder profiling, a maximal decorrelation length of the C60 clusters in the crystal was estimated to be ?150 nm. TEM micrographs exhibit cylindrical latent tracks formed around the projectile trajectory, while the high-resolution observations evidence the amorphization of sapphire in the core of these tracks. The present results have been interpretated within a model of high locally deposited energy densities in the cluster irradiation regime.

S. M. M. Ramos; N. Bonardi; B. Canut; S. Della-Negra

1998-01-01T23:59:59.000Z

413

A classification approach for less popular webpages based on latent semantic analysis and rough set model  

Science Journals Connector (OSTI)

Abstract Nowadays, with the explosive growth of web information, the webpage classification faces great challenge. Computers have difficulty in understanding the semantic meaning of textual or non-textual webpages. Fortunately, Web 2.0 based collaborative tagging system brings new opportunities to solve this problem. It abstracts structured tags from unstructured content in webpages. However, large numbers of webpages on the Internet are less popular. Their tagging information is sparse, which makes their topic unclear and leads to ambiguous classification. Illuminated by the “ambiguous classification”, we name the less popular webpage “hesitant webpage”. In this paper, we propose an advanced approach for hesitant webpages classification. Firstly, hesitant webpages are divided into bridges, hubs and attached webpages according to their roles on the Internet. Secondly, attached webpages are classified by mining and extending their information in two perspectives. One is the latent semantic analysis (LSA) which is applied to fully explore the semantic meaning of sparse tags. It promotes accurate cognition of webpages semantically close to attached webpages. Another is the proposed density-relation-based rough set model which measures the affiliation degree of attached webpages in different categories. Experiment on real data shows that our approach effectively classifies the hesitant webpages base on the semantic meaning.

Jun Wang; Jiaxu Peng; Ou Liu

2015-01-01T23:59:59.000Z

414

Final Technical Report for "Radiative Heating Associated with Tropical Convective Cloud Systems: Its Importance at Meso and Global Scales"  

SciTech Connect (OSTI)

Heating associated with tropical cloud systems drive the global circulation. The overall research objectives of this project were to i) further quantify and understand the importance of heating in tropical convective cloud systems with innovative observational techniques, and ii) use global models to determine the large-scale circulation response to variability in tropical heating profiles, including anvil and cirrus cloud radiative forcing. The innovative observational techniques used a diversity of radar systems to create a climatology of vertical velocities associated with the full tropical convective cloud spectrum along with a dissection of the of the total heating profile of tropical cloud systems into separate components (i.e., the latent, radiative, and eddy sensible heating). These properties were used to validate storm-scale and global climate models (GCMs) and were further used to force two different types of GCMs (one with and one without interactive physics). While radiative heating was shown to account for about 20% of the total heating and did not have a strong direct response on the global circulation, the indirect response was important via its impact on convection, esp. in how radiative heating impacts the tilt of heating associated with the Madden-Julian Oscillation (MJO), a phenomenon that accounts for most tropical intraseasonal variability. This work shows strong promise in determining the sensitivity of climate models and climate processes to heating variations associated with cloud systems.

Schumacher, Courtney

2012-12-13T23:59:59.000Z

415

Geothermal Heat Pumps  

Broader source: Energy.gov [DOE]

The Geothermal Technologies Office focuses only on electricity generation. For additional information about geothermal heating and cooling and ground source heat pumps, please visit the U.S. Department of Energy (DOE)'s Buildings Technologies Office.

416

HEAT TRANSFER FLUIDS  

E-Print Network [OSTI]

The choice of heat transfer fluids has significant effects on the performance, cost, and reliability of solar thermal systems. In this chapter, we evaluate existing heat transfer fluids such as oils and molten salts based ...

Lenert, Andrej

2012-01-01T23:59:59.000Z

417

Residential heating oil price  

Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]

heating oil price decreases The average retail price for home heating oil fell 6.3 cents from a week ago to 2.91 per gallon. That's down 1.10 from a year ago, based on the...

418

Residential heating oil price  

U.S. Energy Information Administration (EIA) Indexed Site

heating oil price decreases The average retail price for home heating oil fell 7.5 cents from a week ago to 2.84 per gallon. That's down 1.22 from a year ago, based on the...

419

Residential heating oil price  

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

heating oil price decreases The average retail price for home heating oil fell 7.6 cents from a week ago to 2.97 per gallon. That's down 1.05 from a year ago, based on the...

420

Residential heating oil price  

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

heating oil price decreases The average retail price for home heating oil fell 3.6 cents from a week ago to 3.04 per gallon. That's down 99.4 cents from a year ago, based on the...

Note: This page contains sample records for the topic "latent heat flux" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Simplified Numerical Description of Latent Storage Characteristics for Phase Change Wallboard  

E-Print Network [OSTI]

H. Manz; "Theory of Phase Change Materials with and withoutand A.K. Sircar; "Phase Change Materials for Heating andContaining a Phase Change Material", Proceedings of the 25th

Fuestel, H.E.

2011-01-01T23:59:59.000Z

422

Simplified Numerical Description of Latent Storage Characteristics for Phase Change Wallboard  

E-Print Network [OSTI]

the discharge of thermal energy storage without "dumping"thermal mass, and • utilize low-energy heating and cooling sources. Large thermal storagelow- energy cooling sources. Large thermal storage devices

Fuestel, H.E.

2011-01-01T23:59:59.000Z

423

Hydrothermal Heat Discharge In The Cascade Range, Northwestern United  

Open Energy Info (EERE)

Page Page Edit History Facebook icon Twitter icon » Hydrothermal Heat Discharge In The Cascade Range, Northwestern United States Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Hydrothermal Heat Discharge In The Cascade Range, Northwestern United States Details Activities (3) Areas (1) Regions (0) Abstract: Hydrothermal heat discharge in the Cascade Range includes the heat discharged by thermal springs, by "slightly thermal" springs that are only a few degrees warmer than ambient temperature, and by fumaroles. Thermal-spring heat discharge is calculated on the basis of chloride-flux measurements and geothermometer temperatures and totals ~ 240 MW in the U.S. part of the Cascade Range, excluding the transient post-1980 discharge

424

Nonlocal fluxes at a plasma sheath  

SciTech Connect (OSTI)

The particle and energy fluxes of electrons at the boundary of a plasma in contact with a perfectly absorbing plate are considered. In general, the fluxes are shown not to be determined by the plasma temperature and density at the plate but rather by a convolution of the plasma profiles in the vicinity of the plate. A simple empirical expression is proposed for the nonlocal fluxes, which approximately reproduces the results of a full kinetic calculation. The implications of this, to divertor plasmas near the neutralizer plate, are discussed.

