Sample records for diffuse radiation gef

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

    E-Print Network [OSTI]

    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 for LI900, a material used in the insulation tile for the space shuttle. Comparisons are presented

  2. Adaptive multigroup radiation diffusion

    E-Print Network [OSTI]

    Williams, Richard B., Sc. D. Massachusetts Institute of Technology

    2005-01-01T23:59:59.000Z

    This thesis describes the development and implementation of an algorithm for dramatically increasing the accuracy and reliability of multigroup radiation diffusion simulations at low group counts. This is achieved by ...

  3. Diffusion processes in general relativistic radiating spheres

    SciTech Connect (OSTI)

    Barreto, W.; Herrera, L.; Santos, N.O. (Oriente Universidad, Cumana (Venezuela); Universidad Central de Venezuela, Caracas; Observatorio Nacional do Brasil, Rio de Janeiro (Brazil))

    1989-09-01T23:59:59.000Z

    The influence of diffusion processes on the dynamics of general relativistic radiating spheres is systematically studied by means of two examples. Differences between the streaming-out limit and the diffusion limit are exhibited, for both models, through the evolution curves of dynamical variables. In particular it is shown the Bondi mass decreases, for both models, in the diffusion limit as compared with its value at the streaming-out regime. 15 refs.

  4. Adaptive Implicit Non-Equilibrium Radiation Diffusion

    SciTech Connect (OSTI)

    Philip, Bobby [ORNL; Wang, Zhen [ORNL; Berrill, Mark A [ORNL; Rodriguez Rodriguez, Manuel [ORNL; Pernice, Michael [Idaho National Laboratory (INL)

    2013-01-01T23:59:59.000Z

    We describe methods for accurate and efficient long term time integra- tion of non-equilibrium radiation diffusion systems: implicit time integration for effi- cient long term time integration of stiff multiphysics systems, local control theory based step size control to minimize the required global number of time steps while control- ling accuracy, dynamic 3D adaptive mesh refinement (AMR) to minimize memory and computational costs, Jacobian Free Newton-Krylov methods on AMR grids for efficient nonlinear solution, and optimal multilevel preconditioner components that provide level independent solver convergence.

  5. Kenya-GEF Projects | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation, searchOf Kilauea Volcano, Hawaii |Island,Kas FarmssourceGEF Projects

  6. Global Environment Fund GEF | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are8COaBulkTransmissionSitingProcess.pdfGetec AG Contracting Jump to:Echo,GEF Jump to: navigation, search Name: Global

  7. Turkmenistan-GEF Projects | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:Ezfeedflag JumpID-fTri Global Energy LLC Place: Dallas, Texas2022 |Turkmenistan-GEF Projects

  8. Radiation monitoring during criticality at a gaseous diffusion plant

    SciTech Connect (OSTI)

    Goebel, G.R.; Hines, T.W.; Carver, A.M.

    1994-12-31T23:59:59.000Z

    The Paducah gaseous diffusion plant (PGDP) has two systems of radiation detection units that monitor radiation associated with a nuclear criticality accident (NCA). The primary system, the criticality accident alarm system (CAAS), is composed of several detection units that alarm when gamma-radiation levels exceed 10 mR/h. The CAAS provides the means to initiate emergency-evacuation procedures in the event of an NCA. This system is augmented with a second system of radiation detectors, which is referred to as the argon gamma graph (AGG) system. The AGG system is utilized specifically for the remote monitoring of radiation during an NCA and is a primary tool used by emergency response personnel. The remote radiation readings supplied by the AGG system provide the means to quickly locate and characterize an NCA. The centralized remote monitoring of radiation during an NCA permits important data to be collected efficiently without subjecting personnel to unknown and unquantified radiation fields. Calculations of the expected radiation readings on the AGG system were performed for a postulated NCA at four different locations at PGDP.

  9. Transforming on-grid renewable energy markets. A review of UNDP-GEF support for feed-in tariffs and related price and market-access instruments

    SciTech Connect (OSTI)

    Glemarec, Yannick; Rickerson, Wilson; Waissbein, Oliver

    2012-11-15T23:59:59.000Z

    As a Global Environment Facility (GEF) founding implementing agency, UNDP has worked on over 230 GEF-supported clean energy projects in close to 100 developing countries since 1992. About 100 of these projects in 80 countries have focused on renewable energy, supported by approximately US $ 293 million in GEF funds and leveraging US $1.48 billion in associated co-financing from national governments, international organizations, the private sector and non-governmental organizations. As part of UNDP efforts to codify and share lessons learnt from these initiatives, this report addresses how scarce public resources can be used to catalyze larger private financial flows for renewable energy. It provides an overview of UNDP-GEF’s extensive work supporting development of national renewable energy policies such as feed-in tariffs. In these activities UNDP-GEF assists developing countries to assess key risks and barriers to technology diffusion and then to identify a mix of policy and financial de-risking measures to remove these barriers and drive investment. This approach is illustrated through three case studies in Uruguay, Mauritius and Kazakhstan. This report is complemented by a companion publication presenting an innovative UNDP financial modeling tool to assist policymakers in appraising different public instruments to promote clean energy.

  10. Ann. Geophysicae 14, 1051--1059 (1996) EGS --Springer-Verlag 1996 Diffuse solar radiation and associated meteorological

    E-Print Network [OSTI]

    Boyer, Edmond

    Ann. Geophysicae 14, 1051--1059 (1996) EGS -- Springer-Verlag 1996 Diffuse solar radiation and the monthly ratios of diffuse to global solar radiation have been examined, with a special emphasis and global solar radiation, a knowledge of the diffuse or sky radiation is required. Diffuse solar radiation

  11. A Coupled Model for Radiative Transfer: Doppler Effects, Equilibrium and Non-Equilibrium Diffusion Asymptotics

    E-Print Network [OSTI]

    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

  12. An Improved Multipyranometer Array for the Measurement of Direct and Diffuse Solar Radiation

    E-Print Network [OSTI]

    Munger, B.; Haberl, J. S.

    1994-01-01T23:59:59.000Z

    This paper describes an improved multipyranometer array (MPA) for the continuous remote measurement of direct and diffuse solar radiation. The MPA described in this paper is an improvement over previously published MPA studies due...

  13. An Improved Multipyranometer Array for the Measurement of Direct and Diffuse Solar Radiation 

    E-Print Network [OSTI]

    Munger, B.; Haberl, J. S.

    1994-01-01T23:59:59.000Z

    This paper describes an improved multipyranometer array (MPA) for the continuous remote measurement of direct and diffuse solar radiation. The MPA described in this paper is an improvement over previously published MPA studies due...

  14. A Module for Radiation Hydrodynamic Calculations With ZEUS-2D Using Flux-Limited Diffusion

    E-Print Network [OSTI]

    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.

  15. Influence of clouds and diffuse radiation on ecosystem-atmosphere CO 2 and CO 18 O exchanges

    E-Print Network [OSTI]

    2009-01-01T23:59:59.000Z

    surface model with BOREAS aspen and jack pine tower fluxes,to diffuse radiation by an aspen-dominated northern hardwood

  16. Effects of Radiative Diffusion on Thin Flux Tubes in Turbulent Solar-like Convection

    E-Print Network [OSTI]

    Weber, Maria A

    2015-01-01T23:59:59.000Z

    We study the combined effects of convection and radiative diffusion on the evolution of thin magnetic flux tubes in the solar interior. Radiative diffusion is the primary supplier of heat to convective motions in the lower convection zone, and it results in a heat input per unit volume of magnetic flux tubes that has been ignored by many previous thin flux tube studies. We use a thin flux tube model subject to convection taken from a rotating spherical shell of turbulent, solar-like convection as described by Weber, Fan, and Miesch (2011, Astrophys. J., 741, 11; 2013, Solar Phys., 287, 239), now taking into account the influence of radiative heating on flux tubes of large-scale active regions. Our simulations show that flux tubes of less than or equal to 60 kG subject to solar-like convective flows do not anchor in the overshoot region, but rather drift upward due to the increased buoyancy of the flux tube earlier in its evolution as a result of the inclusion of radiative diffusion. Flux tubes of magnetic fie...

  17. Electromagnetic Radiation in Hot QCD Matter: Rates, Electric Conductivity, Flavor Susceptibility and Diffusion

    E-Print Network [OSTI]

    Chang-Hwan Lee; Ismail Zahed

    2014-03-07T23:59:59.000Z

    We discuss the general features of the electromagnetic radiation from a thermal hadronic gas as constrained by chiral symmetry. The medium effects on the electromagnetic spectral functions and the partial restoration of chiral symmetry are quantified in terms of the pion densities. The results are compared with the electromagnetic radiation from a strongly interacting quark-gluon plasma in terms of the leading gluon condensate operators. We use the spectral functions as constrained by the emission rates to estimate the electric conductivity, the light flavor susceptibility and diffusion constant across the transition from the correlated hadronic gas to a strongly interacting quark-gluon plasma.

  18. An improved multipyranometer array for the measurement of direct and diffuse solar radiation 

    E-Print Network [OSTI]

    Munger, Bryce Kirtley

    1997-01-01T23:59:59.000Z

    AN IMPROVED MULTIPYRANOMETER ARRAY FOR THE MEASUREMENT OF DIRECT AND DIFFUSE SOLAR RADIATION A Thesis by BRYCE KIRTLEY MUNGER Submitted to the Office of Graduate Studies of Texas AkM University in partial fulffllment of the requirements... Studies of Texas AkM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Approved as to style and content by: Haberl (Co-Chair of ommittee) W. D. Turner (C -Chair of Committee) J. Trost (Member) Suhada...

  19. Development of Simplified Calculations for a Multipyranometer Array for the Measurement of Direct and Diffuse Solar Radiation

    E-Print Network [OSTI]

    Munger, B. K.; Haberl, J. S.

    2000-01-01T23:59:59.000Z

    This paper describes the development of simplified procedures for a multipyranometer array (MPA) for the continuous measurement of direct and diffuse solar radiation. The MPA described in this paper is an improvement over previously published MPA...

  20. ERK1/2 phosphorylate GEF-H1 to enhance its guanine nucleotide exchange activity toward RhoA

    SciTech Connect (OSTI)

    Fujishiro, Shuh-hei; Tanimura, Susumu; Mure, Shogo; Kashimoto, Yuji; Watanabe, Kazushi [Laboratory of Cell Regulation, Department of Pharmaceutical Sciences, Graduate School of Biomedical Sciences, Nagasaki University, 1-14, Bunkyo-machi, Nagasaki 852-8521 (Japan); Kohno, Michiaki [Laboratory of Cell Regulation, Department of Pharmaceutical Sciences, Graduate School of Biomedical Sciences, Nagasaki University, 1-14, Bunkyo-machi, Nagasaki 852-8521 (Japan)], E-mail: kohnom@nagasaki-u.ac.jp

    2008-03-28T23:59:59.000Z

    Rho GTPases play an essential role in the regulation of many cellular processes. Although various guanine nucleotide exchange factors (GEFs) are involved in the activation of Rho GTPases, the precise mechanism regulating such activity remains unclear. We have examined whether ERK1/2 are involved in the phosphorylation of GEF-H1, a GEF toward RhoA, to modulate its activity. Expression of GEF-H1 in HT1080 cells with constitutive ERK1/2 activation induced its phosphorylation at Thr{sup 678}, which was totally abolished by treating the cells with PD184352, an ERK pathway inhibitor. Stimulation of HeLa S3 cells with 12-O-tetradecanoyl-phorbol-13-acetate induced the phosphorylation of GEF-H1 in an ERK-dependent manner. ERK1/2-mediated Thr{sup 678}-phosphorylation enhanced the guanine nucleotide exchange activity of GEF-H1 toward RhoA. These results suggest that the ERK pathway, by enhancing the GEF-H1 activity, contributes to the activation of RhoA to regulate the actin assembly, a necessary event for the induction of cellular responses including proliferation and motility.

  1. Determination of the Dark Matter profile from the EGRET excess of diffuse Galactic gamma radiation

    E-Print Network [OSTI]

    Markus Weber

    2007-10-26T23:59:59.000Z

    The excess above 1 GeV in the energy spectrum of the diffuse Galactic gamma radiation, measured with the EGRET experiment, can be interpreted as the annihilation of Dark Matter (DM) particles. The DM is distributed in a halo around the Milky Way. Considering the directionality of the gamma ray flux it is possible to determine the halo profile. The DM within the halo has a smooth and a clumpy component.These components can have different profiles as suggested by N-body simulations and the data is indeed compatible with a NFW profile for the diffuse component and a cored profile for the clumpy component.These DM clumps can be partly destroyed by tidal forces from interactions with stars and the gravitational potential of the Galactic disc.This effect mainly decreases the annihilation signal from the Galactic centre (GC). In this paper constraints on the different profiles and the survival probability of the clumps are discussed.

  2. Multigroup radiation hydrodynamics with flux-limited diffusion and adaptive mesh refinement

    E-Print Network [OSTI]

    González, Matthias; Commerçon, Benoît; Masson, Jacques

    2015-01-01T23:59:59.000Z

    Radiative transfer plays a key role in the star formation process. Due to a high computational cost, radiation-hydrodynamics simulations performed up to now have mainly been carried out in the grey approximation. In recent years, multi-frequency radiation-hydrodynamics models have started to emerge, in an attempt to better account for the large variations of opacities as a function of frequency. We wish to develop an efficient multigroup algorithm for the adaptive mesh refinement code RAMSES which is suited to heavy proto-stellar collapse calculations. Due to prohibitive timestep constraints of an explicit radiative transfer method, we constructed a time-implicit solver based on a stabilised bi-conjugate gradient algorithm, and implemented it in RAMSES under the flux-limited diffusion approximation. We present a series of tests which demonstrate the high performance of our scheme in dealing with frequency-dependent radiation-hydrodynamic flows. We also present a preliminary simulation of a three-dimensional p...

  3. Solar UV-B in tropical forest gaps: Analysis using direct and diffuse radiation

    SciTech Connect (OSTI)

    Flint, S.D.; Caldwell, M.M. [Utah State Univ., Logan, UT (United States)

    1995-06-01T23:59:59.000Z

    Experiments with natural levels of solar ultraviolet-B radiation (UV-B) have recently shown inhibition of the growth of some tropical forest tree seedlings. A knowledge of forest radiation environments is needed to help assess UV-B effects in natural situations. Although forest canopies strongly attenuate solar radiation, treefall gaps provide a very different radiation environment. We simultaneously measured both UV-B and photosynthetically active radiation (PAR) in forest gaps on Barro Colorado Island, Panama. Outside the forest, UV-B is predominately diffuse even under clear sky conditions. In sunflecks of small forest gaps, most of the UV-B was in the direct beam component. Compared to conditions outside the forest, the UV-B in these sunflecks was low relative to PAR. Shaded portions of the gap, in contrast, had proportionately high levels of UV-B relative to PAR. There are indications in the literature that relatively low UV-B levels may be effective under low PFD. Seasonal trends of PAR and UV-B in different locations in gaps can be inferred from hemispherical canopy photographs.

  4. A Monte Carlo synthetic-acceleration method for solving the thermal radiation diffusion equation

    SciTech Connect (OSTI)

    Evans, Thomas M., E-mail: evanstm@ornl.gov [Oak Ridge National Laboratory, 1 Bethel Valley Rd., Oak Ridge, TN 37831 (United States); Mosher, Scott W., E-mail: moshersw@ornl.gov [Oak Ridge National Laboratory, 1 Bethel Valley Rd., Oak Ridge, TN 37831 (United States); Slattery, Stuart R., E-mail: sslattery@wisc.edu [University of Wisconsin–Madison, 1500 Engineering Dr., Madison, WI 53716 (United States); Hamilton, Steven P., E-mail: hamiltonsp@ornl.gov [Oak Ridge National Laboratory, 1 Bethel Valley Rd., Oak Ridge, TN 37831 (United States)

    2014-02-01T23:59:59.000Z

    We present a novel synthetic-acceleration-based Monte Carlo method for solving the equilibrium thermal radiation diffusion equation in three spatial dimensions. The algorithm performance is compared against traditional solution techniques using a Marshak benchmark problem and a more complex multiple material problem. Our results show that our Monte Carlo method is an effective solver for sparse matrix systems. For solutions converged to the same tolerance, it performs competitively with deterministic methods including preconditioned conjugate gradient and GMRES. We also discuss various aspects of preconditioning the method and its general applicability to broader classes of problems.

  5. Dynamic Implicit 3D Adaptive Mesh Refinement for Non-Equilibrium Radiation Diffusion

    SciTech Connect (OSTI)

    Philip, Bobby [ORNL] [ORNL; Wang, Zhen [ORNL] [ORNL; Berrill, Mark A [ORNL] [ORNL; Rodriguez Rodriguez, Manuel [ORNL] [ORNL; Pernice, Michael [Idaho National Laboratory (INL)] [Idaho National Laboratory (INL)

    2014-01-01T23:59:59.000Z

    The time dependent non-equilibrium radiation diffusion equations are important for solving the transport of energy through radiation in optically thick regimes and find applications in several fields including astrophysics and inertial confinement fusion. The associated initial boundary value problems that are encountered exhibit a wide range of scales in space and time and are extremely challenging to solve. To efficiently and accurately simulate these systems we describe our research on combining techniques that will also find use more broadly for long term time integration of nonlinear multiphysics systems: implicit time integration for efficient long term time integration of stiff multiphysics systems, local control theory based step size control to minimize the required global number of time steps while controlling accuracy, dynamic 3D adaptive mesh refinement (AMR) to minimize memory and computational costs, Jacobian Free Newton Krylov methods on AMR grids for efficient nonlinear solution, and optimal multilevel preconditioner components that provide level independent linear solver convergence.

  6. Measurements and modeling of soot formation and radiation in microgravity jet diffusion flames

    SciTech Connect (OSTI)

    Ku, J.C.; Tong, L. [Wayne State Univ., Detroit, MI (United States). Mechanical Engineering Dept.; Greenberg, P.S. [NASA Lewis Research Center, Cleveland, OH (United States). Microgravity Combustion Branch

    1996-12-31T23:59:59.000Z

    This is a computational and experimental study for soot formation and radiative heat transfer in jet diffusion flames under normal gravity (1-g) and microgravity (0-g) conditions. Instantaneous soot volume fraction maps are measured using a full-field imaging absorption technique developed by the authors. On modeling, the authors have coupled flame structure and soot formation models with detailed radiation transfer calculations. Favre-averaged boundary layer equations with a k-e-g turbulence model are used to predict the flow field, and a conserved scalar approach with an assumed {beta}-pdf are used to predict gaseous species mole fraction. Scalar transport equations are used to describe soot volume fraction and number density distributions, with formation and oxidation terms modeled by one-step rate equations and thermophoretic effects included. An energy equation is included to couple flame structure and radiation analyses through iterations, neglecting turbulence-radiation interactions. The YIX solution for a finite cylindrical enclosure is used for radiative heat transfer calculations. The spectral absorption coefficient for soot aggregates is calculated from the Rayleigh solution using complex refractive index data from a Drude-Lorentz model. The exponential-wide-band model is used to calculate the spectral absorption coefficient for H{sub 2}O and CO{sub 2}. Predicted soot volume fraction and temperature results agree well with published data for a normal gravity co-flow laminar flames and turbulent jet flames. Predicted soot volume fraction results also agree with the data for 1-g and 0-g laminar jet flames as well as 1-g turbulent jet flames.

  7. On linearization and preconditioning for radiation diffusion coupled to material thermal conduction equations

    SciTech Connect (OSTI)

    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.

  8. Hourly global and diffuse radiation of Lagos, Nigeria-correlation with some atmospheric parameters

    SciTech Connect (OSTI)

    Chendo, M.A.C.; Maduekwe, A.A.L. (Univ. of Lagos, Akoka (Nigeria))

    1994-03-01T23:59:59.000Z

    The influence of four climatic parameters on the hourly diffuse fraction in Lagos, Nigeria, has been studied. Using data for two years, new correlations were established. The standard error of the Liu and Jordan-type equation was reduced by 12.83% when solar elevation, ambient temperature, and relative humidity were used together as predictor variables for the entire data set. Ambient temperature and relative humidity proved to be very important variables for predicting the diffuse fraction of the solar radiation passing through the humid atmosphere of the coastal and tropic city of Lagos. Seasonal analysis carried out with the data showed improvements on the standard errors for the new seasonal correlations. In the case of the dry season, the improvement was 18.37%, whole for the wet season, this was 12.37%. Comparison with existing correlations showed that the performance of the one parameter model (namely K[sub t]), of Orgill and Hollands and Reindl, Beckman, and Duffie were very different from the Liu and Jordan-type model obtained for Lagos.

  9. Dynamic implicit 3D adaptive mesh refinement for non-equilibrium radiation diffusion

    SciTech Connect (OSTI)

    B. Philip; Z. Wang; M.A. Berrill; M. Birke; M. Pernice

    2014-04-01T23:59:59.000Z

    The time dependent non-equilibrium radiation diffusion equations are important for solving the transport of energy through radiation in optically thick regimes and find applications in several fields including astrophysics and inertial confinement fusion. The associated initial boundary value problems that are encountered often exhibit a wide range of scales in space and time and are extremely challenging to solve. To efficiently and accurately simulate these systems we describe our research on combining techniques that will also find use more broadly for long term time integration of nonlinear multi-physics systems: implicit time integration for efficient long term time integration of stiff multi-physics systems, local control theory based step size control to minimize the required global number of time steps while controlling accuracy, dynamic 3D adaptive mesh refinement (AMR) to minimize memory and computational costs, Jacobian Free Newton–Krylov methods on AMR grids for efficient nonlinear solution, and optimal multilevel preconditioner components that provide level independent solver convergence.

  10. Time-independent hybrid enrichment for finite element solution of transient conduction–radiation in diffusive grey media

    SciTech Connect (OSTI)

    Mohamed, M. Shadi, E-mail: m.s.mohamed@durham.ac.uk [School of Engineering and Computing Sciences, University of Durham, South Road, Durham DH1 3LE (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)

    2013-10-15T23:59:59.000Z

    We investigate the effectiveness of the partition-of-unity finite element method for transient conduction–radiation problems in diffusive grey media. The governing equations consist of a semi-linear transient heat equation for the temperature field and a stationary diffusion approximation to the radiation in grey media. The coupled equations are integrated in time using a semi-implicit method in the finite element framework. We show that for the considered problems, a combination of hyperbolic and exponential enrichment functions based on an approximation of the boundary layer leads to improved accuracy compared to the conventional finite element method. It is illustrated that this approach can be more efficient than using h adaptivity to increase the accuracy of the finite element method near the boundary walls. The performance of the proposed partition-of-unity method is analyzed on several test examples for transient conduction–radiation problems in two space dimensions.

  11. UNDP-GEF Fuel Cell Bus Programme: Update | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualProperty Edit withTianlin Baxin HydropowerTrinityTurnbull HydroUK CentreMechanismGEF Fuel Cell

  12. Modeling the radiation belt electrons with radial diffusion driven by the solar wind

    E-Print Network [OSTI]

    Li, Xinlin

    in the enhancement of radiation belt electrons yet leaves a significant portion of the variance unaccounted for. We

  13. Mutant Huntingtin Alters Cell Fate in Response to Microtubule Depolymerization via the GEF-H1-RhoA-ERK Pathway*S

    E-Print Network [OSTI]

    Stockwell, Brent R.

    Mutant Huntingtin Alters Cell Fate in Response to Microtubule Depolymerization via the GEF-H1-RhoA-ERK- vated ERK survival signaling. The genotype-selective rescue was dependent upon increased RhoA protein

  14. Asymptotic Accuracy of the Equilibrium Diffusion Approximation and Semi-analytic Solutions of Radiating Shocks

    E-Print Network [OSTI]

    Ferguson, Jim Michael

    2014-01-10T23:59:59.000Z

    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 I.4 State-of-the-art computational methods . . . . . . . . . . . . . . . . . 10 CHAPTER II RADIATION TRANSPORT AND RADIATION HYDRODY- NAMICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 II.1 Radiation transport without material... recombination at the front of the expanding shock. Adapted from the March 24, 2005, Astronomy Picture of the Day [16]. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Figure I.2 SN1987A was viewed from earth on February 23, 1987. Only 168,000 light...

  15. Microstructural Evolution and Radiation Effects of Uranium-Bearing Diffusion Couples 

    E-Print Network [OSTI]

    Wei, Chao-Chen

    2014-12-12T23:59:59.000Z

    bombarded regions. Additionally, the mechanism of intermetallics formation (e.g.Fe23Zr6) and radiation stability were discussed. Second, a matrix of uranium-bearing couples is established. 1) Depleted uranium (DU) was bonded with polycrystalline iron...

  16. Hypofractionation vs Conventional Radiation Therapy for Newly Diagnosed Diffuse Intrinsic Pontine Glioma: A Matched-Cohort Analysis

    SciTech Connect (OSTI)

    Janssens, Geert O., E-mail: g.janssens@rther.umcn.nl [Department of Radiation Oncology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Jansen, Marc H. [Pediatric Oncology/Hematology, VU University Medical Center, Amsterdam (Netherlands)] [Pediatric Oncology/Hematology, VU University Medical Center, Amsterdam (Netherlands); Lauwers, Selmer J. [Department of Radiation Oncology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands)] [Department of Radiation Oncology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Nowak, Peter J. [Department of Radiation Oncology, Erasmus Medical Centre, Rotterdam (Netherlands)] [Department of Radiation Oncology, Erasmus Medical Centre, Rotterdam (Netherlands); Oldenburger, Foppe R. [Department of Radiation Oncology, Academic Medical Centre, Amsterdam (Netherlands)] [Department of Radiation Oncology, Academic Medical Centre, Amsterdam (Netherlands); Bouffet, Eric [Department of Hematology/Oncology, The Hospital for Sick Children, University of Toronto, Toronto (Canada)] [Department of Hematology/Oncology, The Hospital for Sick Children, University of Toronto, Toronto (Canada); Saran, Frank [Department of Pediatric Oncology, The Royal Marsden NHS Foundation Trust, Sutton (United Kingdom)] [Department of Pediatric Oncology, The Royal Marsden NHS Foundation Trust, Sutton (United Kingdom); Kamphuis-van Ulzen, Karin [Department of Radiology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands)] [Department of Radiology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Lindert, Erik J. van [Department of Neurosurgery, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands)] [Department of Neurosurgery, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Schieving, Jolanda H. [Department of Neurology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands)] [Department of Neurology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Boterberg, Tom [Department of Radiation Oncology, Ghent University Hospital, Ghent (Belgium)] [Department of Radiation Oncology, Ghent University Hospital, Ghent (Belgium); Kaspers, Gertjan J. [Pediatric Oncology/Hematology, VU University Medical Center, Amsterdam (Netherlands)] [Pediatric Oncology/Hematology, VU University Medical Center, Amsterdam (Netherlands); Span, Paul N.; Kaanders, Johannes H. [Department of Radiation Oncology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands)] [Department of Radiation Oncology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Gidding, Corrie E. [Department of Pediatric Oncology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands)] [Department of Pediatric Oncology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Hargrave, Darren [Department of Oncology, Great Ormond Street Hospital, London (United Kingdom)] [Department of Oncology, Great Ormond Street Hospital, London (United Kingdom)

    2013-02-01T23:59:59.000Z

    Purpose: Despite conventional radiation therapy, 54 Gy in single doses of 1.8 Gy (54/1.8 Gy) over 6 weeks, most children with diffuse intrinsic pontine glioma (DIPG) will die within 1 year after diagnosis. To reduce patient burden, we investigated the role of hypofractionation radiation therapy given over 3 to 4 weeks. A 1:1 matched-cohort analysis with conventional radiation therapy was performed to assess response and survival. Methods and Materials: Twenty-seven children, aged 3 to 14, were treated according to 1 of 2 hypofractionation regimens over 3 to 4 weeks (39/3 Gy, n=16 or 44.8/2.8 Gy, n=11). All patients had symptoms for {<=}3 months, {>=}2 signs of the neurologic triad (cranial nerve deficit, ataxia, long tract signs), and characteristic features of DIPG on magnetic resonance imaging. Twenty-seven patients fulfilling the same diagnostic criteria and receiving at least 50/1.8 to 2.0 Gy were eligible for the matched-cohort analysis. Results: With hypofractionation radiation therapy, the overall survival at 6, 9, and 12 months was 74%, 44%, and 22%, respectively. Progression-free survival at 3, 6, and 9 months was 77%, 43%, and 12%, respectively. Temporary discontinuation of steroids was observed in 21 of 27 (78%) patients. No significant difference in median overall survival (9.0 vs 9.4 months; P=.84) and time to progression (5.0 vs 7.6 months; P=.24) was observed between hypofractionation vs conventional radiation therapy, respectively. Conclusions: For patients with newly diagnosed DIPG, a hypofractionation regimen, given over 3 to 4 weeks, offers equal overall survival with less treatment burden compared with a conventional regimen of 6 weeks.

  17. The influence of clouds and diffuse radiation on ecosystem-atmosphere CO2 and CO18O exhanges

    SciTech Connect (OSTI)

    Still, C.J.; Riley, W.J.; Biraud, S.C.; Noone, D.C.; Buenning, N.H.; Randerson, J.T.; Torn, M.S.; Welker, J.; White, J.W.C.; Vachon, R.; Farquhar, G.D.; Berry, J.A.

    2009-05-01T23:59:59.000Z

    This study evaluates the potential impact of clouds on ecosystem CO{sub 2} and CO{sub 2} isotope fluxes ('isofluxes') in two contrasting ecosystems (a broadleaf deciduous forest and a C{sub 4} grassland), in a region for which cloud cover, meteorological, and isotope data are available for driving the isotope-enabled land surface model, ISOLSM. Our model results indicate a large impact of clouds on ecosystem CO{sub 2} fluxes and isofluxes. Despite lower irradiance on partly cloudy and cloudy days, predicted forest canopy photosynthesis was substantially higher than on clear, sunny days, and the highest carbon uptake was achieved on the cloudiest day. This effect was driven by a large increase in light-limited shade leaf photosynthesis following an increase in the diffuse fraction of irradiance. Photosynthetic isofluxes, by contrast, were largest on partly cloudy days, as leaf water isotopic composition was only slightly depleted and photosynthesis was enhanced, as compared to adjacent clear sky days. On the cloudiest day, the forest exhibited intermediate isofluxes: although photosynthesis was highest on this day, leaf-to-atmosphere isofluxes were reduced from a feedback of transpiration on canopy relative humidity and leaf water. Photosynthesis and isofluxes were both reduced in the C{sub 4} grass canopy with increasing cloud cover and diffuse fraction as a result of near-constant light limitation of photosynthesis. These results suggest that some of the unexplained variation in global mean {delta}{sup 18}O of CO{sub 2} may be driven by large-scale changes in clouds and aerosols and their impacts on diffuse radiation, photosynthesis, and relative humidity.

  18. A Monte Carlo Synthetic-Acceleration Method for Solving the Thermal Radiation Diffusion Equation

    SciTech Connect (OSTI)

    Evans, Thomas M [ORNL] [ORNL; Mosher, Scott W [ORNL] [ORNL; Slattery, Stuart [University of Wisconsin, Madison] [University of Wisconsin, Madison

    2014-01-01T23:59:59.000Z

    We present a novel synthetic-acceleration based Monte Carlo method for solving the equilibrium thermal radiation diusion equation in three dimensions. The algorithm performance is compared against traditional solution techniques using a Marshak benchmark problem and a more complex multiple material problem. Our results show that not only can our Monte Carlo method be an eective solver for sparse matrix systems, but also that it performs competitively with deterministic methods including preconditioned Conjugate Gradient while producing numerically identical results. We also discuss various aspects of preconditioning the method and its general applicability to broader classes of problems.

  19. Influence of clouds and diffuse radiation on ecosystem-atmosphere CO 2 and CO 18 O exchanges

    E-Print Network [OSTI]

    2009-01-01T23:59:59.000Z

    cover, radiation, meteorological and water isotope data tohere, radiation, cloud property, and aerosol data wereData were obtained from the Atmospheric Radiation

  20. Insights into the Molecular Activation Mechanism of the RhoA-specific Guanine Nucleotide Exchange Factor, PDZRhoGEF

    SciTech Connect (OSTI)

    Bielnicki, Jakub A.; Shkumatov, Alexander V.; Derewenda, Urszula; Somlyo, Avril V.; Svergun, Dmitri I.; Derewenda, Zygmunt S. (EMBL); (UV)

    2012-10-09T23:59:59.000Z

    PDZRhoGEF (PRG) belongs to a small family of RhoA-specific nucleotide exchange factors that mediates signaling through select G-protein-coupled receptors via G{alpha}{sub 12/13} and activates RhoA by catalyzing the exchange of GDP to GTP. PRG is a multidomain protein composed of PDZ, regulators of G-protein signaling-like (RGSL), Dbl-homology (DH), and pleckstrin-homology (PH) domains. It is autoinhibited in cytosol and is believed to undergo a conformational rearrangement and translocation to the membrane for full activation, although the molecular details of the regulation mechanism are not clear. It has been shown recently that the main autoregulatory elements of PDZRhoGEF, the autoinhibitory 'activation box' and the 'GEF switch,' which is required for full activation, are located directly upstream of the catalytic DH domain and its RhoA binding surface, emphasizing the functional role of the RGSL-DH linker. Here, using a combination of biophysical and biochemical methods, we show that the mechanism of PRG regulation is yet more complex and may involve an additional autoinhibitory element in the form of a molten globule region within the linker between RGSL and DH domains. We propose a novel, two-tier model of autoinhibition where the activation box and the molten globule region act synergistically to impair the ability of RhoA to bind to the catalytic DH-PH tandem. The molten globule region and the activation box become less ordered in the PRG-RhoA complex and dissociate from the RhoA-binding site, which may constitute a critical step leading to PRG activation.

  1. Activation of p115-RhoGEF Requires Direct Association of G[alpha subscript 13] and the Dbl Homology Domain

    SciTech Connect (OSTI)

    Chen, Zhe; Guo, Liang; Hadas, Jana; Gutowski, Stephen; Sprang, Stephen R.; Sternweis, Paul C. (IIT); (UTSMC); (Montana)

    2012-09-05T23:59:59.000Z

    RGS-containing RhoGEFs (RGS-RhoGEFs) represent a direct link between the G{sub 12} class of heterotrimeric G proteins and the monomeric GTPases. In addition to the canonical Dbl homology (DH) and pleckstrin homology domains that carry out the guanine nucleotide exchange factor (GEF) activity toward RhoA, these RhoGEFs also possess RGS homology (RH) domains that interact with activated {alpha} subunits of G{sub 12} and G{sub 13}. Although the GEF activity of p115-RhoGEF (p115), an RGS-RhoGEF, can be stimulated by G{alpha}{sub 13}, the exact mechanism of the stimulation has remained unclear. Using combined studies with small angle x-ray scattering, biochemistry, and mutagenesis, we identify an additional binding site for activated G{alpha}{sub 13} in the DH domain of p115. Small angle x-ray scattering reveals that the helical domain of G{alpha}{sub 13} docks onto the DH domain, opposite to the surface of DH that binds RhoA. Mutation of a single tryptophan residue in the {alpha}3b helix of DH reduces binding to activated G{alpha}{sub 13} and ablates the stimulation of p115 by G{alpha}{sub 13}. Complementary mutations at the predicted DH-binding site in the {alpha}B-{alpha}C loop of the helical domain of G{alpha}{sub 13} also affect stimulation of p115 by G{alpha}{sub 13}. Although the GAP activity of p115 is not required for stimulation by G{alpha}{sub 13}, two hydrophobic motifs in RH outside of the consensus RGS box are critical for this process. Therefore, the binding of G{alpha}{sub 13} to the RH domain facilitates direct association of G{alpha}{sub 13} to the DH domain to regulate its exchange activity. This study provides new insight into the mechanism of regulation of the RGS-RhoGEF and broadens our understanding of G protein signaling.

  2. Simulation of Infrared Laser Heating of Silica Using Heat Conduction and Multifrequency Radiation Diffusion Equations Adapted for Homogeneous Refractive Lossy Media

    SciTech Connect (OSTI)

    Shestakov, A I; Matthews, M J; Vignes, R M; Stolken, J S

    2010-10-28T23:59:59.000Z

    Localized, transient heating of materials using micro-scale, highly absorbing laser light has been used in many industries to anneal, melt and ablate material with high precision. Accurate modeling of the relative contributions of conductive, convective and radiative losses as a function of laser parameters is essential to optimizing micro-scale laser processing of materials. In bulk semi-transparent materials such as silicate glass melts, radiation transport is known to play a significantly larger role as the temperature increases. Conventionally, radiation is treated in the frequency-averaged diffusive limit (Rosseland approximation). However, the role and proper treatment of radiative processes under rapidly heated, high thermal gradient conditions, often created through laser-matter interactions, is at present not clear. Starting from the radiation transport equation for homogeneous, refractive lossy media, they derive the corresponding time-dependent multi-frequency diffusion equations. Zeroth and first moments of the transport equation couple the energy density, flux and pressure tensor. The system is closed by neglecting the temporal derivative of the flux and replacing the pressure tensor by its diagonal analogue. The radiation equations are coupled to a diffusion equation for the matter temperature. They are interested in modeling infrared laser heating of silica over sub-millimeter length scales, and at possibly rapid rates. Hence, in contrast to related work, they retain the temporal derivative of the radiation field. They derive boundary conditions at a planar air-silica interface taking account of reflectivities obtained from the Fresnel relations that include absorption. The effect of a temperature-dependent absorption index is explored through construction of a multi-phonon dielectric function that includes mode dispersion. The spectral dimension is discretized into a finite number of intervals yielding a system of multigroup diffusion equations. Simulations are presented. To demonstrate the bulk heat loss due to radiation and the effect of the radiation's temporal derivative, they model cooling of a silica slab, initially at 2500 K, for 10 s. Retaining the derivative enables correctly modeling the loss of photons initially present in the slab. Other simulations model irradiating silica discs (of approximately 5 mm radii and thickness) with a CO2 laser: {lambda} = 10.59 and 4.6 um, Gaussian profile, r{sub 0} = 0.5 mm for 1/e decay. By surrounding the disks in room-temperature air, they make use of the boundary conditions described above.

  3. Atomistic modeling of intrinsic and radiation-enhanced fission gas (Xe) diffusion in UO2 +/- x: Implications for nuclear fuel performance modeling

    SciTech Connect (OSTI)

    Giovanni Pastore; Michael R. Tonks; Derek R. Gaston; Richard L. Williamson; David Andrs; Richard Martineau

    2014-03-01T23:59:59.000Z

    Based on density functional theory (DFT) and empirical potential calculations, the diffusivity of fission gas atoms (Xe) in UO2 nuclear fuel has been calculated for a range of non-stoichiometry (i.e. UO2x), under both out-of-pile (no irradiation) and in-pile (irradiation) conditions. This was achieved by first deriving expressions for the activation energy that account for the type of trap site that the fission gas atoms occupy, which includes the corresponding type of mobile cluster, the charge state of these defects and the chemistry acting as boundary condition. In the next step DFT calculations were used to estimate migration barriers and internal energy contributions to the thermodynamic properties and calculations based on empirical potentials were used to estimate defect formation and migration entropies (i.e. pre-exponentials). The diffusivities calculated for out-of-pile conditions as function of the UO2x nonstoichiometrywere used to validate the accuracy of the diffusion models and the DFT calculations against available experimental data. The Xe diffusivity is predicted to depend strongly on the UO2x non-stoichiometry due to a combination of changes in the preferred Xe trap site and in the concentration of uranium vacancies enabling Xe diffusion, which is consistent with experiments. After establishing the validity of the modeling approach, it was used for studying Xe diffusion under in-pile conditions, for which experimental data is very scarce. The radiation-enhanced Xe diffusivity is compared to existing empirical models. Finally, the predicted fission gas diffusion rates were implemented in the BISON fuel performance code and fission gas release from a Risø fuel rod irradiation experiment was simulated. 2014 Elsevier B.V. All rights

  4. Development of Simplified Calculations for a Multipyranometer Array for the Measurement of Direct and Diffuse Solar Radiation 

    E-Print Network [OSTI]

    Munger, B. K.; Haberl, J. S.

    2000-01-01T23:59:59.000Z

    studies due several new features, including: the incorporation of an artificial horizon that prevents reflected ground radiation from striking the tilted sensors, and a routine that corrects the spectral response of photovoltaic-type sensors used...

  5. Cardiac Mortality in Patients With Stage I and II Diffuse Large B-Cell Lymphoma Treated With and Without Radiation: A Surveillance, Epidemiology, and End-Results Analysis

    SciTech Connect (OSTI)

    Pugh, Thomas J., E-mail: thomas.pugh@ucdenver.ed [Department of Radiation Oncology, University of Colorado Comprehensive Cancer Center, Aurora, Colorado (United States); Ballonoff, Ari; Rusthoven, Kyle E.; McCammon, Robert; Kavanagh, Brian; Newman, Francis; Rabinovitch, Rachel [Department of Radiation Oncology, University of Colorado Comprehensive Cancer Center, Aurora, Colorado (United States)

    2010-03-01T23:59:59.000Z

    Purpose: Standard therapy for stage I and II diffuse large B-cell lymphoma consists of combined modality therapy with anthracycline-based chemotherapy, anti-CD20 antibody, and radiation therapy (RT). Curative approaches without RT typically utilize more intensive and/or protracted chemotherapy schedules. Anthracycline-based chemotherapy regimens are associated with a dose-dependent risk of left ventricular systolic dysfunction. We hypothesize that patients treated without RT, i.e., those who are treated with greater total chemotherapy cycles and hence cumulative anthracycline exposure, are at increased risk of cardiac mortality. Methods and Materials: The rate of cardiac-specific mortality (CSM) was analyzed in patients with stage I and II diffuse large B-cell lymphoma diagnosed between 1988 and 2004 by querying the National Cancer Institute Surveillance, Epidemiology, and End-Results database. Analyzable data included gender, age, race, stage, presence of extranodal disease, and RT administration. Results: A total of 15,454 patients met selection criteria; 6,021 (39%) patients received RT. The median follow-up was 36 months (range, 6-180 months). The median age was 64 years. The actuarial incidence rates of CSM at 5, 10, and 15 years were 4.3%, 9.0%, and 13.8%, respectively, in patients treated with RT vs. 5.9%, 10.8% and 16.1%, respectively, in patients treated without RT (p < 0.0001; hazard ratio, 1.35; 95% confidence interval [CI]: 1.16-1.56). The increase in cardiac deaths for patients treated without RT persisted throughout the follow-up period. On multivariate analysis, treatment without RT remained independently associated with an increased risk of CSM (Cox hazard ratio, 1.32; 95% CI: 1.13-1.54; p = 0.0005). Conclusions: Increased anthracycline exposure in patients treated only with chemotherapy regimens may result in an increase in cardiac deaths, detectable only through analysis of large sample sizes. Confirmatory evaluation through meta-analysis of randomized data and design of large prospective trials is warranted.

