National Library of Energy BETA

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. Radiative heat transfer in this class of material is nonlocalized in the optically thick limit

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

    Open Energy Info (EERE)

    UNEP-GEF Renewable Energy Project Financial Risk Management in Developing Countries Jump to: navigation, search Name UNEP-GEF Renewable Energy Project Financial Risk Management in...

  3. 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)

    2013-01-01

    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.

  4. 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental Jump to:EA EISTJThin Film SolarTown(LECBP) | OpenTrack Wind FarmGEF Projects Jump

  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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsource History View NewGuam:onItronKanosh TownKenetech/Wintech WindPageEnergyEnergyGEF

  6. Diffuse Radiation from the Aquila Rift

    E-Print Network [OSTI]

    Jyothy, S N; Karuppath, Narayanankutty; Sujatha, N V

    2015-01-01

    We present an analysis of the diffuse ultraviolet (UV) background in a low latitude region near the Aquila Rift based on observations made by the Galaxy Evolution Explorer (GALEX). The UV background is at a level of about 2000 ph cm^-2 s^-1 sr^-1 \\AA^-1 with no correlation with either the Galactic latitude or the 100 micron infrared (IR) emission. Rather, the UV emission falls off with distance from the bright B2 star HIP 88149, which is in the centre of the field. We have used a Monte Carlo model to derive an albedo of 0.6 - 0.7 in the UV with a phase function asymmetry factor (g) of 0.2 - 0.4. The value for the albedo is dependent on the dust distribution while g is determined by the extent of the halo.

  7. 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

    2012-11-15

    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.

  8. Radiation monitoring during criticality at a gaseous diffusion plant

    SciTech Connect (OSTI)

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

    1994-12-31

    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. Diffusive radiation in Langmuir turbulence produced by jet shocks

    E-Print Network [OSTI]

    Fleishman, Gregory D

    2007-01-01

    Anisotropic distributions of charged particles including two-stream distributions give rise to generation of either stochastic electric fields (in the form of Langmuir waves, Buneman instability) or random quasi-static magnetic fields (Weibel and filamentation instabilities) or both. These two-stream instabilities are known to play a key role in collisionless shock formation, shock-shock interactions, and shock-induced electromagnetic emission. This paper applies the general non-perturbative stochastic theory of radiation to study electromagnetic emission produced by relativistic particles, which random walk in the stochastic electric fields of the Langmuir waves. This analysis takes into account the cumulative effect of uncorrelated Langmuir waves on the radiating particle trajectory giving rise to angular diffusion of the particle, which eventually modifies the corresponding radiation spectra. We demonstrate that the radiative process considered is probably relevant for emission produced in various kinds of...

  10. Numerical Passage from Radiative Heat Transfer to Nonlinear Diffusion Models \\Lambda

    E-Print Network [OSTI]

    Schmeiser, Christian

    Numerical Passage from Radiative Heat Transfer to Nonlinear Diffusion Models \\Lambda A. Klar y C. Schmeiser z Abstract Radiative heat transfer equations including heat conduction are consid­ ered situations are presented. Keywords. radiative heat transfer, asymptotic analysis, nonlinear diffusion limit

  11. Diffusive radiation in Langmuir turbulence produced by jet shocks

    E-Print Network [OSTI]

    Gregory D. Fleishman; Igor N. Toptygin

    2007-06-03

    Anisotropic distributions of charged particles including two-stream distributions give rise to generation of either stochastic electric fields (in the form of Langmuir waves, Buneman instability) or random quasi-static magnetic fields (Weibel and filamentation instabilities) or both. These two-stream instabilities are known to play a key role in collisionless shock formation, shock-shock interactions, and shock-induced electromagnetic emission. This paper applies the general non-perturbative stochastic theory of radiation to study electromagnetic emission produced by relativistic particles, which random walk in the stochastic electric fields of the Langmuir waves. This analysis takes into account the cumulative effect of uncorrelated Langmuir waves on the radiating particle trajectory giving rise to angular diffusion of the particle, which eventually modifies the corresponding radiation spectra. We demonstrate that the radiative process considered is probably relevant for emission produced in various kinds of astrophysical jets, in particular, prompt gamma-ray burst spectra, including X-ray excesses and prompt optical flashes.

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

    E-Print Network [OSTI]

    Boyer, Edmond

    1996-01-01

    Ann. Geophysicae 14, 1051--1059 (1996) EGS -- Springer-Verlag 1996 Diffuse solar radiation: 15 May 1996/Accepted: 27 May 1996 Abstract. Solar diffuse radiation data including global radiation and the monthly ratios of diffuse to global solar radiation have been examined, with a special emphasis

  13. 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX E LISTStar Energy LLC Jump to: navigation,Summaries |AreteAriane EnvironmentArkGEF

  14. 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental Jump to:EA EISTJThin Film SolarTown(LECBP) |UNDP/GEF-Cambodia-Sustainable Forest

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

    E-Print Network [OSTI]

    Munger, Bryce Kirtley

    1997-01-01

    This thesis describes the development of an improved multipyranometer array (NDA) for the continuous remote measurement of direct and diff-use solar radiation. The NWA described in this thesis is an improvement over ...

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

    E-Print Network [OSTI]

    Munger, B.; Haberl, J. S.

    1994-01-01

    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 ...

  17. Data From HANE-Generated Radiation Belts and the Origin of Diffusion Theory

    SciTech Connect (OSTI)

    Winske, Dan [Los Alamos National Laboratory

    2012-07-16

    In this presentation we briefly review some of the published data regarding the artificial radiation belts produced by the Starfish and R2 high altitude nuclear explosions in 1962. The data showed slow temporal variations of the belts in altitude (L) and pitch angle ({alpha}) that could be modeled as a diffusion process. That early work formed the basis for more complex radiation belt diffusion models that are in use at present.

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

    E-Print Network [OSTI]

    Li, Xinlin

    Modeling the radiation belt electrons with radial diffusion driven by the solar wind A. B. Barker1 October 2005. [1] On the basis of the correlation between the solar wind and radiation belt electron fluxes, we develop a model to simulate the MeV electron phase space density variations from L = 3 to L

  19. Measure of Diffusion Model Error for Thermal Radiation Transport 

    E-Print Network [OSTI]

    Kumar, Akansha

    2013-04-19

    and computational time. However, this approximation often has significant error. Error due to the inherent nature of a physics model is called model error. Information about the model error associated with the diffusion approximation is clearly desirable...

  20. Accurately specifying storm-time ULF wave radial diffusion in the radiation belts

    E-Print Network [OSTI]

    Dimitrakoudis, Stavros; Balasis, Georgios; Papadimitriou, Constantinos; Anastasiadis, Anastasios; Daglis, Ioannis A

    2015-01-01

    Ultra-low frequency (ULF) waves can contribute to the transport, acceleration and loss of electrons in the radiation belts through inward and outward diffusion. However, the most appropriate parameters to use to specify the ULF wave diffusion rates are unknown. Empirical representations of diffusion coefficients often use Kp; however, specifications using ULF wave power offer an improved physics-based approach. We use 11 years of ground-based magnetometer array measurements to statistically parameterise the ULF wave power with Kp, solar wind speed, solar wind dynamic pressure and Dst. We find Kp is the best single parameter to specify the statistical ULF wave power driving radial diffusion. Significantly, remarkable high energy tails exist in the ULF wave power distributions when expressed as a function of Dst. Two parameter ULF wave power specifications using Dst as well as Kp provide a better statistical representation of storm-time radial diffusion than any single variable alone.

  1. Diffusive Radiation in One-dimensional Langmuir Turbulence

    E-Print Network [OSTI]

    Fleishman, Gregory D

    2007-01-01

    We calculate spectra of radiation produced by a relativistic particle in the presence of one-dimensional Langmuir turbulence which might be generated by a streaming instability in the plasma, in particular, in the shock front or at the shock-shock interactions. The shape of the radiation spectra is shown to depend sensitively on the angle between the particle velocity and electric field direction. The radiation spectrum in the case of exactly transverse particle motion is degenerate and similar to that of spatially uniform Langmuir oscillations. In case of oblique propagation, the spectrum is more complex, it consists of a number of power-law regions and may contain a distinct high-frequency spectral peak. %at $\\omega=2\\omega\\pe \\gamma^2$. The emission process considered is relevant to various laboratory plasma settings and for astrophysical objects as gamma-ray bursts and collimated jets.

  2. Diffusive Radiation in One-dimensional Langmuir Turbulence

    E-Print Network [OSTI]

    Gregory D. Fleishman; Igor N. Toptygin

    2007-05-21

    We calculate spectra of radiation produced by a relativistic particle in the presence of one-dimensional Langmuir turbulence which might be generated by a streaming instability in the plasma, in particular, in the shock front or at the shock-shock interactions. The shape of the radiation spectra is shown to depend sensitively on the angle between the particle velocity and electric field direction. The radiation spectrum in the case of exactly transverse particle motion is degenerate and similar to that of spatially uniform Langmuir oscillations. In case of oblique propagation, the spectrum is more complex, it consists of a number of power-law regions and may contain a distinct high-frequency spectral peak. %at $\\omega=2\\omega\\pe \\gamma^2$. The emission process considered is relevant to various laboratory plasma settings and for astrophysical objects as gamma-ray bursts and collimated jets.

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

    E-Print Network [OSTI]

    Chang-Hwan Lee; Ismail Zahed

    2014-03-07

    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.

  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.

    2000-01-01

    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 ...

  5. 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

    2008-03-28

    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.

  6. Shear mixing in stellar radiative zones I. Effect of thermal diffusion and chemical stratification

    E-Print Network [OSTI]

    Prat, Vincent

    2014-01-01

    Turbulent transport of chemical elements in radiative zones of stars is taken into account in current stellar evolution codes thanks to phenomenologically derived diffusion coefficients. Recent local numerical simulations (Prat & Ligni\\`eres 2013, A&A, 551, L3) suggest that the coefficient for radial turbulent diffusion due to radial differential rotation satisfies $D_{\\rm t}\\simeq0.058\\kappa/Ri$, in qualitative agreement with Zahn's model. However, this model does not apply when differential rotation is strong with respect to stable thermal stratification or when chemical stratification has a significant dynamical effect, a situation encountered at the outer boundary of nuclear burning convective cores. We extend our numerical study to consider the effects of chemical stratification and of strong shear, and compare with prescriptions used in stellar evolution codes. We perform local, direct numerical simulations of stably stratified, homogeneous, sheared turbulence in the Boussinesq approximation. Th...

  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)

    2013-03-01

    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))

    1994-03-01

    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

    2014-04-01

    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. Applied Radiation and Isotopes 56 (2002) 953956 Sensitivity of LR115 detector in diffusion chamber to 222

    E-Print Network [OSTI]

    Yu, Peter K.N.

    2002-01-01

    Applied Radiation and Isotopes 56 (2002) 953­956 Sensitivity of LR115 detector in diffusion chamber Determination has been made of the sensitivity of LR115 type 2-track detectors (in units of m) to 222 Rn chamber. r 2002 Elsevier Science Ltd. All rights reserved. Keywords: Radon; Thoron; LR115 track detector

  11. 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

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

    E-Print Network [OSTI]

    Ferguson, Jim Michael

    2014-01-10

    Radiation hydrodynamics (RH) provides a theoretical description for many astrophysical events spanning a wide range of observable phenomena. It is the goal of high-energy-density laboratory astrophysics (HEDLA) to reproduce some of these events...

  13. Self-Similar Radiation-Hydrodynamics Solutions in the Equilibrium Diffusion Limit 

    E-Print Network [OSTI]

    Lane, Taylor Kinsey

    2013-01-31

    , radiation, and shock waves. These phenomena can be found in supernovae explosions, or in inertial confinement fusion applications. Hydrodynamics Model To begin to understand the complex flows involved with RHD, it is important to first consider hydrodynamics...

  14. 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)

    2013-02-01

    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.

  15. Diffusive radiation in one-dimensional Langmuir turbulence G. D. Fleishman1

    E-Print Network [OSTI]

    -dimensional Langmuir turbulence which might be generated by a streaming instability in the plasma, in particular sensi- tively on the angle between the particle velocity and electric field direction. The radiation as gamma-ray bursts and collimated jets. DOI: 10.1103/PhysRevE.76.017401 PACS number s : 52.25.Os, 52.35.Ra

  16. 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.

    2009-05-01

    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.

  17. NEW CONCEPTS FOR STATIC CONCENTRATION OF DIRECT AND DIFFUSE RADIATION A. Luque, J. Eguren, J.M. Ruiz, A. Cuevas, J. del Alamo, J.M. Gomez, M.

    E-Print Network [OSTI]

    del Alamo, Jesús A.

    NEW CONCEPTS FOR STATIC CONCENTRATION OF DIRECT AND DIFFUSE RADIATION A. Luque, J. Eguren, J en,ergy on a cell placed in a static concentrator of minimum entry aperture are derived at a cost estimat~ of $3.19 W/peak. 1. INTRODUCTION Conventional concentrating photovoltai~ devices require

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

    E-Print Network [OSTI]

    2009-01-01

    reductions of surface solar radiation at sites in the Unitedtrends in surface solar radiation? , Science, 308, 850 –changes in surface solar radiation, Science, 308, 847 – 850,

  19. 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

    2014-03-01

    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

  20. Research Update: Reactively sputtered nanometer-thin ZrN film as a diffusion barrier between Al and boron layers for radiation detector applications

    SciTech Connect (OSTI)

    Golshani, Negin, E-mail: negingolshani@gmail.com; Mohammadi, V.; Schellevis, H.; Beenakker, C. I. M.; Ishihara, R. [ECTM, DIMES, Faculty of Electrical Engineering (EWI), Delft University of Technology (TU Delft), Feldmannweg 17, P.O. Box 5053, 2628 CT Delft (Netherlands)

    2014-10-01

    In this paper, optimization of the process flow for PureB detectors is investigated. Diffusion barrier layers between a boron layer and the aluminum interconnect can be used to enhance the performance and visual appearance of radiation detectors. Few nanometers-thin Zirconium Nitride (ZrN) layer deposited by reactive sputtering in a mixture of Ar/N{sub 2}, is identified as a reliable diffusion barrier with better fabrication process compatibility than others. The barrier properties of this layer have been tested for different boron layers deposited at low and high temperatures with extensive optical microscopy analyses, electron beam induced current, SEM, and electrical measurements. This study demonstrated that spiking behavior of pure Al on Si can be prevented by the thin ZrN layer thus improving the performance of the radiation detectors fabricated using boron layer.

  1. Laboratory optical spectroscopy of the thiophenoxy radical and its profile simulation as a diffuse interstellar band based on rotational distribution by radiation and collisions

    SciTech Connect (OSTI)

    Araki, Mitsunori; Niwayama, Kei; Tsukiyama, Koichi

    2014-11-01

    The gas-phase optical absorption spectrum of the thiophenoxy radical (C{sub 6}H{sub 5}S), a diffuse interstellar band (DIB) candidate molecule, was observed in the discharge of thiophenol using a cavity ringdown spectrometer. The ground-state rotational constants of the thiophenoxy radical were theoretically calculated, and the excited-state rotational constants were determined from the observed rotational profile. The rotational profile of a near prolate molecule having C {sub 2v} symmetry was simulated on the basis of a rotational distribution model by radiation and collisions. Although the simulated profile did not agree with the observed DIBs, the upper limit of the column density for the thiophenoxy radical in the diffuse clouds toward HD 204827 was evaluated to be 2 × 10{sup 13} cm{sup –2}. The profile simulation indicates that rotational distribution by radiation and collisions is important to reproduce a rotational profile for a DIB candidate and that the near prolate C {sub 2v} molecule is a possible candidate for DIB with a band width variation dependent on the line of sight.

  2. THE VEX RADIATION MODULE: 2D RADIATION TRANSPORT WITH MIMETIC...

    Office of Scientific and Technical Information (OSTI)

    THE VEX RADIATION MODULE: 2D RADIATION TRANSPORT WITH MIMETIC DIFFUSION FOR EXAFLAG Citation Details In-Document Search Title: THE VEX RADIATION MODULE: 2D RADIATION TRANSPORT WITH...

  3. Resonance zones and quasi-linear diffusion coefficients for radiation belt energetic electron interaction with oblique chorus waves in the Dungey magnetosphere

    SciTech Connect (OSTI)

    Shi Run [Polar Research Institute of China, Shanghai (China); Ni, Binbin [Department of Atmospheric and Oceanic Sciences, UCLA, Los Angeles, California 90095-1565 (United States); Gu Xudong [Institute of Geophysics and Planetary Physics, UCLA, Los Angeles, California 90095-1567 (United States); Zhao Zhengyu; Zhou Chen [Department of Space Physics, Wuhan University, Wuhan, Hubei (China)

    2012-07-15

    The resonance regions for resonant interactions of radiation belt electrons with obliquely propagating whistler-mode chorus waves are investigated in detail in the Dungey magnetic fields that are parameterized by the intensity of uniform southward interplanetary magnetic field (IMF) Bz or, equivalently, by the values of D=(M/B{sub z,0}){sup 1/3} (where M is the magnetic moment of the dipole and B{sub z,0} is the uniform southward IMF normal to the dipole's equatorial plane). Adoption of background magnetic field model can considerably modify the determination of resonance regions. Compared to the results for the case of D = 50 (very close to the dipole field), the latitudinal coverage of resonance regions for 200 keV electrons interacting with chorus waves tends to become narrower for smaller D-values, regardless of equatorial pitch angle, resonance harmonics, and wave normal angle. In contrast, resonance regions for 1 MeV electrons tend to have very similar spatial lengths along the field line for various Dungey magnetic field models but cover different magnetic field intervals, indicative of a strong dependence on electron energy. For any given magnetic field line, the resonance regions where chorus-electron resonant interactions can take place rely closely on equatorial pitch angle, resonance harmonics, and kinetic energy. The resonance regions tend to cover broader latitudinal ranges for smaller equatorial pitch angles, higher resonance harmonics, and lower electron energies, consistent with the results in Ni and Summers [Phys. Plasmas 17, 042902, 042903 (2010)]. Calculations of quasi-linear bounce-averaged diffusion coefficients for radiation belt electrons due to nightside chorus waves indicate that the resultant scattering rates differ from using different Dungey magnetic field models, demonstrating a strong dependence of wave-induced electron scattering effect on the adoption of magnetic field model. Our results suggest that resonant wave-particle interaction processes should be implemented into a sophisticated, accurate global magnetic field model to pursue comprehensive and complete models of radiation belt electron dynamics.

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

    E-Print Network [OSTI]

    Gangisetti, Kavita

    2011-02-22

    are compared against the measured data. Other important parameters such as diffuser jet inlet angle and radiation effect are also considered on the benchmark case to validate the results and to recommend the best fit parameters for room air simulations...

  5. Hierarchical diffusion

    SciTech Connect (OSTI)

    Bachas, C.P.

    1988-02-01

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

  6. Partially Reflected Diffusion

    E-Print Network [OSTI]

    A. Singer; Z. Schuss; D. Holcman

    2007-09-02

    The radiation (reaction, Robin) boundary condition for the continuum diffusion equation is widely used in chemical and biological applications to express reactive boundaries. The underlying trajectories of the diffusing particles are believed to be partially absorbed and partially reflected at the reactive boundary, however, the relation between the reaction (radiation) constant in the Robin boundary condition and the reflection probability is still unclear. In this paper we clarify the issue by finding the relation between the reaction (radiation) constant and the absorption probability of the diffusing trajectories at the boundary. We analyze the Euler scheme for the underlying It\\^o dynamics, which is assumed to have variable drift and diffusion tensor, with partial reflection at the boundary. Trajectories that cross the boundary are terminated with a given probability and otherwise are reflected in a normal or oblique direction. We use boundary layer analysis of the corresponding Wiener path integral to resolve the non-uniform convergence of the probability density function of the numerical scheme to the solution of the Fokker-Planck equation with the Robin boundary condition, as the time step is decreased. We show that the Robin boundary condition is recovered in the limit iff trajectories are reflected in the co-normal direction. We find the relation of the reactive constant to the termination probability. We show the effect of using the new relation in numerical simulations.

  7. The origin of the ionization of the diffuse interstellar medium in spiral galaxies. II. Modelling the distribution of ionizing radiation in NGC 157

    E-Print Network [OSTI]

    A. Zurita; J. E. Beckman; M. Rozas; S. Ryder

    2002-03-15

    In this paper we make a quantitative study of the hypothesis that the diffuse H-alpha emitted from the discs of spiral galaxies owes its origin to the ionizing photons escaping from HII regions. We use the H-alpha measurements of the complete set of HII regions in the spiral NGC 157, for which an HI density map was available, to derive a family of models which predict the ionizing photon distribution in the disc of this galaxy. The predicted diffuse H-alpha surface brightness distributions from our models were compared with the observed distributions showing that, in general terms, the hypothesis of density bounding for the HII regions allows us to predict well the spatial distribution of the diffuse ionized gas. In the model yielding the best fit to the data, the regions of lower luminosity lose a constant fraction of their ionizing flux to their surroundings, while for HII region luminosities above a specific transition value the ionizing escape fraction is a rising function of the Ha luminosity.

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

    E-Print Network [OSTI]

    Grether, D.

    2012-01-01

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

  9. 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)

    2014-06-19

    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.

  10. Arctic and Antarctic diurnal and seasonal variations of snow albedo from multiyear Baseline Surface Radiation Network measurements

    E-Print Network [OSTI]

    Wang, Xianwei; Zender, Charles S

    2011-01-01

    With constant SZA and solar radiation and extreme low airof long?term solar radiation measurements from two BSRNand direct and diffuse solar radiation used here. We thank

  11. Parallel flow diffusion battery

    DOE Patents [OSTI]

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

    1984-01-01

    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.

  12. Parallel flow diffusion battery

    DOE Patents [OSTI]

    Yeh, Hsu-Chi (Albuquerque, NM); Cheng, Yung-Sung (Albuquerque, NM)

    1984-08-07

    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.

  13. Kenya Hourly DNI, GHI and Diffuse Solar Data - Datasets - OpenEI...

    Open Energy Info (EERE)

    Kenya Hourly DNI, GHI and Diffuse Solar Data Abstract Each data file is a set of hourly values of solar radiation (DNI, GHI and diffuse) and meteorological elements for a 1-year...

  14. Discretisation and solution of quasi-diffusion equations 

    E-Print Network [OSTI]

    Valette, Nicolas Dominique

    2002-01-01

    We show how the Quasi-diffusion method performs on radiative transfer problems in slab geometry and XY geometry for steady state, one-energy-group problems. We explain first how we derive for slab geometry, the discretization we use...

  15. Microfabricated diffusion source

    DOE Patents [OSTI]

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

    2008-07-15

    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. 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

  17. Caractérisation de la fraction volumique et de la température des suies d'une flamme de diffusion établie en micropesanteur 

    E-Print Network [OSTI]

    Fuentes, Andres; Legros, Guillaume; Joulain, Pierre; Vantelon, Jean-Pierre; Torero, Jose L

    2005-08-29

    The soot has a dominant radiative role in microgravity diffusion flames. In fact, the radiative losses are particularly important in the trailing edge of the flame, where the combustion products, especially the soot, ...

  18. Diffuse-dynamic multiparameter diffractometry: A review

    SciTech Connect (OSTI)

    Molodkin, V. B. Shpak, A. P.; Kovalchuk, M. V.; Nosik, V. L.; Machulin, V. F.

    2010-12-15

    The results reported at the Conference on Application of X-Rays, Synchrotron Radiation, Neutrons, and Electrons in Nano-, Bio-, Information-, and Cognitive Technologies (RSNE-NBIC 2009) are briefly reviewed. This review is based on a cycle of studies [1-6] where a new method for studying the structure of real crystals-diffuse-dynamic multiparameter diffractometry (DDMD)-was proposed and substantiated.

  19. Glass Membrane For Controlled Diffusion Of Gases

    DOE Patents [OSTI]

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

    2001-05-15

    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.

  20. Cosmology with matter diffusion

    SciTech Connect (OSTI)

    Calogero, Simone; Velten, Hermano E-mail: velten@cce.ufes.br

    2013-11-01

    We construct a viable cosmological model based on velocity diffusion of matter particles. In order to ensure the conservation of the total energy-momentum tensor in the presence of diffusion, we include a cosmological scalar field ? which we identify with the dark energy component of the universe. The model is characterized by only one new degree of freedom, the diffusion parameter ?. The standard ?CDM model can be recovered by setting ? = 0. If diffusion takes place (? > 0) the dynamics of the matter and of the dark energy fields are coupled. We argue that the existence of a diffusion mechanism in the universe may serve as a theoretical motivation for interacting models. We constrain the background dynamics of the diffusion model with Supernovae, H(z) and BAO data. We also perform a perturbative analysis of this model in order to understand structure formation in the universe. We calculate the impact of diffusion both on the CMB spectrum, with particular attention to the integrated Sachs-Wolfe signal, and on the matter power spectrum P(k). The latter analysis places strong constraints on the magnitude of the diffusion mechanism but does not rule out the model.

  1. 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,...

  2. Evaluating aerosol direct radiative effects on global terrestrial ecosystem carbon dynamics from

    E-Print Network [OSTI]

    Zhuang, Qianlai

    loading normally induces lower solar energy arriving at the land surface whereas plant photosynthesis of diffuse solar radiation for plant carbon uptake. Comparing with direct-beam solar radiation, diffuse solar to quantify aerosol effects on downward solar radiation. Simulations with and without considering the aerosol

  3. Diffusion between evolving interfaces

    E-Print Network [OSTI]

    Janne Juntunen; Juha Merikoski

    2010-11-19

    Diffusion in an evolving environment is studied by continuos-time Monte Carlo simulations. Diffusion is modelled by continuos-time random walkers on a lattice, in a dynamic environment provided by bubbles between two one-dimensional interfaces driven symmetrically towards each other. For one-dimensional random walkers constrained by the interfaces, the bubble size distribution domi- nates diffusion. For two-dimensional random walkers, it is also controlled by the topography and dynamics of the interfaces. The results of the one-dimensional case are recovered in the limit where the interfaces are strongly driven. Even with simple hard-core repulsion between the interfaces and the particles, diffusion is found to depend strongly on the details of the dynamical rules of particles close to the interfaces. Article reference: Journal of Physics: Condensed Matter 22, 465402 (2010).