Marchand, R.; Abou-Assaleh, Z.; Matte, J.P. (INRS-Energie, C. P. 1020, Varennes, Quebec, J3X 1S2, Canada (CA))

1990-06-01T23:59:59.000Z

425

Berry-Phase induced Heat Pumping and its Impact on the Fluctuation Theorem  

E-Print Network [OSTI]

Applying adiabatic, cyclic two parameter modulations we investigate quantum heat transfer across an anharmonic molecular junction contacted with two heat baths. We demonstrate that the pumped heat typically exhibits a Berry phase effect in providing an additional geometric contribution to heat flux. Remarkably, a robust fractional quantized geometric phonon response is identified as well. The presence of this geometric phase contribution in turn causes a breakdown of the fluctuation theorem of the Gallavotti-Cohen type for quantum heat transfer. This can be restored only if (i) the geometric phase contribution vanishes and if (ii) the cyclic protocol preserves the detailed balance symmetry.

Ren, Jie; Li, Baowen

2010-01-01T23:59:59.000Z

426

MA HEAT Loan Overview  

Broader source: Energy.gov [DOE]

Presents information on the success of Massachusetts's HEAT loan offerings and how the financing tool is funded.

427

Ductless Heat Pumps  

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

Water Heaters Showerheads Residential Weatherization Performance Tested Comfort Systems Ductless Heat Pumps New Construction Residential Marketing Toolkit Retail Sales...

428

Heat Pump Water Heaters  

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

Water Heaters Showerheads Residential Weatherization Performance Tested Comfort Systems Ductless Heat Pumps New Construction Residential Marketing Toolkit Retail Sales...

429

Solar heat receiver  

DOE Patents [OSTI]

A receiver is described for converting solar energy to heat a gas to temperatures from 700 to 900/sup 0/C. The receiver is formed to minimize impingement of radiation on the walls and to provide maximum heating at and near the entry of the gas exit. Also, the receiver is formed to provide controlled movement of the gas to be heated to minimize wall temperatures. The receiver is designed for use with gas containing fine heat absorbing particles, such as carbon particles.

Hunt, A.J.; Hansen, L.J.; Evans, D.B.

1982-09-29T23:59:59.000Z

430

Electric resistive space heating  

Science Journals Connector (OSTI)

The cost of heating residential buildings using electricity is compared to the cost employing gas or oil. (AIP)

David Bodansky

1985-01-01T23:59:59.000Z

431

Heat Transfer Reduction Across the Walls of Refrigerated Van Trailers by the Application of Phase Change Material  

E-Print Network [OSTI]

. The technology was tested in similar days in terms of temperature and solar insolation. The relevant variables that were monitored were the heat flux across the walls of the simulators and temperatures, including surface and indoor air temperatures. Other...

Ahmed, Mashud

2009-03-13T23:59:59.000Z

432

A 20-Year Dataset of Downwelling Longwave Flux at the Arctic Surface from TOVS Satellite Data  

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

20-Year Dataset of Downwelling Longwave Flux 20-Year Dataset of Downwelling Longwave Flux at the Arctic Surface from TOVS Satellite Data J. Francis Rutgers University New Brunswick, New Jersey A. Schweiger Polar Science Center University of Washington Seattle, Washington J. Key National Oceanic and Atmospheric Administration National Environmental Satellite, Data, and Information Service Madison, Wisconsin Introduction This paper summarizes the progress of a study under way to generate a 20-year dataset of surface downwelling longwave flux (DLF) retrievals from satellite data over the Arctic Ocean. We will produce daily fields between late 1979 and late 1998 on a grid with a spatial resolution of 100 km x 100 km 2 north of 60°N. Surface measurements from the Surface Heat Budget of the Arctic (SHEBA) and the

433

40Ar-39Ar Geochronology Of Magmatic Activity, Magma Flux And Hazards At  

Open Energy Info (EERE)

Ar-39Ar Geochronology Of Magmatic Activity, Magma Flux And Hazards At Ar-39Ar Geochronology Of Magmatic Activity, Magma Flux And Hazards At Ruapehu Volcano, Taupo Volcanic Zone, New Zealand Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: 40Ar-39Ar Geochronology Of Magmatic Activity, Magma Flux And Hazards At Ruapehu Volcano, Taupo Volcanic Zone, New Zealand Details Activities (0) Areas (0) Regions (0) Abstract: We have determined precise eruption ages for andesites from Ruapehu volcano in the Tongariro Volcanic Centre of the Taupo Volcanic Zone (TVZ) using 40Ar/39Ar furnace step-heating of separated groundmass concentrates. The plateau ages indicate several eruptive pulses near 200, 134, 45, 22 and <15 ka and, based on our and previous field mapping confirm the lavas of the Te Herenga Formation as the oldest exposed part of the

434

Influence of process on flux pinning for MTG SmBa2Cu3Oy  

Science Journals Connector (OSTI)

Two SmBa2Cu3Oy samples (Sm1 and Sm3) with different processes were fabricated by the melt-textured growth method to study the effect of heat treatment and argon atmosphere on flux pinning. Magnetic measurement shows that Sm1 is of lower transition temperature, lower irreversibility field and more pronounced second peak effect. But Sm3 has higher Tc, higher Hirr and less pronounced SP. It was found that the flux pinning of SM1 is stranger than that of SM3 in wide range of temperature. It evidences that the irreversibility field and critical current density are independent of each other. Discussion of flux pinning and the effect of Ar and 211 is made.

X. Leng; H. Luo; Y. Liu; S.Y. Ding; L. Xiao; H.T. Reng; Y.L. Jiao; M.H. Zheng

2003-01-01T23:59:59.000Z

435

Liquid heat capacity lasers  

DOE Patents [OSTI]

The heat capacity laser concept is extended to systems in which the heat capacity lasing media is a liquid. The laser active liquid is circulated from a reservoir (where the bulk of the media and hence waste heat resides) through a channel so configured for both optical pumping of the media for gain and for light amplification from the resulting gain.

