Sample records for models assessing surface

  1. NOTES AND CORRESPONDENCE Surface Melting over Ice Shelves and Ice Sheets as Assessed from Modeled

    E-Print Network [OSTI]

    Meissner, Katrin Juliane

    NOTES AND CORRESPONDENCE Surface Melting over Ice Shelves and Ice Sheets as Assessed from Modeled of ice shelves and their progenitor ice sheets. To explore the magnitude of surface melt occurring over modern ice shelves and ice sheets in a climate scenario forced by anthropogenic emissions of carbon

  2. Surface Water Monitoring and Assessment (Ohio)

    Broader source: Energy.gov [DOE]

    This law establishes criteria for three levels of credible data for a surface water quality monitoring and assessment program and establishes the necessary training and experience for persons to...

  3. Integrated Assessment Modeling

    SciTech Connect (OSTI)

    Edmonds, James A.; Calvin, Katherine V.; Clarke, Leon E.; Janetos, Anthony C.; Kim, Son H.; Wise, Marshall A.; McJeon, Haewon C.

    2012-10-31T23:59:59.000Z

    This paper discusses the role of Integrated Assessment models (IAMs) in climate change research. IAMs are an interdisciplinary research platform, which constitutes a consistent scientific framework in which the large-scale interactions between human and natural Earth systems can be examined. In so doing, IAMs provide insights that would otherwise be unavailable from traditional single-discipline research. By providing a broader view of the issue, IAMs constitute an important tool for decision support. IAMs are also a home of human Earth system research and provide natural Earth system scientists information about the nature of human intervention in global biogeophysical and geochemical processes.

  4. Assessing Phosphorous Loss to Protect Surface Water

    E-Print Network [OSTI]

    Garcia, Raul

    2005-01-01T23:59:59.000Z

    . Minimizing phosphorus pollution of surface water from agricultural fields involves manage- ment practices that control both the source and transportation factors of soil. Influences that affect the source and the amount of phosphorus transported include... the type of phosphorus applied and the content in the soil itself. Transportation factors include rainfall, irrigation, erosion, and runoff. The overall aim of environmentally sound practices is to keep soil fertility levels of phos- phorus to a range...

  5. Utility of Social Modeling for Proliferation Assessment - Preliminary Assessment

    SciTech Connect (OSTI)

    Coles, Garill A.; Gastelum, Zoe N.; Brothers, Alan J.; Thompson, Sandra E.

    2009-06-01T23:59:59.000Z

    This Preliminary Assessment draft report will present the results of a literature search and preliminary assessment of the body of research, analysis methods, models and data deemed to be relevant to the Utility of Social Modeling for Proliferation Assessment research. This report will provide: 1) a description of the problem space and the kinds of information pertinent to the problem space, 2) a discussion of key relevant or representative literature, 3) a discussion of models and modeling approaches judged to be potentially useful to the research, and 4) the next steps of this research that will be pursued based on this preliminary assessment. This draft report represents a technical deliverable for the NA-22 Simulations, Algorithms, and Modeling (SAM) program. Specifically this draft report is the Task 1 deliverable for project PL09-UtilSocial-PD06, Utility of Social Modeling for Proliferation Assessment. This project investigates non-traditional use of social and cultural information to improve nuclear proliferation assessment, including nonproliferation assessment, proliferation resistance assessments, safeguards assessments and other related studies. These assessments often use and create technical information about the State’s posture towards proliferation, the vulnerability of a nuclear energy system to an undesired event, and the effectiveness of safeguards. This project will find and fuse social and technical information by explicitly considering the role of cultural, social and behavioral factors relevant to proliferation. The aim of this research is to describe and demonstrate if and how social science modeling has utility in proliferation assessment.

  6. TECHNICAL REPORT: MODEL SENSITIVITY TO SURFACE TOPOGRAPHY

    E-Print Network [OSTI]

    Forget, François

    TECHNICAL REPORT: MODEL SENSITIVITY TO SURFACE TOPOGRAPHY ESTEC Contract 11369/95/NL/JG S. R. Lewis and Consortium Topography . . . . . . . . . . . . . 7 3 Studies of Sensitivity to Surface Topography 9 3.1 Zonal with respect to the surface topography with particular emphasis on any differences which may be important

  7. An Impact Assessment Model for Distributed Adaptive Security Situation Assessment*

    E-Print Network [OSTI]

    California at Davis, University of

    1 An Impact Assessment Model for Distributed Adaptive Security Situation Assessment* Mark Heckman mechanism is not simply to stop attacks, but to protect a computing resource so that the resource can continue to perform its function. A computing resource, however, is only a component of a larger system

  8. Modeling pinnacle reefs and their associated surfaces

    SciTech Connect (OSTI)

    Hamilton, D.E.; Henize, S.

    1989-03-01T23:59:59.000Z

    Although computer mapping programs are becoming widely available, simple to use, and powerful, the blind application of these programs often produces poor results. By considering the environment of deposition, postdepositional events, and scale of map when computer mapping, a better result can be achieved. To demonstrate the importance of these issues, data from Antrim and Kalkaska Counties, Michigan, were used to model pinnacle reefs in the Northern trend of the Michigan basin. The data consisted of 640 wells containing tops, facies, and show information for six units: Niagaran Gray, Niagaran Brown, Salina A1 evaporite, Salina A1 carbonate, Salina A2 evaporite, and Salina A2 carbonate. Building grids and contour maps of the Niagaran Brown (pinnacle) surface, using standard algorithms, produced a surface that either projected below or above the interreef surface. By using a mix of standard algorithms, the pinnacles and interreef surface were acceptably modeled. The Salina evaporites and carbonates are usually modeled using an isochore gridding approach. However, using this approach did not produce surfaces that reflected the geologist's interpretation. Simple modifications of the isochore approach allowed more accurate representation of the geologic interpretation. The evaporite surface models were built assuming they paralleled a paleowater surface. The carbonate surface models were built assuming they draped the surface existing at the time of deposition. Large- and small-scale maps were built for these data. Facies and show information were also mapped. Combined maps of several variables were constructed and evaluated for potential pinnacle locations.

  9. Nonlinear Time Domain Modeling and Simulation of Surface and...

    Office of Environmental Management (EM)

    Nonlinear Time Domain Modeling and Simulation of Surface and Embedded NPPS Nonlinear Time Domain Modeling and Simulation of Surface and Embedded NPPS Nonlinear Time Domain Modeling...

  10. Minimal model for spoof acoustoelastic surface states

    SciTech Connect (OSTI)

    Christensen, J., E-mail: jochri@fotonik.dtu.dk; Willatzen, M. [Department of Photonics Engineering, Technical University of Denmark, DK-2800 Kgs. Lyngby (Denmark); Liang, Z. [College of Electronic Science and Technology, Shenzhen University, Shenzhen (China)

    2014-12-15T23:59:59.000Z

    Similar to textured perfect electric conductors for electromagnetic waves sustaining artificial or spoof surface plasmons we present an equivalent phenomena for the case of sound. Aided by a minimal model that is able to capture the complex wave interaction of elastic cavity modes and airborne sound radiation in perfect rigid panels, we construct designer acoustoelastic surface waves that are entirely controlled by the geometrical environment. Comparisons to results obtained by full-wave simulations confirm the feasibility of the model and we demonstrate illustrative examples such as resonant transmissions and waveguiding to show a few examples of many where spoof elastic surface waves are useful.

  11. Dynamic Modeling of Butterfly Subdivision Surfaces

    E-Print Network [OSTI]

    Qin, Hong

    on control vertices. This provides the user an intuitive and natural feeling that is produced while modeling manipulation of control points, whereas we provide interaction tools that directly manipulate the smooth limitDynamic Modeling of Butterfly Subdivision Surfaces Chhandomay Mandal, Hong Qin, Member, IEEE

  12. Computer Modelling of 3D Geological Surface

    E-Print Network [OSTI]

    Kodge, B G

    2011-01-01T23:59:59.000Z

    The geological surveying presently uses methods and tools for the computer modeling of 3D-structures of the geographical subsurface and geotechnical characterization as well as the application of geoinformation systems for management and analysis of spatial data, and their cartographic presentation. The objectives of this paper are to present a 3D geological surface model of Latur district in Maharashtra state of India. This study is undertaken through the several processes which are discussed in this paper to generate and visualize the automated 3D geological surface model of a projected area.

  13. Surface Vibrations in a Model Hcp Crystal

    E-Print Network [OSTI]

    Allen, Roland E.; Alldredg, GP; DEWITTE, FW.

    1972-01-01T23:59:59.000Z

    , and F. W. de Wette, Phys. Rev. B4, 1661 (1971). PHYSICA L RE VIE W 8 VOLUME 6, NUMBE R 2 15 JULY 1972 Surface Vibrations in a Model hcp Crystal R. E. Allen Department of Physics, Texas A @ M University, College Station, Texas 77843 and G. P.... Alldredge and F. %. de bette Department of Physics, University of Texas, Austin, Texas 78712 (Received 16 February 1972) The surface relaxation, vibrational modes, mean-square amplitudes of vibration, etc. , have been calculated for the (0001) surface...

  14. Assessment of Molecular Modeling & Simulation

    SciTech Connect (OSTI)

    None

    2002-01-03T23:59:59.000Z

    This report reviews the development and applications of molecular and materials modeling in Europe and Japan in comparison to those in the United States. Topics covered include computational quantum chemistry, molecular simulations by molecular dynamics and Monte Carlo methods, mesoscale modeling of material domains, molecular-structure/macroscale property correlations like QSARs and QSPRs, and related information technologies like informatics and special-purpose molecular-modeling computers. The panel's findings include the following: The United States leads this field in many scientific areas. However, Canada has particular strengths in DFT methods and homogeneous catalysis; Europe in heterogeneous catalysis, mesoscale, and materials modeling; and Japan in materials modeling and special-purpose computing. Major government-industry initiatives are underway in Europe and Japan, notably in multi-scale materials modeling and in development of chemistry-capable ab-initio molecular dynamics codes.

  15. ORISE: Dose modeling and assessments

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

    or state regulatory compliance requirements are being met during the decontamination and decommissioning of nuclear facilities. Dose modeling is an important step in the...

  16. Models and parameters for environmental radiological assessments

    SciTech Connect (OSTI)

    Miller, C W [ed.] [ed.

    1984-01-01T23:59:59.000Z

    This book presents a unified compilation of models and parameters appropriate for assessing the impact of radioactive discharges to the environment. Models examined include those developed for the prediction of atmospheric and hydrologic transport and deposition, for terrestrial and aquatic food-chain bioaccumulation, and for internal and external dosimetry. Chapters have been entered separately into the data base. (ACR)

  17. ORISE: Dose modeling and assessments

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

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

  18. Dyadic Green's functions and guided surface waves for a surface conductivity model of graphene

    E-Print Network [OSTI]

    Hanson, George

    Dyadic Green's functions and guided surface waves for a surface conductivity model of graphene current in the presence of a surface conductivity model of graphene. The graphene is represented and transmission is presented, and surface wave propagation along graphene is studied via the poles

  19. Assessing residential exposure to urban noise using environmental models: does the size of the local living

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Assessing residential exposure to urban noise using environmental models: does the size on the quantification of the exposure level in a surface defined as the subject's exposure area. For residential residential buildings. Twelve noise exposure indicators have been used to assess inhabitants' exposure

  20. THE EFFECT OF SURFACE TENSION IN MODELING INTERFACIAL FRACTURE

    E-Print Network [OSTI]

    THE EFFECT OF SURFACE TENSION IN MODELING INTERFACIAL FRACTURE By Tsvetanka Sendova and Jay R: 612-626-7370 URL: http://www.ima.umn.edu #12;The Effect of Surface Tension in Modeling Interfacial. The proposed model of bi-material crack ascribes curvature-dependent surface tension to both the fracture

  1. Diuse interface surface tension models in an expanding ow

    E-Print Network [OSTI]

    Soatto, Stefano

    Diuse interface surface tension models in an expanding ow Wangyi Liu, Andrea L. Bertozzi , and Theodore Kolokolnikov November 22, 2010 Abstract We consider a diusive interface surface tension model principle. 1 Background There is a need to develop simple computational models for surface tension

  2. Model assessment of protective barriers: Part 3

    SciTech Connect (OSTI)

    Fayer, M.J.; Rockhold, M.L.; Holford, D.J.

    1992-02-01T23:59:59.000Z

    Radioactive waste exists at the US Department of Energy's (DOE's) Hanford Site in a variety of locations, including subsurface grout and tank farms, solid waste burial grounds, and contaminated soil sites. Some of these waste sites may need to be isolated from percolating water to minimize the potential for transport of the waste to the ground water, which eventually discharges to the Columbia River. Multilayer protective barriers have been proposed as a means of limiting the flow of water through the waste sites (DOE 1987). A multiyear research program (managed jointly by Pacific Northwest Laboratory (PNL) and Westinghouse Hanford Company for the DOE) is aimed at assessing the performance of these barriers. One aspect of this program involves the use of computer models to predict barrier performance. Three modeling studies have already been conducted and a test plan was produced. The simulation work reported here was conducted by PNL and extends the previous modeling work. The purpose of this report are to understand phenomena that have been observed in the field and to provide information that can be used to improve hydrologic modeling of the protective barrier. An improved modeling capability results in better estimates of barrier performance. Better estimates can be used to improve the design of barriers and the assessment of their long-term performance.

  3. Conductivity Profile Determination by Eddy Current for Shot Peened Superalloy Surfaces Toward Residual Stress Assessment

    SciTech Connect (OSTI)

    Shen, Y.; Lo, C. C. H.; Frishman, A. M.; Lee, C.; Nakagawa, N. [Center for Nondestructive Evaluation, Iowa State University, Ames, Iowa 50011 (United States)

    2007-03-21T23:59:59.000Z

    This paper describes an eddy current model-based method for inverting near-surface conductivity deviation profiles of surface treated materials from swept-high frequency eddy current (SHFEC) data. This work forms part of our current research directed towards the development of an electromagnetic nondestructive technique for assessing residual stress of shot-peened superalloy components. The inversion procedure is based on the use of a parameterized function to describe the near-surface conductivity as a function of depth for a shot-peened surface, and the laterally uniform multi-layer theory of Cheng, Dodd and Deeds to calculate the resulting coil impedance deviations. The convergence of the inversion procedure has been tested against synthesized eddy current data. As a demonstration, the conductivity deviation profiles of a series of Inconel 718 specimens, shot peened at various Almen intensities, have been obtained by inversion. Several consistency tests were conducted to examine the reliability of the inverted conductivity profiles. The results show that conductivity deviation profiles can be reliably determined from SHFEC data within the accuracy of the current measurement system.

  4. Numerical Modeling of Nonlinear Surface Waves caused by Surface Effect Ships Dynamics and Kinematics

    E-Print Network [OSTI]

    Grilli, Stéphan T.

    Numerical Modeling of Nonlinear Surface Waves caused by Surface Effect Ships Dynamics and Kinematics Hong Gun Sung½ and Stephan T. Grilli¾ ½ Korea Ocean Research and Development Institute, Daejeon model fully nonlinear free surface waves caused by a translating dis- turbance made of a pressure patch

  5. From Surfaces to Objects: Recognizing Objects Using Surface Information and Object Models 

    E-Print Network [OSTI]

    Fisher III, Robert B.

    1986-01-01T23:59:59.000Z

    This thesis describes research on recognising partially obscured objects using surface information like Marr's 2½ D sketch ([MAR82]) and surface-based geometrical object models. The goal of the recognition proce88 is to ...

  6. From Surfaces to Objects: Recognizing Objects Using Surface Information and Object Models 

    E-Print Network [OSTI]

    Fisher, Robert B.

    1986-01-01T23:59:59.000Z

    This thesis describes research on recognizing partially obscured objects using surface information like Marr's 2D sketch ([MAR82]) and surface-based geometrical object models. The goal of the recognition process is to ...

  7. Receptor modeling assessment of particle total exposure assessment methodology data

    SciTech Connect (OSTI)

    Yakovleva, E.; Hopke, P.K.; Wallace, L.

    1999-10-15T23:59:59.000Z

    Data from the 1991 Particle Total Exposure Assessment Methodology (PTEAM) study in Riverside, CA, were analyzed using a new receptor modeling method. In this study, ambient (outdoor), indoor, and personal particulate matter (PM) concentrations and elemental concentrations of PM{sub 2.5} and PM{sub 10} were measured for a number of participants. These measurements made is possible to relate the pollution to which people were exposed throughout their daily activities with the outdoor air conditions. Personal daytime concentrations of the PM{sub 10} and majority of elements were significantly higher than outdoor or indoor concentrations, suggesting that a significant part of personal aerosol exposure is the result of personal daily activities. Possible sources of additional particulate mass include resuspension of particles that penetrate from the outdoors and formation of new particles during cooking, smoking, etc. Positive matrix factorization analysis was performed to describe the sources of personal exposure. To identify relative contribution of different sources, regression of the particulate matter mass against the factor contributions was performed. Major sources of PM{sub 2.5} were oil combustion, nonferrous metal operations, and motor vehicles. The mass contributions of particles from these sources were similar for outdoor air and personal exposure. Personal exposure to particles from these sources can be controlled by changing outdoor sources. The primary source of PM{sub 10} was soil.

  8. Assessment of Combustion and Turbulence Models for the Simulation...

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

    Combustion and Turbulence Models for the Simulation of Combustion Processes in a DI Diesel Engine Assessment of Combustion and Turbulence Models for the Simulation of Combustion...

  9. The motion of kelp blades and the surface renewal model

    E-Print Network [OSTI]

    Huang, Ivy

    2011-01-01T23:59:59.000Z

    We consider how the flapping of kelp blades may enhance the flux of nutrients to a blade, by stripping away the diffusive sub-layer and renewing the fluid at the blade surface. The surface renewal model explains the degree ...

  10. Model for assessing bronchial mucus transport

    SciTech Connect (OSTI)

    Agnew, J.E.; Bateman, J.R.M.; Pavia, D.; Clarke, S.W.

    1984-02-01T23:59:59.000Z

    The authors propose a scheme for the assessment of regional mucus transport using inhaled Tc-99m aerosol particles and quantitative analysis of serial gamma-camera images. The model treats input to inner and intermediate lung regions as the total of initial deposition there plus subsequent transport into these regions from more peripheral airways. It allows for interregional differences in the proportion of particles deposited on the mucus-bearing conducting airways, and does not require a gamma image 24 hr after particle inhalation. Instead, distribution of particles reaching the respiratory bronchioles or alveoli is determined from a Kr-81m ventilation image, while the total amount of such deposition is obtained from 24-hr Tc-99m retention measured with a sensitive counter system. The model is applicable to transport by mucociliary action or by cough, and has been tested in ten normal and ten asthmatic subjects.

  11. Gas Migration from Closed Coal Mines to the Surface RISK ASSESSMENT METHODOLOGY AND PREVENTION MEANS

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Gas Migration from Closed Coal Mines to the Surface RISK ASSESSMENT METHODOLOGY AND PREVENTION to the surface is especially significant in the context of coal mines. This is because mine gas can migrate of the scheduled closure of all coal mining operations in France, INERIS has drawn up, at the request of national

  12. Improving land-surface model hydrology: Is an explicit aquifer model better than a deeper soil profile?

    E-Print Network [OSTI]

    2007-01-01T23:59:59.000Z

    land-surface model hydrology: Is an explicit aquifer modelAL. : LAND-SURFACE MODEL HYDROLOGY Changnon, S. , et al. (land-surface model hydrology: Is an explicit aquifer model

  13. BOUSSINESQ MODELING OF SURFACE WAVES DUE TO UNDERWATER LANDSLIDES

    E-Print Network [OSTI]

    topography, and the equations of motion for the landslide and surface waves are solved simultaneously. Introduction Surface waves originating from sudden perturbations of the bottom topography are often termedBOUSSINESQ MODELING OF SURFACE WAVES DUE TO UNDERWATER LANDSLIDES DENYS DUTYKH AND HENRIK KALISCH

  14. BOUSSINESQ MODELING OF SURFACE WAVES DUE TO UNDERWATER LANDSLIDES

    E-Print Network [OSTI]

    topography, and the equations of motion for the landslide and surface waves are solved simultaneouslyBOUSSINESQ MODELING OF SURFACE WAVES DUE TO UNDERWATER LANDSLIDES DENYS DUTYKH AND HENRIK KALISCH Abstract. Consideration is given to the influence of an underwater landslide on waves at the surface

  15. BOUSSINESQ MODELING OF SURFACE WAVES DUE TO UNDERWATER LANDSLIDES

    E-Print Network [OSTI]

    topography, and the equations of motion for the landslide and surface waves are solved simultaneouslyBOUSSINESQ MODELING OF SURFACE WAVES DUE TO UNDERWATER LANDSLIDES DENYS DUTYKH # AND HENRIK KALISCH Abstract. Consideration is given to the influence of an underwater landslide on waves at the surface

  16. Risk assessment compatible fire models (RACFMs)

    SciTech Connect (OSTI)

    Lopez, A.R.; Gritzo, L.A.; Sherman, M.P.

    1998-07-01T23:59:59.000Z

    A suite of Probabilistic Risk Assessment Compatible Fire Models (RACFMs) has been developed to represent the hazard posed by a pool fire to weapon systems transported on the B52-H aircraft. These models represent both stand-off (i.e., the weapon system is outside of the flame zone but exposed to the radiant heat load from fire) and fully-engulfing scenarios (i.e., the object is fully covered by flames). The approach taken in developing the RACFMs for both scenarios was to consolidate, reconcile, and apply data and knowledge from all available resources including: data and correlations from the literature, data from an extensive full-scale fire test program at the Naval Air Warfare Center (NAWC) at China Lake, and results from a fire field model (VULCAN). In the past, a single, effective temperature, T{sub f}, was used to represent the fire. The heat flux to an object exposed to a fire was estimated using the relationship for black body radiation, {sigma}T{sub f}{sup 4}. Significant improvements have been made by employing the present approach which accounts for the presence of temperature distributions in fully-engulfing fires, and uses best available correlations to estimate heat fluxes in stand-off scenarios.

  17. Eutrophication risk assessment in coastal embayments using simple statistical models

    E-Print Network [OSTI]

    Arhonditsis, George B.

    Eutrophication risk assessment in coastal embayments using simple statistical models G. Arhonditsis for assessing the risk of eutrophication in marine coastal embayments. The procedure followed of exogenous nutrient loading. Ã? 2003 Elsevier Ltd. All rights reserved. Keywords: Eutrophication; Coastal

  18. ESD.864 Modeling and Assessment for Policy, Spring 2011

    E-Print Network [OSTI]

    Selin, Noelle

    ESD.864 Modeling and Assessment for Policy explores how scientific information and quantitative models can be used to inform policy decision-making. Students will develop an understanding of quantitative modeling techniques ...

  19. Improving snow albedo processes in WRF/SSiB regional climate model to assess impact of dust and black carbon in snow on surface energy balance and hydrology over western U.S.

    E-Print Network [OSTI]

    2015-01-01T23:59:59.000Z

    Basin: 1. A 6 year record of energy balance, radiation, andorganic carbon aerosol from energy-related combustion, 1850–carbon in snow on surface energy balance and hydrology over

  20. CONTROL-ORIENTED PLANAR MOTION MODELING OF UNMANNED SURFACE VEHICLES

    E-Print Network [OSTI]

    Virginia Tech

    CONTROL-ORIENTED PLANAR MOTION MODELING OF UNMANNED SURFACE VEHICLES C. Sonnenburg, A. Gadre, D effective model-based control design, (2) sufficiently simple to allow straight forward parameter. A first order steering model relates steering angle to turn rate. A second order steering model relates

  1. assessment models risk: Topics by E-print Network

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

    practice in the use of spreadsheets in business. Butler, Raymond J 2008-01-01 13 Eutrophication risk assessment in coastal embayments using simple statistical models...

  2. Use of OCA and APOLLO in Heliosat-4 method for the assessment of surface downwelling solar irradiance

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    the German Aerospace Center (DLR), for the assessment of surface downwelling solar irradiance (SSI). Each-based assessments of surface downwelling solar irradiance (SSI) are more and more used in the domain of solar energy, diffuse and direct surface irradiance for use in various domains: solar energy, biomass, agriculture

  3. A System for 3D Error Visualization and Assessment of Digital Elevation Models

    E-Print Network [OSTI]

    Gousie, Michael B.

    A System for 3D Error Visualization and Assessment of Digital Elevation Models Michael B. Gousie that displays a DEM and possible errors in 3D, along with its associated contour or sparse data and detail. The cutting tool is semi-transparent so that the profile is seen in the context of the 3D surface

  4. Student Learning Assessment: Towards an Environmental Model for

    E-Print Network [OSTI]

    Bieber, Michael

    Student Learning Assessment: Towards an Environmental Model for Academic and Student Services in the classroom. · And, implicitly, design assessment methods that lead to documentation and improvement. #12;MSCHE and Student Learning Assessment #12;The NJIT Academic Affairs Institutional Level Learning Goals 1

  5. Assessing the reliability of linear dynamic transformer thermal modelling

    E-Print Network [OSTI]

    Assessing the reliability of linear dynamic transformer thermal modelling X. Mao, D.J. Tylavsky and G.A. McCulla Abstract: Improving the utilisation of transformers requires that the hot-spot and top. An alternative method for assessing transformer model reliability is provided. 1 Introduction The maximally

  6. Making a 3D Model of the Moon's Surface

    E-Print Network [OSTI]

    Christian, Eric

    information are we lack- ing? What additional information could we learn from a 3D model of the space shuttle? Show the students a 3D model of the space shuttle. What can we learn about the space shuttle from1 Making a 3D Model of the Moon's Surface Learning Objectives: · Students will make estimates about

  7. AN URBAN SURFACE EXCHANGE PARAMETERISATION FOR MESOSCALE MODELS

    E-Print Network [OSTI]

    AN URBAN SURFACE EXCHANGE PARAMETERISATION FOR MESOSCALE MODELS ALBERTO MARTILLI1, , ALAIN CLAPPIER. A scheme to represent the impact of urban buildings on airflow in mesoscale atmospheric models is presented the presence of the buildings. The parameterisation is introduced into a mesoscale model and tested

  8. FIRST PRINCIPLES MODELING FOR LIDAR SENSING OF COMPLEX ICE SURFACES

    E-Print Network [OSTI]

    Kerekes, John

    FIRST PRINCIPLES MODELING FOR LIDAR SENSING OF COMPLEX ICE SURFACES J. Kerekes, A. Goodenough, S of monitoring the dynamics and mass balance of glaciers, ice caps, and ice sheets. However, it is also known that ice surfaces can have complex 3-dimensional structure, which can challenge their accurate retrieval

  9. A Novel Surface Registration Algorithm with Biomedical Modeling Applications

    E-Print Network [OSTI]

    Huang, Heng

    1 A Novel Surface Registration Algorithm with Biomedical Modeling Applications Heng Huang, Li Shen and motion. Matheny et al. [2] used 3D Manuscript received October 19, 2005; revised April 17, 2006. Heng: Heng Huang (heng.huang@dartmouth.edu). and 4D surface harmonics to reconstruct rigid and nonrigid

  10. Modeling Turbulent Hydraulic Fracture Near a Free Surface

    E-Print Network [OSTI]

    Modeling Turbulent Hydraulic Fracture Near a Free Surface Victor C. Tsai Seismological Laboratory consider a hydraulic fracture problem in which the crack grows parallel to a free surface, subject to fully components. wall Wall shear stress. ^· Non-dimensionalized ·. 1 Introduction Hydraulic fracture has been

  11. Modeling Turbulent Hydraulic Fracture Near a Free Surface

    E-Print Network [OSTI]

    Modeling Turbulent Hydraulic Fracture Near a Free Surface Victor C. Tsai Seismological Laboratory consider a hydraulic fracture problem in which the crack grows parallel to a free surface, subject to fully components. ^· Non-dimensionalized ·. 1 Introduction Hydraulic fracture has been studied for many years

  12. Modelling the fate of nonylphenolic compounds in1 the Seine River -part 2: assessing the impact of2

    E-Print Network [OSTI]

    Boyer, Edmond

    with the modelling of the global change10 influence on endocrine disruptor concentrations in surface water. Among1 Modelling the fate of nonylphenolic compounds in1 the Seine River - part 2: assessing the impact.09.0299 10 This study aims at modelling the daily concentrations of nonylphenolic compounds such as 4

  13. Do et al. 1 Full Scale Tests for the Assessment of Wear of Pavement Surfaces

    E-Print Network [OSTI]

    Boyer, Edmond

    Do et al. 1 Full Scale Tests for the Assessment of Wear of Pavement Surfaces Minh-Tan Do subjected to heavy traffic. Reports can be found in (1)(2). Evolution of pavements during its whole service shown in the figure 2. By this way, during tests on one track, pavement construction can be carried out

  14. Importance of thermal effects and sea surface roughness for offshore wind resource assessment

    E-Print Network [OSTI]

    Heinemann, Detlev

    sites. The first large offshore wind farms are currently being built in several countries in EuropeImportance of thermal effects and sea surface roughness for offshore wind resource assessment National Laboratory, Roskilde, Denmark Abstract The economic feasibility of offshore wind power utilisation

  15. Modeling superconductors using surface impedance techniques

    E-Print Network [OSTI]

    Aude, Diana Prado Lopes

    2010-01-01T23:59:59.000Z

    This thesis develops a simulation tool that can be used in conjunction with commercially available electromagnetic simulators to model the behavior of superconductors over a wide range of frequencies. This simulation method ...

  16. Data for surface ionization and complexation modeling

    SciTech Connect (OSTI)

    Not Available

    1990-10-01T23:59:59.000Z

    Objective is to compile the thermodynamic data for using the adsorption subroutines in the MINTEQA2 geochemical simulator. As a test of the applicability of the sorption subroutines to UMTRA (Uranium Mill Tailings Remedical Action) project sites, a test case was run using data from Falls City site. Results suggest that adsorption of uranyl ion onto a mixture of silica (quartz) and goethite has limited the mobility of uranium in the groundwater at Falls City. Given the limited analytical data, variability in pH and alkalinity in groundwater, and variation in sorbent phases, the simulations are reasonable (agree within an order of magnitude). Because thermodynamic data exist for relatively few dissolved constituents and their interactions with even fewer mineral phases, the importance of adsorption for hazardous constituent attenuation is difficult to assess. However, the test case indicates that sorption on even two minerals can contribute to U distribution.

  17. Modelling receding contact lines on superhydrophobic surfaces

    E-Print Network [OSTI]

    B. M. Mognetti; J. M. Yeomans

    2010-10-23T23:59:59.000Z

    We use mesoscale simulations to study the depinning of a receding contact line on a superhydrophobic surface patterned by a regular array of posts. In order that the simulations are feasible, we introduce a novel geometry where a column of liquid dewets a capillary bounded by a superhydrophobic plane which faces a smooth hydrophilic wall of variable contact angle. We present results for the dependence of the depinning angle on the shape and spacing of the posts, and discuss the form of the meniscus at depinning. We find, in agreement with [17], that the local post concentration is a primary factor in controlling the depinning angle, and show that the numerical results agree well with recent experiments. We also present two examples of metastable pinned configurations where the posts are partially wet.

  18. Learning Usability Assessment Models for Web Sites

    E-Print Network [OSTI]

    Davis, Paul

    2012-02-14T23:59:59.000Z

    students pursuing advanced degrees in the area of computer-human interaction. These students were divided into two groups and given different scenarios of use of a Web site. They assessed the usability of Web pages from the site, and their data was divided...

  19. Wind resource assessment with a mesoscale non-hydrostatic model

    E-Print Network [OSTI]

    Boyer, Edmond

    Wind resource assessment with a mesoscale non- hydrostatic model Vincent Guénard, Center for Energy is developed for assessing the wind resource and its uncertainty. The work focuses on an existing wind farm mast measurements. The wind speed and turbulence fields are discussed. It is shown that the k

  20. Assessment of structures and stabilities of defect clusters and surface energies predicted by nine interatomic potentials for UO2

    SciTech Connect (OSTI)

    Stephen A. Taller; Xian-Ming Bai

    2013-11-01T23:59:59.000Z

    The irradiation in nuclear reactors creates many point defects and defect clusters in uranium dioxide (UO2) and their evolution severely degrades the thermal and mechanical properties of the nuclear fuels. Previously many empirical interatomic potentials have been developed for modeling defect production and evolution in UO2. However, the properties of defect clusters and extended defects are usually not fitted into these potentials. In this work nine interatomic potentials for UO2 are examined by using molecular statics and molecular dynamics to assess their applicability in predicting the properties of various types of defect clusters in UO2. The binding energies and structures for these defect clusters have been evaluated for each potential. In addition, the surface energies of voids of different radii and (1 1 0) flat surfaces predicted by these potentials are also evaluated. It is found that both good agreement and significant discrepancies exist for these potentials in predicting these properties. For oxygen interstitial clusters, these potentials predict significantly different defect cluster structures and stabilities; For defect clusters consisting of both uranium and oxygen defects, the prediction is in better agreement; The surface energies predicted by these potentials have significant discrepancies, and some of them are much higher than the experimentally measured values. The results from this work can provide insight on interpreting the outcome of atomistic modeling of defect production using these potentials and may provide guidelines for choosing appropriate potential models to study problems of interest in UO2.

  1. ASSESSING FRANCE AS A MODEL OF SOCIETAL SUCCESS

    E-Print Network [OSTI]

    Boyer, Edmond

    of this "French model": the French economy being heavily regulated, the well-oiled state tightly controls market crisis," "The French model: Vive la difference!"2 ), and also from free-market minded internationalASSESSING FRANCE AS A MODEL OF SOCIETAL SUCCESS �loi Laurent Sciences-Po Michèle Lamont Harvard

  2. Modeling surface backgrounds from radon progeny plate-out

    SciTech Connect (OSTI)

    Perumpilly, G.; Guiseppe, V. E.; Snyder, N. [University of South Dakota, Vermillion, South Dakota 57069 (United States)] [University of South Dakota, Vermillion, South Dakota 57069 (United States)

    2013-08-08T23:59:59.000Z

    The next generation low-background detectors operating deep underground aim for unprecedented low levels of radioactive backgrounds. The surface deposition and subsequent implantation of radon progeny in detector materials will be a source of energetic background events. We investigate Monte Carlo and model-based simulations to understand the surface implantation profile of radon progeny. Depending on the material and region of interest of a rare event search, these partial energy depositions can be problematic. Motivated by the use of Ge crystals for the detection of neutrinoless double-beta decay, we wish to understand the detector response of surface backgrounds from radon progeny. We look at the simulation of surface decays using a validated implantation distribution based on nuclear recoils and a realistic surface texture. Results of the simulations and measured ? spectra are presented.

  3. Binaural model-based speech intelligibility enhancement and assessment in

    E-Print Network [OSTI]

    #12;Binaural model-based speech intelligibility enhancement and assessment in hearing aids beamforming and the effect on binaural cues and speech intelligibility . . . . . . . . . . 31 2.3.4 Cepstral smoothing of masks . . . . . . . . . . . . . . . . . . 35 2.4 Binaural CASA speech

  4. Surface tension in the dilute Ising model. The Wulff construction

    E-Print Network [OSTI]

    Marc Wouts

    2008-04-14T23:59:59.000Z

    We study the surface tension and the phenomenon of phase coexistence for the Ising model on $\\mathbbm{Z}^d$ ($d \\geqslant 2$) with ferromagnetic but random couplings. We prove the convergence in probability (with respect to random couplings) of surface tension and analyze its large deviations : upper deviations occur at volume order while lower deviations occur at surface order. We study the asymptotics of surface tension at low temperatures and relate the quenched value $\\tau^q$ of surface tension to maximal flows (first passage times if $d = 2$). For a broad class of distributions of the couplings we show that the inequality $\\tau^a \\leqslant \\tau^q$ -- where $\\tau^a$ is the surface tension under the averaged Gibbs measure -- is strict at low temperatures. We also describe the phenomenon of phase coexistence in the dilute Ising model and discuss some of the consequences of the media randomness. All of our results hold as well for the dilute Potts and random cluster models.

  5. Surface photovoltage measurements and finite element modeling of SAW devices.

    SciTech Connect (OSTI)

    Donnelly, Christine

    2012-03-01T23:59:59.000Z

    Over the course of a Summer 2011 internship with the MEMS department of Sandia National Laboratories, work was completed on two major projects. The first and main project of the summer involved taking surface photovoltage measurements for silicon samples, and using these measurements to determine surface recombination velocities and minority carrier diffusion lengths of the materials. The SPV method was used to fill gaps in the knowledge of material parameters that had not been determined successfully by other characterization methods. The second project involved creating a 2D finite element model of a surface acoustic wave device. A basic form of the model with the expected impedance response curve was completed, and the model is ready to be further developed for analysis of MEMS photonic resonator devices.

  6. Modeling the surface temperature of Earth-like planets

    E-Print Network [OSTI]

    Vladilo, G; Murante, G; Filippi, L; Provenzale, A

    2015-01-01T23:59:59.000Z

    We introduce a novel Earth-like planet surface temperature model (ESTM) for habitability studies based on the spatial-temporal distribution of planetary surface temperatures. The ESTM adopts a surface Energy Balance Model complemented by: radiative-convective atmospheric column calculations, a set of physically-based parameterizations of meridional transport, and descriptions of surface and cloud properties more refined than in standard EBMs. The parameterization is valid for rotating terrestrial planets with shallow atmospheres and moderate values of axis obliquity (epsilon >= 45^o). Comparison with a 3D model of atmospheric dynamics from the literature shows that the equator-to-pole temperature differences predicted by the two models agree within ~5K when the rotation rate, insolation, surface pressure and planet radius are varied in the intervals 0.5 <= Omega/Omega_o <= 2, 0.75 <= S/S_o <= 1.25, 0.3 <= p/(1 bar) <= 10, and 0.5 <= R/R_o <= 2, respectively. The ESTM has an extremely l...

  7. Modeling electron emission and surface effects from diamond cathodes

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

    Dimitrov, D. A. [Tech-X Corp., Boulder, CO (United States); Ben-Zvi, I. [Brookhaven National Lab. (BNL), Upton, NY (United States); Smithe, D. [Tech-X Corp., Boulder, CO (United States); Cary, J. R. [Tech-X Corp., Boulder, CO (United States); Rao, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Smedley, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Wang, E. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-02-07T23:59:59.000Z

    We developed modeling capabilities, within the Vorpal particle-in-cell code, for three-dimensional (3D) simulations of surface effects and electron emission from semiconductor photocathodes. They include calculation of emission probabilities using general, piece-wise continuous, space-time dependent surface potentials, effective mass and band bending field effects. We applied these models, in combination with previously implemented capabilities for modeling charge generation and transport in diamond, to investigate the emission dependence on applied electric field in the range from approximately 2 MV/m to 17 MV/m along the [100] direction. The simulation results were compared to experimental data. For the considered parameter regime, conservation of transverse electron momentum (in the plane of the emission surface) allows direct emission from only two (parallel to [100]) of the six equivalent lowest conduction band valleys. When the electron affinity ? is the only parameter varied in the simulations, the value ? = 0.31 eV leads to overall qualitative agreement with the probability of emission deduced from experiments. Including band bending in the simulations improves the agreement with the experimental data, particularly at low applied fields, but not significantly. Using surface potentials with different profiles further allows us to investigate the emission as a function of potential barrier height, width, and vacuum level position. However, adding surface patches with different levels of hydrogenation, modeled with position-dependent electron affinity, leads to the closest agreement with the experimental data.

  8. Modeling electron emission and surface effects from diamond cathodes

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

    Dimitrov, D. A.; Ben-Zvi, I.; Smithe, D.; Cary, J. R.; Rao, T.; Smedley, J.; Wang, E.

    2015-02-07T23:59:59.000Z

    We developed modeling capabilities, within the Vorpal particle-in-cell code, for three-dimensional (3D) simulations of surface effects and electron emission from semiconductor photocathodes. They include calculation of emission probabilities using general, piece-wise continuous, space-time dependent surface potentials, effective mass and band bending field effects. We applied these models, in combination with previously implemented capabilities for modeling charge generation and transport in diamond, to investigate the emission dependence on applied electric field in the range from approximately 2 MV/m to 17 MV/m along the [100] direction. The simulation results were compared to experimental data. For the considered parameter regime, conservation of transversemore »electron momentum (in the plane of the emission surface) allows direct emission from only two (parallel to [100]) of the six equivalent lowest conduction band valleys. When the electron affinity ? is the only parameter varied in the simulations, the value ? = 0.31 eV leads to overall qualitative agreement with the probability of emission deduced from experiments. Including band bending in the simulations improves the agreement with the experimental data, particularly at low applied fields, but not significantly. Using surface potentials with different profiles further allows us to investigate the emission as a function of potential barrier height, width, and vacuum level position. However, adding surface patches with different levels of hydrogenation, modeled with position-dependent electron affinity, leads to the closest agreement with the experimental data.« less

  9. The Whitham Equation as a Model for Surface Water Waves

    E-Print Network [OSTI]

    Daulet Moldabayev; Henrik Kalisch; Denys Dutykh

    2014-10-30T23:59:59.000Z

    The Whitham equation was proposed as an alternate model equation for the simplified description of uni-directional wave motion at the surface of an inviscid fluid. As the Whitham equation incorporates the full linear dispersion relation of the water wave problem, it is thought to provide a more faithful description of shorter waves of small amplitude than traditional long wave models such as the KdV equation. In this work, we identify a scaling regime in which the Whitham equation can be derived from the Hamiltonian theory of surface water waves. The Whitham equation is integrated numerically, and it is shown that the equation gives a close approximation of inviscid free surface dynamics as described by the Euler equations. The performance of the Whitham equation as a model for free surface dynamics is also compared to two standard free surface models: the KdV and the BBM equation. It is found that in a wide parameter range of amplitudes and wavelengths, the Whitham equation performs on par with or better than both the KdV and BBM equations.

  10. Coupling the high-complexity land surface model ACASA to the mesoscale model WRF

    E-Print Network [OSTI]

    Pyles, R. D.

    In this study, the Weather Research and Forecasting (WRF) model is coupled with the Advanced Canopy–Atmosphere–Soil Algorithm (ACASA), a high-complexity land surface model. Although WRF is a state-of-the-art regional ...

  11. Coupling the High Complexity Land Surface Model ACASA to the Mesoscale Model WRF

    E-Print Network [OSTI]

    Xu, L.

    In this study, the Weather Research and Forecasting Model (WRF) is coupled with the Advanced Canopy-Atmosphere-Soil Algorithm (ACASA), a high complexity land surface model. Although WRF is a state-of-the-art regional ...

  12. A New Multi-Gaussian Auto-Correlation Function for the Modeling of Realistic Shot Peened Random Rough Surfaces

    SciTech Connect (OSTI)

    Hassan, W. [Honeywell Aerospace, 111 S. 34th Street, M/S 503-118 Phoenix, AZ 85034 (United States); Blodgett, M. [Air Force Research Laboratory (AFRL/MLLP), 2230 10th Street, Suite 1, Dayton, OH 45433 (United States)

    2006-03-06T23:59:59.000Z

    Shot peening is the primary surface treatment used to create a uniform, consistent, and reliable sub-surface compressive residual stress layer in aero engine components. A by-product of the shot peening process is random surface roughness that can affect the measurements of the resulting residual stresses and therefore impede their NDE assessment. High frequency eddy current conductivity measurements have the potential to assess these residual stresses in Ni-base super alloys. However, the effect of random surface roughness is expected to become significant in the desired measurement frequency range of 10 to 100 MHz. In this paper, a new Multi-Gaussian (MG) auto-correlation function is proposed for modeling the resulting pseudo-random rough profiles. Its use in the calculation of the Apparent Eddy Current Conductivity (AECC) loss due to surface roughness is demonstrated. The numerical results presented need to be validated with experimental measurements.

  13. Wetting and free surface flow modeling for potting and encapsulation.

    SciTech Connect (OSTI)

    Brooks, Carlton, F.; Brooks, Michael J. (Los Alamos National Laboratory, Los Alamos, NM); Graham, Alan Lyman (Los Alamos National Laboratory, Los Alamos, NM); Noble, David F. (David Frederick) (.; )); Notz, Patrick K.; Hopkins, Matthew Morgan; Castaneda, Jaime N.; Mahoney, Leo James (Kansas City Plant, Kansas City, MO); Baer, Thomas A.; Berchtold, Kathryn (Los Alamos National Laboratory, Los Alamos, NM); Adolf, Douglas Brian; Wilkes, Edward Dean; Rao, Rekha Ranjana; Givler, Richard C.; Sun, Amy Cha-Tien; Cote, Raymond O.; Mondy, Lisa Ann; Grillet, Anne Mary; Kraynik, Andrew Michael

    2007-06-01T23:59:59.000Z

    As part of an effort to reduce costs and improve quality control in encapsulation and potting processes the Technology Initiative Project ''Defect Free Manufacturing and Assembly'' has completed a computational modeling study of flows representative of those seen in these processes. Flow solutions are obtained using a coupled, finite-element-based, numerical method based on the GOMA/ARIA suite of Sandia flow solvers. The evolution of the free surface is solved with an advanced level set algorithm. This approach incorporates novel methods for representing surface tension and wetting forces that affect the evolution of the free surface. In addition, two commercially available codes, ProCAST and MOLDFLOW, are also used on geometries representing encapsulation processes at the Kansas City Plant. Visual observations of the flow in several geometries are recorded in the laboratory and compared to the models. Wetting properties for the materials in these experiments are measured using a unique flowthrough goniometer.

  14. Statewide and Electricity-Sector Models for Economic Assessments of

    E-Print Network [OSTI]

    Statewide and Electricity-Sector Models for Economic Assessments of Hawai`i Clean Energy Policies 9.2 Deliverable Economic and Environmental Modeling of Island Energy Systems By the Hawai`i Natural of Hawai`i Economic Research Organization August 2012 #12;2 Acknowledgement: This material is based upon

  15. Modeling the interaction between land surface and groundwater

    E-Print Network [OSTI]

    Nebraska-Lincoln, University of

    % of GW for irrigation. Groundwater was managed separately. GW systems and land surface intimately and human factors on GW systems. GW irrigation capacity and efficiency based on a watershed scale. How much-ground water models Irrigation efficiency Materials and methods Development of SGWM #12;Background Groundwater

  16. Model-based Safety Risk Assessment

    E-Print Network [OSTI]

    Lindsay, Peter

    development life-cycle, in order to identify critical system requirements, such as safety requirements their effectiveness, early in the system development life-cycle, on models derived directly from natural language of functional requirements of arbitrary detail ­ whether it is very early in the life-cycle when functions

  17. Assessment of circuit board surface finishes for electronic assembly with lead-free solders

    SciTech Connect (OSTI)

    Ray, U.; Artaki, I.; Finley, D.W.; Wenger, G.M. [Bell Labs., Princeton, NJ (United States). Lucent Technologies; Pan, T.; Blair, H.D.; Nicholson, J.M. [Ford Motor Co., Dearborn, MI (United States); Vianco, P.T. [Sandia National Labs., Albuquerque, NM (United States)

    1996-10-01T23:59:59.000Z

    The suitability of various metallic printed wiring board surface finishes was assessed for new technology applications that incorporate assembly with Lead-free solders. The manufacture of a lead-free product necessitates elimination of lead (Pb) from the solder, the circuit board as well as the component lead termination. It is critical however for the selected interconnect Pb-free solder and the corresponding printed wiring board (PWB) and component lead finishes to be mutually compatible. Baseline compatibility of select Pb-free solders with Pb containing PWB surface finish and components was assessed. This was followed by examining the compatibility of the commercially available CASTIN{trademark} (SnAgCuSb) Pb-free solder with a series of PWB metallic finishes: Ni/Au, Ni/Pd, and Pd/Cu. The compatibility was assessed with respect to assembly performance, solder joint integrity and long term attachment reliability. Solder joint integrity and mechanical behavior of representative 50 mil pitch 20I/O SOICs was determined before and after thermal stress. Mechanical pull test studies demonstrated that the strength of SnAgCuSb solder interconnections is notably greater than that of SnPb interconnections.

