Powered by Deep Web Technologies
Note: This page contains sample records for the topic "radiation transfer models" 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

Improvements to the SHDOM Radiative Transfer Modeling Package  

NLE Websites -- All DOE Office Websites (Extended Search)

to the SHDOM Radiative Transfer Modeling Package K. F. Evans University of Colorado Boulder, Colorado W. J. Wiscombe National Aeronautics and Space Administration...

2

Cross Validation of Satellite Radiation Transfer Models during SWERA  

Open Energy Info (EERE)

Cross Validation of Satellite Radiation Transfer Models during SWERA Cross Validation of Satellite Radiation Transfer Models during SWERA Project in Brazil Dataset Summary Description (Abstract): This work describes the cross validation between two different core radiation transfer models that will be applied during the SWERA (Solar and Wind Energy Assessment): the BRAZIL-SR, and the SUNY-Albany. The model cross validation was performed by using two reference sites in Brazil: at Caicó (06°28'01"S - 037°05'05"W,175.8 m), and Florianópolis (27°34'18"S - 048°31'42"W, 10 m), Satellite data were collected by INPE-CPTEC for GOES-8, that also provides for its quality assessment, sectoring, storing and distribution to the participating teams. In this work we show the first results of this cross-validation along with some discussions on model deviations

3

Modelling of Radiative Transfer in Light Sources  

E-Print Network (OSTI)

. . . . . . . . . . . . . . . 30 2.5.3 Temperature distribution . . . . . . . . . . . . . . . . . . . . . . . . . 32 2-X radiative transition that is responsible for the sulfur lamp's bright sun-like spectrum #12;Contents 1

Eindhoven, Technische Universiteit

4

Multi-model Preconditioning for Radiative Transfer Problems  

E-Print Network (OSTI)

, multigrid, radiative transfer, neutron transport, linear Boltzmann equation 2000 MSC: 65N22, 85A25, 65N30 1 and radiation dominated regions must be combined. Since the character of the equation is very different in those of the monochromatic radiative transfer problem leads to a diffusion equation, approximating the radiative transfer

5

3D Atmospheric Radiative Transfer for Cloud System-Resolving Models: Forward Modelling and Observations  

SciTech Connect

Utilization of cloud-resolving models and multi-dimensional radiative transfer models to investigate the importance of 3D radiation effects on the numerical simulation of cloud fields and their properties.

Howard Barker; Jason Cole

2012-05-17T23:59:59.000Z

6

CROSS VALIDATION OF SATELLITE RADIATION TRANSFER MODELS DURING SWERA PROJECT  

Open Energy Info (EERE)

ISES- 2003 ISES- 2003 CROSS VALIDATION OF SATELLITE RADIATION TRANSFER MODELS DURING SWERA PROJECT IN BRAZIL Enio B. Pereira, Fernando R. Martins 1 Brazilian Institute for Space Research - INPE, São José dos Campos, 12245-970, SP, Brazil Phone + 55 12 39456741, Fax + 55 12 39456810, enio@dge.inpe.br Samuel L. Abreu, Hans Georg Beyer, Sergio Colle, and Solar Energy Laboratory - LABSOLAR - Department of Mechanical Engineering, Federal University of Santa Catarina -UFSC, Florianopolis, 88040-900, (SC), Brazil, Richard Perez The University at Albany (SUNY), ASRC-CESTM, Albany, 12203 (NY), USA Abstract - This work describes the cross validation between two different core radiation transfer models that will be applied during the SWERA (Solar and Wind Energy Assessment): the BRAZIL-SR, and the

7

A dynamic multi-scale model for transient radiative transfer calculations  

E-Print Network (OSTI)

on the radiative transfer equation (RTE) or the diffusion equation (DE). The RTE is a kinetic transport equation-scale model which couples the transient radiative transfer equation (RTE) and the diffusion equation (DE: transient radiative transfer, multi-scale model, finite volume method, diffusion equation, domain

Boyer, Edmond

8

Satellite Data Assimilation in Numerical Weather Prediction Models. Part I: Forward Radiative Transfer and Jacobian Modeling in Cloudy Atmospheres  

Science Journals Connector (OSTI)

Satellite data assimilation requires rapid and accurate radiative transfer and radiance gradient models. For a vertically stratified scattering and emitting atmosphere, the vector discrete-ordinate radiative transfer model (VDISORT) was developed ...

Fuzhong Weng; Quanhua Liu

2003-11-01T23:59:59.000Z

9

Cloudy Sky RRTM Shortwave Radiative Transfer and Comparison to the Revised ECMWF Shortwave Model  

NLE Websites -- All DOE Office Websites (Extended Search)

Cloudy Sky RRTM Shortwave Radiative Transfer and Cloudy Sky RRTM Shortwave Radiative Transfer and Comparison to the Revised ECMWF Shortwave Model M. J. Iacono, J. S. Delamere, E. J. Mlawer, and S. A. Clough Atmospheric and Environmental Research, Inc. Lexington, Massachusetts J.-J. Morcrette European Centre for Medium-Range Weather Forecasts Reading, United Kingdom Introduction An important step toward improving radiative transfer codes in general circulation models (GCMs) is their thorough evaluation by comparison to measurements directly, or to other data-validated radiation models. This work extends the clear-sky shortwave (SW) GCM evaluation presented by Iacono et al. (2001) to computations including clouds. The rapid radiative transfer model (RRTM) SW radiation model accurately reproduces clear-sky direct beam fluxes from the Line-By-Line Radiative Transfer

10

Validation of the Poisson Stochastic Radiative Transfer Model Against Cloud Cascade Models  

NLE Websites -- All DOE Office Websites (Extended Search)

Poisson Stochastic Radiative Transfer Poisson Stochastic Radiative Transfer Model Against Cloud Cascade Models T. B. Zhuravleva Institute of Atmospheric Optics Tomsk, Russia A. Marshak National Aeronautics and Space Administration Goddard Space Flight Center Greenbelt, Maryland Background Starting from a very simple stochastic cloud model by Mullamaa et al. (1972), several different stochastic models have been developed to describe radiative transfer regime in single-layer broken clouds (Kargin 1984; Titov 1990; Malvagi and Pomraning 1992; Barker et al. 1992; Malvagi et al. 1993; Kargin and Prigarin 1994; Prigarin and Titov 1996; Marshak et al. 1998; Prigarin et al. 1998, 2001; Evans et al. 1999, 2001). Recently Kassianov (2003a) generalized the Titov's (1990) stochastic model

11

Retrieving leaf area index using a genetic algorithm with a canopy radiative transfer model  

E-Print Network (OSTI)

Retrieving leaf area index using a genetic algorithm with a canopy radiative transfer model quantities driving the algorithms used in regional and global biogeochemical, ecological and meteorological) and the inversion of a canopy radiative transfer (RT) model. In recent years, applications of the genetic algorithms

Liang, Shunlin

12

An Update on Radiative Transfer Model Development at Atmospheric and Environmental Research, Inc.  

NLE Websites -- All DOE Office Websites (Extended Search)

Update on Radiative Transfer Model Development at Update on Radiative Transfer Model Development at Atmospheric and Environmental Research, Inc. J. S. Delamere, S. A. Clough, E. J. Mlawer, Sid-Ahmed Boukabara, K. Cady-Pereira, and M. Shepard Atmospheric and Environmental Research, Inc. Lexington, Maine Introduction Over the last decade, a suite of radiative transfer models has been developed at Atmospheric and Environmental Research, Inc. (AER) with support from the Atmospheric and Radiation Measurement (ARM) Program. These models span the full spectral regime from the microwave to the ultraviolet, and range from monochromatic to band calculations. Each model combines the latest spectroscopic advancements with radiative transfer algorithms to efficiently compute radiances, fluxes, and cooling

13

Change in regime and transfer function models of global solar radiation in Kuwait  

Science Journals Connector (OSTI)

The development of the models for global solar radiation in Kuwait is based on removing the annual periodicity and seasonal variation. The first methodology used here is the change in regime technique that relies on dividing the observations into two ... Keywords: ARMA model, Harmonic analysis, Solar radiation, Transfer function

S. A. Al-Awadhi

2005-09-01T23:59:59.000Z

14

Cross-Validation of SWERA's Core Radiative Transfer Models - Partial Report  

Open Energy Info (EERE)

Cross-Validation of SWERA's Core Radiative Transfer Models - Partial Report Cross-Validation of SWERA's Core Radiative Transfer Models - Partial Report Dataset Summary Description (Abstract): This partial report describes the results obtained by two of the core radiative transfer models adopted in the SWERA Project for global horizontal solar irradiation during the cross-validation step. They are BRASIL-SR and SUNY-ALBANY models (Martins, 2001; Stuhlmann et al. 1990; Perez et al., 2002). The results from other two other core models, NREL and DLR, are not yet available. The HELIOSAT was included as a reference model at this stage. The HELIOSAT model is widely employed for solar energy assessment in Europe and is well know by the solar energy community worldwide (Beyer et al., 1996; Cano et al., 1986). (Purpose): SWERA solar cross-validation study

15

Development and Evaluation of RRTMG_SW, a Shortwave Radiative Transfer Model for GCM Applications  

NLE Websites -- All DOE Office Websites (Extended Search)

Development and Evaluation of RRTMG_SW, Development and Evaluation of RRTMG_SW, a Shortwave Radiative Transfer Model for General Circulation Model Applications M. J. Iacono, J. S. Delamere, E. J. Mlawer, and S. A. Clough Atmospheric and Environmental Research, Inc. Lexington, Massachusetts J.-J. Morcrette European Center for Medium-Range Weather Forecasts Reading, United Kingdom Y.-T. Hou National Centers for Environmental Prediction Camp Springs, Maryland Introduction The k-distribution shortwave radiation model developed for the Atmospheric Radiation Measurement (ARM) Program, RRTM_SW_V2.4 (Clough et al. 2004), utilizes the discrete ordinates radiative transfer model, DISORT, for scattering calculations and 16 g-points in each of its 16 spectral bands. DISORT provides agreement with line-by-line flux calculations to within 1 Wm

16

Data-driven modelling of shortwave radiation transfer to snow through boreal birch and conifer canopies  

E-Print Network (OSTI)

, Sweden, in spring 2011 and mixed conifer forest near Sodankylä, Finland, in spring 2012. Above models predict canopy shortwave transmission similarly well for leafless birch forest, but for conifersData-driven modelling of shortwave radiation transfer to snow through boreal birch and conifer

17

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

SciTech Connect

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

18

A parametric study of shock jump chemistry, electron temperature, and radiative heat transfer models in hypersonic flows  

E-Print Network (OSTI)

A PARAMETRIC STUDY OF SHOCK JUMP CHEMISTRY, ELECTRON TEMPERATURE, AND RADIATIVE HEAT TRANSFER MODELS IN HYPERSONIC FLOWS A Thesis by ROBERT BRIAN GREENDYKE Submitted to the Graduate College of Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE August 1988 Major Subject: Aerospace Engineering A PARAMETRIC STUDY OF SHOCK JUMP CHEMISTRY, ELECTRON TEMPERATURE, AND RADIATIVE HEAT TRANSFER MODELS IN HYPERSONIC FLOWS A Thesis by ROBERT BRIAN...

Greendyke, Robert Brian

2012-06-07T23:59:59.000Z

19

Development of a GPU-based high-performance radiative transfer model for the Infrared Atmospheric Sounding Interferometer (IASI)  

SciTech Connect

Satellite-observed radiance is a nonlinear functional of surface properties and atmospheric temperature and absorbing gas profiles as described by the radiative transfer equation (RTE). In the era of hyperspectral sounders with thousands of high-resolution channels, the computation of the radiative transfer model becomes more time-consuming. The radiative transfer model performance in operational numerical weather prediction systems still limits the number of channels we can use in hyperspectral sounders to only a few hundreds. To take the full advantage of such high-resolution infrared observations, a computationally efficient radiative transfer model is needed to facilitate satellite data assimilation. In recent years the programmable commodity graphics processing unit (GPU) has evolved into a highly parallel, multi-threaded, many-core processor with tremendous computational speed and very high memory bandwidth. The radiative transfer model is very suitable for the GPU implementation to take advantage of the hardware's efficiency and parallelism where radiances of many channels can be calculated in parallel in GPUs. In this paper, we develop a GPU-based high-performance radiative transfer model for the Infrared Atmospheric Sounding Interferometer (IASI) launched in 2006 onboard the first European meteorological polar-orbiting satellites, METOP-A. Each IASI spectrum has 8461 spectral channels. The IASI radiative transfer model consists of three modules. The first module for computing the regression predictors takes less than 0.004% of CPU time, while the second module for transmittance computation and the third module for radiance computation take approximately 92.5% and 7.5%, respectively. Our GPU-based IASI radiative transfer model is developed to run on a low-cost personal supercomputer with four GPUs with total 960 compute cores, delivering near 4 TFlops theoretical peak performance. By massively parallelizing the second and third modules, we reached 364x speedup for 1 GPU and 1455x speedup for all 4 GPUs, both with respect to the original CPU-based single-threaded Fortran code with the -O{sub 2} compiling optimization. The significant 1455x speedup using a computer with four GPUs means that the proposed GPU-based high-performance forward model is able to compute one day's amount of 1,296,000 IASI spectra within nearly 10 min, whereas the original single CPU-based version will impractically take more than 10 days. This model runs over 80% of the theoretical memory bandwidth with asynchronous data transfer. A novel CPU-GPU pipeline implementation of the IASI radiative transfer model is proposed. The GPU-based high-performance IASI radiative transfer model is suitable for the assimilation of the IASI radiance observations into the operational numerical weather forecast model.

Huang Bormin, E-mail: bormin@ssec.wisc.ed [Space Science and Engineering Center, University of Wisconsin, Madison (United States); Mielikainen, Jarno [Department of Computer Science, University of Eastern Finland, Kuopio (Finland); Oh, Hyunjong; Allen Huang, Hung-Lung [Space Science and Engineering Center, University of Wisconsin, Madison (United States)

2011-03-20T23:59:59.000Z

20

Hyperspectral Aquatic Radiative Transfer Modeling Using a High-Performance Cluster Computing-Based Approach  

SciTech Connect

Abstract For aquatic studies, radiative transfer (RT) modeling can be used to compute hyperspectral above-surface remote sensing reflectance that can be utilized for inverse model development. Inverse models can provide bathymetry and inherent-and bottom-optical property estimation. Because measured oceanic field/organic datasets are often spatio-temporally sparse, synthetic data generation is useful in yielding sufficiently large datasets for inversion model development; however, these forward-modeled data are computationally expensive and time-consuming to generate. This study establishes the magnitude of wall-clock-time savings achieved for performing large, aquatic RT batch-runs using parallel computing versus a sequential approach. Given 2,600 simulations and identical compute-node characteristics, sequential architecture required ~100 hours until termination, whereas a parallel approach required only ~2.5 hours (42 compute nodes) a 40x speed-up. Tools developed for this parallel execution are discussed.

Filippi, Anthony M [ORNL; Bhaduri, Budhendra L [ORNL; Naughton, III, Thomas J [ORNL; King, Amy L [ORNL; Scott, Stephen L [ORNL; Guneralp, Inci [Texas A& M University

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "radiation transfer models" 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

Hyperspectral Aquatic Radiative Transfer Modeling Using a High-Performance Cluster Computing Based Approach  

SciTech Connect

For aquatic studies, radiative transfer (RT) modeling can be used to compute hyperspectral above-surface remote sensing reflectance that can be utilized for inverse model development. Inverse models can provide bathymetry and inherent- and bottom-optical property estimation. Because measured oceanic field/organic datasets are often spatio-temporally sparse, synthetic data generation is useful in yielding sufficiently large datasets for inversion model development; however, these forward-modeled data are computationally expensive and time-consuming to generate. This study establishes the magnitude of wall-clock-time savings achieved for performing large, aquatic RT batch-runs using parallel computing versus a sequential approach. Given 2,600 simulations and identical compute-node characteristics, sequential architecture required {approx}100 hours until termination, whereas a parallel approach required only {approx}2.5 hours (42 compute nodes) - a 40x speed-up. Tools developed for this parallel execution are discussed.

Fillippi, Anthony [Texas A& M University; Bhaduri, Budhendra L [ORNL; Naughton, III, Thomas J [ORNL; King, Amy L [ORNL; Scott, Stephen L [ORNL; Guneralp, Inci [Texas A& M University

2012-01-01T23:59:59.000Z

22

Computation of Domain-Averaged Irradiance with a Simple Two-Stream Radiative Transfer Model Including Vertical Cloud Property Correlations  

NLE Websites -- All DOE Office Websites (Extended Search)

Computation of Domain-Averaged Irradiance Computation of Domain-Averaged Irradiance with a Simple Two-Stream Radiative Transfer Model Including Vertical Cloud Property Correlations S. Kato Center for Atmospheric Sciences Hampton University Hampton, Virginia Introduction Recent development of remote sensing instruments by Atmospheric Radiation Measurement (ARM?) Program provides information of spatial and temporal variability of cloud structures. However it is not clear what cloud properties are required to express complicated cloud fields in a realistic way and how to use them in a relatively simple one-dimensional (1D) radiative transfer model to compute the domain averaged irradiance. To address this issue, a simple shortwave radiative transfer model that can treat the vertical cloud optical property correlation is developed. The model is based on the gamma-weighted

23

RADIATIVE TRANSFER IN ULTRARELATIVISTIC OUTFLOWS  

SciTech Connect

Analytical and numerical solutions are obtained for the equation of radiative transfer in ultrarelativistic opaque jets. The solution describes the initial trapping of radiation, its adiabatic cooling, and the transition to transparency. Two opposite regimes are examined. (1) Matter-dominated outflow. Surprisingly, radiation develops enormous anisotropy in the fluid frame before decoupling from the fluid. The radiation is strongly polarized. (2) Radiation-dominated outflow. The transfer occurs as if radiation propagated in vacuum, preserving the angular distribution and the blackbody shape of the spectrum. The escaping radiation has a blackbody spectrum if (and only if) the outflow energy is dominated by radiation up to the photospheric radius.

Beloborodov, Andrei M., E-mail: amb@phys.columbia.edu [Physics Department and Columbia Astrophysics Laboratory, Columbia University, 538 West 120th Street New York, NY 10027 (United States)

2011-08-20T23:59:59.000Z

24

3D Hydrodynamic & Radiative Transfer Models of X-ray Emission from Colliding Wind Binaries  

E-Print Network (OSTI)

Colliding wind binaries (CWBs) are unique laboratories for X-ray astrophysics. The massive stars in these systems possess powerful stellar winds with speeds up to $\\sim$3000 km s$^{-1}$, and their collision leads to hot plasma (up to $\\sim10^8$K) that emit thermal X-rays (up to $\\sim$10 keV). Many X-ray telescopes have observed CWBs, including Suzaku, and our work aims to model these X-ray observations. We use 3D smoothed particle hydrodynamics (SPH) to model the wind-wind interaction, and then perform 3D radiative transfer to compute the emergent X-ray flux, which is folded through X-ray telescopes' response functions to compare directly with observations. In these proceedings, we present our models of Suzaku observations of the multi-year-period, highly eccentric systems $\\eta$ Carinae and WR 140. The models reproduce the observations well away from periastron passage, but only $\\eta$ Carinae's X-ray spectrum is reproduced at periastron; the WR 140 model produces too much flux during this more complicated p...

Russell, Christopher M P; Owocki, Stanley P; Corcoran, Michael F; Hamaguchi, Kenji; Sugawara, Yasuharu

2014-01-01T23:59:59.000Z

25

RADIATIVE HEAT TRANSFER WITH QUASI-MONTE CARLO METHODS  

E-Print Network (OSTI)

RADIATIVE HEAT TRANSFER WITH QUASI-MONTE CARLO METHODS A. Kersch1 W. Moroko2 A. Schuster1 1Siemens of Quasi-Monte Carlo to this problem. 1.1 Radiative Heat Transfer Reactors In the manufacturing of the problems which can be solved by such a simulation is high accuracy modeling of the radiative heat transfer

26

RADIATIVE HEAT TRANSFER WITH QUASIMONTE CARLO METHODS \\Lambda  

E-Print Network (OSTI)

RADIATIVE HEAT TRANSFER WITH QUASI­MONTE CARLO METHODS \\Lambda A. Kersch 1 W. Morokoff 2 A accuracy modeling of the radiative heat transfer from the heater to the wafer. Figure 1 shows the draft Carlo simulation is often used to solve radiative transfer problems where complex physical phenomena

27

Journal of Quantitative Spectroscopy & Radiative Transfer 72 (2002) 691713  

E-Print Network (OSTI)

: Equation of radiative transfer; Transport theory; Photon propagation; Scattering media; Discrete.elsevier.com/locate/jqsrt Optical tomography using the time-independent equation of radiative transfer -- Part 1: forward model optical tomographic imaging algorithm that is based on the equation of radiative transfer. Using

Hielscher, Andreas

28

Assessment of Low Linear Energy Transfer RadiationInduced Bystander Mutagenesis in a Three-Dimensional Culture Model  

Science Journals Connector (OSTI)

...Department of Energy cleanup operations...mutation was a measurement of changes...with low-energy protons (28...Puck TT. Measurement of mutagenesis...on Radiation Units and Measurements; 1984. 23...low linear energy transfer radiation-induced...

Rudranath Persaud; Hongning Zhou; Sarah E. Baker; Tom K. Hei; and Eric J. Hall

2005-11-01T23:59:59.000Z

29

Lattice Boltzmann method for one-dimensional radiation transfer  

Science Journals Connector (OSTI)

The macroscopic conservation equations of radiation energy and radiation momentum are derived on the basis of radiation hydrodynamics. Based on the Chapman-Enskog method, the lattice Boltzmann model for one-dimensional radiative transfer is proposed from the Boltzmann equation. The numerical simulation results agree well with the exact solution and show that the lattice Boltzmann method developed in this paper has good accuracy and stability for solving one-dimensional radiative transfer problems.

Yu Ma; ShiKui Dong; HePing Tan

2011-07-14T23:59:59.000Z

30

Journal of Quantitative Spectroscopy & Radiative Transfer 94 (2005) 357371  

E-Print Network (OSTI)

rights reserved. Keywords: Time dependent radiation transport; M1 approximation; Multigroup models; Mean that solve the radiative transfer equation at a low cost. Among these models, we find diffusion, flux this equation, see [3] and [4]. The first three angular moments of the radiative intensity are defined as Eðn

Coudière, Yves

31

Radiative Heat Transfer in Enhanced Hydrogen Outgassing of Glass  

E-Print Network (OSTI)

Kaviany and B.P. Singh, Radiative heat transfer in porousmedia, Advances in Heat Transfer, vol. 23, no. 23, pp. 133Thermal radiation heat transfer, Hemisphere Publishing Co. ,

Kitamura, Rei; Pilon, Laurent

2009-01-01T23:59:59.000Z

32

Posters Comparison of Stochastic Radiation Transfer Predictions  

NLE Websites -- All DOE Office Websites (Extended Search)

9 Posters Comparison of Stochastic Radiation Transfer Predictions with Multi-Filter Rotating Shadowband Radiometer Data N. Byrne and G. Ramanathan Science Applications...

33

Kinetic Scheme for Solving the M1 Model of Radiative Transfer  

Science Journals Connector (OSTI)

......of the intensity, but not the energy density. Thus, FLD cannot evaluate...it takes account of only the energy density. Gonzalez, Audit, and Huynh (2007) proposed...radiation field is expressed by the energy density and the flux, i.e......

Yuji Kanno; Tetsuya Harada; Tomoyuki Hanawa

2013-08-25T23:59:59.000Z

34

A high-spectral-resolution radiative transfer model for simulating multi-layered clouds and aerosols in the infrared spectral region  

Science Journals Connector (OSTI)

A fast and flexible model is developed to simulate the transfer of thermal infrared radiation at wavenumbers from 700 to 1300 cm?1 with a spectral resolution of 0.1 cm?1 for scattering/absorbing atmospheres. In a single run and at multiple user-...

Chenxi Wang; Ping Yang; Xu Liu

35

Simple radiative transfer model for relationships between canopy biomass and reflectance  

Science Journals Connector (OSTI)

A modified Kubelka-Munk model has been utilized to derive useful equations for the analysis of apparent canopy reflectance. Based on the solution to the model simple working equations...

Park, J K; Deering, D W

1982-01-01T23:59:59.000Z

36

Multilevel bioluminescence tomography based on radiative transfer equation  

E-Print Network (OSTI)

, "A fast forward solver of radiative transfer equation," Transport Theory and Statistical Physics 38Multilevel bioluminescence tomography based on radiative transfer equation Part 1: l1 approach for bioluminescence tomography based on radiative transfer equation with the emphasis on improving

Soatto, Stefano

37

Radiative heat transfer between dielectric bodies  

E-Print Network (OSTI)

The recent development of a scanning thermal microscope (SThM) has led to measurements of radiative heat transfer between a heated sensor and a cooled sample down to the nanometer range. This allows for comparision of the known theoretical description of radiative heat transfer, which is based on fluctuating electrodynamics, with experiment. The theory itself is a macroscopic theory, which can be expected to break down at distances much smaller than 10-8m. Against this background it seems to be reasonable to revisit the known macroscopic theory of fluctuating electrodynamics and of radiative heat transfer.

Svend-Age Biehs

2011-03-16T23:59:59.000Z

38

Discrete Ordinate Method for Solving Inhomogeneous Vector Radiative Transfer Equation  

E-Print Network (OSTI)

paper.. This type of equation appears when modeling radiative transport in plane parallel media. WeDiscrete Ordinate Method for Solving Inhomogeneous Vector Radiative Transfer Equation We describe here a solution method for equations of the type given by: µ I(,µ) +I(,µ)- () 2 1 -1 Z(,µ,µ )I(,µ )dµ

Pattanaik, Sumanta N.

39

Radiative Heat Transfer between Neighboring Particles  

E-Print Network (OSTI)

The near-field interaction between two neighboring particles is known to produce enhanced radiative heat transfer. We advance in the understanding of this phenomenon by including the full electromagnetic particle response, heat exchange with the environment, and important radiative corrections both in the distance dependence of the fields and in the particle absorption coefficients. We find that crossed terms of electric and magnetic interactions dominate the transfer rate between gold and SiC particles, whereas radiative corrections reduce it by several orders of magnitude even at small separations. Radiation away from the dimer can be strongly suppressed or enhanced at low and high temperatures, respectively. These effects must be taken into account for an accurate description of radiative heat transfer in nanostructured environments.

Alejandro Manjavacas; F. Javier Garcia de Abajo

2012-01-26T23:59:59.000Z

40

A 3D radiative transfer framework: II. line transfer problems  

E-Print Network (OSTI)

Higher resolution telescopes as well as 3D numerical simulations will require the development of detailed 3D radiative transfer calculations. Building upon our previous work we extend our method to include both continuum and line transfer. We present a general method to calculate radiative transfer including scattering in the continuum as well as in lines in 3D static atmospheres. The scattering problem for line transfer is solved via means of an operator splitting (OS) technique. The formal solution is based on a long-characteristics method. The approximate $\\Lambda$ operator is constructed considering nearest neighbors {\\em exactly}. The code is parallelized over both wavelength and solid angle using the MPI library. We present the results of several test cases with different values of the thermalization parameter and two choices for the temperature structure. The results are directly compared to 1D spherical tests. With our current grid setup the interior resolution is much lower in 3D than in 1D, nevertheless the 3D results agree very well with the well-tested 1D calculations. We show that with relatively simple parallelization that the code scales to very large number of processors which is mandatory for practical applications. Advances in modern computers will make realistic 3D radiative transfer calculations possible in the near future. Our current code scales to very large numbers of processors, but requires larger memory per processor at high spatial resolution.

E. Baron; Peter H. Hauschildt

2007-03-16T23:59:59.000Z

Note: This page contains sample records for the topic "radiation transfer models" 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

Approximating the time-domain radiative transfer equation using truncated Fourier series  

Science Journals Connector (OSTI)

The radiative transfer equation describes propagation of light in scattering media. It is widely used model, with applications in medical imaging, astronomy and atmospheric sciences to...

Pulkkinen, Aki; Tarvainen, Tanja

42

Radiative Transfer in Terms of Integral Equations  

Science Journals Connector (OSTI)

... linear integral equation of the Fredholm type. Another year after that (1914), K. Schwarzschild showed that the problem of the radiative equilibrium of an atmosphere leads to a Fredholm ... of an atmosphere leads to a Fredholm equation, and Milne, ten years later, extended Schwarzschild's work by showing how different transfer problems all lead to similar types of integral ...

SVEIN ROSSELAND

1950-07-29T23:59:59.000Z

43

Evaluation of Radiometric Measurements from the NASA Multiangle Imaging Spectroradiometer (MISR): Two- and Three-Dimensional Radiative Transfer Modeling of an Inhomogeneous Stratocumulus Cloud Deck  

SciTech Connect

In December 1999, NASA launched the Terra satellite. This platform carries five instruments that measure important properties of the Earth climate system. One of these instruments is the Multiangle Imaging Spectroradiometer, or MISR. This instrument measures light reflected from the Earth at a spatial resolution of 275-1100 m, at four wavelengths (446, 558, 672, and 866 nm), and at nine different viewing angles that vary from +70 to -70 degrees along the direction of flight [Diner et al., 2002]. These multiangle data have the potential to provide information on aerosols, surface, and cloud characteristics that compliments traditional single-view-direction satellite measurements. Before this potential can be realized, the accuracy of the satellite radiance measurements must be carefully assessed, and the implications of the radiometric accuracy on remote-sensing algorithms must be evaluated. In this article, we compare MISR multiangle measurements against two-dimensional (2-D) and 3-D radiative transfer calculations from an inhomogeneous cloud scene. Inputs to the radiative transfer code are based entirely on independently gathered data (ground-based radar, lidar, microwave radiometer, in situ aircraft data, etc.). The 2-D radiative transfer calculations compare favorably near nadir and in most of the forward scattering directions, but differ by as much as 10% in the backscattering directions. Using 3-D radiative transfer modeling, we show that this difference is due to the 3-D structure of the cloud deck, including variations in the cloud top height on scales less than 275 m, which are not resolved in the 2-D simulations. Comparison of the 2-D calculations to the MISR measurements, after accounting for the 3-D structure, show residual differences that are less than 4% at all angles at the MISR blue and green wavelengths. The comparison also reveals that the MISR measurements at the red and near-infrared wavelengths are too bright relative to measurements in the blue and green bands. On the basis of the results of this study, along with results from five other comparisons, the MISR calibration is being adjusted to reduce the red and nearinfrared Radiances.

Marchand, Roger T.; Ackerman, Thomas P.

2004-09-29T23:59:59.000Z

44

Multilevel bioluminescence tomography based on radiative transfer equation  

E-Print Network (OSTI)

Multilevel bioluminescence tomography based on radiative transfer equation Part 2: total variation with both l1 and total- variation norm for bioluminescence tomography based on radiative transfer equation, Radiative Transfer (Dover Publications, 1960). 14. K. M. Case and P. F. PF Zweifel, Linear Transport Theory

Soatto, Stefano

45

Using radiative transfer models to study the atmospheric water vapor content and to eliminate telluric lines from high-resolution optical spectra  

E-Print Network (OSTI)

The Radiative Transfer Model (RTM) and the retrieval algorithm, incorporated in the SCIATRAN 2.2 software package developed at the Institute of Remote Sensing/Institute of Enviromental Physics of Bremen University (Germany), allows to simulate, among other things, radiance/irradiance spectra in the 2400-24 000 {\\AA} range. In this work we present applications of RTM to two case studies. In the first case the RTM was used to simulate direct solar irradiance spectra, with different water vapor amounts, for the study of the water vapor content in the atmosphere above Sierra Nevada Observatory. Simulated spectra were compared with those measured with a spectrometer operating in the 8000-10 000 {\\AA} range. In the second case the RTM was used to generate telluric model spectra to subtract the atmospheric contribution and correct high-resolution stellar spectra from atmospheric water vapor and oxygen lines. The results of both studies are discussed.

Gardini, A; Prez, E; Quesada, J A; Funke, B

2012-01-01T23:59:59.000Z

46

Journal of Quantitative Spectroscopy & Radiative Transfer 98 (2006) 220237  

E-Print Network (OSTI)

discontinuities associated with the propagation of a radiation front in transient radiation transport. r 2005 q heat flux s geometric path length S source term in the radiative transfer equation t time tc timeJournal of Quantitative Spectroscopy & Radiative Transfer 98 (2006) 220­237 Modified method

Pilon, Laurent

47

Posters The Effects of Radiative Transfer  

NLE Websites -- All DOE Office Websites (Extended Search)

Posters The Effects of Radiative Transfer on Low-Level Cyclogenesis M. J. Leach and S. Raman Department of Marine, Earth and Atmospheric Sciences North Carolina State University Raleigh, North Carolina Introduction Many investigators have documented the role that thermodynamic forcing due to radiative flux divergence plays in the enhancement or generation of circulation. Most of these studies involve large-scale systems (e.g., Slingo et al. 1988), small-scale systems such as thunderstorms (Chen and Cotton 1988), and squall lines (Chin, submitted). The generation of circulation on large scales results from the creation of divergence in the upper troposphere and the maintenance of low-level potentially unstable air, and the maintenance of baroclinicity throughout

48

Journal of Quantitative Spectroscopy & Radiative Transfer 91 (2005) 2746  

E-Print Network (OSTI)

used in the field of transport phenomena simulation, and more specifically in the field of radiative (application of the reciprocity principle to the integral form of the radiative transfer equation), and to netJournal of Quantitative Spectroscopy & Radiative Transfer 91 (2005) 27­46 A boundary-based net

Dufresne, Jean-Louis

49

Radiative Transfer in Interacting Media J.Kenneth Shultis  

E-Print Network (OSTI)

of nuclear energy. Today, radiative transport plays an important role in many other areas besides nuclear, and many others. 1.1 Radiative Transfer Regimes The transport of radiant energy through a medium falls shielding analyses, the radiative transfer equation is linear, and a wealth of numerical techniques exist

Shultis, J. Kenneth

50

Radiative heat transfer in a flow of rheologically complex fluid  

Science Journals Connector (OSTI)

The problem of complex radiative and convective heat transfer in steady-state generalized Couette flow of a nonlinear viscoplastic fluid is examined.

V. F. Volchenok; Z. P. Shul'man

1980-09-01T23:59:59.000Z

51

On the influence of the companion star in Eta Carinae: 2D radiative transfer modeling of the ultraviolet and optical spectra  

E-Print Network (OSTI)

We present 2D radiative transfer modeling of the Eta Carinae binary system accounting for the presence of a wind-wind collision (WWC) cavity carved in the optically-thick wind of the primary star. By comparing synthetic line profiles with HST/STIS spectra obtained near apastron, we show that the WWC cavity has a strong influence on multi-wavelength diagnostics. This influence is regulated by the modification of the optical depth in the continuum and spectral lines. We find that H-alpha, H-beta, and Fe II lines are the most affected by the WWC cavity, since they form over a large volume of the primary wind. These spectral lines depend on latitude and azimuth since, according to the orientation of the cavity, different velocity regions of a spectral line are affected. For 2D models with orientation corresponding to orbital inclination angle 110deg < i < 140deg and longitude of periastron 210deg < omega < 330deg, the blueshifted and zero-velocity regions of the line profiles are the most affected. Th...

Groh, Jose H; Madura, Thomas I; Weigelt, Gerd

2012-01-01T23:59:59.000Z

52

Journal of Quantitative Spectroscopy & Radiative Transfer 73 (2002) 159168  

E-Print Network (OSTI)

-dependence of radiative transport due to the large but ÿnite speed of radiation propagation must be incorporated usion approximation is often used to describe the transient radiation transport [5]. However, recent the fully transient radiative transfer equation. Kumar et al. [8] and Kumar and Mitra [9] were among

Guo, Zhixiong "James"

53

A RADIATION TRANSFER SOLVER FOR ATHENA USING SHORT CHARACTERISTICS  

SciTech Connect

We describe the implementation of a module for the Athena magnetohydrodynamics (MHD) code that solves the time-independent, multi-frequency radiative transfer (RT) equation on multidimensional Cartesian simulation domains, including scattering and non-local thermodynamic equilibrium (LTE) effects. The module is based on well known and well tested algorithms developed for modeling stellar atmospheres, including the method of short characteristics to solve the RT equation, accelerated Lambda iteration to handle scattering and non-LTE effects, and parallelization via domain decomposition. The module serves several purposes: it can be used to generate spectra and images, to compute a variable Eddington tensor (VET) for full radiation MHD simulations, and to calculate the heating and cooling source terms in the MHD equations in flows where radiation pressure is small compared with gas pressure. For the latter case, the module is combined with the standard MHD integrators using operator splitting: we describe this approach in detail, including a new constraint on the time step for stability due to radiation diffusion modes. Implementation of the VET method for radiation pressure dominated flows is described in a companion paper. We present results from a suite of test problems for both the RT solver itself and for dynamical problems that include radiative heating and cooling. These tests demonstrate that the radiative transfer solution is accurate and confirm that the operator split method is stable, convergent, and efficient for problems of interest. We demonstrate there is no need to adopt ad hoc assumptions of questionable accuracy to solve RT problems in concert with MHD: the computational cost for our general-purpose module for simple (e.g., LTE gray) problems can be comparable to or less than a single time step of Athena's MHD integrators, and only few times more expensive than that for more general (non-LTE) problems.

Davis, Shane W. [Canadian Institute for Theoretical Astrophysics, Toronto, ON M5S 3H4 (Canada); Stone, James M.; Jiang Yanfei [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)

2012-03-01T23:59:59.000Z

54

Two-frequency radiative transfer and asymptotic solution  

E-Print Network (OSTI)

radiative transfer equation has been derived with full mathematical rigor [13,14]. In the case the wave nature of the process and is not just about energy transport. Hence the governing equation cannotTwo-frequency radiative transfer and asymptotic solution Albert C. Fannjiang* Department

Fannjiang, Albert

55

Radiative transfer with partial coherence in optically thick plasmas Aix-Marseille Universite, CNRS, PIIM UMR 7345, F-13397 Marseille Cedex 20, France  

E-Print Network (OSTI)

approach to address radiative transfer prob- lems involves a transport equation of Boltzmann-type, referred to as "radiative transfer equation", accounting for radiation-matter interaction processes such as spon- taneous the use of a transport theory for photons unavoidable. Opac- ity models for radiative transfer are widely

Paris-Sud XI, Université de

56

Heat Transfer by Radiation to Surfaces at Low Temperatures  

Science Journals Connector (OSTI)

...August 1948 research-article Heat Transfer by Radiation to Surfaces at Low...E. V. Truter A study of the transfer of heat between the walls of vacuum vessels...more efficient in diminishing the heat transfer than a highly polished surface...

1948-01-01T23:59:59.000Z

57

Near-field radiative heat transfer for structured surfaces  

E-Print Network (OSTI)

We apply an analytical approach for determining the near-field radiative heat transfer between a metallic nanosphere and a planar semi-infinite medium with some given surface structure. This approach is based on a perturbative expansion, and evaluated to first order in the surface profile. With the help of numerical results obtained for some simple model geometries we discuss typical signatures that should be obtainable with a near-field scanning thermal microscope operated in either constant-height or constant-distance mode.

Svend-Age Biehs; Oliver Huth; Felix Rting

2011-03-15T23:59:59.000Z

58

Application of Improved Radiation Modeling to General Circulation Models  

SciTech Connect

This research has accomplished its primary objectives of developing accurate and efficient radiation codes, validating them with measurements and higher resolution models, and providing these advancements to the global modeling community to enhance the treatment of cloud and radiative processes in weather and climate prediction models. A critical component of this research has been the development of the longwave and shortwave broadband radiative transfer code for general circulation model (GCM) applications, RRTMG, which is based on the single-column reference code, RRTM, also developed at AER. RRTMG is a rigorously tested radiation model that retains a considerable level of accuracy relative to higher resolution models and measurements despite the performance enhancements that have made it possible to apply this radiation code successfully to global dynamical models. This model includes the radiative effects of all significant atmospheric gases, and it treats the absorption and scattering from liquid and ice clouds and aerosols. RRTMG also includes a statistical technique for representing small-scale cloud variability, such as cloud fraction and the vertical overlap of clouds, which has been shown to improve cloud radiative forcing in global models. This development approach has provided a direct link from observations to the enhanced radiative transfer provided by RRTMG for application to GCMs. Recent comparison of existing climate model radiation codes with high resolution models has documented the improved radiative forcing capability provided by RRTMG, especially at the surface, relative to other GCM radiation models. Due to its high accuracy, its connection to observations, and its computational efficiency, RRTMG has been implemented operationally in many national and international dynamical models to provide validated radiative transfer for improving weather forecasts and enhancing the prediction of global climate change.

Michael J Iacono

2011-04-07T23:59:59.000Z

59

Enhanced radiative heat transfer between nanostructured gold plates  

E-Print Network (OSTI)

We compute the radiative heat transfer between nanostructured gold plates in the framework of the scattering theory. We predict an enhancement of the heat transfer as we increase the depth of the corrugations while keeping the distance of closest approach fixed. We interpret this effect in terms of the evolution of plasmonic and guided modes as a function of the grating's geometry.

R. Gurout; J. Lussange; F. S. S. Rosa; J. -P. Hugonin; D. A. R. Dalvit; J. -J. Greffet; A. Lambrecht; S. Reynaud

2012-03-07T23:59:59.000Z

60

Radiative heat transfer in 2D Dirac materials  

E-Print Network (OSTI)

We compute the radiative heat transfer between two sheets of 2D Dirac materials, including topological Chern insulators and graphene. Neglecting spatial dispersion, we derive both numerically and analytically the short-distance asymptotics of the near-field heat transfer in these systems, and show that it scales as the inverse of the distance between the two sheets. We argue that this scaling law for the near-field heat transfer is generic for any two-dimensional systems.

Pablo Rodriguez-Lopez; Wang-Kong Tse; Diego A. R. Dalvit

2014-10-16T23:59:59.000Z

Note: This page contains sample records for the topic "radiation transfer models" 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.


61

Di usion Approximation of Radiative Transfer Equations in a Channel  

E-Print Network (OSTI)

direction. 1 #12; 1 Introduction Radiative transport equations were #12;rst used to describe the propagationDi#11;usion Approximation of Radiative Transfer Equations in a Channel Guillaume Bal Department by a di#11;usion equation. However, the thickness of the crust is of the order of the transport mean free

Bal, Guillaume

62

Small distance expansion for radiative heat transfer between curved objects  

E-Print Network (OSTI)

We develop a small distance expansion for the radiative heat transfer between gently curved objects, in terms of the ratio of distance to radius of curvature. A gradient expansion allows us to go beyond the lowest order proximity transfer approximation. The range of validity of such expansion depends on temperature as well as material properties. Generally, the expansion converges faster for the derivative of the transfer than for the transfer itself, which we use by introducing a near-field adjusted plot. For the case of a sphere and a plate, the logarithmic correction to the leading term has a very small prefactor for all materials investigated.

Vladyslav A. Golyk; Matthias Krger; Alexander P. McCauley; Mehran Kardar

2012-10-12T23:59:59.000Z

63

Diffusion Approximation of Radiative Transfer Problems with Guillaume Bal \\Lambda Leonid Ryzhik y  

E-Print Network (OSTI)

Ryzhik y Abstract We derive the diffusion approximation of transport equations with discontinuities at interfaces. The transport equations model the energy density of acoustic waves. The waves are reflected in the high frequency regime by a radiative transfer equation. This model has been first proposed

Ryzhik, Lenya

64

A mesoscopic description of radiative heat transfer at the nanoscale  

E-Print Network (OSTI)

We present a formulation of the nanoscale radiative heat transfer (RHT) using concepts of mesoscopic physics. We introduce the analog of the Sharvin conductance using the quantum of thermal conductance. The formalism provides a convenient framework to analyse the physics of RHT at the nanoscale. Finally, we propose a RHT experiment in the regime of quantized conductance.

Svend-Age Biehs; Emmanuel Rousseau; Jean-Jacques Greffet

2011-03-11T23:59:59.000Z

65

An Efficient Approach for Optical Radiative Transfer Tomography using the Spherical Harmonics Discrete Ordinates Method  

E-Print Network (OSTI)

This paper introduces a method to preform optical tomography, using 3D radiative transfer as the forward model. We use an iterative approach predicated on the Spherical Harmonics Discrete Ordinates Method (SHDOM) to solve the optimization problem in a scalable manner. We illustrate with an application in remote sensing of a cloudy atmosphere.

Levis, Aviad; Aides, Amit; Davis, Anthony B

2015-01-01T23:59:59.000Z

66

Application of Stochastic Radiative Transfer Theory to the ARM Cloud-Radiative Parameterization Problem  

SciTech Connect

This project had two primary goals: (1) development of stochastic radiative transfer as a parameterization that could be employed in an AGCM environment, and (2) exploration of the stochastic approach as a means for representing shortwave radiative transfer through mixed-phase layer clouds. To achieve these goals, climatology of cloud properties was developed at the ARM CART sites, an analysis of the performance of the stochastic approach was performed, a simple stochastic cloud-radiation parameterization for an AGCM was developed and tested, a statistical description of Arctic mixed phase clouds was developed and the appropriateness of stochastic approach for representing radiative transfer through mixed-phase clouds was assessed. Significant progress has been made in all of these areas and is detailed in the final report.

Dana E. Veron

2012-04-09T23:59:59.000Z

67

Radiative heat transfer in 2D Dirac materials  

E-Print Network (OSTI)

We compute the radiative heat transfer between two sheets of 2D Dirac materials, including topological Chern insulators and graphene, within the framework of the local approximation for the optical response of these materials. In this approximation, which neglects spatial dispersion, we derive both numerically and analytically the short-distance asymptotic of the near-field heat transfer in these systems, and show that it scales as the inverse of the distance between the two sheets. Finally, we discuss the limitations to the validity of this scaling law imposed by spatial dispersion in 2D Dirac materials.

Pablo Rodriguez-Lopez; Wang-Kong Tse; Diego A. R. Dalvit

2015-02-02T23:59:59.000Z

68

Radiative heat transfer at nanoscale mediated by surface plasmons for highly doped Emmanuel Rousseau  

E-Print Network (OSTI)

Radiative heat transfer at nanoscale mediated by surface plasmons for highly doped silicon the role of surface plasmons for nanoscale radiative heat transfer between doped silicon surfaces. We derive a new accurate and closed-form expression of the radiative near- field heat transfer. We also

Paris-Sud XI, Université de

69

Calculating Radiative Heat Transfer in an Axisymmetric Closed Chamber: An Application  

E-Print Network (OSTI)

Calculating Radiative Heat Transfer in an Axisymmetric Closed Chamber: An Application to Crystal University of New York at Stony Brook Stony Brook N.Y. 11794 ABSTRACT Radiative heat transfer plays simulating radiative heat transfer in the crystal and in the region above the melt containing gas under

New York at Stoney Brook, State University of

70

Three-dimensional optical tomography with the equation of radiative transfer  

E-Print Network (OSTI)

on a transport-backtransport method applied to the two-dimensional time-dependent equation of radiative transferThree-dimensional optical tomography with the equation of radiative transfer Gassan S. Abdoulaev reconstruction scheme that is based on the time-independent equation of radiative transfer (ERT) and allows

Hielscher, Andreas

71

Heat transfer through a water spray curtain under the effect of a strong radiative source  

E-Print Network (OSTI)

Heat transfer through a water spray curtain under the effect of a strong radiative source P. Boulet - mail Pascal.Boulet@lemta.uhp-nancy.fr Keywords : heat transfer, radiative transfer, vaporization, convection, water spray Abstract Heat transfer inside a participating medium, made of droplets flowing in gas

Paris-Sud XI, Université de

72

WHICH MODEL OF TECHNOLOGY TRANSFER FOR NANOTECHNOLOGY?  