  4. 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

  5. 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History View New PagesSustainable UrbanKentucky:BoreOpenGilliamOhio:Change | OpenInformation

  6. 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsource History View New Pages RecentPlant <SilverChange AssociatesOutlookGlobal

  7. 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsource History View New Pages RecentPlant <SilverChange AssociatesOutlookGlobalGlobal

  8. Solar and Infrared Radiation Station (SIRS) Handbook

    SciTech Connect (OSTI)

    Stoffel, T

    2005-07-01

    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)

  9. Structure of Laminar Sooting Inverse Diffusion Flames

    E-Print Network [OSTI]

    Mikofski, Mark A

    2007-01-01

    Combust. Structure of Laminar Sooting Inverse Diffusion2002, p. 252. Structure of Laminar Sooting Inverse Diffusion219-226. Structure of Laminar Sooting Inverse Diffusion

  10. Sandia Energy - Diffusion Bonding Characterization

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

    bond surface is poor or only the region near this corner. Diffusion 7-8-9 "Diffusion Welding and Brazing," in Welding Handbook, 7th ed., American Welding Society, 1980, p 311-335...

  11. Danger radiations

    ScienceCinema (OSTI)

    None

    2011-04-25

    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.

  12. Global heat transfer analysis in Czochralski silicon furnace with radiation on curved specular surfaces

    E-Print Network [OSTI]

    Guo, Zhixiong "James"

    Global heat transfer analysis in Czochralski silicon furnace with radiation on curved specular method are adopted to solve the global heat transfer and the radiative heat exchange, respectively rate QJ diffuse radiation heat transfer rate QX net rate of radiative heat loss QT heat generation rate

  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)

    2014-05-15

    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. Multiple regimes of diffusion

    E-Print Network [OSTI]

    B. Mehlig; M. Wilkinson; V. Bezuglyy; K. Gustavsson; K. Nakamura

    2009-01-20

    We consider the diffusion of independent particles experiencing random accelerations by a space- and time-dependent force as well as viscous damping. This model can exhibit several asymptotic behaviours, depending upon the limiting cases which are considered, some of which have been discussed in earlier work. Here we explore the full space of dimensionless parameters, and introduce an "asymptotic phase diagram" which delineates the limiting regimes.

  15. Correspondences between Wavelet Shrinkage and Nonlinear Diffusion

    E-Print Network [OSTI]

    variants [8,31], total variation (TV) diffusion [2], or balanced forward-backward (BFB) diffusion [21

  16. Diffusion in silicon isotope heterostructures

    SciTech Connect (OSTI)

    Silvestri, Hughes Howland

    2004-05-14

    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.

  17. RADIATION MONITORING

    E-Print Network [OSTI]

    Thomas, R.H.

    2010-01-01

    Radiation Exposure due to a Boiling Water Reactor Plume fromIN THE VICINITY OF A BOILING WATER REACTOR EXPOSURE RATE

  18. Radiation detector

    DOE Patents [OSTI]

    Fultz, B.T.

    1980-12-05

    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. Modeling IR Radiative Loss from Eppley PSP Pyranometers Frank Vignola

    E-Print Network [OSTI]

    Oregon, University of

    Renewable Energy Laboratory ABSTRACT A method has been developed to estimate IR radiative losses using solar, irradiance, IR, modeling, global, diffuse, PSP 1. INTRODUCTION Since the 1970s, solar radiation data has been Energy Laboratory (NREL) data page3 along with the original global data. Corrections to the PSP

  20. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass mapSpeeding access toOctober 1996Technologies / Ombudsman Ombudsman Y-12'sOmni JawOn

  1. BDP: BrainSuite Diffusion Pipeline

    E-Print Network [OSTI]

    Leahy, Richard M.

    BDP: BrainSuite Diffusion Pipeline Chitresh Bhushan #12; Quantify microstructural tissue ROI Connectivity ROI Statistics MPRAGE Diffusion #12;Diffusion Pipeline Dicom to NIfTI Co ROIs Custom ROIs #12;Diffusion Pipeline Dicom to NIfTI Co-registration Diffusion Modeling Tractography

  2. Portable vapor diffusion coefficient meter

    DOE Patents [OSTI]

    Ho, Clifford K. (Albuquerque, NM)

    2007-06-12

    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.

  3. Radiation dosimeter

    DOE Patents [OSTI]

    Fox, R.J.

    1981-09-01

    A radiation detector readout circuit is provided which produces a radiation dose-rate readout from a detector even through the detector output may be highly energy dependent. A linear charge amplifier including an output charge pump circuit amplifies the charge signal pulses from the detector and pumps the charge into a charge storage capacitor. The discharge rate of the capacitor through a resistor is controlled to provide a time-dependent voltage which when integrated provides an output proportional to the dose-rate of radiation detected by the detector. This output may be converted to digital form for readout on a digital display.

  4. Radiation dosimeter

    DOE Patents [OSTI]

    Fox, Richard J. (Oak Ridge, TN)

    1983-01-01

    A radiation detector readout circuit is provided which produces a radiation dose-rate readout from a detector even though the detector output may be highly energy dependent. A linear charge amplifier including an output charge pump circuit amplifies the charge signal pulses from the detector and pumps the charge into a charge storage capacitor. The discharge rate of the capacitor through a resistor is controlled to provide a time-dependent voltage which when integrated provides an output proportional to the dose-rate of radiation detected by the detector. This output may be converted to digital form for readout on a digital display.

  5. Computation of Neutron Star Surface Emission Spectra for Arbitrary Magnetic Field Directions without Diffusion Approximation

    E-Print Network [OSTI]

    L. W. Yeh; G. T. Chen; H. K. Chang

    2006-12-22

    To derive physical properties of the neutron star surface with observed spectra, a realistic model spectrum of neutron star surface emission is essential. Limited by computing resources, a full computation of the radiative transfer equations without the diffusion approximation has been conducted up to date only for the case of local magnetic fields being perpendicular to the stellar surface. In this paper we report the full-computation result for an arbitrary field direction. For comparison we also compute the radiative transfer equation using the diffusion approximation. For a given effective temperature, the computed spectrum with the diffusion approximation is always softer than that of a full computation at a non-negligible level. It leads to an over-estimate of the effective temperature if the diffusion approximation spectrum is employed in the spectral fitting. Other characteristics for different magnetic field orientations, such as the beaming pattern of the two polarization modes and the structure of the atmosphere, are also discussed.

  6. Diffuser for augmenting a wind turbine

    DOE Patents [OSTI]

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

    1984-01-01

    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.

  7. Incorporating spectral characteristics of Pc5 waves into three-dimensional radiation belt

    E-Print Network [OSTI]

    Elkington, Scot R.

    Incorporating spectral characteristics of Pc5 waves into three-dimensional radiation belt modeling frequency range on radiation belt electrons in a compressed dipole magnetic field is examined-dimensional radiation belt modeling and the diffusion of relativistic electrons, J. Geophys. Res., 110, A03215, doi:10

  8. School science project 'demystifies' Portsmouth Gaseous Diffusion...

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

    School science project 'demystifies' Portsmouth Gaseous Diffusion Plant Site School science project 'demystifies' Portsmouth Gaseous Diffusion Plant Site June 2, 2015 - 10:40am...

  9. 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...

  10. 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...

  11. Hot carrier diffusion in graphene

    E-Print Network [OSTI]

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

    2010-11-01

    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...

  12. Radiation receiver

    DOE Patents [OSTI]

    Hunt, A.J.

    1983-09-13

    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)

    1983-01-01

    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. DIFFUSING ACOUSTIC WAVE TRANSPORT AND SPECTROSCOPY

    E-Print Network [OSTI]

    Page, John

    1 Chapter DIFFUSING ACOUSTIC WAVE TRANSPORT AND SPECTROSCOPY J.H. PAGE, M.L. COWAN Dept. of Physics waves, multiple scattering, energy velocity, Diffusing Acoustic Wave Spectroscopy. Abstract the diffusive transport of ultrasonic waves, and then describe a new ultrasonic technique, Diffusing Acoustic

  15. 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...

  16. DETECTORS FOR RADIATION DOSIMETRY

    E-Print Network [OSTI]

    Perez-Mendez, V.

    2010-01-01

    I. Applications of Radiation Detectors 1) X-Rays, Gammaof the Conference DETECTORS FOR RADIATION DOSIMETRY VictorT E D LBL9651 DETECTORS FOR RADIATION DOSIMETRY - DISCLAIM*

  17. GALEX DIFFUSE OBSERVATIONS OF THE SKY: THE DATA

    SciTech Connect (OSTI)

    Murthy, Jayant

    2014-08-01

    I present tabulations of the diffuse observations made by the GALEX spacecraft in two UV bands (FUV: 1539 Å and NUV: 2316 Å) from the (almost) final data release of the GALEX spacecraft (GR6/GR7). This data release includes all the FUV observations and the majority of the NUV observations. I discuss overall trends in the data but the primary purpose of this paper is to make the data available to the public. The data files described in this paper are hosted by the Mikulski Archive for Space Telescopes at the Space Telescope Science Insitute from whence they may be downloaded. For ease of use, I have also created maps of the diffuse radiation in both bands over the entire observed sky at 6' resolution.

  18. Introduction Epidemic virus diffusion: models Epidemic algorithms Gossip algorithms Epidemic Information Diffusion on

    E-Print Network [OSTI]

    Ricci, Laura

    Introduction Epidemic virus diffusion: models Epidemic algorithms Gossip algorithms EpidemicD in Computer Science #12;Introduction Epidemic virus diffusion: models Epidemic algorithms Gossip algorithms Outline 1 Introduction 2 Epidemic virus diffusion: models 3 Epidemic algorithms 4 Gossip algorithms #12

  19. ConTrack: Finding the most likely pathways between brain regions using diffusion tractography

    E-Print Network [OSTI]

    Wandell, Brian A.

    to identify the most likely pathways connecting two regions. In a series of experiments using human data, we for measuring white matter pathways in the living human brain. DFT is often used to discover new pathways algorithms. Keywords: diffusion imaging, fiber tractography, MT+, corpus callosum, optic radiation Citation

  20. Long Minority Carrier Diffusion Lengths in Bridged Silicon Nanowires M. Triplett,,,

    E-Print Network [OSTI]

    Yu, Dong

    for optoelectronic applications such as solar cells and photodetectors.1-4 Planar devices with single nanowires (NWs diffusion lengths (LD) are an important figure of merit for optoelectronics. To date, the highest LD value or UV radiation and strong chemicals such as hydrofluoric acid (HF) and acetone. Furthermore, oxide

  1. 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.

    2012-02-24

    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.

  2. THE VEX RADIATION MODULE: 2D RADIATION TRANSPORT WITH MIMETIC DIFFUSION FOR

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail. (Conference)Feedback SystemGimbaled X-Ray Head (Journal Article)Article)DATA

  3. THE VEX RADIATION MODULE: 2D RADIATION TRANSPORT WITH MIMETIC DIFFUSION FOR

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail. (Conference)Feedback SystemGimbaled X-Ray Head (Journal Article)Article)DATAEXAFLAG

  4. Intracellular facilitated diffusion: searchers, crowders and blockers

    E-Print Network [OSTI]

    C. A. Brackley; M. E. Cates; D. Marenduzzo

    2013-09-04

    In bacteria, regulatory proteins search for a specific DNA binding target via "facilitated diffusion": a series of rounds of 3D diffusion in the cytoplasm, and 1D linear diffusion along the DNA contour. Using large scale Brownian dynamics simulations we find that each of these steps is affected differently by crowding proteins, which can either be bound to the DNA acting as a road block to the 1D diffusion, or freely diffusing in the cytoplasm. Macromolecular crowding can strongly affect mechanistic features such as the balance between 3D and 1D diffusion, but leads to surprising robustness of the total search time.

  5. Proceedings of Eurotherm78 Computational Thermal Radiation in Participating Media II 5-7 April 2006, Poitiers, France

    E-Print Network [OSTI]

    2006, Poitiers, France A diffusion-based approximate model for radiation heat transfer in a solar An approximate method for fast calculations of the radiation heat transfer in a solar thermochemical reactor cavity is proposed. The two-step method with separate calculations for solar and thermal radiation

  6. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMassR&D100 Winners * Impacts on GlobalRachel Ruggirello RachelRadiation DrySafety Home

  7. Flame Height Measurement of Laminar Inverse Diffusion Flames

    E-Print Network [OSTI]

    Mikofski, Mark A.; Williams, Timothy C.; Shaddix, Christopher R.; Blevins, Linda G.

    2006-01-01

    Flame Height Measurement of Laminar Inverse Diffusion Flamesinverse diffusion flame, laminar, flame height, OH, laserair and methane-air laminar inverse diffusion flames were

  8. Synergistic diffuser/heat-exchanger design

    E-Print Network [OSTI]

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

    2004-01-01

    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 ...

  9. 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

  10. Damage-tolerant nanotwinned metals with nanovoids under radiation environments 

    E-Print Network [OSTI]

    Chen, Y.; Yu, K Y.; Liu, Y.; Shao, S.; Wang, H.; Kirk, M. A.; Wang, J.; Zhang, X.

    2015-04-24

    nanoindentation studies. Appl. Phys. Lett. 104, 231910 (2014). 55. Zinkle, S. J. & Snead, L. L. Designing radiation resistance in materials for fusion energy. Annu. Rev. Mater. Res. 44, 241 (2014). 56. Ziegler, J. F. & Biersack, J. P. SRIM-2008, Stopping Power... and nanovoids along ITBs. Figure 1f shows diffusion channels associated with dislocations at CTBs and ITBs that could potentially transport interstitials and their clusters towards nanovoids. The significance of such ITB-CTB networks on radiation response of nt...

  11. Gravitational Collapse of Null Radiation and a String fluid

    E-Print Network [OSTI]

    K S Govinder; M Govender

    2003-04-03

    We consider the end state of collapsing null radiation with a string fluid. It is shown that, if diffusive transport is assumed for the string, that a naked singularity can form (at least locally). The model has the advantage of not being asymptotically flat. We also analyse the case of a radiation-string two-fluid and show that a locally naked singularity can result in the collapse of such matter. We contrast this model with that of strange quark matter.

  12. Heat Hyperbolic Diffusion in Planck Gas

    E-Print Network [OSTI]

    Miroslaw Kozlowski; Janina Marciak-Kozlowska

    2006-07-06

    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

  13. Diffusion Tubes for Ambient NO2 Monitoring

    E-Print Network [OSTI]

    Short, Daniel

    2 Monitoring: Practical Guidance AEA Energy & Environment iii Foreword Palmes-type diffusion tubesDiffusion Tubes for Ambient NO2 Monitoring: Practical Guidance for Laboratories and Users Report Monitoring: Practical Guidance AEA/ENV/R/2504 ­ Issue 1a Title Diffusion Tubes for Ambient NO2 Monitoring

  14. 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.

    1991-01-01

    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)

  15. Adaptors for radiation detectors

    DOE Patents [OSTI]

    Livesay, Ronald Jason

    2014-04-22

    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.

  16. Adaptors for radiation detectors

    DOE Patents [OSTI]

    Livesay, Ronald Jason

    2015-07-28

    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.

  17. Radiation dosimeters

    DOE Patents [OSTI]

    Hoelsher, James W. (Pullman, WA); Hegland, Joel E. (Pullman, WA); Braunlich, Peter F. (Pullman, WA); Tetzlaff, Wolfgang (Pullman, WA)

    1992-01-01

    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.

  18. LHC Beam Diffusion Dependence on RF Noise: Models And Measurements

    SciTech Connect (OSTI)

    Mastorides, T.; Rivetta, C.; Fox, J.D.; Van Winkle, D.; Baudrenghien, P.; Butterworth, A.; Molendijk, J.; ,

    2010-09-14

    Radio Frequency (RF) accelerating system noise and non-idealities can have detrimental impact on the LHC performance through longitudinal motion and longitudinal emittance growth. A theoretical formalism has been developed to relate the beam and RF loop dynamics with the bunch length growth [1]. Measurements were conducted at LHC to validate the formalism, determine the performance limiting RF components, and provide the foundation for beam diffusion estimates for higher energies and intensities. A brief summary of these results is presented in this work. During a long store, the relation between the energy lost to synchrotron radiation and the noise injected to the beam by the RF accelerating voltage determines the growth of the bunch energy spread and longitudinal emittance. Since the proton synchrotron radiation in the LHC is very low, the beam diffusion is extremely sensitive to RF perturbations. The theoretical formalism presented in [1], suggests that the noise experienced by the beam depends on the cavity phase noise power spectrum, filtered by the beam transfer function, and aliased due to the periodic sampling of the accelerating voltage signal V{sub c}. Additionally, the dependence of the RF accelerating cavity noise spectrum on the Low Level RF (LLRF) configurations has been predicted using time-domain simulations and models [2]. In this work, initial measurements at the LHC supporting the above theoretical formalism and simulation predictions are presented.

  19. Nature Macmillan Publishers Ltd 1998 radiation. On the one hand, as noted above, the increased photo-

    E-Print Network [OSTI]

    source star, ultraviolet radiation will rapidly ionize the skin of the jet until the total recombination its source star is uniform across the jet, and we ignore the diffuse radiation ®eld). An irradiated per year through knots B and C. More detailed future observations of irradiated jets could be used

  20. Quantifying protein diffusion and capture on filaments

    E-Print Network [OSTI]

    Emanuel Reithmann; Louis Reese; Erwin Frey

    2015-03-03

    The functional relevance of regulating proteins is often limited to specific binding sites such as the ends of microtubules or actin-filaments. A localization of proteins on these functional sites is of great importance. We present a quantitative theory for a diffusion and capture process, where proteins diffuse on a filament and stop diffusing when reaching the filament's end. It is found that end-association after one-dimensional diffusion is the main source for tip-localization of such proteins. As a consequence, diffusion and capture is highly efficient in enhancing the reaction velocity of enzymatic reactions, where proteins and filament ends are to each other as enzyme and substrate. We show that the reaction velocity can effectively be described within a Michaelis-Menten framework. Together one-dimensional diffusion and capture beats the (three-dimensional) Smoluchowski diffusion limit for the rate of protein association to filament ends.

  1. Quantifying protein diffusion and capture on filaments

    E-Print Network [OSTI]

    Reithmann, Emanuel; Frey, Erwin

    2015-01-01

    The functional relevance of regulating proteins is often limited to specific binding sites such as the ends of microtubules or actin-filaments. A localization of proteins on these functional sites is of great importance. We present a quantitative theory for a diffusion and capture process, where proteins diffuse on a filament and stop diffusing when reaching the filament's end. It is found that end-association after one-dimensional diffusion is the main source for tip-localization of such proteins. As a consequence, diffusion and capture is highly efficient in enhancing the reaction velocity of enzymatic reactions, where proteins and filament ends are to each other as enzyme and substrate. We show that the reaction velocity can effectively be described within a Michaelis-Menten framework. Together one-dimensional diffusion and capture beats the (three-dimensional) Smoluchowski diffusion limit for the rate of protein association to filament ends.

  2. MODEL OF DIFFUSERS / PERMEATORS FOR HYDROGEN PROCESSING

    SciTech Connect (OSTI)

    Hang, T; William Jacobs, W

    2007-08-27

    Palladium-silver (Pd-Ag) diffusers are mainstays of hydrogen processing. Diffusers separate hydrogen from inert species such as nitrogen, argon or helium. The tubing becomes permeable to hydrogen when heated to more than 250 C and a differential pressure is created across the membrane. The hydrogen diffuses better at higher temperatures. Experimental or experiential results have been the basis for determining or predicting a diffuser's performance. However, the process can be mathematically modeled, and comparison to experimental or other operating data can be utilized to improve the fit of the model. A reliable model-based diffuser system design is the goal which will have impacts on tritium and hydrogen processing. A computer model has been developed to solve the differential equations for diffusion given the operating boundary conditions. The model was compared to operating data for a low pressure diffuser system. The modeling approach and the results are presented in this paper.

  3. DETECTORS FOR RADIATION DOSIMETRY

    E-Print Network [OSTI]

    Perez-Mendez, V.

    2010-01-01

    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.

  4. An asixymmetric diffusion experiment for the determination of diffusion and sorption coefficients of rock samples

    SciTech Connect (OSTI)

    Takeda, M.; Hiratsuka, T.; Ito, K.; Finsterle, S.

    2011-02-01

    Diffusion anisotropy is a critical property in predicting migration of substances in sedimentary formations with very low permeability. The diffusion anisotropy of sedimentary rocks has been evaluated mainly from laboratory diffusion experiments, in which the directional diffusivities are separately estimated by through-diffusion experiments using different rock samples, or concurrently by in-diffusion experiments in which only the tracer profile in a rock block is measured. To estimate the diffusion anisotropy from a single rock sample, this study proposes an axisymmetric diffusion test, in which tracer diffuses between a cylindrical rock sample and a surrounding solution reservoir. The tracer diffusion between the sample and reservoir can be monitored from the reservoir tracer concentrations, and the tracer profile could also be obtained after dismantling the sample. Semi-analytical solutions are derived for tracer concentrations in both the reservoir and sample, accounting for an anisotropic diffusion tensor of rank two as well as the dilution effects from sampling and replacement of reservoir solution. The transient and steady-state analyses were examined experimentally and numerically for different experimental configurations, but without the need for tracer profiling. These experimental configurations are tested for in- and out-diffusion experiments using Koetoi and Wakkanai mudstones and Shirahama sandstone, and are scrutinized by a numerical approach to identify favorable conditions for parameter estimation. The analysis reveals the difficulty in estimating diffusion anisotropy; test configurations are proposed for enhanced identifiability of diffusion anisotropy. Moreover, it is demonstrated that the axisymmetric diffusion test is efficient in obtaining the sorption parameter from both steady-state and transient data, and in determining the effective diffusion coefficient if isotropic diffusion is assumed. Moreover, measuring reservoir concentrations in an axisymmetric diffusion experiment coupled with tracer profiling may be a promising approach to estimate of diffusion anisotropy of sedimentary rocks.

  5. 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)

    2013-12-15

    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.

  6. 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...

  7. RADIATIVE AND PASSIVE COOLING

    E-Print Network [OSTI]

    Martin, M.

    2011-01-01

    Ext. 6782 Radiative and Passive Cooling Marlo Martin andof the Second Nation- al Passive Solar Conference (owned rights. ,I I RADIATIVE AND PASSIVE COOLING* LAIVRENCE

  8. 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)

    2014-10-01

    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.

  9. Radiation Protection and Licensing FNAL Radiation Physics Team

    E-Print Network [OSTI]

    McDonald, Kirk

    (ALARA). January 13, 2012 Radiation Protection and Licensing #12;4 Shielding for Prompt Radiation Protect

  10. 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

  11. 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...

  12. 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History View NewTexas: Energy ResourcesOrder at 8, 13Renewable PowerMismatch |Inves Pozo SolOpen Energy

  13. 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX E LISTStar2-0057-EA Jump to:ofEnia SpAFlexStock Co LtdWiegand GmbH

  14. 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX E LIST OFAMERICA'SHeavy ElectricalsFTL Solar JumpNetworkingGAOH Offshore JumpEnergy

  15. Experience with Palladium Diffusers in Tritium Processing

    SciTech Connect (OSTI)

    Motyka, T.; Clark, E.A.; Dauchess, D.A.; Heung, L.K.; Rabum, R.L.

    1995-01-27

    Hydrogen isotopes are separated from other gases by permeation through palladium and palladium-silver alloy diffusers in the Tritium Facilities at the US Department of Energy Savannah River Site (SRS). Diffusers have provided effective service for almost forty years. This paper is an overview of the operational experience with the various diffuser types that have been employed at SRS. Alternative technologies being developed at SRS for purifying hydrogen isotopes are also discussed.

  16. Nonlinear diffusion in Acetone-Benzene Solution

    E-Print Network [OSTI]

    Obukhovsky, Vjacheslav V

    2010-01-01

    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.

  17. DETECTORS FOR RADIATION DOSIMETRY

    E-Print Network [OSTI]

    Perez-Mendez, V.

    2010-01-01

    RPL) The interaction of radiation with matter in crystallineradiation. Some interactions with crystalline matter are

  18. Characterization of Fuel-Cell Diffusion Media

    E-Print Network [OSTI]

    Gunterman, Haluna Penelope Frances

    2011-01-01

    Characterization of Fuel-Cell Diffusion Media by HalunaFall 2011 Abstract Characterization of Fuel-Cell Diffusionpredictive capabilities. Characterization of DM and their

  19. Metal Nitride Diffusion Barriers for Copper Interconnects 

    E-Print Network [OSTI]

    Araujo, Roy A.

    2010-01-14

    Advancements in the semiconductor industry require new materials with improved performance. With the introduction of copper as the interconnect material for integrated circuits, efficient diffusion barriers are required ...

  20. Portsmouth Gaseous Diffusion Plant Director's Final Findings...

    Office of Environmental Management (EM)

    Portsmouth Gaseous Diffusion Plant Director's Final Findings and Orders, October 4, 1995 State Ohio Agreement Type Federal Facility Agreement Legal Driver(s) FFCAct Scope Summary...

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

    Office of Environmental Management (EM)

    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...