  6. Impact of Consolidation Radiation Therapy in Stage III-IV Diffuse Large B-cell Lymphoma With Negative Post-Chemotherapy Radiologic Imaging

    SciTech Connect (OSTI)

    Dorth, Jennifer A., E-mail: jennifer.dorth@duke.edu [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Prosnitz, Leonard R. [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States)] [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Broadwater, Gloria [Cancer Statistical Center, Duke University Medical Center, Durham, North Carolina (United States)] [Cancer Statistical Center, Duke University Medical Center, Durham, North Carolina (United States); Diehl, Louis F.; Beaven, Anne W. [Department of Medicine, Division of Medical Oncology, Duke University Medical Center, Durham, North Carolina (United States)] [Department of Medicine, Division of Medical Oncology, Duke University Medical Center, Durham, North Carolina (United States); Coleman, R. Edward [Department of Radiology, Division of Nuclear Medicine, Duke University Medical Center, Durham, North Carolina (United States)] [Department of Radiology, Division of Nuclear Medicine, Duke University Medical Center, Durham, North Carolina (United States); Kelsey, Chris R. [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States)] [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States)

    2012-11-01T23:59:59.000Z

    Purpose: While consolidation radiation therapy (i.e., RT administered after chemotherapy) is routine treatment for patients with early-stage diffuse large B-cell lymphoma (DLBCL), the role of consolidation RT in stage III-IV DLBCL is controversial. Methods and Materials: Cases of patients with stage III-IV DLBCL treated from 1991 to 2009 at Duke University, who achieved a complete response to chemotherapy were reviewed. Clinical outcomes were calculated using the Kaplan-Meier method and were compared between patients who did and did not receive RT, using the log-rank test. A multivariate analysis was performed using Cox proportional hazards model. Results: Seventy-nine patients were identified. Chemotherapy (median, 6 cycles) consisted of anti-CD20 antibody rituximab combined with cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP; 65%); cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP; 22%); or other (13%). Post-chemotherapy imaging consisted of positron emission tomography (PET)/computed tomography (CT) (73%); gallium with CT (14%); or CT only (13%). Consolidation RT (median, 25 Gy) was given to involved sites of disease in 38 (48%) patients. Receipt of consolidation RT was associated with improved in-field control (92% vs. 69%, respectively, p = 0.028) and event-free survival (85% vs. 65%, respectively, p = 0.014) but no difference in overall survival (85% vs. 78%, respectively, p = 0.15) when compared to patients who did not receive consolidation RT. On multivariate analysis, no RT was predictive of increased risk of in-field failure (hazard ratio [HR], 8.01, p = 0.014) and worse event-free survival (HR, 4.3, p = 0.014). Conclusions: Patients with stage III-IV DLBCL who achieve negative post-chemotherapy imaging have improved in-field control and event-free survival with low-dose consolidation RT.

  7. Hierarchical diffusion

    SciTech Connect (OSTI)

    Bachas, C.P.

    1988-02-01T23:59:59.000Z

    We review the solution and properties of the diffusion equation in a hierarchical or ultrametric space. 11 refs.

  8. THE EFFECT OF CIRCUMSOLAR RADIATION ON THE ACCURACY OF PYRHELIOMETER MEASUREMENTS OF THE DIRECT SOLAR RADIATION

    E-Print Network [OSTI]

    Grether, D.

    2012-01-01T23:59:59.000Z

    r Presented at the Solar Radiation workshop of Solar Rising,MEASUREMENTS OF THE DIRECT SOLAR RADIATION D. Grether, D.Diffuse, and Total Solar Radiation," Solar Energy, vol. 4,

  9. A Search for a keV Signature of Radiatively Decaying Dark Matter with Suzaku XIS Observations of the X-ray Diffuse Background

    E-Print Network [OSTI]

    Sekiya, Norio; Mitsuda, Kazuhisa

    2015-01-01T23:59:59.000Z

    We performed the deepest search for an X-ray emission line between 0.5 and 7 keV from non-baryonic dark matter with the Suzaku XIS. Dark matter associated with the Milky Way galaxy was selected as the target to obtain the best signal-to-noise ratio. From the Suzaku archive, we selected 187 data sets of blank sky regions which were dominated by the X-ray diffuse background. The data sets were from 2005 to 2013. Instrumental responses were adjusted by multiple calibration data sets of the Crab Nebula. We also improved the technique of subtracting lines of instrumental origin. These energy spectra were well described by X-ray emission due to charge exchange around the Solar System, hot plasma in and around the Milky Way and superposition of extra-galactic point sources. A signal of a narrow emission line was searched for, and the significance of detection was evaluated in consideration of the blind search method (the Look-elsewhere Effect). Our results exhibited no significant detection of an emission line featu...

  10. Radiation and porosity effects on the magnetohydrodynamic flow near a vertical plate that applies shear stress to the fluid with mass diffusion

    SciTech Connect (OSTI)

    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.

  11. Effects of turbulent diffusion on the chemistry of diffuse clouds

    E-Print Network [OSTI]

    P. Lesaffre; M. Gerin; P. Hennebelle

    2007-04-24T23:59:59.000Z

    Aims. We probe the effect of turbulent diffusion on the chemistry at the interface between a cold neutral medium (CNM) cloudlet and the warm neutral medium (WNM). Methods. We perform moving grid, multifluid, 1D, hydrodynamical simulations with chemistry including thermal and chemical diffusion. The diffusion coefficients are enhanced to account for turbulent diffusion. We post-process the steady-states of our simulations with a crude model of radiative transfer to compute line profiles. Results. Turbulent diffusion spreads out the transition region between the CNM and the WNM. We find that the CNM slightly expands and heats up: its CH and H$_2$ content decreases due to the lower density. The change of physical conditions and diffusive transport increase the H$^+$ content in the CNM which results in increased OH and H$_2$O. Diffusion transports some CO out of the CNM. It also brings H$_2$ into contact with the warm gas with enhanced production of CH$^+$, H$_3^+$, OH and H$_2$O at the interface. O lines are sensitive to the spread of the thermal profile in the intermediate region between the CNM and the WNM. Enhanced molecular content at the interface of the cloud broadens the molecular line profiles and helps exciting transitions of intermediate energy. The relative molecular yield are found higher for bigger clouds. Conclusions. Turbulent diffusion can be the source of additional molecular production and should be included in chemical models of the interstellar medium (ISM). It also is a good candidate for the interpretation of observational problems such as warm H$_2$, CH$^+$ formation and presence of H$_3^+$.

  12. Is Arnold diffusion relevant to global diffusion?

    E-Print Network [OSTI]

    Seiichiro Honjo; Kunihiko Kaneko

    2003-07-27T23:59:59.000Z

    Global diffusion of Hamiltonian dynamical systems is investigated by using a coupled standard maps. Arnold web is visualized in the frequency space, using local rotation numbers, while Arnold diffusion and resonance overlaps are distinguished by the residence time distributions at resonance layers. Global diffusion in the phase space is shown to be accelerated by diffusion across overlapped resonances generated by the coupling term, rather than Arnold diffusion along the lower-order resonances. The former plays roles of hubs for transport in the phase space, and accelerate the diffusion.

  13. Parallel flow diffusion battery

    DOE Patents [OSTI]

    Yeh, H.C.; Cheng, Y.S.

    1984-01-01T23:59:59.000Z

    A parallel flow diffusion battery for determining the mass distribution of an aerosol has a plurality of diffusion cells mounted in parallel to an aerosol stream, each diffusion cell including a stack of mesh wire screens of different density.

  14. THE DIFFUSION APPROXIMATION FOR THE LINEAR BOLTZMANN EQUATION

    E-Print Network [OSTI]

    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

  15. Microfabricated diffusion source

    DOE Patents [OSTI]

    Oborny, Michael C. (Albuquerque, NM); Frye-Mason, Gregory C. (Cedar Crest, NM); Manginell, Ronald P. (Albuquerque, NM)

    2008-07-15T23:59:59.000Z

    A microfabricated diffusion source to provide for a controlled diffusion rate of a vapor comprises a porous reservoir formed in a substrate that can be filled with a liquid, a headspace cavity for evaporation of the vapor therein, a diffusion channel to provide a controlled diffusion of the vapor, and an outlet to release the vapor into a gas stream. The microfabricated diffusion source can provide a calibration standard for a microanalytical system. The microanalytical system with an integral diffusion source can be fabricated with microelectromechanical systems technologies.

  16. Continental-scale net radiation and evapotranspiration estimated using MODIS satellite observations

    E-Print Network [OSTI]

    Jin, Yufang; Randerson, James T.; Goulden, Michael L.

    2011-01-01T23:59:59.000Z

    mean direct and diffuse radiation data from the GEWEX/SRBa new generation of radiation budget data that use up to 11Project Surface Radiation Budget (GAPP/SRB) data (http://

  17. Thermo-quantum diffusion

    E-Print Network [OSTI]

    Roumen Tsekov

    2011-04-15T23:59:59.000Z

    A new approach to thermo-quantum diffusion is proposed and a nonlinear quantum Smoluchowski equation is derived, which describes classical diffusion in the field of the Bohm quantum potential. A nonlinear thermo-quantum expression for the diffusion front is obtained, being a quantum generalization of the classical Einstein law. The quantum diffusion at zero temperature is also described and a new dependence of the position dispersion on time is derived. A stochastic Bohm-Langevin equation is also proposed.

  18. SOLAR CELL BASED PYRANOMETERS: EVALUATION OF THE DIFFUSE RESPONSE Frank Vignola

    E-Print Network [OSTI]

    Oregon, University of

    260 SOLAR CELL BASED PYRANOMETERS: EVALUATION OF THE DIFFUSE RESPONSE Frank Vignola Department The responsivity to diffuse radiation of a solar cell based pyranometer is studied. Diffuse measurements are made of the LiCor pyranometer is presented. Implication of the spectral dependence of the solar cell based

  19. Simple Waves in Ideal Radiation Hydrodynamics

    E-Print Network [OSTI]

    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.

  20. Oxygen diffusion in titanite: Lattice diffusion and fast-path diffusion in single crystals

    E-Print Network [OSTI]

    Watson, E. Bruce

    Oxygen diffusion in titanite: Lattice diffusion and fast-path diffusion in single crystals X June 2006 Editor: P. Deines Abstract Oxygen diffusion in natural and synthetic single-crystal titanite be recognized as responsible for oxygen diffusion. The diffusion profiles showed two segments: a steep one close

  1. Glass Membrane For Controlled Diffusion Of Gases

    DOE Patents [OSTI]

    Shelby, James E. (Alfred Station, NY); Kenyon, Brian E. (Pittsburgh, PA)

    2001-05-15T23:59:59.000Z

    A glass structure for controlled permeability of gases includes a glass vessel. The glass vessel has walls and a hollow center for receiving a gas. The glass vessel contains a metal oxide dopant formed with at least one metal selected from the group consisting of transition metals and rare earth metals for controlling diffusion of the gas through the walls of the glass vessel. The vessel releases the gas through its walls upon exposure to a radiation source.

  2. 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,...

  3. Tungsten diffusion in silicon

    SciTech Connect (OSTI)

    De Luca, A.; Texier, M.; Burle, N.; Oison, V.; Pichaud, B. [Aix-Marseille Université, IM2NP UMR 7334, Faculté des Sciences et Techniques, Campus de Saint-Jérôme, Avenue Escadrille Normandie Niemen - Case 142, F-13397 Marseille Cedex (France); Portavoce, A., E-mail: alain.portavoce@im2np.fr [CNRS, IM2NP UMR 7334, Faculté des Sciences et Techniques, Campus de Saint-Jérôme, Avenue Escadrille Normandie Niemen - Case 142, F-13397 Marseille Cedex (France); Grosjean, C. [STMicroelectronics, Rousset (France)

    2014-01-07T23:59:59.000Z

    Two doses (10{sup 13} and 10{sup 15}?cm{sup ?2}) of tungsten (W) atoms were implanted in different Si(001) wafers in order to study W diffusion in Si. The samples were annealed or oxidized at temperatures between 776 and 960?°C. The diffusion profiles were measured by secondary ion mass spectrometry, and defect formation was studied by transmission electron microscopy and atom probe tomography. W is shown to reduce Si recrystallization after implantation and to exhibit, in the temperature range investigated, a solubility limit close to 0.15%–0.2%, which is higher than the solubility limit of usual metallic impurities in Si. W diffusion exhibits unusual linear diffusion profiles with a maximum concentration always located at the Si surface, slower kinetics than other metals in Si, and promotes vacancy accumulation close to the Si surface, with the formation of hollow cavities in the case of the higher W dose. In addition, Si self-interstitial injection during oxidation is shown to promote W-Si clustering. Taking into account these observations, a diffusion model based on the simultaneous diffusion of interstitial W atoms and W-Si atomic pairs is proposed since usual models used to model diffusion of metallic impurities and dopants in Si cannot reproduce experimental observations.

  4. Solar and Infrared Radiation Station (SIRS) Handbook

    SciTech Connect (OSTI)

    Stoffel, T

    2005-07-01T23:59:59.000Z

    The Solar Infrared Radiation Station (SIRS) provides continuous measurements of broadband shortwave (solar) and longwave (atmospheric or infrared) irradiances for downwelling and upwelling components. The following six irradiance measurements are collected from a network of stations to help determine the total radiative flux exchange within the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) Climate Research Facility: • Direct normal shortwave (solar beam) • Diffuse horizontal shortwave (sky) • Global horizontal shortwave (total hemispheric) • Upwelling shortwave (reflected) • Downwelling longwave (atmospheric infrared) • Upwelling longwave (surface infrared)

  5. E-Print Network 3.0 - annihilation radiation telescope Sample...

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

    Collection: Physics 3 MPI Kernphysik, Heidelberg Humboldt Univ. Berlin Summary: Gamma ray bursts Cosmology Diffuse extragalactic radiation fields via cutoff in AGN spectra and...

  6. Journal Diffusion Factors a measure of diffusion? Tove Faber Frandsen

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Journal Diffusion Factors ­ a measure of diffusion? Tove Faber Frandsen Royal School of Library In this paper we show that the measure of diffusion introduced by Ian Rowlands called the Journal Diffusion Factor (JDF) is highly negatively correlated with the number of citations, leading highly cited journals

  7. Characterization of RopGEFs in maize

    E-Print Network [OSTI]

    Lee, Ah Young

    2011-01-01T23:59:59.000Z

    Dedicator of Cytokinesis) proteins lack the conventional DHThe lack of correspondence between maize proteins recognizedlack of chaperones leading to incorrect folding of proteins

  8. Global Environment Facility (GEF) | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation, search OpenEI Reference LibraryAdd toWell2008)Information GlobalGlobal

  9. Global Environment Facility (GEF) | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation, search OpenEI Reference LibraryAdd toWell2008)Information GlobalGlobalGlobal

  10. Danger radiations

    ScienceCinema (OSTI)

    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.

  11. OXYGEN DIFFUSION IN HYPOSTOICHIOMETRIC URANIUM DIOXIDE

    E-Print Network [OSTI]

    Kim, Kee Chul

    2010-01-01T23:59:59.000Z

    Research Division OXYGEN DIFFUSION IN HYPOSTOICHIOMETRIC11905 -DISCLAIMER - OXYGEN DIFFUSION IN HYPOSTOICHIOMETRICc o n e e n i g woroxygen self-diffusion coefficient

  12. Ultra high temperature diffusion apparatus and operating procedures

    SciTech Connect (OSTI)

    Wyrick, S.B.

    1985-11-15T23:59:59.000Z

    It is the purpose of this paper to present an experimental apparatus which is capable of measuring diffusion coefficients of interdiffusing gases in the temperature range 300K to 2500K. Because of the high temperatures which will be encountered, a special alloy of tantalum (T-111) is used to house the diffusion process. This T-111 diffusion cell is heated via radiation heat from a tungsten heating element powered by a Saban saturable reactor power supply. The diffusion cell heating element are encased in a nickel-plated copper cooling can. This entire assembly is enclosed in an Ultek vacuum chamber to prevent oxidation of the diffusion cell. This report covers the construction and calibration of the diffusion cell, details of the gas loading and sampling system, and complete information on the components required to operate the vacuum furnace. Thus far, several experiments have been run in the temperature range 600K to 800K and the resulting diffusion coefficients agree fairly well with previously published values. 21 refs., 9 figs., 4 tabs.

  13. Peridynamic thermal diffusion

    SciTech Connect (OSTI)

    Oterkus, Selda [Department of Aerospace and Mechanical Engineering, The University of Arizona, Tucson, AZ 85721 (United States); Madenci, Erdogan, E-mail: madenci@email.arizona.edu [Department of Aerospace and Mechanical Engineering, The University of Arizona, Tucson, AZ 85721 (United States); Agwai, Abigail [Intel Corporation, Chandler, AZ 85226 (United States)

    2014-05-15T23:59:59.000Z

    This study presents the derivation of ordinary state-based peridynamic heat conduction equation based on the Lagrangian formalism. The peridynamic heat conduction parameters are related to those of the classical theory. An explicit time stepping scheme is adopted for numerical solution of various benchmark problems with known solutions. It paves the way for applying the peridynamic theory to other physical fields such as neutronic diffusion and electrical potential distribution.

  14. Solar Radiation Modeling and Measurements for Renewable Energy Applications: Data and Model Quality; Preprint

    SciTech Connect (OSTI)

    Myers, D. R.

    2003-03-01T23:59:59.000Z

    Measurement and modeling of broadband and spectral terrestrial solar radiation is important for the evaluation and deployment of solar renewable energy systems. We discuss recent developments in the calibration of broadband solar radiometric instrumentation and improving broadband solar radiation measurement accuracy. An improved diffuse sky reference and radiometer calibration and characterization software and for outdoor pyranometer calibrations is outlined. Several broadband solar radiation model approaches, including some developed at the National Renewable Energy Laboratory, for estimating direct beam, total hemispherical and diffuse sky radiation are briefly reviewed. The latter include the Bird clear sky model for global, direct beam, and diffuse terrestrial solar radiation; the Direct Insolation Simulation Code (DISC) for estimating direct beam radiation from global measurements; and the METSTAT (Meteorological and Statistical) and Climatological Solar Radiation (CSR) models that estimate solar radiation from meteorological data. We conclude that currently the best model uncertainties are representative of the uncertainty in measured data.

  15. Diffusion in silicon isotope heterostructures

    SciTech Connect (OSTI)

    Silvestri, Hughes Howland

    2004-05-14T23:59:59.000Z

    The simultaneous diffusion of Si and the dopants B, P, and As has been studied by the use of a multilayer structure of isotopically enriched Si. This structure, consisting of 5 pairs of 120 nm thick natural Si and {sup 28}Si enriched layers, enables the observation of {sup 30}Si self-diffusion from the natural layers into the {sup 28}Si enriched layers, as well as dopant diffusion from an implanted source in an amorphous Si cap layer, via Secondary Ion Mass Spectrometry (SIMS). The dopant diffusion created regions of the multilayer structure that were extrinsic at the diffusion temperatures. In these regions, the Fermi level shift due to the extrinsic condition altered the concentration and charge state of the native defects involved in the diffusion process, which affected the dopant and self-diffusion. The simultaneously recorded diffusion profiles enabled the modeling of the coupled dopant and self-diffusion. From the modeling of the simultaneous diffusion, the dopant diffusion mechanisms, the native defect charge states, and the self- and dopant diffusion coefficients can be determined. This information is necessary to enhance the physical modeling of dopant diffusion in Si. It is of particular interest to the modeling of future electronic Si devices, where the nanometer-scale features have created the need for precise physical models of atomic diffusion in Si. The modeling of the experimental profiles of simultaneous diffusion of B and Si under p-type extrinsic conditions revealed that both species are mediated by neutral and singly, positively charged Si self-interstitials. The diffusion of As and Si under extrinsic n-type conditions yielded a model consisting of the interstitialcy and vacancy mechanisms of diffusion via singly negatively charged self-interstitials and neutral vacancies. The simultaneous diffusion of P and Si has been modeled on the basis of neutral and singly negatively charged self-interstitials and neutral and singly positively charged P species. Additionally, the temperature dependence of the diffusion coefficient of Si in Ge was measured over the temperature range of 550 C to 900 C using a buried Si layer in an epitaxially grown Ge layer.

  16. Microscopic thermal diffusivity mapping using an infrared camera

    SciTech Connect (OSTI)

    Wang, H.; Dinwiddie, R.B.

    1997-12-31T23:59:59.000Z

    Standard flash thermal diffusivity measurements utilize a single-point infrared detector to measure the average temperature rise of the sample surface after a heat pulse. The averaging of infrared radiation over the sample surface could smear out the microscopic thermal diffusivity variations in some specimens, especially in fiber-reinforced composite materials. A high-speed, high-sensitivity infrared camera was employed in this study of composite materials. With a special microscope attachment, the spatial resolution of the camera can reach 5.4 {micro}m. The images can then be processed to generate microscopic thermal diffusivity maps of the material. SRM 1462 stainless steel was tested to evaluate the accuracy of the system. Thermal diffusivity micrographs of carbon-carbon composites and SCS-6/borosilicate glass were generated. Thermal diffusivity values of the carbon fiber bundles parallel to the heat flow were found to be higher than the matrix material. A thermal coupling effect between SCS-6 fiber and matrix was observed. The thermal coupling and measured thermal diffusivity value of the fiber were also dependent upon the thickness of the specimen.

  17. Radiation detector

    DOE Patents [OSTI]

    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.

  18. Radiation detector

    DOE Patents [OSTI]

    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.

  19. The Harrison Diffusion Kinetics Regimes in Solute Grain Boundary Diffusion

    SciTech Connect (OSTI)

    Belova, Irina [University of Newcastle, NSW, Australia; Fiedler, T [University of Newcastle, NSW, Australia; Kulkarni, Nagraj S [ORNL; Murch, Prof. Graeme [University of Newcastle, NSW, Australia

    2012-01-01T23:59:59.000Z

    Knowledge of the limits of the principal Harrison kinetics regimes (Type-A, B and C) for grain boundary diffusion is very important for the correct analysis of the depth profiles in a tracer diffusion experiment. These regimes for self-diffusion have been extensively studied in the past by making use of the phenomenological Lattice Monte Carlo (LMC) method with the result that the limits are now well established. The relationship of those self-diffusion limits to the corresponding ones for solute diffusion in the presence of solute segregation to the grain boundaries remains unclear. In the present study, the influence of solute segregation on the limits is investigated with the LMC method for the well-known parallel grain boundary slab model by showing the equivalence of two diffusion models. It is shown which diffusion parameters are useful for identifying the limits of the Harrison kinetics regimes for solute grain boundary diffusion. It is also shown how the measured segregation factor from the diffusion experiment in the Harrison Type-B kinetics regime may differ from the global segregation factor.

  20. Ultraviolet-radiation-curable paints

    SciTech Connect (OSTI)

    Grosset, A M; Su, W F.A.; Vanderglas, E

    1981-09-30T23:59:59.000Z

    In product finishing lines, ultraviolet radiation curing of paints on prefabricated structures could be more energy efficient than curing by natural gas fired ovens, and could eliminate solvent emission. Diffuse ultraviolet light can cure paints on three dimensional metal parts. In the uv curing process, the spectral output of radiation sources must complement the absorption spectra of pigments and photoactive agents. Photosensitive compounds, such as thioxanthones, can photoinitiate unsaturated resins, such as acrylated polyurethanes, by a free radical mechanism. Newly developed cationic photoinitiators, such as sulfonium or iodonium salts (the so-called onium salts) of complex metal halide anions, can be used in polymerization of epoxy paints by ultraviolet light radiation. One-coat enamels, topcoats, and primers have been developed which can be photoinitiated to produce hard, adherent films. This process has been tested in a laboratory scale unit by spray coating these materials on three-dimensional objects and passing them through a tunnel containing uv lamps.

  1. Microviscometric studies on thermal diffusion 

    E-Print Network [OSTI]

    Reyna, Eddie

    1959-01-01T23:59:59.000Z

    for its improvement. This in~estigation was supported in part by the Convsir Division of General Dynamics Corporation. TABLE OF CONTENTS Chapter III INTRODUCTION EXPERINENTAL NETHODS AND PROCEDUPJIS Thermal Diffusion Column Viscosity Measurements.... The main interest of 6 tais work was the molecular weight dependence of the thermal diffusion coefficient and the suitability of thermal diffusion as a method of frac- tionation of polymers. Since the work of Debye and Bueche, applications of thermal...

  2. RADIATION SAFETY TRAINING MANUAL Radiation Safety Office

    E-Print Network [OSTI]

    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

  3. Turing instability in reaction-diffusion systems with nonlinear diffusion

    SciTech Connect (OSTI)

    Zemskov, E. P., E-mail: zemskov@ccas.ru [Russian Academy of Sciences, Dorodnicyn Computing Center (Russian Federation)

    2013-10-15T23:59:59.000Z

    The Turing instability is studied in two-component reaction-diffusion systems with nonlinear diffusion terms, and the regions in parametric space where Turing patterns can form are determined. The boundaries between super- and subcritical bifurcations are found. Calculations are performed for one-dimensional brusselator and oregonator models.

  4. Measure of Diffusion Model Error for Thermal Radiation Transport

    E-Print Network [OSTI]

    Kumar, Akansha

    2013-04-19T23:59:59.000Z

    : Conservation equation for the left half of cell, m 1 2 ( i;L;g + i;R;g) i 12 ;g + ;i;g hi 2 i;L;g = hi 2 s;g 4 i;L;g + hi 2 s;g 4 (?+ 12) i;L;g (?) i;L;g ; (7.34a) and for the right half of cell, m i...+ 12 ;g 1 2 ( i;L;g + i;R;g) + ;i;g hi 2 i;R;g = hi 2 s;g 4 i;R;g + hi 2 s;g 4 (?+ 12) i;R;g (?) i;R;g ; (7.34b) m 2 1 p 3 ; 1 p 3 ; (7.35a) i;L;g = +i;L;g + i;L;g 2 ; i...

  5. On Correction of Diffuse Radiation Measured by MFRSR

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for RenewableSpeeding accessSpeedingOctoberResearch &CEATOmar Hurricane,Physics ofOn

  6. Features of the action of low-energy gamma radiation on the hydrogen permeability of certain materials

    SciTech Connect (OSTI)

    Tazhibaeva, I.L.; Bekman, I.N.; Rudenko, N.V.; Shestakov, V.P.

    1985-07-01T23:59:59.000Z

    This paper determines the diffusion coefficients, the constants of permeability, and solubility of hydrogen in palladium, nickel, and Armco iron under the action of low-energy gamma radiation. It was established that without radiation all of the kinetic diffusion curves of hydrogen in palladium and nickel straighten well in a functional scale. In armco iron, some deviations are observed.

  7. Radiation Safety

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's PossibleRadiation Protection Radiation Protection Regulations: The Federal Regulation

  8. Analytical and experimental determination of radiation and temperature distributions inside solar receivers

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    concentrated solar radiation is modelized, using the diffuse and semi-gray surface hypothesis and the net absorptance for solar radiation. Theoretical thermal efficiency of the cavity. Surface hemispherical emittance PHYSIQUE APPLIQU�E - TS, N° 2, F�VRIER1980 Incident solar flux density. Net radiative flux density. Net

  9. DIFFUSION IN SOLIDSDIFFUSION IN SOLIDS FICK'S LAWS

    E-Print Network [OSTI]

    Subramaniam, Anandh

    Diffusion bonding To comprehend many materials related phenomenon one must understand Diffusion. The focusDIFFUSION IN SOLIDSDIFFUSION IN SOLIDS FICK'S LAWS KIRKENDALL EFFECT ATOMIC MECHANISMS Diffusion in Solids P.G. Shewmon McGraw-Hill, New York (1963) #12;Oxidation Roles of Diffusion Creep Aging

  10. Portable vapor diffusion coefficient meter

    DOE Patents [OSTI]

    Ho, Clifford K. (Albuquerque, NM)

    2007-06-12T23:59:59.000Z

    An apparatus for measuring the effective vapor diffusion coefficient of a test vapor diffusing through a sample of porous media contained within a test chamber. A chemical sensor measures the time-varying concentration of vapor that has diffused a known distance through the porous media. A data processor contained within the apparatus compares the measured sensor data with analytical predictions of the response curve based on the transient diffusion equation using Fick's Law, iterating on the choice of an effective vapor diffusion coefficient until the difference between the predicted and measured curves is minimized. Optionally, a purge fluid can forced through the porous media, permitting the apparatus to also measure a gas-phase permeability. The apparatus can be made lightweight, self-powered, and portable for use in the field.

  11. Diffuser for augmenting a wind turbine

    DOE Patents [OSTI]

    Foreman, Kenneth M. (North Bellmore, NY); Gilbert, Barry L. (Westbury, NY)

    1984-01-01T23:59:59.000Z

    A diffuser for augmenting a wind turbine having means for energizing the boundary layer at several locations along the diffuser walls is improved by the addition of a short collar extending radially outward from the outlet of the diffuser.

  12. Radiation receiver

    DOE Patents [OSTI]

    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.

  13. Radiation receiver

    DOE Patents [OSTI]

    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.

  14. Gravitational Radiation

    E-Print Network [OSTI]

    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.

  15. Diffusion-controlled spherulite growth in obsidian inferred from H2O concentration profiles

    SciTech Connect (OSTI)

    Watkins, Jim; Watkins, Jim; Manga, Michael; Huber, Christian; Martin, Michael C.

    2007-11-02T23:59:59.000Z

    Spherulites are spherical clusters of radiating crystals that occur naturally in rhyolitic obsidian. The growth of spherulites requires diffusion and uptake of crystal forming components from the host rhyolite melt or glass, and rejection of non-crystal forming components from the crystallizing region. Water concentration profiles measured by synchrotron-source Fourier transform spectroscopy reveal that water is expelled into the surrounding matrix during spherulite growth, and that it diffuses outward ahead of the advancing crystalline front. We compare these profiles to models of water diffusion in rhyolite to estimate timescales for spherulite growth. Using a diffusion-controlled growth law, we find that spherulites can grow on the order of days to months at temperatures above the glass transition. The diffusion-controlled growth law also accounts for spherulite size distribution, spherulite growth below the glass transition, and why spherulitic glasses are not completely devitrified.

  16. Independent Oversight Review, Portsmouth Gaseous Diffusion Plant...

    Office of Environmental Management (EM)

    January 2013 Independent Oversight Review, Portsmouth Gaseous Diffusion Plant - January 2013 January 2013 Review of the Portsmouth Gaseous Diffusion Plant Work Planning and Control...

  17. Independent Activity Report, Portsmouth Gaseous Diffusion Plant...

    Office of Environmental Management (EM)

    Portsmouth Gaseous Diffusion Plant - August 2011 Independent Activity Report, Portsmouth Gaseous Diffusion Plant - August 2011 August 2011 Orientation Visit to the Portsmouth...

  18. Hot carrier diffusion in graphene

    E-Print Network [OSTI]

    Ruzicka, Brian Andrew; Wang, Shuai; Werake, Lalani Kumari; Weintrub, Ben; Loh, Kian Ping; Zhao, Hui

    2010-11-01T23:59:59.000Z

    We report an optical study of charge transport in graphene. Diffusion of hot carriers in epitaxial graphene and reduced graphene oxide samples are studied using an ultrafast pump-probe technique with a high spatial resolution. Spatiotemporal...

  19. 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...

  20. Microviscometric studies on thermal diffusion

    E-Print Network [OSTI]

    Reyna, Eddie

    1959-01-01T23:59:59.000Z

    proportions until Clusiui and Dickel introduced a type of therrail diffusion column 4 which caused a thermal circul~tion in addition to thermal diffusion. With tni' equipment they were able to separate chlorine isotopes. Applying this same method..., it was decided to . onstruct equipment which could measure the viscosity and concentration of 0. 1 ml. samples. It was desired to have the reproduceability of the viscosimeter better than I'X since the dilute solutions to be studied had maximum viscosities...

  1. Boron diffusion in silicon devices

    DOE Patents [OSTI]

    Rohatgi, Ajeet (Atlanta, GA); Kim, Dong Seop (Atlanta, GA); Nakayashiki, Kenta (Smyrna, GA); Rounsaville, Brian (Stockbridge, GA)

    2010-09-07T23:59:59.000Z

    Disclosed are various embodiments that include a process, an arrangement, and an apparatus for boron diffusion in a wafer. In one representative embodiment, a process is provided in which a boric oxide solution is applied to a surface of the wafer. Thereafter, the wafer is subjected to a fast heat ramp-up associated with a first heating cycle that results in a release of an amount of boron for diffusion into the wafer.

  2. Diffusion-driven and excitation-dependent recombination rate in blue InGaN/GaN quantum well structures

    SciTech Connect (OSTI)

    Aleksiej?nas, R.; Gelžinyt?, K.; Nargelas, S., E-mail: saulius.nargelas@ff.vu.lt; Jaraši?nas, K. [Department of Semiconductor Optoelectronics, Institute of Applied Research, Vilnius University, Saul?tekio 9–III, 10222 Vilnius (Lithuania); Vengris, M. [Laser Research Center, Vilnius University, Saul?tekio 10, 10223 Vilnius (Lithuania); Armour, E. A.; Byrnes, D. P.; Arif, R. A.; Lee, S. M.; Papasouliotis, G. D. [Veeco Instruments, Turbodisc Operations, 394 Elizabeth Avenue, Somerset, New Jersey 08873 (United States)

    2014-01-13T23:59:59.000Z

    We report on diffusion-driven and excitation-dependent carrier recombination rate in multiple InGaN/GaN quantum wells by using photoluminescence, light-induced absorption, and diffraction techniques. We demonstrate gradually increasing with excitation carrier diffusivity and its correlation with the recombination rate. At low carrier densities, an increase in radiative emission and carrier lifetime was observed due to partial saturation of non-radiative recombination centers. However, at carrier densities above ?5?×?10{sup 18}?cm{sup ?3}, a typical value of photoluminescence efficiency droop, a further increase of diffusivity forces the delocalized carriers to face higher number of fast non-radiative recombination centers leading to an increase of non-radiative losses.

  3. Nonlinear Data Transformation with Diffusion Map

    E-Print Network [OSTI]

    ) Others: Laplacian eigenmaps, Hessian eigenmaps, LTSA We apply the diffusion map (Coifman & Lafon 2006

  4. Evaluation of Arctic Broadband Surface Radiation Measurements

    SciTech Connect (OSTI)

    Matsui, N.; Long, Charles N.; Augustine, J. A.; Halliwell, D.; Uttal, Taneil; Longenecker, D.; Niebergale, J.; Wendell, J.; Albee, R.

    2012-02-24T23:59:59.000Z

    The Arctic is a challenging environment for making in-situ radiation measurements. A standard suite of radiation sensors is typically designed to measure the total, direct and diffuse components of incoming and outgoing broadband shortwave (SW) and broadband thermal infrared, or longwave (LW) radiation. Enhancements can include various sensors for measuring irradiance in various narrower bandwidths. Many solar radiation/thermal infrared flux sensors utilize protective glass domes and some are mounted on complex mechanical platforms (solar trackers) that rotate sensors and shading devices that track the sun. High quality measurements require striking a balance between locating sensors in a pristine undisturbed location free of artificial blockage (such as buildings and towers) and providing accessibility to allow operators to clean and maintain the instruments. Three significant sources of erroneous data include solar tracker malfunctions, rime/frost/snow deposition on the instruments and operational problems due to limited operator access in extreme weather conditions. In this study, a comparison is made between the global and component sum (direct [vertical component] + diffuse) shortwave measurements. The difference between these two quantities (that theoretically should be zero) is used to illustrate the magnitude and seasonality of radiation flux measurement problems. The problem of rime/frost/snow deposition is investigated in more detail for one case study utilizing both shortwave and longwave measurements. Solutions to these operational problems are proposed that utilize measurement redundancy, more sophisticated heating and ventilation strategies and a more systematic program of operational support and subsequent data quality protocols.

  5. Soot formation and temperature field structure in co-flow laminar methaneair diffusion flames

    E-Print Network [OSTI]

    Gülder, Ömer L.

    at higher pressures mean that the thermal diffusion from the hot regions of the flame towards the flame of the spread of unwanted fires. Soot radiation is the major heat load on combustor components causing mainte gas turbine combustors operate at elevated pressures, our understanding of the effects of pressure

  6. Hindered diffusion of coal liquids

    SciTech Connect (OSTI)

    Tsotsis, T.T.; Sahimi, M. (University of Southern California, Los Angeles, CA (United States). Dept. of Chemical Engineering); Webster, I.A. (Unocal Corp., Los Angeles, CA (United States))

    1992-01-01T23:59:59.000Z

    The molecules comprising coal liquids can range from less than 10 to several hundred [angstrom] in diameter. Their size is, therefore, comparable to the average pore size of most hydroprocessing catalysts. Thus, during processing, transport of these molecules into the catalyst occurs mainly by configurational'' or hindered diffusion,'' which is the result of two phenomena occurring in the pores; the distribution of solute molecules in the pores is affected by the pores and the solute molecules experience an increased hydrodynamic drag. The field of hindered diffusion has been reviewed by Deen [16]. The earliest studies in the filed were by Renkin et al. [17].

  7. Prediction of Room Air Diffusion for Reduced Diffuser Flow Rates 

    E-Print Network [OSTI]

    Gangisetti, Kavita

    2011-02-22T23:59:59.000Z

    and analytical tool for investigating ventilation inside the system and thus to increase thermal comfort and improve indoor air quality. The room air supply diffuser flow rates can be reduced for less loading with the help of a variable air volume unit...

  8. Portsmouth Gaseous Diffusion Plant environmental report for 1991

    SciTech Connect (OSTI)

    Williams, M.F. (ed.)

    1992-10-01T23:59:59.000Z

    This calendar year (CY) 1991 annual report on environmental surveillance of the US Department of Energy's (DOE's) Portsmouth Gaseous Diffusion Plant (PORTS) and its environs consists of two parts: narrative, summaries, and conclusions (Part 1), and data presentation (Part 2). Environmental-monitoring systems at PORTS include emission-monitoring networks for air and surface water discharges; waste sampling and characterization; and ambient-sampling networks for air, surface water, groundwater, drinking water, vegetation (cattle forage), food crops, fish, soil, creek and river sediments, and direct (gamma) radiation levels.

  9. Turbulent Particle Acceleration in the Diffuse Cluster Plasma

    E-Print Network [OSTI]

    J. A. Eilek; J. C. Weatherall

    1999-06-30T23:59:59.000Z

    In situ particle acceleration is probably occuring in cluster radio haloes. This is suggested by the uniformity and extent of the haloes, given that spatial diffusion is slow and that radiative losses limit particle lifetimes. Stochastic acceleration by plasma turbulence is the most likely mechanism. Alfven wave turbulence has been suggested as the means of acceleration, but it is too slow to be important in the cluster environment. We propose, instead, that acceleration occurs via strong lower-hybrid wave turbulence. We find that particle acceleration will be effective in clusters if only a small fraction of the cluster energy density is in this form.

  10. Beta Diffusion Trees Creighton Heaukulani

    E-Print Network [OSTI]

    Edinburgh, University of

    Beta Diffusion Trees Creighton Heaukulani CKH28@CAM.AC.UK David A. Knowles DAVIDKNOWLES Stanford University, Department of Computer Science, Stanford, CA, USA Abstract We define the beta structures over clusters of the particles. With the beta diffu- sion tree, however, multiple copies

  11. Flux-Limited Diffusion Approximation Models of Giant Planet Formation by Disk Instability

    E-Print Network [OSTI]

    Boss, Alan P

    2008-01-01T23:59:59.000Z

    Both core accretion and disk instability appear to be required as formation mechanisms in order to explain the entire range of giant planets found in extrasolar planetary systems. Disk instability is based on the formation of clumps in a marginally-gravitationally unstable protoplanetary disk. These clumps can only be expected to contract and survive to become protoplanets if they are able to lose thermal energy through a combination of convection and radiative cooling. Here we present several new three dimensional, radiative hydrodynamics models of self-gravitating protoplanetary disks, where radiative transfer is handled in the flux-limited diffusion approximation. We show that while the flux-limited models lead to higher midplane temperatures than in a diffusion approximation model without the flux-limiter, the difference in temperatures does not appear to be sufficiently high to have any significant effect on the formation of self-gravitating clumps. Self-gravitating clumps form rapidly in the models both...

  12. Adaptors for radiation detectors

    DOE Patents [OSTI]

    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.

  13. Radiation dosimeters

    DOE Patents [OSTI]

    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.

  14. Adsorption, Desorption, and Diffusion of Nitrogen in a Model...

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

    II. Diffusion Limited Kinetics in Amorphous Adsorption, Desorption, and Diffusion of Nitrogen in a Model Nanoporous Material: II. Diffusion Limited Kinetics in Amorphous Abstract:...

  15. Uranium(VI) Diffusion in Low-Permeability Subsurface Materials...

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

    Uranium(VI) Diffusion in Low-Permeability Subsurface Materials. Uranium(VI) Diffusion in Low-Permeability Subsurface Materials. Abstract: Uranium(VI) diffusion was investigated in...

  16. Bioaugmentation for Reduction of Diffuse Pesticide Contamination

    E-Print Network [OSTI]

    Bioaugmentation for Reduction of Diffuse Pesticide Contamination A Bioprophylactic Concept Karin/Repro, Uppsala 2013 #12;Bioaugmentation for Reduction of Diffuse Pesticide Contamination. A Bioprophylactic Concept. Abstract Pesticides and their residues frequently contaminate surface waters and groundwater so

  17. Synergistic diffuser/heat-exchanger design

    E-Print Network [OSTI]

    Lazzara, David S. (David Sergio), 1980-

    2004-01-01T23:59:59.000Z

    The theoretical and numerical evaluation of synergistic diffusing heat-exchanger design is presented. Motivation for this development is based on current diffuser and heat-exchange technologies in cogeneration plants, which ...

  18. OXYGEN DIFFUSION IN UO2-x

    E-Print Network [OSTI]

    Kim, K.C.

    2013-01-01T23:59:59.000Z

    ~ K.C. K:i.m, "Oxygen Diffusion in Hypostoichiometricsystem for enriching uo 2 in oxygen-18 or for stoichiometry+nal of Nuclear Materials OXYGEN DIFFUSION IN U0 2 _:x K.C.

  19. MICROFLUIDIC CONTROL OF STEM CELL DIFFUSIBLE SIGNALING

    E-Print Network [OSTI]

    Voldman, Joel

    MICROFLUIDIC CONTROL OF STEM CELL DIFFUSIBLE SIGNALING Katarina Blagovi, Lily Y. Kim, Alison M cell differentiation. KEYWORDS: Embryonic stem cells, microfluidic perfusion, diffusible signaling; they secrete molecules to which they respond. Microfluidics offers a potential solution to this challenge

  20. Journal of Quantitative Spectroscopy & Radiative Transfer 99 (2006) 341348

    E-Print Network [OSTI]

    2006-01-01T23:59:59.000Z

    structure on non-LTE, non-diffusive radiation transport and X-ray production is discussed. r 2005 Elsevier Ltd. All rights reserved. Keywords: Z-pinch plasma; K-shell X-ray production and spectroscopy; Opacity tungsten wires [2]. Strong j  B forces implode the wire array, which generates nearly 2 MJ of X-rays in o

  1. Electric Dipole Radiation from Spinning Dust Grains

    E-Print Network [OSTI]

    B. T. Draine; A. Lazarian

    1998-02-18T23:59:59.000Z

    We discuss the rotational excitation of small interstellar grains and the resulting electric dipole radiation from spinning dust. Attention is given to excitation and damping of rotation by: collisions with neutrals; collisions with ions; plasma drag; emission of infrared radiation; emission of microwave radiation; photoelectric emission; and formation of H_2 on the grain surface. We introduce dimensionless functions F and G which allow direct comparison of the contributions of different mechanisms to rotational drag and excitation. Emissivities are estimated for dust in different phases of the interstellar medium, including diffuse HI, warm HI, low-density photoionized gas, and cold molecular gas. Spinning dust grains can explain much, and perhaps all, of the 14-50 GHz background component recently observed in CBR studies. It should be possible to detect rotational emission from small grains by ground-based observations of molecular clouds.