E-Print Network (OSTI)

1 WHICH MODEL OF TECHNOLOGY TRANSFER FOR NANOTECHNOLOGY? A Comparison with Biotech.genet@grenoble-em.com Website: www.nanoeconomics.eu Abstract. Nanotechnologies are often presented as breakthrough innovations. This article investigates the model of knowledge transfer in the nanotechnologies in depth, by comparing

Paris-Sud XI, Université de

73

Radiation Environment Assimilation Model (DREAM).  

NLE Websites -- All DOE Office Websites (Extended Search)

DREAM tool increases space weather DREAM tool increases space weather predictions April 13, 2012 Predicting space weather improved by new DREAM modeling tool Earth's radiation belts can now be studied with a new modeling tool called Dynamic Radiation Environment Assimilation Model (DREAM). Researchers in LANL's Space Science and Applications (ISR-1) group are developing DREAM and described its current capabilities and applications in an article published in Space Weather, a journal of the American Geophysical Union. - 2 - Space environment and its hazards The space environment poses a number of radiation hazards to space systems and their occupants. Relativistic electrons, the dominant source of the radiation dose to spacecraft traveling in the outer radiation belts (3-7 Earth radii), have an electron flux

74

Equivalent isotropic scattering formulation for transient short-pulse radiative transfer in anisotropic  

E-Print Network (OSTI)

of the transient short-pulse radiation transport through forward and backward anisotropic scattering planar media time-resolved transmittance.13­15 The complete transient radiative transfer equation has been conEquivalent isotropic scattering formulation for transient short-pulse radiative transfer

Guo, Zhixiong "James"

75

Project: (version of January 28, 2009) Sparse tensor product methods for radiative transfer  

E-Print Network (OSTI)

simulating a dense gas at very high temperatures, energy transport by means of radiation has to be taken into account. However, as even the non-scattering stationary monochromatic radiative transfer equation s · x. Applying an adaptive sparse discretiza- tion to the radiative transfer equation [1] allows to significantly

Hiptmair, Ralf

76

A FAST FORWARD SOLVER OF RADIATIVE TRANSFER HAO GAO AND HONGKAI ZHAO  

E-Print Network (OSTI)

studying the numerical solutions to the radiative transport equation (RTE) or the within-group neutron transport equation [4, 13] in the field of neutron transport [4], atmospheric radiative transfer [1], heatA FAST FORWARD SOLVER OF RADIATIVE TRANSFER EQUATION HAO GAO AND HONGKAI ZHAO Abstract

Soatto, Stefano

77

Computational study of atmospheric transfer radiation on an equatorial tropical desert (La Tatacoa, Colombia)  

E-Print Network (OSTI)

Radiative transfer models explain and predict interaction between solar radiation and the different elements present in the atmosphere, which are responsible for energy attenuation. In Colombia there have been neither measurements nor studies of atmospheric components such as gases and aerosols that can cause turbidity and pollution. Therefore satellite images cannot be corrected radiometrically in a proper way. When a suitable atmospheric correction is carried out, loss of information is avoided, which may be useful for discriminating image land cover. In this work a computational model was used to find radiative atmospheric attenuation (300 1000nm wavelength region) on an equatorial tropical desert (La Tatacoa, Colombia) in order to conduct an adequate atmospheric correction.

Delgado-Correal, Camilo; Castao, Gabriel

2012-01-01T23:59:59.000Z

78

E-Print Network 3.0 - analytical radiative-transfer solutions...  

NLE Websites -- All DOE Office Websites (Extended Search)

In Illumination Engineering Society... . Stephens. On the fundamental solution of the radiative transfer equation. Journal of Astrophysical Research... . A numerical solution to...

79

Heat transfer in a radiating fluid with slug flow in a parallel-plate channel  

Science Journals Connector (OSTI)

As a step towards a better understanding of combined conduction, convection, and radiation, fully developed heat transfer in slug flow in a flat duct ... , nonblack, isothermal surfaces. The gray radiating fluid ...

R. Viskanta

1964-01-01T23:59:59.000Z

80

Method of Reducing the Error of Transferring the Size of a Unit of Laser Radiation Energy  

Science Journals Connector (OSTI)

A method is considered of reducing the error of transferring the size of a unit of laser radiation energy for a secondary standard of the units of average power and energy of laser radiation by using the readi...

A. N. Shchipunov

2002-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "radiation transfer models" 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

TWO-DIMENSIONAL TRANSIENT RADIATIVE HEAT TRANSFER USING DISCRETE ORDINATES METHOD  

E-Print Network (OSTI)

transport is time-dependent radiative transfer equation. The solution of the hyperbolic transient radiative-pulsed laser radiation interaction and transport within biological tissues. INTRODUCTION With the advent of the short-pulsed laser with the duration of the order of femtoseconds, transient laser radiation transport

Guo, Zhixiong "James"

82

Modified Method of Characteristics for Transient Radiative Transfer  

E-Print Network (OSTI)

conditions. The radiative transport equation is a hyperbolicTo solve the radiative transport equation for collimated

Katika, Kamal M.; Pilon, Laurent

2006-01-01T23:59:59.000Z

83

Radiative Heat Transfer Analysis of Fibrous Insulation Materials Using the ZonalGEF Method  

E-Print Network (OSTI)

Radiative Heat Transfer Analysis of Fibrous Insulation Materials Using the Zonal­GEF Method Walter to analyze radiative heat transfer in high porosity insulation materials which have a large scattering for LI900, a material used in the insulation tile for the space shuttle. Comparisons are presented

Yuen, Walter W.

84

Backbone Additivity in the Transfer Model of Protein Solvation...  

NLE Websites -- All DOE Office Websites (Extended Search)

Solvation. Abstract: The transfer model implying additivity of the peptide backbone free energy of transfer is computationally tested. Molecular dynamics simulations are used...

85

Surface-Phonon Polariton Contribution to Nanoscale Radiative Heat Transfer. Emmanuel Rousseau  

E-Print Network (OSTI)

Surface-Phonon Polariton Contribution to Nanoscale Radiative Heat Transfer. Emmanuel Rousseau-sud Campus Polytechnique RD 128 91127 Palaiseau cedex, France Heat transfer between two plates of polar far-field value. In this article, we show that nanoscale heat transfer is dominated by the coupling

Paris-Sud XI, Université de

86

A 3D radiative transfer framework: I. non-local operator splitting and continuum scattering problems  

E-Print Network (OSTI)

We describe a highly flexible framework to solve 3D radiation transfer problems in scattering dominated environments based on a long characteristics piece-wise parabolic formal solution and an operator splitting method. We find that the linear systems are efficiently solved with iterative solvers such as Gauss-Seidel and Jordan techniques. We use a sphere-in-a-box test model to compare the 3D results to 1D solutions in order to assess the accuracy of the method. We have implemented the method for static media, however, it can be used to solve problems in the Eulerian-frame for media with low velocity fields.

Peter H. Hauschildt; E. Baron

2006-01-09T23:59:59.000Z

87

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

E-Print Network (OSTI)

M. Convective and radiative heat transfer coefficients forH, Katayama T. Convective heat transfer coefficients andequations, and the heat transfer effects of different

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

2014-01-01T23:59:59.000Z

88

PARALLEL COMPUTATIONS OF RADIATIVE HEAT TRANSFER USING THE DISCRETE ORDINATES METHOD  

E-Print Network (OSTI)

the radiative transport equation on parallel computers. Mathematical libraries developed by third parties the discrete ordi- nates method. They observed that the global nature of radiative transport resultedPARALLEL COMPUTATIONS OF RADIATIVE HEAT TRANSFER USING THE DISCRETE ORDINATES METHOD Gautham

Utah, University of

89

Journal of Quantitative Spectroscopy & Radiative Transfer 109 (2008) 727740  

E-Print Network (OSTI)

solution of the Fokker­Planck equation. This equation gives a good approximation to the radiative transport of this method. r 2007 Elsevier Ltd. All rights reserved. Keywords: Radiative transport equation; Fokker tissues is governed by the theory of radiative transport [1]. The radiative transport equation takes

Kim, Arnold D.

90

Three-dimensional Continuum Radiative Transfer Images of a Molecular Cloud Core Evolution  

E-Print Network (OSTI)

We analyze a three-dimensional smoothed particle hydrodynamics simulation of an evolving and later collapsing pre-stellar core. Using a three-dimensional continuum radiative transfer program, we generate images at 7 micron, 15 micron, 175 micron, and 1.3 mm for different evolutionary times and viewing angles. We discuss the observability of the properties of pre-stellar cores for the different wavelengths. For examples of non-symmetric fragments, it is shown that, misleadingly, the density profiles derived from a one-dimensional analysis of the corresponding images are consistent with one-dimensional core evolution models. We conclude that one-dimensional modeling based on column density interpretation of images does not produce reliable structural information and that multidimensional modeling is required.

J. Steinacker; B. Lang; A. Burkert; A. Bacmann; Th. Henning

2004-10-12T23:59:59.000Z

91

Graphene-assisted near-field radiative heat transfer between corrugated polar materials  

SciTech Connect

Graphene has attracted great attention in nanoelectronics, optics, and energy harvesting. Here, the near-field radiative heat transfer between graphene-covered corrugated silica is investigated based on the exact scattering theory. It is found that graphene can improve the radiative heat flux between silica gratings by more than one order of magnitude and alleviate the performance sensitivity to lateral shift. The underlying mechanism is mainly attributed to the improved photon tunneling of modes away from phonon resonances. Besides, coating with graphene leads to nonlocal radiative transfer that breaks Derjaguin's proximity approximation and enables corrugated silica to outperform bulk silica in near-field radiation.

Liu, X. L.; Zhang, Z. M., E-mail: zhuomin.zhang@me.gatech.edu [G. W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)

2014-06-23T23:59:59.000Z

92

Estimating Three-Dimensional Cloudy Radiative Transfer Effects from Time-Height Cross Sections  

NLE Websites -- All DOE Office Websites (Extended Search)

Estimating Three-Dimensional Cloudy Radiative Transfer Estimating Three-Dimensional Cloudy Radiative Transfer Effects from Time-Height Cross Sections C. Hannay and R. Pincus National Oceanic and Atmospheric Administration Climate Diagnostics Center Boulder, Colorado K. F. Evans Program in Atmospheric and Oceanic Sciences University of Colorado Boulder, Colorado Introduction Clouds in the atmosphere are finite in extent and variable in every direction and in time. Long data sets from ground-based profilers, such as lidars or cloud radars, could provide a very valuable set of observations to characterize this variability. We may ask how well such profiling instruments can represent the cloud structure as measured by the magnitude of the three-dimensional (3D) radiative transfer effect. The 3D radiative transfer effect is the difference between the domain average broadband solar surface

93

Near-field thermal radiation transfer controlled by plasmons in graphene  

E-Print Network (OSTI)

It is shown that thermally excited plasmon-polariton modes can strongly mediate, enhance, and tune the near-field radiation transfer between two closely separated graphene sheets. The dependence of near-field heat exchange ...

Ilic, Ognjen

94

Heat transfer during laminar fluid flow in a pipe with radiative heat removal  

Science Journals Connector (OSTI)

The heat-transfer problem is analyzed for laminar fluid flow in the initial section of a ... pipe having a parabolic entry velocity distribution and heat removal by radiation from the surface of...

Ya. S. Kadaner; Yu. P. Rassadkin; . L. Spektor

1971-01-01T23:59:59.000Z

95

Unsteady hydromagnetic free-convection flow with radiative heat transfer in a rotating fluid  

Science Journals Connector (OSTI)

We consider the buoyancy-induced flow of an electrically-conducting fluid with radiative heat transfer past a vertical flat plate of infinite ... vary with temperature, that is a compressible fluid. If the temper...

A. R. Bestman; S. K. Adjepong

96

Numerical simulation of three-dimensional combined convective radiative heat transfer in rectangular channels  

E-Print Network (OSTI)

This dissertation presents a numerical simulation of three-dimensional flow and heat transfer in a channel with a backward-facing step. Flow was considered to be steady, incompressible, and laminar. The flow medium was treated to be radiatively...

Ko, Min Seok

2009-05-15T23:59:59.000Z

97

Experimental Measurement of Radiation Heat Transfer from Complex Fenestration Systems.  

E-Print Network (OSTI)

??A well instrumented facility for the measurement of heat transfer from complex fenestration systems was built and validated. The facility provided very accurate measurements based (more)

Wilson, Barry Allan

2007-01-01T23:59:59.000Z

98

The multiple absorption coefficient zonal method (MACZM), an efficient computational approach for the analysis of radiative heat transfer in multidimensional inhomogeneous nongray media  

E-Print Network (OSTI)

of Radiative Heat Transfer, the P-3 Approximation, AIAAMedia, Journal of Heat Transfer, Vol. 109, No. 3 (1987),Media, Numerical Heat Transfer, Part B, Fundamentals, Vol.

Yuen, W W

2006-01-01T23:59:59.000Z

99

A HIGH-ORDER-ACCURATE GPU-BASED RADIATIVE TRANSFER EQUATION SOLVER FOR COMBUSTION  

E-Print Network (OSTI)

is a dominant mode of heat transfer in combustion systems such as rocket engines, scramjets, and industrial development to result in a robust and fail-safe design. Hydrocarbon combustion results in exhaust gases whichA HIGH-ORDER-ACCURATE GPU-BASED RADIATIVE TRANSFER EQUATION SOLVER FOR COMBUSTION AND PROPULSION

Pilon, Laurent

100

accelerated radiative transfer: Topics by E-print Network  

NLE Websites -- All DOE Office Websites (Extended Search)

Dominated Outflows Astrophysics (arXiv) Summary: Plasma outflows from gamma-ray bursts (GRB), pulsar winds, relativistic jets, and ultra-intense laser targets radiate...

Note: This page contains sample records for the topic "radiation transfer models" 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

Hybrid Characteristics: 3D radiative transfer for parallel adaptive mesh refinement hydrodynamics  

E-Print Network (OSTI)

We have developed a three-dimensional radiative transfer method designed specifically for use with parallel adaptive mesh refinement hydrodynamics codes. This new algorithm, which we call hybrid characteristics, introduces a novel form of ray tracing that can neither be classified as long, nor as short characteristics, but which applies the underlying principles, i.e. efficient execution through interpolation and parallelizability, of both. Primary applications of the hybrid characteristics method are radiation hydrodynamics problems that take into account the effects of photoionization and heating due to point sources of radiation. The method is implemented in the hydrodynamics package FLASH. The ionization, heating, and cooling processes are modelled using the DORIC ionization package. Upon comparison with the long characteristics method, we find that our method calculates the column density with a similarly high accuracy and produces sharp and well defined shadows. We show the quality of the new algorithm in an application to the photoevaporation of multiple over-dense clumps. We present several test problems demonstrating the feasibility of our method for performing high resolution three-dimensional radiation hydrodynamics calculations that span a large range of scales. Initial performance tests show that the ray tracing part of our method takes less time to execute than other parts of the calculation (e.g. hydrodynamics and adaptive mesh refinement), and that a high degree of efficiency is obtained in parallel execution. Although the hybrid characteristics method is developed for problems involving photoionization due to point sources, the algorithm can be easily adapted to the case of more general radiation fields.

Erik-Jan Rijkhorst; Tomasz Plewa; Anshu Dubey; Garrelt Mellema

2005-05-10T23:59:59.000Z

102

Solution of the equation of radiative transfer using a NewtonKrylov approach and adaptive mesh refinement  

E-Print Network (OSTI)

Solution of the equation of radiative transfer using a Newton­Krylov approach and adaptive mesh Available online 25 November 2011 Keywords: Radiation transport Discrete ordinates method Finite ordinates method (DOM) and finite-volume method (FVM) are used exten- sively to solve the radiative transfer

Groth, Clinton P. T.

103

14 Three-Dimensional Radiative Transfer in Vegetation Canopies  

E-Print Network (OSTI)

transport equa- tion. This equation has a very simple physical interpretation; it is a mathematical to correctly de- scribe the photon transport. Second, the radiation regime is substantially influenced, 1981, p. 144). This allows the transport equation to relate micro-scale properties of the medium

Myneni, Ranga B.

104

Radiative Transfer in Photocatalytic Systems Matteo Pasquali and Francesco Santarelli  

E-Print Network (OSTI)

; these components are usually anatase titanium dioxide, near-ultraviolet radiation, and oxygen, respectively as adsorption, chemical oxida- tion, and biodegradation) in that PCO can completely de- grade many classes of toxic organic compounds, forming only carbon dioxide and mineral acids, and it can achieve this within

Natelson, Douglas

105

Author's personal copy Radiative heat transfer in enhanced hydrogen  

E-Print Network (OSTI)

tube and heated in a furnace or by an incandescent lamp. It was observed that hydrogen release from the glass sample was faster and stronger when heated by an incandescent lamp than within a furnace. Here and the glass samples. In brief, the radiation emitted by the incandescent lamp is concentrated between 0

Pilon, Laurent

106

Sensitivity Analysis of the Gap Heat Transfer Model in BISON.  

SciTech Connect

This report summarizes the result of a NEAMS project focused on sensitivity analysis of the heat transfer model in the gap between the fuel rod and the cladding used in the BISON fuel performance code of Idaho National Laboratory. Using the gap heat transfer models in BISON, the sensitivity of the modeling parameters and the associated responses is investigated. The study results in a quantitative assessment of the role of various parameters in the analysis of gap heat transfer in nuclear fuel.

Swiler, Laura Painton; Schmidt, Rodney C.; Williamson, Richard (INL); Perez, Danielle (INL)

2014-10-01T23:59:59.000Z

107

A Shell Model for Atomistic Simulation of Charge Transfer in...  

NLE Websites -- All DOE Office Websites (Extended Search)

Transfer in Titania. Abstract: The derivation of atomistic potential parameters, based on electronic structure calculations, for modeling electron and hole polarons in titania...

108

Incorporation of 3D Shortwave Radiative Effects within the Weather Research and Forecasting Model  

SciTech Connect

A principal goal of the Atmospheric Radiation Measurement (ARM) Program is to understand the 3D cloud-radiation problem from scales ranging from the local to the size of global climate model (GCM) grid squares. For climate models using typical cloud overlap schemes, 3D radiative effects are minimal for all but the most complicated cloud fields. However, with the introduction of ''superparameterization'' methods, where sub-grid cloud processes are accounted for by embedding high resolution 2D cloud system resolving models within a GCM grid cell, the impact of 3D radiative effects on the local scale becomes increasingly relevant (Randall et al. 2003). In a recent study, we examined this issue by comparing the heating rates produced from a 3D and 1D shortwave radiative transfer model for a variety of radar derived cloud fields (O'Hirok and Gautier 2005). As demonstrated in Figure 1, the heating rate differences for a large convective field can be significant where 3D effects produce areas o f intense local heating. This finding, however, does not address the more important question of whether 3D radiative effects can alter the dynamics and structure of a cloud field. To investigate that issue we have incorporated a 3D radiative transfer algorithm into the Weather Research and Forecasting (WRF) model. Here, we present very preliminary findings of a comparison between cloud fields generated from a high resolution non-hydrostatic mesoscale numerical weather model using 1D and 3D radiative transfer codes.

O'Hirok, W.; Ricchiazzi, P.; Gautier, C.

2005-03-18T23:59:59.000Z

109

The dynamic radiation environment assimilation model (DREAM)  

SciTech Connect

The Dynamic Radiation Environment Assimilation Model (DREAM) is a 3-year effort sponsored by the US Department of Energy to provide global, retrospective, or real-time specification of the natural and potential nuclear radiation environments. The DREAM model uses Kalman filtering techniques that combine the strengths of new physical models of the radiation belts with electron observations from long-term satellite systems such as GPS and geosynchronous systems. DREAM includes a physics model for the production and long-term evolution of artificial radiation belts from high altitude nuclear explosions. DREAM has been validated against satellites in arbitrary orbits and consistently produces more accurate results than existing models. Tools for user-specific applications and graphical displays are in beta testing and a real-time version of DREAM has been in continuous operation since November 2009.

Reeves, Geoffrey D [Los Alamos National Laboratory; Koller, Josef [Los Alamos National Laboratory; Tokar, Robert L [Los Alamos National Laboratory; Chen, Yue [Los Alamos National Laboratory; Henderson, Michael G [Los Alamos National Laboratory; Friedel, Reiner H [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

110

Earth-Moon-Mars Radiation Environment Model  

E-Print Network (OSTI)

successful at predicting SEP spectra and radiation dose estimates at different distances in the inner-dependent estimates of organ dose and dose equivalent rates for human crews in deep space from the 26 Oct 2003 solar orbit, Spaceweather, 8, 2010 · Dayeh, et al, Modeling proton intensity gradients and radiation dose

Pringle, James "Jamie"

111

High-energy radiation damage in zirconia: modeling results ....  

NLE Websites -- All DOE Office Websites (Extended Search)

energy radiation damage in zirconia: modeling results . High-energy radiation damage in zirconia: modeling results . Abstract: Zirconia has been viewed as a material of exceptional...

112

Modelling of Heat Transfer in Single Crystal Growth  

E-Print Network (OSTI)

An attempt is made to review the heat transfer and the related problems encountered in the simulation of single crystal growth. The peculiarities of conductive, convective and radiative heat transfer in the different melt, solution, and vapour growth methods are discussed. The importance of the adequate description of the optical crystal properties (semitransparency, specular reflecting surfaces) and their effect on the heat transfer is stresses. Treatment of the unknown phase boundary fluid/crystal as well as problems related to the assessment of the quality of the grown crystals (composition, thermal stresses, point defects, disclocations etc.) and their coupling to the heat transfer/fluid flow problems is considered. Differences between the crystal growth simulation codes intended for the research and for the industrial applications are indicated. The problems of the code verification and validation are discussed; a brief review of the experimental techniques for the study of heat transfer and flow structu...

Zhmakin, Alexander I

2014-01-01T23:59:59.000Z

113

Journal of Quantitative Spectroscopy & Radiative Transfer 64 (2000) 255}273  

E-Print Network (OSTI)

s is the minimum of the total cross-section set, and consider the (vector) transport equation * * ( , )# ( , )" 1 2Journal of Quantitative Spectroscopy & Radiative Transfer 64 (2000) 255}273 A discrete-ordinates solution for multigroup transport theory with upscattering C.E. Siewert Mathematics Department, North

Siewert, Charles E.

114

Impact of surface inhomogeneity on solar radiative transfer under overcast conditions  

E-Print Network (OSTI)

Impact of surface inhomogeneity on solar radiative transfer under overcast conditions Zhanqing Li1. Trishchenko Canada Centre for Remote Sensing, Ottawa, Ontario, Canada Received 20 June 2001; revised 26 to a method of estimating surface spectral areal-mean albedo from downwelling solar transmittance measurements

Li, Zhanqing

115

Human In vivo Dose-Response to Controlled, Low-Dose Low Linear Energy Transfer Ionizing Radiation Exposure  

Science Journals Connector (OSTI)

...biotinylated nucleotide analogue/ribonucleotide mix. The biotinylated cRNA targets were then...dose-response to controlled, low-dose low linear energy transfer ionizing radiation exposure. | The effect of low doses of low-linear energy transfer (photon) ionizing radiation...

Zelanna Goldberg; David M. Rocke; Chad Schwietert; Susanne R. Berglund; Alison Santana; Angela Jones; Jrg Lehmann; Robin Stern; Ruixiao Lu; and Christine Hartmann Siantar

2006-06-15T23:59:59.000Z

116

Use of eigenfunctions for solving radiation transfer in anisotropically scattering, plane?parallel media  

Science Journals Connector (OSTI)

Radiation transfer in an absorbing emitting gray anisotropicallyscattering plane?parallel medium is solved by using the naturally occurring eigenfunctions and expressions for the forward and backward radiation intensities the incident radiation and forward and backward radiation heat fluxes are presented. To illustrate the method of solution the situation involving an externally incident isotropic radiation at the boundary surfacex=0 and no energy sources in the medium is considered for the cases of four different scattering phase functions. It is shown that the convergence to the exact results is fast and that lower order approximations are accurate. In addition the present method of solution has an excellent potential for generalization to problems of plane?parallel media without azimuthal symmetry and to problems in cylindrical and spherical geometries.

S. T. Thynell; M. N. zi?ik

1986-01-01T23:59:59.000Z

117

Effect of electric field on heat transfer performance of automobile radiator at low frontal air velocity  

Science Journals Connector (OSTI)

The effect of electric field on the performance of automobile radiator is investigated in this work. In this experiment, a louvered fin and flat tube automobile radiator was mounted in a wind tunnel and there was heat exchange between a hot water stream circulating inside the tube and a cold air stream flowing through the external surface. The electric field was supplied on the airside of the heat exchanger and its supply voltage was adjusted from 0kV to 12kV. From the experiment, it was found that the unit with electric field pronounced better heat transfer rate, especially at low frontal velocity of air. The correlations for predicting the air-side heat transfer coefficient of the automobile radiator, with and without electric field, at low frontal air velocity were also developed and the predicted results agreed very well with the experimental data.

S. Vithayasai; T. Kiatsiriroat; A. Nuntaphan

2006-01-01T23:59:59.000Z

118

Uncertainty of microwave radiative transfer computations in rain  

E-Print Network (OSTI)

retrieval using new thermodynamic observations; and 3) to investigate the characteristics of four different RT codes. Firstly, a plane-parallel RT Model (RTM) of n layers in light rainfall was used for the analytical and computational derivation...

Hong, Sung Wook

2009-06-02T23:59:59.000Z

119

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

120

Turbulence radiation interaction modeling in hydrocarbon pool fire simulations  

SciTech Connect

The importance of turbulent fluctuations in temperature and species concentration in thermal radiation transport modeling for combustion applications is well accepted by the radiation transport and combustion communities. A number of experimental and theoretical studies over the last twenty years have shown that fluctuations in the temperature and species concentrations may increase the effective emittance of a turbulent flame by as much as 50% to 300% over the value that would be expected from the mean temperatures and concentrations. With the possibility of such a large effect on the principal mode of heat transfer from a fire, it is extremely important for fire modeling efforts that turbulence radiation interaction be well characterized and possible modeling approaches understood. Toward this end, this report seeks to accomplish three goals. First, the principal turbulence radiation interaction closure terms are defined. Second, an order of magnitude analysis is performed to understand the relative importance of the various closure terms. Finally, the state of the art in turbulence radiation interaction closure modeling is reviewed. Hydrocarbon pool fire applications are of particular interest in this report and this is the perspective from which this review proceeds. Experimental and theoretical analysis suggests that, for this type of heavily sooting flame, the turbulent radiation interaction effect is dominated by the nonlinear dependence of the Planck function on the temperature. Additional effects due to the correlation between turbulent fluctuations in the absorptivity and temperature may be small relative to the Planck function effect for heavily sooting flames. This observation is drawn from a number of experimental and theoretical discussions. Nevertheless, additional analysis and data is needed to validate this observation for heavily sooting buoyancy dominated plumes.

BURNS,SHAWN P.

1999-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "radiation transfer models" 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.


121

Analyzing Knowledge Transfer Effectiveness An Agent-Oriented Modeling Approach  

E-Print Network (OSTI)

Analyzing Knowledge Transfer Effectiveness ­ An Agent-Oriented Modeling Approach Markus Strohmaier of knowledge between knowledge workers represents one of the main challenges of knowledge management. Knowledge transfer instruments, such as the experience factory concept, represent means for facilitating knowledge

122

Human In vivo Dose-Response to Controlled, Low-Dose Low Linear Energy Transfer Ionizing Radiation Exposure  

Science Journals Connector (OSTI)

...effects of low-dose low-linear energy transfer ionizing radiation (LDIR) in humans...direct evidence that doses in the range of 1 to 10 cGy...the intentional radiation of healthy tissue...the response to ionizing radiation. Attempts...

Zelanna Goldberg; David M. Rocke; Chad Schwietert; Susanne R. Berglund; Alison Santana; Angela Jones; Jrg Lehmann; Robin Stern; Ruixiao Lu; and Christine Hartmann Siantar

2006-06-15T23:59:59.000Z

123

Evaluation of GCM Column Radiation Models Under Cloudy Conditions with The Arm BBHRP Value Added Product  

SciTech Connect

The overarching goal of the project was to improve the transfer of solar and thermal radiation in the most sophisticated computer tools that are currently available for climate studies, namely Global Climate Models (GCMs). This transfer can be conceptually separated into propagation of radiation under cloudy and under cloudless conditions. For cloudless conditions, the factors that affect radiation propagation are gaseous absorption and scattering, aerosol particle absorption and scattering and surface albedo and emissivity. For cloudy atmospheres the factors are the various cloud properties such as cloud fraction, amount of cloud condensate, the size of the cloud particles, and morphological cloud features such as cloud vertical location, cloud horizontal and vertical inhomogeneity and cloud shape and size. The project addressed various aspects of the influence of the above contributors to atmospheric radiative transfer variability. In particular, it examined: (a) the quality of radiative transfer for cloudless and non-complex cloudy conditions for a substantial number of radiation algorithms used in current GCMs; (b) the errors in radiative fluxes from neglecting the horizontal variabiity of cloud extinction; (c) the statistical properties of cloud horizontal and vertical cloud inhomogeneity that can be incorporated into radiative transfer codes; (d) the potential albedo effects of changes in the particle size of liquid clouds; (e) the gaseous radiative forcing in the presence of clouds; and (f) the relative contribution of clouds of different sizes to the reflectance of a cloud field. To conduct the research in the various facets of the project, data from both the DOE ARM project and other sources were used. The outcomes of the project will have tangible effects on how the calculation of radiative energy will be approached in future editions of GCMs. With better calculations of radiative energy in GCMs more reliable predictions of future climate states will be attainable, thus affecting public policy decisions with great impact to public life.

Dr. Lazaros Oreopoulos and Dr. Peter M. Norris

2010-03-14T23:59:59.000Z

124

Advanced Model and Methodology Development [Heat Transfer and Fluid  

NLE Websites -- All DOE Office Websites (Extended Search)

Advanced Model and Advanced Model and Methodology Development Capabilities Engineering Computation and Design Engineering and Structural Mechanics Systems/Component Design, Engineering and Drafting Heat Transfer and Fluid Mechanics Overview Thermal Hydraulic Optimization of Nuclear Systems Underhood Thermal Management Combustion Simulations Advanced Model and Methodology Development Multi-physics Reactor Performance and Safety Simulations Other Capabilities Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Heat Transfer and Fluid Mechanics Bookmark and Share Advanced Model and Methodology Development Electrorefiner Model for Treatment of Spent Nuclear Fuel Electrorefiner Model for Treatment of Spent Nuclear Fuel. Click on image to

125

MODELING OF HEAT TRANSFER IN ROOMS IN THE MODELICA  

NLE Websites -- All DOE Office Websites (Extended Search)

MODELING MODELING OF HEAT TRANSFER IN ROOMS IN THE MODELICA "BUILDINGS" LIBRARY Michael Wetter, Wangda Zuo, Thierry Stephane Nouidui Simulation Research Group, Building Technologies Department Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory Berkeley, CA 94720, USA ABSTRACT This paper describes the implementation of the room heat transfer model in the free open-source Modelica "Buildings" library. The model can be used as a single room or to compose a multizone building model. We discuss how the model is de- composed into submodels for the individual heat transfer phenomena. We also discuss the main physical assumptions. The room model can be parameterized to use di↵erent modeling assump- tions, leading to linear or non-linear di↵erential algebraic systems of equations. We present nu- merical experiments that show

126

Analytical Model for Rates of Electron Attachment and Intramolecular Electron Transfer in Electron Transfer  

E-Print Network (OSTI)

. As a result, in ECD the primary source of excess energy is the recombination energy released when the electronAnalytical Model for Rates of Electron Attachment and Intramolecular Electron Transfer in Electron-mail: simons@chem.utah.edu Abstract: A new physical model is put forth to allow the prediction of electron

Simons, Jack

127

Thermal heat radiation, near-field energy density and near-field radiative heat transfer of coated materials  

E-Print Network (OSTI)

We investigate the thermal radiation and thermal near-field energy density of a metal-coated semi-infinite body for different substrates. We show that the surface polariton coupling within the metal coating leads to an enhancement of the TM-mode part of the thermal near-field energy density when a polar substrate is used. In this case the result obtained for a free standing metal film is retrieved. In contrast, in the case of a metal substrate there is no enhancement in the TM-mode part, as can also be explained within the framework of surface plasmon coupling within the coating. Finally, we discuss the influence of the enhanced thermal energy density on the near-field radiative heat transfer between a simple semi-infinite and a coated semi-infinite body for different material combinations.

Svend-Age Biehs

2011-03-15T23:59:59.000Z

128

Non-contact pumping of light emitters via non-radiative energy transfer  

DOE Patents (OSTI)

A light emitting device is disclosed including a primary light source having a defined emission photon energy output, and, a light emitting material situated near to said primary light source, said light emitting material having an absorption onset equal to or less in photon energy than the emission photon energy output of the primary light source whereby non-radiative energy transfer from said primary light source to said light emitting material can occur yielding light emission from said light emitting material.

Klimov, Victor I. (Los Alamos, NM); Achermann, Marc (Los Alamos, NM)

2010-01-05T23:59:59.000Z

129

Near-Field Radiative Heat Transfer between Metamaterials coated with Silicon Carbide Film  

E-Print Network (OSTI)

In this letter, we study the near-field radiative heat transfer between two metamaterial substrates coated with silicon carbide (SiC) thin films. It is known that metamaterials can enhance the near-field heat transfer over ordinary materials due to excitation of magnetic plasmons associated with s polarization, while strong surface phonon polariton exists for SiC.By careful tuning of the optical properties of metamaterial it is possible to excite electrical and magnetic resonance for the metamaterial and surface phonon polaritons for SiC at different spectral regions, resulting in the enhanced heat transfer. The effect of the SiC film thickness at different vacuum gaps is investigated. Results obtained from this study will be beneficial for application of thin film coatings for energy harvesting.

Basu, Soumyadipta; Wang, Liping

2014-01-01T23:59:59.000Z

130

Electrochemical mass transfer modeling of a complex two phase heat transfer problem: Case of a prototype slagging gasifier  

Science Journals Connector (OSTI)

The local and averaged forced-convective heat transfer coefficients were estimated from measured local and averaged mass transfer coefficients in a model slagging-gasifier hearth pool using the Chilton-Colburn an...

A. A. Wragg; N. P. Simpson; M. A. Patrick

2008-04-01T23:59:59.000Z

131

Multidimensional mechanistic modeling of interfacial heat and mass transfer  

SciTech Connect

A combined theoretical and computational study in modeling multidimensional, diabatic vapor/liquid flows is presented. Models have been developed governing kinematic aspects of multiphase flow as well as interfacial mass and heat transfer for flows of condensable gas (vapor) and liquids. The modeling formulation is based on the Reynolds averaged Navier-Stokes (RANS) type multi-field approach which utilizes a complete set of conservation equations for each fluid component 1. The modeled interfacial interactions include energy, mass, and momentum transfer. Emphasis in the model development work has been placed on the mechanisms governing coupled interfacial heat and mass transfer between the liquid and vapor fields (condensation and/or boiling). A method for tracking changes in bubble size is presented and tested. Locally based models of multidimensional effects have been analyzed, including distributions of fluid temperatures and volume fractions. The overall model accounts for both kinematic and thermodynamic nonequilibrium between the component fluids including superheated vapor. The model has been implemented in the NPHASE-CMFD computer code. Results from the kinematic model are compared to experimental data and good agreement is demonstrated. The heat and mass transfer model is parametrically tested to show the multidimensional effects on the rate of heat and mass transfer. These effects are explained in terms of local characteristics of the two-phase flow. The model is applied to a scenario of saturated vapor injected into a subcooled flow through a heated, porous wall. This provides a reasonable approximation to subcooled boiling. The results are found to be dependent on the partitioning of the wall heat flux between direct liquid heating and vapor generation. However, the observed dependencies are explained and the modeling is considered consistent. (authors)

Shaver, D. R.; Antal, S. P.; Podowski, M. Z. [Center for Multiphase Research, Rensselaer Polytechnic Inst., Troy, NY (United States)

2012-07-01T23:59:59.000Z

132

PHYSICAL REVIEW B 85, 155422 (2012) Near-field thermal radiation transfer controlled by plasmons in graphene  

E-Print Network (OSTI)

in graphene Ognjen Ilic,1,* Marinko Jablan,2 John D. Joannopoulos,1 Ivan Celanovic,3 Hrvoje Buljan,2 and Marin-field radiation transfer between two closely separated graphene sheets. The dependence of near-field heat exchange interband or intraband processes. We predict maximum transfer at low doping and for plasmons in two graphene

Soljaèiæ, Marin

133

Solving transient conduction and radiation heat transfer problems using the lattice Boltzmann method and the finite volume method  

SciTech Connect

The lattice Boltzmann method (LBM) was used to solve the energy equation of a transient conduction-radiation heat transfer problem. The finite volume method (FVM) was used to compute the radiative information. To study the compatibility of the LBM for the energy equation and the FVM for the radiative transfer equation, transient conduction and radiation heat transfer problems in 1-D planar and 2-D rectangular geometries were considered. In order to establish the suitability of the LBM, the energy equations of the two problems were also solved using the FVM of the computational fluid dynamics. The FVM used in the radiative heat transfer was employed to compute the radiative information required for the solution of the energy equation using the LBM or the FVM (of the CFD). To study the compatibility and suitability of the LBM for the solution of energy equation and the FVM for the radiative information, results were analyzed for the effects of various parameters such as the scattering albedo, the conduction-radiation parameter and the boundary emissivity. The results of the LBM-FVM combination were found to be in excellent agreement with the FVM-FVM combination. The number of iterations and CPU times in both the combinations were found comparable.

Mishra, Subhash C. [Department of Mechanical Engineering, Indian Institute of Technology Guwahati, Guwahati 781039 (India)]. E-mail: scm_iitg@yahoo.com; Roy, Hillol K. [Department of Mechanical Engineering, Indian Institute of Technology Guwahati, Guwahati 781039 (India)

2007-04-10T23:59:59.000Z

134

Simulating corrosion-erosion mass transfer using plaster models  

SciTech Connect

Corrosion-erosion is a term that covers a variety of processes leading to the removal of metal in low-carbon steel piping conveying water or steam/water mixtures at a temperature of 150 {+-} 50{degree}C. One of the most important of these processes is corrosion-dissolution. This is most likely to occur where disturbances or fittings cause local high velocities and thus high mass transfer coefficients. The wear equation, which requires the local mass transfer coefficient, is presented. This paper presents a way of determining the local mass transfer coefficient. This paper reports measurements of both local and nominal mass transfer coefficients on a plaster model of a defective weld in a pipe. Welds are particularly important because they are often the place where wear is the greatest and the pipe is most severely thinned.

Griffith, P.; de Freitas, G.

1989-01-01T23:59:59.000Z

135

Analysis of roll gap heat transfers in hot steel strip rolling through roll temperature sensors and heat transfer models  

E-Print Network (OSTI)

Analysis of roll gap heat transfers in hot steel strip rolling through roll temperature sensors and heat transfer models N. Legrand1,a , N. Labbe1,b D. Weisz-Patrault2,c , A. Ehrlacher2,d , T. Luks3,e heat transfers during pilot hot steel strip rolling. Two types of temperature sensors (drilled and slot

Paris-Sud XI, Université de

136

Radiative heat transfer between two dielectric nanogratings in the scattering approach  

E-Print Network (OSTI)

We present a theoretical study of radiative heat transfer between dielectric nanogratings in the scattering approach. As a comparision with these exact results, we also evaluate the domain of validity of Derjaguin's Proximity Approximation (PA). We consider a system of two corrugated silica plates with various grating geometries, separation distances, and lateral displacement of the plates with respect to one another. Numerical computations show that while the PA is a good approximation for aligned gratings, it cannot be used when the gratings are laterally displaced. We illustrate this by a thermal modulator device for nanosystems based on such a displacement.

J. Lussange; R. Gurout; F. S. S. Rosa; J. -J. Greffet; A. Lambrecht; S. Reynaud

2012-06-01T23:59:59.000Z

137

Milagro Version 2 An Implicit Monte Carlo Code for Thermal Radiative Transfer: Capabilities, Development, and Usage  

SciTech Connect

We have released Version 2 of Milagro, an object-oriented, C++ code that performs radiative transfer using Fleck and Cummings' Implicit Monte Carlo method. Milagro, a part of the Jayenne program, is a stand-alone driver code used as a methods research vehicle and to verify its underlying classes. These underlying classes are used to construct Implicit Monte Carlo packages for external customers. Milagro-2 represents a design overhaul that allows better parallelism and extensibility. New features in Milagro-2 include verified momentum deposition, restart capability, graphics capability, exact energy conservation, and improved load balancing and parallel efficiency. A users' guide also describes how to configure, make, and run Milagro2.

T.J. Urbatsch; T.M. Evans

2006-02-15T23:59:59.000Z

138

Radiation field modeling and optimization of a compact and modular  

NLE Websites -- All DOE Office Websites (Extended Search)

Radiation field modeling and optimization of a compact and modular Radiation field modeling and optimization of a compact and modular multi-plate photocatalytic reactor (MPPR) for air/water purification by Monte Carlo method Title Radiation field modeling and optimization of a compact and modular multi-plate photocatalytic reactor (MPPR) for air/water purification by Monte Carlo method Publication Type Journal Article Year of Publication 2013 Authors Zazueta, Ana Luisa Loo, Hugo Destaillats, and Gianluca Li Puma Journal Chemical Engineering Journal Volume 217 Pagination 475-485 Date Published 02/01/2013 Abstract The radiation field in a multi-plate photocatalytic reactor (MPPR) for air or water purification was modeled and optimized using a Monte Carlo stochastic method. The MPPR consists of parallel photocatalytic plates irradiated by cylindrical UV lamps orthogonal to the plates. The photocatalyst titanium dioxide (TiO2) is supported on the plates as a thin film. The photoreactor design is compact and offers a large irradiated photocatalytic surface area, a high degree of photon utilization, low pressure drop and a modular design which can facilitate scale-up. These features are desirable for the decontamination of indoor air in ventilation ducts or for water detoxification. The Monte Carlo method was applied to determine three dimensionless reactor performance parameters: the photon absorption efficiency (Φ), the uniformity of the distribution of the dimensionless radiation intensity (η) and the overall photonic efficiency (Φ). The emission of photons from the light sources was simulated by the extensive source with superficial emission (ESSE) model. Simulations were performed by varying the catalyst reflectivity albedo, the number and the diameter of lamps, and the dimensions and spacing of the photocatalytic plates. Optimal design for a basic reactor module with one lamp was accomplished for lamp-diameter-to-plate-height ratio (β) of 0.7, while the plate-spacing-to-plate-height ratio (α) was correlated by [αoptimum = 0.191 β2 - 0.5597 β + 0.3854]. A multilamp arrangement leads to a feasible increase in the size and number of the plates and the irradiated photocatalytic surface area. The optimum design was validated by measuring the apparent quantum yield of the oxidation of toluene (7 ppmv) in a humidified air stream using immobilized TiO2 (Degussa P25). Experiments performed varying the geometrical parameter α correlated well with the model calculations, with maximum apparent quantum yield for α = 0.137. The results are directly transferable to the treatment of water by photocatalysis.

139

Posters Radiation Impacts on Global Climate Models F. Baer, N. Arsky, and K. Rocque  

NLE Websites -- All DOE Office Websites (Extended Search)

5 5 Posters Radiation Impacts on Global Climate Models F. Baer, N. Arsky, and K. Rocque University of Maryland College Park, Maryland Climate Prediction and Radiative Heating Climate models are driven by forcing, and these forces are seen primarily by the thermal field in general circulation models (GCMs). The major forces that affect the thermal field are longwave radiative (LWR) heating, shortwave radiative (SWR) heating, and convection (cumulus, etc.). These forcing effects are cycled through the thermal field to the motion field by nonlinear transfer. The dependent variables-in particular, temperature (T), moisture (Q) and especially clouds-evolve in time in a model and determine the subsequent forcing. If the dependent variables are not accurately calculated in space and time, the forcing

140

The radiative and combined mode heat transfer within the L-shaped nonhomogeneous and nongray participating media  

SciTech Connect

The solutions of pure radiative and combined radiative and conductive heat transfer within a L-shaped enclosure are presented. The enclosure contains a mixture of pulverized carbon particles, CO{sub 2}, and N{sub 2}. Three different types of problems are solved: homogeneous radiative properties, nonhomogeneous radiative properties, and combined conduction-radiation problem with nonhomogeneous radiative properties. To obtain solutions for these problems, the YIX method is used. The YIX quadrature uses piecewise constant interpolation of the integrands. To handle the L-shaped enclosure, an ad hoc approach of searching the struck surface node in the line-of-sight is developed. The general approach of handling any arbitrary complex geometry is briefly described. A single point, implicit, quasi-Newton scheme is used to solve the energy equation when both the radiation and conduction heat transfer modes are present. The quasi-Newton works well for a wide range of dimensionless conduction-radiation parameter except when the parameter is less than 0.2, i.e., radiation is the dominant heat transfer mode.

Hsu, P.F. [Florida Inst. of Tech., Melbourne, FL (United States). Mechanical and Aerospace Engineering Programs; Tan, Z. [Univ. of Texas, Austin, TX (United States). Aerospace Engineering and Engineering Mechanics Dept.

1996-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "radiation transfer models" 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

RADIATION HEAT TRANSFER ENVIRONMENT IN FIRE AND FURNACE TESTS OF RADIOACTIVE MATERIALS PAKCAGES  

SciTech Connect

The Hypothetical Accident Conditions (HAC) sequential test of radioactive materials packages includes a thermal test to confirm the ability of the package to withstand a transportation fire event. The test specified by the regulations (10 CFR 71) consists of a 30 minute, all engulfing, hydrocarbon fuel fire, with an average flame temperature of at least 800 C. The requirements specify an average emissivity for the fire of at least 0.9, which implies an essentially black radiation environment. Alternate test which provide equivalent total heat input at the 800 C time averaged environmental temperature may also be employed. When alternate tests methods are employed, such as furnace or gaseous fuel fires, the equivalence of the radiation environment may require justification. The effects of furnace and open confinement fire environments are compared with the regulatory fire environment, including the effects of gases resulting from decomposition of package overpack materials. The results indicate that furnace tests can produce the required radiation heat transfer environment, i.e., equivalent to the postulated pool fire. An open enclosure, with transparent (low emissivity) fire does not produce an equivalent radiation environment.