  2. Anomalous diffusion in fractal globules

    E-Print Network [OSTI]

    Mikhail V. Tamm; Leonid I. Nazarov; Alexey A. Gavrilov; Alexander V. Chertovich

    2016-01-07

    The fractal globule state is a popular model for describing chromatin packing in eukaryotic nuclei. Here we provide a scaling theory and dissipative particle dynamics (DPD) computer simulation for the thermal motion of monomers in the fractal globule state. Simulations starting from different entanglement-free initial states show good convergence which provides evidence supporting the existence of unique metastable fractal globule state. We show monomer motion in this state to be sub-diffusive described by $\\langle X^2 (t)\\rangle \\sim t^{\\alpha_F}$ with $\\alpha_F$ close to 0.4. This result is in good agreement with existing experimental data on the chromatin dynamics which makes an additional argument in support of the fractal globule model of chromatin packing.

  3. 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

  4. Radiation physics, biophysics, and radiation biology

    SciTech Connect (OSTI)

    Hall, E.J.; Zaider, M.

    1991-05-01

    Research at the Radiological Research Laboratory is a blend of physics, chemistry, and biology, involving research at the basic level with the admixture of a small proportion of pragmatic or applied research in support of radiation protection and/or radiotherapy. Current research topics include: oncogenic transformation assays, mutation studies involving interactions between radiation and environmental contaminants, isolation, characterization and sequencing of a human repair gene, characterization of a dominant transforming gene found in C3H 10T1/2 cells, characterize ab initio the interaction of DNA and radiation, refine estimates of the radiation quality factor Q, a new mechanistic model of oncogenesis showing the role of long-term low dose medium LET radiation, and time dependent modeling of radiation induced chromosome damage and subsequent repair or misrepair.

  5. Thermal Expansion and Diffusion Coefficients of Carbon

    E-Print Network [OSTI]

    Wei, Chenyu

    Thermal Expansion and Diffusion Coefficients of Carbon Nanotube-Polymer Composites Chenyu Wei* NASA of carbon nanotube-polyethylene composites. Additions of carbon nanotubes to a polymer matrix are found for polymer-nanotube interface are used to investigate the thermal expansion and diffusion characteristics

  6. Finite-difference schemes for anisotropic diffusion

    SciTech Connect (OSTI)

    Es, Bram van; Koren, Barry; Blank, Hugo J. de

    2014-09-01

    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.

  7. Thermal diffusion shock waves Sorasak Danworaphong1

    E-Print Network [OSTI]

    Craig, Walter

    Thermal diffusion shock waves Sorasak Danworaphong1 , Walter Craig3 , Vitalyi Gusev4 , and Gerald J and are concentrated by a thermal gradient imposed on a salt solution, the separation of the components of a mixture in a thermal field, known as "thermal diffusion", or the Ludwig-Soret effect has been found not only in liquids

  8. Surveying Diffusion in Complex Geometries. An Essay

    E-Print Network [OSTI]

    Denis Grebenkov

    2009-09-08

    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.

  9. Model for Diffusion-Induced Ramsey Narrowing

    E-Print Network [OSTI]

    Alexander Romanenko; Leonid Yatsenko

    2008-01-22

    Diffusion-induced Ramsey narrowing that appears when atoms can leave the interaction region and repeatedly return without lost of coherence is investigated using strong collisions approximation. The effective diffusion equation is obtained and solved for low-dimensional model configurations and three-dimensional real one.

  10. Volumetric Modeling with Diffusion Surfaces Kenshi Takayama

    E-Print Network [OSTI]

    Igarashi, Takeo

    Volumetric Modeling with Diffusion Surfaces Kenshi Takayama The University of Tokyo Olga Sorkine ERATO Abstract The modeling of volumetric objects is still a difficult problem. Solid texture synthesis colors from nearby surfaces. A straightfor- ward way to compute color diffusion is to solve a volumetric

  11. Solid-state diffusion in amorphous zirconolite

    SciTech Connect (OSTI)

    Yang, C.; Dove, M. T.; Trachenko, K.; Zarkadoula, E.; Todorov, I. T.; Geisler, T.; Brazhkin, V. V.

    2014-11-14

    We discuss how structural disorder and amorphization affect solid-state diffusion, and consider zirconolite as a currently important case study. By performing extensive molecular dynamics simulations, we disentangle the effects of amorphization and density, and show that a profound increase of solid-state diffusion takes place as a result of amorphization. Importantly, this can take place at the same density as in the crystal, representing an interesting general insight regarding solid-state diffusion. We find that decreasing the density in the amorphous system increases pre-factors of diffusion constants, but does not change the activation energy in the density range considered. We also find that atomic species in zirconolite are affected differently by amorphization and density change. Our microscopic insights are relevant for understanding how solid-state diffusion changes due to disorder and for building predictive models of operation of materials to be used to encapsulate nuclear waste.

  12. Radiation effects in the environment

    SciTech Connect (OSTI)

    Begay, F.; Rosen, L.; Petersen, D.F.; Mason, C.; Travis, B.; Yazzie, A.; Isaac, M.C.P.; Seaborg, G.T.; Leavitt, C.P.

    1999-04-01

    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.

  13. 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.

    2007-10-01

    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.

  14. Plutonium radiation surrogate

    DOE Patents [OSTI]

    Frank, Michael I. (Dublin, CA)

    2010-02-02

    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.

  15. Diffuse Synchrotron Emission from Galactic Cosmic Ray Electrons

    E-Print Network [OSTI]

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

    2015-01-01

    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.

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

    SciTech Connect (OSTI)

    Not Available

    1994-10-01

    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.

  17. Advances in radiation modeling in ALEGRA :a final report for LDRD-67120, efficient implicit mulitgroup radiation calculations.

    SciTech Connect (OSTI)

    Mehlhorn, Thomas Alan; Kurecka, Christopher J. (University of Michigan, Ann Arbor, MI); McClarren, Ryan (University of Michigan, Ann Arbor, MI); Brunner, Thomas A.; Holloway, James Paul (University of Michigan, Ann Arbor, MI)

    2005-11-01

    The original LDRD proposal was to use a nonlinear diffusion solver to compute estimates for the material temperature that could then be used in a Implicit Monte Carlo (IMC) calculation. At the end of the first year of the project, it was determined that this was not going to be effective, partially due to the concept, and partially due to the fact that the radiation diffusion package was not as efficient as it could be. The second, and final year, of the project focused on improving the robustness and computational efficiency of the radiation diffusion package in ALEGRA. To this end, several new multigroup diffusion methods have been developed and implemented in ALEGRA. While these methods have been implemented, their effectiveness of reducing overall simulation run time has not been fully tested. Additionally a comprehensive suite of verification problems has been developed for the diffusion package to ensure that it has been implemented correctly. This process took considerable time, but exposed significant bugs in both the previous and new diffusion packages, the linear solve packages, and even the NEVADA Framework's parser. In order to manage this large suite of problem, a new tool called Tampa has been developed. It is a general tool for automating the process of running and analyzing many simulations. Ryan McClarren, at the University of Michigan has been developing a Spherical Harmonics capability for unstructured meshes. While still in the early phases of development, this promises to bridge the gap in accuracy between a full transport solution using IMC and the diffusion approximation.

  18. Polymer Composites for Radiation Scintillation

    E-Print Network [OSTI]

    Chen, Qi

    2012-01-01

    Reference G. F. Knoll, Radiation detection and measurement,MI, 1985. G. F. Knoll, Radiation detection and measurement,applications in radiation detection. First, a brief review

  19. Two-dimensional numerical simulation of boron diffusion for pyramidally textured silicon

    SciTech Connect (OSTI)

    Ma, Fa-Jun Duttagupta, Shubham; Shetty, Kishan Devappa; Meng, Lei; Hoex, Bram; Peters, Ian Marius; Samudra, Ganesh S.

    2014-11-14

    Multidimensional numerical simulation of boron diffusion is of great relevance for the improvement of industrial n-type crystalline silicon wafer solar cells. However, surface passivation of boron diffused area is typically studied in one dimension on planar lifetime samples. This approach neglects the effects of the solar cell pyramidal texture on the boron doping process and resulting doping profile. In this work, we present a theoretical study using a two-dimensional surface morphology for pyramidally textured samples. The boron diffusivity and segregation coefficient between oxide and silicon in simulation are determined by reproducing measured one-dimensional boron depth profiles prepared using different boron diffusion recipes on planar samples. The established parameters are subsequently used to simulate the boron diffusion process on textured samples. The simulated junction depth is found to agree quantitatively well with electron beam induced current measurements. Finally, chemical passivation on planar and textured samples is compared in device simulation. Particularly, a two-dimensional approach is adopted for textured samples to evaluate chemical passivation. The intrinsic emitter saturation current density, which is only related to Auger and radiative recombination, is also simulated for both planar and textured samples. The differences between planar and textured samples are discussed.

  20. Migration of Protoplanets in Radiative Disks

    E-Print Network [OSTI]

    Wilhelm Kley; Aurelien Crida

    2008-06-18

    In isothermal disks the migration of protoplanets is directed inward. For small planetary masses the standard type-I migration rates are so fast that this may result in an unrealistic loss of planets into the stars. We investigate the planet-disk interaction in non-isothermal disks and analyze the magnitude and direction of migration for an extended range of planet masses. We have performed detailed two-dimensional numerical simulations of embedded planets including heating/cooling effects as well as radiative diffusion for realistic opacities. In radiative disks, small planets with M_planet < 50 M_Earth do migrate outward with a rate comparable to absolute magnitude of standard type-I migration. For larger masses the migration is inward and approaches the isothermal, type-II migration rate. Our findings are particularly important for the first growth phase of planets and ease the problem of too rapid inward type-I migration.

  1. Asymptotics for the maximum likelihood estimators of diffusion models 

    E-Print Network [OSTI]

    Jeong, Minsoo

    2009-05-15

    In this paper I derive the asymptotics of the exact, Euler, and Milstein ML estimators for diffusion models, including general nonstationary diffusions. Though there have been many estimators for the diffusion model, their asymptotic properties were...

  2. Microfluidic Investigation of Tracer Dye Diffusion in Alumina Nanofluids 

    E-Print Network [OSTI]

    Ozturk, Serdar 1979-

    2012-10-05

    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. 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...

  4. 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...

  5. Review of enhanced vapor diffusion in porous media

    SciTech Connect (OSTI)

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

    1998-08-01

    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.

  6. Radiation protection at CERN

    E-Print Network [OSTI]

    Forkel-Wirth, Doris; Silari, Marco; Streit-Bianchi, Marilena; Theis, Christian; Vincke, Heinz; Vincke, Helmut

    2013-01-01

    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.

  7. RADIONUCLIDE RADIATION PROTECTION

    E-Print Network [OSTI]

    Zakhor, Avideh

    RADIONUCLIDE AND RADIATION PROTECTION DATA HANDBOOK 2002 D. Delacroix* J. P. Guerre** P. Leblanc'Energie Atomique, CEA/Saclay, France ISBN 1 870965 87 6 RADIATION PROTECTION DOSIMETRY Vol. 98 No 1, 2002 Published by Nuclear Technology Publishing #12;RADIONUCLIDE AND RADIATION PROTECTION DATA HANDBOOK 2nd Edition (2002

  8. Facilitated diffusion of proteins on chromatin

    E-Print Network [OSTI]

    O. Benichou; C. Chevalier; B. Meyer; R. Voituriez

    2011-01-26

    We present a theoretical model of facilitated diffusion of proteins in the cell nucleus. This model, which takes into account the successive binding/unbinding events of proteins to DNA, relies on a fractal description of the chromatin which has been recently evidenced experimentally. Facilitated diffusion is shown quantitatively to be favorable for a fast localization of a target locus by a transcription factor, and even to enable the minimization of the search time by tuning the affinity of the transcription factor with DNA. This study shows the robustness of the facilitated diffusion mechanism, invoked so far only for linear conformations of DNA.

  9. Diffusion and transport coefficients in synthetic opals

    SciTech Connect (OSTI)

    Sofo, J. O.; Mahan, G. D.; Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996-1200

    2000-07-15

    Opals are structures composed of close-packed spheres in the size range of nano to micrometers. They are sintered to create small necks at the points of contact. We have solved the diffusion problem in such structures. The relation between the diffusion coefficient and the thermal and electrical conductivity is used to estimate the transport coefficients of opal structures as a function of the neck size and the mean free path of the carriers. The theory presented is also applicable to the diffusion problem in other periodic structures. (c) 2000 The American Physical Society.

  10. Harvesting nanoscale thermal radiation using pyroelectric materials

    E-Print Network [OSTI]

    Fang, Jin; Frederich, Hugo; Pilon, Laurent

    2010-01-01

    eld radiative heat transfer dominates radiation transferstudy Far field radiation Heat transfer coefficient, h r (W/nanoscale radiation to enhance radiative heat transfer. The

  11. Transport diffusion of liquid water and methanol through membranes...

    Office of Scientific and Technical Information (OSTI)

    Transport diffusion of liquid water and methanol through membranes Citation Details In-Document Search Title: Transport diffusion of liquid water and methanol through membranes The...

  12. 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)...

  13. DOE Seeks Small Businesses for Paducah Gaseous Diffusion Plant...

    Office of Environmental Management (EM)

    Paducah Gaseous Diffusion Plant Infrastructure Support Services DOE Seeks Small Businesses for Paducah Gaseous Diffusion Plant Infrastructure Support Services June 10, 2014 -...

  14. DOE Issues Final Request for Proposal for Paducah Gaseous Diffusion...

    Energy Savers [EERE]

    Paducah Gaseous Diffusion Plant Support Services DOE Issues Final Request for Proposal for Paducah Gaseous Diffusion Plant Support Services October 6, 2014 - 4:13pm Addthis Media...

  15. DOE Awards Contract for Paducah Gaseous Diffusion Plant Infrastructure...

    Office of Environmental Management (EM)

    Paducah Gaseous Diffusion Plant Infrastructure Support Services DOE Awards Contract for Paducah Gaseous Diffusion Plant Infrastructure Support Services June 17, 2015 - 5:45pm...

  16. Low cost fuel cell diffusion layer configured for optimized anode...

    Office of Scientific and Technical Information (OSTI)

    Patent: Low cost fuel cell diffusion layer configured for optimized anode water management Citation Details In-Document Search Title: Low cost fuel cell diffusion layer configured...

  17. Biomedical Applications of NMR Imaging and Diffusion Studies

    E-Print Network [OSTI]

    Walsworth, Ronald L.

    Biomedical Applications of NMR Imaging and Diffusion Studies Using Thermal And Hyperpolarized Xenon by ..................................................................................................... David Nelson Chairman, Department of Physics #12;Biomedical Applications of NMR Imaging and Diffusion

  18. Diffusion releases through one and two finite planar zones from...

    Office of Scientific and Technical Information (OSTI)

    Diffusion releases through one and two finite planar zones from a nuclear waste package Citation Details In-Document Search Title: Diffusion releases through one and two finite...

  19. Diffusion releases through one and two finite planar zones from...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Diffusion releases through one and two finite planar zones from a nuclear waste package Citation Details In-Document Search Title: Diffusion releases through one...

  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

    1965-01-01

    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. A general hybrid radiation transport scheme for star formation simulations on an adaptive grid

    SciTech Connect (OSTI)

    Klassen, Mikhail; Pudritz, Ralph E. [Department of Physics and Astronomy, McMaster University 1280 Main Street W, Hamilton, ON L8S 4M1 (Canada); Kuiper, Rolf [Max Planck Institute for Astronomy Königstuhl 17, D-69117 Heidelberg (Germany); Peters, Thomas [Institut für Computergestützte Wissenschaften, Universität Zürich Winterthurerstrasse 190, CH-8057 Zürich (Switzerland); Banerjee, Robi; Buntemeyer, Lars, E-mail: klassm@mcmaster.ca [Hamburger Sternwarte, Universität Hamburg Gojenbergsweg 112, D-21029 Hamburg (Germany)

    2014-12-10

    Radiation feedback plays a crucial role in the process of star formation. In order to simulate the thermodynamic evolution of disks, filaments, and the molecular gas surrounding clusters of young stars, we require an efficient and accurate method for solving the radiation transfer problem. We describe the implementation of a hybrid radiation transport scheme in the adaptive grid-based FLASH general magnetohydrodyanmics code. The hybrid scheme splits the radiative transport problem into a raytracing step and a diffusion step. The raytracer captures the first absorption event, as stars irradiate their environments, while the evolution of the diffuse component of the radiation field is handled by a flux-limited diffusion solver. We demonstrate the accuracy of our method through a variety of benchmark tests including the irradiation of a static disk, subcritical and supercritical radiative shocks, and thermal energy equilibration. We also demonstrate the capability of our method for casting shadows and calculating gas and dust temperatures in the presence of multiple stellar sources. Our method enables radiation-hydrodynamic studies of young stellar objects, protostellar disks, and clustered star formation in magnetized, filamentary environments.

  2. Novel applications of diffusion-driven flow

    E-Print Network [OSTI]

    Allshouse, Michael R

    2010-01-01

    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 ...

  3. 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 ...

  4. Diffusion, dimensionality and noise in transcriptional regulation

    E-Print Network [OSTI]

    Gasper Tkacik; William Bialek

    2007-12-12

    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.

  5. Diffuser Augmented Wind Turbine Analysis Code

    E-Print Network [OSTI]

    Carroll, Jonathan

    2014-05-31

    , it is necessary to develop innovative wind capturing devices that can produce energy in the locations where large conventional horizontal axis wind turbines (HAWTs) are too impractical to install and operate. A diffuser augmented wind turbine (DAWT) is one...

  6. Electrospray emitters For diffusion vacuum pumps

    E-Print Network [OSTI]

    Diaz Gómez Maqueo, Pablo (Pablo Ly)

    2011-01-01

    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 ...

  7. 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

  8. Radiation Safety (Revised March 2010)

    E-Print Network [OSTI]

    of radiation and a unit of exposure 14 Biological effects of radiation and units of dose 19 ALARA policy

  9. 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...

  10. TERSat: Trapped Energetic Radiation Satellite

    E-Print Network [OSTI]

    Clements, Emily B.

    2012-01-01

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

  11. Polymer Composites for Radiation Scintillation

    E-Print Network [OSTI]

    Chen, Qi

    2012-01-01

    Principles of radiation interaction in matter and detection,Principles of radiation interaction in matter and detection,

  12. Excursions of diffusion processes and continued fractions

    E-Print Network [OSTI]

    Alain Comtet; Yves Tourigny

    2010-02-11

    It is well-known that the excursions of a one-dimensional diffusion process can be studied by considering a certain Riccati equation associated with the process. We show that, in many cases of interest, the Riccati equation can be solved in terms of an infinite continued fraction. We examine the probabilistic significance of the expansion. To illustrate our results, we discuss some examples of diffusions in deterministic and in random environments.

  13. Development of anomalous diffusion among crowding proteins

    E-Print Network [OSTI]

    Margaret R. Horton; Felix Höfling; Joachim O. Rädler; Thomas Franosch

    2010-03-19

    In cell membranes, proteins and lipids diffuse in a highly crowded and heterogeneous landscape, where aggregates and dense domains of proteins or lipids obstruct the path of diffusing molecules. In general, hindered motion gives rise to anomalous transport, though the nature of the onset of this behavior is still under debate and difficult to investigate experimentally. Here, we present a systematic study where proteins bound to supported lipid membranes diffuse freely in two dimensions, but are increasingly hindered by the presence of other like proteins. In our model system, the surface coverage of the protein avidin on the lipid bilayer is well controlled by varying the concentration of biotinylated lipid anchors. Using fluorescence correlation spectroscopy (FCS), we measure the time correlation function over long times and convert it to the mean-square displacement of the diffusing proteins. Our approach allows for high precision data and a clear distinction between anomalous and normal diffusion. It enables us to investigate the onset of anomalous diffusion, which takes place when the area coverage of membrane proteins increases beyond approximately 5%. This transition region exhibits pronounced spatial heterogeneities. Increasing the packing fraction further, transport becomes more and more anomalous, manifested in a decrease of the exponent of subdiffusion.

  14. Diffusivity of rocks: Gas diffusion measurements and correlation to porosity and pore size distribution

    E-Print Network [OSTI]

    Hu, Qinhong "Max"

    scenarios, such as geologic disposal of radioactive waste [Gillham et al., 1984], contaminant remediation [e been used to determine gas transport parameters includ- ing permeability, diffusion coefficient

  15. 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

    2007-04-12

    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.

  16. RHOBOT: Radiation hardened robotics

    SciTech Connect (OSTI)

    Bennett, P.C.; Posey, L.D.

    1997-10-01

    A survey of robotic applications in radioactive environments has been conducted, and analysis of robotic system components and their response to the varying types and strengths of radiation has been completed. Two specific robotic systems for accident recovery and nuclear fuel movement have been analyzed in detail for radiation hardness. Finally, a general design approach for radiation-hardened robotics systems has been developed and is presented. This report completes this project which was funded under the Laboratory Directed Research and Development program.

  17. FRONT SPEEDS IN THE VANISHING DIFFUSION LIMIT FOR REACTION-DIFFUSION-CONVECTION EQUATIONS

    E-Print Network [OSTI]

    Mascia, Corrado

    velocity. This convergence also yields a reaction- independent sufficient condition for the minimalFRONT SPEEDS IN THE VANISHING DIFFUSION LIMIT FOR REACTION-DIFFUSION-CONVECTION EQUATIONS E.C.M. CROOKS AND C. MASCIA Abstract. Travelling fronts for scalar balance laws with monostable reaction

  18. A pumping system for measuring coastal diffusion coefficients 

    E-Print Network [OSTI]

    Bolen, Zane Kevin

    1980-01-01

    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...

  19. 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.

  20. 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.

  1. A Comparison of Fick and Maxwell-Stefan Diffusion Formulations in PEMFC Cathode Gas Diffusion Layers

    E-Print Network [OSTI]

    Lindstrom, Michael

    2013-01-01

    This paper explores the mathematical formulations of Fick and Maxwell-Stefan diffusion in the context of polymer electrolyte membrane fuel cell cathode gas diffusion layers. Formulations of diffusion combined with mass-averaged Darcy flow are considered for three component gases. Fick formulations can be considered as approximations of Maxwell-Stefan in a certain sense. For this application, the formulations can be compared computationally in a simple, one dimensional setting. We observe that the predictions of the formulations are very similar, despite their seemingly different structure. Analytic insight is given to the result. In addition, it is seen that for both formulations, diffusion laws are small perturbations from bulk flow. The work is also intended as a reference to multi-component gas diffusion formulations in the fuel cell setting.

  2. Radiation physics, biophysics, and radiation biology

    SciTech Connect (OSTI)

    Hall, E.J.

    1992-05-01

    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.

  3. 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)

    1996-12-31

    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.

  4. Reverse-selective diffusion in nanocomposite membranes

    E-Print Network [OSTI]

    Reghan J. Hill

    2005-10-27

    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.

  5. Fission Enhanced diffusion of uranium in zirconia

    E-Print Network [OSTI]

    Bérerd, N; Moncoffre, N; Sainsot, P; Faust, H; Catalette, H

    2005-01-01

    This paper deals with the comparison between thermal and Fission Enhanced Diffusion (FED) of uranium into zirconia, representative of the inner face of cladding tubes. The experiments under irradiation are performed at the Institut Laue Langevin (ILL) in Grenoble using the Lohengrin spectrometer. A thin $^{235}UO\\_2$ layer in direct contact with an oxidized zirconium foil is irradiated in the ILL high flux reactor. The fission product flux is about 10$^{11}$ ions cm$^{-2}$ s$^{-1}$ and the target temperature is measured by an IR pyrometer. A model is proposed to deduce an apparent uranium diffusion coefficient in zirconia from the energy distribution broadening of two selected fission products. It is found to be equal to 10$^{-15}$ cm$^2$ s$^{-1}$ at 480$\\circ$C and compared to uranium thermal diffusion data in ZrO$\\_2$ in the same pressure and temperature conditions. The FED results are analysed in comparison with literature data.

  6. Maximal energy extraction under discrete diffusive exchange

    E-Print Network [OSTI]

    Michael J. Hay; Jeremy Schiff; Nathaniel J. Fisch

    2015-08-14

    Waves propagating through a bounded plasma can rearrange the densities of states in the six-dimensional velocity-configuration phase space. Depending on the rearrangement, the wave energy can either increase or decrease, with the difference taken up by the total plasma energy. In the case where the rearrangement is diffusive, only certain plasma states can be reached. It turns out that the set of reachable states through such diffusive rearrangements has been described in very different contexts. Building upon those descriptions, and making use of the fact that the plasma energy is a linear functional of the state densities, the maximal extractable energy under diffusive rearrangement can then be addressed through linear programming.

  7. Maximal energy extraction under discrete diffusive exchange

    E-Print Network [OSTI]

    Hay, Michael J; Fisch, Nathaniel J

    2015-01-01

    Waves propagating through a bounded plasma can rearrange the densities of states in the six-dimensional velocity-configuration phase space. Depending on the rearrangement, the wave energy can either increase or decrease, with the difference taken up by the total plasma energy. In the case where the rearrangement is diffusive, only certain plasma states can be reached. It turns out that the set of reachable states through such diffusive rearrangements has been described in very different contexts. Building upon those descriptions, and making use of the fact that the plasma energy is a linear functional of the state densities, the maximal extractable energy under diffusive rearrangement can then be addressed through linear programming.

  8. Diffusion-controlled reactions modeling in Geant4-DNA

    SciTech Connect (OSTI)

    Karamitros, M.; Luan, S.; Bernal, M.A.; Allison, J.; Baldacchino, G.; Davidkova, M.; Francis, Z.; Friedland, W.; Ivantchenko, V.; Ivantchenko, A.; Mantero, A.; Nieminem, P.; Santin, G.; Tran, H.N.; Stepan, V.; Incerti, S.