  2. Heat Hyperbolic Diffusion in Planck Gas

    E-Print Network [OSTI]

    Miroslaw Kozlowski; Janina Marciak-Kozlowska

    2006-07-06T23:59:59.000Z

    In this paper we investigate the diffusion of the thermal pulse in Planck Gas. We show that the Fourier diffusion equation gives the speed of diffusion, v > c and breaks the causality of the thermal processes in Planck gas .For hyperbolic heat transport v

  3. environmental management radiation protection

    E-Print Network [OSTI]

    Entekhabi, Dara

    EHS environmental management biosafety radiation protection industrial hygiene safety Working: Biosafety, Environmental Management, Industrial Hygiene, Radiation Protection and Safety. Each specialized Management Program, Industrial Hygiene, Radiation Protection Program, and the Safety Program. (http

  4. DETECTORS FOR RADIATION DOSIMETRY

    E-Print Network [OSTI]

    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.

  5. Courses on Synchrotron Radiation

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

    Synchrotron Radiation The following is an incomplete list of courses on Synchrotron Radiation. For additional courses, check lightsources.org. XAFS School The APS XAFS School...

  6. Solar radiation resource assessment

    SciTech Connect (OSTI)

    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.

  7. Radiation Control (Virginia)

    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...

  8. Developing the Galactic Diffuse Emission Model for the GLAST Large Area Telescope

    SciTech Connect (OSTI)

    Moskalenko, Igor V.; Strong, Andrew W.; Digel, Seth W.; Porter, Troy A.

    2007-04-30T23:59:59.000Z

    Diffuse emission is produced in energetic cosmic ray (CR) interactions, mainly protons and electrons, with the interstellar gas and radiation field and contains the information about particle spectra in distant regions of the Galaxy. It may also contain information about exotic processes such as dark matter annihilation, black hole evaporation etc. A model of the diffuse emission is important for determination of the source positions and spectra. Calculation of the Galactic diffuse continuum g-ray emission requires a model for CR propagation as the first step. Such a model is based on theory of particle transport in the interstellar medium as well as on many kinds of data provided by different experiments in Astrophysics and Particle and Nuclear Physics. Such data include: secondary particle and isotopic production cross sections, total interaction nuclear cross sections and lifetimes of radioactive species, gas mass calibrations and gas distribution in the Galaxy (H{sub 2}, H I, H II), interstellar radiation field, CR source distribution and particle spectra at the sources, magnetic field, energy losses, g-ray and synchrotron production mechanisms, and many other issues. We are continuously improving the GALPROP model and the code to keep up with a flow of new data. Improvement in any field may affect the Galactic diffuse continuum g-ray emission model used as a background model by the GLAST LAT instrument. Here we report about the latest improvements of the GALPROP and the diffuse emission model.

  9. Service Promotion -Diffusion Raphale LOMBARD

    E-Print Network [OSTI]

    Pellier, Damien

    Service Promotion - Diffusion Raphaële LOMBARD Editions L'Harmattan - 5 Rue de l'Ecole Polytechnique ­ 75005 Paris Tél 01.40.46.79.23 ­ mail : raphaele.lombard@harmattan.fr La mondialisation avance à complémentaires BON DE COMMANDE A retourner à L'HARMATTAN, 7 rue de l'�cole Polytechnique 75005 Paris Veuillez me

  10. RADIATION TRANSPORT FOR EXPLOSIVE OUTFLOWS: OPACITY REGROUPING

    SciTech Connect (OSTI)

    Wollaeger, Ryan T. [Department of Nuclear Engineering and Engineering Physics, University of Wisconsin, Madison 1500 Engineering Drive, 410 ERB, Madison, WI 53706 (United States); Van Rossum, Daniel R., E-mail: wollaeger@wisc.edu, E-mail: daan@flash.uchicago.edu [Flash Center for Computational Science, Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States)

    2014-10-01T23:59:59.000Z

    Implicit Monte Carlo (IMC) and Discrete Diffusion Monte Carlo (DDMC) are methods used to stochastically solve the radiative transport and diffusion equations, respectively. These methods combine into a hybrid transport-diffusion method we refer to as IMC-DDMC. We explore a multigroup IMC-DDMC scheme that in DDMC, combines frequency groups with sufficient optical thickness. We term this procedure ''opacity regrouping''. Opacity regrouping has previously been applied to IMC-DDMC calculations for problems in which the dependence of the opacity on frequency is monotonic. We generalize opacity regrouping to non-contiguous groups and implement this in SuperNu, a code designed to do radiation transport in high-velocity outflows with non-monotonic opacities. We find that regrouping of non-contiguous opacity groups generally improves the speed of IMC-DDMC radiation transport. We present an asymptotic analysis that informs the nature of the Doppler shift in DDMC groups and summarize the derivation of the Gentile-Fleck factor for modified IMC-DDMC. We test SuperNu using numerical experiments including a quasi-manufactured analytic solution, a simple 10 group problem, and the W7 problem for Type Ia supernovae. We find that opacity regrouping is necessary to make our IMC-DDMC implementation feasible for the W7 problem and possibly Type Ia supernova simulations in general. We compare the bolometric light curves and spectra produced by the SuperNu and PHOENIX radiation transport codes for the W7 problem. The overall shape of the bolometric light curves are in good agreement, as are the spectra and their evolution with time. However, for the numerical specifications we considered, we find that the peak luminosity of the light curve calculated using SuperNu is ?10% less than that calculated using PHOENIX.

  11. Configurational diffusion of coal macromolecules

    SciTech Connect (OSTI)

    Guin, J.A.; Curtis, C.W.; Tarrer, A.R.; Kim, S.; Hwang, D.; Chen, C.C.; Chiou, Z.

    1991-01-01T23:59:59.000Z

    The objective of our research was to obtain fundamental information regarding the functional dependence of the diffusion coefficient of coal molecules on the ratio of molecule to pore diameter. That is, the objective of our study was to examine the effect of molecule size and configuration on hindered diffusion of coal macromolecules through as porous medium. To best accomplish this task, we circumvented the complexities of an actual porous catalyst by using a well defined porous matrix with uniform capillaric pores, i.e., a track-etched membrane. In this way, useful information was obtained regarding the relationship of molecular size and configuration on the diffusion rate of coal derived macromolecules through a pore structure with known geometry. Similar studies were performed using a pellet formed of porous alumina, to provide a link between the idealized membranes and the actual complex pore structure of real catalyst extrudates. The fundamental information from our study will be useful toward the tailoring of catalysts to minimize diffusional influences and thereby increase coal conversion and selectivity for desirable products. (VC)

  12. Are Aftershocks of Large Californian Earthquakes Diffusing?

    E-Print Network [OSTI]

    Helmstetter, A; Sornette, D; Helmstetter, Agnes; Ouillon, Guy; Sornette, Didier

    2003-01-01T23:59:59.000Z

    We analyze 21 aftershock sequences of California to test for evidence of space-time diffusion. Aftershock diffusion may result from stress diffusion and is also predicted by any mechanism of stress weakening. Here, we test an alternative mechanism to explain aftershock diffusion, based on multiple cascades of triggering. In order to characterize aftershock diffusion, we develop two methods, one based on a suitable time and space windowing that has been calibrated on the ETAS model of triggered seismicity, the other using a wavelet transform adapted to the removal of background seismicity. Both methods confirm that diffusion of seismic activity is very weak, much weaker than reported in previous studies. A possible mechanism explaining the weakness of observed diffusion is the effect of geometry, including the localization of aftershocks on a fractal fault network and the impact of extended rupture lengths which control the typical distances of interaction between earthquakes.

  13. Optical Spectroscopy of Diffuse Ionized Gas in M31

    E-Print Network [OSTI]

    B. Greenawalt; R. A. M. Walterbos; R. Braun

    1997-01-27T23:59:59.000Z

    We have obtained sensitive long-slit spectra of Diffuse Ionized Gas (DIG) in the Andromeda Galaxy, M31, covering the wavelength range of 3550-6850 Angs. By co-adding extracted DIG spectra, we reached a 1 sigma uncertainty of 9.3E-19 ergs/s/cm^{2}/arcsec^{2} corresponding to .46 pc/cm^{6} in Emission Measure. We present average spectra of DIG at four brightness levels with Emission Measures ranging from 9 to 59 pc/cm^{6}. We present the first measurements of [OII]\\lambda3727 and [OIII]\\lambda5007 of the truly diffuse ionized medium in the disk of an external spiral galaxy. We find that I_[OII]/I_H\\alpha=.9-1.4. The [OIII] line is weak (I_[OIII]/I_H\\beta = .5), but stronger than in the Galactic DIG. Measurements of [NII]\\lambda6583 and [SII](\\lambda6717+\\lambda6731) are also presented. The [SII] lines are clearly stronger than typical HII regions (I_[SII]/I_H\\alpha = .5 compared to .2). Overall, the line ratios are in agreement with predictions of photoionization models for diffuse gas exposed to a dilute stellar radiation field, but the line ratios of the DIG in M31 are somewhat different than observed for Galactic DIG. The differences indicate a less diluted radiation field in the DIG of M31's spiral arms compared to DIG in the Solar Neighborhood of the Milky Way. We have also detected HeI\\lambda5876 emission from the brightest DIG in M31. The HeI line appears to be stronger than in the Galactic DIG, possibly indicating that most of the Helium in the bright DIG in M31 is fully ionized. However, this result is somewhat tentative.

  14. Group classification of systems of non-linear reaction-diffusion equations with general diffusion matrix. II. Generalized Turing systems

    E-Print Network [OSTI]

    A. G. Nikitin

    2007-07-20T23:59:59.000Z

    Group classification of systems of two coupled nonlinear reaction-diffusion equation with a diagonal diffusion matrix is carried out. Symmetries of diffusion systems with singular diffusion matrix and additional first order derivative terms are described.

  15. A simplified model for thermal-wave cavity self-consistent measurement of thermal diffusivity

    SciTech Connect (OSTI)

    Shen, Jun, E-mail: jun.shen@nrc-cnrc.gc.ca; Zhou, Jianqin; Gu, Caikang [Energy, Mining and Environment Portfolio, National Research Council Canada, 4250 East Mall, Vancouver, British Columbia V6T 1W5 (Canada)] [Energy, Mining and Environment Portfolio, National Research Council Canada, 4250 East Mall, Vancouver, British Columbia V6T 1W5 (Canada); Neill, Stuart [Energy, Mining and Environment Portfolio, National Research Council Canada, 1200 Montreal Road, Building M-9, Ottawa, Ontario K1A 0R6 (Canada)] [Energy, Mining and Environment Portfolio, National Research Council Canada, 1200 Montreal Road, Building M-9, Ottawa, Ontario K1A 0R6 (Canada); Michaelian, Kirk H.; Fairbridge, Craig [CanmetENERGY, Natural Resources Canada, One Oil Drive Patch, Devon, Alberta T9G 1A8 (Canada)] [CanmetENERGY, Natural Resources Canada, One Oil Drive Patch, Devon, Alberta T9G 1A8 (Canada); Astrath, Nelson G. C.; Baesso, Mauro L. [Departamento de Física, Universidade Estadual de Maringá, Av. Colombo 5790, Maringá, Paraná 87020-900 (Brazil)] [Departamento de Física, Universidade Estadual de Maringá, Av. Colombo 5790, Maringá, Paraná 87020-900 (Brazil)

    2013-12-15T23:59:59.000Z

    A simplified theoretical model was developed for the thermal-wave cavity (TWC) technique in this study. This model takes thermal radiation into account and can be employed for absolute measurements of the thermal diffusivity of gas and liquid samples without any knowledge of geometrical and thermal parameters of the components of the TWC. Using this model and cavity-length scans, thermal diffusivities of air and distilled water were accurately and precisely measured as (2.191 ± 0.004) × 10{sup ?5} and (1.427 ± 0.009) × 10{sup ?7} m{sup 2}?s{sup ?1}, respectively, in very good agreement with accepted literature values.

  16. By Stanley Micklavzina, James Utterback and Frank Vignola for the Meyer Fund for Sustainable Development and the University of Oregon Department of Physics and Solar Radiation Monitoring Laboratory

    E-Print Network [OSTI]

    Oregon, University of

    Development and the University of Oregon Department of Physics and Solar Radiation Monitoring Laboratory significantly change the incident solar radiation and this will affect the experimental results. The idea, obtains a reading of current from the diffuse solar radiation, light from the sky, ground, surrounding

  17. UNEP-GEF Renewable Energy Project Financial Risk Management in...

    Open Energy Info (EERE)

    Financial Risk Management 1 "This UNEPGEF targeted research project aims to catalyse new thinking in the risk management area, examining existing instruments and approaches and...

  18. Peru-GEF Nationally Appropriate Mitigation Actions in the Energy...

    Open Energy Info (EERE)

    of regional and global partners." Program Focus The program will focus on reducing poverty and inequality, strengthening democratic governance, increasing disaster preparedness...

  19. GEF-Colombia-Geothermal Energy Grant | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual SiteofEvaluating A PotentialJumpGermanFife EnergyFreightFulongFuturoGEA Wiegand

  20. Investing in Sustainable Transport and Urban Systems: The GEF Experience |

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are8COaBulkTransmissionSitingProcess.pdfGetecGtelInterias Solar Energy Jump to:IESInterval Data SystemsInves PozoOpen

  1. GEF-Knowledge Management Initiative | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual Siteof Energy 2,AUDIT REPORTEnergyFarms A S JumpWindfarmFundicion NodularGermany

  2. UNDP/GEF-Cambodia-Sustainable Forest Management | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:Ezfeedflag JumpID-fTri Global Energy LLC Place: Dallas,UGI UtilitiesInformation

  3. Armenia-GEF Climate Projects | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual Siteof EnergyInnovation in Carbon Capture andsoftware andSolar Center Jump to:ArkName

  4. Characterizing unsaturated diffusion in porous tuff gravel

    SciTech Connect (OSTI)

    Hu, Qinhong; Kneafsey, Timothy J.; Roberts, Jeffery J.; Tomutsa, Liviu; Wang, Joseph, S.Y.

    2003-11-12T23:59:59.000Z

    Evaluation of solute diffusion in unsaturated porous gravel is very important for investigations of contaminant transport and remediation, risk assessment, and waste disposal (for example, the potential high-level nuclear waste repository at Yucca Mountain, Nevada). For a porous aggregate medium such as granular tuff, the total water content is comprised of surface water and interior water. The surface water component (water film around grains and pendular water between the grain contacts) could serve as a predominant diffusion pathway. To investigate the extent to which surface water films and contact points affect solute diffusion in unsaturated gravel, we examined the configuration of water using x-ray computed tomography in partially saturated gravel, and made quantitative measurements of diffusion at multiple water contents using two different techniques. In the first, diffusion coefficients of potassium chloride in 2-4 mm granular tuff at multiple water contents were calculated from electrical conductivity measurements using the Nernst-Einstein equation. In the second, we used laser ablation with inductively coupled plasma-mass spectrometry to perform micro-scale mapping, allowing the measurement of diffusion coefficients for a mixture of chemical tracers for tuff cubes and tetrahedrons having two contact geometries (cube-cube and cube-tetrahedron). The x-ray computed tomography images show limited contact between grains, and this could hinder the pathways for diffusive transport. Experimental results show the critical role of surface water in controlling transport pathways and hence the magnitude of diffusion. Even with a bulk volumetric water content of 1.5%, the measured solute diffusion coefficient is as low as 1.5 x 10{sup -14} m{sup 2}/s for tuff gravel. Currently used diffusion models relating diffusion coefficients to total volumetric water content inadequately describe unsaturated diffusion behavior in porous gravel at very low water contents.

  5. Nonlinear diffusion in Acetone-Benzene Solution

    E-Print Network [OSTI]

    Obukhovsky, Vjacheslav V

    2010-01-01T23:59:59.000Z

    The nonlinear diffusion in multicomponent liquids under chemical reactions influence has been studied. The theory is applied to the analysis of mass transfer in a solution of acetone-benzene. It has been shown, that the creation of molecular complexes should be taken into account for the explanation of the experimental data on concentration dependence of diffusion coefficients. The matrix of mutual diffusivities has been found and effective parameters of the system have been computed.

  6. A Rearrangement Inequality for Diffusion Processes /

    E-Print Network [OSTI]

    Gao, Teng

    2013-01-01T23:59:59.000Z

    of the Rearrangement Inequality and its Proba- bilisticRearrangement Inequality . . . . . . 4.5 Some ObservationsSAN DIEGO A Rearrangement Inequality for Diffusion Processes

  7. Independent Oversight Review, Portsmouth Gaseous Diffusion Plant...

    Office of Environmental Management (EM)

    Plant - November 2013 Independent Oversight Review, Portsmouth Gaseous Diffusion Plant - November 2013 November 5, 2013 Review of Preparedness for Severe Natural Phenomena Events...

  8. Independent Oversight Review, Portsmouth Gaseous Diffusion Plant...

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

    April 2013 Independent Oversight Review, Portsmouth Gaseous Diffusion Plant - April 2013 April 2013 Review of the Integrated Safety Management System Phase I Verification Review at...

  9. Quantum Monte Carlo Study of the Optical and Diffusive Properties of theVacancy Defect in Diamond

    E-Print Network [OSTI]

    Kent, Paul

    associated with radiation damage. It is also very interesting scientifically, with a wide variety of physicalQuantum Monte Carlo Study of the Optical and Diffusive Properties of theVacancy Defect in Diamond]. The best-known optical transition, GR1 at 1.673 eV [5], long associated with the neutral vacancy, cannot

  10. Improved Correction of IR Loss in Diffuse Shortwave Measurements: An ARM Value-Added Product

    SciTech Connect (OSTI)

    Younkin, K; Long, CN

    2003-11-01T23:59:59.000Z

    Simple single black detector pyranometers, such as the Eppley Precision Spectral Pyranometer (PSP) used by the Atmospheric Radiation Measurement (ARM) Program, are known to lose energy via infrared (IR) emission to the sky. This is especially a problem when making clear-sky diffuse shortwave (SW) measurements, which are inherently of low magnitude and suffer the greatest IR loss. Dutton et al. (2001) proposed a technique using information from collocated pyrgeometers to help compensate for this IR loss. The technique uses an empirically derived relationship between the pyrgeometer detector data (and alternatively the detector data plus the difference between the pyrgeometer case and dome temperatures) and the nighttime pyranometer IR loss data. This relationship is then used to apply a correction to the diffuse SW data during daylight hours. We developed an ARM value-added product (VAP) called the SW DIFF CORR 1DUTT VAP to apply the Dutton et al. correction technique to ARM PSP diffuse SW measurements.

  11. Radiation effects in the environment

    SciTech Connect (OSTI)

    Begay, F.; Rosen, L.; Petersen, D.F.; Mason, C.; Travis, B. [Los Alamos National Lab., NM (United States); Yazzie, A. [Navajo Nation, Window Rock, AZ (United States). Dept. of History; Isaac, M.C.P.; Seaborg, G.T. [Lawrence Berkeley National Lab., CA (United States); Leavitt, C.P. [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Physics and Astronomy

    1999-04-01T23:59:59.000Z

    Although the Navajo possess substantial resource wealth-coal, gas, uranium, water-this potential wealth has been translated into limited permanent economic or political power. In fact, wealth or potential for wealth has often made the Navajo the victims of more powerful interests greedy for the assets under limited Navajo control. The primary focus for this education workshop on the radiation effects in the environment is to provide a forum where scientists from the nuclear science and technology community can share their knowledge toward the advancement and diffusion of nuclear science and technology issues for the Navajo public. The scientists will make an attempt to consider the following basic questions; what is science; what is mathematics; what is nuclear radiation? Seven papers are included in this report: Navajo view of radiation; Nuclear energy, national security and international stability; ABC`s of nuclear science; Nuclear medicine: 100 years in the making; Radon in the environment; Bicarbonate leaching of uranium; and Computational methods for subsurface flow and transport. The proceedings of this workshop will be used as a valuable reference materials in future workshops and K-14 classrooms in Navajo communities that need to improve basic understanding of nuclear science and technology issues. Results of the Begay-Stevens research has revealed the existence of strange and mysterious concepts in the Navajo Language of nature. With these research results Begay and Stevens prepared a lecture entitled The Physics of Laser Fusion in the Navajo language. This lecture has been delivered in numerous Navajo schools, and in universities and colleges in the US, Canada, and Alaska.

  12. Simulation of neutron radiation damage in silicon semiconductor devices.

    SciTech Connect (OSTI)

    Shadid, John Nicolas; Hoekstra, Robert John; Hennigan, Gary Lee; Castro, Joseph Pete Jr.; Fixel, Deborah A.

    2007-10-01T23:59:59.000Z

    A code, Charon, is described which simulates the effects that neutron damage has on silicon semiconductor devices. The code uses a stabilized, finite-element discretization of the semiconductor drift-diffusion equations. The mathematical model used to simulate semiconductor devices in both normal and radiation environments will be described. Modeling of defect complexes is accomplished by adding an additional drift-diffusion equation for each of the defect species. Additionally, details are given describing how Charon can efficiently solve very large problems using modern parallel computers. Comparison between Charon and experiment will be given, as well as comparison with results from commercially-available TCAD codes.

  13. Plutonium radiation surrogate

    DOE Patents [OSTI]

    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.

  14. Modelling international wind energy diffusion: Are the patterns of induced diffusion `S'

    E-Print Network [OSTI]

    Feigon, Brooke

    Modelling international wind energy diffusion: Are the patterns of induced diffusion `S' shaped datasets, the paper explores the patterns of international wind energy diffusion in OECD countries. The model employed in the paper predicted that wind energy, as a complex and expensive innovation, would

  15. Turbulent diffusion and turbulent thermal diffusion of aerosols in stratified atmospheric flows

    E-Print Network [OSTI]

    Elperin, Tov

    Turbulent diffusion and turbulent thermal diffusion of aerosols in stratified atmospheric flows M to the turbulent diffusion, and its potential impact on aerosol distribution. This phenomenon was predicted a nondiffusive flux of aerosols in the direction of the heat flux and results in formation of long-living aerosol

  16. Radiation Protection Guidance Hospital Staff

    E-Print Network [OSTI]

    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

  17. 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...

  18. WI Radiation Protection

    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...

  19. A model for the directional distribution of the diffuse sky radiance with an application to a CPC collector

    SciTech Connect (OSTI)

    Siala, F.M.F. (Center for Solar Energy Studies, Tripoli (Libya)); Hooper, F.C. (Univ. of Toronto, Ontario (Canada))

    1990-01-01T23:59:59.000Z

    The development of a new, semi-empirical model for the directional distribution of the diffuse radiance is reported. The proposed regression-type model, with the form of its base functions obtained from physical principles, is based on a combination of the purely physical reasoning approach and the purely empirical approach. Direct multiple-scattering calculations are circumvented through the use of the method of successive orders of scattering. The model is calibrated for the mean diffuse radiance estimated under all sky conditions reported in a large and comprehensive diffuse radiance data set. It is found that only a small increase in accuracy is gained by including higher orders of scattering, and this increase does not justify the complexity of the resulting model. Therefore, the single scattering approximation is recommended. The use of the model is illustrated in a typical application, in which the fraction of diffuse radiation intercepted by the receive of a compound parabolic concentrator is computed.

  20. Soot formation and temperature structure in small methane-oxygen diffusion flames at subcritical and supercritical pressures

    SciTech Connect (OSTI)

    Joo, Hyun I.; Guelder, Oemer L. [University of Toronto, Institute for Aerospace Studies, 4925 Dufferin Street, Toronto, Ont. (Canada)

    2010-06-15T23:59:59.000Z

    An experimental study was conducted to examine the characteristics of laminar methane-oxygen diffusion flames up to 100 atmospheres. The influence of pressure on soot formation and on the structure of the temperature field was investigated over the pressure range of 10-90 atmospheres in a high-pressure combustion chamber using a non-intrusive, line-of-sight spectral soot emission diagnostic technique. Two distinct zones characterized the appearance of a methane and pure oxygen diffusion flame: an inner luminous zone similar to the methane-air diffusion flames, and an outer diffusion flame zone which is mostly blue. The flame height, marked by the visible soot radiation emission, was reduced by over 50% over the pressure range of 10-100 atmospheres. Between 10 and 40 atmospheres, the soot levels increased with increasing pressure; however, above 40 atmospheres the soot concentrations decreased with increasing pressure. (author)

  1. Surveying Diffusion in Complex Geometries. An Essay

    E-Print Network [OSTI]

    Denis Grebenkov

    2009-09-08T23:59:59.000Z

    The surrounding world surprises us by the beauty and variety of complex shapes that emerge from nanometric to macroscopic scales. Natural or manufactured materials (sandstones, sedimentary rocks and cement), colloidal solutions (proteins and DNA), biological cells, tissues and organs (lungs, kidneys and placenta), they all present irregularly shaped "scenes" for a fundamental transport "performance", that is, diffusion. Here, the geometrical complexity, entangled with the stochastic character of diffusive motion, results in numerous fascinating and sometimes unexpected effects like diffusion screening or localization. These effects control many diffusion-mediated processes that play an important role in heterogeneous catalysis, biochemical mechanisms, electrochemistry, growth phenomena, oil recovery, or building industry. In spite of a long and rich history of academic and industrial research in this field, it is striking to see how little we know about diffusion in complex geometries, especially the one which occurs in three dimensions. We present our recent results on restricted diffusion. We look into the role of geometrical complexity at different levels, from boundary microroughness to hierarchical structure and connectivity of the whole diffusion-confining domain. We develop a new approach which consists in combining fast random walk algorithms with spectral tools. The main focus is on studying diffusion in model complex geometries (von Koch boundaries, Kitaoka acinus, etc.), as well as on developing and testing spectral methods. We aim at extending this knowledge and at applying the accomplished arsenal of theoretical and numerical tools to structures found in nature and industry.

  2. DIFFUSE RADIO EMISSION IN ABELL 754

    SciTech Connect (OSTI)

    Kale, Ruta; Dwarakanath, K. S. [Raman Research Institute, Bangalore 560080 (India)], E-mail: ruta@rri.res.in, E-mail: dwaraka@rri.res.in

    2009-07-10T23:59:59.000Z

    We present a low-frequency study of the diffuse radio emission in the galaxy cluster A754. We present a new 150 MHz image of the galaxy cluster A754 made with the Giant Metrewave Radio Telescope and discuss the detection of four diffuse features. We compare the 150 MHz image with the images at 74, 330, and 1363 MHz; one new diffuse feature is detected. The flux density upper limits at 330 and 1363 MHz imply a synchrotron spectral index, {alpha}>2 (S {proportional_to} {nu}{sup -{alpha}}), for the new feature. The 'west relic' detected at 74 MHz is not detected at 150 MHz and is thus consistent with its nondetection at 1363 MHz and 330 MHz. Integrated spectra of all the diffuse features are presented. The fourth diffuse feature is located along the proposed merger axis in A754 and 0.7 Mpc away from the peak of X-ray emission; we refer to it as a relic. We have made use of the framework of the adiabatic compression model to obtain spectra. We show that the spectrum of the fourth diffuse feature is consistent with that of a cocoon of a radio galaxy lurking for about 9 x 10{sup 7} yr; no shock compression is required. The other three diffuse emission have spectra steeper than 1.5 and could be cocoons lurking for longer time. We discuss other possibilities such as shocks and turbulent reacceleration being responsible for the diffuse emission in A754.

  3. Diffusive limit for the random Lorentz gas

    E-Print Network [OSTI]

    Alessia Nota

    2014-10-14T23:59:59.000Z

    We review some recent results concerning the derivation of the diffusion equation and the validation of Fick's law for the microscopic model given by the random Lorentz Gas. These results are achieved by using a linear kinetic equation as an intermediate level of description between our original mechanical system and the diffusion equation.

  4. Finite-difference schemes for anisotropic diffusion

    SciTech Connect (OSTI)

    Es, Bram van, E-mail: es@cwi.nl [Centrum Wiskunde and Informatica, P.O. Box 94079, 1090GB Amsterdam (Netherlands); FOM Institute DIFFER, Dutch Institute for Fundamental Energy Research, Association EURATOM-FOM (Netherlands); Koren, Barry [Eindhoven University of Technology (Netherlands); Blank, Hugo J. de [FOM Institute DIFFER, Dutch Institute for Fundamental Energy Research, Association EURATOM-FOM (Netherlands)

    2014-09-01T23:59:59.000Z

    In fusion plasmas diffusion tensors are extremely anisotropic due to the high temperature and large magnetic field strength. This causes diffusion, heat conduction, and viscous momentum loss, to effectively be aligned with the magnetic field lines. This alignment leads to different values for the respective diffusive coefficients in the magnetic field direction and in the perpendicular direction, to the extent that heat diffusion coefficients can be up to 10{sup 12} times larger in the parallel direction than in the perpendicular direction. This anisotropy puts stringent requirements on the numerical methods used to approximate the MHD-equations since any misalignment of the grid may cause the perpendicular diffusion to be polluted by the numerical error in approximating the parallel diffusion. Currently the common approach is to apply magnetic field-aligned coordinates, an approach that automatically takes care of the directionality of the diffusive coefficients. This approach runs into problems at x-points and at points where there is magnetic re-connection, since this causes local non-alignment. It is therefore useful to consider numerical schemes that are tolerant to the misalignment of the grid with the magnetic field lines, both to improve existing methods and to help open the possibility of applying regular non-aligned grids. To investigate this, in this paper several discretization schemes are developed and applied to the anisotropic heat diffusion equation on a non-aligned grid.

  5. CONVERTIBLE BONDS IN A DEFAULTABLE DIFFUSION MODEL

    E-Print Network [OSTI]

    Jeanblanc, Monique

    CONVERTIBLE BONDS IN A DEFAULTABLE DIFFUSION MODEL Tomasz R. Bielecki Department of Applied Research Grant PS12918. #12;2 Convertible Bonds in a Defaultable Diffusion Model 1 Introduction In [4), such as Convertible Bonds (CB), and we provided a rigorous decomposition of a CB into a bond component and a (game

  6. ON DIFFUSION IN HETEROGENEOUS MEDIA YOUXUE ZHANG*,

    E-Print Network [OSTI]

    Liu, Liping

    , heterogeneous media, multi-mineral rocks, multi-phase media, composite materials, kinetics, porous rocks to bulk diffusion, and porous materials (such as plants, soil, rock with partial melt or fluid, sediment of air and moisture in soils, drying of paint, wood, and concrete, diffusion of gases in rubber, movement

  7. Radiation protection at CERN

    E-Print Network [OSTI]

    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.

  8. RADIONUCLIDE RADIATION PROTECTION

    E-Print Network [OSTI]

    Healy, Kevin Edward

    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

  9. Radiation Processing -an overview

    E-Print Network [OSTI]

    of radiation · Facilities ­ Gamma ­ electrons ­ X-ray ­ Safety · Sterilisation of medical devices · Food irradiation · Material modification #12;3 Content ­ Part 2 · Environmental applications · Other applications Radiation · Energy in the form of waves or moving subatomic particles Irradiation · Exposure to radiation

  10. Surveying Diffusion in Complex Geometries. An Essay

    E-Print Network [OSTI]

    Grebenkov, Denis

    2009-01-01T23:59:59.000Z

    The surrounding world surprises us by the beauty and variety of complex shapes that emerge from nanometric to macroscopic scales. Natural or manufactured materials (sandstones, sedimentary rocks and cement), colloidal solutions (proteins and DNA), biological cells, tissues and organs (lungs, kidneys and placenta), they all present irregularly shaped "scenes" for a fundamental transport "performance", that is, diffusion. Here, the geometrical complexity, entangled with the stochastic character of diffusive motion, results in numerous fascinating and sometimes unexpected effects like diffusion screening or localization. These effects control many diffusion-mediated processes that play an important role in heterogeneous catalysis, biochemical mechanisms, electrochemistry, growth phenomena, oil recovery, or building industry. In spite of a long and rich history of academic and industrial research in this field, it is striking to see how little we know about diffusion in complex geometries, especially the one whic...

  11. Inverse diffusion from knowledge of power densities

    E-Print Network [OSTI]

    Bal, Guillaume; Monard, Francois; Triki, Faouzi

    2011-01-01T23:59:59.000Z

    This paper concerns the reconstruction of a diffusion coefficient in an elliptic equation from knowledge of several power densities. The power density is the product of the diffusion coefficient with the square of the modulus of the gradient of the elliptic solution. The derivation of such internal functionals comes from perturbing the medium of interest by acoustic (plane) waves, which results in small changes in the diffusion coefficient. After appropriate asymptotic expansions and (Fourier) transformation, this allow us to construct the power density of the equation point-wise inside the domain. Such a setting finds applications in ultrasound modulated electrical impedance tomography and ultrasound modulated optical tomography. We show that the diffusion coefficient can be uniquely and stably reconstructed from knowledge of a sufficient large number of power densities. Explicit expressions for the reconstruction of the diffusion coefficient are also provided. Such results hold for a large class of boundary...

  12. Monitoring detachment and diffusion of metallic species in polycarbonate

    SciTech Connect (OSTI)

    Bencomo, M. [Department of Physics, Texas A and M U. College Station, TX 77843 (United States); Castro-Colin, M. [Bruker AXS GmbH, 76187, Karlsruhe (Germany); Lopez, J. A.; Ramirez-Homs, E. [Department of Physics, U. of Texas at El Paso, El Paso, TX 79968 (United States)

    2013-07-03T23:59:59.000Z

    Photon absorption is known to create peroxy radicals in polymers, in a process that entails the removal of hydrogen atoms and the subsequent breakage of bonds. Bond-breaking is found to free, from the polymeric matrix, metallic additives which are then able to diffuse out, as evidenced by the change in both the metallic fluorescence yield and the XPS profiles of C, N, and O. Polycarbonate was artificially weathered using UV radiation from mercury emission lines at 365, 405 and 435 nm, followed by thermal treatment. The UV wavelengths used have energies comparable to those of covalent bonds found in polymeric chains. Both processes, light exposure and thermal, have the purpose of stimulating the degradation of polycarbonate.

  13. Diffuse Synchrotron Emission from Galactic Cosmic Ray Electrons

    E-Print Network [OSTI]

    Di Bernardo, Giuseppe; Evoli, Carmelo; Gaggero, Daniele

    2015-01-01T23:59:59.000Z

    Synchrotron diffuse radiation (SDR) emission is one of the major Galactic components, in the 100 MHz up to 100 GHz frequency range. Its spectrum and sky map provide valuable measure of the galactic cosmic ray electrons (GCRE) in the relevant energy range, as well as of the strength and structure of the Galactic magnetic fields (GMF), both regular and random ones. This emission is an astrophysical sky foreground for the study of the Cosmic Microwave Background (CMB), and the extragalactic microwave measurements, and it needs to be modelled as better as possible. In this regard, in order to get an accurate description of the SDR in the Galaxy, we use - for the first time in this context - 3-dimensional GCRE models obtained by running the DRAGON code. This allows us to account for a realistic spiral arm pattern of the source distribution, demanded to get a self-consistent treatment of all relevant energy losses influencing the final synchrotron spectrum.

  14. Defects and diffusion in MeV implanted silicon

    SciTech Connect (OSTI)

    Venezia, V. C.; Haynes, T. E.; Agarwal, Aditya; Gossmann, H.-J.; Pelaz, L.; Jacobson, D. C.; Eaglesham, D. J.; Duggan, J. L. [Bell Laboratories, Lucent Technologies, 600 Mountain Avenue, Murray Hill, New Jersey 07974 (United States); Solid State Division, Oak Ridge National Laboratory, MS-6048, P.O. Box 2008, Oak Ridge, Tennessee 37831 (United States); Semiconductor Equipment Operations, Eaton Corporation, 55 Cherry Hill Drive, Beverly, Massachusetts 01915 (United States); Bell Laboratories, Lucent Technologies, 600 Mountain Avenue, Murray Hill, New Jersey 07974 (United States); Department of Physics, University of North Texas, Denton, Texas 76201 (United States)

    1999-06-10T23:59:59.000Z

    In this work we demonstrate that the defects that are created by 2-MeV Si ions can interact with dopant atoms both during implantation and during post-implant annealing. We show that the interstitials and vacancies created during MeV Si implantation result in a radiation enhanced diffusion of B and Sb markers, respectively, when the temperature of implantation is above the threshold temperature for formation of mobile dopant complexes. With the use of these dopant markers we also demonstrate that a vacancy-rich near surface region results during post-implant annealing of MeV implanted silicon. The depth distribution and the thermal evolution of clustered vacancies was measured by a Au labeling technique.

  15. Paducah Gaseous Diffusion Plant Annual Site Environmental Report for 1993

    SciTech Connect (OSTI)

    Not Available

    1994-10-01T23:59:59.000Z

    The purpose of this document is to summarize effluent monitoring and environmental surveillance results and compliance with environmental laws, regulations, and orders at the Paducah Gaseous Diffusion Plant (PGDP). Environmental monitoring at PGDP consists of two major activities: effluent monitoring and environmental surveillance. Effluent monitoring is direct measurement or the collection and analysis of samples of liquid and gaseous discharges to the environment. Environmental surveillance is direct measurement or the collection and analysis of samples of air, water, soil, foodstuff, biota, and other media. Environmental monitoring is performed to characterize and quantify contaminants, assess radiation exposures of members of the public, demonstrate compliance with applicable standards and permit requirements, and detect and assess the effects (if any) on the local environment. Multiple samples are collected throughout the year and are analyzed for radioactivity, chemical content, and various physical attributes.

  16. COSMOS: A Radiation-Chemo-Hydrodynamics Code for Astrophysical Problems

    E-Print Network [OSTI]

    Peter Anninos; P. Chris Fragile; Stephen D. Murray

    2003-03-10T23:59:59.000Z

    We have developed a new massively-parallel radiation-hydrodynamics code (Cosmos) for Newtonian and relativistic astrophysical problems that also includes radiative cooling, self-gravity, and non-equilibrium, multi-species chemistry. Several numerical methods are implemented for the hydrodynamics, including options for both internal and total energy conserving schemes. Radiation is treated using flux-limited diffusion. The chemistry incorporates 27 reactions, including both collisional and radiative processes for atomic hydrogen and helium gases, and molecular hydrogen chains. In this paper we discuss the equations and present results from test problems carried out to verify the robustness and accuracy of our code in the Newtonian regime. An earlier paper presented tests of the relativistic capabilities of Cosmos.

  17. COSMOS A Radiation-Chemo-Hydrodynamics Code for Astrophysical Problems

    E-Print Network [OSTI]

    Anninos, P; Murray, S D; Anninos, Peter; Murray, Stephen D.

    2003-01-01T23:59:59.000Z

    We have developed a new massively-parallel radiation-hydrodynamics code (Cosmos) for Newtonian and relativistic astrophysical problems that also includes radiative cooling, self-gravity, and non-equilibrium, multi-species chemistry. Several numerical methods are implemented for the hydrodynamics, including options for both internal and total energy conserving schemes. Radiation is treated using flux-limited diffusion. The chemistry incorporates 27 reactions, including both collisional and radiative processes for atomic hydrogen and helium gases, and molecular hydrogen chains. In this paper we discuss the equations and present results from test problems carried out to verify the robustness and accuracy of our code in the Newtonian regime. An earlier paper presented tests of the relativistic capabilities of Cosmos.

  18. Microscopic diffusion of partly ionized metals in the Sun and metal-poor stars

    E-Print Network [OSTI]

    Schlattl, H

    2002-01-01T23:59:59.000Z

    An improved microscopic diffusion in stars is presented considering in detail the partly ionized stages of metals. Besides,the influence of degenerate electron-gas and of the contribution of radiation to the total pressure has been accounted for. The solution of the diffusion equations is then performed following the scheme of Thoul et al. (1994). By defining one mean charged ion per element very few modifications are necessary to solve the improved diffusion scheme. (A portable FORTRAN routine is provided.) The change in the sound-speed profile of a solar model obtained with the new diffusion description is at most about 25% at r=0.6 R(sun). The biggest effect on low-mass stars is expected near the turn-off, where the convective envelope is shallowest. However, only a difference of at most 40 K in the effective temperature could be observed when assuming either fully or partly ionized metals in the diffusion equation. Nevertheless, the surface metal distribution is strongly altered.

  19. Investigation of particle diffusion and suprathermal electrons in a magnetized helium plasma column

    SciTech Connect (OSTI)

    Lefevre, T.; Escarguel, A.; Stamm, R.; Godbert-Mouret, L. [Aix-Marseille Université, CNRS, PIIM UMR 7345, F13397 CEDEX 20, Marseille (France)] [Aix-Marseille Université, CNRS, PIIM UMR 7345, F13397 CEDEX 20, Marseille (France); Rosmej, F. B. [Sorbonne Universités, Pierre et Marie Curie, UMR 7605, LULI, case 128, 4 place Jussieu, F-75252 Paris Cedex 05 (France) [Sorbonne Universités, Pierre et Marie Curie, UMR 7605, LULI, case 128, 4 place Jussieu, F-75252 Paris Cedex 05 (France); LULI, Ecole Polytechnique, CNRS, CEA, Physique Atomique dans les Plasmas Denses PAPD, Route de Saclay, F-91128 Palaiseau (France)

    2014-02-15T23:59:59.000Z

    Studying radiative properties of magnetized helium plasma via high-resolution spectroscopy identified close correlations between the particle diffusion and suprathermal electrons for different modes of operation of the MISTRAL installation. The standard diagnostic emission lines in neutral helium (1s3d {sup 3}D-1s2p {sup 3}P, 1s3s {sup 3}S-1s2p {sup 3}P, 1s3d {sup 1}D-1s2p {sup 1}P, and 1s3s {sup 1}S-1s2p {sup 1}P) show anomalous ratios that are related to enhanced particle diffusion and suprathermal electron generation. The supplementary investigation of singlet/triplet Rydberg series (transitions 1snd {sup 3}D-1s2p {sup 3}P and 1s5p {sup 1}P-1s2s {sup 1}S) as well as ionic lines (HeII, transitions n?=?3–4 at 469?nm and n?=?4–6 at 656?nm) allowed quantitative characterization. Simulations carried out with the atomic physics code SOPHIA demonstrate that simultaneous implementation of diffusion processes and suprathermal electrons matches all experimental findings. Single consideration, however, of either diffusion or hot electrons is in contradiction to the proposed extended set of HeI and HeII emission lines. The high precision achieved with the LSJ-split level structure of SOPHIA coupled to Langmuir probe measurements allowed to conclude to a Bohm type diffusion in MISTRAL.

  20. Analysis of the empirical relations between visible solar radiation, the solar altitude and the transparency of the atmosphere 

    E-Print Network [OSTI]

    Garcia Occhipinti, Antonio

    1965-01-01T23:59:59.000Z

    ls determined by a four parameter system including the two parameters which characterize the transmission of the direct solar radiation. The four parameter model ls )ustified in terms of actual measurements for clear sky conditions. The system... Sketch Illustrating Coordinate System, . 39 4, 2 The Coordinate System Used to Describe the Multiple Scattering Radiation Field 41 4, 3 Optical Thickness Coordinate Schematic of the Zv + 2 Radiant Fluxes of the Diffuse Radiation Field Model 47 4. 5...

  1. Time evolution of negative binomial optical field in diffusion channel

    E-Print Network [OSTI]

    Liu Tang-Kun; Wu Pan-Pan; Shan Chuan-Jia; Liu Ji-Bing; Fan Hong-Yi

    2015-04-17T23:59:59.000Z

    We find time evolution law of negative binomial optical field in diffusion channel. We reveal that by adjusting the diffusion parameter, photon number can controlled. Therefore, the diffusion process can be considered a quantum controlling scheme through photon addition.