Smith, A

2008-12-31T23:59:59.000Z

142

The Escape of Ionizing Photons from OB Associations in Disk Galaxies Radiation Transfer Through Superbubbles  

E-Print Network (OSTI)

By solving the time-dependent radiation transfer problem of stellar radiation through evolving superbubbles within a smoothly varying H I distribution, we have estimated the fraction of ionizing photons emitted by OB associations that escapes the H I disk of our Galaxy. We considered a coeval star-formation history and a Gaussian star-formation history with a time spread sigma_t = 2 Myr. We find that the shells of the expanding superbubbles quickly trap or attenuate the ionizing flux, such that most of the escaping radiation escapes shortly after the formation of the superbubble. Superbubbles of large associations can blowout of the H I disk and form dynamic chimneys, which allow the ionizing radiation directly to escape the H I disk. However, blowout occurs when the ionizing photon luminosity has dropped well below the association's maximum luminosity. For the coeval star-formation history, the fraction of photons that escape each side of the disk in the solar vicinity is f_esc approx 6% (the total fraction ...

Dove, J B; Ferrara, A; Dove, James B.; Ferrara, Andrea

1999-01-01T23:59:59.000Z

143

THERM: Two-Dimensional Building Heat-Transfer Modeling  

NLE Websites -- All DOE Office Websites (Extended Search)

5 5 THERM: Two-Dimensional Building Heat-Transfer Modeling For more information and to download THERM, please visit our website: http://windows.lbl.gov/software/therm The Windows and Daylighting Group's two-year-old computer program THERM 1.0 is a state-of-the-art tool for modeling two-dimensional heat-transfer effects in building components. The thermal property information THERM provides is important for the design and application of building components such as windows, walls, foundations, roofs and doors. This Microsoft Windows-based program has great potential to users such as building component manufacturers, educators, students, architects, engineers and others who are interested in assessing the heat-transfer properties of single products, product interactions, or integrated systems. THERM

144

Stochastic Radiative Transfer in Multilayer Broken Clouds. Part II: Validation Tests  

SciTech Connect

In the second part of our two-part paper we estimated the accuracy and robustness of the approximated equations for the mean radiance that were derived in Part I. In our analysis we used the three-dimensional (3D) cloud fields provided by (i) the stochastic Boolean model, (ii) large-eddy simulation model and (iii) satellite cloud retrieval. The accuracy of the obtained equations was evaluated by comparing the ensemble-averaged radiative properties that were obtained by the numerical averaging method (reference) and the analytical averaging method (approximation). The robustness of these equations was estimated by comparing the domain-averaged radiative properties obtained by using (i) the full 3D cloud structure (reference) and (ii) the bulk cloud statistics (approximation). It was shown that the approximated equations could provide reasonable accuracy ({approx}15%) for both the ensemble-averaged and domain-averaged radiative properties.

Kassianov, Evgueni I.; Ackerman, Thomas P.; Marchand, Roger T.; Ovtchinnikov, Mikhail

2003-04-01T23:59:59.000Z

145

Investigation of hydrogen transfer in coprocessing using model systems  

SciTech Connect

Coprocessing of coal with petroleum resid involves the reaction of two very different materials: coal is aromatic and resid is naphthenic. Hydrogen transfer is an important mechanism in most coal liquefaction systems. When coal is reacted with a coal-derived solvent, a high hydroaromatic content capable of transferring hydrogen in the solvent is desirable for achieving the desired coal conversions. But, resids tend to be naphthenic rather than hydroaromatic in character. The current study evaluated the reactivity of naphthenic compounds as models for resids in the presence of aromatic acceptors that are representative of the coal structure. The model donor used was perhydropyrene and the model acceptors were phenanthrene and anthracene. Thermal and catalytic reactions were performed at 400 and 440{degrees}C for 30 min in a H{sub 2} or N{sub 2} atmosphere with 1:1 and 5:1 ratios of model donor to model acceptor and with slurry phase catalysts, Mo naphthenate and Ni octoate. In reactions containing anthracene, the presence of perhydropyrene had increased the total amount of hydrogen being accepted by anthracene, while excess perhydropyrene was required to increase the hydrogen accepted by the model phenanthrene. Catalysis by Mo naphthenate promoted hydrogen transfer from perhydropyrene to anthracene, but catalysis by Ni octoate did not.

Shen, J.; Curtis, C.W. [Auburn Univ., AL (United States)

1995-12-31T23:59:59.000Z

146

A BAYESIAN MODEL COMMITTEE APPROACH TO FORECASTING GLOBAL SOLAR RADIATION  

E-Print Network (OSTI)

in the realm of solar radiation forecasting. In this work, two forecasting models: Autoregressive Moving1 A BAYESIAN MODEL COMMITTEE APPROACH TO FORECASTING GLOBAL SOLAR RADIATION. The very first results show an improvement brought by this approach. 1. INTRODUCTION Solar radiation

Boyer, Edmond

147

Proceedings of HT2009 2009 ASME Summer Heat Transfer Conference  

E-Print Network (OSTI)

Proceedings of HT2009 2009 ASME Summer Heat Transfer Conference July 19-23, 2009, San Francisco, CA, USA HT2009-88261 SIMULATION OF FOCUSED RADIATION PROPAGATION AND TRANSIENT HEAT TRANSFER IN TURBID-dependent radiation and conduction bio-heat transfer model. Ultrashort pulsed radiation transport in the cylindrical

Guo, Zhixiong "James"

148

Diffusion Approximation of Radiative Transfer Problems with Guillaume Bal \\Lambda Leonid Ryzhik y  

E-Print Network (OSTI)

propagation. The radiative transport equation for the evolution of the average phase space energy density a Ryzhik y September 16, 1998 Abstract We derive the diffusion approximation of transport equations with discontinuities at interfaces. The transport equations model the energy density of acoustic waves. The waves

Bal, Guillaume

149

Modeling of Heat Transfer in Rooms in the Modelica Buildings Library  

E-Print Network (OSTI)

The Future of Building System Modeling and Simulation ofequation-based modeling languages in the building simulationModeling of Heat Transfer in Rooms in the Modelica Buildings

Wetter, Michael

2013-01-01T23:59:59.000Z

150

Measurement and Modeling Implications of Transfer and Transformation  

NLE Websites -- All DOE Office Websites (Extended Search)

Measurement and Modeling Implications of Transfer and Transformation Measurement and Modeling Implications of Transfer and Transformation Processes at the Plant/Air Interface Speaker(s): Randy Maddalena Date: October 13, 1998 - 12:00pm Location: 90-3122 Seminar Host/Point of Contact: Richard Sextro To understand the chemodynamic role of vegetation in a multimedia system, the rate and extent of chemical partitioning from adjacent environmental media and the rate of chemical transformation associated with vegetation need to be determined. An exposure system was used to isolate and expose above ground vegetation to semi-volatile air contaminants. Measurements of phenanthrene, anthracene, fluoranthene and pyrene in the chamber air and the plant tissue were collected during both the uptake and clearance phase of exposure events. The measurements were fitted to the mass balance of the

151

Enhancing the heat transfer in a heat treatment furnace through improving the combustion process in the radiation tubes  

Science Journals Connector (OSTI)

......predicted and measured data. The CFD simulations...methods to improve the heat transfer rate and provide quantitative data which can be used...important in the combustion and the heat transfer processes...models on hydrogen-hydrocarbon combustion modelling......

E. M. Elmabrouk; Y. Wu

2012-02-01T23:59:59.000Z

152

Collisional and radiative excitation transfers in Kr-Xe mixtures: Quenching of Kr  

Science Journals Connector (OSTI)

A detailed study of electronic energy transfers in Kr-Xe mixtures has been made using a 250-keV electron accelerator to excite Kr-Xe mixtures over a wide range of Kr-host-gas pressure and Xe-impurity concentrations. Kr pressure ranged from 25 to 900 Torr with Xe concentrations varying from 0.1% to 10% of Kr partial pressure. Emission spectra taken in the vacuum-ultraviolet (vuv) region indicate that energy is transferred efficiently from Kr to Xe, with radiation from the Xe(3P1) state becoming greatly enhanced as the Xe-impurity concentration is increased. Emission spectra from the vuv also show that the Xe(1P1) state is populated by absorption of photons emitted from the Kr2 * first continuum. Two-body quenching rates with Xe ground-state atoms have been found for the Kr(1P1) [kq(1165 )=1.2105 sec-1/Torr] and for the Kr(3P1) [kq(1236 )=9.5105 sec-1/Torr] resonance states. Time-resolved measurements have also been made on the Kr2 * first and second continua. These measurements show the Kr(3P1) state is the atomic precursor of the Kr2 * first continuum. The results obtained in the Kr2 * second continuum are rate limited by the decay of Kr(3P1) at large Xe-impurity concentrations.

Jerry D. Cook and P. K. Leichner

1985-01-01T23:59:59.000Z

153

Thermodynamics of enhanced heat transfer: a model study  

E-Print Network (OSTI)

Situations where a spontaneous process of energy or matter transfer is enhanced by an external device are widespread in nature (human sweating system, enzyme catalysis, facilitated diffusion across bio-membranes, industrial heat exchangers). The thermodynamics of such processes remains however open. Here we study enhanced heat transfer by a model junction immersed between two thermal baths at different temperatures $T_h$ and $T_c$ ($T_h>T_c$). The transferred heat power is enhanced via controlling the junction by means of external time-dependent fields. Provided that the spontaneous heat flow process is optimized over the junction Hamiltonian, any enhancement of this spontaneous process does demand consumption and subsequent dissipation of work. The efficiency of enhancement is defined via the increment in the heat power divided over the amount of consumed work. We show that this efficiency is bounded from above by $T_c/(T_h-T_c)$. Formally this is identical to the Carnot bound for the efficiency of ordinary refrigerators which transfer heat from cold to hot. It also shares some (but not all) physical features of the Carnot bound.

Karen Hovhannisyan; Armen E. Allahverdyan

2010-07-20T23:59:59.000Z

154

Development of Aerosol Models for Radiative Flux Calculations at ARM Sites: Utility of Trajectory Clustering for Characterizing Aerosol Climatology  

NLE Websites -- All DOE Office Websites (Extended Search)

Development of Aerosol Models for Radiative Flux Development of Aerosol Models for Radiative Flux Calculations at ARM Sites: Utility of Trajectory Clustering for Characterizing Aerosol Climatology E. Andrews Cooperative Institute for Research in the Environment University of Colorado Boulder, Colorado E. Andrews, J. A. Ogren, P. J. Sheridan, and J. M. Harris Climate Monitoring and Diagnostics Laboratory National Oceanic and Atmospheric Administration Boulder, Colorado P. K. Quinn Pacific Marine Environmental Laboratory National Oceanic and Atmospheric Administration Seattle, Washington Abstract The uncertainties associated with assumptions of generic aerosol properties in radiative transfer codes are unknown, which means that these uncertainties are frequently invoked when models and

155

Canopy radiation transmission for an energy balance snowmelt model  

E-Print Network (OSTI)

Canopy radiation transmission for an energy balance snowmelt model Vinod Mahat1 and David G January 2012. [1] To better estimate the radiation energy within and beneath the forest canopy for energy differential equations using a single path assumption were solved analytically to approximate the radiation

Tarboton, David

156

Modeling of fuel-to-steel heat transfer in core disruptive accidents  

E-Print Network (OSTI)

A mathematical model for direct-contact boiling heat transfer between immiscible fluids was developed and tested experimentally. The model describes heat transfer from a hot fluid bath to an ensemble of droplets of a cooler ...

Smith, Russell Charles

1980-01-01T23:59:59.000Z

157

Multilevel bioluminescence tomography based on radiative transfer equation Part 1: l1 regularization  

E-Print Network (OSTI)

problem for the radiative transport equation, Inv. Prob.the beginning, radiative transport equation (RTE) is used as

Gao, Hao; Zhao, Hongkai

2010-01-01T23:59:59.000Z

158

Mass transfer model for two-layer TBP oxidation reactions  

SciTech Connect

To prove that two-layer, TBP-nitric acid mixtures can be safely stored in the canyon evaporators, it must be demonstrated that a runaway reaction between TBP and nitric acid will not occur. Previous bench-scale experiments showed that, at typical evaporator temperatures, this reaction is endothermic and therefore cannot run away, due to the loss of heat from evaporation of water in the organic layer. However, the reaction would be exothermic and could run away if the small amount of water in the organic layer evaporates before the nitric acid in this layer is consumed by the reaction. Provided that there is enough water in the aqueous layer, this would occur if the organic layer is sufficiently thick so that the rate of loss of water by evaporation exceeds the rate of replenishment due to mixing with the aqueous layer. This report presents measurements of mass transfer rates for the mixing of water and butanol in two-layer, TBP-aqueous mixtures, where the top layer is primarily TBP and the bottom layer is comprised of water or aqueous salt solution. Mass transfer coefficients are derived for use in the modeling of two-layer TBP-nitric acid oxidation experiments. Three cases were investigated: (1) transfer of water into the TBP layer with sparging of both the aqueous and TBP layers, (2) transfer of water into the TBP layer with sparging of just the TBP layer, and (3) transfer of butanol into the aqueous layer with sparging of both layers. The TBP layer was comprised of 99% pure TBP (spiked with butanol for the butanol transfer experiments), and the aqueous layer was comprised of either water or an aluminum nitrate solution. The liquid layers were air sparged to simulate the mixing due to the evolution of gases generated by oxidation reactions. A plastic tube and a glass frit sparger were used to provide different size bubbles. Rates of mass transfer were measured using infrared spectrophotometers provided by SRTC/Analytical Development.

Laurinat, J.E.

1994-09-28T23:59:59.000Z

159

A comparison of approximate models for radiation in gas turbines  

Science Journals Connector (OSTI)

Approximate equations for radiative heat transfer equations coupled to an equation for the temperature are stated and a comparative numerical study of the different approximations is given. The approximation methods considered here range from moment methods to simplified PN-approximations. Numerical experiments and comparisons in different space dimensions and for various physical situations are presented.

M. Frank; M. Seaid; A. Klar; R. Pinnau; G. Thommes; J. Janicka

2004-01-01T23:59:59.000Z

160

Validation of the community radiative transfer model Shouguo Ding a  

E-Print Network (OSTI)

changing weather conditions, a rational and computationally efficient method to use satellite cloud of Atmospheric Sciences, Texas A&M University, College Station, TX 77843, USA b Satellite Meteorology and Climatology Division, Center for Satellite Applications and Research, NOAA/NESDIS, Camp Springs, MD 20746, USA

Li, Jun

Note: This page contains sample records for the topic "radiation transfer models" 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

Numerical modeling of fluid flow and heat transfer in a narrow Taylor-Couette-Poiseuille system  

E-Print Network (OSTI)

Numerical modeling of fluid flow and heat transfer in a narrow Taylor-Couette-Poiseuille system S [1, 2] widely validated in various rotor-stator cavities with throughflow [3­5] and heat transfer [6: RANS modeling, Reynolds Stress Model, Taylor-Couette-Poiseuille flow, turbulence, heat transfer. hal

Paris-Sud XI, Université de

162

Spectrally enhancing near-field radiative heat transfer by exciting magnetic polariton in SiC gratings  

E-Print Network (OSTI)

In the present work, we theoretically demonstrate, for the first time, that near field radiative transport between 1D periodic grating microstructures separated by subwavelength vacuum gaps can be significantly enhanced by exciting magnetic resonance or polariton. Fluctuational electrodynamics that incorporates scattering matrix theory with rigorous coupled wave analysis is employed to exactly calculate the near field radiative heat flux between two SiC gratings. Besides the well known coupled surface phonon polaritons (SPhP), an additional spectral radiative heat flux peak, which is due to magnetic polariton, is found within the phonon absorption band of SiC. The mechanisms, behaviors and interplays between magnetic polariton, coupled SPhP, single interface SPhP, and Wood's anomaly in the near field radiative transport are elucidated in detail. The findings will open up a new way to control near field radiative heat transfer by magnetic resonance with micro or nanostructured metamaterials.

Yang, Yue

2015-01-01T23:59:59.000Z

163

Mass Transfer Model for a Breached Waste Package  

SciTech Connect

The degradation of waste packages, which are used for the disposal of spent nuclear fuel in the repository, can result in configurations that may increase the probability of criticality. A mass transfer model is developed for a breached waste package to account for the entrainment of insoluble particles. In combination with radionuclide decay, soluble advection, and colloidal transport, a complete mass balance of nuclides in the waste package becomes available. The entrainment equations are derived from dimensionless parameters such as drag coefficient and Reynolds number and based on the assumption that insoluble particles are subjected to buoyant force, gravitational force, and drag force only. Particle size distributions are utilized to calculate entrainment concentration along with geochemistry model abstraction to calculate soluble concentration, and colloid model abstraction to calculate colloid concentration and radionuclide sorption. Results are compared with base case geochemistry model, which only considers soluble advection loss.

C. Hsu; J. McClure

2004-07-26T23:59:59.000Z

164

Simulation of Static Flying Attitudes with Different Heat Transfer Models for a Flying-Height Control Slider with Thermal Protrusion  

E-Print Network (OSTI)

Zhang, S. , Bogy, D.B. : A heat transfer model for thermal ?A phenomenological heat transfer model for the molecular gasWong, C.H. : A generalized heat transfer model for thin ?lm

Chen, Du; Bogy, David B.

2010-01-01T23:59:59.000Z

165

Thermodynamics of enhanced heat transfer: a model study  

E-Print Network (OSTI)

Situations where a spontaneous process of energy or matter transfer is enhanced by an external device are widespread in nature (human sweating system, enzyme catalysis, facilitated diffusion across bio-membranes, industrial heat exchangers). The thermodynamics of such processes remains however open. Here we study enhanced heat transfer by a model junction immersed between two thermal baths at different temperatures $T_h$ and $T_c$ ($T_h>T_c$). The transferred heat power is enhanced via controlling the junction by means of external time-dependent fields. Provided that the spontaneous heat flow process is optimized over the junction Hamiltonian, any enhancement of this spontaneous process does demand consumption and subsequent dissipation of work. The efficiency of enhancement is defined via the increment in the heat power divided over the amount of consumed work. We show that this efficiency is bounded from above by $T_c/(T_h-T_c)$. Formally this is identical to the Carnot bound for the efficiency of ordinary ...

Hovhannisyan, Karen; 10.1088/1742-5468/2010/06/P06010

2010-01-01T23:59:59.000Z

166

E-Print Network 3.0 - anisotropic k-shell radiation Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

Summary: media. Specifically, we provide: (i) an anisotropic version of the radiative transport equation (RTE... scattering model in section 4. 3 Anisotropic Radiative Transfer The...

167

High linear-energy-transfer radiation can overcome radioresistance of glioma stem-like cells to low linear-energy-transfer radiation  

Science Journals Connector (OSTI)

......irradiation, especially thermal neutron irradiation. Boron-10 (10B) releases alpha (4He) and 7Li particles through...14 Kobayashi T , Kanda K. Analytical calculation of boron-10 dosage in cell nucleus for neutron capture therapy. Radiat......

Yuki Hirota; Shin-Ichiro Masunaga; Natsuko Kondo; Shinji Kawabata; Hirokazu Hirakawa; Hirohiko Yajima; Akira Fujimori; Koji Ono; Toshihiko Kuroiwa; Shin-Ichi Miyatake

2014-01-01T23:59:59.000Z

168

Cosmological Radiative Transfer Codes Comparison Project I: The Static Density Field Tests  

E-Print Network (OSTI)

Radiative transfer simulations are now at the forefront of numerical astrophysics. They are becoming crucial for an increasing number of astrophysical and cosmological problems; at the same time their computational cost has come to the reach of currently available computational power. Further progress is retarded by the considerable number of different algorithms (including various flavours of ray-tracing and moment schemes) developed, which makes the selection of the most suitable technique for a given problem a non-trivial task. Assessing the validity ranges, accuracy and performances of these schemes is the main aim of this paper, for which we have compared 11 independent RT codes on 5 test problems: (0) basic physics, (1) isothermal H II region expansion and (2) H II region expansion with evolving temperature, (3) I-front trapping and shadowing by a dense clump, (4) multiple sources in a cosmological density field. The outputs of these tests have been compared and differences analyzed. The agreement between the various codes is satisfactory although not perfect. The main source of discrepancy appears to reside in the multi-frequency treatment approach, resulting in different thicknesses of the ionized-neutral transition regions and different temperature structure. The present results and tests represent the most complete benchmark available for the development of new codes and improvement of existing ones. To this aim all test inputs and outputs are made publicly available in digital form.

Ilian T. Iliev; Benedetta Ciardi; Marcelo A. Alvarez; Antonella Maselli; Andrea Ferrara; Nickolay Y. Gnedin; Garrelt Mellema; Taishi Nakamoto; Michael L. Norman; Alexei O. Razoumov; Erik-Jan Rijkhorst; Jelle Ritzerveld; Paul R. Shapiro; Hajime Susa; Masayuki Umemura; Daniel J. Whalen

2006-03-08T23:59:59.000Z

169

ht. 1. Han Mass 7h&r. Vol. 13, pp. 13494357. Pergamon Pra 1970. PhIed in Great Britain RADIATIVE TRANSFER IN A CONSERVATIVE  

E-Print Network (OSTI)

involving radiative transport and wall temperature slip in a finite, absorbing, emitting gray medium, equation of transfer then equation (4) reduces to the simpler form where Z(z,Zl)is the radiation intensity, Zlis the In their work on radiative transport and wall direction cosine (as measured from the positive

Siewert, Charles E.

170

Comparison between Model Simulations and Measurements of Hyperspectral Far- infrared Radiation from FIRST during the RHUBC-II Campaign  

E-Print Network (OSTI)

for its dry, cold, and dominantly clear atmosphere, which is optimal for studying the effects, that water vapor and cirrus clouds have on the far-IR. Comparisons with Line-By-Line Discrete Ordinants Radiative Transfer model, LBLDIS, show that FIRST...

Baugher, Elizabeth

2012-02-14T23:59:59.000Z

171

Modelling the Transfer Function for the Dark Energy Survey  

SciTech Connect

We present a forward-modelling simulation framework designed to model the data products from the Dark Energy Survey (DES). This forward-model process can be thought of as a transfer function -- a mapping from cosmological and astronomical signals to the final data products used by the scientists. Using output from the cosmological simulations (the Blind Cosmology Challenge), we generate simulated images (the Ultra Fast Image Simulator, Berge et al. 2013) and catalogs representative of the DES data. In this work we simulate the 244 sq. deg coadd images and catalogs in 5 bands for the DES Science Verification (SV) data. The simulation output is compared with the corresponding data to show that major characteristics of the images and catalogs can be captured. We also point out several directions of future improvements. Two practical examples, star/galaxy classification and proximity effects on object detection, are then used to demonstrate how one can use the simulations to address systematics issues in data analysis. With clear understanding of the simplifications in our model, we show that one can use the simulations side-by-side with data products to interpret the measurements. This forward modelling approach is generally applicable for other upcoming and future surveys. It provides a powerful tool for systematics studies which is sufficiently realistic and highly controllable.

Chang, C.

2014-10-31T23:59:59.000Z

172

The effects of radiative transfer in maintaining the Indian summer monsoon  

SciTech Connect

Atmospheric radiative transfer is an important thermodynamic forcing for the Indian summer monsoon. The monsoon is a component of a larger scale circulation system the principal components of which are the Hadley cell and the Walker Circulation. The Hadley cell is a thermally direct circulation that transports heat toward the poles. In the northern hemispheric summer, the ascending branch of the Hadley cell moves northward, due to heating of the land masses. This ascending branch of the Hadley cell is referred to as the Intertropical Convergence Zone (ITCZ). The return branch of the Hadley cell is characterized by southwesterly surface winds. At the surface, the ITCZ is marked by convergence of southwesterly surface winds from the south and northeasterly surface winds from the north. As the ITCZ moves northward, the southern extent of the northerly surface winds also moves northward, and southerly surface winds from the south side of the ITCZ also move northward. The surface convergence at the ITCZ is a driving mechanism for the summer monsoon circulation. The northward drift of the Hadley cell in the northern summer ITCZ is the deep convection over the warm pool of water in the western tropical Pacific ocean, located at about 160E. The latent heating in the deep convection drives another direct circulation, known as the Walker Circulation. The upper branch of the Walker Circulation over south Asia is easterly winds created by the deep convection in the western tropical Pacific. Convective activity over the Indian peninsula interacts with the Walker Circulation, creating a jet structure over the western part of India and the eastern Arabian Sea. This structure is known as the Tropical Easterly Jet (TEJ). Secondary circulations associated with the Indian convection also help to maintain the baroclinicity, which is essential to the development of monsoon depression, the maintenance of the monsoon trough, and the circulation and hydrology of the region in general.

Leach, M.J.; Raman, S. [North Carolina State Univ., Raleigh, NC (United States)

1995-04-01T23:59:59.000Z

173

FURN3D: A computer code for radiative heat transfer in pulverized coal furnaces  

SciTech Connect

A computer code FURN3D has been developed for assessing the impact of burning different coals on heat absorption pattern in pulverized coal furnaces. The code is unique in its ability to conduct detailed spectral calculations of radiation transport in furnaces fully accounting for the size distributions of char, soot and ash particles, ash content, and ash composition. The code uses a hybrid technique of solving the three-dimensional radiation transport equation for absorbing, emitting and anisotropically scattering media. The technique achieves an optimal mix of computational speed and accuracy by combining the discrete ordinate method (S[sub 4]), modified differential approximation (MDA) and P, approximation in different range of optical thicknesses. The code uses spectroscopic data for estimating the absorption coefficients of participating gases C0[sub 2], H[sub 2]0 and CO. It invokes Mie theory for determining the extinction and scattering coefficients of combustion particulates. The optical constants of char, soot and ash are obtained from dispersion relations derived from reflectivity, transmissivity and extinction measurements. A control-volume formulation is adopted for determining the temperature field inside the furnace. A simple char burnout model is employed for estimating heat release and evolution of particle size distribution. The code is written in Fortran 77, has modular form, and is machine-independent. The computer memory required by the code depends upon the number of grid points specified and whether the transport calculations are performed on spectral or gray basis.

Ahluwalia, R.K.; Im, K.H.

1992-08-01T23:59:59.000Z

174

FURN3D: A computer code for radiative heat transfer in pulverized coal furnaces  

SciTech Connect

A computer code FURN3D has been developed for assessing the impact of burning different coals on heat absorption pattern in pulverized coal furnaces. The code is unique in its ability to conduct detailed spectral calculations of radiation transport in furnaces fully accounting for the size distributions of char, soot and ash particles, ash content, and ash composition. The code uses a hybrid technique of solving the three-dimensional radiation transport equation for absorbing, emitting and anisotropically scattering media. The technique achieves an optimal mix of computational speed and accuracy by combining the discrete ordinate method (S{sub 4}), modified differential approximation (MDA) and P, approximation in different range of optical thicknesses. The code uses spectroscopic data for estimating the absorption coefficients of participating gases C0{sub 2}, H{sub 2}0 and CO. It invokes Mie theory for determining the extinction and scattering coefficients of combustion particulates. The optical constants of char, soot and ash are obtained from dispersion relations derived from reflectivity, transmissivity and extinction measurements. A control-volume formulation is adopted for determining the temperature field inside the furnace. A simple char burnout model is employed for estimating heat release and evolution of particle size distribution. The code is written in Fortran 77, has modular form, and is machine-independent. The computer memory required by the code depends upon the number of grid points specified and whether the transport calculations are performed on spectral or gray basis.

Ahluwalia, R.K.; Im, K.H.

1992-08-01T23:59:59.000Z

175

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

176

Activity Stream - Brazil Direct Normal Solar Radiation Model...  

Open Energy Info (EERE)

Dataset Activity Stream Activity Stream Jay Huggins updated the dataset Brazil Direct Normal Solar Radiation Model (10km) from INPE and LABSOLAR 6 days ago Jay Huggins added the...

177

Heat transfer of a micropolar fluid by the presence of radiation  

Science Journals Connector (OSTI)

An analysis of the steady flow of a micropolar fluid past an unmoving plate by the presence of radiation is considered. Numerical solution for temperature field has been derived and the effect of the radiation...

C. Perdikis; A. Raptis

1996-08-01T23:59:59.000Z

178

Modelling the Transfer Function for the Dark Energy Survey  

E-Print Network (OSTI)

We present a forward-modelling simulation framework designed to model the data products from the Dark Energy Survey (DES). This forward-model process can be thought of as a transfer function -- a mapping from cosmological and astronomical signals to the final data products used by the scientists. Using output from the cosmological simulations (the Blind Cosmology Challenge), we generate simulated images (the Ultra Fast Image Simulator, Berge et al. 2013) and catalogs representative of the DES data. In this work we simulate the 244 sq. deg coadd images and catalogs in 5 bands for the DES Science Verification (SV) data. The simulation output is compared with the corresponding data to show that major characteristics of the images and catalogs can be captured. We also point out several directions of future improvements. Two practical examples, star/galaxy classification and proximity effects on object detection, are then used to demonstrate how one can use the simulations to address systematics issues in data ana...

Chang, C; Wechsler, R H; Refregier, A; Amara, A; Rykoff, E; Becker, M R; Bruderer, C; Gamper, L; Leistedt, B; Peiris, H; Abbott, T; Abdalla, F B; Banerji, M; Bernstein, R A; Bertin, E; Brooks, D; Rosell, A Carnero; Desai, S; da Costa, L N; Cunha, C E; Eifler, T; Evrard, A E; Neto, A Fausti; Gerdes, D; Gruen, D; James, D; Kuehn, K; Maia, M A G; Makler, M; Ogando, R; Plazas, A; Sanchez, E; Schubnell, M; Sevilla-Noarbe, I; Smith, C; Soares-Santos, M; Suchyta, E; Swanson, M E C; Tarle, G; Zuntz, J

2014-01-01T23:59:59.000Z

179

Asymptotic Preserving Unified Gas Kinetic Scheme for Grey Radiative Transfer Equations  

E-Print Network (OSTI)

The solutions of radiative transport equations can cover both optical thin and optical thick regimes due equations, where the radiation transport equation is coupled with the material thermal energy equation(2013), 138-156] from a one-dimensional linear radiation transport equation to a nonlinear two

Xu, Kun

180

Radiative Transfer of Sound Waves in a Random Flow: Turbulent Scattering and ModeCoupling  

E-Print Network (OSTI)

systematically to derive the radiative transport equations that describe the evolution of acoustic correlation : : : : : : : : : : : : : : : : : : : : 8 3.2 The radiative transport equations : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 9 of the radiative transport equations 21 B Derivation of the diffusion equation without flow­straining 23 C

Ryzhik, Lenya

Note: This page contains sample records for the topic "radiation transfer models" 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

Heat and Mass Transfer in the MHD Flow of a Visco-elastic Fluid in a Rotating Porous Channel with Radiative Heat  

Science Journals Connector (OSTI)

This paper deals with heat and mass transfer in the magnetohydrodynamic flow of a visco-elastic fluid in a rotating porous channel with radiative heat. The flow phenomenon has been characterized by the fluid para...

M. Jena; M. Goswami; S. Biswal

2014-12-01T23:59:59.000Z

182

Solar Radiation Estimated Through Mesoscale Atmospheric Modeling over Northeast Brazil  

Science Journals Connector (OSTI)

The use of renewable energy sources like solar wind and biomass is rapidly increasing in recent years with solar radiation as a particularly abundant energy source over Northeast Brazil. A proper quantitative knowledge of the incoming solar radiation is of great importance for energy planning in Brazil serving as basis for developing future projects of photovoltaic power plants and solar energy exploitation. This work presents a methodology for mapping the incoming solar radiation at ground level for Northeast Brazil using a mesoscale atmospheric model (Regional Atmospheric Modeling SystemRAMS) calibrated and validated using data from the network of automatic surface stations from the State Foundation for Meteorology and Water Resources from Cear (Fundao Cearense de Meteorologia e Recursos Hdricos? FUNCEME). The results showed that the model exhibits systematic errors overestimating surface radiation but that after the proper statistical corrections using a relationship between the model?predicted cloud fraction the ground?level observed solar radiation and the incoming solar radiation estimated at the top of the atmosphere a correlation of 0.92 with a confidence interval of 13.5? W / m 2 is found for monthly data. Using this methodology we found an estimate for annual average incoming solar radiation over Cear of 215? W / m 2 (maximum in October: 260? W / m 2 ).

Otacilio Leandro de Menezes Neto; Alexandre Arajo Costa; Fernando Pinto Ramalho; Paulo Henrique Santiago de Maria

2009-01-01T23:59:59.000Z

183

Application Of A Spherical-Radial Heat Transfer Model To Calculate...  

Open Energy Info (EERE)

Spherical-Radial Heat Transfer Model To Calculate Geothermal Gradients From Measurements In Deep Boreholes Jump to: navigation, search OpenEI Reference LibraryAdd to library...

184

A Study of Longwave Radiation Codes for Climate Studies: Validation with ARM Observations and Tests in General Circulation Models  

SciTech Connect

One specific goal of the Atmospheric Radiation Measurements (ARM) program is to improve the treatment of radiative transfer in General Circulation Models (GCMs) under clear-sky, general overcast and broken cloud conditions. Our project was geared to contribute to this goal by attacking major problems associated with one of the dominant radiation components of the problem --longwave radiation. The primary long-term project objectives were to: (1) develop an optimum longwave radiation model for use in GCMs that has been calibrated with state-of-the-art observations for clear and cloudy conditions, and (2) determine how the longwave radiative forcing with an improved algorithm contributes relatively in a GCM when compared to shortwave radiative forcing, sensible heating, thermal advection and convection. The approach has been to build upon existing models in an iterative, predictive fashion. We focused on comparing calculations from a set of models with operationally observed data for clear, overcast and broken cloud conditions. The differences found through the comparisons and physical insights have been used to develop new models, most of which have been tested with new data. Our initial GCM studies used existing GCMs to study the climate model-radiation sensitivity problem. Although this portion of our initial plans was curtailed midway through the project, we anticipate that the eventual outcome of this approach will provide both a better longwave radiative forcing algorithm and from our better understanding of how longwave radiative forcing influences the model equilibrium climate, how improvements in climate prediction using this algorithm can be achieved.

Robert G. Ellingson

2004-09-28T23:59:59.000Z

185

Validation of nuclear models used in space radiation shielding applications  

SciTech Connect

A program of verification and validation has been undertaken to assess the applicability of models to space radiation shielding applications and to track progress as these models are developed over time. In this work, simple validation metrics applicable to testing both model accuracy and consistency with experimental data are developed. The developed metrics treat experimental measurement uncertainty as an interval and are therefore applicable to cases in which epistemic uncertainty dominates the experimental data. To demonstrate the applicability of the metrics, nuclear physics models used by NASA for space radiation shielding applications are compared to an experimental database consisting of over 3600 experimental cross sections. A cumulative uncertainty metric is applied to the question of overall model accuracy, while a metric based on the median uncertainty is used to analyze the models from the perspective of model development by examining subsets of the model parameter space.

Norman, Ryan B., E-mail: Ryan.B.Norman@nasa.gov [NASA Langley Research Center, Hampton, VA 23681 (United States); Blattnig, Steve R. [NASA Langley Research Center, Hampton, VA 23681 (United States)] [NASA Langley Research Center, Hampton, VA 23681 (United States)

2013-01-15T23:59:59.000Z

186

Effects of Radiation on Adaptive Immunity: Contact Hypersensitivity Model  

NLE Websites -- All DOE Office Websites (Extended Search)

Radiation on Adaptive Immunity: Contact Hypersensitivity Model Radiation on Adaptive Immunity: Contact Hypersensitivity Model Gregory Nelson Loma Linda University Abstract It has long been appreciated that cells of the immune system are radiosensitive and use apoptosis as the primary mechanism of cell death following injury. The hypervariability of the immunoglobulin superfamily of genes expressed in lymphoid cells also led to the appreciation of the nonhomologous end joining mechanism of DNA repair. Clinically, whole body irradiation is used in treatment of some lymphomas and as an immunosuppressive agent for bone marrow transplants. Inflammation at sites of radiotherapy is a common side effect. Many studies with radiation have addressed the changes in cell populations following radiation exposure and have shown a reproducible pattern of relative sensitivities amongst

187

Radiation dose modeling using IGRIP and Deneb/ERGO  

SciTech Connect

The Radiological Environment Modeling System (REMS) quantifies dose to humans in radiation environments using the IGRIP (Interactive Graphical Robot Instruction Program) and Deneb/ERGO (Ergonomics) simulation software products. These commercially available products are augmented with custom C code to provide the radiation exposure information to and collect the radiation dose information from the workcell simulations. The emphasis of this paper is on the IGRIP and Deneb/ERGO parts of REMS, since that represents the extension to existing capabilities developed by the authors. Through the use of any radiation transport code or measured data, a radiation exposure input database may be formulated. User-specified IGRIP simulations utilize these database files to compute and accumulate dose to human devices (Deneb`s ERGO human) during simulated operations around radiation sources. Timing, distances, shielding, and human activity may be modeled accurately in the simulations. The accumulated dose is recorded in output files, and the user is able to process and view this output. REMS was developed because the proposed reduction in the yearly radiation exposure limit will preclude or require changes in many of the manual operations currently being utilized in the Weapons Complex. This is particularly relevant in the area of dismantlement activities at the Pantex Plant in Amarillo, TX. Therefore, a capability was needed to be able to quantify the dose associated with certain manual processes so that the benefits of automation could be identified and understood.

Vickers, D.S.; Davis, K.R.; Breazeal, N.L.; Watson, R.A. [Sandia National Labs., Albuquerque, NM (United States); Ford, M.S. [Battelle Pantex, Amarillo, TX (United States). Dept. of Radiation Safety

1995-12-31T23:59:59.000Z

188

A Study on Heat Transfer Model in Sparse Zone of Oxy-Fuel Fired CFB  

Science Journals Connector (OSTI)

A model has been developed to calculate the coefficient heat transfer in sparse zone of oxy-fuel fired circulating fluidized bed boiler (CFBB). The model shows that the convective heat transfer coefficient is enhanced with increase in CO2 density, bed ...

Chunbo Wang; Weijun Hou; Wei Zhang; Guang Lu; Zhihong Huo; Jiao Zhang

2009-10-01T23:59:59.000Z

189

A LATTICE BOLTZMANN MODEL FOR CONVECTION HEAT TRANSFER IN POROUS MEDIA  

E-Print Network (OSTI)

A LATTICE BOLTZMANN MODEL FOR CONVECTION HEAT TRANSFER IN POROUS MEDIA Zhaoli Guo and T. S. Zhao Kong, China A lattice Boltzmann model for convection heat transfer in porous media is proposed-difference, finite-volume, and finite-element methods (e.g., [2, 3]). The lattice Boltzmann method (LBM

Zhao, Tianshou

190

Development of Property-Transfer Models for Estimating the Hydraulic Properties of Deep  

E-Print Network (OSTI)

Development of Property-Transfer Models for Estimating the Hydraulic Properties of Deep Sediments. #12;Development of Property-Transfer Models for Estimating the Hydraulic Properties of Deep Sediments-USGS World Wide Web: http://www.usgs.gov/ Any use of trade, product, or firm names in this publication

191

Brazil PAR Solar Radiation Model (40km) from INPE and LABSOLAR | OpenEI  

Open Energy Info (EERE)

40km) from INPE and LABSOLAR 40km) from INPE and LABSOLAR Dataset Summary Description (Abstract): Photosynthetically active radiation in kWh/m2/day for 1 year organized into cells with 40km x 40km (Purpose): The BRASIL-SR model and the SPRING software (both developed by INPE - National Institute for Space Research) were used to produce the dataset and SHAPE files (Supplemental Information): The assessment of reliability levels of the BRASIL-SR model were performed through the evaluation of the deviations shown by the estimated values for solar radiation flux vis-à-vis the values measured at the surface (ground truth). This evaluation was done in two phases. The first phase consisted in an inter-comparison between the core radiation transfer models adopted by the SWERA Project to map the solar energy in the various countries participating in the project. The HELIOSAT model took part in this phase like benchmark due to its employment to map solar energy resources in countries from European Union. In the second phase, the solar flux estimates provided by the BRASIL-SR model were compared with measured values acquired at several solarimetric stations spread along the Brazilian territory

192

Brazil Direct Normal Solar Radiation Model (40km) from INPE and LABSOLAR |  

Open Energy Info (EERE)

40km) from INPE and LABSOLAR 40km) from INPE and LABSOLAR Dataset Summary Description (Abstract): Normal direct solar radiation in kWh/m2/day for 1 year organized into cells with 40km x 40km (Purpose): To provide a set of consistent, reliable, verifiable, and accessible global data sets for international and in-country investors and other stakeholders (Supplemental Information): The BRASIL-SR model and the SPRING software (both developed by INPE - National Institute for Space Research) were used to produce the dataset and SHAPE files. The assessment of reliability levels of the BRASIL-SR model were performed through the evaluation of the deviations shown by the estimated values for solar radiation flux vis-à-vis the values measured at the surface (ground truth). This evaluation was done in two phases. The first phase consisted in an inter-comparison between the core radiation transfer models adopted by the SWERA Project to map the solar energy in the various countries participating in the project. The HELIOSAT model took part in this phase like benchmark due to its employment to map solar energy resources in countries from European Union. In the second phase, the solar flux estimates provided by the BRASIL-SR model were compared with measured values acquired at several solarimetric stations spread along the Brazilian territory.

193

Brazil Direct Normal Solar Radiation Model (10km) from INPE and LABSOLAR |  

Open Energy Info (EERE)

10km) from INPE and LABSOLAR 10km) from INPE and LABSOLAR Dataset Summary Description (Abstract): Normal direct solar radiation in kWh/m2/day for 1 year organized into cells with 10km x 10km (Purpose): The BRASIL-SR model and the SPRING software (both developed by INPE - National Institute for Space Research) were used to produce the dataset and SHAPE files (Supplemental Information): The assessment of reliability levels of the BRASIL-SR model were performed through the evaluation of the deviations shown by the estimated values for solar radiation flux vis-à-vis the values measured at the surface (ground truth). This evaluation was done in two phases. The first phase consisted in an inter-comparison between the core radiation transfer models adopted by the SWERA Project to map the solar energy in the various countries participating in the project. The HELIOSAT model took part in this phase like benchmark due to its employment to map solar energy resources in countries from European Union. In the second phase, the solar flux estimates provided by the BRASIL-SR model were compared with measured values acquired at several solarimetric stations spread along the Brazilian territory

194

Brazil Global Horizontal Solar Radiation Model (10km) from INPE | OpenEI  

Open Energy Info (EERE)

10km) from INPE 10km) from INPE Dataset Summary Description (Abstract): Global horizontal solar radiation in kWh/m2/day for 1 year organized into cells with 10km x 10km (Purpose): The BRASIL-SR model and the SPRING software (both developed by INPE - National Institute for Space Research) were used to produce the dataset and SHAPE files (Supplemental Information): The assessment of reliability levels of the BRASIL-SR model were performed through the evaluation of the deviations shown by the estimated values for solar radiation flux vis-à-vis the values measured at the surface (ground truth). This evaluation was done in two phases. The first phase consisted in an inter-comparison between the core radiation transfer models adopted by the SWERA Project to map the solar energy in the various countries participating in the project. The HELIOSAT model took part in this phase like benchmark due to its employment to map solar energy resources in countries from European Union. In the second phase, the solar flux estimates provided by the BRASIL-SR model were compared with measured values acquired at several solarimetric stations spread along the Brazilian territory

195

Brazil PAR Solar Radiation Model (10km) from INPE and LABSOLAR | OpenEI  

Open Energy Info (EERE)

10km) from INPE and LABSOLAR 10km) from INPE and LABSOLAR Dataset Summary Description (Abstract): Photosynthetically active radiation in kWh/m2/day for 1 year organized into cells with 10km x 10km (Purpose): The BRASIL-SR model and the SPRING software (both developed by INPE -National Institute for Space Research) were used to produce the dataset and SHAPE files (Supplemental Information): The assessment of reliability levels of the BRASIL-SR model were performed through the evaluation of the deviations shown by the estimated values for solar radiation flux vis-à-vis the values measured at the surface (ground truth). This evaluation was done in two phases. The first phase consisted in an inter-comparison between the core radiation transfer models adopted by the SWERA Project to map the solar energy in the various countries participating in the project. The HELIOSAT model took part in this phase like benchmark due to its employment to map solar energy resources in countries from European Union. In the second phase, the solar flux estimates provided by the BRASIL-SR model were compared with measured values acquired at several solarimetric stations spread along the Brazilian territory

196

Brazil Global Horizontal Solar Radiation Model (40km) from INPE | OpenEI  

Open Energy Info (EERE)

40km) from INPE 40km) from INPE Dataset Summary Description (Abstract): Global horizontal solar radiation in kWh/m2/day for 1 year organized into cells with 40km x 40km (Purpose): To provide a set of consistent, reliable, verifiable, and accessible global data sets for international and in-country investors and other stakeholders (Supplemental Information): The BRASIL-SR model and the SPRING software (both developed by INPE - National Institute for Space Research) were used to produce the dataset and SHAPE files. The assessment of reliability levels of the BRASIL-SR model were performed through the evaluation of the deviations shown by the estimated values for solar radiation flux vis-à-vis the values measured at the surface (ground truth). This evaluation was done in two phases. The first phase consisted in an inter-comparison between the core radiation transfer models adopted by the SWERA Project to map the solar energy in the various countries participating in the project. The HELIOSAT model took art in this phase like benchmark due to its employment to map solar energy resources in countries from European Union. In the second phase, the solar flux estimates provided by the BRASIL-SR model were compared with measured values acquired at several solarimetric stations spread along the Brazilian territory.

197

Brazil Latitude Tilted Solar Radiation Model (10km) from INPE and LABSOLAR  

Open Energy Info (EERE)

10km) from INPE and LABSOLAR 10km) from INPE and LABSOLAR Dataset Summary Description (Abstract): Latitude tilted solar radiation in kWh/m2/day for 1 year organized into cells with 10km x 10km (Purpose): The BRASIL-SR model and the SPRING software (both developed by INPE -National Institute for Space Research) were used to produce the dataset and SHAPE files (Supplemental Information): The assessment of reliability levels of the BRASIL-SR model were performed through the evaluation of the deviations shown by the estimated values for solar radiation flux vis-à-vis the values measured at the surface (ground truth). This evaluation was done in two phases. The first phase consisted in an inter-comparison between the core radiation transfer models adopted by the SWERA Project to map the solar energy in the various countries participating in the project. The HELIOSAT model took part in this phase like benchmark due to its employment to map solar energy resources incountries from European Union. In the second phase, the solar flux estimates providedby the BRASIL-SR model were compared with measured values acquired at several solarimetric stations spread along the Brazilian territory

198

Development of a UF{sub 6} cylinder transient heat transfer/stress analysis model  

SciTech Connect

A heat transfer/stress analysis model is being developed to simulate the heating to a point of rupture of a cylinder containing UF{sub 6} when it is exposed to a fire. The assumptions underlying the heat transfer portion of the model, which has been the focus of work to date, will be discussed. A key aspect of this model is a lumped parameter approach to modeling heat transfer. Preliminary results and future efforts to develop an integrated thermal/stress model will be outlined.

