Phung, Kim-dang.- Le Laboratoire de MathÃ©matiques
I: Heat equation II: SchrÃ¶dinger equation III: Wave equation IV: Radiative transfer equation;I: Heat equation II: SchrÃ¶dinger equation III: Wave equation IV: Radiative transfer equation QUCP: Heat equation II: SchrÃ¶dinger equation III: Wave equation IV: Radiative transfer equation QUCP
Test plan for validation of the radiative transfer equation.
Ricks, Allen Joseph; Grasser, Thomas W.; Kearney, Sean Patrick; Jernigan, Dann A.; Blanchat, Thomas K.
2010-09-01T23:59:59.000Z
As the capabilities of numerical simulations increase, decision makers are increasingly relying upon simulations rather than experiments to assess risks across a wide variety of accident scenarios including fires. There are still, however, many aspects of fires that are either not well understood or are difficult to treat from first principles due to the computational expense. For a simulation to be truly predictive and to provide decision makers with information which can be reliably used for risk assessment the remaining physical processes must be studied and suitable models developed for the effects of the physics. A set of experiments are outlined in this report which will provide soot volume fraction/temperature data and heat flux (intensity) data for the validation of models for the radiative transfer equation. In addition, a complete set of boundary condition measurements will be taken to allow full fire predictions for validation of the entire fire model. The experiments will be performed with a lightly-sooting liquid hydrocarbon fuel fire in the fully turbulent scale range (2 m diameter).
He, Xing; Lee, Euntaek; Wilcox, Lucas; Munipalli, Ramakanth; Pilon, Laurent
2013-01-01T23:59:59.000Z
and M. P. Meng¨ u¸c, “Radiation heat transfer in combustionThermal radiation is a dominant mode of heat transfer inand radiation in the Atlas plume”, AIAA J. Thermophys. Heat Transfer,
He, Xing; Lee, Euntaek; Wilcox, Lucas; Munipalli, Ramakanth; Pilon, Laurent
2013-01-01T23:59:59.000Z
of radiative transfer in combustion systems”, Int. J. Numer.c, “Radiation heat transfer in combustion systems”, Progressin Energy and Combustion Science, vol. 13, no. 2, pp. 97–
Henri PoincarÃ© -Nancy-UniversitÃ©, UniversitÃ©
. Introduction And Main Results Radiative heat transfer coupled with conduction through semi---transparent media---state combined radiative---conductive heat transfer. The media studied were assumed to be homogeneous, grey1 CONVERGENCE OF A NUMERICAL SCHEME FOR A NONLINEAR COUPLED SYSTEM OF RADIATIVE---CONDUCTIVE HEAT
Minimum entropy production closure of the photo-hydrodynamic equations for radiative heat transfer
Thomas Christen; Frank Kassubek
2008-12-17T23:59:59.000Z
In the framework of a two-moment photo-hydrodynamic modelling of radiation transport, we introduce a concept for the determination of effective radiation transport coefficients based on the minimization of the local entropy production rate of radiation and matter. The method provides the nonequilibrium photon distribution from which the effective absorption coefficients and the variable Eddington factor (VEF) can be calculated. The photon distribution depends on the frequency dependence of the absorption coefficient, in contrast to the distribution obtained by methods based on entropy maximization. The calculated mean absorption coefficients are not only correct in the limit of optically thick and thin media, but even provide a reasonable interpolation in the cross-over regime between these limits, notably without introducing any fit parameter. The method is illustrated and discussed for grey matter and for a simple example of non-grey matter with a two-band absorption spectrum. The method is also briefly compared with the maximum entropy concept.
Semi-Analytic Solutions to the Radiative Transfer Equations via Heterogeneous Computing
Holladay, Daniel Alphin
2014-12-10T23:59:59.000Z
to compute reaction rates for many different thermonuclear processes such as inertial confinement fusion. There are several large scale computer codes such as xRage developed at Los Alamos National Laboratory (LANL), KULL developed at Lawrence Livermore Na... spherical radiation source with A = 0.75. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 vii 1. INTRODUCTION If fusion energy is to be harnessed on earth, a thorough understanding of the regime called high energy density physics must...
Semi-Analytic Solutions to the Radiative Transfer Equations via Heterogeneous Computing
Holladay, Daniel Alphin
2014-12-10T23:59:59.000Z
to compute reaction rates for many different thermonuclear processes such as inertial confinement fusion. There are several large scale computer codes such as xRage developed at Los Alamos National Laboratory (LANL), KULL developed at Lawrence Livermore Na... spherical radiation source with A = 0.75. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 vii 1. INTRODUCTION If fusion energy is to be harnessed on earth, a thorough understanding of the regime called high energy density physics must...
Author's personal copy Radiative heat transfer in enhanced hydrogen
Pilon, Laurent
Author's personal copy Radiative heat transfer in enhanced hydrogen outgassing of glass Rei radiation. Combined conduction, radiation, and mass transfer were accounted for by solving the one-dimensional transient mass and energy conservation equations along with the steady-state radiative transfer equation
Radiative transfer in decomposed domains
T. Heinemann; W. Dobler; A. Nordlund; A. Brandenburg
2005-11-09T23:59:59.000Z
An efficient algorithm for calculating radiative transfer on massively parallel computers using domain decomposition is presented. The integral formulation of the transfer equation is used to divide the problem into a local but compute-intensive part for calculating the intensity and optical depth integrals, and a nonlocal part for communicating the intensity between adjacent processors. The waiting time of idle processors during the nonlocal communication part does not have a severe impact on the scaling. The wall clock time thus scales nearly linearly with the inverse number of processors.
Three Dimensional Radiative Transfer
Tom Abel
2000-05-09T23:59:59.000Z
Radiative Transfer (RT) effects play a crucial role in the thermal history of the intergalactic medium. Here I discuss recent advances in the development of numerical methods that introduce RT to cosmological hydrodynamics. These methods can also readily be applied to time dependent problems on interstellar and galactic scales.
Rabindra Nath Das
2007-01-16T23:59:59.000Z
The linear non homogeneous singular integral equation (LNSIE)derived from the nonlinear non homogeneous integral eauation (NNIE)of Chandrsasekhar's H- functions is considered here to develop a new form of H - functions.The Plemelj's formulae are applied to that equation to determine a new linear non homogeneous integral equation(LNIE)for H- functions in complex plane . The analytic properties of this new linear integral equation are assessed and compared with known linear integral equations satisfied by H- functions. The Cauchy integral formulae in complex plane are used to obtain this form of H- functions not dependent on H- function in the integral . This new form of H-function is represented as a simple integral in terms of known functions both for conservative and non conservative cases. This is identical with the form of H- functions derived by this author by application of Wiener HOpf technique. The equivalence of application of the theory of linear singular integral equation in Riemann Hilbert Problem and of the technique of Wiener- Hopf in linear integral in representing the H- functions is therefore eatablished .This new form may be used for solving the problems of radiative transfer in anisotropic and non coherent scattering by the method of Laplace Transform and Wiener -Hopf technique.
General Relativistic Radiative Transfer
S. Knop; P. H. Hauschildt; E. Baron
2006-11-30T23:59:59.000Z
We present a general method to calculate radiative transfer including scattering in the continuum as well as in lines in spherically symmetric systems that are influenced by the effects of general relativity (GR). We utilize a comoving wavelength ansatz that allows to resolve spectral lines throughout the atmosphere. The used numerical solution is an operator splitting (OS) technique that uses a characteristic formal solution. The bending of photon paths and the wavelength shifts due to the effects of GR are fully taken into account, as is the treatment of image generation in a curved spacetime. We describe the algorithm we use and demonstrate the effects of GR on the radiative transport of a two level atom line in a neutron star like atmosphere for various combinations of continuous and line scattering coefficients. In addition, we present grey continuum models and discuss the effects of different scattering albedos on the emergent spectra and the determination of effective temperatures and radii of neutron star atmospheres.
Rabindra Nath Das
2007-02-22T23:59:59.000Z
In Radiative transfer, the intensities of radiation from the bounding faces of finite slab are obtained in terms of X- and Y- functions of Chandrasekhar . Those are non linear non homogeneous coupled integral equations . Those non linear integral equations are meromorphically extended to the complex plane to get linear non homogeneous coupled integral equations. Those linear integral equations are converted to linear singular integral equations with. linear constraints . Those singular integral equations are then transformed to non homogeneous Riemann Hilbert Problems. Solutions of those Riemann Hilbert Problems are obtained using the theory of linear singular integral equations to decouple those X- and Y- functions. New forms of linear non homogeneous decoupled integral equations are derived for X- and Y- function separately with new linear constraints. Those new decoupled integral equations are transformed into linear singular integral equations to get two new separate non homogeneous Riemann Hilbert problems and to find solutions in terms of one known N- function and five new unknown functions in complex plane . All five functions are represented in terms of N-functions using the theory of contour integration >. Those X- and Y- functions are finally expressed in terms of that N - function and also in terms of H- functions of Chandrasekhar and of integrals in Cauchy principal value sense in the complex plane and real plane. both for conservative and non conservative cases . The H - functions for semi infinite atmosphere are derived as a limiting case from the expression of X- function of finite atmosphere.
Radiative Heat Transfer in Enhanced Hydrogen Outgassing of Glass
Kitamura, Rei; Pilon, Laurent
2009-01-01T23:59:59.000Z
and J.R. Howell, Thermal radiation heat transfer, Hemispheremade: 1. The heat, mass, and radiation transfer are treatedOne- dimensional heat, mass, and radiation transfers were
Radiative transfer in molecular lines
A. Asensio Ramos; J. Trujillo Bueno; J. Cernicharo
2001-02-15T23:59:59.000Z
The highly convergent iterative methods developed by Trujillo Bueno and Fabiani Bendicho (1995) for radiative transfer (RT) applications are generalized to spherical symmetry with velocity fields. These RT methods are based on Jacobi, Gauss-Seidel (GS), and SOR iteration and they form the basis of a new NLTE multilevel transfer code for atomic and molecular lines. The benchmark tests carried out so far are presented and discussed. The main aim is to develop a number of powerful RT tools for the theoretical interpretation of molecular spectra.
Three-dimensional Radiative Transfer with Multilevel Atoms
P. Fabiani Bendicho; J. Trujillo Bueno
2007-10-29T23:59:59.000Z
The efficient numerical solution of Non-LTE multilevel transfer problems requires the combination of highly convergent iterative schemes with fast and accurate formal solution methods of the radiative transfer (RT) equation. This contribution begins presenting a method for the formal solution of the RT equation in three-dimensional (3D) media with horizontal periodic boundary conditions. This formal solver is suitable for both, unpolarized and polarized 3D radiative transfer and it can be easily combined with the iterative schemes for solving non-LTE multilevel transfer problems that we have developed over the last few years. We demonstrate this by showing some schematic 3D multilevel calculations that illustrate the physical effects of horizontal radiative transfer. These Non-LTE calculations have been carried out with our code MUGA 3D, a 3D multilevel Non-LTE code based on the Gauss-Seidel iterative scheme that Trujillo Bueno and Fabiani Bendicho (1995) developed for RT applications.
Numerical Passage from Radiative Heat Transfer to Nonlinear Diffusion Models \\Lambda
Schmeiser, Christian
Numerical Passage from Radiative Heat Transfer to Nonlinear Diffusion Models \\Lambda A. Klar y C. Schmeiser z Abstract Radiative heat transfer equations including heat conduction are considÂ ered situations are presented. Keywords. radiative heat transfer, asymptotic analysis, nonlinear diffusion limit
Radiative Heat Transfer in Enhanced Hydrogen Outgassing of Glass
Kitamura, Rei; Pilon, Laurent
2009-01-01T23:59:59.000Z
Kaviany and B.P. Singh, “Radiative heat transfer in porousmedia”, Advances in Heat Transfer, vol. 23, no. 23, pp. 133–Thermal radiation heat transfer, Hemisphere Publishing Co. ,
Adaptive Ray Tracing for Radiative Transfer around Point Sources
Tom Abel; Benjamin D. Wandelt
2001-11-01T23:59:59.000Z
We describe a novel adaptive ray tracing scheme to solve the equation of radiative transfer around point sources in hydrodynamical simulations. The angular resolution adapts to the local hydrodynamical resolution and hence is of use for adaptive meshes as well as adaptive smooth particle hydrodynamical simulations. Recursive creation of rays ensures ease of implementation. The multiple radial integrations needed to solve the time dependent radiative transfer are sped up significantly using a quad-tree once the rays are cast. Simplifications advantageous for methods with one radiation source are briefly discussed. The suggested method is easily generalized to speed up Monte Carlo radiative transfer techniques. In summary a nearly optimal use of long characteristics is presented and aspects of its implementation and comparison to other methods are given.
Modified Method of Characteristics for Transient Radiative Transfer
Katika, Kamal M.; Pilon, Laurent
2006-01-01T23:59:59.000Z
dimensional transient radiation heat transfer modeling usingradiation transport and laser applications”, Advances in Heat Transfer,Radiation element method for transient hyperbolic radiative transfer in plane parallel inhomogenous media”, Numerical Heat
Radiative heat transfer between dielectric bodies
Svend-Age Biehs
2011-03-16T23:59:59.000Z
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.
EXPERIMENTAL MEASUREMENT OF RADIATION HEAT TRANSFER FROM COMPLEX
EXPERIMENTAL MEASUREMENT OF RADIATION HEAT TRANSFER FROM COMPLEX FENESTRATION SYSTEMS By BARRY OF RADIATION HEAT TRANSFER FROM COMPLEX FENESTRATION SYSTEMS Thesis Approved: Dr. Dan Fisher Thesis Adviser Dr
Fresnel Effect in Radiation Transfer in Biological Tissues Kyunghan Kim and Zhixiong Guo*
Guo, Zhixiong "James"
Fresnel Effect in Radiation Transfer in Biological Tissues Kyunghan Kim and Zhixiong Guo* MAE Method (DOM) to incorporate Fresnel's boundary in laser radiation transport in biological tissues is calculated by the use of Snell's law and Fresnel's equation. The radiation fields, including the radiative
Radiative transfer for the FIRST era
J. Trujillo Bueno
2001-02-15T23:59:59.000Z
This paper presents a brief overview of some recent advances in numerical radiative transfer, which may help the molecular astrophysics community to achieve new breakthroughs in the interpretation of spectro-(polarimetric) observations.
Radiative Heat Transfer between Neighboring Particles
Alejandro Manjavacas; F. Javier Garcia de Abajo
2012-01-26T23:59:59.000Z
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.
Goudon, Thierry
A Coupled Model for Radiative Transfer: Doppler Effects, Equilibrium and Non-Equilibrium Diffusion. The interaction terms take into account both scattering and absorption/emission phenomena, as well as Doppler-diffusion equations. Key words. Hydrodynamic limits. Diffusion approximation. Radiative transfer. Doppler correction
RADIATIVE HEAT TRANSFER WITH QUASIMONTE CARLO METHODS \\Lambda
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
RADIATIVE HEAT TRANSFER WITH QUASI-MONTE CARLO METHODS
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
ULTRAFAST RADIATION HEAT TRANSFER IN LASER TISSUE WELDING AND SOLDERING
Guo, Zhixiong "James"
ULTRAFAST RADIATION HEAT TRANSFER IN LASER TISSUE WELDING AND SOLDERING Kyunghan Kim and Zhixiong. The transient radiation heat transfer in the picosecond time scale is numerically investigated for the first surface. Comparisons of radiation heat transfer are made between the spatially square- variance
Radiative heat transfer in inhomogeneous, nongray, and anisotropically scattering media
Guo, Zhixiong "James"
Radiative heat transfer in inhomogeneous, nongray, and anisotropically scattering media Zhixiong Radiative heat transfer in three-dimensional inhomogeneous, nongray and anisotropically scattering of an application of engineering interest, radiative heat transfer in a boiler model with non-isothermal, nongray
Mpemba effect, Newton cooling law and heat transfer equation
Vladan Pankovic; Darko V. Kapor
2012-12-11T23:59:59.000Z
In this work we suggest a simple theoretical solution of the Mpemba effect in full agreement with known experimental data. This solution follows simply as an especial approximation (linearization) of the usual heat (transfer) equation, precisely linearization of the second derivation of the space part of the temperature function (as it is well-known Newton cooling law can be considered as the effective approximation of the heat (transfer) equation for constant space part of the temperature function).
Investigation of spectral radiation heat transfer and NO{sub x} emission in a glass furnace
Golchert, B.; Zhou, C. Q.; Chang, S. L.; Petrick, M.
2000-08-02T23:59:59.000Z
A comprehensive radiation heat transfer model and a reduced NOx kinetics model were coupled with a computational fluid dynamics (CFD) code and then used to investigate the radiation heat transfer, pollutant formation and flow characteristics in a glass furnace. The radiation model solves the spectral radiative transport equation in the combustion space of emitting and absorbing media, i.e., CO{sub 2}, H{sub 2}O, and soot and emission/reflection from the furnace crown. The advanced numerical scheme for calculating the radiation heat transfer is extremely effective in conserving energy between radiation emission and absorption. A parametric study was conducted to investigate the impact of operating conditions on the furnace performance with emphasis on the investigation into the formation of NOx.
FREQUENCY SHAPED LINEAR OPTIMAL CONTROL WXTH TRANSFER FUNCTION RICCATI EQUATIONS*
Moore, John Barratt
and numerical tool in optimal control problems associated with linear systems having state space descriptions optimal controllers for known multivariable linear stochastic systems. There are some inherent robustnessFREQUENCY SHAPED LINEAR OPTIMAL CONTROL WXTH TRANSFER FUNCTION RICCATI EQUATIONS* John B. Moore** D
Near field radiative heat transfer between two nonlocal dielectrics
Singer, F; Joulain, Karl
2015-01-01T23:59:59.000Z
We explore in the present work the near-field radiative heat transfer between two semi-infinite parallel nonlocal dielectric planes by means of fluctuational electrodynamics. We use atheory for the nonlocal dielectric permittivityfunction proposed byHalevi and Fuchs. This theory has the advantage to includedifferent models performed in the literature. According to this theory, the nonlocal dielectric function is described by a Lorenz-Drude like single oscillator model, in which the spatial dispersion effects are represented by an additional term depending on the square of the total wavevector k. The theory takes into account the scattering of the electromagneticexcitation at the surface of the dielectric material, which leads to the need of additional boundary conditions in order to solve Maxwell's equations and treat the electromagnetic transmission problem. The additional boundary conditions appear as additional surface scattering parameters in the expressions of the surface impedances. It is shown that the...
Efficient wireless non-radiative mid-range energy transfer
Efficient wireless non-radiative mid-range energy transfer Aristeidis Karalis a,*, J-range wireless energy transfer. Ó 2007 Elsevier Inc. All rights reserved. Keywords: Wireless energy; Wireless % few*LDEV) wireless energy transfer would be quite useful for many applica- tions. There are several
Bootstrap and momentum transfer dependence in small x evolution equations
G. Chachamis; A. Sabio Vera; C. Salas
2012-11-27T23:59:59.000Z
Using Monte Carlo integration techniques, we investigate running coupling effects compatible with the high energy bootstrap condition to all orders in the strong coupling in evolution equations valid at small values of Bjorken x in deep inelastic scattering. A model for the running of the coupling with analytic behavior in the infrared region and compatible with power corrections to jet observables is used. As a difference to the fixed coupling case, where the momentum transfer acts as an effective strong cut-off of the diffusion to infrared scales, in our running coupling study the dependence on the momentum transfer is much milder.
Small distance expansion for radiative heat transfer between curved objects
Golyk, Vladyslav A.
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 ...
Enhanced radiative heat transfer between nanostructured gold plates
R. Guérout; 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
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.
Modelling of Radiative Transfer in Light Sources
Eindhoven, Technische Universiteit
. . . . . . . . . . . . . . . 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
A convective-radiative heat transfer model for gas core reactors
Chen, G.; Anghaie, S. [Univ. of Florida, Gainesville, FL (United States)
1995-12-31T23:59:59.000Z
A convective-radiative heat transfer model is developed and used to predict the temperature distribution in gaseous fuel nuclear reactor cores. The axisymmetric, thin layer Navier-Stokes equations with diffusive radiation source term are the basis for this modeling approach. An algebraic turbulence model is used to calculate the eddy viscosity. The Rosseland diffusion approximation is used to model the radiative heat transfer. A hybrid implicit-explicit numerical scheme with Gauss-Seidel iterative process and a highly stretched grid system near wall is employed to solve the governing equations. Several cases with different internal heat generation rates are modeled and analyzed. Results of the temperature distribution, wall heat flux and the associated Nusselt number are presented. The influence of the internal heat generation rate and the wall temperature on the radiative and convective wall heat fluxes are discussed. At gas and wall temperatures close to 3,500 K and 1,600 K, respectively, the radiative and convective heat transfer rates have similar values.
Heng, Kevin; Mendonça, João M.; Lee, Jae-Min, E-mail: kevin.heng@csh.unibe.ch, E-mail: joao.mendonca@csh.unibe.ch, E-mail: lee@physik.uzh.ch [University of Bern, Center for Space and Habitability, Sidlerstrasse 5, CH-3012 Bern (Switzerland)
2014-11-01T23:59:59.000Z
We present a comprehensive analytical study of radiative transfer using the method of moments and include the effects of non-isotropic scattering in the coherent limit. Within this unified formalism, we derive the governing equations and solutions describing two-stream radiative transfer (which approximates the passage of radiation as a pair of outgoing and incoming fluxes), flux-limited diffusion (which describes radiative transfer in the deep interior), and solutions for the temperature-pressure profiles. Generally, the problem is mathematically underdetermined unless a set of closures (Eddington coefficients) is specified. We demonstrate that the hemispheric (or hemi-isotropic) closure naturally derives from the radiative transfer equation if energy conservation is obeyed, while the Eddington closure produces spurious enhancements of both reflected light and thermal emission. We concoct recipes for implementing two-stream radiative transfer in stand-alone numerical calculations and general circulation models. We use our two-stream solutions to construct toy models of the runaway greenhouse effect. We present a new solution for temperature-pressure profiles with a non-constant optical opacity and elucidate the effects of non-isotropic scattering in the optical and infrared. We derive generalized expressions for the spherical and Bond albedos and the photon deposition depth. We demonstrate that the value of the optical depth corresponding to the photosphere is not always 2/3 (Milne's solution) and depends on a combination of stellar irradiation, internal heat, and the properties of scattering in both the optical and infrared. Finally, we derive generalized expressions for the total, net, outgoing, and incoming fluxes in the convective regime.
Efficient weakly-radiative wireless energy transfer: An EIT-like approach
Efficient weakly-radiative wireless energy transfer: An EIT-like approach Rafif E. Hamam 2009 Keywords: Wireless energy transfer Coupling Electromagnetically induced transparency (EIT induced trans- parency (EIT), we propose an efficient weakly radiative wireless energy transfer scheme
Numerical methods for multidimensional radiative transfer
radiation plays a key role in various scientific applications, such as combustion physics, thermonuclear fusion and astrophysics. The equa- tion describing the transport of photons or neutrons through a medium
Tominaga, Nozomu; Blinnikov, Sergei I
2015-01-01T23:59:59.000Z
We develop a time-dependent multi-group multidimensional relativistic radiative transfer code, which is required to numerically investigate radiation from relativistic fluids involved in, e.g., gamma-ray bursts and active galactic nuclei. The code is based on the spherical harmonic discrete ordinate method (SHDOM) that evaluates a source function including anisotropic scattering in spherical harmonics and implicitly solves the static radiative transfer equation with a ray tracing in discrete ordinates. We implement treatments of time dependence, multi-frequency bins, Lorentz transformation, and elastic Thomson and inelastic Compton scattering to the publicly available SHDOM code. Our code adopts a mixed frame approach; the source function is evaluated in the comoving frame whereas the radiative transfer equation is solved in the laboratory frame. This implementation is validated with various test problems and comparisons with results of a relativistic Monte Carlo code. These validations confirm that the code ...
Solving radiative transfer with line overlaps using Gauss Seidel algorithms
F. Daniel; J. Cernicharo
2008-07-11T23:59:59.000Z
The improvement in observational facilities requires refining the modelling of the geometrical structures of astrophysical objects. Nevertheless, for complex problems such as line overlap in molecules showing hyperfine structure, a detailed analysis still requires a large amount of computing time and thus, misinterpretation cannot be dismissed due to an undersampling of the whole space of parameters. We extend the discussion of the implementation of the Gauss--Seidel algorithm in spherical geometry and include the case of hyperfine line overlap. We first review the basics of the short characteristics method that is used to solve the radiative transfer equations. Details are given on the determination of the Lambda operator in spherical geometry. The Gauss--Seidel algorithm is then described and, by analogy to the plan--parallel case, we see how to introduce it in spherical geometry. Doing so requires some approximations in order to keep the algorithm competitive. Finally, line overlap effects are included. The convergence speed of the algorithm is compared to the usual Jacobi iterative schemes. The gain in the number of iterations is typically factors of 2 and 4 for the two implementations made of the Gauss--Seidel algorithm. This is obtained despite the introduction of approximations in the algorithm. A comparison of results obtained with and without line overlaps for N2H+, HCN, and HNC shows that the J=3-2 line intensities are significantly underestimated in models where line overlap is neglected.
Demonstration of Strong Near-Field Radiative Heat Transfer between Integrated Nanostructures
Lipson, Michal
Demonstration of Strong Near-Field Radiative Heat Transfer between Integrated Nanostructures-polariton Recently, there has been a growing interest in controlling radiative heat transfer in the near-field,1 ultrahigh contrast rectification of heat transfer.27 Here we show strong near-field radiative heat transfer
A Grey Radiative Transfer Procedure For Gamma-ray Transfer in Supernovae
David J. Jeffery
1998-11-23T23:59:59.000Z
The gamma-ray transfer in supernovae for the purposes of energy deposition in the ejecta can be approximated fairly accurately as frequency-integrated (grey) radiative transfer using a mean opacity as shown by Swartz, Sutherland, & Harkness (SSH). In SSH's grey radiative transfer procedure (unoptimized) the mean opacity is a pure absorption opacity and it is a constant aside from a usually weak composition dependence. In this paper, we present a variation on the SSH procedure which uses multiple mean opacities which have both absorption and scattering components. There is a mean opacity for each order of Compton scattering. A local-state (LS) approximation permits an analytic solution for the gamma-ray transfer of scattered gamma-ray fields. The LS approximation is admittedly crude, but the scattered fields are always of lesser importance to the energy deposition. We call our procedure the LS grey radiative transfer procedure or LS procedure for short. For a standard Type Ia supernova (SN Ia) model the uncertainty in gamma-ray energy deposition is estimated to be of order 10 % or less. The LS procedure code used for this paper can be obtained by request from the author. For completeness and easy reference, we include in this paper a review of the gamma-ray opacities important in supernovae, a discussion of the appropriate mean opacity prescription, and a discussion of the errors arising from neglecting time-dependent and non-static radiative transfer effects.
Guo, Zhixiong "James"
Global heat transfer analysis in Czochralski silicon furnace with radiation on curved specular method are adopted to solve the global heat transfer and the radiative heat exchange, respectively rate QJ diffuse radiation heat transfer rate QX net rate of radiative heat loss QT heat generation rate
Radiative Transfer Models for Gamma-Ray Bursts
Vurm, Indrek
2015-01-01T23:59:59.000Z
We present global radiative transfer models for heated relativistic jets. The simulations include all relevant radiative processes, starting deep in the opaque zone and following the evolution of radiation to and beyond the photosphere of the jet. The transfer models are compared with three gamma-ray bursts GRB 990123, GRB 090902B, and GRB 130427A, which have well-measured and different spectra. The models provide good fits to the observed spectra in all three cases. The fits give estimates for the jet magnetization parameter $\\varepsilon_{\\rm B}$ and the Lorentz factor $\\Gamma$. In the small sample of three bursts, $\\varepsilon_{\\rm B}$ varies between 0.01 and 0.1, and $\\Gamma$ varies between 340 and 1200.
RADIATIVE TRANSFER SIMULATIONS OF NEUTRON STAR MERGER EJECTA
Tanaka, Masaomi [National Astronomical Observatory of Japan, Mitaka, Tokyo (Japan); Hotokezaka, Kenta, E-mail: masaomi.tanaka@nao.ac.jp, E-mail: hotoke@tap.scphys.kyoto-u.ac.jp [Department of Physics, Kyoto University, Kyoto (Japan)
2013-10-01T23:59:59.000Z
Mergers of binary neutron stars (NSs) are among the most promising gravitational wave (GW) sources. Next generation GW detectors are expected to detect signals from NS mergers within about 200 Mpc. The detection of electromagnetic wave (EM) counterparts is crucial to understanding the nature of GW sources. Among the possible EM emission from the NS merger, emission powered by radioactive r-process nuclei is one of the best targets for follow-up observations. However, predictions so far have not taken into account detailed r-process element abundances in the ejecta. We perform for the first time radiative transfer simulations of the NS merger ejecta including all the r-process elements from Ga to U. We show that the opacity of the NS merger ejecta is about ? = 10 cm{sup 2} g{sup –1}, which is higher than that of Fe-rich Type Ia supernova ejecta by a factor of ?100. As a result, the emission is fainter and lasts longer than previously expected. The spectra are almost featureless due to the high expansion velocity and bound-bound transitions of many different r-process elements. We demonstrate that the emission is brighter for a higher mass ratio of the two NSs and a softer equation of state adopted in the merger simulations. Because of the red color of the emission, follow-up observations in red optical and near-infrared (NIR) wavelengths will be the most efficient. At 200 Mpc, the expected brightness of the emission is i = 22-25 AB mag, z = 21-23 AB mag, and 21-24 AB mag in the NIR JHK bands. Thus, observations with wide-field 4 m- and 8 m-class optical telescopes and wide-field NIR space telescopes are necessary. We also argue that the emission powered by radioactive energy can be detected in the afterglow of nearby short gamma-ray bursts.
Dana E. Veron
2012-04-09T23:59:59.000Z
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.
Yuen, W W
2006-01-01T23:59:59.000Z
the effect of radiation heat transfer in multi-dimensionaleffects of the radiation heat transfer, particularly in3-D Surface Radiation Calculation”, Numerical heat Transfer,
Radiative heat transfer in 2D Dirac materials
Pablo Rodriguez-Lopez; Wang-Kong Tse; Diego A. R. Dalvit
2015-02-02T23:59:59.000Z
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.
Calculating Radiative Heat Transfer in an Axisymmetric Closed Chamber: An Application
New York at Stoney Brook, State University of
the parallelization of the radiative heat transfer model introduced by Naraghi and Nunes of Manhattan College [8
Application of three-dimensional solar radiative transfer to mountains Y. Chen,1,2
Liou, K. N.
Application of three-dimensional solar radiative transfer to mountains Y. Chen,1,2 A. Hall,1 and K November 2006. [1] We developed a three-dimensional radiative transfer model simulating solar fluxes over (2006), Application of three-dimensional solar radiative transfer to mountains, J. Geophys. Res., 111, D
Radiative heat transfer at nanoscale mediated by surface plasmons for highly doped Emmanuel Rousseau
Paris-Sud XI, Université de
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
TWO-DIMENSIONAL TRANSIENT RADIATIVE HEAT TRANSFER USING DISCRETE ORDINATES METHOD
Guo, Zhixiong "James"
TWO-DIMENSIONAL TRANSIENT RADIATIVE HEAT TRANSFER USING DISCRETE ORDINATES METHOD Zhixiong Guo for the first time to solve transient radiative heat transfer in a two-dimensional rectangular enclosure of solution method of radiative heat transfer in participating media in recent decades. However, the analysis
Dual-scale 3-D approach for modeling radiative heat transfer in fibrous insulations
Tafreshi, Hooman Vahedi
Dual-scale 3-D approach for modeling radiative heat transfer in fibrous insulations R. Arambakam 2013 Keywords: Radiative heat transfer Dual-scale modeling Insulation media Fibrous media a b s t r a c a fiber diameter for which radiation heat transfer through a fibrous media is min- imal, ranging between 3
Tafreshi, Hooman Vahedi
Modeling the role of microstructural parameters in radiative heat transfer through disordered high-tempera- tures. Traditional studies of radiative heat transfer in fibrous materials have been the performance of fibrous materials used as radiative heat transfer insulation media. Although effective
Glass foams: formation, transport properties, and heat, mass, and radiation transfer
Pilon, Laurent
Glass foams: formation, transport properties, and heat, mass, and radiation transfer Andrei G models for thermophysical and transport properties and heat, mass, and radiation transfer in glass foams. In addition, the new results on simulation of combined conduction and radiation heat transfer in glass foams
Near-Field Radiative Heat Transfer between Macroscopic Planar Surfaces R. S. Ottens,1
Tanner, David B.
Near-Field Radiative Heat Transfer between Macroscopic Planar Surfaces R. S. Ottens,1 V. Quetschke-field, blackbody radiation. Although heat transfer via near-field effects has been discussed for many years.014301 PACS numbers: 44.40.+a, 78.20.Ci Humans knew of radiative heat transfer at least as early
An Investigation of the Radiative Heat Transfer through Nonwoven Fibrous Materials
Tafreshi, Hooman Vahedi
An Investigation of the Radiative Heat Transfer through Nonwoven Fibrous Materials Imad Qashou1 of the Fluent CFD code is used to investigate the response of a fibrous material to the radiative heat transfer in agreement with our experimental study. INTRODUCTION Radiative heat transfer through fibrous media has been
Radiative heat transfer in a hydrous mantle transition zone Sylvia-Monique Thomas a,n
Jacobsen, Steven D.
Radiative heat transfer in a hydrous mantle transition zone Sylvia-Monique Thomas a,n , Craig R contribute significantly to heat transfer in the mantle and demonstrate the importance of radiative heat, radiative heat transfer was considered relatively unimportant in the mantle. Earlier experimental work
Radiative Heat Transfer Analysis of Fibrous Insulation Materials Using the ZonalGEF Method
Yuen, Walter W.
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. Radiative heat transfer in this class of material is nonlocalized in the optically thick limit
Heat transfer through a water spray curtain under the effect of a strong radiative source
Paris-Sud XI, Université de
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
Comparison of methods for solving nonlinear finite-element equations in heat transfer
Cort, G.E.; Graham, A.L.; Johnson, N.L.
1981-01-01T23:59:59.000Z
We have derived two new techniques for solving the finite-element heat-transfer equations with highly nonlinear boundary conditions and material properties. When compared with the more commonly employed successive substitution and Newton-Raphson procedures, the new methods speed convergence rates and simultaneously increase the radius of convergence. We have observed reductions in computation time in excess of 80% when the new techniques are employed. The first method accelerates the standard Newton-Raphson approach when the degree of the nonlinearity is known (for example, radiation boundary conditions or a prescribed temperature dependence in the thermal conductivity). The second technique employs feedback to regulate the solution algorithm during execution. Comparisons of these techniques are given for several practical examples.
Jozef Klacka
2002-01-07T23:59:59.000Z
Relativistically covariant form of equation of motion for real particle (body) under the action of electromagnetic radiation is derived. Equation of motion in the proper frame of the particle uses the radiation pressure cross section 3 $\\times$ 3 matrix. Obtained covariant equation of motion is compared with another covariant equation of motion which was presented more than one year ago.
COUPLING OF DARCY-FORCHHEIMER AND COMPRESSIBLE NAVIER-STOKES EQUATIONS WITH HEAT TRANSFER
Paris-Sud XI, Université de
COUPLING OF DARCY-FORCHHEIMER AND COMPRESSIBLE NAVIER-STOKES EQUATIONS WITH HEAT TRANSFER M. AMARA are respectively described by the Darcy-Forchheimer and the compressible Navier-Stokes equations, together coordinates and consisting of the Darcy- Forchheimer equation coupled with an exhaustive energy balance, has
Radiative transfer with scattering from closely-spaced spheres
Drolen, B.L.
1986-01-01T23:59:59.000Z
Many heat-transfer applications including fluidized and packed beds, microsphere insulations, and reactor fuel pellets require the analysis of radiative transfer in packed-sphere systems. The radiative properties of surface deposits such as paint and soot layers, and of aerosols such as soot, may be determined by treating them as a collection of spheres. These properties are important for predicting heat transfer in furnaces and flames and for assessing atmospheric attenuation in nuclear-winter scenarios. For many applications when the particle size is larger than the wavelength, or when the volume fraction is small, scattering from individual spheres in the medium is independent of the influence of neighboring particles. Therefore the extinction characteristics of these systems are based on the properties of the discrete particles. This approach is shown to be in good agreement with published experimental data for a packed bed of spheres. When dependent scattering is important, effects caused by the proximity of the neighboring particles must be included. This model examines interference between the scattered waves from each of the particles in the medium. The particle centers correlate via a distribution function which represents the distribution of neighboring particles about a central particle.
Gritzo, L.A.; Skocypec, R.D. [Sandia National Labs., Albuquerque, NM (United States); Tong, T.W. [Arizona State Univ., Tempe, AZ (United States). Dept. of Mechanical and Aerospace Engineering
1995-01-11T23:59:59.000Z
Radiation in participating media is an important transport mechanism in many physical systems. The simulation of complex radiative transfer has not effectively exploited high-performance computing capabilities. In response to this need, a workshop attended by members active in the high-performance computing community, members active in the radiative transfer community, and members from closely related fields was held to identify how high-performance computing can be used effectively to solve the transport equation and advance the state-of-the-art in simulating radiative heat transfer. This workshop was held on March 29-30, 1994 in Albuquerque, New Mexico and was conducted by Sandia National Laboratories. The objectives of this workshop were to provide a vehicle to stimulate interest and new research directions within the two communities to exploit the advantages of high-performance computing for solving complex radiative heat transfer problems that are otherwise intractable.
A new nonlocal thermodynamical equilibrium radiative transfer method for cool stars
Lambert, Julien; Ryde, Nils; Faure, Alexandre
2015-01-01T23:59:59.000Z
Context: The solution of the nonlocal thermodynamical equilibrium (non-LTE) radiative transfer equation usually relies on stationary iterative methods, which may falsely converge in some cases. Furthermore, these methods are often unable to handle large-scale systems, such as molecular spectra emerging from, for example, cool stellar atmospheres. Aims: Our objective is to develop a new method, which aims to circumvent these problems, using nonstationary numerical techniques and taking advantage of parallel computers. Methods: The technique we develop may be seen as a generalization of the coupled escape probability method. It solves the statistical equilibrium equations in all layers of a discretized model simultaneously. The numerical scheme adopted is based on the generalized minimum residual method. Result:. The code has already been applied to the special case of the water spectrum in a red supergiant stellar atmosphere. This demonstrates the fast convergence of this method, and opens the way to a wide va...