  18. Modeling for Free Surface Flow with Phase Change

    SciTech Connect (OSTI)

    Luo Xiaoyong; Ni Mingjiu; Ying, Alice; Abdou, M. [University of California, Los Angeles (United States)

    2005-05-15T23:59:59.000Z

    The development of predictive capability for free surface flow with phase change is essential to evaluate liquid wall protection schemes for various fusion chambers in IFE and MFE. This paper presents a numerical methodology for free surface flow with heat and mass transfer to help resolve feasibility issues encountered in the aforementioned fusion engineering fields. The numerical methodology is conducted within the framework of the incompressible flow with the heat and mass transfer model. We present a new second-order projection method, in conjunction with Approximate-Factorization techniques (AF method) for incompressible Navier-Stokes equations. The level set method was used to capture the free surface of the flow and the deformation of the droplets accurately. This numerical investigation identifies the physics characterizing transient heat and mass transfer of the droplet and the free surface flow. The preliminary results show that the numerical methodology is successful in modeling the free surface with heat and mass transfer, though some severe deformation such as breaking and merging occurs. The versatility of the numerical methodology shows that the work can easily handle complex physical conditions in fusion science and engineering.

  19. Modeling Urban Storm-Water Quality Treatment: Model Development and Application to a Surface Sand Filter

    E-Print Network [OSTI]

    Modeling Urban Storm-Water Quality Treatment: Model Development and Application to a Surface Sand management; Urban areas; Hydraulic models; Sand, filter; Parameters; Estimation; Water treatment. Author. Optimized model parameter values were calculated on a storm by storm basis. Thereafter, a gamma distribution

  20. Model and Analytic Processes for Export License Assessments

    SciTech Connect (OSTI)

    Thompson, Sandra E.; Whitney, Paul D.; Weimar, Mark R.; Wood, Thomas W.; Daly, Don S.; Brothers, Alan J.; Sanfilippo, Antonio P.; Cook, Diane; Holder, Larry

    2011-09-29T23:59:59.000Z

    This paper represents the Department of Energy Office of Nonproliferation Research and Development (NA-22) Simulations, Algorithms and Modeling (SAM) Program's first effort to identify and frame analytical methods and tools to aid export control professionals in effectively predicting proliferation intent; a complex, multi-step and multi-agency process. The report focuses on analytical modeling methodologies that alone, or combined, may improve the proliferation export control license approval process. It is a follow-up to an earlier paper describing information sources and environments related to international nuclear technology transfer. This report describes the decision criteria used to evaluate modeling techniques and tools to determine which approaches will be investigated during the final 2 years of the project. The report also details the motivation for why new modeling techniques and tools are needed. The analytical modeling methodologies will enable analysts to evaluate the information environment for relevance to detecting proliferation intent, with specific focus on assessing risks associated with transferring dual-use technologies. Dual-use technologies can be used in both weapons and commercial enterprises. A decision-framework was developed to evaluate which of the different analytical modeling methodologies would be most appropriate conditional on the uniqueness of the approach, data availability, laboratory capabilities, relevance to NA-22 and Office of Arms Control and Nonproliferation (NA-24) research needs and the impact if successful. Modeling methodologies were divided into whether they could help micro-level assessments (e.g., help improve individual license assessments) or macro-level assessment. Macro-level assessment focuses on suppliers, technology, consumers, economies, and proliferation context. Macro-level assessment technologies scored higher in the area of uniqueness because less work has been done at the macro level. An approach to developing testable hypotheses for the macro-level assessment methodologies is provided. The outcome of this works suggests that we should develop a Bayes Net for micro-level analysis and continue to focus on Bayes Net, System Dynamics and Economic Input/Output models for assessing macro-level problems. Simultaneously, we need to develop metrics for assessing intent in export control, including the risks and consequences associated with all aspects of export control.

  1. Fire models for assessment of nuclear power plant fires

    SciTech Connect (OSTI)

    Nicolette, V.F.; Nowlen, S.P.

    1989-01-01T23:59:59.000Z

    This paper reviews the state-of-the-art in available fire models for the assessment of nuclear power plants fires. The advantages and disadvantages of three basic types of fire models (zone, field, and control volume) and Sandia's experience with these models will be discussed. It is shown that the type of fire model selected to solve a particular problem should be based on the information that is required. Areas of concern which relate to all nuclear power plant fire models are identified. 17 refs., 6 figs.

  2. Final Report DE-EE0005380: Assessment of Offshore Wind Farm Effects on Sea Surface, Subsurface and Airborne Electronic Systems

    SciTech Connect (OSTI)

    Ling, Hao [The University of Texas at Austin] [The University of Texas at Austin; Hamilton, Mark F. [The University of Texas at Austin Applied Research Laboratories] [The University of Texas at Austin Applied Research Laboratories; Bhalla, Rajan [Science Applications International Corporation] [Science Applications International Corporation; Brown, Walter E. [The University of Texas at Austin Applied Research Laboratories] [The University of Texas at Austin Applied Research Laboratories; Hay, Todd A. [The University of Texas at Austin Applied Research Laboratories] [The University of Texas at Austin Applied Research Laboratories; Whitelonis, Nicholas J. [The University of Texas at Austin] [The University of Texas at Austin; Yang, Shang-Te [The University of Texas at Austin] [The University of Texas at Austin; Naqvi, Aale R. [The University of Texas at Austin] [The University of Texas at Austin

    2013-09-30T23:59:59.000Z

    Offshore wind energy is a valuable resource that can provide a significant boost to the US renewable energy portfolio. A current constraint to the development of offshore wind farms is the potential for interference to be caused by large wind farms on existing electronic and acoustical equipment such as radar and sonar systems for surveillance, navigation and communications. The US Department of Energy funded this study as an objective assessment of possible interference to various types of equipment operating in the marine environment where offshore wind farms could be installed. The objective of this project was to conduct a baseline evaluation of electromagnetic and acoustical challenges to sea surface, subsurface and airborne electronic systems presented by offshore wind farms. To accomplish this goal, the following tasks were carried out: (1) survey electronic systems that can potentially be impacted by large offshore wind farms, and identify impact assessment studies and research and development activities both within and outside the US, (2) engage key stakeholders to identify their possible concerns and operating requirements, (3) conduct first-principle modeling on the interactions of electromagnetic signals with, and the radiation of underwater acoustic signals from, offshore wind farms to evaluate the effect of such interactions on electronic systems, and (4) provide impact assessments, recommend mitigation methods, prioritize future research directions, and disseminate project findings. This report provides a detailed description of the methodologies used to carry out the study, key findings of the study, and a list of recommendations derived based the findings.

  3. MODELING/GIS, RISK ASSESSMENT, ECONOMIC IMPACT Household Model of Chagas Disease Vectors (Hemiptera: Reduviidae)

    E-Print Network [OSTI]

    Vermont, University of

    MODELING/GIS, RISK ASSESSMENT, ECONOMIC IMPACT Household Model of Chagas Disease Vectors (Hemiptera vectors (Hemiptera: Reduviidae) of the causative parasite Trypanosoma cruzi (Kinetoplastida bitten by infected insect vectors. There are 130 species in the subfamily Triatominae (Hemiptera

  4. Assessing the Power Requirements for Sawtooth Control in ITER Through Modelling and Joint Experiments

    E-Print Network [OSTI]

    Assessing the Power Requirements for Sawtooth Control in ITER Through Modelling and Joint Experiments

  5. Use of land surface remotely sensed satellite and airborne data for environmental exposure assessment in cancer research

    E-Print Network [OSTI]

    cancer and environmental contaminants, focusing primarily on agricultural chemical exposure assessmentUse of land surface remotely sensed satellite and airborne data for environmental exposure assessment in cancer research SUSAN K. MAXWELLa , JAYMIE R. MELIKERb AND PIERRE GOOVAERTSc a U.S. Geological

  6. Assessment of Heliosat-4 surface solar irradiance derived on the basis of SEVIRI-APOLLO cloud products

    E-Print Network [OSTI]

    Boyer, Edmond

    Assessment of Heliosat-4 surface solar irradiance derived on the basis of SEVIRI-APOLLO cloud are crucial for the assessment of SSI. The APOLLO cloud product provided by DLR includes abundant information about the cloud physical and optical properties. The performances of Heliosat-4 when using APOLLO

  7. Microfriction studies of model self-lubricating surfaces

    SciTech Connect (OSTI)

    Blau, P.J.; Yust, C.S. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

    1993-05-06T23:59:59.000Z

    Self-lubricating composites consist of at least one structural (matrix) phase and at least one phase to provide lubrication. Modeling the behavior of such composites involves ascertaining the frictional contributions of each constituent phase under varying conditions of lubricating films coverage. The ORNL friction microprobe (FMP), a specialized microcontact tribometer, was used to investigate the frictional behavior of both matrix and lubricant phases to support the development of self-lubricating, surfaces. Polished CVD-silicon carbide deposits and silicon wafers were used as substrates. The wafers were intended to simulate the thin silica films present on SiC surfaces at elevated temperature. Molybdenum disulfide, in both sputtered and burnished forms, was used as the model lubricant. The effects of CVD-SiC substrate surface roughness and method of lubricant film deposition on the substrate were studied for single passes of a spherical silicon nitride slider (NBD 200 material). In contrast to the smooth sliding exhibit by burnished, films, sputtered MoS{sub 2} surfaces exhibited marked stick-slip behavior, indicating that the frictional behavior of solid lubricating coatings can be quite erratic on a microscale, especially when asperity contacts are elastically compliant.

  8. Thermodynamic assessment of the variation of the surface areas of two synthetic swelling clays during adsorption of water

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Thermodynamic assessment of the variation of the surface areas of two synthetic swelling clays; Synthetic smectite; Water; Adsorption; Surface area; Swelling clay; Interlayer space #12;1. Introduction Synthetic clays are very interesting materials, both for scientific research and for industrial applications

  9. Diagnostic indicators for integrated assessment models of climate policy

    SciTech Connect (OSTI)

    Kriegler, Elmar; Petermann, Nils; Krey, Volker; Schwanitz, Jana; Luderer, Gunnar; Ashina, Shuichi; Bosetti, Valentina; Eom, Jiyong; Kitous, Alban; Mejean, Aurelie; Paroussos, Leonidas; Sano, Fuminori; Turton, Hal; Wilson, Charlie; Van Vuuren, Detlef

    2015-01-01T23:59:59.000Z

    Integrated assessments of how climate policy interacts with energy-economic systems can be performed by a variety of models with different functional structures. This article proposes a diagnostic scheme that can be applied to a wide range of integrated assessment models to classify differences among models based on their carbon price responses. Model diagnostics can uncover patterns and provide insights into why, under a given scenario, certain types of models behave in observed ways. Such insights are informative since model behavior can have a significant impact on projections of climate change mitigation costs and other policy-relevant information. The authors propose diagnostic indicators to characterize model responses to carbon price signals and test these in a diagnostic study with 11 global models. Indicators describe the magnitude of emission abatement and the associated costs relative to a harmonized baseline, the relative changes in carbon intensity and energy intensity and the extent of transformation in the energy system. This study shows a correlation among indicators suggesting that models can be classified into groups based on common patterns of behavior in response to carbon pricing. Such a classification can help to more easily explain variations among policy-relevant model results.

  10. RELAP5/MOD3 subcooled boiling model assessment

    SciTech Connect (OSTI)

    Devkin, A.S.; Podosenov, A.S. [Russian Research Center, Moscow (Russian Federation). Nuclear Safety Inst.

    1998-05-01T23:59:59.000Z

    This report presents the assessment of the RELAP5/Mod3 (5m5 version) code subcooled boiling process model which is based on a variety of experiments. The accuracy of the model is confirmed for a wide range of regime parameters for the case of uniform heating along the channel. The condensation rate is rather underpredicted, which may lead to considerable errors in void fraction behavior prediction in subcooled boiling regimes for nonuniformly or unheated channels.

  11. Model for Dynamic Self-Assembled Magnetic Surface Structures

    E-Print Network [OSTI]

    M. Belkin; A. Glatz; A. Snezhko; I. S. Aranson

    2010-02-02T23:59:59.000Z

    We propose a first-principles model for self-assembled magnetic surface structures on the water-air interface reported in earlier experiments \\cite{snezhko2,snezhko4}. The model is based on the Navier-Stokes equation for liquids in shallow water approximation coupled to Newton equations for interacting magnetic particles suspended on the water-air interface. The model reproduces most of the observed phenomenology, including spontaneous formation of magnetic snake-like structures, generation of large-scale vortex flows, complex ferromagnetic-antiferromagnetic ordering of the snake, and self-propulsion of bead-snake hybrids. The model provides valuable insights into self-organization phenomena in a broad range of non-equilibrium magnetic and electrostatic systems with competing interactions.

  12. Incorporating Carbon Capture and Storage Technologies in Integrated Assessment Models

    E-Print Network [OSTI]

    Incorporating Carbon Capture and Storage Technologies in Integrated Assessment Models J. R. Mc carbon capture and storage, 2) a natural gas combined cycle technology with carbon capture and storage 1 emissions growth. Both the magnitude and rate of technological change toward low- or no-carbon emitting

  13. Assessing streamaquifer interactions through inverse modeling of flow routing q

    E-Print Network [OSTI]

    Szilagyi, Jozsef

    Assessing stream­aquifer interactions through inverse modeling of flow routing q Jozsef Szilagyi a and Nieber, 1977; Troch et al., 1993; Brutsaert and Lopez, 1998; Szilagyi et al., 1998; Par- lange et al., 2001; Szilagyi, 2003a). Knowledge of this inter- action between streamflow and groundwater during flood

  14. Annual report, October 1980-September 1981 Multimedia radionuclide exposure assessment modeling.

    SciTech Connect (OSTI)

    Whelan, G.; Onishi, Y.; Simmons, C.S.; Horst, T.W.; Gupta, S.K.; Orgill, M.M.; Newbill, C.A.

    1982-12-01T23:59:59.000Z

    Pacific Northwest Laboratory (PNL) and Los Alamos National Laboratory (LANL) are jointly developing a methodology for assessing exposures of the air, water, and plants to radionuclides as part of an overall development effort of a radionuclide disposal site evaluation methodology. Work in FY-1981 continued the development of the Multimedia Contaminant Environmental Exposure Assessment (MCEA) methodology and initiated an assessment of radionuclide migration in Los Alamos and Pueblo Canyons, New Mexico, using the methodology. The AIRTRAN model was completed, briefly tested, and documented. In addition, a literature search for existing validation data for AIRTRAN was performed. The feasibility and advisability of including the UNSAT moisture flow model as a submodel of the terrestrial code BIOTRAN was assessed. A preliminary application of the proposed MCEA methodology, as it related to the Mortandad-South Mortandad Canyon site in New Mexico is discussed. This preliminary application represented a scaled-down version of the methodology in which only the terrestrial, overland, and surface water components were used. An update describing the progress in the assessment of radionuclide migration in Los Alamos and Pueblo Canyons is presented. 38 references, 47 figures, 11 tables.

  15. Integrated science model for assessment of climate change

    SciTech Connect (OSTI)

    Jain, A.K.; Wuebbles, D.J. [Lawrence Livermore National Lab., CA (United States); Kheshgi, H.S. [Exxon Research and Engineering Co., Annandale, NJ (United States)

    1994-04-01T23:59:59.000Z

    Integrated assessment models are intended to represent processes that govern physical, ecological, economic and social systems. This report describes a scientific model relating emissions to global temperature and sea level. This model is intended to be one component of an integrated assessment model which is, of course, much more comprehensive. The model is able to reproduce past changes in CO{sub 2} concentration, global temperature, and sea level. The model is used to estimate the emissions rates required to lead to stabilization of CO{sub 2} at various levels. The model is also used to estimate global temperature rise, the rate of temperature change, and sea level rise driven by IPCC emissions scenarios. The emission of fossil fuel CO{sub 2} is modeled to have the largest long term effect on climate. Results do show the importance of expected changes of trace greenhouse gases other than CO{sub 2} in the near future. Because of the importance of these other trace gases, further work is recommended to more accurately estimate their effects.

  16. Comprehensive country energy assessments using the MARKAL-MACRO model

    SciTech Connect (OSTI)

    Reisman, A.W.

    1997-07-01T23:59:59.000Z

    A number of comprehensive country energy assessments were performed in the late 1970s and early 1980s in cooperation with the governments of various countries. The assessments provided a framework for analyzing the impacts of various national strategies for meeting energy requirements. These analyses considered the total energy framework. Economics, energy supply, national resources, energy use, environmental impacts, technologies, energy efficiencies, and sociopolitical impacts were some of the factors addressed. These analyses incorporated the best available data bases and computer models to facilitate the analyses. National policy makers identified the various strategies to examine. The results of the analyses were provided to the national policy makers to support their decision making. Almost 20 years have passed since these assessments were performed. There have been major changes in energy supply and use, technologies, economics, available resources, and environmental concerns. The available tools for performing the assessments have improved drastically. The availability of improved computer modeling, i.e., MARKAL-MACRO, and improved data collection methods and data bases now permit such assessments to be performed in a more sophisticated manner to provide state of the art support to policy makers. The MARKAL-MACRO model was developed by Brookhaven National Laboratory over the last 25 years to support strategic energy planning. It is widely used in the international community for integrating analyses of environmental options, such as reduction of greenhouse gas emissions. It was used to perform the analyses in the least cost energy strategy study for the Energy Policy Act of 1992. Improvements continue to be made to MARKAL-MACRO and its capabilities extended. A methodology to conduct Country Energy Assessments using MARKAL-MACRO is discussed.

  17. Radionuclide release rates from spent fuel for performance assessment modeling

    SciTech Connect (OSTI)

    Curtis, D.B.

    1994-11-01T23:59:59.000Z

    In a scenario of aqueous transport from a high-level radioactive waste repository, the concentration of radionuclides in water in contact with the waste constitutes the source term for transport models, and as such represents a fundamental component of all performance assessment models. Many laboratory experiments have been done to characterize release rates and understand processes influencing radionuclide release rates from irradiated nuclear fuel. Natural analogues of these waste forms have been studied to obtain information regarding the long-term stability of potential waste forms in complex natural systems. This information from diverse sources must be brought together to develop and defend methods used to define source terms for performance assessment models. In this manuscript examples of measures of radionuclide release rates from spent nuclear fuel or analogues of nuclear fuel are presented. Each example represents a very different approach to obtaining a numerical measure and each has its limitations. There is no way to obtain an unambiguous measure of this or any parameter used in performance assessment codes for evaluating the effects of processes operative over many millennia. The examples are intended to suggest by example that in the absence of the ability to evaluate accuracy and precision, consistency of a broadly based set of data can be used as circumstantial evidence to defend the choice of parameters used in performance assessments.

  18. Fuel cycle assessment: A compendium of models, methodologies, and approaches

    SciTech Connect (OSTI)

    Not Available

    1994-07-01T23:59:59.000Z

    The purpose of this document is to profile analytical tools and methods which could be used in a total fuel cycle analysis. The information in this document provides a significant step towards: (1) Characterizing the stages of the fuel cycle. (2) Identifying relevant impacts which can feasibly be evaluated quantitatively or qualitatively. (3) Identifying and reviewing other activities that have been conducted to perform a fuel cycle assessment or some component thereof. (4) Reviewing the successes/deficiencies and opportunities/constraints of previous activities. (5) Identifying methods and modeling techniques/tools that are available, tested and could be used for a fuel cycle assessment.

  19. Solar Resource Assessment: Databases, Measurements, Models, and Information Sources (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2008-10-01T23:59:59.000Z

    Fact sheet for Solar Resource Assessment Workshop, Denver CO, Oct 29, 2008: ?Solar Resource Assessment Databases, Measurements, Models, and Information Sources

  20. Surfaces

    E-Print Network [OSTI]

    DeMaio, Ernest Vincent, 1964-

    1989-01-01T23:59:59.000Z

    Surfaces is a collection of four individual essays which focus on the characteristics and tactile qualities of surfaces within a variety of perceived landscapes. Each essay concentrates on a unique surface theme and purpose; ...

  1. Probing protein orientation near charged surfaces with an implicit-solvent model and the PyGBe code

    E-Print Network [OSTI]

    Cooper, Christopher D

    2015-01-01T23:59:59.000Z

    Protein-surface interactions are ubiquitous in biological processes and bioengineering, yet are not fully understood. In the field of biosensors, a key factor in biosensor performance is the orientation of biomolecules near charged surfaces. The aim of this work is developing and assessing a computational model to study proteins interacting with charged surfaces and obtain orientation data. After extending the implicit-solvent model used in the open-source code PyGBe and deriving an analytical solution for simple geometry, our careful grid-convergence analysis builds confidence on the correctness and value of our approach for probing protein orientation. Further computational experiments support it: they study preferred orientations for protein GB1 D4' and immunoglobulin G. Sampling the free energy for protein GB1 at a range of tilt and rotation angles with respect to the charged surface, we calculated the probability of the protein orientation and observed a dipolar behavior. This result is consistent with p...

  2. Modelling of Remediation Technologies at the Performance Assessment Level

    SciTech Connect (OSTI)

    Parton, N.J.; Paksy, A.; Eden, L.; Trivedi, D.P. [Nexia Solutions Limited, Hinton House, Risley, Warrington, Cheshire, UK, WA (United States)

    2008-07-01T23:59:59.000Z

    This paper presents approaches to modelling three different remediation technologies that are designed to support site operators during their assessment of remediation options for the management of radioactively contaminated land on nuclear licensed sites in the UK. The three selected technologies were soil washing, permeable reactive barrier and in-situ stabilisation. The potential exists to represent electrokinetics in the future. These technologies were chosen because it was considered that enough information already existed for site operators to assess mature technologies such as soil dig and disposal and groundwater pump and treat. Using the software code GoldSim, the models have been designed to allow site operators to make both a reasonable scoping level assessment of the viability of treatment and understand the cost-benefits of each technology. For soil washing, a standard soil leaching technique was simulated whereby the soil is separated into fines and oversize particles, and subsequently a chemical reagent is used to strip contamination off the soil. The cost benefit of this technology in terms of capital costs for the plant and materials, operational costs and waste disposal costs can also be assessed. The permeable reactive barrier (PRB) model can represent either a continuous wall or a funnel and gate system. The model simulates the transport of contaminants through the reactive material contained in the PRB. The outputs from the model include concentration of contaminants in the groundwater flow downstream of the PRB, mass of contaminants retained by the PRB, total mass and volume of waste and the various costs associated with the PRB remediation technology. The in-situ stabilisation (ISS) model has the capability to represent remediation by the addition of reagents that immobilise contaminated soil. The model simulates the release of contaminants from the treated soil over time. Performance is evaluated by comparison of the mass of contaminants retained and released to the area outside the treatment zone. Other outputs include amount of spoil generated (to be treated as waste) and the costs associated with the application of the ISS technology. These models are aimed to help users select a technology or technologies that are potentially suitable for a particular site. It is anticipated that they will prompt the user to undertake more detailed assessments to tailor the selected technology to their site specific circumstances and contaminated land conditions. (author)

  3. Metabolic modeling for the deposition of transuranic nuclides on bone surfaces 

    E-Print Network [OSTI]

    Halter, Donald Anthony

    1997-01-01T23:59:59.000Z

    to bone surfaces. Although only plutonium was used in the evaluation of this model, any bone surface-seeking, alpha-emitting nuclide, and any class compound, can be used with this model....

  4. The Paradoxes of Military Risk Assessment: Will the Enterprise Risk Assessment Model, Composite Risk Management and Associated

    E-Print Network [OSTI]

    Johnson, Chris

    to assess the nation's military preparedness. However, risk management is not a panacea for the problemsThe Paradoxes of Military Risk Assessment: Will the Enterprise Risk Assessment Model, Composite Risk Management and Associated Techniques Provide the Predicted Benefits? Chris. W. Johnson, Glasgow

  5. Literature Review and Assessment of Plant and Animal Transfer Factors Used in Performance Assessment Modeling

    SciTech Connect (OSTI)

    Robertson, David E.; Cataldo, Dominic A.; Napier, Bruce A.; Krupka, Kenneth M.; Sasser, Lyle B.

    2003-07-20T23:59:59.000Z

    A literature review and assessment was conducted by Pacific Northwest National Laboratory (PNNL) to update information on plant and animal radionuclide transfer factors used in performance-assessment modeling. A group of 15 radionuclides was included in this review and assessment. The review is composed of four main sections, not including the Introduction. Section 2.0 provides a review of the critically important issue of physicochemical speciation and geochemistry of the radionuclides in natural soil-water systems as it relates to the bioavailability of the radionuclides. Section 3.0 provides an updated review of the parameters of importance in the uptake of radionuclides by plants, including root uptake via the soil-groundwater system and foliar uptake due to overhead irrigation. Section 3.0 also provides a compilation of concentration ratios (CRs) for soil-to-plant uptake for the 15 selected radionuclides. Section 4.0 provides an updated review on radionuclide uptake data for animal products related to absorption, homeostatic control, approach to equilibration, chemical and physical form, diet, and age. Compiled transfer coefficients are provided for cow’s milk, sheep’s milk, goat’s milk, beef, goat meat, pork, poultry, and eggs. Section 5.0 discusses the use of transfer coefficients in soil, plant, and animal modeling using regulatory models for evaluating radioactive waste disposal or decommissioned sites. Each section makes specific suggestions for future research in its area.

  6. Assessing surface water consumption using remotely-sensed groundwater, evapotranspiration, and precipitation

    E-Print Network [OSTI]

    Anderson, Ray G; Lo, Min-Hui; Famiglietti, James S

    2012-01-01T23:59:59.000Z

    2010), The surface water and ocean topography mission:and the Surface Energy Balance with Topography Algorithm (

  7. Kinetic Modeling and Assessment of Lime Pretreatment of Poplar Wood

    E-Print Network [OSTI]

    Sierra Ramirez, Rocio

    2012-02-14T23:59:59.000Z

    biomass is one of the most promising feedstocks for producing biofuels through fermentation processes. Among lignocellulose choices, poplar wood is appealing because of high energy potential, above-average carbon mitigation potential, fast growth... KINETIC MODELING AND ASSESSMENT OF LIME PRETREATMENT OF POPLAR WOOD A Dissertation by ROCIO SIERRA RAMIREZ Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements...

  8. Model for the prediction of 3D surface topography in 5-axis milling

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Model for the prediction of 3D surface topography in 5-axis milling Sylvain Lavernhe LURPA - ENS surface topography obtained in 5-axis milling in function of the machining conditions. For this purpose to a feed rate prediction model. Thanks to the simulation model of 3D surface topography, the influence

  9. Development of the Flux-Adjusting Surface Data Assimilation System for Mesoscale Models

    E-Print Network [OSTI]

    Niyogi, Dev

    Development of the Flux-Adjusting Surface Data Assimilation System for Mesoscale Models KIRAN and temperature and for surface air temperature and water vapor mixing ratio for mesoscale models. In the FASDAS-field variables. The FASDAS is coupled to a land surface submodel in a three-dimensional mesoscale model and tests

  10. Aquifer sensitivity assessment modeling at a large scale

    SciTech Connect (OSTI)

    Berg, R.C.; Abert, C.C. (Illinois State Geological Survey, Champaign, IL (United States))

    1994-03-01T23:59:59.000Z

    A 480 square-mile region within Will County, northeastern Illinois was used as a test region for an evaluation of the sensitivity of aquifers to contamination. An aquifer sensitivity model was developed using a Geographic Information System (GIS) with ARC/INFO software to overlay and combine several data layers. Many of the input data layers were developed using 2-dimensional surface modeling (Interactive Surface Modeling (ISM)) and 3-dimensional volume modeling (Geologic Modeling Program (GMP)) computer software. Most of the input data layers (drift thickness, thickness of sand and gravel, depth to first aquifer) were derived from interpolation of descriptive logs for water wells and engineering borings from their study area. A total of 2,984 logs were used to produce these maps. The components used for the authors' model are (1) depth to sand and gravel or bedrock, (2) thickness of the uppermost sand and gravel aquifer, (3) drift thickness, and (4) absence or presence of uppermost bedrock aquifer. The model is an improvement over many aquifer sensitivity models because it combines specific information on depth to the uppermost sand and gravel aquifer with information on the thickness of the uppermost sand and gravel aquifer. The manipulation of the source maps according to rules-based assumptions results in a colored aquifer sensitivity map for the Will County study area. This colored map differentiates 42 aquifer sensitivity map areas by using line patterns within colors. The county-scale model results in an aquifer sensitivity map that can be a useful tool for making land-use planning decisions regarding aquifer protection and management of groundwater resources.

  11. PORFLOW Modeling Supporting The H-Tank Farm Performance Assessment

    SciTech Connect (OSTI)

    Jordan, J. M.; Flach, G. P.; Westbrook, M. L.

    2012-08-31T23:59:59.000Z

    Numerical simulations of groundwater flow and contaminant transport in the vadose and saturated zones have been conducted using the PORFLOW code in support of an overall Performance Assessment (PA) of the H-Tank Farm. This report provides technical detail on selected aspects of PORFLOW model development and describes the structure of the associated electronic files. The PORFLOW models for the H-Tank Farm PA, Rev. 1 were updated with grout, solubility, and inventory changes. The aquifer model was refined. In addition, a set of flow sensitivity runs were performed to allow flow to be varied in the related probabilistic GoldSim models. The final PORFLOW concentration values are used as input into a GoldSim dose calculator.

  12. Improved Formulations for Air-Surface Exchanges Related to National Security Needs: Dry Deposition Models

    SciTech Connect (OSTI)

    Droppo, James G.

    2006-07-01T23:59:59.000Z

    The Department of Homeland Security and others rely on results from atmospheric dispersion models for threat evaluation, event management, and post-event analyses. The ability to simulate dry deposition rates is a crucial part of our emergency preparedness capabilities. Deposited materials pose potential hazards from radioactive shine, inhalation, and ingestion pathways. A reliable characterization of these potential exposures is critical for management and mitigation of these hazards. A review of the current status of dry deposition formulations used in these atmospheric dispersion models was conducted. The formulations for dry deposition of particulate materials from am event such as a radiological attack involving a Radiological Detonation Device (RDD) is considered. The results of this effort are applicable to current emergency preparedness capabilities such as are deployed in the Interagency Modeling and Atmospheric Assessment Center (IMAAC), other similar national/regional emergency response systems, and standalone emergency response models. The review concludes that dry deposition formulations need to consider the full range of particle sizes including: 1) the accumulation mode range (0.1 to 1 micron diameter) and its minimum in deposition velocity, 2) smaller particles (less than .01 micron diameter) deposited mainly by molecular diffusion, 3) 10 to 50 micron diameter particles deposited mainly by impaction and gravitational settling, and 4) larger particles (greater than 100 micron diameter) deposited mainly by gravitational settling. The effects of the local turbulence intensity, particle characteristics, and surface element properties must also be addressed in the formulations. Specific areas for improvements in the dry deposition formulations are 1) capability of simulating near-field dry deposition patterns, 2) capability of addressing the full range of potential particle properties, 3) incorporation of particle surface retention/rebound processes, and. 4) development of dry deposition formulations applicable to urban areas. Also to improve dry deposition modeling capabilities, atmospheric dispersion models in which the dry deposition formulations are imbedded need better source-term plume initialization and improved in-plume treatment of particle growth processes. Dry deposition formulations used in current models are largely inapplicable to the complex urban environment. An improved capability is urgently needed to provide surface-specific information to assess local exposure hazard levels in both urban and non-urban areas on roads, buildings, crops, rivers, etc. A model improvement plan is developed with a near-term and far-term component. Despite some conceptual limitations, the current formulations for particle deposition based on a resistance approach have proven to provide reasonable dry deposition simulations. For many models with inadequate dry deposition formulations, adding or improving a resistance approach will be the desirable near-term update. Resistance models however are inapplicable aerodynamically very rough surfaces such as urban areas. In the longer term an improved parameterization of dry deposition needs to be developed that will be applicable to all surfaces, and in particular urban surfaces.

  13. A Hydro-Economic Approach to Representing Water Resources Impacts in Integrated Assessment Models

    SciTech Connect (OSTI)

    Kirshen, Paul H.; Strzepek, Kenneth, M.

    2004-01-14T23:59:59.000Z

    Grant Number DE-FG02-98ER62665 Office of Energy Research of the U.S. Department of Energy Abstract Many Integrated Assessment Models (IAM) divide the world into a small number of highly aggregated regions. Non-OECD countries are aggregated geographically into continental and multiple-continental regions or economically by development level. Current research suggests that these large scale aggregations cannot accurately represent potential water resources-related climate change impacts. In addition, IAMs do not explicitly model the flow regulation impacts of reservoir and ground water systems, the economics of water supply, or the demand for water in economic activities. Using the International Model for Policy Analysis of Agricultural Commodities and Trade (IMPACT) model of the International Food Policy Research Institute (IFPRI) as a case study, this research implemented a set of methodologies to provide accurate representation of water resource climate change impacts in Integrated Assessment Models. There were also detailed examinations of key issues related to aggregated modeling including: modeling water consumption versus water withdrawals; ground and surface water interactions; development of reservoir cost curves; modeling of surface areas of aggregated reservoirs for estimating evaporation losses; and evaluating the importance of spatial scale in river basin modeling. The major findings include: - Continental or national or even large scale river basin aggregation of water supplies and demands do not accurately capture the impacts of climate change in the water and agricultural sector in IAMs. - Fortunately, there now exist gridden approaches (0.5 X 0.5 degrees) to model streamflows in a global analysis. The gridded approach to hydrologic modeling allows flexibility in aligning basin boundaries with national boundaries. This combined with GIS tools, high speed computers, and the growing availability of socio-economic gridded data bases allows assignment of demands to river basins to create hydro-economic zones that respect as much as possible both political and hydrologic integrity in different models. - To minimize pre-processing of data and add increased flexibility to modeling water resources and uses, it is recommended that water withdrawal demands be modeled, not consumptive requirements even though this makes the IAM more complex. - IAMs must consider changes in water availability for irrigation under climate change; ignoring them is more inaccurate than ignoring yield changes in crops under climate change. - Determining water availability and cost in river basins must include modeling streamflows, reservoirs and their operations, and ground water and its interaction with surface water. - Scale issues are important. The results from condensing demands and supplies in a large complex river basin to one node can be misleading for all uses under low flow conditions and instream flow uses under all conditions. Monthly is generally the most accurate scale for modeling river flows and demands. Challenges remain in integrating hydrologic units with political boundaries but the gridded approach to hydrologic modeling allows flexibility in aligning basin boundaries with political boundaries. - Using minimal reservoir cost data, it is possible to use basin topography to estimate reservoir storage costs. - Reservoir evaporation must be considered when assessing the usable water in a watershed. Several methods are available to estimate the relationship between aggregated storage surface area and storage volume. - For existing or future IAMs that can not use the appropriate aggregation for water, a water preprocessor may be required due the finer scale of hydrologic impacts.

  14. CliCrop: a Crop Water-Stress and Irrigation Demand Model for an Integrated Global Assessment Model Approach

    E-Print Network [OSTI]

    Fant, C.A.

    This paper describes the use of the CliCrop model in the context of climate change general assessment

  15. Finite Difference Elastic Wave Modeling Including Surface Topography

    E-Print Network [OSTI]

    Al Muhaidib, Abdulaziz

    2011-01-01T23:59:59.000Z

    Surface topography and the weathered zone (i.e., heterogeneity near the earth’s surface) have great effects on elastic wave propagation. Both surface waves and body waves are contaminated by scattering and conversion by ...

  16. An international land-biosphere model benchmarking activity for the IPCC Fifth Assessment Report (AR5)

    SciTech Connect (OSTI)

    Hoffman, Forrest M [ORNL; Randerson, James T [ORNL; Thornton, Peter E [ORNL; Bonan, Gordon [National Center for Atmospheric Research (NCAR); Erickson III, David J [ORNL; Fung, Inez [University of California, Berkeley

    2009-12-01T23:59:59.000Z

    The need to capture important climate feedbacks in general circulation models (GCMs) has resulted in efforts to include atmospheric chemistry and land and ocean biogeochemistry into the next generation of production climate models, called Earth System Models (ESMs). While many terrestrial and ocean carbon models have been coupled to GCMs, recent work has shown that such models can yield a wide range of results (Friedlingstein et al., 2006). This work suggests that a more rigorous set of global offline and partially coupled experiments, along with detailed analyses of processes and comparisons with measurements, are needed. The Carbon-Land Model Intercomparison Project (C-LAMP) was designed to meet this need by providing a simulation protocol and model performance metrics based upon comparisons against best-available satellite- and ground-based measurements (Hoffman et al., 2007). Recently, a similar effort in Europe, called the International Land Model Benchmark (ILAMB) Project, was begun to assess the performance of European land surface models. These two projects will now serve as prototypes for a proposed international land-biosphere model benchmarking activity for those models participating in the IPCC Fifth Assessment Report (AR5). Initially used for model validation for terrestrial biogeochemistry models in the NCAR Community Land Model (CLM), C-LAMP incorporates a simulation protocol for both offline and partially coupled simulations using a prescribed historical trajectory of atmospheric CO2 concentrations. Models are confronted with data through comparisons against AmeriFlux site measurements, MODIS satellite observations, NOAA Globalview flask records, TRANSCOM inversions, and Free Air CO2 Enrichment (FACE) site measurements. Both sets of experiments have been performed using two different terrestrial biogeochemistry modules coupled to the CLM version 3 in the Community Climate System Model version 3 (CCSM3): the CASA model of Fung, et al., and the carbon-nitrogen (CN) model of Thornton. Comparisons of the CLM3 offline results against observational datasets have been performed and are described in Randerson et al. (2009). CLM version 4 has been evaluated using C-LAMP, showing improvement in many of the metrics. Efforts are now underway to initiate a Nitrogen-Land Model Intercomparison Project (N-LAMP) to better constrain the effects of the nitrogen cycle in biosphere models. Presented will be new results from C-LAMP for CLM4, initial N-LAMP developments, and the proposed land-biosphere model benchmarking activity.

  17. Utilizing CLASIC observations and multiscale models to study the impact of improved Land surface representation on modeling cloud- convection

    SciTech Connect (OSTI)

    Niyogi, Devdutta S. [Purdue

    2013-06-07T23:59:59.000Z

    The CLASIC experiment was conducted over the US southern great plains (SGP) in June 2007 with an objective to lead an enhanced understanding of the cumulus convection particularly as it relates to land surface conditions. This project was design to help assist with understanding the overall improvement of land atmosphere convection initiation representation of which is important for global and regional models. The study helped address one of the critical documented deficiency in the models central to the ARM objectives for cumulus convection initiation and particularly under summer time conditions. This project was guided by the scientific question building on the CLASIC theme questions: What is the effect of improved land surface representation on the ability of coupled models to simulate cumulus and convection initiation? The focus was on the US Southern Great Plains region. Since the CLASIC period was anomalously wet the strategy has been to use other periods and domains to develop the comparative assessment for the CLASIC data period, and to understand the mechanisms of the anomalous wet conditions on the tropical systems and convection over land. The data periods include the IHOP 2002 field experiment that was over roughly same domain as the CLASIC in the SGP, and some of the DOE funded Ameriflux datasets.

  18. A Physically Based Runoff Routing Model for Land Surface and Earth System Models

    SciTech Connect (OSTI)

    Li, Hongyi; Wigmosta, Mark S.; Wu, Huan; Huang, Maoyi; Ke, Yinghai; Coleman, Andre M.; Leung, Lai-Yung R.

    2013-06-13T23:59:59.000Z

    A new physically based runoff routing model, called the Model for Scale Adaptive River Transport (MOSART), has been developed to be applicable across local, regional, and global scales. Within each spatial unit, surface runoff is first routed across hillslopes and then discharged along with subsurface runoff into a ‘‘tributary subnetwork’’ before entering the main channel. The spatial units are thus linked via routing through the main channel network, which is constructed in a scale-consistent way across different spatial resolutions. All model parameters are physically based, and only a small subset requires calibration.MOSART has been applied to the Columbia River basin at 1/ 168, 1/ 88, 1/ 48, and 1/ 28 spatial resolutions and was evaluated using naturalized or observed streamflow at a number of gauge stations. MOSART is compared to two other routing models widely used with land surface models, the River Transport Model (RTM) in the Community Land Model (CLM) and the Lohmann routing model, included as a postprocessor in the Variable Infiltration Capacity (VIC) model package, yielding consistent performance at multiple resolutions. MOSART is further evaluated using the channel velocities derived from field measurements or a hydraulic model at various locations and is shown to be capable of producing the seasonal variation and magnitude of channel velocities reasonably well at different resolutions. Moreover, the impacts of spatial resolution on model simulations are systematically examined at local and regional scales. Finally, the limitations ofMOSART and future directions for improvements are discussed.

  19. Western oil-shale development: a technology assessment. Volume 4. Solid waste from mining and surface retorts

    SciTech Connect (OSTI)

    Not Available

    1982-01-01T23:59:59.000Z

    The overall objectives of this study were to: review and evaluate published information on the disposal, composition, and leachability of solid wastes produced by aboveground shale oil extraction processes; examine the relationship of development to surface and groundwater quality in the Piceance Creek basin of northwestern Colorado; and identify key areas of research necessary to quantitative assessment of impact. Information is presented under the following section headings: proposed surface retorting developments; surface retorting processes; environmental concerns; chemical/mineralogical composition of raw and retorted oil shale; disposal procedures; water quality; and research needs.

  20. An Inspector's Assessment of the New Model Safeguards Approach for Enrichment Plants

    SciTech Connect (OSTI)

    Curtis, Michael M.

    2007-07-31T23:59:59.000Z

    This conference paper assesses the changes that are being made to the Model Safeguards Approach for Gas Centrifuge Enrichment Plants.

  1. Facet Model and Mathematical Morphology for Surface Characterization

    SciTech Connect (OSTI)

    Abidi, B.R.; Goddard, J.S.; Hunt, M.A.; Sari-Sarraf, H.

    1999-11-13T23:59:59.000Z

    This paper describes an algorithm for the automatic segmentation and representation of surface structures and non-uniformities in an industrial setting. The automatic image processing and analysis algorithm is developed as part of a complete on-line web characterization system of a papermaking process at the wet end. The goal is to: (1) link certain types of structures on the surface of the web to known machine parameter values, and (2) find the connection between detected structures at the beginning of the line and defects seen on the final product. Images of the pulp mixture (slurry), carried by a fast moving table, are obtained using a stroboscopic light and a CCD camera. This characterization algorithm succeeded where conventional contrast and edge detection techniques failed due to a poorly controlled environment. The images obtained have poor contrast and contain noise caused by a variety of sources. After a number of enhancement steps, conventional segmentation methods still f ailed to detect any structures and are consequently discarded. Techniques tried include the Canny edge detector, the Sobel, Roberts, and Prewitt's filters, as well as zero crossings. The facet model algorithm, is then applied to the images with various parameter settings and is found to be successful in detecting the various topographic characteristics of the surface of the slurry. Pertinent topographic elements are retained and a filtered image computed. Carefully tailored morphological operators are then applied to detect and segment regions of interest. Those regions are then selected according to their size, elongation, and orientation. Their bounding rectangles are computed and represented. Also addressed in this paper are aspects of the real time implementation of this algorithm for on-line use. The algorithm is tested on over 500 images of slurry and is found to segment and characterize nonuniformities on all 500 images.

  2. Methods for Developing Emissions Scenarios for Integrated Assessment Models

    SciTech Connect (OSTI)

    Prinn, Ronald [MIT; Webster, Mort [MIT

    2007-08-20T23:59:59.000Z

    The overall objective of this research was to contribute data and methods to support the future development of new emissions scenarios for integrated assessment of climate change. Specifically, this research had two main objectives: 1. Use historical data on economic growth and energy efficiency changes, and develop probability density functions (PDFs) for the appropriate parameters for two or three commonly used integrated assessment models. 2. Using the parameter distributions developed through the first task and previous work, we will develop methods of designing multi-gas emission scenarios that usefully span the joint uncertainty space in a small number of scenarios. Results on the autonomous energy efficiency improvement (AEEI) parameter are summarized, an uncertainty analysis of elasticities of substitution is described, and the probabilistic emissions scenario approach is presented.

  3. Review of free-surface MHD experiments and modeling.

    SciTech Connect (OSTI)

    Molokov, S.; Reed, C. B.

    2000-06-02T23:59:59.000Z

    This review paper was prepared to survey the present status of analytical and experimental work in the area of free surface MHD and thus provide a well informed starting point for further work by the Advanced Limiter-diverter Plasma-facing Systems (ALPS) program. ALPS were initiated to evaluate the potential for improved performance and lifetime for plasma-facing systems. The main goal of the program is to demonstrate the advantages of advanced limiter/diverter systems over conventional systems in terms of power density capability, component lifetime, and power conversion efficiency, while providing for safe operation and minimizing impurity concerns for the plasma. Most of the work to date has been applied to free surface liquids. A multi-disciplinary team from several institutions has been organized to address the key issues associated with these systems. The main performance goals for advanced limiters and diverters are a peak heat flux of >50 MW/m{sup 2}, elimination of a lifetime limit for erosion, and the ability to extract useful heat at high power conversion efficiency ({approximately}40%). The evaluation of various options is being conducted through a combination of laboratory experiments, modeling of key processes, and conceptual design studies.

  4. HVAC Modeling for Cost of Ownership Assessment in Biotechnology & Drugs Manufacturing

    E-Print Network [OSTI]

    Broomes, Peter; Dornfeld, David A

    2003-01-01T23:59:59.000Z

    2000 Broomes, Peter. , “HVAC Modeling for Cost of Ownership2000 Broomes, Peter. , “HVAC Results Comparison”, April,HVAC Modeling for Cost of Ownership Assessment in

  5. Why are climate models reproducing the observed global surface warming so well?

    E-Print Network [OSTI]

    Fischlin, Andreas

    Why are climate models reproducing the observed global surface warming so well? Reto Knutti1 global surface warming so well?, Geophys. Res. Lett., 35, L18704, doi:10.1029/ 2008GL034932. 1 models reproduce the observed surface warming better than one would expect given the uncertainties

  6. Modeling drag reduction and meniscus stability of superhydrophobic surfaces comprised of random roughness

    E-Print Network [OSTI]

    Tafreshi, Hooman Vahedi

    Modeling drag reduction and meniscus stability of superhydrophobic surfaces comprised of random reduction and stability of the air-water interface on superhydrophobic surfaces were conducted in aligned or staggered configurations. In this paper, we model the performance of superhydrophobic surfaces

  7. SURFACE TENSION AND WULFF SHAPE FOR A LATTICE MODEL WITHOUT SPIN FLIP SYMMETRY

    E-Print Network [OSTI]

    SURFACE TENSION AND WULFF SHAPE FOR A LATTICE MODEL WITHOUT SPIN FLIP SYMMETRY T. BODINEAU AND E. PRESUTTI Abstract. We propose a new definition of surface tension and check it in a spin model on the phase transitions line and prove: (i) existence of the surface tension in the thermodynamic limit

  8. Modeling the Near-Surface Using High-Resolution Seismic Data

    E-Print Network [OSTI]

    Al-Zayer, Ramzy Mohammed

    2010-01-26T23:59:59.000Z

    In the Arabian Peninsula, the near-surface represents a major challenge in seismic exploration. For accurate deep subsurface reservoir imaging, an accurate near-surface velocity model is required. In this dissertation, I ...

  9. Heating requirements and non-adiabatic surface effects for a model in the National Transonic Facility

    E-Print Network [OSTI]

    Pare, Louis Alphonse

    1984-01-01T23:59:59.000Z

    insulated, adiabatic surface. A heat transfer analysis intended to yield a conservative estimate of the non-adiabatic condition was performed. A Finite element heat transfer computer code was developed and used to compute the steady state temperature... identified regions on the surface of the model susceptible to surface heating and the magnitude of the respective surface temperatures. The addition of insulation within the cavity to limit surface heating was also investigated. The geometry...