Comaskey, Brian J. (Walnut Creek, CA); Scheibner, Karl F. (Tracy, CA); Ault, Earl R. (Livermore, CA)

2007-05-01T23:59:59.000Z

436

Heat Transfer Guest Editorial  

E-Print Network [OSTI]

Journal of Heat Transfer Guest Editorial We are indeed delighted in bringing out this special issue was showcased in diverse areas such as traditional heat and mass transfer, lab-on-chip, sensors, biomedical applica- tions, micromixers, fuel cells, and microdevices. Selected papers in the field of heat transfer

Kandlikar, Satish

437

Acoustic Heating Peter Ulmschneider  

E-Print Network [OSTI]

Acoustic Heating Peter Ulmschneider lnstitut fiir Theoretische Astrophysik der Universitat waves are a viable and prevalent heating mechanism both in early- and in late-type stars. Acoustic heating appears to be a dominant mechanism for situations where magnetic fields are weak or absent

Ulmschneider, Peter

438

Ammoniated salt heat pump  

SciTech Connect (OSTI)

A thermochemical heat pump/energy storage system using liquid ammoniate salts is described. The system, which can be used for space heating or cooling, provides energy storage for both functions. The bulk of the energy is stored as chemical energy and thus can be stored indefinitely. The system is well suited to use with a solar energy source or industrial waste heat.

Haas, W.R.; Jaeger, F.J.; Giordano, T.J.

1981-01-01T23:59:59.000Z

439

Pioneering Heat Pump Project  

Broader source: Energy.gov [DOE]

Project objectives: To install and monitor an innovative WaterFurnace geothermal system that is technologically advanced and evolving; To generate hot water heating from a heat pump that uses non-ozone depleting refrigerant CO2. To demonstrate the energy efficiency of this system ground source heat pump system.

440

Home Heating | Department of Energy  

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

Home Heating Everything you need to know about home heating, including how heating systems work, the different types on the market and proper maintenance. Read more Thermostats...

Note: This page contains sample records for the topic "latent heat flux" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Water Heating | Department of Energy  

Energy Savers [EERE]

Energy Saver Water Heating Water Heating Infographic: Water Heaters 101 Infographic: Water Heaters 101 Everything you need to know about saving money on water heating costs....

442

New configurations of a heat recovery absorption heat pump integrated with a natural gas boiler for boiler efficiency improvement  

SciTech Connect (OSTI)

Conventional natural gas-fired boilers exhaust flue gas direct to the atmosphere at 150 200 C, which, at such temperatures, contains large amount of energy and results in relatively low thermal efficiency ranging from 70% to 80%. Although condensing boilers for recovering the heat in the flue gas have been developed over the past 40 years, their present market share is still less than 25%. The major reason for this relatively slow acceptance is the limited improvement in the thermal efficiency of condensing boilers. In the condensing boiler, the temperature of the hot water return at the range of 50 60 C, which is used to cool the flue gas, is very close to the dew point of the water vapor in the flue gas. Therefore, the latent heat, the majority of the waste heat in the flue gas, which is contained in the water vapor, cannot be recovered. This paper presents a new approach to improve boiler thermal efficiency by integrating absorption heat pumps with natural gas boilers for waste heat recovery (HRAHP). Three configurations of HRAHPs are introduced and discussed. The three configurations are modeled in detail to illustrate the significant thermal efficiency improvement they attain. Further, for conceptual proof and validation, an existing hot water-driven absorption chiller is operated as a heat pump at operating conditions similar to one of the devised configurations. An overall system performance and economic analysis are provided for decision-making and as evidence of the potential benefits. These three configurations of HRAHP provide a pathway to achieving realistic high-efficiency natural gas boilers for applications with process fluid return temperatures higher than or close to the dew point of the water vapor in the flue gas.

Qu, Ming [Purdue University, West Lafayette, IN; Abdelaziz, Omar [ORNL; Yin, Hongxi [Southeast University, Nanjing, China

2014-01-01T23:59:59.000Z

443

A statistical analysis of avalanching heat transport in stationary enhanced core confinement regimes  

SciTech Connect (OSTI)

We present a statistical analysis of heat transport in stationary enhanced confinement regimes obtained from flux-driven gyrofluid simulations. The probability density functions of heat flux in improved confinement regimes, characterized by the Nusselt number, show significant deviation from Gaussian, with a markedly fat tail, implying the existence of heat avalanches. Two types of avalanching transport are found to be relevant to stationary states, depending on the degree of turbulence suppression. In the weakly suppressed regime, heat avalanches occur in the form of quasi-periodic (QP) heat pulses. Collisional relaxation of zonal flow is likely to be the origin of these QP heat pulses. This phenomenon is similar to transient limit cycle oscillations observed prior to edge pedestal formation in recent experiments. On the other hand, a spectral analysis of heat flux in the strongly suppressed regime shows the emergence of a 1/f (f is the frequency) band, suggesting the presence of self-organized criticality (SOC)-like episodic heat avalanches. This episodic 1/f heat avalanches have a long temporal correlation and constitute the dominant transport process in this regime.

Tokunaga, S.; Jhang, Hogun; Kim, S. S. [WCI Center for Fusion Theory, National Fusion Research Institute, 52, Yeoeun-dong, Yusung-Gu, Daejon (Korea, Republic of); Diamond, P. H. [WCI Center for Fusion Theory, National Fusion Research Institute, 52, Yeoeun-dong, Yusung-Gu, Daejon (Korea, Republic of); Center for Astrophysics and Space Sciences and Department of Physics, University of California San Diego, La Jolla, California 92093-0429 (United States)

2012-09-15T23:59:59.000Z

444

Deriving Daytime Variables From the AmeriFlux Standard Eddy Covariance Data Set  

SciTech Connect (OSTI)

A gap-filled, quality assessed eddy covariance dataset has recently become available for the AmeriFluxnetwork. This dataset uses standard processing and produces commonly used science variables. This shared dataset enables robust comparisons across different analyses. Of course, there are many remaining questions. One of those is how to define 'during the day' which is an important concept for many analyses. Some studies have used local time ?for example 9am to 5pm; others have used thresholds on photosynthetic active radiation (PAR). A related question is how to derive quantities such as the Bowen ratio. Most studies compute the ratio of the averages of the latent heat (LE) and sensible heat (H). In this study, we use different methods of defining 'during the day' for GPP, LE, and H. We evaluate the differences between methods in two ways. First, we look at a number of statistics of GPP. Second, we look at differences in the derived Bowen ratio. Our goal is not science per se, but rather informatics in support of the science.