Forristall, R.
2003-10-01T23:59:59.000Z
This report describes the development, validation, and use of a heat transfer model implemented in Engineering Equation Solver. The model determines the performance of a parabolic trough solar collector's linear receiver, also called a heat collector element. All heat transfer and thermodynamic equations, optical properties, and parameters used in the model are discussed. The modeling assumptions and limitations are also discussed, along with recommendations for model improvement.
Impact of surface inhomogeneity on solar radiative transfer under overcast conditions
Li, Zhanqing
Impact of surface inhomogeneity on solar radiative transfer under overcast conditions Zhanqing Li1. Introduction [2] Solar radiative heating is the primary driving force of atmospheric and oceanic movements underlines the impact of surface inhomogeneity on the closure of SW radiative transfer. It also leads
Radiative transfer model for contaminated slabs : experimental validations
Andrieu, François; Schmitt, Bernard; Douté, Sylvain; Brissaud, Olivier
2015-01-01T23:59:59.000Z
This article presents a set of spectro-goniometric measurements of different water ice samples and the comparison with an approximated radiative transfer model. The experiments were done using the spectro-radiogoniometer described in Brissaud et al. (2004). The radiative transfer model assumes an isotropization of the flux after the second interface and is fully described in Andrieu et al. (2015). Two kind of experiments were conducted. First, the specular spot was closely investigated, at high angular resolution, at the wavelength of $1.5\\,\\mbox{\\mu m}$, where ice behaves as a very absorbing media. Second, the bidirectional reflectance was sampled at various geometries, including low phase angles on 61 wavelengths ranging from $0.8\\,\\mbox{\\mu m}$ to $2.0\\,\\mbox{\\mu m}$. In order to validate the model, we made a qualitative test to demonstrate the relative isotropization of the flux. We also conducted quantitative assessments by using a bayesian inversion method in order to estimate the parameters (e.g. sampl...
Howard Barker; Jason Cole
2012-05-17T23:59:59.000Z
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.
Hogan, Robin
Incorporating the Effects of 3D Radiative Transfer in the Presence of Clouds into Two. The 3D effect on shortwave cloud radiative forcing varies between around 225% and around 1100. Therefore, cumulus clouds are of particular im- portance when considering 3D radiative effects: although
Paris-Sud XI, Université de
on the 500±67300 km, 4° inclination EQUATOR-S orbit show that the increase of the energetic electron ¯ux of electrons in the outer radiation belt has been attributed to Pc 5 band ULF waves excited by high speed solar wind ¯ow associated with magnetic storms (Rostoker et al., 1998). The main features
T. A. Carroll; M. Kopf; K. G. Strassmeier
2008-07-24T23:59:59.000Z
The major challenges for a fully polarized radiative transfer driven approach to Zeeman-Doppler imaging are still the enormous computational requirements. In every cycle of the iterative interplay between the forward process (spectral synthesis) and the inverse process (derivative based optimization) the Stokes profile synthesis requires several thousand evaluations of the polarized radiative transfer equation for a given stellar surface model. To cope with these computational demands and to allow for the incorporation of a full Stokes profile synthesis into Doppler- and Zeeman-Doppler imaging applications as well as into large scale solar Stokes profile inversions, we present a novel fast and accurate synthesis method for calculating local Stokes profiles. Our approach is based on artificial neural network models, which we use to approximate the complex non-linear mapping between the most important atmospheric parameters and the corresponding Stokes profiles. A number of specialized artificial neural networks, are used to model the functional relation between the model atmosphere, magnetic field strength, field inclination, and field azimuth, on one hand and the individual components (I,Q,U,V) of the Stokes profiles, on the other hand. We performed an extensive statistical evaluation and show that our new approach yields accurate local as well as disk-integrated Stokes profiles over a wide range of atmospheric conditions. The mean rms errors for the Stokes I and V profiles are well below 0.2% compared to the exact numerical solution. Errors for Stokes Q and U are in the range of 1%. Our approach does not only offer an accurate approximation to the LTE polarized radiative transfer it, moreover, accelerates the synthesis by a factor of more than 1000.
Interpretation of AIRS Data in Thin Cirrus Atmospheres Based on a Fast Radiative Transfer Model
Liou, K. N.
Interpretation of AIRS Data in Thin Cirrus Atmospheres Based on a Fast Radiative Transfer Model of California, Los Angeles, Los Angeles, California B. H. KAHN Jet Propulsion Laboratory, California Institute radiative transfer model has been developed for application to cloudy satellite data assimilation
RADIATION HEAT TRANSFER IN TISSUE WELDING AND SOLDERING WITH ULTRAFAST LASERS
Guo, Zhixiong "James"
RADIATION HEAT TRANSFER IN TISSUE WELDING AND SOLDERING WITH ULTRAFAST LASERS Kyunghan Kim to incorporate transient radiation heat transfer in tissue welding and soldering with use of ultrafast lasers are performed between laser welding and laser soldering. The use of solder is found to substantially enhance
Robert, Pincus
A fast, flexible, approximate technique for computing radiative transfer in inhomogeneous cloud.-J. Morcrette, A fast, flexible, approximate technique for computing radiative transfer in inhomogeneous cloud, which computes fluxes at each level. [3] The description of clouds in current LSMs is quite simple: Most
SKIRT: the design of a suite of input models for Monte Carlo radiative transfer simulations
Baes, Maarten
2015-01-01T23:59:59.000Z
The Monte Carlo method is the most popular technique to perform radiative transfer simulations in a general 3D geometry. The algorithms behind and acceleration techniques for Monte Carlo radiative transfer are discussed extensively in the literature, and many different Monte Carlo codes are publicly available. On the contrary, the design of a suite of components that can be used for the distribution of sources and sinks in radiative transfer codes has received very little attention. The availability of such models, with different degrees of complexity, has many benefits. For example, they can serve as toy models to test new physical ingredients, or as parameterised models for inverse radiative transfer fitting. For 3D Monte Carlo codes, this requires algorithms to efficiently generate random positions from 3D density distributions. We describe the design of a flexible suite of components for the Monte Carlo radiative transfer code SKIRT. The design is based on a combination of basic building blocks (which can...
A Realizability-Preserving Discontinuous Galerkin Method for the $M_1$ Model of Radiative Transfer
Frank, Martin [RWTH Aachen University; Olbrant, Edgar [RWTH Aachen University; Hauck, Cory D [ORNL
2012-01-01T23:59:59.000Z
The M{sub 1} model for radiative transfer coupled to a material energy equation in planar geometry is studied in this paper. For this model to be well-posed, its moment variables must fulfill certain realizability conditions. Our main focus is the design and implementation of an explicit Runge-Kutta discontinuous Galerkin method which, under a more restrictive CFL condition, guarantees the realizability of the moment variables and the positivity of the material temperature. An analytical proof for our realizability-preserving scheme, which also includes a slope-limiting technique, is provided and confirmed by various numerical examples. Among other things, we present accuracy tests showing convergence up to fourth-order, compare our results with an analytical solution in a Riemann problem, and consider a Marshak wave problem.
Bailey, Teresa S
2008-10-10T23:59:59.000Z
) applied to the particle transport equation in two-dimensional cylindrical (RZ) and three-dimensional Cartesian (XYZ) geometries. We have designed this method to be applicable to radiative-transfer problems in radiation-hydrodynamics systems... ..................................................................... 7 II AN INTRODUCTION TO RADIATION HYDRODYNAMICS....... 10 The Euler equations........................................................................ 10 The radiative transfer equations...
Radiative heat transfer in anisotropic many-body systems: Tuning and enhancement
Nikbakht, Moladad, E-mail: mnik@znu.ac.ir [Department of Physics, Faculty of Sciences, University of Zanjan, Zanjan 45371-38791 (Iran, Islamic Republic of)
2014-09-07T23:59:59.000Z
A general formalism for calculating the radiative heat transfer in many body systems with anisotropic component is presented. Our scheme extends the theory of radiative heat transfer in isotropic many body systems to anisotropic cases. In addition, the radiative heating of the particles by the thermal bath is taken into account in our formula. It is shown that the radiative heat exchange (HE) between anisotropic particles and their radiative cooling/heating (RCH) could be enhanced several order of magnitude than that of isotropic particles. Furthermore, we demonstrate that both the HE and RCH can be tuned dramatically by particles relative orientation in many body systems.
Parameterization and Analysis of 3-D Solar Radiative Transfer in Clouds: Final Report
Jerry Y. Harrington
2012-09-21T23:59:59.000Z
This document reports on the research that we have done over the course of our two-year project. The report also covers the research done on this project during a 1 year no-cost extension of the grant. Our work has had two main, inter-related thrusts: The first thrust was to characterize the response of stratocumulus cloud structure and dynamics to systematic changes in cloud infrared radiative cooling and solar heating using one-dimensional radiative transfer models. The second was to couple a three-dimensional (3-D) solar radiative transfer model to the Large Eddy Simulation (LES) model that we use to simulate stratocumulus. The purpose of the studies with 3-D radiative transfer was to examine the possible influences of 3-D photon transport on the structure, evolution, and radiative properties of stratocumulus. While 3-D radiative transport has been examined in static cloud environments, few studies have attempted to examine whether the 3-D nature of radiative absorption and emission influence the structure and evolution of stratocumulus. We undertook this dual approach because only a small number of LES simulations with the 3-D radiative transfer model are possible due to the high computational costs. Consequently, LES simulations with a 1-D radiative transfer solver were used in order to examine the portions of stratocumulus parameter space that may be most sensitive to perturbations in the radiative fields. The goal was then to explore these sensitive regions with LES using full 3-D radiative transfer. Our overall goal was to discover whether 3-D radiative processes alter cloud structure and evolution, and whether this may have any indirect implications for cloud radiative properties. In addition, we collaborated with Dr. Tamas Varni, providing model output fields for his attempt at parameterizing 3-D radiative effects for cloud models.
On exact and perturbation solutions to nonlinear equations for heat transfer models
Francisco M. Fernández
2009-11-03T23:59:59.000Z
We analyze some exact and approximate solutions to nonlinear equations for heat transfer models. We prove that recent results derived from a method based on Lie algebras are either trivial or wrong. We test a simple analytical expression based on the hypervirial theorem and also discuss earlier perturbation results.
Robert, Pincus
The Accuracy of Determining Three-Dimensional Radiative Transfer Effects in Cumulus Clouds Using. Three-dimensional radiative transfer effects and why one might estimate them in two-dimensional clouds expensive independent column approximation is called the 3D radiative transfer effect. Assessing
Tafreshi, Hooman Vahedi
Analytical Monte Carlo Ray Tracing simulation of radiative heat transfer through bimodal fibrous-state radiative heat transfer through fibrous insulation materials. The simulations are conducted in 3-D disor radiation and conduc- tion to be the only modes of heat transfer in fibrous insulation materials
Graphene-assisted near-field radiative heat transfer between corrugated polar materials
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
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.
Near-field thermal radiation transfer controlled by plasmons in graphene
Ilic, Ognjen
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 ...
Electrically tunable near-field radiative heat transfer via ferroelectric materials
Huang, Yi
We explore ways to actively control near-field radiative heat transfer between two surfaces that relies on electrical tuning of phonon modes of ferroelectric materials. Ferroelectrics are widely used for tunable electrical ...
Ko, Min Seok
2009-05-15T23:59:59.000Z
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...
Radiative transfer in the earth's atmosphere-ocean system using Monte Carlo techniques
Bradley, Paul Andrew
1987-01-01T23:59:59.000Z
and ocean has numerous important implications in the fields of mete- orology, oceanography, and physics. One recent example of the power oi radiative transfer theory in studying the Earth's atmosphere is the discovery of the "nuclear winter" phenomenon...
Efficient weakly-radiative wireless energy transfer: An EIT-like approach
Hamam, Rafif E.
Inspired by a quantum interference phenomenon known in the atomic physics community as electromagnetically induced transparency (EIT), we propose an efficient weakly radiative wireless energy transfer scheme between two ...
Global oceanic rainfall estimation from AMSR-E data based on a radiative transfer model
Jin, Kyoung-Wook
2006-04-12T23:59:59.000Z
An improved physically-based rainfall algorithm was developed using AMSR-E data based on a radiative transfer model. In addition, error models were designed and embedded in the algorithm to assess retrieval errors ...
Paris-Sud XI, Université de
-cooled reactor. It is typically made of many prismatic blocks of graphite in which are inserted the nuclear fuel in the homogenization of heat transfer in periodic porous media where the fluid part is made of long thin parallel in the solid part of the domain and by conduction, convection and radiative transfer in the fluid part (the
Modelling dynamics of samples exposed to free-electron-laser radiation with Boltzmann equations
Beata Ziaja; Antonio R. B. de Castro; Edgar Weckert; Thomas Moeller
2005-12-20T23:59:59.000Z
We apply Boltzmann equations for modelling the radiation damage in samples irradiated by photons from free electron laser (FEL). We test this method in a study case of a spherically symmetric xenon cluster irradiated with VUV FEL photons. The results obtained demonstrate the potential of the Boltzmann method for describing the complex and non-equilibrium dynamics of samples exposed to FEL radiation.
Radiative Transfer in the Midwave Infrared Applicable to Full Spectrum Atmospheric
Kerekes, John
of the radiative effects in the MWIR is needed. The MWIR is characterized by a unique combination of reduced solar conditions are stressing (e.g., high moisture, heavy aerosol/particulate loading, partial cloud cover, lowRadiative Transfer in the Midwave Infrared Applicable to Full Spectrum Atmospheric Characterization
Gitelson, Anatoly
Optimizing spectral indices and chemometric analysis of leaf chemical properties using radiative for Sciences, 260 Panama Street, Stanford, CA 94305, USA d Center for Advanced Land Management Information squares regression We used synthetic reflectance spectra generated by a radiative transfer model, PROSPECT
Gitelson, Anatoly
Optimizing spectral indices and chemometric analysis of leaf chemical properties using radiative for Sciences, 260 Panama Street, Stanford, CA 94305, USA d Center for Advanced Land Management Information regression We used synthetic reflectance spectra generated by a radiative transfer model, PROSPECT-5
A Coupled AtmosphereOcean Radiative Transfer System Using the Analytic Four-Stream Approximation
Liou, K. N.
of the ocean. Shortwave radiation from the sun contributes most of the heat fluxes that penetrate the airA Coupled AtmosphereOcean Radiative Transfer System Using the Analytic Four-Stream Approximation WEI-LIANG LEE AND K. N. LIOU Department of Atmospheric and Oceanic Sciences, University of California
Guo, Zhixiong "James"
Equivalent isotropic scattering formulation for transient short-pulse radiative transfer of the transient short-pulse radiation transport through forward and backward anisotropic scattering planar media applications to such systems as industrial furnaces, combustion cham- bers, fibrous and porous insulations
Stramski, Dariusz
Characterization of the solar light field within the ocean mesopelagic zone based on radiative light field Apparent optical properties Mesopelagic zone Radiative transfer modeling a b s t r a c t The solar light field within the ocean from the sea surface to the bottom of the mesopelagic zone
Radiative heat transfer in a parallelogram shaped cavity
Dez, V Le
2015-01-01T23:59:59.000Z
An exact analytical description of the internal radiative field inside an emitting-absorbing gray semi-transparent medium enclosed in a two-dimensional parallelogram cavity is proposed. The expressions of the incident radiation and the radiative flux field are angularly and spatially discretized with a double Gauss quadrature, and the temperature field is obtained by using an iterative process. Some numerical solutions are tabulated and graphically presented as the benchmark solutions. Temperature and two components of the radiative flux are finally sketched on the whole domain. It is shown that the proposed method gives perfectly smooth results.
Atmospheric radiative transfer parametrization for solar energy yield calculations on buildings
Wagner, Jochen E
2015-01-01T23:59:59.000Z
In this paper the practical approach to evaluate the incoming solar radiation on buildings based on atmospheric composition and cloud cover is presented. The effects of absorption and scattering due to atmospheric composition is taken into account to calculate, using radiative transfer models, the net incoming solar radiation at surface level. A specific validation of the Alpine Region in Europe is presented with a special focus on the region of South Tyrol.
The effect of the number of wavebands used in spectral radiation heat transfer calculations
Chang, S. L.; Golchert, B.; Petrick, M.
2000-05-09T23:59:59.000Z
A spectral radiation heat transfer model that conserves emitted and absorbed energy has been developed and used to model the combustion space of an industrial glass furnace. This comprehensive radiation heat transfer model coupled with a computational fluid dynamics (CFD) code was used to investigate the effect of spectral dependencies on the computed results. The results of this work clearly indicate the need for a spectral approach as opposed to a gray body approach since the gray body approach (one waveband) severely underestimates the energy emitted via radiation.
Matthias Krüger; Giuseppe Bimonte; Thorsten Emig; Mehran Kardar
2012-07-16T23:59:59.000Z
We present a detailed derivation of heat radiation, heat transfer and (Casimir) interactions for N arbitrary objects in the framework of fluctuational electrodynamics in thermal non-equilibrium. The results can be expressed as basis-independent trace formulae in terms of the scattering operators of the individual objects. We prove that heat radiation of a single object is positive, and that heat transfer (for two arbitrary passive objects) is from the hotter to a colder body. The heat transferred is also symmetric, exactly reversed if the two temperatures are exchanged. Introducing partial wave-expansions, we transform the results for radiation, transfer and forces into traces of matrices that can be evaluated in any basis, analogous to the equilibrium Casimir force. The method is illustrated by (re)deriving the heat radiation of a plate, a sphere and a cylinder. We analyze the radiation of a sphere for different materials, emphasizing that a simplification often employed for metallic nano-spheres is typically invalid. We derive asymptotic formulae for heat transfer and non-equilibrium interactions for the cases of a sphere in front a plate and for two spheres, extending previous results. As an example, we show that a hot nano-sphere can levitate above a plate with the repulsive non-equilibrium force overcoming gravity -- an effect that is not due to radiation pressure.
Influence of Infrared Radiation on Attic Heat Transfer
Katipamula, S.; Turner, W. D.; Murphy, W. E.; O'Neal, D. L.
1985-01-01T23:59:59.000Z
An experimental study concerned with different modes of heal transfer in fibrous and cellulose insulating material is presented. A series of experiments were conducted using an attic simulator to determine the effects of ventilation on attic heat...
Effective-medium model of wire metamaterials in the problems of radiative heat transfer
Mirmoosa, M. S., E-mail: mohammad.mirmoosa@aalto.fi; Nefedov, I. S., E-mail: igor.nefedov@aalto.fi; Simovski, C. R., E-mail: konstantin.simovski@aalto.fi [Department of Radio Science and Engineering, School of Electrical Engineering, Aalto University, P. O. Box 13000, 00076 Aalto (Finland); Rüting, F., E-mail: felix.ruting@uam.es [Departamento de Física Teorica de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autonoma de Madrid, E-28049 (Spain)
2014-06-21T23:59:59.000Z
In the present work, we check the applicability of the effective medium model (EMM) to the problems of radiative heat transfer (RHT) through so-called wire metamaterials (WMMs)—composites comprising parallel arrays of metal nanowires. It is explained why this problem is so important for the development of prospective thermophotovoltaic (TPV) systems. Previous studies of the applicability of EMM for WMMs were targeted by the imaging applications of WMMs. The analogous study referring to the transfer of radiative heat is a separate problem that deserves extended investigations. We show that WMMs with practically realizable design parameters transmit the radiative heat as effectively homogeneous media. Existing EMM is an adequate tool for qualitative prediction of the magnitude of transferred radiative heat and of its effective frequency band.
Stephens, Graeme L.
in downwelling radiative fluxes at the surface induced by changes in cloud cover and water vapor distributions. 1An Assessment of the Parameterization of Subgrid-Scale Cloud Effects on Radiative Transfer. Part II form 5 January 2005) ABSTRACT The role of horizontal inhomogeneity in radiative transfer through cloud
Cerveny, Vlastislav
1994-01-01T23:59:59.000Z
of radiative heat transfer on the formation of megaplumes in the lower mantle Ctirad Matyska a, Ji~i Moser influence from radiative heat transfer on mantle upwellings and the production of extremely hot thermal and cold regions in lower mantle dynamics. We have considered the possible impact from radiative heat
Asymptotic solution for heat convection-radiation equation
Mabood, Fazle; Ismail, Ahmad Izani Md [School of Mathematical Sciences, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia); Khan, Waqar A. [Department of Engineering Sciences, National University of Sciences and Technology, PN Engineering College, Karachi, 75350 (Pakistan)
2014-07-10T23:59:59.000Z
In this paper, we employ a new approximate analytical method called the optimal homotopy asymptotic method (OHAM) to solve steady state heat transfer problem in slabs. The heat transfer problem is modeled using nonlinear two-point boundary value problem. Using OHAM, we obtained the approximate analytical solution for dimensionless temperature with different values of a parameter ?. Further, the OHAM results for dimensionless temperature have been presented graphically and in tabular form. Comparison has been provided with existing results from the use of homotopy perturbation method, perturbation method and numerical method. For numerical results, we used Runge-Kutta Fehlberg fourth-fifth order method. It was found that OHAM produces better approximate analytical solutions than those which are obtained by homotopy perturbation and perturbation methods, in the sense of closer agreement with results obtained from the use of Runge-Kutta Fehlberg fourth-fifth order method.
Journal of Quantitative Spectroscopy & Radiative Transfer 99 (2006) 341348
2006-01-01T23:59:59.000Z
). 1 Sandia is a multi-program laboratory operated by Sandia Corporation, a Lockheed Martin CompanyV blackbody-like radiators [3] are presently used for inertial confinement fusion studies and other work
Radiative component and combined heat transfer in the thermal calculation of finned tube banks
Stehlik, P. [Technical Univ. of Brno (Czech Republic). Dept. of Process Engineering] [Technical Univ. of Brno (Czech Republic). Dept. of Process Engineering
1999-01-01T23:59:59.000Z
For more exact calculation of combined heat transfer in the case of finned tube banks (e.g., in the convective section of a furnace), the radiative heat transfer cannot be neglected. A new method for relatively simple calculation of total heat flux (convection + radiation + conduction in fins) is fully compatible with that for bare tube banks/bundles developed earlier. It is based on the method of radiative coefficients. However, the resulting value of heat flux must be corrected due to fin thickness and especially due to the fin radiative influence. For this purpose the so-called multiplicator of heat flux was introduced. The applicability of this methods has been demonstrated on a tubular fired heater convective section. A developed computer program based on the method has also been used for an analysis of the influence of selected parameters to show the share of radiation on the total heat flux.
Marinca, Vasile
2015-01-01T23:59:59.000Z
In this paper, Optimal Homotopy Perturbation Method (OHPM) is employed to determine an analytic approximate solutions for nonlinear MHD Jeffery-Hamel flow and heat transfer problem. The Navier-Stokes equations, taking into account Maxwell's electromagnetism and heat transfer lead to two nonlinear ordinary differential equations. The obtained results by means of OHPM show a very good agreement in comparison with the numerical results and with Homotopy Perturbation Method (HPM).
Chang, Hung-Tzu; Cheng, Yuan-Chung [Department of Chemistry and Center for Quantum Science and Engineering, National Taiwan University, Taipei City 106, Taiwan (China)] [Department of Chemistry and Center for Quantum Science and Engineering, National Taiwan University, Taipei City 106, Taiwan (China); Zhang, Pan-Pan [Department of Physics and Institute of Modern Physics, Ningbo University, Ningbo 315211 (China)] [Department of Physics and Institute of Modern Physics, Ningbo University, Ningbo 315211 (China)
2013-12-14T23:59:59.000Z
The small polaron quantum master equation (SPQME) proposed by Jang et al. [J. Chem. Phys. 129, 101104 (2008)] is a promising approach to describe coherent excitation energy transfer dynamics in complex molecular systems. To determine the applicable regime of the SPQME approach, we perform a comprehensive investigation of its accuracy by comparing its simulated population dynamics with numerically exact quasi-adiabatic path integral calculations. We demonstrate that the SPQME method yields accurate dynamics in a wide parameter range. Furthermore, our results show that the accuracy of polaron theory depends strongly upon the degree of exciton delocalization and timescale of polaron formation. Finally, we propose a simple criterion to assess the applicability of the SPQME theory that ensures the reliability of practical simulations of energy transfer dynamics with SPQME in light-harvesting systems.
Heat transfer including radiation and slag particles evolution in MHD channel-I
Im, K.H.; Ahluwalia, R.K.
1980-01-01T23:59:59.000Z
Accurate estimates of convective and radiative heat transfer in the magnetohydrodynamic channel are provided. Calculations performed for a base load-size channel indicate that heat transfer by gas radiation almost equals that by convection for smooth walls, and amounts to 70% as much as the convective heat transfer for rough walls. Carbon dioxide, water vapor, and potassium atoms are the principal participating gases. The evolution of slag particles by homogeneous nucleation and condensation is also investigated. The particle-size spectrum so computed is later utilized to analyze the radiation enhancement by slag particles in the MHD diffuser. The impact of the slag particle spectrum on the selection of a workable and design of an efficient seed collection system is discussed.
Journal of Quantitative Spectroscopy & Radiative Transfer 93 (2005) 163173
Xu, Xianfan
2005-01-01T23:59:59.000Z
to fabricate nano-structures, optical data storage to reach ultra-high storage density, heat assisted magnetic concentrated in the gap between the ridges, which provides the electric dipole-liked behavior. The optimal of radiation according to Huygens principle. If the aperture is large in size in comparison with wavelength
Radiative Transfer in Interacting Media J.Kenneth Shultis
Shultis, J. Kenneth
can a ect the uid ow e.g., shock phenomena, energy loss from thermonuclear plasmas, combustion studies accelerated by neutron and high-energy photon transport methods for both military and civilian applications of nuclear energy. Today, radiative transport plays an important role in many other areas besides nuclear
Nonlocal study of the near field radiative heat transfer between two n-doped semiconductors
Singer, F; Joulain, Karl
2015-01-01T23:59:59.000Z
We study in this work the near-field radiative heat transfer between two semi-infinite parallel planes of highly n-doped semiconductors. Using a nonlocal model of the dielectric permittivity, usually used for the case of metallic planes, we show that the radiative heat transfer coefficientsaturates as the separation distance is reduced for high doping concentration. These results replace the 1/d${}^2$ infinite divergence obtained in the local model case. Different features of the obtained results are shown to relate physically to the parameters of the materials, mainly the doping concentration and the plasmon frequency.
Re ectance comparison between SCIAMACHY and a radiative transfer code in the UV
Tilstra, Gijsbert
Kon i nk l i j k Neder l ands Meteoro l og i sch Inst i tuut Re#29;ectance comparison between SCIAMACHY and a radiative transfer code in the UV L.G. Tilstra, G. van Soest, M. de Graaf, J.R. Acarreta, P#21;2400 nm. We compare its re#29;ectance mea- surements in the UV with calculations by a polarised radiative
Soliton-radiation coupling in the parametrically driven, damped nonlinear Schrödinger equation
V. S. Shchesnovich; I. V. Barashenkov
2001-11-14T23:59:59.000Z
We use the Riemann-Hilbert problem to study the interaction of the soliton with radiation in the parametrically driven, damped nonlinear Schr\\"odinger equation. The analysis is reduced to the study of a finite-dimensional dynamical system for the amplitude and phase of the soliton and the complex amplitude of the long-wavelength radiation. In contrast to previously utilised Inverse Scattering-based perturbation techniques, our approach is valid for arbitrarily large driving strengths and damping coefficients. We show that, contrary to suggestions made in literature, the complexity observed in the soliton's dynamics cannot be accounted for just by its coupling to the long-wavelength radiation.
Second order equation of motion for electromagnetic radiation back-reaction
Tamás Matolcsi; Tamás Fülöp; Mihály Weiner
2014-10-26T23:59:59.000Z
We take the viewpoint that the physically acceptable solutions of the Lorentz-Dirac equation for radiation back-reaction are actually determined by a second order equation of motion in such a way that the self-force can be given as a function of spacetime location and velocity. This self-force function turns out to be determined by a first order partial differential equation. In view of possible practical difficulty in solving that partial differential equation, we propose two iteration methods, too, for obtaining the self-force function. For two example systems, the second order equation of motion is obtained exactly in the nonrelativistic regime via each of the three methods, and the three results are found to coincide. We reveal that, for both systems, back-reaction induces a damping proportional to velocity and, in addition, it decreases the effect of the external force.
Cross, J. E.; Gregori, G. [Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Reville, B., E-mail: j.e.cross@physics.ox.ac.uk [Centre for Plasma Physics, Queen's University Belfast, University Road, Belfast BT7 1NN (United Kingdom)
2014-11-01T23:59:59.000Z
We introduce the equations of magneto-quantum-radiative hydrodynamics. By rewriting them in a dimensionless form, we obtain a set of parameters that describe scale-dependent ratios of characteristic hydrodynamic quantities. We discuss how these dimensionless parameters relate to the scaling between astrophysical observations and laboratory experiments.
ARM - Publications: Science Team Meeting Documents: ARM Radiative Transfer
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article) |govInstrumentsmfrirtA JourneygovCampaignsPajaritogovFieldMapping ofAand Radiative Forcing CloudsValidation of
CROSS VALIDATION OF SATELLITE RADIATION TRANSFER MODELS DURING SWERA PROJECT IN BRAZIL
Heinemann, Detlev
CROSS VALIDATION OF SATELLITE RADIATION TRANSFER MODELS DURING SWERA PROJECT IN BRAZIL Enio B-970, SP, Brazil. Phone + 55 12 39456741, Fax + 55 12 39456810, fernando@dge.inpe.br. Samuel L. Abreu, Hans, Federal University of Santa Catarina -UFSC, Florianópolis, 88040-900, (SC), Brazil. Richard Perez
Liberman, M A; Kiverin, A D
2015-01-01T23:59:59.000Z
In this study we examine influence of the radiation heat transfer on the combustion regimes in the mixture, formed by suspension of fine inert particles in hydrogen gas. The gaseous phase is assumed to be transparent for the thermal radiation, while the radiant heat absorbed by the particles is then lost by conduction to the surrounding gas. The particles and gas ahead of the flame is assumed to be heated by radiation from the original flame. It is shown that the maximum temperature increase due to the radiation preheating becomes larger for a flame with lower velocity. For a flame with small enough velocity temperature of the radiation preheating may exceed the crossover temperature, so that the radiation heat transfer may become a dominant mechanism of the flame propagation. In the case of non-uniform distribution of particles, the temperature gradient formed due to the radiation preheating can initiate either deflagration or detonation ahead of the original flame via the Zel'dovich's gradient mechanism. Th...
Shape-independent limits to near-field radiative heat transfer
Miller, Owen D; Rodriguez, Alejandro W
2015-01-01T23:59:59.000Z
We derive shape-independent limits to the spectral radiative heat-transfer rate between two closely spaced bodies, generalizing the concept of a black body to the case of near-field energy transfer. By conservation of energy, we show that each body of susceptibility $\\chi$ can emit and absorb radiation at enhanced rates bounded by $|\\chi|^2 / \\operatorname{Im} \\chi$, optimally mediated by near-field photon transfer proportional to $1/d^2$ across a separation distance $d$. Dipole--dipole and dipole--plate structures approach restricted versions of the limit, but common large-area structures do not exhibit the material enhancement factor and thus fall short of the general limit. By contrast, we find that particle arrays interacting in an idealized Born approximation exhibit both enhancement factors, suggesting the possibility of orders-of-magnitude improvement beyond previous designs and the potential for radiative heat transfer to be comparable to conductive heat transfer through air at room temperature, and s...
Alan P. Boss
2008-12-12T23:59:59.000Z
The disk instability mechanism for giant planet formation is based on the formation of clumps in a marginally-gravitationally unstable protoplanetary disk, which must lose thermal energy through a combination of convection and radiative cooling if they are to survive and contract to become giant protoplanets. While there is good observational support for forming at least some giant planets by disk instability, the mechanism has become theoretically contentious, with different three dimensional radiative hydrodynamics codes often yielding different results. Rigorous code testing is required to make further progress. Here we present two new analytical solutions for radiative transfer in spherical coordinates, suitable for testing the code employed in all of the Boss disk instability calculations. The testing shows that the Boss code radiative transfer routines do an excellent job of relaxing to and maintaining the analytical results for the radial temperature and radiative flux profiles for a spherical cloud with high or moderate optical depths, including the transition from optically thick to optically thin regions. These radial test results are independent of whether the Eddington approximation, diffusion approximation, or flux-limited diffusion approximation routines are employed. The Boss code does an equally excellent job of relaxing to and maintaining the analytical results for the vertical (theta) temperature and radiative flux profiles for a disk with a height proportional to the radial distance. These tests strongly support the disk instability mechanism for forming giant planets.
THE GENERAL RELATIVISTIC EQUATIONS OF RADIATION HYDRODYNAMICS IN THE VISCOUS LIMIT
Coughlin, Eric R.; Begelman, Mitchell C., E-mail: eric.coughlin@colorado.edu, E-mail: mitch@jila.colorado.edu [JILA, University of Colorado and National Institute of Standards and Technology, UCB 440, Boulder, CO 80309 (United States)
2014-12-20T23:59:59.000Z
We present an analysis of the general relativistic Boltzmann equation for radiation, appropriate to the case where particles and photons interact through Thomson scattering, and derive the radiation energy-momentum tensor in the diffusion limit with viscous terms included. Contrary to relativistic generalizations of the viscous stress tensor that appear in the literature, we find that the stress tensor should contain a correction to the comoving energy density proportional to the divergence of the four-velocity, as well as a finite bulk viscosity. These modifications are consistent with the framework of radiation hydrodynamics in the limit of large optical depth, and do not depend on thermodynamic arguments such as the assignment of a temperature to the zeroth-order photon distribution. We perform a perturbation analysis on our equations and demonstrate that as long as the wave numbers do not probe scales smaller than the mean free path of the radiation, the viscosity contributes only decaying, i.e., stable, corrections to the dispersion relations. The astrophysical applications of our equations, including jets launched from super-Eddington tidal disruption events and those from collapsars, are discussed and will be considered further in future papers.
THE DIFFUSION APPROXIMATION FOR THE LINEAR BOLTZMANN EQUATION
THE DIFFUSION APPROXIMATION FOR THE LINEAR BOLTZMANN EQUATION WITH VANISHING SCATTERING COEFFICIENT equation, Diffusion approximation, Neutron transport equation, Radiative transfer equation subject, 23], neutron transport theory [27]. A typical model linear Boltzmann equation is (t +· x)f(t,x,)= 1
Efficient weakly-radiative wireless energy transfer: An EIT-like approach
Hamam, Rafif E. [Center for Materials Science and Engineering and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)], E-mail: rafif@mit.edu; Karalis, Aristeidis; Joannopoulos, J.D.; Soljacic, Marin [Center for Materials Science and Engineering and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)
2009-08-15T23:59:59.000Z
Inspired by a quantum interference phenomenon known in the atomic physics community as electromagnetically induced transparency (EIT), we propose an efficient weakly radiative wireless energy transfer scheme between two identical classical resonant objects, strongly coupled to an intermediate classical resonant object of substantially different properties, but with the same resonance frequency. The transfer mechanism essentially makes use of the adiabatic evolution of an instantaneous (so called 'dark') eigenstate of the coupled 3-object system. Our analysis is based on temporal coupled mode theory (CMT), and is general enough to be valid for various possible sorts of coupling, including the resonant inductive coupling on which witricity-type wireless energy transfer is based. We show that in certain parameter regimes of interest, this scheme can be more efficient, and/or less radiative than other, more conventional approaches. A concrete example of wireless energy transfer between capacitively-loaded metallic loops is illustrated at the beginning, as a motivation for the more general case. We also explore the performance of the currently proposed EIT-like scheme, in terms of improving efficiency and reducing radiation, as the relevant parameters of the system are varied.
Siewert, Charles E.
-grey heat transfer model is that of SIMMONS and FERZIGER(~)who used the normal modes(4) of the equation
Yuen, Walter W.
-gray radiative heat transfer effect in three-dimensional gas-particle mixtures Walter W. Yuen * Department to assess the accuracy of some commonly accepted approximate approaches to evaluate radiative heat transfer enhance the accuracy of simulation of radiative heat transfer in practical engineering systems. Ó 2009
Svend-Age Biehs
2011-03-15T23:59:59.000Z
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.
Zhang, Yuwen
transfer Non-equilibrium Dual-phase lag a b s t r a c t Based on a nonequilibrium heat transfer model
Greendyke, Robert Brian
1988-01-01T23:59:59.000Z
will examine the radiance model and various step models in order to determine their appropriateness to the flight regime of the AOTV. The final area to be investigated will be the effect of nonequilibrium corrections on the radiative heat transfer models... of T and e T will be valid as long as there is a reasonable amount vNs of nitrogen molecules in the flow. Radiative Heat Transfer Models For this study, four radiative heat transfer models were examined. One of these models is an optically thin radiance...
Feng, Tao, E-mail: fengtao2@mail.ustc.edu.cn [School of Mathematical Sciences, University of Science and Technology of China, Hefei 230052 (China) [School of Mathematical Sciences, University of Science and Technology of China, Hefei 230052 (China); Graduate School of China Academy Engineering Physics, Beijing 100083 (China); An, Hengbin, E-mail: an_hengbin@iapcm.ac.cn [National Key Laboratory of Computational Physics, Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China)] [National Key Laboratory of Computational Physics, Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China); Yu, Xijun, E-mail: yuxj@iapcm.ac.cn [National Key Laboratory of Computational Physics, Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China)] [National Key Laboratory of Computational Physics, Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China); Li, Qin, E-mail: liqin@lsec.cc.ac.cn [Chinese Academy of Mathematics and Systems Science, Beijing 100190 (China)] [Chinese Academy of Mathematics and Systems Science, Beijing 100190 (China); Zhang, Rongpei, E-mail: zhangrongpei@163.com [Graduate School of China Academy Engineering Physics, Beijing 100083 (China)] [Graduate School of China Academy Engineering Physics, Beijing 100083 (China)
2013-03-01T23:59:59.000Z
Jacobian-free Newton–Krylov (JFNK) method is an effective algorithm for solving large scale nonlinear equations. One of the most important advantages of JFNK method is that there is no necessity to form and store the Jacobian matrix of the nonlinear system when JFNK method is employed. However, an approximation of the Jacobian is needed for the purpose of preconditioning. In this paper, JFNK method is employed to solve a class of non-equilibrium radiation diffusion coupled to material thermal conduction equations, and two preconditioners are designed by linearizing the equations in two methods. Numerical results show that the two preconditioning methods can improve the convergence behavior and efficiency of JFNK method.