  10. Discrete Fracture Network Models for Risk Assessment of Carbon Sequestration in Coal

    SciTech Connect (OSTI)

    Jack Pashin; Guohai Jin; Chunmiao Zheng; Song Chen; Marcella McIntyre

    2008-07-01T23:59:59.000Z

    A software package called DFNModeler has been developed to assess the potential risks associated with carbon sequestration in coal. Natural fractures provide the principal conduits for fluid flow in coal-bearing strata, and these fractures present the most tangible risks for the leakage of injected carbon dioxide. The objectives of this study were to develop discrete fracture network (DFN) modeling tools for risk assessment and to use these tools to assess risks in the Black Warrior Basin of Alabama, where coal-bearing strata have high potential for carbon sequestration and enhanced coalbed methane recovery. DFNModeler provides a user-friendly interface for the construction, visualization, and analysis of DFN models. DFNModeler employs an OpenGL graphics engine that enables real-time manipulation of DFN models. Analytical capabilities in DFNModeler include display of structural and hydrologic parameters, compartmentalization analysis, and fluid pathways analysis. DFN models can be exported to third-party software packages for flow modeling. DFN models were constructed to simulate fracturing in coal-bearing strata of the upper Pottsville Formation in the Black Warrior Basin. Outcrops and wireline cores were used to characterize fracture systems, which include joint systems, cleat systems, and fault-related shear fractures. DFN models were constructed to simulate jointing, cleating, faulting, and hydraulic fracturing. Analysis of DFN models indicates that strata-bound jointing compartmentalizes the Pottsville hydrologic system and helps protect shallow aquifers from injection operations at reservoir depth. Analysis of fault zones, however, suggests that faulting can facilitate cross-formational flow. For this reason, faults should be avoided when siting injection wells. DFN-based flow models constructed in TOUGH2 indicate that fracture aperture and connectivity are critical variables affecting the leakage of injected CO{sub 2} from coal. Highly transmissive joints near an injection well have potential to divert a large percentage of an injected CO{sub 2} stream away from a target coal seam. However, the strata-bound nature of Pottsville fracture systems is a natural factor that mitigates the risk of long-range leakage and surface seepage. Flow models indicate that cross-formational flow in strata-bound joint networks is low and is dissipated by about an order of magnitude at each successive bedding contact. These models help confirm that strata-bound joint networks are self-compartmentalizing and that the thick successions of interbedded shale and sandstone separating the Pottsville coal zones are confining units that protect shallow aquifers from injection operations at reservoir depth. DFN models are powerful tools for the simulation and analysis of fracture networks and can play an important role in the assessment of risks associated with carbon sequestration and enhanced coalbed methane recovery. Importantly, the stochastic nature DFN models dictates that they cannot be used to precisely reproduce reservoir conditions in a specific field area. Rather, these models are most useful for simulating the fundamental geometric and statistical properties of fracture networks. Because the specifics of fracture architecture in a given area can be uncertain, multiple realizations of DFN models and DFN-based flow models can help define variability that may be encountered during field operations. Using this type of approach, modelers can inform the risk assessment process by characterizing the types and variability of fracture architecture that may exist in geologic carbon sinks containing natural fractures.

  11. Improving Modeling of Iodine-129 Groundwater Contamination Plumes Using the System Assessment Capability

    SciTech Connect (OSTI)

    Dirkes, J.; Nichols, W.E.; Wurstner, S.K.

    2004-01-01T23:59:59.000Z

    Years of production of radioactive materials at the Hanford Site in southeastern Washington State has resulted in contamination of surface, subsurface, and surface water environments. Cleanup of the site has been aided by various tools, including computer software used to predict contaminant migration in the future and estimate subsequent impacts. The System Assessment Capability (SAC) is a total systems tool designed to simulate the movement of contaminants from all waste sites at Hanford through the vadose zone, the unconfined aquifer, and the Columbia River. Except for iodine-129, most of the contaminants modeled by SAC have acceptably matched field measurements. The two most likely reasons for the inconsistency between the measured field data and SAC modeled predictions are an underestimated inventory and an overestimated sorption value (Kd). Field data tend to be point measurements taken from near the surface of the unconfined aquifer. Thus, the depth of the iodine-129 contamination plume on the site is not well characterized. Geostatistical analyses of the measured data were conducted to determine the mass of iodine-129 for four assumed plume depths within the unconfined aquifer. Several simulations for two different Kd’s using the initial SAC inventory were run to determine the effect of an overestimated sorption value on SAC modeled predictions. The initial SAC inventory was then increased for the two different Kd’s to determine the influence of an underestimated inventory on SAC modeled predictions. It was found that evidence for both an underestimated inventory and for an overestimated sorption value for iodine-129 exist. These results suggest that the Kd for iodine-129 should be reevaluated and that a more complete inventory must be generated in order to more accurately model iodine-129 groundwater contamination plumes that match available field data.

  12. Model Evaluation and Hindcasting: An Experiment with an Integrated Assessment Model

    SciTech Connect (OSTI)

    Chaturvedi, Vaibhav; Kim, Son H.; Smith, Steven J.; Clarke, Leon E.; Zhou, Yuyu; Kyle, G. Page; Patel, Pralit L.

    2013-11-01T23:59:59.000Z

    Integrated assessment models have been extensively used for analyzing long term energy and greenhouse emissions trajectories and have influenced key policies on this subject. Though admittedly these models are focused on the long term trajectories, how well these models are able to capture historical dynamics is an open question. In a first experiment of its kind, we present a framework for evaluation of such integrated assessment models. We use Global Change Assessment Model for this zero order experiment, and focus on the building sector results for USA. We calibrate the model for 1990 and run it forward up to 2095 in five year time steps. This gives us results for 1995, 2000, 2005 and 2010 which we compare to observed historical data at both fuel level and service level. We focus on bringing out the key insights for the wider process of model evaluation through our experiment with GCAM. We begin with highlighting that creation of an evaluation dataset and identification of key evaluation metric is the foremost challenge in the evaluation process. Our analysis highlights that estimation of functional form of the relationship between energy service demand, which is an unobserved variable, and its drivers is a significant challenge in the absence of adequate historical data for both the dependent and driver variables. Historical data availability for key metrics is a serious limiting factor in the process of evaluation. Interestingly, service level data against which such models need to be evaluated are itself a result of models. Thus for energy services, the best we can do is compare our model results with other model results rather than observed and measured data. We show that long term models, by the nature of their construction, will most likely underestimate the rapid growth in some services observed in a short time span. Also, we learn that modeling saturated energy services like space heating is easier than modeling unsaturated services like space cooling and understanding that how far a service is from its saturation level is a key question which we probably don’t have an answer to. Finally and most importantly, even if long term models partially miss the short term dynamics, the long term insights provides by these models is fairly robust. We conclude by highlighting that our work is the first step in the much wider process of integrated assessment model evaluation and will hence have its own limitations. Future evaluation research work should build upon this zero order experiment for improving our modeling of human and coupled earth systems.

  13. An improved vacuum formulation for 2D finite-difference modeling of Rayleigh waves including surface topography and internal discontinuities

    E-Print Network [OSTI]

    Zeng, Chong; Xia, Jianghai; Miller, Richard D.; Tsoflias, Georgios P.

    2012-01-01T23:59:59.000Z

    Rayleigh waves are generated along the free surface and their propagation can be strongly influenced by surface topography. Modeling of Rayleigh waves in the near surface in the presence of topography is fundamental to the study of surface waves...

  14. Tumor Tracking Method Based on a Deformable 4D CT Breathing Motion Model Driven by an External Surface Surrogate

    SciTech Connect (OSTI)

    Fassi, Aurora, E-mail: aurora.fassi@mail.polimi.it [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano (Italy); Schaerer, Joël; Fernandes, Mathieu [CREATIS, CNRS UMR 5220, INSERM U1044, Université Lyon 1, INSA-Lyon, Villeurbanne (France); Department of Radiotherapy, Centre Léon Bérard, Lyon (France); Riboldi, Marco [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano (Italy); Bioengineering Unit, CNAO Foundation, Pavia (Italy); Sarrut, David [CREATIS, CNRS UMR 5220, INSERM U1044, Université Lyon 1, INSA-Lyon, Villeurbanne (France); Department of Radiotherapy, Centre Léon Bérard, Lyon (France); Baroni, Guido [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano (Italy); Bioengineering Unit, CNAO Foundation, Pavia (Italy)

    2014-01-01T23:59:59.000Z

    Purpose: To develop a tumor tracking method based on a surrogate-driven motion model, which provides noninvasive dynamic localization of extracranial targets for the compensation of respiration-induced intrafraction motion in high-precision radiation therapy. Methods and Materials: The proposed approach is based on a patient-specific breathing motion model, derived a priori from 4-dimensional planning computed tomography (CT) images. Model parameters (respiratory baseline, amplitude, and phase) are retrieved and updated at each treatment fraction according to in-room radiography acquisition and optical surface imaging. The baseline parameter is adapted to the interfraction variations obtained from the daily cone beam (CB) CT scan. The respiratory amplitude and phase are extracted from an external breathing surrogate, estimated from the displacement of the patient thoracoabdominal surface, acquired with a noninvasive surface imaging device. The developed method was tested on a database of 7 lung cancer patients, including the synchronized information on internal and external respiratory motion during a CBCT scan. Results: About 30 seconds of simultaneous acquisition of CBCT and optical surface images were analyzed for each patient. The tumor trajectories identified in CBCT projections were used as reference and compared with the target trajectories estimated from surface displacement with the a priori motion model. The resulting absolute differences between the reference and estimated tumor motion along the 2 image dimensions ranged between 0.7 and 2.4 mm; the measured phase shifts did not exceed 7% of the breathing cycle length. Conclusions: We investigated a tumor tracking method that integrates breathing motion information provided by the 4-dimensional planning CT with surface imaging at the time of treatment, representing an alternative approach to point-based external–internal correlation models. Although an in-room radiograph-based assessment of the reliability of the motion model is envisaged, the developed technique does not involve the estimation and continuous update of correlation parameters, thus requiring a less intense use of invasive imaging.

  15. Surface Tension Adjustment in a Pseudo-Potential Lattice Boltzmann Model

    E-Print Network [OSTI]

    Hu, Anjie; Uddin, Rizwan

    2014-01-01T23:59:59.000Z

    Pseudo-potential lattice Boltzmann models have been widely applied in many multiphase simulations. However, most of these models still suffer from some drawbacks such as spurious velocities and untunable surface tension. In this paper, we aim to discuss the surface tension of a popular pseudo-potential model proposed by Kupershtokh et al., which has attracted much attention due to its simplicity and stability. The influence of a parameter on the surface tension in the model is analyzed. Based on the analysis, we proposed a method to adjust surface tension by changing the parameter in the model. However, the density distribution and the stability of the model also depend on the parameter. To adjust the surface tension independently, the pressure tensor modifying method is introduced and numerically tested. The simulation results show that, by applying the pressure tensor modifying method, the surface tension can be adjusted with little influence on the stability and density distributions.

  16. Model Test Setup and Program for Experimental Estimation of Surface Loads of the SSG Kvitsy

    E-Print Network [OSTI]

    Model Test Setup and Program for Experimental Estimation of Surface Loads of the SSG Kvitsøy Pilot Engineering No. 32 ISSN: 1603-9874 Model Test Setup and Program for Experimental Estimation of Surface Loads University October, 2005 #12;#12;Preface This report presents the preparations done prior to model tests

  17. Centrifuge modeling of radioactive waste migration through backfill in a near surface disposal facility

    SciTech Connect (OSTI)

    Gurumoorthy, C.; Kusakabe, O. [Geotechnical Engineering Division, Tokyo Institute of Technology, 2-12-1 Ookayama Meguroku, Tokyo 1528552 (Japan)

    2007-07-01T23:59:59.000Z

    Investigations on the performance of backfill barrier in Near Surface Disposal Facility (NSDF) for radioactive wastes are important to ensure the long term safety of such disposal option. Favorable condition to delay migration of radionuclides from disposed waste to far fields is diffusion process. However, advective dispersion/diffusion mechanism plays an important role due to changes in backfill over a period of time. In order to understand these mechanisms, detailed laboratory experiments are usually conducted for developing mathematical models to assess the behaviour of backfill. However, these experiments are time consuming and suffer with the limitations due to material complexity. Also, there are constraints associated with validation of theoretical predictions due to intricacy of boundary conditions as well as the time scale is quite different as compared to the time required for completion of the processes in the field. Keeping in view these aspects, centrifuge modeling technique has been adopted by various researchers to model and understand various geo-environment problems in order to provide a link between the real life situation termed as the 'Prototype' and its model, which is exposed to a higher gravitational field. An attempt has been made in this paper to investigate the feasibility of this technique to model advective dispersion/diffusion mechanism of radionuclides through saturated Bentonite-Sand (B:S) backfill. Various stages of centrifuge modeling are highlighted. Column tests were conducted in the centrifuge to evaluate the hydraulic conductivity of B:S mixture under prototype NSDF stress conditions. Results showed that steady state hydraulic conductivity under saturated conditions was 2.86 10{sup -11} m/sec. Studies indicate the feasibility of centrifuge modeling technique and usefulness to model advective diffusion of radionuclides through B:S backfill. (authors)

  18. Utility of Social Modeling for Proliferation Assessment - Enhancing a Facility-Level Model for Proliferation Resistance Assessment of a Nuclear Enegry System

    SciTech Connect (OSTI)

    Coles, Garill A.; Brothers, Alan J.; Gastelum, Zoe N.; Olson, Jarrod; Thompson, Sandra E.

    2009-10-26T23:59:59.000Z

    The Utility of Social Modeling for Proliferation Assessment project (PL09-UtilSocial) investigates the use of social and cultural information to improve nuclear proliferation assessments, including nonproliferation assessments, Proliferation Resistance (PR) assessments, safeguards assessments, and other related studies. These assessments often use and create technical information about a host State and its posture towards proliferation, the vulnerability of a nuclear energy system (NES) to an undesired event, and the effectiveness of safeguards. This objective of this project is to find and integrate social and technical information by explicitly considering the role of cultural, social, and behavioral factors relevant to proliferation; and to describe and demonstrate if and how social science modeling has utility in proliferation assessment. This report describes a modeling approach and how it might be used to support a location-specific assessment of the PR assessment of a particular NES. The report demonstrates the use of social modeling to enhance an existing assessment process that relies on primarily technical factors. This effort builds on a literature review and preliminary assessment performed as the first stage of the project and compiled in PNNL-18438. [ T his report describes an effort to answer questions about whether it is possible to incorporate social modeling into a PR assessment in such a way that we can determine the effects of social factors on a primarily technical assessment. This report provides: 1. background information about relevant social factors literature; 2. background information about a particular PR assessment approach relevant to this particular demonstration; 3. a discussion of social modeling undertaken to find and characterize social factors that are relevant to the PR assessment of a nuclear facility in a specific location; 4. description of an enhancement concept that integrates social factors into an existing, technically based nuclear facility assessment; 5. a discussion of a way to engage with the owners of the PR assessment methodology to assess and improve the enhancement concept; 6. a discussion of implementation of the proposed approach, including a discussion of functionality and potential users; and 7. conclusions from the research. This report represents technical deliverables for the NA-22 Simulations, Algorithms, and Modeling program. Specifically this report is the Task 2 and 3 deliverables for project PL09-UtilSocial.

  19. Surface tension model for surfactant solutions at the critical micelle concentration

    E-Print Network [OSTI]

    S. F. Burlatsky; V. V. Atrazhev; D. V. Dmitriev; V. I. Sultanov; E. N. Timokhina; E. A. Ugolkova; S. Tulyani; A. Vincitore

    2013-06-19T23:59:59.000Z

    A model for the limiting surface tension of surfactant solutions (surface tension at and above the critical micelle concentration, cmc) was developed. This model takes advantage of the equilibrium between the surfactant molecules on the liquid/vacuum surface and in micelles in the bulk at the cmc. An approximate analytical equation for the surface tension at the cmc was obtained. The derived equation contains two parameters, which characterize the intermolecular interactions in the micelles, and the third parameter, which is the surface area per surfactant molecule at the interface. These parameters were calculated using a new atomistic modeling approach. The performed calculations of the limiting surface tension for four simple surfactants show good agreement with experimental data (~30% accuracy). The developed model provides the guidance for design of surfactants with low surface tension values.

  20. Multiobjective calibration and sensitivity of a distributed land surface water and energy balance model

    E-Print Network [OSTI]

    Houser, Paul R; Gupta, Hoshin V; Shuttleworth, W. James; Famiglietti, James S

    2001-01-01T23:59:59.000Z

    identification and energy balance models on a tallgrassdata for surface energy balance evaluation of a semiaridWatershed. We are energy balance components over a semiarid

  1. Constructing Irregular Surfaces to Enclose Macromolecular Complexes for Mesoscale Modeling Using the Discrete

    E-Print Network [OSTI]

    Schlick, Tamar

    Constructing Irregular Surfaces to Enclose Macromolecular Complexes for Mesoscale Modeling Using proteins. DiSCO is generally applicable to other interesting macromolecular systems for which mesoscale

  2. Dynamic Model for Assessing Impact of Regeneration Actions on System Availability: Application to Weapon Systems

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Dynamic Model for Assessing Impact of Regeneration Actions on System Availability: Application) Key Words: failure, damage, regeneration, availability assessment, stochastic activity networks, Monte Carlo simulations SUMMARY & CONCLUSIONS Availability is a determining factor in systems characterization

  3. A Formal Model for A System's Attack Surface Pratyusa K. Manadhata Dilsun K. Kaynar

    E-Print Network [OSTI]

    Wing, Jeannette M.

    A Formal Model for A System's Attack Surface Pratyusa K. Manadhata Dilsun K. Kaynar Jeannette M software [18]. In this paper, we propose to use a software system's attack surface measurement as an indicator of the system's security; the larger the attack surface, the more insecure the system. We

  4. Surface Free Energies, Interfacial Tensions and Correlation Lengths of the ABF Models

    E-Print Network [OSTI]

    Pearce, Paul A.

    Surface Free Energies, Interfacial Tensions and Correlation Lengths of the ABF Models David L. O. Abstract The surface free energies, interfacial tensions and correlation lengths of the Andrews been established there are various quan- tities of physical interest, such as the surface free energies

  5. Modeling hydrogen and helium entrapment in flowing liquid metal surfaces as plasma-facing components in

    E-Print Network [OSTI]

    Harilal, S. S.

    Modeling hydrogen and helium entrapment in flowing liquid metal surfaces as plasma the PFC surface (helium and hydrogen isotopes) while accommodating high heat loads. To study this problem rather than requiring a standard vacuum system. Hydrogen isotope (DT) particles that strike the surface

  6. hal00272925, SURFACE TENSION IN THE DILUTE ISING MODEL. THE WULFF

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    hal­00272925, version 1 ­ 14 Apr 2008 SURFACE TENSION IN THE DILUTE ISING MODEL. THE WULFF CONSTRUCTION. MARC WOUTS Abstract. We study the surface tension and the phenomenon of phase coexistence in probability (with respect to random couplings) of surface tension and analyze its large deviations : upper

  7. A continuous surface tension force formulation for diffuse-interface models

    E-Print Network [OSTI]

    Frey, Pascal

    A continuous surface tension force formulation for diffuse-interface models Junseok Kim October 2004 Available online 30 November 2004 Abstract We present a new surface tension force formulation field because pressure includes the gradient terms resulting from the modified surface tension term

  8. Land Surface Model Data Assimilation for Atmospheric Prediction

    E-Print Network [OSTI]

    Walker, Jeff

    remote sensing studies, using visible, thermal infrared (surface temperature) and microwave (passive, the first passive microwave sensor in space with appropriate frequencies for measuring near-surface soil of concurrent data has made evaluation of SMMR-based studies effectively impossible (Walker et al., 2003

  9. Molecular modelling and simulation of the surface tension of real quadrupolar fluids

    E-Print Network [OSTI]

    Stephan Werth; Katrin Stöbener; Peter Klein; Karl-Heinz Küfer; Martin Horsch; Hans Hasse

    2014-08-21T23:59:59.000Z

    Molecular modelling and simulation of the surface tension of fluids with force fields is discussed. 29 real fluids are studied, including nitrogen, oxygen, carbon dioxide, carbon monoxide, fluorine, chlorine, bromine, iodine, ethane, ethylene, acetylene, propyne, propylene, propadiene, carbon disulfide, sulfur hexafluoride, and many refrigerants. The fluids are represented by two-centre Lennard-Jones plus point quadrupole models from the literature. These models were adjusted only to experimental data of the vapour pressure and saturated liquid density so that the results for the surface tension are predictions. The deviations between the predictions and experimental data for the surface tension are of the order of 20 percent. The surface tension is usually overestimated by the models. For further improvements, data on the surface tension can be included in the model development. A suitable strategy for this is multi-criteria optimization based on Pareto sets. This is demonstrated using the model for carbon dioxide as an example.

  10. Inverse Modeling of Hydrologic Parameters Using Surface Flux and Runoff Observations in the Community Land Model

    SciTech Connect (OSTI)

    Sun, Yu; Hou, Zhangshuan; Huang, Maoyi; Tian, Fuqiang; Leung, Lai-Yung R.

    2013-12-10T23:59:59.000Z

    This study demonstrates the possibility of inverting hydrologic parameters using surface flux and runoff observations in version 4 of the Community Land Model (CLM4). Previous studies showed that surface flux and runoff calculations are sensitive to major hydrologic parameters in CLM4 over different watersheds, and illustrated the necessity and possibility of parameter calibration. Two inversion strategies, the deterministic least-square fitting and stochastic Markov-Chain Monte-Carlo (MCMC) - Bayesian inversion approaches, are evaluated by applying them to CLM4 at selected sites. The unknowns to be estimated include surface and subsurface runoff generation parameters and vadose zone soil water parameters. We find that using model parameters calibrated by the least-square fitting provides little improvements in the model simulations but the sampling-based stochastic inversion approaches are consistent - as more information comes in, the predictive intervals of the calibrated parameters become narrower and the misfits between the calculated and observed responses decrease. In general, parameters that are identified to be significant through sensitivity analyses and statistical tests are better calibrated than those with weak or nonlinear impacts on flux or runoff observations. Temporal resolution of observations has larger impacts on the results of inverse modeling using heat flux data than runoff data. Soil and vegetation cover have important impacts on parameter sensitivities, leading to the different patterns of posterior distributions of parameters at different sites. Overall, the MCMC-Bayesian inversion approach effectively and reliably improves the simulation of CLM under different climates and environmental conditions. Bayesian model averaging of the posterior estimates with different reference acceptance probabilities can smooth the posterior distribution and provide more reliable parameter estimates, but at the expense of wider uncertainty bounds.

  11. Impact of Agricultural Practice on Regional Climate in a Coupled Land Surface Mesoscale Model

    E-Print Network [OSTI]

    Cooley, H.S.; Riley, W.J.; Torn, M.S.; He, Y.

    2004-01-01T23:59:59.000Z

    winter wheat belt on the mesoscale environment, Monthlygeneration Penn State/NCAR mesoscale model (MM5), NCAR,in a Coupled Land Surface Mesoscale Model H.S. Cooley Energy

  12. Assessment of a Molecular Diffusion Model in MELCOR

    SciTech Connect (OSTI)

    Chang OH; Richard Moore

    2005-06-01T23:59:59.000Z

    The MELCOR (version 1.8.5) [1] computer code with INEEL revisions is being improved for the analysis of very high temperature gas-cooled reactors [2]. Following a loss-of-coolant accident, flow through the reactor vessel may initially stagnate due to a non-uniform concentration of helium and air. However, molecular diffusion will eventually result in a uniform concentration of air and helium. The differences in fluid temperatures within the reactor vessel will then result in the establishment of a natural circulation flow that can supply significant amounts of air to the reactor core. The heat released by the resulting oxidation of graphite in the reactor core has the potential to increase the peak fuel temperature. In order to analyze the effects of oxidation on the response of the reactor during accidents, a molecular diffusion model was added to MELCOR. The model is based on Fick's Second Law for spatially uniform pressure and temperature. This paper describes equimolal counter diffusion experiments in a two bulb diffusion cell and the results of the assessment calculations.

  13. IEEE TRANSACTION ON VISUALIZATION AND COMPUTER GRAPHICS 1 Water Surface Modeling from A Single

    E-Print Network [OSTI]

    Martin, Ralph R.

    water brings unique challenges [15]. Major difficulties include it- s lack of matchable featuresIEEE TRANSACTION ON VISUALIZATION AND COMPUTER GRAPHICS 1 Water Surface Modeling from A Single and Phillip Willis Abstract--We introduce a video based approach for producing water surface models. Recent

  14. Galerkin method to model thin free surface flows

    E-Print Network [OSTI]

    Lee. Sungyon

    2007-01-01T23:59:59.000Z

    Viscoelastic thin films with free surface are important in industry as well as in nature. However, there does not exist a robust and systematic framework to analyze such films. Lubrication approximations, largely successful ...

  15. 3?D Surface Topography Boundary Conditions in Seismic Wave Modelling

    E-Print Network [OSTI]

    Hestholm, Stig

    2001-01-01T23:59:59.000Z

    New alternative formulations of exact boundary conditions for arbitrary three{dimensional (3?D) free surface topographies on seismic media have been derived. They are shown to be equivalent with previously published ...

  16. Modeling of solar thermal selective surfaces and thermoelectric generators

    E-Print Network [OSTI]

    McEnaney, Kenneth

    2010-01-01T23:59:59.000Z

    A thermoelectric generator is a solid-state device that converts a heat flux into electrical power via the Seebeck effect. When a thermoelectric generator is inserted between a solar-absorbing surface and a heat sink, a ...

  17. Tradespace model for planetary surface exploration hopping vehicles

    E-Print Network [OSTI]

    Cunio, Phillip M

    2012-01-01T23:59:59.000Z

    Robotic planetary surface exploration, which has greatly benefited humankind's scientific knowledge of the solar system, has to date been conducted by sedentary landers or by slow, terrain-limited rovers. However, there ...

  18. Modelling contact angle hysteresis on chemically patterned and superhydrophobic surfaces

    E-Print Network [OSTI]

    H. Kusumaatmaja; J. M. Yeomans

    2006-11-03T23:59:59.000Z

    We investigate contact angle hysteresis on chemically patterned and superhydrophobic surfaces, as the drop volume is quasi-statically increased and decreased. We consider both two, and three, dimensions using analytical and numerical approaches to minimise the free energy of the drop. In two dimensions we find, in agreement with other authors, a slip, jump, stick motion of the contact line. In three dimensions this behaviour persists, but the position and magnitude of the contact line jumps are sensitive to the details of the surface patterning. In two dimensions we identify analytically the advancing and receding contact angles on the different surfaces and we use numerical insights to argue that these provide bounds for the three dimensional cases. We present explicit simulations to show that a simple average over the disorder is not sufficient to predict the details of the contact angle hysteresis, and to support an explanation for the low contact angle hysteresis of suspended drops on superhydrophobic surfaces.

  19. A stochastic model to mimic periodic surface currents in embayments

    E-Print Network [OSTI]

    Paternostro, Christopher Lee

    2001-01-01T23:59:59.000Z

    In a new attempt to solve the fundamental fluid equations, this thesis details an original model with the ultimate goal of aiding commercial oil spill simulations. This model follows the approach employed by lattice gas and molecular dynamics models...

  20. Hydrodynamic and Ecological Assessment of Nearshore Restoration: A Modeling Study

    SciTech Connect (OSTI)

    Yang, Zhaoqing; Sobocinski, Kathryn L.; Heatwole, Danelle W.; Khangaonkar, Tarang; Thom, Ronald M.; Fuller, Roger

    2010-04-10T23:59:59.000Z

    Along the Pacific Northwest coast, much of the estuarine habitat has been diked over the last century for agricultural land use, residential and commercial development, and transportation corridors. As a result, many of the ecological processes and functions have been disrupted. To protect coastal habitats that are vital to aquatic species, many restoration projects are currently underway to restore the estuarine and coastal ecosystems through dike breaches, setbacks, and removals. Information on physical processes and hydrodynamic conditions are critical for the assessment of the success of restoration actions. Restoration of a 160- acre property at the mouth of the Stillaguamish River in Puget Sound has been proposed. The goal is to restore native tidal habitats and estuary-scale ecological processes by removing the dike. In this study, a three-dimensional hydrodynamic model was developed for the Stillaguamish River estuary to simulate estuarine processes. The model was calibrated to observed tide, current, and salinity data for existing conditions and applied to simulate the hydrodynamic responses to two restoration alternatives. Responses were evaluated at the scale of the restoration footprint. Model data was combined with biophysical data to predict habitat responses at the site. Results showed that the proposed dike removal would result in desired tidal flushing and conditions that would support four habitat types on the restoration footprint. At the estuary scale, restoration would substantially increase the proportion of area flushed with freshwater (< 5 ppt) at flood tide. Potential implications of predicted changes in salinity and flow dynamics are discussed relative to the distribution of tidal marsh habitat.

  1. Triangle geometry processing for surface modeling and cartesian grid generation

    DOE Patents [OSTI]

    Aftosmis, Michael J. (San Mateo, CA) [San Mateo, CA; Melton, John E. (Hollister, CA) [Hollister, CA; Berger, Marsha J. (New York, NY) [New York, NY

    2002-09-03T23:59:59.000Z

    Cartesian mesh generation is accomplished for component based geometries, by intersecting components subject to mesh generation to extract wetted surfaces with a geometry engine using adaptive precision arithmetic in a system which automatically breaks ties with respect to geometric degeneracies. During volume mesh generation, intersected surface triangulations are received to enable mesh generation with cell division of an initially coarse grid. The hexagonal cells are resolved, preserving the ability to directionally divide cells which are locally well aligned.

  2. WASTE CONTAINER AND WASTE PACKAGE PERFORMANCE MODELING TO SUPPORT SAFETY ASSESSMENT OF LOW AND INTERMEDIATE-LEVEL RADIOACTIVE WASTE DISPOSAL.

    SciTech Connect (OSTI)

    SULLIVAN, T.

    2004-06-30T23:59:59.000Z

    Prior to subsurface burial of low- and intermediate-level radioactive wastes, a demonstration that disposal of the wastes can be accomplished while protecting the health and safety of the general population is required. The long-time frames over which public safety must be insured necessitates that this demonstration relies, in part, on computer simulations of events and processes that will occur in the future. This demonstration, known as a Safety Assessment, requires understanding the performance of the disposal facility, waste containers, waste forms, and contaminant transport to locations accessible to humans. The objective of the coordinated research program is to examine the state-of-the-art in testing and evaluation short-lived low- and intermediate-level waste packages (container and waste form) in near surface repository conditions. The link between data collection and long-term predictions is modeling. The objective of this study is to review state-of-the-art modeling approaches for waste package performance. This is accomplished by reviewing the fundamental concepts behind safety assessment and demonstrating how waste package models can be used to support safety assessment. Safety assessment for low- and intermediate-level wastes is a complicated process involving assumptions about the appropriate conceptual model to use and the data required to support these models. Typically due to the lack of long-term data and the uncertainties from lack of understanding and natural variability, the models used in safety assessment are simplistic. However, even though the models are simplistic, waste container and waste form performance are often central to the case for making a safety assessment. An overview of waste container and waste form performance and typical models used in a safety assessment is supplied. As illustrative examples of the role of waste container and waste package performance, three sample test cases are provided. An example of the impacts of distributed container failure times on cumulative release and peak concentration is provided to illustrate some of the complexities in safety assessment and how modeling can be used to support the conceptual approach in safety assessment and define data requirements. Two examples of the role of the waste form in controlling release are presented to illustrate the importance of waste form performance to safety assessment. These examples highlight the difficulties in changing the conceptual model from something that is conservative and defensible (such as instant release of all the activity) to more representative conceptual models that account for known physical and chemical processes (such as diffusion), The second waste form example accounts for the experimental observation that often a thin film with low diffusion properties forms on the waste form surface. The implications of formation of such a layer on release are investigated and the implications of attempting to account for this phenomena in a safety assessment are addressed.

  3. Evaluation of Methods to Assess and Reduce Bacterial Contamination of Surface Water from Grazing Lands

    E-Print Network [OSTI]

    Wagner, Kevin

    2012-10-19T23:59:59.000Z

    assessed the ability of alternative water supplies and grazing management to reduce E. coli loading from cattle and evaluated the ability of quantitative polymerase chain reaction analysis of total and bovine-associated Bacteroides markers (AllBac and Bo...

  4. Automated Software Engineering Process Assessment: Supporting Diverse Models using an Ontology

    E-Print Network [OSTI]

    Ulm, Universität

    , ISO 9001). It also provides an in-the-loop automated process assessment capability that can help, ISO 9001), and suitable performance and scalability. The approach can reduce the effort required assessment while simultaneously supporting diverse process assessment reference models (CMMI, ISO/IEC 15504

  5. Modelling of Stochastic Hybrid Systems with Applications to Accident Risk Assessment

    E-Print Network [OSTI]

    Del Moral , Pierre

    Modelling of Stochastic Hybrid Systems with Applications to Accident Risk Assessment #12;The SYSTEMS WITH APPLICATIONS TO ACCIDENT RISK ASSESSMENT DISSERTATION to obtain the doctor's degree promotor Prof. dr. A. Bagchi #12;Contents 1 Introduction 3 1.1 Accident risk assessment

  6. Probing protein orientation near charged surfaces with an implicit-solvent model and the PyGBe code

    E-Print Network [OSTI]

    Christopher D. Cooper; Lorena A. Barba

    2015-03-31T23:59:59.000Z

    Protein-surface interactions are ubiquitous in biological processes and bioengineering, yet are not fully understood. In the field of biosensors, a key factor in biosensor performance is the orientation of biomolecules near charged surfaces. The aim of this work is developing and assessing a computational model to study proteins interacting with charged surfaces and obtain orientation data. After extending the implicit-solvent model used in the open-source code PyGBe and deriving an analytical solution for simple geometry, our careful grid-convergence analysis builds confidence on the correctness and value of our approach for probing protein orientation. Further computational experiments support it: they study preferred orientations for protein GB1 D4' and immunoglobulin G. Sampling the free energy for protein GB1 at a range of tilt and rotation angles with respect to the charged surface, we calculated the probability of the protein orientation and observed a dipolar behavior. This result is consistent with published molecular-dynamics simulations and experimental studies using this protein. The case of immunoglobulin G is more challenging due to the large size of the molecule, but it is also more relevant to biosensor technology. The probability distribution of orientations for this protein at varying surface charge and salt concentration suggests that it is easier to control the antibody orientation with low salt concentration and high surface charge. The results also show that local interactions dominate over dipole moment for this protein. In view of its capacity to deal with much larger biomolecules than direct simulation, this implicit-solvent model can offer a valuable approach in biosensor studies.

  7. Linking RESRAD-OFFSITE and HYDROGEOCHEM Model for Performance Assessment of Low-Level Radioactive Waste Disposal Facility - 13429

    SciTech Connect (OSTI)

    Lin, Wen-Sheng [Hydrotech Research Institute, National Taiwan University, Taiwan (China)] [Hydrotech Research Institute, National Taiwan University, Taiwan (China); Yu, Charley; Cheng, Jing-Jy; Kamboj, Sunita; Gnanapragasam, Emmanuel [Argonne National Laboratory, Argonne, IL 60439 (United States)] [Argonne National Laboratory, Argonne, IL 60439 (United States); Liu, Chen-Wuing [Department of Bioenvironmental Systems Engineering, National Taiwan University, Taiwan (China)] [Department of Bioenvironmental Systems Engineering, National Taiwan University, Taiwan (China); Li, Ming-Hsu [Institute of Hydrological and Oceanic Sciences, National Central University, Taiwan (China)] [Institute of Hydrological and Oceanic Sciences, National Central University, Taiwan (China)

    2013-07-01T23:59:59.000Z

    Performance assessments are crucial steps for the long-term radiological safety requirements of low-level waste (LLW) disposal facility. How much concentration of radionuclides released from the near-field to biosphere and what radiation exposure levels of an individual can influence on the satisfactory performance of the LLW disposal facility and safety disposal environment. Performance assessment methodology for the radioactive waste disposal consists of the reactive transport modeling of safety-concerned radionuclides released from the near-field to the far-field, and the potential exposure pathways and the movements of radionuclides through the geosphere, biosphere and man of which the accompanying dose. Therefore, the integration of hydrogeochemical transport model and dose assessment code, HYDROGEOCHEM code and RESRAD family of codes is imperative. The RESRAD family of codes such as RESRAD-OFFSITE computer code can evaluate the radiological dose and excess cancer risk to an individual who is exposed while located within or outside the area of initial (primary) contamination. The HYDROGEOCHEM is a 3-D numerical model of fluid flow, thermal, hydrologic transport, and biogeochemical kinetic and equilibrium reactions in saturated and unsaturated media. The HYDROGEOCHEM model can also simulate the crucial geochemical mechanism, such as the effect of redox processes on the adsorption/desorption, hydrogeochemical influences on concrete degradation, adsorption/desorption of radionuclides (i.e., surface complexation model) between solid and liquid phase in geochemically dynamic environments. To investigate the safety assessment of LLW disposal facility, linking RESRAD-OFFSITE and HYDROGEOCHEM model can provide detailed tools of confidence in the protectiveness of the human health and environmental impact for safety assessment of LLW disposal facility. (authors)

  8. assessment modeling approach: Topics by E-print Network

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

    an easyEnvironmental impact for offshore wind farms: Geolocalized Life Cycle Assessment (LCA) approach and floating offshore wind farms. This work was undertaken within the EU-...

  9. Surface spectroscopic studies of mono- and bimetallic model catalysts

    E-Print Network [OSTI]

    Yi, Cheol-Woo

    2007-04-25T23:59:59.000Z

    ), temperature programmed desorption (TPD), and x-ray photoelectron spectroscopy (XPS). Electronic, morphological, and chemical properties of the prepared model catalysts were compared to those observed from monometallic single-crystal model catalysts such as Cu...

  10. A stochastic model to mimic periodic surface currents in embayments 

    E-Print Network [OSTI]

    Paternostro, Christopher Lee

    2001-01-01T23:59:59.000Z

    In a new attempt to solve the fundamental fluid equations, this thesis details an original model with the ultimate goal of aiding commercial oil spill simulations. This model follows the approach employed by lattice gas ...

  11. A Statistical Model to Assess Indirect CO2 Emissions of the UAE Residential Sector 

    E-Print Network [OSTI]

    Radhi, H.; Fikry, F.

    2010-01-01T23:59:59.000Z

    This study presents a regional bottom-up model for assessing space cooling energy and related greenhouse gas emissions. The model was developed with the aim of improving the quality and quantity of cooling energy and emission data, especially...

  12. Risk assessment of surface vs subsea blowout preventers (bops) on mobile offshore drilling units focusing on riser failure and the use of subsea shear rams 

    E-Print Network [OSTI]

    Melendez, Jorge Luis

    2006-08-16T23:59:59.000Z

    The use of a slim, high-pressure drilling riser for surface blowout preventer operations in the deepwater Gulf of Mexico was assessed as an alternative to conventional drilling procedures from floating units. Comparison ...

  13. Integrated Assessment Modeling of Carbon Sequestration and Land Use Emissions Using Detailed Model Results and Observations

    SciTech Connect (OSTI)

    Dr. Atul Jain

    2005-04-17T23:59:59.000Z

    This report outlines the progress on the development and application of Integrated Assessment Modeling of Carbon Sequestrations and Land Use Emissions supported by the DOE Office of Biological and Environmental Research (OBER), U.S. Department of Energy, Grant No. DOE-DE-FG02-01ER63069. The overall objective of this collaborative project between the University of Illinois at Urbana-Champaign (UIUC), Oak Ridge National Laboratory (ORNL), Lawrence Livermore National Laboratory (LLNL), and Pacific Northwest National Laboratory (PNNL) was to unite the latest advances in carbon cycle research with scientifically based models and policy-related integrated assessment tools that incorporate computationally efficient representations of the latest knowledge concerning science and emission trajectories, and their policy implications. As part of this research we accomplished the following tasks that we originally proposed: (1) In coordination with LLNL and ORNL, we enhanced the Integrated Science Assessment Model's (ISAM) parametric representation of the ocean and terrestrial carbon cycles that better represent spatial and seasonal variations, which are important to study the mechanisms that influence carbon sequestration in the ocean and terrestrial ecosystems; (2) Using the MiniCAM modeling capability, we revised the SRES (IPCC Special Report on Emission Scenarios; IPCC, 2000) land use emission scenarios; and (3) On the application front, the enhanced version of ISAM modeling capability is applied to understand how short- and long-term natural carbon fluxes, carbon sequestration, and human emissions contribute to the net global emissions (concentrations) trajectories required to reach various concentration (emission) targets. Under this grant, 21 research publications were produced. In addition, this grant supported a number of graduate and undergraduate students whose fundamental research was to learn a disciplinary field in climate change (e.g., ecological dynamics and ocean circulations) and then complete research on how this field could be linked to the other factors we need to consider in its dynamics (e.g., land use, ocean and terrestrial carbon sequestration and climate change).

  14. Surface plasmon for graphene in the Dirac equation model

    E-Print Network [OSTI]

    M. Bordag

    2012-12-09T23:59:59.000Z

    We consider single-layer plane graphene with electronic excitations described by the Dirac equation. Using a known representation of the polarization tensor in terms of the spinor loop we show the existence of surface modes, i.e., of undamped in time excitations of the \\elm field, propagating along the graphene. These show up in the TE polarization and exist at zero temperature.

  15. Multilayer Perceptron Error Surfaces: Visualization, Structure and Modelling

    E-Print Network [OSTI]

    Gallagher, Marcus

    . This is commonly formulated as a multivariate non­linear optimization problem over a very high­dimensional space of analysis are not well­suited to this problem. Visualizing and describ­ ing the error surface are also three related methods. Firstly, Principal Component Analysis (PCA) is proposed as a method

  16. Multi-layer Perceptron Error Surfaces: Visualization, Structure and Modelling

    E-Print Network [OSTI]

    Gallagher, Marcus

    . This is commonly formulated as a multivariate non-linear optimization problem over a very high-dimensional space of analysis are not well-suited to this problem. Visualizing and describ- ing the error surface are also three related methods. Firstly, Principal Component Analysis (PCA) is proposed as a method

  17. Assessing nitrogen losses after sewage sludge spreading: A method based on simulation models and spreader

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Assessing nitrogen losses after sewage sludge spreading: A method based on simulation models performances. We define 45 sewage sludge spreading scenarios covering a wide range of situations in France. Several models are used to (i) assess nitrogen losses due to sewage sludge spreading and (ii) calculate

  18. 11/05/2007 16:29 1 Bayesian Belief Network Model for the Safety Assessment

    E-Print Network [OSTI]

    Fenton, Norman

    11/05/2007 16:29 1 Bayesian Belief Network Model for the Safety Assessment of Nuclear Computer assessment task for computer and software based nuclear systems important to safety. Our model is developed University P.-J. Courtois AV Nuclear Brussels, Belgium Abstract The formalism of Bayesian Belief Networks

  19. Assessment of Managed Aquifer Recharge Site Suitability Using a GIS and Modeling

    E-Print Network [OSTI]

    Fisher, Andrew

    with a regional groundwater model to assess the hydrologic impact of potential MAR placement and operating planning, including evaluation of options for enhancing groundwater resources. Introduction ManagedAssessment of Managed Aquifer Recharge Site Suitability Using a GIS and Modeling by Tess A. Russo1

  20. Achieving tunable surface tension in the pseudopotential lattice Boltzmann modeling of multiphase flows

    E-Print Network [OSTI]

    Q. Li; K. H. Luo

    2013-10-14T23:59:59.000Z

    In this paper, we aim to address an important issue about the pseudopotential lattice Boltzmann (LB) model, which has attracted much attention as a mesoscopic model for simulating interfacial dynamics of complex fluids, but suffers from the problem that the surface tension cannot be tuned independently of the density ratio. In the literature, a multi-range potential was devised to adjust the surface tension [Sbragaglia et al., Phys. Rev. E 75, 026702 (2007)]. However, it was recently found that the density ratio of the system will be changed when the multi-range potential is employed to adjust the surface tension. A new approach is therefore proposed in the present work. The basic strategy is to add a source term to the LB equation so as to tune the surface tension of the pseudopotential LB model. The proposed approach can guarantee that the adjustment of the surface tension does not affect the mechanical stability condition of the pseudopotential LB model, and thus provides a separate control of the surface tension and the density ratio. Meanwhile, it still retains the mesoscopic feature and the computational simplicity of the pseudopotential LB model. Numerical simulations are carried out for stationary droplets, capillary waves, and droplet splashing on a thin liquid film. The numerical results demonstrate that the proposed approach is capable of achieving a tunable surface tension over a very wide range and can keep the density ratio unchanged when adjusting the surface tension.

  1. Ab-initio modeling of electromechanical coupling at Si surfaces

    SciTech Connect (OSTI)

    Hoppe, Sandra; Müller, Stefan, E-mail: stefan.mueller@tuhh.de [Institute of Advanced Ceramics, Hamburg University of Technology, 21073 Hamburg (Germany); Michl, Anja [Institute of Advanced Ceramics, Hamburg University of Technology, 21073 Hamburg (Germany); Institute of Materials Research, Materials Mechanics, Helmholtz-Zentrum Geesthacht, 21502 Geesthacht (Germany); Weissmüller, Jörg [Institute of Materials Research, Materials Mechanics, Helmholtz-Zentrum Geesthacht, 21502 Geesthacht (Germany); Institute of Materials Physics and Technology, Hamburg University of Technology, 21073 Hamburg (Germany)

    2014-08-21T23:59:59.000Z

    The electromechanical coupling at the silicon (100) and (111) surfaces was studied via density functional theory by calculating the response of the ionization potential and the electron affinity to different types of strain. We find a branched strain response of those two quantities with different coupling coefficients for negative and positive strain values. This can be attributed to the reduced crystal symmetry due to anisotropic strain, which partially lifts the degeneracy of the valence and conduction bands. Only the Si(111) electron affinity exhibits a monotonously linear strain response, as the conduction band valleys remain degenerate under strain. The strain response of the surface dipole is linear and seems to be dominated by volume changes. Our results may help to understand the mechanisms behind electromechanical coupling at an atomic level in greater detail and for different electronic and atomic structures.

  2. Langasite Surface Acoustic Wave Gas Sensors: Modeling and Verification

    SciTech Connect (OSTI)

    Zheng, Peng; Greve, David W.; Oppenheim, Irving J.

    2013-01-01T23:59:59.000Z

    We report finite element simulations of the effect of conductive sensing layers on the surface wave velocity of langasite substrates. The simulations include both the mechanical and electrical influences of the conducting sensing layer. We show that three-dimensional simulations are necessary because of the out-of-plane displacements of the commonly used (0, 138.5, 26.7) Euler angle. Measurements of the transducer input admittance in reflective delay-line devices yield a value for the electromechanical coupling coefficient that is in good agreement with the three-dimensional simulations on bare langasite substrate. The input admittance measurements also show evidence of excitation of an additional wave mode and excess loss due to the finger resistance. The results of these simulations and measurements will be useful in the design of surface acoustic wave gas sensors.

  3. Modeling land surface processes of the midwestern United States : predicting soil moisture under a warmer climate

    E-Print Network [OSTI]

    Winter, Jonathan (Jonathan Mark)

    2010-01-01T23:59:59.000Z

    This dissertation seeks to quantify the response of soil moisture to climate change in the midwestern United States. To assess this response, a dynamic global vegetation model, Integrated Biosphere Simulator, was coupled ...

  4. Realistic multisite lattice-gas modeling and KMC simulation of catalytic surface reactions: Kinetics and multiscale spatial behavior for CO-oxidation on metal (100) surfaces

    SciTech Connect (OSTI)

    Liu, Dajiang [Ames Laboratory; Evans, James W. [Ames Laboratory

    2013-12-01T23:59:59.000Z

    A realistic molecular-level description of catalytic reactions on single-crystal metal surfaces can be provided by stochastic multisite lattice-gas (msLG) models. This approach has general applicability, although in this report, we will focus on the example of CO-oxidation on the unreconstructed fcc metal (100) or M(100) surfaces of common catalyst metals M = Pd, Rh, Pt and Ir (i.e., avoiding regimes where Pt and Ir reconstruct). These models can capture the thermodynamics and kinetics of adsorbed layers for the individual reactants species, such as CO/M(100) and O/M(100), as well as the interaction and reaction between different reactant species in mixed adlayers, such as (CO + O)/M(100). The msLG models allow population of any of hollow, bridge, and top sites. This enables a more flexible and realistic description of adsorption and adlayer ordering, as well as of reaction configurations and configuration-dependent barriers. Adspecies adsorption and interaction energies, as well as barriers for various processes, constitute key model input. The choice of these energies is guided by experimental observations, as well as by extensive Density Functional Theory analysis. Model behavior is assessed via Kinetic Monte Carlo (KMC) simulation. We also address the simulation challenges and theoretical ramifications associated with very rapid diffusion and local equilibration of reactant adspecies such as CO. These msLG models are applied to describe adsorption, ordering, and temperature programmed desorption (TPD) for individual CO/M(100) and O/M(100) reactant adlayers. In addition, they are also applied to predict mixed (CO + O)/M(100) adlayer structure on the nanoscale, the complete bifurcation diagram for reactive steady-states under continuous flow conditions, temperature programmed reaction (TPR) spectra, and titration reactions for the CO-oxidation reaction. Extensive and reasonably successful comparison of model predictions is made with experimental data. Furthermore, we discuss the possible transition from traditional mean-field-type bistability and reaction kinetics for lower-pressure to multistability and enhanced fluctuation effects for moderate- or higher-pressure. Behavior in the latter regime reflects a stronger influence of adspecies interactions and also lower diffusivity in the higher-coverage mixed adlayer. We also analyze mesoscale spatiotemporal behavior including the propagation of reaction diffusion fronts between bistable reactive and inactive states, and associated nucleation-mediated transitions between these states. This behavior is controlled by complex surface mass transport processes, specifically chemical diffusion in mixed reactant adlayers for which we provide a precise theoretical formulation. The msLG models together with an appropriate treatment of chemical diffusivity enable equation-free heterogeneous coupled lattice-gas (HCLG) simulations of spatiotemporal behavior. In addition, msLG + HCLG modeling can describe coverage variations across polycrystalline catalysts surfaces, pressure variations across catalyst surfaces in microreactors, and could be incorporated into a multiphysics framework to describe mass and heat transfer limitations for high-pressure catalysis. (C) 2013 Elsevier Ltd. All rights reserved.