Ingen, Catharine van; Agarwal, Deborah A; Humphrey, Marty; Li, Jie

2008-12-06T23:59:59.000Z

445

Exergy of boson and fermion fluxes  

Science Journals Connector (OSTI)

Particles with zero and non-zero rest mass are considered in both the classical and ultra-relativistic limits. Relationships that may be used for both fermions and bosons are derived. The exergy flux of free particles involves an efficiency-like factor affecting the energy flux. This factor contains the ambient temperature and the effective particle flux temperature and it is generally different from both the usual Carnot factor and the Petela factor appearing in the exergy of blackbody radiation fluxes, respectively. Some particular cases considered here show that free Fermi particles carry less available work than Bose particles and that the classical approximation yields higher values of the efficiency-like factors than the ultra-relativistic assumption.

Viorel Badescu

2009-01-01T23:59:59.000Z

446

Muon Fluxes From Dark Matter Annihilation  

E-Print Network [OSTI]

We calculate the muon flux from annihilation of the dark matter in the core of the Sun, in the core of the Earth and from cosmic diffuse neutrinos produced in dark matter annihilation in the halos. We consider model-independent direct neutrino production and secondary neutrino production from the decay of taus produced in the annihilation of dark matter. We illustrate how muon energy distribution from dark matter annihilation has a very different shape than muon flux from atmospheric neutrinos. We consider both the upward muon flux, when muons are created in the rock below the detector, and the contained flux when muons are created in the (ice) detector. We contrast our results to the ones previously obtained in the literature, illustrating the importance of properly treating muon propagation and energy loss. We comment on neutrino flavor dependence and their detection.

Arif Emre Erkoca; Mary Hall Reno; Ina Sarcevic

2009-06-23T23:59:59.000Z

447

High-Latitude Ocean and Sea Ice Surface Fluxes: Requirements and Challenges for Climate Mark Bourassa1  

E-Print Network [OSTI]

temperatures, seasonal sea ice, and the remoteness of the regions all conspire to make observations difficult latitudes - the vertical exchanges of heat, momentum and material between the ocean, atmosphere and ice1 High-Latitude Ocean and Sea Ice Surface Fluxes: Requirements and Challenges for Climate Research

Gille, Sarah T.

448

Micromorphic Balances and Source-flux Duality  

SciTech Connect (OSTI)

This is a further note on the (Gauss-Maxwell) force-flux construct proposed previously (Goddard, J. D., A note on Eringen's moment balances, Int. J. Eng. Sci., in the press, 2011). Motivated in part by its promise as a homogenization technique for constructing micromorphic continua, the present work is focused rather on some additional representations and on novel applications, such as the derivation of dissipative thermodynamic potentials from force-flux relations.

Goddard, J. D. [Department of Mechanical and Aerospace Engineering, University of California, San Diego 9500 Gilman Drive, La Jolla, CA 92093-0411 (United States)

2011-11-29T23:59:59.000Z

449

Soft pion emission from fat flux tubes  

SciTech Connect (OSTI)

The emission of pions from multiquark flux tubes is examined as an explanation of the soft pion puzzle. Although the soft pion spectra from the decay of fat flux tubes can account for some low {ital p}{sub {perpendicular}} enhancement, the dependence on the number of involved quarks is too weak to provide a plausible explanation of the observed enhancement in the pion spectrum at low transverse momenta.

Kusnezov, D.; Danielewicz, P. (National Superconducting Cyclotron Laboratory and Department of Physics Astronomy, Michigan State University, East Lansing, Michigan (USA))

1991-08-01T23:59:59.000Z

450

Friction in Mid-latitude Bob Plant, Stephen Belcher, Bob Beare, Andy Brown  

E-Print Network [OSTI]

Friction in Mid-latitude Cyclones Ian Boutle Bob Plant, Stephen Belcher, Bob Beare, Andy Brown #12;Motivation · Many studies have shown the significance of friction in formation and dissipation of cyclones Dt = + � . F . Diabatic Term: · Surface heat fluxes · Latent heat fluxes Frictional Term

Plant, Robert

451

IEEE GEOSCIENCE AND REMOTE SENSING LETTERS, VOL. 4, NO. 4, OCTOBER 2007 649 A Weak-Constraint-Based Data Assimilation Scheme  

E-Print Network [OSTI]

IEEE GEOSCIENCE AND REMOTE SENSING LETTERS, VOL. 4, NO. 4, OCTOBER 2007 649 A Weak and momentum fluxes, especially sensible and latent heat fluxes, between the land surface and the atmospheric way to achieve this goal of mapping fluxes on a regional scale is to use remote sensing techniques

Liang, Shunlin

452

Residential Heating Oil Prices  

Gasoline and Diesel Fuel Update (EIA)

This chart highlights residential heating oil prices for the current and This chart highlights residential heating oil prices for the current and past heating season. As you can see, prices have started the heating season, about 40 to 50 cents per gallon higher than last year at this time. The data presented are from EIA's State Heating Oil and Propane Program. We normally collect and publish this data twice a month, but given the low stocks and high prices, we started tracking the prices weekly. These data will also be used to determine the price trigger mechanism for the Northeast Heating Oil Reserve. The data are published at a State and regional level on our web site. The slide is to give you some perspective of what is happening in these markets, since you probably will get a number of calls from local residents about their heating fuels bills

453

Active microchannel heat exchanger  

DOE Patents [OSTI]

The present invention is an active microchannel heat exchanger with an active heat source and with microchannel architecture. The microchannel heat exchanger has (a) an exothermic reaction chamber; (b) an exhaust chamber; and (c) a heat exchanger chamber in thermal contact with the exhaust chamber, wherein (d) heat from the exothermic reaction chamber is convected by an exothermic reaction exhaust through the exhaust chamber and by conduction through a containment wall to the working fluid in the heat exchanger chamber thereby raising a temperature of the working fluid. The invention is particularly useful as a liquid fuel vaporizer and/or a steam generator for fuel cell power systems, and as a heat source for sustaining endothermic chemical reactions and initiating exothermic reactions.