Kitzmann, D; Rauer, H
2013-01-01T23:59:59.000Z
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...
and the basic rate equations for conduction, convection, and radiation. 2. Analyze conduction heat transfer the appropriate correlation for convective heat transfer process. 6. Analyze radiation exchange within methods for 2-D conduction 4. Forced Convection 5. Natural/Free Convection 6. Radiation Heat Transfer #12
Proceedings of HTSC 2005: Heat Transfer Summer Conference
Guo, Zhixiong "James"
for describing radiation transfer and heat transfer in the micro/nanoscale devices is presented firstProceedings of HTSC 2005: Heat Transfer Summer Conference San Francisco, CA, July 17-22, 2005 HT's equations which govern the propagation of electromagnetic field and the radiation energy transport
Radiative transfer in the earth's atmosphere-ocean system using Monte Carlo techniques
Bradley, Paul Andrew
1987-01-01T23:59:59.000Z
TRANSFER PROBLEM MONTE CARLO METHOD Assumptions of the Model Photon Pathlength Emulation Techniques Sampling Scattering Functions: Angles and Probabilities Emulation of an Interface Computing the Radiance by Statistical Estimation Determination... radiance values in both the atmosphere and the ocean from the scattering functions and other input data, with a Monte Carlo computer code. The polarization ot the radiation was taken into account by Kattawar et al. s in their computation...
Non-contact pumping of light emitters via non-radiative energy transfer
Klimov, Victor I. (Los Alamos, NM); Achermann, Marc (Los Alamos, NM)
2010-01-05T23:59:59.000Z
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.
Near-Field Radiative Heat Transfer between Metamaterials coated with Silicon Carbide Film
Basu, Soumyadipta; Wang, Liping
2014-01-01T23:59:59.000Z
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.
Ionizing and ultraviolet radiation enhances the efficiency of DNA mediated gene transfer in vitro
Perez, C.F.
1984-08-01T23:59:59.000Z
The enhancement effects of ionizing and non-ionizing radiation on the efficiency of DNA mediated gene transfer were studied. Confluent Rat-2 cells were transfected with purified SV40 viral DNA, irradiated with either X-rays or ultraviolet, trypsinized, plated, and assayed for the formation of foci on Rat-2 monolayers. Both ionizing and ultraviolet radiation enhanced the frequency of A-gene transformants/survivor compared to unirradiated transfected cells. These enhancements were non-linear and dose dependent. A recombinant plasmid, pOT-TK5, was constructed that contained the SV40 virus A-gene and the Herpes Simplex virus (HSV) thymidine kinase (TK) gene. Confluent Rat-2 cells transfected with pOT-TK5 DNA and then immediately irradiated with either X-rays or 330 MeV/amu argon particles at the Berkeley Bevalac showed a higher frequency of HAT/sup +/ colonies/survivor than unirradiated transfected cells. Rat-2 cells transfected with the plasmid, pTK2, containing only the HSV TK-gene were enhanced for TK-transformation by both X-rays and ultraviolet radiation. The results demonstrate that radiation enhancement of the efficiency of DNA mediated gene transfer is not explained by increased nuclear uptake of the transfected DNA. Radiation increases the competence of the transfected cell population for genetic transformation. Three models for this increased competence are presented. The targeted integration model, the inducible recombination model, the partition model, and the utilization of DNA mediated gene transfer for DNA repair studies are discussed. 465 references.
Joulain, Karl; Drevillon, Jeremie; Ben-Abdallah, Philippe
2015-01-01T23:59:59.000Z
We show in this article that phase change materials (PCM) exhibiting a phase transition between a dielectric state and a metallic state are good candidates to perform modulation as well as amplification of radiative thermal flux. We propose a simple situation in plane parallel geometry where a so-called radiative thermal transistor could be achieved. In this configuration, we put a PCM between two blackbodies at different temperatures. We show that the transistor effect can be achieved easily when this material has its critical temperature between the two blackbody temperatures. We also see, that the more the material is reflective in the metallic state, the more switching effect is realized whereas the more PCM transition is stiff in temperature, the more thermal amplification is high. We finally take the example of VO2 that exhibits an insulator-metallic transition at 68{\\textdegree}C. We show that a demonstrator of a radiative transistor could easily be achieved in view of the heat flux levels predicted. F...
Radiative charge transfer in cold and ultracold Sulfur atoms colliding with Protons
Shen, G; Wang, J G; McCann, J F; McLaughlin, B M
2015-01-01T23:59:59.000Z
Radiative decay processes at cold and ultra cold temperatures for Sulfur atoms colliding with protons are investigated. The MOLPRO quantum chemistry suite of codes was used to obtain accurate potential energies and transition dipole moments, as a function of internuclear distance, between low-lying states of the SH$^{+}$ molecular cation. A multi-reference configuration-interaction (MRCI) approximation together with the Davidson correction is used to determine the potential energy curves and transition dipole moments, between the states of interest, where the molecular orbitals (MO's) are obtained from state-averaged multi configuration-self-consistent field (MCSCF) calculations. The collision problem is solved approximately using an optical potential method to obtain radiative loss, and a fully two-channel quantum approach for radiative charge transfer. Cross sections and rate coefficients are determined for the first time for temperatures ranging from 10 $\\mu$ K up to 10,000 K. Results are obtained for all ...
Wang, Chenxi
2013-07-25T23:59:59.000Z
observations and fast radiative transfer models (RTMs). In the first part, we develop two computationally efficient RTMs simulating satellite observations under cloudy-sky conditions in the visible/shortwave infrared (VIS/SWIR) and thermal inferred (IR...
Greendyke, Robert Brian
1988-01-01T23:59:59.000Z
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...
Order Reduction of the Radiative Heat Transfer Model for the Simulation of Plasma Arcs
Fagiano, Lorenzo
2015-01-01T23:59:59.000Z
An approach to derive low-complexity models describing thermal radiation for the sake of simulating the behavior of electric arcs in switchgear systems is presented. The idea is to approximate the (high dimensional) full-order equations, modeling the propagation of the radiated intensity in space, with a model of much lower dimension, whose parameters are identified by means of nonlinear system identification techniques. The low-order model preserves the main structural aspects of the full-order one, and its parameters can be straightforwardly used in arc simulation tools based on computational fluid dynamics. In particular, the model parameters can be used together with the common approaches to resolve radiation in magnetohydrodynamic simulations, including the discrete-ordinate method, the P-N methods and photohydrodynamics. The proposed order reduction approach is able to systematically compute the partitioning of the electromagnetic spectrum in frequency bands, and the related absorption coefficients, tha...
Siewert, Charles E.
Heat transfer between parallel plates: An approach based on the linearized Boltzmann equation a concise and particularly accurate solution of the heat-transfer problem for a binary gas mixture confined.1063/1.2511039 I. INTRODUCTION The heat-transfer problem within the context of rarefied gas dynamics has been
Soljaèiæ, Marin
2012-01-01T23:59:59.000Z
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
Boyer, Edmond
Eurotherm Seminar N°81 Reactive Heat Transfer in Porous Media, Ecole des Mines d'Albi, France June 4-6, 2007 ET81- 1 HEAT TRANSFER BY SIMULTANEOUS RADIATION-CONDUCTION AND CONVECTION IN A HIGH for the packed bed. The comparison between the radiative heat transfer and the exchanges by conduction and forced
Three-dimensional Radiative Transfer Modeling of the Polarization of the Sun's Continuous Spectrum
J. Trujillo Bueno; N. Shchukina
2008-12-18T23:59:59.000Z
Here we formulate and solve the 3D radiative transfer problem of the polarization of the solar continuous radiation. Our approach takes into account not only the anisotropy of the continuum radiation, but also the symmetry-breaking effects caused by the horizontal atmospheric inhomogeneities produced by the solar surface convection. Interestingly, our radiative transfer modeling in a well-known 3D hydrodynamical model of the solar photosphere shows remarkable agreement with the empirical data, significantly better than that obtained via the use of 1D atmospheric models. Although this result confirms that the above-mentioned 3D model was indeed a suitable choice for our Hanle-effect estimation of the substantial amount of "hidden" magnetic energy that is stored in the quiet solar photosphere, we have found however some small discrepancies whose origin may be due to uncertainties in the empirical data and/or in the thermal and density structure of the 3D model. For this reason, we have paid some attention also to other (more familiar) observables, like the center-limb variation of the continuum intensity, which we have calculated taking into account the scattering contribution to the continuum source function. The overall agreement with the observed center-limb variation turns out to be impressive, but we find a hint that the model's temperature gradients in the continuum forming layers could be slightly too steep, perhaps because all current simulations of solar surface convection and magnetoconvection compute the radiative flux divergence ignoring the fact that the effective polarizability is not completely negligible, especially in the downward-moving intergranular lane plasma.
Investigation of Radiation and Chemical Resistance of Flexible HLW Transfer Hose
E. Skidmore; Billings, K.; Hubbard, M.
2010-03-24T23:59:59.000Z
A chemical transfer hose constructed of an EPDM (ethylene-propylene diene monomer) outer covering with a modified cross-linked polyethylene (XLPE) lining was evaluated for use in high level radioactive waste transfer applications. Laboratory analysis involved characterization of the hose liner after irradiation to doses of 50 to 300 Mrad and subsequent exposure to 25% NaOH solution at 93 C for 30 days, simulating 6 months intermittent service. The XLPE liner mechanical and structural properties were characterized at varying dose levels. Burst testing of irradiated hose assemblies was also performed. Literature review and test results suggest that radiation effects below doses of 100 kGy are minimal, with acceptable property changes to 500 kGy. Higher doses may be feasible. At a bounding dose of 2.5 MGy, the burst pressure is reduced to the working pressure (1.38 MPa) at room temperature. Radiation exposure slightly reduces liner tensile strength, with more significant decrease in liner elongation. Subsequent exposure to caustic solutions at elevated temperature slightly increases elongation, suggesting an immersion/hydrolytic effect or possible thermal annealing of radiation damage. This paper summarizes the laboratory results and recommendations for field deployment.
Harvesting nanoscale thermal radiation using pyroelectric materials
Fang, Jin; Frederich, Hugo; Pilon, Laurent
2010-01-01T23:59:59.000Z
eld radiative heat transfer dominates radiation transferstudy Far field radiation Heat transfer coefficient, h r (W/nanoscale radiation to enhance radiative heat transfer. The
Radiative heat transfer between two dielectric nanogratings in the scattering approach
J. Lussange; R. Guérout; F. S. S. Rosa; J. -J. Greffet; A. Lambrecht; S. Reynaud
2012-06-01T23:59:59.000Z
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.
Alan M. Watson; William J. Henney
2001-08-30T23:59:59.000Z
We describe an efficient Monte Carlo algorithm for a restricted class of scattering problems in radiation transfer. This class includes many astrophysically interesting problems, including the scattering of ultraviolet and visible light by grains. The algorithm correctly accounts for multiply-scattered light. We describe the algorithm, present a number of important optimizations, and explicity show how the algorithm can be used to estimate quantities such as the emergent and mean intensity. We present two test cases, examine the importance of the optimizations, and show that this algorithm can be usefully applied to optically-thin problems, a regime sometimes considered limited to explicit single-scattering plus attenuation approximations.
Multi--dimensional Cosmological Radiative Transfer with a Variable Eddington Tensor Formalism
Nickolay Y. Gnedin; Tom Abel
2001-06-15T23:59:59.000Z
We present a new approach to numerically model continuum radiative transfer based on the Optically Thin Variable Eddington Tensor (OTVET) approximation. Our method insures the exact conservation of the photon number and flux (in the explicit formulation) and automatically switches from the optically thick to the optically thin regime. It scales as N logN with the number of hydrodynamic resolution elements and is independent of the number of sources of ionizing radiation (i.e. works equally fast for an arbitrary source function). We also describe an implementation of the algorithm in a Soften Lagrangian Hydrodynamic code (SLH) and a multi--frequency approach appropriate for hydrogen and helium continuum opacities. We present extensive tests of our method for single and multiple sources in homogeneous and inhomogeneous density distributions, as well as a realistic simulation of cosmological reionization.
Frequency-Selective Near-Field Radiative Heat Transfer between Photonic Crystal Slabs-selective near-field radiative heat transfer between patterned (photonic-crystal) slabs at designable frequencies and separations, exploiting a general numerical approach for computing heat transfer in arbitrary geometries
RADIATION HEAT TRANSFER ENVIRONMENT IN FIRE AND FURNACE TESTS OF RADIOACTIVE MATERIALS PAKCAGES
Smith, A
2008-12-31T23:59:59.000Z
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.
A. H. M. Kierkels; J. J. L. Velázquez
2014-10-08T23:59:59.000Z
We study the mathematical properties of a kinetic equation which describes the long time behaviour of solutions to the weak turbulence equation associated to the cubic nonlinear Schr\\"odinger equation. In particular, we give a precise definition of weak solutions and prove global existence of solutions for all initial data with finite mass. We also prove that any nontrivial initial datum yields the instantaneous onset of a condensate, i.e. a Dirac mass at the origin for any positive time. Furthermore we show that the only stationary solutions with finite total measure are Dirac masses at the origin. We finally construct solutions with finite energy, which is transferred to infinity in a self-similar manner.
3D hydrodynamical and radiative transfer modeling of Eta Carinae's colliding winds
Madura, Thomas I; Gull, Theodore R; Kruip, Chael J H; Paardekooper, Jan-Pieter; Icke, Vincent
2015-01-01T23:59:59.000Z
We present results of full 3D hydrodynamical and radiative transfer simulations of the colliding stellar winds in the massive binary system Eta Carinae. We accomplish this by applying the SimpleX algorithm for 3D radiative transfer on an unstructured Voronoi-Delaunay grid to recent 3D smoothed particle hydrodynamics (SPH) simulations of the binary colliding winds. We use SimpleX to obtain detailed ionization fractions of hydrogen and helium, in 3D, at the resolution of the original SPH simulations. We investigate several computational domain sizes and Luminous Blue Variable primary star mass-loss rates. We furthermore present new methods of visualizing and interacting with output from complex 3D numerical simulations, including 3D interactive graphics and 3D printing. While we initially focus on Eta Car, the methods employed can be applied to numerous other colliding wind (WR 140, WR 137, WR 19) and dusty 'pinwheel' (WR 104, WR 98a) binary systems. Coupled with 3D hydrodynamical simulations, SimpleX simulatio...
The dusty MOCASSIN: fully self-consistent 3D photoionisation and dust radiative transfer models
B. Ercolano; M. J. Barlow; P. J. Storey
2005-07-02T23:59:59.000Z
We present the first 3D Monte Carlo (MC) photoionisation code to include a fully self-consistent treatment of dust radiative transfer (RT) within a photoionised region. This is the latest development (Version 2.0) of the gas-only photoionisation code MOCASSIN (Ercolano et al., 2003a), and employs a stochastic approach to the transport of radiation, allowing both the primary and secondary components of the radiation field to be treated self-consistently, whilst accounting for the scattering of radiation by dust grains mixed with the gas, as well as the absorption and emission of radiation by both the gas and the dust components. A set of rigorous benchmark tests have been carried out for dust-only spherically symmetric geometries and 2D disk configurations. MOCASSIN's results are found to be in agreement with those obtained by well established dust-only RT codes that employ various approaches to the solution of the RT problem. A model of the dust and of the photoionised gas components of the planetary nebula (PN) NGC 3918 is also presented as a means of testing the correct functioning of the RT procedures in a case where both gas and dust opacities are present. The two components are coupled via the heating of dust grains by the absorption of both UV continuum photons and resonance line photons emitted by the gas. The MOCASSIN results show agreement with those of a 1D dust and gas model of this nebula published previously, showing the reliability of the new code, which can be applied to a variety of astrophysical environments.
Radiative charge transfer in cold and ultracold Sulfur atoms colliding with Protons
G Shen; P C Stancil; J G Wang; J F McCann; B M McLaughlin
2015-02-25T23:59:59.000Z
Radiative decay processes at cold and ultra cold temperatures for Sulfur atoms colliding with protons are investigated. The MOLPRO quantum chemistry suite of codes was used to obtain accurate potential energies and transition dipole moments, as a function of internuclear distance, between low-lying states of the SH$^{+}$ molecular cation. A multi-reference configuration-interaction (MRCI) approximation together with the Davidson correction is used to determine the potential energy curves and transition dipole moments, between the states of interest, where the molecular orbitals (MO's) are obtained from state-averaged multi configuration-self-consistent field (MCSCF) calculations. The collision problem is solved approximately using an optical potential method to obtain radiative loss, and a fully two-channel quantum approach for radiative charge transfer. Cross sections and rate coefficients are determined for the first time for temperatures ranging from 10 $\\mu$ K up to 10,000 K. Results are obtained for all isotopes of Sulfur, colliding with H$^{+}$ and D$^{+}$ ions and comparison is made to a number of other collision systems.
Quasiballistic heat transfer studied using the frequency-dependent Boltzmann transport equation
Chen, Gang
Quasiballistic heat transfer occurs when there is a temperature gradient over length scales comparable to phonon mean free paths (MFPs). This regime has been of interest recently because observation of quasiballistic ...
Song, XiaoGeng, Ph. D. Massachusetts Institute of Technology
2009-01-01T23:59:59.000Z
In this dissertation, we discuss two methods developed during my PhD study to simulate electron transfer systems. The first method, the semi-classical approximation, is derived from the stationary phase approximation to ...
Claudio Coriano; Antonio Costantini; Marta Dell'Atti; Luigi Delle Rose
2015-07-11T23:59:59.000Z
We extend a previous phenomenological analysis of photon lensing in an external gravitational background to the case of a massless neutrino, and propose a method to incorporate radiative effects in the classical lens equations of neutrinos and photons. The study is performed for a Schwarzschild metric, generated by a point-like source, and expanded in the Newtonian potential at first order. We use a semiclassical approach, where the perturbative corrections to neutrino scattering, evaluated at one-loop in the Standard Model, are compared with the Einstein formula for the deflection using an impact parameter formulation. For this purpose, we use the renormalized expression of the graviton/fermion/fermion vertex presented in previous studies. We show the agreement between the classical and the semiclassical formulations, for values of the impact parameter $b_h$ of the neutrinos of the order of $b_h\\sim 20$, measured in units of the Schwarzschild radius. The analysis is then extended with the inclusion of the post Newtonian corrections in the external gravity field, showing that this extension finds application in the case of the scattering of a neutrino/photon off a primordial black hole. The energy dependence of the deflection, generated by the quantum corrections, is then combined with the standard formulation of the classical lens equations. We illustrate our approach by detailed numerical studies, using as a reference both the thin lens and the nonlinear Virbhadra-Ellis lens.
Constraints on Blazar Jet Conditions During Gamma-Ray Flaring from Radiative Transfer Modeling
Aller, Margo F; Aller, Hugh D; Hovatta, Talvikki
2013-01-01T23:59:59.000Z
As part of a program to investigate jet flow conditions during GeV gamma-ray flares detected by Fermi, we are using UMRAO multi-frequency, centimeter-band total flux density and linear polarization monitoring observations to constrain radiative transfer models incorporating propagating shocks orientated at an arbitrary angle to the flow direction. We describe the characteristics of the model, illustrate how the data are used to constrain the models, and present results for three program sources with diverse characteristics: PKS 0420-01, OJ 287, and 1156+295. The modeling of the observed spectral behavior yields information on the sense, strength and orientation of the shocks producing the radio-band flaring; on the energy distribution of the radiating particles; and on the observer's viewing angle with respect to the jet independent of VLBI data. We present evidence that, while a random component dominates the jet magnetic field, a distinguishing feature of those radio events with an associated gamma-ray flar...
O Star X-ray Line Profiles Explained by Radiation Transfer in Inhomogeneous Stellar Wind
L. M. Oskinova; A. Feldmeier; W. -R. Hamann
2005-11-01T23:59:59.000Z
It is commonly adopted that X-rays from O stars are produced deep inside the stellar wind, and transported outwards through the bulk of the expanding matter which attenuates the radiation and affects the shape of emission line profiles. The ability of Chandra and XMM-Newton to resolve these lines spectroscopically provided a stringent test for the theory of X-ray production. It turned out that none of the existing models was able to reproduce the observations consistently. The major caveat of these models was the underlying assumption of a smooth stellar wind. Motivated by the various observational evidence that the stellar winds are in fact structured, we present a 2-D model of a stochastic, inhomogeneous wind. The X-ray radiative transfer is derived for such media. It is shown that profiles from a clumped wind differ drastically from those predicted by conventional homogeneous models. We review the up-to-date observations of X-ray line profiles from stellar winds and present line fits obtained from the inhomogeneous wind model. The necessity to account for inhomogeneities in calculating the X-ray transport in massive star winds, including for HMXB is highlighted.
Radiation heat transfer in multitube, alkaline-metal thermal-to-electric converter
Tournier, J.M.P.; El-Genk, M.S. [Univ. of New Mexico, Albuquerque, NM (United States)
1999-02-01T23:59:59.000Z
Vapor anode, multitube Alkali-Metal Thermal-to-Electric Converters (AMTECs) are being considered for a number of space missions, such as the NASA Pluto/Express (PX) and Europa missions, scheduled for the years 2004 and 2005, respectively. These static converters can achieve a high fraction of Carnot efficiency at relatively low operating temperatures. An optimized cell can potentially provide a conversion efficiency between 20 and 30 percent, when operated at a hot-side temperature of 1000--1200 K and a cold-side temperature of 550--650 K. A comprehensive modeling and testing program of vapor anode, multitube AMTEC cells has been underway for more than three years at the Air Force Research Laboratory`s Power and Thermal Group (AFRL/VSDVP), jointly with the University of New Mexico`s Institute for Space and Nuclear Power Studies. The objective of this program is to demonstrate the readiness of AMTECs for flight on future US Air Force space missions. A fast, integrated AMTEC Performance and Evaluation Analysis Model (APEAM) has been developed to support ongoing vacuum tests at AFRL and perform analyses and investigate potential design changes to improve the PX-cell performance. This model consists of three major components (Tournier and El-Genk 1998a, b): (a) a sodium vapor pressure loss model, which describes continuum, transition and free-molecule flow regimes in the low-pressure cavity of the cell; (b) an electrochemical and electrical circuit model; and (c) a radiation/conduction heat transfer model, for calculating parasitic heat losses. This Technical Note describes the methodology used to calculate the radiation view factors within the enclosure of the PX-cells, and the numerical procedure developed in this work to determine the radiation heat transport and temperatures within the cell cavity.
Zhou Gang; Michael Weinstein
2008-11-03T23:59:59.000Z
Nonlinear Schrodinger / Gross-Pitaevskii equations play a central role in the understanding of nonlinear optical and macroscopic quantum systems. The large time dynamics of such systems is governed by interactions of the nonlinear ground state manifold, discrete neutral modes (``excited states'') and dispersive radiation. Systems with symmetry, in spatial dimensions larger than one, typically have degenerate neutral modes. Thus, we study the large time dynamics of systems with degenerate neutral modes. This requires a new normal form (nonlinear matrix Fermi Golden Rule) governing the system's large time asymptotic relaxation to the ground state (soliton) manifold.
Baes, Maarten
2008-01-01T23:59:59.000Z
that is inherent in Monte Carlo radiative transfer simulations. As the typical detectors used in Monte Carlo negligible, we recommend the use of smart detectors in Monte Carlo radiative transfer simulations. Key wordsMon. Not. R. Astron. Soc. 391, 617623 (2008) doi:10.1111/j.1365-2966.2008.13941.x Smart detectors
Yang, Yue
2015-01-01T23:59:59.000Z
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.
Solutions of the equation of radiative transfer by matrix operator techniques
Catchings, Frances Eugenia King
1973-01-01T23:59:59.000Z
X X N~xkkaR 11F 0. 0 0, 2 0. % 0, 6 0. 8 1 0 0. 8 0, 6 0. 4 0. 2 0. 0 Figure 17 Downward Radiance for uo ~ 0. 1882, A ~ 1, and ) 0 and 180 (Rayleigh). See Fig. 2 for key. 10' q 0. 1882 A 1. 0 4 Do 4-180o tran 10 ' CC C3 C) CL ~ 10-& C3... Fig. 2 for key. ac=0. 9379 A=O. O e 0 e 180 CI: C3 CZ CI: C) CL Q. I ~ ( I' I " 'T I ej X X X 1 X e~e e X +J X X X X X X X + j + x, x x + e-I + x ~x + + + + 8 + e+ e + ' e+ + + + 8 k 8 8 8 8 8 8 $&$&y~ 1 0' I 10 10a y 10...
Lyalpha RADIATIVE TRANSFER WITH DUST: ESCAPE FRACTIONS FROM SIMULATED HIGH-REDSHIFT GALAXIES
Laursen, Peter; Sommer-Larsen, Jesper; Andersen, Anja C., E-mail: pela@dark-cosmology.d, E-mail: jslarsen@astro.ku.d [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100, Copenhagen Oe (Denmark)
2009-10-20T23:59:59.000Z
The Lyalpha emission line is an essential diagnostic tool for probing galaxy formation and evolution. Not only is it commonly the strongest observable line from high-redshift galaxies, but from its shape detailed information about its host galaxy can be revealed. However, due to the scattering nature of Lyalpha photons increasing their path length in a nontrivial way, if dust is present in the galaxy, the line may be severely suppressed and its shape altered. In order to interpret observations correctly, it is thus of crucial significance to know how much of the emitted light actually escapes the galaxy. In the present work, using a combination of high-resolution cosmological hydrosimulations and an adaptively refinable Monte Carlo Lyalpha radiative transfer code including an environment dependent model of dust, the escape fractions f {sub esc} of Lyalpha radiation from high-redshift (z = 3.6) galaxies are calculated. In addition to the average escape fraction, the variation of f {sub esc} in different directions and from different parts of the galaxies is investigated, as well as the effect on the emergent spectrum. Escape fractions from a sample of simulated galaxies of representative physical properties are found to decrease for increasing galaxy virial mass M {sub vir}, from f {sub esc} approaching unity for M {sub vir} approx 10{sup 9} M {sub sun} to f {sub esc} less than 10% for M {sub vir} approx 10{sup 12} M {sub sun}. In spite of dust being almost gray, it is found that the emergent spectrum is affected nonuniformly, with the escape fraction of photons close to the line center being much higher than of those in the wings, thus effectively narrowing the Lyalpha line.
Radiative-transfer models for supernovae IIb/Ib/Ic from binary-star progenitors
Dessart, Luc; Woosley, Stan; Livne, Eli; Waldman, Roni; Yoon, Sung-Chul; Langer, Norbert
2015-01-01T23:59:59.000Z
We present 1-D non-Local-Thermodynamic-Equilibrium time-dependent radiative-transfer simulations for supernovae (SNe) of type IIb, Ib, and Ic that result from the terminal explosion of the mass donor in a close-binary system. Here, we select three ejecta with a total kinetic energy of ~1.2e51erg, but characterised by different ejecta masses (2-5Msun), composition, and chemical mixing. The type IIb/Ib models correspond to the progenitors that have retained their He-rich shell at the time of explosion. The type Ic model arises from a progenitor that has lost its helium shell, but retains 0.32Msun of helium in a CO-rich core of 5.11Msun. We discuss their photometric and spectroscopic properties during the first 2-3 months after explosion, and connect these to their progenitor and ejecta properties including chemical stratification. For these three models, Arnett's rule overestimates the 56Ni mass by ~50% while the procedure of Katz et al., based on an energy argument, yields a more reliable estimate. The presenc...
Ly{alpha} RADIATIVE TRANSFER IN COSMOLOGICAL SIMULATIONS USING ADAPTIVE MESH REFINEMENT
Laursen, Peter [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100, Copenhagen Oe (Denmark); Razoumov, Alexei O. [Institute for Computational Astrophysics, Department of Astronomy and Physics, Saint Mary's University, Halifax, NS, B3H3C3 (Canada); Sommer-Larsen, Jesper [Excellence Cluster Universe, Technische Universitaet Muenchen, Boltzmannstrasse 2, D-85748 Garching (Germany)], E-mail: pela@dark-cosmology.dk, E-mail: razoumov@ap.smu.ca, E-mail: jslarsen@astro.ku.dk
2009-05-01T23:59:59.000Z
A numerical code for solving various Ly{alpha} radiative transfer (RT) problems is presented. The code is suitable for an arbitrary, three-dimensional distribution of Ly{alpha} emissivity, gas temperature, density, and velocity field. Capable of handling Ly{alpha} RT in an adaptively refined grid-based structure, it enables detailed investigation of the effects of clumpiness of the interstellar (or intergalactic) medium. The code is tested against various geometrically and physically idealized configurations for which analytical solutions exist, and subsequently applied to three different simulated high-resolution 'Lyman-break galaxies', extracted from high-resolution cosmological simulations at redshift z = 3.6. Proper treatment of the Ly{alpha} scattering reveals a diversity of surface brightness (SB) and line profiles. Specifically, for a given galaxy the maximum observed SB can vary by an order of magnitude, and the total flux by a factor of 3-6, depending on the viewing angle. This may provide an explanation for differences in observed properties of high-redshift galaxies, and in particular a possible physical link between Lyman-break galaxies and regular Ly{alpha} emitters.
A new scheme of radiation transfer in H II regions including transient heating of grains
S. K. Ghosh; R. P. Verma
2000-09-21T23:59:59.000Z
A new scheme of radiation transfer for understanding infrared spectra of H II regions, has been developed. This scheme considers non-equilibrium processes (e. g. transient heating of the very small grains, VSG; and the polycyclic aromatic hydrocarbon, PAH) also, in addition to the equilibrium thermal emission from normal dust grains (BG). The spherically symmetric interstellar dust cloud is segmented into a large number of "onion skin" shells in order to implement the non-equilibrium processes. The scheme attempts to fit the observed SED originating from the dust component, by exploring the following parameters : (i) geometrical details of the dust cloud, (ii) PAH size and abundance, (iii) composition of normal grains (BG), (iv) radial distribution of all dust (BG, VSG & PAH). The scheme has been applied to a set of five compact H II regions (IRAS 18116- 1646, 18162-2048, 19442+2427, 22308+5812 & 18434-0242) whose spectra are available with adequate spectral resolution. The best fit models and inferences about the parameters for these sources are presented.
Kravis, S. D.; Church, David A.; Johnson, B. M.; Meron, M.; Jones, K. W.; Levin, J. C.; Sellin, I. A.; Azuma, Y.; Berrahmansour, N.; Berry, H. G.; Druetta, M.
1992-01-01T23:59:59.000Z
PHYSICAL REVIEW A VOLUME 45, NUMBER 9 1 MAY 1992 Electron transfer from H2 and Ar to stored multiply charged argon ions produced by synchrotron radiation S. D. Kravis* and D. A. Church Physics Department, Texas A &M University, College Station... Ridge National Laboratory, Oak Ridge, Tennessee 37831 Y. Azuma, N. Berrah-Mansour, and H. G. Berry Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 M. Druetta Laboratoire Traitement du Signal et Instrumentation, Universite de St...
Moncada-Villa, Edwin; Garcia-Vidal, Francisco J; Garcia-Martin, Antonio; Cuevas, Juan Carlos
2015-01-01T23:59:59.000Z
We present a comprehensive theoretical study of the magnetic field dependence of the near-field radiative heat transfer (NFRHT) between two parallel plates. We show that when the plates are made of doped semiconductors, the near-field thermal radiation can be severely affected by the application of a static magnetic field. We find that irrespective of its direction, the presence of a magnetic field reduces the radiative heat conductance, and dramatic reductions up to 700% can be found with fields of about 6 T at room temperature. We show that this striking behavior is due to the fact that the magnetic field radically changes the nature of the NFRHT. The field not only affects the electromagnetic surface waves (both plasmons and phonon polaritons) that normally dominate the near-field radiation in doped semiconductors, but it also induces hyperbolic modes that progressively dominate the heat transfer as the field increases. In particular, we show that when the field is perpendicular to the plates, the semicond...
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Davis, Anthony B.; Xu, Feng; Collins, William D.
2015-03-01T23:59:59.000Z
Atmospheric hyperspectral VNIR sensing struggles with sub-pixel variability of clouds and limited spectral resolution mixing molecular lines. Our generalized radiative transfer model addresses both issues with new propagation kernels characterized by power-law decay in space.
Alberto Barchielli
2015-06-24T23:59:59.000Z
The quantum stochastic Schroedinger equation or Hudson-Parthasareathy (HP) equation is a powerful tool to construct unitary dilations of quantum dynamical semigroups and to develop the theory of measurements in continuous time via the construction of output fields. An important feature of such an equation is that it allows to treat not only absorption and emission of quanta, but also scattering processes, which however had very few applications in physical modelling. Moreover, recent developments have shown that also some non-Markovian dynamics can be generated by suitable choices of the state of the quantum noises involved in the HP-equation. This paper is devoted to an application involving these two features, non-Markovianity and scattering process. We consider a micro-mirror mounted on a vibrating structure and reflecting a laser beam, a process giving rise to a radiation-pressure force on the mirror. We show that this process needs the scattering part of the HP-equation to be described. On the other side, non-Markovianity is introduced by the dissipation due to the interaction with some thermal environment which we represent by a phonon field, with a nearly arbitrary excitation spectrum, and by the introduction of phase noise in the laser beam. Finally, we study the full power spectrum of the reflected light and we show how the laser beam can be used as a temperature probe.
Mott, David Ray
1993-01-01T23:59:59.000Z
An existing axisymmetric body viscous shock layer code including chemical, thermal, and thermodynamic nonequilibrium and nonequilibrium radiative gasdynamic coupling is adapted to simulate the one-dimensional flow within a shock tube. A suitable...
da Costa, Fatima Rubio; Petrosian, Vahe'; Carlsson, Mats
2015-01-01T23:59:59.000Z
Solar flares involve complex processes that are coupled together and span a wide range of temporal, spatial, and energy scales. Modeling such processes self-consistently has been a challenge in the past. Here we present such a model to simulate the coupling of high-energy particle kinetics with hydrodynamics of the atmospheric plasma. We combine the Stanford unified Fokker-Planck code that models particle acceleration, transport, and bremsstrahlung radiation with the RADYN hydrodynamic code that models the atmospheric response to collisional heating by non-thermal electrons through detailed radiative transfer calculations. We perform simulations using different injection electron spectra, including an {\\it ad hoc} power law and more realistic spectra predicted by the stochastic acceleration model due to turbulence or plasma waves. Surprisingly, stochastically accelerated electrons, even with energy flux $\\ll 10^{10}$ erg s$^{-1}$ cm$^{-2}$, cause "explosive" chromospheric evaporation and drive stronger up- an...
Camps, Peter; Bianchi, Simone; Lunttila, Tuomas; Pinte, Christophe; Natale, Giovanni; Juvela, Mika; Fischera, Joerg; Fitzgerald, Michael P; Gordon, Karl; Baes, Maarten; Steinacker, Juergen
2015-01-01T23:59:59.000Z
We define an appropriate problem for benchmarking dust emissivity calculations in the context of radiative transfer (RT) simulations, specifically including the emission from stochastically heated dust grains. Our aim is to provide a self-contained guide for implementors of such functionality, and to offer insights in the effects of the various approximations and heuristics implemented by the participating codes to accelerate the calculations. The benchmark problem definition includes the optical and calorimetric material properties, and the grain size distributions, for a typical astronomical dust mixture with silicate, graphite and PAH components; a series of analytically defined radiation fields to which the dust population is to be exposed; and instructions for the desired output. We process this problem using six RT codes participating in this benchmark effort, and compare the results to a reference solution computed with the publicly available dust emission code DustEM. The participating codes implement...
Jha, Naresh, E-mail: naresh.jha@albertahealthservices.ca [University of Alberta, Cross Cancer Institute, Edmonton, Alberta (Canada)] [University of Alberta, Cross Cancer Institute, Edmonton, Alberta (Canada); Harris, Jonathan [Radiation Therapy Oncology Group Statistical Center, Philadelphia, Pennsylvania (United States)] [Radiation Therapy Oncology Group Statistical Center, Philadelphia, Pennsylvania (United States); Seikaly, Hadi [University of Alberta, Edmonton, Alberta (Canada)] [University of Alberta, Edmonton, Alberta (Canada); Jacobs, John R. [Wayne State University School of Medicine, Detroit, Michigan (United States)] [Wayne State University School of Medicine, Detroit, Michigan (United States); McEwan, A.J.B. [University of Alberta, Cross Cancer Institute, Edmonton, Alberta (Canada)] [University of Alberta, Cross Cancer Institute, Edmonton, Alberta (Canada); Robbins, K. Thomas [St. John's Hospital Cancer Institute, Springfield, Illinois (United States)] [St. John's Hospital Cancer Institute, Springfield, Illinois (United States); Grecula, John [Ohio State University Medical Center, Columbus, Ohio (United States)] [Ohio State University Medical Center, Columbus, Ohio (United States); Sharma, Anand K. [Medical University of South Carolina, Charleston, South Carolina (United States)] [Medical University of South Carolina, Charleston, South Carolina (United States); Ang, K. Kian [University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [University of Texas MD Anderson Cancer Center, Houston, Texas (United States)
2012-10-01T23:59:59.000Z
Purpose: We report the results of a phase II study to determine the reproducibility of a submandibular salivary gland transfer (SGT) surgical technique for prevention of radiation (XRT)-induced xerostomia in a multi-institutional setting and to assess severity of xerostomia. Methods and Materials: Eligible patients had surgery for primary, neck dissection, and SGT, followed by XRT, during which the transferred salivary gland was shielded. Intensity modulated radiation therapy, amifostine, and pilocarpine were not allowed, but postoperative chemotherapy was allowed. Each operation was reviewed by 2 reviewers and radiation by 1 reviewer. If 13 or more (of 43) were 'not per protocol,' then the technique would be considered not reproducible as per study design. The secondary endpoint was the rate of acute xerostomia, grade 2 or higher, and a rate of {<=}51% was acceptable. Results: Forty-four of the total 49 patients were analyzable: male (81.8%), oropharynx (63.6%), stage IV (61.4%), median age 56.5 years. SGT was 'per protocol' or within acceptable variation in 34 patients (77.3%) and XRT in 79.5%. Nine patients (20.9%) developed grade 2 acute xerostomia; 2 had grade 0-1 xerostomia (4.7%) but started on amifostine/pilocarpine. Treatment for these 11 patients (25.6%) was considered a failure for the xerostomia endpoint. Thirteen patients died; median follow-up for 31 surviving patients was 2.9 years. Two-year overall and disease-free survival rates were 76.4% and 71.7%, respectively. Conclusions: The technique of submandibular SGT is reproducible in a multicenter setting. Seventy-four percent of patients were prevented from XRT-induced acute xerostomia.