  5. Computation Modeling and Assessment of Nanocoatings for Ultra Supercritical Boilers

    SciTech Connect (OSTI)

    J. Shingledecker; D. Gandy; N. Cheruvu; R. Wei; K. Chan

    2011-06-21T23:59:59.000Z

    Forced outages and boiler unavailability of coal-fired fossil plants is most often caused by fire-side corrosion of boiler waterwalls and tubing. Reliable coatings are required for Ultrasupercritical (USC) application to mitigate corrosion since these boilers will operate at a much higher temperatures and pressures than in supercritical (565 C {at} 24 MPa) boilers. Computational modeling efforts have been undertaken to design and assess potential Fe-Cr-Ni-Al systems to produce stable nanocrystalline coatings that form a protective, continuous scale of either Al{sub 2}O{sub 3} or Cr{sub 2}O{sub 3}. The computational modeling results identified a new series of Fe-25Cr-40Ni with or without 10 wt.% Al nanocrystalline coatings that maintain long-term stability by forming a diffusion barrier layer at the coating/substrate interface. The computational modeling predictions of microstructure, formation of continuous Al{sub 2}O{sub 3} scale, inward Al diffusion, grain growth, and sintering behavior were validated with experimental results. Advanced coatings, such as MCrAl (where M is Fe, Ni, or Co) nanocrystalline coatings, have been processed using different magnetron sputtering deposition techniques. Several coating trials were performed and among the processing methods evaluated, the DC pulsed magnetron sputtering technique produced the best quality coating with a minimum number of shallow defects and the results of multiple deposition trials showed that the process is repeatable. scale, inward Al diffusion, grain growth, and sintering behavior were validated with experimental results. The cyclic oxidation test results revealed that the nanocrystalline coatings offer better oxidation resistance, in terms of weight loss, localized oxidation, and formation of mixed oxides in the Al{sub 2}O{sub 3} scale, than widely used MCrAlY coatings. However, the ultra-fine grain structure in these coatings, consistent with the computational model predictions, resulted in accelerated Al diffusion from the coating into the substrate. An effective diffusion barrier interlayer coating was developed to prevent inward Al diffusion. The fire-side corrosion test results showed that the nanocrystalline coatings with a minimum number of defects have a great potential in providing corrosion protection. The coating tested in the most aggressive environment showed no evidence of coating spallation and/or corrosion attack after 1050 hours exposure. In contrast, evidence of coating spallation in isolated areas and corrosion attack of the base metal in the spalled areas were observed after 500 hours. These contrasting results after 500 and 1050 hours exposure suggest that the premature coating spallation in isolated areas may be related to the variation of defects in the coating between the samples. It is suspected that the cauliflower-type defects in the coating were presumably responsible for coating spallation in isolated areas. Thus, a defect free good quality coating is the key for the long-term durability of nanocrystalline coatings in corrosive environments. Thus, additional process optimization work is required to produce defect-free coatings prior to development of a coating application method for production parts.

  6. Direct releases to the surface and associated complementary cumulative distribution functions in the 1996 performance assessments for the Waste Isolation Pilot Plant: Direct brine release

    SciTech Connect (OSTI)

    STOELZEL,D.M.; O'BRIEN,D.G.; GARNER,J.W.; HELTON,JON CRAIG; JOHNSON,J.D.; SCOTT,L.N.

    2000-05-19T23:59:59.000Z

    The following topics related to the treatment of direct brine releases to the surface environment in the 1996 performance assessment for the Waste Isolation Pilot Plant (WIPP) are presented (1) mathematical description of models, (2) uncertainty and sensitivity analysis results arising from subjective (i.e., epistemic) uncertainty for individual releases, (3) construction of complementary cumulative distribution functions (CCDFs) arising from stochastic (i.e., aleatory) uncertainty, and (4) uncertainty and sensitivity analysis results for CCDFs. The presented analyses indicate that direct brine releases do not constitute a serious threat to the effectiveness of the WIPP as a disposal facility for transuranic waste. Even when the effects of uncertain analysis inputs are taken into account, the CCDFs for direct brine releases fall substantially to the left of the boundary line specified in the US Environmental Protection Agency's standard for the geologic disposal of radioactive waste (4O CFR 191.40 CFR 194).

  7. Plutonium-238 observations as a test of modeled transport and surface deposition of meteoric smoke particles

    E-Print Network [OSTI]

    Chipperfield, Martyn

    Plutonium-238 observations as a test of modeled transport and surface deposition of meteoric smoke chemistry-climate model (CCM) to simulate the transport and deposition of plutonium- 238 oxide nanoparticles. P. Chipperfield, and J. M. C. Plane (2013), Plutonium-238 observations as a test of modeled

  8. Water at the Surfaces of Aligned Phospholipid Multibilayer Model Membranes Probed with Ultrafast Vibrational

    E-Print Network [OSTI]

    Fayer, Michael D.

    Water at the Surfaces of Aligned Phospholipid Multibilayer Model Membranes Probed with Ultrafast@stanford.edu Abstract: The dynamics of water at the surface of artificial membranes composed of aligned multibilayers pump-probe spectroscopy. The experiments are performed at various hydration levels, x ) 2 - 16 water

  9. Modeling the free energy surfaces of electron transfer in condensed phases

    E-Print Network [OSTI]

    Matyushov, Dmitry

    PROOF COPY 509037JCP Modeling the free energy surfaces of electron transfer in condensed phases analytical solution for the ET free energy surfaces demonstrates the following features: i the range of ET reaction coordinates is limited by a one-sided fluctuation band, ii the ET free energies are infinite

  10. Inverse modeling of surface emissions for local pollution: A new methodology applied to academic test cases

    E-Print Network [OSTI]

    Menut, Laurent

    Inverse modeling of surface emissions for local pollution: A new methodology applied to academic; (2) LISA Creteil France Needs: Optimize surface emissions using daily recorded ozone and NOX by PRIMEQUAL2, program of the french ministry of environment Firstguess emissions inventory for the Paris

  11. Discrepancies in the Prediction of Solar Wind using Potential Field Source Surface Model: An

    E-Print Network [OSTI]

    Zhao, Xuepu

    Discrepancies in the Prediction of Solar Wind using Potential Field Source Surface Model. This inverse relation has been made use of in the prediction of solar wind speed at 1 AU using a potential between the magnetic flux tube expansion factor (FTE) at the source surface and the solar wind speed

  12. A Subbasin-based framework to represent land surface processes in an Earth System Model

    SciTech Connect (OSTI)

    Tesfa, Teklu K.; Li, Hongyi; Leung, Lai-Yung R.; Huang, Maoyi; Ke, Yinghai; Sun, Yu; Liu, Ying

    2014-05-20T23:59:59.000Z

    Realistically representing spatial heterogeneity and lateral land surface processes within and between modeling units in earth system models is important because of their implications to surface energy and water exchange. The traditional approach of using regular grids as computational units in land surface models and earth system models may lead to inadequate representation of lateral movements of water, energy and carbon fluxes, especially when the grid resolution increases. Here a new subbasin-based framework is introduced in the Community Land Model (CLM), which is the land component of the Community Earth System Model (CESM). Local processes are represented assuming each subbasin as a grid cell on a pseudo grid matrix with no significant modifications to the existing CLM modeling structure. Lateral routing of water within and between subbasins is simulated with the subbasin version of a recently-developed physically based routing model, Model for Scale Adaptive River Routing (MOSART). As an illustration, this new framework is implemented in the topographically diverse region of the U.S. Pacific Northwest. The modeling units (subbasins) are delineated from high-resolution Digital Elevation Model while atmospheric forcing and surface parameters are remapped from the corresponding high resolution datasets. The impacts of this representation on simulating hydrologic processes are explored by comparing it with the default (grid-based) CLM representation. In addition, the effects of DEM resolution on parameterizing topography and the subsequent effects on runoff processes are investigated. Limited model evaluation and comparison showed that small difference between the averaged forcing can lead to more significant difference in the simulated runoff and streamflow because of nonlinear horizontal processes. Topographic indices derived from high resolution DEM may not improve the overall water balance, but affect the partitioning between surface and subsurface runoff. More systematic analyses are needed to determine the relative merits of the subbasin representation compared to the commonly used grid-based representation, especially when land surface models are approaching higher resolutions.

  13. [10-386] Assessing and Improving the Scale Dependence of Ecosystem Processes in Earth System Models

    E-Print Network [OSTI]

    . Goodale Cornell U. *Overall Project Lead *Lead Institution Intellectual Merit: Earth system models include policies. Our research assesses and improves Earth system model simulations of the carbon cycle, ecosystem of the Community Climate System Model/Community Earth System Model, which includes statistical meteorological

  14. IEEE JOURNAL OF OCEANIC ENGINEERING, VOL. 34, NO. 3, JULY 2009 239 Modeling Surface Multipath Effects

    E-Print Network [OSTI]

    Bhargava, Rohit

    IEEE JOURNAL OF OCEANIC ENGINEERING, VOL. 34, NO. 3, JULY 2009 239 Modeling Surface Multipath_davis@hotmail.com; bryn@uiuc.edu). P. T. Gough is with the Electrical and Computer Engineering Depart- ment, University

  15. A framework for comparing geomechanical models of InSAR-measured surface deformation

    E-Print Network [OSTI]

    De Laplante, Neil Edward James

    2011-01-01T23:59:59.000Z

    High-quality Interferometric Synthetic Aperture Radar (InSAR) surface deformation data for field sites around the world has become widely available over the past decade. Geomechanical models based on InSAR data occur ...

  16. A Lattice-Based Equivalent Circuit Model for Frequency Selective Surfaces

    E-Print Network [OSTI]

    Rolando, David

    2014-12-11T23:59:59.000Z

    This work introduces a novel analytical framework for designing and synthesizing frequency selective surfaces (FSSs). In this framework, referred to as the “lattice model”, a periodic FSS is represented as an infinite lattice of interconnected...

  17. NUMERICAL MODELING FOR THE FORMATION MECHANISM OF 3D TOPOGRAPHY ON MICROBIAL MAT SURFACES

    E-Print Network [OSTI]

    Patel, Harsh Jay

    2013-09-27T23:59:59.000Z

    , an innovative modeling approach was employed that focuses on the interface growth of the microbial mat surfaces using a combined stochastic and deterministic approach. A range of different initial conditions were simulated to evaluate the 3D topography evolution...

  18. Development of legged, wheeled, and hybrid rover mobility models to facilitate planetary surface exploration mission analysis

    E-Print Network [OSTI]

    McCloskey, Scott H. (Scott Haddon)

    2007-01-01T23:59:59.000Z

    This work discusses the Mars Surface Exploration (MSE) tool and its adaptation to model rovers featuring legged, wheeled, and hybrid mobility. MSE is a MATLAB based systems engineering tool that is capable of rapidly ...

  19. Modeling toxic endpoints for improving human health risk assessment

    E-Print Network [OSTI]

    Bruce, Erica Dawn

    2009-05-15T23:59:59.000Z

    Risk assessment procedures for mixtures of polycyclic aromatic hydrocarbons (PAHs) present a problem due to the lack of available potency and toxicity data on mixtures and individual compounds. This study examines the toxicity of parent compound...

  20. Model for a web based medical technology assessment system

    E-Print Network [OSTI]

    Prabhu, Gopal

    1999-01-01T23:59:59.000Z

    Technology is the primary driving force for change in today's healthcare environment. Understanding the dynamics of medical technology and applying probative management measures can be accomplished with a medical technology assessment program...

  1. Model for dynamic self-assembled magnetic surface structures.

    SciTech Connect (OSTI)

    Belkin, M.; Glatz, A.; Snezhko, A.; Aranson, I. S.; Materials Science Division; Northwestern Univ.

    2010-07-07T23:59:59.000Z

    We propose a first-principles model for the dynamic self-assembly of magnetic structures at a water-air interface reported in earlier experiments. The model is based on the Navier-Stokes equation for liquids in shallow water approximation coupled to Newton equations for interacting magnetic particles suspended at a water-air interface. The model reproduces most of the observed phenomenology, including spontaneous formation of magnetic snakelike structures, generation of large-scale vortex flows, complex ferromagnetic-antiferromagnetic ordering of the snake, and self-propulsion of bead-snake hybrids.

  2. Model for a web based medical technology assessment system 

    E-Print Network [OSTI]

    Prabhu, Gopal

    1999-01-01T23:59:59.000Z

    . 6. Figure 3. 7. Figure 3. 8. Figure 3. 9. Telemetry Assessment 37 ECG Assessment. 39 The Home Page 43 Clinical Engineer Registration. Clinical Engineer Login. . 44 45 Search Results When User Searches for Defibrillator by ID. . 41 Figure... to those, which your facility is considering, or the information may be dated (pers. comm. N. Cram). The Internet is a computer network that connects millions of computers globally and provides worldwide communications to businesses, homes, schools...

  3. Assessing Models of Public Understanding In ELSI Outreach Materials

    SciTech Connect (OSTI)

    Bruce V. Lewenstein, Ph.D.; Dominique Brossard, Ph.D.

    2006-03-01T23:59:59.000Z

    Advances in the science of genetics have implications for individuals and society, and have to be taken into account at the policy level. Studies of ethical, legal and social issues related to genomic research have therefore been integrated in the Human Genome Project (HGP) since the earliest days of the project. Since 1990, three to five percent of the HGP annual budget has been devoted to such studies, under the umbrella of the Ethical, Legal, and Social Implications (ELSI) Programs of the National Human Genome Research Institute of the National Institute of Health, and of the Office of Biological and Environmental Research of the U.S. Department of Energy (DOE). The DOE-ELSI budget has been used to fund a variety of projects that have aimed at ?promoting education and help guide the conduct of genetic research and the development of related medical and public policies? (HGP, 2003). As part of the educational component, a significant portion of DOE-ELSI funds have been dedicated to public outreach projects, with the underlying goal of promoting public awareness and ultimately public discussion of ethical, legal, and social issues surrounding availability of genetic information (Drell, 2002). The essential assumption behind these projects is that greater access to information will lead to more knowledge about ethical, legal and social issues, which in turn will lead to enhanced ability on the part of individuals and communities to deal with these issues when they encounter them. Over the same period of time, new concepts of ?public understanding of science? have emerged in the theoretical realm, moving from a ?deficit? or linear dissemination of popularization, to models stressing lay-knowledge, public engagement and public participation in science policy-making (Lewenstein, 2003). The present project uses the base of DOE-funded ELSI educational project to explore the ways that information about a new and emerging area of science that is intertwined with public issues has been used in educational public settings to affect public understanding of science. After a theoretical background discussion, our approach is three-fold. First, we will provide an overview, a ?map? of DOE-funded of outreach programs within the overall ELSI context to identify the importance of the educational component, and to present the criteria we used to select relevant and representative case studies. Second, we will document the history of the case studies. Finally, we will explore an intertwined set of research questions: (1) To identify what we can expect such projects to accomplish -in other words to determine the goals that can reasonably be achieved by different types of outreach, (2) To point out how the case study approach could be useful for DOE-ELSI outreach as a whole, and (3) To use the case study approach as a basis to test theoretical models of science outreach in order to assess to what extent those models accord with real world outreach activities. For this last goal, we aim at identifying what practices among ELSI outreach activities contribute most to dissemination, or to participation, in other words in which cases outreach materials spark action in terms of public participation in decisions about scientific issues.

  4. Transport and dispersion of pollutants in surface impoundments: a finite difference model

    SciTech Connect (OSTI)

    Yeh, G.T.

    1980-07-01T23:59:59.000Z

    A surface impoundment model by finite-difference (SIMFD) has been developed. SIMFD computes the flow rate, velocity field, and the concentration distribution of pollutants in surface impoundments with any number of islands located within the region of interest. Theoretical derivations and numerical algorithm are described in detail. Instructions for the application of SIMFD and listings of the FORTRAN IV source program are provided. Two sample problems are given to illustrate the application and validity of the model.

  5. Simulating the Transverse Ising Model on a Quantum Computer: Error Correction with the Surface Code

    E-Print Network [OSTI]

    Hao You; Michael R. Geller; P. C. Stancil

    2013-03-29T23:59:59.000Z

    We estimate the resource requirements for the quantum simulation of the ground state energy of the one dimensional quantum transverse Ising model (TIM), based on the surface code implementation of a fault tolerant quantum computer. The surface code approach has one of the highest known tolerable error rates (1%) which makes it currently one of the most practical quantum computing schemes. Compared to results of the same model using the concatenated Steane code, the current results indicate that the simulation time is comparable but the number of physical qubits for the surface code is 2-3 orders of magnitude larger than that of the concatenation code. Considering that the error threshold requirements of the surface code is four orders of magnitude higher than the concatenation code, building a quantum computer with a surface code implementation appears more promising given current physical hardware capabilities.

  6. Piezoresistive Effect for Near-Surface Eddy Current Residual Stress Assessment

    SciTech Connect (OSTI)

    Yu, F.; Nagy, P.B. [Department of Aerospace Engineering and Engineering Mechanics, University of Cincinnati, Cincinnati, Ohio 45221-0070 (United States)

    2005-04-09T23:59:59.000Z

    This paper discusses the relationship between isothermal and adiabatic piezoresistive properties of metals. The piezoresistive effect, i.e., stress-dependence of the electrical resistivity, can be exploited for nondestructive residual stress assessment using eddy current measurements. First, the paper establishes the relationship between the familiar isothermal piezoresistivity coefficients measured under uniaxial tension and hydrostatic pressure and the relevant isothermal electroelastic coefficients measured under uniaxial and biaxial stress conditions either by non-directional circular or directional elliptical eddy current coils. In order to quantitatively assess the prevailing residual stress from eddy current conductivity measurements, the electroelastic coefficients must be first determined. These calibration measurements are usually conducted on a reference specimen of the material to be tested using cyclic uniaxial loads between 0.1 and 10 Hz, which is fast enough to produce adiabatic conditions. It is demonstrated that in high-conductivity metals such calibration measurements must be corrected for the thermoelastic effect, which is always positive, i.e., it increases the conductivity in tension, when the material cools down, and reduces it in compression, when the material heats up.

  7. Climate Change Modeling and Downscaling Issues and Methodological Perspectives for the U.S. National Climate Assessment

    SciTech Connect (OSTI)

    Janetos, Anthony C.; Collins, William D.; Wuebbles, D.J.; Diffenbaugh, Noah; Hayhoe, Katharine; Hibbard, Kathleen A.; Hurtt, George

    2012-03-31T23:59:59.000Z

    This is the full workshop report for the modeling workshop we did for the National Climate Assessment, with DOE support.

  8. SU-E-J-171: Surface Imaging Based Intrafraction Motion Assessments for Whole Brain Radiotherapy

    SciTech Connect (OSTI)

    Wiant, D; Vanderstraeten, C; Maurer, J; Pursley, J; Terrell, J; Sintay, B [Cone Health Cancer Center, Greensboro, NC (United States)

    2014-06-01T23:59:59.000Z

    Purpose: To quantify and characterize intrafraction motion for whole brain radiotherapy treatments in open face masks using 3D surface imaging. Methods: Fifteen whole brain patients were monitored with 3D surface imaging over a total of 202 monitoring sessions. Mean translations and rotations were calculated over each minute, each session, and over all sessions combined. The percentage of each session that the root mean square (RMS) of the linear translations were outside of 2 mm, 3 mm, 4 mm, and 5 mm were determined for each patient. Correlations between mean translations per minute and time and between standard deviation per minute and time were evaluated using Pearson's r value. Results: The mean RMS translation averaged over all patients was 1.45 mm +/? 1.52 mm. The patients spent an average of 18%, 10%, 6%, and 3% of the monitoring time outside of 2 mm, 3 mm, 4 mm, and 5 mm RMS tolerances, respectively. The RMS values averaged over all patients were 1.31 mm +/? 0.98 mm, 1.52 +/- 1.04, and 1.30 mm +/? 0.71 mm over the 1th, 5th, and 10th minutes of monitoring, respectively. Neither, the RMS values (p = 0.15) or the standard deviations of the RMS values (p = 0.16) showed significant correlations with time. Conclusion: The patients were positioned within 2 mm of isocenter, which was the initial set-up tolerance, for the majority of their treatments. The average position changed by < 0.3 mm over 10 minutes of monitoring. Short term movements, reflected by the standard deviations, where on the order of 1 mm. This immobilization system provides adequate immobilization over a course of treatment for whole brain radiotherapy. This system may also be suitable for head and neck or stereotactic radiosurgery treatments as well.

  9. Application of a Hydrodynamic Model for Assessing the Hydraulic Capacity and Flow Field at Willamette Falls Dam, Oregon

    SciTech Connect (OSTI)

    Lee, Cheegwan; Yang, Zhaoqing; Khangaonkar, Tarang P.; Divers, Arya-Behbehani

    2006-08-03T23:59:59.000Z

    The Willamette Falls Hydroelectric Power Dam, operated by Portland General Electric (PGE), is located on the Willamette River, Oregon. The Project site consists of T.W. Sullivan Power Plant and a 2,950-ft-long spillway located on the top of the Willamette Falls Dam. As part of the effort of protection and enhancement of environmental resources, a flow control structure at the dam was proposed to improve the flow field and enhance the downstream juvenile fish passage in the region just upstream of the forebay (pre-forebay). The flow in the pre-forebay of Willamette Falls Dam is affected by the complex geometry and bathymetry, powerhouse flow, fish ladder flow and the spillway around the dam. The expectation was that the flow would be sensitive to the proposed flow control structures and could be modified to enhance downstream migration. In this study, a three-dimensional, free-surface hydrodynamic model (EFDC) was developed for the pre-forebay region of Willamette Falls to evaluate the feasibility of the proposed alternative and its effect on the flow field in two different flow regimes (low and high river flow), as well as to assess the hydraulic capacity of flow control structures. One of the key challenges in this modeling study was to properly specify the free open boundary conditions along the 2,950-feet-long spillway. In this study, a pressure boundary condition based on hydraulic head rating curves was applied to the free spillway boundary. The numerical model was calibrated with ADP velocity measurements at 17 stations for the existing low flow condition. Good agreements between model results and measured data were obtained, indicating the successful application of pressure boundary condition on the free spillway boundary. The calibrated model was applied to simulate the flow field and free surface elevation in the high flow region near the control flow structures under different alternative conditions. The model results were used to evaluate the effectiveness of flow control structure alternative for downstream fish passage. The model was also used to estimate the hydraulic capacity based on the water surface head drops upstream of the structures. This model application demonstrated that a free surface coastal model can be used successfully to examine free surface hydraulic problems near high velocity regions upstream of spillways at dams.

  10. Ventilation performance prediction for buildings: Model Assessment Qingyan Chena,b,*

    E-Print Network [OSTI]

    Chen, Qingyan "Yan"

    1 Ventilation performance prediction for buildings: Model Assessment Qingyan Chena,b,* , Kisup Leeb ventilation systems for buildings requires a suitable tool to assess the system performance-scale experimental, multizone network, zonal, and CFD) for predicting ventilation performance in buildings, which can

  11. U.S. GEOLOGICAL SURVEY ASSESSMENT MODEL FOR UNDISCOVERED CONVENTIONAL OIL, GAS, AND NGL

    E-Print Network [OSTI]

    Laughlin, Robert B.

    AM-i Chapter AM U.S. GEOLOGICAL SURVEY ASSESSMENT MODEL FOR UNDISCOVERED CONVENTIONAL OIL, GAS Survey (USGS) periodically conducts assessments of the oil, gas, and natural-gas liquids (NGL) resources by the USGS in1998 for undiscovered oil, gas, and NGL resources that reside in conventional accumulations

  12. A simplified physical model for assessing solar radiation over Brazil using GOES 8 visible imagery

    E-Print Network [OSTI]

    A simplified physical model for assessing solar radiation over Brazil using GOES 8 visible imagery; published 30 January 2004. [1] Solar radiation assessment by satellite is constrained by physical Composition and Structure: Transmission and scattering of radiation; KEYWORDS: solar radiation, satellite

  13. Probabilistic performance-assessment modeling of the mixed waste landfill at Sandia National Laboratories.

    SciTech Connect (OSTI)

    Peace, Gerald L.; Goering, Timothy James (GRAM, Inc.); Miller, Mark Laverne; Ho, Clifford Kuofei

    2005-11-01T23:59:59.000Z

    A probabilistic performance assessment has been conducted to evaluate the fate and transport of radionuclides (americium-241, cesium-137, cobalt-60, plutonium-238, plutonium-239, radium-226, radon-222, strontium-90, thorium-232, tritium, uranium-238), heavy metals (lead and cadmium), and volatile organic compounds (VOCs) at the Mixed Waste Landfill (MWL). Probabilistic analyses were performed to quantify uncertainties inherent in the system and models for a 1,000-year period, and sensitivity analyses were performed to identify parameters and processes that were most important to the simulated performance metrics. Comparisons between simulated results and measured values at the MWL were made to gain confidence in the models and perform calibrations when data were available. In addition, long-term monitoring requirements and triggers were recommended based on the results of the quantified uncertainty and sensitivity analyses. At least one-hundred realizations were simulated for each scenario defined in the performance assessment. Conservative values and assumptions were used to define values and distributions of uncertain input parameters when site data were not available. Results showed that exposure to tritium via the air pathway exceeded the regulatory metric of 10 mrem/year in about 2% of the simulated realizations when the receptor was located at the MWL (continuously exposed to the air directly above the MWL). Simulations showed that peak radon gas fluxes exceeded the design standard of 20 pCi/m{sup 2}/s in about 3% of the realizations if up to 1% of the containers of sealed radium-226 sources were assumed to completely degrade in the future. If up to 100% of the containers of radium-226 sources were assumed to completely degrade, 30% of the realizations yielded radon surface fluxes that exceeded the design standard. For the groundwater pathway, simulations showed that none of the radionuclides or heavy metals (lead and cadmium) reached the groundwater during the 1,000-year evaluation period. Tetrachloroethylene (PCE) was used as a proxy for other VOCs because of its mobility and potential to exceed maximum contaminant levels in the groundwater relative to other VOCs. Simulations showed that PCE reached the groundwater, but only 1% of the realizations yielded aquifer concentrations that exceeded the regulatory metric of 5 {micro}g/L. Based on these results, monitoring triggers have been proposed for the air, surface soil, vadose zone, and groundwater at the MWL. Specific triggers include numerical thresholds for radon concentrations in the air, tritium concentrations in surface soil, infiltration through the vadose zone, and uranium and select VOC concentrations in groundwater. The proposed triggers are based on U.S. Environmental Protection Agency and Department of Energy regulatory standards. If a trigger is exceeded, then a trigger evaluation process will be initiated which will allow sufficient data to be collected to assess trends and recommend corrective actions, if necessary.

  14. Multi-model assessment of stratospheric ozone return dates and ozone recovery in

    E-Print Network [OSTI]

    Wirosoetisno, Djoko

    Multi- model assessment of stratospheric ozone return dates and ozone recovery in CCMVal-2 models of stratospheric ozone return dates and ozone recovery in CCMVal-2 models V. Eyring1, I. Cionni1, G. E. Bodeker2, A September 2010 ­ Published: 7 October 2010 Abstract. Projections of stratospheric ozone from a suite

  15. Towing tank PIV measurement system, data and uncertainty assessment for DTMB Model 5512

    E-Print Network [OSTI]

    Gui, Lichuan

    Basin (DTMB) model 5512. The mean velocities are compared with previous 5-hole pitot probe dataTowing tank PIV measurement system, data and uncertainty assessment for DTMB Model 5512 L. Gui, J stresses at the nominal-wake plane of a model-scale ship. The mean velocities are compared with previous 5

  16. Assessing ocean-model sensitivity to wind forcing uncertainties I. Andreu Burillo,1

    E-Print Network [OSTI]

    Assessing ocean-model sensitivity to wind forcing uncertainties I. Andreu Burillo,1 G. Caniaux,1 M-equation open-ocean model, induced by uncertainties in wind forcing. Statistics calculated from an ensemble-model sensitivity to wind forcing uncertainties, Geophys. Res. Lett., 29(18), 1858, doi:10.1029/2001GL014473, 2002

  17. Conceptual design of an integrated technology model for carbon policy assessment.

    SciTech Connect (OSTI)

    Backus, George A.; Dimotakes, Paul E. (NASA Jet Propulsion Laboratory, Pasadena, CA)

    2011-01-01T23:59:59.000Z

    This report describes the conceptual design of a technology choice model for understanding strategies to reduce carbon intensity in the electricity sector. The report considers the major modeling issues affecting technology policy assessment and defines an implementable model construct. Further, the report delineates the basis causal structure of such a model and attempts to establish the technical/algorithmic viability of pursuing model development along with the associated analyses.

  18. A model for the ultrasonic detection of surface-breaking cracks by the Scanning

    E-Print Network [OSTI]

    Huerta, Antonio

    A model for the ultrasonic detection of surface-breaking cracks by the Scanning Laser Source, Northwestern University, Evanston, IL 60208, USA Abstract A model for the Scanning Laser Source (SLS) technique- breaking cracks. The generated ultrasonic signal is monitored as a line-focused laser is scanned over

  19. Modelling of a captive unmanned aerial system teledetecting oil pollution on sea surface

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    -Water Horizon crisis in the Gulf of Mexico, numerous aerial means were used to detect oil pollution locationsModelling of a captive unmanned aerial system teledetecting oil pollution on sea surface F. Muttin-spill, detection, dynamic modelling, winch, maritime pollution. 1 Introduction During 2010, and the Deep

  20. Models used to assess the performance of photovoltaic systems.

    SciTech Connect (OSTI)

    Stein, Joshua S.; Klise, Geoffrey T.

    2009-12-01T23:59:59.000Z

    This report documents the various photovoltaic (PV) performance models and software developed and utilized by researchers at Sandia National Laboratories (SNL) in support of the Photovoltaics and Grid Integration Department. In addition to PV performance models, hybrid system and battery storage models are discussed. A hybrid system using other distributed sources and energy storage can help reduce the variability inherent in PV generation, and due to the complexity of combining multiple generation sources and system loads, these models are invaluable for system design and optimization. Energy storage plays an important role in reducing PV intermittency and battery storage models are used to understand the best configurations and technologies to store PV generated electricity. Other researcher's models used by SNL are discussed including some widely known models that incorporate algorithms developed at SNL. There are other models included in the discussion that are not used by or were not adopted from SNL research but may provide some benefit to researchers working on PV array performance, hybrid system models and energy storage. The paper is organized into three sections to describe the different software models as applied to photovoltaic performance, hybrid systems, and battery storage. For each model, there is a description which includes where to find the model, whether it is currently maintained and any references that may be available. Modeling improvements underway at SNL include quantifying the uncertainty of individual system components, the overall uncertainty in modeled vs. measured results and modeling large PV systems. SNL is also conducting research into the overall reliability of PV systems.

  1. Assessing Uncertainty in Spatial Exposure Models for Air Pollution Health Effects Assessment

    E-Print Network [OSTI]

    2007-01-01T23:59:59.000Z

    Spatial analysis of air pollution and mor- tality in Loslinking chronic air pollution exposure to health outcomes. J2006. Bayesian modeling of air pollution health effects with

  2. Integrated modelling and assessment of regional groundwater resources in Germany and Benin, West Africa

    E-Print Network [OSTI]

    Cirpka, Olaf Arie

    1 Integrated modelling and assessment of regional groundwater resources in Germany and Benin, West.J.S. SONNEVELD [1] Institute of Hydraulic Engineering, Universitaet Stuttgart, Germany (Roland Conservation University of Bonn, Germany [3] Institute of Landscape Planning and Ecology, University

  3. Implementation of surface tension with wall adhesion effects in a three-dimensional finite element model for fluid flow

    E-Print Network [OSTI]

    Boyer, Edmond

    - 1 - Implementation of surface tension with wall adhesion effects in a three-dimensional finite element modelling of surface tension. The external stress vectors associated with surface tension a drop of liquid on a plane is treated. Keywords : surface tension, finite element method, average

  4. Computational modeling of GTA (gas tungsten arc) welding with emphasis on surface tension effects

    SciTech Connect (OSTI)

    Zacharia, T.; David, S.A.

    1990-01-01T23:59:59.000Z

    A computational study of the convective heat transfer in the weld pool during gas tungsten arch (GTA) welding of Type 304 stainless steel is presented. The solution of the transport equations is based on a control volume approach which utilized directly, the integral form of the governing equations. The computational model considers buoyancy and electromagnetic and surface tension forces in the solution of convective heat transfer in the weld pool. In addition, the model treats the weld pool surface as a deformable free surface. The computational model includes weld metal vaporization and temperature dependent thermophysical properties. The results indicate that consideration of weld pool vaporization effects and temperature dependent thermophysical properties significantly influence the weld model predictions. Theoretical predictions of the weld pool surface temperature distributions and the cross-sectional weld pool size and shape wee compared with corresponding experimental measurements. Comparison of the theoretically predicted and the experimentally obtained surface temperature profiles indicated agreement with {plus minus} 8%. The predicted weld cross-section profiles were found to agree very well with actual weld cross-sections for the best theoretical models. 26 refs., 8 figs.

  5. analytical model assessing: Topics by E-print Network

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

    272 Coupled thermodynamic-dynamic semi-analytical model of Free Piston Stirling engines CERN Preprints Summary: The study of free piston Stirling engine (FPSE) requires both...

  6. Modeling Exposure to Persistent Chemicals in Hazard and Risk Assessment

    E-Print Network [OSTI]

    Cowan-Ellsberry, Christina E.

    2010-01-01T23:59:59.000Z

    chlorinated pesticides, e.g. , DDT) based on Swedish marketInvestigating the global fate of DDT: Model evaluation anddichlorodiphenyltrichloroethane (DDT), and its degradation

  7. A new analytic-adaptive model for EGS assessment, development...

    Open Energy Info (EERE)

    Investigator(s) George Danko, UNR Other Principal Investigators Jens Birkholzer, LBNL; Jaak Daemen, UNR Targets Milestones The model development work follows three main...

  8. assessment models version: Topics by E-print Network

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

    Szilagyi a is modeled with a spatially and temporally discretized version of the linear kinematic wave equation written-aquifer interactions; Baseflow separation; Flow routing;...

  9. assessment model version: Topics by E-print Network

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

    Szilagyi a is modeled with a spatially and temporally discretized version of the linear kinematic wave equation written-aquifer interactions; Baseflow separation; Flow routing;...

  10. Utility of Social Modeling in Assessment of a State’s Propensity for Nuclear Proliferation

    SciTech Connect (OSTI)

    Coles, Garill A.; Brothers, Alan J.; Whitney, Paul D.; Dalton, Angela C.; Olson, Jarrod; White, Amanda M.; Cooley, Scott K.; Youchak, Paul M.; Stafford, Samuel V.

    2011-06-01T23:59:59.000Z

    This report is the third and final report out of a set of three reports documenting research for the U.S. Department of Energy (DOE) National Security Administration (NASA) Office of Nonproliferation Research and Development NA-22 Simulations, Algorithms, and Modeling program that investigates how social modeling can be used to improve proliferation assessment for informing nuclear security, policy, safeguards, design of nuclear systems and research decisions. Social modeling has not to have been used to any significant extent in a proliferation studies. This report focuses on the utility of social modeling as applied to the assessment of a State's propensity to develop a nuclear weapons program.

  11. Chaotic Vibration of a Quarter-Car Model Excited by the Road Surface Profile

    E-Print Network [OSTI]

    Grzegorz Litak; Marek Borowiec; Michael I. Friswell; Kazimierz Szabelski

    2006-01-14T23:59:59.000Z

    The Melnikov criterion is used to examine a global homoclinic bifurcation and transition to chaos in the case of a quarter car model excited kinematically by the road surface profile. By analyzing the potential an analytic expression is found for the homoclinic orbit. By introducing an harmonic excitation term and damping as perturbations, the critical Melnikov amplitude of the road surface profile is found, above which the system can vibrate chaotically.

  12. Diosmacycloalkanes as models for the formation of hydrocarbons from surface methylenes

    SciTech Connect (OSTI)

    Norton, J.R.

    1993-05-01T23:59:59.000Z

    The report is divided into: vibrational models for surface ethylidenes (on catalyst surfaces); alpha vs beta hydrogen elimination in formation of propene from an osmacyclobutane; mechanism of formation and fragmentation of diosmacyclobutanes; reaction of dienes and allenes with diosmacyclobutanes; structure of Os(CO)[sub 4](C[sub 2]H[sub 4]), an osmacyclopropane; and reaction of [mu]-oxobis [(trifluoromethanesulfanato) (phenyl)iodine(III)] with Group 14 propargyl derivatives and a propargyl ether. 16 refs, figs.

  13. Surface tension and curvature energy of quark matter in the NJL model

    E-Print Network [OSTI]

    G. Lugones; A. G. Grunfeld; M. Al Ajmi

    2013-10-14T23:59:59.000Z

    In this paper we study the surface tension and the curvature energy of three-flavor quark matter in equilibrium under weak interactions within the Nambu-Jona-Lasinio model. We include the effect of color superconductivity and describe finite size effects within the multiple reflection expansion (MRE) framework. Our calculations result in large values of the surface tension which disfavor the formation of mixed phases at the hadron-quark inter-phase inside a hybrid star.

  14. Model Fire Protection Assessment Guide | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(FactDepartment3311,OfficialProducts | Department of EnergyMobileAssessment

  15. CAirTOX: A compartment model for assessing the fate of and human exposure to toxic-chemical emissions to air

    SciTech Connect (OSTI)

    McKone, T.E.

    1993-10-01T23:59:59.000Z

    CAirTOX has been developed as a spreadsheet model to assist in making a risk assessment of toxic air emissions. With CAirTOX, one can address how contaminants released to an air basin can lead to contamination of soil, food, surface water, and sediments. The modeling effort includes a multimedia transport and transformation model, exposure scenario models, and efforts to quantify uncertainty in multimedia, multiple-pathway exposure assessments. The multimedia transport and transformation model is a steady-state, but non-equilibrium model that can be used to assess concentrations of contaminants released continuously to air. In Part 1, the authors describe the multimedia transport and transformation model used to determine the fate of air emissions. In Part 2, they describe inputs and data needs for CAirTOX and the development of a set of landscape factors, which can be used to represent regional air basin/water-shed systems in California. In Part 3, they describe the multiple-pathway exposure scenarios and exposure algorithms. In Part 4, they compare the HRA approach and results and the CAirTOX exposure equations. In Part 5, they consider model sensitivity and uncertainty to determine how variability and uncertainty in model inputs affects the precision, accuracy, and credibility of the model output.

  16. Modeling laser-induced periodic surface structures: Finite-difference time-domain feedback simulations

    SciTech Connect (OSTI)

    Skolski, J. Z. P., E-mail: j.z.p.skolski@utwente.nl; Vincenc Obona, J. [Materials innovation institute M2i, Faculty of Engineering Technology, Chair of Applied Laser Technology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); Römer, G. R. B. E.; Huis in 't Veld, A. J. [Faculty of Engineering Technology, Chair of Applied Laser Technology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands)

    2014-03-14T23:59:59.000Z

    A model predicting the formation of laser-induced periodic surface structures (LIPSSs) is presented. That is, the finite-difference time domain method is used to study the interaction of electromagnetic fields with rough surfaces. In this approach, the rough surface is modified by “ablation after each laser pulse,” according to the absorbed energy profile, in order to account for inter-pulse feedback mechanisms. LIPSSs with a periodicity significantly smaller than the laser wavelength are found to “grow” either parallel or orthogonal to the laser polarization. The change in orientation and periodicity follow from the model. LIPSSs with a periodicity larger than the wavelength of the laser radiation and complex superimposed LIPSS patterns are also predicted by the model.

  17. A comparison of radiological risk assessment models: Risk assessment models used by the BEIR V Committee, UNSCEAR, ICRP, and EPA (for NESHAP)

    SciTech Connect (OSTI)

    Wahl, L.E.

    1994-03-01T23:59:59.000Z

    Radiological risk assessments and resulting risk estimates have been developed by numerous national and international organizations, including the National Research Council`s fifth Committee on the Biological Effects of Ionizing Radiations (BEIR V), the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), and the International Commission on Radiological Protection (ICRP). A fourth organization, the Environmental Protection Agency (EPA), has also performed a risk assessment as a basis for the National Emission Standards for Hazardous Air Pollutants (NESHAP). This paper compares the EPA`s model of risk assessment with the models used by the BEIR V Committee, UNSCEAR, and ICRP. Comparison is made of the values chosen by each organization for several model parameters: populations used in studies and population transfer coefficients, dose-response curves and dose-rate effects, risk projection methods, and risk estimates. This comparison suggests that the EPA has based its risk assessment on outdated information and that the organization should consider adopting the method used by the BEIR V Committee, UNSCEAR, or ICRP.

  18. assessing local model: Topics by E-print Network

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

    Ying; Peng Xinguang 243 Web tool for energy policy decision-making through geo-localized LCA models: A focus on offshore wind farms in Northern Europe Physics Websites Summary: 1...

  19. Model Assessment with Renormalization Group in Statistical Learning

    E-Print Network [OSTI]

    GingQuo, Wang

    2013-01-01T23:59:59.000Z

    Clustering: 50 years beyond K-means,” Pattern Recognitionas Fig. 2a). Perform the k-means clustering algorithm, whichThe coarse set and model. The k-means clustering algorithm—

  20. Using species distribution models to inform IUCN Red List assessments

    E-Print Network [OSTI]

    Syfert, Mindy M.; Joppa, Lucas; Smith, Matthew J.; Coomes, David A.; Bachman, Steven P.; Brummitt, Neil A.

    2014-07-26T23:59:59.000Z

    .g. hurricanes) or anthropogenic effects (e.g. deforestation) not included in the model fitting process (Elith and Leathwick 2009). Additionally, the SDM approach we have taken here does not explicitly take into account non-equilibrium species dynamics. While...

  1. Assessment of reduced mechanisms using One Dimensional Stochastic Turbulence model

    E-Print Network [OSTI]

    Chien, Li-Chun

    2010-01-01T23:59:59.000Z

    turbulence model for a syngas jet flame. Proceeding of FallKerstein 2002), a turbulent syngas (CO/H2/NO) jet flame wasand DNS results of the syngas jet flame was recently done

  2. Kinetic model for electric-field induced point defect redistribution near semiconductor surfaces

    SciTech Connect (OSTI)

    Gorai, Prashun; Seebauer, Edmund G., E-mail: eseebaue@illinois.edu [Department of Chemical and Biomolecular Engineering, University of Illinois, Urbana, Illinois 61801 (United States)

    2014-07-14T23:59:59.000Z

    The spatial distribution of point defects near semiconductor surfaces affects the efficiency of devices. Near-surface band bending generates electric fields that influence the spatial redistribution of charged mobile defects that exchange infrequently with the lattice, as recently demonstrated for pile-up of isotopic oxygen near rutile TiO{sub 2} (110). The present work derives a mathematical model to describe such redistribution and establishes its temporal dependence on defect injection rate and band bending. The model shows that band bending of only a few meV induces significant redistribution, and that the direction of the electric field governs formation of either a valley or a pile-up.

  3. Surface Modes of Vibration in Rigid-Ion Model of Nacl

    E-Print Network [OSTI]

    CHEN, TS; Allen, Roland E.; Alldredg, GP; WETTE, FWD.

    1972-01-01T23:59:59.000Z

    SURFACE MEAN-SQUARE AMPLITUDES OF VIBRATION FOR NaC1 627 A78 (1965). A. A. Lucas, J. Chem. Phys. 48, 3156 (1968). Benson and co-workers have found that oversimplified models which allow different displacements for different ions tend... and T. Paakkari, Acta Cryst. ~23 1107 (1967). PHYSICAL REVIEW B VOLUME 6, NUMBER 2 15 JULY 1972 Surface Modes of Vibration in the Rigid-Ion Model of NaC1~ T. S. Chen, G. P. Alldredge, and F. W. de Wette Department of Physics, University of Texas...

  4. A surface renewal model to analyze infrared image sequences of the ocean surface for the study of air-sea heat

    E-Print Network [OSTI]

    Garbe, Christoph S.

    A surface renewal model to analyze infrared image sequences of the ocean surface for the study of air-sea heat and gas exchange C. S. Garbe Interdisciplinary Center for Scientific Computing renewal, the net heat flux, and the heat transfer velocity during nighttime. The techniques are based

  5. Using beryllium-7 to assess cross-tropopause1 transport in global models2

    E-Print Network [OSTI]

    Liu, Hongyu

    1 Using beryllium-7 to assess cross-tropopause1 transport in global models2 3 Hongyu Liu1 , David B, MA13 14 Short Title: Beryllium-7 and cross-tropopause transport15 Index Terms: 0368 Troposphere Initiative (GMI) modeling framework the29 utility of cosmogenic beryllium-7 (7 Be), a natural aerosol tracer

  6. The Lifecycle of Bayesian Network Models Developed for Multi-Source Signature Assessment of Nuclear Programs

    SciTech Connect (OSTI)

    Gastelum, Zoe N.; White, Amanda M.; Whitney, Paul D.; Gosink, Luke J.; Sego, Landon H.

    2013-06-04T23:59:59.000Z

    The Multi-Source Signatures for Nuclear Programs project, part of Pacific Northwest National Laboratory’s (PNNL) Signature Discovery Initiative, seeks to computationally capture expert assessment of multi-type information such as text, sensor output, imagery, or audio/video files, to assess nuclear activities through a series of Bayesian network (BN) models. These models incorporate knowledge from a diverse range of information sources in order to help assess a country’s nuclear activities. The models span engineering topic areas, state-level indicators, and facility-specific characteristics. To illustrate the development, calibration, and use of BN models for multi-source assessment, we present a model that predicts a country’s likelihood to participate in the international nuclear nonproliferation regime. We validate this model by examining the extent to which the model assists non-experts arrive at conclusions similar to those provided by nuclear proliferation experts. We also describe the PNNL-developed software used throughout the lifecycle of the Bayesian network model development.

  7. A flow resistance model for assessing the impact of vegetation on flood routing mechanics

    E-Print Network [OSTI]

    Katul, Gabriel

    control in urban storm water runoff [Kirby et al., 2005], and linking tidal hydrodynamic forcing to flow and field studies. The proposed model asymptotically recovers the flow resistance formulation when the waterA flow resistance model for assessing the impact of vegetation on flood routing mechanics Gabriel G

  8. A next-generation modeling capability assesses wind turbine array fluid dynamics and aeroelastic simulations

    E-Print Network [OSTI]

    A next-generation modeling capability assesses wind turbine array fluid dynamics and aeroelastic simulations Characterizing and optimizing overall performance of wind plants composed of large numbers at the National Renewable Energy Laboratory (NREL) are coupling physical models of the atmosphere and wind

  9. An Assessment of Converter Modelling Needs for Offshore Wind Power Plants Connected via VSC-

    E-Print Network [OSTI]

    Bak, Claus Leth

    An Assessment of Converter Modelling Needs for Offshore Wind Power Plants Connected via VSC- HVDC, especially in case of connection of offshore wind power plants (OWPPs). Modelling challenges are faced Networks Jakob Glasdam, Lorenzo Zeni, Jesper Hjerrild, Lukasz Kocewiak, Bo Hesselbaek Wind Power

  10. Environmental Modeling and Assessment (2005) 10:6379 DOI 10.1007/s10666-004-4267-z Springer 2005

    E-Print Network [OSTI]

    Risbey, James S.