    2014-10-01

    Context Under irradiation, a biological system undergoes a cascade of chemical reactions that can lead to an alteration of its normal operation. There are different types of radiation and many competing reactions. As a result the kinetics of chemical species is extremely complex. The simulation becomes then a powerful tool which, by describing the basic principles of chemical reactions, can reveal the dynamics of the macroscopic system. To understand the dynamics of biological systems under radiation, since the 80s there have been on-going efforts carried out by several research groups to establish a mechanistic model that consists in describing all the physical, chemical and biological phenomena following the irradiation of single cells. This approach is generally divided into a succession of stages that follow each other in time: (1) the physical stage, where the ionizing particles interact directly with the biological material; (2) the physico-chemical stage, where the targeted molecules release their energy by dissociating, creating new chemical species; (3) the chemical stage, where the new chemical species interact with each other or with the biomolecules; (4) the biological stage, where the repairing mechanisms of the cell come into play. This article focuses on the modeling of the chemical stage. Method This article presents a general method of speeding-up chemical reaction simulations in fluids based on the Smoluchowski equation and Monte-Carlo methods, where all molecules are explicitly simulated and the solvent is treated as a continuum. The model describes diffusion-controlled reactions. This method has been implemented in Geant4-DNA. The keys to the new algorithm include: (1) the combination of a method to compute time steps dynamically with a Brownian bridge process to account for chemical reactions, which avoids costly fixed time step simulations; (2) a k–d tree data structure for quickly locating, for a given molecule, its closest reactants. The performance advantage is presented in terms of complexity, and the accuracy of the new algorithm is demonstrated by simulating radiation chemistry in the context of the Geant4-DNA project. Application The time-dependent radiolytic yields of the main chemical species formed after irradiation are computed for incident protons at different energies (from 50 MeV to 500 keV). Both the time-evolution and energy dependency of the yields are discussed. The evolution, at one microsecond, of the yields of hydroxyls and solvated electrons with respect to the linear energy transfer is compared to theoretical and experimental data. According to our results, at high linear energy transfer, modeling radiation chemistry in the trading compartment representation might be adopted.

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

    DOE Patents [OSTI]

    Tadir, Yona (Irvine, CA); Berns, Michael W. (Trabuco Canyon, CA); Svaasand, Lars O. (Trondheim, NO); Tromberg, Bruce J. (Irvine, CA)

    1995-01-01

    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.

  10. 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.

    1995-12-26

    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.

  11. LOCAL RADIATION MAGNETOHYDRODYNAMIC INSTABILITIES IN MAGNETICALLY STRATIFIED MEDIA

    SciTech Connect (OSTI)

    Tao, Ted; Blaes, Omer

    2011-11-20

    We study local radiation magnetohydrodynamic instabilities in static, optically thick, vertically stratified media with constant flux mean opacity. We include the effects of vertical gradients in a horizontal background magnetic field. Assuming rapid radiative diffusion, we use the zero gas pressure limit as an entry point for investigating the coupling between the photon bubble instability and the Parker instability. Apart from factors that depend on wavenumber orientation, the Parker instability exists for wavelengths longer than a characteristic wavelength {lambda}{sub tran}, while photon bubbles exist for wavelengths shorter than {lambda}{sub tran}. The growth rate in the Parker regime is independent of the orientation of the horizontal component of the wavenumber when radiative diffusion is rapid, but the range of Parker-like wavenumbers is extended if there exists strong horizontal shear between field lines (i.e., horizontal wavenumber perpendicular to the magnetic field). Finite gas pressure introduces an additional short-wavelength limit to the Parker-like behavior, and also limits the growth rate of the photon bubble instability to a constant value at short wavelengths. We also consider the effects of differential rotation with accretion disk applications in mind. Our results may explain why photon bubbles have not yet been observed in recent stratified shearing box accretion disk simulations. Photon bubbles may physically exist in simulations with high radiation to gas pressure ratios, but higher spatial resolution will be needed to resolve the asymptotically growing unstable wavelengths.

  12. Self- and zinc diffusion in gallium antimonide

    SciTech Connect (OSTI)

    Nicols, Samuel Piers

    2002-03-26

    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.

  13. Analytical solutions to matrix diffusion problems

    SciTech Connect (OSTI)

    Kekäläinen, Pekka

    2014-10-06

    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.

  14. ON THE JITTER RADIATION

    SciTech Connect (OSTI)

    Kelner, S. R. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-6917 Heidelberg (Germany); Aharonian, F. A. [Dublin Institute for Advanced Studies, 31 Fitzwilliam Place, Dublin 2 (Ireland); Khangulyan, D., E-mail: skelner@rambler.ru, E-mail: Felix.Aharonian@mpi-hd.mpg.de, E-mail: khangul@astro.isas.jaxa.jp [Institute of Space and Astronautical Science/JAXA, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan)

    2013-09-01

    In a small-scale turbulent medium, when the nonrelativistic Larmor radius R{sub L} = mc {sup 2}/eB exceeds the correlation length {lambda} of the magnetic field, the magnetic Bremsstrahlung radiation of charged relativistic particles unavoidably proceeds to the so-called jitter radiation regime. The cooling timescale of parent particles is identical to the synchrotron cooling time, thus this radiation regime can be produced with very high efficiency in different astrophysical sources characterized by high turbulence. The jitter radiation has distinct spectral features shifted toward high energies, compared to synchrotron radiation. This effect makes the jitter mechanism an attractive broad-band gamma-ray production channel, which, in highly magnetized and turbulent environments, can compete or even dominate over other high-energy radiation mechanisms. In this paper, we present a novel study of the spectral properties of the jitter radiation performed within the framework of perturbation theory. The derived general expression for the spectral power of radiation is presented in a compact and convenient form for numerical calculations.

  15. Radiative Flux Analysis

    SciTech Connect (OSTI)

    Long, Chuck

    2008-05-14

    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.

  16. Radiation-resistant microorganism

    DOE Patents [OSTI]

    Fliermans, Carl B.

    2010-06-15

    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.

  17. Photochemistry Radiation and Photolysis

    E-Print Network [OSTI]

    Toohey, Darin W.

    energy is done (i.e. energy per unit time) #12;Sample Problem: A microwave oven puts out radiation at 50? How does a microwave oven heat food anyway? First note that 50 GHz is a frequency (Hz = s-1) E = hn, as a function of l · Amount of solar radiation, as a function of

  18. Appendix G. Radiation Appendix G. Radiation

    E-Print Network [OSTI]

    Pennycook, Steve

    energy, is energy in the form of waves or particles moving through space. Visi- ble light, heat, radio in the form of electromagnetic waves. Examples include gamma rays, ultraviolet light, and radio waves waves, and alpha particles are examples of radiation. When people feel warmth from sunlight

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

    E-Print Network [OSTI]

    Nathan Smith; Richard McCray

    2007-10-18

    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.

  20. Quantification of the precipitation loss of radiation belt electrons observed by SAMPEX

    E-Print Network [OSTI]

    Li, Xinlin

    Click Here for Full Article Quantification of the precipitation loss of radiation belt electrons/PET observations, the rates and the spatial and temporal variations of electron loss to the atmosphere in the Earth and pitch angle diffusion. The measured electrons by SAMPEX can be distinguished as trapped, quasi trapped

  1. 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

  2. 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

    2015-01-01

    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 ...

  3. RADIATION DAMAGE OF GERMANIUM DETECTORS

    E-Print Network [OSTI]

    Pehl, Richard H.

    2011-01-01

    occurring within the detector, radiation may also change theLBL-7967 RADIATION DAMAGE OF GERMANIUM DETECTORS Richard H.LBL-7967 RADIATION DAMAGE OF GERMANIUM DETECTORS* Richard H.

  4. Molecular Modeling of Diffusion on a Crystalline PETN Surface

    SciTech Connect (OSTI)

    Lin, P; Khare, R; Gee, R H; Weeks, B L

    2007-07-13

    Surface diffusion on a PETN crystal was investigated by treating the surface diffusion as an activated process in the formalism of transition state theory. In particular, surface diffusion on the (110) and (101) facets, as well as diffusion between these facets, were considered. We successfully obtained the potential energy barriers required for PETN surface diffusion. Our results show that the (110) surface is more thermally active than the (101) surface and PETN molecules mainly diffuses from the (110) to (101) facet. These results are in good agreement with experimental observations and previous simulations.

  5. CARBON DIFFUSION ACROSS DISSIMILAR STEEL WELDS

    E-Print Network [OSTI]

    Cambridge, University of

    CARBON DIFFUSION ACROSS DISSIMILAR STEEL WELDS By Julia Margaret Race St. John's College, Cambridge. 111 #12;#12;ABSTRACT Dissimilar steel welds are used extensively in the power generation industry to the high alloy side of the weld. This leaves an area on one side of the weld denuded of carbon

  6. Acoustic Enhancement of Surface Diffusion Chengping Wu,

    E-Print Network [OSTI]

    Zhigilei, Leonid V.

    provides an attractive alternative to thermal activation in thin film growth on heat-sensitive substrates to the thermal activation in thin film growth on heat-sensitive substrates. 2. MECHANISMS OF ACOUSTIC ACTIVATION, Russia *S Supporting Information ABSTRACT: The idea of acoustic activation of surface diffusion

  7. Diffusion Processes in Turbulent Magnetic Fields

    E-Print Network [OSTI]

    Alex Lazarian

    2007-07-05

    We study of the effect of turbulence on diffusion processes within magnetized medium. While we exemplify our treatment with heat transfer processes, our results are quite general and are applicable to different processes, e.g. diffusion of heavy elements. Our treatment is also applicable to describing the diffusion of cosmic rays arising from magnetic field wandering. In particular, we find that when the energy injection velocity is smaller than the Alfven speed the heat transfer is partially suppressed, while in the opposite regime the effects of turbulence depend on the intensity of driving. In fact, the scale $l_A$ at which the turbulent velocity is equal the Alfven velocity is a new important parameter. When the electron mean free path $\\lambda$ is larger than $l_A$, the stronger the the turbulence, the lower thermal conductivity by electrons is. The turbulent motions, however, induces their own advective transport, that can provide effective diffusivity. For clusters of galaxies, we find that the turbulence is the most important agent for heat transfer. We also show that the domain of applicability of the subdiffusion concept is rather limited.

  8. Particle Size Dependence of the Ionic Diffusivity

    E-Print Network [OSTI]

    Bazant, Martin Z.

    material for rechargeable lithium batteries, specifically explaining why it functions exclusively on the nanoscale. KEYWORDS Batteries, diffusion, nano, ab initio T he benefit of nanosizing materials on bulk for rechargeable Li+ ion batteries that only operates in batteries when in nanoform, though the results should

  9. Diffusive Acceleration of Ions at Interplanetary Shocks

    E-Print Network [OSTI]

    Matthew G. Baring; Errol J. Summerlin

    2005-06-08

    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.

  10. APPARENT PULSE DIFFUSION DUE TO DISORDERED MICROSTRUCTURE

    E-Print Network [OSTI]

    Solna, Knut

    APPARENT PULSE DIFFUSION DUE TO DISORDERED MICROSTRUCTURE A. Nachbin \\Lambda and K. Sølna y \\Lambda, and it is important to describe when and how fine scale heterogeneities interact with a traveling seismic pulse. We are interested in pulse shaped waves that interact with the rapidly varying features (i.e. microstruture

  11. Magnetic flux diffusion through HTS shields

    E-Print Network [OSTI]

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

    1998-06-01

    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...

  12. Forecasting Turbulent Modes with Nonparametric Diffusion Models

    E-Print Network [OSTI]

    Tyrus Berry; John Harlim

    2015-01-27

    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.

  13. Reaction-diffusion approach in soft diffraction

    E-Print Network [OSTI]

    Rodion Kolevatov; Konstantin Boreskov

    2013-11-29

    We apply the reaction-diffusion (stochastic) approach to the numerical calculation of the elastic amplitude in the Reggeon Field Theory (RFT) and its single diffractive cut. Fits to the total, integrated and differential elastic cross sections with account of all Pomeron loops are reported together with all-loop calculation of the single difraction dissociation cross section.

  14. 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

  15. Cosmic ray penetration in diffuse clouds

    E-Print Network [OSTI]

    Morlino, G; Krause, J

    2015-01-01

    Cosmic rays are a fundamental source of ionization for molecular and diffuse clouds, influencing their chemical, thermal, and dynamical evolution. The amount of cosmic rays inside a cloud also determines the $\\gamma$-ray flux produced by hadronic collisions between cosmic rays and cloud material. We study the spectrum of cosmic rays inside and outside of a diffuse cloud, by solving the stationary transport equation for cosmic rays including diffusion, advection and energy losses due to ionization of neutral hydrogen atoms. We found that the cosmic ray spectrum inside a diffuse cloud differs from the one in the interstellar medium (ISM) for energies smaller than $E_{br}\\approx 100$ MeV, irrespective of the model details. Below $E_{br}$, the spectrum is harder (softer) than that in the ISM if the latter is a power law $\\propto p^{-s}$ with $s$ larger (smaller) than $\\sim0.42$. As a consequence also the ionization rate due to CRs is strongly affected. Assuming an average Galactic spectrum similar to the one infe...

  16. FY2008 Report on GADRAS Radiation Transport Methods.

    SciTech Connect (OSTI)

    Mattingly, John K.; Mitchell, Dean James; Harding, Lee; Varley, Eric S.; Hilton, Nathan R.

    2008-10-01

    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

  17. Bounce- and MLT-averaged diffusion coefficients in a physics-based magnetic field geometry obtained from RAM-SCB for the March 17 2013 storm

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

    Zhao, Lei; Yu, Yiqun; Delzanno, Gian Luca; Jordanova, Vania K.

    2015-04-01

    Local acceleration via whistler wave and particle interaction plays a significant role in particle dynamics in the radiation belt. In this work we explore gyro-resonant wave-particle interaction and quasi-linear diffusion in different magnetic field configurations related to the March 17 2013 storm. We consider the Earth's magnetic dipole field as a reference and compare the results against non-dipole field configurations corresponding to quiet and stormy conditions. The latter are obtained with the ring current-atmosphere interactions model with a self-consistent magnetic field RAM-SCB, a code that models the Earth's ring current and provides a realistic modeling of the Earth's magnetic field.more »By applying quasi-linear theory, the bounce- and MLT-averaged electron pitch angle, mixed term, and energy diffusion coefficients are calculated for each magnetic field configuration. For radiation belt (~1 MeV) and ring current (~100 keV) electrons, it is shown that at some MLTs the bounce-averaged diffusion coefficients become rather insensitive to the details of the magnetic field configuration, while at other MLTs storm conditions can expand the range of equatorial pitch angles where gyro-resonant diffusion occurs and significantly enhance the diffusion rates. When MLT average is performed at drift shell L = 4.25 (a good approximation to drift average), the diffusion coefficients become quite independent of the magnetic field configuration for relativistic electrons, while the opposite is true for lower energy electrons. These results suggest that, at least for the March 17 2013 storm and for L ? 4.25, the commonly adopted dipole approximation of the Earth's magnetic field can be safely used for radiation belt electrons, while a realistic modeling of the magnetic field configuration is necessary to describe adequately the diffusion rates of ring current electrons.« less

  18. Bounce- and MLT-averaged diffusion coefficients in a physics-based magnetic field geometry obtained from RAM-SCB for the March 17 2013 storm

    SciTech Connect (OSTI)

    Zhao, Lei; Yu, Yiqun; Delzanno, Gian Luca; Jordanova, Vania K.

    2015-04-01

    Local acceleration via whistler wave and particle interaction plays a significant role in particle dynamics in the radiation belt. In this work we explore gyro-resonant wave-particle interaction and quasi-linear diffusion in different magnetic field configurations related to the March 17 2013 storm. We consider the Earth's magnetic dipole field as a reference and compare the results against non-dipole field configurations corresponding to quiet and stormy conditions. The latter are obtained with the ring current-atmosphere interactions model with a self-consistent magnetic field RAM-SCB, a code that models the Earth's ring current and provides a realistic modeling of the Earth's magnetic field. By applying quasi-linear theory, the bounce- and MLT-averaged electron pitch angle, mixed term, and energy diffusion coefficients are calculated for each magnetic field configuration. For radiation belt (~1 MeV) and ring current (~100 keV) electrons, it is shown that at some MLTs the bounce-averaged diffusion coefficients become rather insensitive to the details of the magnetic field configuration, while at other MLTs storm conditions can expand the range of equatorial pitch angles where gyro-resonant diffusion occurs and significantly enhance the diffusion rates. When MLT average is performed at drift shell L = 4.25 (a good approximation to drift average), the diffusion coefficients become quite independent of the magnetic field configuration for relativistic electrons, while the opposite is true for lower energy electrons. These results suggest that, at least for the March 17 2013 storm and for L ? 4.25, the commonly adopted dipole approximation of the Earth's magnetic field can be safely used for radiation belt electrons, while a realistic modeling of the magnetic field configuration is necessary to describe adequately the diffusion rates of ring current electrons.

  19. Radiation Damage/Materials Modification

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

    ion irradiation is an important tool for studying radiation damage effects Materials in a nuclear reactor are exposed to extreme temperature and radiation conditions that degrade...

  20. 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...

  1. Radiation Safety System

    SciTech Connect (OSTI)

    Vylet, Vaclav; Liu, James C.; Walker, Lawrence S.; /Los Alamos

    2012-04-04

    The goal of this work is to provide an overview of a Radiation safety system (RSS) designed for protection from prompt radiation hazard at accelerator facilities. RSS design parameters, functional requirements and constraints are derived from hazard analysis and risk assessment undertaken in the design phase of the facility. The two main subsystems of a RSS are access control system (ACS) and radiation control system (RCS). In this text, a common approach to risk assessment, typical components of ACS and RCS, desirable features and general design principles applied to RSS are described.

  2. Composition for radiation shielding

    DOE Patents [OSTI]

    Kronberg, James W. (Aiken, SC)

    1994-01-01

    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.

  3. Miniaturized radiation chirper

    DOE Patents [OSTI]

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

    1980-01-01

    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.

  4. Self-Diffusion and Collective Diffusion of Charged colloids Studied by Dynamic Light Scattering

    E-Print Network [OSTI]

    Jacqueline Appell; Grégoire Porte; Eric Buhler

    2005-06-24

    A microemulsion of decane droplets stabilized by a non-ionic surfactant film is progressively charged by substitution of a non-ionic surfactant molecule by a cationic surfactant. We check that the microemulsion droplets remain identical within the explored range of volume fraction (0.02 to 0.18) and of the number of charge per droplets (0 to 40) . We probe the dynamics of these microemulsions by dynamic light scattering. Despite the similar structure of the uncharged and charged microemulsions the dynamics are very different . In the neutral microemulsion the fluctuations of polarization relax, as is well known, via the collective diffusion of the droplets. In the charged microemulsions, two modes of relaxation are observed. The fast one is ascribed classically to the collective diffusion of the charged droplets coupled to the diffusion of the counterions. The slow one has, to our knowledge, not been observed previously neither in similar microemulsions nor in charged spherical colloids. We show that the slow mode is also diffusive and suggest that its possible origine is the relaxation of local charge fluctuations via local exchange of droplets bearing different number of charges . The diffusion coefficient associated with this mode is then the self diffusion coefficient of the droplets.

  5. Fractionation of soil gases by diffusion of water vapor, gravitational settling, and thermal diffusion

    SciTech Connect (OSTI)

    Severinghaus, J.P.; Bender, M.L. [Univ. of Rhode Island, RI (United States)] [Univ. of Rhode Island, RI (United States); Keeling, R.F. [Scripps Institution of Oceanography, LaJolla, CA (United States)] [Scripps Institution of Oceanography, LaJolla, CA (United States); Broecker, W.S. [Lamont-Doherty Earth Observatory, Palisades, NY (United States)] [Lamont-Doherty Earth Observatory, Palisades, NY (United States)

    1996-03-01

    Air sampled from the moist unsaturated zone in a sand dune exhibits depletion in the heavy isotopes of N{sub 2} and O{sub 2}. We propose that the depletion is caused by a diffusive flux of water vapor out of the dune, which sweeps out the other gases, forcing them to diffuse back into the dune. The heavy isotopes of N{sub 2} and O{sub 2} diffuse back more slowly, resulting in a steady-state depletion of the heavy isotopesin the dune interior. We predict the effect`s magnitude with molecular diffusion theory and reproduce it in a laboratory simulation, finding good agreement between field, theory, and lab. The magnitude of the effect is governed by the ratio of the binary diffusivities against water vapor of a pair of gases, and increases {approximately} linearly with the difference between the water vapor mole fraction of the site and the advectively mixed reservoir with which it is in diffusive contact (in most cases the atmosphere). 32 refs., 1 fig., 3 tabs.

  6. Use of finite volume radiation for predicting the Knudsen minimum in 2D channel flow

    SciTech Connect (OSTI)

    Malhotra, Chetan P.; Mahajan, Roop L.

    2014-12-09

    In an earlier paper we employed an analogy between surface-to-surface radiation and free-molecular flow to model Knudsen flow through tubes and onto planes. In the current paper we extend the analogy between thermal radiation and molecular flow to model the flow of a gas in a 2D channel across all regimes of rarefaction. To accomplish this, we break down the problem of gaseous flow into three sub-problems (self-diffusion, mass-motion and generation of pressure gradient) and use the finite volume method for modeling radiation through participating media to model the transport in each sub-problem as a radiation problem. We first model molecular self-diffusion in the stationary gas by modeling the transport of the molecular number density through the gas starting from the analytical asymptote for free-molecular flow to the kinetic theory limit of gaseous self-diffusion. We then model the transport of momentum through the gas at unit pressure gradient to predict Poiseuille flow and slip flow in the 2D gas. Lastly, we predict the generation of pressure gradient within the gas due to molecular collisions by modeling the transport of the forces generated due to collisions per unit volume of gas. We then proceed to combine the three radiation problems to predict flow of the gas over the entire Knudsen number regime from free-molecular to transition to continuum flow and successfully capture the Knudsen minimum at Kn ? 1.

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

    E-Print Network [OSTI]

    St. Laurent, Louis C

    1999-01-01

    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 ...

  8. Moisture Diffusion in Asphalt Binders and Fine Aggregate Mixtures 

    E-Print Network [OSTI]

    Vasconcelos, Kamilla L.

    2011-08-08

    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...

  9. Modelling of unidirectional thermal diffusers in shallow water

    E-Print Network [OSTI]

    Lee, Joseph Hun-Wei

    1977-01-01

    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 ...

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

    E-Print Network [OSTI]

    Smith, Wendy Marie

    1987-01-01

    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 ...

  11. Dynamics of multiphoton excitation and quantum diffusion in Rydberg atoms

    E-Print Network [OSTI]

    Chu, Shih-I; Wang, Kwanghsi

    1989-02-15

    with a different excitation mechanism. In this paper, we emphasize the study of the two major excitation mechanisms: quantum diffusion and multiphoton resonant excitation. The region dominated by quantum diffusion lies in the frequency range ?c

  12. Role of carbon surface diffusion and strain on the epitaxial...

    Office of Scientific and Technical Information (OSTI)

    Role of carbon surface diffusion and strain on the epitaxial growth of graphene on SiC(0001). Citation Details In-Document Search Title: Role of carbon surface diffusion and strain...

  13. Portsmouth Gaseous Diffusion Plant environmental report for 1989

    SciTech Connect (OSTI)

    Turner, J.W. )

    1990-10-01

    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.

  14. Portal radiation monitor

    DOE Patents [OSTI]

    Kruse, L.W.

    1982-03-23

    A portal radiation monitor combines .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.

  15. Portal radiation monitor

    DOE Patents [OSTI]

    Kruse, Lyle W. (Albuquerque, NM)

    1985-01-01

    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.

  16. Amorphous silicon radiation detectors

    DOE Patents [OSTI]

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

    1992-01-01

    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.

  17. Amorphous silicon radiation detectors

    DOE Patents [OSTI]

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

    1992-11-17

    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.

  18. Radiative-convective instability

    E-Print Network [OSTI]

    Wing, Allison A.

    Radiative-moist-convective equilibrium (RCE) is a simple paradigm for the statistical equilibrium the earth's climate would exhibit in the absence of lateral energy transport. It has generally been assumed that for a given ...

  19. Ionizing radiation detector

    DOE Patents [OSTI]

    Thacker, Louis H. (Knoxville, TN)

    1990-01-01

    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.

  20. Method of enhancing radiation response of radiation detection materials

    DOE Patents [OSTI]

    Miller, Steven D. (Richland, WA)

    1997-01-01

    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.

  1. 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

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

    E-Print Network [OSTI]

    2012-10-17

    Oct 18, 2012 ... Key words: Inverse source problem, production-diffusion equation, Tikhonov regularization. 1 Introduction. Helium isotopes are used ...

  3. Handbook of radiation effects

    SciTech Connect (OSTI)

    Holmes-Siedle, A. (ed.) (Radiation Experiments and Monitors, Oxford (United Kingdom) Univ. of West London (United Kingdom)); Adams, L. (ed.) (European Space Agency-ESTEC, Noordwijk (Netherlands). Radiation Effects and Analysis Techniques Unit)

    1993-01-01

    This handbook is intended to serve as a tool for designers of equipment and scientific instruments in cases where they are required to ensure the survival of the equipment in radiation environments. High-technology materials, especially semiconductors and optics, tend to degrade on exposure to radiation in many different ways. Intense high-energy radiation environments are found in nuclear reactors and accelerators, machines for radiation therapy, industrial sterilization, and space. Some engineers have to build equipment which will survive a nuclear explosion from a hostile source. Proper handling of a disaster with radioactive materials requires equipment which depends utterly on semiconductor microelectronics and imaging devices. Thus the technology of radiation-tolerant electronics is an instrument for good social spheres as diverse as disaster planning and the exploration of Mars. In order to design equipment for intense environments like those described above, then degradation from high-energy irradiation must be seen as a basic design parameter. The aim of this handbook is to assist the engineer or student in that thought; to make it possible to write intelligent specifications; to offer some understanding of the complex variety of effects which occur when high-technology components encounter high-energy radiation; and to go thoroughly into the balance of choices of how to alleviate the effects and hence achieve the design aims of the project. Separate abstracts were prepared for 15 chapters of this book.