Parabolized Stability Equation Models for Turbulent Jets and Their Radiated Sound
Dabiri, John O.
surface just outside the jet shear layers in order Work supported by NAVAIR/TTC Technologies, Inc. Ph stability analysis and measurements from a phased microphone array, indicating that energy transfer between.D. Candidate, Mechanical Engineering, California Institute of Technology, Pasadena, CA 91125, Student Member
HEAT AND MOISTURE TRANSFER THROUGH CLOTHING
Voelker, Conrad; Hoffmann, Sabine; Kornadt, Oliver; Arens, Edward; Zhang, Hui; Huizenga, Charlie
2009-01-01T23:59:59.000Z
R. C. Eberhart (ed), Heat transfer in medicine and biology.between convective heat transfer and mass transferConvective and radiative heat transfer coefficients for
Heat and moisture transfer through clothing
Voelker, Conrad; Hoffmann, Sabine; Kornadt, Oliver; Arens, Edward; Zhang, Hui; Huizenga, Charlie
2009-01-01T23:59:59.000Z
R. C. Eberhart (ed), Heat transfer in medicine and biology.Convective and radiative heat transfer coefficients forbetween convective heat transfer and mass transfer
Clementel, Nicola; Kruip, Chael J H; Paardekooper, Jan-Pieter
2015-01-01T23:59:59.000Z
Spectral observations of the massive colliding wind binary Eta Carinae show phase-dependent variations, in intensity and velocity, of numerous helium emission and absorption lines throughout the entire 5.54-year orbit. Approaching periastron, the 3D structure of the wind-wind interaction region (WWIR) gets highly distorted due to the eccentric ($e \\sim 0.9$) binary orbit. The secondary star ($\\eta_{\\mathrm{B}}$) at these phases is located deep within the primary's dense wind photosphere. The combination of these effects is thought to be the cause of the particularly interesting features observed in the helium lines at periastron. We perform 3D radiative transfer simulations of $\\eta$ Car's interacting winds at periastron. Using the SimpleX radiative transfer algorithm, we post-process output from 3D smoothed particle hydrodynamic simulations of the inner 150 au of the $\\eta$ Car system for two different primary star mass-loss rates ($\\dot{M}_{\\eta_{\\mathrm{A}}}$). Using previous results from simulations at ap...
Smart, John P.; Patel, Rajeshriben; Riley, Gerry S. [RWEnpower, Windmill Hill Business Park, Whitehill Way, Swindon, Wiltshire SN5 6PB, England (United Kingdom)
2010-12-15T23:59:59.000Z
This paper focuses on results of co-firing coal and biomass under oxy-fuel combustion conditions on the RWEn 0.5 MWt Combustion Test Facility (CTF). Results are presented of radiative and convective heat transfer and burnout measurements. Two coals were fired: a South African coal and a Russian Coal under air and oxy-fuel firing conditions. The two coals were also co-fired with Shea Meal at a co-firing mass fraction of 20%. Shea Meal was also co-fired at a mass fraction of 40% and sawdust at 20% with the Russian Coal. An IFRF Aerodynamically Air Staged Burner (AASB) was used. The thermal input was maintained at 0.5 MWt for all conditions studied. The test matrix comprised of varying the Recycle Ratio (RR) between 65% and 75% and furnace exit O{sub 2} was maintained at 3%. Carbon-in-ash samples for burnout determination were also taken. Results show that the highest peak radiative heat flux and highest flame luminosity corresponded to the lowest recycle ratio. The effect of co-firing of biomass resulted in lower radiative heat fluxes for corresponding recycle ratios. Furthermore, the highest levels of radiative heat flux corresponded to the lowest convective heat flux. Results are compared to air firing and the air equivalent radiative and convective heat fluxes are fuel type dependent. Reasons for these differences are discussed in the main text. Burnout improves with biomass co-firing under both air and oxy-fuel firing conditions and burnout is also seen to improve under oxy-fuel firing conditions compared to air. (author)
Higginbottom, Nick; Knigge, Christian; Matthews, James H. [School of Physics and Astronomy, University of Southampton, Highfield, Southampton, SO17 1BJ (United Kingdom); Proga, Daniel [Department of Physics and Astronomy, University of Nevada, Las Vegas, 4505 South Maryland Parkway, Las Vegas, NV 89154-4002 (United States); Long, Knox S. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Sim, Stuart A., E-mail: nick_higginbottom@fastmail.fm [School of Mathematics and Physics, Queens University Belfast, University Road, Belfast, BT7 1NN (United Kingdom)
2014-07-01T23:59:59.000Z
Accretion disk winds are thought to produce many of the characteristic features seen in the spectra of active galactic nuclei (AGNs) and quasi-stellar objects (QSOs). These outflows also represent a natural form of feedback between the central supermassive black hole and its host galaxy. The mechanism for driving this mass loss remains unknown, although radiation pressure mediated by spectral lines is a leading candidate. Here, we calculate the ionization state of, and emergent spectra for, the hydrodynamic simulation of a line-driven disk wind previously presented by Proga and Kallman. To achieve this, we carry out a comprehensive Monte Carlo simulation of the radiative transfer through, and energy exchange within, the predicted outflow. We find that the wind is much more ionized than originally estimated. This is in part because it is much more difficult to shield any wind regions effectively when the outflow itself is allowed to reprocess and redirect ionizing photons. As a result, the calculated spectrum that would be observed from this particular outflow solution would not contain the ultraviolet spectral lines that are observed in many AGN/QSOs. Furthermore, the wind is so highly ionized that line driving would not actually be efficient. This does not necessarily mean that line-driven winds are not viable. However, our work does illustrate that in order to arrive at a self-consistent model of line-driven disk winds in AGN/QSO, it will be critical to include a more detailed treatment of radiative transfer and ionization in the next generation of hydrodynamic simulations.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Lee, W. -L.; Gu, Y.; Liou, K. N.; Leung, L. R.; Hsu, H. -H.
2014-12-15T23:59:59.000Z
We investigate 3-D mountain effects on solar flux distributions and their impact on surface hydrology over the Western United States, specifically the Rocky Mountains and Sierra Nevada using CCSM4 (CAM4/CLM4) global model with a 0.23° × 0.31° resolution for simulations over 6 years. In 3-D radiative transfer parameterization, we have updated surface topography data from a resolution of 1 km to 90 m to improve parameterization accuracy. In addition, we have also modified the upward-flux deviation [3-D - PP (plane-parallel)] adjustment to ensure that energy balance at the surface is conserved in global climate simulations based on 3-D radiation parameterization.more »We show that deviations of the net surface fluxes are not only affected by 3-D mountains, but also influenced by feedbacks of cloud and snow in association with the long-term simulations. Deviations in sensible heat and surface temperature generally follow the patterns of net surface solar flux. The monthly snow water equivalent (SWE) deviations show an increase in lower elevations due to reduced snowmelt, leading to a reduction in cumulative runoff. Over higher elevation areas, negative SWE deviations are found because of increased solar radiation available at the surface. Simulated precipitation increases for lower elevations, while decreases for higher elevations with a minimum in April. Liquid runoff significantly decreases in higher elevations after April due to reduced SWE and precipitation.« less
Mott, David Ray
1993-01-01T23:59:59.000Z
term (Eq. (12)) density relaxation time inelastic energy exchange term (Eq. (12)) Subscripts and Superscripts b b c cal e f 1 i initial J P r s tr v V backward reaction boundary center, as in X, calibration constant electron... such experiments vital in the verification of nonequilibrium chemical and radiation models. PUMPING ASSEMBLT CDAxIAL CABLE HousING L ? --I r- 2sTDPFARAb )'V& DRIVER HIGHPRESSURE DIAPHRAGM TRANSITION SECTION Cl~ ALUMINUM TUBE TUBE t2OFTI TUBE I 10 F...
Jones, Peter JS
the scope to include structurally complex 3-D plant architectures with and without background topography/need for RT models to accurately reproduce local estimates of radiative quantities under conditions) to a reassessment of the role, scope, and opportunities of the RAMI project in the future. Citation: Widlowski, J
PARALLEL COMPUTATIONS OF RADIATIVE HEAT TRANSFER USING THE DISCRETE ORDINATES METHOD
Utah, University of
of the important radiatively active species (CO2, H2O, soot) and temperature, which are calculated on the spatially increasingly tractable. Issues relating to the use of high-performance computing in participating media heat properties. First we summarize previous applications of spatial decomposition strategies to finite
Ko, Min Seok
2009-05-15T23:59:59.000Z
? =0.1, 0.2, and 0.4) and scattering albedo ( ?=0, 0.25, 0.5, 0.75 and 1). Variation of thermophysical properties with temperature was considered in this study. In this work consideration was given only to cooling. Effects of those radiative...
Huang, Dong [Brookhaven National Laboratory (BNL), Upton, NY (United States); Liu, Yangang [Brookhaven National Laboratory (BNL), Upton, NY (United States). Environmental and Climate Sciences Dept.
2014-12-18T23:59:59.000Z
Subgrid-scale variability is one of the main reasons why parameterizations are needed in large-scale models. Although some parameterizations started to address the issue of subgrid variability by introducing a subgrid probability distribution function for relevant quantities, the spatial structure has been typically ignored and thus the subgrid-scale interactions cannot be accounted for physically. Here we present a new statistical-physics-like approach whereby the spatial autocorrelation function can be used to physically capture the net effects of subgrid cloud interaction with radiation. The new approach is able to faithfully reproduce the Monte Carlo 3D simulation results with several orders less computational cost, allowing for more realistic representation of cloud radiation interactions in large-scale models.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Huang, Dong; Liu, Yangang
2014-12-18T23:59:59.000Z
Subgrid-scale variability is one of the main reasons why parameterizations are needed in large-scale models. Although some parameterizations started to address the issue of subgrid variability by introducing a subgrid probability distribution function for relevant quantities, the spatial structure has been typically ignored and thus the subgrid-scale interactions cannot be accounted for physically. Here we present a new statistical-physics-like approach whereby the spatial autocorrelation function can be used to physically capture the net effects of subgrid cloud interaction with radiation. The new approach is able to faithfully reproduce the Monte Carlo 3D simulation results with several orders less computational cost,more »allowing for more realistic representation of cloud radiation interactions in large-scale models.« less
The radiative heat transfer between a rotating nanoparticle and a plane surface
Vahid Ameri; Mehdi Shafei Aporvari; Fardin Kheirandish
2015-06-03T23:59:59.000Z
Based on a microscopic approach, we propose a Lagrangian for the combined system of a rotating dielectric nanoparticle above a plane surface in the presence of electromagnetic vacuum fluctuations. In the framework of canonical quantization, the electromagnetic vacuum field is quantized in the presence of dielectric fields describing the nanoparticle and a semi-infinite dielectric with planar interface. The radiative heat power absorbed by the rotating nanoparticle is obtained and the result is in agreement with previous results when the the rotational frequency of the nanoparticle is zero or much smaller than the relaxation frequency of the dielectrics. The well known near field effect is reexamined and discussed in terms of the rotational frequency. The radiative heat power absorbed by the nanoparticle for well-known peak frequencies, is plotted in terms of the rotational frequency showing an interesting effect resembling a phase transition around a critical frequency, determined by the relaxation frequency of the dielectrics.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Huang, Dong [Brookhaven National Laboratory (BNL), Upton, NY (United States); Liu, Yangang [Brookhaven National Laboratory (BNL), Upton, NY (United States)
2014-12-01T23:59:59.000Z
Subgrid-scale variability is one of the main reasons why parameterizations are needed in large-scale models. Although some parameterizations started to address the issue of subgrid variability by introducing a subgrid probability distribution function for relevant quantities, the spatial structure has been typically ignored and thus the subgrid-scale interactions cannot be accounted for physically. Here we present a new statistical-physics-like approach whereby the spatial autocorrelation function can be used to physically capture the net effects of subgrid cloud interaction with radiation. The new approach is able to faithfully reproduce the Monte Carlo 3D simulation results with several orders less computational cost, allowing for more realistic representation of cloud radiation interactions in large-scale models.
Mills, Peter
2012-01-01T23:59:59.000Z
Microwave emissivity models of sea ice are poorly validated empirically. Typical validation studies involve using averaged or stereotyped profiles of ice parameters against averaged radiance measurements. Measurement sites are rarely matched and even less often point-by-point. Because of saline content, complex permittivity of sea ice is highly variable and difficult to predict. Therefore, to check the validity of a typical, plane-parallel, radiative-transfer-based ice emissivity model, we apply it to fresh water ice instead of salt-water ice. Radiance simulations for lake ice are compared with measurements over Lake Superior from the Advanced Microwave Scanning Radiometer on EOS (AMSR-E). AMSR-E measurements are also collected over Antarctic icepack. For each pixel, a thermodynamic model is driven by four years of European Center for Medium Range Weather Forecasts (ECMWF) reanalysis data and the resulting temperature profiles used to drive the emissivity model. The results suggest that the relatively simple ...
Klaus M. Pontoppidan; Cornelis P. Dullemond; Ewine F. van Dishoeck; Geoffrey A. Blake; Adwin C. A. Boogert; Neal J. Evans II; Jacqueline E. Kessler-Silacci; Fred Lahuis
2004-11-13T23:59:59.000Z
We present 5.2-37.2 micron spectroscopy of the edge-on circumstellar disk CRBR 2422.8-3423 obtained using the InfraRed Spectrograph (IRS) of the Spitzer Space Telescope. The IRS spectrum is combined with ground-based 3-5 micron spectroscopy to obtain a complete inventory of solid state material present along the line of sight toward the source. We model the object with a 2D axisymmetric (effectively 3D) Monte Carlo radiative transfer code. It is found that the model disk, assuming a standard flaring structure, is too warm to contain the very large observed column density of pure CO ice, but is possibly responsible for up to 50% of the water, CO2 and minor ice species. In particular the 6.85 micron band, tentatively due to NH4+, exhibits a prominent red wing, indicating a significant contribution from warm ice in the disk. It is argued that the pure CO ice is located in the dense core Oph-F in front of the source seen in the submillimeter imaging, with the CO gas in the core highly depleted. The model is used to predict which circumstances are most favourable for direct observations of ices in edge-on circumstellar disks. Ice bands will in general be deepest for inclinations similar to the disk opening angle, i.e. ~70 degrees. Due to the high optical depths of typical disk mid-planes, ice absorption bands will often probe warmer ice located in the upper layers of nearly edge-on disks. The ratios between different ice bands are found to vary by up to an order of magnitude depending on disk inclination due to radiative transfer effects caused by the 2D structure of the disk. Ratios between ice bands of the same species can therefore be used to constrain the location of the ices in a circumstellar disk. [Abstract abridged
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Lee, W.-L.; Gu, Y.; Liou, K. N.; Leung, L. R.; Hsu, H.-H.
2015-01-01T23:59:59.000Z
We investigate 3-D mountain effects on solar flux distributions and their impact on surface hydrology over the western United States, specifically the Rocky Mountains and the Sierra Nevada, using the global CCSM4 (Community Climate System Model version 4; Community Atmosphere Model/Community Land Model – CAM4/CLM4) with a 0.23° × 0.31° resolution for simulations over 6 years. In a 3-D radiative transfer parameterization, we have updated surface topography data from a resolution of 1 km to 90 m to improve parameterization accuracy. In addition, we have also modified the upward-flux deviation (3-D–PP (plane-parallel)) adjustment to ensure that the energy balance atmore »the surface is conserved in global climate simulations based on 3-D radiation parameterization. We show that deviations in the net surface fluxes are not only affected by 3-D mountains but also influenced by feedbacks of cloud and snow in association with the long-term simulations. Deviations in sensible heat and surface temperature generally follow the patterns of net surface solar flux. The monthly snow water equivalent (SWE) deviations show an increase in lower elevations due to reduced snowmelt, leading to a reduction in cumulative runoff. Over higher-elevation areas, negative SWE deviations are found because of increased solar radiation available at the surface. Simulated precipitation increases for lower elevations, while it decreases for higher elevations, with a minimum in April. Liquid runoff significantly decreases at higher elevations after April due to reduced SWE and precipitation.« less
K. Parand; S. Abbasbandy; S. Kazem; A. R. Rezaei
2010-08-16T23:59:59.000Z
In this paper two common collocation approaches based on radial basis functions have been considered; one be computed through the integration process (IRBF) and one be computed through the differentiation process (DRBF). We investigated the two approaches on natural convection heat transfer equations embedded in porous medium which are of great importance in the design of canisters for nuclear wastes disposal. Numerical results show that the IRBF be performed much better than the common DRBF, and show good accuracy and high rate of convergence of IRBF process.
Parand, K; Kazem, S; Rezaei, A R; 10.1016/j.cnsns.2010.07.011
2010-01-01T23:59:59.000Z
In this paper two common collocation approaches based on radial basis functions have been considered; one be computed through the integration process (IRBF) and one be computed through the differentiation process (DRBF). We investigated the two approaches on natural convection heat transfer equations embedded in porous medium which are of great importance in the design of canisters for nuclear wastes disposal. Numerical results show that the IRBF be performed much better than the common DRBF, and show good accuracy and high rate of convergence of IRBF process.
Siewert, Charles E.
subject to Fresnel boundary and interface conditions R.D.M. Garcia a,Ã, C.E. Siewert b a Instituto de: Radiative transfer Nascent delta function Fresnel conditions Discrete-ordinates method a b s t r a c in a plane-parallel, multi-layer medium subject to Fresnel boundary and interface conditions. As a result
Schaerer, Daniel
2008-01-01T23:59:59.000Z
Using our 3D Lya radiation transfer code, we compute the radiation transfer of Lya and UV continuum photons including dust. Observational constraints on the neutral gas (column density, kinematics, etc.) are taken from other analysis of this object. RESULTS: The observed Lya profile of MS 1512--cB58 is reproduced for the first time taking radiation transfer and all observational constraints into account. The observed absorption profile is found to result naturally from the observed amount of dust and the relatively high HI column density. Radiation transfer effects and suppresion by dust transform a strong intrinsic Lya emission with EW(Lya)>~ 60 Ang into the observed faint superposed Lya emission peak. We propose that the vast majority of LBGs have intrinsically EW(Lya)~60-80 Ang or larger, and that the main physical parameter responsible for the observed variety of Lya strengths and profiles in LBGs is N_H and the accompanying variation of the dust content. Observed EW(Lya) distributions, Lya luminosity fun...
Gustavsen, Arild
2009-01-01T23:59:59.000Z
of convection and radiation heat transfer and developconvection and radiation heat transfer in three dimensionsaccount for 3- D radiation heat transfer on indoor surfaces.
, Kuadasi, Turkey RAD-13-040 SPECTRAL RADIATIVE PROPERTIES OF THREE-DIMENSIONALLY ORDERED MACROPOROUS CERIA
which should be as simple as possible to be implemented in the combined heat transfer model. In general as a component of the multidimensional combined heat transfer model for soft thermal treatment of superficial
Radiative cooling of laser ablated vapor plumes: experimental and theoretical analyses
Wen, Sy-Bor; Mao, Xianglei; Grief, Ralph; Russo, Richard E.
2006-01-01T23:59:59.000Z
J. , Thermal radiation heat transfer, 4 th ed, (Taylor &in the calculation of the radiation heat transfer, only thelines, the thermal radiation heat transfer is given by [16
Zhang, Zhibo
2009-05-15T23:59:59.000Z
This dissertation consists of three parts, each devoted to a particular issue of significant importance for satellite-based remote sensing of cirrus clouds. In the first part, we develop and present a fast infrared radiative transfer model...
Zhang, Zhibo
2009-05-15T23:59:59.000Z
This dissertation consists of three parts, each devoted to a particular issue of significant importance for satellite-based remote sensing of cirrus clouds. In the first part, we develop and present a fast infrared radiative transfer model...
Bioheat Transfer Valvano, page 1 Bioheat Transfer
a technically challenging task. First, tissue heat transfer includes conduction, convection, radiation and by heat transfer due to blood flow near the probe. In vivo, the instrument measures effective thermal properties that are the combination of conductive and convective heat transfer. Thermal properties
Light Transfer Simulation Tools in Photobiological Fuel Production
Lee, Euntaek
2013-01-01T23:59:59.000Z
and M. P. Meng¨ u¸c, “Radiation heat transfer in combustionand radiation in the Atlas plume”, Journal of Thermophysics and Heat Transfer,Thermal radiation is a dominant mode of heat transfer in
Jiri Stepan; Petr Heinzel; Sylvie Sahal-Brechot
2007-01-22T23:59:59.000Z
Context. We present a theoretical review of the effect of impact polarization of a hydrogen H$\\alpha$ line due to an expected proton beam bombardment in solar flares. Aims. Several observations indicate the presence of the linear polarization of the hydrogen H$\\alpha$ line observed near the solar limb above 5% and preferentially in the radial direction. We theoretically review the problem of deceleration of the beam originating in the coronal reconnection site due to its interaction with the chromospheric plasma, and describe the formalism of the density matrix used in our description of the atomic processes and the treatment of collisional rates. Methods. We solve the self-consistent NLTE radiation transfer problem for the particular semiempirical chromosphere models for both intensity and linear polarization components of the radiation field. Results. In contrast to recent calculations, our results show that the energy distribution of the proton beam at H$\\alpha$ formation levels and depolarizing collisions by background electrons and protons cause a significant reduction of the effect below 0.1%. The radiation transfer solution shows that tangential resonance-scattering polarization dominates over the impact polarization effect in all considered models. Conclusions. In the models studied, proton beams are unlikely to be a satisfying explanation for the observed linear polarization of the H$\\alpha$ line.
Ivanov, Michael A Liberman M F
2015-01-01T23:59:59.000Z
We examines regimes of the hydrogen flames propagation and ignition of mixtures heated by the radiation emitted from the flame. The gaseous phase is assumed to be transparent for radiation, while the suspended particles of the dust cloud ahead of the flame absorb and reemit the radiation. The radiant heat absorbed by the particles is then lost by conduction to the surrounding unreacted gaseous phase so that the gas phase temperature lags that of the particles. The direct numerical simulations solve the full system of two phase gas dynamic time-dependent equations with a detailed chemical kinetics for a plane flames propagating through a dust cloud. Depending on the spatial distribution of the dispersed particles and on the value of radiation absorption length the consequence of the radiative preheating of the unreacted mixture can be either the increase of the flame velocity for uniformly dispersed particles or ignition deflagration or detonation ahead of the flame via the Zel'dovich gradient mechanism in the...
Huang, Yi
The properties of thermal radiation exchange between hot and cold objects can be strongly modified if they interact in the near field where electromagnetic coupling occurs across gaps narrower than the dominant wavelength ...
Computation of radiative heat transport across a nanoscale vacuum gap
Budaev, Bair V., E-mail: bair@berkeley.edu; Bogy, David B., E-mail: dbogy@berkeley.edu [University of California, Etcheverry Hall, MC 1740, Berkeley, California 94720-1740 (United States)
2014-02-10T23:59:59.000Z
Radiation heat transport across a vacuum gap between two half-spaces is studied. By consistently applying only the fundamental laws of physics, we obtain an algebraic equation that connects the temperatures of the half-spaces and the heat flux between them. The heat transport coefficient generated by this equation for such structures matches available experimental data for nanoscale and larger gaps without appealing to any additional specific mechanisms of energy transfer.
Kravis, S. D.; Church, David A.; Johnson, B. M.; Meron, M.; Jones, K. W.; Levin, J. C.; Sellin, I. A.; Azuma, Y.; Berrahmansour, N.; Berry, H. G.; Druetta, M.
1992-01-01T23:59:59.000Z
-shell photoionization of Ar atoms, using broadband synchrotron x-ray radiation. K-electron removal resulted in vacancy cascading, yielding a distribution of argon-ion charge states peaked near Ar4+. The stored ion gas had an initial temperature near 480 K. The basic...
Homogenization of a spectral equation with drift in linear Guillaume Bal
Bal, Guillaume
theory posed in a periodic heterogeneous domain. This equation models the stability of nuclear reactor Introduction The power distribution in a nuclear reactor is determined by solving a linear transport spectral in radiative transfer theory, which models the propagation of acoustic, electromagnetic, or elastic waves
Efficiency Factors and Radiation Characteristics of Spherical Scatterers in Absorbing Media
Yin, Juan; Pilon, Laurent
2006-01-01T23:59:59.000Z
Howell, Thermal radiation heat transfer - Third Edition,properties, and heat, mass, and radiation transfer”, Journalradiation characteristics of fused quartz containing bubbles”, Journal of Thermophysics and Heat Transfer, (
Gardini, A; Pérez, E; Quesada, J A; Funke, B
2012-01-01T23:59:59.000Z
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.
Smith, R. M.; Liu, B.; Bai, J.; Wang, T., E-mail: t.wang@sheffield.ac.uk [Department of Electrical and Electronic Engineering, University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom)
2014-10-27T23:59:59.000Z
Hybrid organic/inorganic white light emitting structures have been fabricated based on a combination of high efficiency InGaN/GaN multiple quantum well (MQW) nanorod arrays and a yellow emitting co-polymer F8BT, leading to a minimised separation between them in order to achieve high efficiency non-radiative energy transfer (NRET). The NRET efficiency has been found 6.7 times higher at room temperature than at 7?K. This is attributed to the existence of strong exciton localization the InGaN MQWs, which can undergo thermally activated delocalization at high temperatures. The enhanced NRET efficiency is not only due to the delocalized MQW excitons, but also enhanced by the increased exciton diffusion at higher temperatures. This behaviour highlights the potential for high efficiency NRET in down-conversion hybrid white light emitting diodes operating at room temperature.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Huang, Dong; Liu, Yangang
2014-09-27T23:59:59.000Z
The effects of subgrid cloud variability on grid-average microphysical rates and radiative fluxes are examined by use of long-term retrieval products at the Tropical West Pacific, Southern Great Plains, and North Slope of Alaska sites of the Department of Energy's Atmospheric Radiation Measurement program. Four commonly used distribution functions, the truncated Gaussian, Gamma, lognormal, and Weibull distributions, are constrained to have the same mean and standard deviation as observed cloud liquid water content. The probability density functions are then used to upscale relevant physical processes to obtain grid-average process rates. It is found that the truncated Gaussian representation results inmore »up to 30% mean bias in autoconversion rate, whereas the mean bias for the lognormal representation is about 10%. The Gamma and Weibull distribution function performs the best for the grid-average autoconversion rate with the mean relative bias less than 5%. For radiative fluxes, the lognormal and truncated Gaussian representations perform better than the Gamma and Weibull representations. The results show that the optimal choice of subgrid cloud distribution function depends on the nonlinearity of the process of interest, and thus, there is no single distribution function that works best for all parameterizations. Examination of the scale (window size) dependence of the mean bias indicates that the bias in grid-average process rates monotonically increases with increasing window sizes, suggesting the increasing importance of subgrid variability with increasing grid sizes.« less
Huang, Dong [Brookhaven National Lab. (BNL), Upton, NY (United States); Liu, Yangang [Brookhaven National Lab. (BNL), Upton, NY (United States)
2014-09-27T23:59:59.000Z
The effects of subgrid cloud variability on grid-average microphysical rates and radiative fluxes are examined by use of long-term retrieval products at the Tropical West Pacific, Southern Great Plains, and North Slope of Alaska sites of the Department of Energy's Atmospheric Radiation Measurement program. Four commonly used distribution functions, the truncated Gaussian, Gamma, lognormal, and Weibull distributions, are constrained to have the same mean and standard deviation as observed cloud liquid water content. The probability density functions are then used to upscale relevant physical processes to obtain grid-average process rates. It is found that the truncated Gaussian representation results in up to 30% mean bias in autoconversion rate, whereas the mean bias for the lognormal representation is about 10%. The Gamma and Weibull distribution function performs the best for the grid-average autoconversion rate with the mean relative bias less than 5%. For radiative fluxes, the lognormal and truncated Gaussian representations perform better than the Gamma and Weibull representations. The results show that the optimal choice of subgrid cloud distribution function depends on the nonlinearity of the process of interest, and thus, there is no single distribution function that works best for all parameterizations. Examination of the scale (window size) dependence of the mean bias indicates that the bias in grid-average process rates monotonically increases with increasing window sizes, suggesting the increasing importance of subgrid variability with increasing grid sizes.
A Green's function formalism of energy and momentum transfer in fluctuational electrodynamics
Arvind Narayanaswamy; Yi Zheng
2013-02-03T23:59:59.000Z
Radiative energy and momentum transfer due to fluctuations of electromagnetic fields arising due to temperature difference between objects is described in terms of the cross-spectral densities of the electromagnetic fields. We derive relations between thermal non-equilibrium contributions to energy and momentum transfer and surface integrals of tangential components of the dyadic Green's functions of the vector Helmholtz equation. The expressions derived here are applicable to objects of arbitrary shapes, dielectric functions, as well as magnetic permeabilities. For the case of radiative transfer, we derive expressions for the generalized transmissivity and generalized conductance that are shown to obey reciprocity and agree with theory of black body radiative transfer in the appropriate limit.
Heat transfer pathways in underfloor air distribution (UFAD) systems
Bauman, F.; Jin, H.; Webster, T.
2006-01-01T23:59:59.000Z
radiative heat transfer, since radiation was neglectedradiation striking the floor makes up the majority of the total heat transferheat transfer processes: conduction through the slab and floor panels and into the supply plenum via convection; radiation
Signatures of Radiation Reaction in Ultra-Intense Laser Fields
C. Harvey; T. Heinzl; M. Marklund
2011-10-04T23:59:59.000Z
We discuss radiation reaction effects on charges propagating in ultra-intense laser fields. Our analysis is based on an analytic solution of the Landau-Lifshitz equation. We suggest to measure radiation reaction in terms of a symmetry breaking parameter associated with the violation of null translation invariance in the direction opposite to the laser beam. As the Landau-Lifshitz equation is nonlinear the energy transfer within the pulse is rather sensitive to initial conditions. This is elucidated by comparing colliding and fixed target modes in electron laser collisions.
A Module for Radiation Hydrodynamic Calculations With ZEUS-2D Using Flux-Limited Diffusion
N. J. Turner; J. M. Stone
2001-02-08T23:59:59.000Z
A module for the ZEUS-2D code is described which may be used to solve the equations of radiation hydrodynamics to order unity in v/c, in the flux-limited diffusion (FLD) approximation. In this approximation, the tensor Eddington factor f which closes the radiation moment equations is chosen to be an empirical function of radiation energy density. This is easier to implement and faster than full-transport techniques, in which f is computed by solving the transfer equation. However, FLD is less accurate when the flux has a component perpendicular to the gradient in radiation energy density, and in optically thin regions when the radiation field depends strongly on angle. The material component of the fluid is here assumed to be in local thermodynamic equilibrium. The energy equations are operator-split, with transport terms, radiation diffusion term, and other source terms evolved separately. Transport terms are applied using the same consistent transport algorithm as in ZEUS-2D. The radiation diffusion term is updated using an alternating-direction implicit method with convergence checking. Remaining source terms are advanced together implicitly using numerical root-finding. However when absorption opacity is zero, accuracy is improved by treating compression and expansion source terms using time-centered differencing. Results are discussed for test problems including radiation-damped linear waves, radiation fronts propagating in optically-thin media, subcritical and supercritical radiating shocks, and an optically-thick shock in which radiation dominates downstream pressure.
Rydberg, Bjorn; Cooper, Brian; Cooper, Priscilla K.; Holley, William; Chatterjee, Aloke
2004-01-01T23:59:59.000Z
S. Kim, and R. M. Myers. Radiation hybrid mapping: a somaticformulation of dual radiation action. Radiat. Res. 75: 471-High-Linear Energy Transfer Radiation in Human Fibroblasts.
Aller, M F; Aller, H D; Jorstad, S G; Marscher, A P; Bala, V; Hovatta, T
2015-01-01T23:59:59.000Z
As part of a program to identify the physical conditions in the jets of gamma-ray-flaring blazars detected by Fermi, including the role of shocks in the production of high-energy flaring, we obtained 4 years of 3-frequency, centimeter-band total flux density and linear polarization monitoring observations of the radio-bright blazar S5 0716+714 with the University of Michigan 26-m paraboloid. Light curves constructed from these data exhibit a series of rapid, high-amplitude, centimeter-band total flux density outbursts, and changes in the linear polarization consistent with the passage of shocks during the gamma-ray flaring. The observed spectral evolution of the radio-band flares, in combination with radiative transfer simulations incorporating propagating shocks, was used to constrain the shock and jet flow conditions in the parsec-scale regions of the jet. Eight forward-moving, transverse shocks with unusually-strong shock compression factors, a very fast Lorentz factor of the shocks of 77, a bulk Lorentz f...
Heat and Mass Transfer Wrme-und Stoffbertragung
Guo, Zhixiong "James"
Transfer (2013) 49:405-412 DOI 10.1007/s00231-012-1077-8 Natural convection and radiation heat transfer 12 months after publication. #12;ORIGINAL Natural convection and radiation heat transfer wall temperature, both the natural convection and radiation heat transfer are enhanced
Gustavsen, Arild
2009-01-01T23:59:59.000Z
free convection. In: Heat Transfer and Turbulent Buoyantof convection heat transfer and develop correlations.and radiation heat transfer and develop correlations for
Harvesting nanoscale thermal radiation using pyroelectric materials
Fang, Jin; Frederich, Hugo; Pilon, Laurent
2010-01-01T23:59:59.000Z
the other hand, energy transfer by thermal radiation betweenit was shown that energy transfer by thermal radi- ationpyroelectric energy conversion and nanoscale thermal
Gustavsen, Arlid
2008-01-01T23:59:59.000Z
be used to calculate radiation heat transfer. The convectionat about 5×10 -10 ). Radiation heat transfer was included inof rays in the radiation heat-transfer algorithm of the CFD
THE FURNACE COMBUSTION AND RADIATION CHARACTERISTICS OF METHANOL AND A METHANOL/COAL SLURRY
Grosshandler, W.L.
2010-01-01T23:59:59.000Z
the structure and radiation heat transfer in a pure methanolHowell, Thermal Radiation Heat Transfer, McGraw-Hill Bookof in- creased radiation heat transfer from the flame zone
ME 544 Advanced Heat Transfer Spring 2013 Time: 2pm-3pm MWF
Connors, Daniel A.
and engineering applications of heat transfer including conduction, convection, and radiation. Course Learning, convection, and radiation heat transfer modes. 2. Determine the dominant modes of heat transfer, and apply fields. The last part of the course is concerned with radiation heat transfer, specifically radiation
Modeling the comfort effects of short-wave solar radiation indoors
Arens, Edward; Hoyt, Tyler; Zhou, Xin; Huang, Li; Zhang, Hui; Schiavon, Stefano
2015-01-01T23:59:59.000Z
7]); h r is the radiation heat transfer coefficient (W/m 2Unit °C W/m 2 h r Radiation heat transfer coefficient W/m
Generalized linear Boltzmann equations for particle transport in polycrystals
Jens Marklof; Andreas Strömbergsson
2015-02-13T23:59:59.000Z
The linear Boltzmann equation describes the macroscopic transport of a gas of non-interacting point particles in low-density matter. It has wide-ranging applications, including neutron transport, radiative transfer, semiconductors and ocean wave scattering. Recent research shows that the equation fails in highly-correlated media, where the distribution of free path lengths is non-exponential. We investigate this phenomenon in the case of polycrystals whose typical grain size is comparable to the mean free path length. Our principal result is a new generalized linear Boltzmann equation that captures the long-range memory effects in this setting. A key feature is that the distribution of free path lengths has an exponential decay rate, as opposed to a power-law distribution observed in a single crystal.
Menguec, M.P.; Manickavasagam, S.; Govindan, R.; Ghosal, S.
1995-04-01T23:59:59.000Z
In large-scale coal-fired flames, radiative transfer is significant as a large portion of the energy generated during the char pyrolysis and soot oxidation is transferred to the surroundings by radiation (due to emission). The relatively cold gases and particles which are not burning yet are heated by this incoming energy (absorption), which may have originated not only from the immediate surroundings of the control volume of interest but the entire flame. It is obvious that if the emission and absorption of radiation in such a flame are not accounted for correctly, it is not possible to determine other underlying phenomena with accuracy, as the fundamental principle of conservation of energy would be violated. In order to consider the effect of radiation heat transfer in coal-fired furnaces, we have to (1) model the radiative transfer equation to satisfy the conservation of radiant energy principle; (2) use the correct radiative properties of combustion gases and particles; (3) account for the interaction of radiation with the flow and energy equations. The radiative properties for a participating medium of spherical particles can be expressed in terms of the spectral absorption, extinction, and scattering efficiencies and the phase function for a single particle, and can be calculated from the Lorenz-Mie theory. For small size particles, the expressions are based on the Rayleigh limit of Lorenz-Mie theory, and are significantly simpler. The details are readily available in the literature.