    2005-01-01T23:59:59.000Z

    Environmental Modeling and Assessment (2005) 10:63­79 DOI 10.1007/s10666-004-4267-z Springer 2005 Application of a checklist for quality assistance in environmental modelling to an energy model James Risbey a present considerable challenges to develop and test. Uncertainty assessments of such models provide only

  11. First Prev Next Last Go Back Full Screen Close Quit Model Assessment

    E-Print Network [OSTI]

    Spang, Rainer

    ·First ·Prev ·Next ·Last ·Go Back ·Full Screen ·Close ·Quit Model Assessment and Selection Axel ·Prev ·Next ·Last ·Go Back ·Full Screen ·Close ·Quit Model Assessment and Selection 2 Topics Predictive · Restriction · Selection · Regularization #12;·First ·Prev ·Next ·Last ·Go Back ·Full Screen ·Close ·Quit Model

  12. Geometric effects modelling for the PJM interconnection system. Part 1; Earth surface potentials computation

    SciTech Connect (OSTI)

    Towle, J.N. (Diversified EM, Seattle, WA (US)); Prabhakara, F.S. (Power Technologies, Inc., Schenectady, NY (US)); Ponder, J.Z. (PJM Interconnection, Norristown, PA (US))

    1992-07-01T23:59:59.000Z

    This paper describes an ionospheric source current model and development of an earth resistivity model used to calculate geomagnetic induced currents (GIC) on the Pennsylvania-New Jersey-Maryland Interconnection (PJM). Ionospheric current is modelled as a gaussian distributed current sheet above the earth. Geological details are included by dividing the PJM service area into 11 different earth resistivity regions. The resulting earth surface potential (ESP) at each power system substation is then calculated. A companion paper describes how this ESP is applied to the power system model to calculate the geomagnetic induced current in the power system equipment and facilities.

  13. Incorporating carbon capture and storage technologies in integrated assessment models

    E-Print Network [OSTI]

    and storage of CO2 from electric power plants. The electric power sector accounts for a substant a methodology for incorporating technologies into computable general equilibrium economic models and demonstrate; Climate; Technology; General equilibrium; Diffusion 1. Introduction Over the past century, technological

  14. Towards an assessment of skill acquisition in student modelling

    E-Print Network [OSTI]

    Yacef, Kalina

    /her operational skill in dynamic and highly risky domains, such as Air Traffic Control, nuclear plant operations,leila]@cmis.csiro.au Abstract: This paper presents an approach to student modelling in the context of a simulation-based ITS of the expertise. Examples are given in the domain of Air Traffic Control simulation training for conflict

  15. Common-Cause Failure Treatment in Event Assessment: Basis for a Proposed New Model

    SciTech Connect (OSTI)

    Dana Kelly; Song-Hua Shen; Gary DeMoss; Kevin Coyne; Don Marksberry

    2010-06-01T23:59:59.000Z

    Event assessment is an application of probabilistic risk assessment in which observed equipment failures and outages are mapped into the risk model to obtain a numerical estimate of the event’s risk significance. In this paper, we focus on retrospective assessments to estimate the risk significance of degraded conditions such as equipment failure accompanied by a deficiency in a process such as maintenance practices. In modeling such events, the basic events in the risk model that are associated with observed failures and other off-normal situations are typically configured to be failed, while those associated with observed successes and unchallenged components are assumed capable of failing, typically with their baseline probabilities. This is referred to as the failure memory approach to event assessment. The conditioning of common-cause failure probabilities for the common cause component group associated with the observed component failure is particularly important, as it is insufficient to simply leave these probabilities at their baseline values, and doing so may result in a significant underestimate of risk significance for the event. Past work in this area has focused on the mathematics of the adjustment. In this paper, we review the Basic Parameter Model for common-cause failure, which underlies most current risk modelling, discuss the limitations of this model with respect to event assessment, and introduce a proposed new framework for common-cause failure, which uses a Bayesian network to model underlying causes of failure, and which has the potential to overcome the limitations of the Basic Parameter Model with respect to event assessment.

  16. Numerical study of three-dimensional PIC for the surface plasmon excitation based on Drude model

    E-Print Network [OSTI]

    Liu, La-Qun; Wang, Hui-Hui; Liu, Da-Gang

    2015-01-01T23:59:59.000Z

    This paper explores the time-domain equations of noble metals, in which Drude model is adopted to describe the dielectric constant, to implement three-dimensional particle-in-cell (PIC) simulations for the surface plasmon excitation with the finite-difference time-domain method (FDTD). A three-dimensional model for an electron bunch movement near the metal film is constructed, and particle-in-cell (PIC) simulations are carried out with various metal films of different thicknesses. The frequency of surface plasmon obtained from PIC simulation is agreed with that from theory. Furthermore, the surface plasmon wave properties of excitation and propagation with the metal film is summarized by PIC results.

  17. The structure of the free energy surface of coarse-grained off-lattice protein models

    E-Print Network [OSTI]

    E. Akturk; H. Arkin Olgar; T. Celik

    2007-03-23T23:59:59.000Z

    We have performed multicanonical simulations of hydrophobic-hydrophilic heteropolymers with a simple effective, coarse-grained off-lattice model to study the structure and the topology of the energy surface. The multicanonical method samples the whole rugged energy landscape, in particular the low-energy part, and enables one to better understand the critical behaviors and visualize the folding pathways of the considered protein model.

  18. Effect of One-Dimensional Field Data Assimilation on Land Surface Model Flux Estimates with Implications

    E-Print Network [OSTI]

    Walker, Jeff

    .W. Western1 1 Department of Civil and Environmental Engineering, The University of Melbourne, Victoria, Australia 2 CSIRO Marine and Atmospheric Research, Aspendale, Victoria, Australia Email: r Model (CBM) represent the exchange of energy and water between the earth's surface and lower atmosphere

  19. A three-dimensional surface waveocean circulation coupled model and its initial testing

    E-Print Network [OSTI]

    Ezer,Tal

    models is established based on Reynolds stresses and fluxes terms derived from surface wave to 0.93 with wave influence. The wave-induced Reynolds stress can reach up to about 5% of the wind stress in high latitudes, and drive 2­3 Sv transport in the global ocean in the form of mesoscale eddies

  20. One-dimensional snow water and energy balance model for vegetated surfaces

    E-Print Network [OSTI]

    Yang, Zong-Liang

    One-dimensional snow water and energy balance model for vegetated surfaces Jiming Jin,2 Xiaogang heat ¯ux (W mÀ2 ) Iprec heat ¯ux of precipitation (W mÀ2) I5 s downwelling solar radiation (W mÀ2, USA. Email: jjm@hwr.arizona.edu or gao@hwr.arizona.edu Contract grant sponsor: NASA

  1. A simple numerical model of the apparent loss of eddy current conductivity due to surface roughness

    E-Print Network [OSTI]

    Nagy, Peter B.

    A simple numerical model of the apparent loss of eddy current conductivity due to surface roughness of eddy current conductivity has been suggested as a possible means to allow the nondestructive evaluation, the path of the eddy current must follow a more tortuous route in the material, which produces a reduction

  2. Risk-based modelling of surface water quality: a case study of the Charles River, Massachusetts

    E-Print Network [OSTI]

    Wagener, Thorsten

    : Water quality; Risk; Monte Carlo; Sensitivity analysis; Eutrophication 1. Introduction 1.1. Motivation recognised in the development of some decision-support tools, for example, QUAL2E- UNCAS (Brown and BarnwellRisk-based modelling of surface water quality: a case study of the Charles River, Massachusetts

  3. Surface kinetics and plasma equipment model for Si etching by fluorocarbon plasmas

    E-Print Network [OSTI]

    Kushner, Mark

    Surface kinetics and plasma equipment model for Si etching by fluorocarbon plasmas Da Zhanga of fluorocarbon radicals on the reactor walls, polymer erosion rates and F atom diffusion through the polymer during Si etching using fluorocarbon gases in an induc- tively coupled plasma ICP reactor.4 They observed

  4. Shell Model Dynamics of HCl on the MgO(001) Surface Terrace Andreas Markmann,1

    E-Print Network [OSTI]

    Markmann, Andreas

    are then used to aid the analysis of MD calculations. After equilibrium dynamics, a sudden excitation of the OH of molecular dynamics using specially tailored laser fields. The reaction of hydrogen chloride moleculesShell Model Dynamics of HCl on the MgO(001) Surface Terrace Andreas Markmann,1 Jacob L. Gavartin,2

  5. The influence of the land surface on hydrometeorology and ecology: new advances from modeling and satellite

    E-Print Network [OSTI]

    Small, Eric

    Resolution Imaging Spectroradiometer (MODIS) and EOS Advanced Microwave Scanning Radiometer (AMSR and through model initialization of soil moisture from High Resolution Land Data Assimilation System (HRLDAS moisture and sensible heat fluxes. For example, the variations of surface energy and moisture fluxes

  6. Developing a TeraGrid Based Land Surface Hydrology and Weather Modeling Interface

    E-Print Network [OSTI]

    Jiang, Wen

    Developing a TeraGrid Based Land Surface Hydrology and Weather Modeling Interface Hsin-I Chang1 iclimate@purdue.edu -------------------- -------------------- 1 INTRODUCTION Real world hydrologic cyberinfrastructure (CI) has been articulated in many workshops and meetings of the environmental and hydrologic

  7. A FETCH DEPENDENT MODEL OF SEA SURFACE ROUGHNESS FOR OFFSHORE WIND POWER UTILISATION

    E-Print Network [OSTI]

    Heinemann, Detlev

    , Resources, Roughness, Coastal Sea Areas, Waves, Rødsand 1 INTRODUCTION Large offshore wind farms are beingA FETCH DEPENDENT MODEL OF SEA SURFACE ROUGHNESS FOR OFFSHORE WIND POWER UTILISATION Bernhard Lange wind conditions of offshore sites, since the higher energy yield has to compensate the additional

  8. Incorporating and Evaluating Environmental Instream Flows in a Priority Order Based Surface Water Allocation Model

    E-Print Network [OSTI]

    Pauls, Mark

    2014-03-18T23:59:59.000Z

    ............................................................................................................ 120 Figure 20. Comparison of Engaged Period Reliability versus Allowable Deficit (M3B) between Trinity WAM Control Points for All Instream Flow Targets... INCORPORATING AND EVALUATING ENVIRONMENTAL INSTREAM FLOWS IN A PRIORITY ORDER BASED SURFACE WATER ALLOCATION MODEL A Thesis by MARK ALLEN PAULS Submitted to the Office of Graduate and Professional Studies of Texas A&M University...

  9. Surface energies in a two-dimensional mass-spring model for crystals

    E-Print Network [OSTI]

    Theil, Florian

    Surface energies in a two-dimensional mass-spring model for crystals Florian Theil Mathematics an atomistic pair potential-energy E(n)(y) that describes the elastic behavior of two- dimensional crystals analysis of the ground state energy as n tends to infinity. We show in a suitable scaling regime where

  10. Fractional advection-dispersion equations for1 modeling transport at the Earth surface2

    E-Print Network [OSTI]

    Bäumer, Boris

    Fractional advection-dispersion equations for1 modeling transport at the Earth surface2 Rina partial differential equations such as the advection-dispersion equation12 (ADE) begin with assumptions biomechanical transport and mixing29 by bioturbation, and the transport of sediment particles and sediment

  11. Inferring surface heat flux distributions guided by a global seismic model: particular application to Antarctica

    E-Print Network [OSTI]

    Shapiro, Nikolai

    -flow measurements are rare or entirely absent. This will result in a smooth global heat-flow map that may proveInferring surface heat flux distributions guided by a global seismic model: particular application to Antarctica Nikolai M. Shapiro*, Michael H. Ritzwoller Department of Physics, Center for Imaging the Earth

  12. Comparative evaluation of life cycle assessment models for solid waste management

    SciTech Connect (OSTI)

    Winkler, Joerg [Institute for Waste Management and Contaminated Sites Treatment, TU Dresden Faculty of Forestry, Geo and Hydro Sciences, Pratzschwitzer Str. 15, 01796 Pirna (Germany); Bilitewski, Bernd [Institute for Waste Management and Contaminated Sites Treatment, TU Dresden Faculty of Forestry, Geo and Hydro Sciences, Pratzschwitzer Str. 15, 01796 Pirna (Germany)], E-mail: abfall@rcs.urz.tu-dresden.de

    2007-07-01T23:59:59.000Z

    This publication compares a selection of six different models developed in Europe and America by research organisations, industry associations and governmental institutions. The comparison of the models reveals the variations in the results and the differences in the conclusions of an LCA study done with these models. The models are compared by modelling a specific case - the waste management system of Dresden, Germany - with each model and an in-detail comparison of the life cycle inventory results. Moreover, a life cycle impact assessment shows if the LCA results of each model allows for comparable and consecutive conclusions, which do not contradict the conclusions derived from the other models' results. Furthermore, the influence of different level of detail in the life cycle inventory of the life cycle assessment is demonstrated. The model comparison revealed that the variations in the LCA results calculated by the models for the case show high variations and are not negligible. In some cases the high variations in results lead to contradictory conclusions concerning the environmental performance of the waste management processes. The static, linear modelling approach chosen by all models analysed is inappropriate for reflecting actual conditions. Moreover, it was found that although the models' approach to LCA is comparable on a general level, the level of detail implemented in the software tools is very different.

  13. A Preliminary Study to Assess Model Uncertainties in Fluid Flows

    E-Print Network [OSTI]

    Delchini, Marc Olivier

    2011-08-08T23:59:59.000Z

    of the fluid. ? The sound speed, c, is assumed to be constant even if it usually depends on the temperature and the pressure. This is a good approximation for liquids but not for gases. The sound speed is reactor-dependent. ? The Equation Of State (EOS... to the temperature. This parameter is assumed constant in this model. 7 ? ???P is the dilatation of the density due to the pressure. This parameter is also assumed constant but is different for different sound speeds. Its expression is as follows: ?? ?P = 1...

  14. hal-00272925,version1-14Apr2008 SURFACE TENSION IN THE DILUTE ISING MODEL. THE WULFF

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    hal-00272925,version1-14Apr2008 SURFACE TENSION IN THE DILUTE ISING MODEL. THE WULFF CONSTRUCTION. MARC WOUTS Abstract. We study the surface tension and the phenomenon of phase coexistence for the Ising respect to random couplings) of surface tension and analyze its large deviations : upper deviations occur

  15. Modeling and Simulation of Long-Term Performance of Near-Surface Barriers

    SciTech Connect (OSTI)

    Piet, S. J.; Jacobson, J. J.; Martian, P.; Martineau, R.; Soto, R.

    2003-02-25T23:59:59.000Z

    Society has and will continue to generate hazardous wastes whose risks must be managed. For exceptionally toxic, long-lived, and feared waste, the solution is deep burial, e.g., deep geological disposal at Yucca Mtn. For some waste, recycle or destruction/treatment is possible. The alternative for other wastes is storage at or near the ground level (in someone's back yard); most of these storage sites include a surface barrier (cap) to prevent migration of the waste due to infiltration of surface water. The design lifespan for such barriers ranges from 30 to 1000 years, depending on hazard and regulations. In light of historical performance, society needs a better basis for predicting barrier performance over long time periods and tools for optimizing maintenance of barriers while in service. We believe that, as in other industries, better understanding of the dynamics of barrier system degradation will enable improved barriers (cheaper, longer-lived, simpler, easier to maintain) and improved maintenance. We are focusing our research on earthen caps, especially those with evapo-transpiration and capillary breaks. Typical cap assessments treat the barrier's structure as static prior to some defined lifetime. Environmental boundary conditions such as precipitation and temperature are treated as time dependent. However, other key elements of the barrier system are regarded as constant, including engineered inputs (e.g., fire management strategy, irrigation, vegetation control), surface ecology (critical to assessment of plant transpiration), capillary break interface, material properties, surface erosion rate, etc. Further, to be conservative, only harmful processes are typically considered. A more holistic examination of both harmful and beneficial processes will provide more realistic pre-service prediction and in-service assessment of performance as well as provide designers a tool to encourage beneficial processes while discouraging harmful processes. Thus, the INEEL started a new project on long-term barrier integrity in April 2002 that aims to catalyze a Barrier Improvement Cycle (iterative learning and application) and thus enable Remediation System Performance Management (doing the right maintenance neither too early nor too late, prior to system-level failure). This paper describes our computer simulation approach for better understanding the relationships and dynamics between the various components and management decisions in a cap. The simulation is designed to clarify the complex relationships between the various components within the cap system and the various management practices that affect the barrier performance. We have also conceptualized a time-dependent 3-D simulation with rigorous solution to unsaturated flow physics with complex surface boundary conditions.

  16. Modeling and Simulation of Long-Term Performance of Near-Surface Barriers

    SciTech Connect (OSTI)

    Piet, Steven James; Jacobson, Jacob Jordan; Soto, Rafael; Martian, Pete; Martineau, Richard Charles

    2003-02-01T23:59:59.000Z

    Society has and will continue to generate hazardous wastes whose risks must be managed. For exceptionally toxic, long-lived, and feared waste, the solution is deep burial, e.g., deep geological disposal at Yucca Mtn. For some waste, recycle or destruction/treatment is possible. The alternative for other wastes is storage at or near the ground level (in someone’s back yard); most of these storage sites include a surface barrier (cap) to prevent migration of the waste due to infiltration of surface water. The design lifespan for such barriers ranges from 30 to 1000 years, depending on hazard and regulations. In light of historical performance, society needs a better basis for predicting barrier performance over long time periods and tools for optimizing maintenance of barriers while in service. We believe that, as in other industries, better understanding of the dynamics of barrier system degradation will enable improved barriers (cheaper, longer-lived, simpler, easier to maintain) and improved maintenance. We are focusing our research on earthen caps, especially those with evapo-transpiration and capillary breaks. Typical cap assessments treat the barrier’s structure as static prior to some defined lifetime. Environmental boundary conditions such as precipitation and temperature are treated as time dependent. However, other key elements of the barrier system are regarded as constant, including engineered inputs (e.g., fire management strategy, irrigation, vegetation control), surface ecology (critical to assessment of plant transpiration), capillary break interface, material properties, surface erosion rate, etc. Further, to be conservative, only harmful processes are typically considered. A more holistic examination of both harmful and beneficial processes will provide more realistic pre-service prediction and in-service assessment of performance as well as provide designers a tool to encourage beneficial processes while discouraging harmful processes. Thus, the INEEL started a new project on long-term barrier integrity in April 2002 that aims to catalyze a Barrier Improvement Cycle (iterative learning and application) and thus enable Remediation System Performance Management (doing the right maintenance neither too early nor too late, prior to system-level failure). This paper describes our computer simulation approach for better understanding the relationships and dynamics between the various components and management decisions in a cap. The simulation is designed to clarify the complex relationships between the various components within the cap system and the various management practices that affect the barrier performance. We have also conceptualized a time-dependent 3-D simulation with rigorous solution to unsaturated flow physics with complex surface boundary conditions.

  17. SOCIAL MODELING IN ASSESSEMENT OF A STATE’S PROPENSITY FOR NUCLEAR PROLIFERATION

    SciTech Connect (OSTI)

    Dalton, Angela C.; Whitney, Paul D.; Coles, Garill A.; Brothers, Alan J.

    2011-07-17T23:59:59.000Z

    This paper presents approach for assessing a State’s propensity for nuclear weapons proliferation using social modeling. We supported this modeling by first reviewing primarily literature by social scientists on factors related to the propensity of a State to proliferation and by leveraging existing relevant data compiled by social scientists. We performed a number of validation tests on our model including one that incorporates use of benchmark data defining the proliferation status of countries in the years between 1945 and 2000. We exercise the BN model against a number of country cases representing different perceived levels of proliferation risk. We also describe how the BN model could be further refined to be a proliferation assessment tool for decision making.

  18. Atomic imaging and modeling of H{sub 2}O{sub 2}(g) surface passivation, functionalization, and atomic layer deposition nucleation on the Ge(100) surface

    SciTech Connect (OSTI)

    Kaufman-Osborn, Tobin [Materials Science and Engineering Program, University of California, San Diego, La Jolla, California 92093 (United States); Chagarov, Evgueni A. [Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093 (United States); Kummel, Andrew C., E-mail: akummel@ucsd.edu [Materials Science and Engineering Program, University of California, San Diego, La Jolla, California 92093 (United States); Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093 (United States)

    2014-05-28T23:59:59.000Z

    Passivation, functionalization, and atomic layer deposition nucleation via H{sub 2}O{sub 2}(g) and trimethylaluminum (TMA) dosing was studied on the clean Ge(100) surface at the atomic level using scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS). Chemical analysis of the surface was performed using x-ray photoelectron spectroscopy, while the bonding of the precursors to the substrate was modeled with density functional theory (DFT). At room temperature, a saturation dose of H{sub 2}O{sub 2}(g) produces a monolayer of a mixture of –OH or –O species bonded to the surface. STS confirms that H{sub 2}O{sub 2}(g) dosing eliminates half-filled dangling bonds on the clean Ge(100) surface. Saturation of the H{sub 2}O{sub 2}(g) dosed Ge(100) surface with TMA followed by a 200?°C anneal produces an ordered monolayer of thermally stable Ge–O–Al bonds. DFT models and STM simulations provide a consistent model of the bonding configuration of the H{sub 2}O{sub 2}(g) and TMA dosed surfaces. STS verifies the TMA/H{sub 2}O{sub 2}/Ge surface has an unpinned Fermi level with no states in the bandgap demonstrating the ability of a Ge–O–Al monolayer to serve as an ideal template for further high-k deposition.

  19. Mixed Layer Mesoscales for OGCMs: Model development and assessment with T/P, WOCE and Drifter data

    E-Print Network [OSTI]

    Canuto, V M; Leboissetier, A

    2011-01-01T23:59:59.000Z

    We present a model for mixed layer (ML) mesoscale (M) fluxes of an arbitrary tracer in terms of the resolved fields (mean tracer and mean velocity). The treatment of an arbitrary tracer, rather than only buoyancy, is necessary since OGCMs time step T, S, CO2, etc and not buoyancy. The particular case of buoyancy is used to assess the model results. The paper contains three parts: derivation of the results, discussion of the results and assessment of the latter using, among others, WOCE, T/P and Drifter data. Derivation. To construct the M fluxes, we first solve the ML M dynamic equations for the velocity and tracer M fields. The goal of the derivation is to emphasize the different treatments of the non-linear terms in the adiabatic vs. diabatic ocean (deep ocean vs. mixed layer). Results. We derive analytic expressions for the following variables: a) vertical and horizontal M fluxes of an arbitrary tracer, b) M diffusivity in terms of the EKE, c) surface value of the EKE in terms of the vertical M buoyancy fl...

  20. Computational Modeling and Assessment Of Nanocoatings for Ultra Supercritical Boilers

    SciTech Connect (OSTI)

    David W. Gandy; John P. Shingledecker

    2011-04-11T23:59:59.000Z

    Forced outages and boiler unavailability in conventional coal-fired fossil power plants is most often caused by fireside corrosion of boiler waterwalls. Industry-wide, the rate of wall thickness corrosion wastage of fireside waterwalls in fossil-fired boilers has been of concern for many years. It is significant that the introduction of nitrogen oxide (NOx) emission controls with staged burners systems has increased reported waterwall wastage rates to as much as 120 mils (3 mm) per year. Moreover, the reducing environment produced by the low-NOx combustion process is the primary cause of accelerated corrosion rates of waterwall tubes made of carbon and low alloy steels. Improved coatings, such as the MCrAl nanocoatings evaluated here (where M is Fe, Ni, and Co), are needed to reduce/eliminate waterwall damage in subcritical, supercritical, and ultra-supercritical (USC) boilers. The first two tasks of this six-task project-jointly sponsored by EPRI and the U.S. Department of Energy (DE-FC26-07NT43096)-have focused on computational modeling of an advanced MCrAl nanocoating system and evaluation of two nanocrystalline (iron and nickel base) coatings, which will significantly improve the corrosion and erosion performance of tubing used in USC boilers. The computational model results showed that about 40 wt.% is required in Fe based nanocrystalline coatings for long-term durability, leading to a coating composition of Fe-25Cr-40Ni-10 wt.% Al. In addition, the long term thermal exposure test results further showed accelerated inward diffusion of Al from the nanocrystalline coatings into the substrate. In order to enhance the durability of these coatings, it is necessary to develop a diffusion barrier interlayer coating such TiN and/or AlN. The third task 'Process Advanced MCrAl Nanocoating Systems' of the six-task project jointly sponsored by the Electric Power Research Institute, EPRI and the U.S. Department of Energy (DE-FC26-07NT43096)- has focused on processing of advanced nanocrystalline coating systems and development of diffusion barrier interlayer coatings. Among the diffusion interlayer coatings evaluated, the TiN interlayer coating was found to be the optimum one. This report describes the research conducted under the Task 3 workscope.

  1. An empirical model for the mean-velocity profiles of a turbulent boundary layer under the effects of surface curvature 

    E-Print Network [OSTI]

    Huynh, Long Quang

    1994-01-01T23:59:59.000Z

    An empirical model has been developed to predict the mean-velocity profile of a turbulent boundary layer under the influence of surface curvature. The model proposed is able to determine the profiles for both a convex and concave curvature...

  2. An empirical model for the mean-velocity profiles of a turbulent boundary layer under the effects of surface curvature

    E-Print Network [OSTI]

    Huynh, Long Quang

    1994-01-01T23:59:59.000Z

    An empirical model has been developed to predict the mean-velocity profile of a turbulent boundary layer under the influence of surface curvature. The model proposed is able to determine the profiles for both a convex and concave curvature...

  3. Response Surface Energy Modeling of an Electric Vehicle over a Reduced Composite Drive Cycle

    SciTech Connect (OSTI)

    Jehlik, Forrest [Argonne National Laboratory (ANL)] [Argonne National Laboratory (ANL); LaClair, Tim J [ORNL] [ORNL

    2014-01-01T23:59:59.000Z

    Response surface methodology (RSM) techniques were applied to develop a predictive model of electric vehicle (EV) energy consumption over the Environmental Protection Agency's (EPA) standardized drive cycles. The model is based on measurements from a synthetic composite drive cycle. The synthetic drive cycle is a minimized statistical composite of the standardized urban (UDDS), highway (HWFET), and US06 cycles. The composite synthetic drive cycle is 20 minutes in length thereby reducing testing time of the three standard EPA cycles by over 55%. Vehicle speed and acceleration were used as model inputs for a third order least squared regression model predicting vehicle battery power output as a function of the drive cycle. The approach reduced three cycles and 46 minutes of drive time to a single test of 20 minutes. Application of response surface modeling to the synthetic drive cycle is shown to predict energy consumption of the three EPA cycles within 2.6% of the actual measured values. Additionally, the response model may be used to predict energy consumption of any cycle within the speed/acceleration envelope of the synthetic cycle. This technique results in reducing test time, which additionally provides a model that may be used to expand the analysis and understanding of the vehicle under consideration.

  4. Transport and dispersion of pollutants in surface impoundments: a finite element model

    SciTech Connect (OSTI)

    Yeh, G.T.

    1980-07-01T23:59:59.000Z

    A surface impoundment model in finite element (SIMFE) is presented to enable the simulation of flow circulations and pollutant transport and dispersion in natural or artificial lakes, reservoirs or ponds with any number of islands. This surface impoundment model consists of two sub-models: hydrodynamic and pollutant transport models. Both submodels are simulated by the finite element method. While the hydrodynamic model is solved by the standard Galerkin finite element scheme, the pollutant transport model can be solved by any of the twelve optional finite element schemes built in the program. Theoretical approximations and the numerical algorithm of SIMFE are described. Detail instruction of the application are given and listing of FORTRAN IV source program are provided. Two sample problems are given. One is for an idealized system with a known solution to show the accuracy and partial validation of the models. The other is applied to Prairie Island for a set of hypothetical input data, typifying a class of problems to which SIMFE may be applied.

  5. One-way coupling of an integrated assessment model and a water resources model: evaluation and implications of future changes over the US Midwest

    SciTech Connect (OSTI)

    Voisin, Nathalie; Liu, Lu; Hejazi, Mohamad I.; Tesfa, Teklu K.; Li, Hongyi; Huang, Maoyi; Liu, Ying; Leung, Lai-Yung R.

    2013-11-18T23:59:59.000Z

    An integrated model is being developed to advance our understanding of the interactions between human activities, terrestrial system and water cycle, and how system interactions will be affected by a changing climate at the regional scale. As a first step towards that goal, a global integrated assessment model including a waterdemand model is coupled offline with a land surface hydrology – routing – water resources management model. A spatial and temporal disaggregation approach is developed to project the annual regional water demand simulations into a daily time step and subbasin representation. The model demonstrated reasonable ability to represent the historical flow regulation and water supply over the Midwest (Missouri, Upper Mississippi and Ohio). Implications for the future flow regulation, water supply and supply deficit are investigated using a climate change projection with the B1 emission scenario which affects both natural flow and water demand. Over the Midwest, changes in flow regulation are mostly driven by the change in natural flow due to the limited storage capacity over the Ohio and Upper Mississippi river basins. The changes in flow and demand have a combined effect on the Missouri Summer regulated flow. The supply deficit tends to be driven by the change in flow over the region. Spatial analysis demonstrates the relationship between the supply deficit and the change in demand over urban areas not along a main river or with limited storage, and over areas upstream of groundwater dependent fields with therefore overestimated demand.

  6. Development of High Resolution Land Surface Parameters for the Community Land Model

    SciTech Connect (OSTI)

    Ke, Yinghai; Leung, Lai-Yung R.; Huang, Maoyi; Coleman, Andre M.; Li, Hongyi; Wigmosta, Mark S.

    2012-11-06T23:59:59.000Z

    There is a growing need for high-resolution land surface parameters as land surface models are being applied at increasingly higher spatial resolution offline as well as in regional and global models. The default land surface parameters for the most recent version of the Community Land Model (i.e. CLM 4.0) are at 0.5° or coarser resolutions, released with the Community Earth System Model (CESM). Plant Functional Types (PFTs), vegetation properties such as Leaf Area Index (LAI), Stem Area Index (SAI), and non-vegetated land covers were developed using remotely sensed datasets retrieved in late 1990’s and the beginning of this century. In this study, we developed new land surface parameters for CLM 4.0, specifically PFTs, LAI, SAI and non-vegetated land cover composition, at 0.05° resolution globally based on the most recent MODIS land cover and improved MODIS LAI products. Compared to the current CLM 4.0 parameters, the new parameters produced a decreased coverage by bare soil and trees, but an increased coverage by shrub, grass, and cropland. The new parameters result in a decrease in global seasonal LAI, with the biggest decrease in boreal forests; however, the new parameters also show a large increase in LAI in tropical forest. Differences between the new and the current parameters are mainly caused by changes in the sources of remotely sensed data and the representation of land cover in the source data. Advantages and disadvantages of each dataset were discussed in order to provide guidance on the use of the data. The new high-resolution land surface parameters have been used in a coupled land-atmosphere model (WRF-CLM) applied to the western U.S. to demonstrate their use in high-resolution modeling. A remapping method from the latitude/longitude grid of the CLM data to the WRF grids with map projection was also demonstrated. Future work will include global offline CLM simulations to examine the impacts of source data resolution and subsequent land parameter changes on simulated land surface processes.

  7. SUMO, System performance assessment for a high-level nuclear waste repository: Mathematical models

    SciTech Connect (OSTI)

    Eslinger, P.W.; Miley, T.B.; Engel, D.W.; Chamberlain, P.J. II

    1992-09-01T23:59:59.000Z

    Following completion of the preliminary risk assessment of the potential Yucca Mountain Site by Pacific Northwest Laboratory (PNL) in 1988, the Office of Civilian Radioactive Waste Management (OCRWM) of the US Department of Energy (DOE) requested the Performance Assessment Scientific Support (PASS) Program at PNL to develop an integrated system model and computer code that provides performance and risk assessment analysis capabilities for a potential high-level nuclear waste repository. The system model that has been developed addresses the cumulative radionuclide release criteria established by the US Environmental Protection Agency (EPA) and estimates population risks in terms of dose to humans. The system model embodied in the SUMO (System Unsaturated Model) code will also allow benchmarking of other models being developed for the Yucca Mountain Project. The system model has three natural divisions: (1) source term, (2) far-field transport, and (3) dose to humans. This document gives a detailed description of the mathematics of each of these three divisions. Each of the governing equations employed is based on modeling assumptions that are widely accepted within the scientific community.

  8. Optimisation of Accurate Rutile TiO2 (110), (100), (101) and (001) Surface Models from Periodic DFT Calculations

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Title Optimisation of Accurate Rutile TiO2 (110), (100), (101) and (001) Surface Models from of this study was to optimise accurate rutile TiO2 surfaces models that will be used in further calculations(1)69156869 Fax: +0033(1)69157150 Abstract In this paper, geometric bulk parameters, bulk moduli, energy gaps

  9. An image-based four-source surface energy balance model to estimate crop evapotranspiration from solar

    E-Print Network [OSTI]

    Boyer, Edmond

    An image-based four-source surface energy balance model to estimate crop evapotranspiration from solar reflectance/thermal emission data (SEB-4S) Olivier Merlin,a , Jonas Chirouzea , Albert Oliosob, 84000 Avignon, France Abstract A remote sensing-based surface energy balance model is developed

  10. ALE3D Simulations of Gap Closure and Surface Ignition for Cookoff Modeling

    SciTech Connect (OSTI)

    Howard, W M; McClelland, M A; Nichols, A L

    2006-06-22T23:59:59.000Z

    We are developing ALE3D models to describe the thermal, chemical and mechanical behavior during the heating, ignition and explosive phases of various cookoff phenomena. The candidate models and numerical strategies are being evaluated using benchmark cookoff experiments. ALE3D is a three-dimensional computer code capable of solving the model equations in a coupled fashion through all the phases of the cookoff in a single calculation. For the cookoff experiments, we are interested in representing behavior on widely varying timescales. We have used an implicit hydrodynamics option during the heating phase and an explicit solution method during the explosive phase. To complicate the modeling problem, high heat fluxes cause rapid temperature increases in boundary layers and lead to the formation of gaps between energetic and structural materials and ignition on surfaces. The initially solid energetic and structural materials react to produce gases, which fill the gaps. These materials can also melt and flow. Since an implicit solution method is used, simple no-strength materials models can no longer be used for liquids and gases. In this paper, we discuss and demonstrate choices of materials models for solid/liquid/gas mixtures to be used in conjunction with the implicit solution method. In addition, results are given for mesh movement strategies applied to the opening, closing, and surface ignition within gaps.

  11. Scalability of grid- and subbasin-based land surface modeling approaches for hydrologic simulations

    SciTech Connect (OSTI)

    Tesfa, Teklu K.; Leung, Lai-Yung R.; Huang, Maoyi; Li, Hongyi; Voisin, Nathalie; Wigmosta, Mark S.

    2014-03-27T23:59:59.000Z

    This paper investigates the relative merits of grid- and subbasin-based land surface modeling approaches for hydrologic simulations, with a focus on their scalability (i.e., abilities to perform consistently across a range of spatial resolutions) in simulating runoff generation. Simulations produced by the grid- and subbasin-based configurations of the Community Land Model (CLM) are compared at four spatial resolutions (0.125o, 0.25o, 0.5o and 1o) over the topographically diverse region of the U.S. Pacific Northwest. Using the 0.125o resolution simulation as the “reference”, statistical skill metrics are calculated and compared across simulations at 0.25o, 0.5o and 1o spatial resolutions of each modeling approach at basin and topographic region levels. Results suggest significant scalability advantage for the subbasin-based approach compared to the grid-based approach for runoff generation. Basin level annual average relative errors of surface runoff at 0.25o, 0.5o, and 1o compared to 0.125o are 3%, 4%, and 6% for the subbasin-based configuration and 4%, 7%, and 11% for the grid-based configuration, respectively. The scalability advantages of the subbasin-based approach are more pronounced during winter/spring and over mountainous regions. The source of runoff scalability is found to be related to the scalability of major meteorological and land surface parameters of runoff generation. More specifically, the subbasin-based approach is more consistent across spatial scales than the grid-based approach in snowfall/rainfall partitioning, which is related to air temperature and surface elevation. Scalability of a topographic parameter used in the runoff parameterization also contributes to improved scalability of the rain driven saturated surface runoff component, particularly during winter. Hence this study demonstrates the importance of spatial structure for multi-scale modeling of hydrological processes, with implications to surface heat fluxes in coupled land-atmosphere modeling.

  12. Soil moisture in complex terrain: quantifying effects on atmospheric boundary layer flow and providing improved surface boundary conditions for mesoscale models

    E-Print Network [OSTI]

    Daniels, Megan Hanako

    2010-01-01T23:59:59.000Z

    groundwater, land-surface, and mesoscale atmospheric model-and modification of mesoscale circulations. , Mon. Wea.J. Davis, The effects of mesoscale surface heterogeneity on

  13. A Multi-Model Assessment of Regional Climate Disparities Caused by Solar Geoengineering

    E-Print Network [OSTI]

    Robock, Alan

    1 A Multi-Model Assessment of Regional Climate Disparities Caused by Solar Geoengineering Normal University, Beijing, China. 9 School of Engineering and Applied Sciences, Harvard University levels. G1 involves a reduction in solar irradiance to counteract the radiative forcing5 in abrupt4xCO2

  14. Assessing Seasonal Confounding and Model Selection Bias in Air Pollution Epidemiology Using Positive and

    E-Print Network [OSTI]

    Washington at Seattle, University of

    Assessing Seasonal Confounding and Model Selection Bias in Air Pollution Epidemiology Using July 15, 1999 #12;Abstract Much of the evidence for health e ects of particulate air pollution has come standards for ambient air pollutants to protect the public from adverse e ects. Much of the evidence for air

  15. Models for Assessing Power Fluctuations from Large Wind Farms N. A. Cutululis1)

    E-Print Network [OSTI]

    that the active power supplied from the first large 160 MW offshore wind farm in this system, Horns Rev today). Figure 1. Power generation of Horns Rev offshore wind farm and onshore turbines, January 18 2005Models for Assessing Power Fluctuations from Large Wind Farms N. A. Cutululis1) , P. Sørensen1) , A

  16. Use of models and observations to assess trends in the 19502005 water balance and climate

    E-Print Network [OSTI]

    ) was about 50% of normal during 2000­2001. The ensuing drought-related water shortage led to seriousUse of models and observations to assess trends in the 1950­2005 water balance and climate of Upper-driven interannual (and longer) variability is evident. Evaporation and the other components of the water balance

  17. Refinement of weed risk assessments for biofuels using Camelina sativa as a model species

    E-Print Network [OSTI]

    Peterson, Robert K. D.

    Refinement of weed risk assessments for biofuels using Camelina sativa as a model species Philip B and Environmental Sciences, Montana State University, PO Box 173120, Bozeman, MT 59717-3120, USA Summary 1. Biofuel. However, concerns have been raised on the invasiveness of biofuel feedstocks. Estimating invasion

  18. ASSESSMENT OF THE MODELS FOR THE ESTIMATION OF THE CO2 RELEASES TOXIC EFFECTS

    E-Print Network [OSTI]

    Boyer, Edmond

    the global warming due to high concentration of CO2 in the atmosphere. However, in case of massive accidental to specific properties regarding its triple point. Then, this CO2 flakes creation may be followed1 ASSESSMENT OF THE MODELS FOR THE ESTIMATION OF THE CO2 RELEASES TOXIC EFFECTS Frédéric Antoine

  19. Hydrodynamic Modeling, Optimization and Performance Assessment for Ducted and Non-ducted Tidal Turbines

    E-Print Network [OSTI]

    Pedersen, Tom

    Turbines by Michael Robert Shives B.Eng., Carleton University, 2008 A Dissertation Submitted in Partial Hydrodynamic Modeling, Optimization and Performance Assessment for Ducted and Non-ducted Tidal Turbines) #12;iii ABSTRACT This thesis examines methods for designing and analyzing kinetic turbines based

  20. Hydrodynamic Modeling, Optimization and Performance Assessment for Ducted and Non-ducted Tidal Turbines

    E-Print Network [OSTI]

    Victoria, University of

    Turbines by Michael Robert Shives B.Eng., Carleton University, 2008 A Thesis Submitted in Partial Hydrodynamic Modeling, Optimization and Performance Assessment for Ducted and Non-ducted Tidal Turbines examines methods for designing and analyzing kinetic turbines based on blade element momentum (BEM) theory

  1. An idealised experimental model of ocean surface wave transmission by an ice floe

    E-Print Network [OSTI]

    Bennetts, Luke; Meylan, Michael; Cavaliere, Claudio; Babanin, Alexander; Toffoli, Alessandro

    2015-01-01T23:59:59.000Z

    An experimental model of transmission of ocean waves by an ice floe is presented. Thin plastic plates with different material properties and thicknesses are used to model the floe. Regular incident waves with different periods and steepnesses are used, ranging from gently-sloping to storm-like conditions. A wave gauge is used to measure the water surface elevation in the lee of the floe. The depth of wave overwash on the floe is measured by a gauge in the centre of the floe's upper surface. Results show transmitted waves are regular for gently-sloping incident waves but irregular for storm-like incident waves. The proportion of the incident wave transmitted is shown to decrease as incident wave steepness increases, and to be at its minimum for an incident wavelength equal to the floe length. Further, a trend is noted for transmission to decrease as the mean wave height in the overwash region increases.

  2. The detection and modelling of surface thermal structures and ground water discharges

    E-Print Network [OSTI]

    Roberts, Douglas Vincent

    1985-01-01T23:59:59.000Z

    . , Southern Illinois University Chairman of Advisory Committee: Dr. Earl R. Hoskins On March 29, 1973, data were collected by a thermal infrared scanner mounted in a twin-engine aircraft over a 55-mile stretch of the Clark Fork River in northwestern... on a VAX Il/750 interfaced with an I'S Model 70 processing system. Both qualitative and quantitative processing techniques were employed to identify and describe the surface temperature patterns and ground water discharges into the river. Computer...

  3. Modeling surfaces in the context of pulsed-power : work functions, electron emission and dynamic response.

    SciTech Connect (OSTI)

    Cochrane, Kyle Robert (Ktech Corporation, Albuquerque, NM); Chantrenne, Sophie (SAIC, Albuquerque, NM); Mattsson, Thomas Kjell Rene; Faleev, Sergey V. (SNAMI Inc., AL)

    2009-09-01T23:59:59.000Z

    The ability to quickly understand and deal with issues on ZR, or to virtually design a future ZX accelerator, requires a physics-based capability to simulate all key pulsed power components. Highly important for gas switches and transmission lines are surface phenomena: thermionic emission, photoemission, field emission, and ion-surface dynamics. These are complex processes even at normal conditions, when coupled to the dynamic environment in pulsed power components, the current state of the art of understanding is not at the level of science based predictive modeling. Modeling efforts at the macroscopic level (finite element based hydrodynamic simulations) require detailed information of these processes to yield more reliable results. This is the final report of an LDRD project in the science of extreme environments investment area; the project was focused on describing the physics of surfaces of materials of interest in pulsed-power components. We have calculated the temperature dependence of work functions for metals from first principles using density functional theory (DFT) as well as investigated the effect of initial oxidation and alloying. By using the GW method, we have gone beyond DFT to calculate work functions for Al. The GW work required base-lining the GW results for different systems, since GW lacks a description of total energy. Lastly, we investigated the more macroscopic physics of how a surface and bulk material responds to a very high current under a short time, representative for current loads in pulsed-power components, with emphasis on materials modeling. These simulations were made using two hydrodynamic codes, ALEGRA and MACH2, in order to focus on the materials models themselves.

  4. Greenland ice sheet surface mass-balance modeling in a 131-year perspective, 1950-2080

    SciTech Connect (OSTI)

    Mernild, Sebastian Haugard [Los Alamos National Laboratory; Liston, Glen [COLORADO STATE UNIV.; Hiemstra, Christopher [COLORADO STATE UNIV.; Christensen, Jens [DANISH METEOROLOGICAL INS.

    2009-01-01T23:59:59.000Z

    Fluctuations in the Greenland Ice Sheet (GrIS) surface mass-balance (SMB) and freshwater influx to the surrounding oceans closely follow climate fluctuations and are of considerable importance to the global eustatic sea level rise. SnowModel, a state-of-the-art snow-evolution modeling system, was used to simulate variations in the GrIS melt extent, surface water balance components, changes in SMB, and freshwater influx to the ocean. The simulations are based on the IPCC scenario AlB modeled by the HIRHAM4 RCM (using boundary conditions from ECHAM5 AOGCM) from 1950 through 2080. In-situ meteorological station (GC-Net and WMO DMI) observations from inside and outside the GrIS were used to validate and correct RCM output data before it was used as input for SnowModel. Satellite observations and independent SMB studies were used to validate the SnowModel output and confirm the model's robustness. We simulated a {approx}90% increase in end-of-summer surface melt extent (0.483 x 10{sup 6} km{sup 2}) from 1950 to 2080, and a melt index (above 2,000-m elevation) increase of 138% (1.96 x 10{sup 6} km{sup 2} x days). The greatest difference in melt extent occured in the southern part of the GrIS, and the greatest changes in the number of melt days was seen in the eastern part of the GrIS ({approx}50-70%) and was lowest in the west ({approx}20-30%). The rate of SMB loss, largely tied to changes in ablation processes, lead to an enhanced average loss of 331 km{sup 3} from 1950 to 2080, an average 5MB level of -99 km{sup 3} for the period 2070-2080. GrIS surface freshwater runoff yielded an eustatic rise in sea level from 0.8 {+-} 0.1 (1950-1959) to 1.9 {+-} 0.1 mm (2070-2080) sea level equivalent (SLE) y{sup -1}. The accumulated GrIS freshwater runoff contribution from surface melting equaled 160 mm SLE from 1950 through 2080.

  5. The critical indices of the Quark-Gluon Bags with Surface Tension Model with tricritical endpoint

    E-Print Network [OSTI]

    A. I. Ivanytskyi

    2011-04-11T23:59:59.000Z

    The critical indices \\alpha', \\beta, \\gamma' and \\delta of the Quark Gluon Bags with Surface Tension Model with the tricritical endpoint are calculated as functions of the usual parameters of this model and two newly introduces parameters (indices). They are compared with the critical exponents of other models. It is shown that for the newly introduced indices \\chi = 0 and \\xi^T < 1 there is a branch of solutions for which the critical exponents of the present model and the statistical multifragmentation model coincide, otherwise these models belong to different universality classes. It is shown that for realistic values of the parameter \\varkappa the critical exponents \\alpha', \\beta, \\gamma' and \\delta of simple liquids and 3-dimensional Ising model can be only described by the branch of solutions in which all indices except for \\alpha' correspond to their values within the statistical multifragmentation model. The scaling relations for the found critical exponents are verified and it is demonstrated that for the standard definition of the index \\alpha' the Fisher and Griffiths scaling inequalities are not fulfilled for some values of the model parameters, whereas the Liberman scaling inequality is always obeyed. Although it is shown that the specially defined index \\alpha'_s recovers the scaling relations, another possibility, an existence of the non-Fisher universality classes, is also discussed.

  6. Indoor Air Nuclear, Biological, and Chemical Health Modeling and Assessment System

    SciTech Connect (OSTI)

    Stenner, Robert D.; Hadley, Donald L.; Armstrong, Peter R.; Buck, John W.; Hoopes, Bonnie L.; Janus, Michael C.