  2. Microfluidic Investigation of Tracer Dye Diffusion in Alumina Nanofluids 

    E-Print Network [OSTI]

    Ozturk, Serdar 1979-

    2012-10-05T23:59:59.000Z

    on enhanced mass diffusion and the possibility of tailoring mass transport by direct manipulation of molecular diffusion. Therefore, a microfluidic approach capable of directly probing tracer diffusion between nanoparticle-laden fluid streams was developed...

  3. Synchrotron Radiation in Polymer Science

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

    Synchrotron Radiation in Polymer Science Synchrotron Radiation in Polymer Science March 30-April 2, 2012; San Francisco...

  4. TERSat: Trapped Energetic Radiation Satellite

    E-Print Network [OSTI]

    Clements, Emily B.

    2012-01-01T23:59:59.000Z

    Radiation damage caused by interactions with high-energy particles in the Van Allen Radiation Belts is a leading

  5. Sandia National Laboratories: Diffusion Bonding Characterization

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

    Laboratory (NESL) Transient Nuclear Fuels Testing Radiation Effects Sciences Solar Electric Propulsion Nuclear Energy Safety Technologies Experimental Testing...

  6. Temperature measurements using multicolor pyrometry in thermal radiation heating environments

    SciTech Connect (OSTI)

    Fu, Tairan, E-mail: trfu@mail.tsinghua.edu.cn [Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University, Beijing 100084 (China) [Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University, Beijing 100084 (China); Beijing Key Laboratory of CO2 Utilization and Reduction Technology, Beijing 100084 (China); Liu, Jiangfan; Duan, Minghao; Zong, Anzhou [Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University, Beijing 100084 (China)] [Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University, Beijing 100084 (China)

    2014-04-15T23:59:59.000Z

    Temperature measurements are important for thermal-structural experiments in the thermal radiation heating environments such as used for thermal-structural stress analyses. This paper describes the use of multicolor pyrometry for the measurements of diffuse surfaces in thermal radiation environments that eliminates the effects of background radiation reflections and unknown emissivities based on a least-squares algorithm. The near-infrared multicolor pyrometer had a spectral range of 1100–2400 nm, spectrum resolution of 6 nm, maximum sampling frequency of 2 kHz, working distance of 0.6 m to infinity, temperature range of 700–1700 K. The pyrometer wavelength response, nonlinear intensity response, and spectral response were all calibrated. The temperature of a graphite sample irradiated by quartz lamps was then measured during heating and cooling using the least-squares algorithm based on the calibrated irradiation data. The experiments show that higher temperatures and longer wavelengths are more suitable for the thermal measurements in the quartz lamp radiation heating system. This analysis provides a valuable method for temperature measurements of diffuse surfaces in thermal radiation environments.

  7. Review of enhanced vapor diffusion in porous media

    SciTech Connect (OSTI)

    Webb, S.W.; Ho, C.K.

    1998-08-01T23:59:59.000Z

    Vapor diffusion in porous media in the presence of its own liquid has often been treated similar to gas diffusion. The gas diffusion rate in porous media is much lower than in free space due to the presence of the porous medium and any liquid present. However, enhanced vapor diffusion has also been postulated such that the diffusion rate may approach free-space values. Existing data and models for enhanced vapor diffusion, including those in TOUGH2, are reviewed in this paper.

  8. Flux-Limited Diffusion Approximation Models of Giant Planet Formation by Disk Instability

    E-Print Network [OSTI]

    Alan P. Boss

    2008-01-28T23:59:59.000Z

    Both core accretion and disk instability appear to be required as formation mechanisms in order to explain the entire range of giant planets found in extrasolar planetary systems. Disk instability is based on the formation of clumps in a marginally-gravitationally unstable protoplanetary disk. These clumps can only be expected to contract and survive to become protoplanets if they are able to lose thermal energy through a combination of convection and radiative cooling. Here we present several new three dimensional, radiative hydrodynamics models of self-gravitating protoplanetary disks, where radiative transfer is handled in the flux-limited diffusion approximation. We show that while the flux-limited models lead to higher midplane temperatures than in a diffusion approximation model without the flux-limiter, the difference in temperatures does not appear to be sufficiently high to have any significant effect on the formation of self-gravitating clumps. Self-gravitating clumps form rapidly in the models both with and without the flux-limiter. These models suggest that the reason for the different outcomes of numerical models of disk instability by different groups cannot be attributed solely to the handling of radiative transfer, but rather appears to be caused by a range of numerical effects and assumptions. Given the observational imperative to have disk instability form at least some extrasolar planets, these models imply that disk instability remains as a viable giant planet formation mechanism.

  9. ar diffusion coefficient: Topics by E-print Network

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

    diffusion is examined. Kazuhiko Seki; Saurabh Mogre; Shigeyuki Komura 2014-02-05 4 Fractal diffusion coefficient from dynamical zeta functions Nonlinear Sciences (arXiv)...

  10. axial diffusion coefficient: Topics by E-print Network

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

    diffusion is examined. Kazuhiko Seki; Saurabh Mogre; Shigeyuki Komura 2014-02-05 5 Fractal diffusion coefficient from dynamical zeta functions Nonlinear Sciences (arXiv)...

  11. Pore-Scale Simulation of Intragranular Diffusion: Effects of...

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

    Simulation of Intragranular Diffusion: Effects of Incomplete Mixing on Macroscopic Manifestations. Pore-Scale Simulation of Intragranular Diffusion: Effects of Incomplete Mixing on...

  12. Hydrogen diffusion in Lead Zirconate Titanate and Barium Titanate...

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

    diffusion in Lead Zirconate Titanate and Barium Titanate. Hydrogen diffusion in Lead Zirconate Titanate and Barium Titanate. Abstract: Hydrogen is a potential clean-burning,...

  13. Quantitative analysis of the diffusion of hydrogen peroxide through teeth

    E-Print Network [OSTI]

    Petersen, Brenden Kyle

    2012-01-01T23:59:59.000Z

    activation  properties  of  hydrogen  peroxide  diffusion  the   transport   properties   of   hydrogen   peroxide  Hydrogen   peroxide   has   been   shown   to   readily   diffuse   through   both   enamel   and   dentin,   with   transport   properties  

  14. Mixing it up - Measuring diffusion in supercooled liquid solutions...

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

    Mixing it up - Measuring diffusion in supercooled liquid solutions of methanol and ethanol at temperatures near the glass Mixing it up - Measuring diffusion in supercooled liquid...

  15. Microscopic Reactive Diffusion of Uranium in the Contaminated...

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

    Reactive Diffusion of Uranium in the Contaminated Sediments at Hanford, United States. Microscopic Reactive Diffusion of Uranium in the Contaminated Sediments at Hanford, United...

  16. Oxygen Diffusion (OD) Dramatically Improves Wear-Resistance of...

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

    Oxygen Diffusion (OD) Dramatically Improves Wear-Resistance of Titanium Oxygen Diffusion (OD) Dramatically Improves Wear-Resistance of Titanium 2007 Diesel Engine-Efficiency &...

  17. Portsmouth Gaseous Diffusion Plant - Quadrant I Groundwater Investigat...

    Office of Environmental Management (EM)

    Portsmouth Gaseous Diffusion Plant - Quadrant I Groundwater Investigative (5-Unit) Area Plume Portsmouth Gaseous Diffusion Plant - Quadrant I Groundwater Investigative (5-Unit)...

  18. OPserver: interactive online-computations of opacities and radiative accelerations

    E-Print Network [OSTI]

    C. Mendoza; M. J. Seaton; P. Buerger; A. Bellorin; M. Melendez; J. Gonzalez; L. S. Rodriguez; F. Delahaye; E. Palacios; A. K. Pradhan; C. J. Zeippen

    2007-04-12T23:59:59.000Z

    Codes to compute mean opacities and radiative accelerations for arbitrary chemical mixtures using the Opacity Project recently revised data have been restructured in a client--server architecture and transcribed as a subroutine library. This implementation increases efficiency in stellar modelling where element stratification due to diffusion processes is depth dependent, and thus requires repeated fast opacity reestimates. Three user modes are provided to fit different computing environments, namely a web browser, a local workstation and a distributed grid.

  19. Molecular diffusion in plasma-polymerized tetrafluoroethylene

    SciTech Connect (OSTI)

    Butler, M.A.; Buss, R.J. (Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States))

    1992-11-01T23:59:59.000Z

    Diffusion of an array of molecules in micrometer-thick films of plasma-polymerized tetrafluoroethylene has been measured using an optical interferometric technique. The diffusivity is approximately independent of molecular size up to a molar volume of about 100 cm{sup 3} and drops rapidly for larger molecules. For much larger molecules no penetration of the films is observed. These results suggest that plasma-polymerized tetrafluoroethylene films are heavily cross linked and that this limits the size of the molecules that can penetrate the polymer. The temperature dependence and the molecular size dependence of the diffusivities are discussed in the context of free-volume theory.

  20. Radiation physics, biophysics, and radiation biology

    SciTech Connect (OSTI)

    Hall, E.J.; Zaider, M.

    1993-05-01T23:59:59.000Z

    Research at the Center for Radiological Research is a multidisciplenary blend of physics, chemistry and biology aimed at understanding the mechanisms involved in the health problems resulting from human exposure to ionizing radiations. The focus is increased on biochemistry and the application of the techniques of molecular biology to the problems of radiation biology. Research highlights of the program from the past year are described. A mathematical model describing the production of single-strand and double-strand breaks in DNA as a function radiation quality has been completed. For the first time Monte Carlo techniques have been used to obtain directly the spatial distribution of DNA moieties altered by radiation. This information was obtained by including the transport codes a realistic description of the electronic structure of DNA. We have investigated structure activity relationships for the potential oncogenicity of a new generation of bioreductive drugs that function as hypoxic cytotoxins. Experimental and theoretical investigation of the inverse dose rate effect, whereby medium LET radiations actually produce an c effect when the dose is protracted, is now at a point where the basic mechanisms are reasonably understood and the complex interplay between dose, dose rate and radiation quality which is necessary for the effect to be present can now be predicted at least in vitro. In terms of early radiobiological damage, a quantitative link has been established between basic energy deposition and locally multiply damaged sites, the radiochemical precursor of DNA double strand breaks; specifically, the spatial and energy deposition requirements necessary to form LMDs have been evaluated. For the first time, a mechanically understood biological fingerprint'' of high-LET radiation has been established. Specifically measurement of the ratio of inter-to intra-chromosomal aberrations produces a unique signature from alpha-particles or neutrons.

  1. JUMP DIFFUSION OPTION WITH TRANSACTION COSTS

    E-Print Network [OSTI]

    Mocioalca, Oana

    JUMP DIFFUSION OPTION WITH TRANSACTION COSTS "non-systematic" risk, inclusive of transaction costs. We compute the total transac- tion costs and the turnover for different options, transaction costs, and revision intervals

  2. Determination of diffusion coefficient for unsaturated soils 

    E-Print Network [OSTI]

    Sood, Eeshani

    2005-08-29T23:59:59.000Z

    is non-linear but due to the complexity involved it has been simplified to a linear problem. The nonlinear behavior has been studied during this research. Therefore, certain refinements have been applied in the determination of the diffusion coefficient...

  3. Diffusion, dimensionality and noise in transcriptional regulation

    E-Print Network [OSTI]

    Gasper Tkacik; William Bialek

    2007-12-12T23:59:59.000Z

    The precision of biochemical signaling is limited by randomness in the diffusive arrival of molecules at their targets. For proteins binding to the specific sites on the DNA and regulating transcription, the ability of the proteins to diffuse in one dimension by sliding along the length of the DNA, in addition to their diffusion in bulk solution, would seem to generate a larger target for DNA binding, consequently reducing the noise in the occupancy of the regulatory site. Here we show that this effect is largely cancelled by the enhanced temporal correlations in one dimensional diffusion. With realistic parameters, sliding along DNA has surprisingly little effect on the physical limits to the precision of transcriptional regulation.

  4. Diffuse reflectance imaging with astronomical applications

    E-Print Network [OSTI]

    Hasinoff, Samuel W.

    Diffuse objects generally tell us little about the surrounding lighting, since the radiance they reflect blurs together incident lighting from many directions. In this paper we discuss how occlusion geometry can help invert ...

  5. Electrospray emitters For diffusion vacuum pumps

    E-Print Network [OSTI]

    Diaz Gómez Maqueo, Pablo (Pablo Ly)

    2011-01-01T23:59:59.000Z

    Following similar principles as regular diffusion vacuum pumps, an electrospray emitter is set to produce a jet of charged particles that will drag air molecules out of a volume. To be a feasible concept, the emitted ...

  6. Princeton University Diffusion of Networking Technologies

    E-Print Network [OSTI]

    Goldberg, Sharon

    Electronic Commerce (EC'12) Valencia, Spain June 7, 2012 ISP #12;Seedset: A set of nodes that can kick off, photovoltaics, fax, computers, Internet, video games, ... Source: Rogers. "The Diffusion of Home Computers Among

  7. DIFFUSION MEDIATED TRANSPORT AND THE BROWNIAN MOTOR

    E-Print Network [OSTI]

    DIFFUSION MEDIATED TRANSPORT AND THE BROWNIAN MOTOR David Kinderlehrer Center for Nonlinear in small viscous systems and provide brief illustrations to brownian motor or molecular rachet situations which are found in intracellular transport. Keywords: Brownian motor, molecular rachet, motor protein

  8. An AMR Capable Finite Element Diffusion Solver

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

    Rd. Berkeley, CA 94720, USA E-mail: fisher47@llnl.gov Abstract. We present a novel method for the solution of the diffusion equation on a composite AMR mesh. This approach is...

  9. Novel applications of diffusion-driven flow

    E-Print Network [OSTI]

    Allshouse, Michael R

    2010-01-01T23:59:59.000Z

    Diffusion-driven flow is the result of a conflict between hydrostatic equilibrium in a density stratified fluid and the no-flux boundary condition that must be obeyed on impermeable boundaries that are sloping with respect ...

  10. NREL Solar Radiation Resource Assessment Project: Status and outlook

    SciTech Connect (OSTI)

    Renne, D.; Riordan, C.; Maxwell, E.; Stoffel, T.; Marion, B.; Rymes, M.; Wilcox, S.; Myers, D.

    1992-05-01T23:59:59.000Z

    This report summarizes the activities and accomplishments of NREL's Solar Radiation Resource Assessment Project during fiscal year 1991. Currently, the primary focus of the SRRAP is to produce a 1961--1990 National Solar Radiation Data Base, providing hourly values of global horizontal, diffuse, and direct normal solar radiation at approximately 250 sites around the United States. Because these solar radiation quantities have been measured intermittently at only about 50 of these sites, models were developed and applied to the majority of the stations to provide estimates of these parameters. Although approximately 93% of the data base consists of modeled data this represents a significant improvement over the SOLMET/ERSATZ 1952--1975 data base. The magnitude and importance of this activity are such that the majority of SRRAP human and financial in many other activities, which are reported here. These include the continued maintenance of a solar radiation monitoring network in the southeast United States at six Historically Black Colleges and Universities (HBCU's), the transfer of solar radiation resource assessment technology through a variety of activities, participation in international programs, and the maintenance and operation of NREL's Solar Radiation Research Laboratory. 17 refs.

  11. Diffusion Preconditioner for Discontinuous Galerkin Transport Problems

    E-Print Network [OSTI]

    Barbu, Anthony Petru

    2011-08-08T23:59:59.000Z

    DIFFUSION PRECONDITIONER FOR DISCONTINUOUS GALERKIN TRANSPORT PROBLEMS A Thesis by ANTHONY PETRU BARBU Submitted to the O ce of Graduate Studies of Texas A&M University in partial ful llment of the requirements for the degree of MASTER... OF SCIENCE May 2011 Major Subject: Nuclear Engineering DIFFUSION PRECONDITIONER FOR DISCONTINUOUS GALERKIN TRANSPORT PROBLEMS A Thesis by ANTHONY PETRU BARBU Submitted to the O ce of Graduate Studies of Texas A&M University in partial ful llment...

  12. Diffusion Simulation and Lifetime Calculation at RHIC

    SciTech Connect (OSTI)

    Abreu,N.P.; Fischer, W.; Luo, Y.; Robert-Demolaize, G.

    2009-01-02T23:59:59.000Z

    The beam lifetime is an important parameter for any storage ring. For protons in RHIC it is dominated by the non-linear nature of the head-on collisions that causes the particles to diffuse outside the stable area in phase space. In this report we show results from diffusion simulation and lifetime calculation for the 2006 and 2008 polarized proton runs in RHIC.

  13. Generalizing the flash technique in the front-face configuration to measure the thermal diffusivity of semitransparent solids

    SciTech Connect (OSTI)

    Pech-May, Nelson Wilbur [Departamento de Física Aplicada I, Escuela Técnica Superior de Ingeniería, Universidad del País Vasco UPV/EHU, Alameda Urquijo s/n, 48013 Bilbao (Spain); Department of Applied Physics, CINVESTAV Unidad Mérida, carretera Antigua a Progreso km6, A.P. 73 Cordemex, Mérida Yucatán 97310, México (Mexico); Mendioroz, Arantza; Salazar, Agustín, E-mail: agustin.salazar@ehu.es [Departamento de Física Aplicada I, Escuela Técnica Superior de Ingeniería, Universidad del País Vasco UPV/EHU, Alameda Urquijo s/n, 48013 Bilbao (Spain)

    2014-10-15T23:59:59.000Z

    In this work, we have extended the front-face flash method to retrieve simultaneously the thermal diffusivity and the optical absorption coefficient of semitransparent plates. A complete theoretical model that allows calculating the front surface temperature rise of the sample has been developed. It takes into consideration additional effects, such as multiple reflections of the heating light beam inside the sample, heat losses by convection and radiation, transparency of the sample to infrared wavelengths, and heating pulse duration. Measurements performed on calibrated solids, covering a wide range of absorption coefficients (from transparent to opaque) and thermal diffusivities, validate the proposed method.

  14. Solar radiation intensity calculations

    E-Print Network [OSTI]

    Levine, Randolph Steven

    1978-01-01T23:59:59.000Z

    SOLAR RADIATION INTENSITY CALCULATIONS A Thesis by RANDOLPH STEVEN LEVINE Submitted to the Graduate College of Texas A&M University in partia'l fulfillment of the requirement for the degree of MASTER OF SCIENCE December 1978 Major Subject...: Physics SOLAR RADIATION INTENSITY CALCULATIONS A Thesis by RANDOLPH STEVEN LEVINE Approved as to style and content by: (Chairman of Committee) (Member) (Member) ( member) (Head of Department) December 1978 f219 037 ABSTRACT Solar Radiation...

  15. Radiative Torques on Interstellar Grains: I. Superthermal Spinup

    E-Print Network [OSTI]

    B. T. Draine; Joseph C. Weingartner

    1996-05-09T23:59:59.000Z

    Irregular dust grains are subject to radiative torques when irradiated by interstellar starlight. It is shown how these radiative torques may be calculated using the discrete dipole approximation. Calculations are carried out for one irregular grain geometry, and three different grain sizes. It is shown that radiative torques can play an important dynamical role in spinup of interstellar dust grains, resulting in rotation rates which may exceed even those expected from H_2 formation on the grain surface. Because the radiative torque on an interstellar grain is determined by the overall grain geometry rather than merely the state of the grain surface, the resulting superthermal rotation is expected to be long-lived. By itself, long-lived superthermal rotation would permit grain alignment by normal paramagnetic dissipation on the "Davis-Greenstein" timescale. However, radiative torques arising from anisotropy of the starlight background can act directly to alter the grain alignment on much shorter timescales, and are therefore central to the process of interstellar grain alignment. Radiative torques depend strongly on the grain size, measured by a_eff, the radius of a sphere of equal volume. In diffuse clouds, radiative torques dominate the torques due to H2 formation for a_eff=0.2micron grains, but are relatively unimportant for a_eff0.1 micron grains in diffuse clouds are aligned, while there is little alignment of a_eff superthermal rotation within quiescent dark clouds, but can be very effective in star-forming regions such as the M17 molecular cloud.

  16. Coherent Synchrotron Radiation Analysis

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

    Upton, NY 11973, USA Abstract Coherent Synchrotron Radiation (CSR) effects in bunch compressors are analyzed. Schemes for reducing the CSR effects are presented. 1 INTRODUCTION...

  17. Atomic Radiation (Illinois)

    Broader source: Energy.gov [DOE]

    This article states permissible levels of radiation in unrestricted areas, environmental standards for uranium fuel cycle and information about notification of incidents.

  18. Radiation Hazards Program (Minnesota)

    Broader source: Energy.gov [DOE]

    These regulations, promulgated by the Department of Health, set allowable radiation standards and mitigation practices, as well as procedures for the transportation of hazardous material.

  19. Rotating bubble membrane radiator

    DOE Patents [OSTI]

    Webb, Brent J. (West Richland, WA); Coomes, Edmund P. (West Richland, WA)

    1988-12-06T23:59:59.000Z

    A heat radiator useful for expelling waste heat from a power generating system aboard a space vehicle is disclosed. Liquid to be cooled is passed to the interior of a rotating bubble membrane radiator, where it is sprayed into the interior of the bubble. Liquid impacting upon the interior surface of the bubble is cooled and the heat radiated from the outer surface of the membrane. Cooled liquid is collected by the action of centrifical force about the equator of the rotating membrane and returned to the power system. Details regarding a complete space power system employing the radiator are given.

  20. Radiation physics, biophysics, and radiation biology

    SciTech Connect (OSTI)

    Hall, E.J.

    1992-05-01T23:59:59.000Z

    The following research programs from the Center for Radiological Research of Columbia University are described: Design and development of a new wall-less ultra miniature proportional counter for nanodosimetry; some recent measurements of ionization distributions for heavy ions at nanometer site sizes with a wall-less proportional counter; a calculation of exciton energies in periodic systems with helical symmetry: application to a hydrogen fluoride chain; electron energy-loss function in polynucleotide and the question of plasmon excitation; a non-parametric, microdosimetric-based approach to the evaluation of the biological effects of low doses of ionizing radiation; high-LET radiation risk assessment at medium doses; high-LET radiobiological effects: increased lesion severity or increased lesion proximity; photoneutrons generated by high energy medical linacs; the biological effectiveness of neutrons; implications for radiation protection; molecular characterization of oncogenes induced by neutrons; and the inverse dose-rate effect for oncogenic transformation by charged particles is LET dependent.

  1. COLUMBIA UNIVERSITY Radiation Safety Program

    E-Print Network [OSTI]

    Jia, Songtao

    for increased protection from ionizing radiation for declared pregnant radiation workers. The radiation doseCOLUMBIA UNIVERSITY Radiation Safety Program Medical Center - T: 212-305-0303 F: 212 regulations of the Rules of the City of New York, Article 175, Radiation Control, there is a requirement

  2. Determination of Matrix Diffusion Properties of Granite

    SciTech Connect (OSTI)

    Holtta, Pirkko; Siitari-Kauppi, Marja; Huittinen, Nina [Laboratory of Radiochemistry, P.O. Box 55, University of Helsinki, FI-00014 (Finland); Poteri, Antti [VTT Processes, P.O. Box 1608, VTT, FI-02044 (Finland)

    2007-07-01T23:59:59.000Z

    Rock-core column experiments were introduced to estimate the diffusion and sorption properties of Kuru Grey granite used in block-scale experiments. The objective was to examine the processes causing retention in solute transport through rock fractures, especially matrix diffusion. The objective was also to estimate the importance of retention processes during transport in different scales and flow conditions. Rock-core columns were constructed from cores drilled into the fracture and were placed inside tubes to form flow channels in the 0.5 mm gap between the cores and the tube walls. Tracer experiments were performed using uranin, HTO, {sup 36}Cl, {sup 131}I, {sup 22}Na and {sup 85}Sr at flow rates of 1-50 {mu}L.min{sup -1}. Rock matrix was characterized using {sup 14}C-PMMA method, scanning electron microscopy (SEM), energy dispersive X-ray micro analysis (EDX) and the B.E.T. method. Solute mass flux through a column was modelled by applying the assumption of a linear velocity profile and molecular diffusion. Coupling of the advection and diffusion processes was based on the model of generalised Taylor dispersion in the linear velocity profile. Experiments could be modelled applying a consistent parameterization and transport processes. The results provide evidence that it is possible to investigate matrix diffusion at the laboratory scale. The effects of matrix diffusion were demonstrated on the slightly-sorbing tracer breakthrough curves. Based on scoping calculations matrix diffusion begins to be clearly observable for non-sorbing tracer when the flow rate is 0.1 {mu}L.min{sup -1}. The experimental results presented here cannot be transferred directly to the spatial and temporal scales that prevail in an underground repository. However, the knowledge and understanding of transport and retention processes gained from this study is transferable to different scales from laboratory to in-situ conditions. (authors)

  3. Radiation-resistant microorganism

    DOE Patents [OSTI]

    Fliermans, Carl B.

    2010-06-15T23:59:59.000Z

    An isolated and purified bacterium is provided which was isolated from a high-level radioactive waste site of mixed waste. The isolate has the ability to degrade a wide variety of organic contaminants while demonstrating high tolerance to ionizing radiation. The organism is uniquely suited to bioremediation of a variety or organic contaminants while in the presence of ionizing radiation.

  4. Nonclassicality of Thermal Radiation

    E-Print Network [OSTI]

    Lars M. Johansen

    2004-02-16T23:59:59.000Z

    It is demonstrated that thermal radiation of small occupation number is strongly nonclassical. This includes most forms of naturally occurring radiation. Nonclassicality can be observed as a negative weak value of a positive observable. It is related to negative values of the Margenau-Hill quasi-probability distribution.

  5. Radiative Flux Analysis

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

    Long, Chuck [NOAA

    The Radiative Flux Analysis is a technique for using surface broadband radiation measurements for detecting periods of clear (i.e. cloudless) skies, and using the detected clear-sky data to fit functions which are then used to produce continuous clear-sky estimates. The clear-sky estimates and measurements are then used in various ways to infer cloud macrophysical properties.

  6. Radiation-resistant microorganism

    DOE Patents [OSTI]

    Fliermans, Carl B.

    2007-01-09T23:59:59.000Z

    An isolated and purified bacterium is provided which was isolated from a high-level radioactive waste site of mixed waste. The isolate has the ability to degrade a wide variety of organic contaminants while demonstrating high tolerance to ionizing radiation. The organism is uniquely suited to bioremediation of a variety or organic contaminants while in the presence of ionizing radiation.

  7. Radiation detection system

    DOE Patents [OSTI]

    Franks, Larry A. (Santa Barbara, CA); Lutz, Stephen S. (Santa Barbara, CA); Lyons, Peter B. (Los Alamos, NM)

    1981-01-01T23:59:59.000Z

    A radiation detection system including a radiation-to-light converter and fiber optic wave guides to transmit the light to a remote location for processing. The system utilizes fluors particularly developed for use with optical fibers emitting at wavelengths greater than about 500 nm and having decay times less than about 10 ns.

  8. Paducah Gaseous Diffusion Plant Deactivation Services Section...

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

    Disease Prevention Program. d) Ensure adequate access to health programsambulatory care, and beryllium and radiation worker health surveillance programs. These services are...

  9. diffusion-fundamentals The Open-Access Journal for the Basic Principles of Diffusion Theory, Experiment and Application

    E-Print Network [OSTI]

    Schuck, Götz

    × 10­10 H+ -Diffusion, symmetr. H-bond (TD) ~0.3 4 × 10­09 The method allowing us to isolate specificdiffusion-fundamentals The Open-Access Journal for the Basic Principles of Diffusion Theory, Experiment and Application www.diffusion-fundamentals.org, ISSN 1862-4138; © 2005-2010 Diffusion Fundamentals

  10. Nuclear radiation actuated valve

    DOE Patents [OSTI]

    Christiansen, David W. (Kennewick, WA); Schively, Dixon P. (Richland, WA)

    1985-01-01T23:59:59.000Z

    A nuclear radiation actuated valve for a nuclear reactor. The valve has a valve first part (such as a valve rod with piston) and a valve second part (such as a valve tube surrounding the valve rod, with the valve tube having side slots surrounding the piston). Both valve parts have known nuclear radiation swelling characteristics. The valve's first part is positioned to receive nuclear radiation from the nuclear reactor's fuel region. The valve's second part is positioned so that its nuclear radiation induced swelling is different from that of the valve's first part. The valve's second part also is positioned so that the valve's first and second parts create a valve orifice which changes in size due to the different nuclear radiation caused swelling of the valve's first part compared to the valve's second part. The valve may be used in a nuclear reactor's core coolant system.

  11. A pumping system for measuring coastal diffusion coefficients 

    E-Print Network [OSTI]

    Bolen, Zane Kevin

    1980-01-01T23:59:59.000Z

    system was used to measure surface horizontal diffusion coefficients in the vicin- ity of the diffuser. These experiments were also used to develop tech- niques of underway sampling as well as measuring site specific horizon- tal diffusion... coefficients. Measurement of horizontal diffusion coef- ficients used a continuous point source of tracer material to produce a plume that could be profiled using the pumping system connected to a fluorometer. The resultant horizontal diffusion coefficients...

  12. Subsurface and surface oceanic diffusion experiments near Freeport, Texas

    E-Print Network [OSTI]

    Berry, Alan Dale

    1981-01-01T23:59:59.000Z

    . The results indicate that a power law relationship between the dye distribution variance and the diffusion time is appropriate for horizontal diffusion and that Fickian diffusion adequately describes vertical diffusion. Recommended horizontal and vertical... as From Equations 2 and 3, it can be seen that K may not increase Y linearly with time, but instead by time raised to a power, which will be discussed later in this report. Harramoes (11) suggests that the Fickian diffusion equation is appropriate when...

  13. Fermi Large Area Telescope Measurements of the Diffuse Gamma-Ray Emission at Intermediate Galactic Latitudes

    SciTech Connect (OSTI)

    Abdo, A.A.; /Naval Research Lab, Wash., D.C.; Ackermann, M.; Ajello, M.; /SLAC; Anderson, B.; Atwood, W.B.; /UC, Santa Cruz; Axelsson, M.; /Stockholm U. /Stockholm U., OKC; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, G.; /INFN, Trieste /Trieste U.; Bastieri, D.; /INFN, Padua /Padua U.; Baughman, B.M.; /Taiwan, Natl. Taiwan U. /Ohio State U.; Bechtol, K.; /SLAC; Bellazzini, R.; /INFN, Pisa; Berenji, B.; Blandford, R.D.; Bloom, E.D.; /SLAC; Bonamente, E.; /INFN, Perugia /Perugia U.; Borgland, A.W.; /SLAC; Bregeon, J.; Brez, A.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari /Ecole Polytechnique /Washington U., Seattle /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /IASF, Milan /DAPNIA, Saclay /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /Naval Research Lab, Wash., D.C. /George Mason U. /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /Montpellier U. /Stockholm U. /Stockholm U., OKC /Royal Inst. Tech., Stockholm /Padua U. /Naval Research Lab, Wash., D.C. /Udine U. /INFN, Trieste /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /INFN, Pisa /UC, Santa Cruz /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /CENBG, Gradignan /CENBG, Gradignan /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /Montpellier U. /Bari U. /INFN, Bari /Ecole Polytechnique /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /Udine U. /INFN, Trieste /Hiroshima U. /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /Bari U. /INFN, Bari /INFN, Pisa /INFN, Bari /NASA, Goddard /Maryland U.; /more authors..

    2012-04-11T23:59:59.000Z

    The diffuse galactic {gamma}-ray emission is produced by cosmic rays (CRs) interacting with the interstellar gas and radiation field. Measurements by the Energetic Gamma-Ray Experiment Telescope (EGRET) instrument on the Compton Gamma-Ray Observatory indicated excess {gamma}-ray emission {ge}1 GeV relative to diffuse galactic {gamma}-ray emission models consistent with directly measured CR spectra (the so-called 'EGRET GeV excess'). The Large Area Telescope (LAT) instrument on the Fermi Gamma-Ray Space Telescope has measured the diffuse {gamma}-ray emission with improved sensitivity and resolution compared to EGRET. We report on LAT measurements for energies 100 MeV to 10 GeV and galactic latitudes 10{sup o} {le} |b| {le} 20{sup o}. The LAT spectrum for this region of the sky is well reproduced by a diffuse galactic {gamma}-ray emission model that is consistent with local CR spectra and inconsistent with the EGRET GeV excess.

  14. The Diffusive Finite State Projection Algorithm for Efficient Simulation of the Stochastic Reaction-Diffusion Master

    E-Print Network [OSTI]

    Petzold, Linda R.

    strategy. A novel formulation of the Finite State Projection (FSP) method, called the Diffusive FSP (DFSP (FSP) method [8], called the Diffusive FSP (DFSP) method, for the efficient and accurate simulation with DFSP and reactions with SSA. The dynamics of spatially inhomogeneous stochastic systems are governed

  15. RADIATION SAFETY MANUAL POLICIES AND PROCEDURES

    E-Print Network [OSTI]

    Zhang, Yuanlin

    RADIATION SAFETY MANUAL POLICIES AND PROCEDURES FOR RADIATION PROTECTION AT TEXAS TECH UNIVERSITY................................................................................................................I-1 B. Radiation Protection Program...............................................................................I-3 D. Radiation Safety Management

  16. Radiative and climate impacts of absorbing aerosols

    E-Print Network [OSTI]

    Zhu, Aihua

    2010-01-01T23:59:59.000Z

    V. Ramanathan (2008), Solar radiation budget and radiativeV. Ramanathan (2008), Solar radiation budget and radiativeapproximation for solar radiation in the NCAR Community

  17. Modeling proton intensity gradients and radiation dose equivalents in the inner

    E-Print Network [OSTI]

    Pringle, James "Jamie"

    Modeling proton intensity gradients and radiation dose equivalents in the inner heliosphere using exposure in IP space. In this paper, we utilize EMMREM to study the radial dependence of proton peak crossfield diffusion at large radial distances. Our results show that radial dependencies of proton peak

  18. Interpreting the unresolved intensity of cosmologically redshifted line radiation

    E-Print Network [OSTI]

    Switzer, Eric R; Masui, Kiyoshi W; Pen, Ue-Li; Voytek, Tabitha C

    2015-01-01T23:59:59.000Z

    Intensity mapping experiments survey the spectrum of diffuse line radiation rather than detect individual objects at high signal-to-noise. Spectral maps of unresolved atomic and molecular line radiation contain three-dimensional information about the density and environments of emitting gas, and efficiently probe cosmological volumes out to high redshift. Intensity mapping survey volumes also contain all other sources of radiation at the frequencies of interest. Continuum foregrounds are typically ~10^2-10^3 times brighter than the cosmological signal. The instrumental response to bright foregrounds will produce new spectral degrees of freedom that are not known in advance, nor necessarily spectrally smooth. The intrinsic spectra of foregrounds may also not be well-known in advance. We describe a general class of quadratic estimators to analyze data from single-dish intensity mapping experiments, and determine contaminated spectral modes from the data itself. The key attribute of foregrounds is not that they ...

  19. COLUMBIA UNIVERSITY Radiation Safety Program

    E-Print Network [OSTI]

    Jia, Songtao

    COLUMBIA UNIVERSITY Radiation Safety Program Medical Center - T: 212-305-0303 F: 212 Psychiatric Institute Radiation Safety Office (Please complete this form within 24 hours and send a copy to your supervisor and The Radiation Safety Office) Your Name

  20. COLUMBIA UNIVERSITY Radiation Safety Program

    E-Print Network [OSTI]

    Jia, Songtao

    COLUMBIA UNIVERSITY Radiation Safety Program Medical Center - T: 212-305-0303 F: 212: _______________ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Radiation Safety Office Approval: ______________________ Date: ________________________ Waste containers in place: Yes ___ No ___ Radiation signage on door: Yes ___ No ___ Room monitoring: Dates

  1. Radiation Safety (Revised March 2010)

    E-Print Network [OSTI]

    Kay, Mark A.

    to Workers; Inspections 27 10 CFR Part 20Standards for Protection Against Radiation 28 10 CFR Part 35Radiation Safety Manual (Revised March 2010) Updated December 2012 Stanford University, Stanford California #12; #12; Radiation Safety Manual (Revised March 2010) Updated

  2. Topology, finite time Lyapunov exponents, and barriers for diffusive transport in advection-diffusion problems

    SciTech Connect (OSTI)

    Tang, Xianzhu [College of William and Mary, Williamsburg, VA (United States); Boozer, A.H. [Columbia Univ., New York, NY (United States)

    1996-12-31T23:59:59.000Z

    A wide range of transport problems are of advection-diffusion type. Typical fluid problems of this type are the relaxation of temperature differences in a room or the spread of a contaminant in a river. Important examples in plasma include the relaxation of electrons in a region of stochastic magnetic field lines and the evolution of the magnetic field embedded in a conducting fluid. The archetypal model equation is the advection-diffusion equation. The quantity being transported is {phi}. The flow velocity of the medium, v(x, t), is assumed given and independent of {phi}. The diffusive flux is {Tau}{sub d} = -D{del}{phi}. If the flow is chaotic, the properties of the transport are determined by the spatial and time dependence of the finite time Lyapunov exponent {lambda}({xi}, t). The rapid diffusive transport occurs only along the field line (s line) of the vector s, which defines the stable direction in which neighboring points asymptotically converge. The topology of the s lines affects the diffusive transport through the finite time Lyapunov exponent. We discover that the spatial variation of the finite time Lyapunov exponent along the s lines is smooth and determined by the topology of the s lines. For example, the finite time Lyapunov exponent reaches local minima if the s line makes a sharp bend. These topological bends hinder the diffusive transport and act as a barrier for diffusive relaxation. Such barriers for diffusion reside inside the chaotic region and they persist even the flow is highly chaotic. In the case of the electron relaxation in a region of stochastic field lines, there is a rapid diffusive relaxation of the spatial inhomogeneity in the electron distribution function which is typical of the chaotic transport of a passive scalar. But the diffusive relaxation of the pitch angle distribution is much slower.

  3. Intrauterine device for laser light diffusion and method of using the same

    DOE Patents [OSTI]

    Tadir, Y.; Berns, M.W.; Svaasand, L.O.; Tromberg, B.J.

    1995-12-26T23:59:59.000Z

    An improved device for delivery of photoenergy from a light source, such as a laser, into a uterine cavity for photodynamic therapy is comprised of a plurality of optic fibers, which are bundled together and inserted into the uterine cavity by means of a uterine cannula. The cannula is positioned within the uterine cavity at a preferred location and then withdrawn thereby allowing the plurality of optic fibers to splay or diverge one from the other within the cavity. Different portions of the distal tip of the optic fiber is provided with a light diffusing tip, the remainder being provided with a nondiffusing tip portion. The fiber optic shape, as well as the segment which is permitted to actively diffuse light through the tip, is selected in order to provide a more uniform exposure intensity of the photo energy or at least sufficient radiation directed to each segment of the uterine walls. 5 figs.

  4. FY2008 Report on GADRAS Radiation Transport Methods.

    SciTech Connect (OSTI)

    Mattingly, John K.; Mitchell, Dean James; Harding, Lee; Varley, Eric S.; Hilton, Nathan R. [Sandia National Laboratories, Livermore, CA

    2008-10-01T23:59:59.000Z

    The primary function of the Gamma Detector Response and Analysis Software (GADRAS) is the solution of inverse radiation transport problems, by which the con-figuration of an unknown radiation source is inferred from one or more measured radia-tion signatures. GADRAS was originally developed for the analysis of gamma spec-trometry measurements. During fiscal years 2007 and 2008, GADRAS was augmented to implement the simultaneous analysis of neutron multiplicity measurements. This report describes the radiation transport methods developed to implement this new capability. This work was performed at the direction of the National Nuclear Security Administration's Office of Nonproliferation Research and Development. It was executed as an element of the Proliferation Detection Program's Simulation, Algorithm, and Modeling element. Acronyms BNL Brookhaven National Laboratory CSD Continuous Slowing-Down DU depleted uranium ENSDF Evaluated Nuclear Structure Data Files GADRAS Gamma Detector Response and Analysis Software HEU highly enriched uranium LANL Los Alamos National Laboratory LLNL Lawrence Livermore National Laboratory NA-22 Office of Nonproliferation Research and Development NNDC National Nuclear Data Center NNSA National Nuclear Security Administration ODE ordinary differential equation ONEDANT One-dimensional diffusion accelerated neutral particle transport ORNL Oak Ridge National Laboratory PARTISN Parallel time-dependent SN PDP Proliferation Detection Program RADSAT Radiation Scenario Analysis Toolkit RSICC Radiation Safety Information Computational Center SAM Simulation, Algorithms, and Modeling SNL Sandia National Laboratories SNM special nuclear material ToRI Table of Radioactive Isotopes URI uniform resource identifier XML Extensible Markup Language

  5. 30TH INTERNATIONAL COSMIC RAY CONFERENCE Measuring TeV Gamma-Ray Diffuse Emission from the Galactic Plane with Milagro

    E-Print Network [OSTI]

    Moskalenko, Igor V.

    mechanisms such as the annihilation of dark matter particles [5]. At TeV energies, Milagro has previously@lanl.gov Abstract: Diffuse gamma radiation produced in the interaction of cosmic-ray particles with matter and long observation time the Milagro Gamma-Ray Observatory ­ a water Cherenkov detector in New Mexico, USA

  6. Reverse-selective diffusion in nanocomposite membranes

    E-Print Network [OSTI]

    Reghan J. Hill

    2005-10-27T23:59:59.000Z

    The permeability of certain polymer membranes with impenetrable nanoinclusions increases with the particle volume fraction (Merkel et al., Science, 296, 2002). This intriguing observation contradicts even qualitative expectations based on Maxwell's classical theory of conduction/diffusion in composites with homogeneous phases. This letter presents a simple theoretical interpretation based on classical models of diffusion and polymer physics. An essential feature of the theory is a polymer-segment depletion layer at the inclusion-polymer interface. The accompanying increase in free volume leads to a significant increase in the local penetrant diffusivity, which, in turn, increases the bulk permeability while exhibiting reverse selectivity. This model captures the observed dependence of the bulk permeability on the inclusion size and volume fraction, providing a straightforward connection between membrane microstructure and performance.

  7. Robust diffusion imaging framework for clinical studies

    E-Print Network [OSTI]

    Maximov, Ivan I; Neuner, Irene; Shah, N Jon

    2015-01-01T23:59:59.000Z

    Clinical diffusion imaging requires short acquisition times and good image quality to permit its use in various medical applications. In turn, these demands require the development of a robust and efficient post-processing framework in order to guarantee useful and reliable results. However, multiple artefacts abound in in vivo measurements; from either subject such as cardiac pulsation, bulk head motion, respiratory motion and involuntary tics and tremor, or imaging hardware related problems, such as table vibrations, etc. These artefacts can severely degrade the resulting images and render diffusion analysis difficult or impossible. In order to overcome these problems, we developed a robust and efficient framework enabling the use of initially corrupted images from a clinical study. At the heart of this framework is an improved least trimmed squares diffusion tensor estimation algorithm that works well with severely degraded datasets with low signal-to-noise ratio. This approach has been compared with other...

  8. Diffusion in a rough potential revisited

    E-Print Network [OSTI]

    Banerjee, Saikat; Seki, Kazuhiko; Bagchi, Biman

    2014-01-01T23:59:59.000Z

    Rugged energy landscapes find wide applications in diverse fields ranging from astrophysics to protein folding. We study the dependence of diffusion coefficient $(D)$ of a Brownian particle on the distribution width $(\\varepsilon)$ of randomness in a Gaussian random landscape by simulations and theoretical analysis. We first show that the elegant expression of Zwanzig [PNAS, 85, 2029 (1988)] for $D(\\varepsilon)$ can be reproduced exactly by using the Rosenfeld diffusion-entropy scaling relation. Our simulations show that Zwanzig's expression overestimates $D$ in an uncorrelated Gaussian random lattice - differing by almost an order of magnitude at moderately high ruggedness. The disparity originates from the presence of "three-site traps" (TST) on the landscape -- which are formed by the presence of deep minima flanked by high barriers on either side. Using mean first passage time formalism, we derive a general expression for the effective diffusion coefficient in the presence of TST, that quantitatively repr...