Power transfer through strongly coupled resonances
Kurs, André
2007-01-01T23:59:59.000Z
Using self-resonant coils in a strongly coupled regime, we experimentally demonstrate efficient non-radiative power transfer over distances of up to eight times the radius of the coils. We use this system to transfer 60W ...
Heat transfer pathways in underfloor air distribution (UFAD) systems
Bauman, F.; Jin, H.; Webster, T.
2006-01-01T23:59:59.000Z
is little radiative heat transfer and little impact on thereturn air extrac- tion and heat transfer to the plenum. ItUFAD is often used and heat transfer out of the room through
Proceedings of HT2009 2009 ASME Summer Heat Transfer Conference
Guo, Zhixiong "James"
-dependent radiation and conduction bio-heat transfer model. Ultrashort pulsed radiation transport in the cylindrical a combined transient heat transfer and Pennes bio-heat transfer model is developed to simulate the heat transfer models; and concluded that the Pennes model is still the most practical for fast prediction
Zhai, Pengwang
2009-06-02T23:59:59.000Z
meter. 60 20 Geometry of a scattering event. . . . . . . . . . . . . . . . . . . . . . 63 21 An example of the atmosphere model used in the 3D Monte Carlo code for the vector radiative transfer systems. Inhomogeneous layers are divided into voxels... cases can be solved analytically. Several popular numerical methods include the T-matrix method [15, 16, 17, 18, 19], finite-element method [20, 21], finite-difference time-domain(FDTD)method[22,23,24,25,26,27,28,29,30,31,32], point-matching method [33...
Wireless transfer of electric power
Moffatt, Robert Alexander
2009-01-01T23:59:59.000Z
In this dissertation, I describe the design and construction of a system which can transfer electric power wirelessly. This is accomplished using inductive, near-field, non-radiative coupling between self-resonant copper ...
Chardin, Jonathan; Aubert, Dominique; Puchwein, Ewald
2015-01-01T23:59:59.000Z
We calibrate here cosmological radiative transfer simulation with ATON/RAMSES with a range of measurements of the Lyman alpha opacity from QSO absorption spectra. We find the Lyman alpha opacity to be very sensitive to the exact timing of hydrogen reionisation. Models reproducing the measured evolution of the mean photoionisation rate and average mean free path reach overlap at z ~ 7 and predict an accelerated evolution of the Lyman alpha opacity at z > 6 consistent with the rapidly evolving luminosity function of Lyman alpha emitters in this redshift range. Similar to "optically thin" simulations our full radiative transfer simulations fail, however, to reproduce the high-opacity tail of the Lyman alpha opacity PDF at z > 5. We argue that this is due to spatial UV fluctuations in the post-overlap phase of reionisation on substantially larger scales than predicted by our source model, where the ionising emissivity is dominated by large numbers of sub-L* galaxies. We further argue that this suggests a signific...
Micro/Nanoscale Heat Transfer: Interfacial Effects Dominate the
Kostic, Milivoje M.
conduction 2. Convective heat transfer 3. Thermal radiation 4. Conclusions 1.1 Thermal conductivity3/15/2012 1 Micro/Nanoscale Heat Transfer: Interfacial Effects Dominate the Heat Transfer 1 Xing/nanoscale heat transfer becomes critical. What is the dominant factor in micro/nanosclae heat transfer
Modest, Michael
2013-11-15T23:59:59.000Z
The effects of radiation in particle-laden flows were the object of the present research. The presence of particles increases optical thickness substantially, making the use of the “optically thin” approximation in most cases a very poor assumption. However, since radiation fluxes peak at intermediate optical thicknesses, overall radiative effects may not necessarily be stronger than in gas combustion. Also, the spectral behavior of particle radiation properties is much more benign, making spectral models simpler (and making the assumption of a gray radiator halfway acceptable, at least for fluidized beds when gas radiation is not large). On the other hand, particles scatter radiation, making the radiative transfer equation (RTE) much more di#14;fficult to solve. The research carried out in this project encompassed three general areas: (i) assessment of relevant radiation properties of particle clouds encountered in fluidized bed and pulverized coal combustors, (ii) development of proper spectral models for gas–particulate mixtures for various types of two-phase combustion flows, and (iii) development of a Radiative Transfer Equation (RTE) solution module for such applications. The resulting models were validated against artificial cases since open literature experimental data were not available. The final models are in modular form tailored toward maximum portability, and were incorporated into two research codes: (i) the open-source CFD code OpenFOAM, which we have extensively used in our previous work, and (ii) the open-source multi-phase flow code MFIX, which is maintained by NETL.
Liou, K. N.
On the correlation between ice water content and ice crystal size and its application to radiative analysis involving ice water content (IWC) and mean effective ice crystal size (De) intended, K. N., Y. Gu, Q. Yue, and G. McFarguhar (2008), On the correlation between ice water content and ice
Code Number :.............. HEAT TRANSFER QUALIFYING EXAM
Feeny, Brian
is at 40 °C, estimate the heat transfer per unit length by radiation and convection between the twoCode Number :.............. HEAT TRANSFER QUALIFYING EXAM January 2010 OPEN BOOK (only one book) The heat transfer coefficient c) The length of pipe needed for a 35 °C increase in mean temperature d
Radiation Chemistry Radiation causes changes in molecules by both
Massey, Thomas N.
Module 4 Radiation Chemistry · Radiation causes changes in molecules by both direct and indirect radiation on the target molecules · Indirect Action - energy transported by chemical species to cause damage or Pyrimidene. · Loss of Purine or Pyrimidine · Free radical transfer causing the loss of base and chain
Radiative Properties of Biological Surfaces , J. Preciado1
led researchers to also study the effects of radiation heat transfer1 . Previous research has focused the radiation heat transfer. PROPOSED METHODS Transmission and reflection measurements of single polar bear to determine the radiation heat transfer. #12;ACKNOWLEDGMENTS We are indebted to Dr. Michael Martin of the ALS
Kostic, Milivoje M.
radiation, it is deduced here, that for a conduction heat transfer or mechanical work transfer, there has-energy equivalence [2] and thermal radiation, it is reasoned here that for a conduction heat transfer (e.g., through. It is widely believed that thermal heat conduction and mechanical work transfer are "massless" phenomena [1]. I
Fainman, Yeshaiahu
to heat transfer in ducts and external boundary layers. Introduction to heat conduction and radiation and radiative heat transfer 1.2 Students will be able to recognize applications in which heat transfer transfer by radiation Objective 3 3.1 Students will demonstrate the ability to analyze heat exchangers 3
ME 339 Heat Transfer ABET EC2000 syllabus
Ben-Yakar, Adela
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
Avalanche Photon Cooling by Induced Compton Scattering: Higher-Order Kompaneets Equation
Tanaka, Shuta J; Terasawa, Toshio
2015-01-01T23:59:59.000Z
Induced Compton scattering (ICS) is an interaction between intense electro-magnetic radiations and plasmas, where ICS transfers the energy from photons to plasmas. Although ICS is important for laser plasma interactions in laboratory experiments and for radio emission from pulsars propagating in pulsar wind plasmas, the detail of photon cooling process has not been understood. The problem is that, when ICS dominates, evolution of photon spectra is described as a nonlinear convection equation, which makes photon spectra to be multi-valued. Here, we propose a new approach to treat evolution of photon spectra affected by ICS. Starting from the higher-order Kompaneets equation, we find a new equation that resolves the unphysical behavior of photon spectra. In addition, we find the steady-state analytic solution, which is linearly stable. We also successfully simulate the evolution of photon spectra without artificial viscosity. We find that photons rapidly lose their energy by ICS with continuously forming solita...
Radiation Sources and Radioactive Materials (Connecticut)
Broader source: Energy.gov [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...
None
2011-12-05T23:59:59.000Z
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 night—when the sun is not out—to drive a turbine and produce electricity. In nuclear storage systems, heat can be stored in these materials at night and released to produce electricity during daytime peak-demand hours. 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. USF’s PCMs remain stable at temperatures from 600 to 1,000°C and can be used for solar thermal power storage, nuclear thermal power storage, and other applications.
Development of a Heat Transfer Model for the Integrated Facade Heating
Gong, X.; Archer, D. H.; Claridge, D. E.
2007-01-01T23:59:59.000Z
the heat transfer process of facade heating (mullion radiators) in a pilot research project in Pittsburgh, PA. The heat transfer model for facade heating is developed and verified by measured data. The comparison shows that the heat transfer model predicts...
Development of a Heat Transfer Model for the Integrated Facade Heating
Gong, X.; Archer, D. H.; Claridge, D. E.
2007-01-01T23:59:59.000Z
the heat transfer process of facade heating (mullion radiators) in a pilot research project in Pittsburgh, PA. The heat transfer model for facade heating is developed and verified by measured data. The comparison shows that the heat transfer model predicts...
Measure of Diffusion Model Error for Thermal Radiation Transport
Kumar, Akansha
2013-04-19T23:59:59.000Z
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... +1 0 dE Z 4 d !r ; E; ! ; t : (4.2) The term ! F ( !r ; t) is the \\ ux", given by ! J ( !r ; t) = Z +1 0 dE Z 4 d ! !r ; E; ! ; t : (4.3) The above equation of transfer for speci c intensity is equivalent...
Radiative Flow in a Luminous Disk II
Jun Fukue
2006-01-07T23:59:59.000Z
Radiatively-driven transfer flow perpendicular to a luminous disk is examined in the subrelativistic regime of $(v/c)^1$, taking into account the gravity of the central object. The flow is assumed to be vertical, and the gas pressure is ignored, while internal heating is assumed to be proportional to the gas density. The basic equations were numerically solved as a function of the optical depth, and the flow velocity, the height, the radiative flux, and the radiation pressure were obtained for a given radius, an initial optical depth, and initial conditions at the flow base (disk ``inside''), whereas the mass-loss rate was determined as an eigenvalue of the boundary condition at the flow top (disk ``surface''). For sufficiently luminous cases, the flow resembles the case without gravity. For less-luminous cases, however, the flow velocity decreases, and the flow would be impossible due to the existence of gravity in the case that the radiative flux is sufficiently small. Application to a supercritical accretion disk with mass loss is briefly discussed.
Aller, M F; Aller, H D; Latimer, G E; Hovatta, T
2014-01-01T23:59:59.000Z
To investigate parsec-scale jet flow conditions during GeV gamma-ray flares detected by the Fermi Large Angle Telescope, we obtained centimeter-band total flux density and linear polarization monitoring observations from 2009.5 through 2012.5 with the 26-meter Michigan radio telescope for a sample of core-dominated blazars. We use these data to constrain radiative transfer simulations incorporating propagating shocks oriented at an arbitrary angle to the flow direction in order to set limits on the jet flow and shock parameters during flares temporally associated with gamma-ray flares in 0420-014, OJ 287, and 1156+295; these AGN exhibited the expected signature of shocks in the linear polarization data. Both the number of shocks comprising an individual radio outburst (3-4) and the range of the compression ratios of the individual shocks (0.5-0.8) are similar in all three sources; the shocks are found to be forward-moving with respect to the flow. While simulations incorporating transverse shocks provide good...
Sniadecki, Nathan J.
for 5 calendar years after disposal of material! Collected by RSS mCi A. Animal Carcasses & Waste B to delete previously reported disposal en 160T RADIOACTIVE MATERIAL TRANSFER AND USAGE RECORD (9/12) I. Transferred From AUI transferring
Relativistic Radiative Flow in a Luminous Disk II
Jun Fukue; Chizuru Akizuki
2007-11-03T23:59:59.000Z
Radiatively-driven transfer flow perpendicular to a luminous disk is examined in the relativistic regime of $(v/c)^2$, taking into account the gravity of the central object. The flow is assumed to be vertical, and the gas pressure as well as the magnetic field are ignored. Using a velocity-dependent variable Eddington factor, we can solve the rigorous equations of the relativistic radiative flow accelerated up to the {\\it relativistic} speed. For sufficiently luminous cases, the flow resembles the case without gravity. For less-luminous or small initial radius cases, however, the flow velocity decreases due to gravity. Application to a supercritical accretion disk with mass loss is briefly discussed.
Ghost Imaging with Blackbody Radiation
Yangjian Cai; Shiyao Zhu
2004-07-29T23:59:59.000Z
We present a theoretical study of ghost imaging by using blackbody radiation source. A Gaussian thin lens equation for the ghost imaging, which depends on both paths, is derived. The dependences of the visibility and quality of the image on the transverse size and temperature of the blackbody are studied. The main differences between the ghost imaging by using the blackbody radiation and by using the entangled photon pairs are image-forming equation, and the visibility and quality of the image
Heat Transfer in Complex Fluids
Mehrdad Massoudi
2012-01-01T23:59:59.000Z
Amongst the most important constitutive relations in Mechanics, when characterizing the behavior of complex materials, one can identify the stress tensor T, the heat flux vector q (related to heat conduction) and the radiant heating (related to the radiation term in the energy equation). Of course, the expression 'complex materials' is not new. In fact, at least since the publication of the paper by Rivlin & Ericksen (1955), who discussed fluids of complexity (Truesdell & Noll, 1992), to the recently published books (Deshpande et al., 2010), the term complex fluids refers in general to fluid-like materials whose response, namely the stress tensor, is 'non-linear' in some fashion. This non-linearity can manifest itself in variety of forms such as memory effects, yield stress, creep or relaxation, normal-stress differences, etc. The emphasis in this chapter, while focusing on the constitutive modeling of complex fluids, is on granular materials (such as coal) and non-linear fluids (such as coal-slurries). One of the main areas of interest in energy related processes, such as power plants, atomization, alternative fuels, etc., is the use of slurries, specifically coal-water or coal-oil slurries, as the primary fuel. Some studies indicate that the viscosity of coal-water mixtures depends not only on the volume fraction of solids, and the mean size and the size distribution of the coal, but also on the shear rate, since the slurry behaves as shear-rate dependent fluid. There are also studies which indicate that preheating the fuel results in better performance, and as a result of such heating, the viscosity changes. Constitutive modeling of these non-linear fluids, commonly referred to as non-Newtonian fluids, has received much attention. Most of the naturally occurring and synthetic fluids are non-linear fluids, for example, polymer melts, suspensions, blood, coal-water slurries, drilling fluids, mud, etc. It should be noted that sometimes these fluids show Newtonian (linear) behavior for a given range of parameters or geometries; there are many empirical or semi-empirical constitutive equations suggested for these fluids. There have also been many non-linear constitutive relations which have been derived based on the techniques of continuum mechanics. The non-linearities oftentimes appear due to higher gradient terms or time derivatives. When thermal and or chemical effects are also important, the (coupled) momentum and energy equations can give rise to a variety of interesting problems, such as instability, for example the phenomenon of double-diffusive convection in a fluid layer. In Conclusion, we have studied the flow of a compressible (density gradient type) non-linear fluid down an inclined plane, subject to radiation boundary condition. The heat transfer is also considered where a source term, similar to the Arrhenius type reaction, is included. The non-dimensional forms of the equations are solved numerically and the competing effects of conduction, dissipation, heat generation and radiation are discussed. It is observed that the velocity increases rapidly in the region near the inclined surface and is slower in the region near the free surface. Since R{sub 7} is a measure of the heat generation due to chemical reaction, when the reaction is frozen (R{sub 7}=0.0) the temperature distributions would depend only on R{sub 1}, and R{sub 2}, representing the effects of the pressure force developed in the material due to the distribution, R{sub 3} and R{sub 4} viscous dissipation, R{sub 5} the normal stress coefficient, R{sub 6} the measure of the emissivity of the particles to the thermal conductivity, etc. When the flow is not frozen (RP{sub 7} > 0) the temperature inside the flow domain is much higher than those at the inclined and free surfaces. As a result, heat is transferred away from the flow toward both the inclined surface and the free surface with a rate that increases as R{sub 7} increases. For a given temperature, an increase in {zeta} implies that the activation energy is smaller and thus, the reaction ra
M. Marklund; P. K. Shukla; B. Eliasson
2005-03-08T23:59:59.000Z
We present a new dispersion relation for photons that are nonlinearly interacting with a radiation gas of arbitrary intensity due to photon-photon scattering. It is found that the photon phase velocity decreases with increasing radiation intensity, it and attains a minimum value in the limit of super-intense fields. By using Hamilton's ray equations, a self-consistent kinetic theory for interacting photons is formulated. The interaction between an electromagnetic pulse and the radiation gas is shown to produce pulse self-compression and nonlinear saturation. Implications of our new results are discussed.
Posters Comparison of Stochastic Radiation Transfer Predictions
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5(Million Cubic Feet) Oregon (Including Vehicle Fuel) (Million Cubic Feet)sets safety record |PersonalPhotos7CommitteesProgram -decadal91 Posters9
Posters The Effects of Radiative Transfer
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5(Million Cubic Feet) Oregon (Including Vehicle Fuel) (Million Cubic Feet)sets safety record |PersonalPhotos7CommitteesProgram -decadal917 Posters3313
Three-Dimensional Dust Radiative Transfer
Baes, Maarten
data using 3D dust RT codes. We end with an outlook on the bright future of this field. 63 Annu such as the Solar System (Hoppe et al. 2010), comets and meteoroids (K¨uppers et al. 2005), substellar atmospheres
Journal of Quantitative Spectroscopy & Radiative Transfer ] (
Gamache, Robert R.
with the new set of molecular data is evaluated directly from vertical H2O concentration profiles. r 2004 Elsevier Ltd. All rights reserved. Keywords: Diode laser; Near-infrared spectrometer; Ab initio and carbon dioxide in the lower stratosphere [1]. Both sensors have been involved in several European
A unified radiative magnetohydrodynamics code for lightning-like discharge simulations
Chen, Qiang, E-mail: cq0405@126.com; Chen, Bin, E-mail: emcchen@163.com; Xiong, Run; Cai, Zhaoyang [National Key Laboratory of Electromagnetic Environment and Electro-optical Engineering, PLA University of Science and Technology, Nanjing 210007 (China)] [National Key Laboratory of Electromagnetic Environment and Electro-optical Engineering, PLA University of Science and Technology, Nanjing 210007 (China); Chen, P. F., E-mail: chenpf@nju.edu.cn [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China)
2014-03-15T23:59:59.000Z
A two-dimensional Eulerian finite difference code is developed for solving the non-ideal magnetohydrodynamic (MHD) equations including the effects of self-consistent magnetic field, thermal conduction, resistivity, gravity, and radiation transfer, which when combined with specified pulse current models and plasma equations of state, can be used as a unified lightning return stroke solver. The differential equations are written in the covariant form in the cylindrical geometry and kept in the conservative form which enables some high-accuracy shock capturing schemes to be equipped in the lightning channel configuration naturally. In this code, the 5-order weighted essentially non-oscillatory scheme combined with Lax-Friedrichs flux splitting method is introduced for computing the convection terms of the MHD equations. The 3-order total variation diminishing Runge-Kutta integral operator is also equipped to keep the time-space accuracy of consistency. The numerical algorithms for non-ideal terms, e.g., artificial viscosity, resistivity, and thermal conduction, are introduced in the code via operator splitting method. This code assumes the radiation is in local thermodynamic equilibrium with plasma components and the flux limited diffusion algorithm with grey opacities is implemented for computing the radiation transfer. The transport coefficients and equation of state in this code are obtained from detailed particle population distribution calculation, which makes the numerical model is self-consistent. This code is systematically validated via the Sedov blast solutions and then used for lightning return stroke simulations with the peak current being 20?kA, 30?kA, and 40?kA, respectively. The results show that this numerical model consistent with observations and previous numerical results. The population distribution evolution and energy conservation problems are also discussed.
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AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article) |govInstrumentsmfrirtA Journey Inside theFacebookTechnicalBio-InspiredtechnologiesTechnology Transfer Since 1974, the
Bridging conduction and radiation : investigating thermal transport in nanoscale gaps
Chiloyan, Vazrik
2015-01-01T23:59:59.000Z
Near field radiation transfer between objects separated by small gaps is a widely studied field in heat transfer and has become more important than ever. Many technologies such as heat assisted magnetic recording, aerogels, ...
4. Reaction equilibria 4.1 The Saha equation
Pohl, Martin Karl Wilhelm
4. Reaction equilibria 4.1 The Saha equation If particles and radiation are in equilibrium volume with all electrons, and thus d3 x = n-1 e . Hence we finally derive the Saha equation that, using into Saha's equation then gives the ionization fraction = Ni+1 Ni + Ni+1 2 1 - 10-7 3 · 10-4 (4
Radiation: Radiation Control (Indiana)
Broader source: Energy.gov [DOE]
It is the policy of the state to encourage the constructive uses of radiation and to control its harmful effects. This section contains regulations pertaining to the manufacture, use,...
Electromagnetic radiation and motion of arbitrarily shaped particle
Jozef Klacka
2001-07-06T23:59:59.000Z
Covariant form of equation of motion for arbitrarily shaped particle in the electromagnetic radiation field is presented. Equation of motion in the proper frame of the particle uses the radiation pressure cross section 3 $\\times$ 3 matrix. The obtained equation of motion is compared with known result.
Wormholes supported by pure ghost radiation
Sean A. Hayward
2002-02-17T23:59:59.000Z
Traversible wormhole space-times are found as static, spherically symmetric solutions to the Einstein equations with ingoing and outgoing pure ghost radiation, i.e. pure radiation with negative energy density. Switching off the radiation causes the wormhole to collapse to a Schwarzschild black hole.
Heat Transfer between Graphene and Amorphous SiO2
B. N. J. Persson; H. Ueba
2010-07-22T23:59:59.000Z
We study the heat transfer between graphene and amorphous SiO2. We include both the heat transfer from the area of real contact, and between the surfaces in the non-contact region. We consider the radiative heat transfer associated with the evanescent electromagnetic waves which exist outside of all bodies, and the heat transfer by the gas in the non-contact region. We find that the dominant contribution to the heat transfer result from the area of real contact, and the calculated value of the heat transfer coefficient is in good agreement with the value deduced from experimental data.
Dynamics of heat transfer between nano systems
Svend-Age Biehs; Girish S. Agarwal
2012-10-18T23:59:59.000Z
We develop a dynamical theory of heat transfer between two nano systems. In particular, we consider the resonant heat transfer between two nanoparticles due to the coupling of localized surface modes having a finite spectral width. We model the coupled nanosystem by two coupled quantum mechanical oscillators, each interacting with its own heat bath, and obtain a master equation for the dynamics of heat transfer. The damping rates in the master equation are related to the lifetimes of localized plasmons in the nanoparticles. We study the dynamics towards the steady state and establish connection with the standard theory of heat transfer in steady state. For strongly coupled nano particles we predict Rabi oscillations in the mean occupation number of surface plasmons in each nano particle.
Radiation Reaction in Quantum Vacuum
Keita Seto
2014-11-02T23:59:59.000Z
From the development of the electron theory by H. A. Lorentz in 1906, many authors have tried to reformulate this model named "radiation reaction". P. A. M. Dirac derived the relativistic-classical electron model in 1938, which is now called the Lorentz-Abraham-Dirac model. But this model has the big difficulty of the run-away solution. Recently, this equation has become important for ultra-intense laser-electron (plasma) interactions. Therefore, it is desirable to stabilize this model of the radiation reaction for estimations. Via my recent research, I found a stabilized model of radiation reaction in quantum vacuum. This leads us to an updated Fletcher-Millikan's charge to mass ratio including radiation, de/dm, derived as the 4th order tensor measure. In this paper, I will discuss the latest update of the model and the ability of the equation of motion with radiation reaction in quantum vacuum via photon-photon scatterings.
Shumway, R.W.
1987-10-01T23:59:59.000Z
The ATHENA computer program has many features that make it desirable to use as a space reactor evaluation tool. One of the missing features was a surface-to-surface thermal radiation model. A model was developed that allows any of the regular ATHENA heat slabs to radiate to any other heat slab. The view factors and surface emissivities must be specified by the user. To verify that the model was properly accounting for radiant energy transfer, two different types of test calculations were performed. Both calculations have excellent results. The updates have been used on both the INEL CDC-176 and the Livermore Cray. 7 refs., 2 figs., 6 tabs.
Nozomu Kawakatu; Masayuki Umemura
2001-11-22T23:59:59.000Z
We quantitatively scrutinize the effects of the radiation drag arising from the radiation fields in a galactic bulge in order to examine the possibility that the radiation drag could be an effective mechanism to extract angular momentum in a spheroidal system like a bulge and allow plenty of gas to accrete onto the galactic center. For this purpose, we numerically solve the relativistic radiation hydrodynamical equation coupled with the accurate radiative transfer and quantitatively assess the radiation drag efficiency. As a result, we find that in an optically thick regime the radiation drag efficiency is sensitively dependent on the density distributions of interstellar medium (ISM). The efficiency drops according to $\\tau_{\\rm T}^{-2}$ in an optically thick {\\it uniform} ISM, where $\\tau_{\\rm T}$ is the total optical depth of the dusty ISM, whereas the efficiency remains almost constant at a high level if the ISM is {\\it clumpy}. Hence, if the bulge formation begins with a star formation event in a clumpy ISM, the radiation drag will effectively work to remove the angular momentum and the accreted gas may form a supermassive black hole. As a natural consequence, this mechanism reproduces a putative linear relation between the mass of a supermassive black hole and the mass of a galactic bulge, although further detailed modeling for stellar evolution is required for the more precise prediction.
About convective heat transfer in geothermal systems
Pashkevich, R.I. [Kamchatsky Complex Department of NIPIgeotherm Institute, Petropavlovsk-Kamchatsky (Russian Federation)
1996-12-31T23:59:59.000Z
The interphase fluid-rock heat exchange in convective beat transfer in geothermal systems is investigated Nonlinear model of interphase heat exchange is suggested. Calculation for one dimension case and comparison with known Anzelius-Schumann solution is presented Generalized type block heat transfer model is formulated. The model is adequate for case of geothermal systems and reservoir when a rock block size is comparable with filtration path length. Criterion equations for nonstationary coefficients of interphase heat exchange we presented these equations were obtained in laboratory experiments with diorites.
Discretisation and solution of quasi-diffusion equations
Valette, Nicolas Dominique
2002-01-01T23:59:59.000Z
We show how the Quasi-diffusion method performs on radiative transfer problems in slab geometry and XY geometry for steady state, one-energy-group problems. We explain first how we derive for slab geometry, the discretization ...
Electromagnetic Radiation and Motion of Really Shaped Particle
Jozef Klacka
2001-08-13T23:59:59.000Z
Relativistically covariant form of equation of motion for real particle (neutral in charge) under the action of electromagnetic radiation is derived. Various formulations of the equation of motion in the proper frame of reference of the particle are used. Main attention is devoted to the reformulation of the equation of motion in the general frame of reference, e. g., in the frame of reference of the source of electromagnetic radiation. This is the crucial form of equation of motion in applying it to motion of particles (cosmic dust, asteroids, ...) in the Universe if electromagnetic radiation acts on the particles. General relativistic equation of motion is presented.
Aristophanes Dimakis; Folkert Mueller-Hoissen
2014-09-27T23:59:59.000Z
It is shown that higher Bruhat orders admit a decomposition into a higher Tamari order, the corresponding dual Tamari order, and a "mixed order". We describe simplex equations (including the Yang-Baxter equation) as realizations of higher Bruhat orders. Correspondingly, a family of "polygon equations" realizes higher Tamari orders. They generalize the well-known pentagon equation. The structure of simplex and polygon equations is visualized in terms of deformations of maximal chains in posets forming 1-skeletons of polyhedra. The decomposition of higher Bruhat orders induces a reduction of the N-simplex equation to the (N+1)-gon equation, its dual, and a compatibility equation.
Ionizing Radiation in Smoothed Particle Hydrodynamics
O. Kessel-Deynet; A. Burkert
2000-02-11T23:59:59.000Z
A new method for the inclusion of ionizing radiation from uniform radiation fields into 3D Smoothed Particle Hydrodynamics (SPHI) simulations is presented. We calculate the optical depth for the Lyman continuum radiation from the source towards the SPHI particles by ray-tracing integration. The time-dependent ionization rate equation is then solved locally for the particles within the ionizing radiation field. Using test calculations, we explore the numerical behaviour of the code with respect to the implementation of the time-dependent ionization rate equation. We also test the coupling of the heating caused by the ionization to the hydrodynamical part of the SPHI code.
Radiation Center and TRIGA Report Annual Report
the requirements of : A. U.S. Nuclear Regulatory Commission, License No. R-106 (Docket No. 50-243), Technical Waste Generated and Transferred 34 V 4 Monthly Summary of Gaseous Effluent Releases 35 V 5 Annual Summary of Solid Waste Generated and Transferred 36 V 6 Annual Summary of Personnel Radiation Doses
Passive-solar directional-radiating cooling system
Hull, J.R.; Schertz, W.W.
1985-06-27T23:59:59.000Z
A radiative cooling system for use with an ice-making system having a radiating surface aimed at the sky for radiating energy at one or more wavelength bands for which the atmosphere is transparent and a cover thermally isolated from the radiating surface and transparent at least to the selected wavelength or wavelengths, the thermal isolation reducing the formation of condensation on the radiating surface and/or cover and permitting the radiation to continue when the radiating surface is below the dewpoint of the atmosphere, and a housing supporting the radiating surface, cover and heat transfer means to an ice storage reservoir.
Passive-solar directional-radiating cooling system
Hull, John R. (Hinsdale, IL); Schertz, William W. (Batavia, IL)
1986-01-01T23:59:59.000Z
A radiative cooling system for use with an ice-making system having a radiating surface aimed at the sky for radiating energy at one or more wavelength bands for which the atmosphere is transparent and a cover thermally isolated from the radiating surface and transparent at least to the selected wavelength or wavelengths, the thermal isolation reducing the formation of condensation on the radiating surface and/or cover and permitting the radiation to continue when the radiating surface is below the dewpoint of the atmosphere, and a housing supporting the radiating surface, cover and heat transfer means to an ice storage reservoir.
Solar Radiation and Asteroidal Motion
Jozef Klacka
2000-09-07T23:59:59.000Z
Effects of solar wind and solar electromagnetic radiation on motion of asteroids are discussed. The results complete the statements presented in Vokrouhlick\\'{y} and Milani (2000). As for the effect of electromagnetic radiation, the complete equation of motion is presented to the first order in $v/c$ -- the shape of asteroid (spherical body is explicitly presented) and surface distribution of albedo should be taken into account. Optical quantities must be calculated in proper frame of reference.
Incoherent Energy Transfer within Light-harvesting Complexes
Juhi-Lian Julian Ting
1999-04-27T23:59:59.000Z
Rate equations are used to model spectroscopic observation of incoherent energy transfer in light-harvesting antenna systems based upon known structures. A two-parameter two-dimensional model is proposed. The transfer rates obtained, by matching the fluorescent decay, are self-consistent within our model.
Heat transfer in proteinwater interfaces Anders Lervik,ab
Kjelstrup, Signe
Heat transfer in proteinwater interfaces Anders Lervik,ab Fernando Bresme,*ac Signe Kjelstrup of the heat diffusion equation we compute the thermal conductivity and thermal diffusivity of the proteins by about 4 nm.4 It is expected that the energy transfer between these sites may involve the concerted
Relativistic quaternionic wave equation
Schwartz, C
2006-01-01T23:59:59.000Z
Majorana representation of the Dirac equation, i ? ? ? ? ? = m ? , where all four of the gamma matrices
High flux heat transfer in a target environment
McDonald, Kirk
Valid for: Consider turbulent heat transfer in a 1.5mm diameter pipe Dittus Boelter correlationHigh flux heat transfer in a target environment T. Davenne High Power Targets Group Rutherford · Radiation Cooling · Forced Convection · Nucleate Boiling · Critical Heat Flux · Other ideas · Summary #12
None
2011-04-25T23:59:59.000Z
Le conférencier Mons.Hofert parle des dangers et risques des radiations, le contrôle des zones et les précautions à prendre ( p.ex. film badge), comment mesurer les radiations etc.
Cooperative heat transfer and ground coupled storage system
Metz, Philip D. (Rocky Point, NY)
1982-01-01T23:59:59.000Z
A cooperative heat transfer and ground coupled storage system wherein collected solar heat energy is ground stored and permitted to radiate into the adjacent ground for storage therein over an extended period of time when such heat energy is seasonally maximally available. Thereafter, when said heat energy is seasonally minimally available and has propagated through the adjacent ground a substantial distance, the stored heat energy may be retrieved by a circumferentially arranged heat transfer means having a high rate of heat transfer.
FINITE ELEMENT METHOD IN FLUID MECHANICS & HEAT TRANSFER
Camci, Cengiz
completed this course should be able to perform quick analysis of small problems using the finite element of Fluid Mechanics and Heat Transfer An Introduction to Finite Element Analysis Using "Galerkin Weak of Euler's Equation in Finite Element Analysis Generalized Form of Euler's Equation in Three Dimensional
NOMENCLATURE (Journal of Heat Transfer, Vol. 121, No. 4. pp 770-773, November 1999)
NOMENCLATURE (Journal of Heat Transfer, Vol. 121, No. 4. pp 770-773, November 1999) QUANTITY SYMBOL (constant v or p) molar (constant v or p) ratio cp/cv C pcvc , pcvc , J/K J/kg K J/kmol K Heat Transfer COHERENT SI UNIT Absorptivity (radiation) Absorption Coefficient (radiation) m-1 Activation Energy
Matter Wave Radiation Leading to Matter Teleportation
Yong-Yi Huang
2015-02-12T23:59:59.000Z
The concept of matter wave radiation is put forward, and its equation is established for the first time. The formalism solution shows that the probability density is a function of displacement and time. A free particle and a two-level system are reinvestigated considering the effect of matter wave radiation. Three feasible experimental designs, especially a modified Stern-Gerlach setup, are proposed to verify the existence of matter wave radiation. Matter wave radiation effect in relativity has been formulated in only a raw formulae, which offers another explanation of Lamb shift. A possible mechanics of matter teleportation is predicted due to the effect of matter wave radiation.
Electromagnetic Radiation and Motion of Real Particle
Jozef Klacka
2001-06-21T23:59:59.000Z
Relativistically covariant equation of motion for real dust particle under the action of electromagnetic radiation is derived. The particle is neutral in charge. Equation of motion is expressed in terms of particle's optical properties, standardly used in optics for stationary particles.
Evolution equations of the probabilistic generalization of the Voigt profile function
Gianni Pagnini; Francesco Mainardi
2008-06-12T23:59:59.000Z
The spectrum profile that emerges in molecular spectroscopy and atmospheric radiative transfer as the combined effect of Doppler and pressure broadenings is known as the Voigt profile function. Because of its convolution integral representation, the Voigt profile can be interpreted as the probability density function of the sum of two independent random variables with Gaussian density (due to the Doppler effect) and Lorentzian density (due to the pressure effect). Since these densities belong to the class of symmetric L\\'evy stable distributions, a probabilistic generalization is proposed as the convolution of two arbitrary symmetric L\\'evy densities. We study the case when the widths of the considered distributions depend on a scale-factor $\\tau$ that is representative of spatial inhomogeneity or temporal non-stationarity. The evolution equations for this probabilistic generalization of the Voigt function are here introduced and interpreted as generalized diffusion equations containing two Riesz space-fractional derivatives, thus classified as space-fractional diffusion equations of double order.
Discussion on spin-flip synchrotron radiation
V. A. Bordovitsyn; V. S. Gushchina; A. N. Myagkii
2001-02-12T23:59:59.000Z
Quantum spin-flip transitions are of great importance in the synchrotron radiation theory. For better understanding of the nature of this phenomenon, it is necessary to except the effects connected with the electric charge radiation from observation. This fact explains the suggested choice of the spin-flip radiation model in the form of radiation of the electric neutral Dirac-Pauli particle moving in the homogeneous magnetic field. It is known that in this case, the total radiation in the quantum theory is conditioned by spin-flip transitions. The idea is that spin-flip radiation is represented as a nonstationary process connected with spin precession. We shall shown how to construct a solution of the classical equation of the spin precession in the BMT theory having the exact solution of the Dirac-Pauli equation.Thus, one will find the connection of the quantum spin-flip transitions with classical spin precession.
Cheng-Yi Sun; Yu Song; Rui-Hong Yue
2011-10-09T23:59:59.000Z
It was found that the model with interaction between cold dark matter (CDM) and dark energy (DE) proportional to the energy density of CDM $\\rho_m$ and constant equation of state of DE $w_d$ suffered from instabilities of the density perturbations on the supper-Hubble scales. Here we suggest a new covariant model for the energy-momentum transfer between CDM and DE. Then using the covariant model, we analyze the evolution of density perturbations on the supper-Hubble scale. We find that the instabilities can be avoided in the model with constant $w_d$ and interaction proportional to $\\rho_m$. Furthermore, we analyze the dominant non-adiabatic mode in the radiation era and find that the mode grows regularly.
Anisotropic radiation from accretion disc-coronae in active galactic nuclei
Xu, Ya-Di
2015-01-01T23:59:59.000Z
In the unification scheme of active galactic nuclei (AGN), Seyfert 1s and Seyfert 2s are intrinsically same, but they are viewed at different angles. However, the Fe K\\alpha emission line luminosity of Seyfert 1s was found in average to be about twice of that of Seyfert 2s at given X-ray continuum luminosity in the previous work (Ricci et al. 2014). We construct an accretion disc-corona model, in which a fraction of energy dissipated in the disc is extracted to heat the corona above the disc. The radiation transfer equation containing Compton scattering processes is an integro-differential equation, which is solved numerically for the corona with a parallel plane geometry. We find that the specific intensity of X-ray radiation from the corona changes little with the viewing angle \\theta when \\theta is small (nearly face-on), and it is sensitive to \\theta if the viewing angle is large (\\theta> 40 degrees). The radiation from the cold disc, mostly in infrared/optical/UV bands, is almost proportional to cos\\thet...