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

    DOE Patents [OSTI]

    Roybal, Lyle Gene

    2010-06-08

    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.

  5. Development of a robust modeling tool for radiation-induced segregation in austenitic stainless steels

    SciTech Connect (OSTI)

    Yang, Ying; Field, Kevin G; Allen, Todd R.; Busby, Jeremy T

    2015-09-01

    Irradiation-assisted stress corrosion cracking (IASCC) of austenitic stainless steels in Light Water Reactor (LWR) components has been linked to changes in grain boundary composition due to irradiation induced segregation (RIS). This work developed a robust RIS modeling tool to account for thermodynamics and kinetics of the atom and defect transportation under combined thermal and radiation conditions. The diffusion flux equations were based on the Perks model formulated through the linear theory of the thermodynamics of irreversible processes. Both cross and non-cross phenomenological diffusion coefficients in the flux equations were considered and correlated to tracer diffusion coefficients through Manning’s relation. The preferential atomvacancy coupling was described by the mobility model, whereas the preferential atom-interstitial coupling was described by the interstitial binding model. The composition dependence of the thermodynamic factor was modeled using the CALPHAD approach. Detailed analysis on the diffusion fluxes near and at grain boundaries of irradiated austenitic stainless steels suggested the dominant diffusion mechanism for chromium and iron is via vacancy, while that for nickel can swing from the vacancy to the interstitial dominant mechanism. The diffusion flux in the vicinity of a grain boundary was found to be greatly influenced by the composition gradient formed from the transient state, leading to the oscillatory behavior of alloy compositions in this region. This work confirms that both vacancy and interstitial diffusion, and segregation itself, have important roles in determining the microchemistry of Fe, Cr, and Ni at irradiated grain boundaries in austenitic stainless steels.

  6. Diffusing acoustic wave spectroscopy M. L. Cowan,1

    E-Print Network [OSTI]

    Page, John

    Diffusing acoustic wave spectroscopy M. L. Cowan,1 I. P. Jones,1, * J. H. Page,1,2, and D. A. Weitz called diffusing acoustic wave spec- troscopy DAWS . In this technique, the motion of the scatterers e the particle velocity correlation function. Potential appli- cations of diffusing acoustic wave spectroscopy

  7. Proton Diffusion in Nickel Hydroxide Prediction of Active Material Utilization

    E-Print Network [OSTI]

    Weidner, John W.

    Proton Diffusion in Nickel Hydroxide Prediction of Active Material Utilization Sathya Motupally of the active material is controlled by the diffusion rate of protons through the film. This hypothesis- tion by including the effect of proton diffusion through the active material of the nickel electrode.6

  8. Transport approximations in partially diffusive media Guillaume Bal

    E-Print Network [OSTI]

    Bal, Guillaume

    Transport approximations in partially diffusive media Guillaume Bal Department of Applied Physics concerns the analysis of approximations of transport equations in diffusive media. Firstly, we consider a variational formulation for the first-order transport equation that has the correct diffusive behavior

  9. 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

  10. Usage Policies Notebook for Thermco Atmospheric Diffusion Furnace system

    E-Print Network [OSTI]

    Mease, Kenneth D.

    Usage Policies Notebook for Thermco Atmospheric Diffusion Furnace system Revision date September 2014 #12;2 Emergency Plan for Diffusion Furnaces Standard Operating Procedures for Emergencies Contact;4 Usage Policies for Thermco Atmospheric Diffusion Furnace Standard policies for usage The Atmospheric

  11. Optoelectronic switches based on diffusive conduction Hilmi Volkan Demira

    E-Print Network [OSTI]

    Demir, Hilmi Volkan

    Optoelectronic switches based on diffusive conduction Hilmi Volkan Demira and Fatih Hakan Koklu the process of diffusive conduction that we use in our optoelectronic switches to achieve rapid optical switching on a picosecond time scale . We present the characteristic Green's function of the diffusive

  12. A model for the diffuse attenuation coefficient of downwelling irradiance

    E-Print Network [OSTI]

    Lee, Zhongping

    A model for the diffuse attenuation coefficient of downwelling irradiance Zhong-Ping Lee1 Naval] The diffuse attenuation coefficient for downwelling irradiance (Kd) is an important parameter for ocean of downwelling irradiance, J. Geophys. Res., 110, C02016, doi:10.1029/2004JC002275. 1. Introduction [2] Diffuse

  13. Repeated interaction model for diffusion-induced Ramsey narrowing

    E-Print Network [OSTI]

    Walsworth, Ronald L.

    Repeated interaction model for diffusion-induced Ramsey narrowing Yanhong Xiao 1, Irina Novikova 2. Xiao et al., Phys. Rev. Lett. 96, 043601 (2006)] we characterized diffusion-induced Ramsey narrowing presentation of the repeated interaction model of diffusion-induced Ramsey narrowing, with particular focus

  14. 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

  15. 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

  16. Variational principle for general diffusion problems June 28, 2004

    E-Print Network [OSTI]

    Tudorascu, Adrian

    -homogeneous nonlinear diffusion problems (of Fokker-Planck type) with time dependent coefficients. This work greatly with time-interpolants of minimizers arising from Wasserstein-type implicit schemes ([1], [11], [13], [14]: diffusion in plasmas, surface growth and transport of fluid in porous media, relative diffusion in turbulent

  17. Intermittency in Turbulent Diffusion Models with a Mean Gradient

    E-Print Network [OSTI]

    Majda, Andrew J.

    Intermittency in Turbulent Diffusion Models with a Mean Gradient Andrew J Majda and Xin T TongE30, 62G32 Submitted to: Nonlinearity 1. Introduction Turbulent diffusion is the transportation and diffusion. Its application ranges from the spread of hazardous plumes and mixing properties of turbulent

  18. DETAILED CHEMISTRY MODELING OF LAMINAR DIFFUSION FLAMES ON PARALLEL COMPUTERS

    E-Print Network [OSTI]

    . The gas­jet diffusion flame is the basic element of many combustion systems, such as gas turbines, ram­speed, three­dimensional, turbulent reacting systems, gas­jet laminar diffusion flames constitute a problem jets, and industrial furnaces. Furthermore, the fundamental understand­ ing of laminar diffusion flames

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

    SciTech Connect (OSTI)

    NONE

    1998-08-01

    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.

  20. COLUMBIA UNIVERSITY Radiation Safety Program

    E-Print Network [OSTI]

    Jia, Songtao

    this form to Radiation Safety's Dosimetry Program.) ___ Yes ___ No 1. Was the Dosimeter placed or stored

  1. Radiation oncogenesis in cell culture

    SciTech Connect (OSTI)

    Borek, C.

    1982-01-01

    This review article examines the oncogenic effects of radiation with emphasis on ionizing radiations. Cell transformation in vitro is examined with respect to culture systems currently used in these studies, initiation and phenotypic expression of transformation and criteria for transformation. The section of radiation oncogenesis in vitro includes ionizing and nonionizing radiation studies and cocarcinogens and modulators of radiogenic transformations.

  2. REPORT NO. 8 radiation hazards

    E-Print Network [OSTI]

    REPORT NO. 8 REVISED guidance for the control of radiation hazards in uranium mining SEPTEMBER 1967 OF RADIATION HAZARDS IN URANIUM MINING SEPTEMBER 1967 Staff Report of the FEDERAL RADIATION COUNCIL #12;FEDERAL...... .... .._ _.... Section I. Introduction. . . Section II. The Radiation Environment AssociatedWith Uranium Mining. Section

  3. Biosensor as a Reaction-Diffusion System

    E-Print Network [OSTI]

    Ghosh, Surya K; Sain, Anirban

    2012-01-01

    We model a biosensor as a reaction-diffusion process in a confined geometry. When a solution containing unknown concentration of antigens are injected into the closed chamber of the sensor, the antigens diffuse and react with a functionalised surface. These surface reactions are then converted to an optical signal, the intensity of which indicates the level of antigen content in the solution. We probe the spatio-temporal behavior of the system by studying the governing equations, using mean field approximation and numerical integration. Mean field analysis gives important insights about the dynamics, but in order to compare with real experiments and extract the values of the relevant kinetic parameters, numerical integration was necessary. We track down the operating conditions for quick and efficient response of the sensor.

  4. Reaction Diffusion patterns in Pseudoplatystoma fishes

    E-Print Network [OSTI]

    Aldo Ledesma-Durán; Héctor Juárez-Valencia; Iván Santamaría-Holek

    2016-01-05

    This paper studies how patterns derived from a system of reaction-diffusion equations may vary significantly depending upon boundary and initial conditions, as well as in the spatial dependence of the coefficients involved. From an extensive numerical study of the BVAM model, we demonstrate that the geometric pattern of a reaction-diffusion system is not uniquely determined by the value of the parameters in the equation. From this result, we suggest that the variability of patterns among individuals of the same species may have its roots in this sensitivity. Furthermore, this study analyzes briefly how the inclusion of the advection and the space dependency in the parameters of the model influences the forms of a specific pattern. The results of this study are compared to the skin patterns that appear in Pseudoplatystom} fishes.

  5. Diffusive Shock Acceleration: the Fermi Mechanism

    E-Print Network [OSTI]

    Matthew G. Baring

    1997-11-16

    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.

  6. Diffusion barriers in modified air brazes

    DOE Patents [OSTI]

    Weil, Kenneth Scott (Richland, WA); Hardy, John S. (Richland, WA); Kim, Jin Yong (Richland, WA); Choi, Jung-Pyung (Richland, WA)

    2010-04-06

    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.

  7. Memory effects and active Brownian diffusion

    E-Print Network [OSTI]

    Ghosh, Pulak K; Marchegiani, Giampiero; Marchesoni, Fabio

    2015-01-01

    A self-propelled artificial microswimmer is often modeled as a ballistic Brownian particle moving with constant speed aligned along one of its axis, but changing direction due to random collisions with the environment. Similarly to thermal noise, its angular randomization is described as a memoryless stochastic process. Here, we speculate that finite-time correlations in the orientational dynamics can affect the swimmer's diffusivity. To this purpose we propose and solve two alternative models. In the first one we simply assume that the environmental fluctuations governing the swimmer's propulsion are exponentially correlated in time, whereas in the second one we account for possible damped fluctuations of the propulsion velocity around the swimmer's axis. The corresponding swimmer's diffusion constants are predicted to get, respectively, enhanced or suppressed upon increasing the model memory time. Possible consequences of this effect on the interpretation of the experimental data are discussed.

  8. Memory effects and active Brownian diffusion

    E-Print Network [OSTI]

    Pulak K. Ghosh; Yunyun Li; Giampiero Marchegiani; Fabio Marchesoni

    2015-11-19

    A self-propelled artificial microswimmer is often modeled as a ballistic Brownian particle moving with constant speed aligned along one of its axis, but changing direction due to random collisions with the environment. Similarly to thermal noise, its angular randomization is described as a memoryless stochastic process. Here, we speculate that finite-time correlations in the orientational dynamics can affect the swimmer's diffusivity. To this purpose we propose and solve two alternative models. In the first one we simply assume that the environmental fluctuations governing the swimmer's propulsion are exponentially correlated in time, whereas in the second one we account for possible damped fluctuations of the propulsion velocity around the swimmer's axis. The corresponding swimmer's diffusion constants are predicted to get, respectively, enhanced or suppressed upon increasing the model memory time. Possible consequences of this effect on the interpretation of the experimental data are discussed.

  9. 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)

    1997-12-09

    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.

  10. Methodology and apparatus for diffuse photon imaging

    DOE Patents [OSTI]

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

    1997-12-09

    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.

  11. 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)

    2011-07-15

    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.

  12. Diffusion barriers in modified air brazes

    DOE Patents [OSTI]

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

    2013-04-23

    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.

  13. Analytical Models of Exoplanetary Atmospheres. II. Radiative Transfer via the Two-Stream Approximation

    E-Print Network [OSTI]

    Heng, Kevin; Lee, Jaemin

    2014-01-01

    We present a comprehensive analytical study of radiative transfer using the method of moments and include the effects of non-isotropic scattering in the coherent limit. Within this unified formalism, we derive the governing equations and solutions describing two-stream radiative transfer (which approximates the passage of radiation as a pair of outgoing and incoming fluxes), flux-limited diffusion (which describes radiative transfer in the deep interior) and solutions for the temperature-pressure profiles. Generally, the problem is mathematically under-determined unless a set of closures (Eddington coefficients) is specified. We demonstrate that the hemispheric (or hemi-isotropic) closure naturally derives from the radiative transfer equation if energy conservation is obeyed, while the Eddington closure produces spurious enhancements of both reflected light and thermal emission. We further demonstrate that traditional non-isothermal treatments of each atmospheric layer lead to unphysical contributions to the ...

  14. Multicomponent Gas Diffusion in Porous Electrodes

    E-Print Network [OSTI]

    Fu, Yeqing; Dutta, Abhijit; Mohanram, Aravind; Pietras, John D; Bazant, Martin Z

    2014-01-01

    Multicomponent gas transport is investigated with unprecedented precision by AC impedance analysis of porous YSZ anode-supported solid oxide fuel cells. A fuel gas mixture of H2-H2O-N2 is fed to the anode, and impedance data are measured across the range of hydrogen partial pressure (10-100%) for open circuit conditions at three temperatures (800C, 850C and 900C) and for 300mA applied current at 800C. For the first time, analytical formulae for the diffusion resistance (Rb) of three standard models of multicomponent gas transport (Fick, Stefan-Maxwell, and Dusty Gas) are derived and tested against the impedance data. The tortuosity is the only fitting parameter since all the diffusion coefficients are known. Only the Dusty Gas model leads to a remarkable data collapse for over twenty experimental conditions, using a constant tortuosity consistent with permeability measurements and the Bruggeman relation. These results establish the accuracy of the Dusty Gas model for multicomponent gas diffusion in porous med...

  15. Transport and diffusion in the embedding map

    E-Print Network [OSTI]

    N. Nirmal Thyagu; Neelima Gupte

    2009-05-20

    We study the transport properties of passive inertial particles in a $2-d$ incompressible flows. Here the particle dynamics is represented by the $4-d$ dissipative embedding map of $2-d$ area-preserving standard map which models the incompressible flow. The system is a model for impurity dynamics in a fluid and is characterized by two parameters, the inertia parameter $\\alpha$, and the dissipation parameter $\\gamma$. We obtain the statistical characterisers of transport for this system in these dynamical regimes. These are, the recurrence time statistics, the diffusion constant, and the distribution of jump lengths. The recurrence time distribution shows a power law tail in the dynamical regimes where there is preferential concentration of particles in sticky regions of the phase space, and an exponential decay in mixing regimes. The diffusion constant shows behaviour of three types - normal, subdiffusive and superdiffusive, depending on the parameter regimes. Phase diagrams of the system are constructed to differentiate different types of diffusion behaviour, as well as the behaviour of the absolute drift. We correlate the dynamical regimes seen for the system at different parameter values with the transport properties observed at these regimes, and in the behaviour of the transients. This system also shows the existence of a crisis and unstable dimension variability at certain parameter values. The signature of the unstable dimension variability is seen in the statistical characterisers of transport. We discuss the implications of our results for realistic systems.

  16. Detector dependency of diffusive quantum monitorings

    E-Print Network [OSTI]

    Shakib Daryanoosh; Howard M. Wiseman; Jay M. Gambetta

    2015-05-01

    Continuous measurements play a pivotal role in the study of dynamical open quantum systems. `Dyne' detections are among the most widespread and efficient measurement schemes, and give rise to quantum diffusion of the conditioned state. In this work we study under what conditions the detector dependency of the conditional state of a quantum system subject to diffusive monitoring can be demonstrated experimentally, in the sense of ruling our any detector-independent pure-state dynamical model for the system. We consider an arbitrary number L of environments to which the system is coupled, and an arbitrary number K of different types of dyne detections. We prove that non-trivial necessary conditions for such a demonstration can be determined efficiently by semi-definite programming. To determine sufficient conditions, different physical environmental couplings and Hamiltonians for a qubit, and different sets of diffusive monitorings are scrutinized. We compare the threshold efficiencies that are sufficient in the various cases, as well as cases previously considered in the literature, to suggest the most feasible experimental options.

  17. A Convergent Reaction-Diffusion Master Equation

    E-Print Network [OSTI]

    Samuel A Isaacson

    2013-06-28

    The reaction-diffusion master equation (RDME) is a lattice stochastic reaction-diffusion model that has been used to study spatially distributed cellular processes. The RDME is often interpreted as an approximation to spatially-continuous models in which molecules move by Brownian motion and react by one of several mechanisms when sufficiently close. In the limit that the lattice spacing approaches zero, in two or more dimensions, the RDME has been shown to lose bimolecular reactions. The RDME is therefore not a convergent approximation to any spatially-continuous model that incorporates bimolecular reactions. In this work we derive a new convergent RDME (CRDME) by finite volume discretization of a spatially-continuous stochastic reaction-diffusion model popularized by Doi. We demonstrate the numerical convergence of reaction time statistics associated with the CRDME. For sufficiently large lattice spacings or slow bimolecular reaction rates, we also show the reaction time statistics of the CRDME may be approximated by those from the RDME. The original RDME may therefore be interpreted as an approximation to the CRDME in several asymptotic limits.

  18. Diffusion Processes Satisfying a Conservation Law Constraint

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

    Bakosi, J.; Ristorcelli, J. R.

    2014-03-04

    We investigate coupled stochastic differential equations governing N non-negative continuous random variables that satisfy a conservation principle. In various fields a conservation law requires that a set of fluctuating variables be non-negative and (if appropriately normalized) sum to one. As a result, any stochastic differential equation model to be realizable must not produce events outside of the allowed sample space. We develop a set of constraints on the drift and diffusion terms of such stochastic models to ensure that both the non-negativity and the unit-sum conservation law constraint are satisfied as the variables evolve in time. We investigate the consequencesmore »of the developed constraints on the Fokker-Planck equation, the associated system of stochastic differential equations, and the evolution equations of the first four moments of the probability density function. We show that random variables, satisfying a conservation law constraint, represented by stochastic diffusion processes, must have diffusion terms that are coupled and nonlinear. The set of constraints developed enables the development of statistical representations of fluctuating variables satisfying a conservation law. We exemplify the results with the bivariate beta process and the multivariate Wright-Fisher, Dirichlet, and Lochner’s generalized Dirichlet processes.« less

  19. Diffuse ?-ray emission from galactic pulsars

    SciTech Connect (OSTI)

    Calore, F. [GRAPPA Institute, University of Amsterdam, Science Park 904, 1090 GL Amsterdam (Netherlands); Di Mauro, M.; Donato, F., E-mail: f.calore@uva.nl, E-mail: mattia.dimauro@to.infn.it, E-mail: donato@to.infn.it [Dipartimento di Fisica, Torino University and INFN, Sezione di Torino, Via P. Giuria 1, I-10125 Torino (Italy)

    2014-11-20

    Millisecond pulsars (MSPs) are old fast-spinning neutron stars that represent the second most abundant source population discovered by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope (Fermi). As guaranteed ?-ray emitters, they might contribute non-negligibly to the diffuse emission measured at high latitudes by Fermi-LAT (i.e., the Isotropic Diffuse ?-Ray Background (IDGRB)), which is believed to arise from the superposition of several components of galactic and extragalactic origin. Additionally, ?-ray sources also contribute to the anisotropy of the IDGRB measured on small scales by Fermi-LAT. In this manuscript we aim to assess the contribution of the unresolved counterpart of the detected MSPs population to the IDGRB and the maximal fraction of the measured anisotropy produced by this source class. To this end, we model the MSPs' spatial distribution in the Galaxy and the ?-ray emission parameters by considering observational constraints coming from the Australia Telescope National Facility pulsar catalog and the Second Fermi-LAT Catalog of ?-ray pulsars. By simulating a large number of MSP populations through a Monte Carlo simulation, we compute the average diffuse emission and the anisotropy 1? upper limit. We find that the emission from unresolved MSPs at 2 GeV, where the peak of the spectrum is located, is at most 0.9% of the measured IDGRB above 10° in latitude. The 1? upper limit on the angular power for unresolved MSP sources turns out to be about a factor of 60 smaller than Fermi-LAT measurements above 30°. Our results indicate that this galactic source class represents a negligible contributor to the high-latitude ?-ray sky and confirm that most of the intensity and geometrical properties of the measured diffuse emission are imputable to other extragalactic source classes (e.g., blazars, misaligned active galactic nuclei, or star-forming galaxies). Nevertheless, because MSPs are more concentrated toward the galactic center, we expect them to contribute significantly to the ?-ray diffuse emission at low latitudes. Because, along the galactic disk, the population of young pulsars overcomes in number that of MSPs, we compute the ?-ray emission from the whole population of unresolved pulsars, both young and millisecond, in two low-latitude regions: the inner Galaxy and the galactic center.

  20. Systematic variations in argon diffusion in feldspars: Constraints on diffusion lengthscales, diffusive anisotropy, and non-linear Arrhenius arrays and implications for noble gas thermochronometry

    E-Print Network [OSTI]

    Cassata, William

    2012-01-01

    pluton from 40 Ar/ 39 Ar geochronology and thermal modeling.for 40 Ar/ 39 Ar geochronology of naturally deformed rocks.1995. Multipath diffusion in geochronology. Contributions to

  1. Unsteady behavior of locally strained diffusion flames affected by curvature and preferential diffusion

    SciTech Connect (OSTI)

    Yoshida, Kenji; Takagi, Toshimi

    1999-07-01

    Experimental and numerical studies are made of transient H{sub 2}/N{sub 2}--air counterflow diffusion flames unsteadily strained by an impinging micro jet. Two-dimensional temperature measurements by laser Rayleigh scattering method and numerical computations taking into account detailed chemical kinetics are conducted paying attention to transient local extinction and reignition in relation to the unsteadiness, flame curvature and preferential diffusion effects. The results are as follows. (1) Transient local flame extinction is observed where the micro jet impinges. But, the transient flame can survive instantaneously in spite of quite high stretch rate where the steady flame cannot exist. (2) Reignition is observed after the local extinction due to the micro air jet impingement. The temperature after reignition becomes significantly higher than that of the original flame. This high temperature is induced by the concentration of H{sub 2} species due to the preferential diffusion in relation to the concave curvature. The predicted behaviors of the local transient extinction and reignition are well confirmed by the experiments. (3) The reignition is induced after the formation of combustible premixed gas mixture and the consequent flame propagation. (4) The reignition is hardly observed after the extinction by micro fuel jet impingement. This is due to the dilution of H{sub 2} species induced by the preferential diffusion in relation to the convex curvature. (5) The maximum flame temperature cannot be rationalized by the stretch rate but changes widely depending on the unsteadiness and the flame curvature in relation with preferential diffusion.

  2. Packet personal radiation monitor

    DOE Patents [OSTI]

    Phelps, J.E.

    1988-03-31

    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.

  3. Remote radiation dosimetry

    DOE Patents [OSTI]

    Braunlich, Peter F. (Pullman, WA); Tetzlaff, Wolfgang (Pullman, WA); Hegland, Joel E. (Pullman, WA); Jones, Scott C. (Pullman, WA)

    1991-01-01

    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 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.

  4. Remote radiation dosimetry

    DOE Patents [OSTI]

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

    1991-03-12

    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.

  5. 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.

    1996-06-01

    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).

  6. Motivation Methods Model configuration Results Forecasting Summary & Outlook Retrieving direct and diffuse radiation with the

    E-Print Network [OSTI]

    Heinemann, Detlev

    Motivation Methods Model configuration Results Forecasting Summary & Outlook 1/ 14 Retrieving. 17, 2015 #12;Motivation Methods Model configuration Results Forecasting Summary & Outlook 2/ 14 Motivation Sky Imager based shortest-term solar irradiance forecasts for local solar energy applications

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

    E-Print Network [OSTI]

    Wei, Chao-Chen

    2014-12-12

    Metallic nuclear fuels, as potential candidates in advanced reactors development, have been extensively studied for over five decades. The main challenges are the fuel performance designed for higher burn-up and higher temperatures. Fuel...

  8. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shines light on77 PAGEMission MissionModeling distributed generation in theheat

  9. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effect Photovoltaics - Energy InnovationOscillation

  10. A 2D Radiation Transport Package with Mimetic Diffusion for ExaFlag

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield MunicipalTechnicalInformation4563 LLNL Small-scaleCoherent Light Source (Journal Article)

  11. A 2D Radiation Transport Package with Mimetic Diffusion for ExaFlag

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield MunicipalTechnicalInformation4563 LLNL Small-scaleCoherent Light Source (Journal

  12. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformationJessework uses concrete andGoniometer-based Femtosecond Macromolecular2 -

  13. Composition for radiation shielding

    DOE Patents [OSTI]

    Kronberg, J.W.

    1994-08-02

    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.

  14. Pediatric radiation oncology

    SciTech Connect (OSTI)

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

    1989-01-01

    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.

  15. Semiconductor radiation detector

    DOE Patents [OSTI]

    Bell, Zane W. (Oak Ridge, TN); Burger, Arnold (Knoxville, TN)

    2010-03-30

    A semiconductor detector for ionizing electromagnetic radiation, neutrons, and energetic charged particles. The detecting element is comprised of a compound having the composition I-III-VI.sub.2 or II-IV-V.sub.2 where the "I" component is from column 1A or 1B of the periodic table, the "II" component is from column 2B, the "III" component is from column 3A, the "IV" component is from column 4A, the "V" component is from column 5A, and the "VI" component is from column 6A. The detecting element detects ionizing radiation by generating a signal proportional to the energy deposited in the element, and detects neutrons by virtue of the ionizing radiation emitted by one or more of the constituent materials subsequent to capture. The detector may contain more than one neutron-sensitive component.