Williams, W.R. [Martin Marietta Energy Systems, Inc., Oak Ridge, TN (United States)

1991-12-31T23:59:59.000Z

199

Bayesian decision theory as a model of human visual perception: Testing Bayesian transfer  

E-Print Network (OSTI)

Bayesian decision theory as a model of human visual perception: Testing Bayesian transfer LAURENCE November 12, 2008) Abstract Bayesian decision theory (BDT) is a mathematical framework that allows without learning. Keywords: Perception, Bayesian decision theory, Statistical models, Loss function

Maloney, Laurence T.

200

Three-dimensional CFD analysis for simulating the greenhouse effect in solar chimney power plants using a two-band radiation model  

Science Journals Connector (OSTI)

Abstract The greenhouse effect in the solar collector has a fundamental role to produce the upward buoyancy force in solar chimney power plant systems. This study underlines the importance of the greenhouse effect on the buoyancy-driven flow and heat transfer characteristics through the system. For this purpose, a three-dimensional unsteady model with the RNG k? turbulence closure was developed, using computational fluid dynamics techniques. In this model, to solve the radiative transfer equation the discrete ordinates (DO) radiation model was implemented, using a two-band radiation model. To simulate radiation effects from the sun's rays, the solar ray tracing algorithm was coupled to the calculation via a source term in the energy equation. Simulations were carried out for a system with the geometry parameters of the Manzanares power plant. The effects of the solar insolation and pressure drop across the turbine on the flow and heat transfer of the system were considered. Based on the numerical results, temperature profile of the ground surface, thermal collector efficiency and power output were calculated and the results were validated by comparing with experimental data of this prototype power plant. Furthermore, enthalpy rise through the collector and energy loss from the chimney outlet between 1-band and two-band radiation model were compared. The analysis showed that simulating the greenhouse effect has an important role to accurately predict the characteristics of the flow and heat transfer in solar chimney power plant systems.

Ehsan Gholamalizadeh; Man-Hoe Kim

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "radiation transfer models" 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

Development of a mathematical model and simulation of mass transfer of solar ethanol distillation in modified brewery tank  

Science Journals Connector (OSTI)

Abstract The objective of this study was to develop a mathematical model of the mass transfer in a modified brewery tank for producing fuel ethanol. To reduce fossil fuel consumption, 50 flat-plate solar collectors were used as the heat source for the two stages of a distillation process for increasing the ethanol concentration. A 350-L distillation tank with 10%v/v (Stage 1) and a 70-L distillation tank with 40%v/v (Stage 2) were employed in the experiment used to develop the mathematical model of the mass transfer. A difference of approximately 10% was observed between the model predictions and the experimental results of the distillation product of Stage 1, whereas the predicted concentration was approximately 30% higher than that of the experiment, although this was reduced to approximately 5% by homogeneous mixing of the solution. Regarding the distillation process of Stage 2, there was approximately 10% difference between the predicted and experimental products, and approximately 3% difference between the predicted and experimental concentrations. The differences are attributed to errors in the heat transfer rate prediction of the model, which varies directly with the solar radiation values.

J. Jareanjit; P. Siangsukone; K. Wongwailikhit; J. Tiansuwan

2014-01-01T23:59:59.000Z

202

Handbook of anatomical models for radiation dosimetry  

Science Journals Connector (OSTI)

......Hardbound). Handbook of Anatomical Models...Boolean algebraic operations (union, intersection...scenarios around nuclear power stations both in...treatment planning system based on the EGS...solving a large system of Kirchoff's...may be noted that Handbook of Anatomical Models......

Gianfranco Gualdrini; Paolo Ferrari

2011-01-01T23:59:59.000Z

203

E-Print Network 3.0 - atmospheric radiative transfer Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

Earth and Atmospheric Sciences, Cornell University Collection: Geosciences 49 The Greenhouse Effect without Feedbacks Summary: Number microns10.016.7 7.14 T261K 12;Radiative...

204

Atmospheric transmittance model for photosynthetically active radiation  

SciTech Connect

A parametric model of the atmospheric transmittance in the PAR band is presented. The model can be straightforwardly applied for calculating the beam, diffuse and global components of the PAR solar irradiance. The required inputs are: air pressure, ozone, water vapor and nitrogen dioxide column content, ngstrm's turbidity coefficient and single scattering albedo. Comparison with other models and ground measured data shows a reasonable level of accuracy for this model, making it suitable for practical applications. From the computational point of view the calculus is condensed into simple algebra which is a noticeable advantage. For users interested in speed-intensive computation of the effective PAR solar irradiance, a PC program based on the parametric equations along with a user guide are available online at http://solar.physics.uvt.ro/srms.

Paulescu, Marius; Stefu, Nicoleta; Gravila, Paul; Paulescu, Eugenia; Boata, Remus; Pacurar, Angel; Mares, Oana [Physics Department, West University of Timisoara, V Parvan 4, 300223 Timisoara (Romania); Pop, Nicolina [Department of Physical Foundations of Engineering, Politehnica University of Timisoara, V Parvan 2, 300223 Timisoara (Romania); Calinoiu, Delia [Mechanical Engineering Faculty, Politehnica University of Timisoara, Mihai Viteazu 1, 300222 Timisoara (Romania)

2013-11-13T23:59:59.000Z

205

Three-body radiative heat transfer and Casimir-Lifshitz force out of thermal equilibrium for arbitrary bodies  

E-Print Network (OSTI)

We study the Casimir-Lifshitz force and the radiative heat transfer in a system consisting of three bodies held at three independent temperatures and immersed in a thermal environment, the whole system being in a stationary configuration out of thermal equilibrium. The theory we develop is valid for arbitrary bodies, i.e. for any set of temperatures, dielectric and geometrical properties, and describes each body by means of its scattering operators. For the three-body system we provide a closed-form unified expression of the radiative heat transfer and of the Casimir-Lifshitz force (both in and out of thermal equilibrium). This expression is thus first applied to the case of three planar parallel slabs. In this context we discuss the non-additivity of the force at thermal equilibrium, as well as the equilibrium temperature of the intermediate slab as a function of its position between two external slabs having different temperatures. Finally, we consider the force acting on an atom inside a planar cavity. We show that, differently from the equilibrium configuration, the absence of thermal equilibrium admits one or more positions of minima for the atomic potential. While the corresponding atomic potential depths are very small for typical ground state atoms, they may become particularly relevant for Rydberg atoms, becoming a promising tool to produce an atomic trap.

Riccardo Messina; Mauro Antezza

2014-02-11T23:59:59.000Z

206

Atmospheric radiation measurement: A program for improving radiative forcing and feedback in general circulation models  

SciTech Connect

The Atmospheric Radiation Measurement (ARM) Program is a key element of the Department of Energy`s (DOE`s) global change research strategy. ARM represents a long-term commitment to conduct comprehensive studies of the spectral atmospheric radiative energy balance profile for a wide range of cloud conditions and surface types, and to develop the knowledge necessary to improve parameterizations of radiative processes under various cloud regimes for use in general circulation models (GCMs) and related models. The importance of the ARM program is a apparent from the results of model assessments of the impact on global climate change. Recent studies suggest that radiatively active trace gas emissions caused by human activity can lead to a global warming of 1.5 to 4.5 degrees Celsius and to important changes in water availability during the next century (Cess, et al. 1989). These broad-scale changes can be even more significant at regional levels, where large shifts in temperature and precipitation patterns are shown to occur. However, these analyses also indicate that considerable uncertainty exists in these estimates, with the manner in which cloud radiative processes are parameterized among the most significant uncertainty. Thus, although the findings have significant policy implications in assessment of global and regional climate change, their uncertainties greatly influence the policy debate. ARM`s highly focused observational and analytical research is intended to accelerate improvements and reduce key uncertainties associated with the way in which GCMs treat cloud cover and cloud characteristics and the resulting radiative forcing. This paper summarizes the scientific context for ARM, ARM`s experimental approach, and recent activities within the ARM program.

Patrinos, A.A. [USDOE, Washington, DC (United States); Renne, D.S.; Stokes, G.M. [Pacific Northwest Lab., Richland, WA (United States); Ellingson, R.G. [Maryland Univ., College Park, MD (United States)

1991-01-01T23:59:59.000Z

207

Atmospheric radiation measurement: A program for improving radiative forcing and feedback in general circulation models  

SciTech Connect

The Atmospheric Radiation Measurement (ARM) Program is a key element of the Department of Energy's (DOE's) global change research strategy. ARM represents a long-term commitment to conduct comprehensive studies of the spectral atmospheric radiative energy balance profile for a wide range of cloud conditions and surface types, and to develop the knowledge necessary to improve parameterizations of radiative processes under various cloud regimes for use in general circulation models (GCMs) and related models. The importance of the ARM program is a apparent from the results of model assessments of the impact on global climate change. Recent studies suggest that radiatively active trace gas emissions caused by human activity can lead to a global warming of 1.5 to 4.5 degrees Celsius and to important changes in water availability during the next century (Cess, et al. 1989). These broad-scale changes can be even more significant at regional levels, where large shifts in temperature and precipitation patterns are shown to occur. However, these analyses also indicate that considerable uncertainty exists in these estimates, with the manner in which cloud radiative processes are parameterized among the most significant uncertainty. Thus, although the findings have significant policy implications in assessment of global and regional climate change, their uncertainties greatly influence the policy debate. ARM's highly focused observational and analytical research is intended to accelerate improvements and reduce key uncertainties associated with the way in which GCMs treat cloud cover and cloud characteristics and the resulting radiative forcing. This paper summarizes the scientific context for ARM, ARM's experimental approach, and recent activities within the ARM program.

Patrinos, A.A. (USDOE, Washington, DC (United States)); Renne, D.S.; Stokes, G.M. (Pacific Northwest Lab., Richland, WA (United States)); Ellingson, R.G. (Maryland Univ., College Park, MD (United States))

1991-01-01T23:59:59.000Z

208

Low Dose Radiation Research Program: Modeling Intercellular Interactions  

NLE Websites -- All DOE Office Websites (Extended Search)

Modeling Intercellular Interactions During Radiation Carcinogenesis Modeling Intercellular Interactions During Radiation Carcinogenesis Authors: Rainer K Sachs,1 Michael Chan,2 Lynn Hlatky,3 Philip Hahnfeldt3 Institutions: 1Departments of Mathematics and Physics, University of California Berkeley California; 2School of Medicine, University of California at San Diego, La Jolla California; 3Department of Radiation Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston Massachusetts Abstract By modulating the microenvironment of malignant or pre-malignant epithelial cells, inhibitory or stimulatory signals from nearby cells, including those in stromal and vascular tissues, can play a key role in carcinogenesis; cancer is ultimately a disease of a whole-cell community, not just of a single cell, clone, or cell lineage. However, current commonly used

209

Radiation protection in inhomogeneous betagamma fields and modelling of hand phantoms with MCNPX  

Science Journals Connector (OSTI)

......performed using the MCNPX software. In order to investigate...recommendations regarding radiation protection measures...Karlsruhe GmbH, Central Safety Department, KES...Simulation Gamma Rays Hand radiation effects Humans Models...radiation effects Software...

Ch. Blunck; F. Becker; L. Hegenbart; B. Heide; J. Schimmelpfeng; M. Urban

2009-02-01T23:59:59.000Z

210

Modeling Io's Sublimation-Driven Atmosphere: Gas Dynamics and Radiation Emission  

SciTech Connect

Io's sublimation-driven atmosphere is modeled using the direct simulation Monte Carlo method. These rarefied gas dynamics simulations improve upon earlier models by using a three-dimensional domain encompassing the entire planet computed in parallel. The effects of plasma impact heating, planetary rotation, and inhomogeneous surface frost are investigated. Circumplanetary flow is predicted to develop from the warm subsolar region toward the colder night-side. The non-equilibrium thermal structure of the atmosphere, including vibrational and rotational temperatures, is also presented. Io's rotation leads to an asymmetric surface temperature distribution which is found to strengthen circumplanetary flow near the dusk terminator. Plasma heating is found to significantly inflate the atmosphere on both day- and night-sides. The plasma energy flux also causes high temperatures at high altitudes but permits relatively cooler temperatures at low altitudes near the dense subsolar point due to plasma energy depletion. To validate the atmospheric model, a radiative transfer model was developed utilizing the backward Monte Carlo method. The model allows the calculation of the atmospheric radiation from emitting/absorbing and scattering gas using an arbitrary scattering law and an arbitrary surface reflectivity. The model calculates the spectra in the {nu}{sub 2} vibrational band of SO{sub 2} which are then compared to the observational data.

Walker, Andrew C.; Goldstein, David B.; Varghese, Philip L.; Trafton, Laurence M.; Moore, Chris H.; Stewart, Benedicte [University of Texas at Austin, Department of Aerospace Engineering, 210 East 24. Street W. R. Woolrich Laboratories 1 University Station, C0600 Austin, TX 78712 (United States); Gratiy, Sergey L.; Levin, Deborah A. [Pennsylvania State University, Department of Aerospace Engineering, 229 Hammond, University Park, PA 16802 (United States)

2008-12-31T23:59:59.000Z

211

Modeling heat transfer in supercritical fluid using the lattice Boltzmann method  

Science Journals Connector (OSTI)

A lattice Boltzmann model has been developed to simulate heat transfer in supercritical fluids. A supercritical viscous fluid layer between two plates heated from the bottom has been studied. It is demonstrated that the model can be used to study heat transfer near the critical point where the so-called piston effect speeds up the transfer of heat and results in homogeneous heating in the bulk of the layer. We have also studied the onset of convection in a Rayleigh-Bnard configuration. It is shown that our model can well predict qualitatively the onset of convection near the critical point, where there is a crossover between the Rayleigh and Schwarzschild criteria.

Gbor Hzi and Attila Mrkus

2008-02-21T23:59:59.000Z

212

Nonequilibrium statistics of a reduced model for energy transfer in waves  

E-Print Network (OSTI)

Non­equilibrium statistics of a reduced model for energy transfer in waves R. E. LEE DEVILLE, Bah´ia Blanca, Argentina ESTEBAN G. TABAK Courant Institute AND ERIC VANDEN-EIJNDEN Courant Institute Abstract We study energy transfer in a "resonant duet" -- a resonant quartet where symme- tries support

DeVille, Lee

213

Nonequilibrium Statistics of a Reduced Model for Energy Transfer in Waves  

E-Print Network (OSTI)

Nonequilibrium Statistics of a Reduced Model for Energy Transfer in Waves R. E. LEE DEVILLE Courant, with the subsequent dynamics transferring the energy to longer scales. The main dissipation mechanism is wave breaking, which usually acts on much longer (gravity) waves that intermittently remove energy from the wave system

Milewski, Paul

214

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

215

Journal of Quantitative Spectroscopy & Radiative Transfer 64 (2000) 219}226  

E-Print Network (OSTI)

of the discrete-ordinates approximation to the transport equation in plane geometry. The Green's function of papers [1}3] concerning radiation-transport problems in plane geometry, linear-algebra techniques were of the Fourier-component (m50) problems basic to the general azimuth-dependent transport equation [6], and since

Siewert, Charles E.

216

On radiative transfer in water spray curtains using the Discrete Ordinates Method  

E-Print Network (OSTI)

addressed in conditions similar to devices used in fire protection systems. The radiation propagation from solutions involved in fire protection systems. In this case, the expected aim is to protect given devices of the spray efficiency would be a useful tool for people concerned with fire protection. Our group is involved

Paris-Sud XI, Université de

217

Characterization of the solar light field within the ocean mesopelagic zone based on radiative transfer simulations  

E-Print Network (OSTI)

Characterization of the solar light field within the ocean mesopelagic zone based on radiative t The solar light field within the ocean from the sea surface to the bottom of the mesopelagic zone there is sufficient amount of solar light to support the process of photosynthesis, and below by the aphotic

Stramski, Dariusz

218

Automotive Underhood Thermal Management Analysis Using 3-D Coupled Thermal-Hydrodynamic Computer Models: Thermal Radiation Modeling  

SciTech Connect

The goal of the radiation modeling effort was to develop and implement a radiation algorithm that is fast and accurate for the underhood environment. As part of this CRADA, a net-radiation model was chosen to simulate radiative heat transfer in an underhood of a car. The assumptions (diffuse-gray and uniform radiative properties in each element) reduce the problem tremendously and all the view factors for radiation thermal calculations can be calculated once and for all at the beginning of the simulation. The cost for online integration of heat exchanges due to radiation is found to be less than 15% of the baseline CHAD code and thus very manageable. The off-line view factor calculation is constructed to be very modular and has been completely integrated to read CHAD grid files and the output from this code can be read into the latest version of CHAD. Further integration has to be performed to accomplish the same with STAR-CD. The main outcome of this effort is to obtain a highly scalable and portable simulation capability to model view factors for underhood environment (for e.g. a view factor calculation which took 14 hours on a single processor only took 14 minutes on 64 processors). The code has also been validated using a simple test case where analytical solutions are available. This simulation capability gives underhood designers in the automotive companies the ability to account for thermal radiation - which usually is critical in the underhood environment and also turns out to be one of the most computationally expensive components of underhood simulations. This report starts off with the original work plan as elucidated in the proposal in section B. This is followed by Technical work plan to accomplish the goals of the project in section C. In section D, background to the current work is provided with references to the previous efforts this project leverages on. The results are discussed in section 1E. This report ends with conclusions and future scope of work in section F.

Pannala, S.; D'Azevedo, E.; Zacharia, T.

2002-02-26T23:59:59.000Z

219

RADIATION CARCINOGENESIS IN MAN: INFLUENCE OF DOSE-RESPONSE MODELS AND RISK PROJECTION MODELS IN THE ESTIMATION OF RISK COEFFICIENTS FOLLOWING EXPOSURE TO LOW-LEVEL RADIATION  

E-Print Network (OSTI)

RADIATION CARCINOGENESIS IN MAN: INFLUENCE OF DOSE-RESPONSE MODELS AND RISK PROJECTION MODELS IN THE ESTIMATIONRADIATION CARCINOGENESIS IN HAN: INFLUENCE OF DOSE-RESPONSE MODELS AND RISK PROJECTION MODELS IN THE ESTIMATION

Fabrikant, J.I.

2010-01-01T23:59:59.000Z

220

Mass Transfer Models for Hydrolysis 965 Applied Biochemistry and Biotechnology Vol. 113116, 2004  

E-Print Network (OSTI)

Mass Transfer Models for Hydrolysis 965 Applied Biochemistry and Biotechnology Vol. 113­116, 2004 Biochemistry and Biotechnology Vol. 113­116, 2004 ity (2). For example, significant differences are observed

California at Riverside, University of

Note: This page contains sample records for the topic "radiation transfer models" 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

Numerical and analytical modeling of heat transfer between fluid and fractured rocks  

E-Print Network (OSTI)

Modeling of heat transfer between fluid and fractured rocks is of particular importance for energy extraction analysis in EGS, and therefore represents a critical component of EGS design and performance evaluation. In ...

Li, Wei, S.M. Massachusetts Institute of Technology

2014-01-01T23:59:59.000Z

222

FLUID FLOW MODELING OF RESIN TRANSFER MOLDING FOR COMPOSITE MATERIAL WIND TURBINE BLADE STRUCTURES  

E-Print Network (OSTI)

FLUID FLOW MODELING OF RESIN TRANSFER MOLDING FOR COMPOSITE MATERIAL WIND TURBINE BLADE STRUCTURES the guidance and direction provided by my advisors: Dr. Mandell, Dr. Cairns and Dr. Larsen. I would also like

223

Development of a computational model for nuclear electric orbital transfer vehicles  

E-Print Network (OSTI)

DEVELOPMENT OF A COMPUTATIONAL MODEL FOR NUCLEAR ELECTRIC ORBITAL TRANSFER VEHICLES A Thesis by WILLIAM FOUNTAIN LYON III Submitted to the Office of Graduate Studies of Texas ARM University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE August 1989 Major Subject: Nuclear Engineering DEVELOPMENT OF A COMPUTATIONAL MODEL FOR NUCLEAR ELECTRIC ORBITAL TRANSFER VEHICLES A Thesis by WILLIAM FOUNTAIN LYON III Approved as to style and content by: K. L...

Lyon, William Fountain

2012-06-07T23:59:59.000Z

224

General Relativistic Radiative Transfer and GeneralRelativistic MHD Simulations of Accretion and Outflows of Black Holes  

SciTech Connect

We calculate the emission from relativistic flows in black hole systems using a fully general relativistic radiative transfer formulation, with flow structures obtained by general relativistic magneto-hydrodynamic simulations. We consider thermal free-free emission and thermal synchrotron emission. Bright filament-like features protrude (visually) from the accretion disk surface, which are enhancements of synchrotron emission where the magnetic field roughly aligns with the line-of-sight in the co-moving frame. The features move back and forth as the accretion flow evolves, but their visibility and morphology are robust. We propose that variations and drifts of the features produce certain X-ray quasi-periodic oscillations (QPOs) observed in black-hole X-ray binaries.

Fuerst, Steven V.; /KIPAC, Menlo Park; Mizuno, Yosuke; /USRA, Huntsville; Nishikawa, Ken-Ichi; /USRA, Huntsville /Alabama U., Huntsville; Wu, Kinwah; /Mullard Space Sci.

2007-01-05T23:59:59.000Z

225

E-Print Network 3.0 - atmospheric models testing Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

and Tectonics (COMET) Collection: Geosciences 7 BTRAM: An Interactive Atmospheric Radiative Transfer Model I.M. Chapman1 Summary: BTRAM: An Interactive Atmospheric Radiative...

226

E-Print Network 3.0 - atmospheric test models Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

and Tectonics (COMET) Collection: Geosciences 7 BTRAM: An Interactive Atmospheric Radiative Transfer Model I.M. Chapman1 Summary: BTRAM: An Interactive Atmospheric Radiative...

227

Low Dose Radiation Research Program: Computational Modeling of Biochemical  

NLE Websites -- All DOE Office Websites (Extended Search)

Computational Modeling of Biochemical Pathways Linking Ionizing Computational Modeling of Biochemical Pathways Linking Ionizing Radiation to Cell Cycle Arrest, Apoptosis, and Tumor Incidence Authors: Yuchao Maggie Zhao and Rory Conolly Institutions: Center for Computational Systems Biology CIIT Centers for Health Research Long-Range Goal: To develop an integrated, computational framework for the prediction of low-dose-response to ionizing radiation (IR) in people. Methodology: To provide a flexible framework to evaluate mechanisms of cellular adaptive responses after exposure to IR, three progressively more complicated descriptions of biochemical pathways linking DNA damage with cell-cycle checkpoint control and apoptosis were developed. These descriptions focus on p53-dependent checkpoint arrest and apoptosis, p73-dependent apoptosis, and Chk2-dependent checkpoint arrest,

228

A new predictive dynamic model describing the effect of1 the ambient temperature and the convective heat transfer2  

E-Print Network (OSTI)

and the convective heat transfer2 coefficient on bacterial growth3 4 H. Ben Yaghlenea,b* , I. Leguerinela , M. Hamdib Ratkowsky "square root" model and a simplified two-parameter20 heat transfer model regarding an infinite air temperature, the convective heat transfer22 coefficient and the growth parameters of the micro

Paris-Sud XI, Université de

229

Spreader-Bar Radiation Detection System Enhancements: A Modeling and Simulation Study  

SciTech Connect

This report provides the modeling and simulation results of the investigation of enhanced spreader bar radiation detection systems.

Ely, James H.; Ashbaker, Eric D.; Batdorf, Michael T.; Baciak, James E.; Hensley, Walter K.; Jarman, Kenneth D.; Robinson, Sean M.; Sandness, Gerald A.; Schweppe, John E.

2012-11-13T23:59:59.000Z

230

Astrophysical S factor for the radiative capture (12)N(p,gamma)(13)O determined from the (14)N((12)N,(13)O)(13)C proton transfer reaction  

E-Print Network (OSTI)

The cross section of the radiative proton capture reaction on the drip line nucleus (12)N was investigated using the asymptotic normalization coefficient (ANC) method. We have used the (14)N((12)N,(13)O)(13)C proton transfer reaction at 12 Me...

Banu, A.; Al-Abdullah, T.; Fu, C.; Gagliardi, Carl A.; McCleskey, M.; Mukhamedzhanov, A. M.; Tabacaru, G.; Trache, L.; Tribble, Robert E.; Zhai, Y.; Carstoiu, F.; Burjan, V.; Kroha, V.

2009-01-01T23:59:59.000Z

231

Frequency-Selective Near-Field Radiative Heat Transfer between Photonic Crystal Slabs: A Computational Approach for Arbitrary Geometries and Materials  

E-Print Network (OSTI)

of energy from a hot to a cold body is well known to be enhanced (even exceeding the black- body limit) whenFrequency-Selective Near-Field Radiative Heat Transfer between Photonic Crystal Slabs of Mathematics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA 3 Department

Soljaèiæ, Marin

232

PARALLELIZATION OF THE P-1 RADIATION MODEL Gautham Krishnamoorthy, Rajesh Rawat, and Philip J. Smith  

E-Print Network (OSTI)

radiation model is spatially decomposed to solve the radiative transport equation on parallel computers describes the paralle- lization of the P-1 approximation to the radiative transport equation (RTE to the discretized transport equations consumes the maximum time in most radiation algorithms. Therefore, the speed

Utah, University of

233

Steam-Methane Reformer Kinetic Computer Model with Heat Transfer and Geometry Options  

SciTech Connect

A kinetic computer model of a steam/methane reformer has been developed as a design and analytical tool for a fuel cell system's fuel conditioner. This model has reaction, geometry, flow arrangement, and heat transfer options. Model predictions have been compared to previous experimental data, and close agreement was obtained. Initially, the Leva-type, packed-bed, heat transfer correlations were used. However, calculations based upon the reacting, reformer gases indicate a considerably higher heat transfer coefficient for this reforme design. Data analysis from similar designs in the literature also shows this phenomenon. This is thought to be reaction-induced effect, brought about by the changing of gas composition, the increased gas velocity, the lower catalyst temperature during reaction, and the higher thermal and reaction gradients involved in compact fuel cell reformer designs. Future experimental work is planned to verify the model's predictions further.

Murray, A.P.; Snyder, T.S.

1985-04-01T23:59:59.000Z

234

Lineal energy and radiation quality in radiation therapy: model calculations and comparison with experiment  

Science Journals Connector (OSTI)

Microdosimetry is a recommended method for characterizing radiation quality in situations when the biological effectiveness under test is not well known. In such situations, the radiation beams are described by their lineal energy probability distributions. Results from radiobiological investigations in the beams are then used to establish response functions that relate the lineal energy to the relative biological effectiveness (RBE). In this paper we present the influence of the size of the simulated volume on the relation to the clinical RBE values (or weighting factors). A single event probability distribution of the lineal energy is approximated by its dose average lineal energy () which can be measured or calculated for volumes from a few micrometres down to a few nanometres. The clinical RBE values were approximated as the ratio of the ?-values derived from the LQ-relation. Model calculations are presented and discussed for the SOBP of a 12C ion (290 MeV u?1) and the reference 60Co ? therapy beam. Results were compared with those for a conventional x-ray therapy beam, a 290 MeV proton beam and a neutron therapy beam. It is concluded that for a simulated volume of about 10nm, the ?-ratio increases approximately linearly with the -ratio for all the investigated beams. The correlation between y and ? provides the evidence to characterize a radiation therapy beam by the lineal energy when, for instance, weighting factors are to be estimated.

L Lindborg; M Hultqvist; Carlsson Tedgren; H Nikjoo

2013-01-01T23:59:59.000Z

235

Low Dose Radiation Research Program: Use of Computational Modeling to  

NLE Websites -- All DOE Office Websites (Extended Search)

Use of Computational Modeling to Evaluate Hypotheses about the Use of Computational Modeling to Evaluate Hypotheses about the Molecular and Cellular Mechanisms of Bystander Effects Authors: Yuchao “Maggie” Zhao and Rory Conolly Institutions: CIIT Centers for Health Research, 6 Davis Drive, Research Triangle Park, North Carolina A detailed understanding of the biological mechanisms of radiation-induced damage at the molecular and cellular levels is needed for accurate assessment of the shape of the dose-response curve for radiationinduced health effects in the intact organism. Computational models can contribute to the improved understanding of mechanisms through integration of data and quantitative evaluation of hypotheses. We propose to develop a novel computational model of bystander effects elicited by oxidative stress and a

236

Nonlinear State Space Model of a Hydraulic Wind Power Transfer Masoud Vaezi1  

E-Print Network (OSTI)

Nonlinear State Space Model of a Hydraulic Wind Power Transfer Masoud Vaezi1 , Majid Deldar1 1, IUPUI. Gearless hydraulic wind power systems are considered as nonlinear models because of some discrete nonlinear governing equations for the elements in the proposed hydraulic wind power configuration. Nonlinear

Zhou, Yaoqi

237

An Efficient Instantiation Algorithm for Simulating Radiant Energy Transfer in Plant Models  

E-Print Network (OSTI)

in agronomy concerning the influence of light over the production of a cultivated crop under differentAn Efficient Instantiation Algorithm for Simulating Radiant Energy Transfer in Plant Models Cyril simu- lation of light energy exchange inside plants models. This is obviously useful for visual

Boyer, Edmond

238

Modeling of offshore wind turbine noise radiation and propagation  

Science Journals Connector (OSTI)

Noisegenerated by offshore wind turbine and support structure can radiate and propagate through the air water and sediment. Predicting noise levels around wind turbinestructures at sea is required for the estimation of effects of the noise on marine life. To predict radiated noise we used a finite element analysis(FEA) of a cylindrical shell model of a monopile structure. In the finite element modeling transient modal dynamic analysis and steady state dynamic analysis (direct and modal) were implemented to simulate both construction and operational noise. The effect of various sediment types and foundation designs are investigated. The FEA package used was ABAQUS version 6.10. The output of the FEAanalysis is used as starting field for acoustic propagation models such as PE to produce long range predictions. We present predictions of particle velocity at the structure-acoustic medium interface and sound pressure level as function of frequency at various distances from the structure. Laboratory experiments using scale models of the cylindrical shell have been carried out to verify the noise predictions. Comparison of the FEAmodel results and experimental data will be presented.

Huikwan Kim; Gopu R. Potty; James H. Miller; Christopher Baxter

2011-01-01T23:59:59.000Z

239

Energy transfers in shell models for MHD turbulence  

E-Print Network (OSTI)

A systematic procedure to derive shell models for MHD turbulence is proposed. It takes into account the conservation of ideal quadratic invariants such as the total energy, the cross-helicity and the magnetic helicity as well as the conservation of the magnetic energy by the advection term in the induction equation. This approach also leads to simple expressions for the energy exchanges as well as to unambiguous definitions for the energy fluxes. When applied to the existing shell models with nonlinear interactions limited to the nearest neighbour shells, this procedure reproduces well known models but suggests a reinterpretation of the energy fluxes.

T. Lessinnes; M. K. Verma; D. Carati

2008-07-31T23:59:59.000Z

240

Radiation Modeling In Fluid Flow Iain D. Boyd  

E-Print Network (OSTI)

Collector #12;4 Fundamentals of Radiation (1) � All matter with non-zero temperature emits thermal radiation with energy flux given by the Stefan-Boltzmann Law: e.g., Sun: T=5800 K, total radiated power = 4 distribution (Planck spectrum) !q =T 4 W/m2 #12;5 Planck Radiation Spectrum #12;6 Solar Radiation Spectrum

Wang, Wei

Note: This page contains sample records for the topic "radiation transfer models" 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

Radiative transfer in the earth's atmosphere-ocean system using Monte Carlo techniques  

E-Print Network (OSTI)

are described in the next chapter. The books by Morgan and Hammersley and Handscomb describe the theory and some methods of variance reduction for general applications. One item that is required of any Monte Carlo simulation is a supply of randoni numbers... be checked through modification of the model since the same sequeiice of random numbers may be generated repeatedly. Discussions on the properties ot' random nuinbers and their generation may be found in the books by Morgan' and Hammersley and Handscomb...

Bradley, Paul Andrew

2012-06-07T23:59:59.000Z

242

A High-Order-Accurate GPU-Based Radiative Transfer Equation Solver for Combustion and Propulsion Applications  

E-Print Network (OSTI)

radiative heat flux through the grid element boundary sstair-case grid. Figure 5 shows the net radiative heat fluxgrid consisted of 6872 tetrahedral elements. The dimensionless radiative heat

He, Xing; Lee, Euntaek; Wilcox, Lucas; Munipalli, Ramakanth; Pilon, Laurent

2013-01-01T23:59:59.000Z

243

Heat and moisture transfer through clothing  

E-Print Network (OSTI)

R. C. Eberhart (ed), Heat transfer in medicine and biology.Convective and radiative heat transfer coefficients forsimulation of heat and moisture transfer in a human-

Voelker, Conrad; Hoffmann, Sabine; Kornadt, Oliver; Arens, Edward; Zhang, Hui; Huizenga, Charlie

2009-01-01T23:59:59.000Z

244

Investigation of hydrogen transfer in coprocessing using model systems  

SciTech Connect

The objective of this research was to evaluate the role of the resid in the coprocessing of coal and petroleum resid. The question being asked was whether the resid is an active solvent in coprocessing reactions and whether resid donates any hydrogen to coal during coprocessing. An effective means of determining whether resid participates in the reactions at coprocessing conditions is to use model systems and trace their reaction pathways. The research performed in this study evaluated the hydrogen donability of a naphthenic compound perhydropyrene, a compound type prevalent in resids that are hydrogen-rich. Model species were also used as acceptors that represented the aromatic aspect of coal. The model acceptors that were used were anthracene and phenanthrene.

Shen, Jing; Curtis, C.W. [Auburn Univ., AL (United States)

1995-12-31T23:59:59.000Z

245

Brazil Direct Normal Solar Radiation Model (10km) from INPE and...  

Open Energy Info (EERE)

Dataset Activity Stream Brazil Direct Normal Solar Radiation Model (10km) from INPE and LABSOLAR (Abstract): Normal direct solar radiation in kWhm2day for 1 year organized into...

246

Golden rule kinetics of transfer reactions in condensed phase: The microscopic model of electron transfer reactions in disordered solid matrices  

SciTech Connect

The algorithm for a theoretical calculation of transfer reaction rates for light quantum particles (i.e., the electron and H-atom transfers) in non-polar solid matrices is formulated and justified. The mechanism postulated involves a local mode (an either intra- or inter-molecular one) serving as a mediator which accomplishes the energy exchange between the reacting high-frequency quantum mode and the phonon modes belonging to the environment. This approach uses as a background the Fermi golden rule beyond the usually applied spin-boson approximation. The dynamical treatment rests on the one-dimensional version of the standard quantum relaxation equation for the reduced density matrix, which describes the frequency fluctuation spectrum for the local mode under consideration. The temperature dependence of a reaction rate is controlled by the dimensionless parameter ?{sub 0}=??{sub 0}/k{sub B}T where ?{sub 0} is the frequency of the local mode and T is the temperature. The realization of the computational scheme is different for the high/intermediate (?{sub 0} < 1 ? 3) and for low (?{sub 0}? 1) temperature ranges. For the first (quasi-classical) kinetic regime, the Redfield approximation to the solution of the relaxation equation proved to be sufficient and efficient in practical applications. The study of the essentially quantum-mechanical low-temperature kinetic regime in its asymptotic limit requires the implementation of the exact relaxation equation. The coherent mechanism providing a non-vanishing reaction rate has been revealed when T? 0. An accurate computational methodology for the cross-over kinetic regime needs a further elaboration. The original model of the hopping mechanism for electronic conduction in photosensitive organic materials is considered, based on the above techniques. The electron transfer (ET) in active centers of such systems proceeds via local intra- and intermolecular modes. The active modes, as a rule, operate beyond the kinetic regimes, which are usually postulated in the existing theories of the ET. Our alternative dynamic ET model for local modes immersed in the continuum harmonic medium is formulated for both classical and quantum regimes, and accounts explicitly for the mode/medium interaction. The kinetics of the energy exchange between the local ET subsystem and the surrounding environment essentially determine the total ET rate. The efficient computer code for rate computations is elaborated on. The computations are available for a wide range of system parameters, such as the temperature, external field, local mode frequency, and characteristics of mode/medium interaction. The relation of the present approach to the Marcus ET theory and to the quantum-statistical reaction rate theory [V. G. Levich and R. R. Dogonadze, Dokl. Akad. Nauk SSSR, Ser. Fiz. Khim. 124, 213 (1959); J. Ulstrup, Charge Transfer in Condensed Media (Springer, Berlin, 1979); M. Bixon and J. Jortner, Adv. Chem. Phys. 106, 35 (1999)] underlying it is discussed and illustrated by the results of computations for practically important target systems.

Basilevsky, M. V.; Mitina, E. A. [Photochemistry Center, Russian Academy of Sciences, 7a, Novatorov ul., Moscow (Russian Federation)] [Photochemistry Center, Russian Academy of Sciences, 7a, Novatorov ul., Moscow (Russian Federation); Odinokov, A. V. [Photochemistry Center, Russian Academy of Sciences, 7a, Novatorov ul., Moscow (Russian Federation) [Photochemistry Center, Russian Academy of Sciences, 7a, Novatorov ul., Moscow (Russian Federation); National Research Nuclear University MEPhI, 31, Kashirskoye shosse, Moscow (Russian Federation); Titov, S. V. [Karpov Institute of Physical Chemistry, 3-1/12, Building 6, Obuha pereulok, Moscow (Russian Federation)] [Karpov Institute of Physical Chemistry, 3-1/12, Building 6, Obuha pereulok, Moscow (Russian Federation)

2013-12-21T23:59:59.000Z

247

Two-dimensional Radiative Transfer in Protostellar Envelopes. II. An Evolutionary Sequence  

Science Journals Connector (OSTI)

We present model spectral energy distributions (SEDs), colors, polarization, and images for an evolutionary sequence of a low-mass protostar from the early collapse stage (Class 0) to the remnant disk stage (Class III). We find a substantial overlap in colors and SEDs between protostars embedded in envelopes (Class 0-I) and T Tauri disks (Class II), especially at mid-IR wavelengths. Edge-on Class I-II sources show double-peaked SEDs, with a short-wavelength hump due to scattered light and a long-wavelength hump due to thermal emission. These are the bluest sources in mid-IR color-color diagrams. Since Class 0 and I sources are diffuse, the size of the aperture over which fluxes are integrated has a substantial effect on the computed colors, with larger aperture results showing significantly bluer colors. Viewed through large apertures, the Class 0 colors fall in the same regions of mid-IR color-color diagrams as Class I sources and are even bluer than Class II-III sources in some colors. It is important to take this into account when comparing color-color diagrams of star formation regions at different distances or different sets of observations of the same region. However, the near-IR polarization of the Class 0 sources is much higher than the Class I-II sources, providing a means to separate these evolutionary states. We varied the grain properties in the circumstellar envelope, allowing for larger grains in the disk midplane and smaller grains in the envelope. In comparing with models with the same grain properties throughout, we find that the SED of the Class 0 source is sensitive to the grain properties of the envelope onlythat is, grain growth in the disk in Class 0 sources cannot be detected from the SED. Grain growth in disks of Class I sources can be detected at wavelengths greater than 100 ?m. Our image calculations predict that the diffuse emission from edge-on Class I and II sources should be detectable in the mid-IR with the Space Infrared Telescope Facility (SIRTF) in nearby star-forming regions (out to several hundred parsecs).

Barbara A. Whitney; Kenneth Wood; J. E. Bjorkman; Martin Cohen

2003-01-01T23:59:59.000Z

248

Radiative Hydrodynamic Models of the Optical and Ultraviolet Emission from Solar Flares  

E-Print Network (OSTI)

We report on radiative hydrodynamic simulations of moderate and strong solar flares. The flares were simulated by calculating the atmospheric response to a beam of non-thermal electrons injected at the apex of a one-dimensional closed coronal loop, and include heating from thermal soft X-ray, extreme ultraviolet and ultraviolet (XEUV) emission. The equations of radiative transfer and statistical equilibrium were treated in non-LTE and solved for numerous transitions of hydrogen, helium, and Ca II allowing the calculation of detailed line profiles and continuum emission. This work improves upon previous simulations by incorporating more realistic non-thermal electron beam models and includes a more rigorous model of thermal XEUV heating. We find XEUV backwarming contributes less than 10% of the heating, even in strong flares. The simulations show elevated coronal and transition region densities resulting in dramatic increases in line and continuum emission in both the UV and optical regions. The optical continuum reaches a peak increase of several percent which is consistent with enhancements observed in solar white light flares. For a moderate flare (~M-class), the dynamics are characterized by a long gentle phase of near balance between flare heating and radiative cooling, followed by an explosive phase with beam heating dominating over cooling and characterized by strong hydrodynamic waves. For a strong flare (~X-class), the gentle phase is much shorter, and we speculate that for even stronger flares the gentle phase may be essentially non-existent. During the explosive phase, synthetic profiles for lines formed in the upper chromosphere and transition region show blue shifts corresponding to a plasma velocity of ~120 km/s, and lines formed in the lower chromosphere show red shifts of ~40 km/s.

J. C. Allred; S. L. Hawley; W. P. Abbett; M. Carlsson

2005-07-13T23:59:59.000Z

249

MODELLING OF TRANSPORT PHENOMENA FOR THE HYPERSONIC STAGNATION POINT HEAT TRANSFER PROBLEM  

E-Print Network (OSTI)

MODELLING OF TRANSPORT PHENOMENA FOR THE HYPERSONIC STAGNATION POINT HEAT TRANSFER PROBLEM A to vibrational mode el refers to electronic mode Introduction One of the major problems encountered in hypersonic. The hypersonic flow about such surfaces is charac­ terized by a strong bow shock, which converts the major part

250

Turbulent models of ice giant internal dynamics: Dynamos, heat transfer, and zonal flows  

E-Print Network (OSTI)

Turbulent models of ice giant internal dynamics: Dynamos, heat transfer, and zonal flows K Magnetic fields a b s t r a c t The ice giant planets, Uranus and Neptune, have magnetic fields to yield small-scale and disorganized turbulence. In agreement with ice giant observations, both

251

On the multidimensional modeling of fluid flow and heat transfer in SCWRS  

SciTech Connect

The Supercritical Water Reactor (SCWR) has been proposed as one of the six Generation IV reactor design concepts under consideration. The key feature of the SCWR is that water at supercritical pressures is used as the reactor coolant. Although at such pressures, fluids do not undergo phase change as they are heated, the fluid properties experience dramatic variations throughout what is known as the pseudo-critical region. Highly nonuniform temperature and fluid property distributions are expected in the reactor core, which will have a significant impact on turbulence and heat transfer in future SCWRs. The goal of the present work has been to understand and predict the effects of these fluid property variations on turbulence and heat transfer throughout the reactor core. Spline-type property models have been formulated for water at supercritical pressures in order to include the dependence of properties on both temperature and pressure into a numerical solver. New models of turbulence and heat transfer for variable-property fluids have been developed and implemented into the NPHASE-CMFD software. The results for these models have been compared to experimental data from the Korea Atomic Energy Research Inst. (KAERI) for various heat transfer regimes. It is found that the Low-Reynolds {kappa}-{epsilon} model performs best at predicting the experimental data. (authors)

Gallaway, T.; Antal, S. P.; Podowski, M. Z. [Center for Multiphase Research, Rensselaer Polytechnic Inst., 110 8th St., Troy, NY (United States)

2012-07-01T23:59:59.000Z

252

Solar-radiation-maintained glacier recession on Kilimanjaro drawn from combined ice-radiation geometry modeling  

E-Print Network (OSTI)

Solar-radiation-maintained glacier recession on Kilimanjaro drawn from combined ice of Massachusetts, Amherst, Massachusetts, USA Georg Kaser Tropical Glaciology Group, Department of Geography retreat during the twentieth century. To evaluate the role of solar radiation in maintaining glacier

Massachusetts at Amherst, University of

253

Nuisance Source Population Modeling for Radiation Detection System Analysis  

SciTech Connect

A major challenge facing the prospective deployment of radiation detection systems for homeland security applications is the discrimination of radiological or nuclear 'threat sources' from radioactive, but benign, 'nuisance sources'. Common examples of such nuisance sources include naturally occurring radioactive material (NORM), medical patients who have received radioactive drugs for either diagnostics or treatment, and industrial sources. A sensitive detector that cannot distinguish between 'threat' and 'benign' classes will generate false positives which, if sufficiently frequent, will preclude it from being operationally deployed. In this report, we describe a first-principles physics-based modeling approach that is used to approximate the physical properties and corresponding gamma ray spectral signatures of real nuisance sources. Specific models are proposed for the three nuisance source classes - NORM, medical and industrial. The models can be validated against measured data - that is, energy spectra generated with the model can be compared to actual nuisance source data. We show by example how this is done for NORM and medical sources, using data sets obtained from spectroscopic detector deployments for cargo container screening and urban area traffic screening, respectively. In addition to capturing the range of radioactive signatures of individual nuisance sources, a nuisance source population model must generate sources with a frequency of occurrence consistent with that found in actual movement of goods and people. Measured radiation detection data can indicate these frequencies, but, at present, such data are available only for a very limited set of locations and time periods. In this report, we make more general estimates of frequencies for NORM and medical sources using a range of data sources such as shipping manifests and medical treatment statistics. We also identify potential data sources for industrial source frequencies, but leave the task of estimating these frequencies for future work. Modeling of nuisance source populations is only useful if it helps in understanding detector system performance in real operational environments. Examples of previous studies in which nuisance source models played a key role are briefly discussed. These include screening of in-bound urban traffic and monitoring of shipping containers in transit to U.S. ports.

Sokkappa, P; Lange, D; Nelson, K; Wheeler, R

2009-10-05T23:59:59.000Z

254

A comparison of two heat transfer models for estimating thermal drawdown in Hot Dry Rock reservoirs  

SciTech Connect

Estimates of thermal drawdown in Hot Dry Rock geothermal systems have been made with two different models of heat transfer from hydraulically fractured reservoir rock blocks to water circulated through the fracture permeability. One model is based on deconvolution of experimental tracer response curves into a network of flowpaths connected in parallel with heat transfer calculated individually in each flowpath. The second model is based on one-dimensional flow through the rock with a block size distribution described as a group of equivalent-radius spheres for which the heat transfer equations can be solved analytically. The two models were applied to the planned Phase II long-term thermal drawdown experiment at Fenton Hill, NM. The results show good agreement between the two models, with estimates of temperature cooldown from 240C to 150C in a few years depending on selected operation parameters, but with somewhat differing cooldown curve characteristic shapes. Data from the long-term experiment will be helpful in improving the two models.