Wireless adiabatic power transfer
Rangelov, A.A., E-mail: rangelov@phys.uni-sofia.bg [Department of Physics, Sofia University, James Bourchier 5 blvd., 1164 Sofia (Bulgaria); Suchowski, H.; Silberberg, Y. [Department of Physics of Complex System, Weizmann Institute of Science, Rehovot 76100 (Israel); Vitanov, N.V. [Department of Physics, Sofia University, James Bourchier 5 blvd., 1164 Sofia (Bulgaria)
2011-03-15T23:59:59.000Z
Research Highlights: > Efficient and robust mid-range wireless energy transfer between two coils. > The adiabatic energy transfer is analogous to adiabatic passage in quantum optics. > Wireless energy transfer is insensitive to any resonant constraints. > Wireless energy transfer is insensitive to noise in the neighborhood of the coils. - Abstract: We propose a technique for efficient mid-range wireless power transfer between two coils, by adapting the process of adiabatic passage for a coherently driven two-state quantum system to the realm of wireless energy transfer. The proposed technique is shown to be robust to noise, resonant constraints, and other interferences that exist in the neighborhood of the coils.
Radiation and Dynamics of Dust Particle
Jozef Klacka
2002-09-23T23:59:59.000Z
Relativistically covariant form of equation of motion for arbitrarily shaped dust particle (neutral in charge) under the action of electromagnetic radiation is derived -- emission, scattering and absorption of radiation is considered. The result is presented in the form of optical quantities used in optics of dust particles. The obtained equation of motion represents a generalization of the Poynting-Robertson (P-R) effect, which is standardly used in orbital evolution of dust particles in astrophysics. Simultaneous action of electromagnetic radiation and gravitational fields of the central body -- star -- on the motion of the particle is discussed.
On an Improvement of the Planck radiation Energy Distribution
Diego Saa
2006-07-18T23:59:59.000Z
The probability distribution function for thermodynamics and econophysics is obtained by solving an equilibrium equation. This approach is different from the common one of optimizing the entropy of the system or obtaining the state of maximum probability, which usually obtains as a result the Boltzmann distribution. The Gamma distribution is proposed as a better equation to describe the blackbody radiation in substitution of Planck's radiation equation. Also, a new form of entropy is proposed, that maintains the correct relation with the Clausius' formula.
Lenert, Andrej
2012-01-01T23:59:59.000Z
The choice of heat transfer fluids has significant effects on the performance, cost, and reliability of solar thermal systems. In this chapter, we evaluate existing heat transfer fluids such as oils and molten salts based ...
Hofstetter, K; Donna Beals, D; Ken Odell, K; Robert Eakle, R; Russell Huffman, R; Larry Harpring, L
2006-05-12T23:59:59.000Z
A unique radiation monitor has been developed for performing wide-area field surveys for radiation sources. This device integrates the real-time output of multiple radiation detectors into a hand-held personal computer (e.g., a PDA) containing an intuitive graphical user interface. An independent hardware module supplies high voltage to the detectors and contains a rapid sampling system for transferring the detector count rates through an interface to the PDA. The imbedded firmware can be changed for various applications using a programmable memory card. As presently configured, the instrument contains a series of Geiger-Mueller (GM) tubes in a flexible detector string. This linear array of multiple sensors can be used by US Coast Guard and Customs container inspection personnel to measure radiation intensity in stacks of transport containers where physical access is impeded.
Kandlikar, Satish
Journal of Heat Transfer Guest Editorial We are indeed delighted in bringing out this special issue was showcased in diverse areas such as traditional heat and mass transfer, lab-on-chip, sensors, biomedical applica- tions, micromixers, fuel cells, and microdevices. Selected papers in the field of heat transfer
Solar radiation intensity calculations
Levine, Randolph Steven
1978-01-01T23:59:59.000Z
, radiation per unit area per unit time, on a flat-plate collector is given by: I = I cos B (2. 1a) where I is the solar constant. insolation received at one astro- nomical unit from the sun. Since clear sky conditions are assumed I o w i 1 1 b e a.... INSOLATION EQUATIONS TABLE OF CONTENTS Page III. RESULTS AND CONCLUSIONS REFERENCES APPENDIX VITA 25 47 48 52 Vi LIST OF TABLES TABLE I. Optimal Inclination for Ap=O, No Checks for Ip &0 and a Time Independent Solar Constant. II. Optimal...
Solar radiation intensity calculations
Levine, Randolph Steven
1978-01-01T23:59:59.000Z
, radiation per unit area per unit time, on a flat-plate collector is given by: I = I cos B (2. 1a) where I is the solar constant. insolation received at one astro- nomical unit from the sun. Since clear sky conditions are assumed I o w i 1 1 b e a.... INSOLATION EQUATIONS TABLE OF CONTENTS Page III. RESULTS AND CONCLUSIONS REFERENCES APPENDIX VITA 25 47 48 52 Vi LIST OF TABLES TABLE I. Optimal Inclination for Ap=O, No Checks for Ip &0 and a Time Independent Solar Constant. II. Optimal...
Fultz, Brent T. (Berkeley, CA)
1983-01-01T23:59:59.000Z
Apparatus is provided for detecting radiation such as gamma rays and X-rays generated in backscatter Mossbauer effect spectroscopy and X-ray spectrometry, which has a large "window" for detecting radiation emanating over a wide solid angle from a specimen and which generates substantially the same output pulse height for monoenergetic radiation that passes through any portion of the detection chamber. The apparatus includes a substantially toroidal chamber with conductive walls forming a cathode, and a wire anode extending in a circle within the chamber with the anode lying closer to the inner side of the toroid which has the least diameter than to the outer side. The placement of the anode produces an electric field, in a region close to the anode, which has substantially the same gradient in all directions extending radially from the anode, so that the number of avalanche electrons generated by ionizing radiation is independent of the path of the radiation through the chamber.
Fultz, B.T.
1980-12-05T23:59:59.000Z
Apparatus is provided for detecting radiation such as gamma rays and x-rays generated in backscatter Moessbauer effect spectroscopy and x-ray spectrometry, which has a large window for detecting radiation emanating over a wide solid angle from a specimen and which generates substantially the same output pulse height for monoenergetic radiation that passes through any portion of the detection chamber. The apparatus includes a substantially toroidal chamber with conductive walls forming a cathode, and a wire anode extending in a circle within the chamber with the anode lying closer to the inner side of the toroid which has the least diameter than to the outer side. The placement of the anode produces an electric field, in a region close to the anode, which has substantially the same gradient in all directions extending radially from the anode, so that the number of avalanche electrons generated by ionizing radiation is independent of the path of the radiation through the chamber.
Not Available
1980-03-07T23:59:59.000Z
A heat transfer system for a nuclear reactor is described. Heat transfer is accomplished within a sealed vapor chamber which is substantially evacuated prior to use. A heat transfer medium, which is liquid at the design operating temperatures, transfers heat from tubes interposed in the reactor primary loop to spaced tubes connected to a steam line for power generation purposes. Heat transfer is accomplished by a two-phase liquid-vapor-liquid process as used in heat pipes. Condensible gases are removed from the vapor chamber through a vertical extension in open communication with the chamber interior.
McGuire, Joseph C. (Richland, WA)
1982-01-01T23:59:59.000Z
A heat transfer system for a nuclear reactor. Heat transfer is accomplished within a sealed vapor chamber which is substantially evacuated prior to use. A heat transfer medium, which is liquid at the design operating temperatures, transfers heat from tubes interposed in the reactor primary loop to spaced tubes connected to a steam line for power generation purposes. Heat transfer is accomplished by a two-phase liquid-vapor-liquid process as used in heat pipes. Condensible gases are removed from the vapor chamber through a vertical extension in open communication with the chamber interior.
E. Minguzzi
2014-10-01T23:59:59.000Z
A mechanical covariant equation is introduced which retains all the effectingness of the Lagrange equation while being able to describe in a unified way other phenomena including friction, non-holonomic constraints and energy radiation (Lorentz-Abraham-Dirac force equation). A quantization rule adapted to the dissipative degrees of freedom is proposed which does not pass through the variational formulation.
Radiation back reaction on moving branes
Ian G. Moss; James P Norman
2004-08-14T23:59:59.000Z
This paper addresses the radiation back reaction problem for cosmological branes. A general framework is provided in which results are given for the radiation reaction with massles and massive scalar fields with flat extra dimensions and massless conformal fields in anti-de Sitter extra dimensions. For massless scalar field radiation the back reaction terms in the equation of motion are non-analytic. The interpretation of the radiation reaction terms is discussed and the equations of motion solved in simple cases. Nucleosynthesis bounds on dark radiation give a lower bound on the string vacuum energy scale of $\\sqrt{A_T} m_p$, where $A_T$ is the tensor perturbation amplitude in the cosmic microwave background.
ON THE SOLAR RADIATION BUDGET AND THE CLOUD ABSORPTION ANOMALY DEBATE
Li, Zhanqing
ON THE SOLAR RADIATION BUDGET AND THE CLOUD ABSORPTION ANOMALY DEBATE ZHANQING LI Department-of-the-art radiative transfer models. 1. Introduction Solar radiation is the ultimate source of energy for the planet of solar radiation, which is unfortunately still fraught with large uncertainties (Wild et al. 1995; Li et
Genomic instability and bystander effects induced by high-LET radiation Eric J Hall*,1
of the radiobiological effects of high- linear energy transfer (LET) radiation is essential for radiation protectionGenomic instability and bystander effects induced by high-LET radiation Eric J Hall*,1 and Tom K, it has always been accepted that the deleterious effects of ionizing radiation, such as mutation
Khandekar, Sameer
Pulsating Heat Pipe Radiators by Infrared Thermography Vadiraj A. Hemadri1 , Sameer Khandekar2 1: Dept of Closed Loop Pulsating Heat pipe (CLPHP) embedded radiator plates subjected to conjugate heat transfer by embedding PHP structure. Keywords: Pulsating Heat Pipes, Space Radiators, Conjugate Heat Transfer 1
Loinger, A
2015-01-01T23:59:59.000Z
The physical results of quantum field theory are independent of the various specializations of Dirac's gamma-matrices, that are employed in given problems. Accordingly, the physical meaning of Majorana's equation is very dubious,considering that it is a consequence of ad hoc matrix representations of the gamma-operators. Therefore, it seems to us that this equation cannot give the equation of motion of the neutral WIMPs (weakly interacting massive particles), the hypothesized constitutive elements of the Dark Matter.
Separable Differential Equations
PRETEX (Halifax NS) #1 1054 1999 Mar 05 10:59:16
2010-01-20T23:59:59.000Z
Feb 16, 2007 ... preceding differential equation and several mem- bers of the given family of curves. Describe the family of orthogonal trajectories. 34. Consider ...
First order differential equations
Samy Tindel
2015-09-29T23:59:59.000Z
Chemical pollution example (2). Notation: Q(t) ? quantity of ... Initial velocity v0, upward. Air resistance negligible ... Air resistance neglected. Equation: v = ?g.
Integrating the Jacobian equation
Airton von Sohsten de Medeiros; Ráderson Rodrigues da Silva
2014-09-16T23:59:59.000Z
We show essentially that the differential equation $\\frac{\\partial (P,Q)}{\\partial (x,y)} =c \\in {\\mathbb C}$, for $P,\\,Q \\in {\\mathbb C}[x,y]$, may be "integrated", in the sense that it is equivalent to an algebraic system of equations involving the homogeneous components of $P$ and $Q$. Furthermore, the first equations in this system give explicitly the homogeneous components of $Q$ in terms of those of $P$. The remaining equations involve only the homogeneous components of $P$.
RADIATION SAFETY TRAINING MANUAL Radiation Safety Office
Sibille, Etienne
protection and the potential risks of ionizing radiation. Radiation Safety Office personnel provide.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 II. OVERVIEW OF REGULATIONS, PROTECTION STANDARDS, AND RADIATION SAFETY ORGANIZATION.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 V. BASIC RADIATION PROTECTION PRINCIPLES
Jun'ichi Sato; Keisuke Sawada; Naofumi Ohnishi
2003-04-14T23:59:59.000Z
Two-dimensional numerical simulations of an accretion flow in a close binary system are performed by solving the Euler equations with radiative transfer. In the present study, the specific heat ratio is assumed to be constant while radiative cooling effect is included as a non-adiabatic process. The cooling effect of the disc is considered by discharging energy in the vertical directions from the top and bottom surfaces of the disc. We use the flux-limited diffusion approximation to calculate the radiative heat flux values. Our calculations show that a disc structure appears and the spiral shocks are formed on the disc. These features are similar to that observed in the case of an adiabatic gas with a lower specific heat ratio, $\\gamma=1.01$. It is found that when radiative cooling effect is accounted for, the mass of the disc becomes larger than that assuming $\\gamma=5/3$, and smaller than that assuming $\\gamma=1.01$. It is concluded that employing an adiabatic gas with a lower specific heat ratio is almost a valid assumption for simulating accretion disc with radiative cooling effect.
Sergei Kuksin; Alberto Maiocchi
2015-01-17T23:59:59.000Z
In this chapter we present a general method of constructing the effective equation which describes the behaviour of small-amplitude solutions for a nonlinear PDE in finite volume, provided that the linear part of the equation is a hamiltonian system with a pure imaginary discrete spectrum. The effective equation is obtained by retaining only the resonant terms of the nonlinearity (which may be hamiltonian, or may be not); the assertion that it describes the limiting behaviour of small-amplitude solutions is a rigorous mathematical theorem. In particular, the method applies to the three-- and four--wave systems. We demonstrate that different possible types of energy transport are covered by this method, depending on whether the set of resonances splits into finite clusters (this happens, e.g. in case of the Charney-Hasegawa-Mima equation), or is connected (this happens, e.g. in the case of the NLS equation if the space-dimension is at least two). For equations of the first type the energy transition to high frequencies does not hold, while for equations of the second type it may take place. In the case of the NLS equation we use next some heuristic approximation from the arsenal of wave turbulence to show that under the iterated limit "the volume goes to infinity", taken after the limit "the amplitude of oscillations goes to zero", the energy spectrum of solutions for the effective equation is described by a Zakharov-type kinetic equation. Evoking the Zakharov ansatz we show that stationary in time and homogeneous in space solutions for the latter equation have a power law form. Our method applies to various weakly nonlinear wave systems, appearing in plasma, meteorology and oceanology.
Synchrotron radiation from massless charge
Gal'tsov, D V
2015-01-01T23:59:59.000Z
Classical radiation power from an accelerated massive charge diverges in the zero-mass limit, while some general arguments suggest that strictly massless charge does not not radiate at all. On the other hand, the regularized classical radiation reaction force, though looking odd, is non-zero and finite. To clarify this controversy, we consider radiation problem in massless scalar quantum electrodynamics in the external magnetic field. In this framework, synchrotron radiation is found to be non-zero, finite, and essentially quantum. Its spectral distribution is calculated using Schwinger's proper time technique for {\\em ab initio} massless particle of zero spin. Provided $E^2\\gg eH$, the maximum in the spectrum is shown to be at $\\hbar \\omega=E/3$, and the average photon energy is $4E/9$. The normalized spectrum is universal, depending neither on $E$ nor on $H$. Quantum nature of radiation makes classical radiation reaction equation meaningless for massless charge. Our results are consistent with the view (sup...
Townsend, Harold E. (Campbell, CA); Barbanti, Giancarlo (Cupertino, CA)
1994-01-01T23:59:59.000Z
A nuclear fuel bundle fuel transfer system includes a transfer pool containing water at a level above a reactor core. A fuel transfer machine therein includes a carriage disposed in the transfer pool and under the water for transporting fuel bundles. The carriage is selectively movable through the water in the transfer pool and individual fuel bundles are carried vertically in the carriage. In a preferred embodiment, a first movable bridge is disposed over an upper pool containing the reactor core, and a second movable bridge is disposed over a fuel storage pool, with the transfer pool being disposed therebetween. A fuel bundle may be moved by the first bridge from the reactor core and loaded into the carriage which transports the fuel bundle to the second bridge which picks up the fuel bundle and carries it to the fuel storage pool.
Townsend, H.E.; Barbanti, G.
1994-03-01T23:59:59.000Z
A nuclear fuel bundle fuel transfer system includes a transfer pool containing water at a level above a reactor core. A fuel transfer machine therein includes a carriage disposed in the transfer pool and under the water for transporting fuel bundles. The carriage is selectively movable through the water in the transfer pool and individual fuel bundles are carried vertically in the carriage. In a preferred embodiment, a first movable bridge is disposed over an upper pool containing the reactor core, and a second movable bridge is disposed over a fuel storage pool, with the transfer pool being disposed therebetween. A fuel bundle may be moved by the first bridge from the reactor core and loaded into the carriage which transports the fuel bundle to the second bridge which picks up the fuel bundle and carries it to the fuel storage pool. 6 figures.
Cosmological fluctuations of a random field and radiation fluid
Bastero-Gil, Mar [Departamento de Física Teórica y del Cosmos, Campus de Fuentenueva, Universidad de Granada, Granada, 18071 (Spain); Berera, Arjun [SUPA, School of Physics and Astronomy, University of Edinburgh, Edinburgh, EH9 3JZ (United Kingdom); Moss, Ian G. [School of Mathematics and Statistics, Newcastlle University, Newcastle upon Tyne, NE1 7RU (United Kingdom); Ramos, Rudnei O., E-mail: mbg@ugr.es, E-mail: ab@ph.ed.ac.uk, E-mail: ian.moss@ncl.ac.uk, E-mail: rudnei@uerj.br [Departamento de Física Teórica, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, 20550-013 Brazil (Brazil)
2014-05-01T23:59:59.000Z
A generalization of the random fluid hydrodynamic fluctuation theory due to Landau and Lifshitz is applied to describe cosmological fluctuations in systems with radiation and scalar fields. The viscous pressures, parametrized in terms of the bulk and shear viscosity coefficients, and the respective random fluctuations in the radiation fluid are combined with the stochastic and dissipative scalar evolution equation. This results in a complete set of equations describing the perturbations in both scalar and radiation fluids. These derived equations are then studied, as an example, in the context of warm inflation. Similar treatments can be done for other cosmological early universe scenarios involving thermal or statistical fluctuations.
Expanding, axisymmetric pure-radiation gravitational fields with a simple twist
B. V. Ivanov
2001-03-27T23:59:59.000Z
New expanding, axisymmetric pure-radiation solutions are found, exploiting the analogy with the Euler-Darboux equation for aligned colliding plane waves.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
MTAXX-XXX 1 MATERIAL TRANSFER AGREEMENT for Manufacturing Demonstration Facility and Carbon Fiber Technology Facility In order for the RECIPIENT to obtain materials, the RECIPIENT...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
July 29, 2013 Scientists gain first quantitative insights into electron transfer from minerals to microbes Scientists have gained the first quantitative insights into electron...
Broader source: Energy.gov [DOE]
As DOE facilities become excess, many that are radioactively and/or chemically contaminated will become candidate for transfer to DOE-EM for deactivation and decommissioning.
An enriched finite element model with q-refinement for radiative boundary layers in glass cooling
Mohamed, M. Shadi [Institute for Infrastructure and Environment, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom)] [Institute for Infrastructure and Environment, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Seaid, Mohammed; Trevelyan, Jon [School of Engineering and Computing Sciences, University of Durham, South Road, Durham DH1 3LE (United Kingdom)] [School of Engineering and Computing Sciences, University of Durham, South Road, Durham DH1 3LE (United Kingdom); Laghrouche, Omar [Institute for Infrastructure and Environment, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom)] [Institute for Infrastructure and Environment, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom)
2014-02-01T23:59:59.000Z
Radiative cooling in glass manufacturing is simulated using the partition of unity finite element method. The governing equations consist of a semi-linear transient heat equation for the temperature field and a stationary simplified P{sub 1} approximation for the radiation in non-grey semitransparent media. To integrate the coupled equations in time we consider a linearly implicit scheme in the finite element framework. A class of hyperbolic enrichment functions is proposed to resolve boundary layers near the enclosure walls. Using an industrial electromagnetic spectrum, the proposed method shows an immense reduction in the number of degrees of freedom required to achieve a certain accuracy compared to the conventional h-version finite element method. Furthermore the method shows a stable behaviour in treating the boundary layers which is shown by studying the solution close to the domain boundaries. The time integration choice is essential to implement a q-refinement procedure introduced in the current study. The enrichment is refined with respect to the steepness of the solution gradient near the domain boundary in the first few time steps and is shown to lead to a further significant reduction on top of what is already achieved with the enrichment. The performance of the proposed method is analysed for glass annealing in two enclosures where the simplified P{sub 1} approximation solution with the partition of unity method, the conventional finite element method and the finite difference method are compared to each other and to the full radiative heat transfer as well as the canonical Rosseland model.
A phase-field method for 3D simulation of two-phase heat transfer , H. Babaee a
Dong, Suchuan "Steven"
A phase-field method for 3D simulation of two-phase heat transfer X. Zheng a , H. Babaee a , S s t r a c t We formulate new multi-phase convective heat transfer equations by combining the three for convergence in time/space including a conjugate heat transfer problem and also for a realistic tran- sient
De Castro, Carlos Armando
2011-01-01T23:59:59.000Z
In this paper is developed a simple mathematical model of transient heat transfer under soil with plastic mulch in order to determine with numerical studies the influence of different plastic mulches on the soil temperature and the evolutions of temperatures at different depths with time. The governing differential equations are solved by a Galerkin Finite Element Model, taking into account the nonlinearities due to radiative heat exchange between the soil surface, the plastic mulch and the atmosphere. The model was validated experimentally giving good approximation of the model to the measured data. Simulations were run with the validated model in order to determine the optimal combination of mulch optical properties to maximize the soil temperature with a Taguchi's analysis, proving that the material most used nowadays in Colombia is not the optimal and giving quantitative results of the properties the optimal mulch must possess.
Wireless adiabatic power transfer
A. A. Rangelov; H. Suchowski; Y. Silberberg; N. V. Vitanov
2010-10-30T23:59:59.000Z
We propose a technique for efficient mid-range wireless power transfer between two coils, by adapting the process of adiabatic passage for a coherently driven two-state quantum system to the realm of wireless energy transfer. The proposed technique is shown to be robust to noise, resonant constraints, and other interferences that exist in the neighborhood of the coils.
Hunt, Arlon J. (Oakland, CA)
1983-01-01T23:59:59.000Z
The apparatus for collecting radiant energy and converting same to alternate energy form includes a housing having an interior space and a radiation transparent window allowing, for example, solar radiation to be received in the interior space of the housing. Means are provided for passing a stream of fluid past said window and for injecting radiation absorbent particles in said fluid stream. The particles absorb the radiation and because of their very large surface area, quickly release the heat to the surrounding fluid stream. The fluid stream particle mixture is heated until the particles vaporize. The fluid stream is then allowed to expand in, for example, a gas turbine to produce mechanical energy. In an aspect of the present invention properly sized particles need not be vaporized prior to the entrance of the fluid stream into the turbine, as the particles will not damage the turbine blades. In yet another aspect of the invention, conventional fuel injectors are provided to inject fuel into the fluid stream to maintain the proper temperature and pressure of the fluid stream should the source of radiant energy be interrupted. In yet another aspect of the invention, an apparatus is provided which includes means for providing a hot fluid stream having hot particles disbursed therein which can radiate energy, means for providing a cooler fluid stream having cooler particles disbursed therein, which particles can absorb radiant energy and means for passing the hot fluid stream adjacent the cooler fluid stream to warm the cooler fluid and cooler particles by the radiation from the hot fluid and hot particles.
Hunt, A.J.
1983-09-13T23:59:59.000Z
The apparatus for collecting radiant energy and converting same to alternate energy form includes a housing having an interior space and a radiation transparent window allowing, for example, solar radiation to be received in the interior space of the housing. Means are provided for passing a stream of fluid past said window and for injecting radiation absorbent particles in said fluid stream. The particles absorb the radiation and because of their very large surface area, quickly release the heat to the surrounding fluid stream. The fluid stream particle mixture is heated until the particles vaporize. The fluid stream is then allowed to expand in, for example, a gas turbine to produce mechanical energy. In an aspect of the present invention properly sized particles need not be vaporized prior to the entrance of the fluid stream into the turbine, as the particles will not damage the turbine blades. In yet another aspect of the invention, conventional fuel injectors are provided to inject fuel into the fluid stream to maintain the proper temperature and pressure of the fluid stream should the source of radiant energy be interrupted. In yet another aspect of the invention, an apparatus is provided which includes means for providing a hot fluid stream having hot particles disbursed therein which can radiate energy, means for providing a cooler fluid stream having cooler particles disbursed therein, which particles can absorb radiant energy and means for passing the hot fluid stream adjacent the cooler fluid stream to warm the cooler fluid and cooler particles by the radiation from the hot fluid and hot particles. 5 figs.
Bernard F Schutz
2000-03-16T23:59:59.000Z
Gravity is one of the fundamental forces of Nature, and it is the dominant force in most astronomical systems. In common with all other phenomena, gravity must obey the principles of special relativity. In particular, gravitational forces must not be transmitted or communicated faster than light. This means that when the gravitational field of an object changes, the changes ripple outwards through space and take a finite time to reach other objects. These ripples are called gravitational radiation or gravitational waves. This article gives a brief introduction to the physics of gravitational radiation, including technical material suitable for non-specialist scientists.
Relativistic Guiding Center Equations
White, R. B. [PPPL; Gobbin, M. [Euratom-ENEA Association
2014-10-01T23:59:59.000Z
In toroidal fusion devices it is relatively easy that electrons achieve relativistic velocities, so to simulate runaway electrons and other high energy phenomena a nonrelativistic guiding center formalism is not sufficient. Relativistic guiding center equations including flute mode time dependent field perturbations are derived. The same variables as used in a previous nonrelativistic guiding center code are adopted, so that a straightforward modifications of those equations can produce a relativistic version.
Heat transfer between elastic solids with randomly rough surfaces
B. N. J. Persson; B. Lorenz; A. I. Volokitin
2009-08-27T23:59:59.000Z
We study the heat transfer between elastic solids with randomly rough surfaces. We include both the heat transfer from the area of real contact, and the heat transfer between the surfaces in the noncontact regions. We apply a recently developed contact mechanics theory, which accounts for the hierarchical nature of the contact between solids with roughness on many different length scales. For elastic contact, at the highest (atomic) resolution the area of real contact typically consists of atomic (nanometer) sized regions, and we discuss the implications of this for the heat transfer. For solids with very smooth surfaces, as is typical in many modern engineering applications, the interfacial separation in the non-contact regions will be very small, and for this case we show the importance of the radiative heat transfer associated with the evanescent electromagnetic waves which exist outside of all bodies.
ATS 351, Spring 2010 Energy & Radiation 60 points
Rutledge, Steven
energy per wave? Why? Shorter wavelengths carry more energy per wave. Therefore, the sun's radiationATS 351, Spring 2010 Lab #2 Energy & Radiation 60 points Please show your work for calculations Question #1: Energy (11 points) Heat is a measure of the transfer of energy from a body with a higher
Solving Symbolic Equations with PRESS
Sterling, L.; Bundy, Alan; Byrd, L.; O'Keefe, R.; Silver, B.
1982-01-01T23:59:59.000Z
We outline a program, PRESS (PRolog Equation Solving System) for solving symbolic, transcendental, non-differential equations. The methods used for solving equations are described, together with the service facilities. The ...
Radiation Protection Act (Pennsylvania)
Broader source: Energy.gov [DOE]
This Act combines the radiation safety provisions of The Atomic Energy Development and Radiation Control Act and the Environmental Radiation Protection Act, and empowers the Department of...
DETECTORS FOR RADIATION DOSIMETRY
Perez-Mendez, V.
2010-01-01T23:59:59.000Z
I. Applications of Radiation Detectors 1) X-Rays, Gammaof the Conference DETECTORS FOR RADIATION DOSIMETRY VictorT E D LBL9651 DETECTORS FOR RADIATION DOSIMETRY - DISCLAIM*
Not Available
1994-01-01T23:59:59.000Z
This document, Technology Transfer 94, is intended to communicate that there are many opportunities available to US industry and academic institutions to work with DOE and its laboratories and facilities in the vital activity of improving technology transfer to meet national needs. It has seven major sections: Introduction, Technology Transfer Activities, Access to Laboratories and Facilities, Laboratories and Facilities, DOE Office, Technologies, and an Index. Technology Transfer Activities highlights DOE`s recent developments in technology transfer and describes plans for the future. Access to Laboratories and Facilities describes the many avenues for cooperative interaction between DOE laboratories or facilities and industry, academia, and other government agencies. Laboratories and Facilities profiles the DOE laboratories and facilities involved in technology transfer and presents information on their missions, programs, expertise, facilities, and equipment, along with data on whom to contact for additional information on technology transfer. DOE Offices summarizes the major research and development programs within DOE. It also contains information on how to access DOE scientific and technical information. Technologies provides descriptions of some of the new technologies developed at DOE laboratories and facilities.
INSTITUTE OF NUCLEAR TECHNOLOGY RADIATION PROTECTION
INSTITUTE OF NUCLEAR TECHNOLOGY RADIATION PROTECTION ANNUAL REPORT 2005 - 2006 #12;2 #12;3 ANNUAL. Papazoglou #12;5 PREFACE The Institute has continued transferring know how from Nuclear Technology to other of the Institute page 34 7. Publications page 36 8. Research Projects page 72 #12;4 ORGANISATIONAL CHART 2006
Anomalous Near-Field Heat Transfer between a Cylinder and a Perforated Surface
Rodriguez-Wong, Alejandro
We predict that the near-field radiative heat-transfer rate between a cylinder and a perforated surface depends nonmonotonically on their separation. This anomalous behavior, which arises due to evanescent-wave effects, ...
Differential Equations of Mathematical Physics
Max Lein
2015-08-16T23:59:59.000Z
These lecture notes for the course APM 351 at the University of Toronto are aimed at mathematicians and physicists alike. It is not meant as an introductory course to PDEs, but rather gives an overview of how to view and solve differential equations that are common in physics. Among others, I cover Hamilton's equations, variations of the Schr\\"odinger equation, the heat equation, the wave equation and Maxwells equations.
Kyasov, A A
2015-01-01T23:59:59.000Z
We have developed a self-consistent description of the radiation heat transfer and dynamics of large perfectly black spherical bodies with sizes much greater than the characteristic wavelength of radiation moving in a photon gas with relativistic velocity. The results can be important in astrophysics.
Eloranta, Edwin W.
Arctic-Winter Climatology and Radiative Effects of Clouds and Aerosols Based on Lidar and Radar Atmospheric Radiative Transfer (SBDART) code. Results on the climatology and radiative effects of clouds, arctic regions are the site of interactions between aerosols, clouds, radiation and precipitations
Thermal radiation and conduction in microscale structures. Final report
Tien, C.L.
1998-09-02T23:59:59.000Z
The general objective of the current research program is to achieve a better understanding of the fundamental mechanisms of thermal radiation and heat conduction in microscale structures commonly encountered in engineering applications. Specifically, the program includes both experimental and analytical investigations of radiative heat transfer in microstructures, conductive heat transfer in micro devices, and short-pulse laser material interactions. Future work is planned to apply the knowledge of microscale heat transfer gained in this project to developing thermal insulating aerogel materials, thermal design schemes for quantum well lasers, and short-pulse laser micro-fabrication techniques. A listing of publications by Chang-Lin Tien is included.
V. Suleimanov; K. Werner
2007-02-15T23:59:59.000Z
Emergent model spectra of neutron star atmospheres are widely used to fit the observed soft X-ray spectra of different types of isolated neutron stars. We investigate the effect of Compton scattering on the emergent spectra of hot (T_eff > 10^6 K) isolated neutron stars with weak magnetic fields. In order to compute model atmospheres in hydrostatic and radiative equilibrium we solve the radiation transfer equation with the Kompaneets operator. We calculate a set of models with effective temperatures in the range 1 - 5 * 10^6 K, with two values of surface gravity (log g = 13.9 and 14.3) and different chemical compositions. Radiation spectra computed with Compton scattering are softer than those computed without Compton scattering at high energies (E > 5 keV) for light elements (H or He) model atmospheres. The Compton effect is more significant in H model atmospheres and models with low surface gravity. The emergent spectra of the hottest (T_eff > 3 * 10^6 K) model atmospheres can be described by diluted blackbody spectra with hardness factors ~ 1.6 - 1.9. Compton scattering is less important in models with solar abundance of heavy elements.
Ames Lab 101: Technology Transfer
Covey, Debra
2012-08-29T23:59:59.000Z
Ames Laboratory Associate Laboratory Director, Sponsored Research Administration, Debra Covey discusses technology transfer. Covey also discusses Ames Laboratory's most successful transfer, lead-free solder.
ME 360N Intermediate Heat Transfer ABET EC2000 syllabus
Ben-Yakar, Adela
and Internal), Heat Exchangers (1) 3. Heat Exchanger Analysis (1) 4. Radiation (Intro) (Properties, Surface (1) 22. Nat'l. Conv. (1) 23. Intro Heat Exchangers & Energy Balances (1) 24. Overall H.T. Coeff Intermediate Heat Transfer Page 2 ABET EC2000 syllabus Class/Laboratory Schedule (Type, number and duration
Proton Transfer in Nucleobases is Mediated by Water Kirill Khistyaev,
Krylov, Anna I.
Proton Transfer in Nucleobases is Mediated by Water Kirill Khistyaev, Amir Golan, Ksenia B. Bravaya, and facilitating efficient proton transport through ion channels and interfaces. This study investigates proton and tunable vacuum ultraviolet synchrotron radiation, we show that water shuts down ionization-induced proton
MULTI-DIMENSIONAL FEATURES OF NEUTRINO TRANSFER IN CORE-COLLAPSE SUPERNOVAE
Sumiyoshi, K. [Numazu College of Technology, Ooka 3600, Numazu, Shizuoka 410-8501 (Japan); Takiwaki, T. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Matsufuru, H. [Computing Research Center, High Energy Accelerator Research Organization 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Yamada, S., E-mail: sumi@numazu-ct.ac.jp, E-mail: takiwaki.tomoya@nao.ac.jp, E-mail: hideo.matsufuru@kek.jp, E-mail: shoichi@heap.phys.waseda.ac.jp [Science and Engineering and Advanced Research Institute for Science and Engineering, Waseda University, Okubo, 3-4-1, Shinjuku, Tokyo 169-8555 (Japan)
2015-01-01T23:59:59.000Z
We study the multi-dimensional properties of neutrino transfer inside supernova cores by solving the Boltzmann equations for neutrino distribution functions in genuinely six-dimensional phase space. Adopting representative snapshots of the post-bounce core from other supernova simulations in three dimensions, we solve the temporal evolution to stationary states of neutrino distribution functions using our Boltzmann solver. Taking advantage of the multi-angle and multi-energy feature realized by the S {sub n} method in our code, we reveal the genuine characteristics of spatially three-dimensional neutrino transfer, such as nonradial fluxes and nondiagonal Eddington tensors. In addition, we assess the ray-by-ray approximation, turning off the lateral-transport terms in our code. We demonstrate that the ray-by-ray approximation tends to propagate fluctuations in thermodynamical states around the neutrino sphere along each radial ray and overestimate the variations between the neutrino distributions on different radial rays. We find that the difference in the densities and fluxes of neutrinos between the ray-by-ray approximation and the full Boltzmann transport becomes ?20%, which is also the case for the local heating rate, whereas the volume-integrated heating rate in the Boltzmann transport is found to be only slightly larger (?2%) than the counterpart in the ray-by-ray approximation due to cancellation among different rays. These results suggest that we should carefully assess the possible influences of various approximations in the neutrino transfer employed in current simulations of supernova dynamics. Detailed information on the angle and energy moments of neutrino distribution functions will be profitable for the future development of numerical methods in neutrino-radiation hydrodynamics.
Tachyonic equations to reduce the divergent integral of QED
Z. Wang
2009-11-12T23:59:59.000Z
If the total integral including both 0
Policy on Cost Transfer Policy on Cost Transfer
Sridhar, Srinivas
Policy on Cost Transfer 12/22/2014 Policy on Cost Transfer I. Purpose and Scope The University has posting of a cost to the general ledger, initiated by payroll charges, purchase orders or check requests (and the purchasing card). Cost Transfer means any subsequent transfer of the original charge
Resources, framing, and transfer p. 1 Resources, framing, and transfer
Hammer, David
Resources, framing, and transfer p. 1 Resources, framing, and transfer David Hammer Departments. #12;Resources, framing, and transfer p. 2 Resources, framing, and transfer David Hammer, Andrew Elby of activating resources, a language with an explicitly manifold view of cognitive structure. In this chapter, we
HEAT TRANSFERS IN A DOUBLE SKIN ROOF VENTILATED BY NATURAL CONVECTION IN SUMMER TIME
Boyer, Edmond
1 HEAT TRANSFERS IN A DOUBLE SKIN ROOF VENTILATED BY NATURAL CONVECTION IN SUMMER TIME P. H and the sheet metal: This is ventilation by natural convection. The remaining conductive heat from the sheet or in tropical and arid countries. In this work, radiation, convection and conduction heat transfers
Liu, Hongyu
Radiative effect of clouds on tropospheric chemistry in a global three-dimensional chemical. (2006), Radiative effect of clouds on tropospheric chemistry in a global three-dimensional chemical frequencies are calculated using the Fast-J radiative transfer algorithm. The GEOS-3 global cloud optical
RSSC GLOSSARY 8/99 GL-1 GLOSSARY OF BASIC RADIATION PROTECTION TERMINOLOGY
Slatton, Clint
RSSC GLOSSARY 8/99 GL-1 GLOSSARY OF BASIC RADIATION PROTECTION TERMINOLOGY ABSORBED DOSE: The amount of energy absorbed, as a result of radiation passing through a material, per unit mass of material by which energy from radiation is transferred to matter by interactions with the constituents of the matter
Study of heat transfer in attics with a small scale simulator
Katipamula, Srinivas
1985-01-01T23:59:59.000Z
University Chairman of Advisory Committee: W. D. Turner An experimental study concerned with different modes of heat. transfer in fibrous and cellulose insulating material is presented. A series of experiments was conducted using an attic simulator... to deter- mine the effects of ventilation on attic heat transfer. and the effect of infrared radiation on the thcrn&al conductivity of th& insulation sys- tem and on attic heat transfer. All the tests were perl'ormed at, steady state conditions...