  16. Oxygen diffusion of anodic surface oxide film on titanium studied by Auger electron spectroscopy. [Oxygen diffusivity

    SciTech Connect (OSTI)

    Wang, P.S.; Wittberg, T.N.; Keil, R.G.

    1982-01-01

    TiO/sub 2/ films of about 1000 A were grown onto titanium foils anodically under galvanostatic conditions at 20 mA/cm/sup 2/ in saturated aqueous solutions of ammonium tetraborate. The samples were then aged at 450, 500, and 550/sup 0/C, and oxygen diffusion was observed by Auger electron spectroscopy (AES) profilings. The oxygen diffusivities were calculated by Fick's Second Law, using the Boltzmann-Matano solution, to be 9.4 x 10/sup -17/, 2.6 x 10/sup -16/, and 1.2 x 10/sup -15/ cm/sup 2//sec at 450, 500, and 550/sup 0/C, respectively. The diffusivities obtained by this method were also compared with those obtained using an exact solution to Fick's Second Law. The activation energy was calculated to be 30 kcal/mole.

  17. Radiative Magnetic Reconnection in Astrophysics

    E-Print Network [OSTI]

    Uzdensky, Dmitri A

    2015-01-01

    I review a new rapidly growing area of high-energy plasma astrophysics --- radiative magnetic reconnection, i.e., a reconnection regime where radiation reaction influences reconnection dynamics, energetics, and nonthermal particle acceleration. This influence be may be manifested via a number of astrophysically important radiative effects, such as radiation-reaction limits on particle acceleration, radiative cooling, radiative resistivity, braking of reconnection outflows by radiation drag, radiation pressure, viscosity, and even pair creation at highest energy densities. Self-consistent inclusion of these effects in magnetic reconnection theory and modeling calls for serious modifications to our overall theoretical approach to the problem. In addition, prompt reconnection-powered radiation often represents our only observational diagnostic tool for studying remote astrophysical systems; this underscores the importance of developing predictive modeling capabilities to connect the underlying physical condition...

  18. Stairs, G. R. BIOLOGY AND MEDICINE; AGE; DIFFRACTION; DIFFUSION...

    Office of Scientific and Technical Information (OSTI)

    levels of radiation, but were sporadic in appearance. It is suggested that many of the radiation damaged acorns abscised from the tree and thus escaped detection. (auth) Yale...

  19. ATHENA radiation model

    SciTech Connect (OSTI)

    Shumway, R.W.

    1987-10-01

    The ATHENA computer program has many features that make it desirable to use as a space reactor evaluation tool. One of the missing features was a surface-to-surface thermal radiation model. A model was developed that allows any of the regular ATHENA heat slabs to radiate to any other heat slab. The view factors and surface emissivities must be specified by the user. To verify that the model was properly accounting for radiant energy transfer, two different types of test calculations were performed. Both calculations have excellent results. The updates have been used on both the INEL CDC-176 and the Livermore Cray. 7 refs., 2 figs., 6 tabs.

  20. Wireless passive radiation sensor

    DOE Patents [OSTI]

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

    2013-12-03

    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.

  1. Radiation monitor for liquids

    DOE Patents [OSTI]

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

    1999-03-02

    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.

  2. Radiation monitor for liquids

    DOE Patents [OSTI]

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

    1999-01-01

    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.

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

    E-Print Network [OSTI]

    Alan P. Boss

    2008-12-12

    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.

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

    SciTech Connect (OSTI)

    Sridharan, Kumar; Allen, Todd; Cole, James

    2013-02-27

    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.

  5. Diffuse Irradiance Study Planned for October

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalent BondingMeetingDifferences Between Tropical and Trade-Wind3 Diffuse

  6. Band Formation during Gaseous Diffusion in Aerogels

    E-Print Network [OSTI]

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

    1997-06-18

    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.

  7. ARM - Field Campaign - Diffuse Shortwave IOP

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve4AJ01) (See22,MicrophysicalgovCampaignsComplexgovCampaignsDiffuse

  8. Radiation detector spectrum simulator

    DOE Patents [OSTI]

    Wolf, Michael A. (Los Alamos, NM); Crowell, John M. (Los Alamos, NM)

    1987-01-01

    A small battery operated nuclear spectrum simulator having a noise source nerates pulses with a Gaussian distribution of amplitudes. A switched dc bias circuit cooperating therewith generates 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. Radiation detector spectrum simulator

    DOE Patents [OSTI]

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

    1985-04-09

    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.

  10. Radiation Source Replacement Workshop

    SciTech Connect (OSTI)

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

    2010-12-01

    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.

  11. Thermal radiation Ron Zevenhoven

    E-Print Network [OSTI]

    Zevenhoven, Ron

    .00032, similarly for 2·T = 0.7·2500 = 1750 µmK4 this gives f0-2 = 0.03392. Thus for 0.4 - 0.7 µm, f1-2 = 0Thermal radiation revisited Ron Zevenhoven Åbo Akademi University Thermal and Flow Engineering Laboratory / Värme- och strömningsteknik tel. 3223 ; ron.zevenhoven@abo.fi Process Engineering

  12. Three Dimensional Radiative Transfer

    E-Print Network [OSTI]

    Tom Abel

    2000-05-09

    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.

  13. Thermostatic Radiator Valve Evaluation

    SciTech Connect (OSTI)

    Dentz, Jordan; Ansanelli, Eric

    2015-01-01

    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.

  14. Local microwave background radiation

    E-Print Network [OSTI]

    Domingos Soares

    2014-11-13

    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.

  15. Radiation Chemistry Radiation causes changes in molecules by both

    E-Print Network [OSTI]

    Massey, Thomas N.

    Module 4 Radiation Chemistry · Radiation causes changes in molecules by both direct and indirect radiation on the target molecules · Indirect Action - energy transported by chemical species to cause damage or Pyrimidene. · Loss of Purine or Pyrimidine · Free radical transfer causing the loss of base and chain

  16. Radiation Safety Manual March 21, 2015 RADIATION SAFETY

    E-Print Network [OSTI]

    Lance, Veronica P.

    . Radioactive Drug Research Committee D. Radiation Safety Officers E. Authorized Users Chapter II: Radiation. Clinical Applications C. Loans and Transfers of Radioactive Materials Chapter VI: Occupational Exposure of Packages Containing Radioactive Materials A. Packages Delivered to the Radiation Safety Office B. Packages

  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. 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.

  19. 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

    2013-08-27

    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.

  20. RADIATION DAMAGE OF GERMANIUM DETECTORS

    E-Print Network [OSTI]

    Pehl, Richard H.

    2011-01-01

    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

  1. TIME DOMAIN SIMULATIONS OF RADIATION

    E-Print Network [OSTI]

    ;Introduction Fan Noise Forward Radiation Fan Noise Aft Radiation Jet Noise (separate LES Code)Traditional CFD a 16-processor machine yourself : 8 dual-processor workstations 800 MHz Pentium III processors 1 GB RAM

  2. Reaction and diffusion in turbulent combustion

    SciTech Connect (OSTI)

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

    1993-12-01

    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. Commercial Building Partnerships Replication and Diffusion

    SciTech Connect (OSTI)

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

    2013-09-16

    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.

  4. Generalized Transformation Design: metrics, speeds, and diffusion

    E-Print Network [OSTI]

    Kinsler, Paul

    2015-01-01

    We show that a unified and maximally generalized approach to spatial transformation design is possible, one that encompasses all second order waves, rays, or diffusion processes in anisotropic media. At the design step it is \\emph{not} necessary to specify the physical process for which a specific device will be -- or is intended to be -- built. The primary approximation required is that the effect of wave impedance is neglected, an attribute that plays no role in ray propagation, and therefore is not relevant for pure ray devices; another constraint is that spatial variation in material parameters may need to be sufficiently small. Device construction relies on how we can re-imagine the abstract mathematical notion of a metric on a manifold as a speed-squared matrix (or a diffusion matrix), a step which also specifies the means by which transformation devices will actually be built. Notably, we can conclude that a generalised ray theory that allows for anisotropic indexes (speeds) generates the same predicti...

  5. Distributed Wind Diffusion Model Overview (Presentation)

    SciTech Connect (OSTI)

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

    2014-07-01

    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.

  6. Diffusion of n-type dopants in germanium

    SciTech Connect (OSTI)

    Chroneos, A.; Bracht, H.

    2014-03-15

    Germanium is being actively considered by the semiconductor community as a mainstream material for nanoelectronic applications. Germanium has advantageous materials properties; however, its dopant-defect interactions are less understood as compared to the mainstream material, silicon. The understanding of self- and dopant diffusion is essential to form well defined doped regions. Although p-type dopants such as boron exhibit limited diffusion, n-type dopants such as phosphorous, arsenic, and antimony diffuse quickly via vacancy-mediated diffusion mechanisms. In the present review, we mainly focus on the impact of intrinsic defects on the diffusion mechanisms of donor atoms and point defect engineering strategies to restrain donor atom diffusion and to enhance their electrical activation.

  7. Narrow groove welding gas diffuser assembly and welding torch

    DOE Patents [OSTI]

    Rooney, Stephen J. (East Berne, NY)

    2001-01-01

    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.

  8. 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.

  9. Gamma radiation field intensity meter

    DOE Patents [OSTI]

    Thacker, L.H.

    1995-10-17

    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.

  10. Gamma radiation field intensity meter

    DOE Patents [OSTI]

    Thacker, L.H.

    1994-08-16

    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.

  11. Gamma radiation field intensity meter

    DOE Patents [OSTI]

    Thacker, Louis H. (Knoxville, TN)

    1995-01-01

    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.

  12. Gamma radiation field intensity meter

    DOE Patents [OSTI]

    Thacker, Louis H. (Knoxville, TN)

    1994-01-01

    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.

  13. COLUMBIA UNIVERSITY Radiation Safety Program

    E-Print Network [OSTI]

    Jia, Songtao

    and will be maintained in a separate file from personnel radiation dosimeter records. All workers are specifically

  14. Protein motors induced enhanced diffusion in intracellular transport

    E-Print Network [OSTI]

    I. Santamaria-Holek; M. H. Vainstein; J. M. Rubi; F. A. Oliveira

    2009-02-04

    Diffusion of transported particles in the intracellular medium is described by means of a generalized diffusion equation containing forces due to the cytoskeleton network and to the protein motors. We find that the enhanced diffusion observed in experiments depends on the nature of the force exerted by the protein motors and on parameters characterizing the intracellular medium which is described in terms of a generalized Debye spectrum for the noise density of states.

  15. Control of light diffusion in a disordered photonic waveguide

    SciTech Connect (OSTI)

    Sarma, Raktim; Cao, Hui; Golubev, Timofey; Yamilov, Alexey

    2014-07-28

    We control the diffusion of light in a disordered photonic waveguide by modulating the waveguide geometry. In a single waveguide of varying cross-section, the diffusion coefficient changes spatially in two dimensions due to localization effects. The intensity distribution inside the waveguide agrees with the prediction of the self-consistent theory of localization. Our work shows that wave diffusion can be efficiently manipulated without modifying the structural disorder.

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

    E-Print Network [OSTI]

    Rousseau, Cecil Clyde

    1962-01-01

    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...

  17. Working With Radiation For Research

    E-Print Network [OSTI]

    Jia, Songtao

    flight New York to LA 5 Moving from east coast to Denver for one year 50 Moving from frame house to brick with an ever-present background of radiation. Radiation & Life 1* *2 #12;3 · Radiation is energy traveling with sufficiently energy to remove electrons from the atoms or molecules of the substances it passes through. Can

  18. 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...

  19. EM Begins Demolishing K-31 Gaseous Diffusion Building | Department...

    Office of Environmental Management (EM)

    East Tennessee Technology Park (ETTP) began Wednesday, marking the removal of the fourth of five gaseous diffusion buildings at the former uranium enrichment site. The...

  20. 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)

    2013-11-15

    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.

  1. Optical processing furnace with quartz muffle and diffuser plate

    DOE Patents [OSTI]

    Sopori, Bhushan L. (Denver, CO)

    1995-01-01

    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 door or wall of the muffle is also provided for controlling the source of optical energy. The quartz for the diffuser plate is surface etched (to give the quartz diffusive qualities) in the furnace during a high intensity burn-in process.

  2. Robust Equilibrated Residual Error Estimator for Diffusion Problems ...

    E-Print Network [OSTI]

    2011-11-11

    Nov 11, 2011 ... Let T = {K} be a finite element partition of the domain ? that is regular, ... dominant diffusion problem are done through a partition of the unity.

  3. COMBUSTION OF COAL IN AN OPPOSED FLOW DIFFUSION BURNER

    E-Print Network [OSTI]

    Chin, W.K.

    2010-01-01

    an Opposed Flow Diffusion Burner Environment Division Chinmodel furnaces, flat flame burners, flow reactors, shocktubes, single particle burners, and, no doubt, others have

  4. Seismic triggering by rectified diffusion in geothermal systems

    E-Print Network [OSTI]

    Sturtevant, Bradford; Kanamori, Hiroo; Brodsky, Emily E.

    1996-01-01

    diffusion in geothermal systems Bradford Sturtevant Graduateof pressure In geothermal systems, fluid flow throughsystems. The modeled geothermal system consists of fractured

  5. 18.366 Random Walks and Diffusion, Spring 2003

    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, ...

  6. 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, ...

  7. Influences of Exciton Diffusion and Exciton-Exciton Annihilation...

    Office of Scientific and Technical Information (OSTI)

    Influences of Exciton Diffusion and Exciton-Exciton Annihilation on Photon Emission Statistics of Carbon Nanotubes Citation Details In-Document Search This content will become...

  8. Fluorescence optical diffusion tomography using multiple-frequency data

    E-Print Network [OSTI]

    .6280, 290.7050, 100.3010, 100.3190, 100.6950, 170.3010, 290.3200. 1. INTRODUCTION Optical diffusion

  9. The Digital Road to Scientific Knowledge Diffusion; A Faster...

    Office of Scientific and Technical Information (OSTI)

    of knowledge. In particular, it is important to understand whether advances in Internet searching can speed up the diffusion of scientific knowledge and accelerate...

  10. Federal Facility Agreement for the Paducah Gaseous Diffusion...

    Office of Environmental Management (EM)

    Federal Facility Agreement for the Paducah Gaseous Diffusion Plant State Kentucky Agreement Type Federal Facility Agreement Legal Driver(s) CERCLARCRA Scope Summary Ensure that...

  11. 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)

    2013-07-15

    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.

  12. Uranium and Strontium Batch Sorption and Diffusion Kinetics into...

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

    Uranium and Strontium Batch Sorption and Diffusion Kinetics into Mesoporous Silica Friday, February 27, 2015 Figure 1 Figure 1. Transmission electron microscopy images of (A)...

  13. Lithium Ion Solvation and Diffusion in Bulk Organic Electrolytes...

    Office of Scientific and Technical Information (OSTI)

    Lithium Ion Solvation and Diffusion in Bulk Organic Electrolytes from First Principles and Classical Reactive Molecular Dynamics Citation Details In-Document Search Title: Lithium...

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

    SciTech Connect (OSTI)

    MEACHAM, J.E.

    2003-11-10

    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.

  15. Vapor Barriers or Vapor Diffusion Retarders | Department of Energy

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

    retarders. Materials such as rigid foam insulation, reinforced plastics, aluminum, and stainless steel are relatively resistant to water vapor diffusion. These types of vapor...

  16. Diffusion MRI Methods for Improved Treatment Monitoring in Breast Cancer

    E-Print Network [OSTI]

    Aliu, Sheye

    2009-01-01

    Breast Cancer Overview 2.1 Breast Anatomy . . . . .2.2 Breast Cancer Demographics . . . . . . . . 2.3 Breastii References Diffusion Tensor Imaging in Breast Cancer 5.1

  17. rev December 2010 Radiation Safety Manual Section 9 Radiation Protection Procedures

    E-Print Network [OSTI]

    Sniadecki, Nathan J.

    rev December 2010 Radiation Safety Manual Section 9 ­ Radiation Protection Procedures Page 9-1 Section 9 Radiation Protection Procedures Contents Section 9 9-1 Radiation Protection Procedures Protective Measures - External Radiation.....................................9-5 1. Time

  18. Multilayer radiation shield

    DOE Patents [OSTI]

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

    2009-06-16

    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.

  19. Handheld CZT radiation detector

    DOE Patents [OSTI]

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

    2004-08-24

    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.

  20. 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)

    2002-01-01

    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.

  1. General Relativistic Radiative Transfer

    E-Print Network [OSTI]

    S. Knop; P. H. Hauschildt; E. Baron

    2006-11-30

    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.

  2. Radiation shielding composition

    DOE Patents [OSTI]

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

    2000-12-26

    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.

  3. Radiation shielding composition

    DOE Patents [OSTI]

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

    1998-01-01

    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. Time encoded radiation imaging

    DOE Patents [OSTI]

    Marleau, Peter; Brubaker, Erik; Kiff, Scott

    2014-10-21

    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.

  5. Radiation shielding composition

    DOE Patents [OSTI]

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

    1998-07-28

    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.

  6. Terahertz radiation mixer

    DOE Patents [OSTI]

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

    2008-05-20

    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.

  7. Current Committee Membership Radiation Protection, Committee on

    E-Print Network [OSTI]

    Polz, Martin

    Current Committee Membership Radiation Protection, Committee on The Committee on Radiation Protection is responsible for the establishment and continuing review of an adequate radiation protection's compliance with radiation protection regulations promulgated by state, federal, and local agencies

  8. Radiation tolerance of nanocrystalline ceramics: Insights from yttria stabilized zirconia

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

    Dey, Sanchita; Drazin, John W.; Wang, Yongqiang; Valdez, James A.; Holesinger, Terry G.; Uberuaga, Blas P.; Castro, Ricardo H. R.

    2015-01-13

    Materials for applications in hostile environments, such as nuclear reactors or radioactive waste immobilization, require extremely high resistance to radiation damage, such as resistance to amorphization or volume swelling. Nanocrystalline materials have been reported to present exceptionally high radiation-tolerance to amorphization. In principle, grain boundaries that are prevalent in nanomaterials could act as sinks for point-defects, enhancing defect recombination. In this paper we present evidence for this mechanism in nanograined Yttria Stabilized Zirconia (YSZ), associated with the observation that the concentration of defects after irradiation using heavy ions (Kr?, 400 keV) is inversely proportional to the grain size. HAADF imagesmore »suggest the short migration distances in nanograined YSZ allow radiation induced interstitials to reach the grain boundaries on the irradiation time scale, leaving behind only vacancy clusters distributed within the grain. Because of the relatively low temperature of the irradiations and the fact that interstitials diffuse thermally more slowly than vacancies, this result indicates that the interstitials must reach the boundaries directly in the collision cascade, consistent with previous simulation results. Concomitant radiation-induced grain growth was observed which, as a consequence of the non-uniform implantation, caused cracking of the nano-samples induced by local stresses at the irradiated/non-irradiated interfaces.« less

  9. Photon Clusters in Thermal Radiation

    E-Print Network [OSTI]

    Aleksey Ilyin

    2014-10-30

    Within the framework of Bose-Einstein statistics, it is shown that the blackbody radiation, in addition to single photons, contains photon clusters, or coalescent photons. The probability to find a k-photon cluster versus radiation frequency and temperature is found, as well as the statistics of clusters. Spectra of photon-cluster radiation are calculated as functions of blackbody temperature. The Planck's radiation law is derived based on the existence of photon clusters. The possibility of experimental observation of photon clusters in thermal radiation is discussed.

  10. Continuum Study of Heavy Quark Diffusion

    E-Print Network [OSTI]

    Thomas Neuhaus

    2015-04-28

    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 $N_\\tau \\le 22$.

  11. Role of Luddism on Innovation Diffusion

    E-Print Network [OSTI]

    Mellor, Andrew; Redner, Sidney; Rucklidge, Alastair M; Ward, Jonathan A

    2015-01-01

    We generalize the classical Bass model of innovation diffusion to include a new class of agents --- Luddites --- that oppose the spread of innovation. Our model also incorporates ignorants, susceptibles, and adopters. When an ignorant and a susceptible meet, the former is converted to a susceptible at a given rate, while a susceptible spontaneously adopts the innovation at a constant rate. In response to the \\emph{rate} of adoption, an ignorant may become a Luddite and permanently reject the innovation. Instead of reaching complete adoption, the final state generally consists of a population of Luddites, ignorants, and adopters. The evolution of this system is investigated analytically and by stochastic simulations. We determine the stationary distribution of adopters, the time needed to reach the final state, and the influence of the network topology on the innovation spread. Our model exhibits an important dichotomy: when the rate of adoption is low, an innovation spreads slowly but widely; in contrast, whe...

  12. Universal energy diffusion in a quivering billiard

    E-Print Network [OSTI]

    Jeffery Demers; Christopher Jarzynski

    2015-09-15

    We introduce and study a model of time-dependent billiard systems with billiard boundaries undergoing infinitesimal wiggling motions. The so-called quivering billiard is simple to simulate, straightforward to analyze, and is a faithful representation of time-dependent billiards in the limit of small boundary displacements. We assert that when a billiard's wall motion approaches the quivering motion, deterministic particle dynamics become inherently stochastic. Particle ensembles in a quivering billiard are shown to evolve to a universal energy distribution through an energy diffusion process, regardless of the billiard's shape or dimensionality, and as a consequence universally display Fermi acceleration. Our model resolves a known discrepancy between the one-dimensional Fermi-Ulam model and the simplified static wall approximation. We argue that the quivering limit is the true fixed wall limit of the Fermi-Ulam model.

  13. Method for microbeam radiation therapy

    DOE Patents [OSTI]

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

    1994-08-16

    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

  14. Method for microbeam radiation therapy

    DOE Patents [OSTI]

    Slatkin, Daniel N. (Sound Beach, NY); Dilmanian, F. Avraham (Yaphank, NY); Spanne, Per O. (Shoreham, NY)

    1994-01-01

    A method 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, 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.

  15. Influence of Extraterrestrial Radiation on Radiation Portal Monitors

    SciTech Connect (OSTI)

    Keller, Paul E.; Kouzes, Richard T.

    2009-06-01

    Cosmic radiation and solar flares can be a major source of background radiation at the Earth’s surface. This paper examines the relationship between extraterrestrial radiation and the detectable background in radiation portal monitors used for homeland security applications. Background radiation data from 13 radiation portal monitor facilities are examined and compared against external sources of data related to extraterrestrial radiation, including measurements at neutron monitors located at 53 cosmic-ray observatories around the Earth, four polar orbiting satellites, three geostationary satellites, ground-based geomagnetic field data from observatories around the Earth, a solar magnetic index, solar radio flux data, and sunspot activity data. Four-years (January 2003 through December 2006) of data are used in this study, which include the latter part of Solar Cycle 23 as solar activity was on the decline. The analysis shows a significant relationship between some extraterrestrial radiation and the background detected in the radiation portal monitors. A demonstrable decline is shown in the average gamma ray and neutron background at the radiation portal monitors as solar activity declined over the period of the study.

  16. 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)

    2013-04-20

    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.

  17. Radiation chemistry in the reprocessing and recycling of spent nuclear fuels

    SciTech Connect (OSTI)

    Bruce J. Mincher

    2015-04-01

    The interaction of ionizing radiation with solvent extraction solutions results in the ionization, excitation, and decay to neutral radicals of mainly diluent molecules. These produced reactive species diffuse into the bulk solution to react with solvent extraction ligands. Ligand reactions often result in deleterious effects such as loss in ligand concentration or the production of decomposition products that may also be complexing agents. This often interferes with desired separations. The common radiolysis reactions and their potential effects on solvent extraction are reviewed here.

  18. DIFFUSING ACOUSTIC WAVE SPECTROSCOPY: FIELD FLUCTUATION SPECTROSCOPY WITH MULTIPLY

    E-Print Network [OSTI]

    Page, John

    DIFFUSING ACOUSTIC WAVE SPECTROSCOPY: FIELD FLUCTUATION SPECTROSCOPY WITH MULTIPLY SCATTERED Martyrs, B.P. 166, 38042 Grenoble Cedex 9, France Abstract. Diffusing Acoustic Wave Spectroscopy (DAWS that acoustic waves, and ultrasonic waves in particular, are playing in understanding the rich diversity of wave

  19. Use of Neural Networks with Advection-Diffusion-Reaction Models

    E-Print Network [OSTI]

    Hawai'i at Manoa, University of

    Use of Neural Networks with Advection-Diffusion-Reaction Models to Estimate Large-Scale Movements-350 #12;Adam, M. S., and J. R. Sibert, Use of Neural Networks with Advection-Diffusion-Reaction Models Motivation 2 2 The model 2 3 Parameterizing movement fields 4 3.1 User of neural networks 5 3.2 Scaling

  20. Transverse Diffusion of Laminar Flow Profiles To Produce Capillary Nanoreactors

    E-Print Network [OSTI]

    Krylov, Sergey

    Transverse Diffusion of Laminar Flow Profiles To Produce Capillary Nanoreactors Victor Okhonin, Xin We introduce transverse diffusion of laminar flow profiles (TDLFP), the first generic method the capillary by pressure as a series of consecutive plugs. Due to the laminar nature of flow inside

  1. Optical processing furnace with quartz muffle and diffuser plate

    DOE Patents [OSTI]

    Sopori, Bhushan L. (Denver, CO)

    1996-01-01

    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.

  2. 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

  3. 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

  4. Diffusion-Induced Ramsey Narrowing Yanhong Xiao,1

    E-Print Network [OSTI]

    Walsworth, Ronald L.