  9. Cosmic-ray diffusion in magnetized turbulence

    E-Print Network [OSTI]

    Tautz, R C

    2015-01-01T23:59:59.000Z

    The problem of cosmic-ray scattering in the turbulent electromagnetic fields of the interstellar medium and the solar wind is of great importance due to the variety of applications of the resulting diffusion coefficients. Examples are diffusive shock acceleration, cosmic-ray observations, and, in the solar system, the propagation of coronal mass ejections. In recent years, it was found that the simple diffusive motion that had been assumed for decades is often in disagreement both with numerical and observational results. Here, an overview is given of the interaction processes of cosmic rays and turbulent electromagnetic fields. First, the formation of turbulent fields due to plasma instabilities is treated, where especially the non-linear behavior of the resulting unstable wave modes is discussed. Second, the analytical and the numerical side of high-energy particle propagation will be reviewed by presenting non-linear analytical theories and Monte-Carlo simulations. For the example of the solar wind, the im...

  10. Florida Radiation Protection Act (Florida)

    Broader source: Energy.gov [DOE]

    The Department of Public Health is responsible for administering a statewide radiation protection program. The program is designed to permit development and utilization of sources of radiation for...

  11. SYNCHROTRON RADIATION SOURCES

    SciTech Connect (OSTI)

    HULBERT,S.L.; WILLIAMS,G.P.

    1998-07-01T23:59:59.000Z

    Synchrotron radiation is a very bright, broadband, polarized, pulsed source of light extending from the infrared to the x-ray region. It is an extremely important source of Vacuum Ultraviolet radiation. Brightness is defined as flux per unit area per unit solid angle and is normally a more important quantity than flux alone particularly in throughput limited applications which include those in which monochromators are used. It is well known from classical theory of electricity and magnetism that accelerating charges emit electromagnetic radiation. In the case of synchrotron radiation, relativistic electrons are accelerated in a circular orbit and emit electromagnetic radiation in a broad spectral range. The visible portion of this spectrum was first observed on April 24, 1947 at General Electric's Schenectady facility by Floyd Haber, a machinist working with the synchrotron team, although the first theoretical predictions were by Lienard in the latter part of the 1800's. An excellent early history with references was presented by Blewett and a history covering the development of the utilization of synchrotron radiation was presented by Hartman. Synchrotron radiation covers the entire electromagnetic spectrum from the infrared region through the visible, ultraviolet, and into the x-ray region up to energies of many 10's of kilovolts. If the charged particles are of low mass, such as electrons, and if they are traveling relativistically, the emitted radiation is very intense and highly collimated, with opening angles of the order of 1 milliradian. In electron storage rings there are three possible sources of synchrotron radiation; dipole (bending) magnets; wigglers, which act like a sequence of bending magnets with alternating polarities; and undulators, which are also multi-period alternating magnet systems but in which the beam deflections are small resulting in coherent interference of the emitted light.

  12. Shell-shocked diffusion model for the light curve of SN2006gy

    E-Print Network [OSTI]

    Nathan Smith; Richard McCray

    2007-10-18T23:59:59.000Z

    We explore a simple model for the high luminosity of SN 2006gy involving photon diffusion of shock-deposited thermal energy. The distinguishing property of the model is that the large ``stellar'' radius of 160 AU required to prevent adiabatic losses is not the true stellar radius, but rather, the radius of an opaque, unbound circumstellar envelope, created when 10 Msun was ejected in the decade before the supernova in an eruption analogous to that of eta Carinae. The supernova light is produced primarily by diffusion of thermal energy following the passage of the blast wave through this shell. This model differs from traditional models of supernova debris interacting with external CSM in that here the shell is optically thick and the escape of radiation is delayed. We show that any model attempting to account for SN2006gy's huge luminosity with radiation emitted by ongoing CSM interaction fails for the following basic reason: the CSM density required to achieve the observed luminosity makes the same circumstellar envelope opaque, forcing a thermal diffusion solution. In our model, the weaker CSM interaction giving rise to SN2006gy's characteristic Type IIn spectrum and soft X-rays is not linked to the power source of the visual continuum; instead, it arises after the blast wave breaks free of the opaque shell into the surrounding wind. While a simple diffusion model can explain the gross properties of the early light curve of SN2006gy, it predicts that the light curve must plummet rapidly at late-times, unless an additional power source is present.

  13. The Intense Radiation Gas

    E-Print Network [OSTI]

    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.

  14. Composition for radiation shielding

    DOE Patents [OSTI]

    Kronberg, James W. (Aiken, SC)

    1994-01-01T23:59:59.000Z

    A composition for use as a radiation shield. The shield has a depleted urum core for absorbing gamma rays and a bismuth coating for preventing chemical corrosion and absorbing gamma rays. Alternatively, a sheet of gadolinium may be positioned between the uranium core and the bismuth coating for absorbing neutrons. The composition is preferably in the form of a container for storing materials that emit radiation such as gamma rays and neutrons. The container is preferably formed by casting bismuth around a pre-formed uranium container having a gadolinium sheeting, and allowing the bismuth to cool. The resulting container is a structurally sound, corrosion-resistant, radiation-absorbing container.

  15. Miniaturized radiation chirper

    DOE Patents [OSTI]

    Umbarger, C. John (Los Alamos, NM); Wolf, Michael A. (Los Alamos, NM)

    1980-01-01T23:59:59.000Z

    The disclosure relates to a miniaturized radiation chirper for use with a small battery supplying on the order of 5 volts. A poor quality CdTe crystal which is not necessarily suitable for high resolution gamma ray spectroscopy is incorporated with appropriate electronics so that the chirper emits an audible noise at a rate that is proportional to radiation exposure level. The chirper is intended to serve as a personnel radiation warning device that utilizes new and novel electronics with a novel detector, a CdTe crystal. The resultant device is much smaller and has much longer battery life than existing chirpers.

  16. Self- and zinc diffusion in gallium antimonide

    SciTech Connect (OSTI)

    Nicols, Samuel Piers

    2002-03-26T23:59:59.000Z

    The technological age has in large part been driven by the applications of semiconductors, and most notably by silicon. Our lives have been thoroughly changed by devices using the broad range of semiconductor technology developed over the past forty years. Much of the technological development has its foundation in research carried out on the different semiconductors whose properties can be exploited to make transistors, lasers, and many other devices. While the technological focus has largely been on silicon, many other semiconductor systems have applications in industry and offer formidable academic challenges. Diffusion studies belong to the most basic studies in semiconductors, important from both an application as well as research standpoint. Diffusion processes govern the junctions formed for device applications. As the device dimensions are decreased and the dopant concentrations increased, keeping pace with Moore's Law, a deeper understanding of diffusion is necessary to establish and maintain the sharp dopant profiles engineered for optimal device performance. From an academic viewpoint, diffusion in semiconductors allows for the study of point defects. Very few techniques exist which allow for the extraction of as much information of their properties. This study focuses on diffusion in the semiconductor gallium antimonide (GaSb). As will become clear, this compound semiconductor proves to be a powerful one for investigating both self- and foreign atom diffusion. While the results have direct applications for work on GaSb devices, the results should also be taken in the broader context of III-V semiconductors. Results here can be compared and contrasted to results in systems such as GaAs and even GaN, indicating trends within this common group of semiconductors. The results also have direct importance for ternary and quaternary semiconductor systems used in devices such as high speed InP/GaAsSb/InP double heterojunction bipolar transistors (DHBT) [Dvorak, (2001)]. Many of the findings which will be reported here were previously published in three journal articles. Hartmut Bracht was the lead author on two articles on self-diffusion studies in GaSb [Bracht, (2001), (2000)], while this report's author was the lead author on Zn diffusion results [Nicols, (2001)]. Much of the information contained herein can be found in those articles, but a more detailed treatment is presented here.

  17. Fractal diffusion coefficient from dynamical zeta functions

    E-Print Network [OSTI]

    G. Cristadoro

    2005-09-28T23:59:59.000Z

    Dynamical zeta functions provide a powerful method to analyze low dimensional dynamical systems when the underlying symbolic dynamics is under control. On the other hand even simple one dimensional maps can show an intricate structure of the grammar rules that may lead to a non smooth dependence of global observable on parameters changes. A paradigmatic example is the fractal diffusion coefficient arising in a simple piecewise linear one dimensional map of the real line. Using the Baladi-Ruelle generalization of the Milnor-Thurnston kneading determinant we provide the exact dynamical zeta function for such a map and compute the diffusion coefficient from its smallest zero.

  18. Analytical solutions to matrix diffusion problems

    SciTech Connect (OSTI)

    Kekäläinen, Pekka, E-mail: pekka.kekalainen@helsinki.fi [Laboratory of Radiochemistry, Department of Chemistry, P.O. Box 55, FIN-00014 University of Helsinki (Finland)

    2014-10-06T23:59:59.000Z

    We report an analytical method to solve in a few cases of practical interest the equations which have traditionally been proposed for the matrix diffusion problem. In matrix diffusion, elements dissolved in ground water can penetrate the porous rock surronuding the advective flow paths. In the context of radioactive waste repositories this phenomenon provides a mechanism by which the area of rock surface in contact with advecting elements is greatly enhanced, and can thus be an important delay mechanism. The cases solved are relevant for laboratory as well for in situ experiments. Solutions are given as integral representations well suited for easy numerical solution.

  19. Effect of Diffusion on Bunched Beam Echo

    SciTech Connect (OSTI)

    Stupakov, G.V.; Chao, A.W.; /SLAC

    2011-09-01T23:59:59.000Z

    When a beam receives a dipole kick, its centroid signal decoheres due to the betatron tune spread in the beam. Long after the signal has decohered, however, a followup quadrupole kick to the beam brings a pronounced echo back to the centroid signal. This echo effect has been analyzed for the case of a bunched beam in Ref. [1]. In this work, the perturbation calculation of Ref. [1] is extended to include a diffusion in betatron amplitude. The effect of diffusion on the magnitude of the echo is then parameterized and studied.

  20. Portal radiation monitor

    DOE Patents [OSTI]

    Kruse, Lyle W. (Albuquerque, NM)

    1985-01-01T23:59:59.000Z

    A portal radiation monitor combines 0.1% FAR with high sensitivity to special nuclear material. The monitor utilizes pulse shape discrimination, dynamic compression of the photomultiplier output and scintillators sized to maintain efficiency over the entire portal area.

  1. The Gravitational Cherenkov Radiation

    E-Print Network [OSTI]

    A. M. Ignatov

    2001-10-26T23:59:59.000Z

    An example of discontinuity of the energy-momentum tensor moving at superluminal velocity is discussed. It is shown that the gravitational Mach cone is formed. The power spectrum of the corresponding Cherenkov radiation is evaluated.

  2. Radiation from Accelerated Branes

    E-Print Network [OSTI]

    Mohab Abou-Zeid; Miguel S. Costa

    2000-01-29T23:59:59.000Z

    The radiation emitted by accelerated fundamental strings and D-branes is studied within the linear approximation to the supergravity limit of string theory. We show that scalar, gauge field and gravitational radiation is generically emitted by such branes. In the case where an external scalar field accelerates the branes, we derive a Larmor-type formula for the emitted scalar radiation and study the angular distribution of the outgoing energy flux. The classical radii of the branes are calculated by means of the corresponding Thompson scattering cross sections. Within the linear approximation, the interaction of the external scalar field with the velocity fields of the branes gives a contribution to the observed gauge field and gravitational radiation.

  3. Ionizing radiation detector

    DOE Patents [OSTI]

    Thacker, Louis H. (Knoxville, TN)

    1990-01-01T23:59:59.000Z

    An ionizing radiation detector is provided which is based on the principle of analog electronic integration of radiation sensor currents in the sub-pico to nano ampere range between fixed voltage switching thresholds with automatic voltage reversal each time the appropriate threshold is reached. The thresholds are provided by a first NAND gate Schmitt trigger which is coupled with a second NAND gate Schmitt trigger operating in an alternate switching state from the first gate to turn either a visible or audible indicating device on and off in response to the gate switching rate which is indicative of the level of radiation being sensed. The detector can be configured as a small, personal radiation dosimeter which is simple to operate and responsive over a dynamic range of at least 0.01 to 1000 R/hr.

  4. Amorphous silicon radiation detectors

    DOE Patents [OSTI]

    Street, Robert A. (Palo Alto, CA); Perez-Mendez, Victor (Berkeley, CA); Kaplan, Selig N. (El Cerrito, CA)

    1992-01-01T23:59:59.000Z

    Hydrogenated amorphous silicon radiation detector devices having enhanced signal are disclosed. Specifically provided are transversely oriented electrode layers and layered detector configurations of amorphous silicon, the structure of which allow high electric fields upon application of a bias thereby beneficially resulting in a reduction in noise from contact injection and an increase in signal including avalanche multiplication and gain of the signal produced by incoming high energy radiation. These enhanced radiation sensitive devices can be used as measuring and detection means for visible light, low energy photons and high energy ionizing particles such as electrons, x-rays, alpha particles, beta particles and gamma radiation. Particular utility of the device is disclosed for precision powder crystallography and biological identification.

  5. Amorphous silicon radiation detectors

    DOE Patents [OSTI]

    Street, R.A.; Perez-Mendez, V.; Kaplan, S.N.

    1992-11-17T23:59:59.000Z

    Hydrogenated amorphous silicon radiation detector devices having enhanced signal are disclosed. Specifically provided are transversely oriented electrode layers and layered detector configurations of amorphous silicon, the structure of which allow high electric fields upon application of a bias thereby beneficially resulting in a reduction in noise from contact injection and an increase in signal including avalanche multiplication and gain of the signal produced by incoming high energy radiation. These enhanced radiation sensitive devices can be used as measuring and detection means for visible light, low energy photons and high energy ionizing particles such as electrons, x-rays, alpha particles, beta particles and gamma radiation. Particular utility of the device is disclosed for precision powder crystallography and biological identification. 13 figs.

  6. Radiation Safety Training Basic Radiation Safety Training for

    E-Print Network [OSTI]

    Dai, Pengcheng

    Radiation Safety Training Basic Radiation Safety Training for X-ray Users for Physics 461 & 462 Protocol Title: Basic Radiation Safety Training for X-ray Users Drafted By: Chris Millsaps, RSS Reviewers: ZB, TU, GS Purpose: To provide basic radiation safety training to the users of x-ray producing

  7. Radiation Safety Manual Dec 2012 Page 1 RADIATION SAFETY

    E-Print Network [OSTI]

    Grishok, Alla

    of External and Internal Doses E. Reports and Notices to Workers Chapter VII: Radiation ProtectionRadiation Safety Manual ­ Dec 2012 Page 1 RADIATION SAFETY MANUAL For Columbia University NewYork-Presbyterian Hospital New York State Psychiatric Institute Barnard College December 2012 #12;Radiation Safety Manual

  8. Method of enhancing radiation response of radiation detection materials

    DOE Patents [OSTI]

    Miller, Steven D. (Richland, WA)

    1997-01-01T23:59:59.000Z

    The present invention is a method of increasing radiation response of a radiation detection material for a given radiation signal by first pressurizing the radiation detection material. Pressurization may be accomplished by any means including mechanical and/or hydraulic. In this application, the term "pressure" includes fluid pressure and/or mechanical stress.

  9. Radiative Transitions in Charmonium

    SciTech Connect (OSTI)

    Jozef Dudek; Robert Edwards; David Richards

    2005-10-01T23:59:59.000Z

    The form factors for the radiative transitions between charmonium mesons are investigated. We employ an anisotropic lattice using a Wilson gauge action, and domain-wall fermion action. We extrapolate the form factors to Q{sup 2} = 0, corresponding to a real photon, using quark-model-inspired functions. Finally, comparison is made with photocouplings extracted from the measured radiative widths, where known. Our preliminary results find photocouplings commensurate with these experimentally extracted values.

  10. Radiative Processes Working Group

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's PossibleRadiation Protection Radiation Protection Regulations: The

  11. Radiation analysis devices, radiation analysis methods, and articles of manufacture

    DOE Patents [OSTI]

    Roybal, Lyle Gene

    2010-06-08T23:59:59.000Z

    Radiation analysis devices include circuitry configured to determine respective radiation count data for a plurality of sections of an area of interest and combine the radiation count data of individual of sections to determine whether a selected radioactive material is present in the area of interest. An amount of the radiation count data for an individual section is insufficient to determine whether the selected radioactive material is present in the individual section. An article of manufacture includes media comprising programming configured to cause processing circuitry to perform processing comprising determining one or more correction factors based on a calibration of a radiation analysis device, measuring radiation received by the radiation analysis device using the one or more correction factors, and presenting information relating to an amount of radiation measured by the radiation analysis device having one of a plurality of specified radiation energy levels of a range of interest.

  12. Gravitational Tunneling Radiation

    E-Print Network [OSTI]

    Mario Rabinowitz

    2002-12-11T23:59:59.000Z

    The isolated black hole radiation of both Hawking and Zel'dovich are idealized abstractions as there is always another body to distort the potential. This is considered with respect to both gravitational tunneling, and black hole "no-hair" theorems. The effects of a second body are to lower the gravitational barrier of a black hole and to give the barrier a finite rather than infinite width so tha a particle can escape by tunneling (as in field emission) or over the top of the lowered barrier (as in Schottky emission). Thus radiation may be emitted from black holes in a process differing from that of Hawking radiation, P SH, which has been undetected for over 24 years. The radiated power from a black hole derived here is PR e ^2__ PSH, where e ^2__ is he ransmission probability for radiation through the barrier. This is similar to electric field emission of electrons from a metal in that the emission can in principle be modulated and beamed. The temperature and entropy of black holes are reexamined. Miniscule black holes herein may help explain the missing mass of the universe, accelerated expansion of the universe, and anomalous rotation of spiral galaxies. A gravitational interference effect for black hole radiation similar to the Aharonov-Bohm effect is also examined.

  13. Packet personal radiation monitor

    DOE Patents [OSTI]

    Phelps, James E. (Knoxville, TN)

    1989-01-01T23:59:59.000Z

    A personal radiation monitor of the chirper type is provided for detecting ionizing radiation. A battery powered high voltage power supply is used to generate and apply a high voltage bias to a G-M tube radiation sensor. The high voltage is monitored by a low-loss sensing network which generates a feedback signal to control the high voltage power supply such that the high voltage bias is recharged to +500 VDC when the current pulses of the sensor, generated by the detection of ionizing radiation events, discharges the high voltage bias to +450 VDC. During the high voltage recharge period an audio transducer is activated to produce an audible "chirp". The rate of the "chirps" is controlled by the rate at which the high voltage bias is recharged, which is proportional to the radiation field intensity to which the sensor is exposed. The chirp rate sensitivity is set to be approximately 1.5 (chirps/min/MR/hr.). The G-M tube sensor is used in a current sensing mode so that the device does not paralyze in a high radiation field.

  14. JOHNSON-MATTHEY DIFFUSER CHARACTERIZATION TESTING

    SciTech Connect (OSTI)

    Foster, P; James Klein, J; Henry Sessions, H; Gregg Morgan, G

    2007-08-02T23:59:59.000Z

    A diffuser/permeator commercially fabricated by Johnson-Matthey was purchased for characterization testing at the Savannah River National Laboratory (SRNL). A test system was fabricated to not only feed and bleed flows and pressures, but also permeate pressure for flows up to 20 SLPM.

  15. Fluctuation bounds on charge and heat diffusion

    E-Print Network [OSTI]

    Pavel Kovtun

    2014-07-02T23:59:59.000Z

    We study thermal fluctuation corrections to charge and heat conductivity in systems with locally conserved energy and charge, but without locally conserved momentum. Thermal fluctuations may naturally lead to a lower bound on diffusion constants for thermoelectric transport, and need to be taken into account when discussing potential bounds on transport coefficients.

  16. Diffusive Acceleration of Ions at Interplanetary Shocks

    E-Print Network [OSTI]

    Matthew G. Baring; Errol J. Summerlin

    2005-06-08T23:59:59.000Z

    Heliospheric shocks are excellent systems for testing theories of particle acceleration in their environs. These generally fall into two classes: (1) interplanetary shocks that are linear in their ion acceleration characteristics, with the non-thermal ions serving as test particles, and (2) non-linear systems such as the Earth's bow shock and the solar wind termination shock, where the accelerated ions strongly influence the magnetohydrodynamic structure of the shock. This paper explores the modelling of diffusive acceleration at a particular interplanetary shock, with an emphasis on explaining in situ measurements of ion distribution functions. The observational data for this event was acquired on day 292 of 1991 by the Ulysses mission. The modeling is performed using a well-known kinetic Monte Carlo simulation, which has yielded good agreement with observations at several heliospheric shocks, as have other theoretical techniques, namely hybrid plasma simulations, and numerical solution of the diffusion-convection equation. In this theory/data comparison, it is demonstrated that diffusive acceleration theory can, to first order, successfully account for both the proton distribution data near the shock, and the observation of energetic protons farther upstream of this interplanetary shock than lower energy pick-up protons, using a single turbulence parameter. The principal conclusion is that diffusive acceleration of inflowing upstream ions can model this pick-up ion-rich event without the invoking any seed pre-acceleration mechanism, though this investigation does not rule out the action of such pre-acceleration.

  17. Magnetic flux diffusion through HTS shields

    E-Print Network [OSTI]

    Wong, Kai-Wai; Fan, C. X.; Havenhill, A. D.

    1998-06-01T23:59:59.000Z

    Slow field leakage in a polycrystalline superconducting cupshield placed in an external axial field (H-ext) much weaker than H-C1 shows a diffusive time dependence with a time scale of 10(2) s. As the field strength increases but is still less than...

  18. Inverse Problems for Fractional Diffusion Equations

    E-Print Network [OSTI]

    Zuo, Lihua

    2013-06-21T23:59:59.000Z

    and preliminaries in Section 1 and 2, in the third section we consider our first inverse boundary problem. This is where an unknown boundary condition is to be determined from overposed data in a time- fractional diffusion equation. Based upon the fundamental...

  19. Ternary gas mixture for diffuse discharge switch

    DOE Patents [OSTI]

    Christophorou, Loucas G. (Oak Ridge, TN); Hunter, Scott R. (Oak Ridge, TN)

    1988-01-01T23:59:59.000Z

    A new diffuse discharge gas switch wherein a mixture of gases is used to take advantage of desirable properties of the respective gases. There is a conducting gas, an insulating gas, and a third gas that has low ionization energy resulting in a net increase in the number of electrons available to produce a current.

  20. Mathematical analysis for fractional diffusion equations: forward

    E-Print Network [OSTI]

    Boyer, Franck

    or dumping WasteGroundwater flow Base rock Underground storage Soil gapsmicro scale about 100m Field: macro-Diffusion equation Result of Field Test (Adams& Gelhar, 1992) t0 t1 t2 t3 t0 Pollution source Model Prediction Univ. #12;· Determination of contamination source t u = u + F We need detailed mathematical researches

  1. Diffusion in Flexible Pipes Susanne Brogaard Kristensen

    E-Print Network [OSTI]

    . . . . . . . . . . . . . . . . . . . . . 51 7.5.3 Carbon dioxide diffusion . . . . . . . . . . . . . . . . . 52 7.5.4 52Effect of C it may cause the outer sheath to burst. Also if large amounts of carbon dioxide, hydrogen sulfide . . . . . . . . . . . . . . . . . . . . . . . 39 1 . #12;7.3 Thermodynamic properties , . . . . . . . . . . . . . . . . . . . 45 7.4 First approach

  2. Forecasting Turbulent Modes with Nonparametric Diffusion Models

    E-Print Network [OSTI]

    Tyrus Berry; John Harlim

    2015-01-27T23:59:59.000Z

    This paper presents a nonparametric diffusion modeling approach for forecasting partially observed noisy turbulent modes. The proposed forecast model uses a basis of smooth functions (constructed with the diffusion maps algorithm) to represent probability densities, so that the forecast model becomes a linear map in this basis. We estimate this linear map by exploiting a previously established rigorous connection between the discrete time shift map and the semi-group solution associated to the backward Kolmogorov equation. In order to smooth the noisy data, we apply diffusion maps to a delay embedding of the noisy data, which also helps to account for the interactions between the observed and unobserved modes. We show that this delay embedding biases the geometry of the data in a way which extracts the most predictable component of the dynamics. The resulting model approximates the semigroup solutions of the generator of the underlying dynamics in the limit of large data and in the observation noise limit. We will show numerical examples on a wide-range of well-studied turbulent modes, including the Fourier modes of the energy conserving Truncated Burgers-Hopf (TBH) model, the Lorenz-96 model in weakly chaotic to fully turbulent regimes, and the barotropic modes of a quasi-geostrophic model with baroclinic instabilities. In these examples, forecasting skills of the nonparametric diffusion model are compared to a wide-range of stochastic parametric modeling approaches, which account for the nonlinear interactions between the observed and unobserved modes with white and colored noises.

  3. Working With Radiation For Research

    E-Print Network [OSTI]

    Jia, Songtao

    working with radiation The radiation badge is not a protective device It cannot shield you from ­ Negative Exponential Protection From Radiation #12;18 Time Distance Shielding Basic Principles #121 Working With Radiation For Research Thomas Cummings Junior Physicist Environmental Health

  4. Radiation Safety Annual Refresher Training

    E-Print Network [OSTI]

    Thomas, David D.

    Radiation Safety Annual Refresher Training Radiation Protection Division Department of Environmental Health & Safety #12;Topics in Radiation Safety (applicable RPD Manual sections indicated) User;Topics in Radiation Safety (applicable RPD Manual sections indicated) User and Non-user topics Types

  5. Probing the brain’s white matter with diffusion MRI and a tissue dependent diffusion model 

    E-Print Network [OSTI]

    Piatkowski, Jakub Przemyslaw

    2014-06-27T23:59:59.000Z

    While diffusion MRI promises an insight into white matter microstructure in vivo, the axonal pathways that connect different brain regions together can only partially be segmented using current methods. Here we present ...

  6. A Diffusion Study of the Federally Mandated School Wellness Policy

    E-Print Network [OSTI]

    Harriger, Dinah Jane

    2012-10-19T23:59:59.000Z

    Using Diffusion of Innovations (DOI) in Organizations as a theoretical framework, this dissertation analyzed the diffusion process of the federally mandated School Wellness Policy (SWP) in three separate studies. Beginning with a content analysis...

  7. The effects of double-diffusion on a baroclinic vortex

    E-Print Network [OSTI]

    Smith, Wendy Marie

    1987-01-01T23:59:59.000Z

    Laboratory experiments were performed to study the combined effects of double-diffusion and rotation on an oceanic intrusion. Intrusions are driven across density-compensated fronts by the divergence of the double-diffusive ...

  8. Diapycnal advection by double diffusion and turbulence in the ocean

    E-Print Network [OSTI]

    St. Laurent, Louis C

    1999-01-01T23:59:59.000Z

    Observations of diapycnal mixing rates are examined and related to diapycnal advection for both double-diffusive and turbulent regimes. The role of double-diffusive mixing at the site of the North Atlantic Tracer Release ...

  9. Shell Model for Atomistic Simulation of Lithium Diffusion in...

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

    Shell Model for Atomistic Simulation of Lithium Diffusion in Mixed MnTi Oxides. Shell Model for Atomistic Simulation of Lithium Diffusion in Mixed MnTi Oxides. Abstract: Mixed...

  10. Moisture Diffusion in Asphalt Binders and Fine Aggregate Mixtures

    E-Print Network [OSTI]

    Vasconcelos, Kamilla L.

    2011-08-08T23:59:59.000Z

    cost in highway maintenance and vehicle operations. One key mechanism of how moisture reaches the asphalt-aggregate interface is by its permeation or diffusion through the asphalt binder or mastic. Different techniques are available for diffusion...

  11. Modelling of unidirectional thermal diffusers in shallow water

    E-Print Network [OSTI]

    Lee, Joseph Hun-Wei

    1977-01-01T23:59:59.000Z

    This study is an experimental and theoretical investigation of the temperature field and velocity field induced by a unidirectional thermal diffuser in shallow water. A multiport thermal diffuser is essentially a pipe laid ...

  12. Imaging Intrinsic Diffusion of Bridge-Bonded Oxygen Vacancies...

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

    Intrinsic Diffusion of Bridge-Bonded Oxygen Vacancies on TiO2(110). Imaging Intrinsic Diffusion of Bridge-Bonded Oxygen Vacancies on TiO2(110). Abstract: Since oxygen atom...

  13. CODED SPECTROSCOPY FOR ETHANOL DETECTION IN DIFFUSE, FLUORESCENT MEDIA

    E-Print Network [OSTI]

    ABSTRACT CODED SPECTROSCOPY FOR ETHANOL DETECTION IN DIFFUSE, FLUORESCENT MEDIA by Scott Thomas Mc FOR ETHANOL DETECTION IN DIFFUSE, FLUORESCENT MEDIA by Scott Thomas McCain Department of Electrical

  14. Portsmouth Gaseous Diffusion Plant environmental report for 1989

    SciTech Connect (OSTI)

    Turner, J.W. (ed.) (Martin Marietta Energy Systems, Inc., Oak Ridge, TN (USA))

    1990-10-01T23:59:59.000Z

    This calendar year 1989 annual report on environmental surveillance of the US Department of Energy's (DOE) Portsmouth Gaseous Diffusion Plant (PORTS) and its environs consists of two parts: the Summary, Discussion, and Conclusions (Part 1) and the Data Presentation (Part 2). The objectives of this report are the following: report 1989 monitoring data for the installation and its environs that may have been affected by operations on the plant site, provide reasonably detailed information about the plant site and plant operations, provide detailed information on input and assumptions used in all calculations, provide trend analyses (where appropriate) to indicate increases and decreases in environmental impact, and provide general information on plant quality assurance. Routine monitoring and sampling for radiation, radioactive materials, and chemical substances on and off the DOE site are used to document compliance with appropriate standards, to identify trends, to provide information for the public, and to contribute to general environmental knowledge. The surveillance program assists in fulfilling the DOE policy of protecting the public, employees, and environment from harm that could be caused by its activities and reducing negative environmental impacts to the greatest degree practicable. Environmental-monitoring information complements data on specific releases, trends, and summaries. 26 refs.

  15. Radiation delivery system and method

    DOE Patents [OSTI]

    Sorensen, Scott A. (Overland Park, KS); Robison, Thomas W. (Los Alamos, NM); Taylor, Craig M. V. (Jemez Springs, NM)

    2002-01-01T23:59:59.000Z

    A radiation delivery system and method are described. The system includes a treatment configuration such as a stent, balloon catheter, wire, ribbon, or the like, a portion of which is covered with a gold layer. Chemisorbed to the gold layer is a radiation-emitting self-assembled monolayer or a radiation-emitting polymer. The radiation delivery system is compatible with medical catheter-based technologies to provide a therapeutic dose of radiation to a lesion following an angioplasty procedure.

  16. Radiation Protection and Safety Training | Environmental Radiation

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)IntegratedSpeedingTechnicalPurchase, Delivery, andSmartRadiation EffectsProtection

  17. Spatial curvature effects on molecular transport by diffusion

    E-Print Network [OSTI]

    J. Balakrishnan

    2003-08-25T23:59:59.000Z

    For a substance diffusing on a curved surface, we obtain an explicit relation valid for very small values of the time, between the local concentration, the diffusion coefficient, the intrinsic spatial curvature and the time. We recover the known solution of Fick's law of diffusion in the flat space limit. In the biological context, this result would be useful in understanding the variations in the diffusion rates of integral proteins and other molecules on membranes.

  18. Investigation of porous media structures using NMR restricted diffusion measurements 

    E-Print Network [OSTI]

    Miao, Peizhi

    1993-01-01T23:59:59.000Z

    be observed in the literature. Woessner measured the apparent diffusion coefficients for three systems: water in silica suspensions; water in a sandstone core; and benzene- rubber. He employed a constant field gradient spin-echo technique and observed.... For the application of NMR technique to extract pore structure information from restricted diffusion measurements, we will follow a two-step scheme, 1) determine the distribution of apparent diffusion coefficient from NMR measurement of fluid diffusion in porous...

  19. LETTRES A LA RDACTION DIFFUSION LASTIQUE DES PHOTONS

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    spectrometrie par scintillation 6choue, 6 cause des empilements de photons diffus6s de basse énergie. FIG. 1

  20. Remote radiation dosimetry

    DOE Patents [OSTI]

    Braunlich, P.F.; Tetzlaff, W.; Hegland, J.E.; Jones, S.C.

    1991-03-12T23:59:59.000Z

    Disclosed are methods and apparatus for remotely measuring radiation levels. Such are particularly useful for measuring relatively high levels or dosages of radiation being administered in radiation therapy. They are also useful for more general radiation level measurements where remote sensing from the remaining portions of the apparatus is desirable. The apparatus uses a beam generator, such as a laser beam, to provide a stimulating beam. The stimulating beam is preferably of wavelengths shorter than 6 microns, or more advantageously less than 2 microns. The stimulating beam is used to stimulate a remote luminescent sensor mounted in a probe which emits stored luminescent energy resulting from exposure of the sensor to ionizing radiation. The stimulating beam is communicated to the remote luminescent sensor via a transmissive fiber which also preferably serves to return the emission from the luminescent sensor. The stimulating beam is advantageously split by a beam splitter to create a detector beam which is measured for power during a reading period during which the luminescent phosphor is read. The detected power is preferably used to control the beam generator to thus produce desired beam power during the reading period. The luminescent emission from the remote sensor is communicated to a suitable emission detector, preferably after filtering or other selective treatment to better isolate the luminescent emission. 8 figures.

  1. Packet personal radiation monitor

    DOE Patents [OSTI]

    Phelps, J.E.

    1988-03-31T23:59:59.000Z

    A personal radiation monitor of the chirper type is provided for detecting ionizing radiation. A battery powered high voltage power supply is used to generate and apply a high voltage bias to a G-M tube radiation sensor. The high voltage is monitored by a low-loss sensing network which generates a feedback signal to control the high voltage power supply such that the high voltage bias is recharged to +500 VDC when the current pulses of the sensor, generated by the detection of ionizing radiatonevents, discharges the high voltage bias to +450 VDC. During the high voltage recharge period an audio transducer is activated to produce an audible ''chirp''. The rate of the ''chirps'' is controlled by the rate at which the high voltage bias is recharged, which is proportional to the radiation field intensity to which the sensor is exposed. The chirp rate sensitivity is set to be approximately 1.5 (chirps/min/MR/hr.). The G-M tube sensor is used in a current sensing mode so that the device does not paralyze in a high radiation field. 2 figs.

  2. EFFECT OF BROWNIAN AND THERMOPHORETIC DIFFUSIONS OF NANOPARTICLES ON

    E-Print Network [OSTI]

    Zhang, Yuwen

    EFFECT OF BROWNIAN AND THERMOPHORETIC DIFFUSIONS OF NANOPARTICLES ON NONEQUILIBRIUM HEAT CONDUCTION of Brownian and thermophoretic diffusions on nonequilibrium heat conduction in a nanofluid layer with periodic, and period of the surface heat flux. Effects of Brownian and thermophoretic diffusions of nanoparticles

  3. Technical Note Correction of Eddy-Current Distortions in Diffusion

    E-Print Network [OSTI]

    Technical Note Correction of Eddy-Current Distortions in Diffusion Tensor Images Using the Known,2 Purpose: To correct eddy-current artifacts in diffusion ten- sor (DT) images without the need to obtain- tortions caused by eddy currents induced by large diffusion gradients. We propose a new postacquisition

  4. New Monte Carlo schemes for simulating diffusions in discontinuous media

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    New Monte Carlo schemes for simulating diffusions in discontinuous media Antoine Lejay1,2,3,4,5 Sylvain Maire6,7 April 28, 2012 Abstract We introduce new Monte Carlo simulation schemes for diffusions in a dis- continuous media divided in subdomains with piecewise constant diffusivity. These schemes

  5. New Monte Carlo schemes for simulating diffusions in discontinuous media

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    New Monte Carlo schemes for simulating diffusions in discontinuous media Antoine Lejay1,2,3,4,5 Sylvain Maire6,7 December 13, 2012 Abstract We introduce new Monte Carlo simulation schemes for diffusions in a dis- continuous media divided in subdomains with piecewise constant diffusivity. These schemes

  6. Convergence Speed of GARCH Option Price to Diffusion Option Price

    E-Print Network [OSTI]

    Wang, Yazhen

    Convergence Speed of GARCH Option Price to Diffusion Option Price Jin-Chuan Duan National constructed GARCH model will weakly converge to a bi- variate diffusion. Naturally the European option price under the GARCH model will also converge to its bivariate diffusion counterpart. This paper investigates

  7. Nonlinear analysis of a reaction-diffusion system: Amplitude equations

    SciTech Connect (OSTI)

    Zemskov, E. P., E-mail: zemskov@ccas.ru [Russian Academy of Sciences, Dorodnicyn Computing Center (Russian Federation)

    2012-10-15T23:59:59.000Z

    A reaction-diffusion system with a nonlinear diffusion term is considered. Based on nonlinear analysis, the amplitude equations are obtained in the cases of the Hopf and Turing instabilities in the system. Turing pattern-forming regions in the parameter space are determined for supercritical and subcritical instabilities in a two-component reaction-diffusion system.

  8. Modelling precipitation of niobium carbide in austenite: multicomponent diffusion, capillarity,

    E-Print Network [OSTI]

    Cambridge, University of

    Modelling precipitation of niobium carbide in austenite: multicomponent diffusion, capillarity, and coarsening N. Fujita and H. K. D. H. Bhadeshia The growth of niobium carbide in austenite involves the diffusion of both niobium and carbon. These elements diffuse at very different rates. A model is presented

  9. Chapter 1 Introduction 1.1 Why Diffusion in Polymers

    E-Print Network [OSTI]

    Goddard III, William A.

    I - 1 Chapter 1 Introduction 1.1 Why Diffusion in Polymers Various industrial applications of polymers involve diffusion of gases through polymersi . Membrane separation of gases in the gas and oil involve impeding the diffusion of gases through thin polymer films, commonly used as packaging food

  10. A Diffusion Model in Population Genetics with Mutation and Dynamic

    E-Print Network [OSTI]

    O'Leary, Michael

    A Diffusion Model in Population Genetics with Mutation and Dynamic Fitness Mike O'Leary Department of Mathematics Towson University May 24, 2008 Mike O'Leary (Towson University) A Diffusion Model in Genetics May Miller, Georgetown University Mike O'Leary (Towson University) A Diffusion Model in Genetics May 24, 2008

  11. Mixed waste storage facility CDR review, Paducah Gaseous Diffusion Plant; Solid waste landfill CDR review, Paducah Gaseous Diffusion Plant

    SciTech Connect (OSTI)

    NONE

    1998-08-01T23:59:59.000Z

    This report consists of two papers reviewing the waste storage facility and the landfill projects proposed for the Paducah Gaseous Diffusion Plant complex. The first paper is a review of DOE`s conceptual design report for a mixed waste storage facility. This evaluation is to review the necessity of constructing a separate mixed waste storage facility. The structure is to be capable of receiving, weighing, sampling and the interim storage of wastes for a five year period beginning in 1996. The estimated cost is assessed at approximately $18 million. The review is to help comprehend and decide whether a new storage building is a feasible approach to the PGDP mixed waste storage problem or should some alternate approach be considered. The second paper reviews DOE`s conceptual design report for a solid waste landfill. This solid waste landfill evaluation is to compare costs and the necessity to provide a new landfill that would meet State of Kentucky regulations. The assessment considered funding for a ten year storage facility, but includes a review of other facility needs such as a radiation detection building, compactor/baler machinery, material handling equipment, along with other personnel and equipment storage buildings at a cost of approximately $4.1 million. The review is to help discern whether a landfill only or the addition of compaction equipment is prudent.

  12. Coherent Nuclear Radiation

    E-Print Network [OSTI]

    V. I. Yukalov; E. P. Yukalova

    2004-06-22T23:59:59.000Z

    The main part of this review is devoted to the comprehensive description of coherent radiation by nuclear spins. The theory of nuclear spin superradiance is developed and the experimental observations of this phenomenon are considered. The intriguing problem of how coherence develops from initially incoherent quantum fluctuations is analysed. All main types of coherent radiation by nuclear spins are discussed, which are: free nuclear induction, collective induction, maser generation, pure superradiance, triggered superradiance, pulsing superradiance, punctuated superradiance, and induced emission. The influence of electron-nuclear hyperfine interactions and the role of magnetic anisotropy are studied. Conditions for realizing spin superradiance by magnetic molecules are investigated. The possibility of nuclear matter lasing, accompanied by pion or dibaryon radiation, is briefly touched.

  13. Pediatric radiation oncology

    SciTech Connect (OSTI)

    Halperin, E.C.; Kun, L.E.; Constine, L.S.; Tarbell, N.J.

    1989-01-01T23:59:59.000Z

    This text covers all aspects of radiation therapy for treatment of pediatric cancer. The book describes the proper use of irradiation in each of the malignancies of childhood, including tumors that are rarely encountered in adult practice. These include acute leukemia; supratentorial brain tumors; tumors of the posterior fossa of the brain and spinal canal; retinoblastoma and optic nerve glioma; neuroblastoma; Hodgkin's disease; malignant lymphoma; Ewing's sarcoma; osteosarcoma; rhabdomyosarcoma; Desmoid tumor; Wilms' tumor; liver and biliary tumors; germ cell and stromal cell tumors of the gonads; endocrine, aerodigestive tract, and breast tumors; Langerhans' cell histiocytosis; and skin cancer and hemangiomas. For each type of malignancy, the authors describe the epidemiology, common presenting signs and symptoms, staging, and proper diagnostic workup. Particular attention is given to the indications for radiation therapy and the planning of a course of radiotherapy, including the optimal radiation dose, field size, and technique.

  14. Composition for radiation shielding

    DOE Patents [OSTI]

    Kronberg, J.W.

    1994-08-02T23:59:59.000Z

    A composition for use as a radiation shield is disclosed. The shield has a depleted uranium core for absorbing gamma rays and a bismuth coating for preventing chemical corrosion and absorbing gamma rays. Alternatively, a sheet of gadolinium may be positioned between the uranium core and the bismuth coating for absorbing neutrons. The composition is preferably in the form of a container for storing materials that emit radiation such as gamma rays and neutrons. The container is preferably formed by casting bismuth around a pre-formed uranium container having a gadolinium sheeting, and allowing the bismuth to cool. The resulting container is a structurally sound, corrosion-resistant, radiation-absorbing container. 2 figs.

  15. Radiation monitor for liquids

    DOE Patents [OSTI]

    Koster, J.E.; Bolton, R.D.

    1999-03-02T23:59:59.000Z

    A radiation monitor for use with liquids that utilizes air ions created by alpha radiation emitted by the liquids as its detectable element. A signal plane, held at an electrical potential with respect to ground, collects these air ions. A guard plane or guard rings is used to limit leakage currents. In one embodiment, the monitor is used for monitoring liquids retained in a tank. Other embodiments monitor liquids flowing through a tank, and bodies of liquids, such as ponds, lakes, rivers and oceans. 4 figs.