Robinson, Bruce A.; Kruger, Paul

1988-01-01T23:59:59.000Z

255

New model of calculating the energy transfer efficiency for the spherical theta-pinch device  

E-Print Network (OSTI)

Ion-beam-plasma-interaction plays an important role in the field of Warm Dense Matter (WDM) and Inertial Confinement Fusion (ICF). A spherical theta pinch is proposed to act as a plasma target in various applications including a plasma stripper cell. One key parameter for such applications is the free electron density. A linear dependency of this density to the amount of energy transferred into the plasma from an energy storage was found by C. Teske. Since the amount of stored energy is known, the energy transfer efficiency is a reliable parameter for the design of a spherical theta pinch device. The traditional two models of energy transfer efficiency are based on assumptions which comprise the risk of systematical errors. To obtain precise results, this paper proposes a new model without the necessity of any assumption to calculate the energy transfer efficiency for an inductively coupled plasma device. Further, a comparison of these three different models is given at a fixed operation voltage for the full ...

Xu, G; Loisch, G; Xiao, G; Jacoby, J; Weyrich, K; Li, Y; Zhao, Y

2015-01-01T23:59:59.000Z

256

The booster to AGS transfer line: comparison between model and measurements  

SciTech Connect

The Booster to AGS (BtA) transfer line was to match both ions and protons into the AGS lattice. For proton beam operation the only constraint on the optics is to define a match to the AGS lattice. For ion operation there are additional constraints introduced by a stripping foil in the upstream part of the transfer line. For polarized proton operation there is the complication that the AGS lattice is distorted by the presence of two partial snake magnets. In the 2008 polarized proton run it was observed that there was a significant optical injection mismatch. Beam experiments were conducted that showed disagreement with the model of the BtA line. In addition, these studies revealed some minor problems with the instrumentation in the line. A new model and more reliable measurements of the transfer line magnet currents have been implemented. Another series of experiments was conducted to test these modifications and to collect a more complete set of data to allow better understanding of the beam dynamics during the transfer and better understanding of the instrumentation. In this paper we will present the results of these experiments and the comparison to the new model of the BtA.

Brown,K.A.; Ahrens, L.; Bonati, R.; Gassner, D.; Glenn, W.; Huang, H.; Morris, J.; Nida, S.; Tsoupas, N.; Schoefer, V.; Zeno, K.

2009-05-04T23:59:59.000Z

257

Modeling proton intensity gradients and radiation dose equivalents in the inner  

E-Print Network (OSTI)

Modeling proton intensity gradients and radiation dose equivalents in the inner heliosphere using a significant radiation hazard for manned and unmanned interplanetary (IP) space missions. In order to estimate intensities, event fluences, and radiation dose equivalents of 27­31 May 2003 SEP events at eight different

Pringle, James "Jamie"

258

Numerical Weather Prediction (NWP) and hybrid ARMA/ANN model to predict global radiation  

E-Print Network (OSTI)

Numerical Weather Prediction (NWP) and hybrid ARMA/ANN model to predict global radiation Cyril a hybrid ARMA/ANN model and data issued from a numerical weather prediction model (ALADIN). We particularly@gmail.com #12;Abstract. We propose in this paper an original technique to predict global radiation using

Paris-Sud XI, Université de

259

A phenomenological model of dynamical arrest of electron transfer in solvents in the glass-transition region  

E-Print Network (OSTI)

A phenomenological model of dynamical arrest of electron transfer in solvents in the glass 2004; published online 17 February 2005 A phenomenological model of electron transfer reactions-acceptor energy gaps dashed line in Fig. 1 differs from the equilibrium distribution. The present phenomenological

Matyushov, Dmitry

260

Multi-Dimensional Broadband IR Radiative Forcing of Marine Stratocumulus in a Large Eddy Simulation Model  

SciTech Connect

In order to address the interactive and evolutionary nature of the cloud-radiation interaction, we have coupled to a Large Eddy Simulation (LES) model the sophisticated multi-dimensional radiative transfer (MDRT) scheme of Evans (Spherical Harmonics Discrete Ordinate Method; 1998). Because of computational expense, we are at this time only able to run 2D experiments. Preliminary runs consider only the broadband longwave component, in large part because IR cloud top cooling is the significant forcing mechanism for marine stratocumulus. Little difference is noted in the evolution of unbroken stratocumulus between three-hour runs using MDRT and independent pixel approximation (IPA) for 2D domains of 50 km in the horizontal and 1.5 km in the vertical. Local heating rates differ slightly near undulating regions of cloud top, and a slight bias in mean heating rate from 1 to 3 h is present, yet the differences are never strong enough to result in a pronounced evolutionary bias in typical boundary layer metrics (e.g. inversion height, vertical velocity variance, TKE). Longer integration times may eventually produce a physical response to the bias in radiative cooling rates. A low-CCN case, designed to produce significant drizzle and induce cloud breakup does show subtle differences between MDRT and IPA. Over the course of the 6 hour simulations, entrainment is slightly less in the MDRT case, and the transition to the surface-based trade cumulus regime is delayed. Mean cooling rates appear systematically weaker in the MDRT case, indicative of a less energetic PBL and reflected in profiles of vertical velocity variance and TKE.

Mechem, David B.; Ovtchinnikov, Mikhail; Kogan, Y. L.; Davis, Anthony B; Cahalan, Robert F.; Takara, Ezra E.; Ellingson, Robert G.

2002-06-03T23:59:59.000Z

Note: This page contains sample records for the topic "radiation transfer models" 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

Clouds in the atmospheres of extrasolar planets. IV. On the scattering greenhouse effect of CO2 ice particles: Numerical radiative transfer studies  

E-Print Network (OSTI)

Owing to their wavelengths dependent absorption and scattering properties, clouds have a strong impact on the climate of planetary atmospheres. Especially, the potential greenhouse effect of CO2 ice clouds in the atmospheres of terrestrial extrasolar planets is of particular interest because it might influence the position and thus the extension of the outer boundary of the classic habitable zone around main sequence stars. We study the radiative effects of CO2 ice particles obtained by different numerical treatments to solve the radiative transfer equation. The comparison between the results of a high-order discrete ordinate method and simpler two-stream approaches reveals large deviations in terms of a potential scattering efficiency of the greenhouse effect. The two-stream methods overestimate the transmitted and reflected radiation, thereby yielding a higher scattering greenhouse effect. For the particular case of a cool M-type dwarf the CO2 ice particles show no strong effective scattering greenhouse eff...

Kitzmann, D; Rauer, H

2013-01-01T23:59:59.000Z

262

7, 72357275, 2007 Adaptive radiative  

E-Print Network (OSTI)

Discussions Two adaptive radiative transfer schemes for numerical weather prediction models V. Venema 1 , A numerical weather prediction (NWP) and climate models. The atmosphere and the land surface are complex-stream approximation. In most weather prediction models these parameterisation schemes are therefore called infre

Boyer, Edmond

263

Radiator Labs | Department of Energy  

NLE Websites -- All DOE Office Websites (Extended Search)

of steam buildings. Radiator Labs developed a mechanism that allows heating systems to control heat transfer at each radiator. The Radiator Labs design utilizes an...

264

A Semi-Analytical Line Transfer (SALT) model to interpret the spectra of galaxy outflows  

E-Print Network (OSTI)

We present a Semi-Analytical Line Transfer model, SALT, to study the absorption and re-emission line profiles from expanding galactic envelopes. The envelopes are described as a superposition of shells with density and velocity varying with the distance from the center. We adopt the Sobolev approximation to describe the interaction between the photons escaping from each shell and the remaining of the envelope. We include the effect of multiple scatterings within each shell, properly accounting for the atomic structure of the scattering ions. We also account for the effect of a finite circular aperture on actual observations. For equal geometries and density distributions, our models reproduce the main features of the profiles generated with more complicated transfer codes. Also, our SALT line profiles nicely reproduce the typical asymmetric resonant absorption line profiles observed in star-forming/starburst galaxies whereas these absorption profiles cannot be reproduced with thin shells moving at a fixed out...

Scarlata, C

2015-01-01T23:59:59.000Z

265

Application Of A Spherical-Radial Heat Transfer Model To Calculate  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Application Of A Spherical-Radial Heat Transfer Model To Calculate Geothermal Gradients From Measurements In Deep Boreholes Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Application Of A Spherical-Radial Heat Transfer Model To Calculate Geothermal Gradients From Measurements In Deep Boreholes Details Activities (0) Areas (0) Regions (0) Abstract: This paper presents estimates of the undisturbed formation temperatures in a geothermal exploration well drilled in the Ceboruco area in the western part of the Mexican Volcanic Belt. The method used assumes

266

Development and adaptation of conduction and radiation heat-transfer computer codes for the CFTL. [Core Flow Test Loop; RODCON; HOTTEL  

SciTech Connect

RODCON and HOTTEL are two computational methods used to calculate thermal and radiation heat transfer for the Core Flow Test Loop (CFTL) analysis efforts. RODCON was developed at ORNL to calculate the internal temperature distribution of the fuel rod simulator (FRS) for the CFTL. RODCON solves the time-dependent heat transfer equation in two-dimensional (R angle) cylindrical coordinates at an axial plane with user-specified radial material zones and time- and position-variant surface conditions at the FRS periphery. Symmetry of the FRS periphery boundary conditions is not necessary. The governing elliptic, partial differential heat equation is cast into a fully implicit, finite-difference form by approximating the derivatives with a forward-differencing scheme with variable mesh spacing. The heat conduction path is circumferentially complete, and the potential mathematical problem at the rod center can be effectively ignored. HOTTEL is a revision of an algorithm developed by C.B. Baxi at the General Atomic Company (GAC) to be used in calculating radiation heat transfer in a rod bundle enclosed in a hexagonal duct. HOTTEL uses geometric view factors, surface emissivities, and surface areas to calculate the gray-body or composite view factors in an enclosure having multiple reflections in a nonparticipating medium.

Conklin, J.C.

1981-08-01T23:59:59.000Z

267

Radiative Importance of ThinŽ Liquid Water Clouds  

NLE Websites -- All DOE Office Websites (Extended Search)

Program Program Accomplishments of the Instantaneous Radiative Flux (IRF) Working Group August 2006 AERI Observations at Southern Great Plains Improve Infrared Radiative Transfer Models Turner et al., JAS, 2004 * AERI observations used to evaluate clear sky IR radiative transfer models * Long-term comparisons have improved - Spectral line database parameters - Water vapor continuum absorption models * Reduced errors in computation of downwelling radiative IR flux by approx 4; current uncertainty is on the order of 1.5 W/m 2 AERI - (Pre-ARM Model) AERI - (Model in 2003) 1 RU = 1 mW / (m 2 sr cm -1 ) Excellent Agreement in Clear Sky Shortwave Radiative Transfer Between Obs and Calcs Shortwave Flux Bias (Solid) Shortwave Flux RMS (Hatched) W m -2 * Comparison of shortwave radiative flux at the surface

268

INTERROOM RADIATIVE COUPLINGS THROUGH WINDOWS AND LARGE OPENINGS IN BUILDINGS : PROPOSAL OF A SIMPLIFIED MODEL  

E-Print Network (OSTI)

INTERROOM RADIATIVE COUPLINGS THROUGH WINDOWS AND LARGE OPENINGS IN BUILDINGS : PROPOSAL OF A SIMPLIFIED MODEL H. Boyer1 , M. Bojic2 , H. Ennamiri1 , D. Calogine1 , S. Guichard1 1 University of La Corresponding author : harry.boyer@univ-reunion.fr ABSTRACT A simplified model of indoor short wave radiation

Paris-Sud XI, Université de

269

Stochastic modeling of the cell killing effect for low- and high-LET radiation  

E-Print Network (OSTI)

length distribution, with deterministic RMR models. For low LET radiation and at high dose rates the stochastic survival results agree well with the deterministic survival results. Also the stochastic model allows for non-linearity at low doses due...

Partouche, Julien

2005-02-17T23:59:59.000Z

270

Measurements and model calculations of radiative fluxes for the...  

NLE Websites -- All DOE Office Websites (Extended Search)

of radiative fluxes for the Cabauw Experimental Site for Atmospheric Research, the Netherlands Knap, Wouter Royal Netherlands Meteorological Institute KNMI Los, Alexander KNMI...

271

Calculation of probabilities of transfer, recurrence intervals, and positional indices for linear compartment models. Environmental Sciences Division Publication no. 1544  

SciTech Connect

Six indices are presented for linear compartment systems that quantify the probable pathways of matter or energy transfer, the likelihood of recurrence if the model contains feedback loops, and the number of steps (transfers) through the system. General examples are used to illustrate how these indices can simplify the comparison of complex systems or organisms in unrelated systems.

Carney, J.H.; DeAngelis, D.L.; Gardner, R.H.; Mankin, J.B.; Post, W.M.

1981-02-01T23:59:59.000Z

272

Coupled flow and heat transfer in viscoelastic fluid with CattaneoChristov 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 Fouriers Law and the CattaneoChristov heat flux model is also presented.

Shihao Han; Liancun Zheng; Chunrui Li; Xinxin Zhang

2014-01-01T23:59:59.000Z

273

A new one-dimensional radiative equilibrium model for investigating atmospheric radiation entropy flux  

Science Journals Connector (OSTI)

...solar constant Q 0, TOA SW albedo alpha TOA, Sun's temperature T Sun, the empirical constant a 0 and the overall...the relationship between radiative entropy and temperature distributions. J. Atmos. Sci. 47, 795-803. ( doi...

2010-01-01T23:59:59.000Z

274

Coherence in a Model of Interacting Radiation and Matter  

Science Journals Connector (OSTI)

Some preliminary results of a theoretical investigation of the origin of laser coherence properties are presented. A model consisting of N two-level atoms in a perfect cavity interacting through their dipole moments with a single mode of the radiation field is adopted, and the resulting many-body problem is made solvable through the introduction of the self-consistent-field approximation (SCFA). It is shown that the SCFA is consistent with Glauber's suggestion that an ideal laser might be in a "coherent state," or pure eigenstate of the positive-frequency part of the electric-field operator. A conservation law is derived which assures the positive definiteness of the field-density operator, and it is shown that Glauber's coherent state is that solution of the SCFA equations which minimizes the corresponding constant of the motion. When the SCFA is modified by the introduction of particle-field correlations, the conservation law is destroyed, and the coherent state is no longer and allowed solution.

R. H. Picard and C. R. Willis

1965-07-05T23:59:59.000Z

275

A simple model for exploring the role of quantum coherence and the environment in excitonic energy transfer  

E-Print Network (OSTI)

We investigate the role of quantum coherence in modulating the energy transfer rate between two energy donors and a single acceptor participating in an excitonic energy transfer process. The energy transfer rate depends explicitly on the nature of the initial coherent superposition state of the two donors and we connect it to the observed absorption profile of the acceptor and the stimulated emission profile of the energy donors. We consider simple models with mesoscopic environments interacting with the donors and the acceptor and compare the expression we obtained for the energy transfer rate with the results of numerical integration.

Sreenath K Manikandan; Anil Shaji

2014-11-17T23:59:59.000Z

276

A simple model for exploring the role of quantum coherence and the environment in excitonic energy transfer  

E-Print Network (OSTI)

We investigate the role of quantum coherence in modulating the energy transfer rate between two energy donors and a single acceptor participating in an excitonic energy transfer process. The energy transfer rate depends explicitly on the nature of the initial coherent superposition state of the two donors and we connect it to the observed absorption profile of the acceptor and the stimulated emission profile of the energy donors. We consider simple models with mesoscopic environments interacting with the donors and the acceptor and compare the expression we obtained for the energy transfer rate with the results of numerical integration.

Manikandan, Sreenath K

2014-01-01T23:59:59.000Z

277

Mass transfer model for two-layer TBP oxidation reactions: Revision 1  

SciTech Connect

To prove that two-layer, TBP-nitric acid mixtures can be safely stored in the Canyon evaporators, it must be demonstrated that a runaway reaction between TBP and nitric acid will not occur. Previous bench-scale experiments showed that, at typical evaporator temperatures, this reaction is endothermic and therefore cannot run away, due to the loss of heat from evaporation of water in the organic layer. However, the reaction would be exothermic and could run away if the small amount of water in the organic layer evaporates before the nitric acid in this layer is consumed by the reaction. Provided that there is enough water in the aqueous layer, this would occur if the organic layer is sufficiently thick so that the rate of loss of water by evaporation exceeds the rate of replenishment due to mixing with the aqueous layer. Bubbles containing reaction products enhance the rate of transfer of water from the aqueous layer to the organic layer. These bubbles are generated by the oxidation of TBP and its reaction products in the organic layer and by the oxidation of butanol in the aqueous layer. Butanol is formed by the hydrolysis of TBP in the organic layer. For aqueous-layer bubbling to occur, butanol must transfer into the aqueous layer. Consequently, the rate of oxidation and bubble generation in the aqueous layer strongly depends on the rate of transfer of butanol from the organic to the aqueous layer. This report presents measurements of mass transfer rates for the mixing of water and butanol in two-layer, TBP-aqueous mixtures, where the top layer is primarily TBP and the bottom layer is comprised of water or aqueous salt solution. Mass transfer coefficients are derived for use in the modeling of two-layer TBP-nitric acid oxidation experiments.

Laurinat, J.E.

1994-11-04T23:59:59.000Z

278

Monte Carlo solution methods in a moment-based scale-bridging algorithm for thermal radiative transfer problems: Comparison with Fleck and Cummings  

SciTech Connect

We have developed a moment-based scale-bridging algorithm for thermal radiative transfer problems. The algorithm takes the form of well-known nonlinear-diffusion acceleration which utilizes a low-order (LO) continuum problem to accelerate the solution of a high-order (HO) kinetic problem. The coupled nonlinear equations that form the LO problem are efficiently solved using a preconditioned Jacobian-free Newton-Krylov method. This work demonstrates the applicability of the scale-bridging algorithm with a Monte Carlo HO solver and reports the computational efficiency of the algorithm in comparison to the well-known Fleck-Cummings algorithm. (authors)

Park, H. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Densmore, J. D. [Bettis Atomic Power Laboratory, West Mifflin, PA 15122 (United States); Wollaber, A. B.; Knoll, D. A.; Rauenzahn, R. M. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

2013-07-01T23:59:59.000Z

279

Posters A One-Dimensional Radiative Convective Model with Detailed Cloud Microphysics  

NLE Websites -- All DOE Office Websites (Extended Search)

5 5 Posters A One-Dimensional Radiative Convective Model with Detailed Cloud Microphysics J. Simmons, O. Lie-Svendsen, and K. Stamnes Geophysical Institute University of Alaska Fairbanks, Alaska The Arctic is a key element in determining the radiation budget of the earth. Within the polar regions, the net radiation (incoming solar radiation minus outgoing infrared radiation) is negative. To understand the role this energy deficit plays in the overall radiation budget, one must examine the prevalent atmospheric features of the Arctic. One such feature is a persistent layer of low-altitude, stratiform clouds found over the central Arctic predominantly from April to September (Tsay et al. 1984). These Arctic stratus clouds (ASC) modulate the earth's radiation budget

280

Normal Tissue Complication Probability Modeling of Radiation-Induced Hypothyroidism After Head-and-Neck Radiation Therapy  

SciTech Connect

Purpose: To determine the dose-response relationship of the thyroid for radiation-induced hypothyroidism in head-and-neck radiation therapy, according to 6 normal tissue complication probability models, and to find the best-fit parameters of the models. Methods and Materials: Sixty-five patients treated with primary or postoperative radiation therapy for various cancers in the head-and-neck region were prospectively evaluated. Patient serum samples (tri-iodothyronine, thyroxine, thyroid-stimulating hormone [TSH], free tri-iodothyronine, and free thyroxine) were measured before and at regular time intervals until 1 year after the completion of radiation therapy. Dose-volume histograms (DVHs) of the patients' thyroid gland were derived from their computed tomography (CT)-based treatment planning data. Hypothyroidism was defined as increased TSH (subclinical hypothyroidism) or increased TSH in combination with decreased free thyroxine and thyroxine (clinical hypothyroidism). Thyroid DVHs were converted to 2 Gy/fraction equivalent doses using the linear-quadratic formula with {alpha}/{beta} = 3 Gy. The evaluated models included the following: Lyman with the DVH reduced to the equivalent uniform dose (EUD), known as LEUD; Logit-EUD; mean dose; relative seriality; individual critical volume; and population critical volume models. The parameters of the models were obtained by fitting the patients' data using a maximum likelihood analysis method. The goodness of fit of the models was determined by the 2-sample Kolmogorov-Smirnov test. Ranking of the models was made according to Akaike's information criterion. Results: Twenty-nine patients (44.6%) experienced hypothyroidism. None of the models was rejected according to the evaluation of the goodness of fit. The mean dose model was ranked as the best model on the basis of its Akaike's information criterion value. The D{sub 50} estimated from the models was approximately 44 Gy. Conclusions: The implemented normal tissue complication probability models showed a parallel architecture for the thyroid. The mean dose model can be used as the best model to describe the dose-response relationship for hypothyroidism complication.

Bakhshandeh, Mohsen [Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of)] [Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Hashemi, Bijan, E-mail: bhashemi@modares.ac.ir [Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of)] [Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Mahdavi, Seied Rabi Mehdi [Department of Medical Physics, Faculty of Medical Sciences, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)] [Department of Medical Physics, Faculty of Medical Sciences, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Nikoofar, Alireza; Vasheghani, Maryam [Department of Radiation Oncology, Hafte-Tir Hospital, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)] [Department of Radiation Oncology, Hafte-Tir Hospital, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Kazemnejad, Anoshirvan [Department of Biostatistics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of)] [Department of Biostatistics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of)

2013-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "radiation transfer models" 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

A diffusion-kinetic model for pulverized-coal combustion and heat-and-mass transfer in a gas stream  

Science Journals Connector (OSTI)

A diffusion-kinetic model for pulverized-coal combustion and heat-and-mass transfer in a gas stream is proposed, and the results of numerical simulation of the burnout dynamics of Kansk-Achinsk coals in the pu...

E. A. Boiko; S. V. Pachkovskii

2008-12-01T23:59:59.000Z

282

Lattice Boltzmann modeling of boiling heat transfer: The boiling curve and the effects of wettability  

E-Print Network (OSTI)

A hybrid thermal lattice Boltzmann (LB) model is presented to simulate thermal multiphase flows with phase change based on an improved pseudopotential LB approach [Q. Li, K. H. Luo, and X. J. Li, Phys. Rev. E 87, 053301 (2013)]. The present model does not suffer from the spurious term caused by the forcing-term effect, which was encountered in some previous thermal LB models for liquid-vapor phase change. Using the model, the liquid-vapor boiling process is simulated. The boiling curve together with the three boiling stages (nucleate boiling, transition boiling, and film boiling) is numerically reproduced in the LB community for the first time. The numerical results show that the basic features and the fundamental characteristics of boiling heat transfer are well captured, such as the severe fluctuation of transient heat flux in the transition boiling and the feature that the maximum heat transfer coefficient lies at a lower wall superheat than that of the maximum heat flux. Furthermore, the effects of the he...

Li, Q; Francois, M M; He, Y L; Luo, K H

2015-01-01T23:59:59.000Z

283

Proceedings of the 8 International Symposium on Heat Transfer  

E-Print Network (OSTI)

, contributions from radiation can be determined via solution of the Equation of Radiative Transfer (ERT equation can lead to significant error, due to the short time-duration of the transport processes, Beijing, China ISHT8-07-05 MODELING OF ULTRAFAST LASER TRANSPORT AND APPLICATIONS Zhixiong Guo Rutgers

Guo, Zhixiong "James"

284

The OceanLandAtmosphere Model: Optimization and Evaluation of Simulated Radiative Fluxes and Precipitation  

Science Journals Connector (OSTI)

This work continues the presentation and evaluation of the OceanLandAtmosphere Model (OLAM), focusing on the models ability to represent radiation and precipitation. OLAM is a new, state-of-the-art earth system model, capable of user-specified ...

David Medvigy; Robert L. Walko; Martin J. Otte; Roni Avissar

2010-05-01T23:59:59.000Z

285

he Impact of Primary Marine Aerosol on Atmospheric Chemistry, Radiation and Climate: A CCSM Model Development Study  

SciTech Connect

This project examined the potential large-scale influence of marine aerosol cycling on atmospheric chemistry, physics and radiative transfer. Measurements indicate that the size-dependent generation of marine aerosols by wind waves at the ocean surface and the subsequent production and cycling of halogen-radicals are important but poorly constrained processes that influence climate regionally and globally. A reliable capacity to examine the role of marine aerosol in the global-scale atmospheric system requires that the important size-resolved chemical processes be treated explicitly. But the treatment of multiphase chemistry across the breadth of chemical scenarios encountered throughout the atmosphere is sensitive to the initial conditions and the precision of the solution method. This study examined this sensitivity, constrained it using high-resolution laboratory and field measurements, and deployed it in a coupled chemical-microphysical 3-D atmosphere model. First, laboratory measurements of fresh, unreacted marine aerosol were used to formulate a sea-state based marine aerosol source parameterization that captured the initial organic, inorganic, and physical conditions of the aerosol population. Second, a multiphase chemical mechanism, solved using the Max Planck Institute for Chemistry??s MECCA (Module Efficiently Calculating the Chemistry of the Atmosphere) system, was benchmarked across a broad set of observed chemical and physical conditions in the marine atmosphere. Using these results, the mechanism was systematically reduced to maximize computational speed. Finally, the mechanism was coupled to the 3-mode modal aerosol version of the NCAR Community Atmosphere Model (CAM v3.6.33). Decadal-scale simulations with CAM v.3.6.33, were run both with and without reactive-halogen chemistry and with and without explicit treatment of particulate organic carbon in the marine aerosol source function. Simulated results were interpreted (1) to evaluate influences of marine aerosol production on the microphysical properties of aerosol populations and clouds over the ocean and the corresponding direct and indirect effects on radiative transfer; (2) atmospheric burdens of reactive halogen species and their impacts on O3, NOx, OH, DMS, and particulate non-sea-salt SO42-; and (3) the global production and influences of marine-derived particulate organic carbon. The model reproduced major characteristics of the marine aerosol system and demonstrated the potential sensitivity of global, decadal-scale climate metrics to multiphase marine-derived components of Earth??s troposphere. Due to the combined computational burden of the coupled system, the currently available computational resources were the limiting factor preventing the adequate statistical analysis of the overall impact that multiphase chemistry might have on climate-scale radiative transfer and climate.

Keene, William C. [University of Virginia] [University of Virginia; Long, Michael S. [University of Virginia] [University of Virginia

2013-05-20T23:59:59.000Z

286

The convergence of an explicit finite difference solution for transient heat transfer in solids with radiation at one boundary  

E-Print Network (OSTI)

at the Interior Point 'n ' 17 8 ? 01 Temperature Resp C 2'( C 1, Wi Constant Tempera x = L, and Havin Transfer to a He Degree Absolute Calculated With Modulus as Per S at x/L = 0. 0 onse th a ture g Ra at S Temp a Mr tabi of Hea at dian ink.... The Fourier equation for one? dimensional heat conduction in solids with constant physical properties is BT K 0 T Qe gC Q~x (3 ? 01) The net radiant heat transfer rate between two gray bodies A and B at absolute temperature T and T will be B according...

Patel, Bhagubhai Desaibhai

2012-06-07T23:59:59.000Z

287

A spatiotemporal auto-regressive moving average model for solar radiation  

E-Print Network (OSTI)

1). Solar radiation, averaged over ten minute intervals, was recorded at each site for two yearsA spatiotemporal auto-regressive moving average model for solar radiation C.A. Glasbey and D, is important in many hydrological, agricultural and energy contexts. To assess solar energy potential, data

Stone, J. V.

288

On the transferability of three water models developed by adaptive force matching  

E-Print Network (OSTI)

Water is perhaps the most simulated liquid. Recently three water models have been developed following the adaptive force matching (AFM) method that provides excellent predictions of water properties with only electronic structure information as a reference. Compared to many other electronic structure based force fields that rely on fairly sophisticated energy expressions, the AFM water models use point-charge based energy expressions that are supported by most popular molecular dynamics packages. An outstanding question regarding simple force fields is whether such force fields provide reasonable transferability outside of their conditions of parameterization. A survey of three AFM water models, B3LYPD-4F, BLYPSP-4F, and WAIL are provided for simulations under conditions ranging from the melting point up to the critical point. By including ice-Ih configurations in the training set, the WAIL potential predicts the melting temperate, TM, of ice-Ih correctly. Without training for ice, BLYPSP-4F underestimates TM...

Hu, Hongyi; Wang, Feng

2015-01-01T23:59:59.000Z

289

Spray Cooling Modeling: Droplet Sub-Cooling Effect on Heat Transfer  

SciTech Connect

Spray cooling has become increasingly popular as a thermal management solution for high-heat flux (>100 W/cm{sup 2}) applications such as laser diodes and radars. Research has shown that using sub-cooled liquid can increase the heat flux from the hot surface. The objective of this study was to use a multi-phase numerical model to simulate the effect of a sub-cooled droplet impacting a growing vapor bubble in a thin (<100 {mu}m) liquid film. The two-phase model captured the liquid-vapor interface using the level set method. The effects of surface tension, viscosity, gravity and phase change were accounted for by using a modification to the incompressible Navier-Stokes equations, which were solved using the finite difference method. The computed liquid-vapor interface and temperature distributions were visualized for better understanding of the heat removal process. To understand the heat transfer mechanisms of sub-cooled droplet impact on a growing vapor bubble, various initial droplet temperatures were modeled (from 20 deg. C below saturation temperature to saturation temperature). This may provide insights into how to improve the heat transfer in future spray cooling systems.

Johnston, Joseph E.; Selvam, R. P. [Power Electronics Leveling Solutions LLC, 700 Research Boulevard, Fayetteville, AR 72701 (United States); Bell 4190 University of Arkansas, Fayetteville, AR 72701 (United States); Silk, Eric A. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2008-01-21T23:59:59.000Z

290

Heat transfer in the spin-boson model: A comparative study in the incoherent tunneling regime  

Science Journals Connector (OSTI)

We study the transfer of heat in the nonequilibrium spin-boson model with an Ohmic dissipation. In the nonadiabatic limit we derive a formula for the thermal conductance based on a rate equation formalism at the level of the noninteracting blip approximation, valid for temperatures T>TK, with TK as the Kondo temperature. We evaluate this expression analytically assuming either weak or strong couplings, and demonstrate that our results agree with exact relations. Far-from-equilibrium situations are further examined, showing a close correspondence to the linear response limit.

Dvira Segal

2014-07-31T23:59:59.000Z

291

A Nonhuman Primate Model of Human Radiation-Induced Venocclusive Liver Disease and Hepatocyte Injury  

SciTech Connect

Background: Human liver has an unusual sensitivity to radiation that limits its use in cancer therapy or in preconditioning for hepatocyte transplantation. Because the characteristic veno-occlusive lesions of radiation-induced liver disease do not occur in rodents, there has been no experimental model to investigate the limits of safe radiation therapy or explore the pathogenesis of hepatic veno-occlusive disease. Methods and Materials: We performed a dose-escalation study in a primate, the cynomolgus monkey, using hypofractionated stereotactic body radiotherapy in 13 animals. Results: At doses ?40 Gy, animals developed a systemic syndrome resembling human radiation-induced liver disease, consisting of decreased albumin, elevated alkaline phosphatase, loss of appetite, ascites, and normal bilirubin. Higher radiation doses were lethal, causing severe disease that required euthanasia approximately 10 weeks after radiation. Even at lower doses in which radiation-induced liver disease was mild or nonexistent, latent and significant injury to hepatocytes was demonstrated by asialoglycoprotein-mediated functional imaging. These monkeys developed hepatic failure with encephalopathy when they received parenteral nutrition containing high concentrations of glucose. Histologically, livers showed central obstruction via an unusual intimal swelling that progressed to central fibrosis. Conclusions: The cynomolgus monkey, as the first animal model of human veno-occlusive radiation-induced liver disease, provides a resource for characterizing the early changes and pathogenesis of venocclusion, for establishing nonlethal therapeutic dosages, and for examining experimental therapies to minimize radiation injury.

Yannam, Govardhana Rao [Department of Surgery, University of Nebraska Medical Center, Omaha, Nebraska (United States); Han, Bing [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Department of Hepatobiliary Surgery, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi (China); Setoyama, Kentaro [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Yamamoto, Toshiyuki [Department of Surgery, University of Nebraska Medical Center, Omaha, Nebraska (United States); Ito, Ryotaro; Brooks, Jenna M. [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Guzman-Lepe, Jorge [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Department of Pathology, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); Galambos, Csaba [Department of Pathology, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); Fong, Jason V. [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Deutsch, Melvin; Quader, Mubina A. [Department of Radiation Oncology, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); Yamanouchi, Kosho [Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, New York (United States); Marion Bessin Liver Research Center, Albert Einstein College of Medicine, Bronx, New York (United States); Kabarriti, Rafi; Mehta, Keyur [Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, New York (United States); Soto-Gutierrez, Alejandro [Department of Pathology, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); and others

2014-02-01T23:59:59.000Z

292

High-energy radiation damage in zirconia: modeling results  

SciTech Connect

Zirconia is viewed as a material of exceptional resistance to amorphization by radiation damage, and consequently proposed as a candidate to immobilize nuclear waste and serve as an inert nuclear fuel matrix. Here, we perform molecular dynamics simulations of radiation damage in zirconia in the range of 0.1-0.5 MeV energies with account of electronic energy losses. We nd that the lack of amorphizability co-exists with a large number of point defects and their clusters. These, importantly, are largely isolated from each other and therefore represent a dilute damage that does not result in the loss of long-range structural coherence and amorphization. We document the nature of these defects in detail, including their sizes, distribution and morphology, and discuss practical implications of using zirconia in intense radiation environments.

Zarkadoula, Evangelia [Queen Mary, University of London] [Queen Mary, University of London; Devanathan, Ram [Pacific Northwest National Laboratory (PNNL)] [Pacific Northwest National Laboratory (PNNL); Weber, William J [ORNL] [ORNL; Seaton, M [Daresbury Laboratory, UK] [Daresbury Laboratory, UK; Todorov, I T [Daresbury Laboratory, UK] [Daresbury Laboratory, UK; Nordlund, Kai [University of Helsinki] [University of Helsinki; Dove, Martin T [Queen Mary, University of London] [Queen Mary, University of London; Trachenko, Kostya [Queen Mary, University of London] [Queen Mary, University of London

2014-01-01T23:59:59.000Z

293

Earth Radiation Budget and Cloudiness Simulations with a General Circulation Model  

Science Journals Connector (OSTI)

The UCLA/GLA general circulation model has been endowed with new parameterizations of solar and terrestrial radiation, as well as new parameterized cloud optical properties. A simple representation of the cloud liquid water feedback is included. ...

Harshvardhan; David A. Randall; Thomas G. Corsetti

1989-07-01T23:59:59.000Z

294

Excitational energy transfer enhancing ionization and spatial-temporal evolution of air breakdown with UV laser radiation  

E-Print Network (OSTI)

with UV laser radiation Jason S. Hummelta and John E. Scharer Department of Electrical and Computer of oxygen has on the ionization of nitrogen in laser air breakdown. Plasma is created by focusing a 193 nm ArF excimer laser using an 18 cm focal length lens, producing a cylindrical 540 m wide spot

Scharer, John E.

295

USING LEARNING MACHINES TO CREATE SOLAR RADIATION MAPS FROM NUMERICAL WEATHER PREDICTION MODELS,  

E-Print Network (OSTI)

USING LEARNING MACHINES TO CREATE SOLAR RADIATION MAPS FROM NUMERICAL WEATHER PREDICTION MODELS simulation by means of a Numerical Weather Prediction Model (NWP), Skiron. After that, we have made spatial solar resource map. 2.1. Meteorological simulation The numerical weather prediction model used is SKIRON

Paris-Sud XI, Université de

296

Working Group Reports Calibration of Radiation Codes Used in Climate Models:  

NLE Websites -- All DOE Office Websites (Extended Search)

Working Group Reports Calibration of Radiation Codes Used in Climate Models: Comparison of Clear-Sky Calculations with Observations from the Spectral Radiation Experiment and the Atmospheric Radiation Measurement Program R. G. Ellingson, S. Shen, and J. Warner University of Maryland College Park, Maryland Background The InterComparison of Radiation Codes in Climate Models (ICRCCM) showed large differences between model calculations of longwave fluxes and heating rates-even for clear-sky conditions (Luther et al. 1988). The discrepancies could not be resolved with either pyrgeometer measurements or line-by-line calculations because * Pyrgeometer errors are the magnitude of the discrepancies. * Uncertainties in the physics of line wings and in the proper treatment of the continuum make it impossible

297

Induction and Persistence of Large ?H2AX Foci by High Linear Energy Transfer Radiation in DNA-Dependent protein kinaseDeficient Cells  

SciTech Connect

Purpose: To evaluate the cell response to DNA double-strand breaks induced by low and high linear energy transfer (LET) radiations when the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs), an essential protein of the nonhomologous end-joining repair pathway, lacks kinase activity. Methods and Materials: CHO10B2, a Chinese hamster ovary cell line, and its derived radiosensitive mutant cell line, irs-20, lacking DNA-PKcs activity, were evaluated after 0 to 3 Gy of ?-rays, plateau and Bragg peak protons, and lithium beams by clonogenic assay, and as a measurement of double-strand breaks, phosphorylated H2AX (?H2AX) foci number and size were quantified by immunocytofluorescence. Results: Irs-20 exhibited greater radiosensitivity and a higher amount of ?H2AX foci than CHO10B2 at 6 hours after irradiation for all types of radiations. Remarkably, CHO10B2 and irs-20 maintained their difference in radiosensitivity after high-LET radiation. Six hours after low-LET radiations, irs-20 did not reach basal levels of ?H2AX at high doses, whereas CHO10B2 recovered basal levels for all doses. After high-LET radiation, only CHO10B2 exhibited a reduction in ?H2AX foci, but it never reached basal levels. Persistent foci in irs-20 confirmed a repair deficiency. Interestingly, after 30 minutes of high-LET radiation both cell lines exhibited large foci (size >0.9 ?m{sup 2}) related to the damage nature, whereas at 6 hours irs-20 showed a higher amount of large foci than CHO10B2, with a 7-fold increase at 3 Gy, that could also be associated to radiosensitivity. Conclusions: We demonstrated, for the first time, an association between deficient DNA-PKcs activity and not only high levels of H2AX phosphorylation but also persistence and size increase of ?H2AX foci after high-LET irradiation.

Bracalente, Candelaria; Ibaez, Irene L. [Departamento de Micro y Nanotecnologa, Comisin Nacional de Energa Atmica, San Martn, Buenos Aires (Argentina); Consejo Nacional de Investigaciones Cientficas y Tcnicas, Buenos Aires (Argentina); Molinari, Beatriz [Departamento de Radiobiologa, Comisin Nacional de Energa Atmica, San Martn, Buenos Aires (Argentina); Consejo Nacional de Investigaciones Cientficas y Tcnicas, Buenos Aires (Argentina); Palmieri, Mnica [Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires (Argentina); Kreiner, Andrs [Consejo Nacional de Investigaciones Cientficas y Tcnicas, Buenos Aires (Argentina); Gerencia de Investigacin y Aplicaciones, Comisin Nacional de Energa Atmica, San Martn, Buenos Aires (Argentina); Escuela de Ciencia y Tecnologa, Universidad Nacional de San Martn, San Martn, Buenos Aires (Argentina); Valda, Alejandro [Escuela de Ciencia y Tecnologa, Universidad Nacional de San Martn, San Martn, Buenos Aires (Argentina); and others

2013-11-15T23:59:59.000Z

298

Principal component analysis and radiative transfer modelling of Spitzer Infrared Spectrograph spectra of ultraluminous infrared galaxies  

Science Journals Connector (OSTI)

......St, Engomi, 1516 Nicosia, Cyprus The mid-infrared spectra of...ULIRGs is a result of dust and gas reprocessing the optical and...densities (n HS) and assuming a gas-to-dust ratio of 150. The...information in IRS spectra, it is natural to use the PCs as a classification......

P. D. Hurley; S. Oliver; D. Farrah; L. Wang; A. Efstathiou

2012-08-11T23:59:59.000Z

299

Global oceanic rainfall estimation from AMSR-E data based on a radiative transfer model  

E-Print Network (OSTI)

framework for inter-comparison with the experimental algorithm, the current operational algorithm (NASA, level 3 algorithm) was also updated with respect to AMSR-E data. The experimental algorithm was compared with the operational algorithm for both AMSR...

Jin, Kyoung-Wook

2006-04-12T23:59:59.000Z

300

Cloud-Resolving Model Simulation and Mosaic Treatment of Subgrid Cloud-Radiation Interaction  

NLE Websites -- All DOE Office Websites (Extended Search)

Cloud-Resolving Model Simulation and Mosaic Treatment Cloud-Resolving Model Simulation and Mosaic Treatment of Subgrid Cloud-Radiation Interaction X. Wu Department of Geological and Atmospheric Sciences Iowa State University Ames, Iowa X.-Z. Liang Illinois State Water Survey University of Illinois at Urbana-Champaign Champaign, Illinois Introduction Improving the representation of cloud-radiation interaction is a major challenge for the global climate simulation. The development of cloud-resolving models (CRMs) and the extensive Atmospheric Radiation Measurements (ARMs) provide a unique opportunity for shading some lights on this problem. Current general circulation models (GCMs) predict cloud cover fractions and hydrometeor concentra- tions only in individual model layers, where clouds are assumed to be horizontally homogeneous in a

Note: This page contains sample records for the topic "radiation transfer models" 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

Modeling of the radiation belt megnetosphere in decisional timeframes  

DOE Patents (OSTI)

Systems and methods for calculating L* in the magnetosphere with essentially the same accuracy as with a physics based model at many times the speed by developing a surrogate trained to be a surrogate for the physics-based model. The trained model can then beneficially process input data falling within the training range of the surrogate model. The surrogate model can be a feedforward neural network and the physics-based model can be the TSK03 model. Operatively, the surrogate model can use parameters on which the physics-based model was based, and/or spatial data for the location where L* is to be calculated. Surrogate models should be provided for each of a plurality of pitch angles. Accordingly, a surrogate model having a closed drift shell can be used from the plurality of models. The feedforward neural network can have a plurality of input-layer units, there being at least one input-layer unit for each physics-based model parameter, a plurality of hidden layer units and at least one output unit for the value of L*.

Koller, Josef; Reeves, Geoffrey D; Friedel, Reiner H.W.

2013-04-23T23:59:59.000Z

302

A FAST MULTILEVEL ALGORITHM FOR THE SOLUTION OF NONLINEAR SYSTEMS OF CONDUCTIVERADIATIVE HEAT TRANSFER EQUATIONS IN TWO  

E-Print Network (OSTI)

#12; The isotropic, monoenergetic, radiative transport equation is [10], [25], [34], \\Omega \\Delta r r­ differential equations that model steady­state combined conductive­radiative heat transfer in two spaceA FAST MULTILEVEL ALGORITHM FOR THE SOLUTION OF NONLINEAR SYSTEMS OF CONDUCTIVE­RADIATIVE HEAT

303

Constraints on general second-order scalar-tensor models from gravitational Cherenkov radiation  

SciTech Connect

We demonstrate that the general second-order scalar-tensor theories, which have attracted attention as possible modified gravity models to explain the late time cosmic acceleration, could be strongly constrained from the argument of the gravitational Cherenkov radiation. To this end, we consider the purely kinetic coupled gravity and the extended galileon model on a cosmological background. In these models, the propagation speed of tensor mode could be less than the speed of light, which puts very strong constraints from the gravitational Cherenkov radiation.

Kimura, Rampei; Yamamoto, Kazuhiro, E-mail: rampei@theo.phys.sci.hiroshima-u.ac.jp, E-mail: kazuhiro@hiroshima-u.ac.jp [Department of Physical Science, Hiroshima University, Higashi-Hiroshima 739-8526 (Japan)

2012-07-01T23:59:59.000Z

304

Does really BornOppenheimer approximation break down in charge transfer processes? An exactly solvable model  

Science Journals Connector (OSTI)

Effects of deviation from the BornOppenheimer approximation (BOA) on the non-adiabatic transition probability for the transfer of a quantum particle in condensed media are studied within an exactly solvable model. The particle and the medium are modeled by a set of harmonic oscillators. The dynamic interaction of the particle with a single local mode is treated explicitly without the use of BOA. Two particular situations (symmetric and non-symmetric systems) are considered. It is shown that the difference between the exact solution and the true BOA is negligibly small at realistic parameters of the model. However, the exact results differ considerably from those of the crude Condon approximation (CCA) which is usually considered in the literature as a reference point for BOA (MarcusHushDogonadze formula). It is shown that the exact rate constant can be smaller (symmetric system) or larger (non-symmetric one) than that obtained in CCA. The non-Condon effects are also studied.

Alexander M. Kuznetsov; Igor G. Medvedev

2006-01-01T23:59:59.000Z

305

HEAT AND MOISTURE TRANSFER THROUGH CLOTHING  

E-Print Network (OSTI)

R. C. Eberhart (ed), Heat transfer in medicine and biology.Convective and radiative heat transfer coefficients forCheng, X. -Y. 2005. Heat and moisture transfer with sorption

Voelker, Conrad; Hoffmann, Sabine; Kornadt, Oliver; Arens, Edward; Zhang, Hui; Huizenga, Charlie

2009-01-01T23:59:59.000Z

306

3D CFD ELECTROCHEMICAL AND HEAT TRANSFER MODEL OF AN INTERNALLY MANIFOLDED SOLID OXIDE ELECTROLYSIS CELL  

SciTech Connect

A three-dimensional computational fluid dynamics (CFD) electrochemical model has been created to model high-temperature electrolysis cell performance and steam electrolysis in an internally manifolded planar solid oxide electrolysis cell (SOEC) stack. This design is being evaluated at the Idaho National Laboratory for hydrogen production from nuclear power and process heat. Mass, momentum, energy, and species conservation and transport are provided via the core features of the commercial CFD code FLUENT. A solid-oxide fuel cell (SOFC) model adds the electrochemical reactions and loss mechanisms and computation of the electric field throughout the cell. The FLUENT SOFC user-defined subroutine was modified for this work to allow for operation in the SOEC mode. Model results provide detailed profiles of temperature, operating potential, steam-electrode gas composition, oxygen-electrode gas composition, current density and hydrogen production over a range of stack operating conditions. Single-cell and five-cell results will be presented. Flow distribution through both models is discussed. Flow enters from the bottom, distributes through the inlet plenum, flows across the cells, gathers in the outlet plenum and flows downward making an upside-down ''U'' shaped flow pattern. Flow and concentration variations exist downstream of the inlet holes. Predicted mean outlet hydrogen and steam concentrations vary linearly with current density, as expected. Effects of variations in operating temperature, gas flow rate, oxygen-electrode and steam-electrode current density, and contact resistance from the base case are presented. Contour plots of local electrolyte temperature, current density, and Nernst potential indicate the effects of heat transfer, reaction cooling/heating, and change in local gas composition. Results are discussed for using this design in the electrolysis mode. Discussion of thermal neutral voltage, enthalpy of reaction, hydrogen production, cell thermal efficiency, cell electrical efficiency, and Gibbs free energy are discussed and reported herein.