    Diffusion-Induced Ramsey Narrowing Yanhong Xiao,1 Irina Novikova,1 David F. Phillips,1 and Ronald L February 2006) Diffusion-induced Ramsey narrowing is characterized and identified as a general phenomenon of interaction (inside the laser beam), in analogy to Ramsey spectroscopy [4]. In many cases of interest

  5. Hybrid simulations of lateral diffusion in fluctuating membranes

    E-Print Network [OSTI]

    Ellen Reister-Gottfried; Stefan M. Leitenberger; Udo Seifert

    2006-11-21

    In this paper we introduce a novel method to simulate lateral diffusion of inclusions in a fluctuating membrane. The regarded systems are governed by two dynamic processes: the height fluctuations of the membrane and the diffusion of the inclusion along the membrane. While membrane fluctuations can be expressed in terms of a dynamic equation which follows from the Helfrich Hamiltonian, the dynamics of the diffusing particle is described by a Langevin or Smoluchowski equation. In the latter equations, the curvature of the surface needs to be accounted for, which makes particle diffusion a function of membrane fluctuations. In our scheme these coupled dynamic equations, the membrane equation and the Langevin equation for the particle, are numerically integrated to simulate diffusion in a membrane. The simulations are used to study the ratio of the diffusion coefficient projected on a flat plane and the intramembrane diffusion coefficient for the case of free diffusion. We compare our results with recent analytical results that employ a preaveraging approximation and analyze the validity of this approximation. A detailed simulation study of the relevant correlation functions reveals a surprisingly large range where the approximation is applicable.

  6. A Simulation of Moisture Diffusion Process in Furniture-Grade

    E-Print Network [OSTI]

    made for solid wood along the three principal directions Partial vapor pressure ­ the most proper for the moisture diffusion process through MDF using partial vapor pressure as the driving force, and (c/cm/mmHg/Hr) P = partial vapor pressure (mmHg) X = dimension coordinate (cm) Diffusion Cell RH1, P1 RH2, P2 Salt

  7. Research Article A Social Diffusion Model with an Application on

    E-Print Network [OSTI]

    Chen, Sheng-Wei

    may not intuitively interpret such scenario. This work is to design a diffusion model which is capable of managing the aforementioned scenario. To demonstrate the usefulness of our model, we simulate the diffusion Huge success of viral marketing nowadays clearly shows that acquaintances indeed greatly influence

  8. 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

  9. 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

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

    SciTech Connect (OSTI)

    Vasil’ev, I. V. Ivanov, A. S.; Churin, V. A.

    2014-12-15

    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.

  11. Sorption and Diffusion of Organic Vapors in Two Fluoroelastomers

    E-Print Network [OSTI]

    Wang, Ping

    ; fluoroelastomers; self-diffusion coefficient; in- teraction parameters; barrier properties INTRODUCTION FluorelSorption and Diffusion of Organic Vapors in Two Fluoroelastomers PING WANG,* NATHANIEL S. SCHNEIDER and Aflas are two fluoroelastomers designed to provide superior solvent resistance and, in the case

  12. Hydrodynamics and Fluctuations Outside of Local Equilibrium: Driven Diffusive Systems

    E-Print Network [OSTI]

    ago by Price between the covariance matrix of electrical current noise and the bulk diffusion matrix¨unchen, Germany 1 #12; Abstract We derive hydrodynamic equations for systems not in local thermodynamic systems(DDS), such as electrical conductors in an applied field with diffusion of charge carriers

  13. Kinetic Modeling of Counterflow Diffusion Flames of Butadiene

    E-Print Network [OSTI]

    Senkan, Selim M.

    Kinetic Modeling of Counterflow Diffusion Flames of Butadiene SILVIA GRANATA, TIZIANO FARAVELLI structures of counterflow diffusion and fuel-rich premixed 1,3-butadiene flames, to better understand the need for improved models and also the opportunity of new experiments of butadiene oxidation

  14. Inter-Industry Diffusion of Technology That Results

    E-Print Network [OSTI]

    April 2003 Inter-Industry Diffusion of Technology That Results From ATP Projects ADVANCED TECHNOLOGY PROGRAMADVANCED TECHNOLOGY PROGRAM NIST GCR 03-848 National Institute of Standards and Technology Funding Joel Popkin #12;NIST GCR 03-848 Inter-Industry Diffusion of Technology That Results From ATP

  15. Effect of superbanana diffusion on fusion reactivity in stellarators

    SciTech Connect (OSTI)

    Hinton, Fred L. [Center for Astrophysics and Space Sciences, University of California, San Diego, La Jolla, California 92093-0424 (United States)

    2012-08-15

    Fusion reactivity is usually obtained using a Maxwellian distribution. However, energy-dependent radial diffusion can modify the energy distribution. Superbanana diffusion is energy-dependent and occurs in nonaxisymmetric magnetic confinement devices, such as stellarators, because of ripple-trapped particles which can take large steps between collisions. In this paper, the D-T fusion reactivity is calculated using a non-Maxwellian energy distribution obtained by solving the Fokker-Planck equation numerically, including radial superbanana diffusion as well as energy scattering. The ions in the tail of the distribution, with energies larger than thermal, which are most needed for fusion, are depleted by superbanana diffusion. In this paper, it is shown that the D-T fusion reactivity is reduced by tail ion depletion due to superbanana diffusion, by roughly a factor of 0.5 for the parameters used in the calculation.

  16. SRS history and experience with palladium diffusers. Revision 1

    SciTech Connect (OSTI)

    Clark, E.A.; Dauchess, D.A.; Heung, L.K.; Rabun, R.L.; Motyka, T.

    1995-08-11

    The Savannah River Site (SRS) has processed tritium in support of national defense programs since 1955. Palladium diffusers have been used extensively for separating hydrogen isotopes from inert gases (such as argon, helium, and nitrogen). In almost forty years of service, the design of the diffuser has been steadily improving. Several diffuser designs from different manufacturers have been evaluated at SRS. The operating experience gained from these designs together with failure analyses performed on failed units have led to several recommendations for improved diffuser designs and operating methods. This experience gained at SRS and the following recommendations form the basis of this report. Even though palladium diffuser technology has proven to be reliable, SRS has examined several alternative technologies over the past several years. This report will also review some of these promising alternatives.

  17. Grain boundary and triple junction diffusion in nanocrystalline copper

    SciTech Connect (OSTI)

    Wegner, M. Leuthold, J.; Peterlechner, M.; Divinski, S. V.; Song, X.; Wilde, G.

    2014-09-07

    Grain boundary and triple junction diffusion in nanocrystalline Cu samples with grain sizes, ?d?, of ?35 and ?44?nm produced by spark plasma sintering were investigated by the radiotracer method using the {sup 63}Ni isotope. The measured diffusivities, D{sub eff}, are comparable with those determined previously for Ni grain boundary diffusion in well-annealed, high purity, coarse grained, polycrystalline copper, substantiating the absence of a grain size effect on the kinetic properties of grain boundaries in a nanocrystalline material at grain sizes d???35?nm. Simultaneously, the analysis predicts that if triple junction diffusion of Ni in Cu is enhanced with respect to the corresponding grain boundary diffusion rate, it is still less than 500?D{sub gb} within the temperature interval from 420?K to 470?K.

  18. Analysis of Contribution from Edge Radiation to Optical Diffraction Radiation

    SciTech Connect (OSTI)

    C. Liu, P. Evtushenko, A. Freyberger, C. Liu, A.H. Lumpkin

    2009-05-01

    Beam size measurement with near-field optical diffraction radiation (ODR) has been carried out successfully at CEBAF. The ODR station is installed on the Hall-A beam line after eight bending magnets. The ODR images were affected by an unexpected radiation. Some calculations for analyzing the source of the radiation will be presented. Furthermore, two schemes will be proposed to alleviate the contamination.

  19. Solar radiation intensity calculations 

    E-Print Network [OSTI]

    Levine, Randolph Steven

    1978-01-01

    , 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...

  20. Radiation imaging apparatus

    DOE Patents [OSTI]

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

    1983-07-26

    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.

  1. Radiation imaging apparatus

    DOE Patents [OSTI]

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

    1983-01-01

    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.

  2. RADIATION LABORATO DISCLAIMER

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMassR&D100 Winners * Impacts on Global Technology OUTSIDE FRONT7a.R : . . . RADIATION

  3. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMassR&D100 Winners * Impacts on GlobalRachel RuggirelloRadiative Influences onmeeting,

  4. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservation of Fe(II) by Carbon-RichProton Delivery andInnovationsRSSProtectionRadiation

  5. 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.

  6. Thermal radiation, radiation force and dynamics of a polarizable particle

    E-Print Network [OSTI]

    G. V. Dedkov; A. A. Kyasov

    2015-08-26

    We discuss basic expressions and interrelations between various physical quantities describing the fluctuation-electromagnetic interaction of a small polarizable particle during relativistic motion relative to the blackbody radiation, namely tangential radiation force, rate of heating, intensity of thermal radiation/absorption, the change of the rest mass of a particle, and acceleration. We obtain an explicit formula for the frictional force acting on the particle in its rest frame and discuss its connection with the particle acceleration and the tangential force given in the reference frame of background radiation. The criticism of our previous results in recent paper by A. I. Volokitin (Phys. Rev. A81, 2015, 032505) is refuted.

  7. The 21 cm Signature of Shock Heated and Diffuse Cosmic String Wakes

    E-Print Network [OSTI]

    Oscar F. Hernandez; Robert H. Brandenberger

    2012-07-31

    The analysis of the 21 cm signature of cosmic string wakes is extended in several ways. First we consider the constraints on $G\\mu$ from the absorption signal of shock heated wakes laid down much later than matter radiation equality. Secondly we analyze the signal of diffuse wake, that is those wakes in which there is a baryon overdensity but which have not shock heated. Finally we compare the size of these signals compared to the expected thermal noise per pixel which dominates over the background cosmic gas brightness temperature and find that the cosmic string signal will exceed the thermal noise of an individual pixel in the Square Kilometre Array for string tensions $G\\mu > 2.5 \\times 10^{-8}$.

  8. Diffusive Shock Acceleration of Electrons and Radio Emission from Large Diameter Shell-Type Supernova Remnants

    E-Print Network [OSTI]

    A. I. Asvarov

    2000-01-21

    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.

  9. The 21 cm signature of shock heated and diffuse cosmic string wakes

    SciTech Connect (OSTI)

    Hernández, Oscar F.; Brandenberger, Robert H. E-mail: rhb@physics.mcgill.ca

    2012-07-01

    The analysis of the 21 cm signature of cosmic string wakes is extended in several ways. First we consider the constraints on G? from the absorption signal of shock heated wakes laid down much later than matter radiation equality. Secondly we analyze the signal of diffuse wake, that is those wakes in which there is a baryon overdensity but which have not shock heated. Finally we compare the size of these signals to the expected thermal noise per pixel which dominates over the background cosmic gas brightness temperature and find that the cosmic string signal will exceed the thermal noise of an individual pixel in the Square Kilometre Array for string tensions G? > 2.5 × 10{sup ?8}.

  10. 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)

    2014-10-14

    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?.??Ge?.??: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?.??Ge?.??:C than for Si:C. In Si?.??Ge?.??: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.

  11. DOE 2010 occupational radiation exposure

    SciTech Connect (OSTI)

    none,

    2011-11-01

    The U.S. Department of Energy (DOE) Office of Analysis within the Office of Health, Safety and Security (HSS) publishes the annual DOE Occupational Radiation Exposure Report to provide an overview of the status of radiation protection practices at DOE.* The DOE 2010 Occupational Radiation Exposure Report provides an evaluation of DOE-wide performance regarding compliance with DOE Part 835 dose limits and as low as reasonably achievable (ALARA) process requirements. In addition, the report provides data to DOE organizations responsible for developing policies for protection of individuals from the effects of radiation. The report provides a summary and an analysis of occupational radiation exposure information from the monitoring of individuals involved in DOE activities. The occupational radiation exposure information is analyzed in terms of aggregate data, dose to individuals, and dose by site over the past 5 years.

  12. Diffuse X-ray Emission in a Deep Chandra Image of the Galactic Center

    E-Print Network [OSTI]

    M. P. Muno; F. K. Baganoff; M. W. Bautz; E. D. Feigelson; G. P. Garmire; M. R. Morris; S. Park; G. R. Ricker; L. K. Townsley

    2004-06-01

    We examine the spectrum of diffuse emission detected in the 17' by 17' field around Sgr A* during 625 ks of Chandra observations. The spectrum exhibits He-like and H-like lines from Si, S, Ar, Ca, and Fe, that are consistent with originating in a two-temperature plasma, as well as a prominent low-ionization Fe line. The cooler, kT=0.8 keV plasma differs in surface brightness across the image by a factor of 9. This soft plasma is probably heated by supernovae. The radiative cooling rate of the plasma within the inner 20 pc of the Galaxy could be balanced by 1% of the kinetic energy of one supernova every 300,000 y. The hotter, kT=8 keV component is more spatially uniform, ranging over a factor of 2 in surface brightness. The intensity of the hard plasma is correlated with that of the soft, but they are probably only indirectly related, because supernova remnants are not observed to produce thermal plasma hotter than kT=3 keV. Moreover, a kT=8 keV plasma is too hot to be bound to the Galactic center, and therefore would form a slow wind or fountain of plasma. The energy required to sustain such a freely-expanding plasma within the inner 20 pc of the Galaxy is ~10^40 erg/s, which corresponds to the entire kinetic energy of one supernova every 3000 y. This rate is unreasonably high. However, alternative explanations for the kT=8 keV diffuse emission are equally unsatisfying. We are left to conclude that either the diffuse emission is heated by an unanticipated source of energy, or that a population of faint (< 10^31 erg/s), hard X-ray sources that are a factor of 10 more numerous than CVs remains to be discovered. (Abridged)

  13. 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)

    2013-05-10

    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.

  14. The evolution of planetary nebulae. V. The diffuse X-ray emission

    E-Print Network [OSTI]

    M. Steffen; D. Schoenberner; A. Warmuth

    2008-09-05

    Observations with space-borne X-ray telescopes revealed the existence of soft, diffuse X-ray emission from the inner regions of planetary nebulae. Although the existing images support the idea that this emission arises from the hot shocked central-star wind which fills the inner cavity of a planetary nebula, existing models have difficulties to explain the observations consistently. We investigate how the inclusion of thermal conduction changes the physical parameters of the hot shocked wind gas and the amount of X-ray emission predicted by time-dependent hydrodynamical models of planetary nebulae with central stars of normal, hydrogen-rich surface composition. The radiation hydrodynamical models show that heat conduction leads to lower temperatures and higher densities within a bubble and brings the physical properties of the X-ray emitting domain into close agreement with the values derived from observations. Depending on the central-star mass and the evolutionary phase, our models predict X-ray [0.45--2.5 keV] luminosities between $10^{-8}$ and $10^{-4}$ of the stellar bolometric luminosities, in good agreement with the observations. Less than 1% of the wind power is radiated away in this X-ray band. Although temperature, density, and also the mass of the hot bubble is significantly altered by heat conduction, the dynamics of the whole system remains practically the same. Heat conduction allows the construction of nebular models which predict the correct amount of X-ray emission and at the same time are fully consistent with the observed mass-loss rate and wind speed. Thermal conduction must be considered as a viable physical process for explaining the diffuse X-ray emission from planetary nebulae with closed inner cavities. Magnetic fields must then be absent or extremely weak.

  15. Frequency-Dependent Photothermal Measurement of Transverse Thermal Diffusivity of Organic Semiconductors

    E-Print Network [OSTI]

    J. W. Brill; Maryam Shahi; Marcia M. Payne; Jesper Edberg; Y. Yao; Xavier Crispin; J. E. Anthony

    2015-09-08

    We have used a photothermal technique, in which chopped light heats the front surface of a small ( ~ 1 mm2) sample and the chopping frequency dependence of thermal radiation from the back surface is measured with a liquid nitrogen cooled infrared detector. In our system, the sample is placed directly in front of the detector within its dewar. Because the detector is also sensitive to some of the incident light which leaks around or through the sample, measurements are made for the detector signal that is in quadrature with the chopped light. Results are presented for layered crystals of semiconducting 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-pn) and for papers of cellulose nanofibrils coated with semiconducting poly(3,4-ethylene-dioxythiophene):poly(styrene-sulfonate) (NFC-PEDOT). For NFC-PEDOT, we have found that the transverse diffusivity, smaller than the in-plane value, varies inversely with thickness, suggesting that texturing of the papers varies with thickness. For TIPS-pn, we have found that the interlayer diffusivity is an order of magnitude larger than the in-plane value, consistent with previous estimates, suggesting that low-frequency optical phonons, presumably associated with librations in the TIPS side-groups, carry most of the heat.

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

    E-Print Network [OSTI]

    Tamborra, Irene

    2015-01-01

    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. Frequency-Dependent Photothermal Measurement of Transverse Thermal Diffusivity of Organic Semiconductors

    E-Print Network [OSTI]

    J. W. Brill; Maryam Shahi; Marcia M. Payne; Jesper Edberg; Y. Yao; Xavier Crispin; J. E. Anthony

    2015-08-13

    We have used a photothermal technique, in which chopped light heats the front surface of a small ( ~ 1 mm2) sample and the chopping frequency dependence of thermal radiation from the back surface is measured with a liquid nitrogen cooled infrared detector. In our system, the sample is placed directly in front of the detector within its dewar. Because the detector is also sensitive to some of the incident light which leaks around or through the sample, measurements are made for the detector signal that is in quadrature with the chopped light. Results are presented for layered crystals of semiconducting 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-pn) and for papers of cellulose nanofibrils coated with semiconducting poly(3,4-ethylene-dioxythiophene):poly(styrene-sulfonate) (NFC-PEDOT). For NFC-PEDOT, we have found that the transverse diffusivity, smaller than the in-plane value, varies inversely with thickness, suggesting that texturing of the papers varies with thickness. For TIPS-pn, we have found that the interlayer diffusivity is an order of magnitude larger than the in-plane value, consistent with previous estimates, suggesting that low-frequency optical phonons, presumably associated with librations in the TIPS side-groups, carry most of the heat.

  18. Angular Signatures of Dark Matter in the Diffuse Gamma Ray Spectrum

    SciTech Connect (OSTI)

    Hooper, Dan; Serpico, Pasquale D.; /Fermilab

    2007-02-01

    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.

  19. Radiation Embrittlement Archive Project

    SciTech Connect (OSTI)

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

    2013-01-01

    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.

  20. The GALEX Ultraviolet Virgo Cluster Survey (GUViCS). V. Ultraviolet diffuse emission and cirrus properties in the Virgo cluster direction

    E-Print Network [OSTI]

    Boissier, S; Voyer, E; Bianchi, S; Pappalardo, C; Guhathakurta, P; Heinis, S; Cortese, L; Duc, P -A; Cuillandre, J -C; Davies, J I; Smith, M W L

    2015-01-01

    CONTEXT: The Virgo direction has been observed at many wavelengths in the recent years, in particular in the ultraviolet with GALEX. The far ultraviolet (FUV) diffuse light detected by GALEX bears interesting information on the large scale distribution of Galactic dust, owing to the GALEX FUV band sensitivity and resolution. AIMS: We aim to characterise the ultraviolet large scale distribution of diffuse emission in the Virgo direction. A map of this emission may become useful for various studies by identifying regions where dust affects observations by either scattering light or absorbing radiation. METHODS: We construct mosaics of the FUV and near ultraviolet diffuse emission over a large sky region (RA 12 to 13 hours, DEC 0 to 20 degrees) surrounding the Virgo cluster, using all the GALEX available data in the area. We test for the first time the utilisation of the FUV diffuse light as a Galactic extinction E(B-V) tracer. RESULTS: The FUV diffuse light scattered on cirrus reveals details in their geometry....

  1. 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.

    2010-05-01

    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.

  2. RSSC RADIATION DETECTORS & SURVEY INSTRUMENTS 8/99 4-1 RADIATION DETECTORS AND SURVEY INSTRUMENTS

    E-Print Network [OSTI]

    Slatton, Clint

    RSSC RADIATION DETECTORS & SURVEY INSTRUMENTS 8/99 4-1 CHAPTER 4 RADIATION DETECTORS AND SURVEY........................................................................................................... 4-3 II. Use of Radiation Survey Instruments

  3. APRIORI BOUNDS FOR REACTION-DIFFUSION SYSTEMS ARISING IN CHEMICAL JEFF S. MCGOUGH AND KYLE RILEY

    E-Print Network [OSTI]

    McGough, Jeff S.

    APRIORI BOUNDS FOR REACTION-DIFFUSION SYSTEMS ARISING IN CHEMICAL KINETICS JEFF S. MCGOUGH AND KYLE RILEY Abstract. The authors investigate reaction diffusion equations which arise in chemical kinetics diffusion equations, gradient bounds, chemical kinetics, autocatalytic reactions AMS subject classifications

  4. 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 ...

  5. Electromagnetic radiation by gravitating bodies

    E-Print Network [OSTI]

    Iwo Bialynicki-Birula; Zofia Bialynicka-Birula

    2008-05-06

    Gravitating bodies in motion, regardless of their constitution, always produce electromagnetic radiation in the form of photon pairs. This phenomenon is an analog of the radiation caused by the motion of dielectric (or magnetic) bodies. It is a member of a wide class of phenomena named dynamical Casimir effects, and it may be viewed as the squeezing of the electromagnetic vacuum. Production of photon pairs is a purely quantum-mechanical effect. Unfortunately, as we show, the emitted radiation is extremely weak as compared to radiation produced by other mechanisms.

  6. 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...

  7. Radiation Shielding and Radiological Protection

    E-Print Network [OSTI]

    Shultis, J. Kenneth

    Radiation Shielding and Radiological Protection J. Kenneth Shultis Richard E. Faw Department Shielding and Radiological Protection .. Example Calculations for Distributed Sources

  8. Scintillator Waveguide For Sensing Radiation

    DOE Patents [OSTI]

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

    2003-04-22

    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.

  9. Irreversible reactions and diffusive escape: Stationary properties

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

    Krapivsky, Paul L.; Ben-Naim, Eli

    2015-05-01

    We study three basic diffusion-controlled reaction processes—annihilation, coalescence, and aggregation. We examine the evolution starting with the most natural inhomogeneous initial configuration where a half-line is uniformly filled by particles, while the complementary half-line is empty. We show that the total number of particles that infiltrate the initially empty half-line is finite and has a stationary distribution. We determine the evolution of the average density from which we derive the average total number N of particles in the initially empty half-line; e.g. for annihilation $\\langle N\\rangle = \\frac{3}{16}+\\frac{1}{4\\?}$ . For the coalescence process, we devise a procedure that in principlemore »allows one to compute P(N), the probability to find exactly N particles in the initially empty half-line; we complete the calculations in the first non-trivial case (N = 1). As a by-product we derive the distance distribution between the two leading particles.« less

  10. Thick diffusion limit boundary layer test problems

    SciTech Connect (OSTI)

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

    2013-07-01

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

  11. Chaotic Diffusion of Resonant Kuiper Belt Objects

    E-Print Network [OSTI]

    Matthew S. Tiscareno; Renu Malhotra

    2009-07-06

    We carried out extensive numerical orbit integrations to probe the long-term chaotic dynamics of the two strongest mean motion resonances of Neptune in the Kuiper belt, the 3:2 (Plutinos) and 2:1 (Twotinos). Our primary results include a computation of the relative volumes of phase space characterized by large- and small-resonance libration amplitudes, and maps of resonance stability measured by mean chaotic diffusion rate. We find that Neptune's 2:1 resonance has weaker overall long-term stability than the 3:2 -- only ~15% of Twotinos are projected to survive for 4 Gyr, compared to ~27% of Plutinos, based on an extrapolation from our 1-Gyr integrations. We find that Pluto has only a modest effect, causing a ~4% decrease in the Plutino population that survives to 4 Gyr. Given current observational estimates, and assuming an initial distribution of particles proportional to the local phase space volume in the resonance, we conclude that the primordial populations of Plutinos and Twotinos formerly made up more than half the population of the classical and resonant Kuiper Belt. We also conclude that Twotinos were originally nearly as numerous as Plutinos; this is consistent with predictions from early models of smooth giant planet migration and resonance sweeping of the Kuiper Belt, and provides a useful constraint for more detailed models.

  12. Puzzling Phenomenon of Diffuse Interstellar Bands

    E-Print Network [OSTI]

    B. Wszolek

    2007-12-10

    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. Linear diffusion into a Faraday cage.

    SciTech Connect (OSTI)

    Warne, Larry Kevin; Lin, Yau Tang; Merewether, Kimball O.; Chen, Kenneth C.

    2011-11-01

    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.

  14. Irreversible Reactions and Diffusive Escape: Stationary Properties

    E-Print Network [OSTI]

    P. L. Krapivsky; E. Ben-Naim

    2015-03-24

    We study three basic diffusion-controlled reaction processes -- annihilation, coalescence, and aggregation. We examine the evolution starting with the most natural inhomogeneous initial configuration where a half-line is uniformly filled by particles, while the complementary half-line is empty. We show that the total number of particles that infiltrate the initially empty half-line is finite and has a stationary distribution. We determine the evolution of the average density from which we derive the average total number N of particles in the initially empty half-line; e.g., for annihilation \\langle N\\rangle = 3/16+1/(4\\pi). For the coalescence process, we devise a procedure that in principle allows one to compute P(N), the probability to find exactly N particles in the initially empty half-line; we complete the calculations in the first non-trivial case (N=1). As a by-product we derive the distance distribution between the two leading particles.

  15. Diffusivity bounds for 1D Brownian polymers

    E-Print Network [OSTI]

    Pierre Tarrès; Bálint Tóth; Benedek Valkó

    2012-06-08

    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.

  16. 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)

    2013-12-14

    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.