    2001-03-01T23:59:59.000Z

    Indoor air quality effects on human health are of increasing concern to public health agencies and building owners. The prevention and treatment of 'sick building' syndrome and the spread of air-borne diseases in hospitals, for example, are well known priorities. However, increasing attention is being directed to the vulnerability of our public buildings/places, public security and national defense facilities to terrorist attack or the accidental release of air-borne biological pathogens, harmful chemicals, or radioactive contaminants. The Indoor Air Nuclear, Biological, and Chemical Health Modeling and Assessment System (IA-NBC-HMAS) was developed to serve as a health impact analysis tool for use in addressing these concerns. The overall goal was to develop a user-friendly fully functional prototype Health Modeling and Assessment system, which will operate under the PNNL FRAMES system for ease of use and to maximize its integration with other modeling and assessment capabilities accessible within the FRAMES system (e.g., ambient air fate and transport models, water borne fate and transport models, Physiologically Based Pharmacokinetic models, etc.). The prototype IA-NBC-HMAS is designed to serve as a functional Health Modeling and Assessment system that can be easily tailored to meet specific building analysis needs of a customer. The prototype system was developed and tested using an actual building (i.e., the Churchville Building located at the Aberdeen Proving Ground) and release scenario (i.e., the release and measurement of tracer materials within the building) to ensure realism and practicality in the design and development of the prototype system. A user-friendly "demo" accompanies this report to allow the reader the opportunity for a "hands on" review of the prototype system's capability.

  7. Interaction between surface wind and ocean circulation in the Carolina Capes in a coupled low-order model

    SciTech Connect (OSTI)

    Xie, L.; Pietrafesa, L.J.; Raman, S.

    1997-03-18T23:59:59.000Z

    Interactions between surface winds and ocean currents over an east-coast continental shelf are studied using a simple mathematical model. The model physics include cross-shelf advection of sea surface temperature (SST) by Ekman drift, upwelling due to Ekman transport divergence, differential heating of the low-level atmosphere by a cross-shelf SST gradient, and the Coriolis effect. Additionally, the effects of diabatic cooling of surface waters due to air-sea heat exchange and of the vertical density stratification on the thickness of the upper ocean Ekman layer are considered. The model results are qualitatively consistent with observed wind-driven coastal ocean circulation and surface wind signatures induced by SST. This simple model also demonstrates that two-way air-sea interaction plays a significant role in the subtidal frequency variability of coastal ocean circulation and mesoscale variability of surface wind fields over coastal waters.

  8. Modeling and Analysis of The Pressure Die Casting Using Response Surface Methodology

    SciTech Connect (OSTI)

    Kittur, Jayant K.; Herwadkar, T. V. [KLS Gogte Institute of Technology, Belgaum -590 008, Karnataka (India); Parappagoudar, M. B. [Chhatrapati Shivaji Institute of Technology, Durg (C.G)-491001 (India)

    2010-10-26T23:59:59.000Z

    Pressure die casting is successfully used in the manufacture of Aluminum alloys components for automobile and many other industries. Die casting is a process involving many process parameters having complex relationship with the quality of the cast product. Though various process parameters have influence on the quality of die cast component, major influence is seen by the die casting machine parameters and their proper settings. In the present work, non-linear regression models have been developed for making predictions and analyzing the effect of die casting machine parameters on the performance characteristics of die casting process. Design of Experiments (DOE) with Response Surface Methodology (RSM) has been used to analyze the effect of effect of input parameters and their interaction on the response and further used to develop nonlinear input-output relationships. Die casting machine parameters, namely, fast shot velocity, slow shot to fast shot change over point, intensification pressure and holding time have been considered as the input variables. The quality characteristics of the cast product were determined by porosity, hardness and surface rough roughness (output/responses). Design of experiments has been used to plan the experiments and analyze the impact of variables on the quality of casting. On the other-hand Response Surface Methodology (Central Composite Design) is utilized to develop non-linear input-output relationships (regression models). The developed regression models have been tested for their statistical adequacy through ANOVA test. The practical usefulness of these models has been tested with some test cases. These models can be used to make the predictions about different quality characteristics, for the known set of die casting machine parameters, without conducting the experiments.

  9. Research priorities in land use and land-cover change for the Earth system and integrated assessment modelling

    E-Print Network [OSTI]

    Hibbard, Kathy; Janetos, Anthony; van Vuuren, Detlef P.; Pongtatz, Julia; Rose, Steven K.; Betts, Richard; Herold, Martin; Feddema, Johannes J.

    2010-01-01T23:59:59.000Z

    ). Copyright ? 2010 Royal Meteorological Society and Crown Copyright. KEY WORDS land use; land cover; Earth system models; integrated assessment models; research priorities Received 12 January 2009; Revised 9 March 2010; Accepted 14 March 2010 1. Introduction 1... biogeophysical, socio- economic and human decision-making perspectives. The Earth System Modeling (ESM) and the Integrated Assessment Modeling (IAM) communities play an impor- tant role in understanding and quantifying Earth system analysis and, specifically...

  10. On the Use of Computational Models for Wave Climate Assessment in Support of the Wave Energy Industry

    E-Print Network [OSTI]

    Victoria, University of

    On the Use of Computational Models for Wave Climate Assessment in Support of the Wave Energy On the Use of Computational Models for Wave Climate Assessment in Support of the Wave Energy Industry Effective, economic extraction of ocean wave energy requires an intimate under- standing of the ocean wave

  11. Surface Wave Effects in the NEMO Ocean Model: Forced and Coupled Experiments

    E-Print Network [OSTI]

    Breivik, Øyvind; Bidlot, Jean-Raymond; Balmaseda, Magdalena Alonso; Janssen, Peter A E M

    2015-01-01T23:59:59.000Z

    The NEMO general circulation ocean model is extended to incorporate three physical processes related to ocean surface waves, namely the surface stress (modified by growth and dissipation of the oceanic wave field), the turbulent kinetic energy flux from breaking waves, and the Stokes-Coriolis force. Experiments are done with NEMO in ocean-only (forced) mode and coupled to the ECMWF atmospheric and wave models. Ocean-only integrations are forced with fields from the ERA-Interim reanalysis. All three effects are noticeable in the extra-tropics, but the sea-state dependent turbulent kinetic energy flux yields by far the largest difference. This is partly because the control run has too vigorous deep mixing due to an empirical mixing term in NEMO. We investigate the relation between this ad hoc mixing and Langmuir turbulence and find that it is much more effective than the Langmuir parameterization used in NEMO. The biases in sea surface temperature as well as subsurface temperature are reduced, and the total oce...

  12. Theoretical Standard Model Rates of Proton to Neutron Conversions Near Metallic Hydride Surfaces

    E-Print Network [OSTI]

    Widom, A

    2006-01-01T23:59:59.000Z

    The process of radiation induced electron capture by protons or deuterons producing new ultra low momentum neutrons and neutrinos may be theoretically described within the standard field theoretical model of electroweak interactions. For protons or deuterons in the neighborhoods of surfaces of condensed matter metallic hydride cathodes, such conversions are determined in part by the collective plasma modes of the participating charged particles, e.g. electrons and protons. The radiation energy required for such low energy nuclear reactions may be supplied by the applied voltage required to push a strong charged current across a metallic hydride surface employed as a cathode within a chemical cell. The electroweak rates of the resulting ultra low momentum neutron production are computed from these considerations.

  13. Towards a tool to design vegetated strips for mitigation of pesticides transfers in surface runoff. Assessment of different

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    (Simunek et al,1999) coupled with a kinematic wave equation, which represents both surface runoff pollutions. Water pollution control division. Cemagref. 3 Bis Quai Chauveau. 69 336 LYON 09. France. * nadia fields towards surface waters. However, as the efficiency of these structures is closely related

  14. Model Components of the Certification Framework for Geologic Carbon Sequestration Risk Assessment

    SciTech Connect (OSTI)

    Oldenburg, Curtis M.; Bryant, Steven L.; Nicot, Jean-Philippe; Kumar, Navanit; Zhang, Yingqi; Jordan, Preston; Pan, Lehua; Granvold, Patrick; Chow, Fotini K.

    2009-06-01T23:59:59.000Z

    We have developed a framework for assessing the leakage risk of geologic carbon sequestration sites. This framework, known as the Certification Framework (CF), emphasizes wells and faults as the primary potential leakage conduits. Vulnerable resources are grouped into compartments, and impacts due to leakage are quantified by the leakage flux or concentrations that could potentially occur in compartments under various scenarios. The CF utilizes several model components to simulate leakage scenarios. One model component is a catalog of results of reservoir simulations that can be queried to estimate plume travel distances and times, rather than requiring CF users to run new reservoir simulations for each case. Other model components developed for the CF and described here include fault characterization using fault-population statistics; fault connection probability using fuzzy rules; well-flow modeling with a drift-flux model implemented in TOUGH2; and atmospheric dense-gas dispersion using a mesoscale weather prediction code.

  15. Modeling threat assessments of water supply systems using markov latent effects methodology.

    SciTech Connect (OSTI)

    Silva, Consuelo Juanita

    2006-12-01T23:59:59.000Z

    Recent amendments to the Safe Drinking Water Act emphasize efforts toward safeguarding our nation's water supplies against attack and contamination. Specifically, the Public Health Security and Bioterrorism Preparedness and Response Act of 2002 established requirements for each community water system serving more than 3300 people to conduct an assessment of the vulnerability of its system to a terrorist attack or other intentional acts. Integral to evaluating system vulnerability is the threat assessment, which is the process by which the credibility of a threat is quantified. Unfortunately, full probabilistic assessment is generally not feasible, as there is insufficient experience and/or data to quantify the associated probabilities. For this reason, an alternative approach is proposed based on Markov Latent Effects (MLE) modeling, which provides a framework for quantifying imprecise subjective metrics through possibilistic or fuzzy mathematics. Here, an MLE model for water systems is developed and demonstrated to determine threat assessments for different scenarios identified by the assailant, asset, and means. Scenario assailants include terrorists, insiders, and vandals. Assets include a water treatment plant, water storage tank, node, pipeline, well, and a pump station. Means used in attacks include contamination (onsite chemicals, biological and chemical), explosives and vandalism. Results demonstrated highest threats are vandalism events and least likely events are those performed by a terrorist.

  16. MHD modelling of liquid metal films for fusion divertor surface protection

    SciTech Connect (OSTI)

    Morley, N.B.

    1991-12-31T23:59:59.000Z

    In order to counter adverse effects resulting from the impingement of high energy plasmas on solid material surfaces, especially as this relates to fusion reactor high heat flux components, the idea of protecting the material surface with a thin film of liquid metal has been advanced. In principle, this film would protect the underlying substrate from physical sputtering and reduce thermal stresses in the structure. However, serious concerns related to establishing such a liquid metal flow and its performance in a fusion environment need to be addressed. In particular, the interaction of the conducting metal film with the complicated magnetic fields typical of a diverted reactor plasma may lead to retardation of the film resulting in channel flooding, velocity profiles not conducive to effective heat transfer, and possibly even detachment of the film from the substrate. In addition, the momentum carried by the plasma particles may deform the film shape to a significant extent, possibly disrupting the flow or leaving sections on the substrate inadequately protected. Proposed here are several mathematical and experimental models intended to address these specific questions. Mathematical models will be derived from the basic set of incompressible magnetohydrodynamic equations for the cases of fully developed and developing film flow. The fully developed flow model allows simplification of the governing equations to two dimensions, facilitating their solution. The data obtained from this formulation will yield the velocity, induced magnetic field, and height of the film as a function of space and flow parameters. From this data the effect of the plasma momentum on the shape of the surface will be seen, as will the velocity structure across the channel, a structure that is only assumed in previous modeling attempts. The developing film model, based on simplifying assumptions for the height and velocity profiles determined from the previous model for the fully developed case, will account for spatial and temporal varying magnetic fields. In this way it will be possible to model more fusion relevant field distributions and establish their effect on the evolution of the film and its possible flooding or detachment as it flows along the substrate.

  17. A multi-model assessment of pollution transport to the Arctic

    SciTech Connect (OSTI)

    Shindell, D T; Chin, M; Dentener, F; Doherty, R M; Faluvegi, G; Fiore, A M; Hess, P; Koch, D M; MacKenzie, I A; Sanderson, M G; Schultz, M G; Schulz, M; Stevenson, D S; Teich, H; Textor, C; Wild, O; Bergmann, D J; Bey, I; Bian, H; Cuvelier, C; Duncan, B N; Folberth, G; Horowitz, L W; Jonson, J; Kaminski, J W; Marmer, E; Park, R; Pringle, K J; Schroeder, S; Szopa, S; Takemura, T; Zeng, G; Keating, T J; Zuber, A

    2008-03-13T23:59:59.000Z

    We examine the response of Arctic gas and aerosol concentrations to perturbations in pollutant emissions from Europe, East and South Asia, and North America using results from a coordinated model intercomparison. These sensitivities to regional emissions (mixing ratio change per unit emission) vary widely across models and species. Intermodel differences are systematic, however, so that the relative importance of different regions is robust. North America contributes the most to Arctic ozone pollution. For aerosols and CO, European emissions dominate at the Arctic surface but East Asian emissions become progressively more important with altitude, and are dominant in the upper troposphere. Sensitivities show strong seasonality: surface sensitivities typically maximize during boreal winter for European and during spring for East Asian and North American emissions. Mid-tropospheric sensitivities, however, nearly always maximize during spring or summer for all regions. Deposition of black carbon (BC) onto Greenland is most sensitive to North American emissions. North America and Europe each contribute {approx}40% of total BC deposition to Greenland, with {approx}20% from East Asia. Elsewhere in the Arctic, both sensitivity and total BC deposition are dominated by European emissions. Model diversity for aerosols is especially large, resulting primarily from differences in aerosol physical and chemical processing (including removal). Comparison of modeled aerosol concentrations with observations indicates problems in the models, and perhaps, interpretation of the measurements. For gas phase pollutants such as CO and O{sub 3}, which are relatively well-simulated, the processes contributing most to uncertainties depend on the source region and altitude examined. Uncertainties in the Arctic surface CO response to emissions perturbations are dominated by emissions for East Asian sources, while uncertainties in transport, emissions, and oxidation are comparable for European and North American sources. At higher levels, model-to-model variations in transport and oxidation are most important. Differences in photochemistry appear to play the largest role in the intermodel variations in Arctic ozone sensitivity, though transport also contributes substantially in the mid-troposphere.

  18. Phase diagram and surface tension in the three-flavor Polyakov-quark-meson model

    E-Print Network [OSTI]

    Bruno W. Mintz; Rudnei O. Ramos; Juergen Schaffner-Bielich; Rainer Stiele

    2013-02-28T23:59:59.000Z

    We obtain the in-medium effective potential of the three-flavor Polyakov-Quark-Meson model as a real function of real variables in the Polyakov loop variable, to allow for the study of all possible minima of the model. At finite quark chemical potential, the real and imaginary parts of the effective potential, in terms of the Polyakov loop variables, are made apparent, showing explicitly the fermion sign problem of the theory. The phase diagram and other equilibrium observables, obtained from the real part of the effective potential, are calculated in the mean-field approximation. The obtained results are compared to those found with the so-called saddle-point approach. Our procedure also allows the calculation of the surface tension between the chirally broken and confined phase, and the chirally restored and deconfined phase. The values of surface tension we find for low temperatures are very close to the ones recently found for two-flavor chiral models. Some consequences of our results for the early Universe, for heavy-ion collisions, and for proto-neutron stars are briefly discussed.

  19. IEEE GEOSCIENCE AND REMOTE SENSING LETTERS, VOL. X, NO. X, NOVEMBER 200X 1 Digital Topography Models for Martian Surfaces

    E-Print Network [OSTI]

    Stepinski, Tomasz F.

    IEEE GEOSCIENCE AND REMOTE SENSING LETTERS, VOL. X, NO. X, NOVEMBER 200X 1 Digital Topography Models for Martian Surfaces Tomasz Stepinski and Ricardo Vilalta Abstract-- We introduce a concept of the digital topography model, an extension to the familiar notion of the digital elevation model. The new

  20. Global estimation of evapotranspiration using a leaf area index-based surface energy and water balance model

    E-Print Network [OSTI]

    Martin, Timothy

    using Advanced Very High Res- olution Radiometer Lai data, Climate Research Unit climate dataGlobal estimation of evapotranspiration using a leaf area index-based surface energy and water-relative-humidity-based two-source (ARTS) E model that simulates the surface energy balance, soil water balance

  1. Discrepancies in the prediction of solar wind using potential field source surface model: An investigation of possible sources

    E-Print Network [OSTI]

    California at Berkeley, University of

    Discrepancies in the prediction of solar wind using potential field source surface model expansion factor (FTE) at the source surface and the solar wind speed (SWS) observed at Earth, which has been made use of in the prediction of solar wind speed near the Earth with reasonable accuracy. However

  2. Decision Making Under Conditions of Uncertainty: Experimental Assessment of Decision Models

    E-Print Network [OSTI]

    Vedlitz, Arnold; Mintz, Alex; Redd, Steven B.; Liu, Xinsheng; Alston, Letitia T.

    2013-12-19T23:59:59.000Z

    . The computerized Decision Board records key features of the decision-making process: (a) the sequence in which decision makers acquire the information, (b) the number of items that respondents view for every alternative along every dimension, and (c) the amount... Decision Making Under Conditions of Uncertainty: Experimental Assessment of Decision Models March 31, 2003 ? March 31, 2005 This research was funded by the National Defense University Contract No. DABJ29-03-P-0084 INSTITUTE FOR SCIENCE...

  3. Performance Assessment Modeling and Sensitivity Analyses of Generic Disposal System Concepts.

    SciTech Connect (OSTI)

    Sevougian, S. David; Freeze, Geoffrey A. [Sandia National Laboratories, Albuquerque, NM; Gardner, William Payton [Sandia National Laboratories, Albuquerque, NM; Hammond, Glenn Edward [Sandia National Laboratories, Albuquerque, NM; Mariner, Paul [Sandia National Laboratories, Albuquerque, NM

    2014-09-01T23:59:59.000Z

    directly, rather than through simplified abstractions. It also a llows for complex representations of the source term, e.g., the explicit representation of many individual waste packages (i.e., meter - scale detail of an entire waste emplacement drift). This report fulfills the Generic Disposal System Analysis Work Packa ge Level 3 Milestone - Performance Assessment Modeling and Sensitivity Analyses of Generic Disposal System Concepts (M 3 FT - 1 4 SN08080 3 2 ).

  4. Water balance in the Amazon basin from a land surface model ensemble

    SciTech Connect (OSTI)

    Getirana, Augusto; Dutra, Emanuel; Guimberteau, Matthieu; Kam, Jonghun; Li, Hongyi; Decharme, Bertrand; Zhang, Zhengqiu J.; Ducharne, Agnes; Boone, Aaron; Balsamo, Gianpaolo; Rodell, Matthew; Mounirou Toure, Ally; Xue, Yongkang; Peters-Lidard, Christa D.; Kumar, Sujay V.; Arsenault, Kristi Rae; Drapeau, Guillaume; Leung, Lai-Yung R.; Ronchail, Josyane; Sheffield, Justin

    2014-12-06T23:59:59.000Z

    Despite recent advances in modeling and remote sensing of land surfaces, estimates of the global water budget are still fairly uncertain. The objective of this study is to evaluate the water budget of the Amazon basin based on several state-of-the-art land surface model (LSM) outputs. Water budget variables [total water storage (TWS), evapotranspiration (ET), surface runoff (R) and baseflow (B)] are evaluated at the basin scale using both remote sensing and in situ data. Fourteen LSMs were run using meteorological forcings at a 3-hourly time step and 1-degree spatial resolution. Three experiments are performed using precipitation which has been rescaled to match monthly global GPCP and GPCC datasets and the daily HYBAM dataset for the Amazon basin. R and B are used to force the Hydrological Modeling and Analysis Platform (HyMAP) river routing scheme and simulated discharges are compared against observations at 165 gauges. Simulated ET and TWS are compared against FLUXNET and MOD16A2 evapotranspiration, and GRACE TWS estimates in different catchments. At the basin scale, simulated ET ranges from 2.39mm.d-1 to 3.26mm.d-1 and a low spatial correlation between ET and P indicates that evapotranspiration does not depend on water availability over most of the basin. Results also show that other simulated water budget variables vary significantly as a function of both the LSM and precipitation used, but simulated TWS generally agree at the basin scale. The best water budget simulations resulted from experiments using the HYBAM dataset, mostly explained by a denser rainfall gauge network the daily rescaling.

  5. Analytical modeling of localized surface plasmon resonance in heterostructure copper sulfide nanocrystals

    SciTech Connect (OSTI)

    Caldwell, Andrew H.; Ha, Don-Hyung; Robinson, Richard D., E-mail: rdr82@cornell.edu [Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853 (United States); Ding, Xiaoyue [School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853 (United States)

    2014-10-28T23:59:59.000Z

    Localized surface plasmon resonance (LSPR) in semiconductor nanocrystals is a relatively new field of investigation that promises greater tunability of plasmonic properties compared to metal nanoparticles. A novel process by which the LSPR in semiconductor nanocrystals can be altered is through heterostructure formation arising from solution-based cation exchange. Herein, we describe the development of an analytical model of LSPR in heterostructure copper sulfide-zinc sulfide nanocrystals synthesized via a cation exchange reaction between copper sulfide (Cu{sub 1.81}S) nanocrystals and Zn ions. The cation exchange reaction produces dual-interface, heterostructure nanocrystals in which the geometry of the copper sulfide phase can be tuned from a sphere to a thin disk separating symmetrically-grown sulfide (ZnS) grains. Drude model electronic conduction and Mie-Gans theory are applied to describe how the LSPR wavelength changes during cation exchange, taking into account the morphology evolution and changes to the local permittivity. The results of the modeling indicate that the presence of the ZnS grains has a significant effect on the out-of-plane LSPR mode. By comparing the results of the model to previous studies on solid-solid phase transformations of copper sulfide in these nanocrystals during cation exchange, we show that the carrier concentration is independent of the copper vacancy concentration dictated by its atomic phase. The evolution of the effective carrier concentration calculated from the model suggests that the out-of-plane resonance mode is dominant. The classical model was compared to a simplified quantum mechanical model which suggested that quantum mechanical effects become significant when the characteristic size is less than ?8 nm. Overall, we find that the analytical models are not accurate for these heterostructured semiconductor nanocrystals, indicating the need for new model development for this emerging field.

  6. A comparison of observed and modeled surface waves in southern Lake Michigan and the implications for models of sediment resuspension.

    SciTech Connect (OSTI)

    Hawley, N.; Lesht, B. M.; Schwab, D. J.; Environmental Research; Great Lakes Environmental Research Lab

    2004-06-25T23:59:59.000Z

    Subsurface pressure sensors were used to make measurements of surface waves during 18 deployments in southern Lake Michigan between 1998 and 2000. Most of the observations were made during the unstratified period (November--May) in water depths between 10 and 55 m. The observations (as well as those obtained from the National Data Buoy Center (NDBC) buoy 45007, which is located in the middle of the southern basin of the lake) were compared to the results obtained from the Great Lakes Environmental Research Laboratory (GLERL)-Donelan wave model implemented on a 2-km grid. The results show that the wave model does a good job of calculating the wave heights, but consistently underestimates the wave periods. In over 80% of the cases the bottom stresses calculated from both the observations and the wave model results agree as to whether or not resuspension occurs, but over 70% of this agreement is for cases when resuspension does not occur; both stresses predict resuspension about 6% of the time. Since the bottom stresses calculated from the model results are usually lower than those calculated from the observations, resuspension estimates based on the wave model parameters are also lower than those calculated from the observed waves.

  7. Journal of Nondestructive Evaluation, Vol. 23, No. 3, September 2004 ( C 2004) Eddy Current Assessment of Near-Surface Residual

    E-Print Network [OSTI]

    Nagy, Peter B.

    Journal of Nondestructive Evaluation, Vol. 23, No. 3, September 2004 ( C 2004) Eddy Current in eddy current conductivity at increasing inspection frequencies, which can be exploited components, lend themselves easily for eddy current residual stress assessment lies in their favorable

  8. Assessment of clear and cloudy sky parameterizations for daily downwelling longwave radiation over different land surfaces in

    E-Print Network [OSTI]

    meteorological data, resulting in reliable quantification of net radiation and evapotranspiration in FloridaAssessment of clear and cloudy sky parameterizations for daily downwelling longwave radiation over sky downwelling longwave radiation (Rldc) and cloudy sky downwelling longwave radiation (Rld) formulas

  9. An experimental evaluation of a theoretical model of the microwave emission of a natural surface

    E-Print Network [OSTI]

    Richerson, Jerry Anton

    1971-01-01T23:59:59.000Z

    to thank Dr. Jack F. Paris, Dr. Kirk W. Brown, and Michael L. Wiebe from Texas AIM Uni- versity for their assistance in this study. The financial support of the National Aeronautics and Space Administra- tion under grant NsG 239-62, the College... ump ti ons De f in i tions Relation of Emissivity to Scattering 10 10 10 12 17 Apparent Temperature of a Natural Surface . 22 ~Ch t P~ae Survey of Models Applicable to Microwave Emis s ions Introduction Gene ral App roach 25 25...

  10. Modelling risk and risking models: the diffusive boundary between science and policy in volcanic risk assessment

    E-Print Network [OSTI]

    Donovan, Amy R.; Oppenheimer, Clive

    2014-11-27T23:59:59.000Z

    (Stirling, 151 2008). For Massey, space is dynamic: it must be thought of in relation to time. It resists 152 enclosure in a model. In considering geographical models in light of this, O’Sullivan (2004) 153 suggests that “it is vital that modelling... , 215 noting the presence of social, psychological and geographical uncertainties (see also Stirling, 216 2007, 2008; Wynne, 1992; Jasanoff, 2004, 2005). Understanding the complex ways in which 217 uncertainty is generated is critical in appreciating...

  11. Impact of Hillslope-Scale Organization of Topography, Soil Moisture, Soil Temperature, and Vegetation on Modeling Surface Microwave Radiation Emission

    E-Print Network [OSTI]

    Flores, Alejandro N.

    Microwave radiometry will emerge as an important tool for global remote sensing of near-surface soil moisture in the coming decade. In this modeling study, we find that hillslope-scale topography (tens of meters) influences ...

  12. Impact of Rotor Surface Velocity, Leakage Models and Real Gas Properties on Rotordynamic Force Predictions of Gas Labyrinth Seals

    E-Print Network [OSTI]

    Thorat, Manish R.

    2010-07-14T23:59:59.000Z

    Rotordynamic coefficients of a gas labyrinth seal are assumed to be frequency independent. However, this assumption loses its validity as rotor surface velocity approaches Mach 1. The solution procedure of 1CV model by Childs and Scharrer which...

  13. Post-2020 climate agreements in the major economies assessed in the light of global models

    SciTech Connect (OSTI)

    Tavoni, Massimo; Kriegler, Elmar; Riahi, Keywan; Van Vuuren, Detlef; Aboumahboub, Tino; Bowen, Alex; Calvin, Katherine V.; Campiglio, Emanuele; Kober, Tom; Jewell, Jessica; Luderer, Gunnar; Marangoni, Giacomo; McCollum, David; van Sluisveld, Mariesse; Zimmer, Anne; van der Zwaan, Bob

    2014-12-15T23:59:59.000Z

    Integrated assessment models can help in quantifying the implications of international climate agreements and regional climate action. This paper reviews scenario results from model intercomparison projects to explore different possible outcomes of post-2020 climate negotiations, recently announced pledges and their relation to the 2°C target. We provide key information for all the major economies, such as the year of emission peaking, regional carbon budgets and emissions allowances. We highlight the distributional consequences of climate policies, and discuss the role of carbon markets for financing clean energy investments, and achieving efficiency and equity.

  14. Model assessment of protective barriers: Part 3. Status of FY 1990 work

    SciTech Connect (OSTI)

    Fayer, M.J.; Rockhold, M.L.; Holford, D.J.

    1992-02-01T23:59:59.000Z

    Radioactive waste exists at the US Department of Energy`s (DOE`s) Hanford Site in a variety of locations, including subsurface grout and tank farms, solid waste burial grounds, and contaminated soil sites. Some of these waste sites may need to be isolated from percolating water to minimize the potential for transport of the waste to the ground water, which eventually discharges to the Columbia River. Multilayer protective barriers have been proposed as a means of limiting the flow of water through the waste sites (DOE 1987). A multiyear research program [managed jointly by Pacific Northwest Laboratory (PNL) and Westinghouse Hanford Company for the DOE] is aimed at assessing the performance of these barriers. One aspect of this program involves the use of computer models to predict barrier performance. Three modeling studies have already been conducted and a test plan was produced. The simulation work reported here was conducted by PNL and extends the previous modeling work. The purpose of this report are to understand phenomena that have been observed in the field and to provide information that can be used to improve hydrologic modeling of the protective barrier. An improved modeling capability results in better estimates of barrier performance. Better estimates can be used to improve the design of barriers and the assessment of their long-term performance.

  15. Development of Simplified Probabilistic Risk Assessment Model for Seismic Initiating Event

    SciTech Connect (OSTI)

    S. Khericha; R. Buell; S. Sancaktar; M. Gonzalez; F. Ferrante

    2012-06-01T23:59:59.000Z

    ABSTRACT This paper discusses a simplified method to evaluate seismic risk using a methodology built on dividing the seismic intensity spectrum into multiple discrete bins. The seismic probabilistic risk assessment model uses Nuclear Regulatory Commission’s (NRC’s) full power Standardized Plant Analysis Risk (SPAR) model as the starting point for development. The seismic PRA models are integrated with their respective internal events at-power SPAR model. This is accomplished by combining the modified system fault trees from the full power SPAR model with seismic event tree logic. The peak ground acceleration is divided into five bins. The g-value for each bin is estimated using the geometric mean of lower and upper values of that particular bin and the associated frequency for each bin is estimated by taking the difference between upper and lower values of that bin. The component’s fragilities are calculated for each bin using the plant data, if available, or generic values of median peak ground acceleration and uncertainty values for the components. For human reliability analysis (HRA), the SPAR HRA (SPAR-H) method is used which requires the analysts to complete relatively straight forward worksheets that include the performance shaping factors (PSFs). The results are then used to estimate human error probabilities (HEPs) of interest. This work is expected to improve the NRC’s ability to include seismic hazards in risk assessments for operational events in support of the reactor oversight program (e.g., significance determination process).

  16. Models for environmental impact assessments of releases of radioactive substances from CERN facilities

    E-Print Network [OSTI]

    Vojtyla, P

    2005-01-01T23:59:59.000Z

    The document describes generic models for environmental impact assessments of releases of radioactive substances from CERN facilities. Except for few models developed in the Safety Commission, the models are based on the 1997 Swiss directive HSK-R-41 and on the 2001 IAEA Safety Report No. 19. The writing style is descriptive, facilitating the practical implementation of the models at CERN. There are four scenarios assumed for airborne releases: (1) short-term releases for release limit calculations, (2) actual short-term releases, (3) short-term releases during incidents/accidents, and (4) chronic long-term releases during the normal operation of a facility. For water releases, two scenarios are considered: (1) a release into a river, and (2) a release into a water treatment plant. The document shall be understood as a reference for specific environmental studies involving radioactive releases and as a recommendation of the Safety Commission.

  17. Models for Assessment of the environmental impact of Radioactive releases from CERN facilities

    E-Print Network [OSTI]

    Vojtyla, P

    2002-01-01T23:59:59.000Z

    The document describes generic models for environmental impact assessment of radioactive releases from CERN facilities. Except for few models developed in the TIS Division, the models are based on the 1997 Swiss directive HSK-R-41 and on the 2001 IAEA Safety Report No. 19. The writing style is descriptive, facilitating the practical implementation of the models at CERN. There are four scenarios assumed for airborne releases: (1) short-term releases for release limit calcu¬lations, (2) actual short-term releases, (3) short-term releases during incidents/accidents, and (4) chronic long-term releases during the normal operation of a facility. For water releases, two scenarios are considered: (1) a release into a river, and (2) a release into a water treatment plant. The document shall be understood as a reference for specific environmental studies involving radioactive releases and as a recommendation of the TIS Division.

  18. Forecast of surface layer meteorological parameters at Cerro Paranal with a mesoscale atmospherical model

    E-Print Network [OSTI]

    Lascaux, Franck; Fini, Luca

    2015-01-01T23:59:59.000Z

    This article aims at proving the feasibility of the forecast of all the most relevant classical atmospherical parameters for astronomical applications (wind speed and direction, temperature) above the ESO ground-base site of Cerro Paranal with a mesoscale atmospherical model called Meso-Nh. In a precedent paper we have preliminarily treated the model performances obtained in reconstructing some key atmospherical parameters in the surface layer 0-30~m studying the bias and the RMSE on a statistical sample of 20 nights. Results were very encouraging and it appeared therefore mandatory to confirm such a good result on a much richer statistical sample. In this paper, the study was extended to a total sample of 129 nights between 2007 and 2011 distributed in different parts of the solar year. This large sample made our analysis more robust and definitive in terms of the model performances and permitted us to confirm the excellent performances of the model. Besides, we present an independent analysis of the model p...

  19. Modeling Electrochemical Decomposition of Fluoroethylene Carbonate on Silicon Anode Surfaces in Lithium Ion Batteries

    E-Print Network [OSTI]

    Leung, Kevin; Foster, Michael E; Ma, Yuguang; del la Hoz, Julibeth M Martinez; Sai, Na; Balbuena, Perla B

    2014-01-01T23:59:59.000Z

    Fluoroethylene carbonate (FEC) shows promise as an electrolyte additive for improving passivating solid-electrolyte interphase (SEI) films on silicon anodes used in lithium ion batteries (LIB). We apply density functional theory (DFT), ab initio molecular dynamics (AIMD), and quantum chemistry techniques to examine excess-electron-induced FEC molecular decomposition mechanisms that lead to FEC-modified SEI. We consider one- and two-electron reactions using cluster models and explicit interfaces between liquid electrolyte and model Li(x)Si(y) surfaces, respectively. FEC is found to exhibit more varied reaction pathways than unsubstituted ethylene carbonate. The initial bond-breaking events and products of one- and two-electron reactions are qualitatively similar, with a fluoride ion detached in both cases. However, most one-electron products are charge-neutral, not anionic, and may not coalesce to form effective Li+-conducting SEI unless they are further reduced or take part in other reactions. The implication...

  20. Production of excitons in grazing collisions of protons with LiF surfaces: An onion model

    SciTech Connect (OSTI)

    Miraglia, J. E.; Gravielle, M. S. [Instituto de Astronomia y Fisica del Espacio, Consejo Nacional de Investigaciones Cientificas y Tecnicas and Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Casilla de Correo 67, Sucursal 28, (C1428EGA) Buenos Aires (Argentina)

    2011-12-15T23:59:59.000Z

    In this work we evaluate the production of excitons of a lithium fluoride crystal induced by proton impact in the intermediate and high energy regime (from 100 keV to 1 MeV). A simple model is proposed to account for the influence of the Coulomb grid of the target by dressing crystal ions to transform them in what we call onions. The excited states of these onions can be interpreted as excitons. Within this model, total cross section and stopping power are calculated by using the first Born and the continuum distorted-wave (CDW) eikonal initial-state (EIS) approximations. We found that between 7 and 30 excitons per incident proton are produced in grazing collisions with LiF surfaces, becoming a relevant mechanism of inelastic transitions.

  1. An Integrated Model for Assessment of Sustainable Agricultural Residue Removal Limits for Bioenergy Systems

    SciTech Connect (OSTI)

    D. Muth; K. M. Bryden

    2003-12-01T23:59:59.000Z

    Agricultural residues have been identified as a significant potential resource for bioenergy production, but serious questions remain about the sustainability of harvesting residues. Agricultural residues play an important role in limiting soil erosion from wind and water and in maintaining soil organic carbon. Because of this, multiple factors must be considered when assessing sustainable residue harvest limits. Validated and accepted modeling tools for assessing these impacts include the Revised Universal Soil Loss Equation Version 2 (RUSLE2), the Wind Erosion Prediction System (WEPS), and the Soil Conditioning Index. Currently, these models do not work together as a single integrated model. Rather, use of these models requires manual interaction and data transfer. As a result, it is currently not feasible to use these computational tools to perform detailed sustainable agricultural residue availability assessments across large spatial domains or to consider a broad range of land management practices. This paper presents an integrated modeling strategy that couples existing datasets with the RUSLE2 water erosion, WEPS wind erosion, and Soil Conditioning Index soil carbon modeling tools to create a single integrated residue removal modeling system. This enables the exploration of the detailed sustainable residue harvest scenarios needed to establish sustainable residue availability. Using this computational tool, an assessment study of residue availability for the state of Iowa was performed. This study included all soil types in the state of Iowa, four representative crop rotation schemes, variable crop yields, three tillage management methods, and five residue removal methods. The key conclusions of this study are that under current management practices and crop yields nearly 26.5 million Mg of agricultural residue are sustainably accessible in the state of Iowa, and that through the adoption of no till practices residue removal could sustainably approach 40 million Mg. However, when considering the economics and logistics of residue harvest, yields below 2.25 Mg ha-1 are generally considered to not be viable for a commercial bioenergy system. Applying this constraint, the total agricultural residue resource available in Iowa under current management practices is 19 million Mg. Previously published results have shown residue availability from 22 million Mg to over 50 million Mg in Iowa.

  2. Soil-to-Plant Concentration Ratios for Assessing Food Chain Pathways in Biosphere Models

    SciTech Connect (OSTI)

    Napier, Bruce A.; Fellows, Robert J.; Krupka, Kenneth M.

    2007-10-01T23:59:59.000Z

    This report describes work performed for the U.S. Nuclear Regulatory Commission’s project Assessment of Food Chain Pathway Parameters in Biosphere Models, which was established to assess and evaluate a number of key parameters used in the food-chain models used in performance assessments of radioactive waste disposal facilities. Section 2 of this report summarizes characteristics of samples of soils and groundwater from three geographical regions of the United States, the Southeast, Northwest, and Southwest, and analyses performed to characterize their physical and chemical properties. Because the uptake and behavior of radionuclides in plant roots, plant leaves, and animal products depends on the chemistry of the water and soil coming in contact with plants and animals, water and soil samples collected from these regions of the United States were used in experiments at Pacific Northwest National Laboratory to determine radionuclide soil-to-plant concentration ratios. Crops and forage used in the experiments were grown in the soils, and long-lived radionuclides introduced into the groundwater provide the contaminated water used to water the grown plants. The radionuclides evaluated include 99Tc, 238Pu, and 241Am. Plant varieties include alfalfa, corn, onion, and potato. The radionuclide uptake results from this research study show how regional variations in water quality and soil chemistry affect radionuclide uptake. Section 3 summarizes the procedures and results of the uptake experiments, and relates the soil-to-plant uptake factors derived. In Section 4, the results found in this study are compared with similar values found in the biosphere modeling literature; the study’s results are generally in line with current literature, but soil- and plant-specific differences are noticeable. This food-chain pathway data may be used by the NRC staff to assess dose to persons in the reference biosphere (e.g., persons who live and work in an area potentially affected by radionuclide releases) of waste disposal facilities and decommissioning sites.

  3. From near-surface to root-zone soil moisture using an exponential filter: an assessment of the method based on

    E-Print Network [OSTI]

    Boyer, Edmond

    provides a means to quantitatively describe the water content of a shallow near-surface soil layer, wg of the method based on in-situ observations and model simulations C. Albergel1 , C. Rüdiger1,* , T. Pellarin2. A recursive exponential filter equation using a time constant, T, is used to compute a soil water index

  4. CHEMICAL MODELING OF INFRARED DARK CLOUDS: THE ROLE OF SURFACE CHEMISTRY

    SciTech Connect (OSTI)

    Vasyunina, T.; Vasyunin, A. I.; Herbst, Eric [Department of Chemistry, University of Virginia, Charlottesville, VA 22904 (United States); Linz, H. [Max Planck Institute for Astronomy (MPIA), Koenigstuhl 17, D-69117 Heidelberg (Germany)

    2012-06-01T23:59:59.000Z

    We simulate the chemistry of infrared dark clouds (IRDCs) with a model in which the physical conditions are homogeneous and time independent. The chemistry is solved as a function of time with three networks: one purely gas phase, one that includes accretion and desorption, and one, the complete gas-grain network, that includes surface chemistry in addition. We compare our results with observed molecular abundances for two representative IRDCs-IRDC013.90-1 and IRDC321.73-1-using the molecular species N{sub 2}H{sup +}, HC{sub 3}N, HNC, HCO{sup +}, HCN, C{sub 2}H, NH{sub 3}, and CS. IRDC013.90-1 is a cold IRDC, with a temperature below 20 K, while IRDC321.73-1 is somewhat warmer, in the range 20-30 K. We find that the complete gas-grain model fits the data very well, but that the goodness of fit is not sharply peaked at a particular temperature. Surface processes are important for the explanation of the high gas-phase abundance of N{sub 2}H{sup +} in IRDC321.73-1. The general success of the zero-dimensional model in reproducing single-dish observations of our limited sample of eight species shows that it is probably sufficient for an explanation of this type of data. To build and justify more complicated models, including spatial temperature and density structure, contraction, and heating, we require high-resolution interferometric data.

  5. Waste package performance assessment: Deterministic system model, program scope and specification

    SciTech Connect (OSTI)

    O`Connell, W.J.; Drach, R.S.

    1986-10-02T23:59:59.000Z

    Integrated assessments of the performance of nuclear waste package designs must be made in order to qualify waste package designs with respect to containment time and release-rate requirements. PANDORA is a computer-based model of the waste package and of the processes affecting it over the long terms, specific to conditions at the proposed Yucca Mountain, Nevada, site. The processes PANDORA models include: changes in inventories due to radioactive decay, gamma radiation dose rate in and near the package, heat transfer, mechanical behavior, groundwater contact, corrosion, waste form alteration, and radionuclide release. The model tracks the development and coupling of these processes over time. The process models are simplified ones that focus on major effects and on coupling. This report documents our conceptual model development and provides a specification for the computer program. The current model is the first in a series. Succeeding models will use guidance from results of preceding models in the PANDORA series and will incorporate results of recently completed experiments and calculations on processes affecting performance. 22 refs., 21 figs., 9 tabs.

  6. Solar surface emerging flux regions: a comparative study of radiative MHD modeling and Hinode SOT observations

    E-Print Network [OSTI]

    M. C. M. Cheung; M. Schuessler; T. D. Tarbell; A. M. Title

    2008-10-31T23:59:59.000Z

    We present results from numerical modeling of emerging flux regions on the solar surface. The modeling was carried out by means of 3D radiative MHD simulations of the rise of buoyant magnetic flux tubes through the convection zone and into the photosphere. Due to the strong stratification of the convection zone, the rise results in a lateral expansion of the tube into a magnetic sheet, which acts as a reservoir for small-scale flux emergence events at the scale of granulation. The interaction of the convective downflows and the rising magnetic flux undulates it to form serpentine field lines emerging into the photosphere. Observational characteristics including the pattern of emerging flux regions, the cancellation of surface flux and associated high speed downflows, the convective collapse of photospheric flux tubes, the appearance of anomalous darkenings, the formation of bright points and the possible existence of transient kilogauss horizontal fields are discussed in the context of new observations from the Hinode Solar Optical Telescope. Implications for the local helioseismology of emerging flux regions are also discussed.

  7. Impact of Agricultural Practice on Regional Climate in a CoupledLand Surface Mesoscale Model

    SciTech Connect (OSTI)

    Cooley, H.S.; Riley, W.J.; Torn, M.S.; He, Y.

    2004-07-01T23:59:59.000Z

    The land surface has been shown to form strong feedbacks with climate due to linkages between atmospheric conditions and terrestrial ecosystem exchanges of energy, momentum, water, and trace gases. Although often ignored in modeling studies, land management itself may form significant feedbacks. Because crops are harvested earlier under drier conditions, regional air temperature, precipitation, and soil moisture, for example, affect harvest timing, particularly of rain-fed crops. This removal of vegetation alters the land surface characteristics and may, in turn, affect regional climate. We applied a coupled climate(MM5) and land-surface (LSM1) model to examine the effects of early and late winter wheat harvest on regional climate in the Department of Energy Atmospheric Radiation Measurement (ARM) Climate Research Facility in the Southern Great Plains, where winter wheat accounts for 20 percent of the land area. Within the winter wheat region, simulated 2 m air temperature was 1.3 C warmer in the Early Harvest scenario at mid-day averaged over the two weeks following harvest. Soils in the harvested area were drier and warmer in the top 10 cm and wetter in the 10-20 cm layer. Midday soils were 2.5 C warmer in the harvested area at mid-day averaged over the two weeks following harvest. Harvest also dramatically altered latent and sensible heat fluxes. Although differences between scenarios diminished once both scenarios were harvested, the short-term impacts of land management on climate were comparable to those from land cover change demonstrated in other studies.

  8. First-Principles Assessment of H[subscript 2]S and H[subscript 2]O Reaction Mechanisms and the Subsequent Hydrogen Absorption on the CeO[subscript 2](111) Surface

    E-Print Network [OSTI]

    Marrocchelli, Dario

    The main goal of this study is to assess the resistance of ceria against hydrogen penetration into its bulk, in the context of its application as a protective surface coating against hydrogen embrittlement in metals. We ...

  9. Review of uncertainty estimates associated with models for assessing the impact of breeder reactor radioactivity releases

    SciTech Connect (OSTI)

    Miller, C.; Little, C.A.

    1982-08-01T23:59:59.000Z

    The purpose is to summarize estimates based on currently available data of the uncertainty associated with radiological assessment models. The models being examined herein are those recommended previously for use in breeder reactor assessments. Uncertainty estimates are presented for models of atmospheric and hydrologic transport, terrestrial and aquatic food-chain bioaccumulation, and internal and external dosimetry. Both long-term and short-term release conditions are discussed. The uncertainty estimates presented in this report indicate that, for many sites, generic models and representative parameter values may be used to calculate doses from annual average radionuclide releases when these calculated doses are on the order of one-tenth or less of a relevant dose limit. For short-term, accidental releases, especially those from breeder reactors located in sites dominated by complex terrain and/or coastal meteorology, the uncertainty in the dose calculations may be much larger than an order of magnitude. As a result, it may be necessary to incorporate site-specific information into the dose calculation under these circumstances to reduce this uncertainty. However, even using site-specific information, natural variability and the uncertainties in the dose conversion factor will likely result in an overall uncertainty of greater than an order of magnitude for predictions of dose or concentration in environmental media following shortterm releases.

  10. Assessment of Food Chain Pathway Parameters in Biosphere Models: Annual Progress Report for Fiscal Year 2004

    SciTech Connect (OSTI)

    Napier, Bruce A.; Krupka, Kenneth M.; Fellows, Robert J.; Cataldo, Dominic A.; Valenta, Michelle M.; Gilmore, Tyler J.

    2004-12-02T23:59:59.000Z

    This Annual Progress Report describes the work performed and summarizes some of the key observations to date on the U.S. Nuclear Regulatory Commission’s project Assessment of Food Chain Pathway Parameters in Biosphere Models, which was established to assess and evaluate a number of key parameters used in the food-chain models used in performance assessments of radioactive waste disposal facilities. Section 2 of this report describes activities undertaken to collect samples of soils from three regions of the United States, the Southeast, Northwest, and Southwest, and perform analyses to characterize their physical and chemical properties. Section 3 summarizes information gathered regarding agricultural practices and common and unusual crops grown in each of these three areas. Section 4 describes progress in studying radionuclide uptake in several representative crops from the three soil types in controlled laboratory conditions. Section 5 describes a range of international coordination activities undertaken by Project staff in order to support the underlying data needs of the Project. Section 6 provides a very brief summary of the status of the GENII Version 2 computer program, which is a “client” of the types of data being generated by the Project, and for which the Project will be providing training to the US NRC staff in the coming Fiscal Year. Several appendices provide additional supporting information.

  11. Hydrophobic force field as molecular alternative to surface-area models

    SciTech Connect (OSTI)

    Hummer, G.

    1999-07-07T23:59:59.000Z

    An effective force field for hydrophobic interactions is developed based on a modified potential-of-mean-force (PMF) expansion of the effective many-body interactions between nonpolar molecules in water. For the simplest nonpolar solutes in water, hard particles, the modified PMF expansion is exact in both limiting cases of infinite separation and perfect overlap. The hydrophobic interactions are parametrized by using the information-theory model of hydrophobic hydration. The interactions between nonpolar solutes are short-ranged and can be evaluated efficiently on a computer. The force field is compared with simulation data for alkane conformational equilibria in water as well as a model for the formation of a hydrophobic core of a protein. The modified PMF expansion can be extended to solutes with attractive interactions. The observed accuracy, computational efficiency, and atomic detail of the model suggest that this simple hydrophobic force field can lead to a molecular alternative for phenomenological surface-area models with applications in ligand-binding and protein-folding studies.