Grant L. Hawkes; James E. O'Brien; Greg Tao

2011-11-01T23:59:59.000Z

307

Measure of Diffusion Model Error for Thermal Radiation Transport  

E-Print Network (OSTI)

cm2 sh keV c Speed of light 2:99 102 cmsh D Di usion coe cient ( 13 t ) cm F Radiation ux jkcm2 sh k Time iteration t Di erence between consecutive time steps shakes(sh) hi Size of spatial cell, i cm ! Direction of photon propagation ster... backward Euler implicit di erencing in time and lumped LD in space to (5.5), we get 1 c t (k+ 12) i;L (k 12) i;L hi 2 + F (k+ 12) i F (k+ 12) i 12 + hi 2 a (k+ 12) i;L = QL hi 2 ; (8.2a) 1 c t (k+ 12) i;R (k...

Kumar, Akansha

2013-04-19T23:59:59.000Z

308

HIV-1 integrase strand-transfer inhibitors: Design, synthesis and molecular modeling investigation  

Science Journals Connector (OSTI)

This study is focused on a new series of benzylindole derivatives with various substituents at the benzene-fused ring, suggested by our 3D pharmacophore model developed for HIV-1 integrase inhibitors (INIs). All synthesized compounds proved to be active in the nanomolar range (635nM) on the strand-transfer step (ST). In particular, derivative 4-[1-(4-fluorobenzyl)-5,7-dimethoxy-1H-indol-3-yl]-2-hydroxy-4-oxobut-2-enoic acid (8e), presenting the highest best-fit value on pharmacophore model, showed a potency comparable to that of clinical \\{INSTIs\\} GS 9137 (1) and MK-0518 (2). The binding mode of our molecules has been investigated using the recently published crystal structure of the complex of full-length integrase from the prototype foamy virus in complex with its cognate DNA (PFV-IN/DNA). The results highlighted the ability of derivative 8e to assume the same binding mode of MK-0518 and GS 9137.

Laura De Luca; Sara De Grazia; Stefania Ferro; Rosaria Gitto; Frauke Christ; Zeger Debyser; Alba Chimirri

2011-01-01T23:59:59.000Z

309

Shielded cells transfer automation  

SciTech Connect

Nuclear waste from shielded cells is removed, packaged, and transferred manually in many nuclear facilities. Radiation exposure is absorbed by operators during these operations and limited only through procedural controls. Technological advances in automation using robotics have allowed a production waste removal operation to be automated to reduce radiation exposure. The robotic system bags waste containers out of glove box and transfers them to a shielded container. Operators control the system outside the system work area via television cameras. 9 figures.

Fisher, J J

1984-01-01T23:59:59.000Z

310

Broadband Model Performance for an Updated National Solar Radiation Database in the United States of America: Preprint  

SciTech Connect

Updated review of broadband model performance in a project being done to update the existing United States National Solar Radiation Database (NSRDB).

Myers, D. R.; Wilcox, S.; Marion, W.; George, R.; Anderberg, M.

2005-09-01T23:59:59.000Z

311

Model calculations of radiative capture of nucleons in MeV region  

SciTech Connect

We address calculations of the neutron and the proton radiative capture at incident energies up to 20 MeV on medium and heavy nuclei. The main formalism used is the pre-equilibrium (exciton) model of {gamma} emission. A link to the Consistent Direct-Semidirect model is noticed as well. The resulting pre-equilibrium (plus equilibrium) calculations of the radiative capture excitation functions are compared to experimental data and also some cross section trends important for possible production of therapeutic radioisotopes are extracted.

Betak, E. [Institute of Physics, Slovak Acad. Sciences, 84511 Bratislava (Slovakia); Faculty of Philosophy and Sciences, Silesian Univ., 74601 Opava (Czech Republic)

2006-03-13T23:59:59.000Z

312

Heat transfer modeling at an interface between a porous medium and a free region.  

E-Print Network (OSTI)

??This work deals with the study of heat transfer between a porous medium and a free medium, using multi scale approaches. First, we derive the (more)

D'hueppe, Alinor

2011-01-01T23:59:59.000Z

313

Computational fluid dynamic modelling of enhanced heat transfer in tubes with inserts.  

E-Print Network (OSTI)

??Heat transfer is an important process in many different industrial processes including oil refming and energy generation. A shell and tube heat exchanger is one (more)

Osley, William Gruffydd

2014-01-01T23:59:59.000Z

314

The Development of a Non-Equilibrium Dispersed Flow Film Boiling Heat Transfer Modeling Package.  

E-Print Network (OSTI)

??The dispersed flow film boiling (DFFB) heat transfer regime is important to several applications including cryogenics, rocket engines, steam generators, and in the safety analysis (more)

Meholic, Michael

2011-01-01T23:59:59.000Z

315

Three-dimensional particle scale modeling of heat transfer in fluidized beds.  

E-Print Network (OSTI)

??Heat transfer between particle-fluid media and solid surfaces has wide applications in industries such as power plant, steel heat treatment, and chemical processes. One of (more)

Wahyudi, Hadi

2014-01-01T23:59:59.000Z

316

An extended model for measuring the technology transfer potentials at the industrial level.  

E-Print Network (OSTI)

??Technology contributes to the development of society and economy of the nation through the invention, diffusion, transfer, and application of new knowledge. In the emerging (more)

Pachamuthu, Sathayanarayanan

2011-01-01T23:59:59.000Z

317

Modeling of the Cryogenic Liquid Pool Evaporation and the Effect of the Convective Heat Transfer from Atmosphere  

E-Print Network (OSTI)

of this activity. This includes the prediction of the consequences of potential loss of containment of LNG, which requires the modelling of the vaporization rate of LNG resulting from the heat transfer between the pool and surroundings. The present work focuses...

Nawaz, Waqas

2014-04-25T23:59:59.000Z

318

ON THE ROLE OF THERMOELECTRIC HEAT TRANSFER IN THE DESIGN OF SMA ACTUATORS: THEORETICAL MODELING AND EXPERIMENT  

E-Print Network (OSTI)

current densities. As a #12;rst step towards the design of an actuator, a thermoelectric module. Semiconductorshave been used for localized cooling, employing the thermoelectricPeltier eect. DependingON THE ROLE OF THERMOELECTRIC HEAT TRANSFER IN THE DESIGN OF SMA ACTUATORS: THEORETICAL MODELING

319

The Los Alamos dynamic radiation environment assimilation model (DREAM) for space weather specification and forecasting  

SciTech Connect

The Dynamic Radiation Environment Assimilation Model (DREAM) was developed at Los Alamos National Laboratory to assess, quantify, and predict the hazards from the natural space environment and the anthropogenic environment produced by high altitude nuclear explosions (HANE). DREAM was initially developed as a basic research activity to understand and predict the dynamics of the Earth's Van Allen radiation belts. It uses Kalman filter techniques to assimilate data from space environment instruments with a physics-based model of the radiation belts. DREAM can assimilate data from a variety of types of instruments and data with various levels of resolution and fidelity by assigning appropriate uncertainties to the observations. Data from any spacecraft orbit can be assimilated but DREAM was designed to function with as few as two spacecraft inputs: one from geosynchronous orbit and one from GPS orbit. With those inputs, DREAM can be used to predict the environment at any satellite in any orbit whether space environment data are available in those orbits or not. Even with very limited data input and relatively simple physics models, DREAM specifies the space environment in the radiation belts to a high level of accuracy. DREAM has been extensively tested and evaluated as we transition from research to operations. We report here on one set of test results in which we predict the environment in a highly-elliptical polar orbit. We also discuss long-duration reanalysis for spacecraft design, using DREAM for real-time operations, and prospects for 1-week forecasts of the radiation belt environment.

Reeves, Geoffrey D [Los Alamos National Laboratory; Friedel, Reiner H W [Los Alamos National Laboratory; Chen, Yue [Los Alamos National Laboratory; Koller, Josef [Los Alamos National Laboratory; Henderson, Michael G [Los Alamos National Laboratory

2008-01-01T23:59:59.000Z

320

Using transfer functions to quantify El Nio Southern Oscillation dynamics in data and models  

Science Journals Connector (OSTI)

...Transfer function tools commonly used in engineering control analysis can be used to better...transfer function is taken from the control engineering literature [12], and it refers to...modified periodograms. IEEE Trans. Audio Electroacoust. AU-15, 70-73...

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "radiation transfer models" 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

Modelling of radiation exposure at high altitudes during solar storms  

Science Journals Connector (OSTI)

......with a different energy spectrum. To estimate...exposure due to solar flares, a model...measuring the flux of solar and galactic particles...and the high-energy proton and alpha...Exposure during Solar Maximum) project. One flight from......

H. Al Anid; B. J. Lewis; L. G. I. Bennett; M. Takada

2009-10-01T23:59:59.000Z

322

Low Dose Radiation Research Program: Modeling the Physics of Damage Cluster  

NLE Websites -- All DOE Office Websites (Extended Search)

Modeling the Physics of Damage Cluster Formation in a Cellular Environment Modeling the Physics of Damage Cluster Formation in a Cellular Environment Larry Toburen East Carolina University Why This Project Modern tools of radiobiology are leading to many new discoveries regarding how cells and tissues respond to radiation exposure. We can now irradiate single cells and observe responses in adjacent cells. We can also measure clusters of radiation damage produced in DNA. The primary tools available to describe the initial spatial pattern of damage formed by the absorption of ionizing radiation are based on (MC) Monte Carlo simulations of the structure of charged particle tracks. Although many MC codes exist and considerable progress is being made in the incorporation of detailed macromolecular target structures into these codes, much of the interaction

323

STOCHASTIC MODELS OF SPACE RADIATION DNA DAMAGE RESPONSES AND CANCER RISKS  

NLE Websites -- All DOE Office Websites (Extended Search)

STOCHASTIC MODELS OF SPACE RADIATION DNA DAMAGE STOCHASTIC MODELS OF SPACE RADIATION DNA DAMAGE RESPONSES AND CANCER RISKS Francis A. Cucinotta 1 , Janice M. Pluth 2 , Artem Ponomarev 3 , Shaowen Hu 3 , Jennifer Anderson 4 , Jane Harper 4 , and Peter O'Neill 4 1 NASA Lyndon B. Johnson Space Center, Houston TX, USA; 2 Lawrence Berkeley National Laboratory, Berkeley CA, USA; 3 U.S.R.A., Division of Life Sciences, Houston TX, USA; 4 MRC Radiation and Genome Stability Unit, Harwell, Didcot, UK Abstract: On space missions astronauts are exposed to a steady flux of galactic cosmic rays (GCR) consisting of high-energy protons and heavy ions. In the next decades long- term missions of up to 200 days to the Earth's moon and 1100 days to Mars are planed by NASA where cumulative doses will not be low (>100 mSv) albeit dose-

324

CFD simulation of heat transfer enhancement of Al2O3/water and Al2O3/ethylene glycol nanofluids in a car radiator  

Science Journals Connector (OSTI)

Abstract The present numerical study simulated turbulent and laminar flow heat transfer in nanofluids (Al2O3 particles in water and ethylene glycol-based fluid) passing through a flat tube in 3D using computational fluid dynamics (CFD) for single and two-phase approaches. The advantages over pure base fluids were evaluated. Empirical correlations were used to calculate nanofluid viscosity and thermal conductivity as a function of the volumetric concentration of the nanoparticles. First, the Nusselt numbers of the pure water and pure ethylene glycol in flat tubes were compared with the experimental data. Next, the Nusselt numbers for both approaches were compared with those for experimental data at the same Reynolds number for different concentrations of nanoparticles. A small difference in the friction factors of the tube was observed between the two approaches and the Nusselt number for the two-phase model was markedly different from that for the single-phase model; however, the volumetric flow for the same heat transfer rate decreased and less pumping power was required for the nanofluids.

Vahid Delavari; Seyed Hassan Hashemabadi

2014-01-01T23:59:59.000Z

325

Theory and computational modeling: Medium reorganization and donor/acceptor coupling in electron transfer processes  

SciTech Connect

The continuing goal is to convert the rapidly accumulating mechanistic information about electron transfer (et) kinetics (often representable in terms of simple rate constants) into precise tools for fine-tuned control of the kinetics and for design of molecular-based systems which meet specified et characteristics. The present treatment will be limited to the kinetic framework defined by the assumption of transition state theory (TST). The primary objective of this paper is to report recent advances in the theoretical formulation, calculation, and analysis of energetics and electronic coupling pertinent to et in complex molecular aggregates. The control of et kinetics (i.e., enhancing desired processes, while inhibiting others) involves, of course, both system energetics (especially reorganization energies (E{sub r}) and free energy changes ({Delta}G{sup 0})) and electronic coupling of local D and A sites, which for thermal processes is most directly relevant only after the system has reached the appropriate point (or region) along the reaction coordinate (i.e., the transition state). The authors first discuss TST rate constant models, emphasizing genetic features, but also noting some special features arising when metal electrodes are involved. They then turn to a consideration of detailed aspects of medium reorganization and donor/acceptor coupling. With these theoretical tools in hand, they examine the results of recent applications to complex molecular systems using the techniques of computational quantum chemistry and electrostatics, together with detailed analysis of the numerical results and comparison with recent electrochemical kinetic data.

Newton, M.D.; Feldberg, S.W.; Smalley, J.F.

1998-03-01T23:59:59.000Z

326

Wind mass transfer in S-type symbiotic binaries I. Focusing by the wind compression model  

E-Print Network (OSTI)

Context: Luminosities of hot components in symbiotic binaries require accretion rates that are higher than those that can be achieved via a standard Bondi-Hoyle accretion. This implies that the wind mass transfer in symbiotic binaries has to be more efficient. Aims: We suggest that the accretion rate onto the white dwarfs (WDs) in S-type symbiotic binaries can be enhanced sufficiently by focusing the wind from their slowly rotating normal giants towards the binary orbital plane. Methods: We applied the wind compression model to the stellar wind of slowly rotating red giants in S-type symbiotic binaries. Results: Our analysis reveals that for typical terminal velocities of the giant wind, 20 to 50 km/s, and measured rotational velocities between 6 and 10 km/s, the densities of the compressed wind at a typical distance of the accretor from its donor correspond to the mass-loss rate, which can be a factor of $\\sim$10 higher than for the spherically symmetric wind. This allows the WD to accrete at rates of $10^{-...

Skopal, Augustin

2014-01-01T23:59:59.000Z

327

Computational modeling of laser-plasma interactions: Pulse self-modulation and energy transfer between intersecting laser pulses  

Science Journals Connector (OSTI)

The nonlinear interaction of intense femtosecond laser pulses with a self-induced plasma channel in air and the energy transfer between two intersecting laser pulses were simulated using the finite-difference time-domain particle-in-cell method. Implementation of a simple numerical code enabled modeling of various phenomena, including pulse self-modulation in the spatiotemporal and spectral domains, conical emission, and energy transfer between two intersecting laser beams. The mechanism for energy transfer was found to be related to a plasma waveguide array induced by Moir patterns of the interfering electric fields. The simulation results provide a persuasive replication and explanation of previous experimental results, when carried out under comparable physical conditions, and lead to prediction of others. This approach allows us to further examine the effect of the laser and plasma parameters on the simulation results and to investigate the underlying physics.

Rotem Kupfer; Boris Barmashenko; Ilana Bar

2013-07-17T23:59:59.000Z

328

Design and Testing of a Heat Transfer Model of a Raccon (Procyon Lotor) in a Closed Tree Den Author(s): Jeffrey Thorkelson and Robert K. Maxwell  

E-Print Network (OSTI)

Design and Testing of a Heat Transfer Model of a Raccon (Procyon Lotor) in a Closed Tree Den Author. http://www.jstor.org #12;Ecology (1974) 55: pp. 29-39 DESIGN AND TESTING OF A HEAT TRANSFER MODEL of Ecology and Behavioral Biology, Universityof Minnesota, St. Paul, Minnesota 55101 Aabstract. A heat

Minnesota, University of

329

Evaluation of the Multi-scale Modeling Framework Using Data from the Atmospheric Radiation Measurement Program  

SciTech Connect

One of the goals of the Atmospheric Radiation Measurement (ARM) program is to provide long-term observations for evaluating and improving cloud and radiation treatment in global climate models. Unfortunately, the traditional parametric approach of diagnosing cloud and radiation properties for gridcells that are tens to hundreds kilometers across from large-scale model fields is not well suited for comparison with time series of ground based observations at selected locations. A recently emerging approach called a multi-scale modeling framework (MMF) has shown promise to bridge the scale gap. The MMF consists of a two-dimensional or small three-dimensional cloud resolving model (CRM) embedded into each grid column of the Community Atmospheric Model (CAM), thereby computing cloud properties at a scale that is more consistent with observations. We present a comparison of data from two ARM sites, one at the Southern Great Plains (SGP) in Oklahoma and one at Nauru Island in the Tropical Western Pacific (TWP) region, with output from both the CAM and MMF. Two sets of one year long simulations are considered: one using climatological sea surface temperatures (SST) and another using 1999 SST. Each set includes a run with the MMF as well as the CAM run with traditional or standard cloud and radiation treatment. Time series of cloud fraction, precipitation intensity, and downwelling solar radiation flux at the surface are statistically analyzed. For the TWP site, nearly all parameters of frequency distributions of these variables from the MMF run are shown to be more consistent with observation than those from the CAM run. This change is attributed to the improved representation of convective clouds in the MMF compared to the conventional climate model. For the SGP, the MMF shows little to no improvement in predicting the same quantities. Possible causes of this lack of improvement are discussed.

Ovtchinnikov, Mikhail; Ackerman, Thomas P.; Marchand, Roger T.; Khairoutdinov, Marat

2006-05-01T23:59:59.000Z

330

Testing Radiative Neutrino Mass Models at the LHC  

E-Print Network (OSTI)

The Large Hadron Collider provides us new opportunities to search for the origin of neutrino mass. Beyond the minimal see-saw models a plethora of models exist which realise neutrino mass at tree- or loop-level, and it is important to be sure that these possibilities are satisfactorily covered by searches. The purpose of this paper is to advance a systematic approach to this problem. Majorana neutrino mass models can be organised by SM-gauge-invariant operators which violate lepton number by two units. In this paper we write down the minimal ultraviolet completions for all of the mass-dimension 7 operators. We predict vector-like quarks, vector-like leptons, scalar leptoquarks, a charged scalar, and a scalar doublet, whose properties are constrained by neutrino oscillation data. A detailed collider study is presented for $O_3=LLQ\\bar dH$ and $O_8 = L\\bar d\\bar e^\\dagger \\bar u^\\dagger H$ completions with a vector-like quark $\\chi\\sim(3, 2, -\\frac{5}{6})$ and a leptoquark $\\phi\\sim(\\bar 3,1,\\frac{1}{3})$. The existing LHC limits extracted from searches for vector-like fermions and sbottoms/stops are $m_\\chi \\gtrsim 620$ GeV and $m_\\phi\\gtrsim 600$ GeV.

Yi Cai; Jackson D. Clarke; Michael A. Schmidt; Raymond R. Volkas

2014-10-22T23:59:59.000Z

331

Molecular mechanisms of radiation carcinogenesis and the linear, non-threshold dose response model of radiation risk estimation  

Science Journals Connector (OSTI)

Recent research in molecular radiation carcinogenesis is reviewed with the specific aim of exploring the implications this research may have on the dose response relationship of radiation-induced cancer at low...

K. R. Trott; M. Rosemann

2000-06-01T23:59:59.000Z

332

Radiated seismic energy based on dynamic rupture models of faulting and Ralph J. Archuleta1  

E-Print Network (OSTI)

Radiated seismic energy based on dynamic rupture models of faulting Shuo Ma1 and Ralph J. Archuleta energy from three hypothetical crustal events, 30° dipping reverse fault, 60° dipping normal fault, and 0.34 MPa for the reverse, normal, and strike-slip faults, respectively. The energy distribution

Archuleta, Ralph

333

INVENTORY OF SOLAR RADIATION/SOLAR ENERGY SYSTEMS ESTIMATORS, MODELS, SITE-SPECIFIC DATA, AND PUBLICATIONS  

E-Print Network (OSTI)

INVENTORY OF SOLAR RADIATION/SOLAR ENERGY SYSTEMS ESTIMATORS, MODELS, SITE-SPECIFIC DATA, and Buildings Systems Integration Center National Renewable Energy Laboratory 8 July 2009 SOLAR SYSTEM POTENTIAL/calculators/PVWATTS/version1/ http://rredc.nrel.gov/solar/calculators/PVWATTS/version2/ Estimates the electrical energy

334

EVALUATION OF NUMERICAL WEATHER PREDICTION IN MODELING CLOUD-RADIATION INTERACTIONS OVER THE SOUTHERN GREAT PLAINS  

E-Print Network (OSTI)

EVALUATION OF NUMERICAL WEATHER PREDICTION IN MODELING CLOUD- RADIATION INTERACTIONS OVER.bnl.gov ABSTRACT Numerical weather prediction (NWP) is the basis for present-day weather forecasts, and NWP- and satellite- based observations over the Southern Great Plains to evaluate how well cloud

Johnson, Peter D.

335

The Impact of Spatial Resolution on Model-Derived Radiative Heating  

NLE Websites -- All DOE Office Websites (Extended Search)

Impact of Spatial Resolution Impact of Spatial Resolution on Model-Derived Radiative Heating W. O'Hirok and C. Gautier Institute for Computational Earth System Science University of California Santa Barbara, California C. Gautier Department of Geography University of California Santa Barbara, California Introduction At the typical spatial resolution of climate and weather forecasting models, clouds are portrayed as uniform plane-parallel entities with three-dimensional (3D) radiative effects generally considered not important. However, as the resolution of these models increase, and with the development of "super parameterizations" (embedded cloud resolving models), there is a need to assess the spatial resolution where 3D effects should not be neglected (Khairoutdinov and Randall 2001). In this study, we perform

336

A model for noise radiated by submerged piles and towers in littoral environments  

Science Journals Connector (OSTI)

Pile driving in shallow water during the construction of bridges and other structures can produce transient broadband noise of sufficient intensity to kill fish and disturb marine mammals. Sustained tonal noise radiated by towers supporting offshore wind turbines contains energy in frequency bands that may inhibit detection of coastal activities via passive sonar and seismic sensors. Understanding the generation and propagation of underwater noise due to pile driving and wind farms is important for determining the best strategies for mitigating the environmental impact of these noisesources. An analytic model based on a Green's function approach is presented for the sound radiated in the water column by a submerged cylindrical structure embedded in horizontally stratified layers of sediment. The sediment layers are modeled as viscoelastic media and the Green's function is derived via angular spectrum decomposition. Noise radiation due to both vibration of the structure and impulses delivered to the sediment is considered. Contributions to the pressure field in the water column due to radiation directly into the water radiation from the sediment into the water and Scholte waves propagating along the sediment-water interface will be discussed. [Work supported by the ARL:UT IR&D program.

Todd A. Hay; Yurii A. Ilinskii; Evgenia A. Zabolotskaya; Preston S. Wilson; Mark F. Hamilton

2011-01-01T23:59:59.000Z

337

Evaluation of the Multi-Scale Modeling Framework using Data from the Atmospheric Radiation Measurement Program  

SciTech Connect

One of the goals of the Atmospheric Radiation Measurement (ARM) program was to provide long-term observations for evaluation of cloud and radiation treatment in global climate models. Unfortunately, traditional parametric approach of diagnosing cloud and radiation properties from large-scale model fields is not well suited for comparison with observed time series at selected locations. A recently emerging approach called the multi-scale modeling framework (MMF) has shown promise to bridge the gap. MMF consists of a two-dimensional cloud system resolving model (CSRM) embedded into each CAM grid column of the Community Atmospheric Model (CAM), thereby computing cloud properties at a scale that is more consistent with observations. Because the approach is computationally expensive only limited simulations have been carried out. In this presentation, we will present a comparison of data from two ARM sites, one at the Southern Great Plains (SGP) in Oklahoma and one at Nauru island in the Tropical Western Pacific (TWP) region, with output from both CAM and MMF. Two sets of one year long simulations are considered: one using climatological sea surface temperatures (SST) and another using 1999 SST. Each set includes a run with MMF as well as CAM run with traditional or standard cloud and radiation treatment. Time series of cloud fraction, precipitation intensity, and downwelling solar radiation flux at the surface are statistically analyzed. For the TWP site, nearly all parameters of frequency distributions of these variables from MMF run are shown to be more consistent with observation than those from CAM run. For the SGP, the improvements are marginal.

Ovchinnikov, Mikhail; Ackerman, Thomas P.; Marchand, Roger T.; Khairoutdinov, Marat

2004-07-01T23:59:59.000Z

338

Smoothness- transferred random field  

E-Print Network (OSTI)

We propose a new random field (RF) model, smoothness-transfer random field (ST-RF) model, for image modeling. In the objective function of RF models, smoothness energy is defined with compatibility function to capture the ...

Wei, Donglai

2013-01-01T23:59:59.000Z

339

Simulation and modeling for the stand-off radiation detection system (SORDS) using GEANT4  

SciTech Connect

A Stand-Off Radiation Detection System (SORDS) is being developed through a joint effort by Raytheon, Los Alamos National Laboratory, Bubble Technology Industries, Radiation Monitoring Devices, and the Massachusetts Institute of Technology, for the Domestic Nuclear Detection Office (DNDO). The system is a mobile truck-based platform performing detection, imaging, and spectroscopic identification of gamma-ray sources. A Tri-Modal Imaging (TMI) approach combines active-mask coded aperture imaging, Compton imaging, and shadow imaging techniques. Monte Carlo simulation and modeling using the GEANT4 toolkit was used to generate realistic data for the development of imaging algorithms and associated software code.

Hoover, Andrew S [Los Alamos National Laboratory; Wallace, Mark [Los Alamos National Laboratory; Galassi, Mark [Los Alamos National Laboratory; Mocko, Michal [Los Alamos National Laboratory; Palmer, David [Los Alamos National Laboratory; Schultz, Larry [Los Alamos National Laboratory; Tornga, Shawn [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

340

3D Continuum radiative transfer in complex dust configurations around young stellar objects and active nuclei II. 3D Structure of the dense molecular cloud core Rho Oph D  

E-Print Network (OSTI)

Constraints on the density and thermal 3D structure of the dense molecular cloud core Rho Oph D are derived from a detailed 3D radiative transfer modeling. Two ISOCAM images at 7 and 15 micron are fitted simultaneously by representing the dust distribution in the core with a series of 3D Gaussian density profiles. Size, total density, and position of the Gaussians are optimized by simulated annealing to obtain a 2D column density map. The projected core density has a complex elongated pattern with two peaks. We propose a new method to calculate an approximate temperature in an externally illuminated complex 3D structure from a mean optical depth. This T(tau)-method is applied to a 1.3 mm map obtained with the IRAM 30m telescope to find the approximate 3D density and temperature distribution of the core Rho Oph D. The spatial 3D distribution deviates strongly from spherical symmetry. The elongated structure is in general agreement with recent gravo-turbulent collapse calculations for molecular clouds. We discuss possible ambiguities of the background determination procedure, errors of the maps, the accuracy of the T(tau)-method, and the influence of the assumed dust particle sizes and properties.

J. Steinacker; A. Bacmann; Th. Henning; R. Klessen; M. Stickel

2004-10-26T23:59:59.000Z

Note: This page contains sample records for the topic "radiation transfer models" 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

Modeling of two-dimensional interrelated heat and mass transfer problems and structure transformation  

Science Journals Connector (OSTI)

A numerical method to solve interrelated heat and mass transfer problems with structure transformation for easily deformable disperse capillary-porous media is suggested. Structure transformations of bodies of...

G. P. Brovka; V. A. Sychevskii

342

Effects of turbulence model on convective heat transfer of coolant flow in a prismatic very high temperature reactor core  

SciTech Connect

The existing study of Spall et al. shows that only {nu}{sup 2}-f turbulence model well matches with the experimental data of Shehata and McEligot which were obtained under strongly heated gas flows. Significant over-predictions in those literatures were observed in the convective heat transfer with the other famous turbulence models such as the k-{epsilon} and k-{omega} models. In spite of such good evidence about the performance of the{nu}{sup 2}-f model, the application of the {nu}{sup 2}-f model to the thermo-fluid analysis of a prismatic core is very rare. In this paper, therefore, the convective heat transfer of the coolant flow in a prismatic core has been investigated using the {nu}{sup 2}-f model. Computational fluid dynamics (CFD) calculations have been carried out for the typical unit cell geometry of a prismatic fuel column with typical operating conditions of prismatic designs. The tested Reynolds numbers of the coolant flow are 10,000, 20,000, 30,000 and 50,000. The predicted Nusselt numbers with the {nu}{sup 2}-f model are compared with the results by the other turbulence models (k-{epsilon} and SST) as well as the empirical correlations. (authors)

Lee, S. N.; Tak, N. I.; Kim, M. H.; Noh, J. M. [Korea Atomic Energy Research Inst., Daedeok-daero 989-11, Yuseong-gu, Daejeon (Korea, Republic of)

2012-07-01T23:59:59.000Z

343

Modeling of plasma-controlled evaporation and surface condensation of Al induced by 1.06 and 0.248 {mu}m laser radiations  

SciTech Connect

Phase transition on the surface of an aluminum target and vapor plasma induced by laser irradiation in the nanosecond regime at the wavelengths of 1.06 {mu}m in the infrared range and 0.248 {mu}m in the ultraviolet range with an intensity of 10{sup 8}-10{sup 9} W/cm{sup 2} in vacuum are analyzed. Special attention is paid to the wavelength dependence of the observed phenomena and the non-one-dimensional effects caused by the nonuniform (Gaussian) laser intensity distribution and the lateral expansion of the plasma plume. A transient two-dimensional model is used which includes conductive heat transfer in the condensed phase, radiative gas dynamics, and laser radiation transfer in the plasma as well as surface evaporation and back condensation at the phase interface. It was shown that distinctions in phase transition dynamics for the 1.06 and 0.248 {mu}m radiations result from essentially different characteristics of the laser-induced plasmas. For the 1.06 {mu}m radiation, evaporation stops after the formation of hot optically thick plasma, can occasionally resume at a later stage of the pulse, and proceeds nonuniformly in the spot area, and the major contribution to the mass removal occurs in the outer part of the irradiated region. Plasma induced by the 0.248 {mu}m laser is colder and partially transparent since it transmits 30%-70% of the incident radiation; therefore evaporation does not stop but continues in the subsonic regime with the Mach number of about 0.1. The amount of evaporated matter that condenses back to the surface is as high as 15%-20% and less than 10% for the 1.06 and 0.248 {mu}m radiations, respectively. For a beam radius smaller than {approx}100 {mu}m, the screening and retarding effect of the plasma weakens because of the lateral expansion, thickness of the removed layer increases, and condensation after the end of the pulse is not observed. Comparison of the numerical and experimental results on the removed layer thickness has shown, in particular, the importance of accounting for the plasma effect to predict the correct trends for radiation intensity and beam radius.

Mazhukin, V. I.; Nossov, V. V.; Smurov, I. [Institute of Mathematical Modeling of RAS, 4a Miusskaya Square, 125047 Moscow (Russian Federation); Ecole Nationale d'Ingenieurs de Saint-Etienne, 58 rue Jean Parot, 42023 Saint-Etienne Cedex 2 (France)

2007-01-15T23:59:59.000Z

344

5. Heat transfer Ron Zevenhoven  

E-Print Network (OSTI)

1/120 5. Heat transfer Ron Zevenhoven ?bo Akademi University Thermal and Flow Engineering / Värme Three heat transfer mechanisms Conduction Convection Radiation 2/120 Pic: B?88 ?bo Akademi University | Thermal and Flow Engineering | 20500 Turku | Finland #12;3/120 5.1 Conductive heat transfer ?bo Akademi

Zevenhoven, Ron

345

A unified model for radiation-resistance of advanced space solar cells  

SciTech Connect

1-MeV electron irradiation effects on MBE-grown InGaAs and AlGaAs solar cells have been examined in comparison with previous results for radiation damage of InP and GaAs solar cells in order to clarify radiation-resistance of advanced space solar cells. Moreover, 1-MeV electron irradiation results of several space solar cells such as InP, InGaP, InGaAsP, GaAs, AlGaAs, InGaAs, Si, Ge, and CuInSe{sub 2} cells have also been analyzed by considering their damage constants, bandgap energies and optical absorption coefficients. The authors believe that this study will provide a unified model for radiation-resistance of advanced space solar cells.

Yamaguchi, Masafumi [Toyota Technical Inst., Nagoya (Japan); Katsumoto, Shingo [Univ. of Tokyo (Japan); Amano, Chikara [NTT Opto-Electrical Labs., Kanagawa (Japan)

1994-12-31T23:59:59.000Z

346

Experimental techniques for measuring temperature and velocity fields to improve the use and validation of building heat transfer models  

SciTech Connect

When modeling thermal performance of building components and envelopes, researchers have traditionally relied on average surface heat-transfer coefficients that often do not accurately represent surface heat-transfer phenomena at any specific point on the component being evaluated. The authors have developed new experimental techniques that measure localized surface heat-flow phenomena resulting from convection. The data gathered using these new experimental procedures can be used to calculate local film coefficients and validate complex models of room and building envelope heat flows. These new techniques use a computer-controlled traversing system to measure both temperatures and air velocities in the boundary layer near the surface of a building component, in conjunction with current methods that rely on infrared (IR) thermography to measure surface temperatures. Measured data gathered using these new experimental procedures are presented here for two specimens: (1) a Calibrated Transfer Standard (CTS) that approximates a constant-heat-flux, flat plate; and (2) a dual-glazed, low-emittance (low-e), wood-frame window. The specimens were tested under steady-state heat flow conditions in laboratory thermal chambers. Air temperature and mean velocity data are presented with high spatial resolution (0.25- to 25-mm density). Local surface heat-transfer film coefficients are derived from the experimental data by means of a method that calculates heat flux using a linear equation for air temperature in the inner region of the boundary layer. Local values for convection surface heat-transfer rate vary from 1 to 4.5 W/m{sup 2} {center_dot} K. Data for air velocity show that convection in the warm-side thermal chamber is mixed forced/natural, but local velocity maximums occur from 4 to 8 mm from the window glazing.

Griffith, Brent; Turler, Daniel; Goudey, Howdy; Arasteh, Dariush

1998-04-01T23:59:59.000Z

347

A quasi-steady state model to predict attic heat transfer and energy savings in residences using radiant barriers  

E-Print Network (OSTI)

[10-14] for Oak Ridge National Laboratories (ORNL) has focused on comparing energy reduction on three experimental houses operated by ORNL. Their research has consisted of both summer and winter tests of radiant barriers. Radiant Barrier...A QUASI-STEADY STATE MODEL TO PREDICT ATTIC HEAT TRANSFER AND ENERGY SAVINGS IN RESIDENCES USING RADIANT BARRIERS A Thesis by DAVID WALTER WINIARSKI Submitted to the Office of Graduate Studies of Texas ARM University in partial fulfillment...

Winiarski, David Walter

2012-06-07T23:59:59.000Z

348

Evaluation of Cloud Type Occurrences and Radiative Forcings Simulated by a Cloud Resolving Model Using Observations from Sa...  

NLE Websites -- All DOE Office Websites (Extended Search)

Cloud Type Occurrences Cloud Type Occurrences and Radiative Forcings Simulated by a Cloud Resolving Model Using Observations from Satellite and Cloud Radar Y. Luo and S. K. Krueger University of Utah Salt Lake City, Utah Introduction Because of both the various effects clouds exert on the earth-atmospheric system and the cloud feedback, correct representations of clouds in numerical models are critical for accurate climate modeling and weather forecast. Unfortunately, determination of clouds and their radiative feedback processes is still the weakest component of current general circulation models (e.g., Senior and Mitchell 1993, Cess et al. 1996). Using radiative fluxes at the top of atmosphere (TOA) available from satellite observations made by the Earth Radiation Budget Experiment (ERBE; Barkstrom 1984), one could assess cloud radiative effects

349

A model of heat and moisture transfer through clothing integratedwith 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

350

Modelling of radiative divertor operation towards detachment in experimental advanced superconducting tokamak  

SciTech Connect

In order to actively control power load on the divertor target plates and study the effect of radiative divertor on plasma parameters in divertor plasmas and heat fluxes to the targets, dedicated experiments with Ar impurity seeding have been performed on experimental advanced superconducting tokamak in typical L-mode discharge with single null divertor configuration, ohmic heating power of 0.5 MW, and lower hybrid wave heating power of 1.0 MW. Ar is puffed into the divertor plasma at the outer target plate near the separatrix strike point with the puffing rate 1.26 Multiplication-Sign 10{sup 20} s{sup -1}. The radiative divertor is formed during the Ar puffing. The SOL/divertor plasma in the L-mode discharge with radiative divertor has been modelled by using SOLPS5.2 code package [V. Rozhansky et al., Nucl. Fusion 49, 025007 (2009)]. The modelling shows the cooling of the divertor plasma due to Ar seeding and is compared with the experimental measurement. The changes of peak electron temperature and heat fluxes at the targets with the shot time from the modelling results are similar to the experimental measurement before and during the Ar impurity seeding, but there is a major difference in time scales when Ar affects the plasma in between experiment and modelling.

Chen Yiping; Wang, F. Q.; Hu, L. Q.; Guo, H. Y.; Wu, Z. W.; Zhang, X. D.; Wan, B. N.; Li, J. G. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Zha, X. J. [Department of Applied Physics, College of Sciences, Donghua University, Shanghai 201620 (China)

2013-02-15T23:59:59.000Z

351

Brazil Latitude Tilted Solar Radiation Model (40km) from INPE and LABSOLAR  

Open Energy Info (EERE)

40km) from INPE and LABSOLAR 40km) from INPE and LABSOLAR Dataset Summary Description (Abstract): Latitude tilted solar radiation in kWh/m2/day for 1 year organized into cells with 40km x 40km (Purpose): To provide a set of consistent, reliable, verifiable, and accessible global data sets for international and in-country investors and other stakeholders (Supplemental Information): The BRASIL-SR model and the SPRING software (both developed by INPE - National Institute for Space Research) were used to produce the dataset and SHAPE files.The assessment of reliability levels of the BRASIL-SR model were performed through the evaluation of the deviations shown by the estimated values for solar radiation flux vis-à-vis the values measured at the surface (ground truth). This evaluation was done in two phases. The first phase

352

Modeling radiation in particle clouds: On the importance of inter-particle radiation for pulverized solid fuel combustion  

E-Print Network (OSTI)

The importance of inter-particle radiation for clusters of gray and diffuse particles is investigated. The radiative cooling of each individual particle is found to vary strongly with its position in the cluster, and a mean radiative particle cooling term is proposed for single particle simulations of particle clusters or for high detail simulation, like Direct Numerical Simulations of small sub-volumes of large clusters of particles. Radiative cooling is shown to be important both for furnaces for coal gasification and coal combustion. Broadening the particle size distribution is found to have just a minor effect on the radiative particle cooling. This is particularly the case for large and dense particle clusters where there is essentially no effect of size distribution broadening at all. For smaller and more dilute particle clusters, the effect of distribution broadening is clear but still not dominant.

Haugen, Nils Erland L

2014-01-01T23:59:59.000Z

353

Knowledge transfer and utilization in IT outsourcing partnerships: A preliminary model of antecedents and outcomes  

Science Journals Connector (OSTI)

We developed a nomological network of antecedents and outcomes of knowledge transfer and utilization in IT outsourcing relationships, and tested it using a survey of 146 IT outsourcing partnerships in Singapore. Our findings showed that the characteristics ... Keywords: IT partnerships, Knowledge management, Outsourcing, Survey research

Thompson S. H. Teo, Anol Bhattacherjee

2014-03-01T23:59:59.000Z

354

Numerical Weather Prediction (NWP) and hybrid ARMA/ANN model to predict global radiation  

E-Print Network (OSTI)

We propose in this paper an original technique to predict global radiation using a hybrid ARMA/ANN model and data issued from a numerical weather prediction model (ALADIN). We particularly look at the Multi-Layer Perceptron. After optimizing our architecture with ALADIN and endogenous data previously made stationary and using an innovative pre-input layer selection method, we combined it to an ARMA model from a rule based on the analysis of hourly data series. This model has been used to forecast the hourly global radiation for five places in Mediterranean area. Our technique outperforms classical models for all the places. The nRMSE for our hybrid model ANN/ARMA is 14.9% compared to 26.2% for the na\\"ive persistence predictor. Note that in the stand alone ANN case the nRMSE is 18.4%. Finally, in order to discuss the reliability of the forecaster outputs, a complementary study concerning the confidence interval of each prediction is proposed

Voyant, Cyril; Paoli, Christophe; Nivet, Marie Laure

2012-01-01T23:59:59.000Z

355

12.815 Atmospheric Radiation, Fall 2005  

E-Print Network (OSTI)

Introduction to the physics of atmospheric radiation and remote sensing including use of computer codes. Radiative transfer equation including emission and scattering, spectroscopy, Mie theory, and numerical solutions. ...

Prinn, Ronald G.

356

Improvement of the equivalent sphere model for better estimates of skin or eye dose in space radiation environments  

E-Print Network (OSTI)

sphere Radiation transport a b s t r a c t It is often useful to get a quick estimate of the dose or dose drastically improves the accuracy of the estimates of dose and dose equivalent in space radiation environmentsImprovement of the equivalent sphere model for better estimates of skin or eye dose in space

Lin, Zi-wei

357

Modeling the Dynamical Coupling of Solar Convection with the Radiative Interior  

Science Journals Connector (OSTI)

The global dynamics of a rotating star like the Sun involves the coupling of a highly turbulent convective envelope overlying a seemingly benign radiative interior. We use the anelastic spherical harmonic code to develop a new class of three-dimensional models that nonlinearly couple the convective envelope to a deep stable radiative interior. The numerical simulation assumes a realistic solar stratification from r = 0.07 up to 0.97R (with R the solar radius), thus encompassing part of the nuclear core up through most of the convection zone. We find that a tachocline naturally establishes itself between the differentially rotating convective envelope and the solid body rotation of the interior, with a slow spreading that is here diffusively controlled. The rapid angular momentum redistribution in the convective envelope leads to a fast equator and slow poles, with a conical differential rotation achieved at mid-latitudes, much as has been deduced by helioseismology. The convective motions are able to overshoot downward about 0.04R into the radiative interior. However, the convective meridional circulation there is confined to a smaller penetration depth and is directed mostly equatorward at the base of the convection zone. Thermal wind balance is established in the lower convection zone and tachocline but departures are evident in the upper convection zone. Internal gravity waves are excited by the convective overshooting, yielding a complex wave field throughout the radiative interior.

Allan Sacha Brun; Mark S. Miesch; Juri Toomre

2011-01-01T23:59:59.000Z

358

Radiation Pneumonitis After Hypofractionated Radiotherapy: Evaluation of the LQ(L) Model and Different Dose Parameters  

SciTech Connect

Purpose: To evaluate the linear quadratic (LQ) model for hypofractionated radiotherapy within the context of predicting radiation pneumonitis (RP) and to investigate the effect if a linear (L) model in the high region (LQL model) is used. Methods and Materials: The radiation doses used for 128 patients treated with hypofractionated radiotherapy were converted to the equivalent doses given in fractions of 2 Gy for a range of {alpha}/{beta} ratios (1 Gy to infinity) according to the LQ(L) model. For the LQL model, different cut-off values between the LQ model and the linear component were used. The Lyman model parameters were fitted to the events of RP grade 2 or higher to derive the normal tissue complication probability (NTCP). The lung dose was calculated as the mean lung dose and the percentage of lung volume (V) receiving doses higher than a threshold dose of xGy (V{sub x}). Results: The best NTCP fit was found if the mean lung dose, or V{sub x}, was calculated with an {alpha}/{beta} ratio of 3 Gy. The NTCP fit of other {alpha}/{beta} ratios and the LQL model were worse but within the 95% confidence interval of the NTCP fit of the LQ model with an {alpha}/{beta} ratio of 3 Gy. The V{sub 50} NTCP fit was better than the NTCP fit of lower threshold doses. Conclusions: For high fraction doses, the LQ model with an {alpha}/{beta} ratio of 3 Gy was the best method for converting the physical lung dose to predict RP.

Borst, Gerben R. [Department of Radiation Oncology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands); Ishikawa, Masayori [Department of Radiology, Hokkaido University School of Medicine, Sapporo (Japan); Nijkamp, Jasper [Department of Radiation Oncology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands)

2010-08-01T23:59:59.000Z

359

Climate Studies with a Multi-Layer Energy Balance Model. Part I: Model Description and Sensitivity to the Solar Constant  

Science Journals Connector (OSTI)

A nine-layer, zonally averaged, steady-state model has been developed for use in climate sensitivity studies. The model is based upon thermal energy balance and includes recently developed accurate treatment of radiative transfer, parameterized ...

Li Peng; Ming-Dah Chou; Albert Arking

1982-12-01T23:59:59.000Z

360

Eurotherm Seminar N81 Reactive Heat Transfer in Porous Media, Ecole des Mines d'Albi, France June 4-6, 2007 ET81-1 HEAT TRANSFER BY SIMULTANEOUS RADIATION-CONDUCTION  

E-Print Network (OSTI)

of a packed bed reactor for gasifying coal in mixed control using concentrated solar radiation is proposed], Taylor et al. [3], Belghit et al. [4]). A moving bed reactor, for gasifying coconut charcoal with CO2 the radiative exchange in the porous medium. Case's normal-mode expansion technique [6] is used to obtain

Boyer, Edmond

Note: This page contains sample records for the topic "radiation transfer models" 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

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

362

Convective heat transfer in the vertical channel flow of a clear fluid adjacent to a nanofluid layer: a two-fluid model  

Science Journals Connector (OSTI)

A two-fluid vertical channel flow and convective heat transfer model in which one of the two fluids is a nanofluid demonstrates that the nanofluid can modify the fluid velocity at the interface of the two fluids,...

Robert A. Van Gorder; K. V. Prasad; K. Vajravelu

2012-07-01T23:59:59.000Z

363

A two-temperature model of radiation damage in {alpha}-quartz  

SciTech Connect

Two-temperature models are used to represent the physics of the interaction between atoms and electrons during thermal transients such as radiation damage, laser heating, and cascade simulations. We introduce a two-temperature model applied to an insulator, {alpha}-quartz, to model heat deposition in a SiO{sub 2} lattice. Our model of the SiO{sub 2} electronic subsystem is based on quantum simulations of the electronic response in a SiO{sub 2} repeat cell. We observe how the parametrization of the electronic subsystem impacts the degree of permanent amorphization of the lattice, especially compared to a metallic electronic subsystem. The parametrization of the insulator electronic subsystem has a significant effect on the amount of residual defects in the crystal after 10 ps. While recognizing that more development in the application of two-temperature models to insulators is needed, we argue that the inclusion of a simple electronic subsystem substantially improves the realism of such radiation damage simulations.