  16. Radiation monitor for liquids

    DOE Patents [OSTI]

    Koster, James E. (Los Alamos, NM); Bolton, Richard D. (Los Alamos, NM)

    1999-01-01T23:59:59.000Z

    A radiation monitor for use with liquids that utilizes air ions created by alpha radiation emitted by the liquids as its detectable element. A signal plane, held at an electrical potential with respect to ground, collects these air ions. A guard plane or guard rings is used to limit leakage currents. In one embodiment, the monitor is used for monitoring liquids retained in a tank. Other embodiments monitor liquids flowing through a tank, and bodies of liquids, such as ponds, lakes, rivers and oceans.

  17. Wireless passive radiation sensor

    DOE Patents [OSTI]

    Pfeifer, Kent B; Rumpf, Arthur N; Yelton, William G; Limmer, Steven J

    2013-12-03T23:59:59.000Z

    A novel measurement technique is employed using surface acoustic wave (SAW) devices, passive RF, and radiation-sensitive films to provide a wireless passive radiation sensor that requires no batteries, outside wiring, or regular maintenance. The sensor is small (<1 cm.sup.2), physically robust, and will operate unattended for decades. In addition, the sensor can be insensitive to measurement position and read distance due to a novel self-referencing technique eliminating the need to measure absolute responses that are dependent on RF transmitter location and power.

  18. Radiation.cdr

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)IntegratedSpeedingTechnicalPurchase, Delivery, andSmartRadiationRadiation Safety Work

  19. Methodology and apparatus for diffuse photon imaging

    DOE Patents [OSTI]

    Feng, S.C.; Zeng, F.; Zhao, H.L.

    1997-12-09T23:59:59.000Z

    Non-invasive near infrared optical medical imaging devices for both hematoma detection in the brain and early tumor detection in the breast is achieved using image reconstruction which allows a mapping of the position dependent contrast diffusive propagation constants, which are related to the optical absorption coefficient and scattering coefficient in the tissue, at near infrared wavelengths. Spatial resolutions in the range of 5 mm for adult brain sizes and breast sizes can be achieved. The image reconstruction utilizes WKB approximation on most probable diffusion paths which has as lowest order approximation the straight line-of-sight between the plurality of sources and the plurality of detectors. The WKB approximation yields a set of linear equations in which the contrast optical absorption coefficients are the unknowns and for which signals can be generated to produce a pixel map of the contrast optical resolution of the scanned tissue. 58 figs.

  20. Methodology and apparatus for diffuse photon mimaging

    DOE Patents [OSTI]

    Feng, Shechao C. (Los Angeles, CA); Zeng, Fanan (Los Angeles, CA); Zhao, Hui-Lin (Los Angeles, CA)

    1997-12-09T23:59:59.000Z

    Non-invasive near infrared optical medical imaging devices for both hematoma detection in the brain and early tumor detection in the breast is achieved using image reconstruction which allows a mapping of the position dependent contrast diffusive propagation constants, which are related to the optical absorption coefficient and scattering coefficient in the tissue, at near infrared wavelengths. Spatial resolutions in the range of 5 mm for adult brain sizes and breast sizes can be achieved. The image reconstruction utilizes WKB approximation on most probable diffusion paths which has as lowest order approximation the straight line-of-sight between the plurality of sources and the plurality of detectors. The WKB approximation yields a set of linear equations in which the contrast optical absorption coefficients are the unknowns and for which signals can be generated to produce a pixel map of the contrast optical resolution of the scanned tissue.

  1. Diffusion barriers in modified air brazes

    DOE Patents [OSTI]

    Weil, Kenneth Scott; Hardy, John S; Kim, Jin Yong; Choi, Jung-Pyung

    2013-04-23T23:59:59.000Z

    A method for joining two ceramic parts, or a ceramic part and a metal part, and the joint formed thereby. The method provides two or more parts, a braze consisting of a mixture of copper oxide and silver, a diffusion barrier, and then heats the braze for a time and at a temperature sufficient to form the braze into a bond holding the two or more parts together. The diffusion barrier is an oxidizable metal that forms either a homogeneous component of the braze, a heterogeneous component of the braze, a separate layer bordering the braze, or combinations thereof. The oxidizable metal is selected from the group Al, Mg, Cr, Si, Ni, Co, Mn, Ti, Zr, Hf, Pt, Pd, Au, lanthanides, and combinations thereof.

  2. Diffusive Shock Acceleration: the Fermi Mechanism

    E-Print Network [OSTI]

    Matthew G. Baring

    1997-11-16T23:59:59.000Z

    The mechanism of diffusive Fermi acceleration at collisionless plasma shock waves is widely invoked in astrophysics to explain the appearance of non-thermal particle populations in a variety of environments, including sites of cosmic ray production, and is observed to operate at several sites in the heliosphere. This review outlines the principal results from the theory of diffusive shock acceleration, focusing first on how it produces power-law distributions in test-particle regimes, where the shock dynamics are dominated by the thermal populations that provide the seed particles for the acceleration process. Then the importance of non-linear modifications to the shock hydrodynamics by the accelerated particles is addressed, emphasizing how these subsequently influence non-thermal spectral formation.

  3. State protection under collective damping and diffusion

    SciTech Connect (OSTI)

    Ponte, M. A. de [Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, Caixa Postal 369, 13560-590 Sao Carlos, SP (Brazil); Departamento de Fisica, Universidade Regional do Cariri, 63010-970 Juazeiro do Norte, CE (Brazil); Mizrahi, S. S. [Departamento de Fisica, Universidade Federal de Sao Carlos, 13565-905 Sao Carlos, SP (Brazil); Moussa, M. H. Y. [Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, Caixa Postal 369, 13560-590 Sao Carlos, SP (Brazil)

    2011-07-15T23:59:59.000Z

    In this paper we provide a recipe for state protection in a network of oscillators under collective damping and diffusion. Our strategy is to manipulate the network topology, i.e., the way the oscillators are coupled together, the strength of their couplings, and their natural frequencies, in order to create a relaxation-diffusion-free channel. This protected channel defines a decoherence-free subspace (DFS) for nonzero-temperature reservoirs. Our development also furnishes an alternative approach to build up DFSs that offers two advantages over the conventional method: it enables the derivation of all the network-protected states at once, and also reveals, through the network normal modes, the mechanism behind the emergence of these protected domains.

  4. Diffusion limited reactions in confined environments

    E-Print Network [OSTI]

    Jeremy D. Schmit; Ercan Kamber; Jané Kondev

    2007-11-19T23:59:59.000Z

    We study the effect of confinement on diffusion limited bimolecular reactions within a lattice model where a small number of reactants diffuse amongst a much larger number of inert particles. When the number of inert particles is held constant the rate of the reaction is slow for small reaction volumes due to limited mobility from crowding, and for large reaction volumes due to the reduced concentration of the reactants. The reaction rate proceeds fastest at an intermediate confinement corresponding to volume fraction near 1/2 and 1/3 in two and three dimensions, respectively. We generalize the model to off-lattice systems with hydrodynamic coupling and predict that the optimal reaction rate for monodisperse colloidal systems occurs when the volume fraction is ~0.18. Finally, we discuss the application of our model to bimolecular reactions inside cells as well as the dynamics of confined polymers.

  5. Analytical Solutions for Radiative Transfer: Implications for Giant Planet Formation by Disk Instability

    E-Print Network [OSTI]

    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.

  6. 8. Particle Diffusion and Acceleration Proceedings of the Workshop: ``Diffuse Thermal and Relativistic Plasma in Galaxy Clusters''

    E-Print Network [OSTI]

    Boehringer, Hans

    8. Particle Diffusion and Acceleration #12; #12; Proceedings of the Workshop: ``Diffuse Thermal. Feretti & P. Schuecker, MPE Report 271, pp. 249­253 Turbulent Particle Acceleration in the Diffuse Cluster Abstract. In situ particle acceleration is probably occur­ ing in cluster radio haloes. This is suggested

  7. Distributed Energy Resources Market Diffusion Model

    SciTech Connect (OSTI)

    Maribu, Karl Magnus; Firestone, Ryan; Marnay, Chris; Siddiqui,Afzal S.

    2006-06-16T23:59:59.000Z

    Distributed generation (DG) technologies, such as gas-fired reciprocating engines and microturbines, have been found to be economically beneficial in meeting commercial-sector electrical, heating, and cooling loads. Even though the electric-only efficiency of DG is lower than that offered by traditional central stations, combined heat and power (CHP) applications using recovered heat can make the overall system energy efficiency of distributed energy resources (DER) greater. From a policy perspective, however, it would be useful to have good estimates of penetration rates of DER under various economic and regulatory scenarios. In order to examine the extent to which DER systems may be adopted at a national level, we model the diffusion of DER in the US commercial building sector under different technical research and technology outreach scenarios. In this context, technology market diffusion is assumed to depend on the system's economic attractiveness and the developer's knowledge about the technology. The latter can be spread both by word-of-mouth and by public outreach programs. To account for regional differences in energy markets and climates, as well as the economic potential for different building types, optimal DER systems are found for several building types and regions. Technology diffusion is then predicted via two scenarios: a baseline scenario and a program scenario, in which more research improves DER performance and stronger technology outreach programs increase DER knowledge. The results depict a large and diverse market where both optimal installed capacity and profitability vary significantly across regions and building types. According to the technology diffusion model, the West region will take the lead in DER installations mainly due to high electricity prices, followed by a later adoption in the Northeast and Midwest regions. Since the DER market is in an early stage, both technology research and outreach programs have the potential to increase DER adoption, and thus, shift building energy consumption to a more efficient alternative.

  8. Collective motion in quantum diffusive environment

    E-Print Network [OSTI]

    V. M. Kolomietz; S. Å berg; S. V. Radionov

    2007-06-16T23:59:59.000Z

    The general problem of dissipation in macroscopic large-amplitude collective motion and its relation to energy diffusion of intrinsic degrees of freedom of a nucleus is studied. By applying the cranking approach to the nuclear many-body system, a set of coupled dynamical equations for the collective classical variable and the quantum mechanical occupancies of the intrinsic nuclear states is derived. Different dynamical regimes of the intrinsic nuclear motion and its consequences on time properties of collective dissipation are discussed.

  9. Uranium enrichment export control guide: Gaseous diffusion

    SciTech Connect (OSTI)

    Not Available

    1989-09-01T23:59:59.000Z

    This document was prepared to serve as a guide for export control officials in their interpretation, understanding, and implementation of export laws that relate to the Zangger International Trigger List for gaseous diffusion uranium enrichment process components, equipment, and materials. Particular emphasis is focused on items that are especially designed or prepared since export controls are required for these by States that are party to the International Nuclear Nonproliferation Treaty.

  10. Metal Nitride Diffusion Barriers for Copper Interconnects

    E-Print Network [OSTI]

    Araujo, Roy A.

    2010-01-14T23:59:59.000Z

    nanocrystalline TiN film enhances grain boundary sliding and grain boundary diffusion related creep phenomena, and the ductility of the coatings is also improved. On the other hand, compositional designed TiN based alloys, such as cubic-phase Ti1-xAlxN thin... Nitrides ...................... 26 2.3 Composition and Structures of TiN, TaN and HfN ................. 33 2.4 Nitride Formation, Electronegativity, Atomic Radius and Bonding...

  11. Gas mixture for diffuse-discharge switch

    DOE Patents [OSTI]

    Christophorou, L.G.; Carter, J.G.; Hunter, S.R.

    1982-08-31T23:59:59.000Z

    Gaseous medium in a diffuse-discharge switch of a high-energy pulse generator is formed of argon combined with a compound selected from the group consisting of CF/sub 4/, C/sub 2/F/sub 6/, C/sub 3/F/sub 8/, n-C/sub 4/F/sub 10/, WF/sub 6/, (CF/sub 3/)/sub 2/S and (CF/sub 3/)/sub 2/O.

  12. Diffusion method of seperating gaseous mixtures

    DOE Patents [OSTI]

    Pontius, Rex B. (Rochester, NY)

    1976-01-01T23:59:59.000Z

    A method of effecting a relatively large change in the relative concentrations of the components of a gaseous mixture by diffusion which comprises separating the mixture into heavier and lighter portions according to major fraction mass recycle procedure, further separating the heavier portions into still heavier subportions according to a major fraction mass recycle procedure, and further separating the lighter portions into still lighter subportions according to a major fraction equilibrium recycle procedure.

  13. Gamma radiological surveys of the Oak Ridge Reservation, Paducah Gaseous Diffusion Plant, and Portsmouth Gaseous Diffusion Plant, 1990-1993, and overview of data processing and analysis by the Environmental Restoration Remote Sensing Program, Fiscal Year 1995

    SciTech Connect (OSTI)

    Smyre, J.L.; Moll, B.W.; King, A.L.

    1996-06-01T23:59:59.000Z

    Three gamma radiological surveys have been conducted under auspices of the ER Remote Sensing Program: (1) Oak Ridge Reservation (ORR) (1992), (2) Clinch River (1992), and (3) Portsmouth Gaseous Diffusion Plant (PORTS) (1993). In addition, the Remote Sensing Program has acquired the results of earlier surveys at Paducah Gaseous Diffusion Plant (PGDP) (1990) and PORTS (1990). These radiological surveys provide data for characterization and long-term monitoring of U.S. Department of Energy (DOE) contamination areas since many of the radioactive materials processed or handled on the ORR, PGDP, and PORTS are direct gamma radiation emitters or have gamma emitting daughter radionuclides. High resolution airborne gamma radiation surveys require a helicopter outfitted with one or two detector pods, a computer-based data acquisition system, and an accurate navigational positioning system for relating collected data to ground location. Sensors measure the ground-level gamma energy spectrum in the 38 to 3,026 KeV range. Analysis can provide gamma emission strength in counts per second for either gross or total man-made gamma emissions. Gross count gamma radiation includes natural background radiation from terrestrial sources (radionuclides present in small amounts in the earth`s soil and bedrock), from radon gas, and from cosmic rays from outer space as well as radiation from man-made radionuclides. Man-made count gamma data include only the portion of the gross count that can be directly attributed to gamma rays from man-made radionuclides. Interpretation of the gamma energy spectra can make possible the determination of which specific radioisotopes contribute to the observed man-made gamma radiation, either as direct or as indirect (i.e., daughter) gamma energy from specific radionuclides (e.g., cesium-137, cobalt-60, uranium-238).

  14. Diffuse emission of high-energy neutrinos from gamma-ray burst fireballs

    E-Print Network [OSTI]

    Irene Tamborra; Shin'ichiro Ando

    2015-04-01T23:59:59.000Z

    Gamma-ray bursts (GRBs) have been suggested as possible sources of the high-energy neutrino flux recently detected by the IceCube telescope. We revisit the fireball emission model and elaborate an analytical prescription to estimate the high-energy neutrino prompt emission from pion and kaon decays, assuming that the leading mechanism for the neutrino production is lepto-hadronic. To this purpose, we include hadronic, radiative and adiabatic cooling effects and discuss their relevance for long- (including high- and low-luminosity) and short-duration GRBs. The expected diffuse neutrino background is derived, by requiring that the GRB high-energy neutrino counterparts follow up-to-date gamma-ray luminosity functions and redshift evolutions of the long and short GRBs. Although dedicated stacking searches have been unsuccessful up to now, we find that the GRBs could contribute up to a few percents to the observed IceCube high-energy neutrino flux for sub-PeV energies, assuming that the latter has a diffuse origin. The high-luminosity component gives the dominant contribution to the diffuse neutrino emission, while the fluxes from both the low-luminosity and the short-duration GRBs are significantly smaller. Our findings confirm the most-recent IceCube results on the GRB searches and suggest that larger exposure is mandatory to detect high-energy neutrinos from GRBs in the near future.

  15. Interactive Volume Rendering of Diffusion Tensor Data

    SciTech Connect (OSTI)

    Hlawitschka, Mario; Weber, Gunther; Anwander, Alfred; Carmichael, Owen; Hamann, Bernd; Scheuermann, Gerik

    2007-03-30T23:59:59.000Z

    As 3D volumetric images of the human body become an increasingly crucial source of information for the diagnosis and treatment of a broad variety of medical conditions, advanced techniques that allow clinicians to efficiently and clearly visualize volumetric images become increasingly important. Interaction has proven to be a key concept in analysis of medical images because static images of 3D data are prone to artifacts and misunderstanding of depth. Furthermore, fading out clinically irrelevant aspects of the image while preserving contextual anatomical landmarks helps medical doctors to focus on important parts of the images without becoming disoriented. Our goal was to develop a tool that unifies interactive manipulation and context preserving visualization of medical images with a special focus on diffusion tensor imaging (DTI) data. At each image voxel, DTI provides a 3 x 3 tensor whose entries represent the 3D statistical properties of water diffusion locally. Water motion that is preferential to specific spatial directions suggests structural organization of the underlying biological tissue; in particular, in the human brain, the naturally occuring diffusion of water in the axon portion of neurons is predominantly anisotropic along the longitudinal direction of the elongated, fiber-like axons [MMM+02]. This property has made DTI an emerging source of information about the structural integrity of axons and axonal connectivity between brain regions, both of which are thought to be disrupted in a broad range of medical disorders including multiple sclerosis, cerebrovascular disease, and autism [Mos02, FCI+01, JLH+99, BGKM+04, BJB+03].

  16. Microstructural Evolution and Radiation Effects of Uranium-Bearing Diffusion Couples

    E-Print Network [OSTI]

    Wei, Chao-Chen

    2014-12-12T23:59:59.000Z

    -cladding chemical interaction, or FCCI, is one of the primary material problems during reactor operations. A series of tests using uranium-bearing fuel alloys and various cladding materials were performed to assess the diffusional interactions. However...

  17. An improved multipyranometer array for the measurement of direct and diffuse solar radiation

    E-Print Network [OSTI]

    Munger, Bryce Kirtley

    1997-01-01T23:59:59.000Z

    Corrected and Switched MPA Solution. . . . . 66 Table 5. 2: Hourly RMSE & R2 . 67 Table 5. 3: Curtiss Ib, T/C & Uniform Albedo Results (from Curtiss (1990)). . . . . . . . . . 67 Table D. I: Geometric Shade Factors for the Eppley Shadow Band (Eppley Labs...

  18. SOLUTION OF EQUILIBRIUM RADIATION DIFFUSION PROBLEMS USING IMPLICIT ADAPTIVE MESH REFINEMENT

    E-Print Network [OSTI]

    Kurien, Susan

    , and combustion applications such as modeling of coal-fired power generation systems and wildfire spread

  19. Modeling heat conduction and radiation transport with the diffusion equation in

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHighandSWPA / SPRA /Ml'. William Hirst HirstModelingAssessing theheat

  20. Microsoft Word - Construction of Accuracy-Preserving Surrogate for the Eigenvalue Radiation Diffusion and Transport Problem

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHighandSWPA / SPRA / USACE SWPAURTeC:8 3.After-Hoursof76D 1 Pennsylvania2 -

  1. Sensitivity of Clear-Sky Diffuse Radiation to In Situ Aerosol Scattering Parameters

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over Our Instagram Secretary Moniz is TakingDepartmentSensitivities of SCMs toSensitivity

  2. Anisotropic diffusion of spherical particles in closely confining microchannels

    E-Print Network [OSTI]

    Dettmer, Simon L; Misiunas, Karolis; Keyser, Ulrich F

    2014-01-01T23:59:59.000Z

    We present here the measurement of the diffusivity of spherical particles closely confined by narrow microchannels. Our experiments yield a 2D map of the position-dependent diffusion coefficients parallel and perpendicular to the channel axis with a resolution down to 129 nm. The diffusivity was measured simultaneously in the channel interior, the bulk reservoirs as well as the channel entrance region. In the channel interior we found strongly anisotropic diffusion. While the perpendicular diffusion coefficient close to the confining walls decreased down to approximately 25 % of the value on the channel axis, the parallel diffusion coefficient remained constant throughout the entire channel width. In addition to the experiment, we performed finite element simulations for the diffusivity in the channel interior and found good agreement with the measurements. Our results reveal the distinctive influence of strong confinement on Brownian motion which is of significance to microfluidics as well as quantitative mo...

  3. Creep effects in diffusion bonding of oxygen-free copper

    E-Print Network [OSTI]

    Moilanen, Antti

    Diffusion is the transport of atoms or particles through the surrounding material. Various microstructural changes in metals are based on the diffusion phenomena. In solid metals the diffusion is closely related to crystallographic defects. In single-component metals the dominant mechanism of diffusion is the vacancy mechanism. Diffusion bonding is a direct technological application of diffusion. It is an advanced solidstate joining process in which the surfaces of two components are brought to contact with each other and heated under a pressing load in a controlled environment. During the process, the contact surfaces are bonded by atomic diffusion across the interface and as a result, one solid piece is formed. The condition of high temperature and low applied stress combined with relatively long process duration enables the creep effects to take place in bonded metals. Furthermore, creep causes unwanted permanent deformations in the bonded components. Some authors suggest that there could be a threshold fo...

  4. Local microwave background radiation

    E-Print Network [OSTI]

    Domingos Soares

    2014-11-13T23:59:59.000Z

    An inquiry on a possible local origin for the Microwave Background Radiation is made. Thermal MBR photons are contained in a system called {\\it magnetic bottle} which is due to Earth magnetic field and solar wind particles, mostly electrons. Observational tests are anticipated.

  5. Radiation Source Replacement Workshop

    SciTech Connect (OSTI)

    Griffin, Jeffrey W.; Moran, Traci L.; Bond, Leonard J.

    2010-12-01T23:59:59.000Z

    This report summarizes a Radiation Source Replacement Workshop in Houston Texas on October 27-28, 2010, which provided a forum for industry and researchers to exchange information and to discuss the issues relating to replacement of AmBe, and potentially other isotope sources used in well logging.

  6. Thermostatic Radiator Valve Evaluation

    SciTech Connect (OSTI)

    Dentz, Jordan [Advanced Residential Integrated Energy Solutions Collaborative, New York, NY (United States); Ansanelli, Eric [Advanced Residential Integrated Energy Solutions Collaborative, New York, NY (United States)

    2015-01-01T23:59:59.000Z

    A large stock of multifamily buildings in the Northeast and Midwest are heated by steam distribution systems. Losses from these systems are typically high and a significant number of apartments are overheated much of the time. Thermostatically controlled radiator valves (TRVs) are one potential strategy to combat this problem, but have not been widely accepted by the residential retrofit market.

  7. Three Dimensional Radiative Transfer

    E-Print Network [OSTI]

    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.

  8. Radiation detector spectrum simulator

    DOE Patents [OSTI]

    Wolf, M.A.; Crowell, J.M.

    1985-04-09T23:59:59.000Z

    A small battery operated nuclear spectrum simulator having a noise source generates pulses with a Gaussian distribution of amplitudes. A switched dc bias circuit cooperating therewith to generate several nominal amplitudes of such pulses and a spectral distribution of pulses that closely simulates the spectrum produced by a radiation source such as Americium 241.

  9. Photovoltaic radiation detector element

    DOE Patents [OSTI]

    Agouridis, D.C.

    1980-12-17T23:59:59.000Z

    A radiation detector element is formed of a body of semiconductor material, a coating on the body which forms a photovoltaic junction therewith, and a current collector consisting of narrow metallic strips, the aforesaid coating having an opening therein in the edge of which closely approaches but is spaced from the current collector strips.

  10. Structure, Vol. 11, 1319, January, 2003, 2003 Elsevier Science Ltd. All rights reserved. PII S0969-2126(02)00910-3 Notes from the BenchHow does Radiation

    E-Print Network [OSTI]

    Harrison, Stephen C.

    -2126(02)00910-3 Notes from the BenchHow does Radiation Damage in Protein Crystals Depend on X-Ray Dose? as heat free radical diffusion altogether, secondary damage becomes insig-Is radiation damage to cryopreserved does not appearThe smallest crystal that can yield a full data set to to provide greater protection

  11. Radiation Characteristics of Glass Containing Gas Bubbles

    E-Print Network [OSTI]

    Pilon, Laurent; Viskanta, Raymond

    2003-01-01T23:59:59.000Z

    B. L. Drolen, “Thermal radiation in particulate media withRadiation Characteristics of Glass Containing Gas Bubblesthermophysical properties and radiation characteristics of

  12. Radiation damage evolution in ceramics. | EMSL

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

    Radiation damage evolution in ceramics. Radiation damage evolution in ceramics. Abstract: A review is presented of recent results on radiation damage production, defect...

  13. Preliminary radiation shielding design for BOOMERANG

    E-Print Network [OSTI]

    Donahue, Richard J.

    2002-01-01T23:59:59.000Z

    Preliminary Radiation Shielding Design for BOOMERANG R. J.2003 Abstract Preliminary radiation shielding speci?cationsElectron Photon Stray Radiation from a High Energy Electron

  14. Terahertz radiation from laser accelerated electron bunches

    E-Print Network [OSTI]

    2004-01-01T23:59:59.000Z

    NUMBER 5 MAY 2004 Terahertz radiation from laser acceleratedand millimeter wave radiation from laser acceleratedNo. 5, May 2004 Terahertz radiation from laser accelerated

  15. Meeting Report--NASA Radiation Biomarker Workshop

    E-Print Network [OSTI]

    Straume, Tore

    2008-01-01T23:59:59.000Z

    ionizing radiation. In: Advances in Medical Physics (A. B.for medical management of radiation casualties. ADVANCES INMedical Center presented the radiation oncology perspective on biomarkers. Advances

  16. Nanoscale Engineering Of Radiation Tolerant Silicon Carbide....

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

    Engineering Of Radiation Tolerant Silicon Carbide. Nanoscale Engineering Of Radiation Tolerant Silicon Carbide. Abstract: Radiation tolerance is determined by how effectively the...

  17. Radiation Safety Training Basic Radiation Safety Training for

    E-Print Network [OSTI]

    Dai, Pengcheng

    Radiation Safety Training Basic Radiation Safety Training for Sealed Source Users for Physics 461 Protocol Title: Training for Sealed Source Users Drafted By: Chris Millsaps, RSS Reviewers: ZB, TU, GS Purpose: To provide basic radiation safety training to the users of sealed sources located

  18. Radiation effects on microstructures and properties of irradiated materials

    SciTech Connect (OSTI)

    Mansur, L.K.

    1996-12-01T23:59:59.000Z

    Development of structural materials to withstand aggressive radiation environments has been carried out on an international scale over the past four decades. Major radiation-induced changes in properties include swelling, creep and embrittlement. The basic work, stimulated by technology, to understand and control these phenomena, has been heavily oriented toward the evolution of microstructures and their effects on properties. Microstructural research has coupled analyses by high resolution techniques with theoretical modeling to describe and predict microscopic features and the resulting macroscopic properties. A short summary is presented of key physical considerations that drive these changes during irradiation. Such processes begin with displacement cascades, and lead to property changes through the diffusion and clustering of defects.

  19. Historically Black Colleges and Universities (HBCU) Solar Radiation Monitoring Network

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

    The Historically Black Colleges and Universities (HBCU) Solar Radiation Monitoring Network operated from November 1985 through December 1996. The six-station network provided 5-minute averaged measurements of global and diffuse horizontal solar irradiance. The data were processed at the National Renewable Energy Laboratory (NREL) to improve the assessment of the solar radiation resources in the southeastern United States. Three of the stations also measured the direct-normal solar irradiance with a pyrheliometer mounted in an automatic sun tracker. All data are archived in the Standard Broadband Format (SBF) with quality-assessment indicators. Monthly data summaries and plots are also available for each month. In January 1997 the HBCU sites became part of the CONFRRM solar monitoring network.

  20. Pacific Northwest Solar Radiation Data

    E-Print Network [OSTI]

    Oregon, University of

    Pacific Northwest Solar Radiation Data UO SOLAR MONITORING LAB Physics Department -- Solar Energy Center 1274 University of Oregon Eugene, Oregon 97403-1274 April 1, 1999 #12;Hourly solar radiation data

  1. RADIATION DAMAGE OF GERMANIUM DETECTORS

    E-Print Network [OSTI]

    Pehl, Richard H.

    2011-01-01T23:59:59.000Z

    the high-energy proton damage than was the planar detector.as far as radiation damage is concerned. Unfortunately, some28-29, 1978 LBL-7967 RADIATION DAMAGE OF GERMANIUM DETECTORS

  2. DOE Radiation Records Contacts List

    Broader source: Energy.gov [DOE]

    DOE radiation records contact list for individuals to obtain records of occupational exposure directly from a DOE site.

  3. Gamma radiation field intensity meter

    DOE Patents [OSTI]

    Thacker, L.H.

    1994-08-16T23:59:59.000Z

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode. 4 figs.

  4. Gamma radiation field intensity meter

    DOE Patents [OSTI]

    Thacker, Louis H. (Knoxville, TN)

    1995-01-01T23:59:59.000Z

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode.

  5. Gamma radiation field intensity meter

    DOE Patents [OSTI]

    Thacker, L.H.

    1995-10-17T23:59:59.000Z

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode. 4 figs.

  6. Gamma radiation field intensity meter

    DOE Patents [OSTI]

    Thacker, Louis H. (Knoxville, TN)

    1994-01-01T23:59:59.000Z

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode.

  7. Development of Diffusion barrier coatings and Deposition Technologies for Mitigating Fuel Cladding Chemical Interactions (FCCI)

    SciTech Connect (OSTI)

    Sridharan, Kumar; Allen, Todd; Cole, James

    2013-02-27T23:59:59.000Z

    The goal of this project is to develop diffusion barrier coatings on the inner cladding surface to mitigate fuel-cladding chemical interaction (FCCI). FCCI occurs due to thermal and radiation enhanced inter-diffusion between the cladding and fuel materials, and can have the detrimental effects of reducing the effective cladding wall thickness and lowering the melting points of the fuel and cladding. The research is aimed at the Advanced Burner Reactor (ABR), a sodium-cooled fast reactor, in which higher burn-ups will exacerbate the FCCI problem. This project will study both diffusion barrier coating materials and deposition technologies. Researchers will investigate pure vanadium, zirconium, and titanium metals, along with their respective oxides, on substrates of HT-9, T91, and oxide dispersion-strengthened (ODS) steels; these materials are leading candidates for ABR fuel cladding. To test the efficacy of the coating materials, the research team will perform high-temperature diffusion couple studies using both a prototypic metallic uranium fuel and a surrogate�¢����the rare-earth element lanthanum. Ion irradiation experiments will test the stability of the coating and the coating-cladding interface. A critical technological challenge is the ability to deposit uniform coatings on the inner surface of cladding. The team will develop a promising non-line-of-sight approach that uses nanofluids . Recent research has shown the feasibility of this simple yet novel approach to deposit coatings on test flats and inside small sections of claddings. Two approaches will be investigated: 1) modified electrophoretic deposition (MEPD) and 2) boiling nanofluids. The coatings will be evaluated in the as-deposited condition and after sintering.

  8. NCSRNCSR ""DEMOKRITOSDEMOKRITOS"" INSTITUTE OF NUCLEAR TECHNOLOGY & RADIATION PROTECTIONINSTITUTE OF NUCLEAR TECHNOLOGY & RADIATION PROTECTION

    E-Print Network [OSTI]

    PROTECTIONINSTITUTE OF NUCLEAR TECHNOLOGY & RADIATION PROTECTION ·· ENVIRONMENTAL RESEARCH LABORATORYENVIRONMENTAL·· NCSRNCSR ""DEMOKRITOSDEMOKRITOS"" ·· INSTITUTE OF NUCLEAR TECHNOLOGY & RADIATION

  9. COLUMBIA UNIVERSITY Radiation Safety Program

    E-Print Network [OSTI]

    Jia, Songtao

    COLUMBIA UNIVERSITY Radiation Safety Program Medical Center - T: 212-305-0303 F: 212-305-0318 rso-clinical@columbia by more than 50 percent. #12;COLUMBIA UNIVERSITY Radiation Safety Program Medical Center - T: 212 ________________________________________________________ ________________________________________________________ #12;COLUMBIA UNIVERSITY Radiation Safety Program Medical Center - T: 212-305-0303 F: 212-305-0318 rso-clinical@columbia

  10. 6, 52315250, 2006 Radiative properties

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    the short- wave (SW) and longwave (LW) cloud radiative effects (CRE), but the impact is small: 0.02 W m-2 tests are conducted to evaluate the impact that5 such an over-layer would have on the radiative effects, terrestrial) radiation. The SW "albedo" effect brings about cooling and the LW "greenhouse" effect warming

  11. Comparative analysis of radiation effects on the electroluminescence of Si and SiGe/Si(001) heterostructures with self-assembled Islands

    SciTech Connect (OSTI)

    Krasilnik, Z. F.; Kudryavtsev, K. E. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Kachemtsev, A. N. [Sedakov Scientific-Research Institute (Russian Federation); Lobanov, D. N., E-mail: dima@ipm.sci-nnov.ru; Novikov, A. V. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Obolenskiy, S. V. [Nizhni Novgorod State University (Russian Federation); Shengurov, D. V. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation)

    2011-02-15T23:59:59.000Z

    The effect of neutron radiation on the electroluminescence of the Si p-i-n diode containing a multilayered Ge/Si heterostructure with self-assembled nanoislands is studied. In comparison with bulk Si, the diodes containing Ge(Si) nanoislands exhibit a higher radiation hardness of the electroluminescence signal, which is attributed to spatial localization of charge carriers in the Ge/Si nanostructures. The spatial localization of charge carriers impedes their diffusion to radiation defects followed by nonradiative recombination at the defects. The results show the possibilities of using Ge/Si heterostructures with self-assembled nanoislands for the development of optoelectronic devices resistant to radiation.

  12. Causal Baryon Diffusion and Colored Noise

    E-Print Network [OSTI]

    J. I. Kapusta; C. Young

    2014-04-18T23:59:59.000Z

    We construct a model of baryon diffusion which has the desired properties of causality and analyticity. The model also has the desired property of colored noise, meaning that the noise correlation function is not a Dirac delta function in space and time; rather, it depends on multiple time and length constants. The model can readily be incorporated in 3+1 dimensional second order viscous hydro-dynamical models of heavy ion collisions, which is particularly important at beam energies where the baryon density is large.

  13. Thermo-quantum diffusion in periodic potentials

    E-Print Network [OSTI]

    R. Tsekov

    2012-01-18T23:59:59.000Z

    Quantum Brownian motion in a periodic cosine potential is studied and a simple estimate of the tunneling effect is obtained in the frames of a quasi-equilibrium semiclassical approach. It is shown that the latter is applicable for heavy particles but electrons cannot be described properly since the quantum effects dominate over the thermal ones. The purely quantum electron diffusion is investigated at zero temperature and demonstrates that electrons do not obey the classical Einstein law of Brownian motion in the field of periodic potentials, since the dispersion of the wave packet increases logarithmically in time.

  14. How Nuclear Diffuseness Affects RHIC Data

    E-Print Network [OSTI]

    Klaus Werner

    2006-03-10T23:59:59.000Z

    The fact that nuclei have diffuse surfaces (rather than being simple spheres) has dramatic consequences on the interpretation of RHIC heavy-ion data. The effect is quite small (but not negligible) for central collisions, but gets increasingly important with decreasing centrality. One may actually divide the collision zone into a central part ("core"), with expected high energy densities, and a peripheral part ("corona"), with smaller energy densities, more like in pp or pA collisions. We will discuss that many complicated "features" observed at RHIC become almost trivial after subtracting the corona background. We are focussing on AuAu collisions at 200 GeV.

  15. Band Formation during Gaseous Diffusion in Aerogels

    E-Print Network [OSTI]

    M. A. Einarsrud; F. A. Maao; A. Hansen; M. Kirkedelen; J. Samseth

    1997-06-18T23:59:59.000Z

    We study experimentally how gaseous HCl and NH_3 diffuse from opposite sides of and react in silica aerogel rods with porosity of 92 % and average pore size of about 50 nm. The reaction leads to solid NH_4Cl, which is deposited in thin sheet-like structures. We present a numerical study of the phenomenon. Due to the difference in boundary conditions between this system and those usually studied, we find the sheet-like structures in the aerogel to differ significantly from older studies. The influence of random nucleation centers and inhomogeneities in the aerogel is studied numerically.

  16. Diffusion Databases for ICME | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny:Revised Finding of No53197E T A * SEnergyTemperatureDepartmentICME Diffusion

  17. Terahertz radiation mixer

    DOE Patents [OSTI]

    Wanke, Michael C. (Albuquerque, NM); Allen, S. James (Santa Barbara, CA); Lee, Mark (Albuquerque, NM)

    2008-05-20T23:59:59.000Z

    A terahertz radiation mixer comprises a heterodyned field-effect transistor (FET) having a high electron mobility heterostructure that provides a gatable two-dimensional electron gas in the channel region of the FET. The mixer can operate in either a broadband pinch-off mode or a narrowband resonant plasmon mode by changing a grating gate bias of the FET. The mixer can beat an RF signal frequency against a local oscillator frequency to generate an intermediate frequency difference signal in the microwave region. The mixer can have a low local oscillator power requirement and a large intermediate frequency bandwidth. The terahertz radiation mixer is particularly useful for terahertz applications requiring high resolution.

  18. National Ambient Radiation Database

    SciTech Connect (OSTI)

    Dziuban, J.; Sears, R.

    2003-02-25T23:59:59.000Z

    The U.S. Environmental Protection Agency (EPA) recently developed a searchable database and website for the Environmental Radiation Ambient Monitoring System (ERAMS) data. This site contains nationwide radiation monitoring data for air particulates, precipitation, drinking water, surface water and pasteurized milk. This site provides location-specific as well as national information on environmental radioactivity across several media. It provides high quality data for assessing public exposure and environmental impacts resulting from nuclear emergencies and provides baseline data during routine conditions. The database and website are accessible at www.epa.gov/enviro/. This site contains (1) a query for the general public which is easy to use--limits the amount of information provided, but includes the ability to graph the data with risk benchmarks and (2) a query for a more technical user which allows access to all of the data in the database, (3) background information on ER AMS.

  19. Time encoded radiation imaging

    DOE Patents [OSTI]

    Marleau, Peter; Brubaker, Erik; Kiff, Scott

    2014-10-21T23:59:59.000Z

    The various technologies presented herein relate to detecting nuclear material at a large stand-off distance. An imaging system is presented which can detect nuclear material by utilizing time encoded imaging relating to maximum and minimum radiation particle counts rates. The imaging system is integrated with a data acquisition system that can utilize variations in photon pulse shape to discriminate between neutron and gamma-ray interactions. Modulation in the detected neutron count rates as a function of the angular orientation of the detector due to attenuation of neighboring detectors is utilized to reconstruct the neutron source distribution over 360 degrees around the imaging system. Neutrons (e.g., fast neutrons) and/or gamma-rays are incident upon scintillation material in the imager, the photons generated by the scintillation material are converted to electrical energy from which the respective neutrons/gamma rays can be determined and, accordingly, a direction to, and the location of, a radiation source identified.

  20. Radiation shielding composition

    DOE Patents [OSTI]

    Quapp, William J. (Idaho Falls, ID); Lessing, Paul A. (Idaho Falls, ID)

    2000-12-26T23:59:59.000Z

    A composition for use as a radiation shield. The shield is a concrete product containing a stable uranium aggregate for attenuating gamma rays and a neutron absorbing component, the uranium aggregate and neutron absorbing component being present in the concrete product in sufficient amounts to provide a concrete having a density between about 4 and about 15 grams/cm.sup.3 and which will at a predetermined thickness, attenuate gamma rays and absorb neutrons from a radioactive material of projected gamma ray and neutron emissions over a determined time period. The composition is preferably in the form of a container for storing radioactive materials that emit gamma rays and neutrons. The concrete container preferably comprises a metal liner and/or a metal outer shell. The resulting radiation shielding container has the potential of being structurally sound, stable over a long period of time, and, if desired, readily mobile.

  1. Semiconductor radiation detector

    DOE Patents [OSTI]

    Patt, Bradley E. (Sherman Oaks, CA); Iwanczyk, Jan S. (Los Angeles, CA); Tull, Carolyn R. (Orinda, CA); Vilkelis, Gintas (Westlake Village, CA)

    2002-01-01T23:59:59.000Z

    A semiconductor radiation detector is provided to detect x-ray and light photons. The entrance electrode is segmented by using variable doping concentrations. Further, the entrance electrode is physically segmented by inserting n+ regions between p+ regions. The p+ regions and the n+ regions are individually biased. The detector elements can be used in an array, and the p+ regions and the n+ regions can be biased by applying potential at a single point. The back side of the semiconductor radiation detector has an n+ anode for collecting created charges and a number of p+ cathodes. Biased n+ inserts can be placed between the p+ cathodes, and an internal resistor divider can be used to bias the n+ inserts as well as the p+ cathodes. A polysilicon spiral guard can be implemented surrounding the active area of the entrance electrode or surrounding an array of entrance electrodes.

  2. General Relativistic Radiative Transfer

    E-Print Network [OSTI]

    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.

  3. Radiation shielding composition

    DOE Patents [OSTI]

    Quapp, William J. (Idaho Falls, ID); Lessing, Paul A. (Idaho Falls, ID)

    1998-01-01T23:59:59.000Z

    A composition for use as a radiation shield. The shield is a concrete product containing a stable uranium aggregate for attenuating gamma rays and a neutron absorbing component, the uranium aggregate and neutron absorbing component being present in the concrete product in sufficient amounts to provide a concrete having a density between about 4 and about 15 grams/cm.sup.3 and which will at a predetermined thickness, attenuate gamma rays and absorb neutrons from a radioactive material of projected gamma ray and neutron emissions over a determined time period. The composition is preferably in the form of a container for storing radioactive materials that emit gamma rays and neutrons. The concrete container preferably comprises a metal liner and/or a metal outer shell. The resulting radiation shielding container has the potential of being structurally sound, stable over a long period of time, and, if desired, readily mobile.

  4. Radiation shielding composition

    DOE Patents [OSTI]

    Quapp, W.J.; Lessing, P.A.

    1998-07-28T23:59:59.000Z

    A composition is disclosed for use as a radiation shield. The shield is a concrete product containing a stable uranium aggregate for attenuating gamma rays and a neutron absorbing component, the uranium aggregate and neutron absorbing component being present in the concrete product in sufficient amounts to provide a concrete having a density between about 4 and about 15 grams/cm{sup 3} and which will at a predetermined thickness, attenuate gamma rays and absorb neutrons from a radioactive material of projected gamma ray and neutron emissions over a determined time period. The composition is preferably in the form of a container for storing radioactive materials that emit gamma rays and neutrons. The concrete container preferably comprises a metal liner and/or a metal outer shell. The resulting radiation shielding container has the potential of being structurally sound, stable over a long period of time, and, if desired, readily mobile. 5 figs.

  5. Multilayer radiation shield

    DOE Patents [OSTI]

    Urbahn, John Arthur (Saratoga Springs, NY); Laskaris, Evangelos Trifon (Niskayuna, NY)

    2009-06-16T23:59:59.000Z

    A power generation system including: a generator including a rotor including a superconductive rotor coil coupled to a rotatable shaft; a first prime mover drivingly coupled to the rotatable shaft; and a thermal radiation shield, partially surrounding the rotor coil, including at least a first sheet and a second sheet spaced apart from the first sheet by centripetal force produced by the rotatable shaft. A thermal radiation shield for a generator including a rotor including a super-conductive rotor coil including: a first sheet having at least one surface formed from a low emissivity material; and at least one additional sheet having at least one surface formed from a low emissivity material spaced apart from the first sheet by centripetal force produced by the rotatable shaft, wherein each successive sheet is an incrementally greater circumferential arc length and wherein the centripetal force shapes the sheets into a substantially catenary shape.