  12. Modeling gas and brine migration for assessing compliance of the Waste Isolation Pilot Plant

    SciTech Connect (OSTI)

    Vaughn, P. [Applied Physics, Inc., Albuquerque, NM (United States); Butcher, B. [Sandia National Labs., Albuquerque, NM (United States); Helton, J. [Arizona State Univ., Tempe, AZ (United States); Swift, P. [Tech. Reps., Inc., Albuquerque, NM (United States)

    1993-10-01T23:59:59.000Z

    At the request of the WIPP Project Integration Office (WPIO) of the DOE, the WIPP Performance Assessment (PA) Department of Sandia National Laboratories (SNL) has completed preliminary uncertainty and sensitivity analyses of gas and brine migration away from the undisturbed repository. This paper contains descriptions of the numerical model and simulations, including model geometries and parameter values, and a summary of major conclusions from sensitivity analyses. Because significant transport of contaminants can only occur in a fluid (gas or brine) medium, two-phase flow modeling can provide an estimate of the distance to which contaminants can migrate. Migration of gas or brine beyond the RCRA ``disposal-unit boundary`` or the Standard`s accessible environment constitutes a potential, but not certain, violation and may require additional evaluations of contaminant concentrations.

  13. Control Model Integrated Management and Assessment System. These materials are from April 2000 and pertain to Savanna

    E-Print Network [OSTI]

    Boone, Randall B.

    Control Model #12;134 Integrated Management and Assessment System. These materials are from AprilView for contacts. Total biomass, by plant groups As you have already likely noticed, the control model includes and dead biomass, for a typical April to July NCA-Savanna Control Model #12;135 Root biomass for herbaceous

  14. On the applicability of the Heliosat-2 method to assess surface solar irradiance in the Intertropical Convergence Zone,

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    on the Earth's surface and its geographical distribution is of prime importance for numerous solar-3027" DOI : 10.1080/01431161.2012.756598 #12;2 energy systems for heating and electrical power generation satisfactory for Europe, including Madeira Island (Aculinin 2008; Blanc et al. 2011; Lefèvre et al. 2007

  15. Result Summary for the Area 5 Radioactive Waste Management Site Performance Assessment Model Version 4.113

    SciTech Connect (OSTI)

    Shott, G. J.

    2012-04-15T23:59:59.000Z

    Preliminary results for Version 4.113 of the Nevada National Security Site Area 5 Radioactive Waste Management Site performance assessment model are summarized. Version 4.113 includes the Fiscal Year 2011 inventory estimate.

  16. Statistical Modelling of the Relationship Between Main Development Region Sea Surface Temperature and Atlantic Basin Hurricane Numbers

    E-Print Network [OSTI]

    Binter, R; Khare, S; Binter, Roman; Jewson, Stephen; Khare, Shree

    2007-01-01T23:59:59.000Z

    We are building a hurricane number prediction scheme that relies, in part, on statistical modelling of the empirical relationship between Atlantic sea surface temperatures and Atlantic basin hurricane numbers. We test out a number of simple statistical models for this relationship, using data from 1900 to 2005 and data from 1950 to 2005, and for both all hurricane numbers and intense hurricane numbers.

  17. IEEE GEOSCIENCE AND REMOTE SENSING LETTERS, VOL. X, NO. X, NOVEMBER 200X 1 Digital Topography Models for Martian Surfaces

    E-Print Network [OSTI]

    Vilalta, Ricardo

    IEEE GEOSCIENCE AND REMOTE SENSING LETTERS, VOL. X, NO. X, NOVEMBER 200X 1 Digital Topography Models for Martian Surfaces Tomasz Stepinski and Ricardo Vilalta Abstract-- We propose to use and geologic mapping of the planet. We construct a digital topography model (DTM), a multi-layer grid

  18. Optimization of the GB/SA Solvation Model for Predicting the Structure of Surface Loops in Proteins

    E-Print Network [OSTI]

    Meirovitch, Hagai

    Optimization of the GB/SA Solvation Model for Predicting the Structure of Surface Loops in ProteinsVed: October 10, 2005; In Final Form: December 1, 2005 Implicit solvation models are commonly optimized the force field is sometimes not considered. In previous studies, we have developed an optimization

  19. Modeling and Quantification of Team Performance in Human Reliability Analysis for Probabilistic Risk Assessment

    SciTech Connect (OSTI)

    Jeffrey C. JOe; Ronald L. Boring

    2014-06-01T23:59:59.000Z

    Probabilistic Risk Assessment (PRA) and Human Reliability Assessment (HRA) are important technical contributors to the United States (U.S.) Nuclear Regulatory Commission’s (NRC) risk-informed and performance based approach to regulating U.S. commercial nuclear activities. Furthermore, all currently operating commercial NPPs in the U.S. are required by federal regulation to be staffed with crews of operators. Yet, aspects of team performance are underspecified in most HRA methods that are widely used in the nuclear industry. There are a variety of "emergent" team cognition and teamwork errors (e.g., communication errors) that are 1) distinct from individual human errors, and 2) important to understand from a PRA perspective. The lack of robust models or quantification of team performance is an issue that affects the accuracy and validity of HRA methods and models, leading to significant uncertainty in estimating HEPs. This paper describes research that has the objective to model and quantify team dynamics and teamwork within NPP control room crews for risk informed applications, thereby improving the technical basis of HRA, which improves the risk-informed approach the NRC uses to regulate the U.S. commercial nuclear industry.

  20. A Home Ignition Assessment Model Applied to Structures in the Wildland-Urban Interface

    SciTech Connect (OSTI)

    Biswas, Kaushik [ORNL; Werth, David [Savannah River National Laboratory, Aiken, SC; Gupta, Narendra [Savannah River National Laboratory, Aiken, SC

    2013-01-01T23:59:59.000Z

    The issue of exterior fire threat to buildings, from either wildfires in the wildland-urban interface or neighboring structure fires, is critically important. To address this, theWildfire Ignition Resistant Home Design (WIRHD) program was initiated. The WIRHD program developed a tool, theWildFIREWizard, that will allow homeowners to estimate the external fire threat to their homes based on specific features and characteristics of the homes and yards. The software then makes recommendations to reduce the threat. The inputs include the structural and material features of the home and information about any ignition sources or flammable objects in its immediate vicinity, known as the home ignition zone. The tool comprises an ignition assessment model that performs explicit calculations of the radiant and convective heating of the building envelope from the potential ignition sources. This article describes a series of material ignition and flammability tests that were performed to calibrate and/or validate the ignition assessment model. The tests involved exposing test walls with different external siding types to radiant heating and/or direct flame contact.The responses of the test walls were used to determine the conditions leading to melting, ignition, or any other mode of failure of the walls. Temperature data were used to verify the model predictions of temperature rises and ignition times of the test walls.

  1. Analytical modeling of AlGaN/AlN/GaN heterostructures including effects of distributed surface donor states

    SciTech Connect (OSTI)

    Goyal, Nitin, E-mail: nitin@unik.no [Carinthian Tech Research CTR AG, Europastraße 4/1, Technologiepark Villach, A-9524 Villach/St. Magdalen (Austria); Department of Electronics and Telecommunication, Norwegian University of Science and Technology, Trondheim NO7034 (Norway); Fjeldly, Tor A. [Department of Electronics and Telecommunication, Norwegian University of Science and Technology, Trondheim NO7034 (Norway)

    2014-07-14T23:59:59.000Z

    In this paper, a physics based analytical model is presented for calculation of the two-dimensional electron gas density and the bare surface barrier height of AlGaN/AlN/GaN material stacks. The presented model is based on the concept of distributed surface donor states and the self-consistent solution of Poisson equation at the different material interfaces. The model shows good agreement with the reported experimental data and can be used for the design and characterization of advanced GaN devices for power and radio frequency applications.

  2. Molecular adsorption of alkanes on platinum surfaces: A predictive theoretical model

    SciTech Connect (OSTI)

    Stinnett, J.A.; Madix, R.J. [Department of Chemical Engineering, Stanford University, Stanford, California 94305 (United States)] [Department of Chemical Engineering, Stanford University, Stanford, California 94305 (United States)

    1996-07-01T23:59:59.000Z

    The adsorption probabilities of methane and propane on Pt(111), and propane on Pt(110)-(1{times}2) have been successfully predicted for a wide range of incident energies and angles with classical stochastic trajectory simulations, using a pairwise additive Morse methyl{endash}platinum potential previously developed from the measured trapping probabilities of ethane on Pt(111). These predictions, along with those for ethane adsorption on Pt(110){endash}(1{times}2), comprise a unified model for the molecular adsorption of alkanes on platinum surfaces. The simulations show the initial trapping probabilities of methane and propane on Pt(111) are determined to within approximately 10{percent} by the fate of the first bounce. They also indicate that at normal incidence on Pt(111) energy conversions from perpendicular translational motion to both cartwheeling rotation and lattice phonons play increasingly important roles in increasing the trapping probability as the alkane increases in size and molecular weight. For methane itself excitation of parallel translational momentum after the first bounce serves as the most effective energy storage mechanism which facilitates trapping, whereas for propane cartwheel rotational motion plays the dominant role. Excessive excitation of these modes of motion, however, can cause scattering on subsequent bounces by reconversion of the energy into perpendicular translational energy. Collisions of methane with the hollow and bridge sites on the Pt(111) surface appear less effective in trapping than do atop sites. The simulations also suggest excitation of the C{endash}C{endash}C bending mode of propane has little effect on the trapping of propane on platinum surfaces for beam energies below 55 kJ/mol. {copyright} {ital 1996 American Institute of Physics.}

  3. Economic analysis and assessment of syngas production using a modeling approach

    SciTech Connect (OSTI)

    Kim, Hakkwan; Parajuli, Prem B.; Yu, Fei; Columbus, Eugene P.

    2011-08-10T23:59:59.000Z

    Economic analysis and modeling are essential and important issues for the development of current feedstock and process technology for bio-gasification. The objective of this study was to develop an economic model and apply to predict the unit cost of syngas production from a micro-scale bio-gasification facility. An economic model was programmed in C++ computer programming language and developed using a parametric cost approach, which included processes to calculate the total capital costs and the total operating costs. The model used measured economic data from the bio-gasification facility at Mississippi State University. The modeling results showed that the unit cost of syngas production was $1.217 for a 60 Nm-3 h-1 capacity bio-gasifier. The operating cost was the major part of the total production cost. The equipment purchase cost and the labor cost were the largest part of the total capital cost and the total operating cost, respectively. Sensitivity analysis indicated that labor costs rank the top as followed by equipment cost, loan life, feedstock cost, interest rate, utility cost, and waste treatment cost. The unit cost of syngas production increased with the increase of all parameters with exception of loan life. The annual cost regarding equipment, labor, feedstock, waste treatment, and utility cost showed a linear relationship with percent changes, while loan life and annual interest rate showed a non-linear relationship. This study provides the useful information for economic analysis and assessment of the syngas production using a modeling approach.

  4. Modeling and Risk Assessment of CO{sub 2} Sequestration at the Geologic-basin Scale

    SciTech Connect (OSTI)

    Juanes, Ruben

    2013-08-31T23:59:59.000Z

    Objectives. The overall objective of this proposal was to develop tools for better understanding, modeling and risk assessment of CO{sub 2} permanence in geologic formations at the geologic basin scale. The main motivation was that carbon capture and storage (CCS) will play an important role as a climate change mitigation technology only if it is deployed at scale of gigatonne per year injections over a period of decades. Continuous injection of this magnitude must be understood at the scale of a geologic basin. Specifically, the technical objectives of this project were: (1) to develop mathematical models of capacity and injectivity at the basin scale; (2) to apply quantitative risk assessment methodologies that will inform on CO{sub 2} permanence; (3) to apply the models to geologic basins across the continental United States. These technical objectives go hand-in-hand with the overarching goals of: (1) advancing the science for deployment of CCS at scale; and (2) contributing to training the next generation of scientists and engineers that will implement and deploy CCS in the United States and elsewhere. Methods. The differentiating factor of this proposal was to perform fundamental research on migration and fate of CO{sub 2} and displaced brine at the geologic basin scale. We developed analytical sharp-interface models of the evolution of CO{sub 2} plumes over the duration of injection (decades) and after injection (centuries). We applied the analytical solutions of CO{sub 2} plume migration and pressure evolution to specific geologic basins, to estimate the maximum footprint of the plume, and the maximum injection rate that can be sustained during a certain injection period without fracturing the caprock. These results have led to more accurate capacity estimates, based on fluid flow dynamics, rather than ad hoc assumptions of an overall “efficiency factor.” We also applied risk assessment methodologies to evaluate the uncertainty in our predictions of storage capacity and leakage rates. This was possible because the analytical mathematical models provide ultrafast forward simulation and they contain few parameters. Impact. The project has been enormously successful both in terms of its scientific output (journal publications) as well as impact in the government and industry. The mathematical models and uncertainty quantification methodologies developed here o?er a physically-based approach for estimating capacity and leakage risk at the basin scale. Our approach may also facilitate deployment of CCS by providing the basis for a simpler and more coherent regulatory structure than an “individual-point-of-injection” permitting approach. It may also lead to better science-based policy for post-closure design and transfer of responsibility to the State.

  5. Environmental Assessment

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

    surface and the lower part of the atmosphere; this phenomenon is called the greenhouse effect. U.S. Department of Energy DOEEA-1728D Draft Environmental Assessment 32 June...

  6. Uncertainty analysis of an aviation climate model and an aircraft price model for assessment of environmental effects

    E-Print Network [OSTI]

    Jun, Mina

    2007-01-01T23:59:59.000Z

    Estimating, presenting, and assessing uncertainties are important parts in assessment of a complex system. This thesis focuses on the assessment of uncertainty in the price module and the climate module in the Aviation ...

  7. Preliminary performance assessment for the Waste Isolation Pilot Plant, December 1992. Volume 3, Model parameters: Sandia WIPP Project

    SciTech Connect (OSTI)

    Not Available

    1992-12-29T23:59:59.000Z

    This volume documents model parameters chosen as of July 1992 that were used by the Performance Assessment Department of Sandia National Laboratories in its 1992 preliminary performance assessment of the Waste Isolation Pilot Plant (WIPP). Ranges and distributions for about 300 modeling parameters in the current secondary data base are presented in tables for the geologic and engineered barriers, global materials (e.g., fluid properties), and agents that act upon the WIPP disposal system such as climate variability and human-intrusion boreholes. The 49 parameters sampled in the 1992 Preliminary Performance Assessment are given special emphasis with tables and graphics that provide insight and sources of data for each parameter.

  8. Diosmacycloalkanes as models for the formation of hydrocarbons from surface methylenes. Progress report, November 1, 1992--October 31, 1993

    SciTech Connect (OSTI)

    Norton, J.R.

    1993-05-01T23:59:59.000Z

    The report is divided into: vibrational models for surface ethylidenes (on catalyst surfaces); alpha vs beta hydrogen elimination in formation of propene from an osmacyclobutane; mechanism of formation and fragmentation of diosmacyclobutanes; reaction of dienes and allenes with diosmacyclobutanes; structure of Os(CO){sub 4}(C{sub 2}H{sub 4}), an osmacyclopropane; and reaction of {mu}-oxobis [(trifluoromethanesulfanato) (phenyl)iodine(III)] with Group 14 propargyl derivatives and a propargyl ether. 16 refs, figs.

  9. PORFLOW MODELING FOR A PRELIMINARY ASSESSMENT OF THE PERFORMANCE OF NEW SALTSTONE DISPOSAL UNIT DESIGNS

    SciTech Connect (OSTI)

    Smith, F.

    2012-08-06T23:59:59.000Z

    At the request of Savannah River Remediation (SRR), SRNL has analyzed the expected performance obtained from using seven 32 million gallon Saltstone Disposal Units (SDUs) in the Z-Area Saltstone Disposal Facility (SDF) to store future saltstone grout. The analysis was based on preliminary SDU final design specifications. The analysis used PORFLOW modeling to calculate the release of 20 radionuclides from an SDU and transport of the radionuclides and daughters through the vadose zone. Results from this vadose zone analysis were combined with previously calculated releases from existing saltstone vaults and FDCs and a second PORFLOW model run to calculate aquifer transport to assessment points located along a boundary 100 m from the nearest edge of the SDF sources. Peak concentrations within 12 sectors spaced along the 100 m boundary were determined over a period of evaluation extending 20,000 years after SDF closure cap placement. These peak concentrations were provided to SRR to use as input for dose calculations.

  10. Need to understand "Uncertainty Assessment" in the system development modeling process

    E-Print Network [OSTI]

    Kardile, Vilas Vasantrao

    2011-01-01T23:59:59.000Z

    In the early stage of software life cycle project manager are inefficient to estimate the effort, schedule, cost estimation and its development approach .This in turn, confuses the manager to bid effectively on software project and choose incorrect development approach. That will directly effect on productivity cycle and increase level of uncertainty. This becomes a strong cause of project failure. So to avoid such problem if we know level and sources of uncertainty in model design, It will directive the developer to design accurate software cost and schedule estimation. Which are essential for software project success . However once the required efforts have estimated, little is done to recalibrate and reduce the uncertainty of the initial estimates. This paper demonstrates terminology and typology of uncertainty is presented together with a framework for the modeling process, Brief reviews have been made of 14 different (partly complementary) methods commonly used in uncertainty assessment its interaction w...

  11. Probabilistic performance-assessment modeling of the mixed waste landfill at Sandia National Laboratories.

    SciTech Connect (OSTI)

    Peace, Gerald (Jerry) L. (.); Goering, Timothy James (GRAM, Inc.); Miller, Mark Laverne; Ho, Clifford Kuofei

    2007-01-01T23:59:59.000Z

    A probabilistic performance assessment has been conducted to evaluate the fate and transport of radionuclides (americium-241, cesium-137, cobalt-60, plutonium-238, plutonium-239, radium-226, radon-222, strontium-90, thorium-232, tritium, uranium-238), heavy metals (lead and cadmium), and volatile organic compounds (VOCs) at the Mixed Waste Landfill (MWL). Probabilistic analyses were performed to quantify uncertainties inherent in the system and models for a 1,000-year period, and sensitivity analyses were performed to identify parameters and processes that were most important to the simulated performance metrics. Comparisons between simulated results and measured values at the MWL were made to gain confidence in the models and perform calibrations when data were available. In addition, long-term monitoring requirements and triggers were recommended based on the results of the quantified uncertainty and sensitivity analyses.

  12. Detailed comparative study and a mechanistic model of resuspension of spherical particles from rough and smooth surfaces

    E-Print Network [OSTI]

    Shnapp, Ron

    2014-01-01T23:59:59.000Z

    Resuspension of solid particles by a tornado-like vortex from surfaces of different roughness is studied using a three-dimensional particle tracking velocimetry (3D-PTV) method. By utilizing the three-dimensional information on particle positions, velocities and accelerations before, during and after the resuspension (lift-off) event, we demonstrate that the resuspension efficiency is significantly higher from the rough surface, and propose a mechanistic model of this peculiar effect. The results indicate that for all Reynolds numbers tested, the resuspension rate, as well as particle velocities and accelerations, are higher over the rough surface, as compared to the smooth counterpart. The results and the model can help to improve modeling and analysis of resuspension rates in engineering and environmental applications.

  13. Modeling Electrochemical Decomposition of Fluoroethylene Carbonate on Silicon Anode Surfaces in Lithium Ion Batteries

    E-Print Network [OSTI]

    Kevin Leung; Susan B. Rempe; Michael E. Foster; Yuguang Ma; Julibeth M. Martinez del la Hoz; Na Sai; Perla B. Balbuena

    2014-01-17T23:59:59.000Z

    Fluoroethylene carbonate (FEC) shows promise as an electrolyte additive for improving passivating solid-electrolyte interphase (SEI) films on silicon anodes used in lithium ion batteries (LIB). We apply density functional theory (DFT), ab initio molecular dynamics (AIMD), and quantum chemistry techniques to examine excess-electron-induced FEC molecular decomposition mechanisms that lead to FEC-modified SEI. We consider one- and two-electron reactions using cluster models and explicit interfaces between liquid electrolyte and model Li(x)Si(y) surfaces, respectively. FEC is found to exhibit more varied reaction pathways than unsubstituted ethylene carbonate. The initial bond-breaking events and products of one- and two-electron reactions are qualitatively similar, with a fluoride ion detached in both cases. However, most one-electron products are charge-neutral, not anionic, and may not coalesce to form effective Li+-conducting SEI unless they are further reduced or take part in other reactions. The implications of these reactions to silicon-anode based LIB are discussed.

  14. Modelling of a captive unmanned aerial system teledetecting oil pollution on sea surface

    E-Print Network [OSTI]

    Muttin, Frédéric

    2013-01-01T23:59:59.000Z

    Recent major oil-spills were tracked using observations with sufficient altitudes over the sea surface, to detect oil slick locations. For oil-spill responders, we propose a captive Unmanned Aerial System, UAS acting like a periscope over a ship or supply vessel. The system is composed of an umbilical deployed from ship deck, and there are few studies that have examined elasticity within cable dynamic during take-off or landing (TOL) and normal flight phases. Therefore, the safest approach for the control-commands of the system is through umbilical dynamic modelling. We give a time-dependant finite-element formulation, using improved elastic non-linear cable elements. Two kinds of boundary condition, natural or essential, are discussed for roll-in or roll-out of the umbilical. A numerical convergence and a validation with an exact solution are provided, using two examples for the flight parameters. Finally, sensitivity of the model potentially extends its capacity for the system equilibrium prediction, under ...

  15. Coupling GIS and LCA for biodiversity assessments of land use: Part 1: Inventory modeling

    E-Print Network [OSTI]

    Geyer, Roland; Stoms, David M.; Lindner, Jan P.; Davis, Frank W.; Wittstock, Bastian

    2010-01-01T23:59:59.000Z

    explicit manner, while life cycle assessment (LCA) does notuse impacts in life cycle assessment. Int J LCA 11(5):363–Int J LCA Kim S, Dale BE (2005b) Life cycle assessment of

  16. Surface spectroscopic characterization of oxide thin films and bimetallic model catalysts

    E-Print Network [OSTI]

    Wei, Tao

    2009-05-15T23:59:59.000Z

    . The interaction of metal clusters (Ag) with defects was examined by work function measurements. On various Pd related bimetallic alloy surfaces, CO chemisorption behavior was addressed by IRAS and TPD. Observed changes in the surface chemical properties during...

  17. CONTAIN code analyses of direct containment heating (DCH) experiments: Model assessment and phenomenological interpretation

    SciTech Connect (OSTI)

    Williams, D.C.; Griffith, R.O.; Tadios, E.L.; Washington, K.E.

    1995-05-12T23:59:59.000Z

    Models for direct containment heating (DCH) in the CONTAIN code for severe accident analysis have been reviewed and a standard input prescription for their use has been defined. The code has been exercised against a large subset of the available DCH data base. Generally good agreement with the experimental results for containment pressurization ({Delta}P) and hydrogen generation has been obtained. Extensive sensitivity studies have been performed which permit assessment of many of the strengths and weaknesses of specific model features. These include models for debris transport and trapping, DCH heat transfer and chemistry, atmosphere-structure heat transfer, interactions between nonairborne debris and blowdown steam, potential effects of debris-water interactions, and hydrogen combustion under DCH conditions. Containment compartmentalization is an important DCH mitigator in the calculations, in agreement with experimental results. The CONTAIN model includes partially parametric treatments for some processes that are not well understood. The importance of the associated uncertainties depends upon the details of the DCH scenario being analyzed. Recommended sensitivity studies are summarized that allow the user to obtain a reasonable estimate of the uncertainties in the calculated results.

  18. Simulating the Transverse Ising Model on a Quantum Computer: Error Correction with the Surface Code

    E-Print Network [OSTI]

    Geller, Michael R.

    of a fault- tolerant quantum computer. The surface code approach has one of the highest known tolerable error of the surface code is four orders of magnitude higher than the concatenation code, building a quantum computer implementation, a new approach to building a quantum computer with the surface code (which is a kind

  19. Proceedings of the 2007 Aging Aircraft Conference Cost Model for Assessing the Transition to Lead-Free Electronics

    E-Print Network [OSTI]

    Sandborn, Peter

    Proceedings of the 2007 Aging Aircraft Conference Cost Model for Assessing the Transition to Lead the cost ramifications of the transition from tin- lead to lead-free electronic parts. All tin-lead, all lead-free and mixed assembly approaches are considered. The model makes basic assumptions of a fixed

  20. Numerical Modeling of Salt Tectonics on Passive Continental Margins: Preliminary Assessment of the Effects of Sediment Loading,

    E-Print Network [OSTI]

    Beaumont, Christopher

    Numerical Modeling of Salt Tectonics on Passive Continental Margins: Preliminary Assessment Sciences The University of Leeds LS2 9JT Leeds United Kingdom Abstract Salt tectonics in passive model of frictional-plastic sedimentary overburden overlying a linear viscous salt layer. We present

  1. Assessment of managed aquifer recharge site suitability and influence using a GIS and3 numerical modeling4

    E-Print Network [OSTI]

    Fisher, Andrew

    " for20 MAR. Results from the GIS analysis were used with a regional groundwater model to assess the groundwater flowing to the ocean over the long term. Modeling results28 illustrate considerable variability evaluation of options for32 enhancing groundwater resources.33 34 1. Introduction35 Groundwater

  2. A global model simulation for 3-D radiative transfer impact on surface hydrology over Sierra Nevada and Rocky Mountains

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

    Lee, W.-L.; Gu, Y.; Liou, K. N.; Leung, L. R.; Hsu, H.-H.

    2014-01-01T23:59:59.000Z

    We investigate 3-D mountain effects on solar flux distributions and their impact on surface hydrology over the Western United States, specifically the Rocky Mountains and Sierra Nevada using CCSM4 (CAM4/CLM4) global model with a 0.23° × 0.31° resolution for simulations over 6 years. In 3-D radiative transfer parameterization, we have updated surface topography data from a resolution of 1 km to 90 m to improve parameterization accuracy. In addition, we have also modified the upward-flux deviation [3-D ? PP (plane-parallel)] adjustment to ensure that energy balance at the surface is conserved in global climate simulations based on 3-D radiation parameterization.more »We show that deviations of the net surface fluxes are not only affected by 3-D mountains, but also influenced by feedbacks of cloud and snow in association with the long-term simulations. Deviations in sensible heat and surface temperature generally follow the patterns of net surface solar flux. The monthly snow water equivalent (SWE) deviations show an increase in lower elevations due to reduced snowmelt, leading to a reduction in cumulative runoff. Over higher elevation areas, negative SWE deviations are found because of increased solar radiation available at the surface. Simulated precipitation increases for lower elevations, while decreases for higher elevations with a minimum in April. Liquid runoff significantly decreases in higher elevations after April due to reduced SWE and precipitation.« less

  3. Recommended Method To Account For Daughter Ingrowth For The Portsmouth On-Site Waste Disposal Facility Performance Assessment Modeling

    SciTech Connect (OSTI)

    Phifer, Mark A.; Smith, Frank G. III

    2013-06-21T23:59:59.000Z

    A 3-D STOMP model has been developed for the Portsmouth On-Site Waste Disposal Facility (OSWDF) at Site D as outlined in Appendix K of FBP 2013. This model projects the flow and transport of the following radionuclides to various points of assessments: Tc-99, U-234, U-235, U-236, U-238, Am-241, Np-237, Pu-238, Pu-239, Pu-240, Th-228, and Th-230. The model includes the radioactive decay of these parents, but does not include the associated daughter ingrowth because the STOMP model does not have the capability to model daughter ingrowth. The Savannah River National Laboratory (SRNL) provides herein a recommended method to account for daughter ingrowth in association with the Portsmouth OSWDF Performance Assessment (PA) modeling.

  4. Testing, Modeling, and Monitoring to Enable Simpler, Cheaper, Longer-Lived Surface Caps

    SciTech Connect (OSTI)

    Piet, Steven James; Breckenridge, Robert Paul; Burns, Douglas Edward

    2003-02-01T23:59:59.000Z

    Society has and will continue to generate hazardous wastes whose risks must be managed. For exceptionally toxic, long-lived, and feared waste, the solution is deep burial, e.g., deep geological disposal at Yucca Mtn. For some waste, recycle or destruction/treatment is possible. The alternative for other wastes is storage at or near the ground level (in someone’s back yard); most of these storage sites include a surface barrier (cap) to prevent downward water migration. Some of the hazards will persist indefinitely. As society and regulators have demanded additional proof that caps are robust against more threats and for longer time periods, the caps have become increasingly complex and expensive. As in other industries, increased complexity will eventually increase the difficulty in estimating performance, in monitoring system/component performance, and in repairing or upgrading barriers as risks are managed. An approach leading to simpler, less expensive, longer-lived, more manageable caps is needed. Our project, which started in April 2002, aims to catalyze a Barrier Improvement Cycle (iterative learning and application) and thus enable Remediation System Performance Management (doing the right maintenance neither too early nor too late). The knowledge gained and the capabilities built will help verify the adequacy of past remedial decisions, improve barrier management, and enable improved solutions for future decisions. We believe it will be possible to develop simpler, longer-lived, less expensive caps that are easier to monitor, manage, and repair. The project is planned to: a) improve the knowledge of degradation mechanisms in times shorter than service life; b) improve modeling of barrier degradation dynamics; c) develop sensor systems to identify early degradation; and d) provide a better basis for developing and testing of new barrier systems. This project combines selected exploratory studies (benchtop and field scale), coupled effects accelerated aging testing at the intermediate meso-scale, testing of new monitoring concepts, and modeling of dynamic systems. The emphasis on meso-scale (coupled) tests, accelerated effects testing, and dynamic modeling differentiates the project from other efforts, while simultaneously building on that body of knowledge. The performance of evapotranspiration, capillary, and grout-based barriers is being examined. To date, the project can report new approaches to the problem, building new experimental and modeling capabilities, and a few preliminary results.

  5. Testing, Modeling, and Monitoring to Enable Simpler, Cheaper, Longer-lived Surface Caps

    SciTech Connect (OSTI)

    Piet, S. J.; Breckenridge, R. P.; Burns, D. E.

    2003-02-25T23:59:59.000Z

    Society has and will continue to generate hazardous wastes whose risks must be managed. For exceptionally toxic, long-lived, and feared waste, the solution is deep burial, e.g., deep geological disposal at Yucca Mtn. For some waste, recycle or destruction/treatment is possible. The alternative for other wastes is storage at or near the ground level (in someone's back yard); most of these storage sites include a surface barrier (cap) to prevent downward water migration. Some of the hazards will persist indefinitely. As society and regulators have demanded additional proof that caps are robust against more threats and for longer time periods, the caps have become increasingly complex and expensive. As in other industries, increased complexity will eventually increase the difficulty in estimating performance, in monitoring system/component performance, and in repairing or upgrading barriers as risks are managed. An approach leading to simpler, less expensive, longer-lived, more manageable caps is needed. Our project, which started in April 2002, aims to catalyze a Barrier Improvement Cycle (iterative learning and application) and thus enable Remediation System Performance Management (doing the right maintenance neither too early nor too late). The knowledge gained and the capabilities built will help verify the adequacy of past remedial decisions, improve barrier management, and enable improved solutions for future decisions. We believe it will be possible to develop simpler, longer-lived, less expensive caps that are easier to monitor, manage, and repair. The project is planned to: (a) improve the knowledge of degradation mechanisms in times shorter than service life; (b) improve modeling of barrier degradation dynamics; (c) develop sensor systems to identify early degradation; and (d) provide a better basis for developing and testing of new barrier systems. This project combines selected exploratory studies (benchtop and field scale), coupled effects accelerated aging testing at the intermediate meso-scale, testing of new monitoring concepts, and modeling of dynamic systems. The emphasis on meso-scale (coupled) tests, accelerated effects testing, and dynamic modeling differentiates the project from other efforts, while simultaneously building on that body of knowledge. The performance of evapotranspiration, capillary, and grout-based barriers is being examined. To date, the project can report new approaches to the problem, building new experimental and modeling capabilities, and a few preliminary results.

  6. Model for cradle-to-gate life cycle assessment of clinker production

    SciTech Connect (OSTI)

    Michael Elias Boesch; Annette Koehler; Stefanie Hellweg [ETH Zurich, Zurich (Switzerland). Institute of Environmental Engineering

    2009-10-01T23:59:59.000Z

    A model for input- and technology-dependent cradle-to-gate life cycle assessments (LCA) was constructed to quantify emissions and resource consumption of various clinker production options. The model was compiled using data of more than 100 clinker production lines and complemented with literature data and best judgment from experts. It can be applied by the cement industry for the selection of alternative fuels and raw materials (AFR) and by authorities for decision-support regarding the permission of waste co-processing in cement kilns. In the field of sustainable construction, the model can be used to compare clinker production options. Two case studies are presented. First, co-processing of four different types of waste is analyzed at a modern precalciner kiln system. Second, clinker production is compared between five kiln systems. Results show that the use of waste (tires, prepared industrial waste, dried sewage sludge, blast furnace slag) led to reduced greenhouse gas emissions, decreased resource consumption, and mostly to reduced aggregated environmental impacts. Regarding the different kiln systems, the environmental impact generally increased with decreasing energy efficiency. 35 refs., 2 figs., 2 tabs.

  7. PERFLUOROCARBON GAS TRACER STUDIES TO SUPPORT RISK ASSESSMENT MODELING OF CRITICAL INFRASTRUCTURE SUBJECTED TO TERRORIST ATTACKS.

    SciTech Connect (OSTI)

    SULLIVAN, T.M.; HEISER, J.; WATSON, T.; ALLWINE, K.J.; FLAHERTY, J.E.

    2006-05-06T23:59:59.000Z

    Development of real-time predictive modeling to identify the dispersion and/or source(s) of airborne weapons of mass destruction including chemical, biological, radiological, and nuclear material in urban environments is needed to improve response to potential releases of these materials via either terrorist or accidental means. These models will also prove useful in defining airborne pollution dispersion in urban environments for pollution management/abatement programs. Predicting gas flow in an urban setting on a scale of less than a few kilometers is a complicated and challenging task due to the irregular flow paths that occur along streets and alleys and around buildings of different sizes and shapes, i.e., ''urban canyons''. In addition, air exchange between the outside and buildings and subway areas further complicate the situation. Transport models that are used to predict dispersion of WMD/CBRN materials or to back track the source of the release require high-density data and need defensible parameterizations of urban processes. Errors in the data or any of the parameter inputs or assumptions will lead to misidentification of the airborne spread or source release location(s). The need for these models to provide output in a real-time fashion if they are to be useful for emergency response provides another challenge. To improve the ability of New York City's (NYC's) emergency management teams and first response personnel to protect the public during releases of hazardous materials, the New York City Urban Dispersion Program (UDP) has been initiated. This is a four year research program being conducted from 2004 through 2007. This paper will discuss ground level and subway Perfluorocarbon tracer (PFT) release studies conducted in New York City. The studies released multiple tracers to study ground level and vertical transport of contaminants. This paper will discuss the results from these tests and how these results can be used for improving transport models needed for risk assessment.

  8. A global model simulation for 3-D radiative transfer impact on surface hydrology over the Sierra Nevada and Rocky Mountains

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

    Lee, W.-L.; Gu, Y.; Liou, K. N.; Leung, L. R.; Hsu, H.-H.

    2015-01-01T23:59:59.000Z

    We investigate 3-D mountain effects on solar flux distributions and their impact on surface hydrology over the western United States, specifically the Rocky Mountains and the Sierra Nevada, using the global CCSM4 (Community Climate System Model version 4; Community Atmosphere Model/Community Land Model – CAM4/CLM4) with a 0.23° × 0.31° resolution for simulations over 6 years. In a 3-D radiative transfer parameterization, we have updated surface topography data from a resolution of 1 km to 90 m to improve parameterization accuracy. In addition, we have also modified the upward-flux deviation (3-D–PP (plane-parallel)) adjustment to ensure that the energy balance atmore »the surface is conserved in global climate simulations based on 3-D radiation parameterization. We show that deviations in the net surface fluxes are not only affected by 3-D mountains but also influenced by feedbacks of cloud and snow in association with the long-term simulations. Deviations in sensible heat and surface temperature generally follow the patterns of net surface solar flux. The monthly snow water equivalent (SWE) deviations show an increase in lower elevations due to reduced snowmelt, leading to a reduction in cumulative runoff. Over higher-elevation areas, negative SWE deviations are found because of increased solar radiation available at the surface. Simulated precipitation increases for lower elevations, while it decreases for higher elevations, with a minimum in April. Liquid runoff significantly decreases at higher elevations after April due to reduced SWE and precipitation.« less

  9. Statistical Modelling of the Relationship Between Main Development Region Sea Surface Temperature and \\emph{Landfalling} Atlantic Basin Hurricane Numbers

    E-Print Network [OSTI]

    Binter, R; Khare, S; Binter, Roman; Jewson, Stephen; Khare, Shree

    2007-01-01T23:59:59.000Z

    We are building a hurricane number prediction scheme that relies, in part, on statistical modelling of the empirical relationship between Atlantic sea surface temperatures and landfalling hurricane numbers. We test out a number of simple statistical models for that relationship, using data from 1900 to 2005 and data from 1950 to 2005, and for both all hurricane numbers and intense hurricane numbers. The results are very different from the corresponding analysis for basin hurricane numbers.

  10. Repository Integration Program: RIP performance assessment and strategy evaluation model theory manual and user`s guide

    SciTech Connect (OSTI)

    NONE

    1995-11-01T23:59:59.000Z

    This report describes the theory and capabilities of RIP (Repository Integration Program). RIP is a powerful and flexible computational tool for carrying out probabilistic integrated total system performance assessments for geologic repositories. The primary purpose of RIP is to provide a management tool for guiding system design and site characterization. In addition, the performance assessment model (and the process of eliciting model input) can act as a mechanism for integrating the large amount of available information into a meaningful whole (in a sense, allowing one to keep the ``big picture`` and the ultimate aims of the project clearly in focus). Such an integration is useful both for project managers and project scientists. RIP is based on a `` top down`` approach to performance assessment that concentrates on the integration of the entire system, and utilizes relatively high-level descriptive models and parameters. The key point in the application of such a ``top down`` approach is that the simplified models and associated high-level parameters must incorporate an accurate representation of their uncertainty. RIP is designed in a very flexible manner such that details can be readily added to various components of the model without modifying the computer code. Uncertainty is also handled in a very flexible manner, and both parameter and model (process) uncertainty can be explicitly considered. Uncertainty is propagated through the integrated PA model using an enhanced Monte Carlo method. RIP must rely heavily on subjective assessment (expert opinion) for much of its input. The process of eliciting the high-level input parameters required for RIP is critical to its successful application. As a result, in order for any project to successfully apply a tool such as RIP, an enormous amount of communication and cooperation must exist between the data collectors, the process modelers, and the performance. assessment modelers.

  11. Trace Metal Bioremediation: Assessment of Model Components from Laboratory and Field Studies to Identify Critical Variables

    SciTech Connect (OSTI)

    Peter Jaffe; Herschel Rabitz

    2003-02-14T23:59:59.000Z

    The objective of this project was to gain an insight into the modeling support needed for the understanding, design, and operation of trace metal/radionuclide bioremediation. To achieve this objective, a workshop was convened to discuss the elements such a model should contain. A ''protomodel'' was developed, based on the recommendations of the workshop, and was used to perform sensitivity analysis as well as some preliminary simulations in support for bioremediation test experiments at UMTRA sites. To simulate the numerous biogeochemical processes that will occur during the bioremediation of uranium contaminated aquifers, a time-dependent one-dimensional reactive transport model has been developed. The model consists of a set of coupled, steady state mass balance equations, accounting for advection, diffusion, dispersion, and a kinetic formulation of the transformations affecting an organic substrate, electron acceptors, corresponding reduced species, and uranium. This set of equations is solved numerically, using a finite element scheme. The redox conditions of the domain are characterized by estimating the pE, based on the concentrations of the dominant terminal electron acceptor and its corresponding reduced specie. This pE and the concentrations of relevant species are passed to a modified version of MINTEQA2, which calculates the speciation and solubilities of the species of interest. Kinetics of abiotic reactions are described as being proportional to the difference between the actual and equilibrium concentration. A global uncertainty assessment, determined by Random Sampling High Dimensional Model Representation (RS-HDMR), was performed to attain a phenomenological understanding of the origins of output variability and to suggest input parameter refinements as well as to provide guidance for field experiments to improve the quality of the model predictions. Results indicated that for the usually high nitrate contents found ate many DOE sites, overall bioremediation of trace metals was highly sensitive to the formulation of the denitrification process. Simulations were performed to illustrate the effect of biostimulation on the transport and precipitation of uranium in the subsurface, at conditions equivalent to UMTRA sites. These simulations predicted that uranium would precipitate in bands that are located relatively close to the acetate injection well. The simulations also showed the importance of properly determining U(IV) oxidative dissolution rates, in order to assess the stability of precipitates once oxygenated water reenters the aquifer after bioremediation is discontinued. The objective of this project was to provide guidance to NABIR's Systems Integration Element, on the development of models to simulate the bioremediation of trace metals and radionuclides. Such models necessarily need to integrate hydrological, geochemical, and microbiological processes. In order to gain a better understanding of the key processes that such a model should contain, it was deemed desirable to convene a workshop with experts from these different fields. The goal was to obtain a preliminary consensus on the required level of detail for the formulations of these different chemical, physical, and microbiological processes. The workshop was held on December 18, 1998.

  12. Extended defense systems :I. adversary-defender modeling grammar for vulnerability analysis and threat assessment.

    SciTech Connect (OSTI)

    Merkle, Peter Benedict

    2006-03-01T23:59:59.000Z

    Vulnerability analysis and threat assessment require systematic treatments of adversary and defender characteristics. This work addresses the need for a formal grammar for the modeling and analysis of adversary and defender engagements of interest to the National Nuclear Security Administration (NNSA). Analytical methods treating both linguistic and numerical information should ensure that neither aspect has disproportionate influence on assessment outcomes. The adversary-defender modeling (ADM) grammar employs classical set theory and notation. It is designed to incorporate contributions from subject matter experts in all relevant disciplines, without bias. The Attack Scenario Space U{sub S} is the set universe of all scenarios possible under physical laws. An attack scenario is a postulated event consisting of the active engagement of at least one adversary with at least one defended target. Target Information Space I{sub S} is the universe of information about targets and defenders. Adversary and defender groups are described by their respective Character super-sets, (A){sub P} and (D){sub F}. Each super-set contains six elements: Objectives, Knowledge, Veracity, Plans, Resources, and Skills. The Objectives are the desired end-state outcomes. Knowledge is comprised of empirical and theoretical a priori knowledge and emergent knowledge (learned during an attack), while Veracity is the correspondence of Knowledge with fact or outcome. Plans are ordered activity-task sequences (tuples) with logical contingencies. Resources are the a priori and opportunistic physical assets and intangible attributes applied to the execution of associated Plans elements. Skills for both adversary and defender include the assumed general and task competencies for the associated plan set, the realized value of competence in execution or exercise, and the opponent's planning assumption of the task competence.

  13. A model for materials scientists: Water runs off the surface of a lotus leaf without a trace. Researchers

    E-Print Network [OSTI]

    on the water, not only dry but, most importantly, clean. As the water runs off, it rinses away the dirt, whichA model for materials scientists: Water runs off the surface of a lotus leaf without a trace. Researchers in Mainz use this concept to develop coatings that repel both water and oil. #12;TEXT ROLAND

  14. RAMI4PILPS: An intercomparison of formulations for the partitioning of solar radiation in land surface models

    E-Print Network [OSTI]

    Ni-Meister, Wenge

    RAMI4PILPS: An intercomparison of formulations for the partitioning of solar radiation in land for the partitioning of solar radiation in land surface models, J. Geophys. Res., 116, G02019, doi:10.1029/2010JG001511 [e.g., Zeng et al., 2000; Dai et al., 2004]. The partitioning of solar radiation between

  15. The motion of kelp blades and the surface renewal model Ivy Huang, Jeffrey Rominger, and Heidi Nepf*

    E-Print Network [OSTI]

    Nepf, Heidi M.

    The motion of kelp blades and the surface renewal model Ivy Huang, Jeffrey Rominger, and Heidi Nepf* Massachusetts Institute of Technology, Cambridge, Massachusetts Abstract We consider how the flapping of kelp kelp blades of Laminaria saccharina, Macrocystis pyrifera, and Nereocystis luetkeana under uni

  16. Journal of Materials Processing Technology 189 (2007) 192198 Modelling of surface finish and tool flank wear in turning

    E-Print Network [OSTI]

    Ozel, Tugrul

    2007-01-01T23:59:59.000Z

    flank wear in turning of AISI D2 steel with ceramic wiper inserts Tugrul ¨Ozela,, Yigit Karpata, Lu (60 HRC) using ceramic wiper (multi-radii) design inserts. Multiple linear regression models. Experimental results indicate that surface roughness Ra values as low as 0.18­0.20 m are attainable with wiper

  17. A direct method for modeling and unfolding developable surfaces and its application to the Ventura Basin (California)

    E-Print Network [OSTI]

    A direct method for modeling and unfolding developable surfaces and its application to the Ventura Mountain area in the Ventura basin). This particular structure has been already balanced by a trial. q 2005 Published by Elsevier Ltd. Keywords: Developable; Mesh; Restoration; Unfold; Ventura Basin 1

  18. Improving Surface Radiation in a Satellite-Based Physical Model (Poster)

    SciTech Connect (OSTI)

    Sengupta, M.; Habte, A.; Gotseff, P.

    2013-10-01T23:59:59.000Z

    This poster provides an overview of the solar resource assessment work needed to achieve high penetrations of concentrating solar power or photovoltaics on the grid.

  19. Zangerl, C., Eberhardt, E., Loew, S., Evans, K., Coupled hydromechanical modelling of surface subsidence in crystalline rock masses due to tunnel drainage. ISRM 2003Technology roadmap for rock mechanics, South African Institute of Mining and Metallurgy, 2

    E-Print Network [OSTI]

    , South African Institute of Mining and Metallurgy, 2003. Coupled hydromechanical modelling of surface

  20. SLUDGE BATCH 4: MODEL BASED ASSESSMENTS OF THE FEBRUARY 2007 SLUDGE PROJECTION

    SciTech Connect (OSTI)

    Peeler, D; Tommy Edwards, T; Kevin Fox, K

    2007-03-22T23:59:59.000Z

    The Savannah River National Laboratory (SRNL) has developed, and continues to enhance, its integrated capability to evaluate the impact of proposed sludge preparation plans on the Defense Waste Processing Facility's (DWPF's) operation. One of the components of this integrated capability focuses on frit development which identifies a viable frit or frits for each sludge option being contemplated for DWPF processing. A frit is considered viable if its composition allows for economic fabrication and if, when it is combined with the sludge option under consideration, the DWPF property/composition models (the models of DWPF's Product Composition Control System (PCCS)) indicate that the combination has the potential for an operating window (a waste loading (WL) interval over which the sludge/frit glass system satisfies processability and durability constraints) that would allow DWPF to meet its goals for waste loading and canister production. This report documents the results of SRNL's efforts to identify candidate frit compositions and corresponding predicted operating windows (defined in terms of WL intervals) for the February 2007 compositional projection of Sludge Batch 4 (SB4) developed by the Liquid Waste Organization (LWO). The nominal compositional projection was used to assess projected operating windows (in terms of a waste loading interval over which all predicted properties were classified as acceptable) for various frits, evaluate the applicability of the 0.6 wt% SO{sub 4}{sup =} PCCS limit to the glass systems of interest, and determine the impact (or lack thereof) to the previous SB4 variability studies. It should be mentioned that the information from this report will be coupled with assessments of melt rate to recommend a frit for SB4 processing. The results of this paper study suggest that candidate frits are available to process the nominal SB4 composition over attractive waste loadings of interest to DWPF. Specifically, two primary candidate frits for SB4 processing, Frit 510 and Frit 418, have projected operating windows that should allow for successful processing at DWPF. While Frit 418 has been utilized at DWPF, Frit 510 is a higher B{sub 2}O{sub 3} based frit which could lead to improvements in melt rate. These frits provide relatively large operating windows and demonstrate robustness to possible sludge compositional variation while avoiding potential nepheline formation issues. In addition, assessments of SO{sub 4}{sup =} solubility indicate that the 0.6 wt% SO{sub 4}{sup =} limit in PCCS is applicable for the Frit 418 and the Frit 510 based SB4 glass systems.