Phillips, Carolyn L. [Applied Physics, University of Michigan, Ann Arbor, Michigan 48109 (United States); Magyar, Rudolph J.; Crozier, Paul S. [Department of Multiscale Dynamic Materials Modeling, Sandia National Laboratories, P.O. Box 5800, MS 1322, Albuquerque, New Mexico 87185-1322 (United States)

2010-10-14T23:59:59.000Z

364

High-resolution maps of solar collector performance using a climatological solar radiation model  

SciTech Connect

This paper will present a new methodology for producing estimates of the monthly and annual average performance of different types of flat-plate and concentrating solar collectors. The estimates are made on a uniform spatial grid with 40 km resolution. These estimates should be highly useful both to create maps to facilitate visualization of the solar resource, and as the basic data behind analytical studies of solar resources, deployment scenarios, CO{sub 2} mitigation strategies, and economic assessments. Their initial use of this methodology will be in the continental United States, where supporting data is available to evaluate the model outputs. In future years the authors hope to utilize this technique world-wide, especially in areas where the surface data are lacking. The National Renewable Energy Laboratory (NREL, Golden, CO) has developed the Climatological Solar Radiation (CSR) model to estimate climatological averages of daily-total solar radiation at a 40 km spatial resolution. The CSR model is operational and has been usefully applied to the US as well as several international areas. The model uses, as input, monthly climatological mean values of cloud cover, precipitable water vapor, aerosol optical depth, surface albedo, and total column ozone. These input parameters are available from various sources such as NASA and NCDC (National Climatic Data Center). The outputs from the original version of CSR are monthly mean daily total values of Global Horizontal, Direct Normal, and Diffuse radiation. Their latest revision of the model allows them to calculate the monthly mean output for the various collector types such as tilted flat-plate surfaces, one- and two-axis flat-plate collectors, and concentrating collectors.

George, R.L.; Maxwell, E.L.

1999-07-01T23:59:59.000Z

365

A Mountain-Scale Thermal Hydrologic Model for Simulating Fluid Flow and Heat Transfer in Unsaturated Fractured Rock  

E-Print Network (OSTI)

for Simulating Fluid Flow and Heat Transfer in Unsaturatedcomplex multiphase fluid flow and heat-transfer processes.of the coupled fluid-flow and heat-transfer processes has

Wu, Yu-Shu; Mukhopadhyay, Sumit; Zhang, Keni; Bodvarsson, Gudmundur S.

2005-01-01T23:59:59.000Z

366

Convective heat transfer on leeward building walls in an urban environment: Measurements in an outdoor scale model  

E-Print Network (OSTI)

surface, Proc. 5 th Int. Heat Transfer Conf. 3 (1974) 129-a vertical plate, J. Heat Transfer 109(1) [13] K. Patel,Experimental study of heat transfer in turbulent flows over

Nottrott, A.; Onomura, S.; Inagaki, A.; Kanda, M.; Kleissl, J.

2011-01-01T23:59:59.000Z

367

A Refined Model of Stationary Heat Transfer in Composite Bodies Reinforced with Pipes Containing a Heat-Transfer Fluid Moving in Laminar Flow Conditions  

Science Journals Connector (OSTI)

Equations describing the stationary heat conduction of composite bodies spatially reinforced with ... of smooth pipes, through which an incompressible heat-transfer fluid is pumped in laminar flow conditions, are...

A. P. Yankovskii

2014-03-01T23:59:59.000Z

368

A numerical model of convective heat transfer in a three dimensional channel with baffles  

E-Print Network (OSTI)

to minimize the effects of the temperature. Chandrupatla and Sastri (1977) used a finite difference method to study laminar heat transfer and fluid flow for Non-Newtonian fluids. In the limiting case of Newtonian fluids their results showed good agreement... and Sastri (1977) for developing laminar flow in a rectangular smooth channel. Figure 4. 1 shows the numerically predicted centerline axial velocity compared with the experimental data of Goldstein and Kreid (1967). The agreement between the numerical...

Lopez Buso, Jorge Ricardo

2012-06-07T23:59:59.000Z

369

Model for electron cooling by radiation losses in plasmas: application to soft x-ray laser development  

SciTech Connect

We present a simple model which may be used to evaluate the suitability of different ions for rapid plasma cooling by line radiation in recombination pumped x-ray laser schemes.

Skinner, C.H.; Keane, C.

1986-02-01T23:59:59.000Z

370

Response of the NCAR Community Climate Model to the Radiative Forcing by the Naturally Occurring Tropospheric Aerosol  

Science Journals Connector (OSTI)

We insert the effect of naturally occurring tropospheric aerosols on solar radiation into the NCAR Community Climate Model (CCM). The effect of the aerosol depends on concentration and type (continental, maritime), surface albedo, solar zenith ...

James A. Coakley Jr.; Robert D. Cess

1985-08-01T23:59:59.000Z

371

A screening model for depleted uranium testing using environmental radiation monitoring data  

SciTech Connect

Information from an ecological risk assessment of depleted uranium test areas at Yuma Proving Ground (YPG) was used to update the required environmental radiation monitoring (ERM) plan. Data to be collected for the ERM can also be used to evaluate the potential for adverse radiological and toxicological effects to terrestrial reptiles and mammals in the affected areas. We developed a spreadsheet-based screening model that incorporates the ERM data and associated uncertainties. The purpose of the model is to provide a conservative estimate of radiological exposure of terrestrial, biota to DU using the ERM data. The uncertainty in the estimate is also predicted so that the variation in the radiological exposure can be used in assessing potential adverse effects from DU testing. Toxicological effects are evaluated as well as radiological effects in the same program using the same data. Our presentation shows an example data set, model calculations, and the report of expected radiation dose rates and probable kidney burdens of select mammals and reptiles. The model can also be used in an inverse mode to calculate the soil concentration required to give either a radiological dose that would produce a potential adverse effect such as fatal cancer or a toxicological dose that would result in nephrotoxic effects in mammals.

Dunfrund, F.L. [Yuma Proving Ground, AZ (United States); Ebinger, M.H.; Hansen, W.R. [Los Alamos National Laboratory, NM (United States)] [and others

1996-06-01T23:59:59.000Z

372

Numerical simulation of fluid flow and heat transfer inside a rotating disk-cylinder configuration by a lattice Boltzmann model  

Science Journals Connector (OSTI)

A simple lattice Boltzmann model for numerical simulation of fluid flow and heat transfer inside a rotating disk-cylinder configuration, which is of fundamental interest and practical importance in science as well as in engineering, is proposed in this paper. Unlike existing lattice Boltzmann models for such flows, which were based on primitive-variable Navier-Stokes equations, the target macroscopic equations of the present model for the flow field are vorticitystream function equations, inspired by our recent work designed for nonrotating flows [S. Chen, J. Tlke, and M. Krafczyk, Phys. Rev. E 79, 016704 (2009); S. Chen, J. Tlke, S. Geller, and M. Krafczyk, Phys. Rev. E 78, 046703 (2008)]. The flow field and the temperature field both are solved by the D2Q5 model. Compared with the previous models, the present model is more efficient, more stable, and much simpler. It was found that, even though with a relatively low grid resolution, the present model can still work well when the Grashof number is very high. The advantages of the present model are validated by numerical experiments.

Sheng Chen; Jonas Tlke; Manfred Krafczyk

2009-07-14T23:59:59.000Z

373

Determination of High-Frequency Current Distribution Using EMTP-Based Transmission Line Models with Resulting Radiated Electromagnetic Fields  

SciTech Connect

Application of BPL technologies to existing overhead high-voltage power lines would benefit greatly from improved simulation tools capable of predicting performance - such as the electromagnetic fields radiated from such lines. Existing EMTP-based frequency-dependent line models are attractive since their parameters are derived from physical design dimensions which are easily obtained. However, to calculate the radiated electromagnetic fields, detailed current distributions need to be determined. This paper presents a method of using EMTP line models to determine the current distribution on the lines, as well as a technique for using these current distributions to determine the radiated electromagnetic fields.

Mork, B; Nelson, R; Kirkendall, B; Stenvig, N

2009-11-30T23:59:59.000Z

374

Modelling electron distributions within ESA's Gaia satellite CCD pixels to mitigate radiation damage  

E-Print Network (OSTI)

The Gaia satellite is a high-precision astrometry, photometry and spectroscopic ESA cornerstone mission, currently scheduled for launch in 2012. Its primary science drivers are the composition, formation and evolution of the Galaxy. Gaia will achieve its unprecedented positional accuracy requirements with detailed calibration and correction for radiation damage. At L2, protons cause displacement damage in the silicon of CCDs. The resulting traps capture and emit electrons from passing charge packets in the CCD pixel, distorting the image PSF and biasing its centroid. Microscopic models of Gaia's CCDs are being developed to simulate this effect. The key to calculating the probability of an electron being captured by a trap is the 3D electron density within each CCD pixel. However, this has not been physically modelled for the Gaia CCD pixels. In Seabroke, Holland & Cropper (2008), the first paper of this series, we motivated the need for such specialised 3D device modelling and outlined how its future resu...

Seabroke, G M; Burt, D; Robbins, M S

2009-01-01T23:59:59.000Z

375

Radiation-MHD models of elephant trunks and globules in H II regions  

E-Print Network (OSTI)

We study the formation and evolution of pillars of dense gas, known as elephant trunks, at the boundaries of H II regions, formed by shadowing of ionising radiation by dense clumps. The effects of magnetic fields on this process are investigated using 3D radiation-magnetohydrodynamics simulations. For a simulation in which an initially uniform magnetic field of strength |B|=50 uG is oriented perpendicular to the radiation propagation direction, the field is swept into alignment with the pillar during its dynamical evolution, in agreement with observations of the "Pillars of Creation" in M16, and of some cometary globules. This effect is significantly enhanced when the simulation is re-run with a weaker field of 18 uG. A stronger field with |B|=160 uG is sufficient to prevent this evolution completely, also significantly affecting the photoionisation process. Using a larger simulation domain it is seen that the pillar formation models studied in Mackey & Lim (2010) ultimately evolve to cometary structures ...

Mackey, Jonathan

2011-01-01T23:59:59.000Z

376

Modeling heat conduction and radiation transport with the diffusion equation in  

NLE Websites -- All DOE Office Websites (Extended Search)

heat conduction and radiation transport with the diffusion equation in NIF ALE-AMR heat conduction and radiation transport with the diffusion equation in NIF ALE-AMR This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2010 J. Phys.: Conf. Ser. 244 022075 (http://iopscience.iop.org/1742-6596/244/2/022075) Download details: IP Address: 50.136.219.251 The article was downloaded on 18/04/2013 at 01:36 Please note that terms and conditions apply. View the table of contents for this issue, or go to the journal homepage for more Home Search Collections Journals About Contact us My IOPscience Modeling Heat Conduction and Radiation Transport with the Diffusion Equation in NIF ALE-AMR A.C. Fisher 1 , D.S. Bailey 1 , T.B. Kaiser 1 , B.T.N. Gunney 1 , N.D. Masters 1 , A.E. Koniges 2 , D.C. Eder 1 , R.W. Anderson 1 1: Lawrence Livermore National Laboratory,

377

The modeling and calculation of sound radiation from facilities with gas flowed pipes  

Science Journals Connector (OSTI)

Computer modeling of industrial facilities like chemical plants refineries or other production areas is the first and most important step in the calculation of sound exposure in the environment. The pipework with gas flows is often contributing relevant to the sound radiation of the complete facility. This radiation can be determined applying the methods described in technical papers like VDI 3733 and ISO 15664. On the basis of these descriptions a software tool was developed that allows to create pipework in 3D models with line sources and to calculate the sound propagation with methods like ISO 9613-2. The line sources are linked with the technical parameters like pipe cross section flow rate pressure density and temperature of the gas and material parameters of the pipe wall. The sound power emission from the pipe to the environment and the internal flow of sound powerlinked to the next section of pipingis calculated on the basis of these parameters. The same technique is used to calculate the sound emission of cooling towers electric and fuel driven motors gears pumps and other devices. This powerful technique allows creating sustainable models that can be adapted to different operation conditions with minimum time and effort.

2013-01-01T23:59:59.000Z

378

The modeling and calculation of sound radiation from facilities with gas flowed pipes  

Science Journals Connector (OSTI)

Computer modeling of industrial facilities like chemical plants refineries or other production areas is the first and most important step in the calculation of sound exposure in the environment. The pipework with gas flows is often contributing relevant to the sound radiation of the complete facility. This radiation can be determined applying the methods described in technical papers like VDI3733 and ISO15664. On the basis of these descriptions a software tool was developed that allows to create pipework in 3D models with line sources and to calculate the sound propagation with methods like ISO9613-2. The line sources are linked with the technical parameters like pipe cross section flow rate pressure density and temperature of the gas and material parameters of the pipe wall. The sound power emission from the pipe to the environment and the internal flow of sound power - linked to the next section of piping - is calculated on the basis of these parameters. The same technique is used to calculate the sound emission of cooling towers electric and fuel driven motors gears pumps and other devices. This powerful technique allows creating sustainable models that can be adapted to different operation conditions with minimum time and effort.

Fabian Probst

2013-01-01T23:59:59.000Z

379

Technology Transfer  

NLE Websites -- All DOE Office Websites (Extended Search)

Technology Transfer Since 1974, the Federal Laboratory Consortium (FLC) Award for Excellence in Technology Transfer has recognized scientists and engineers at federal government...

380

GOLDSIM models of long-term radiation impact of conditionally cleared radioactive material  

Science Journals Connector (OSTI)

Abstract Management of waste materials from the decommissioning of nuclear installations offers opportunities for optimization. Large amounts of waste materials with low contents of various radionuclides could be recycled to save financial resources or repository capacity. The increase of the share of recycled materials compared to the current practice could be accomplished by applying the conditional clearance concept. Conditional clearance, as up to now is an unproven theoretical concept, demands utilization of the cleared material for the previously defined purpose (e.g., building construction). Safety studies needed for realization of this practice have to prove that conditionally cleared material will not cause radiation impact exceeding levels prescribed in health and safety regulations. Safety studies assess radiation impact during all manipulations with low level radioactive material (e.g., melting, component manufacturing, building of construction, etc.) as well as its impact on inhabitants living near the construction built using conditionally cleared material. The article is focused on modeling and calculation of long-term radiation impact on inhabitants living near the constructions. Models (scenarios) of various building applications were simulated using GOLDSIM software with Radionuclide Transport Module. Scenarios were selected according to information from the civil engineering business to cover the types of buildings most suitable for application of conditionally cleared material. The results of the calculations showed that conditional clearance represents no significant safety issue in the long-term. Calculated individual effective doses received by inhabitants did not exceed the given dose constraint (10?Sv/year) in case of any scenario evaluated. Detailed and transparent studies of the long-term impact of conditionally cleared materials are important especially for winning of public acceptance.

Michal Panik; Vladimir Necas

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "radiation transfer models" 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

Polarization of high-energy pulsar radiation in the striped wind model  

E-Print Network (OSTI)

The Stokes parameters of the pulsed synchrotron radiation produced in the striped pulsar wind model are computed and compared with optical observations of the Crab pulsar. We assume the main contribution to the wind emissivity comes from a thin transition layer where the dominant toroidal magnetic field reverses its polarity. The radial component of the field is neglected, but a small meridional component is added. The resulting radiation is linearly polarized (Stokes V=0). In the off-pulse region, the electric vector lies in the direction of the projection on the sky of the rotation axis of the pulsar. This property is unique to the wind model and in good agreement with the data. Other properties such as a reduced degree of polarization and a characteristic sweep of the polarization angle within the pulses are also reproduced. These properties are qualitatively unaffected by variations of the wind Lorentz factor, the electron injection power law index and the inclination of the line of sight.

J. Petri; J. Kirk

2005-05-20T23:59:59.000Z

382

Validated Models for Radiation Response and Signal Generation in Scintillators: Final Report  

SciTech Connect

This Final Report presents work carried out at Pacific Northwest National Laboratory (PNNL) under the project entitled Validated Models for Radiation Response and Signal Generation in Scintillators (Project number: PL10-Scin-theor-PD2Jf) and led by Drs. Fei Gao and Sebastien N. Kerisit. This project was divided into four tasks: 1) Electronic response functions (ab initio data model) 2) Electron-hole yield, variance, and spatial distribution 3) Ab initio calculations of information carrier properties 4) Transport of electron-hole pairs and scintillation efficiency Detailed information on the results obtained in each of the four tasks is provided in this Final Report. Furthermore, published peer-reviewed articles based on the work carried under this project are included in Appendix. This work was supported by the National Nuclear Security Administration, Office of Nuclear Nonproliferation Research and Development (DNN R&D/NA-22), of the U.S. Department of Energy (DOE).

Kerisit, Sebastien N.; Gao, Fei; Xie, YuLong; Campbell, Luke W.; Van Ginhoven, Renee M.; Wang, Zhiguo; Prange, Micah P.; Wu, Dangxin

2014-12-01T23:59:59.000Z

383

Shell-model picture of virtual detour transitions in Ca41 radiative electron-capture decay  

Science Journals Connector (OSTI)

For the first forbidden unique (1u) radiative electron-capture ? decay of Ca41, a contribution of the ?/? detour transitions via virtual nuclear states to the bremsstrahlung spectrum has been considered in terms of the shell model. Calculations of the matrix elements for the virtual E1 ? and allowed Gamow-Teller ? transitions have been performed with the use of the Warburton, Becker, Millener, and Brown interactions. For the effective charge, which describes the contribution of the detour transitions, an interval 0.96model predictions are fairly close to the experimental value eeff=0.78. A possible origin of the small remaining deviation is discussed. 1996 The American Physical Society.

J. L. ?ylicz; M. Pftzner; S. G. Rohozi?ski; B. A. Brown

1996-04-01T23:59:59.000Z

384

E-Print Network 3.0 - adoptive transfer model Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

and Modelling Guest Editors: Alain Haurie, HEC-Management Studies, University of Geneva David... abatement, R&D in technology development, emissions reduction, and subsidization...

385

Modeling of Heat Transfer in Rooms in the Modelica Buildings Library  

E-Print Network (OSTI)

Multizone Air- flow Model in Modelica. Edited by ChristianRecent developments of the Modelica buildings library forof the 8-th International Modelica Conference. Modelica

Wetter, Michael

2013-01-01T23:59:59.000Z

386

A Computational Model for Pyrolysis, Heat Transfer, and Combustion in a Fixed-bed Waste Gasifier.  

E-Print Network (OSTI)

??The overarching goal of the study presented in this dissertation is to develop a predictive computational model that can describe the detailed chemical and physical (more)

Tsai, Chung-Yin

2011-01-01T23:59:59.000Z

387

Development of a Transient Heat and Mass Transfer Model of Residential Attics to Predict Energy Savings Produced by the Use of Radiant Barriers  

E-Print Network (OSTI)

A transient heat and mass transfer model was developed to predict ceiling heat gain/loss through the attic space in residences and to accurately estimate savings in cooling and heating loads produced by the use of radiant barriers. The model...

Medina, M. A.

388

Modeling marrow damage from response data: Morphallaxis from radiation biology to benzene toxicity  

SciTech Connect

Consensus principles from radiation biology were used to describe a generic set of nonlinear, first-order differential equations for modeling of toxicity-induced compensatory cell kinetics in terms of sublethal injury, repair, direct killing, killing of cells with unrepaired sublethal injury, and repopulation. This cellular model was linked to a probit model of hematopoietic mortality that describes death from infection and/or hemorrhage between {approximately} 5 and 30 days. Mortality data from 27 experiments with 851 doseresponse groups, in which doses were protracted by rate and/or fractionation, were used to simultaneously estimate all rate constants by maximum-likelihood methods. Data used represented 18,940 test animals distributed according to: (mice, 12,827); (rats, 2,925); (sheep, 1,676); (swine, 829); (dogs, 479); and (burros, 204). Although a long-term, repopulating hematopoietic stem cell is ancestral to all lineages needed to restore normal homeostasis, the dose-response data from the protracted irradiations indicate clearly that the particular lineage that is ``critical`` to hematopoietic recovery does not resemble stem-like cells with regard to radiosensitivity and repopulation rates. Instead, the weakest link in the chain of hematopoiesis was found to have an intrinsic radioresistance equal to or greater than stromal cells and to repopulate at the same rates. Model validation has been achieved by predicting the LD{sub 50} and/or fractional group mortality in 38 protracted-dose experiments (rats and mice) that were not used in the fitting of model coefficients.

Jones, T.D.; Morris, M.D.; Hasan, J.S.

1995-12-01T23:59:59.000Z

389

Estimation of Mutation Frequencies of Mice Caused by Radiation -- Application of LDM Model I  

E-Print Network (OSTI)

In a separate paper [Y. Manabe et al: arxiv:1204.2324], we propose a mathematical model to estimate biological damage caused by radiation, which we call LDM (Low Dose Meeting) Model, hereafter. By using LDM model, we calculate the mutation frequency of mice and compare our results with the existing data, the frequency of transmitted specific-locus mutations induced in mouse spermatogonia stem-cells, which was reported by Russell and Kelly [W. L. Russell. et al: Proc. Natl. Acad. Sci. USA 79 (1982), 542-544]. By fixing the two parameters of LDM model, c and {\\mu}, we can reproduce the observed data almost well. They are determined by experimental value of mutation frequency together with the corresponding total dose and dose rate. For a moment, we had to adopt simple assumption due to the lack of detailed information. If we have information of the exposure process exactly, it is easy to estimate the dose-rate effectiveness factor (DDREF) almost exactly. Thus LDM model may be applied to total dose and dose rate...

Manabe, Yuichiro

2012-01-01T23:59:59.000Z

390

Second-order discretization in space and time for radiation hydrodynamics  

SciTech Connect

We present a method for solving the equations of radiation hydrodynamics that is second-order accurate in space and time. This method combines the MUSCL-Hancock method for solving the Euler equations with the TR/BDF2 scheme in time for solving the equations of radiative transfer. We use an LDFEM to discretize the radiative transfer equations in space, which, though uncommon for radiation diffusion calculations, is a standard for radiation transport applications. We address the challenges inherent to using different spatial discretizations for the hydrodynamics and radiation and demonstrate how these may be overcome. We define our method for a 1-D model of compressible fluid dynamics coupled with grey radiation diffusion. Using the method of manufactured solutions, we show that the method is second-order accurate in space and time for both the equilibrium diffusion and streaming limit. (authors)

Edwards, J. D.; Morel, J. E. [Department of Nuclear Engineering, TAMU 3133, Texas A and M University, College Station, TX 77843 (United States); Lowrie, R. B. [Computational Physics Group CCS-2, M.S. D413, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

2013-07-01T23:59:59.000Z

391

Low Dose Radiation Research Program: Research Institutions  

NLE Websites -- All DOE Office Websites (Extended Search)

Institutions Institutions Lovelace Respiratory Research Institute Biological Bases for Radiation Adaptive Responses in the Lung-Lovelace Respiratory Research Institute, Albuquerque, NM USA Contact: Dr. Bobby R. Scott Program Objective Our research focuses on elucidating the biological bases for radiation adaptive responses in the lung and for suppressing lung cancer, and to use the knowledge gained to produce an improved systems-biology-based, risk model for lung cancer induction by low-dose, low linear-energy-transfer (LET) radiation. Research was initiated in October 2009. This research should help foster a new era of low-dose radiation risk/benefit assessment. It will have important implications for possible use of low-dose diagnostic radiation (e.g., X-rays) in cancer therapy. It

392

Assessing Ecosystem Effects of Reservoir Operations Using Food WebEnergy Transfer and Water Quality Models  

Science Journals Connector (OSTI)

We investigated the effects on the reservoir food web of a new temperature control device (TCD) on the dam at Shasta Lake, California. We followed a linked modeling approach that used a specialized reservoir wate...

Laurel Saito; Brett M. Johnson; John Bartholow; R. Blair Hanna

2001-03-01T23:59:59.000Z

393

Modeling Polychlorinated Biphenyl Mass Transfer after Amendment of Contaminated Sediment with Activated Carbon  

Science Journals Connector (OSTI)

The sorption kinetics and concentration of polychlorinated biphenyls (PCBs) in historically polluted sediment is modeled to assess a remediation strategy based on in situ PCB sequestration by mixing with activated carbon (AC). We extend our evaluation of ...

David Werner; Upal Ghosh; Richard G. Luthy

2006-05-24T23:59:59.000Z

394

Overview of heat transfer and fluid flow problem areas encountered in stirling engine modeling  

SciTech Connect

NASA Lewis Research Center has been managing Stirling engine development programs for over a decade. In addition to contractual programs, this work has included in-house engine testing and development of engine computer models. Attempts to validate Stirling engine computer models with test data have demonstrated that engine thermodynamic losses need better characterization. Various Stirling engine thermodynamic losses and efforts that are underway to characterize these losses are discussed.

Tew, R.C. Jr.

1988-02-01T23:59:59.000Z

395

Relating geo-meteorological parameters to global solar radiation for Egypt by Iranna-Bapat's estimation models  

Science Journals Connector (OSTI)

Estimation of solar radiation is considered as the most important parameter for the design and development of various solar energy systems. But, the availability of the required data is very scarce and often not readily accessible. The foremost objective of the present study was to estimate the monthly average global solar radiation (GSR) at various locations for Egypt, by the generalised Iranna-Bapat's model. Iranna-Bapat's model is developed to estimate the value of global solar radiation at any location on earth surface. This model uses the most commonly measurable meteorological parameters such as ambient temperature, humidity, windspeed, moisture for a given location. A total of 11 locations spread across the country are used to validate this model. The computed values from Iranna-Bapat's model are compared with the measured values. Iranna-Bapat's model demonstrated acceptable results, and statistically displayed lower RMSE. Therefore this model could be a good estimator for predicting the global solar radiation at other locations for Egypt, where such data is not available.

Iranna Korachagaon; V.N. Bapat

2013-01-01T23:59:59.000Z

396

Transferring Data  

NLE Websites -- All DOE Office Websites (Extended Search)

Transferring Data Transferring Data to and from NERSC Yushu Yao 1 Tuesday, March 8, 2011 Overview 2 * Structure of NERSC Systems and Disks * Data Transfer Nodes * Transfer Data from/to NERSC - scp/sftp - bbcp - GridFTP * Sharing Data Within NERSC Tuesday, March 8, 2011 Systems and Disks 3 System Hopper Franklin Carver Euclid Data Transfer Node PDSF Global Home ($HOME) Global Scratch ($GSCRATCH) Project Directory Local Non-shared Scratch Data transfer nodes can access most of the disks, suggested for transferring data in/out NERSC Tuesday, March 8, 2011 Data Transfer Nodes * Two Servers Available Now: - dtn01.nersc.gov and dtn02.nersc.gov - Accessible by all NERSC users * Designed to Transfer Data: - High speed connection to HPSS and NGF (Global Home, Project, and Global Scratch) - High speed ethernet to wide area network

397

A WSRC-MS-g8-00318 Heat Transfer Model of Above and Underground Insulated Piping  

Office of Scientific and Technical Information (OSTI)

WSRC-MS-g8-00318 Heat Transfer Model of Above and Underground Insulated Piping Systems by K. C. Kwon Westinghouse Savannah River Company Savannah River Site Aiken, South Carolina 29808 A document prepared for ASME CONFERENCE - HEAT EXCHANGER COMMITTEE MEETING 8 , INTERNATIONAL JOINT POWER GENERATION CONFERENCE 1998 at Baltimore, MA, USA from 8/23/98 - 8/26/98. DOE Contract No. DE-AC09-96SR18500 This paper was prepared in connection with work done under the above contract number with the U. S. Department of Energy. By acceptance of this paper, the publisher and/or recipient acknowledges the U. S. Government's right to retain a nonexclusive, royalty-free license in and to any copyright covering this paper, along with the right to reproduce and to authorize others to reproduce all or part of the copyrighted paper.

398

MRO/CRISM Retrieval of Surface Lambert Albedos for Multispectral Mapping of Mars with DISORT-based Rad. Transfer Modeling: Phase 1 - Using Historical Climatology for Temperatures, Aerosol Opacities, & Atmo. Pressures  

E-Print Network (OSTI)

We discuss the DISORT-based radiative transfer pipeline ('CRISM_LambertAlb') for atmospheric and thermal correction of MRO/CRISM data acquired in multispectral mapping mode (~200 m/pixel, 72 spectral channels). Currently, in this phase-one version of the system, we use aerosol optical depths, surface temperatures, and lower-atmospheric temperatures, all from climatology derived from Mars Global Surveyor Thermal Emission Spectrometer (MGS-TES) data, and surface altimetry derived from MGS Mars Orbiter Laser Altimeter (MOLA). The DISORT-based model takes as input the dust and ice aerosol optical depths (scaled to the CRISM wavelength range), the surface pressures (computed from MOLA altimetry, MGS-TES lower-atmospheric thermometry, and Viking-based pressure climatology), the surface temperatures, the reconstructed instrumental photometric angles, and the measured I/F spectrum, and then outputs a Lambertian albedo spectrum. The Lambertian albedo spectrum is valuable geologically since it allows the mineralogical ...

McGuire, P C; Smith, M D; Arvidson, R E; Murchie, S L; Clancy, R T; Roush, T L; Cull, S C; Lichtenberg, K A; Wiseman, S M; Green, R O; Martin, T Z; Milliken, R E; Cavender, P J; Humm, D C; Seelos, F P; Seelos, K D; Taylor, H W; Ehlmann, B L; Mustard, J F; Pelkey, S M; Titus, T N; Hash, C D; Malaret, E R

2009-01-01T23:59:59.000Z

399

Modeling polychlorinated biphenyl mass transfer after amendment of contaminated sediment with activated carbon  

SciTech Connect

The sorption kinetics and concentration of polychlorinated biphenyls (PCBs) in historically polluted sediment is modeled to assess a remediation strategy based on in situ PCB sequestration by mixing with activated carbon (AC). The authors extend their evaluation of a model based on intraparticle diffusion by including a biomimetic semipermeable membrane device (SPMD) and a first-order degradation rate for the aqueous phase. The model predictions are compared with the previously reported experimental PCB concentrations in the bulk water phase and in SPMDs. The simulated scenarios comprise a marine and a freshwater sediment, four PCB congeners, two AC grain sizes, four doses of AC, and comparison with laboratory experiments. The modeling approach distinguishes between two different sediment particles types: a light-density fraction representing carbonaceous particles such as charcoal, coal, coke, cenospheres, or wood, and a heavy-density fraction representing the mineral phase with coatings of organic matter. A third particle type in the numerical model is AC. The model qualitatively reproduces the observed shifts in the PCB distribution during repartitioning after AC amendment but overestimates the overall effect of the treatment in reducing aqueous and SPMD concentrations of PCBs by a factor of 2-6. For the AC application in sediment, competitive sorption of the various solutes apparently requires a reduction by a factor of 16 of the literature values for the AC-water partitioning coefficient measured in pure aqueous systems. With this correction, model results and measurements agree within a factor of 3. After AC amendment is homogeneously mixed into the sediment and then left undisturbed, aqueous PCB concentrations tend toward the same reduction after 5 years. 19 refs., 5 figs., 4 tabs.

David Werner; Upal Ghosh; Richard G. Luthy [University of Newcastle upon Tyne, Newcastle (United Kingdom)

2006-07-01T23:59:59.000Z

400

Improvement of Moist and Radiative Processes in Highly Parallel Atmospheric General Circulation Models: Validation and Development  

SciTech Connect

Research on designing an integrated moist process parameterization package was carried. This work began with a study that coupled an ensemble of cloud models to a boundary layer model to examine the feasibility of such a methodology for linking boundary layer and cumulus parameterization schemes. The approach proved feasible, prompting research to design and evaluate a coupled parameterization package for GCMS. This research contributed to the development of an Integrated Cumulus Ensemble-Turbulence (ICET) parameterization package. This package incorporates a higher-order turbulence boundary layer that feeds information concerning updraft properties and the variances of temperature and water vapor to the cloud parameterizations. The cumulus ensemble model has been developed, and initial sensitivity tests have been performed in the single column model (SCM) version of CCM2. It is currently being coupled to a convective wake/gust front model. The major function of the convective wake/gust front model is to simulate the partitioning of the boundary layer into disturbed and undisturbed regions. A second function of this model is to predict the nonlinear enhancement of surface to air sensible heat and moisture fluxes that occur in convective regimes due to correlations between winds and anomalously cold, dry air from downdrafts in the gust front region. The third function of the convective wake/gust front model is to predict the amount of undisturbed boundary layer air lifted by the leading edge of the wake and the height to which this air is lifted. The development of the wake/gust front model has been completed, and it has done well in initial testing as a stand-alone component. The current task, to be completed by the end of the funding period, is to tie the wake model to a cumulus ensemble model and to install both components into the single column model version of CCM3 for evaluation. Another area of parametrization research has been focused on the representation of cloud radiative properties. An examination of the CCM2 simulation characteristics indicated that many surface temperature and warm land precipitation problems were linked to deficiencies in the specification of cloud optical properties, which allowed too much shortwave radiation to reach the surface. In-cloud liquid water path was statically specified in the CCM2 using a "prescribed, meridionally and height varying, but time independent, cloud liquid water density profile, which was analytically determined from a meridionally specified liquid water scale height. Single-column model integrations were conducted to explore alternative formulations for the cloud liquid water path diagnostic, converging on an approach that employs a similar, but state-dependent technique for determining in-cloud liquid water concentration. The new formulation, results in significant improvements to both the top-of- atmosphere and surface energy budgets. In particular, when this scheme is incorporated in the three-dimensional GCM, simulated July surface temperature biases are substantially reduced, where summer precipitation over the northern hemisphere continents, as well as precipitation rates over most all warm land areas, is more consistent with observations". This improved parameterization has been incorporated in the CCM3.

Frank, William M.; Hack, James J.; Kiehl, Jeffrey T.

1997-02-24T23:59:59.000Z

Note: This page contains sample records for the topic "radiation transfer models" 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

Proceedings of Eurotherm78 Computational Thermal Radiation in Participating Media II 5-7 April 2006, Poitiers, France  

E-Print Network (OSTI)

advantages over the combustion- based technology. Energy is efficiently transferred via direct irradiation production or upgrade, the final product contains chemically stored solar energy. Example applications 2006, Poitiers, France A diffusion-based approximate model for radiation heat transfer in a solar

402

Mathematical modeling and heat transfer experiments for an annular bed methane-steam reformer  

SciTech Connect

A new type of catalytic reactor has been proposed for conducting endothermic chemical reactions. The reactor catalyst bed is in the form of a tubular reactor with an annular cross-section. Heat is supplied to the catalyst bed by countercurrent flowing gases on opposite sides of the annulus walls. This study consisted of the development of a mathematical model to describe the performance of an annular bed reactor employing the methane-steam reforming reaction for the production of hydrogen. The model is two-dimensional, and predicts both axial and radial temperature and concentration profiles throughout the reactor. The model was used to perform parameter sensitivity studies, reactor size optimization, and reactor scaleup.

Summers, W.A.

1986-01-01T23:59:59.000Z

403

A steady-state heat-transfer model for solids deposition from waxy mixtures in a pipeline  

Science Journals Connector (OSTI)

Abstract A steady-state heat-transfer model is presented for the formation of a deposit-layer from waxsolvent waxy mixtures in a pipeline under turbulent flow. The waxy mixture is taken to enter the pipeline under the single-phase hot flow regime (where the average mixture temperature is higher than its wax appearance temperature, WAT) and, upon gradual cooling, the mixture transitions into the cold flow regime (where its average temperature is lower than its WAT). The cold flow regime is characterized by two-phase flow, in which solid particles are suspended in the liquid phase. The effect of deposit aging is incorporated via a shear-induced deformation approach proposed in the literature. The model predictions are reported for the deposit thickness, waxy mixture temperature, pressure drop and the rate of heat loss in the hot flow and cold flow regimes for a range of inlet mixture temperature, surrounding temperature, and the Reynolds number. The predicted deposit thickness is shown to increase axially in the hot flow regime, to reach a maximum as the liquid temperature approaches the WAT of the waxsolvent mixture, and to decrease gradually to zero in the cold flow regime. The trends in the model predictions compare satisfactorily with those reported from bench-scale experimental studies as well as the predictions from an unsteady state moving boundary problem formulation.

Samira Haj-Shafiei; Dalia Serafini; Anil K. Mehrotra

2014-01-01T23:59:59.000Z

404

A COMPUTATIONAL MODEL OF COUPLED HEAT AND MOISTURE TRANSFER WITH PHASE CHANGE  

E-Print Network (OSTI)

, The University of Greenwich, London, UK Mark C. Leaper Formerly The Wolfson Centre for Bulk Solids Handling Technology, The University of Greenwich, London, UK As part of a comprehensive effort to predict=cycling. The resulting model partial differential equations were solved using finite-volume procedures in the context

Christakis, Nikolaos

405

Real-time data transfer to 3D modelmaximizing wellbore value  

Science Journals Connector (OSTI)

...this point, the geosteering team expected changes in log characteristics and signs of greater apparent dip angle. Real-time data...earth model and correlations on a Web-based page. This Intranet page could be accessed by any team member connected to the...

Hugh Nicholson; Per Gunnar Folstad; Terje A. Pedersen

406

Radiative corrections to ZZ?ZZ in the electroweak standard model  

Science Journals Connector (OSTI)

The cross section for ZZ?ZZ with arbitrarily polarized Z bosons is calculated within the electroweak standard model including the complete O(?) corrections. We show the numerical importance of the radiative corrections and elaborate its characteristic features. The treatment of the Higgs-boson resonance is discussed in different schemes including the S-matrix-motivated pole scheme and the background-field method. The numerical accuracy of the equivalence theorem is investigated by comparing the cross sections for purely longitudinal Z bosons obtained from the equivalence theorem and from the complete calculation. In this context the full O(?) corrections are also confronted with the enhanced corrections of O(?MH2/sW2MW2), which were frequently used in the literature.

A. Denner; S. Dittmaier; T. Hahn

1997-07-01T23:59:59.000Z

407

Source level model for propeller blade rate radiation for the worlds merchant fleet  

Science Journals Connector (OSTI)

A model is developed for the acoustic source strength of blade rate line energy produced by single?screw merchant vessels. These source strengths are based on observed cavitation time histories on merchant vessels and on limitations imposed by considerations of propeller design procedures and ship vibration criteria. Relationships are presented for the expected value of the blade rate source strength for ships of different lengths expressed both as a monopole source strength located at a known depth below a free surface and as a dipole source strength that describes the pressure radiated to the farfield. These relationships are based on a small sample of merchant shipcharacteristics and are exercised for the estimated population of ships at sea. This calculation yields a statistical description of the distribution of source level and frequency of propeller blade rate acoustic energy for the fleet of single?screw merchant vessels.

Leslie M. Gray; David S. Greeley

1980-01-01T23:59:59.000Z

408

Radiation Damage in Nuclear Fuel for Advanced Burner Reactors: Modeling and Experimental Validation  

SciTech Connect

The consortium has completed its existence and we are here highlighting work and accomplishments. As outlined in the proposal, the objective of the work was to advance the theoretical understanding of advanced nuclear fuel materials (oxides) toward a comprehensive modeling strategy that incorporates the different relevant scales involved in radiation damage in oxide fuels. Approaching this we set out to investigate and develop a set of directions: 1) Fission fragment and ion trajectory studies through advanced molecular dynamics methods that allow for statistical multi-scale simulations. This work also includes an investigation of appropriate interatomic force fields useful for the energetic multi-scale phenomena of high energy collisions; 2) Studies of defect and gas bubble formation through electronic structure and Monte Carlo simulations; and 3) an experimental component for the characterization of materials such that comparisons can be obtained between theory and experiment.

Niels Gronbech Jensen; Mark Asta; Nigel Browning'Vidvuds Ozolins; Axel van de Walle; Christopher Wolverton

2011-12-29T23:59:59.000Z

409

Radiative Generation of Quark Masses and Mixing Angles in the Two Higgs Doublet Model  

E-Print Network (OSTI)

We present a framework to generate the quark mass hierarchies and mixing angles by extending the Standard Model with one extra Higgs doublet. The charm and strange quark masses are generated by small quantum effects, thus explaining the hierarchy between the second and third generation quark masses. All the mixing angles are also generated by small quantum effects: the Cabibbo angle is generated at zero-th order in perturbation theory, while the remaining off-diagonal entries of the Cabibbo-Kobayashi-Maskawa matrix are generated at first order, hence explaining the observed hierarchy $|V_{ub}|,|V_{cb}|\\ll |V_{us}|$. The values of the radiatively generated parameters depend only logarithmically on the heavy Higgs mass, therefore this framework can be reconciled with the stringent limits on flavor violation by postulating a sufficiently large new physics scale.

Alejandro Ibarra; Ana Solaguren-Beascoa

2014-07-04T23:59:59.000Z

410

General Heat Transfer Characterization and Empirical Models of Material Storage Temperatures for the Los Alamos Nuclear Materials Storage Facility  

SciTech Connect

The Los Alamos National Laboratory's Nuclear Materials Storage Facility (NMSF) is being renovated for long-term storage of canisters designed to hold heat-generating nuclear materials. A fully passive cooling scheme, relying on the transfer of heat by conduction, free convection, and radiation has been proposed as a reliable means of maintaining material at acceptable storage temperatures. The storage concept involves placing radioactive materials, with a net heat-generation rate of 10 W to 20 W, inside a set of nested steel canisters. The canisters are, in placed in holding fixtures and positioned vertically within a steel storage pipe. Several hundred drywells are arranged in a linear array within a large bay and dissipate the waste heat to the surrounding air, thus creating a buoyancy driven airflow pattern that draws cool air into the storage facility and exhausts heated air through an outlet stack. In this study, an experimental apparatus was designed to investigate the thermal characteristics of simulated nuclear materials placed inside two nested steel canisters positioned vertically on an aluminum fixture plate and placed inside a section of steel pipe. The heat-generating nuclear materials were simulated with a solid aluminum cylinder containing .an embedded electrical resistance heater. Calibrated type T thermocouples (accurate to ~ O.1 C) were used to monitor temperatures at 20 different locations within the apparatus. The purposes of this study were to observe the heat dissipation characteristics of the proposed `canister/fixture plate storage configuration, to investigate how the storage system responds to changes in various parameters, and to develop and validate empirical correlations to predict material temperatures under various operating conditions

J. D. Bernardin; W. S. Gregory

1998-10-01T23:59:59.000Z

411

1 Copyright 2012 by ASME Proceedings of the ASME 2012 Summer Heat Transfer Conference  

E-Print Network (OSTI)

with biological media during biomedical laser therapeutic applications [1-6], involve the transport of radiative of radiative transfer, accurate solutions of the Equation of Radiative Transfer (ERT) are required. The ERT 8-12, 2012, Rio Grande, Puerto Rico HT2012-58307 NORMALIZATION FOR ULTRAFAST RADIATIVE TRANSFER

Guo, Zhixiong "James"

412

E-Print Network 3.0 - abscopal radiation effects Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

will introduce the theory of radiative transfer; the second part Summary: to greenhouse effect and solar radiation 6. Radiative heating and cooling a. The Chapman layer b....

413

Modeling radiation-induced mixing at interfaces between low solubility metals  

E-Print Network (OSTI)

This thesis studies radiation-induced mixing at interfaces between low solubility metals using molecular dynamics (MD) computer simulations. It provides original contributions on the fundamental mechanisms of radiation-induced ...

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

2014-01-01T23:59:59.000Z

414

Modeling lidar waveforms with time-dependent stochastic radiative transfer theory for remote estimations of forest structure  

E-Print Network (OSTI)

with field data from two conifer forest stands (southern old jack pine and southern old black spruce estimations of forest structure Svetlana Y. Kotchenova,1 Nikolay V. Shabanov,1 Yuri Knyazikhin,1 Anthony B (lidars) have demonstrated a potential for accurate remote sensing of forest biomass and structure

Goldberg, Bennett

415

Area-Average Solar Radiative Transfer in Three-Dimensionally Inhomogeneous Clouds: The Independently Scattering Cloudlet Model  

Science Journals Connector (OSTI)

A new conceptual and computational basis is described for renormalizing the single-scatter and extinction properties (optical depth, single-scatter albedo, and scattering phase function or asymmetry parameter) of a three-dimensionally ...

Grant W. Petty

2002-10-01T23:59:59.000Z

416

Assessment of Low Linear Energy Transfer RadiationInduced Bystander Mutagenesis in a Three-Dimensional Culture Model  

Science Journals Connector (OSTI)

...them in order to generate high quality proteomics fingerprints. We...stocks so that samples used for quality controls could last for at...example, method settings, laser energy, matrix blaster shots, and...also dramatically affected the quality of the spectrum. The results...

Rudranath Persaud; Hongning Zhou; Sarah E. Baker; Tom K. Hei; and Eric J. Hall

2005-11-01T23:59:59.000Z

417

Investigation of Thin Cirrus Cloud Optical and Microphysical Properties on the Basis of Satellite Observations and Fast Radiative Transfer Models  

E-Print Network (OSTI)

function of ?CALIOP. the frequency is scaled by dividing the largest frequency in each ?CALIOP bin. Data are from collocated MODIS and CALIOP measurements made in August 2006. ............... 126 5.7 Daytime frequencies of (a) cloud, (b) ice cloud, (c...) and Stubenrauch et al. (2006) investigated the climatology of thin cirrus properties. 1.2.2 Limb-view-instrument-based observations Limb-view-instruments observe cloud or atmosphere by eliminating the signals from the surface and therefore increase the SNRs...

Wang, Chenxi

2013-07-25T23:59:59.000Z

418

Biokinetic and dosimetric modelling in the estimation of radiation risks from internal  

Science Journals Connector (OSTI)

The International Commission on Radiological Protection (ICRP) has developed biokinetic and dosimetric models that enable the calculation of organ and tissue doses for a wide range of radionuclides. These are used to calculate equivalent and effective dose coefficients (dose in SvBq?1 intake), considering occupational and environmental exposures. Dose coefficients have also been given for a range of radiopharmaceuticals used in diagnostic medicine. Using equivalent and effective dose, exposures from external sources and from different radionuclides can be summed for comparison with dose limits, constraints and reference levels that relate to risks from whole-body radiation exposure. Risk estimates are derived largely from follow-up studies of the survivors of the atomic bombings at Hiroshima and Nagasaki in 1945. New dose coefficients will be required following the publication in 2007 of new ICRP recommendations. ICRP biokinetic and dosimetric models are subject to continuing review and improvement, although it is arguable that the degree of sophistication of some of the most recent models is greater than required for the calculation of effective dose to a reference person for the purposes of regulatory control. However, the models are also used in the calculation of best estimates of doses and risks to individuals, in epidemiological studies and to determine probability of cancer causation. Models are then adjusted to best fit the characteristics of the individuals and population under consideration. For example, doses resulting from massive discharges of strontium-90 and other radionuclides to the Techa River from the Russian Mayak plutonium plant in the early years of its operation are being estimated using models adapted to take account of measurements on local residents and other population-specific data. Best estimates of doses to haemopoietic bone marrow, in utero and postnatally, are being used in epidemiological studies of radiation-induced leukaemia. Radon-222 is the one internal emitter for which control of exposure is based on direct information on cancer risks, with extensive information available on lung cancer induction by radon progeny in mines and consistent data on risks in homes. The dose per unit 222Rn exposure can be calculated by comparing lung cancer risk estimates derived for 222Rn exposure and for external exposure of the Japanese survivors. Remarkably similar values are obtained by this method and by calculations using the ICRP model of the respiratory tract, providing good support for model assumptions. Other informative comparisons with risks from external exposure can be made for Thorotrast-induced liver cancer and leukaemia, and radium-induced bone cancer. The bone-seeking alpha emitters, plutonium-239 and radium isotopes, are poorer leukaemogens than predicted by models. ICRP dose coefficients are published as single values without consideration of uncertainties. However, it is clear that full consideration of uncertainties is appropriate when considering best estimates of doses and risks to individuals or specific population groups. An understanding of the component uncertainties in the calculation of dose coefficients can be seen as an important goal and should help inform judgements on the control of exposures. The routine consideration of uncertainties in dose assessments, if achievable, would be of questionable value when doses are generally maintained at small fractions of limits.