Outside heat transfer coefficients for atmospheric coolers
George, David Mark
1950-01-01T23:59:59.000Z
? the equation in integral form becomes for both steady state conditions and a constant cross sectional area A, ~c ~J? -KA t, (3) $ = K A(f-f )/( , g g ) If (tl - t2' is called 4t, the temperature difference asso- ciated with the heat transferred, and (x2.... th as that for the ma)or equipment First, ths 90 pound steam to the U tube bundle is ini- tially controlled by a 1-1/g inch master valve and then by either a 3/4. inch of 1A inch valve, Figure 9. Two valves of this size are necessary at this point...
NNSA Transfers Responsibility for Radiation Detection System to China
National Nuclear Security Administration (NNSA)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,Separation 23Tribal EnergyCatalytic Co - PANuclear SecurityApplyMaterial |AchievementStreamlines OperationsCustoms
Present and Future Computing Requirements Radiative Transfer of Astrophysical Explosions
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5(Million Cubic Feet) Oregon (Including Vehicle Fuel) (Million Cubic Feet)sets safety recordPotentialfewPredictingCashing inComputational Cosmology
Radiative Heat Transfer in Enhanced Hydrogen Outgassing of Glass
Kitamura, Rei; Pilon, Laurent
2009-01-01T23:59:59.000Z
with lamp heating than with furnace heating and (2) hydrogensilica tube and heated in a furnace or by an incandescentan incandescent lamp than within furnace. Here, sample and
Monte Carlo radiative heat transfer simulation on a reconfigurable computer
Gokhale, M. (Maya); Ahrens, C. M. (Christine Marie); Frigo, J. (Janette); Minnich, R. G. (Ronald G.); Tripp J. L. (Justin L.)
2004-01-01T23:59:59.000Z
Recently, the appearance of very large (3-10M gate) FPGAs with embedded arithmetic units has opened the door to the possibility of floating point computation on these devices. While previous researchers have described peak performance or kernel matrix operations, there is as yet little experience with mapping an application-specific floating point pipeline onto FPGAs. In this work, we port a supercomputer application benchmark onto Xilinx Virtex II and II Pro FPGAs and compare performance with comparable microprocessor implementation. Our results show that this application-specific pipeline, with 12 multiply, 10 add/subtract, one divide, and two compare modules of single precision floating point data type, shows speedup of 1.6x-1.7x. We analyze the trade-offs between hardware and software 'sweet spots' to characterize the algorithms that will perform well on current and future FPGA architectures.
Journal of Quantitative Spectroscopy & Radiative Transfer 109 (2008) 10431059
Chance, Kelly
2008-01-01T23:59:59.000Z
Laboratoire Inter-Universitaire des Syste`mes Atmosphe´riques, Faculte´ des Sciences et Technologie, 61 avenue Groupe de Spectrome´trie Mole´culaire et Atmosphe´rique, Universite´ de Reims-Champagne-Ardenne, 51062 91109, USA h Laboratoire de Physique Mole´culaire pour l'Atmosphe`re et l'Astrophysique, Universite
Radiative Heat Transfer in Enhanced Hydrogen Outgassing of Glass
Kitamura, Rei; Pilon, Laurent
2009-01-01T23:59:59.000Z
transport in a machinable glass-ceramic”, Journal of Non-in soda-lime-silicate glasses by reaction with hydrogen”,1971. [16] I. Fanderlik, Glass Science and Technology, Vol.
Influence of Infrared Radiation on Attic Heat Transfer
Katipamula, S.; Turner, W. D.; Murphy, W. E.; O'Neal, D. L.
1985-01-01T23:59:59.000Z
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...
Journal of Quantitative Spectroscopy & Radiative Transfer 98 (2006) 220237
Pilon, Laurent
2006-01-01T23:59:59.000Z
-short pulsed lasers are also used in remote sensing of the atmosphere, combustion chambers and other to the local time and length scales [1]. Of late, with the advent of ultra-short pulsed lasers, this assumption at which the peak of an ultra-short pulse occurs tp pulse width Dt time step ^s direction unit vector x, y
Radiative Heat Transfer in Enhanced Hydrogen Outgassing of Glass
Kitamura, Rei; Pilon, Laurent
2009-01-01T23:59:59.000Z
slabs. Moreover, the total heat input during furnace heatingperformed for the same heat input. The optical propertiesheating for the same total heat input. Similarly, Figure 7
Measurement of Electromagnetic Radiation Emitted during Rapid Intramolecular Electron Transfer
, photosynthesis, artificial photosynthesis, redox chemistry, photography, xerog- raphy, and other processes all
Radiation-transparent windows, method for imaging fluid transfers
Shu, Deming (Darien, IL); Wang, Jin (Burr Ridge, IL)
2011-07-26T23:59:59.000Z
A thin, x-ray-transparent window system for environmental chambers involving pneumatic pressures above 40 bar is presented. The window allows for x-ray access to such phenomena as fuel sprays injected into a pressurized chamber that mimics realistic internal combustion engine cylinder operating conditions.
Uniqueness and non-uniqueness in inverse radiative transfer
2008-09-13T23:59:59.000Z
... Department of Mathematics, University of Central Florida,. 4000 Central Florida Blvd., Orlando, FL, 32816, USA. E-mail address: tamasan@math.ucf.edu.
General Relativistic Radiative Transfer and GeneralRelativistic MHD
Office of Scientific and Technical Information (OSTI)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,SeparationConnect Journal Article: DiscreteFELIX: Thenerve(Technical Report)SciTech ConnectGeneral
General Relativistic Radiative Transfer and GeneralRelativistic MHD
Office of Scientific and Technical Information (OSTI)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,SeparationConnect Journal Article: DiscreteFELIX: Thenerve(Technical Report)SciTech
Improvements to the SHDOM Radiative Transfer Modeling Package
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article)41clothThe Bonneville PowerTariff Pages default Sign In About | CareersUSING PVImpactInnovationImprovements to MARFA
CROSS VALIDATION OF SATELLITE RADIATION TRANSFER MODELS DURING SWERA PROJECT
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousPlasmaP a gHigh4-FD-aBeijing SinohytecBrownville, Maine:Butte,CEPIS Jump to:CO2 CaptureCPower (Texas)
Radiative transfer and thermal performance levels in foam insulation boardstocks
Moreno, John David
1991-01-01T23:59:59.000Z
The validity of predictive models for the thermal conductivity of foam insulation is established based on the fundamental geometry of the closed-cell foam. The extinction coefficient is experimentally and theoretically ...
Uncertainty of microwave radiative transfer computations in rain
Hong, Sung Wook
2009-06-02T23:59:59.000Z
of the vertical resolution effect on the BT. Secondly, a new temperature profile based on observations was absorbed in the Texas A&M University (TAMU) algorithm. The Precipitation Radar (PR) and Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI...
Uncertainty of microwave radiative transfer computations in rain
Hong, Sung Wook
2009-06-02T23:59:59.000Z
Currently, the effect of the vertical resolution on the brightness temperature (BT) has not been examined in depth. The uncertainty of the freezing level (FL) retrieved using two different satellites' data is large. Various ...
Radiative Heat Transfer in Enhanced Hydrogen Outgassing of Glass
Kitamura, Rei; Pilon, Laurent
2009-01-01T23:59:59.000Z
Photo-induced hydrogen outgassing of glass”, Journal of Non-Photo-induced hydrogen outgassing of glass, PhD thesis,in Enhanced Hydrogen Outgassing of Glass Rei Kitamura and
Radiation Pressure in Massive Star Formation
Mark R. Krumholz; Richard I. Klein; Christopher F. McKee
2005-10-14T23:59:59.000Z
Stars with masses of >~ 20 solar masses have short Kelvin times that enable them to reach the main sequence while still accreting from their natal clouds. The resulting nuclear burning produces a huge luminosity and a correspondingly large radiation pressure force on dust grains in the accreting gas. This effect may limit the upper mass of stars that can form by accretion. Indeed, simulations and analytic calculations to date have been unable to resolve the mystery of how stars of 50 solar masses and up form. We present two new ideas to solve the radiation pressure problem. First, we use three-dimensional radiation hydrodynamic adaptive mesh refinement simulations to study the collapse of massive cores. We find that in three dimensions a configuration in which radiation holds up an infalling envelope is Rayleigh-Taylor unstable, leading radiation driven bubbles to collapse and accretion to continue. We also present Monte Carlo radiative transfer calculations showing that the cavities created by protostellar winds provides a valve that allow radiation to escape the accreting envelope, further reducing the ability of radiation pressure to inhibit accretion.
Jacobson, C.
1982-05-31T23:59:59.000Z
Testimony by Lawrence J. Brady, Commerce Assistant Secretary for Trade Administration, at Congressional hearings on the national security issues of technology transfers to the Soviet Union identified steps the US needs to take to deal effectively with the problem. These steps include an understanding of how the Soviet Union has and will benefit militarily by acquiring Western technology and efforts to work with other countries, counterintelligence agencies, and industries to stem the flow of technological information. Brady outlined changes in technology development that complicate the enforcement of transfer rules, and emphasized the importance of a close relationship between the business community and the Commerce Department. (DCK)
Ganapathy, V.
1982-01-01T23:59:59.000Z
Heat transfer principles are discussed with emphasis on the practical aspects of the problems. Correlations for heat transfer and pressure drop from several worldwide sources for flow inside and outside of tubes, including finned tubes are presented, along with design and performance calculations of heat exchangers economizers, air heaters, condensers, waste-heat boilers, fired heaters, superheaters, and boiler furnaces. Vibration analysis for tube bundles and heat exchangers are also discussed, as are estimating gas-mixture properties at atmospheric and elevated pressures and life-cycle costing techniques. (JMT)
Effects of radiation reaction in relativistic laser acceleration
Hadad, Y.; Labun, L.; Rafelski, J.; Elkina, N.; Klier, C.; Ruhl, H. [Departments of Physics and Mathematics, University of Arizona, Tucson, Arizona, 85721 (United States); Department fuer Physik der Ludwig-Maximillians-Universitaet, Theresienstrasse 37A, 80333 Muenchen (Germany)
2010-11-01T23:59:59.000Z
The goal of this paper is twofold: to explore the response of classical charges to electromagnetic force at the level of unity in natural units and to establish a criterion that determines physical parameters for which the related radiation-reaction effects are detectable. In pursuit of this goal, the Landau-Lifshitz equation is solved analytically for an arbitrary (transverse) electromagnetic pulse. A comparative study of the radiation emission of an electron in a linearly polarized pulse for the Landau-Lifshitz equation and for the Lorentz force equation reveals the radiation-reaction-dominated regime, in which radiation-reaction effects overcome the influence of the external fields. The case of a relativistic electron that is slowed down by a counterpropagating electromagnetic wave is studied in detail. We further show that when the electron experiences acceleration of order unity, the dynamics of the Lorentz force equation, the Landau-Lifshitz equation and the Lorentz-Abraham-Dirac equation all result in different radiation emission that could be distinguished in experiment. Finally, our analytic and numerical results are compared with those appearing in the literature.
A grey gamma-ray transfer procedure for supernovae
David J Jeffery
1998-02-17T23:59:59.000Z
The gamma-ray transfer in supernovae for the purposes of energy deposition in the ejecta can be approximated as grey radiative transfer using mean opacities. In past work there is a single pure absorption mean opacity which is a free parameter. Accurate results can be obtained by varying this mean opacity to fit the results of more accurate procedures. In this paper, we present a grey gamma-ray transfer procedure for energy deposition in which there are multiple mean opacities that are not free parameters and that have both absorption and scattering components. This procedure is based on a local-state (LS) approximation, and so we call it the LS grey gamma-ray transfer procedure or LS procedure for short.
Exact solution to the Landau-Lifshitz equation in a constant electromagnetic field
Yurij Yaremko
2014-12-04T23:59:59.000Z
We are interested in the motion of a classical charge acted upon an external constant electromagnetic field where the back reaction of the particle's own field is taken into account. The Landau-Lifshitz approximation to the Lorentz-Abraham-Dirac equation is solved exactly and in closed form. It is shown that the ultrarelativistic limit of the Landau-Lifshitz equation for a radiating charge is the equation for eigenvalues and eigenvectors of the external electromagnetic field tensor.
Application of Improved Radiation Modeling to General Circulation Models
Michael J Iacono
2011-04-07T23:59:59.000Z
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.
Deviation differential equations. Jacobi fields
G. Sardanashvily
2013-04-02T23:59:59.000Z
Given a differential equation on a smooth fibre bundle Y, we consider its canonical vertical extension to that, called the deviation equation, on the vertical tangent bundle VY of Y. Its solutions are Jacobi fields treated in a very general setting. In particular, the deviation of Euler--Lagrange equations of a Lagrangian L on a fibre bundle Y are the Euler-Lagrange equations of the canonical vertical extension of L onto VY. Similarly, covariant Hamilton equations of a Hamiltonian form H are the Hamilton equations of the vertical extension VH of H onto VY.
Adaptors for radiation detectors
Livesay, Ronald Jason
2014-04-22T23:59:59.000Z
Described herein are adaptors and other devices for radiation detectors that can be used to make accurate spectral measurements of both small and large bulk sources of radioactivity, such as building structures, soils, vessels, large equipment, and liquid bodies. Some exemplary devices comprise an adaptor for a radiation detector, wherein the adaptor can be configured to collimate radiation passing through the adapter from an external radiation source to the radiation detector and the adaptor can be configured to enclose a radiation source within the adapter to allow the radiation detector to measure radiation emitted from the enclosed radiation source.
Hoelsher, James W. (Pullman, WA); Hegland, Joel E. (Pullman, WA); Braunlich, Peter F. (Pullman, WA); Tetzlaff, Wolfgang (Pullman, WA)
1992-01-01T23:59:59.000Z
Radiation dosimeters and dosimeter badges. The dosimeter badges include first and second parts which are connected to join using a securement to produce a sealed area in which at least one dosimeter is held and protected. The badge parts are separated to expose the dosimeters to a stimulating laser beam used to read dose exposure information therefrom. The badge is constructed to allow automated disassembly and reassembly in a uniquely fitting relationship. An electronic memory is included to provide calibration and identification information used during reading of the dosimeter. Dosimeter mounts which reduce thermal heating requirements are shown. Dosimeter constructions and production methods using thin substrates and phosphor binder-layers applied thereto are also taught.
Virginia Tech
Heat Transfer - 2 A pure platinum wire with diameter D = 3 mm and length L = 20 mm is placed outside on a day when air temperature T = 10o C. The heat transfer coefficient at the wire's surface h equation that includes all heat transfer mechanisms involved in this problem. Write this energy balance
Radiation detector system having heat pipe based cooling
Iwanczyk, Jan S.; Saveliev, Valeri D.; Barkan, Shaul
2006-10-31T23:59:59.000Z
A radiation detector system having a heat pipe based cooling. The radiation detector system includes a radiation detector thermally coupled to a thermo electric cooler (TEC). The TEC cools down the radiation detector, whereby heat is generated by the TEC. A heat removal device dissipates the heat generated by the TEC to surrounding environment. A heat pipe has a first end thermally coupled to the TEC to receive the heat generated by the TEC, and a second end thermally coupled to the heat removal device. The heat pipe transfers the heat generated by the TEC from the first end to the second end to be removed by the heat removal device.
Simple Waves in Ideal Radiation Hydrodynamics
Bryan M. Johnson
2008-11-24T23:59:59.000Z
In the dynamic diffusion limit of radiation hydrodynamics, advection dominates diffusion; the latter primarily affects small scales and has negligible impact on the large scale flow. The radiation can thus be accurately regarded as an ideal fluid, i.e., radiative diffusion can be neglected along with other forms of dissipation. This viewpoint is applied here to an analysis of simple waves in an ideal radiating fluid. It is shown that much of the hydrodynamic analysis carries over by simply replacing the material sound speed, pressure and index with the values appropriate for a radiating fluid. A complete analysis is performed for a centered rarefaction wave, and expressions are provided for the Riemann invariants and characteristic curves of the one-dimensional system of equations. The analytical solution is checked for consistency against a finite difference numerical integration, and the validity of neglecting the diffusion operator is demonstrated. An interesting physical result is that for a material component with a large number of internal degrees of freedom and an internal energy greater than that of the radiation, the sound speed increases as the fluid is rarefied. These solutions are an excellent test for radiation hydrodynamic codes operating in the dynamic diffusion regime. The general approach may be useful in the development of Godunov numerical schemes for radiation hydrodynamics.
Hawking radiation in moving plasmas
L. C. Garcia de Andrade
2005-09-07T23:59:59.000Z
Bi-metricity and Hawking radiation are exhibit in non-relativistic moving magnetohydrodynamics (MHD) plasma medium generating two Riemannian effective spacetimes. The first metric is a flat metric although the speed of "light" is given by a time dependent signal where no Hawking radiation or effective black holes are displayed. This metric comes from a wave equation which the scalar function comes from the scalar potential of the background velocity of the fluid and depends on the perturbation of the magnetic background field. The second metric is an effective spacetime metric which comes from the perturbation of the background MHD fluid. This Riemann metric exhibits a horizon and Hawking radiation which can be expressed in terms of the background constant magnetic field. The effective velocity is given Alfven wave velocity of plasma physics. The effective black hole found here is analogous to the optical black hole in moving dielectrics found by De Lorenci et al [Phys. Rev. D (2003)] where bi-metricity and Hawking radiation in terms of the electric field are found.
Evangelos Chaliasos
2006-11-12T23:59:59.000Z
As we know, from the Einstein equations the vanishing of the four-divergence of the energy-momentum tensor follows. This is the case because the four-divergence of the Einstein tensor vanishes identically. Inversely, we find that from the vanishing of the four-divergence of the energy-momentum tensor not only the Einstein equations follow. Besides, the so-named anti-Einstein equations follow. These equations must be considered as complementary to the Einstein equations. And while from the Einstein equations the energy density (or the pressure) can be found, from the anti-Einstein equations the pressure (or the energy density) can be also found, without having to use an additional (but arbitrary) equation of state.
Noncommutativity and the Friedmann Equations
Sabido, M.; Socorro, J. [Physics Department of the Division of Science and Engineering of the University of Guanajuato, Campus Leon P.O. Box E-143, 37150 Leon Gto. (Mexico); Guzman, W. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, 21945-970, Rio de Janeiro (Brazil)
2010-07-12T23:59:59.000Z
In this paper we study noncommutative scalar field cosmology, we find the noncommutative Friedmann equations as well as the noncommutative Klein-Gordon equation, interestingly the noncommutative contributions are only present up to second order in the noncommutitive parameter.
Quantum Black Hole Model and Hawking's Radiation
V. A. Berezin
1996-02-12T23:59:59.000Z
The black hole model with a self-gravitating charged spherical symmetric dust thin shell as a source is considered. The Schroedinger-type equation for such a model is derived. This equation appeared to be a finite differences equation. A theory of such an equation is developed and general solution is found and investigated in details. The discrete spectrum of the bound state energy levels is obtained. All the eigenvalues appeared to be infinitely degenerate. The ground state wave functions are evaluated explicitly. The quantum black hole states are selected and investigated. It is shown that the obtained black hole mass spectrum is compatible with the existence of Hawking's radiation in the limit of low temperatures both for large and nearly extreme Reissner-Nordstrom black holes. The above mentioned infinite degeneracy of the mass (energy) eigenvalues may appeared helpful in resolving the well known information paradox in the black hole physics.
Dwarf galaxies with ionizing radiation feedback. II. Spatially resolved star formation relation
Kim, Ji-hoon; Krumholz, Mark R.; Goldbaum, Nathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Wise, John H. [Center for Relativistic Astrophysics, School of Physics, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Turk, Matthew J. [Department of Astronomy and Astrophysics, Columbia University, New York, NY 10027 (United States); Abel, Tom, E-mail: me@jihoonkim.org [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305 (United States)
2013-12-10T23:59:59.000Z
We investigate the spatially resolved star formation relation using a galactic disk formed in a comprehensive high-resolution (3.8 pc) simulation. Our new implementation of stellar feedback includes ionizing radiation as well as supernova explosions, and we handle ionizing radiation by solving the radiative transfer equation rather than by a subgrid model. Photoheating by stellar radiation stabilizes gas against Jeans fragmentation, reducing the star formation rate (SFR). Because we have self-consistently calculated the location of ionized gas, we are able to make simulated, spatially resolved observations of star formation tracers, such as H? emission. We can also observe how stellar feedback manifests itself in the correlation between ionized and molecular gas. Applying our techniques to the disk in a galactic halo of 2.3 × 10{sup 11} M {sub ?}, we find that the correlation between SFR density (estimated from mock H? emission) and H{sub 2} density shows large scatter, especially at high resolutions of ?75 pc that are comparable to the size of giant molecular clouds (GMCs). This is because an aperture of GMC size captures only particular stages of GMC evolution and because H? traces hot gas around star-forming regions and is displaced from the H{sub 2} peaks themselves. By examining the evolving environment around star clusters, we speculate that the breakdown of the traditional star formation laws of the Kennicutt-Schmidt type at small scales is further aided by a combination of stars drifting from their birthplaces and molecular clouds being dispersed via stellar feedback.
DETECTORS FOR RADIATION DOSIMETRY
Perez-Mendez, V.
2010-01-01T23:59:59.000Z
J. Price, "Nuclear Radiation Detection" (2nd ed. , New York:4) G. F. Knoll, "Radiation Detection and Measurement" (NewSons, Inc. from "Radiation Detection and Measurement," G. F.
Cost Transfer Procedures How And When To Make Cost Transfers
Hammack, Richard
Cost Transfer Procedures How And When To Make Cost Transfers Effective February 9, 2003, cost elsewhere. Federal regulations require additional documentation to support cost transfers to sponsored program indexes. Costs may not be shifted to other research projects or from one budget period to the next
Assignment II Saha & Boltzmann equations
Spoon, Henrik
Assignment II Saha & Boltzmann equations January 21, 2002 This assignment is meant to give you some practical experience in using the Saha and Boltzmann equations that govern the level populations in atoms;s =kT the partition function of ionization stage r. The Saha equation: N r+1 N r = 2U r+1 U r P e #18
Chan, Hue Sun
University of Toronto - Office for Environmental Health and Safety; Radiation Protection Service Treatment Other (state): Reserved for U of T Radiation Protection Service Radiation dose (Sv/hr): @external transferred to: Radioactive Materials Licence Expiry date (please provide a copy) User Name: Radiation Safety
Alexandrov, D. V., E-mail: Dmitri.Alexandrov@usu.ru; Malygin, A. P. [Ural Federal University (Russian Federation)
2012-02-15T23:59:59.000Z
Analytic solutions to the heat and mass transfer equations, which were obtained in [1], are corrected. It is shown that the dependence of the growth rate of the Earth's inner core on heat flux changes in this case.
William H. Lee
2001-08-14T23:59:59.000Z
We present the results of three-dimensional hydrodynamical simulations of the final stages of inspiral in a black hole-neutron star binary, when the separation is comparable to the stellar radius. We use a Newtonian Smooth Particle Hydrodynamics (SPH) code to model the evolution of the system, and take the neutron star to be a polytrope with a soft (adiabatic index G=2 and G=5/3) equation of state and the black hole to be a Newtonian point mass. The only non-Newtonian effect we include is a gravitational radiation back reaction force, computed in the quadrupole approximation for point masses. We use irrotational binaries as initial conditions for our dynamical simulations, which are begun when the system is on the verge of initiating mass transfer and followed for approximately 23 ms. For all the cases studied we find that the star is disrupted on a dynamical time-scale, and forms a massive (the disc mass is approximately 0.2 solar masses) accretion torus around the spinning (Kerr) black hole. The rotation axis is clear of baryons (less than 1.e-5 solar masses within 10 degrees) to an extent that would not preclude the formation of a relativistic fireball capable of powering a cosmological gamma ray burst. Some mass (the specific amount is sensitive to the stiffness of the equation of state) may be dynamically ejected from the system during the coalescence and could undergo r-process nucleosynthesis. We calculate the waveforms, luminosities and energy spectra of the gravitational radiation signal and show how they reflect the global outcome of the coalescence process.
Mass and temperature limits for blackbody radiation
Alessandro Pesci
2006-03-24T23:59:59.000Z
A spherically symmetric distribution of classical blackbody radiation is considered, at conditions in which gravitational self-interaction effects become not negligible. Static solutions to Einstein field equations are searched for, for each choice of the assumed central energy density. Spherical cavities at thermodynamic equilibrium, i.e. filled with blackbody radiation, are then studied, in particular for what concerns the relation among the mass M of the ball of radiation contained in them and their temperature at center and at the boundary. For these cavities it is shown, in particular, that: i) there is no absolute limit to M as well to their central and boundary temperatures; ii) when radius R is fixed, however, limits exist both for mass and for boundary energy density rho_B: M temperature) of the ball of radiation.
Natale, Michael J.
the smaller cloaked vessel before she had a chance to de-cloak and fire, the Enterprise had virtually disabled the scoutship. Now, the innocent people on Omnicron I could at least get a break from the barrage of disrupter fire from orbit, and the Enterprise... into destroying the Klingon vessel. But, if they were going to threaten innocents on Omnicron I, then the Enterprise could play the role of executioner adequately. "Mr. Sulu, fire main phasers!" "Locking phasers.....firing, sir!" The Human Equation Page...
Nondisclosure & Material Transfer Agreements | ORNL
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
NDA(s) and MTA(s) SHARE Non-Disclosure and Material Transfer Agreements Two other frequently used agreements are the Nondisclosure Agreement (NDA) and the Material Transfer...
Faculty Positions Heat Transfer and
Faculty Positions Heat Transfer and Thermal/Energy Sciences Naval Postgraduate School Monterey-track faculty position at the assistant professor level in the areas of Heat Transfer and Thermal/Fluid Sciences
Broader source: Energy.gov [DOE]
The Department of Health is responsible for regulating radiation and radioactive materials in the Commonwealth of Virginia. Although the Department's Radiation Control Program primarily focuses on...
Solar radiation resource assessment
Not Available
1990-11-01T23:59:59.000Z
The bulletin discusses the following: introduction; Why is solar radiation resource assessment important Understanding the basics; the solar radiation resource assessment project; and future activities.
QER- Comment of Energy Transfer
Broader source: Energy.gov [DOE]
From: Lee Hanse Executive Vice President Interstate Energy Transfer Mobile - 210 464 2929 Office - 210 403 6455
Christiansen, Robert M. (Blackfoot, ID); Mills, William C. (McKeesport, PA)
1992-01-01T23:59:59.000Z
The swipe transfer assembly is a mechanical assembly which is used in conjunction with glove boxes and other sealed containments. It is used to pass small samples into or out of glove boxes without an open breach of the containment, and includes a rotational cylinder inside a fixed cylinder, the inside cylinder being rotatable through an arc of approximately 240.degree. relative to the outer cylinder. An offset of 120.degree. from end to end allows only one port to be opened at a time. The assembly is made of stainless steel or aluminum and clear acrylic plastic to enable visual observation. The assembly allows transfer of swipes and smears from radiological and other specially controlled environments.
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:DepartmentExecutiveBuildingSmallFebruary 2010 Technical StandardsEnergy 3TransferTechnology
Plastic container bagless transfer
Tibrea, Steven L.; D'Amelio, Joseph A.; Daugherty, Brent A.
2003-11-18T23:59:59.000Z
A process and apparatus are provided for transferring material from an isolated environment into a storage carrier through a conduit that can be sealed with a plug. The plug and conduit can then be severed to provide a hermetically sealed storage carrier containing the material which may be transported for storage or disposal and to maintain a seal between the isolated environment and the ambient environment.
Mass transfer andMass transfer and Mass transfer andMass transfer and
Zevenhoven, Ron
't be determined A correlation for Sherwood number (Sh) based on di i l l i b d l i Sh diff idimensional analysis for mass transfer with convection: I l f d fl d b (l b l ) Internal forced flow: inside a tube (laminar A in fluid medium B in a flow with characteristic velocity and size characteristic d: kA = f(d, w, (= fluid
Scattering of particles by radiation fields: a comparative analysis
Donato Bini; Andrea Geralico; Maria Haney; Robert T. Jantzen
2014-08-22T23:59:59.000Z
The features of the scattering of massive neutral particles propagating in the field of a gravitational plane wave are compared with those characterizing their interaction with an electromagnetic radiation field. The motion is geodesic in the former case, whereas in the case of an electromagnetic pulse it is accelerated by the radiation field filling the associated spacetime region. The interaction with the radiation field is modeled by a force term entering the equations of motion proportional to the 4-momentum density of radiation observed in the particle's rest frame. The corresponding classical scattering cross sections are evaluated too.
Radiation Protection and Licensing FNAL Radiation Physics Team
McDonald, Kirk
(ALARA). January 13, 2012 Radiation Protection and Licensing #12;4 Shielding for Prompt Radiation Protect
A relativistic parton cascade with radiation
Ghi R. Shin; Berndt Müller
2002-08-08T23:59:59.000Z
We consider the evolution of a parton system which is formed at the central rapidity region just after an ultrarelativistic heavy ion collision. The evolution of the system, which is composed of gluons, quarks and antiquarks, is described by a relativistic Boltzmann equations with collision terms including radiation and retardation effects. The equations are solved by the test particle method using Monte-Carlo sampling. Our simulations do not show any evidence of kinetic equilibration, unless the cross sections are artificially increased to unrealistically large values.
Black Hole Radiation and Volume Statistical Entropy
Mario Rabinowitz
2005-06-29T23:59:59.000Z
The simplest possible equation for Hawking radiation, and other black hole radiated power is derived in terms of black hole density. Black hole density also leads to the simplest possible model of a gas of elementary constituents confined inside a gravitational bottle of Schwarzchild radius at tremendous pressure, which yields identically the same functional dependence as the traditional black hole entropy. Variations of Sbh can be obtained which depend on the occupancy of phase space cells. A relation is derived between the constituent momenta and the black hole radius which is similar to the Compton wavelength relation.
Martin Frimmer; Lukas Novotny
2014-09-26T23:59:59.000Z
Coherent control of a quantum mechanical two-level system is at the heart of magnetic resonance imaging, quantum information processing, and quantum optics. Among the most prominent phenomena in quantum coherent control are Rabi oscillations, Ramsey fringes and Hahn echoes. We demonstrate that these phenomena can be derived classically by use of a simple coupled harmonic oscillator model. The classical problem can be cast in a form that is formally equivalent to the quantum mechanical Bloch equations with the exception that the longitudinal and the transverse relaxation times ($T_1$ and $T_2$) are equal. The classical analysis is intuitive and well suited for familiarizing students with the basic concepts of quantum coherent control, while at the same time highlighting the fundamental differences between classical and quantum theories.
The Schroedinger equation with friction from the quantum trajectory perspective
Garashchuk, Sophya; Dixit, Vaibhav; Gu Bing; Mazzuca, James [Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208 (United States)
2013-02-07T23:59:59.000Z
Similarity of equations of motion for the classical and quantum trajectories is used to introduce a friction term dependent on the wavefunction phase into the time-dependent Schroedinger equation. The term describes irreversible energy loss by the quantum system. The force of friction is proportional to the velocity of a quantum trajectory. The resulting Schroedinger equation is nonlinear, conserves wavefunction normalization, and evolves an arbitrary wavefunction into the ground state of the system (of appropriate symmetry if applicable). Decrease in energy is proportional to the average kinetic energy of the quantum trajectory ensemble. Dynamics in the high friction regime is suitable for simple models of reactions proceeding with energy transfer from the system to the environment. Examples of dynamics are given for single and symmetric and asymmetric double well potentials.
A Master Equation Approach to the `3 + 1' Dirac Equation
Keith A. Earle
2011-02-06T23:59:59.000Z
A derivation of the Dirac equation in `3+1' dimensions is presented based on a master equation approach originally developed for the `1+1' problem by McKeon and Ord. The method of derivation presented here suggests a mechanism by which the work of Knuth and Bahrenyi on causal sets may be extended to a derivation of the Dirac equation in the context of an inference problem.
Near-field heat transfer between gold nanoparticle arrays
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
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.
Energy of gravitational radiation in plane-symmetric space-times
Sean A. Hayward
2008-05-19T23:59:59.000Z
Gravitational radiation in plane-symmetric space-times can be encoded in a complex potential, satisfying a non-linear wave equation. An effective energy tensor for the radiation is given, taking a scalar-field form in terms of the potential, entering the field equations in the same way as the matter energy tensor. It reduces to the Isaacson energy tensor in the linearized, high-frequency approximation. An energy conservation equation is derived for a quasi-local energy, essentially the Hawking energy. A transverse pressure exerted by interacting low-frequency gravitational radiation is predicted.
Diffusive mass transfer by non equilibrium fluctuations: Fick's law revisited
Doriano Brogioli; Alberto Vailati
2000-06-09T23:59:59.000Z
Recent experimental and theoretical works have shown that giant fluctuations are present during diffusion in liquid systems. We use linearized fluctuating hydrodynamics to calculate the net mass transfer due to these non equilibrium fluctuations. Surprisingly the mass flow turns out to coincide with the usual Fick's one. The renormalization of the hydrodynamic equations allows us to quantify the gravitational modifications of the diffusion coefficient induced by the gravitational stabilization of long wavelength fluctuations.
Fourier analysis of conductive heat transfer for glazed roofing materials
Roslan, Nurhana Lyana; Bahaman, Nurfaradila; Almanan, Raja Noorliyana Raja; Ismail, Razidah [Faculty of Computer and Mathematical Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia); Zakaria, Nor Zaini [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia)
2014-07-10T23:59:59.000Z
For low-rise buildings, roof is the most exposed surface to solar radiation. The main mode of heat transfer from outdoor via the roof is conduction. The rate of heat transfer and the thermal impact is dependent on the thermophysical properties of roofing materials. Thus, it is important to analyze the heat distribution for the various types of roofing materials. The objectives of this paper are to obtain the Fourier series for the conductive heat transfer for two types of glazed roofing materials, namely polycarbonate and polyfilled, and also to determine the relationship between the ambient temperature and the conductive heat transfer for these materials. Ambient and surface temperature data were collected from an empirical field investigation in the campus of Universiti Teknologi MARA Shah Alam. The roofing materials were installed on free-standing structures in natural ventilation. Since the temperature data are generally periodic, Fourier series and numerical harmonic analysis are applied. Based on the 24-point harmonic analysis, the eleventh order harmonics is found to generate an adequate Fourier series expansion for both glazed roofing materials. In addition, there exists a linear relationship between the ambient temperature and the conductive heat transfer for both glazed roofing materials. Based on the gradient of the graphs, lower heat transfer is indicated through polyfilled. Thus polyfilled would have a lower thermal impact compared to polycarbonate.
A Theoretical Investigation Into Energy Transfer In Photosynthetic Open Quantum Systems
Wilkins, David M
2015-01-01T23:59:59.000Z
This thesis looks at the electronic energy transfer in the Fenna-Matthews-Olson complex, in which evidence of long-lived coherence has been observed in 2-dimensional infrared experiments. I use three techniques: the numerically exact Hierarchical Equations of Motion, and the perturbative Redfield and Foerster theories, the latter of which ignores quantum coherence in the transfer. Both of the approximate methods perform very well - and while oscillations in site populations (a hallmark of coherence) are present in the exact transfer dynamics and absent in the dynamics of Foerster theory, the latter gives a reasonable prediction of transfer rates and steady-state populations, despite being incoherent - suggesting that coherence is not vital for the dynamics of transfer. Since Foerster theory is very inexpensive to run and performs so well, I then apply it to calculate the effects of static disorder in bacteriochlorophyll site energies and of a more structured spectral density. Ultimately, the energy transfer i...