  17. Multi-source quantitative PAT in diffusive regime Guillaume Bal

    E-Print Network [OSTI]

    Ren, Kui

    that the first step of PAT, namely the reconstruction of a map of absorbed radiation from ultrasound boundary- tively reconstructing the optical coefficients from knowledge of the absorbed radiation map. We present consists of reconstructing the absorbed radiation map H(x) from the pressure measurements. For reference

  18. Diffusion on (110) Surface of Molecular Crystal Pentaerythritol Tetranitrate

    SciTech Connect (OSTI)

    Wang, J; Golfinopoulos, T; Gee, R H; Huang, H

    2007-01-25

    Using classical molecular dynamics simulations, we investigate the diffusion mechanisms of admolecules on the (110) surface of molecular crystal pentaerythritol tetranitrate. Our results show that (1) admolecules are stable at off lattice sites, (2) admolecules diffuse along close-packed [1{bar 1}1] and [{bar 1}11] directions, and (3) admolecules detach from the surface at 350K and above. Based on the number of diffusion jumps as a function of temperature, we estimate the jump frequency to be v=1.14 x 10{sup 12} e{sup -0.08eV/kT} per second.

  19. Non-Brownian molecular self-diffusion in bulk water

    E-Print Network [OSTI]

    Janez Stepišnik; Aleš Mohori?; Igor Serša

    2010-10-06

    The paper presents the velocity autocorrelation spectrum of bulk water measured by a new technique of NMR modulated gradient spin echo method. This technique is unprecedented for the spectrum measurement in the frequency interval between a few Hz to about 100 kHz with respect to directness and clarity of results and shows that a simple model of Brownian self-diffusion is not applicable to describe the diffusion dynamics of water molecules. The observed temperature dependant spectra of water show the existence of a slow chain-like dynamics in water, which we explain by coupling of diffusing molecule to broken bonds in the hydrogen bond network.

  20. Diffusive mesh relaxation in ALE finite element numerical simulations

    SciTech Connect (OSTI)

    Dube, E.I.

    1996-06-01

    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.

  1. Jump-Diffusion Risk-Sensitive Asset Management II: Jump-Diffusion Factor Model

    E-Print Network [OSTI]

    Davis, Mark

    2011-01-01

    In this article we extend earlier work on the jump-diffusion risk-sensitive asset management problem [SIAM J. Fin. Math. (2011) 22-54] by allowing jumps in both the factor process and the asset prices, as well as stochastic volatility and investment constraints. In this case, the HJB equation is a partial integro-differential equation (PIDE). By combining viscosity solutions with a change of notation, a policy improvement argument and classical results on parabolic PDEs we prove that the HJB PIDE admits a unique smooth solution. A verification theorem concludes the resolution of this problem.

  2. A LOCAL PROJECTION STABILIZATION FINITE ELEMENT METHOD WITH NONLINEAR CROSSWIND DIFFUSION FOR

    E-Print Network [OSTI]

    John, Volker

    A LOCAL PROJECTION STABILIZATION FINITE ELEMENT METHOD WITH NONLINEAR CROSSWIND DIFFUSION and phrases. finite element method; local projection stabilization; crosswind diffusion; convection

  3. Protein Diffusiophoresis and Salt Osmotic Diffusion in Aqueous Onofrio Annunziata,* Daniela Buzatu,

    E-Print Network [OSTI]

    Annunziata, Onofrio

    Protein Diffusiophoresis and Salt Osmotic Diffusion in Aqueous Solutions Onofrio Annunziata salt osmotic diffusion induced by a protein concentration gradient, and is related to protein

  4. X. CORRELATIONS BETWEEN DIFFUSE AND GLOBAL IRRADIANCE For numerous applications, particularly those

    E-Print Network [OSTI]

    Oregon, University of

    33 X. CORRELATIONS BETWEEN DIFFUSE AND GLOBAL IRRADIANCE For numerous applications, particularly these components, values for direct beam and diffuse irradiance are usu- ally unavailable. However, considerable in

  5. Thermostatic Radiator Valve Evaluation

    SciTech Connect (OSTI)

    Dentz, J.; Ansanelli, E.

    2015-01-01

    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. In this project, the ARIES team sought to better understand the current usage of TRVs by key market players in steam and hot water heating and to conduct limited experiments on the effectiveness of new and old TRVs as a means of controlling space temperatures and reducing heating fuel consumption. The project included a survey of industry professionals, a field experiment comparing old and new TRVs, and cost-benefit modeling analysis using BEopt™ (Building Energy Optimization software).

  6. St. Louis Sites Fact Sheet RADIATION BASICS

    E-Print Network [OSTI]

    US Army Corps of Engineers

    , radiation is described as either non-ionizing (low energy) or ionizing (high energy). Non-ionizing radiation or concrete. WHAT IS DOSE? HOW IS RADIATION MEASURED? The dose is the quantity of radiation or energy received dose and takes into account the type of radiation absorbed into the body and the likelihood of damage

  7. UNIVERSITY OF TORONTO RADIATION PROTECTION SERVICE

    E-Print Network [OSTI]

    Chan, Hue Sun

    UNIVERSITY OF TORONTO RADIATION PROTECTION SERVICE MEMORANDUM SUBJECT: SAFE USE OF RADIOGRAPHY, visitors, or experimental animals, plants, or cell lines, the Radiation Protection Service has a permit to the Radiation Protection Service. Sandu Sonoc Radiation Safety Officer 416-978-2028 Hector Rocca Radiation

  8. THE UNIVERSITY OF UTAH RADIATION PROTECTION PROGRAM

    E-Print Network [OSTI]

    THE UNIVERSITY OF UTAH RADIATION PROTECTION PROGRAM The use of radiation sources at the University. The Radiation Safety Policy Manual contains the policies and general procedures for radiation protection of Utah entails both legal and moral obligations to provide training on the nature of radiation sources

  9. RADIATION SAFETY MANUAL 2014 RICE UNIVERSITY 1

    E-Print Network [OSTI]

    Natelson, Douglas

    microscopes. Notify the RSO of any new radiation sources. Notify the RSO if any radiation sources with radioactive materials must attend formal radiation safety training provided by EHS. #12;RADIATION SAFETY with information concerning risk. 4. Provide suggestions for reducing exposure. 5. Monitor your radiation dose wit

  10. Radiation Hydrodynamics Test Problems with Linear Velocity Profiles

    SciTech Connect (OSTI)

    Hendon, Raymond C. [Los Alamos National Laboratory; Ramsey, Scott D. [Los Alamos National Laboratory

    2012-08-22

    As an extension of the works of Coggeshall and Ramsey, a class of analytic solutions to the radiation hydrodynamics equations is derived for code verification purposes. These solutions are valid under assumptions including diffusive radiation transport, a polytropic gas equation of state, constant conductivity, separable flow velocity proportional to the curvilinear radial coordinate, and divergence-free heat flux. In accordance with these assumptions, the derived solution class is mathematically invariant with respect to the presence of radiative heat conduction, and thus represents a solution to the compressible flow (Euler) equations with or without conduction terms included. With this solution class, a quantitative code verification study (using spatial convergence rates) is performed for the cell-centered, finite volume, Eulerian compressible flow code xRAGE developed at Los Alamos National Laboratory. Simulation results show near second order spatial convergence in all physical variables when using the hydrodynamics solver only, consistent with that solver's underlying order of accuracy. However, contrary to the mathematical properties of the solution class, when heat conduction algorithms are enabled the calculation does not converge to the analytic solution.

  11. 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

  12. RADIATION AND CLOUD MONITORING STATIONS

    E-Print Network [OSTI]

    Reeves, Geoffrey D.

    how they affect the energy balance between incoming solar radiation and heat re-radiated from Earth's surface back into space -- is crucial to improving the general circulation models used for climate students. #12;A MONTHLY PUBLICATION OF THE PUBLIC AFFAIRS OFFICE OF LOS ALAMOS NATIONAL LABORATORY LOS

  13. 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 can be obtained from the University of Oregon Solar Moni- toring Laboratory after obtaining permission

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

    E-Print Network [OSTI]

    Fabrikant, J.I.

    2010-01-01

    carcinogenic risk of low-dose, low-LET radiation is subjectcan be made for low-dose, low- LET radiation. Nevertheless,for radiation carcino­ Extrapolation to low doses. Radiation

  15. Position Sensitive Radiation Detector Integrated with an FPGA for Radiation Tolerant Computing

    E-Print Network [OSTI]

    LaMeres, Brock J.

    Position Sensitive Radiation Detector Integrated with an FPGA for Radiation Tolerant Computing radiation sensor was modeled, developed and fabricated then interfaced with a field programmable gate array (FPGA) to create a radiation hardened computing platform. The system exploits environmental information

  16. Effects of multi-component diffusion and heat release on laminar diffusion flame liftoff

    SciTech Connect (OSTI)

    Li, Zhiliang; Chen, Ruey-Hung [Department of Mechanical, Materials and Aerospace Engineering, University of Central Florida, Orlando, FL 32816-2450 (United States); Phuoc, Tran X. [National Energy Technology Laboratory, Department of Energy, P.O. Box 10940, MS 84-340, Pittsburgh, PA 15261 (United States)

    2010-08-15

    Numerical simulations were conducted of the liftoff and stabilization phenomena of laminar jet diffusion flames of inert-diluted C{sub 3}H{sub 8} and CH{sub 4} fuels. Both non-reacting and reacting jets were investigated, including multi-component diffusivities and heat release effects (buoyancy and gas expansion). The role of Schmidt number for non-reacting jets was investigated, with no conclusive Schmidt number criterion for liftoff previously arrived at in similarity solutions. The cold-flow simulation for He-diluted CH{sub 4} fuel does not predict flame liftoff; however, adding heat release reaction lead to the prediction of liftoff, which is consistent with experimental observations. Including reaction was also found to improve liftoff height prediction for C{sub 3}H{sub 8} flames, with the flame base location differing from that in the similarity solution - the intersection of the stoichiometric and iso-velocity (equal to 1-D flame speed) is not necessary for flame stabilization (and thus liftoff). Possible mechanisms other than that proposed for similarity solution may better help to explain the stabilization and liftoff phenomena. (author)

  17. A Measurement of the Spatial Distribution of Diffuse TeV Gamma Ray Emission from the Galactic Plane with Milagro

    E-Print Network [OSTI]

    A. A. Abdo; B. Allen; T. Aune; D. Berley; E. Blaufuss; S. Casanova; C. Chen; B. L. Dingus; R. W. Ellsworth; L. Fleysher; R. Fleysher; M. M. Gonzalez; J. A. Goodman; C. M. Hoffman; P. H. H"untemeyer; B. E. Kolterman; C. P. Lansdell; J. T. Linnemann; J. E. McEnery; A. I. Mincer; I. V. Moskalenko; P. Nemethy; D. Noyes; T. A. Porter; J. Pretz; J. M. Ryan; P. M. Saz Parkinson; A. Shoup; G. Sinnis; A. J. Smith; A. W. Strong; G. W. Sullivan; V. Vasileiou; G. P. Walker; D. A. Williams; G. B. Yodh

    2008-08-19

    Diffuse $\\gamma$-ray emission produced by the interaction of cosmic-ray particles with matter and radiation in the Galaxy can be used to probe the distribution of cosmic rays and their sources in different regions of the Galaxy. With its large field of view and long observation time, the Milagro Gamma Ray Observatory is an ideal instrument for surveying large regions of the Northern Hemisphere sky and for detecting diffuse $\\gamma$-ray emission at very high energies. Here, the spatial distribution and the flux of the diffuse $\\gamma$-ray emission in the TeV energy range with a median energy of 15 TeV for Galactic longitudes between 30$^\\circ$ and 110$^\\circ$ and between 136$^\\circ$ and 216$^\\circ$ and for Galactic latitudes between -10$^\\circ$ and 10$^\\circ$ are determined. The measured fluxes are consistent with predictions of the GALPROP model everywhere except for the Cygnus region ($l\\in[65^\\circ,85^\\circ]$). For the Cygnus region, the flux is twice the predicted value. This excess can be explained by the presence of active cosmic ray sources accelerating hadrons which interact with the local dense interstellar medium and produce gamma rays through pion decay.

  18. A Measurement of the Spatial Distribution of Diffuse TeV Gamma Ray Emission from the Galactic Plane with Milagro

    E-Print Network [OSTI]

    Abdo, A A; Aune, T; Berley, D; Blaufuss, E; Casanova, S; Chen, C; Dingus, B L; Ellsworth, R W; Fleysher, L; Fleysher, R; González, M M; Goodman, J A; Hoffman, C M; H"untemeyer, P H; Kolterman, B E; Lansdell, C P; Linnemann, J T; McEnery, J E; Mincer, A I; Nemethy, I V Moskalenko P; Noyes, D; Porter, T A; Pretz, J; Ryan, J M; Parkinson, P M Saz; Shoup, A; Sinnis, G; Smith, A J; Strong, A W; Sullivan, G W; Vasileiou, V; Walker, G P; Williams, D A; Yodh, G B

    2008-01-01

    Diffuse $\\gamma$-ray emission produced by the interaction of cosmic-ray particles with matter and radiation in the Galaxy can be used to probe the distribution of cosmic rays and their sources in different regions of the Galaxy. With its large field of view and long observation time, the Milagro Gamma Ray Observatory is an ideal instrument for surveying large regions of the Northern Hemisphere sky and for detecting diffuse $\\gamma$-ray emission at very high energies. Here, the spatial distribution and the flux of the diffuse $\\gamma$-ray emission in the TeV energy range with a median energy of 15 TeV for Galactic longitudes between 30$^\\circ$ and 110$^\\circ$ and between 136$^\\circ$ and 216$^\\circ$ and for Galactic latitudes between -10$^\\circ$ and 10$^\\circ$ are determined. The measured fluxes are consistent with predictions of the GALPROP model everywhere except for the Cygnus region ($l\\in[65^\\circ,85^\\circ]$). For the Cygnus region, the flux is twice the predicted value. This excess can be explained by the...

  19. A Simulation Study of Diffusion in Microporous Materials

    E-Print Network [OSTI]

    Abouelnasr, Mahmoud Kamal Forrest

    2013-01-01

    of new zeolite-like materials. Phys. Chem. Chem. Phys. 13,screening of carbon-capture materials. Nat. Mater. 11, 633–Diffusion in nanoporous materials. (Wiley- VCH, 2012). 48.

  20. Overcoming the Exciton Diffusion Bottleneck in Organic Photovoltaic...

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

    Overcoming the Exciton Diffusion Bottleneck in Organic Photovoltaic Cells May 20, 2009 at 3pm36-428 Russell J.Holmes Department of Chemical Engineering and Materials Science,...

  1. Thermodynamic properties and diffusion of water + methane binary mixtures

    SciTech Connect (OSTI)

    Shvab, I.; Sadus, Richard J.

    2014-03-14

    Thermodynamic and diffusion properties of water + methane mixtures in a single liquid phase are studied using NVT molecular dynamics. An extensive comparison is reported for the thermal pressure coefficient, compressibilities, expansion coefficients, heat capacities, Joule-Thomson coefficient, zero frequency speed of sound, and diffusion coefficient at methane concentrations up to 15% in the temperature range of 298–650 K. The simulations reveal a complex concentration dependence of the thermodynamic properties of water + methane mixtures. The compressibilities, heat capacities, and diffusion coefficients decrease with increasing methane concentration, whereas values of the thermal expansion coefficients and speed of sound increase. Increasing methane concentration considerably retards the self-diffusion of both water and methane in the mixture. These effects are caused by changes in hydrogen bond network, solvation shell structure, and dynamics of water molecules induced by the solvation of methane at constant volume conditions.

  2. Multiple scattering of classical waves: microscopy, mesoscopy, and diffusion 

    E-Print Network [OSTI]

    van Rossum, Mark; Nieuwenhuizen, Th.M

    1999-01-01

    A tutorial discussion of the propagation of waves in random media is presented. To a first approximation the transport of the multiple scattered waves is given by diffusion theory, but important corrections are presented. ...

  3. Demolition of K-31 gaseous diffusion building begins | Department...

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

    OREM began demolition of the 750,000 sq. ft. K-31 Building, marking the removal of the fourth of five gaseous diffusion buildings at the former uranium enrichment site. OREM began...

  4. Diffuse Atomic and Molecular Theodore P. Snow1

    E-Print Network [OSTI]

    McCall, Benjamin J.

    Diffuse Atomic and Molecular Clouds Theodore P. Snow1 and Benjamin J. McCall2 1 Center for Astrophysics and Space Astronomy, University of Colorado, Boulder, Colorado 80309; email: theodore.snow

  5. International diffusion practice : lessons from South Korea's New Village Movement

    E-Print Network [OSTI]

    Kim, Jung Hwa, M.C.P. Massachusetts Institute of Technology

    2013-01-01

    This research focuses on how South Korea's development model-namely, the Saemaul Undong, or the New Village Movement-is diffused internationally, in particular, to the developing country of Vietnam. South Korea's successful ...

  6. Transportation cost inequalities for diffusions under uniform distance

    E-Print Network [OSTI]

    Ali Suleyman Ustunel

    2010-11-04

    We prove the transportation inequality with the uniform norm for the laws of diffusion processes with Lipschitz and/or dissipative coefficients and apply them to some singular stochastic differential equations of interest.

  7. Measurement and Modeling of Solute Diffusion Coefficients in Unsaturated Soils

    E-Print Network [OSTI]

    Chou, Hsin-Yi

    2010-01-01

    Diffusion and flow in gravel, soil, and whole rock, AppliedEds. ) (2002), Methods of Soil Analysis Part 4 PhysicalUnsaturated Volcanic Ash Soils, Vadose Zone Journal, 8(4),

  8. Diffusion of tungsten clusters on tungsten (110) surface

    SciTech Connect (OSTI)

    Chen, Dong; Hu, Wangyu; Yang, Jianyu; Deng, Huiqiu; Sun, Lixian; Gao, Fei

    2009-04-01

    Using molecular dynamics simulation and modified analytic embedded-atom method, we have investigated the self-diffusion of clusters on a tungsten (110) surface. As compared to the linear-chain configuration, the close-packed islands for tungsten clusters containing more than nine adatoms have been predicted to be more stable with the relatively lower binding energies. The migration energies show an interesting and oscillating behavior with increasing cluster size. The tetramer, hexamer and octamer have obviously higher migration energies than the others. The different atomic configurations and diffusion mechanisms have been determined during the diffusion processes. It is clear that the dimer-shearing mechanism occurs inside the hexamer, while it occurs at the periphery of heptamer. The successive hopping mechanism of individual atom is of critical importance in the migration of the clusters containing five or fewer adatoms. In addition, the diffusion of a cluster with nine adatoms is achieved through the changes of the cluster shape.

  9. Fast Explicit Operator Splitting Method for Convection-Diffusion Equations

    E-Print Network [OSTI]

    Kurganov, Alexander

    to the one- and two-dimensional systems of convection-diffusion equations which model the polymer flooding) processes in fluid mechanics, astrophysics, me- teorology, multiphase flow in oil reservoirs, polymer flow

  10. Integration by Parts and Time Reversal for Diffusion Processes

    E-Print Network [OSTI]

    Millet, A.; Nualart, David; Sanz, M.

    1989-01-05

    In this paper we obtain necessary and sufficient conditions for the reversibility of the diffusion property, assuming the existence of a density at every time t. The proofs are based on techniques of the stochastic calculus ...

  11. PIECEWISELINEAR DIFFUSION PROCESSES Sid Browne and Ward Whitt

    E-Print Network [OSTI]

    Whitt, Ward

    PIECEWISE­LINEAR DIFFUSION PROCESSES by Sid Browne and Ward Whitt Graduate School of Business AT&T Bell Laboratories Columbia University Murray Hill, NJ 07974­0636 New York, NY 10027 May 17, 1994 #12

  12. Contribution of GRB Emission to the GeV Extragalactic Diffuse Gamma-Ray Flux

    E-Print Network [OSTI]

    S. Casanova; B. L. Dingus; Bing Zhang

    2006-11-03

    TeV gamma rays emitted by GRBs are converted into electron-positron pairs via interactions with the extragalactic infrared radiation fields. In turn the pairs produced, whose trajectories are randomized by magnetic fields, will inverse Compton scatter off the cosmic microwave background photons. The beamed TeV gamma ray flux from GRBs is thus transformed into a GeV isotropic gamma ray flux, which contributes to the total extragalactic gamma-ray background emission. Assuming a model for the extragalactic radiation fields, for the GRB redshift distribution and for the GRB luminosity function, we evaluate the contribution of the GRB prompt and scattered emissions to the measured extragalactic gamma-ray flux. To estimate this contribution we optimistically require that the energy flux at TeV energies is about 10 times stronger than the energy flux at MeV energies. The resulting gamma-ray diffuse background is only a small fraction of what is observed, allowing blazars and other sources to give the dominant contribution.

  13. Heat transfer including radiation and slag particles evolution in MHD channel-I

    SciTech Connect (OSTI)

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

    1980-01-01

    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.

  14. Radiation-Induced Segregation and Phase Stability in Candidate Alloys for the Advanced Burner Reactor

    SciTech Connect (OSTI)

    Gary S. Was; Brian D. Wirth

    2011-05-29

    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.

  15. CO diffusion into amorphous H2O ices

    E-Print Network [OSTI]

    Lauck, Trish; Shulenberger, Katherine; Rajappan, Mahesh; Oberg, Karin I; Cuppen, Herma M

    2015-01-01

    The mobility of atoms, molecules and radicals in icy grain mantles regulate ice restructuring, desorption, and chemistry in astrophysical environments. Interstellar ices are dominated by H2O, and diffusion on external and internal (pore) surfaces of H2O-rich ices is therefore a key process to constrain. This study aims to quantify the diffusion kinetics and barrier of the abundant ice constituent CO into H2O dominated ices at low temperatures (15-23 K), by measuring the mixing rate of initially layered H2O(:CO2)/CO ices. The mixed fraction of CO as a function of time is determined by monitoring the shape of the infrared CO stretching band. Mixing is observed at all investigated temperatures on minute time scales, and can be ascribed to CO diffusion in H2O ice pores. The diffusion coefficient and final mixed fraction depend on ice temperature, porosity, thickness and composition. The experiments are analyzed by applying Fick's diffusion equation under the assumption that mixing is due to CO diffusion into an i...

  16. Meeting Report--NASA Radiation Biomarker Workshop

    E-Print Network [OSTI]

    Straume, Tore

    2008-01-01

    analysis of low–dose radiation -associated changes incellular responses to low-dose radiation using genomic gene-cellular responses to low-dose radiation and to reduce the

  17. Radiation-induced lung injury

    SciTech Connect (OSTI)

    Rosiello, R.A.; Merrill, W.W. )

    1990-03-01

    The use of radiation therapy is limited by the occurrence of the potentially fatal clinical syndromes of radiation pneumonitis and fibrosis. Radiation pneumonitis usually becomes clinically apparent from 2 to 6 months after completion of radiation therapy. It is characterized by fever, cough, dyspnea, and alveolar infiltrates on chest roentgenogram and may be difficult to differentiate from infection or recurrent malignancy. The pathogenesis is uncertain, but appears to involve both direct lung tissue toxicity and an inflammatory response. The syndrome may resolve spontaneously or may progress to respiratory failure. Corticosteroids may be effective therapy if started early in the course of the disease. The time course for the development of radiation fibrosis is later than that for radiation pneumonitis. It is usually present by 1 year following irradiation, but may not become clinically apparent until 2 years after radiation therapy. It is characterized by the insidious onset of dyspnea on exertion. It most often is mild, but can progress to chronic respiratory failure. There is no known successful treatment for this condition. 51 references.

  18. Radiative Gaugino Masses

    E-Print Network [OSTI]

    Glennys R. Farrar; Antonio Masiero

    1995-01-12

    We investigate the possibility that gauginos are massless at tree level and that the U(1) R-invariance is broken spontaneously by Higgs vevs, like the chiral symmetry of quarks in the standard model, or else explicitly by dimension 2 or 3 SUSY-breaking terms in the low energy effective Lagrangian. Gluino and lightest neutralino masses then depend on only a few parameters. For a SUSY-breaking scale <~ 400 GeV, the gluino and lightest neutralino have masses typically in the range 1/10 ~ 2 1/2 GeV. On the other hand, for a SUSY-breaking scale several TeV or larger, radiative contributions can yield gluino and lightest neutralino masses of O(50-300) GeV and O(10-30) GeV, respectively. As long as the Higgs vev is the only source of R-invariance breaking, or if SUSY breaking only appears in dimension 2 terms in the effective Lagrangian, the gluino is generically the lightest SUSY particle, modifying the usual phenomenology in interesting ways.

  19. Radiation detection system

    DOE Patents [OSTI]

    Riedel, Richard A. (Knoxville, TN); Wintenberg, Alan L. (Knoxville, TN); Clonts, Lloyd G. (Knoxville, TN); Cooper, Ronald G. (Oak Ridge, TN)

    2012-02-14

    A preamplifier circuit for processing a signal provided by a radiation detector includes a transimpedance amplifier coupled to receive a current signal from a detector and generate a voltage signal at its output. A second amplification stage has an input coupled to an output of the transimpedance amplifier for providing an amplified voltage signal. Detector electronics include a preamplifier circuit having a first and second transimpedance amplifier coupled to receive a current signal from a first and second location on a detector, respectively, and generate a first and second voltage signal at respective outputs. A second amplification stage has an input coupled to an output of the transimpedance amplifiers for amplifying the first and said second voltage signals to provide first and second amplified voltage signals. A differential output stage is coupled to the second amplification stage for receiving the first and second amplified voltage signals and providing a pair of outputs from each of the first and second amplified voltage signals. Read out circuitry has an input coupled to receive both of the pair of outputs, the read out circuitry having structure for processing each of the pair of outputs, and providing a single digital output having a time-stamp therefrom.

  20. 10 CFR 835- Occupational Radiation Protection

    Broader source: Energy.gov [DOE]

    The rules in this part establish radiation protection standards, limits, and program requirements for protecting individuals from ionizing radiation resulting from the conduct of DOE activities.