John Harrison

2009-01-01T23:59:59.000Z

419

Theoretical Multipolar Atom Model Transfer in Nitro-Derivatives of N-Methylaniline  

Science Journals Connector (OSTI)

The nitroanilines are an example of compounds in which the coexistence of electron-rich and electron-deficient substituents, connected through a conjugated ?-electronic system, makes their molecular second-order hyperpolarizability and second-harmonic ...The theoretically derived multipole parameters have been applied for the examination of molecular model improvement. The individual electron properties of molecules were analyzed in the charge density distribution along with changes in aromaticity due to the ring substitutions. The intermolecular interactions were studied using Hirschfeld surfaces and dissociation energy estimation from topological data.

Katarzyna Gajda; Zdzis?aw Daszkiewicz; Ewelina Kozubek; Krzysztof Ejsmont; Bartosz Zarychta

2014-10-15T23:59:59.000Z

420

Surface Radiation from GOES: A Physical Approach; Preprint  

SciTech Connect

Models to compute Global Horizontal Irradiance (GHI) and Direct Normal Irradiance (DNI) have been in development over the last 3 decades. These models can be classified as empirical or physical, based on the approach. Empirical models relate ground based observations with satellite measurements and use these relations to compute surface radiation. Physical models consider the radiation received from the earth at the satellite and create retrievals to estimate surface radiation. While empirical methods have been traditionally used for computing surface radiation for the solar energy industry the advent of faster computing has made operational physical models viable. The Global Solar Insolation Project (GSIP) is an operational physical model from NOAA that computes GHI using the visible and infrared channel measurements from the GOES satellites. GSIP uses a two-stage scheme that first retrieves cloud properties and uses those properties in a radiative transfer model to calculate surface radiation. NREL, University of Wisconsin and NOAA have recently collaborated to adapt GSIP to create a 4 km GHI and DNI product every 30 minutes. This paper presents an outline of the methodology and a comprehensive validation using high quality ground based solar data from the National Oceanic and Atmospheric Administration (NOAA) Surface Radiation (SURFRAD) (http://www.srrb.noaa.gov/surfrad/sitepage.html) and Integrated Surface Insolation Study (ISIS) http://www.srrb.noaa.gov/isis/isissites.html), the Solar Radiation Research Laboratory (SRRL) at National Renewable Energy Laboratory (NREL), and Sun Spot One (SS1) stations.

Habte, A.; Sengupta, M.; Wilcox, S.

2012-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "radiation transfer models" 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

Handbook of Anatomical Models for Radiation Dosimetry (To be published in 2009 in "Series in Medical Physics and Biomedical Engineering")  

E-Print Network (OSTI)

Handbook of Anatomical Models for Radiation Dosimetry (To be published in 2009 in "Series in Medical Physics and Biomedical Engineering") Edited by X. George Xu, Ph.D., Rensselaer Polytechnic Reference Computational Phantoms Maria Zankl, Keith F Eckerman, Wesley E. Bolch Chapter 16 Physical Phantoms

Linhardt, Robert J.

422

Biological Basis for Radiation Adaptive Responses that Protect Against  

NLE Websites -- All DOE Office Websites (Extended Search)

Basis for Radiation Adaptive Responses that Protect Against Basis for Radiation Adaptive Responses that Protect Against Bronchial Epithelial Cell Transformation Wenshu Chen Lovelace Respiratory Research Institute Abstract The major hypothesis in this project is that low-dose, low linear-energy-transfer (LET) radiation stimulates an adaptive response that protects cells from neoplastic transformation involving modulation of paracrine factors (e.g., cytokines), cell survival/death signaling pathways, and reprogramming of the epigenome. To test this hypothesis, a validated, sensitive in vitro transformation model and a media transfer method were used to study the mechanisms of low-LET gamma radiation activated natural protection (ANP) against chemical carcinogen-induced bronchial cell transformation. Immortalized human bronchial epithelial cell

423

Uncertainty in Modeling Dust Mass Balance and Radiative Forcing from Size Parameterization  

SciTech Connect

This study examines the uncertainties in simulating mass balance and radiative forcing of mineral dust due to biases in the aerosol size parameterization. Simulations are conducted quasi-globally (180oW-180oE and 60oS-70oN) using the WRF24 Chem model with three different approaches to represent aerosol size distribution (8-bin, 4-bin, and 3-mode). The biases in the 3-mode or 4-bin approaches against a relatively more accurate 8-bin approach in simulating dust mass balance and radiative forcing are identified. Compared to the 8-bin approach, the 4-bin approach simulates similar but coarser size distributions of dust particles in the atmosphere, while the 3-mode pproach retains more fine dust particles but fewer coarse dust particles due to its prescribed og of each mode. Although the 3-mode approach yields up to 10 days longer dust mass lifetime over the remote oceanic regions than the 8-bin approach, the three size approaches produce similar dust mass lifetime (3.2 days to 3.5 days) on quasi-global average, reflecting that the global dust mass lifetime is mainly determined by the dust mass lifetime near the dust source regions. With the same global dust emission (~6000 Tg yr-1), the 8-bin approach produces a dust mass loading of 39 Tg, while the 4-bin and 3-mode approaches produce 3% (40.2 Tg) and 25% (49.1 Tg) higher dust mass loading, respectively. The difference in dust mass loading between the 8-bin approach and the 4-bin or 3-mode approaches has large spatial variations, with generally smaller relative difference (<10%) near the surface over the dust source regions. The three size approaches also result in significantly different dry and wet deposition fluxes and number concentrations of dust. The difference in dust aerosol optical depth (AOD) (a factor of 3) among the three size approaches is much larger than their difference (25%) in dust mass loading. Compared to the 8-bin approach, the 4-bin approach yields stronger dust absorptivity, while the 3-mode approach yields weaker dust absorptivity. Overall, on quasi-global average, the three size parameterizations result in a significant difference of a factor of 2~3 in dust surface cooling (-1.02~-2.87 W m-2) and atmospheric warming (0.39~0.96 W m-2) and in a tremendous difference of a factor of ~10 in dust TOA cooling (-0.24~-2.20 W m-2). An uncertainty of a factor of 2 is quantified in dust emission estimation due to the different size parameterizations. This study also highlights the uncertainties in modeling dust mass and number loading, deposition fluxes, and radiative forcing resulting from different size parameterizations, and motivates further investigation of the impact of size parameterizations on modeling dust impacts on air quality, climate, and ecosystem.

Zhao, Chun; Chen, Siyu; Leung, Lai-Yung R.; Qian, Yun; Kok, Jasper; Zaveri, Rahul A.; Huang, J.

2013-11-05T23:59:59.000Z

424

ARM - Evaluation Product - Radiatively Important Parameters Best Estimate  

NLE Websites -- All DOE Office Websites (Extended Search)

ProductsRadiatively Important Parameters Best ProductsRadiatively Important Parameters Best Estimate (RIPBE) Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Evaluation Product : Radiatively Important Parameters Best Estimate (RIPBE) 2002.03.01 - 2007.06.30 Site(s) SGP General Description The Radiatively Important Parameters Best Estimate (RIPBE) VAP combines multiple input datastreams, each with their own temporal and vertical resolution, to create a complete set of radiatively important parameters on a uniform vertical and temporal grid with quality control and source information for use as input to a radiative transfer model. One of the main drivers for RIPBE was to create input files for the BroadBand Heating Rate Profiles (BBHRP) VAP, but we also envision use of RIPBE files for user-run

425

A two-dimensional model for the heat transfer on the external circuit of a Stirling engine for a dish/Stirling system  

SciTech Connect

In this paper the {kappa}-{var{underscore}epsilon} turbulent model for the incompressible fluid flow has been used to describe the heat transfer and gas dynamical processes on the external circuit of a Stirling Engine as used on a Solar Dish/Stirling System. The problem considered, in this work for a cavity-type heat receiver of the Stirling Engine, is that of the heat transfer in the body of the shell of the heat exchangers of the engine due to the thermal conductivity, the convective heat transfer between the working fluid and the walls of the engine internal gas circuit and the heat transfer due to the forced convection of the air in the cavity and in the attached air domain. The boundary conditions employed on the engines internal circuit were obtained using the developed one-dimensional second level mathematical model of the engine working cycle. Physical models for the distribution of the solar insolation on the bottom and side walls of the heat receiver have been taken into account and the temperature fields for the heat receiver and the air velocity have been obtained for the case when the heat receiver is affected by wind. The numerical results show that it is in the region of the boundary of the input window of the heat receiver where there is the largest reduction in the temperature in the shell of the heat exchangers and this is due to the convection of the air.

Makhkamov, K.K.; Ingham, D.B.

1998-07-01T23:59:59.000Z

426

Enhanced heat transfer for thermionic power modules  

SciTech Connect

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

427

Spectrally selective laminated glazing consisting of solar control and heat mirror coated glass: preparation, characterization and modelling of heat transfer  

Science Journals Connector (OSTI)

In this study, solar control coatings were prepared by sequential depositions of thin films of ZnS (40nm)CuS (150nm) and ZnS (40nm)Bi2S3 (75nm)CuS (150nm) from chemical baths on 3mm thick commercial sheet glass. These were laminated to 3mm thick clear glass or commercially available SnO2 based heat mirror coating of sheet resistance 15? on float glass of 3mm thickness using a poly(ethylene vinyl acetate), EVA, sheet of 0.36mm thickness in a vacuum process at 120C for 30min. In total, the thickness of the glazing was 6.35mm. The glazings possess visible transmittance, weighted for D65 solar spectra and sensitivity of the human eye for daylight vision, of 36% or 14% with solar absorptance of 71% or 78% depending on the coating type, i.e ZnSCuS or ZnSBi2S3CuS-heat mirror respectively. The solar heat gain coefficient (SHGC) was evaluated for these glazings at exterior temperatures of 15 and 32C for an exterior convective heat transfer coefficient (hex) of 6100Wm?2K?1 using a mathematical model. The model predicts the extent of reduction in SHGC through the presence of the heat mirror coating as a function of hex and hence helps to decide on the relative benefit, which may be derived through their use in different locations. Though the deposition technique mentioned here involves longer duration compared with vacuum techniques, it may be developed into a low throughput, low-capital alternate technology for small-scale production.

G. Alvarez; J.J. Flores; J.O. Aguilar; O. Gmez-Daza; C.A. Estrada; M.T.S. Nair; P.K. Nair

2005-01-01T23:59:59.000Z

428

Modeling the Action of Protons and Heavier Ions in Biological Targets: Nuclear Interactions in Hadrontherapy and Space Radiation Protection  

Science Journals Connector (OSTI)

Tumor treatment with protons and Carbon ions can allow for a better optimization of Tumor Control Probability and Normal Tissue Complication Probability especially for radio?resistant tumors. Exposure to protons and heavier ions is also of concern for manned space missions such as future travels to the Moon and Mars. Nuclear reactions with the human body constituents the beam line components (for hadrontherapy) and the spacecraft walls and shielding (for space radiation protection) can significantly modify the characteristics of the primary radiation field and thus the dose distributions in the various target tissues. In this context the FLUKA Monte Carlo transport code integrated with radiobiological data and coupled with anthropomorphic phantoms was applied to the characterization of therapeutic proton beams and the calculation of space radiation organ doses with focus on the role of nuclear interactions. Besides absorbed and equivalent doses distributions of biological dose (modeled as the average number of DNA clustered lesions per cell induced in a given organ or tissue) were calculated as well. Concerning space radiation protection exposure to Galactic Cosmic Rays (GCR) and Solar Particle Events (SPE) under different shielding conditions was simulated. Both for hadrontherapy and for space radiation exposure nuclear reaction products were found to play a more important role for the equivalent and biological dose than for the absorbed dose. Furthermore while for SPEs the doses (both absorbed and equivalent/biological) decreased dramatically by increasing the shield thickness the GCR doses showed a slight shielding dependence. Overall these examples of application of FLUKA to radiotherapy and radiation protection problems emphasized the need of further models and data typically double?differential cross sections for nucleus?nucleus interactions at energies below a few hundred MeV/n.

F. Ballarini; G. Battistoni; F. Cerutti; E. Gadioli; M. V. Garzelli; A. Ottolenghi; V. Parini; M. Pelliccioni; P. Sala; D. Scannicchio

2005-01-01T23:59:59.000Z

429

Retinal Degeneration and Ionizing Radiation Hypersensitivity in a Mouse Model for Cockayne Syndrome  

Science Journals Connector (OSTI)

...sensitive to a single dose of ionizing radiation at doses up to 10 Gy. In marked...least within the age range investigated, the...photoreceptor cells for ionizing radiation. This finding underscores...experiment (cumulative dose, 35 kJ/m2). The...

Theo G. M. F. Gorgels; Ingrid van der Pluijm; Renata M. C. Brandt; George A. Garinis; Harry van Steeg; Gerard van den Aardweg; Gerard H. Jansen; Jan M. Ruijter; Arthur A. B. Bergen; Dirk van Norren; Jan H. J. Hoeijmakers; Gijsbertus T. J. van der Horst

2006-12-04T23:59:59.000Z

430

Space Radiation Risk Limits and Earth-Moon-Mars Environmental Models  

E-Print Network (OSTI)

-term dose limits are used to prevent in-flight radiation sickness or death through restriction of the doses and skin dose limits, respectively. Large uncertainties exist in estimating the health risks of space radiation chiefly the understanding of the radiobiology of heavy ions, and dose-rate and dose protraction

Pringle, James "Jamie"

431

Three-dimensional radiative properties of hot accretion flows on to the Galactic Centre black hole  

Science Journals Connector (OSTI)

......discs|black hole physics|MHD|plasmas|radiative transfer...inefficient accretion flows modelled by MHD simulations. The synthetic images...baseline-correlated flux density diagram of the recent very-long-baseline...the first time that our 3-D MHD model with differing density......

Y. Kato; M. Umemura; K. Ohsuga

2009-12-21T23:59:59.000Z

432

An accurate program for radiation modelling in the desigh of high-tempersature furnaces  

Science Journals Connector (OSTI)

......they maintain computational efficiency without loss of accuracy...example, the production of turbine blades-- the stock temperature...was judged by examining the efficiency of the heat transfer to the...Shape Tube positions Soak Efficiency time % Lateral uniformity......

D. A. LAWSON; C.D. ZIESLER

1996-03-01T23:59:59.000Z

433

Theoretical and Numerical Analysis of Polarization for Time Dependent Radiative  

E-Print Network (OSTI)

transport equation with respect to the polariza- tion parameters solve the matrix-valued radiative transferTheoretical and Numerical Analysis of Polarization for Time Dependent Radiative Transfer Equations@math.stanford.edu Abstract We consider the matrix-valued radiative transfer equations for the Stokes param- eters

Bal, Guillaume

434

ME 339 Heat Transfer ABET EC2000 syllabus  

E-Print Network (OSTI)

ME 339­ Heat Transfer Page 1 ABET EC2000 syllabus ME 339 ­ Heat Transfer Spring 2010 Required convection; radiation; introduction to phase change heat transfer and to heat exchangers. Prerequisite(s): ME, Fundamentals of Heat and Mass Transfer, 6th ed., Wiley Other Required Material: NA Course Objectives

Ben-Yakar, Adela

435

Numerical modeling of dish-Stirling reflux solar receivers  

SciTech Connect

Using reflux solar receivers to collect solar energy for dish-Stirling electric power generation systems is currently being investigated by several organizations, including Sandia National Laboratories, Albuquerque, New Mexico. In support of this program, Sandia has developed two numerical models describing the energy transfer within and thermal performance of pool-boiler and heat-pipe receivers. Both models are applicable to axisymmetric geometries and they both consider the radiative and convective energy transfer within the receiver cavity, the conductive and convective energy transfer within the receiver cavity, the conductive and convective energy transfer from the receiver housing, and the energy transfer to the receiver working fluid. In these models, the radiative transfer within the receiver is analyzed using a two-band (solar and infrared) net-radiation formulation for enclosure radiation. Empirical convective correlations describe the convective heat transfer from the cavity to the surroundings. The primary difference between the models is the level of detail in modeling the heat conduction through the receiver walls. The more detailed model uses a two-dimensional finite control volume method, whereas the simpler model uses a one-dimensional thermal resistance approach. 20 refs., 7 figs., 2 tabs.

Hogan, R.E.

1990-01-01T23:59:59.000Z

436

Near-field heat transfer between gold nanoparticle arrays  

SciTech Connect

The radiative heat transfer between gold nanoparticle layers is presented using the coupled dipole method. Gold nanoparticles are modelled as effective electric and magnetic dipoles interacting via electromagnetic fluctuations. The effect of higher-order multipoles is implemented in the expression of electric polarizability to calculate the interactions at short distances. Our findings show that the near-field radiation reduces as the radius of the nanoparticles is increased. Also, the magnetic dipole contribution to the heat exchange becomes more important for larger particles. When one layer is displayed in parallel with respect to the other layer, the near-field heat transfer exhibits oscillatory-like features due to the influence of the individual nanostructures. Further details about the effect of the nanoparticles size are also discussed.

Phan, Anh D., E-mail: anhphan@mail.usf.edu [Department of Physics, University of South Florida, Tampa, Florida 33620 (United States); Institute of Physics, Vietnam Academy of Science and Technology, 10 Dao Tan, Ba Dinh, Hanoi 10000 (Viet Nam); Phan, The-Long, E-mail: ptlong2512@yahoo.com [Department of Physics, Chungbuk National University, Cheongju 361-763 (Korea, Republic of); Woods, Lilia M. [Department of Physics, University of South Florida, Tampa, Florida 33620 (United States)

2013-12-07T23:59:59.000Z

437

Efficient Phase-Change Materials: Development of a Low-Cost Thermal Energy Storage System Using Phase-Change Materials with Enhanced Radiation Heat Transfer  

SciTech Connect

HEATS Project: USF is developing low-cost, high-temperature phase-change materials (PCMs) for use in thermal energy storage systems. 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 nightwhen the sun is not outto 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. Most PCMs do not conduct heat very well. Using an innovative, electroless encapsulation technique, USF is enhancing the heat transfer capability of its PCMs. The inner walls of the capsules will be lined with a corrosion-resistant, high-infrared emissivity coating, and the absorptivity of the PCM will be controlled with the addition of nano-sized particles. USFs PCMs remain stable at temperatures from 600 to 1,000C and can be used for solar thermal power storage, nuclear thermal power storage, and other applications.

None

2011-12-05T23:59:59.000Z

438

THE PHOTOSPHERIC RADIATION MODEL FOR THE PROMPT EMISSION OF GAMMA-RAY BURSTS: INTERPRETING FOUR OBSERVED CORRELATIONS  

SciTech Connect

We show that the empirical E{sub p}-L, {Gamma}-L, E{sub p}-{Gamma}, and {eta}-bar{sub {gamma}}-E{sub p} correlations (where L is the time-averaged luminosity of the prompt emission, E{sub p} is the spectral peak energy, {Gamma} is the bulk Lorentz factor, and {eta}-bar{sub {gamma}} is the emission efficiency of gamma-ray bursts, GRBs) are well consistent with the relations between the analogous parameters predicted in the photospheric radiation model of the prompt emission of GRBs. The time-resolved thermal radiation of GRB 090902B does follow the E{sub p}-L and {Gamma}-L correlations. A reliable interpretation of the four correlations in alternative models is still lacking. These may point toward a photospheric origin of prompt emission of some GRBs.

Fan Yizhong; Wei Daming; Zhang Fuwen [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China); Zhang Binbin, E-mail: yzfan@pmo.ac.cn, E-mail: dmwei@pmo.ac.cn, E-mail: fwzhang@pmo.ac.cn, E-mail: bbzhang@psu.edu [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States)

2012-08-10T23:59:59.000Z

439

Skill of Direct Solar Radiation Predicted by the ECMWF Global Atmospheric Model over Australia  

Science Journals Connector (OSTI)

Prediction of direct solar radiation is key in sectors such as solar power and agriculture; for instance, it can enable more efficient production of energy from concentrating solar power plants. An assessment of the quality of the direct solar ...

Alberto Troccoli; Jean-Jacques Morcrette

2014-11-01T23:59:59.000Z

440

Space radiation-induced bystander signaling in 2D and 3D skin tissue models  

E-Print Network (OSTI)

Space radiation poses a significant hazard to astronauts on long-duration missions, and the low fluences of charged particles characteristic of this field suggest that bystander effects, the phenomenon in which a greater ...

Lumpkins, Sarah B

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "radiation transfer models" 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

AndreiG.Fedorov Title: George W. Woodruff Professorship in Heat Transfer, Combustion and  

E-Print Network (OSTI)

AndreiG.Fedorov Title: George W. Woodruff Professorship in Heat Transfer, Combustion and Energy Research Areas of Interest Heat Transfer, combustion, and energy systems Bioengineering, lab ionization and imaging for bioanalytical mass spectrometry Thermal radiation heat transfer Thermal

Garmestani, Hamid

442

A combined heat-transfer analysis of a single-fiber CVD reactor  

SciTech Connect

In high-temperature applications, structural fibers such as SiC are currently being considered for reinforcement of both ceramic and intermetallic matrices. A combined-conjugated heat-transfer and fluid-flow analysis is presented for coating fibers by CVD in a vertical cylindrical quartz reactor. The numerical model focuses on radiation and natural convection. Three case studies are performed, and the wall temperature predictions are compared to experimental measurements. In the first case, the flowing gas is hydrogen, and conduction is more important than both radiation and convection, in which case measured and predicted wall temperatures agree excellently. In the second, hydrogen is replaced by argon, thus making radiation heat transfer more important than the previous situation. Three radiation models with increasing degrees of sophistication are compared: an approximate nongray model (no wavelength dependence of emissivity), an approximate semigray model, and a rigorous semigray model with view factor calculations. Comparison with experiments suggest that a semigray radiative analysis is needed for correct determination of wall temperatures. The third involves argon at a lower flow rate, where natural convection effects are more pronounced. Checking the validity of the Boussinesq approximation by incorporating the explicit dependence of density on temperature in the model shows a slight difference between the velocity fields predicted using the Boussinesq approximation and those obtained using the explicit dependence of density on temperature. However, there is negligible difference between the temperature fields predicted in the two cases.

Kassemi, M.; Gokoglu, S.A.; Panzarella, C.H.; Veitch, L.C. (NASA Lewis Research Center, Cleveland, OH (United States))

1993-10-01T23:59:59.000Z

443

Radiation Sources and Radioactive Materials (Connecticut)  

Energy.gov (U.S. Department of Energy (DOE))

These regulations apply to persons who receive, transfer, possess, manufacture, use, store, handle, transport or dispose of radioactive materials and/or sources of ionizing radiation. Some...

444

DART-RAY: a 3D ray-tracing radiative transfer code for calculating the propagation of light in dusty galaxies  

Science Journals Connector (OSTI)

......non-local in space (photons propagate...distances from the stars heating the dust. Table...an HEALPix main sector (see Fig.-4...zero Dust self-heating The dust absorption...this model is the construction of an efficient...before, dust self-heating needs to be included......

G. Natale; C. C. Popescu; R. J. Tuffs; D. Semionov

2014-01-01T23:59:59.000Z

445

Curcumin Regulates Low-Linear Energy Transfer {gamma}-Radiation-Induced NF{kappa}B-Dependent Telomerase Activity in Human Neuroblastoma Cells  

SciTech Connect

Purpose: We recently reported that curcumin attenuates ionizing radiation (IR)-induced survival signaling and proliferation in human neuroblastoma cells. Also, in the endothelial system, we have demonstrated that NF{kappa}B regulates IR-induced telomerase activity (TA). Accordingly, we investigated the effect of curcumin in inhibiting IR-induced NF{kappa}B-dependent hTERT transcription, TA, and cell survival in neuroblastoma cells. Methods and Materials: SK-N-MC or SH-SY5Y cells exposed to IR and treated with curcumin (10-100 nM) with or without IR were harvested after 1 h through 24 h. NF{kappa}B-dependent regulation was investigated either by luciferase reporter assays using pNF{kappa}B-, pGL3-354-, pGL3-347-, or pUSE-I{kappa}B{alpha}-Luc, p50/p65, or RelA siRNA-transfected cells. NF{kappa}B activity was analyzed using an electrophoretic mobility shift assay and hTERT expression using the quantitative polymerase chain reaction. TA was determined using the telomerase repeat amplification protocol assay and cell survival using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltertrazolium bromide and clonogenic assay. Results: Curcumin profoundly inhibited IR-induced NF{kappa}B. Consequently, curcumin significantly inhibited IR-induced TA and hTERT mRNA at all points investigated. Furthermore, IR-induced TA is regulated at the transcriptional level by triggering telomerase reverse transcriptase (TERT) promoter activation. Moreover, NF{kappa}B becomes functionally activated after IR and mediates TA upregulation by binding to the {kappa}B-binding region in the promoter region of the TERT gene. Consistently, elimination of the NF{kappa}B-recognition site on the telomerase promoter or inhibition of NF{kappa}B by the I{kappa}B{alpha} mutant compromises IR-induced telomerase promoter activation. Significantly, curcumin inhibited IR-induced TERT transcription. Consequently, curcumin inhibited hTERT mRNA and TA in NF{kappa}B overexpressed cells. Furthermore, curcumin enhanced the IR-induced inhibition of cell survival. Conclusions: These results strongly suggest that curcumin inhibits IR-induced TA in an NF{kappa}B dependent manner in human neuroblastoma cells.

Aravindan, Natarajan, E-mail: naravind@ouhsc.ed [Department of Radiation Oncology, University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States); Veeraraghavan, Jamunarani; Madhusoodhanan, Rakhesh; Herman, Terence S. [Department of Radiation Oncology, University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States); Natarajan, Mohan [Department of Otolaryngology, Head and Neck Surgery, University of Texas Health Sciences Center at San Antonio, San Antonio, TX (United States)

2011-03-15T23:59:59.000Z

446

Modeling boundary measurements of scattered light using the corrected  

E-Print Network (OSTI)

to numerical solutions of the radiative transport equation. © 2012 Optical Society of America OCIS codes: (170Adams and B. J. Tromberg, "Boundary conditions for the diffusion equation in radiative transfer," J. Opt. Soc element method to solve the diffusion equation. We show that this corrected diffusion approximation models

Kim, Arnold D.

447

A revised model of the kidney for medical internal radiation dose calculations  

E-Print Network (OSTI)

are frequently the organs receiving the highest level of radioactivity and, therefore, the largest radiation dose. Short lived radiopharmaceuticals, that are now injected in millicurie quantities in nuclear medicine for rapid-sequence imaging of the brain... radionuclides (Appendix B). 17 These include the following radionuclides presently used in nuclear medicine: P-32, Cr-51, Co-57, Ga-67, Tc-99m, In-ill, I-123, Xe-127, I-131, Xe-133, and T1-201. If the radionuclide emits penetrating radiation, the code...

Patel, Jyoti Shivabhai

1988-01-01T23:59:59.000Z

448

Performance model and annual yield comparison of parabolic-trough solar thermal power plants with either nitrogen or synthetic oil as heat transfer fluid  

Science Journals Connector (OSTI)

Abstract The majority of commercial parabolic-trough plants in the world operate with synthetic oil as heat transfer fluid in the solar field. However, the synthetic oils that are available at affordable cost present some challenges such as their flammability, environmental toxicity and a temperature limitation of around 400C. As alternative, this work proposes the use of pressurized nitrogen as heat transfer fluid. In order to analyze the feasibility of this technology, a comparison between a plant with nitrogen and a conventional plant with synthetic oil has been carried out. In both cases, 50MWe parabolic-trough plants with 6h of thermal storage are used as reference. A performance model including the solar field, the thermal storage system and the power block has been developed for each plant in the TRNSYS simulation software. This paper also describes the specifications, design and sizing of the solar field and explains the basic operation strategy applied in each model. Both annual simulations have been performed considering the same location, Almera (Spain), and meteorological data. In summary, the results show that similar net annual electricity productions can be attained for parabolic-trough plants with the same collection area using either nitrogen or synthetic oil as heat transfer fluid.

Mario Biencinto; Lourdes Gonzlez; Eduardo Zarza; Luis E. Dez; Javier Muoz-Antn

2014-01-01T23:59:59.000Z

449

Optimization in the Parikh-Wilczek tunneling model of Hawking radiation for Kerr-Newman Black Holes  

E-Print Network (OSTI)

In this short report, we investigate the mutual information hidden in the Parikh-Wilczek tunneling model of Hawking radiation for Kerr-Newman black holes. By assuming the radiation as an optimization process, we discuss its effect on time evolution of rotating (charged and uncharged) black holes. For uncharged rotating black holes evaporating under the maximum mutual information optimization, their scale invariant rotation parameter $a_*=a/M$ is almost constant at the early stage but rapidly increase at the very last stage of the evaluation process. The value of rotation parameter at the final state of evaporation depends on the initial condition of the black hole. We also found that the presence of electric charge can cause the black holes lose their angular momentum more rapidly than they lose mass. The charged-rotating black holes asymptotically approach a state which is described by $a_*= 0$ and $Q/M = 1$.

Auttakit Chatrabhuti; Khem Upathambhakul

2014-03-17T23:59:59.000Z

450

Frster Resonance Energy Transfer Measurements Are Consistent with a Helical Bundle Model for Lipid-Free Apolipoprotein A-I  

Science Journals Connector (OSTI)

The molten globule will not exhibit this level of cooperativity since it is an ensemble of structures with different energies and different amounts of residual structure, even though they may share a common structural feature (37). ... In these two reports, multiple constructs containing a single acrylodan at different locations were used to measure energy transfer from the constellation of five tryptophans within the protein. ...

Christie G. Brouillette; Wen-Ji Dong; Zhengrong W. Yang; Marjorie J. Ray; Irina I. Protasevich; Herbert C. Cheung; Jeffrey A. Engler

2005-11-19T23:59:59.000Z

451

Evaluation of cloud fraction and its radiative effect simulated by IPCC AR4 global models against ARM surface observations  

SciTech Connect

Cloud Fraction (CF) is the dominant modulator of radiative fluxes. In this study, we evaluate CF simulations in the IPCC AR4 GCMs against ARM ground measurements, with a focus on the vertical structure, total amount of cloud and its effect on cloud shortwave transmissivity, for both inter-model deviation and model-measurement discrepancy. Our intercomparisons of three CF or sky-cover related dataset reveal that the relative differences are usually less than 10% (5%) for multi-year monthly (annual) mean values, while daily differences are quite significant. The results also show that the model-observation and the inter-model deviations have a similar magnitude for the total CF (TCF) and the normalized cloud effect, and they are twice as large as the surface downward solar radiation and cloud transmissivity. This implies that the other cloud properties, such as cloud optical depth and height, have a similar magnitude of disparity to TCF among the GCMs, and suggests that a better agreement among the GCMs in solar radiative fluxes could be the result of compensating errors in either cloud vertical structure, cloud optical depth or cloud fraction. Similar deviation pattern between inter-model and model-measurement suggests that the climate models tend to generate larger bias against observations for those variables with larger inter-model deviation. The simulated TCF from IPCC AR4 GCMs are very scattered through all seasons over three ARM sites: Southern Great Plains (SGP), Manus, Papua New Guinea and North Slope of Alaska (NSA). The GCMs perform better at SGP than at Manus and NSA in simulating the seasonal variation and probability distribution of TCF; however, the TCF in these models is remarkably underpredicted and cloud transmissivity is less susceptible to the change of TCF than the observed at SGP. Much larger inter-model deviation and model bias are found over NSA than the other sites in estimating the TCF, cloud transmissivity and cloud-radiation interaction, suggesting that the Arctic region continues to challenge cloud simulations in climate models. Most of the GCMs tend to underpredict CF and fail to capture the seasonal variation of CF at middle and low levels in the tropics. The high altitude CF is much larger in the GCMs than the observation and the inter-model variability of CF also reaches maximum at high levels in the tropics. Most of the GCMs tend to underpredict CF by 50-150% relative to the measurement average at low and middle levels over SGP. While the GCMs generally capture the maximum CF in the boundary layer and vertical variability, the inter-model deviation is largest near surface over the Arctic. The internal variability of CF simulated in ensemble runs with the same model is very minimal.

Qian, Yun; Long, Charles N.; Wang, Hailong; Comstock, Jennifer M.; McFarlane, Sally A.; Xie, Shaocheng

2012-02-17T23:59:59.000Z

452

Exploring the Limits of Boiling and Evaporative Heat Transfer Using Micro/Nano Structures  

E-Print Network (OSTI)

Comparison of various heat transfer coefficient models inpool boiling In summary, high heat transfer coefficientin boiling heat transfer can be generally explained by the

Lu, Ming-Chang

2010-01-01T23:59:59.000Z

453

BNL Photo- and Radiation Chemistry Group Members  

NLE Websites -- All DOE Office Websites (Extended Search)

and Radiation Chemistry Group and Radiation Chemistry Group Chemistry Department, Brookhaven National Laboratory Staff Diane E. Cabelli Redox chemistry of high oxidation state transition-metal complexes, particularly CuIII, MnIII/MnIV; Superoxide chemistry in aqueous solutions: dismutation of superoxide radical; copper-zinc superoxide dismutase and model compounds. Andrew R. Cook Excited state structure, dynamics and electron transfer reactions of a variety of organic radicals in both low temperature matrices and room temperature solutions using radiation chemistry techniques. Robert A. Crowell Ultrafast reaction phenomena. Etsuko Fujita Photochemistry of transition-metal complexes, small molecule activation by high- and low-oxidation state metal complexes; and biomimetic chemistry of porphyrins and enzymes.

454

Radiative Heating in Underexplored Bands Campaign (RHUBC)  

NLE Websites -- All DOE Office Websites (Extended Search)

Bands Campaign (RHUBC) D. Turner and E. Mlawer RHUBC Breakout Session 2008 ARM Science Team Meeting 13 March, 2008 Norfolk, Virginia Motivation * Radiative heating/cooling in the mid-troposphere modulate the vertical motions of the atmosphere - This heating/cooling occurs primarily in water vapor absorption bands that are opaque at the surface * Approximately 40% of the OLR comes from the far-IR * Until recently, the observational tools were not available to evaluate the accuracy of the far-IR radiative transfer models - Spectrally resolved far-IR radiances, accurate PWV * Need to validate both clear sky (WV) absorption and cirrus scattering properties in these normally opaque bands Scientific Objectives * Conduct clear sky radiative closure studies in order to reduce uncertainties

455

Vertical structure and turbulent saturation level in fully radiative protoplanetary disc models  

Science Journals Connector (OSTI)

......Unlike, for example, the solar butterfly diagram, the field reversals shown in Fig. 2...OUTLOOK We have performed 3D radiative MHD simulations of MRI-turbulent protoplanetary...sufficient to justify the assumption of ideal MHD. The logical next step will be to include......

M. Flaig; W. Kley; R. Kissmann

2010-12-21T23:59:59.000Z

456

Evaluating the present-day simulation of clouds, precipitation, and radiation in climate models  

E-Print Network (OSTI)

] This paper describes a set of metrics for evaluating the simulation of clouds, radiation, and precipitation in the present-day climate. As with the skill scores used to measure the accuracy of short-term weather forecasts, these metrics are low-order statistical measures of agreement with relevant, well-observed physical quantities

Robert, Pincus

457

Technology Transfer  

NLE Websites -- All DOE Office Websites (Extended Search)

Energy Efficiency & Renewable and Energy - Commercialization Energy Efficiency & Renewable and Energy - Commercialization Deployment SBIR/STTR - Small Business Innovation Research and Small Business Technology Transfer USEFUL LINKS Contract Opportunities: FBO.gov FedConnect.net Grant Opportunities DOE Organization Chart Association of University Technology Managers (AUTM) Federal Laboratory Consortium (FLC) Feedback Contact us about Tech Transfer: Mary.McManmon@science.doe.gov Mary McManmon, 202-586-3509 link to Adobe PDF Reader link to Adobe Flash player Licensing Guide and Sample License The Technology Transfer Working Group (TTWG), made up of representatives from each DOE Laboratory and Facility, recently created a Licensing Guide and Sample License [762-KB PDF]. The Guide will serve to provide a general understanding of typical contract terms and provisions to help reduce both

458

Posters Radiation Singularities, Multiple Scattering  

NLE Websites -- All DOE Office Websites (Extended Search)

mean C 1 0.75 and Levy index 1.35 (as empirically observed) and apply to it the Radiative Transfer Equation in the perfect scattering case. We have analytical and numerical...

459

Changing the Climate Sensitivity of an Atmospheric General Circulation Model through Cloud Radiative Adjustment  

E-Print Network (OSTI)

Conducting probabilistic climate projections with a particular climate model requires the ability to vary the models characteristics, such as its climate sensitivity. In this study, the authors implement and validate a ...

Sokolov, Andrei P.

460

Workshop on electronic and ionic collision cross sections needed in the modeling of radiation interactions with matter: proceedings  

SciTech Connect

The term modeling in the Workship title refers to the mathematical analysis of the consequences of many collision processes for characterizing the physical stage of radiation actions. It requires as input some knowledge of collision cross sections. Traditionally, work on cross sections and work on the modeling are conducted by separate groups of scientists. It was the purpose of the Workshop to bring these two groups together in a forum that would promote effective communication. Cross-section workers described the status of their work and told what data were available or trustworthy. Modeling workers told what kind of data were needed or were most important. Twenty-two items from the workshop were prepared separately for the data base.

Not Available

1984-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "radiation transfer models" 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

Millimeter radiation from a 3D model of the solar atmosphere I. Diagnosing chromospheric thermal structure  

E-Print Network (OSTI)

Aims. We use advanced 3D NLTE radiative magnetohydrodynamic simulations of the solar atmosphere to carry out detailed tests of chromospheric diagnostics at millimeter and submillimeter wavelengths. Methods. We focused on the diagnostics of the thermal structure of the chromosphere in the wavelength bands from 0.4 mm up to 9.6 mm that can be accessed with the Atacama Large Millimeter/Submillimeter Array (ALMA) and investigated how these diagnostics are affected by the instrumental resolution. Results. We find that the formation height range of the millimeter radiation depends on the location in the simulation domain and is related to the underlying magnetic structure. Nonetheless, the brightness temperature is a reasonable measure of the gas temperature at the effective formation height at a given location on the solar surface. There is considerable scatter in this relationship, but this is significantly reduced when very weak magnetic fields are avoided. Our results indicate that although instrumental smearin...

Loukitcheva, Maria; Carlsson, Mats; White, Stephen

2015-01-01T23:59:59.000Z

462

Linear Kinetic Heat Transfer: Moment Equations, Boundary Conditions, and Knudsen  

E-Print Network (OSTI)

] and phonons [6], and the radiative transfer equation [7]. The solution of any kinetic equation is usually][25], radiative transfer [7][26], and phonon transport in crystals [6]. Despite the long history, and success method, and the methods employed in [18][19][20], are based solely on the transport equations in the bulk, and

Struchtrup, Henning

463

Simultaneous Spectral Albedo Measurements Near the Atmospheric Radiation Measurement Southern Great Plains (ARM SGP) Central Facility  

SciTech Connect

In this study, a data analysis is performed to determine the area-averaged, spectral albedo at ARM's SGP central facility site. The spectral albedo is then fed into radiation transfer models to show that the diffuse discrepancy is diminished when the spectral albedo is used (as opposed to using the broadband albedo).

Michalsky, Joseph J.; Min, Qilong; Barnard, James C.; Marchand, Roger T.; Pilewskie, Peter

2003-04-30T23:59:59.000Z

464

Pump radiation distribution in multi-element first cladding laser fibres  

SciTech Connect

Pump radiation transfer is studied experimentally in multi-element first cladding laser fibres. A model of this process is proposed, which is in good agreement with experimental results. An all-fibre single-mode cw ytterbium laser based on a three-element first cladding fibre with an output power of 100W is fabricated. (lasers)

Mel'kumov, Mikhail A; Bufetov, Igor' A; Bubnov, M M; Shubin, Aleksei V; Semenov, S L; Dianov, Evgenii M [Fiber Optics Research Center, Russian Academy of Sciences, Moscow (Russian Federation)

2005-11-30T23:59:59.000Z

465

Coherence Transfer in Magnetic Fields  

Science Journals Connector (OSTI)

Some results recently discussed by Chiu for interatomic coherence transfer are shown to have a simple physical interpretation, to be independent of collision model assumed, and to be applicable also to intra -atomic coherence transfer. A derivation using density matrices is presented which takes both depolarizing collisions and backtransfer of coherence into account.

W. E. Baylis

1973-03-01T23:59:59.000Z

466

Technology Transfer: Available Technologies  

NLE Websites -- All DOE Office Websites (Extended Search)

Software and Information Technologies Software and Information Technologies Algorithm for Correcting Detector Nonlinearites Chatelet: More Accurate Modeling for Oil, Gas or Geothermal Well Production Collective Memory Transfers for Multi-Core Processors Energy Efficiency Software EnergyPlus:Energy Simulation Software for Buildings Tools, Guides and Software to Support the Design and Operation of Energy Efficient Buildings Flexible Bandwidth Reservations for Data Transfer Genomic and Proteomic Software LABELIT - Software for Macromolecular Diffraction Data Processing PHENIX - Software for Computational Crystallography Vista/AVID: Visualization and Allignment Software for Comparative Genomics Geophysical Software Accurate Identification, Imaging, and Monitoring of Fluid Saturated Underground Reservoirs

467

E-Print Network 3.0 - advanced space radiators Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

to investigate radiation variations across land cover discontinuities, to advance... radiative transfer properties Timothy E. Link,1 * Danny Marks2 and Janet P. Hardy3 1...

468

Charge transfer effects in surface?enhanced Raman scatteringa)  

Science Journals Connector (OSTI)

Surface?enhanced Raman scattering(SERS) due to charge?transferinteractions between the adsorbed molecule and the metal surface is analyzed using the semiempirical WolfsbergHelmholz method to relate the moleculesurface interactions and the resulting charge?transfer states to the overlap integrals between the metal conduction?band orbitals and an acceptor or donor molecular orbital of the molecule. Calculations for the model system of ethylene adsorbed on silver with charge?transfer excitation of an electron from the metal to the antibonding etylene ? orbital show that charge?transfer Raman enhancements of the order of 10 to 1000 are possible if the charge?transfer band is partially resonant with the exciting radiation. Symmetric vibrations usually will be enhanced substantially more than nonsymmetric ones by this mechanism because the vibrational coupling is primarily FranckCondon rather than HerzbergTeller. The presence of overtone and combination bands in charge?transfer?enhanced Raman spectra is also possible.

Frank J. Adrian

1982-01-01T23:59:59.000Z

469

Electron Transfer  

NLE Websites -- All DOE Office Websites (Extended Search)

3 3 Pierre Kennepohl1,2 and Edward Solomon1* 1Department of Chemistry, Stanford University, Stanford, CA 94305 Electron transfer, or the act of moving an electron from one place to another, is amongst the simplest of chemical processes, yet certainly one of the most critical. The process of efficiently and controllably moving electrons around is one of the primary regulation mechanisms in biology. Without stringent control of electrons in living organisms, life could simply not exist. For example, photosynthesis and nitrogen fixation (to name but two of the most well-known biochemical activities) are driven by electron transfer processes. It is unsurprising, therefore, that much effort has been placed on understanding the fundamental principles that control and define the simple act of adding and/or removing electrons from chemical species.

470

TECHNOLOGY TRANSFER  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

404-NOV. 1, 2000 404-NOV. 1, 2000 TECHNOLOGY TRANSFER COMMERCIALIZATION ACT OF 2000 VerDate 11-MAY-2000 04:52 Nov 16, 2000 Jkt 089139 PO 00000 Frm 00001 Fmt 6579 Sfmt 6579 E:\PUBLAW\PUBL404.106 APPS27 PsN: PUBL404 114 STAT. 1742 PUBLIC LAW 106-404-NOV. 1, 2000 Public Law 106-404 106th Congress An Act To improve the ability of Federal agencies to license federally owned inventions. Be it enacted by the Senate and House of Representatives of the United States of America in Congress assembled, SECTION 1. SHORT TITLE. This Act may be cited as the ''Technology Transfer Commer- cialization Act of 2000''. SEC. 2. FINDINGS. The Congress finds that- (1) the importance of linking our unparalleled network of over 700 Federal laboratories and our Nation's universities with United States industry continues to hold great promise

471

Dichotomy of hot electron relaxation and delocalized polarons for optimal energy transfer in a model organic donor-acceptor interface  

E-Print Network (OSTI)

Charge separation at donor-acceptor interfaces is a complex process that can be strongly limited by the combined action of phonon-induced relaxation and Coulomb potential binding for an electron/hole pair. We propose a fully quantum microscopic approach to this problem, and show that molecular vibrations modulate the trapping probability in a non-monotonous fashion as a function of injection energy, due to polaron formation. This mechanism should control sensitively the efficiency of energy transfer in photovoltaic organic molecules, and bridge the gap between several current conflicting theories.

Bera, Soumya; Fratini, Simone; Ciuchi, Sergio; Florens, Serge

2014-01-01T23:59:59.000Z

472

The Effect of g-Jitter on Heat Transfer  

Science Journals Connector (OSTI)

...research-article The Effect of g-Jitter on Heat Transfer Norsarahaida Amin In a gravity-free...in the absence of radiation, heat transfer in a fluid medium is effected...investigation is centred upon the heat transfer from a sphere, maintained at...

1988-01-01T23:59:59.000Z

473

LANL* V1.0: a radiation belt drift shell model suitable for real-time and reanalysis applications  

SciTech Connect

Space weather modeling, forecasts, and predictions, especially for the radiation belts in the inner magnetosphere, require detailed information about the Earth's magnetic field. Results depend on the magnetic field model and the L* (pron. L-star) values which are used to describe particle drift shells. Space wather models require integrating particle motions along trajectories that encircle the Earth. Numerical integration typically takes on the order of 10{sup 5} calls to a magnetic field model which makes the L* calculations very slow, in particular when using a dynamic and more accurate magnetic field model. Researchers currently tend to pick simplistic models over more accurate ones but also risking large inaccuracies and even wrong conclusions. For example, magnetic field models affect the calculation of electron phase space density by applying adiabatic invariants including the drift shell value L*. We present here a new method using a surrogate model based on a neural network technique to replac