  6. Handheld CZT radiation detector

    DOE Patents [OSTI]

    Murray, William S.; Butterfield, Kenneth B.; Baird, William

    2004-08-24T23:59:59.000Z

    A handheld CZT radiation detector having a CZT gamma-ray sensor, a multichannel analyzer, a fuzzy-logic component, and a display component is disclosed. The CZT gamma-ray sensor may be a coplanar grid CZT gamma-ray sensor, which provides high-quality gamma-ray analysis at a wide range of operating temperatures. The multichannel analyzer categorizes pulses produce by the CZT gamma-ray sensor into channels (discrete energy levels), resulting in pulse height data. The fuzzy-logic component analyzes the pulse height data and produces a ranked listing of radioisotopes. The fuzzy-logic component is flexible and well-suited to in-field analysis of radioisotopes. The display component may be a personal data assistant, which provides a user-friendly method of interacting with the detector. In addition, the radiation detector may be equipped with a neutron sensor to provide an enhanced mechanism of sensing radioactive materials.

  7. The Radiative Kicked Oscillator: A Stochastic Web or Chaotic Attractor ?

    E-Print Network [OSTI]

    Y. Ashkenazy; L. P. Horwitz

    1999-05-11T23:59:59.000Z

    A relativistic charged particle moving in a uniform magnetic field and kicked by an electric field is considered. Under the assumption of small magnetic field, an iterative map is developed. We consider both the case in which no radiation is assumed and the radiative case, using the Lorentz-Dirac equation to describe the motion. Comparison between the non-radiative case and the radiative case shows that in both cases one can observe a stochastic web structure for weak magnetic fields, and, although there are global differences in the result of the map, that both cases are qualitatively similar in their small scale behavior. We also develop an iterative map for strong magnetic fields. In that case the web structure no longer exists; it is replaced by a rich chaotic behavior. It is shown that the particle does not diffuse to infinite energy; it is limited by the boundaries of an attractor (the boundaries are generally much smaller than light velocity). Bifurcation occurs, converging rapidly to Feigenbaum's universal constant. The chaotic behavior appears to be robust. For intermediate magnetic fields, it is more difficult to observe the web structure, and the influence of the unstable fixed point is weaker.

  8. Low cost fuel cell diffusion layer configured for optimized anode water management

    DOE Patents [OSTI]

    Owejan, Jon P; Nicotera, Paul D; Mench, Matthew M; Evans, Robert E

    2013-08-27T23:59:59.000Z

    A fuel cell comprises a cathode gas diffusion layer, a cathode catalyst layer, an anode gas diffusion layer, an anode catalyst layer and an electrolyte. The diffusion resistance of the anode gas diffusion layer when operated with anode fuel is higher than the diffusion resistance of the cathode gas diffusion layer. The anode gas diffusion layer may comprise filler particles having in-plane platelet geometries and be made of lower cost materials and manufacturing processes than currently available commercial carbon fiber substrates. The diffusion resistance difference between the anode gas diffusion layer and the cathode gas diffusion layer may allow for passive water balance control.

  9. Training For Radiation Emergencies, First Responder Operations...

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

    Training For Radiation Emergencies, First Responder Operations - Instructors Guide Training For Radiation Emergencies, First Responder Operations - Instructors Guide COURSE...

  10. POLARIZATION OF THE COSMIC BACKGROUND RADIATION

    E-Print Network [OSTI]

    Lubin, Philip Lubin

    2010-01-01T23:59:59.000Z

    a 45° angle. Radiation whose electric field (polarization)radiation field, it can be uniquely characterized by its electric

  11. Overview of SIMS-Based Experimental Studies of Tracer Diffusion in Solids and Application to Mg Self-Diffusion

    SciTech Connect (OSTI)

    Kulkarni, Nagraj S [ORNL; Warmack, Robert J Bruce [ORNL; Radhakrishnan, Balasubramaniam [ORNL; HunterJr., Jerry [Virginia Polytechnic Institute and State University; Sohn, Yong Ho [University of Central Florida; Coffey, Kevin [University of Central Florida; Murch, Prof. Graeme [University of Newcastle, NSW, Australia; Belova, Irina [University of Newcastle, NSW, Australia

    2014-01-01T23:59:59.000Z

    Tracer diffusivities provide the most fundamental information on diffusion in materials and are the foundation of robust diffusion databases. Compared to traditional radiotracer techniques that utilize radioactive isotopes, the secondary ion mass spectrometry (SIMS) based thin-film technique for tracer diffusion is based on the use of enriched stable isotopes that can be accurately profiled using SIMS. Experimental procedures & techniques that are utilized for the measurement of tracer diffusion coefficients are presented for pure magnesium, which presents some unique challenges due to the ease of oxidation. The development of a modified Shewmon-Rhines diffusion capsule for annealing Mg and an ultra-high vacuum (UHV) system for sputter deposition of Mg isotopes are discussed. Optimized conditions for accurate SIMS depth profiling in polycrystalline Mg are provided. An automated procedure for the correction of heat-up and cool-down times during tracer diffusion annealing is discussed. The non-linear fitting of a SIMS depth profile data using the thin film Gaussian solution to obtain the tracer diffusivity along with the background tracer concentration and tracer film thickness is discussed. An Arrhenius fit of the Mg self-diffusion data obtained using the low-temperature SIMS measurements from this study and the high-temperature radiotracer measurements of Shewmon and Rhines (1954) was found to be a good representation of both types of diffusion data that cover a broad range of temperatures between 250 - 627 C (523 900 K).

  12. Chemical oxygen diffusion coefficient measurement by conductivity relaxation--correlation between tracer diffusion

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Chemical oxygen diffusion coefficient measurement by conductivity relaxation--correlation between J. P., Grenier J. C., Loup J. P. ABSTRACT Chemical oxygen diusion coecient ¯(D)was measured the oxygen partial pressure in the surrounding atmosphere of the sample. The consequent evolution

  13. The role of radiation transport in the thermal response of semitransparent materials to localized laser heating

    SciTech Connect (OSTI)

    Colvin, Jeffrey; Shestakov, Aleksei; Stoelken, James; Vignes, Ryan [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA 94551 (United States)

    2011-03-01T23:59:59.000Z

    Lasers are widely used to modify the internal structure of semitransparent materials for a wide variety of applications, including waveguide fabrication and laser glass damage healing. The gray diffusion approximation used in past models to describe radiation cooling is not adequate for these materials, particularly near the heated surface layer. In this paper we describe a computational model based upon solving the radiation transport equation in 1D by the P{sub n} method with {approx}500 photon energy bands, and by multi-group radiation diffusion in 2D with fourteen photon energy bands. The model accounts for the temperature-dependent absorption of infrared laser light and subsequent redistribution of the deposited heat by both radiation and conductive transport. We present representative results for fused silica irradiated with 2-12 W of 4.6 or 10.6 {mu}m laser light for 5-10 s pulse durations in a 1 mm spot, which is small compared to the diameter and thickness of the silica slab. We show that, unlike the case for bulk heating, in localized infrared laser heating radiation transport plays only a very small role in the thermal response of silica.

  14. A convective-radiative heat transfer model for gas core reactors

    SciTech Connect (OSTI)

    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.

  15. Global aspects of radiation memory

    E-Print Network [OSTI]

    J. Winicour

    2014-10-11T23:59:59.000Z

    Gravitational radiation has a memory effect represented by a net change in the relative positions of test particles. Both the linear and nonlinear sources proposed for this radiation memory are of the "electric" type, or E mode, as characterized by the even parity of the polarization pattern. Although "magnetic" type, or B mode, radiation memory is mathematically possible, no physically realistic source has been identified. There is an electromagnetic counterpart to radiation memory in which the velocity of charged particles obtain a net "kick". Again, the physically realistic sources of electromagnetic radiation memory that have been identified are of the electric type. In this paper, a global null cone description of the electromagnetic field is applied to establish the non-existence of B mode radiation memory and the non-existence of E mode radiation memory due to a bound charge distribution.

  16. Method for microbeam radiation therapy

    DOE Patents [OSTI]

    Slatkin, D.N.; Dilmanian, F.A.; Spanne, P.O.

    1994-08-16T23:59:59.000Z

    A method is disclosed of performing radiation therapy on a patient, involving exposing a target, usually a tumor, to a therapeutic dose of high energy electromagnetic radiation, preferably X-ray radiation. The dose is in the form of at least two non-overlapping microbeams of radiation, each microbeam having a width of less than about 1 millimeter. Target tissue exposed to the microbeams receives a radiation dose during the exposure that exceeds the maximum dose that such tissue can survive. Non-target tissue between the microbeams receives a dose of radiation below the threshold amount of radiation that can be survived by the tissue, and thereby permits the non-target tissue to regenerate. The microbeams may be directed at the target from one direction, or from more than one direction in which case the microbeams overlap within the target tissue enhancing the lethal effect of the irradiation while sparing the surrounding healthy tissue. No Drawings

  17. Non-Fickian ionic diffusion across high-concentration gradients

    SciTech Connect (OSTI)

    Carey, A.E.; Wheatcraft, S.W. [Univ. of Nevada, Reno, NV (United States)] [Univ. of Nevada, Reno, NV (United States); Glass, R.J. [Sandia National Laboratory, Albuquerque, NM (United States)] [and others] [Sandia National Laboratory, Albuquerque, NM (United States); and others

    1995-09-01T23:59:59.000Z

    A non-Fickian physico-chemical model for electrolyte transport in high-ionic strength systems is developed and tested with laboratory experiments with copper sulfate as an example electrolyte. The new model is based on irreversible thermodynamics and uses measured mutual diffusion coefficients, varying with concentration. Compared to a traditional Fickian model, the new model predicts less diffusion and asymmetric diffusion profiles. Laboratory experiments show diffusion rates even smaller than those predicted by our non-Fickian model, suggesting that there are additional, unaccounted for processes retarding diffusion. Ionic diffusion rates maybe a limiting factor in transporting salts whose effect on fluid density will in turn significantly affect the flow regime. These findings have important implications for understanding and predicting solute transport in geologic settings where dense, saline solutions occur. 30 refs., 5 figs.

  18. Narrow groove welding gas diffuser assembly and welding torch

    DOE Patents [OSTI]

    Rooney, Stephen J. (East Berne, NY)

    2001-01-01T23:59:59.000Z

    A diffuser assembly is provided for narrow groove welding using an automatic gas tungsten arc welding torch. The diffuser assembly includes a manifold adapted for adjustable mounting on the welding torch which is received in a central opening in the manifold. Laterally extending manifold sections communicate with a shield gas inlet such that shield gas supplied to the inlet passes to gas passages of the manifold sections. First and second tapered diffusers are respectively connected to the manifold sections in fluid communication with the gas passages thereof. The diffusers extend downwardly along the torch electrode on opposite sides thereof so as to release shield gas along the length of the electrode and at the distal tip of the electrode. The diffusers are of a transverse width which is on the order of the thickness of the electrode so that the diffusers can, in use, be inserted into a narrow welding groove before and after the electrode in the direction of the weld operation.

  19. Diffusion and Interdiffusion in Binary Metallic Melts

    E-Print Network [OSTI]

    P. Kuhn; J. Horbach; F. Kargl; A. Meyer; Th. Voigtmann

    2014-08-09T23:59:59.000Z

    We discuss the dependence of self- and interdiffusion coefficients on temperature and composition for two prototypical binary metallic melts, Al-Ni and Zr-Ni, in molecular-dynamics (MD) computer simulations and the mode-coupling theory of the glass transition (MCT). Dynamical processes that are mainly entropic in origin slow down mass transport (as expressed through self diffusion) in the mixture as compared to the ideal-mixing contribution. Interdiffusion of chemical species is a competition of slow kinetic modes with a strong thermodynamic driving force that is caused by non-entropic interactions. The combination of both dynamic and thermodynamic effects causes qualitative differences in the concentration dependence of self-diffusion and interdiffusion coefficients. At high temperatures, the thermodynamic enhancement of interdiffusion prevails, while at low temperatures, kinetic effects dominate the concentration dependence, rationalized within MCT as the approach to its ideal-glass transition temperature $T_c$. The Darken equation relating self- and interdiffusion qualitatively reproduces the concentration-dependence in both Zr-Ni and Al-Ni, but quantitatively, the kinetic contributions to interdiffusion can be slower than the lower bound suggested by the Darken equation. As temperature is decreased, the agreement with Darken's equation improves, due to a strong coupling of all kinetic modes that is a generic feature predicted by MCT.

  20. Diffusion in biofilms respiring on electrodes

    SciTech Connect (OSTI)

    Renslow, Ryan S.; Babauta, Jerome T.; Majors, Paul D.; Beyenal, Haluk

    2013-02-15T23:59:59.000Z

    The goal of this study was to measure spatially and temporally resolved effective diffusion coefficients (De) in biofilms respiring on electrodes. Two model electrochemically active biofilms, Geobacter sulfurreducens PCA and Shewanella oneidensis MR-1, were investigated. A novel nuclear magnetic resonance microimaging perfusion probe capable of simultaneous electrochemical and pulsed-field gradient nuclear magnetic resonance (PFG-NMR) techniques was used. PFG-NMR allowed for noninvasive, nondestructive, high spatial resolution in situ De measurements in living biofilms respiring on electrodes. The electrodes were polarized so that they would act as the sole terminal electron acceptor for microbial metabolism. We present our results as both two-dimensional De heat maps and surface-averaged relative effective diffusion coefficient (Drs) depth profiles. We found that (1) Drs decreases with depth in G. sulfurreducens biofilms, following a sigmoid shape; (2) Drs at a given location decreases with G. sulfurreducens biofilm age; (3) average De and Drs profiles in G. sulfurreducens biofilms are lower than those in S. oneidensis biofilms—the G. sulfurreducens biofilms studied here were on average 10 times denser than the S. oneidensis biofilms; and (4) halting the respiration of a G. sulfurreducens biofilm decreases the De values. Density, reflected by De, plays a major role in the extracellular electron transfer strategies of electrochemically active biofilms.

  1. Commercial Building Partnerships Replication and Diffusion

    SciTech Connect (OSTI)

    Antonopoulos, Chrissi A.; Dillon, Heather E.; Baechler, Michael C.

    2013-09-16T23:59:59.000Z

    This study presents findings from survey and interview data investigating replication efforts of Commercial Building Partnership (CBP) partners that worked directly with the Pacific Northwest National Laboratory (PNNL). PNNL partnered directly with 12 organizations on new and retrofit construction projects, which represented approximately 28 percent of the entire U.S. Department of Energy (DOE) CBP program. Through a feedback survey mechanism, along with personal interviews, PNNL gathered quantitative and qualitative data relating to replication efforts by each organization. These data were analyzed to provide insight into two primary research areas: 1) CBP partners’ replication efforts of technologies and approaches used in the CBP project to the rest of the organization’s building portfolio (including replication verification), and, 2) the market potential for technology diffusion into the total U.S. commercial building stock, as a direct result of the CBP program. The first area of this research focused specifically on replication efforts underway or planned by each CBP program participant. Factors that impact replication include motivation, organizational structure and objectives firms have for implementation of energy efficient technologies. Comparing these factors between different CBP partners revealed patterns in motivation for constructing energy efficient buildings, along with better insight into market trends for green building practices. The second area of this research develops a diffusion of innovations model to analyze potential broad market impacts of the CBP program on the commercial building industry in the United States.

  2. Reaction and diffusion in turbulent combustion

    SciTech Connect (OSTI)

    Pope, S.B. [Mechanical and Aerospace Engineering, Ithaca, NY (United States)

    1993-12-01T23:59:59.000Z

    The motivation for this project is the need to obtain a better quantitative understanding of the technologically-important phenomenon of turbulent combustion. In nearly all applications in which fuel is burned-for example, fossil-fuel power plants, furnaces, gas-turbines and internal-combustion engines-the combustion takes place in a turbulent flow. Designers continually demand more quantitative information about this phenomenon-in the form of turbulent combustion models-so that they can design equipment with increased efficiency and decreased environmental impact. For some time the PI has been developing a class of turbulent combustion models known as PDF methods. These methods have the important virtue that both convection and reaction can be treated without turbulence-modelling assumptions. However, a mixing model is required to account for the effects of molecular diffusion. Currently, the available mixing models are known to have some significant defects. The major motivation of the project is to seek a better understanding of molecular diffusion in turbulent reactive flows, and hence to develop a better mixing model.

  3. Distributed Wind Diffusion Model Overview (Presentation)

    SciTech Connect (OSTI)

    Preus, R.; Drury, E.; Sigrin, B.; Gleason, M.

    2014-07-01T23:59:59.000Z

    Distributed wind market demand is driven by current and future wind price and performance, along with several non-price market factors like financing terms, retail electricity rates and rate structures, future wind incentives, and others. We developed a new distributed wind technology diffusion model for the contiguous United States that combines hourly wind speed data at 200m resolution with high resolution electricity load data for various consumer segments (e.g., residential, commercial, industrial), electricity rates and rate structures for utility service territories, incentive data, and high resolution tree cover. The model first calculates the economics of distributed wind at high spatial resolution for each market segment, and then uses a Bass diffusion framework to estimate the evolution of market demand over time. The model provides a fundamental new tool for characterizing how distributed wind market potential could be impacted by a range of future conditions, such as electricity price escalations, improvements in wind generator performance and installed cost, and new financing structures. This paper describes model methodology and presents sample results for distributed wind market potential in the contiguous U.S. through 2050.

  4. Lattice Boltzmann computations for reaction-diffusion equations

    SciTech Connect (OSTI)

    Ponce Dawson, S.; Chen, S.; Doolen, G.D. (Center for Nonlinear Studies and Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States))

    1993-01-15T23:59:59.000Z

    A lattice Boltzmann model for reaction-diffusion systems is developed. The method provides an efficient computational scheme for simulating a variety of problems described by the reaction-diffusion equations. Diffusion phenomena, the decay to a limit cycle, and the formation of Turing patterns are studied. The results of lattice Boltzmann calculations are compared with the lattice gas method and with theoretical predictions, showing quantitative agreement. The model is extended to include velocity convection in chemically reacting fluid flows.

  5. Diffusion in associated and non-associated homologous series 

    E-Print Network [OSTI]

    Alhamid, Khalid A.

    1990-01-01T23:59:59.000Z

    ) measured diffusion coefficients at infinite dilution in associated and non-associated solvents in order to determine the effect of hydrogen bonding on the diffusion coefficient and to predict a correlation for such systems. Of these solvents, water... number. Derlacki et al. (1985) determined the diffusion coefficients for the methanol ? water system over the entire concentration range. The measurements were made at 5 and 25 'C using the diaphragm cell from which velocity correlation coefficients...

  6. A study of diffusion in binary solutions using spin echoes 

    E-Print Network [OSTI]

    Rousseau, Cecil Clyde

    1962-01-01T23:59:59.000Z

    of Experimentally Determined Diffusion Coefficients of Cyclohexane and Acetone with the Results of NcCall, Douglass, and Anderson . . . . . . . . . 23 INTRODUCTION The available descriptions of the liquid state form a continuous spectrum that extends from... the liquid with unit velocity. The intrinsic diffusion coefficient is now given by Di kT Equation (1-11) is known as the Einstein relation. Thus far, no explicit statement has been made concerning diffusion in binary systems. In addition to the intrinsic...

  7. SATURATION OF THE MAGNETO-ROTATIONAL INSTABILITY IN STRONGLY RADIATION-DOMINATED ACCRETION DISKS

    SciTech Connect (OSTI)

    Jiang Yanfei; Stone, James M. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Davis, Shane W. [Canadian Institute for Theoretical Astrophysics, Toronto, ON M5S3H4 (Canada)

    2013-04-20T23:59:59.000Z

    The saturation level of the magneto-rotational instability (MRI) in a strongly radiation-dominated accretion disk is studied using a new Godunov radiation MHD code in the unstratified shearing box approximation. Since vertical gravity is neglected in this work, our focus is on how the MRI saturates in the optically thick mid-plane of the disk. We confirm that turbulence generated by the MRI is very compressible in the radiation-dominated regime, as found by previous calculations using the flux-limited diffusion approximation. We also find little difference in the saturation properties in calculations that use a larger horizontal domain (up to four times the vertical scale height in the radial direction). However, in strongly radiation pressure dominated disks (one in which the radiation energy density reaches {approx}1% of the rest mass energy density of the gas), we find that Maxwell stress from the MRI turbulence is larger than the value produced when radiation pressure is replaced with the same amount of gas pressure. At the same time, the ratio between Maxwell stress and Reynolds stress is increased by almost a factor of eight compared with the gas pressure dominated case. We suggest that this effect is caused by radiation drag, which acts like bulk viscosity and changes the effective magnetic Prandtl number of the fluid. Radiation viscosity significantly exceeds both the microscopic plasma viscosity and resistivity, ensuring that radiation-dominated systems occupy the high magnetic Prandtl number regime. Nevertheless, we find that radiative shear viscosity is negligible compared to the Maxwell stress and Reynolds stress in the flow. This may have important implications for the structure of radiation-dominated accretion disks.

  8. aerospace knowledge diffusion: Topics by E-print Network

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

    to codify: Implications for the knowledge - based economy" Prometheus 19 Richards, Debbie 15 Inverse diffusion from knowledge of power densities Guillaume Bal Mathematics...

  9. adrenal diffuse large: Topics by E-print Network

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

    diffusion is the effect of geometry, including the localization of aftershocks on a fractal fault network and the impact of extended rupture lengths which control the typical...

  10. advanced diffusion barriers: Topics by E-print Network

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

    distances. O. A. Dvoretskaya; P. S. Kondratenko 2011-10-26 5 Anomalous transport in fractal media with randomly inhomogeneous diffusion barrier Condensed Matter (arXiv) Summary:...

  11. anomalous diffusion dynamics: Topics by E-print Network

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

    transport became a very important topic over the past couple Wright, Francis 5 Fractal Location and Anomalous Diffusion Dynamics for Oil Wells from the KY Geological Survey...

  12. Measuring Diffusivity in Supercooled Liquid Nanoscale Films using...

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

    gas has been shown to be an effective probe of the diffusivity of supercooled liquid methanol in the experimentally challenging regime near the glass transition temperature. The...

  13. Big Data Projects on Solar Technology Evolution and Diffusion...

    Energy Savers [EERE]

    Projects on Solar Technology Evolution and Diffusion: Kickoff Meeting Graphic showing a web of people with energy bolts connecting them. Through the SEEDS program, seven projects...

  14. Diffusion coefficient of three-dimensional Yukawa liquids

    SciTech Connect (OSTI)

    Dzhumagulova, K. N.; Ramazanov, T. S.; Masheeva, R. U. [IETP, Al Farabi Kazakh National University, 71, al Farabi ave., Almaty 050040 (Kazakhstan)] [IETP, Al Farabi Kazakh National University, 71, al Farabi ave., Almaty 050040 (Kazakhstan)

    2013-11-15T23:59:59.000Z

    The purpose of this work is an investigation of the diffusion coefficient of the dust component in complex plasma. The computer simulation of the Yukawa liquids was made on the basis of the Langevin equation, which takes into account the influence of buffer plasma on the dust particles dynamics. The Green–Kubo relation was used to calculate the diffusion coefficient. Calculations of the diffusion coefficient for a wide range of the system parameters were performed. Using obtained numerical data, we constructed the interpolation formula for the diffusion coefficient. We also show that the interpolation formula correctly describes experimental data obtained under microgravity conditions.

  15. Diffusion and Adsorption of Uranyl Carbonate Species in Nanosized...

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

    and Adsorption of Uranyl Carbonate Species in Nanosized Mineral Fractures. Diffusion and Adsorption of Uranyl Carbonate Species in Nanosized Mineral Fractures. Abstract: Atomistic...

  16. Adsorption, Desorption, and Diffusion of Nitrogen in a Model...

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

    I. Surface Limited Desorption Kinetics in Adsorption, Desorption, and Diffusion of Nitrogen in a Model Nanoporous Material: I. Surface Limited Desorption Kinetics in Abstract: The...

  17. FLAMMABLE GAS DIFFUSION THROUGH SINGLE SHELL TANK (SST) DOMES

    SciTech Connect (OSTI)

    MEACHAM, J.E.

    2003-11-10T23:59:59.000Z

    This report quantified potential hydrogen diffusion through Hanford Site Single-Shell tank (SST) domes if the SSTs were hypothetically sealed airtight. Results showed that diffusion would keep headspace flammable gas concentrations below the lower flammability limit in the 241-AX and 241-SX SST. The purpose of this document is to quantify the amount of hydrogen that could diffuse through the domes of the SSTs if they were hypothetically sealed airtight. Diffusion is assumed to be the only mechanism available to reduce flammable gas concentrations. The scope of this report is limited to the 149 SSTs.

  18. Using Rare Gas Permeation to Probe Methanol Diffusion near the...

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

    at temperatures just above the glass transition. The diffusivity near the glass transition is characterized by an activation energy and prefactor that are seven and 1030...

  19. Orientation Visit to the Portsmouth Gaseous Diffusion Plant

    Office of Environmental Management (EM)

    Analysis (DSA) and Technical Safety Requirements (TSR) for Portsmouth Gaseous Diffusion Plant Category 2 Non-leased Facilities: X-345 Special Nuclear Material Storage Facility;...

  20. Non-Destructive Analysis Calibration Standards for Gaseous Diffusion...

    Energy Savers [EERE]

    surrogates are required to verify and validate NDA methods used to support characterization of gaseous diffusion equipment within the D&D project. Because working reference...

  1. Diffusion model of the non-stoichiometric uranium dioxide

    SciTech Connect (OSTI)

    Moore, Emily, E-mail: emily.moore@cea.fr [CEA Saclay, DEN-DPC-SCCME, 91191 Gif-sur-Yvette Cedex (France); Guéneau, Christine, E-mail: christine.gueneau@cea.fr [CEA Saclay, DEN-DPC-SCCME, 91191 Gif-sur-Yvette Cedex (France); Crocombette, Jean-Paul, E-mail: jean-paul.crocombette@cea.fr [CEA Saclay, DEN DEN, Service de Recherches de Métallurgie Physique, 91191 Gif-sur-Yvette Cedex (France)

    2013-07-15T23:59:59.000Z

    Uranium dioxide (UO{sub 2}), which is used in light water reactors, exhibits a large range of non-stoichiometry over a wide temperature scale up to 2000 K. Understanding diffusion behavior of uranium oxides under such conditions is essential to ensure safe reactor operation. The current understanding of diffusion properties is largely limited by the stoichiometric deviations inherent to the fuel. The present DICTRA-based model considers diffusion across non-stoichiometric ranges described by experimentally available data. A vacancy and interstitial model of diffusion is applied to the U–O system as a function of its defect structure derived from CALPHAD-type thermodynamic descriptions. Oxygen and uranium self and tracer diffusion coefficients are assessed for the construction of a mobility database. Chemical diffusion coefficients of oxygen are derived with respect to the Darken relation and migration energies of defects are evaluated as a function of stoichiometric deviation. - Graphical abstract: Complete description of Oxygen–Uranium diffusion as a function of composition at various temperatures according to the developed Dictra model. - Highlights: • Assessment of a uranium–oxygen diffusion model with Dictra. • Complete description of U–O diffusion over wide temperature and composition range. • Oxygen model includes terms for interstitial and vacancy migration. • Interaction terms between defects help describe non-stoichiometric domain of UO{sub 2±x}. • Uranium model is separated into mobility terms for the cationic species.

  2. 18.366 Random Walks and Diffusion, Spring 2005

    E-Print Network [OSTI]

    Bazant, Martin Z.

    Discrete and continuum modeling of diffusion processes in physics, chemistry, and economics. Topics include central limit theorems, continuous-time random walks, Levy flights, correlations, extreme events, mixing, ...

  3. altered water diffusivity: Topics by E-print Network

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

    Geometry Hyperspectral Imagery Hyperspectral Imagery Material embedding Figure: Dark blue (0): Water. Blue (1): Clay. Light blue (2): Soil Hirn, Matthew 47 Cross-Diffusion...

  4. Radiogenic Source Identification for the Helium Production-Diffusion ...

    E-Print Network [OSTI]

    2012-10-17T23:59:59.000Z

    Oct 18, 2012 ... Production-Diffusion Equation. Gang Bao1, Todd A. Ehlers2 and Peijun Li3,?. 1 Department of Mathematics, Zhejiang University, Hangzhou ...

  5. absorption diffusion physical: Topics by E-print Network

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

    of Low Temperature Physics, Vol. 72, Nos. 56, 1988 Pressure Diffusion and Sound Absorption in Physics Websites Summary: of the usual transport coefficients (viscosity...

  6. Calibration of a thin metal foil for infrared imaging video bolometer to estimate the spatial variation of thermal diffusivity using a photo-thermal technique

    SciTech Connect (OSTI)

    Pandya, Shwetang N., E-mail: pandya.shwetang@LHD.nifs.ac.jp; Sano, Ryuichi [The Graduate University of Advanced Studies, 322-6 Oroshi-cho, Toki 509-5292 (Japan)] [The Graduate University of Advanced Studies, 322-6 Oroshi-cho, Toki 509-5292 (Japan); Peterson, Byron J.; Mukai, Kiyofumi; Akiyama, Tsuyoshi; Watanabe, Takashi [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292 (Japan)] [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292 (Japan); Drapiko, Evgeny A. [Fusion Centre, 1, Akademika Kurchatova pl., Moscow 123182 (Russian Federation)] [Fusion Centre, 1, Akademika Kurchatova pl., Moscow 123182 (Russian Federation); Alekseyev, Andrey G. [Kurchatov Institute, 1, Akademika Kurchatova pl., Moscow 123182 (Russian Federation)] [Kurchatov Institute, 1, Akademika Kurchatova pl., Moscow 123182 (Russian Federation); Itomi, Muneji [Graduate School of Engineering, Hokkaido University, Kita-13, Nishi-8, Kita-ku, Sapporo 060-8628 (Japan)] [Graduate School of Engineering, Hokkaido University, Kita-13, Nishi-8, Kita-ku, Sapporo 060-8628 (Japan)

    2014-05-15T23:59:59.000Z

    A thin metal foil is used as a broad band radiation absorber for the InfraRed imaging Video Bolometer (IRVB), which is a vital diagnostic for studying three-dimensional radiation structures from high temperature plasmas in the Large Helical Device. The two-dimensional (2D) heat diffusion equation of the foil needs to be solved numerically to estimate the radiation falling on the foil through a pinhole geometry. The thermal, physical, and optical properties of the metal foil are among the inputs to the code besides the spatiotemporal variation of temperature, for reliable estimation of the exhaust power from the plasma illuminating the foil. The foil being very thin and of considerable size, non-uniformities in these properties need to be determined by suitable calibration procedures. The graphite spray used for increasing the surface emissivity also contributes to a change in the thermal properties. This paper discusses the application of the thermographic technique for determining the spatial variation of the effective in-plane thermal diffusivity of the thin metal foil and graphite composite. The paper also discusses the advantages of this technique in the light of limitations and drawbacks presented by other calibration techniques being practiced currently. The technique is initially applied to a material of known thickness and thermal properties for validation and finally to thin foils of gold and platinum both with two different thicknesses. It is observed that the effect of the graphite layer on the estimation of the thermal diffusivity becomes more pronounced for thinner foils and the measured values are approximately 2.5–3 times lower than the literature values. It is also observed that the percentage reduction in thermal diffusivity due to the coating is lower for high thermal diffusivity materials such as gold. This fact may also explain, albeit partially, the higher sensitivity of the platinum foil as compared to gold.

  7. Radiation imaging apparatus

    DOE Patents [OSTI]

    Anger, Hal O. (Berkeley, CA); Martin, Donn C. (Berkeley, CA); Lampton, Michael L. (Berkeley, CA)

    1983-01-01T23:59:59.000Z

    A radiation imaging system using a charge multiplier and a position sensitive anode in the form of periodically arranged sets of interconnected anode regions for detecting the position of the centroid of a charge cloud arriving thereat from the charge multiplier. Various forms of improved position sensitive anodes having single plane electrode connections are disclosed. Various analog and digital signal processing systems are disclosed, including systems which use the fast response of microchannel plates, anodes and preamps to perform scintillation pulse height analysis digitally.

  8. Radiation Field on Superspace

    E-Print Network [OSTI]

    P. F. Gonzalez-Diaz

    1994-03-18T23:59:59.000Z

    We study the dynamics of multiwormhole configurations within the framework of the Euclidean Polyakov approach to string theory, incorporating a modification to the Hamiltonian which makes it impossible to interpret the Coleman Alpha parameters of the effective interactions as a quantum field on superspace, reducible to an infinite tower of fields on space-time. We obtain a Planckian probability measure for the Alphas that allows $\\frac{1}{2}\\alpha^{2}$ to be interpreted as the energy of the quanta of a radiation field on superspace whose values may still fix the coupling constants.

  9. Solar radiation intensity calculations 

    E-Print Network [OSTI]

    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...

  10. Radiative ?(1S) decays

    E-Print Network [OSTI]

    Baringer, Philip S.

    1990-03-01T23:59:59.000Z

    — wW~ ii~ ~ + v~ 1''&WV'' V 0.20 0.45 0.70 ~y ~ EBFA~ 0.95 l.20 FIG. 4. Energy spectrum (normalized to beam energy) for Y~y2(h+h ) event candidates, with continuum data and ex- pected background from Y~m 2(h +h ) overplotted. 40 30— ~ 20— LLI IO— hl...PHYSICAL REVIEW 0 VOLUME 41, NUMBER 5 Radiative T(lS) decays 1 MARCH 1990 R. Fulton, M. Hempstead, T. Jensen, D. R. Johnson, H. Kagan, R. Kass, F. Morrow, and J. Whitmore Ohio State University, Columbus, Ohio 43210 W.-Y. Chen, J. Dominick, R. L. Mc...

  11. Radiation imaging apparatus

    DOE Patents [OSTI]

    Anger, H.O.; Martin, D.C.; Lampton, M.L.

    1983-07-26T23:59:59.000Z

    A radiation imaging system using a charge multiplier and a position sensitive anode in the form of periodically arranged sets of interconnected anode regions for detecting the position of the centroid of a charge cloud arriving thereat from the charge multiplier. Various forms of improved position sensitive anodes having single plane electrode connections are disclosed. Various analog and digital signal processing systems are disclosed, including systems which use the fast response of microchannel plates, anodes and preamps to perform scintillation pulse height analysis digitally. 15 figs.

  12. Radiation Emergency Procedure Demonstrations

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)IntegratedSpeedingTechnicalPurchase, Delivery, andSmartRadiation Effects

  13. Radiation Safety Test

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)IntegratedSpeedingTechnicalPurchase, Delivery, andSmartRadiation

  14. Radiation Control Program and Radiation Control Act (Nebraska)

    Broader source: Energy.gov [DOE]

    This statute authorizes the state to implement a regulatory program for sources of radiation, and contains rules for the Department, licensing and registration, and taxation of radioactive materials.

  15. Virtual Gamma Ray Radiation Sources through Neutron Radiative Capture

    SciTech Connect (OSTI)

    Scott Wilde, Raymond Keegan

    2008-07-01T23:59:59.000Z

    The countrate response of a gamma spectrometry system from a neutron radiation source behind a plane of moderating material doped with a nuclide of a large radiative neutron capture cross-section exhibits a countrate response analogous to a gamma radiation source at the same position from the detector. Using a planar, surface area of the neutron moderating material exposed to the neutron radiation produces a larger area under the prompt gamma ray peak in the detector than a smaller area of dimensions relative to the active volume of the gamma detection system.

  16. RADIATIVE RAYLEIGH-TAYLOR INSTABILITIES

    SciTech Connect (OSTI)

    Jacquet, Emmanuel [Laboratoire de Mineralogie et Cosmochimie de Museum (LMCM), CNRS and Museum National d'Histoire Naturelle, UMR 7202, 57 rue Cuvier, 75005 Paris (France); Krumholz, Mark R., E-mail: ejacquet@mnhn.fr, E-mail: krumholz@ucolick.org [Department of Astronomy, University of California, Santa Cruz, CA 95064 (United States)

    2011-04-01T23:59:59.000Z

    We perform analytic linear stability analyses of an interface separating two stratified media threaded by a radiation flux, a configuration relevant in several astrophysical contexts. We develop a general framework for analyzing such systems and obtain exact stability conditions in several limiting cases. In the optically thin, isothermal regime, where the discontinuity is chemical in nature (e.g., at the boundary of a radiation pressure-driven H II region), radiation acts as part of an effective gravitational field, and instability arises if the effective gravity per unit volume toward the interface overcomes that away from it. In the optically thick 'adiabatic' regime where the total (gas plus radiation) specific entropy of a Lagrangian fluid element is conserved, for example at the edge of radiation pressure-driven bubble around a young massive star, we show that radiation acts like a modified equation of state and derive a generalized version of the classical Rayleigh-Taylor stability condition.

  17. Continuum Study of Heavy Quark Diffusion

    E-Print Network [OSTI]

    Thomas Neuhaus

    2015-04-28T23:59:59.000Z

    We report on a lattice investigation of heavy quark momentum diffusion within the pure SU(3) plasma above the deconfinement transition with the quarks treated to leading order in the heavy mass expansion. We measure the relevant "colour-electric" Euclidean correlator and based on several lattice spacing's perform the continuum extrapolation. This is necessary not only to remove cut-off effects but also the analytic continuation for the extraction of transport coefficients is well-defined only when a continuous function of the Euclidean time variable is available. We pay specific attention to scale setting in SU(3). In particular we present our determination for the critical temperature $T_c=1/({N_\\tau}a) $ at values of $N_\\tau \\le 22$.

  18. Mapping the geographical diffusion of new words

    E-Print Network [OSTI]

    Eisenstein, Jacob; Smith, Noah A; Xing, Eric P

    2012-01-01T23:59:59.000Z

    Language in social media is rich with linguistic innovations, most strikingly in the new words and spellings that constantly enter the lexicon. Despite assertions about the power of social media to connect people across the world, we find that many of these neologisms are restricted to geographically compact areas. Even for words that become ubiquituous, their growth in popularity is often geographical, spreading from city to city. Thus, social media text offers a unique opportunity to study the diffusion of lexical change. In this paper, we show how an autoregressive model of word frequencies in social media can be used to induce a network of linguistic influence between American cities. By comparing the induced network with the geographical and demographic characteristics of each city, we can measure the factors that drive the spread of lexical innovation.

  19. Bevacizumab as Therapy for Radiation Necrosis in Four Children With Pontine Gliomas

    SciTech Connect (OSTI)

    Liu, Arthur K., E-mail: arthur.liu@ucdenver.ed [University of Colorado Denver, Department of Radiation Oncology, Aurora, CO (United States); Macy, Margaret E.; Foreman, Nicholas K. [Children's Hospital, Denver, Department of Neuro-Oncology, Aurora, CO (United States)

    2009-11-15T23:59:59.000Z

    Purpose: Diffuse pontine gliomas are a pediatric brain tumor that is fatal in nearly all patients. Given the poor prognosis for patients with this tumor, their quality of life is very important. Radiation therapy provides some palliation, but can result in radiation necrosis and associated neurologic decline. The typical treatment for this necrosis is steroid therapy. Although the steroids are effective, they have numerous side effects that can often significantly compromise quality of life. Bevacizumab, an antibody against vascular endothelial growth factor, has been suggested as a treatment for radiation necrosis. We report on our initial experience with bevacizumab therapy for radiation necrosis in pediatric pontine gliomas. Materials and Methods: Four children with pontine gliomas treated at the Children's Hospital in Denver and the University of Colorado Denver developed evidence of radiation necrosis both clinically and on imaging. Those 4 children then received bevacizumab as a treatment for the radiation necrosis. We reviewed the clinical outcome and imaging findings. Results: After bevacizumab therapy, 3 children had significant clinical improvement and were able to discontinue steroid use. One child continued to decline, and, in retrospect, had disease progression, not radiation necrosis. In all cases, bevacizumab was well tolerated. Conclusions: In children with pontine gliomas, bevacizumab may provide both therapeutic benefit and diagnostic information. More formal evaluation of bevacizumab in these children is needed.

  20. NREL Solar Radiation Resource Assessment Project: Status and outlook. FY 1991 annual progress report

    SciTech Connect (OSTI)

    Renne, D.; Riordan, C.; Maxwell, E.; Stoffel, T.; Marion, B.; Rymes, M.; Wilcox, S.; Myers, D.

    1992-05-01T23:59:59.000Z

    This report summarizes the activities and accomplishments of NREL`s Solar Radiation Resource Assessment Project during fiscal year 1991. Currently, the primary focus of the SRRAP is to produce a 1961--1990 National Solar Radiation Data Base, providing hourly values of global horizontal, diffuse, and direct normal solar radiation at approximately 250 sites around the United States. Because these solar radiation quantities have been measured intermittently at only about 50 of these sites, models were developed and applied to the majority of the stations to provide estimates of these parameters. Although approximately 93% of the data base consists of modeled data this represents a significant improvement over the SOLMET/ERSATZ 1952--1975 data base. The magnitude and importance of this activity are such that the majority of SRRAP human and financial in many other activities, which are reported here. These include the continued maintenance of a solar radiation monitoring network in the southeast United States at six Historically Black Colleges and Universities (HBCU`s), the transfer of solar radiation resource assessment technology through a variety of activities, participation in international programs, and the maintenance and operation of NREL`s Solar Radiation Research Laboratory. 17 refs.

  1. Radiator Labs | Department of Energy

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's PossibleRadiation Protection Radiation Protection Regulations: TheCompetition » Radiator Labs

  2. Split SUSY Radiates Flavor

    E-Print Network [OSTI]

    Matthew Baumgart; Daniel Stolarski; Thomas Zorawski

    2014-09-19T23:59:59.000Z

    Radiative flavor models where the hierarchies of Standard Model (SM) fermion masses and mixings are explained via loop corrections are elegant ways to solve the SM flavor puzzle. Here we build such a model in the context of Mini-Split Supersymmetry (SUSY) where both flavor and SUSY breaking occur at a scale of 1000 TeV. This model is consistent with the observed Higgs mass, unification, and WIMP dark matter. The high scale allows large flavor mixing among the sfermions, which provides part of the mechanism for radiative flavor generation. In the deep UV, all flavors are treated democratically, but at the SUSY breaking scale, the third, second, and first generation Yukawa couplings are generated at tree level, one loop, and two loops, respectively. Save for one, all the dimensionless parameters in the theory are O(1), with the exception being a modest and technically natural tuning that explains both the smallness of the bottom Yukawa coupling and the largeness of the Cabibbo angle.

  3. Radiation Embrittlement Archive Project

    SciTech Connect (OSTI)

    Klasky, Hilda B [ORNL] [ORNL; Bass, Bennett Richard [ORNL] [ORNL; Williams, Paul T [ORNL] [ORNL; Phillips, Rick [ORNL] [ORNL; Erickson, Marjorie A [ORNL] [ORNL; Kirk, Mark T [ORNL] [ORNL; Stevens, Gary L [ORNL] [ORNL

    2013-01-01T23:59:59.000Z

    The Radiation Embrittlement Archive Project (REAP), which is being conducted by the Probabilistic Integrity Safety Assessment (PISA) Program at Oak Ridge National Laboratory under funding from the U.S. Nuclear Regulatory Commission s (NRC) Office of Nuclear Regulatory Research, aims to provide an archival source of information about the effect of neutron radiation on the properties of reactor pressure vessel (RPV) steels. Specifically, this project is an effort to create an Internet-accessible RPV steel embrittlement database. The project s website, https://reap.ornl.gov, provides information in two forms: (1) a document archive with surveillance capsule(s) reports and related technical reports, in PDF format, for the 104 commercial nuclear power plants (NPPs) in the United States, with similar reports from other countries; and (2) a relational database archive with detailed information extracted from the reports. The REAP project focuses on data collected from surveillance capsule programs for light-water moderated, nuclear power reactor vessels operated in the United States, including data on Charpy V-notch energy testing results, tensile properties, composition, exposure temperatures, neutron flux (rate of irradiation damage), and fluence, (Fast Neutron Fluence a cumulative measure of irradiation for E>1 MeV). Additionally, REAP contains data from surveillance programs conducted in other countries. REAP is presently being extended to focus on embrittlement data analysis, as well. This paper summarizes the current status of the REAP database and highlights opportunities to access the data and to participate in the project.