Tonkovich, Anna Lee Y. (Pasco, WA) [Pasco, WA; Roberts, Gary L. (West Richland, WA) [West Richland, WA; Call, Charles J. (Pasco, WA) [Pasco, WA; Wegeng, Robert S. (Richland, WA) [Richland, WA; Wang, Yong (Richland, WA) [Richland, WA

2001-01-01T23:59:59.000Z

454

Nanofluid heat capacities  

Science Journals Connector (OSTI)

Significant increases in the heat capacity of heat transfer fluids are needed not only to reduce the costs of liquid heating and cooling processes but also to bring clean energy producing technologies like concentrating solar power (CSP) to price parity with conventional energy generation. It has been postulated that nanofluids could have higher heat capacities than conventional fluids. In this work nano- and micron-sized particles were added to five base fluids (poly-? olefin mineral oil ethylene glycol a mixture of water and ethylene glycol and calcium nitrate tetrahydrate) and the resulting heat capacities were measured and compared with those of the neat base fluids and the weighted average of the heat capacities of the components. The particles used were inert metals and metal oxides that did not undergo any phase transitions over the temperature range studied. In the nanofluids studied here we found no increase in heat capacity upon the addition of the particles larger than the experimental error.

Anne K. Starace; Judith C. Gomez; Jun Wang; Sulolit Pradhan; Greg C. Glatzmaier

2011-01-01T23:59:59.000Z

455

A model for improvement of water heating heat exchanger designs for residential heat pump water heaters.  

E-Print Network [OSTI]

??Heat pump water heaters are a promising technology to reduce energy use and greenhouse gas emissions. A key component is the water heating heat exchanger.… (more)

Weerawoot, Arunwattana

2010-01-01T23:59:59.000Z

456

Atopic phenotypes identified with latent class analyses at age 2 years  

Science Journals Connector (OSTI)

Background Atopic sensitization (ie, atopy) is the most commonly reported risk factor for asthma. Recent studies have begun to suggest that atopy, as conventionally defined, might be an umbrella term that obfuscates more specific allergic disease types. Objective We sought to determine whether distinct and meaningful atopic phenotypes exist within a racially diverse birth cohort using 10 allergen-specific serum IgE (sIgE) measurements from children aged 2 years. Methods Using the Wayne County Health, Environment, Allergy and Asthma Longitudinal Study (WHEALS) birth cohort (62% black), we analyzed sIgE data on 10 allergens (Dermatophagoides farinae, dog, cat, timothy grass, ragweed, Alternaria alternata, egg, peanut, milk, and German cockroach) obtained from 594 children at age 2 years. Conventional atopy was defined as at least 1 sIgE level of 0.35 IU/mL or greater. Results A 4-class solution (latent class model) was the best fit. Class types were labeled “low to no sensitization” (76.9% of sample), “highly sensitized” (2.7%), “milk and egg dominated” (15.3%), and “peanut and inhalant(s)” (5.1%). Almost one third (32.2%) of the low to no sensitization group met the criteria for conventional atopy. The highly sensitized group was significantly associated with a doctor's diagnosis of asthma after age 4 years (odds ratio [OR], 5.3; 95% CI, 1.6-17.4), whereas the milk and egg dominated and peanut and inhalant(s) groups were not (ORs of 1.6 [95% CI, 0.8-3.0] and 1.8 [95% CI, 0.6-4.9], respectively). Children of black race were more likely to be in the 3 multisensitized groups (P = .04). Conclusion Classification by sIgE patterns defined groups whose membership is more strongly associated with atopic dermatitis, wheeze, and asthma compared with conventional atopy.

Suzanne Havstad; Christine Cole Johnson; Haejin Kim; Albert M. Levin; Edward M. Zoratti; Christine L.M. Joseph; Dennis R. Ownby; Ganesa Wegienka

2014-01-01T23:59:59.000Z

457

Energy-efficient heat recovery systems for air conditioning of indoor swimming pools  

SciTech Connect (OSTI)

Analysis of a conventional air-conditioning system for indoor swimming pools during the summer season is presented. The analysis showed that the cooling load is characterized by a large latent heat fraction. As a result, a reheating process must be used downstream of the cooling coil to achieve the proper design comfort condition in the pool area. This, in turn, increases the energy requirement per unit cooling load of the pool. Two heat recovery systems are proposed to reduce this energy. In the first system, ambient air is used for the reheating process in an air-to-air heat exchanger. In the second system, mixed air--recirculated and ambient air--is used for the reheating process. Heat recovery efficiency is defined as an index of the energy savings resulting from the use of the heat recovery system compared to that of a conventional air-conditioning system. At a wide range of ambient conditions it is found that the energy savings could be up to 70% of the energy required to operate a conventional air-conditioning system. A parametric study was carried out to size the air-to-air heat exchanger associated with these heat recovery systems, and the results showed that a heat exchanger having an effectiveness of 0.5 would give satisfactory results. The proposed heat recovery systems are also compared to the case of reheating using the heat rejection from the condenser of the refrigeration machine. The comparison showed that the proposed systems save more energy than reheating using the condenser heat. A typical case study is given to demonstrate the savings in energy consumption when these systems are used.

Elsayed, M.M.; El-Refaee, M.M. [Kuwait Univ., Safat (Kuwait). Mechanical Engineering Dept.; Borhan, Y.A. [Gulf Engineering Co., Safat (Kuwait)

1997-12-31T23:59:59.000Z

458

PERFORMANCE OF A STIRLING ENGINE POWERED HEAT ACTIVATED HEAT PUMP  

E-Print Network [OSTI]

PERFORMANCE OF A STIRLING ENGINE POWERED HEAT ACTIVATED HEAT PUMP W. D. C. Richards and W. L. Auxer General Electric Company Space Division King of Prussia, Pa. ABSTRACT A heat activated heat pump (HAHP for space heating since it directly utilizes the engine waste heat in addition to the energy obtained

Oak Ridge National Laboratory

459

Control of Large-Scale Heat Transport by Small-Scale Mixing PAOLA CESSI, W. R. YOUNG, AND JEFF A. POLTON  

E-Print Network [OSTI]

of entropy production, mechanical energy balance, and heat trans- port. The flow is rapidly rotating- ports heat up the gradient of Ts(y); that is, the heat flux ( T, wT) is cooling where Ts(y) is a minimum

Young, William R.

460

CRAD, Fire Protection - Oak Ridge National Laboratory High Flux...  

Broader source: Energy.gov (indexed) [DOE]

Fire Protection - Oak Ridge National Laboratory High Flux Isotope Reactor CRAD, Fire Protection - Oak Ridge National Laboratory High Flux Isotope Reactor February 2006 A section of...

Note: This page contains sample records for the topic "latent heat flux" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

CRAD, Engineering - Oak Ridge National Laboratory High Flux Isotope...  

Broader source: Energy.gov (indexed) [DOE]

Oak Ridge National Laboratory High Flux Isotope Reactor CRAD, Engineering - Oak Ridge National Laboratory High Flux Isotope Reactor February 2007 A section of Appendix C to DOE G...