None
2013-11-19T23:59:59.000Z
Wireless Power Transfer is an innovative approach using magnetic resonance coupling of air core transformers designed for today's growing plug-in electric vehicle market. This technology can provide a convenient, safe and flexible means to charge electric vehicles under stationary and dynamic conditions. Plug-in Electric Vehicles (PEV) are burdened by the need for cable and plug charger, galvanic isolation of the on-board electronics, bulk and cost of this charger and the large energy storage system (ESS) packs needed. With a system where you have to physically plug in there are a number of occasions where the owner could very well forget to charge the vehicle. For stationary applications (like charging of a PHEV at home), ORNL's innovative wireless power transfer technology adds a convenience factor compared to actually plugging in which will mean that the vehicle will have a full charge every morning. Electric vehicle charging must be safe, compact and efficient in order to be convenient for customers. By reconfiguring the transformer and altering the resonance frequency, energy is transferred to the battery with lower energy losses and with fewer demands on the primary circuit by the rest of the transformer system. The ORNL discovery shows that sufficient power for the battery can be transferred from the primary to secondary circuits without significant energy losses if the operating frequency is set at 50% to 95% of the resonance frequency of the circuit. The electrical power is then transmitted to the chargeable battery, which is electrically coupled to the secondary circuit through the air core transformer. Some advantages include: Reduced energy losses during transfer of energy to the battery; A charge potential that is relatively unaffected by up to 25% misalignment of vehicle; and Other receiving components draw less power from the primary circuit. These advantages allow wireless power technology applications to expand at the workplace and beyond as the demand for EV rises. For vehicles that operate over a fixed route such as busses and shuttle vehicles, Wireless Power Transfer (WPT) means that a smaller battery pack can be used. In the traditional system, the battery pack is designed to accommodate the needs of the entire route or shift. With WPT the battery can be downsized because it can be charged when the vehicle stops on its route (a rental car shuttle bus, for example, can charge when it waits in the terminal and again when it waits at the rental car place. Thus the battery only needs enough charge to get to the next stop. This decrease in battery size means significant cost savings to electrify the vehicle. This technology enables efficient "opportunity charging stations" for predefined routes and planned stops reducing down time. Charging can occur in minutes. This improvement also eliminates the harmful emissions that occur in garages while buses are at idle during charging. In larger cities, dynamic charging offers an even greater impact utilizing existing infrastructure. As vehicles travel along busy freeways and interstate systems, wireless charging can occur while the vehicle is in motion. With this technology a vehicle essentially has unlimited electric range while using a relatively small battery pack. In-motion charging stations use vehicle sensors to alert the driver. Traveling at normal speeds, sensors establish in-motion charging. WPT transmit pads sequentially energize to the negotiated power level based on vehicle speed and its requested charging energy. Lower power when vehicle speed is slow and much higher power for faster moving vehicles. Vehicle to Infrastructure communications (V2I) coordinates WPT charging level according to on-board battery pack state-of-charge. V2I activates the roadway transmit pads placing them in standby mode and negotiates charging fee based on prevailing grid rate and vehicle energy demand. Dynamic charging would allow electricity to supply a very large fraction of the energy for the transportation sector and reduce greatly petroleum consump
None
2013-07-22T23:59:59.000Z
Wireless Power Transfer is an innovative approach using magnetic resonance coupling of air core transformers designed for today's growing plug-in electric vehicle market. This technology can provide a convenient, safe and flexible means to charge electric vehicles under stationary and dynamic conditions. Plug-in Electric Vehicles (PEV) are burdened by the need for cable and plug charger, galvanic isolation of the on-board electronics, bulk and cost of this charger and the large energy storage system (ESS) packs needed. With a system where you have to physically plug in there are a number of occasions where the owner could very well forget to charge the vehicle. For stationary applications (like charging of a PHEV at home), ORNL's innovative wireless power transfer technology adds a convenience factor compared to actually plugging in which will mean that the vehicle will have a full charge every morning. Electric vehicle charging must be safe, compact and efficient in order to be convenient for customers. By reconfiguring the transformer and altering the resonance frequency, energy is transferred to the battery with lower energy losses and with fewer demands on the primary circuit by the rest of the transformer system. The ORNL discovery shows that sufficient power for the battery can be transferred from the primary to secondary circuits without significant energy losses if the operating frequency is set at 50% to 95% of the resonance frequency of the circuit. The electrical power is then transmitted to the chargeable battery, which is electrically coupled to the secondary circuit through the air core transformer. Some advantages include: Reduced energy losses during transfer of energy to the battery; A charge potential that is relatively unaffected by up to 25% misalignment of vehicle; and Other receiving components draw less power from the primary circuit. These advantages allow wireless power technology applications to expand at the workplace and beyond as the demand for EV rises. For vehicles that operate over a fixed route such as busses and shuttle vehicles, Wireless Power Transfer (WPT) means that a smaller battery pack can be used. In the traditional system, the battery pack is designed to accommodate the needs of the entire route or shift. With WPT the battery can be downsized because it can be charged when the vehicle stops on its route (a rental car shuttle bus, for example, can charge when it waits in the terminal and again when it waits at the rental car place. Thus the battery only needs enough charge to get to the next stop. This decrease in battery size means significant cost savings to electrify the vehicle. This technology enables efficient "opportunity charging stations" for predefined routes and planned stops reducing down time. Charging can occur in minutes. This improvement also eliminates the harmful emissions that occur in garages while buses are at idle during charging. In larger cities, dynamic charging offers an even greater impact utilizing existing infrastructure. As vehicles travel along busy freeways and interstate systems, wireless charging can occur while the vehicle is in motion. With this technology a vehicle essentially has unlimited electric range while using a relatively small battery pack. In-motion charging stations use vehicle sensors to alert the driver. Traveling at normal speeds, sensors establish in-motion charging. WPT transmit pads sequentially energize to the negotiated power level based on vehicle speed and its requested charging energy. Lower power when vehicle speed is slow and much higher power for faster moving vehicles. Vehicle to Infrastructure communications (V2I) coordinates WPT charging level according to on-board battery pack state-of-charge. V2I activates the roadway transmit pads placing them in standby mode and negotiates charging fee based on prevailing grid rate and vehicle energy demand. Dynamic charging would allow electricity to supply a very large fraction of the energy for the transportation sector and reduce greatly petroleum consump
Rafael I. Nepomechie
2013-07-28T23:59:59.000Z
An inhomogeneous T-Q equation has recently been proposed by Cao, Yang, Shi and Wang for the open spin-1/2 XXX chain with general (nondiagonal) boundary terms. We argue that a simplified version of this equation describes all the eigenvalues of the transfer matrix of this model. We also propose a generating function for the inhomogeneous T-Q equations of arbitrary spin.
Nepomechie, Rafael I
2013-01-01T23:59:59.000Z
An inhomogeneous T-Q equation has recently been proposed by Cao, Yang, Shi and Wang for the open spin-1/2 XXX chain with general (nondiagonal) boundary terms. We argue that a simplified version of this equation describes all the eigenvalues of the transfer matrix of this model. We also propose a generating function for the inhomogeneous T-Q equations of arbitrary spin.
Policastro, A.J.; Pfingston, J.M.; Maloney, D.M.; Wasmer, F.; Pentecost, E.D.
1992-03-01T23:59:59.000Z
The Atmospheric Radiation Measurement (ARM) Program is aimed at supplying improved predictive capability of climate change, particularly the prediction of cloud-climate feedback. The objective will be achieved by measuring the atmospheric radiation and physical and meteorological quantities that control solar radiation in the earth`s atmosphere and using this information to test global climate and related models. The proposed action is to construct and operate a Cloud and Radiation Testbed (CART) research site in the southern Great Plains as part of the Department of Energy`s Atmospheric Radiation Measurement Program whose objective is to develop an improved predictive capability of global climate change. The purpose of this CART research site in southern Kansas and northern Oklahoma would be to collect meteorological and other scientific information to better characterize the processes controlling radiation transfer on a global scale. Impacts which could result from this facility are described.
Manipulator mounted transfer platform
Dobbins, James C. (Idaho Falls, ID); Hoover, Mark A. (Idaho Falls, ID); May, Kay W. (Idaho Falls, ID); Ross, Maurice J. (Pocatello, ID)
1990-01-01T23:59:59.000Z
A transfer platform for the conveyance of objects by a manipulator includes a bed frame and saddle clamp secured along an edge of the bed frame and adapted so as to secure the bed frame to a horizontal crosspiece of the manipulator. The platform may thus move with the manipulator in a reciprocal linear path defined by a guide rail. A bed insert may be provided for the support of conveyed objects and a lifting bail may be provided to permit the manipulator arm to install the bed frame upon the crosspiece under remote control.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article) |govInstrumentsmfrirt DocumentationSitesWeather6 Shares ofdefault Sign22 to Sept. 10,Promise andDarinDataDTN Data Transfer
On the generalized Jacobi equation
Volker Perlick
2007-10-14T23:59:59.000Z
The standard text-book Jacobi equation (equation of geodesic deviation) arises by linearizing the geodesic equation around some chosen geodesic, where the linearization is done with respect to the coordinates and the velocities. The generalized Jacobi equation, introduced by Hodgkinson in 1972 and further developed by Mashhoon and others, arises if the linearization is done only with respect to the coordinates, but not with respect to the velocities. The resulting equation has been studied by several authors in some detail for timelike geodesics in a Lorentzian manifold. Here we begin by briefly considering the generalized Jacobi equation on affine manifolds, without a metric; then we specify to lightlike geodesics in a Lorentzian manifold. We illustrate the latter case by considering particular lightlike geodesics (a) in Schwarzschild spacetime and (b) in a plane-wave spacetime.
Energy Conservation Equations of Motion
Vinokurov, Nikolay A
2015-01-01T23:59:59.000Z
A conventional derivation of motion equations in mechanics and field equations in field theory is based on the principle of least action with a proper Lagrangian. With a time-independent Lagrangian, a function of coordinates and velocities that is called energy is constant. This paper presents an alternative approach, namely derivation of a general form of equations of motion that keep the system energy, expressed as a function of generalized coordinates and corresponding velocities, constant. These are Lagrange equations with addition of gyroscopic forces. The important fact, that the energy is defined as the function on the tangent bundle of configuration manifold, is used explicitly for the derivation. The Lagrangian is derived from a known energy function. A development of generalized Hamilton and Lagrange equations without the use of variational principles is proposed. The use of new technique is applied to derivation of some equations.
Simulation of Strongly Heated Internal Gas Flows Using a Near-Wall Two-Equation Heat Flux Model
Richards, Adam H.; Spall, Robert E. [Utah State University, 1400 Old Main Hill Logan, Utah 84322-1400 (United States)
2006-07-01T23:59:59.000Z
A two-equation k-{omega} model is used to model a strongly heated, low-Mach number gas flowing upward in a vertical tube. Heating causes significant property variation and thickening of the viscous sublayer, consequently a fully developed flow does not evolve. Two-equation turbulence models generally perform poorly under such conditions. Consequently, in the present work, a near-wall two-equation heat transfer model is utilized in conjunction with the k-{omega} model to improve heat transfer predictions. (authors)
Photon rockets and gravitational radiation
T. Damour
1994-12-21T23:59:59.000Z
The absence of gravitational radiation in Kinnersley's ``photon rocket'' solution of Einstein's equations is clarified by studying the mathematically well-defined problem of point-like photon rockets in Minkowski space (i.e. massive particles emitting null fluid anisotro\\-pically and accelerating because of the recoil). We explicitly compute the (uniquely defined) {\\it linearized} retarded gravitational waves emitted by such objects, which are the coherent superposition of the gravitational waves generated by the motion of the massive point-like rocket and of those generated by the energy-momentum distribution of the photon fluid. In the special case (corresponding to Kinnersley's solution) where the anisotropy of the photon emission is purely dipolar we find that the gravitational wave amplitude generated by the energy-momentum of the photons exactly cancels the usual $1/r$ gravitational wave amplitude generated by the accelerated motion of the rocket. More general photon anisotropies would, however, generate genuine gravitational radiation at infinity. Our explicit calculations show the compatibility between the non-radiative character of Kinnersley's solution and the currently used gravitational wave generation formalisms based on post-Minkowskian perturbation theory.
Schroeder's Equation in Several Variables
1910-10-20T23:59:59.000Z
2000 Mathematics Subject Classification: Primary: 32H50. Secondary: 30D05, 39B32, 47B33. Keywords: Schroeder's functional equation, iteration, composition
Tropical Cloud Properties and Radiative Heating Profiles
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Mather, James
We have generated a suite of products that includes merged soundings, cloud microphysics, and radiative fluxes and heating profiles. The cloud microphysics is strongly based on the ARM Microbase value added product (Miller et al., 2003). We have made a few changes to the microbase parameterizations to address issues we observed in our initial analysis of the tropical data. The merged sounding product is not directly related to the product developed by ARM but is similar in that it uses the microwave radiometer to scale the radiosonde column water vapor. The radiative fluxes also differ from the ARM BBHRP (Broadband Heating Rate Profile) product in terms of the radiative transfer model and the sampling interval.
Radiation physics, biophysics, and radiation biology
Hall, E.J.; Zaider, M.
1991-05-01T23:59:59.000Z
Research at the Radiological Research Laboratory is a blend of physics, chemistry, and biology, involving research at the basic level with the admixture of a small proportion of pragmatic or applied research in support of radiation protection and/or radiotherapy. Current research topics include: oncogenic transformation assays, mutation studies involving interactions between radiation and environmental contaminants, isolation, characterization and sequencing of a human repair gene, characterization of a dominant transforming gene found in C3H 10T1/2 cells, characterize ab initio the interaction of DNA and radiation, refine estimates of the radiation quality factor Q, a new mechanistic model of oncogenesis showing the role of long-term low dose medium LET radiation, and time dependent modeling of radiation induced chromosome damage and subsequent repair or misrepair.
TRANSFORMING THE HEUN EQUATION TO THE HYPERGEOMETRIC EQUATION
TRANSFORMING THE HEUN EQUATION TO THE HYPERGEOMETRIC EQUATION: I. POLYNOMIAL TRANSFORMATIONS ROBERT by rational changes of its in dependent variable are classified. Heuntohypergeometric transformationstohypergeometric transformations) of Goursat. However, a transformation is possible only if the singular point location parameter
TRANSFORMING THE HEUN EQUATION TO THE HYPERGEOMETRIC EQUATION
Maier, Robert S.
TRANSFORMING THE HEUN EQUATION TO THE HYPERGEOMETRIC EQUATION: I. POLYNOMIAL TRANSFORMATIONS ROBERT by rational changes of its independent variable are classi#12;ed. Heun-to-hypergeometric transformations-to-hypergeometric transforma- tions) of Goursat. However, a transformation is possible only if the singular point location
TRANSFORMING THE HEUN EQUATION TO THE HYPERGEOMETRIC EQUATION
Maier, Robert S.
TRANSFORMING THE HEUN EQUATION TO THE HYPERGEOMETRIC EQUATION: I. POLYNOMIAL TRANSFORMATIONS ROBERT changes of its in- dependent variable are classified. Heun-to-hypergeometric transformations are analogous to the classical hypergeo- metric identities (i.e., hypergeometric-to-hypergeometric transformations) of Goursat
Aspects of the Structure of the QCD Radiation Field
Reinhold Brueckner
2001-02-12T23:59:59.000Z
We consider the classical radiative solution to the QCD (quantum chromodynamics) dynamical equations and find trivial solutions similar to the electrodynamic situation when one considers singlet (colorless) radiation sources. We transpose the findings to quantum fields and identify radiation from hadron (meson) sources with gluon packages of 3 (2) gluons. Invoking the singlet character of the QCD matter and radiation field, we deduce that the blank (singlet) gluon packages are the elementary building blocks of QCD radiation, just as blank hadrons and mesons are the building blocks of baryon matter. Colorlessness of the gluon packages suggests a possibly simpler quasi-abelian behaviour, as far as linear superposition is involved, of the QCD singlet radiation field.
An algebraic approach to the minimum-cost multi-impulse orbit transfer problem
Martin Avendano; Verónica Martín-Molina; Jorge Martín-Morales; Jorge Ortigas-Galindo
2015-08-10T23:59:59.000Z
We present a purely algebraic formulation (i.e. polynomial equations only) of the minimum-cost multi-impulse orbit transfer problem without time constraints, while keeping all the variables with a precise physical meaning. We apply general algebraic techniques to solve these equations (resultants, Gr\\"obner bases, etc.) in several situations of practical interest of different degrees of generality. For instance, we provide a proof of the optimality of the Hohmann transfer for the minimum fuel 2-impulse circular to circular orbit transfer problem, and we provide a general formula for the optimal 2-impulse in-plane transfer between two rotated elliptical orbits under a mild symmetry assumption on the two points where the impulses are applied (which we conjecture that can be removed).
Radiative Torques on Interstellar Grains; 2, Grain Alignment
Draine, B T; Weingartner, Joseph C.
1996-01-01T23:59:59.000Z
Radiative torques on irregular dust grains, in addition to producing superthermal rotation, play a direct dynamical role in the alignment of interstellar dust with the local magnetic field. The equations governing the orientation of spinning, precessing grains are derived; H_2 formation torques and paramagnetic dissipation are included in the dynamics. Stationary solutions (constant alignment angle and spin rate) are found; these solutions may be stable ("attractors") or unstable ("repellors"). The equations of motion are numerically integrated for three exemplary irregular grain geometries, exposed to anisotropic radiation with the spectrum of interstellar starlight. The resulting "trajectory maps" are classified as "noncyclic", "semicyclic", or "cyclic", with examples of each given. We find that radiative torques result in rapid grain alignment, even in the absence of paramagnetic dissipation. It appears that radiative torques due to starlight can account for the observed alignment of interstellar grains wi...
Technology Transfer Success Stories, Security
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Thin Films (FNTF), developed by PNNL is a low-cost, highly-selective means for detecting heavy metals in aqueous environments. Autoinduction system FEATURED TECH TRANSFER...
Control of excitation transfer in coupled quantum dots by a nonresonant laser pulse
P. A. Golovinski; V. A. Astapenko; A. V. Yakovets
2014-08-06T23:59:59.000Z
We study theoretically fast transfer of excitons between pairs of coupled quantum dots driven by the optical Stark effect that is produced by a short nonresonant laser pulse. The Schr\\"odinger equation, in which the relative position of energy levels of quantum dot subsystems is time-dependent, is solved numerically. Computer simulation shows a way to achieve efficient excitation transfer by the action of a picosecond laser pulse with a rectangular envelope function.
Rotor dynamic analysis of multi-line systems using the polynomial transfer matrix method
Troxler, Paul Joseph
1990-01-01T23:59:59.000Z
is based on the polynomial transfer matrix method. The transfer matrices for the general point mass and flexible beam are presented. The model has the capability to include a number of different options such as stator gyroscopic terms (to model... polynomial coefficients a = mass and beam matrix elements 1J A = cross sectional Area A, B = matrices b; = coefficients of polynomial after removing quadratic factor B&g ? variables used in deriving foundation equations c = scale factor c...
Effective equations for quantum dynamics
Benjamin Schlein
2012-08-01T23:59:59.000Z
We report on recent results concerning the derivation of effective evolution equations starting from many body quantum dynamics. In particular, we obtain rigorous derivations of nonlinear Hartree equations in the bosonic mean field limit, with precise bounds on the rate of convergence. Moreover, we present a central limit theorem for the fluctuations around the Hartree dynamics.
Media with no Fresnel equation
Peinke, Joachim
Media with no Fresnel equation Alberto Favaro & Ismo V. Lindell Outline Part 1: Local linear media Part 2: Jump conditions Part 3: media with no G(q) Conclusions Electromagnetic media with no Fresnel with no Fresnel equation Alberto Favaro & Ismo V. Lindell Outline Part 1: Local linear media Part 2: Jump
Frank, Michael I. (Dublin, CA)
2010-02-02T23:59:59.000Z
A self-contained source of gamma-ray and neutron radiation suitable for use as a radiation surrogate for weapons-grade plutonium is described. The source generates a radiation spectrum similar to that of weapons-grade plutonium at 5% energy resolution between 59 and 2614 keV, but contains no special nuclear material and emits little .alpha.-particle radiation. The weapons-grade plutonium radiation surrogate also emits neutrons having fluxes commensurate with the gamma-radiation intensities employed.
Radiation reaction in strong fields from an alternative perspective
Yevgen Kravets
2014-08-19T23:59:59.000Z
Current classical theory of radiation reaction has several deficiencies such as "runaway solutions" and violation of causality. The Landau-Lifshitz approximation to the exact equation introduced by Lorentz, Abraham and Dirac is widely used, though questions remain regarding its domain of validity. This thesis explores an alternative treatment of the motion of a radiating electron, based on an equation first proposed by Ford and O'Connell. A general condition is found for solutions of this equation to deviate from those of Landau-Lifshitz. By exploring radiation reaction effects on a particle colliding with an ultra-intense laser pulse we show that the regime where there is a significant deviation of these two approaches can never be reached with existing or proposed laser facilities. The methods used to explore single particle interaction with an intense laser pulse are extended to describe the interaction of a particle bunch with various realistic laser pulses. We find that the interaction leads to a decrease in average momentum and relative momentum spread. However, the decrease appears to be independent of the length of the pulse and depends only on the energy in the pulse regardless of how it is distributed. Radiation reaction effects occuring during the scattering of an electron by a heavy, highly-charged nucleus are studied. Radiation reaction is seen to affect the particle's motion. We find noticeable differences between the predictions of the Ford-O'Connell and Landau-Lifshitz equations, albeit in regimes where quantum effects would be important.
Cosmological perturbations for an inflaton field coupled to radiation
Visinelli, Luca, E-mail: Luca.Visinelli@utah.edu [Department of Physics and Astronomy, University of Utah, 115 South 1400 East #201, Salt Lake City, Utah 84112-0830 (United States)
2015-01-01T23:59:59.000Z
Within the framework of the interacting fluid formalism, we provide the numerical solution to the Boltzmann equation describing the evolution of an inflaton field coupled to radiation. We study the behavior of the system during the slow-roll regime, in the case in which an additional stochastic source term is included in the set of equations, and we recover the expression for the cosmological perturbations previously obtained in the Warm inflation scenarios.
Finite element analysis of conjugate heat transfer in axisymmetric pipe flows
Fithen, Robert Miller
1987-01-01T23:59:59.000Z
to x=L. In the unheated section of the tube x(0 and x)L, adiabatic condition apply on the tube exterior. A schematic of the heat transfer model is shown in figure l. The energy equation for i'ully developed laminar flow is 2pcrub 1 ? ? = Kf... ? + ? +? Equation (1) expressed in non ? dimensional form where &q Pe ctR' R i)R r R=- Ti 2pcsubri Pe = f (2) u(r) ri nine noded lagrangian element Fig. 1 Heat transfer model for a circular tube for constant heat flux for constant temperature case From...
Frank, Jeffrey I.; Rosengart, Axel J.; Kasza, Ken; Yu, Wenhua; Chien, Tai-Hsin; Franklin, Jeff
2006-10-10T23:59:59.000Z
Apparatuses, systems, methods, and computer code for, among other things, monitoring the health of samples such as the brain while providing local cooling or heating. A representative device is a heat transfer probe, which includes an inner channel, a tip, a concentric outer channel, a first temperature sensor, and a second temperature sensor. The inner channel is configured to transport working fluid from an inner inlet to an inner outlet. The tip is configured to receive at least a portion of the working fluid from the inner outlet. The concentric outer channel is configured to transport the working fluid from the inner outlet to an outer outlet. The first temperature sensor is coupled to the tip, and the second temperature sensor spaced apart from the first temperature sensor.
Not Available
1995-01-01T23:59:59.000Z
Technology Transfer 1995 is intended to inform the US industrial and academic sectors about the many opportunities they have to form partnerships with the US Department of Energy (DOE) for the mutual advantage of the individual institutions, DOE, and the nation as a whole. It also describes some of the growing number of remarkable achievements resulting from such partnerships. These partnership success stories offer ample evidence that Americans are learning how to work together to secure major benefits for the nation--by combining the technological, scientific, and human resources resident in national laboratories with those in industry and academia. The benefits include more and better jobs for Americans, improved productivity and global competitiveness for technology-based industries, and a more efficient government laboratory system.
Selective radiative heating of nanostructures using hyperbolic metamaterials
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Ding, Ding; Minnich, Austin J
2015-01-01T23:59:59.000Z
Hyperbolic metamaterials (HMM) are of great interest due to their ability to break the diffraction limit for imaging and enhance near-field radiative heat transfer. Here we demonstrate that an annular, transparent HMM enables selective heating of a sub-wavelength plasmonic nanowire by controlling the angular mode number of a plasmonic resonance. A nanowire emitter, surrounded by an HMM, appears dark to incoming radiation from an adjacent nanowire emitter unless the second emitter is surrounded by an identical lens such that the wavelength and angular mode of the plasmonic resonance match. Our result can find applications in radiative thermal management.
Dr. Lazaros Oreopoulos and Dr. Peter M. Norris
2010-03-14T23:59:59.000Z
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.
Dark energy as a fixed point of the Einstein Yang-Mills Higgs Equations
Rinaldi, Massimiliano
2015-01-01T23:59:59.000Z
We study the Einstein Yang-Mills Higgs equations in the $SO(3)$ representation on a isotropic and homogeneous flat Universe, in the presence of radiation and matter fluids. We map the equations of motion into a closed dynamical system of first-order differential equations and we find the equilibrium points. We show that there is only one stable fixed point that corresponds to an accelerated expanding Universe in the future. In the past, instead, there is an unstable fixed point that implies a stiff-matter domination. In between, we find three other unstable fixed points, corresponding, in chronological order, to radiation domination, to matter domination, and, finally, to a transition from decelerated expansion to accelerated expansion. We solve the system numerically and we confirm that there are smooth trajectories that correctly describe the evolution of the Universe, from a remote past dominated by radiation to a remote future dominated by dark energy, passing through a matter-dominated phase.
Dark energy as a fixed point of the Einstein Yang-Mills Higgs Equations
Massimiliano Rinaldi
2015-09-02T23:59:59.000Z
We study the Einstein Yang-Mills Higgs equations in the $SO(3)$ representation on a isotropic and homogeneous flat Universe, in the presence of radiation and matter fluids. We map the equations of motion into an autonomous dynamical system of first-order differential equations and we find the equilibrium points. We show that there is only one stable fixed point that corresponds to an accelerated expanding Universe in the future. In the past, instead, there is an unstable fixed point that implies a stiff-matter domination. In between, we find three other unstable fixed points, corresponding, in chronological order, to radiation domination, to matter domination, and, finally, to a transition from decelerated expansion to accelerated expansion. We solve the system numerically and we confirm that there are smooth trajectories that correctly describe the evolution of the Universe, from a remote past dominated by radiation to a remote future dominated by dark energy, passing through a matter-dominated phase.
Self-force via energy-momentum and angular momentum balance equations
Yurij Yaremko
2012-07-20T23:59:59.000Z
The radiation reaction for a point-like charge coupled to a massive scalar field is considered. The retarded Green's function associated with the Klein-Gordon wave equation has support not only on the future light cone of the emission point (direct part), but extends inside the light cone as well (tail part). Dirac's scheme of decomposition of the retarded electromagnetic field into the "mean of the advanced and retarded field" and the "radiation" field is adapted to theories where Green's function consists of the direct and the tail parts. The Harish-Chandra equation of motion of radiating scalar charge under the influence of an external force is obtained. This equation includes effect of particle's own field. The self force produces a time-changing inertial mass.
Recent Heat Transfer Improvements to the RELAP5-3D Code
Riemke, Richard A; Davis, Cliff B; Oh, Chang
2007-05-01T23:59:59.000Z
The heat transfer section of the RELAP5-3D computer program has been recently improved. The improvements are as follows: (1) the general cladding rupture model was modified (more than one heat structure segment connected to the hydrodynamic volume and heat structure geometry’s internal gap pressure), (2) the cladding rupture model was modified for reflood, and (3) the heat transfer minor edits/plots were extended to include radiation/enclosure heat flux and generation (internal heat source).
Khan, Arshad; Khan, Ilyas; Shafie, Sharidan [Faculty of Science, Universiti Teknologi Malaysia (Malaysia)
2014-06-19T23:59:59.000Z
This article studies the radiation and porosity effects on the unsteady magnetohydrodynamic free convection flow of an incompressible viscous fluid past an infinite vertical plate that applies a shear stress f(t) to the fluid. Conjugate phenomenon of heat and mass transfer is considered. General solutions of the dimensionless governing equations along with imposed initial and boundary conditions are determined using Laplace transform technique. The solution of velocity is presented as a sum of mechanical and non mechanical parts. These solutions satisfy all imposed initial and boundary conditions and reduce to some known solutions from the literature as special cases. The results for embedded parameters are shown graphically. Numerical results for skin friction, Nusselt number and Sherwood number are computed and presented in tabular forms.
Development of Pattern Recognition Software for Tracks of Ionizing Radiation In Medipix2-Based
Vilalta, Ricardo
, and area monitors to characterize the general background radiation environment harmful to humans needed to support an operational dosimeter that can assess the radiation environment during space with similar Linear Energy Transfers (LETs) for calibration purposes. We describe two modules of our pattern
Time-resolved energy transfer from single chloride-terminated nanocrystals to graphene
Ajayi, O. A., E-mail: oaa2114@columbia.edu, E-mail: cww2104@columbia.edu; Wong, C. W., E-mail: oaa2114@columbia.edu, E-mail: cww2104@columbia.edu [Optical Nanostructures Laboratory, Center for Integrated Science and Engineering, Solid-State Science and Engineering, Columbia University, New York, New York 10027 (United States); Department of Mechanical Engineering, Columbia University, New York, New York 10027 (United States); Anderson, N. C.; Wolcott, A.; Owen, J. S. [Department of Chemistry, Columbia University, New York, New York 10027 (United States); Cotlet, M. [Brookhaven National Laboratory, Upton, New York, New York 11973 (United States); Petrone, N.; Hone, J. [Department of Mechanical Engineering, Columbia University, New York, New York 10027 (United States); Gu, T.; Gesuele, F. [Optical Nanostructures Laboratory, Center for Integrated Science and Engineering, Solid-State Science and Engineering, Columbia University, New York, New York 10027 (United States)
2014-04-28T23:59:59.000Z
We examine the time-resolved resonance energy transfer of excitons from single n-butyl amine-bound, chloride-terminated nanocrystals to two-dimensional graphene through time-correlated single photon counting. The radiative biexponential lifetime kinetics and blinking statistics of the individual surface-modified nanocrystal elucidate the non-radiative decay channels. Blinking modification as well as a 4× reduction in spontaneous emission were observed with the short chloride and n-butylamine ligands, probing the energy transfer pathways for the development of graphene-nanocrystal nanophotonic devices.
Radiation Protection Guidance Hospital Staff
Kay, Mark A.
Page 1 Radiation Protection Guidance For Hospital Staff Prepared for Stanford ..................................................................................................................... 17 The Basic Principles of Radiation Protection........................................................... 17 Protection against Radiation Exposure
Heat transfer mechanism with thin filaments including ceramic high temperature heat exchanger
Im, K.H.; Ahluwalia, R.K.
1994-10-18T23:59:59.000Z
A radiative heat transfer mechanism in a furnace is described having burners through which pulverized coal and air are burned producing combustion gases and contaminants. A plurality of elongated conduits are positioned inside the furnace proximate to the burners generally parallel to the flow of combustion gases in the furnace. A plurality of thin filaments are inside each of the elongated hollow conduits, the filaments having diameters in the range of from about 1 micrometer to about 1,000 micrometers and having an infrared radiation cross-section sufficient to cause the filaments to heat upon exposure to infrared radiation. Blower mechanism is associated with the elongated conduits for limiting the amount of soot and ash which deposit on the conduits to preserve the radiative and convective transfer of heat energy from the combustion gases to the conduits. 7 figs.
Heat transfer mechanism with thin filaments including ceramic high temperature heat exchanger
Im, Kwan H. (Naperville, IL); Ahluwalia, Rajesh K. (Burr Ridge, IL)
1994-01-01T23:59:59.000Z
A radiative heat transfer mechanism in a furnace having burners through which pulverized coal and air are burned producing combustion gases and contaminants. A plurality of elongated conduits are positioned inside the furnace proximate to the burners generally parallel to the flow of combustion gases in the furnace. A plurality of thin filaments are inside each of the elongated hollow conduits, the filaments having diameters in the range of from about 1 micrometer to about 1,000 micrometers and having an infrared radiation cross-section sufficient to cause the filaments to heat upon exposure to infrared radiation. Blower mechanism is associated with the elongated conduits for limiting the amount of soot and ash which deposit on the conduits to preserve the radiative and convective transfer of heat energy from the combustion gases to the conduits.
Calculation of unsteady-state heat and mass transfer in steam injection wells
Ruddy, Kenneth Edward
1986-01-01T23:59:59.000Z
) and (5) are defined as the fluid flow equations for the gas and liquid phases, respectively. Mass Balance E uation The thermodynamic system under consideration is a vertical cylindri- cal conduit as depicted in figure 1. A mass balance applied... Equation Method of Solution. RESULTS Comparison with Field Data. Comparison with Results from Steady-State Mass Transfer Model CONCLUSIONS NOMENCLATURE . REFERENCES APPENDIX A: TURBULENCE FACTOR. APPENDIX B: RELATIVE FLUID CONDUCTIVITT. Page vi...
Effect of translucence of engineering ceramics on heat transfer in diesel engines
Wahiduzzaman, S.; Morel, T. (Integral Technologies, Inc., Westmont, IL (United States))
1992-04-01T23:59:59.000Z
This report describes the experimental portion of a broader study undertaken to assess the effects of translucence of ceramic materials used as thermal barrier coatings in diesel engines. In an earlier analytical work a parametric study was performed, varying several radiative properties over ranges typical of engineering ceramics, thereby identifying the most important radiative properties and their impact on in-cylinder heat transfer. In the current study these properties were experimentally determined for several specific zirconia coatings considered for thermal barrier applications in diesel engines. The methodology of this study involved formulation of a model capable of describing radiative transfer through a semitransparent medium as a function of three independent model parameters, ie, absorption coefficient, scattering coefficient and refractive index. For the zirconia-based ceramics investigated in this study, it was concluded that for usual coating thicknesses (1.5--2.5 mm) these ceramics are optically thick and hence, are effective as radiative heat transfer barriers. These ceramics possess high scattering coefficients and low absorption coefficients causing them to be highly reflective (60-80%) in the spectral region where thermal radiation is important. The performance of the investigated ceramics and the mechanism of heat transfer were found to depend on surface condition, specifically on soot deposition. Thus, to insure the optimum thermal barrier operation for either clean or heavily sooted surfaces, a ceramic material with high scattering coefficient provides the best choice.
Effect of translucence of engineering ceramics on heat transfer in diesel engines. Final report
Wahiduzzaman, S.; Morel, T. [Integral Technologies, Inc., Westmont, IL (United States)
1992-04-01T23:59:59.000Z
This report describes the experimental portion of a broader study undertaken to assess the effects of translucence of ceramic materials used as thermal barrier coatings in diesel engines. In an earlier analytical work a parametric study was performed, varying several radiative properties over ranges typical of engineering ceramics, thereby identifying the most important radiative properties and their impact on in-cylinder heat transfer. In the current study these properties were experimentally determined for several specific zirconia coatings considered for thermal barrier applications in diesel engines. The methodology of this study involved formulation of a model capable of describing radiative transfer through a semitransparent medium as a function of three independent model parameters, ie, absorption coefficient, scattering coefficient and refractive index. For the zirconia-based ceramics investigated in this study, it was concluded that for usual coating thicknesses (1.5--2.5 mm) these ceramics are optically thick and hence, are effective as radiative heat transfer barriers. These ceramics possess high scattering coefficients and low absorption coefficients causing them to be highly reflective (60-80%) in the spectral region where thermal radiation is important. The performance of the investigated ceramics and the mechanism of heat transfer were found to depend on surface condition, specifically on soot deposition. Thus, to insure the optimum thermal barrier operation for either clean or heavily sooted surfaces, a ceramic material with high scattering coefficient provides the best choice.
Maryland Radiation Act (Maryland)
Broader source: Energy.gov [DOE]
The policy of the state is to provide for the constructive use of radiation and control radiation emissions. This legislation authorizes the Department of the Environment to develop comprehensive...
Broader source: Energy.gov [DOE]
This statute seeks to regulate radioactive materials, to encourage the constructive uses of radiation, and to prohibit and prevent exposure to radiation in amounts which are or may be detrimental...
Forkel-Wirth, Doris; Silari, Marco; Streit-Bianchi, Marilena; Theis, Christian; Vincke, Heinz; Vincke, Helmut
2013-01-01T23:59:59.000Z
This paper gives a brief overview of the general principles of radiation protection legislation; explains radiological quantities and units, including some basic facts about radioactivity and the biological effects of radiation; and gives an overview of the classification of radiological areas at CERN, radiation fields at high-energy accelerators, and the radiation monitoring system used at CERN. A short section addresses the ALARA approach used at CERN.
Electron transfer networks Murad Banaji
Banaji,. Murad
Electron transfer networks Murad Banaji§ Stephen Baigent June 4, 2007 Abstract In this paper we study electron transfer networks. These are generalisations of electron transport chains, and consist electrons to the oxidised forms, and there are some electron inflow and outflow processes. We show
RADIONUCLIDE RADIATION PROTECTION
Zakhor, Avideh
RADIONUCLIDE AND RADIATION PROTECTION DATA HANDBOOK 2002 D. Delacroix* J. P. Guerre** P. Leblanc'Energie Atomique, CEA/Saclay, France ISBN 1 870965 87 6 RADIATION PROTECTION DOSIMETRY Vol. 98 No 1, 2002 Published by Nuclear Technology Publishing #12;RADIONUCLIDE AND RADIATION PROTECTION DATA HANDBOOK 2nd Edition (2002
Study of the Spin-weighted Spheroidal Equation in the Case of s=1
Yue Sun; Guihua Tian; Kun Dong
2010-11-15T23:59:59.000Z
We present series study of using the method of super-symmetric quantum mechanics(SUSYQM) solving the spin-weighted spheroidal wave equation. In this paper, we obtain the first four terms of super-potential of the spin-weighted spheroidal wave equation in the case of s=1. These results may help summary the general form for the n-th term of the super-potential, which is proved correct by means of induction. We finally compute the ground eigenvalues and ground eigenfunction. All the results may be of significative for studies of electromagnetic radiation processes near rotating black holes and compute radiation reaction in curved space-time.
Coherent Radiation in Gamma-Ray Bursts and Relativistic Collisionless Shocks
Kunihito Ioka
2005-10-27T23:59:59.000Z
We suggest that coherent radiation may occur in relativistic collisionless shocks via two-stream Weibel instabilities. The coherence amplifies the radiation power by many orders [$\\sim 10^{12}$ in Gamma-Ray Bursts (GRBs)] and particles cool very fast before being randomized. We imply (1) GRBs accompany strong infrared emission, (2) protons efficiently transfer energy to electrons and (3) prompt GRBs might be the upscattered coherent radiation.
Sorensen, F.C.
1992-09-01T23:59:59.000Z
Pine cones were collected from 272 trees at 189 locations uniformly distributed over the east slopes of the Oregon Cascade Range and Warner Mountains. Variation in seed and seedling traits was related to (1) seed source latitude, distance from the Cascade crest, elevation, slope, and aspect in multiple regression analyses; and (2) seed zone and elevation band in classification analyses. Provisional seed transfer guidelines are presented. These include a regression equation for guiding seed transfer and estimating transfer risk, and a new outline of fixed seed zones.
Plasma wake field XUV radiation source
Prono, Daniel S. (Los Alamos, NM); Jones, Michael E. (Los Alamos, NM)
1997-01-01T23:59:59.000Z
A XUV radiation source uses an interaction of electron beam pulses with a gas to create a plasma radiator. A flowing gas system (10) defines a circulation loop (12) with a device (14), such as a high pressure pump or the like, for circulating the gas. A nozzle or jet (16) produces a sonic atmospheric pressure flow and increases the density of the gas for interacting with an electron beam. An electron beam is formed by a conventional radio frequency (rf) accelerator (26) and electron pulses are conventionally formed by a beam buncher (28). The rf energy is thus converted to electron beam energy, the beam energy is used to create and then thermalize an atmospheric density flowing gas to a fully ionized plasma by interaction of beam pulses with the plasma wake field, and the energetic plasma then loses energy by line radiation at XUV wavelengths Collection and focusing optics (18) are used to collect XUV radiation emitted as line radiation when the high energy density plasma loses energy that was transferred from the electron beam pulses to the plasma.
Copyright @ 2003 by ASME1 Proceedings of
Guo, Zhixiong "James"
transient radiation transfer equation in cylindrical coordinates is developed for radiation heat transfer as the irradiation source. The characteristics of transient radiation heat transfer in ultrafast laser tissue welding and reduce the surface radiative heat flux accordingly. Comparisons of transient radiation heat transfer