  4. EPIDEMIOLOGICAL STUDIES ON RADIATION CARCINOGENESIS IN HUMAN POPULATIONS FOLLOWING ACUTE EXPOSURE: NUCLEAR EXPLOSIONS AND MEDICAL RADIATION

    E-Print Network [OSTI]

    Fabrikant, J.I.

    2010-01-01T23:59:59.000Z

    EXPOSURE: NUCLEAR EXPLOSIONS AND MEDICAL RADIATION . Jacobexposed to nuclear explosions and medical radiation. Sinceto nuclear explo ions or medical radiation, describes the

  5. Aerosols and their influence on radiation partitioning and savanna productivity in northern Australia

    SciTech Connect (OSTI)

    Kanniah, K. D.; Beringer, J.; Tapper, N. J.; Long, Charles N.

    2010-05-01T23:59:59.000Z

    We investigated the effect of aerosols and clouds on the Net Ecosystem Productivity (NEP) of savannas in northern Australia using aerosol optical depth, clouds and radiation data from the Atmospheric Radiation Measurement (ARM) site in Darwin and carbon flux data measured from eddy covariance techniques from a site at Howard Springs, 35km southeast of Darwin. Generally we found that the concentration of aerosols in this region was relatively low than observed at other sites, therefore the proportion of diffuse radiation reaching the earths surface was only ~ 30%. As a result, we observed only a modest change in carbon uptake under aerosol laden skies and there was no significant difference for dry season Radiation Use Efficiency (RUE) between clear sky, aerosols or thin clouds. On the other hand thick clouds in the wet season produce much more diffuse radiation than aerosols or thin clouds and therefore the initial canopy quantum efficiency was seen to increase 45 and 2.5 times more than under thin clouds and aerosols respectively. The normalized carbon uptake under thick clouds is 57% and 50% higher than under aerosols and thin clouds respectively even though the total irradiance received under thick clouds was reduced 59% and 50% than under aerosols and thin clouds respectively. However, reduction in total irradiance decreases the mean absolute carbon uptake as much as 22% under heavy cloud cover compared to thin clouds or aerosols. Thus, any increase in aerosol concentration or cloud cover that can enhance the diffuse component may have large impacts on productivity in this region.

  6. Radiation Safety Work Control Form

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

    Radiation Safety Work Control Form (see instructions on pg-3) Rev. May 2014 Area: Form : Date: Preliminary Applicability Screen: (a) Will closing the beam line injection stoppers...

  7. Inverse problem for Bremsstrahlung radiation

    SciTech Connect (OSTI)

    Voss, K.E.; Fisch, N.J.

    1991-10-01T23:59:59.000Z

    For certain predominantly one-dimensional distribution functions, an analytic inversion has been found which yields the velocity distribution of superthermal electrons given their Bremsstrahlung radiation. 5 refs.

  8. Enhanced radiation resistant fiber optics

    DOE Patents [OSTI]

    Lyons, P.B.; Looney, L.D.

    1993-11-30T23:59:59.000Z

    A process for producing an optical fiber having enhanced radiation resistance is provided, the process including maintaining an optical fiber within a hydrogen-containing atmosphere for sufficient time to yield a hydrogen-permeated optical fiber having an elevated internal hydrogen concentration, and irradiating the hydrogen-permeated optical fiber at a time while the optical fiber has an elevated internal hydrogen concentration with a source of ionizing radiation. The radiation source is typically a cobalt-60 source and the fiber is pre-irradiated with a dose level up to about 1000 kilorads of radiation. 4 figures.

  9. Radiating Levi-Civita Spacetime

    E-Print Network [OSTI]

    Ozgur Delice

    2005-06-06T23:59:59.000Z

    This paper has been withdrawn by the author, See J.Krishna Rao, J. Phys. A: Gen. Phys., 4, 17 (1971) for radiating Levi-Civita metric.

  10. Scintillator Waveguide For Sensing Radiation

    DOE Patents [OSTI]

    Bliss, Mary (West Richland, WA); Craig, Richard A. (West Richland, WA); Reeder; Paul L. (Richland, WA)

    2003-04-22T23:59:59.000Z

    The present invention is an apparatus for detecting ionizing radiation, having: a waveguide having a first end and a second end, the waveguide formed of a scintillator material wherein the therapeutic ionizing radiation isotropically generates scintillation light signals within the waveguide. This apparatus provides a measure of radiation dose. The apparatus may be modified to permit making a measure of location of radiation dose. Specifically, the scintillation material is segmented into a plurality of segments; and a connecting cable for each of the plurality of segments is used for conducting scintillation signals to a scintillation detector.

  11. Enhanced radiation resistant fiber optics

    DOE Patents [OSTI]

    Lyons, Peter B. (Los Alamos, NM); Looney, Larry D. (Los Alamos, NM)

    1993-01-01T23:59:59.000Z

    A process for producing an optical fiber having enhanced radiation resitance is provided, the process including maintaining an optical fiber within a hydrogen-containing atmosphere for sufficient time to yield a hydrogen-permeated optical fiber having an elevated internal hydrogen concentration, and irradiating the hydrogen-permeated optical fiber at a time while the optical fiber has an elevated internal hydrogen concentration with a source of ionizing radiation. The radiation source is typically a cobalt-60 source and the fiber is pre-irradiated with a dose level up to about 1000 kilorads of radiation.

  12. Quality Services: Radiation (New York)

    Broader source: Energy.gov [DOE]

    These regulations establish standards for protection against ionizing radiation resulting from the disposal and discharge of radioactive material to the environment. The regulations apply to any...

  13. Uranium and cesium diffusion in fuel cladding of electrogenerating channel

    SciTech Connect (OSTI)

    Vasil’ev, I. V., E-mail: fnti@mail.ru; Ivanov, A. S.; Churin, V. A. [National Research Center Kurchatov Institute (Russian Federation)

    2014-12-15T23:59:59.000Z

    The results of reactor tests of a carbonitride fuel in a single-crystal cladding from a molybdenum-based alloy can be used in substantiating the operational reliability of fuels in developing a project of a megawatt space nuclear power plant. The results of experimental studies of uranium and cesium penetration into the single-crystal cladding of fuel elements with a carbonitride fuel are interpreted. Those fuel elements passed nuclear power tests in the Ya-82 pilot plant for 8300 h at a temperature of about 1500°C. It is shown that the diffusion coefficients for uranium diffusion into the cladding are virtually coincident with the diffusion coefficients measured earlier for uranium diffusion into polycrystalline molybdenum. It is found that the penetration of uranium into the cladding is likely to occur only in the case of a direct contact between the cladding and fuel. The experimentally observed nonmonotonic uranium-concentration profiles are explained in terms of predominant uranium diffusion along grain boundaries. It is shown that a substantially nonmonotonic behavior observed in our experiment for the uranium-concentration profile may be explained by the presence of a polycrystalline structure of the cladding in the surface region from its inner side. The diffusion coefficient is estimated for the grain-boundary diffusion of uranium. The diffusion coefficients for cesium are estimated on the basis of experimental data obtained in the present study.

  14. SUNLIGHT TRANSMISSION THROUGH DESERT DUST AND MARINE AEROSOLS: DIFFUSE LIGHT

    E-Print Network [OSTI]

    SUNLIGHT TRANSMISSION THROUGH DESERT DUST AND MARINE AEROSOLS: DIFFUSE LIGHT CORRECTIONS TO SUN transmission through desert dust and marine aerosols: Diffuse light corrections to Sun photometry 2004; published 27 April 2004. [1] Desert dust and marine aerosols are receiving increased scientific

  15. Thermal diffusivity mapping of 4D carbon-carbon composites

    SciTech Connect (OSTI)

    Wang, H.; Dinwiddie, R.B.

    1997-03-01T23:59:59.000Z

    High resolution, 2-D thermal diffusivity maps of carbon-carbon composites were obtained by a state-of-the-art infrared thermal imaging system. Unlike the traditional single-point IR detector used for thermal diffusivity measurements, the IR camera is capable of capturing images in its 256 x 256 pixel Focal Plane Array detector in a snap-shot mode. The camera takes up to 200 images at a rate of 120 frames/second. The temperature resolution of the Ir camera is 0.015 C and the spatial resolution is 20 {micro}m. Thermal diffusivity was calculated for each pixel. Four-direction carbon-carbon composites were used for the thermal diffusivity mapping study. The fiber bundles along the heat flow direction were found to have 25% higher diffusivity values than the surrounding matrix. The diffusivity map also showed detailed local variations in diffusivity which were impossible to measure using a single-point detector. Accurate diffusivity maps are very important to the design of composite materials.

  16. Einstein relation for reversible diffusions in random environment

    E-Print Network [OSTI]

    Gantert, Nina

    Einstein relation for reversible diffusions in random environment N. Gantert P. Mathieu A the Einstein re- lation for this model. It says that the derivative at 0 of the effective velocity under an additional local drift equals the diffusivity of the model without drift. The Einstein rela- tion

  17. Beta Advection-Diffusion Model Columbia Basin Research

    E-Print Network [OSTI]

    Washington at Seattle, University of

    Beta Advection-Diffusion Model Jim Norris Columbia Basin Research University of Washington Box Model (SSM) is loosely called a Beta Advection-Diffusion model. The SSM estimates a single parameter this single parameter characterized fish migration. The purpose of this note is to define the Beta Advection

  18. Peer Effects in the Diffusion of Solar Photovoltaic Panels

    E-Print Network [OSTI]

    Lee, Daeyeol

    Peer Effects in the Diffusion of Solar Photovoltaic Panels Bryan Bollinger NYU Stern School base of consumers in the reference group. We study the diffusion of solar photovoltaic panels of an environmentally beneficial technology, solar photovoltaic (PV) panels. Policymakers are particularly interested

  19. Diffuse optical imaging of the whole head Maria Angela Franceschini

    E-Print Network [OSTI]

    Diffuse optical imaging of the whole head Maria Angela Franceschini Danny K. Joseph Theodore J@nmr.mgh.harvard.edu Abstract. Near-Infrared Spectroscopy NIRS and diffuse optical im- aging DOI are increasingly used to detect of optodes in NIRS instruments has hampered measurement of optical signals from diverse brain regions. Our

  20. A RECONSTRUCTION ALGORITHM FOR ULTRASOUND-MODULATED DIFFUSE OPTICAL

    E-Print Network [OSTI]

    Garnier, Josselin

    A RECONSTRUCTION ALGORITHM FOR ULTRASOUND-MODULATED DIFFUSE OPTICAL TOMOGRAPHY HABIB AMMARI is to develop an efficient reconstruction algorithm for ultrasound-modulated diffuse optical tomography wave is propagating inside the medium, the optical parameter of the medium is perturbed. Using cross

  1. Microstructure of Gas Diffusion Layers for PEM Fuel Cells

    E-Print Network [OSTI]

    Endres. William J.

    Microstructure of Gas Diffusion Layers for PEM Fuel Cells N. Parikh1 , J. S. Allen1 , R. S. Yassar1 Introduction A gas diffusion layer (GDL) in a proton exchange mem- brane fuel cell (PEMFC) often is comprised porosimetry (MSP) [5]. The general procedure for obtaining the pore size distribution is to inject a fluid

  2. Convergence Speed of GARCH Option Price to Diffusion Option Price

    E-Print Network [OSTI]

    Chaudhuri, Sanjay

    Convergence Speed of GARCH Option Price to Diffusion Option Price Jin-Chuan Duan, Yazhen Wang that as the time interval between two consecutive observations shrinks to zero, a properly constructed GARCH model will weakly converge to a bivariate diffusion. Naturally the European option price under the GARCH model

  3. Electro-diffusion in a plasma with two ion species

    SciTech Connect (OSTI)

    Kagan, Grigory; Tang Xianzhu [Theoretical Division Los Alamos National Laboratory Los Alamos, New Mexico 87545 (United States)

    2012-08-15T23:59:59.000Z

    Electric field is a thermodynamic force that can drive collisional inter-ion-species transport in a multicomponent plasma. In an inertial confinement fusion capsule, such transport causes fuel ion separation even with a target initially prepared to have equal number densities for the two fuel ion species. Unlike the baro-diffusion driven by ion pressure gradient and the thermo-diffusion driven by ion and electron temperature gradients, electro-diffusion has a critical dependence on the charge-to-mass ratio of the ion species. Specifically, it is shown here that electro-diffusion vanishes if the ion species have the same charge-to-mass ratio. An explicit expression for the electro-diffusion ratio is obtained and used to investigate the relative importance of electro- and baro-diffusion mechanisms. In particular, it is found that electro-diffusion reinforces baro-diffusion in the deuterium and tritium mix, but tends to cancel it in the deuterium and helium-3 mix.

  4. Optical processing furnace with quartz muffle and diffuser plate

    DOE Patents [OSTI]

    Sopori, Bhushan L. (Denver, CO)

    1996-01-01T23:59:59.000Z

    An optical furnace for annealing a process wafer comprising a source of optical energy, a quartz muffle having a door to hold the wafer for processing, and a quartz diffuser plate to diffuse the light impinging on the quartz muffle; a feedback system with a light sensor located in the wall of the muffle is also provided for controlling the source of optical energy.

  5. Slippery diffusion-limited aggregation Clair R. Seager1,

    E-Print Network [OSTI]

    Weeks, Eric R.

    can translationally diffuse over the surface of the other. By contrast, shear-rigid bonding createsSlippery diffusion-limited aggregation Clair R. Seager1, * and Thomas G. Mason2, 1 Department attractions in liquids form irreversible "slippery" bonds that are not shear-rigid. Through event

  6. MULTISCALE MODELING OF DIFFUSION-INDUCED DEFORMATION PROCESSES

    E-Print Network [OSTI]

    Ponce, V. Miguel

    MULTISCALE MODELING OF DIFFUSION- INDUCED DEFORMATION PROCESSES Dr. Eugene Olevsky Friday, February 19, 2010 Engineering Bldg. Room E 300 Sintering is a high temperature process of bonding together of matter transport by different diffusion mechanisms driven by the high surface energy of aggregates

  7. Diffusion with dissolution and precipitation in a porous media

    E-Print Network [OSTI]

    Herbin, Raphaèle

    Diffusion with dissolution and precipitation in a porous media approximation by a finite volume. Quelques tests numériques sont ensuite montrés. KEYWORDS: diffusion, dissolution­precipitation, porous­ ficiency of such disposals relies on material barriers. For such a use, cement concrete offers

  8. Diffusion with dissolution and precipitation in a porous media

    E-Print Network [OSTI]

    Herbin, Raphaèle

    Diffusion with dissolution and precipitation in a porous media approximation by a finite volume numériques sont ensuite montrés. KEYWORDS: diffusion, dissolution-precipitation, porous media, finite volumes barriers. For such a use, cement concrete offers the advantage of having a weak porosity. However, disposal

  9. A Mesoscale Diffusion Model in Population Genetics with

    E-Print Network [OSTI]

    O'Leary, Michael

    ' & $ % A Mesoscale Diffusion Model in Population Genetics with Dynamic Fitness Mike O'Leary Towson University Judith R. Miller Georgetown University 1 #12;A mesoscale diffusion model in population genetics that dominance and epistasis are absent. April 28, 2005 Mike O'Leary and Judith Miller Slide 2 #12;A mesoscale

  10. Diffusion Bonding Aluminium Alloys and Composites: New Approaches and Modelling

    E-Print Network [OSTI]

    Cambridge, University of

    Diffusion Bonding Aluminium Alloys and Composites: New Approaches and Modelling Amir A. Shirzadi for advanced aluminium alloys and composites will enable them to be more widely used. The aim of this Ph of the research, two new methods for TLP diffusion bonding of aluminium-based composites (aluminium alloys

  11. Diffusive Shock Acceleration of Electrons and Radio Emission from Large Diameter Shell-Type Supernova Remnants

    E-Print Network [OSTI]

    A. I. Asvarov

    2000-01-21T23:59:59.000Z

    In present study I examine the capability of diffusive shock acceleration mechanism to explain existing data on radio emission from evolved large diameter shell-type adiabatic supernova remnants (SNRs). Time-dependent ''onion-shell'' model for the radio emission of SNRs is developed, which is based on the assumptions: a) acceleration takes place from thermal energies and test-particle approximation is valid; b) the problem of injection is avoided by introducing, like Bell (1978), two injection parameters; c) to take into consideration very late stages of SNR evolution the analytic approximation of Cox and Andersen (1982) for the shell structure is used; c)no radiative cooling. Constructed Surface Brightness - Diameter $(\\Sigma -D)$ tracks are compared with the empirical $\\Sigma -D$ diagram. The main conclusion of the study is that the DSA mechanism is capable of explaining all the statistics of radio SNRs including very large diameter remnants and giant galactic loops.

  12. Diffuse scattering measurements of static atomic displacements in crystalline binary solid solutions

    SciTech Connect (OSTI)

    Ice, G.E.; Sparks, C.J.; Jiang, X.; Robertson, L.

    1997-09-01T23:59:59.000Z

    Diffuse x-ray scattering from crystalline solid solutions is sensitive to both local chemical order and local bond distances. In short-range ordered alloys, fluctuations of chemistry and bond distances break the long-range symmetry of the crystal within a local region and contribute to the total energy of the alloy. Recent use of tunable synchrotron radiation to change the x-ray scattering contrast between elements has greatly advanced the measurement of bond distances between the three kinds of atom pairs found in crystalline binary alloys. The estimated standard deviation on these recovered static displacements approaches {+-}0.001 {angstrom} (0.0001 nm) which is an order of magnitude more precise than obtained with EXAFS. In addition, both the radial and tangential displacements can be recovered to five near neighbors and beyond. These static displacement measurements provide new information which challenges the most advanced theoretical models of binary crystalline alloys. 29 refs., 8 figs., 2 tabs.

  13. Diffusion, convection, and solidification in cw-mode free electron laser nitrided titanium

    SciTech Connect (OSTI)

    Hoeche, Daniel; Mueller, Sven [II. Physikalisches Institut, Universitaet Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen (Germany); Shinn, Michelle [Free Electron Laser Group, Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States); Schaaf, Peter [Institut fuer Werkstofftechnik, FG Werkstoffe der Elektrotechnik, TU Ilmenau, Postfach 10 05 65, 98684 Ilmenau (Germany)

    2009-04-15T23:59:59.000Z

    Titanium sheets were irradiated by free electron laser radiation in cw mode in pure nitrogen. Due to the interaction, nitrogen diffusion occurs and titanium nitride was synthesized in the tracks. Overlapping tracks have been utilized to create coatings in order to improve the tribological properties of the sheets. Caused by the local heating and the spatial dimension of the melt pool, convection effects were observed and related to the track properties. Stress, hardness, and nitrogen content were investigated with x-ray diffraction, nanoindention, and resonant nuclear reaction analysis. The measured results were correlated with the scan parameters, especially to the lateral track shift. Cross section micrographs were prepared and investigated by means of scanning electron microscopy. They show the solidification behavior, phase formation, and the nitrogen distribution. The experiments give an insight into the possibilities of materials processing using such a unique heat source.

  14. Effects of carbon on phosphorus diffusion in SiGe:C and the implications on phosphorus diffusion mechanisms

    SciTech Connect (OSTI)

    Lin, Yiheng; Xia, Guangrui [Department of Materials Engineering, The University of British Columbia, 309-6350 Stores Rd, Vancouver, British Columbia V6T 1Z4 (Canada); Yasuda, Hiroshi; Wise, Rick [Texas Instruments, 13121 TI Blvd., Dallas, Texas 75243 (United States); Schiekofer, Manfred; Benna, Bernhard [Texas Instruments Deutschland GmbH, Haggertystrasse 1, 85356 Freising (Germany)

    2014-10-14T23:59:59.000Z

    The use of carbon (C) in SiGe base layers is an important approach to control the base layer dopant phosphorus (P) diffusion and thus enhance PNP heterojunction bipolar transistor (HBT) performance. This work quantitatively investigated the carbon impacts on P diffusion in Si{sub 0.82}Ge{sub 0.18}:C and Si:C under rapid thermal anneal conditions. The carbon molar fraction is up to 0.32%. The results showed that the carbon retardation effect on P diffusion is less effective for Si{sub 0.82}Ge{sub 0.18}:C than for Si:C. In Si{sub 0.82}Ge{sub 0.18}:C, there is an optimum carbon content at around 0.05% to 0.1%, beyond which more carbon incorporation does not retard P diffusion any more. This behavior is different from the P diffusion behavior in Si:C and the B in Si:C and low Ge SiGe:C, which can be explained by the decreased interstitial-mediated diffusion fraction f{sub I}{sup P,?SiGe} to 95% as Ge content increases to 18%. Empirical models were established to calculate the time-averaged point defect concentrations and effective diffusivities as a function of carbon and was shown to agree with previous studies on boron, phosphorus, arsenic and antimony diffusion with carbon.

  15. CONSTRAINTS ON DARK MATTER ANNIHILATION IN CLUSTERS OF GALAXIES FROM DIFFUSE RADIO EMISSION

    SciTech Connect (OSTI)

    Storm, Emma; Jeltema, Tesla E.; Profumo, Stefano [Department of Physics, University of California, 1156 High St., Santa Cruz, CA 95064 (United States); Rudnick, Lawrence [Minnesota Institute for Astrophysics, School of Physics and Astronomy, University of Minnesota, 116 Church Street SE, Minneapolis, MN 55455 (United States)

    2013-05-10T23:59:59.000Z

    Annihilation of dark matter can result in the production of stable Standard Model particles including electrons and positrons that, in the presence of magnetic fields, lose energy via synchrotron radiation, observable as radio emission. Galaxy clusters are excellent targets to search for or to constrain the rate of dark matter annihilation, as they are both massive and dark matter dominated. In this study, we place limits on dark matter annihilation in a sample of nearby clusters using upper limits on the diffuse radio emission, low levels of observed diffuse emission, or detections of radio mini-halos. We find that the strongest limits on the annihilation cross section are better than limits derived from the non-detection of clusters in the gamma-ray band by a factor of {approx}3 or more when the same annihilation channel and substructure model, but different best-case clusters, are compared. The limits on the cross section depend on the assumed amount of substructure, varying by as much as two orders of magnitude for increasingly optimistic substructure models as compared to a smooth Navarro-Frenk-White profile. In our most optimistic case, using the results of the Phoenix Project, we find that the derived limits reach below the thermal relic cross section of 3 Multiplication-Sign 10{sup -26} cm{sup 3} s{sup -1} for dark matter masses as large as 400 GeV, for the b b-bar annihilation channel. We discuss uncertainties due to the limited available data on the magnetic field structure of individual clusters. We also report the discovery of diffuse radio emission from the central 30-40 kpc regions of the groups M49 and NGC 4636.

  16. Diffuse emission of high-energy neutrinos from gamma-ray burst fireballs

    E-Print Network [OSTI]

    Tamborra, Irene

    2015-01-01T23:59:59.000Z

    Gamma-ray bursts (GRBs) have been suggested as possible sources of the high-energy neutrino flux recently detected by the IceCube telescope. We revisit the fireball emission model and elaborate an analytical prescription to estimate the high-energy neutrino prompt emission from pion and kaon decays, assuming that the leading mechanism for the neutrino production is lepto-hadronic. To this purpose, we include hadronic, radiative and adiabatic cooling effects and discuss their relevance for long- (including high- and low-luminosity) and short-duration GRBs. The expected diffuse neutrino background is derived, by requiring that the GRB high-energy neutrino counterparts follow up-to-date gamma-ray luminosity functions and redshift evolutions of the long and short GRBs. Although dedicated stacking searches have been unsuccessful up to now, we find that the GRBs could contribute up to a few percents to the observed IceCube high-energy neutrino flux for sub-PeV energies, assuming that the latter has a diffuse origin...

  17. Angular Signatures of Dark Matter in the Diffuse Gamma Ray Spectrum

    SciTech Connect (OSTI)

    Hooper, Dan; Serpico, Pasquale D.; /Fermilab

    2007-02-01T23:59:59.000Z

    Dark matter annihilating in our Galaxy's halo and elsewhere in the universe is expected to generate a diffuse flux of gamma rays, potentially observable with next generation satellite-based experiments, such as GLAST. In this article, we study the signatures of dark matter in the angular distribution of this radiation. Pertaining to the extragalactic contribution, we discuss the effect of the motion of the solar system with respect to the cosmological rest frame, and anisotropies due to the structure of our local universe. For the gamma ray flux from dark matter in our own Galactic halo, we discuss the effects of the offset position of the solar system, the Compton-Getting effect, the asphericity of the Milky Way halo, and the signatures of nearby substructure. We explore the prospects for the detection of these features by the GLAST satellite and find that, if {approx} 10% or more of the diffuse gamma ray background observed by EGRET is the result of dark matter annihilations, then GLAST should be sensitive to anisotropies down to the 0.1% level. Such precision would be sufficient to detect many, if not all, of the signatures discussed in this paper.

  18. Impurity Diffusion Coefficients of Al and Zn in Mg Determined from Solid-to-Solid Diffusion Couples

    SciTech Connect (OSTI)

    Kammerer, Catherine [University of Central Florida, Orlando; Kulkarni, Nagraj S [ORNL; Warmack, Robert J Bruce [ORNL; Perry, Kelly A [ORNL; Belova, Irina [University of Newcastle, NSW, Australia; Murch, Prof. Graeme [University of Newcastle, NSW, Australia; Sohn, Yong Ho [University of Central Florida

    2013-08-01T23:59:59.000Z

    Increasing use and development of lightweight Mgalloys have led to the desire for more fundamental research in and understanding of Mg-based systems. As property enhancing components, Al and Zn are two of the most important and common alloying elements for Mg-alloys. We have investigated the concentration dependent interdiffusion of Al and Zn in Mg using diffusion couples of pure polycrystalline Mg mated to Mg solid solutions containing either <9 at.% Al or <3 at.% Zn. Concentration profiles were determined by electron micro-probe microanalysis of the diffusion zone. The interdiffusion coefficients were determined by the classical Boltzmann-Matano method within the Mg solid solution. As the concentration of Al or Zn approaches the dilute ends, we employ an analytical approach based on the Hall method to estimate the impurity diffusion coefficients. Results of Al and Zn impurity diffusion in Mg are reported and compared to published impurity diffusion coefficients typically determined by thin film techniques.

  19. THERMOHALINE INSTABILITIES INSIDE STARS: A SYNTHETIC STUDY INCLUDING EXTERNAL TURBULENCE AND RADIATIVE LEVITATION

    SciTech Connect (OSTI)

    Vauclair, Sylvie; Theado, Sylvie, E-mail: sylvie.vauclair@irap.omp.eu [Universite de Toulouse, UPS-OMP and CNRS, Institut de Recherche en Astrophysique et Planetologie, 14 avenue Edouard Belin, F-31400 Toulouse (France)

    2012-07-01T23:59:59.000Z

    We have derived a new expression for the thermohaline mixing coefficient in stars, including the effects of radiative levitation and external turbulence, by solving Boussinesq equations in a nearly incompressible stratified fluid with a linear approximation. It is well known that radiative levitation of individual elements can lead to their accumulation in specific stellar layers. In some cases, it can induce important effects on the stellar structure. Here we confirm that this accumulation is moderated by thermohaline convection due to the resulting inverse {mu}-gradient. The new coefficient that we have derived shows that the effect of radiative accelerations on the thermohaline instability itself is small. This effect must however be checked in all computations. We also confirm that the presence of large horizontal turbulence can reduce or even suppress the thermohaline convection. These results are important as they concern all the cases of heavy element accumulation in stars. Computations of radiative diffusion must be revisited to include thermohaline convection and its consequences. It may be one of the basic reasons for the fact that the observed abundances are always smaller than those predicted by pure atomic diffusion. In any case, these processes have to compete with rotation-induced mixing, but this competition is more complex than previously thought due to their mutual interaction.

  20. Hawking radiation and Quasinormal modes

    E-Print Network [OSTI]

    SangChul Yoon

    2005-10-05T23:59:59.000Z

    The spectrum of Hawking radiation by quantum fields in the curved spacetime is continuous, so the explanation of Hawking radiation using quasinormal modes can be suspected to be impossible. We find that quasinormal modes do not explain the relation between the state observed in a region far away from a black hole and the short distance behavior of the state on the horizon.

  1. Radiation trapping in coherent media

    E-Print Network [OSTI]

    A. B. Matsko; I. Novikova; M. O. Scully; G. R. Welch

    2001-01-31T23:59:59.000Z

    We show that the effective decay rate of Zeeman coherence, generated in a Rb87 vapor by linearly polarized laser light, increases significantly with the atomic density. We explain this phenomenon as the result of radiation trapping. Our study shows that radiation trapping must be taken into account to fully understand many electromagnetically induced transparency experiments with optically thick media.

  2. Review Article RADIATION SHIELDING TECHNOLOGY

    E-Print Network [OSTI]

    Shultis, J. Kenneth

    Review Article RADIATION SHIELDING TECHNOLOGY J. Kenneth Shultis and Richard E. Faw* Abstract Physics Society INTRODUCTION THIS IS a review of the technology of shielding against the effects to the review. The first treats the evolution of radiation-shielding technology from the beginning of the 20th

  3. Understanding the Regional Variability of Eddy Diffusivity in the Pacific Sector of the Southern Ocean

    E-Print Network [OSTI]

    Shuckburgh, Emily

    A diagnostic framework is presented, based on the Nakamura effective diffusivity, to investigate the regional variation in eddy diffusivity. Comparison of three different diffusivity calculations enables the effects of ...

  4. The limiting mutual diffusion coefficients of Fischer-Tropsch synthesis products in near-critical hydrocarbons 

    E-Print Network [OSTI]

    Noel, James Michael

    1994-01-01T23:59:59.000Z

    is the molecular diffusivity of the organic in the supercritical fluid. However, data for diffusivities in supercritical fluids are scarce. Because diffusion coefficients cannot be determined a priofi, it is necessary to measure them. We have utilized the Taylor...

  5. Abdominal radiation causes bacterial translocation

    SciTech Connect (OSTI)

    Guzman-Stein, G.; Bonsack, M.; Liberty, J.; Delaney, J.P.

    1989-02-01T23:59:59.000Z

    The purpose of this study was to determine if a single dose of radiation to the rat abdomen leads to bacterial translocation into the mesenteric lymph nodes (MLN). A second issue addressed was whether translocation correlates with anatomic damage to the mucosa. The radiated group (1100 cGy) which received anesthesia also was compared with a control group and a third group which received anesthesia alone but no abdominal radiation. Abdominal radiation lead to 100% positive cultures of MLN between 12 hr and 4 days postradiation. Bacterial translocation was almost nonexistent in the control and anesthesia group. Signs of inflammation and ulceration of the intestinal mucosa were not seen until Day 3 postradiation. Mucosal damage was maximal by Day 4. Bacterial translocation onto the MLN after a single dose of abdominal radiation was not apparently dependent on anatomical, histologic damage of the mucosa.

  6. Gravitational Radiation From Cosmological Turbulence

    E-Print Network [OSTI]

    Arthur Kosowsky; Andrew Mack; Tinatin Kahniashvili

    2002-06-27T23:59:59.000Z

    An injection of energy into the early Universe on a given characteristic length scale will result in turbulent motions of the primordial plasma. We calculate the stochastic background of gravitational radiation arising from a period of cosmological turbulence, using a simple model of isotropic Kolmogoroff turbulence produced in a cosmological phase transition. We also derive the gravitational radiation generated by magnetic fields arising from a dynamo operating during the period of turbulence. The resulting gravitational radiation background has a maximum amplitude comparable to the radiation background from the collision of bubbles in a first-order phase transition, but at a lower frequency, while the radiation from the induced magnetic fields is always subdominant to that from the turbulence itself. We briefly discuss the detectability of such a signal.

  7. Transition Radiation in QCD matter

    E-Print Network [OSTI]

    Magdalena Djordjevic

    2005-12-22T23:59:59.000Z

    In ultrarelativistic heavy ion collisions a finite size QCD medium is created. In this paper we compute radiative energy loss to zeroth order in opacity by taking into account finite size effects. Transition radiation occurs on the boundary between the finite size medium and the vacuum, and we show that it lowers the difference between medium and vacuum zeroth order radiative energy loss relative to the infinite size medium case. Further, in all previous computations of light parton radiation to zeroth order in opacity, there was a divergence caused by the fact that the energy loss is infinite in the vacuum and finite in the QCD medium. We show that this infinite discontinuity is naturally regulated by including the transition radiation.

  8. Radiation Reaction in Quantum Vacuum

    E-Print Network [OSTI]

    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.

  9. Reduction of phosphorus diffusion in germanium by fluorine implantation

    SciTech Connect (OSTI)

    El Mubarek, H. A. W. [School of Electrical and Electronic Engineering, University of Manchester, Manchester M13 9PL (United Kingdom)

    2013-12-14T23:59:59.000Z

    The control of phosphorus (P) diffusion in germanium (Ge) is essential for the realisation of ultrashallow n-type junctions in Ge. This work reports a detailed study of the effect of fluorine (F) co-implantation on P diffusion in Ge. P and F profiles were characterized by secondary ion mass spectroscopy. The ion implantation damage was investigated using cross sectional transmission electron microscopy. It is shown that F co-implantation reduces the implanted P profile width and reduces both intrinsic and extrinsic P diffusion in Ge. A defect mediated mechanism for the strong influence of F co-implantation on P diffusion in Ge is proposed and invokes the formation of F{sub n}V{sub m} clusters in the F-amorphized Ge layer. A fraction of these F{sub n}V{sub m} clusters decorate the interstitial type end-of-range defects in the re-grown Ge layer and the rest react during re-growth with interstitial germanium atoms diffusing back from the amorphous crystalline interface. The Ge vacancies are then annihilated and mobile interstitial F is released and out diffuses from the surface. This results in a re-grown Ge layer which has a low vacancy concentration and in which the P diffusion rate is reduced. These results open the way to the realization of enhanced Ge n-type devices.

  10. Heat transfer including radiation and slag particles evolution in MHD channel-I

    SciTech Connect (OSTI)

    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.

  11. Spectral Components Analysis of Diffuse Emission Processes

    SciTech Connect (OSTI)

    Malyshev, Dmitry; /KIPAC, Menlo Park

    2012-09-14T23:59:59.000Z

    We develop a novel method to separate the components of a diffuse emission process based on an association with the energy spectra. Most of the existing methods use some information about the spatial distribution of components, e.g., closeness to an external template, independence of components etc., in order to separate them. In this paper we propose a method where one puts conditions on the spectra only. The advantages of our method are: 1) it is internal: the maps of the components are constructed as combinations of data in different energy bins, 2) the components may be correlated among each other, 3) the method is semi-blind: in many cases, it is sufficient to assume a functional form of the spectra and determine the parameters from a maximization of a likelihood function. As an example, we derive the CMB map and the foreground maps for seven yeas of WMAP data. In an Appendix, we present a generalization of the method, where one can also add a number of external templates.

  12. Puzzling Phenomenon of Diffuse Interstellar Bands

    E-Print Network [OSTI]

    B. Wszolek

    2007-12-10T23:59:59.000Z

    The discovery of the first diffuse interstellar bands (DIBs) dates back to the pioneering years of stellar spectroscopy. Today, we know about 300 absorption structures of this kind. There exists a great variety of the profiles and intensities of DIBs, so they can not be readily described, classified or characterized. To the present day no reliable identification of the DIBs' carriers has been found. Many carriers of DIBs have been proposed over the years. They ranged from dust grains to free molecules of different kinds, and to more exotic specimens, like hydrogen negative ion. Unfortunately, none of them is responsible for observed DIBs. Furthermore, it was shown that a single carrier cannot be responsible for all known DIBs. It is hard to estimate how many carriers can participate in producing these bands. The problem is further complicated by the fact that to this day it is still impossible to find any laboratory spectrum of any substance which would match the astrophysical spectra. Here, a historical outline concerning DIBs is followed by a brief description of their whole population. Then, a special attention is focused on the procedures trying to extract spectroscopic families within the set of all known DIBs.

  13. Diffusivity bounds for 1D Brownian polymers

    E-Print Network [OSTI]

    Pierre Tarrès; Bálint Tóth; Benedek Valkó

    2012-06-08T23:59:59.000Z

    We study the asymptotic behavior of a self-interacting one-dimensional Brownian polymer first introduced by Durrett and Rogers [Probab. Theory Related Fields 92 (1992) 337--349]. The polymer describes a stochastic process with a drift which is a certain average of its local time. We show that a smeared out version of the local time function as viewed from the actual position of the process is a Markov process in a suitably chosen function space, and that this process has a Gaussian stationary measure. As a first consequence, this enables us to partially prove a conjecture about the law of large numbers for the end-to-end displacement of the polymer formulated in Durrett and Rogers [Probab. Theory Related Fields 92 (1992) 337--349]. Next we give upper and lower bounds for the variance of the process under the stationary measure, in terms of the qualitative infrared behavior of the interaction function. In particular, we show that in the locally self-repelling case (when the process is essentially pushed by the negative gradient of its own local time) the process is super-diffusive.

  14. Linear diffusion into a Faraday cage.

    SciTech Connect (OSTI)

    Warne, Larry Kevin; Lin, Yau Tang; Merewether, Kimball O.; Chen, Kenneth C.

    2011-11-01T23:59:59.000Z

    Linear lightning diffusion into a Faraday cage is studied. An early-time integral valid for large ratios of enclosure size to enclosure thickness and small relative permeability ({mu}/{mu}{sub 0} {le} 10) is used for this study. Existing solutions for nearby lightning impulse responses of electrically thick-wall enclosures are refined and extended to calculate the nearby lightning magnetic field (H) and time-derivative magnetic field (HDOT) inside enclosures of varying thickness caused by a decaying exponential excitation. For a direct strike scenario, the early-time integral for a worst-case line source outside the enclosure caused by an impulse is simplified and numerically integrated to give the interior H and HDOT at the location closest to the source as well as a function of distance from the source. H and HDOT enclosure response functions for decaying exponentials are considered for an enclosure wall of any thickness. Simple formulas are derived to provide a description of enclosure interior H and HDOT as well. Direct strike voltage and current bounds for a single-turn optimally-coupled loop for all three waveforms are also given.

  15. Diffuse interstellar bands in M33

    E-Print Network [OSTI]

    Smith, Keith T; Evans, Christopher J; Cox, Nick L J; Sarre, Peter J

    2013-01-01T23:59:59.000Z

    We present the first sample of diffuse interstellar bands (DIBs) in the nearby galaxy M33. Studying DIBs in other galaxies allows the behaviour of the carriers to be examined under interstellar conditions which can be quite different from those of the Milky Way, and to determine which DIB properties can be used as reliable probes of extragalactic interstellar media. Multi-object spectroscopy of 43 stars in M33 has been performed using Keck/DEIMOS. The stellar spectral types were determined and combined with literature photometry to determine the M33 reddenings E(B-V)_M33. Equivalent widths or upper limits have been measured for the {\\lambda}5780 DIB towards each star. DIBs were detected towards 20 stars, demonstrating that their carriers are abundant in M33. The relationship with reddening is found to be at the upper end of the range observed in the Milky Way. The line of sight towards one star has an unusually strong ratio of DIB equivalent width to E(B-V)_M33, and a total of seven DIBs were detected towards...

  16. Radiation-Induced Segregation and Phase Stability in Candidate Alloys for the Advanced Burner Reactor

    SciTech Connect (OSTI)

    Gary S. Was; Brian D. Wirth

    2011-05-29T23:59:59.000Z

    Major accomplishments of this project were the following: 1) Radiation induced depletion of Cr occurs in alloy D9, in agreement with that observed in austenitic alloys. 2) In F-M alloys, Cr enriches at PAG grain boundaries at low dose (<7 dpa) and at intermediate temperature (400°C) and the magnitude of the enrichment decreases with temperature. 3) Cr enrichment decreases with dose, remaining enriched in alloy T91 up to 10 dpa, but changing to depletion above 3 dpa in HT9 and HCM12A. 4) Cr has a higher diffusivity than Fe by a vacancy mechanism and the corresponding atomic flux of Cr is larger than Fe in the opposite direction to the vacancy flux. 5) Cr concentration at grain boundaries decreases as a result of vacancy transport during electron or proton irradiation, consistent with Inverse Kirkendall models. 6) Inclusion of other point defect sinks into the KLMC simulation of vacancy-mediated diffusion only influences the results in the low temperature, recombination dominated regime, but does not change the conclusion that Cr depletes as a result of vacancy transport to the sink. 7) Cr segregation behavior is independent of Frenkel pair versus cascade production, as simulated for electron versus proton irradiation conditions, for the temperatures investigated. 8) The amount of Cr depletion at a simulated planar boundary with vacancy-mediated diffusion reaches an apparent saturation value by about 1 dpa, with the precise saturation concentration dependent on the ratio of Cr to Fe diffusivity. 9) Cr diffuses faster than Fe by an interstitial transport mechanism, and the corresponding atomic flux of Cr is much larger than Fe in the same direction as the interstitial flux. 10) Observed experimental and computational results show that the radiation induced segregation behavior of Cr is consistent with an Inverse Kirkendall mechanism.

  17. Radiation events in astronomical CCD images

    E-Print Network [OSTI]

    2001-01-01T23:59:59.000Z

    268. 10. “On the Rates of Radiation Events in CCD’s (Excerpt23 Jan 2002 LBNL-49316 Radiation events in astronomical CCDof depleted silicon to ionizing radiation is a nuisance to

  18. High efficiency, radiation-hard solar cells

    E-Print Network [OSTI]

    Ager III, J.W.; Walukiewicz, W.

    2004-01-01T23:59:59.000Z

    J. F. Geisz, “Superior radiation resistance of In 1-x Ga x Nand H. Itoh, “Proton radiation analysis of multi-junction56326 High efficiency, radiation-hard solar cells Final

  19. Energy diffusion in strongly driven quantum chaotic systems

    E-Print Network [OSTI]

    P. V. Elyutin

    2005-04-14T23:59:59.000Z

    The energy evolution of a quantum chaotic system under the perturbation that harmonically depends on time is studied for the case of large perturbation, in which the rate of transition calculated from the Fermi golden rule exceeds the frequency of perturbation. It is shown that the energy evolution retains its diffusive character, with the diffusion coefficient that is asymptotically proportional to the magnitude of perturbation and to the square root of the density of states. The results are supported by numerical calculation. They imply the absence of the quantum-classical correspondence for the energy diffusion and the energy absorption in the classical limit $\\hbar \\to 0$.

  20. Diffusive mesh relaxation in ALE finite element numerical simulations

    SciTech Connect (OSTI)

    Dube, E.I.

    1996-06-01T23:59:59.000Z

    The theory for a diffusive mesh relaxation algorithm is developed for use in three-dimensional Arbitary Lagrange/Eulerian (ALE) finite element simulation techniques. This mesh relaxer is derived by a variational principle for an unstructured 3D grid using finite elements, and incorporates hourglass controls in the numerical implementation. The diffusive coefficients are based on the geometric properties of the existing mesh, and are chosen so as to allow for a smooth grid that retains the general shape of the original mesh. The diffusive mesh relaxation algorithm is then applied to an ALE code system, and results from several test cases are discussed.