462

CRAD, Maintenance - Oak Ridge National Laboratory High Flux Isotope...  

Broader source: Energy.gov (indexed) [DOE]

Maintenance - Oak Ridge National Laboratory High Flux Isotope Reactor CRAD, Maintenance - Oak Ridge National Laboratory High Flux Isotope Reactor February 2007 A section of...

463

CRAD, Nuclear Safety - Oak Ridge National Laboratory High Flux...  

Broader source: Energy.gov (indexed) [DOE]

Nuclear Safety - Oak Ridge National Laboratory High Flux Isotope Reactor CRAD, Nuclear Safety - Oak Ridge National Laboratory High Flux Isotope Reactor February 2007 A section of...

464

CRAD, Safety Basis - Oak Ridge National Laboratory High Flux...  

Broader source: Energy.gov (indexed) [DOE]

Oak Ridge National Laboratory High Flux Isotope Reactor Contractor ORR CRAD, Safety Basis - Oak Ridge National Laboratory High Flux Isotope Reactor Contractor ORR February 2007 A...

465

CRAD, Engineering - Oak Ridge National Laboratory High Flux Isotope...  

Broader source: Energy.gov (indexed) [DOE]

Engineering - Oak Ridge National Laboratory High Flux Isotope Reactor Contractor ORR CRAD, Engineering - Oak Ridge National Laboratory High Flux Isotope Reactor Contractor ORR...

466

CRAD, Maintenance - Oak Ridge National Laboratory High Flux Isotope...  

Broader source: Energy.gov (indexed) [DOE]

Maintenance - Oak Ridge National Laboratory High Flux Isotope Reactor Contractor ORR CRAD, Maintenance - Oak Ridge National Laboratory High Flux Isotope Reactor Contractor ORR...

467

CRAD, Management- Oak Ridge National Laboratory High Flux Isotope...  

Broader source: Energy.gov (indexed) [DOE]

Management- Oak Ridge National Laboratory High Flux Isotope Reactor CRAD, Management- Oak Ridge National Laboratory High Flux Isotope Reactor February 2007 A section of Appendix C...

468

John Hsu, Oak Ridge National Laboratory, Flux Coupling Machines...  

Broader source: Energy.gov (indexed) [DOE]

& Publications Integration of Novel Flux Coupling Motor and Current Source Inverter Integration of Novel Flux Coupling Motor and Current Source Inverter Electric Machine R&D...

469

Novel Flux Coupling Machine without Permanent Magnets - U Machine...  

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

Novel Flux Coupling Machine without Permanent Magnets - U Machine Novel Flux Coupling Machine without Permanent Magnets - U Machine 2009 DOE Hydrogen Program and Vehicle...

470

Measurement of advective soil gas flux: Results of field and...  

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

Measurement of advective soil gas flux: Results of field and laboratory experiments with CO2. Measurement of advective soil gas flux: Results of field and laboratory experiments...

471

High Flux Isotope Reactor system RELAP5 input model  

SciTech Connect (OSTI)

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

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

1993-01-01T23:59:59.000Z

472

Heat pump system  

DOE Patents [OSTI]

An air heating and cooling system for a building includes an expansion type refrigeration circuit and a vapor power circuit. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The vapor power circuit includes two heat exchangers, one of which is disposed in series air flow relationship with the indoor refrigeration circuit heat exchanger and the other of which is disposed in series air flow relationship with the outdoor refrigeration circuit heat exchanger. Fans powered by electricity generated by a vapor power circuit alternator circulate indoor air through the two indoor heat exchangers and circulate outside air through the two outdoor heat exchangers. The system is assembled as a single roof top unit, with a vapor power generator and turbine and compressor thermally insulated from the heat exchangers, and with the indoor heat exchangers thermally insulated from the outdoor heat exchangers.

Swenson, Paul F. (Shaker Heights, OH); Moore, Paul B. (Fedhaven, FL)

1983-01-01T23:59:59.000Z

473

Radiative Heating of the ISCCP Upper Level Cloud Regimes and its Impact on the Large-scale Tropical Circulation  

SciTech Connect (OSTI)

Radiative heating profiles of the International Satellite Cloud Climatology Project (ISCCP) cloud regimes (or weather states) were estimated by matching ISCCP observations with radiative properties derived from cloud radar and lidar measurements from the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) sites at Manus, Papua New Guinea, and Darwin, Australia. Focus was placed on the ISCCP cloud regimes containing the majority of upper level clouds in the tropics, i.e., mesoscale convective systems (MCSs), deep cumulonimbus with cirrus, mixed shallow and deep convection, and thin cirrus. At upper levels, these regimes have average maximum cloud occurrences ranging from 30% to 55% near 12 km with variations depending on the location and cloud regime. The resulting radiative heating profiles have maxima of approximately 1 K/day near 12 km, with equal heating contributions from the longwave and shortwave components. Upper level minima occur near 15 km, with the MCS regime showing the strongest cooling of 0.2 K/day and the thin cirrus showing no cooling. The gradient of upper level heating ranges from 0.2 to 0.4 K/(day?km), with the most convectively active regimes (i.e., MCSs and deep cumulonimbus with cirrus) having the largest gradient. When the above heating profiles were applied to the 25-year ISCCP data set, the tropics-wide average profile has a radiative heating maximum of 0.45Kday-1 near 250 hPa. Column-integrated radiative heating of upper level cloud accounts for about 20% of the latent heating estimated by the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR). The ISCCP radiative heating of tropical upper level cloud only slightly modifies the response of an idealized primitive equation model forced with the tropics-wide TRMM PR latent heating, which suggests that the impact of upper level cloud is more important to large-scale tropical circulation variations because of convective feedbacks rather than direct forcing by the cloud radiative heating profiles. However, the height of the radiative heating maxima and gradient of the heating profiles are important to determine the sign and patterns of the horizontal circulation anomaly driven by radiative heating at upper levels.

Li, Wei; Schumacher, Courtney; McFarlane, Sally A.

2013-01-31T23:59:59.000Z

474

Policies supporting Heat Pump Technologies  

E-Print Network [OSTI]

Policies supporting Heat Pump Technologies in Canada IEA Heat Pump Workshop London, UK November 13 in the world, with an average of 16,995 kilowatt-hours per annum. #12;Canada's Context for Heat Pumps Impacts avenues: Ground source heat pumps for cold climates (heating and cooling) Reversible air source heat

Oak Ridge National Laboratory

475

Fluidized bed heat treating system  

DOE Patents [OSTI]

Systems for heat treating materials are presented. The systems typically involve a fluidized bed that contains granulated heat treating material. In some embodiments a fluid, such as an inert gas, is flowed through the granulated heat treating medium, which homogenizes the temperature of the heat treating medium. In some embodiments the fluid may be heated in a heating vessel and flowed into the process chamber where the fluid is then flowed through the granulated heat treating medium. In some embodiments the heat treating material may be liquid or granulated heat treating material and the heat treating material may be circulated through a heating vessel into a process chamber where the heat treating material contacts the material to be heat treated. Microwave energy may be used to provide the source of heat for heat treating systems.

Ripley, Edward B; Pfennigwerth, Glenn L

2014-05-06T23:59:59.000Z

476

Flameless heat generator  

SciTech Connect (OSTI)

A heating device generates heat by working a liquid in a closed container with a rotating stack of finely perforate square plates and recovering the heat from the thus heated liquid. In one embodiment a stack of a multiplicity of flat square plates radially offset one from another is rotated in an oil bath in a container under an inner perforate non-rotating cover over which is a similar non-rotating cover that is imperforate. The thermal energy developed through the mechanical working of the liquid is transferred to the main liquid bath and is then removed, as for example, by circulating air or a liquid around the outside of the container with the thus heated air or liquid being used to heat a house or the like.

Leary, C. L.; Leary, G. C.

1983-12-13T23:59:59.000Z

477

Process for heating coal-oil slurries  

DOE Patents [OSTI]

Controlling gas to slurry volume ratio to achieve a gas holdup of about 0.4 when heating a flowing coal-oil slurry and a hydrogen containing gas stream allows operation with virtually any coal to solvent ratio and permits operation with efficient heat transfer and satisfactory pressure drops. The critical minimum gas flow rate for any given coal-oil slurry will depend on numerous factors such as coal concentration, coal particle size distribution, composition of the solvent (including recycle slurries), and type of coal. Further system efficiency can be achieved by operating with multiple heating zones to provide a high heat flux when the apparent viscosity of the gas saturated slurry is highest. Operation with gas flow rates below the critical minimum results in system instability indicated by temperature excursions in the fluid and at the tube wall, by a rapid increase and then decrease in overall pressure drop with decreasing gas flow rate, and by increased temperature differences between the temperature of the bulk fluid and the tube wall. At the temperatures and pressures used in coal liquefaction preheaters the coal-oil slurry and hydrogen containing gas stream behaves essentially as a Newtonian fluid at shear rates in excess of 150 sec[sup [minus]1]. The gas to slurry volume ratio should also be controlled to assure that the flow regime does not shift from homogeneous flow to non-homogeneous flow. Stable operations have been observed with a maximum gas holdup as high as 0.72. 29 figs.

Braunlin, W.A.; Gorski, A.; Jaehnig, L.J.; Moskal, C.J.; Naylor, J.D.; Parimi, K.; Ward, J.V.

1984-01-03T23:59:59.000Z

478

Process for heating coal-oil slurries  

DOE Patents [OSTI]

Controlling gas to slurry volume ratio to achieve a gas holdup of about 0.4 when heating a flowing coal-oil slurry and a hydrogen containing gas stream allows operation with virtually any coal to solvent ratio and permits operation with efficient heat transfer and satisfactory pressure drops. The critical minimum gas flow rate for any given coal-oil slurry will depend on numerous factors such as coal concentration, coal particle size distribution, composition of the solvent (including recycle slurries), and type of coal. Further system efficiency can be achieved by operating with multiple heating zones to provide a high heat flux when the apparent viscosity of the gas saturated slurry is highest. Operation with gas flow rates below the critical minimum results in system instability indicated by temperature excursions in the fluid and at the tube wall, by a rapid increase and then decrease in overall pressure drop with decreasing gas flow rate, and by increased temperature differences between the temperature of the bulk fluid and the tube wall. At the temperatures and pressures used in coal liquefaction preheaters the coal-oil slurry and hydrogen containing gas stream behaves essentially as a Newtonian fluid at shear rates in excess of 150 sec.sup. -1. The gas to slurry volume ratio should also be controlled to assure that the flow regime does not shift from homogeneous flow to non-homogeneous flow. Stable operations have been observed with a maximum gas holdup as high as 0.72.

Braunlin, Walter A. (Spring, TX); Gorski, Alan (Lovington, NM); Jaehnig, Leo J. (New Orleans, LA); Moskal, Clifford J. (Oklahoma City, OK); Naylor, Joseph D. (Houston, TX); Parimi, Krishnia (Allison Park, PA); Ward, John V. (Arvada, CO)

1984-01-03T23:59:59.000Z

479

Mechanical Compression Heat Pumps  

E-Print Network [OSTI]

MECHANICAL COMPRESSION HEAT PUMPS Thomas-L. Apaloo and K. Kawamura Mycom Corporation, Los Angeles, California J. Matsuda, Mayekawa Mfg. Co., Tokyo, Japan ABSTRACT Mechanical compression heat pumping is not new in industrial applications.... In fact, industry history suggests that the theoretical concept was developed before 1825. Heat pump manufacturers gained the support of consultants and end-users when the energy crisis hit this country in 1973. That interest, today, has been...

Apaloo, T. L.; Kawamura, K.; Matsuda, J.

480

Sorption heat engines  

E-Print Network [OSTI]

For a simple free energy generating device - driven by thermal cycling and based on alternating adsorption and desorption - that has not been explicitly recognized as heat engine the name sorption heat engine is proposed. The mechanism is generally applicable to the fields of physics, chemistry, geology, and possibly, if relevant to the origin of life, biology. Four kinds of sorption heat engines are distinguished depending on the occurrence of changes in composition of the adsorbent or adsorbate during the thermal cycle.

Muller, A W J; Muller, Anthonie W. J.; Schulze-Makuch, Dirk

2005-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "latent heat flux" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

Product Volatilization as a Probe of the Physics and Chemistry of Latent Image Formation in Chemically Amplified Resists,  

Science Journals Connector (OSTI)

Product Volatilization as a Probe of the Physics and Chemistry of Latent Image Formation in Chemically Amplified Resists†,‡ ... The products pass through an all-glass line that uses a high-flow gas stream to extract a small fraction of the product gases through a capillary for analysis. ... Because the rates of each of the sequential steps leading to thickness lossdeprotection, volatilization, and densificationcan be no slower than the overall observed rate of densification, the data in Table 3 provide a lower limit for the rates of volatilization and film densification at 100 °C. ...

W. D. Hinsberg; F. A. Houle; G. M. Poliskie; D. Pearson; M. I. Sanchez; H. Ito

2002-08-15T23:59:59.000Z

482

Combined Heat and Power  

Office of Environmental Management (EM)

energy costs and 31 emissions while also providing more resilient and reliable electric power and thermal energy 1 . CHP 32 systems combine the production of heat (for both...

483

Waste Heat Recovery  

Office of Environmental Management (EM)

DRAFT - PRE-DECISIONAL - DRAFT 1 Waste Heat Recovery 1 Technology Assessment 2 Contents 3 1. Introduction to the TechnologySystem ......

484

Solar Heating in Uppsala.  

E-Print Network [OSTI]

?? The housing corporation Uppsalahem has installed asolar heating system in the neighbourhood Haubitsen,which was renovated in 2011. This report examineshow much energy the solar… (more)

Blomqvist, Emelie; Häger, Klara

2012-01-01T23:59:59.000Z

485

HEATS: Thermal Energy Storage  

SciTech Connect (OSTI)

HEATS Project: The 15 projects that make up ARPA-E’s HEATS program, short for “High Energy Advanced Thermal Storage,” seek to develop revolutionary, cost-effective ways to store thermal energy. HEATS focuses on 3 specific areas: 1) developing high-temperature solar thermal energy storage capable of cost-effectively delivering electricity around the clock and thermal energy storage for nuclear power plants capable of cost-effectively meeting peak demand, 2) creating synthetic fuel efficiently from sunlight by converting sunlight into heat, and 3) using thermal energy storage to improve the driving range of electric vehicles (EVs) and also enable thermal management of internal combustion engine vehicles.

None

2012-01-01T23:59:59.000Z

486

Solar heating in Colombia.  

E-Print Network [OSTI]

?? This report describes the process of a thesis implemented in Colombia concerning solar energy. The project was to install a self-circulating solar heating system,… (more)

Skytt, Johanna

2012-01-01T23:59:59.000Z

487

Passive solar space heating  

SciTech Connect (OSTI)

An overview of passive solar space heating is presented indicating trends in design, new developments, performance measures, analytical design aids, and monitored building results.

Balcomb, J.D.

1980-01-01T23:59:59.000Z

488

Combined Heat & Power  

Broader source: Energy.gov (indexed) [DOE]

available today." -American Council for an Energy-Efficient Economy What is Combined Heat & Power (CHP)? Federal Utility Partnership Working Group May 7 - 8, 2014 Virginia...

489

Heat rejection system  

DOE Patents [OSTI]

A cooling system for rejecting waste heat consists of a cooling tower incorporating a plurality of coolant tubes provided with cooling fins and each having a plurality of cooling channels therein, means for directing a heat exchange fluid from the power plant through less than the total number of cooling channels to cool the heat exchange fluid under normal ambient temperature conditions, means for directing water through the remaining cooling channels whenever the ambient temperature rises above the temperature at which dry cooling of the heat exchange fluid is sufficient and means for cooling the water.

Smith, Gregory C. (Richland, WA); Tokarz, Richard D. (Richland, WA); Parry, Jr., Harvey L. (Richland, WA); Braun, Daniel J. (Richland, WA)

1980-01-01T23:59:59.000Z

490

Heat transfer dynamics  

SciTech Connect (OSTI)

As heat transfer technology increases in complexity, it becomes more difficult for those without thermal dynamics engineering training to choose between competitive heat transfer systems offered to meet their drying requirements. A step back to the basics of heat transfer can help professional managers and papermakers make informed decisions on alternative equipment and methods. The primary forms of heat and mass transfer are reviewed with emphasis on the basics, so a practical understanding of each is gained. Finally, the principles and benefits of generating infrared energy by combusting a gaseous hydrocarbon fuel are explained.

Smith, T.M. (Marsden, Inc., Pennsauken, NJ (United States))

1994-08-01T23:59:59.000Z

491

ARM - Atmospheric Heat Budget  

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

ListAtmospheric Heat Budget Outreach Home Room News Publications Traditional Knowledge Kiosks Barrow, Alaska Tropical Western Pacific Site Tours Contacts Students Study Hall About...

492

Color Magnetic Flux Tubes in Dense QCD  

E-Print Network [OSTI]

QCD is expected to be in the color-flavor locking phase in high baryon density, which exhibits color superconductivity. The most fundamental topological objects in the color superconductor are non-Abelian vortices which are topologically stable color magnetic flux tubes. We present numerical solutions of the color magnetic flux tube for diverse choices of the coupling constants. We also analytically study its asymptotic profiles and find that they are different from the case of usual superconductors. We propose the width of color magnetic fluxes and find that it is larger than naive expectation of the Compton wave length of the massive gluon when the gluon mass is larger than the scalar mass.

Minoru Eto; Muneto Nitta

2009-07-07T23:59:59.000Z

493

Color magnetic flux tubes in dense QCD  

SciTech Connect (OSTI)

QCD is expected to be in the color-flavor locking phase in high baryon density, which exhibits color superconductivity. The most fundamental topological objects in the color superconductor are non-Abelian vortices which are topologically stable color magnetic flux tubes. We present numerical solutions of the color magnetic flux tube for diverse choices of the coupling constants based on the Ginzburg-Landau Lagrangian. We also analytically study its asymptotic profiles and find that they are different from the case of usual superconductors. We propose the width of color magnetic fluxes and find that it is larger than naive expectation of the Compton wavelength of the massive gluon when the gluon mass is larger than the scalar mass.

Eto, Minoru [Theoretical Physics Laboratory, RIKEN, Saitama 351-0198 (Japan); Nitta, Muneto [Department of Physics, and Research and Education Center for Natural Sciences, Keio University, 4-1-1 Hiyoshi, Yokohama, Kanagawa 223-8521 (Japan)

2009-12-15T23:59:59.000Z

494

Spatially resolved temperature and heat flux measurements for slow evaporating droplets heated by a microfabricated heater array  

E-Print Network [OSTI]

The evaporation phenomenon of a liquid droplet was investigated by using microfabricated heaters. All 32 microheaters were designed to have the same resistance. Gold microheaters worked both as temperature indicators and as heaters. The first...

Paik, Sokwon

2006-08-16T23:59:59.000Z