  1. Unified Model for Contact Angle Hysteresis on Heterogeneous and Superhydrophobic Surfaces

    E-Print Network [OSTI]

    Raj, Rishi

    Understanding the complexities associated with contact line dynamics on chemically heterogeneous and superhydrophobic surfaces is important for a wide variety of engineering problems. Despite significant efforts to capture ...

  2. EXPERIMENTAL DESIGN APPLICATIONS FOR MODELING AND ASSESSING CARBON DIOXIDE SEQUESTRATION IN SALINE AQUIFERS

    SciTech Connect (OSTI)

    Rogers, John

    2014-08-31T23:59:59.000Z

    This project was a computer modeling effort to couple reservoir simulation and ED/RSM using Sensitivity Analysis, Uncertainty Analysis, and Optimization Methods, to assess geologic, geochemical, geomechanical, and rock-fluid effects and factors on CO2 injectivity, capacity, and plume migration. The project objective was to develop proxy models to simplify the highly complex coupled geochemical and geomechanical models in the utilization and storage of CO2 in the subsurface. The goals were to investigate and prove the feasibility of the ED/RSM processes and engineering development, and bridge the gaps regarding the uncertainty and unknowns of the many geochemical and geomechanical interacting parameters in the development and operation of anthropogenic CO2 sequestration and storage sites. The bottleneck in this workflow is the high computational effort of reactive transport simulation models and large number of input variables to optimize with ED/RSM techniques. The project was not to develop the reactive transport, geomechanical, or ED/RSM software, but was to use what was commercially and/or publically available as a proof of concept to generate proxy or surrogate models. A detailed geologic and petrographic mineral assemblage and geologic structure of the doubly plunging anticline was defined using the USDOE RMOTC formations of interest data (e.g., Lower Sundance, Crow Mountain, Alcova Limestone, and Red Peak). The assemblage of 23 minerals was primarily developed from literature data and petrophysical (well log) analysis. The assemblage and structure was input into a commercial reactive transport simulator to predict the effects of CO2 injection and complex reactions with the reservoir rock. Significant impediments were encountered during the execution phase of the project. The only known commercial reactive transport simulator was incapable of simulating complex geochemistry modeled in this project. Significant effort and project funding was expended to determine the limitations of both the commercial simulator and the Lawrence Berkeley National Laboratory (LBNL) R&D simulator, TOUGHREACT available to the project. A simplified layer cake model approximating the volume of the RMOTC targeted reservoirs was defined with 1-3 minerals eventually modeled with limited success. Modeling reactive transport in porous media requires significant computational power. In this project, up to 24 processors were used to model a limited mineral set of 1-3 minerals. In addition, geomechanical aspects of injecting CO2 into closed, semi-open, and open systems in various well completion methods was simulated. Enhanced Oil Recovery (EOR) as a storage method was not modeled. A robust and stable simulation dataset or base case was developed and used to create a master dataset with embedded instructions for input to the ED/RSM software. Little success was achieved toward the objective of the project using the commercial simulator or the LBNL simulator versions available during the time of this project. Several hundred realizations were run with the commercial simulator and ED/RSM software, most having convergence problems and terminating prematurely. A proxy model for full field CO2 injection sequestration utilization and storage was not capable of being developed with software available for this project. Though the chemistry is reasonably known and understood, based on the amount of effort and huge computational time required, predicting CO2 sequestration storage capacity in geologic formations to within the program goals of ±30% proved unsuccessful.

  3. AURORA: A FORTRAN program for modeling well stirred plasma and thermal reactors with gas and surface reactions

    SciTech Connect (OSTI)

    Meeks, E.; Grcar, J.F.; Kee, R.J. [Sandia National Labs., Livermore, CA (United States). Thermal and Plasma Processes Dept.] [Sandia National Labs., Livermore, CA (United States). Thermal and Plasma Processes Dept.; Moffat, H.K. [Sandia National Labs., Albuquerque, NM (United States). Surface Processing Sciences Dept.] [Sandia National Labs., Albuquerque, NM (United States). Surface Processing Sciences Dept.

    1996-02-01T23:59:59.000Z

    The AURORA Software is a FORTRAN computer program that predicts the steady-state or time-averaged properties of a well mixed or perfectly stirred reactor for plasma or thermal chemistry systems. The software was based on the previously released software, SURFACE PSR which was written for application to thermal CVD reactor systems. AURORA allows modeling of non-thermal, plasma reactors with the determination of ion and electron concentrations and the electron temperature, in addition to the neutral radical species concentrations. Well stirred reactors are characterized by a reactor volume, residence time or mass flow rate, heat loss or gas temperature, surface area, surface temperature, the incoming temperature and mixture composition, as well as the power deposited into the plasma for non-thermal systems. The model described here accounts for finite-rate elementary chemical reactions both in the gas phase and on the surface. The governing equations are a system of nonlinear algebraic relations. The program solves these equations using a hybrid Newton/time-integration method embodied by the software package TWOPNT. The program runs in conjunction with the new CHEMKIN-III and SURFACE CHEMKIN-III packages, which handle the chemical reaction mechanisms for thermal and non-thermal systems. CHEMKIN-III allows for specification of electron-impact reactions, excitation losses, and elastic-collision losses for electrons.

  4. Assessment of CCFL model of RELAP5/MOD3 against simple vertical tubes and rod bundle tests. International Agreement Report

    SciTech Connect (OSTI)

    Cho, S.; Arne, N. [Korea Electric Power Corp., Taejon (KR). Research Center; Chung, B.D.; Kim, H.J. [Korea Inst. of Nuclear Safety, Taejon (KR)

    1993-06-01T23:59:59.000Z

    The CCFL model used in RELAP5/MOD3 version 5m5 has been assessed against simple vertical tubes and bundle tests performed at a facility of Korea Atomic Energy Research Institute. The effect of changes in tube diameter and nodalization of tube section were investigated. The roles of interfacial drags on the flooding characteristics are discussed. Differences between the calculation and the experiment are also discussed. A comparison between model assessment results and the test data showed that the calculated value lay well on the experimental flooding curve specified by user, but the pressure jump before onset of flooding was not calculated.

  5. A Markov Model for Assessing the Reliability of a Digital Feedwater Control System

    SciTech Connect (OSTI)

    Chu,T.L.; Yue, M.; Martinez-Guridi, G.; Lehner, J.

    2009-02-11T23:59:59.000Z

    A Markov approach has been selected to represent and quantify the reliability model of a digital feedwater control system (DFWCS). The system state, i.e., whether a system fails or not, is determined by the status of the components that can be characterized by component failure modes. Starting from the system state that has no component failure, possible transitions out of it are all failure modes of all components in the system. Each additional component failure mode will formulate a different system state that may or may not be a system failure state. The Markov transition diagram is developed by strictly following the sequences of component failures (i.e., failure sequences) because the different orders of the same set of failures may affect the system in completely different ways. The formulation and quantification of the Markov model, together with the proposed FMEA (Failure Modes and Effects Analysis) approach, and the development of the supporting automated FMEA tool are considered the three major elements of a generic conceptual framework under which the reliability of digital systems can be assessed.

  6. Assessing the Effects of Anthropogenic Aerosols on Pacific Storm Track Using a Multiscale Global Climate Model

    SciTech Connect (OSTI)

    Wang, Yuan; Wang, Minghuai; Zhang, Renyi; Ghan, Steven J.; Lin, Yun; Hu, Jiaxi; Pan, Bowen; Levy, Misti; Jiang, Jonathan; Molina, Mario J.

    2014-05-13T23:59:59.000Z

    Atmospheric aerosols impact weather and global general circulation by modifying cloud and precipitation processes, but the magnitude of cloud adjustment by aerosols remains poorly quantified and represents the largest uncertainty in estimated forcing of climate change. Here we assess the impacts of anthropogenic aerosols on the Pacific storm track using a multi-scale global aerosol-climate model (GCM). Simulations of two aerosol scenarios corresponding to the present day and pre-industrial conditions reveal long-range transport of anthropogenic aerosols across the north Pacific and large resulting changes in the aerosol optical depth, cloud droplet number concentration, and cloud and ice water paths. Shortwave and longwave cloud radiative forcing at the top of atmosphere are changed by - 2.5 and + 1.3 W m-2, respectively, by emission changes from pre-industrial to present day, and an increased cloud-top height indicates invigorated mid-latitude cyclones. The overall increased precipitation and poleward heat transport reflect intensification of the Pacific storm track by anthropogenic aerosols. Hence, this work provides for the first time a global perspective of the impacts of Asian pollution outflows from GCMs. Furthermore, our results suggest that the multi-scale modeling framework is essential in producing the aerosol invigoration effect of deep convective clouds on the global scale.

  7. Retrieving snow mass from GRACE terrestrial water storage change with a land surface model

    E-Print Network [OSTI]

    Yang, Zong-Liang

    by the Advanced Very High Resolution Radio- meter (AVHRR) is decreasing since middle 1980s in response to global are variations in surface albedo and surface energy budgets, sensible heat and water vapor fluxes-chan- nel Microwave Radiometer (SMMR) and the Advanced Microwave Scanning Radiometer (AMSR) provide a capa

  8. Progress In Electromagnetics Research B, Vol. 25, 293314, 2010 IMPROVED ANALYTICAL MODEL FOR SURFACE-

    E-Print Network [OSTI]

    Boyer, Edmond

    a large influence on the airgap magnetic field distribution and therefore on the motor performances (noise FOR SURFACE- MOUNTED PM MOTORS CONSIDERING SLOTTING EFFECTS AND ARMATURE REACTION T. Lubin, S. Mezani, and A of the magnetic field distribution in surface-mounted permanent-magnet (PM) motors for any pole and slot

  9. ASSESSMENT FOR THE SOUTHWEST

    E-Print Network [OSTI]

    Wong, Pak Kin

    SERVICE CLIMATE CHANGE & CULTURAL RESOURCE PLANNING PROGRAM 17 EARTH SYSTEM MODELS 18 CLIMATE ASSESSMENTS

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

    SciTech Connect (OSTI)

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

    2012-08-10T23:59:59.000Z

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

  11. Assessment of environmental correlates with the distribution of fish stocks using a spatially explicit model

    E-Print Network [OSTI]

    Robinson, Allan R.

    Assessment of environmental correlates with the distribution of fish stocks using a spatially-mail: msundermeyer@umassd.edu phone: (508) 999-8812 fax: (508) 910-6371 Running title: Assessing environmental;INTRODUCTION We present here a method for assessing the explanatory skill of environmental correlates

  12. Framework for Modeling the Uncertainty of Future Events in Life Cycle Assessment

    E-Print Network [OSTI]

    Chen, Yi-Fen; Simon, Rachel; Dornfeld, David

    2013-01-01T23:59:59.000Z

    INTRODUCTION Life Cycle Assessment (LCA) is a leadingLife Cycle Assessment by including predictable disruptions to the life cycle, thereby increasing the meaningfulness of LCALife Cycle Assessment is a very important factor to consider in order to ensure the accuracy of estimated emissions and meaningfulness of LCA

  13. TransCom model simulations of CH? and related species: linking transport, surface flux and chemical loss with CH? variability in the troposphere and lower stratosphere

    E-Print Network [OSTI]

    Patra, P. K.

    A chemistry-transport model (CTM) intercomparison experiment (TransCom-CH?) has been designed to investigate the roles of surface emissions, transport and chemical loss in simulating the global methane distribution. Model ...

  14. Albedo estimates for land surface models and support for a new paradigm based on foliage nitrogen concentration

    SciTech Connect (OSTI)

    Hollinger, D. [USDA Forest Service; Ollinger, S. V. [University of Hew Hampshire; Richardson, A. D. [University of Hew Hampshire; Martin, M. E. [University of New Hampshire; Meyers, T. P. [NOAA ATDD; Dail, D. B. [University of Maine; Scott, N. A. [Queens University, Kingston, ON, Canada; Arkebauer, T. J. [University of Nebraska, Lincoln; Baldocchi, D. D. [University of California, Berkeley; Clark, K. L. [USDA Forest Service; Curtis, Peter [Ohio State University, The, Columbus; Davis, K. J. [Pennsylvania State University; Desai, Desai Ankur R. [University of Wisconsin, Madison; Dragoni, Danilo [Indiana University; Goulden, M. L. [University of California, Irvine; Gu, Lianhong [ORNL; Katul, G. G. [Duke University; Pallardy, Stephen G. [University of Missouri; Pawu, K. T. [University of California, Davis; Schmid, H. P. [IFU, FZK IMK, Institute of Meteorology & Climate, Garmisch Partenkirchen, Germany; Stoy, P. C. [University of Edinburgh; Suyker, A. E. [University of Nebraska, Lincoln; Verma, Shashi [University of Nebraska

    2009-02-01T23:59:59.000Z

    Vegetation albedo is a critical component of the Earth s climate system, yet efforts to evaluate and improve albedo parameterizations in climate models have lagged relative to other aspects of model development. Here, we calculated growing season albedos for deciduous and evergreen forests, crops, and grasslands based on over 40 site-years of data from the AmeriFlux network and compared them with estimates presently used in the land surface formulations of a variety of climate models. Generally, the albedo estimates used in land surface models agreed well with this data compilation. However, a variety of models using fixed seasonal estimates of albedo overestimated the growing season albedo of northerly evergreen trees. In contrast, climatemodels that rely on a common two-stream albedo submodel provided accurate predictions of boreal needle-leaf evergreen albedo but overestimated grassland albedos. Inverse analysis showed that parameters of the two-stream model were highly correlated. Consistent with recent observations based on remotely sensed albedo, the AmeriFlux dataset demonstrated a tight linear relationship between canopy albedo and foliage nitrogen concentration (for forest vegetation: albedo 50.0110.071%N, r250.91; forests, grassland, and maize: albedo50.0210.067%N, r250.80). However, this relationship saturated at the higher nitrogen concentrations displayed by soybean foliage. We developed similar relationships between a foliar parameter used in the two-stream albedo model and foliage nitrogen concentration. These nitrogen-based relationships can serve as the basis for a new approach to land surface albedo modeling that simplifies albedo estimation while providing a link to other important ecosystem processes.

  15. Hepatocyte-based in vitro model for assessment of drug-induced cholestasis

    SciTech Connect (OSTI)

    Chatterjee, Sagnik, E-mail: Sagnik.Chatterjee@pharm.kuleuven.be [Drug Delivery and Disposition, KU Leuven Department of Pharmaceutical and Pharmacological Sciences, O and N2, Herestraat 49 — bus 921, 3000 Leuven (Belgium); Richert, Lysiane, E-mail: l.richert@kaly-cell.com [KaLy-Cell, 20A rue du Général Leclerc, 67115 Plobsheim (France); Augustijns, Patrick, E-mail: Patrick.Augustijns@pharm.kuleuven.be [Drug Delivery and Disposition, KU Leuven Department of Pharmaceutical and Pharmacological Sciences, O and N2, Herestraat 49 — bus 921, 3000 Leuven (Belgium); Annaert, Pieter, E-mail: Pieter.Annaert@pharm.kuleuven.be [Drug Delivery and Disposition, KU Leuven Department of Pharmaceutical and Pharmacological Sciences, O and N2, Herestraat 49 — bus 921, 3000 Leuven (Belgium)

    2014-01-01T23:59:59.000Z

    Early detection of drug-induced cholestasis remains a challenge during drug development. We have developed and validated a biorelevant sandwich-cultured hepatocytes- (SCH) based model that can identify compounds causing cholestasis by altering bile acid disposition. Human and rat SCH were exposed (24–48 h) to known cholestatic and/or hepatotoxic compounds, in the presence or in the absence of a concentrated mixture of bile acids (BAs). Urea assay was used to assess (compromised) hepatocyte functionality at the end of the incubations. The cholestatic potential of the compounds was expressed by calculating a drug-induced cholestasis index (DICI), reflecting the relative residual urea formation by hepatocytes co-incubated with BAs and test compound as compared to hepatocytes treated with test compound alone. Compounds with clinical reports of cholestasis, including cyclosporin A, troglitazone, chlorpromazine, bosentan, ticlopidine, ritonavir, and midecamycin showed enhanced toxicity in the presence of BAs (DICI ? 0.8) for at least one of the tested concentrations. In contrast, the in vitro toxicity of compounds causing hepatotoxicity by other mechanisms (including diclofenac, valproic acid, amiodarone and acetaminophen), remained unchanged in the presence of BAs. A safety margin (SM) for drug-induced cholestasis was calculated as the ratio of lowest in vitro concentration for which was DICI ? 0.8, to the reported mean peak therapeutic plasma concentration. SM values obtained in human SCH correlated well with reported % incidence of clinical drug-induced cholestasis, while no correlation was observed in rat SCH. This in vitro model enables early identification of drug candidates causing cholestasis by disturbed BA handling. - Highlights: • Novel in vitro assay to detect drug-induced cholestasis • Rat and human sandwich-cultured hepatocytes (SCH) as in vitro models • Cholestatic compounds sensitize SCH to toxic effects of accumulating bile acids • Drug-induced cholestasis index (DICI) as measure of a drug's cholestatic signature • In vitro findings correlate well with clinical reports on cholestasis.

  16. Carbon sequestration by patch fertilization: A comprehensive assessment using coupled physical-ecological-biogeochemical models

    SciTech Connect (OSTI)

    Jorge L. Sarmiento - Princeton PI, Anand Gnanadesikan - Princeton Co-I, Nicolas Gruber - UCLA PI, Xin Jin - UCLA PostDoc, Robert Armstrong - SUNY /Stony Brook Consultant

    2007-06-21T23:59:59.000Z

    This final report summarizes research undertaken collaboratively between Princeton University, the NOAA Geophysical Fluid Dynamics Laboratory on the Princeton University campus, the State University of New York at Stony Brook, and the University of California, Los Angeles between September 1, 2000, and November 30, 2006, to do fundamental research on ocean iron fertilization as a means to enhance the net oceanic uptake of CO2 from the atmosphere. The approach we proposed was to develop and apply a suite of coupled physical-ecological-biogeochemical models in order to (i) determine to what extent enhanced carbon fixation from iron fertilization will lead to an increase in the oceanic uptake of atmospheric CO2 and how long this carbon will remain sequestered (efficiency), and (ii) examine the changes in ocean ecology and natural biogeochemical cycles resulting from iron fertilization (consequences). The award was funded in two separate three-year installments: • September 1, 2000 to November 30, 2003, for a project entitled “Ocean carbon sequestration by fertilization: An integrated biogeochemical assessment.” A final report was submitted for this at the end of 2003 and is included here as Appendix 1. • December 1, 2003 to November 30, 2006, for a follow-on project under the same grant number entitled “Carbon sequestration by patch fertilization: A comprehensive assessment using coupled physical-ecological-biogeochemical models.” This report focuses primarily on the progress we made during the second period of funding subsequent to the work reported on in Appendix 1. When we began this project, we were thinking almost exclusively in terms of long-term fertilization over large regions of the ocean such as the Southern Ocean, with much of our focus being on how ocean circulation and biogeochemical cycling would interact to control the response to a given fertilization scenario. Our research on these types of scenarios, which was carried out largely during the first three years of our project, led to several major new insights on the interaction between ocean biogeochemistry and circulation. This work, which is described in the following Section II on “Large scale fertilization,” has continued to appear in the literature over the past few years, including two high visibility papers in Nature. Early on in the first three years of our project, it became clear that small "patch-scale" fertilizations over limited regions of order 100 km diameter were much more likely than large scale fertilization, and we carried out a series of idealized patch fertilization simulations reported on in Gnanadesikan et al. (2003). Based on this paper and other results we had obtained by the end of our first three-year grant, we identified a number of important issues that needed to be addressed in the second three-year period of this grant. Section III on “patch fertilization” discusses the major findings of this phase of our research, which is described in two major manuscripts that will be submitted for publication in the near future. This research makes use of new more realistic ocean ecosystem and iron cycling models than our first paper on this topic. We have several major new insights into what controls the efficiency of iron fertilization in the ocean. Section IV on “model development” summarizes a set of papers describing the progress that we made on improving the ecosystem models we use for our iron fertilization simulations.

  17. High-Resolution Modeling to Assess Tropical Cyclone Activity in Future Climate Regimes

    SciTech Connect (OSTI)

    Lackmann, Gary

    2013-06-10T23:59:59.000Z

    Applied research is proposed with the following objectives: (i) to determine the most likely level of tropical cyclone intensity and frequency in future climate regimes, (ii) to provide a quantitative measure of uncertainty in these predictions, and (iii) to improve understanding of the linkage between tropical cyclones and the planetary-scale circulation. Current mesoscale weather forecasting models, such as the Weather Research and Forecasting (WRF) model, are capable of simulating the full intensity of tropical cyclones (TC) with realistic structures. However, in order to accurately represent both the primary and secondary circulations in these systems, model simulations must be configured with sufficient resolution to explicitly represent convection (omitting the convective parameterization scheme). Most previous numerical studies of TC activity at seasonal and longer time scales have not utilized such explicit convection (EC) model runs. Here, we propose to employ the moving nest capability of WRF to optimally represent TC activity on a seasonal scale using a downscaling approach. The statistical results of a suite of these high-resolution TC simulations will yield a realistic representation of TC intensity on a seasonal basis, while at the same time allowing analysis of the feedback that TCs exert on the larger-scale climate system. Experiments will be driven with analyzed lateral boundary conditions for several recent Atlantic seasons, spanning a range of activity levels and TC track patterns. Results of the ensemble of WRF simulations will then be compared to analyzed TC data in order to determine the extent to which this modeling setup can reproduce recent levels of TC activity. Next, the boundary conditions (sea-surface temperature, tropopause height, and thermal/moisture profiles) from the recent seasons will be altered in a manner consistent with various future GCM/RCM scenarios, but that preserves the large-scale shear and incipient disturbance activity. This will allow (i) a direct comparison of future TC activity that could be expected for an active or inactive season in an altered climate regime, and (ii) a measure of the level of uncertainty and variability in TC activity resulting from different carbon emission scenarios.

  18. Calibration of an EnergyPlus Building Energy Model to Assess the Impact of Demand Response Measures

    E-Print Network [OSTI]

    Lavigne, K.; Sansregret, S.; Daoud, A.; Leclair, L. A.

    2013-01-01T23:59:59.000Z

    1 Karine Lavigne Simon Sansregret Ahmed DaoudLouis-Alexandre Leclaire CALIBRATION OF AN ENERGYPLUS BUILDING ENERGY MODEL TO ASSESS THE IMPACT OF DEMAND RESPONSE MEASURES ICEBO 2013, Montr?al Groupe ? Technologie2 ICEBO-2013 Contextualization... ICEBO-2013 Groupe ? Technologie Calibrated Results 22 ICEBO-2013 12 Groupe ? Technologie Conclusion 23 ICEBO-2013 > Calibrating model for a demand response objective : Challenging and High Effort > Capturing building and human erratic behaviour...

  19. Experiences with the Application of the Non-Hydrostatic Mesoscale Model GESIMA for assessing Wind Potential in

    E-Print Network [OSTI]

    Heinemann, Detlev

    the wind energy potential are re- quired. While the European Wind Atlas [3] has been proven to be suitableExperiences with the Application of the Non-Hydrostatic Mesoscale Model GESIMA for assessing Wind.physik.uni-oldenburg.de/ehf *GKSS Research Center Geesthacht, Max-Planck-StraÃ?e 1, D-21494 Geesthacht, Germany To asses wind

  20. Post-Mining 2005, November 16-17, Nancy, France 1 MODELING AND ASSESSMENT FOR SUBSIDENCE HAZARD IN INCLINED IRON

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Post-Mining 2005, November 16-17, Nancy, France 1 MODELING AND ASSESSMENT FOR SUBSIDENCE HAZARD IN INCLINED IRON MINING. RENAUD Vincent1 , TRITSCH Jean-Jacques2 , FRANCK Christian3 1 INERIS LAEGO - Ecole Nationale Supérieure des Mines de Nancy, Parc de Saurupt ­ F 54042 Nancy Cedex, France. vincent

  1. Performance Assessment Transport Modeling of Uranium at the Area 5 Radioactive Waste Management Site at the Nevada National Security Site

    SciTech Connect (OSTI)

    NSTec Radioactive Waste

    2010-10-12T23:59:59.000Z

    Following is a brief summary of the assumptions that are pertinent to the radioactive isotope transport in the GoldSim Performance Assessment model of the Area 5 Radioactive Waste Management Site, with special emphasis on the water-phase reactive transport of uranium, which includes depleted uranium products.

  2. A Multi-State Model for the Reliability Assessment of a Distributed Generation System via Universal Generating Function

    E-Print Network [OSTI]

    Boyer, Edmond

    , Milan, Italy, Dipartimento di Energia Enrico.zio@polimi.it Abstract The current and future developments renewable technology (e.g. wind or solar, etc.) whose behavior is described by a binary state, working assessment, multi-state modeling, universal generating function #12;2 Notations Solar irradiance Total number

  3. THE STABILITY OF LOW SURFACE BRIGHTNESS DISKS BASED ON MULTI-WAVELENGTH MODELING

    E-Print Network [OSTI]

    MacLachlan, J. M.

    To investigate the structure and composition of the dusty interstellar medium (ISM) of low surface brightness (LSB) disk galaxies, we have used multi-wavelength photometry to construct spectral energy distributions for ...

  4. Surface Myoelectric Signal Classification Using the AR-GARCH Model Ghulam Rasoolb,

    E-Print Network [OSTI]

    Bouaynaya, Nidhal

    signals. In the pattern classification paradigm for controlling myoelectric prosthesis, the autoregressive, it is normally assumed that the necessary control information can be extracted from the surface myoelectric, myoelectric control. 1. Introduction The pattern classification for myoelectric control is based

  5. Modeling of three-dimensional viscoelastic flows with free surfaces using a finite element method

    E-Print Network [OSTI]

    Adrian, David Joseph

    2010-01-01T23:59:59.000Z

    A framework and code have been developed to simulate fiber and film processes; the code can handle three-dimensional, isothermal, incompressible, creeping flow of a Giesekus fluid with free surfaces at infinite capillary ...

  6. Assessment of the Value, Impact, and Validity of the Jobs and Economic Development Impacts (JEDI) Suite of Models

    SciTech Connect (OSTI)

    Billman, L.; Keyser, D.

    2013-08-01T23:59:59.000Z

    The Jobs and Economic Development Impacts (JEDI) models, developed by the National Renewable Energy Laboratory (NREL) for the U.S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy (EERE), use input-output methodology to estimate gross (not net) jobs and economic impacts of building and operating selected types of renewable electricity generation and fuel plants. This analysis provides the DOE with an assessment of the value, impact, and validity of the JEDI suite of models. While the models produce estimates of jobs, earnings, and economic output, this analysis focuses only on jobs estimates. This validation report includes an introduction to JEDI models, an analysis of the value and impact of the JEDI models, and an analysis of the validity of job estimates generated by JEDI model through comparison to other modeled estimates and comparison to empirical, observed jobs data as reported or estimated for a commercial project, a state, or a region.

  7. 6D F-theory models and elliptically fibered Calabi-Yau threefolds over semi-toric base surfaces

    E-Print Network [OSTI]

    Gabriella Martini; Washington Taylor

    2015-04-20T23:59:59.000Z

    We carry out a systematic study of a class of 6D F-theory models and associated Calabi-Yau threefolds that are constructed using base surfaces with a generalization of toric structure. In particular, we determine all smooth surfaces with a structure invariant under a single C^* action (sometimes called "T-varieties" in the mathematical literature) that can act as bases for an elliptic fibration with section of a Calabi-Yau threefold. We identify 162,404 distinct bases, which include as a subset the previously studied set of strictly toric bases. Calabi-Yau threefolds constructed in this fashion include examples with previously unknown Hodge numbers. There are also bases over which the generic elliptic fibration has a Mordell-Weil group of sections with nonzero rank, corresponding to non-Higgsable U(1) factors in the 6D supergravity model; this type of structure does not arise for generic elliptic fibrations in the purely toric context.

  8. Computer models to support investigations of surface subsidence and associated ground motion induced by underground coal gasification. [STEALTH Codes

    SciTech Connect (OSTI)

    Langland, R.T.; Trent, B.C.

    1981-01-01T23:59:59.000Z

    Two computer codes compare surface subsidence induced by underground coal gasification at Hoe Creek, Wyoming, and Centralia, Washington. Calculations with the STEALTH explicit finite-difference code are shown to match equivalent, implicit finite-element method solutions for the removal of underground material. Effects of removing roof material, varying elastic constants, investigating thermal shrinkage, and burning multiple coal seams are studied. A coupled, finite-difference continuum rigid-block caving code is used to model underground opening behavior. Numerical techniques agree qualitatively with empirical studies but, so far, underpredict ground surface displacement. The two methods, numerical and empirical, are most effective when used together. It is recommended that the thermal characteristics of coal measure rock be investigated and that additional calculations be carried out to longer times so that cooling influences can be modeled.

  9. Computer models to support investigations of surface subsidence and associated ground motion induced by underground coal gasification

    SciTech Connect (OSTI)

    Trent, B.C.; Langland, R.T.

    1981-08-01T23:59:59.000Z

    Two computer codes compare surface subsidence induced by underground coal gasification at Hoe Creek, Wyoming, and Centralia, Washington. Calculations with the STEALTH explicit finite-difference code are shown to match equivalent, implicit finite-element method solutions for the removal of underground material. Effects of removing roof material, varying elastic constants, investigating thermal shrinkage, and burning multiple coal seams are studied. A coupled, finite-difference continuum rigid-block caving code is used to model underground opening behavior. Numerical techniques agree qualitatively with empirical studies but, so far, underpredict ground surface displacement. The two methods, numerical and empirical, are most effective when used together. It is recommended that the thermal characteristics of coal measure rock be investigated and that additional calculations be carried out to longer times so that cooling influences can be modeled.

  10. Modeling and comparative assessment of municipal solid waste gasification for energy production

    SciTech Connect (OSTI)

    Arafat, Hassan A., E-mail: harafat@masdar.ac.ae; Jijakli, Kenan

    2013-08-15T23:59:59.000Z

    Highlights: • Study developed a methodology for the evaluation of gasification for MSW treatment. • Study was conducted comparatively for USA, UAE, and Thailand. • Study applies a thermodynamic model (Gibbs free energy minimization) using the Gasify software. • The energy efficiency of the process and the compatibility with different waste streams was studied. - Abstract: Gasification is the thermochemical conversion of organic feedstocks mainly into combustible syngas (CO and H{sub 2}) along with other constituents. It has been widely used to convert coal into gaseous energy carriers but only has been recently looked at as a process for producing energy from biomass. This study explores the potential of gasification for energy production and treatment of municipal solid waste (MSW). It relies on adapting the theory governing the chemistry and kinetics of the gasification process to the use of MSW as a feedstock to the process. It also relies on an equilibrium kinetics and thermodynamics solver tool (Gasify®) in the process of modeling gasification of MSW. The effect of process temperature variation on gasifying MSW was explored and the results were compared to incineration as an alternative to gasification of MSW. Also, the assessment was performed comparatively for gasification of MSW in the United Arab Emirates, USA, and Thailand, presenting a spectrum of socioeconomic settings with varying MSW compositions in order to explore the effect of MSW composition variance on the products of gasification. All in all, this study provides an insight into the potential of gasification for the treatment of MSW and as a waste to energy alternative to incineration.

  11. Risk and Vulnerability Assessment Using Cybernomic Computational Models: Tailored for Industrial Control Systems

    SciTech Connect (OSTI)

    Abercrombie, Robert K [ORNL; Sheldon, Federick T. [University of Memphis; Schlicher, Bob G [ORNL

    2015-01-01T23:59:59.000Z

    There are many influencing economic factors to weigh from the defender-practitioner stakeholder point-of-view that involve cost combined with development/deployment models. Some examples include the cost of countermeasures themselves, the cost of training and the cost of maintenance. Meanwhile, we must better anticipate the total cost from a compromise. The return on investment in countermeasures is essentially impact costs (i.e., the costs from violating availability, integrity and confidentiality / privacy requirements). The natural question arises about choosing the main risks that must be mitigated/controlled and monitored in deciding where to focus security investments. To answer this question, we have investigated the cost/benefits to the attacker/defender to better estimate risk exposure. In doing so, it s important to develop a sound basis for estimating the factors that derive risk exposure, such as likelihood that a threat will emerge and whether it will be thwarted. This impact assessment framework can provide key information for ranking cybersecurity threats and managing risk.

  12. Research utilization in the building industry: decision model and preliminary assessment

    SciTech Connect (OSTI)

    Watts, R.L.; Johnson, D.R.; Smith, S.A.; Westergard, E.J.

    1985-10-01T23:59:59.000Z

    The Research Utilization Program was conceived as a far-reaching means for managing the interactions of the private sector and the federal research sector as they deal with energy conservation in buildings. The program emphasizes a private-public partnership in planning a research agenda and in applying the results of ongoing and completed research. The results of this task support the hypothesis that the transfer of R and D results to the buildings industry can be accomplished more efficiently and quickly by a systematic approach to technology transfer. This systematic approach involves targeting decision makers, assessing research and information needs, properly formating information, and then transmitting the information through trusted channels. The purpose of this report is to introduce elements of a market-oriented knowledge base, which would be useful to the Building Systems Division, the Office of Buildings and Community Systems and their associated laboratories in managing a private-public research partnership on a rational systematic basis. This report presents conceptual models and data bases that can be used in formulating a technology transfer strategy and in planning technology transfer programs.

  13. Model Components of the Certification Framework for Geologic Carbon Sequestration Risk Assessment

    E-Print Network [OSTI]

    Oldenburg, Curtis M.

    2009-01-01T23:59:59.000Z

    to two geologic carbon sequestration sites, Energy Procedia,for Geologic Carbon Sequestration Based on Effectivefor geologic carbon sequestration risk assessment, Energy

  14. Language Assessment as a System: Best Practices, Stakeholders, Models, and Testimonials

    E-Print Network [OSTI]

    Avineri, Netta; Londe, Zsuzsa; Hardacre, Bahiyyih; Carris, Lauren; So, Youngsoon; Majidpour, Mostafa

    2010-01-01T23:59:59.000Z

    language assessment. Mostafa Majidpour is a second-year PhDcoordinator), and Mostafa Majidpour (current UCLA electricalYoungsoon So and Mostafa Majidpour). When one considers the

  15. Framework for Modeling the Uncertainty of Future Events in Life Cycle Assessment

    E-Print Network [OSTI]

    Chen, Yi-Fen; Simon, Rachel; Dornfeld, David

    2013-01-01T23:59:59.000Z

    M. , ( 2010), Product carbon footprint (PCF) assessment ofand Pflueger J. , (2012), Carbon footprint of a dell rackin 65% of the product carbon footprint of a laptop used in

  16. NUMERICAL MODELING FOR THE FORMATION MECHANISM OF 3D TOPOGRAPHY ON MICROBIAL MAT SURFACES 

    E-Print Network [OSTI]

    Patel, Harsh Jay

    2013-09-27T23:59:59.000Z

    determined. A deterministic model includes both a dynamic model, and a static model. Compared to a deterministic solute diffusion model, a stochastic diffusion model has one or more stochastic elements. Concentration diffusion system formulated... solute diffusion equation, which merely appears in the form of a number line, the quasi-2D solute diffusion equation forms a Cartesian grid system. Also, for the explicit quasi-2D solute diffusion equation (Eq. 4), concentration variation is measured...

  17. An integral-balance nonlinear model to simulate changes in soil moisture, groundwater and surface runoff dynamics at the hillslope scale

    E-Print Network [OSTI]

    Jay, Laurent O.

    An integral-balance nonlinear model to simulate changes in soil moisture, groundwater and surface-state integral-balance model for soil moisture and groundwater dynamics. Development of the model was motivated. Ã? 2014 Elsevier Ltd. All rights reserved. 1. Introduction Recent studies on the modeling

  18. Bottom-up Representation of Industrial Energy Efficiency Technologies in Integrated Assessment Models for the Cement Sector

    SciTech Connect (OSTI)

    Sathaye, J.; Xu, T.; Galitsky, C.

    2010-08-15T23:59:59.000Z

    Adoption of efficient end-use technologies is one of the key measures for reducing greenhouse gas (GHG) emissions. How to effectively analyze and manage the costs associated with GHG reductions becomes extremely important for the industry and policy makers around the world. Energy-climate (EC) models are often used for analyzing the costs of reducing GHG emissions for various emission-reduction measures, because an accurate estimation of these costs is critical for identifying and choosing optimal emission reduction measures, and for developing related policy options to accelerate market adoption and technology implementation. However, accuracies of assessing of GHG-emission reduction costs by taking into account the adoption of energy efficiency technologies will depend on how well these end-use technologies are represented in integrated assessment models (IAM) and other energy-climate models.

  19. Atomic imaging and modeling of H2O2(g) surface passivation, functionalization, and atomic layer deposition nucleation on the Ge(100) surface

    E-Print Network [OSTI]

    Kummel, Andrew C.

    deposition nucleation on the Ge(100) surface Tobin Kaufman-Osborn, Evgueni A. Chagarov, and Andrew C. Kummel-ray photoemission study of the thermal stability of the Al2O3/Ge (100) interface as a function of surface.1116/1.3678206 Atomic imaging of nucleation of trimethylaluminum on clean and H2O functionalized Ge(100) surfaces J

  20. Coupling GIS and LCA for biodiversity assessments of land use: Part 1: Inventory modeling

    E-Print Network [OSTI]

    Geyer, Roland; Stoms, David M.; Lindner, Jan P.; Davis, Frank W.; Wittstock, Bastian

    2010-01-01T23:59:59.000Z

    of land use Part 1: Inventory modeling Roland Geyer & Davidthe use of GIS-based inventory modeling to generatedemonstrated that GIS-based inventory modeling of land use

  1. Nuclear-deformation energies according to a liquid-drop model with a sharp surface

    SciTech Connect (OSTI)

    Blocki, J.; Swiatecki, W.J.

    1982-05-01T23:59:59.000Z

    We present an atlas of 665 deformation-energy maps and 150 maps of other properties of interest, relevant for nuclear systems idealized as uniformly charged drops endowed with a surface tension. The nuclear shapes are parametrized in terms of two spheres modified by a smoothly fitted quadratic surface of revolution and are specified by three variables: asymmetry, sphere separation, and a neck variable (that goes over into a fragment-deformation variable after scission). The maps and related tables should be useful for the study of macroscopic aspects of nuclear fission and of collisions between any two nuclei in the periodic table.

  2. Assessing the prospective environmental impacts of photovoltaic systems based on a simplified LCA model

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Assessing the prospective environmental impacts of photovoltaic systems based on a simplified LCA the environmental impacts of PV systems are small during their operating phase, they are more significant during the use of LCA to assess the environmental impacts of one electricity-production technology. To address

  3. Home composting as an alternative treatment option for organic household waste in Denmark: An environmental assessment using life cycle assessment-modelling

    SciTech Connect (OSTI)

    Andersen, J.K.; Boldrin, A.; Christensen, T.H. [Department of Environmental Engineering, Technical University of Denmark, DK-2800 Kongens Lyngby (Denmark); Scheutz, C., E-mail: chas@env.dtu.dk [Department of Environmental Engineering, Technical University of Denmark, DK-2800 Kongens Lyngby (Denmark)

    2012-01-15T23:59:59.000Z

    An environmental assessment of the management of organic household waste (OHW) was performed from a life cycle perspective by means of the waste-life cycle assessment (LCA) model EASEWASTE. The focus was on home composting of OHW in Denmark and six different home composting units (with different input and different mixing frequencies) were modelled. In addition, incineration and landfilling was modelled as alternatives to home composting. The most important processes contributing to the environmental impact of home composting were identified as greenhouse gas (GHG) emissions (load) and the avoided emissions in relation to the substitution of fertiliser and peat when compost was used in hobby gardening (saving). The replacement of fertiliser and peat was also identified as one of the most sensible parameters, which could potentially have a significant environmental benefit. Many of the impact categories (especially human toxicity via water (HTw) and soil (HTs)) were affected by the heavy metal contents of the incoming OHW. The concentrations of heavy metals in the compost were below the threshold values for compost used on land and were thus not considered to constitute a problem. The GHG emissions were, on the other hand, dependent on the management of the composting units. The frequently mixed composting units had the highest GHG emissions. The environmental profiles of the home composting scenarios were in the order of -2 to 16 milli person equivalents (mPE) Mg{sup -1} wet waste (ww) for the non-toxic categories and -0.9 to 28 mPE Mg{sup -1} ww for the toxic categories. Home composting performed better than or as good as incineration and landfilling in several of the potential impact categories. One exception was the global warming (GW) category, in which incineration performed better due to the substitution of heat and electricity based on fossil fuels.

  4. Assessment of Uncertainties in the Response of the African Monsoon Precipitation to Land Use change simulated by a regional model

    SciTech Connect (OSTI)

    Hagos, Samson M.; Leung, Lai-Yung R.; Xue, Yongkang; Boone, Aaron; de Sales, Fernando; Neupane, Naresh; Huang, Maoyi; Yoon, Jin-Ho

    2014-02-22T23:59:59.000Z

    Land use and land cover over Africa have changed substantially over the last sixty years and this change has been proposed to affect monsoon circulation and precipitation. This study examines the uncertainties on the effect of these changes on the African Monsoon system and Sahel precipitation using an ensemble of regional model simulations with different combinations of land surface and cumulus parameterization schemes. Although the magnitude of the response covers a broad range of values, most of the simulations show a decline in Sahel precipitation due to the expansion of pasture and croplands at the expense of trees and shrubs and an increase in surface air temperature.

  5. Unified formal reduction for fluid models of free-surface shallow gravity-flows

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    modelling of the rheology in e.g. mud flows and land- slides, which are still much investigated model provided the assumptions used for the derivation hold. We obtain a synthetic viewpoint of various

  6. Modeling the topography of the salar de Uyuni, Bolivia as an equipotential surface of Earth’s gravity field

    E-Print Network [OSTI]

    Borsa, Adrian

    2008-01-01T23:59:59.000Z

    study on the sea surface topography, Geophysical Journalequipotential surface estimated above with topography fromBills (2004), Topography of the flattest surface on Earth:

  7. Science Highlight December 2010 Electrochemical Surface Science: Hard X-rays Probe Fuel Cell Model Catalyst

    E-Print Network [OSTI]

    Wechsler, Risa H.

    Science Highlight ­ December 2010 Electrochemical Surface Science: Hard X-rays Probe Fuel Cell. Proton exchange membrane fuel cells (PEMFCs) are promising power sources since they can generate distribution network. Large-scale deployment of fuel cells, however, has been hampered by cost and performance

  8. LOCAL UNIFIED MODELS OF BACKSCATTERING FROM OCEAN-LIKE SURFACES AT MODERATE INCIDENCE ANGLES

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    expanded up to the order two, like the SSA2 and LCA2. Electromagnetic scattering by rough surfaces, Random of the scattering matrix as SSA2, like the LCA2, were published by Elfouhaily et al. [10, 11]. It is well known is presented and tested for microwave frequencies and different wind speeds. The paper is organized as follows

  9. Modeling of impact dynamics of tennis ball with a flat surface

    E-Print Network [OSTI]

    Jafri, Syed M.

    2005-08-29T23:59:59.000Z

    contact forces using the piezo disks. They show the inelasticity of the vertical incident collisions for the cases of collisions of steel ball bearings and plumber?s putty balls with pads made of different surfaces. They derived the relationship between...

  10. Annals of Glaciology 52(59) 2011 99 Modeling surface-roughness/solar-ablation feedback

    E-Print Network [OSTI]

    Abbot, Dorian Schuyler

    of Atmospheric, Oceanic and Space Sciences, University of Michigan, 2455 Hayward Street, Ann Arbor, MI 48109 to small-scale surface channels and crevasses of the Greenland ice sheet L. Maclagan CATHLES,1 Dorian S. ABBOT,1 Jeremy N. BASSIS,2 Douglas R. MacAYEAL1 1 Department of Geophysical Sciences, University

  11. Metabolic modeling for the deposition of transuranic nuclides on bone surfaces

    E-Print Network [OSTI]

    Halter, Donald Anthony

    1997-01-01T23:59:59.000Z

    to recalculate integrated activity over fifty years, U, values, as a function of intake for use in dose calculations for plutonium deposit on bone surfaces. These values were compared with those in ICRP-30 and showed a substantial decrease in the estimated dose...

  12. Mockup Builder: Direct 3D Modeling On and Above the Surface in a Continuous Interaction Space

    E-Print Network [OSTI]

    Casiez, Géry

    and manipulate three-dimensional shapes. Another important ob- stacle, lies in that powerful modeling systems popularity of Virtual Environments, they have yet to replace desktop CAD systems when it comes to modeling 3D with models through widgets to control their parameters. However, new and affordable technologies

  13. A validation of heat and carbon fluxes from highresolution land surface and regional models

    E-Print Network [OSTI]

    D'Andrea, Fabio

    ) or regional climate models (RCMs) [Alessandri et al., 2007; Steiner et al., 2009]. [3., 2006; Alessandri et al., 2007; Jarlan et al., 2008; Steiner et al., 2009]. However, the SVAT models models do not account for the role of terrestrial vegetation in the carbon cycle variability [Alessandri

  14. Developing an Integrated Model Framework for the Assessment of Sustainable Agricultural Residue Removal Limits for Bioenergy Systems

    SciTech Connect (OSTI)

    David Muth, Jr.; Jared Abodeely; Richard Nelson; Douglas McCorkle; Joshua Koch; Kenneth Bryden

    2011-08-01T23:59:59.000Z

    Agricultural residues have significant potential as a feedstock for bioenergy production, but removing these residues can have negative impacts on soil health. Models and datasets that can support decisions about sustainable agricultural residue removal are available; however, no tools currently exist capable of simultaneously addressing all environmental factors that can limit availability of residue. The VE-Suite model integration framework has been used to couple a set of environmental process models to support agricultural residue removal decisions. The RUSLE2, WEPS, and Soil Conditioning Index models have been integrated. A disparate set of databases providing the soils, climate, and management practice data required to run these models have also been integrated. The integrated system has been demonstrated for two example cases. First, an assessment using high spatial fidelity crop yield data has been run for a single farm. This analysis shows the significant variance in sustainably accessible residue across a single farm and crop year. A second example is an aggregate assessment of agricultural residues available in the state of Iowa. This implementation of the integrated systems model demonstrates the capability to run a vast range of scenarios required to represent a large geographic region.

  15. Modifying the Soil and Water Assessment Tool to Simulate Cropland Carbon Flux: Model Development and Initial Evaluation

    SciTech Connect (OSTI)

    Zhang, Xuesong; Izaurralde, Roberto C.; Arnold, Jeffrey; Williams, Jimmy R.; Srinivasan, Raghavan

    2013-10-01T23:59:59.000Z

    Climate change is one of the most compelling modern issues and has important implications for almost every aspect of natural and human systems. The Soil and Water Assessment Tool (SWAT) model has been applied worldwide to support sustainable land and water management in a changing climate. However, the inadequacies of the existing carbon algorithm in SWAT limit its application in assessing impacts of human activities on CO2 emission, one important source of greenhouse gases (GHGs) that traps heat in the earth system and results in global warming. In this research, we incorporate a revised version of the CENTURY carbon model into SWAT to describe dynamics of soil organic matter (SOM)- residue and simulate land-atmosphere carbon exchange.

  16. Assessment and preliminary model development of shape memory polymers mechanical counter pressure space suits

    E-Print Network [OSTI]

    Wee, Brian (Brian J.)

    2013-01-01T23:59:59.000Z

    This thesis seeks to assess the viability of a space qualified shape memory polymer (SMP) mechanical counter pressure (MCP) suit. A key development objective identified by the International Space Exploration Coordination ...

  17. Development and assessment of a soot emissions model for aircraft gas turbine engines

    E-Print Network [OSTI]

    Martini, Bastien

    2008-01-01T23:59:59.000Z

    Assessing candidate policies designed to address the impact of aviation on the environment requires a simplified method to estimate pollutant emissions for current and future aircraft gas turbine engines under different ...

  18. Modeling mining economics and materials markets to inform criticality assessment and mitigation

    E-Print Network [OSTI]

    Poulizac, Claire Marie Franc?oise

    2013-01-01T23:59:59.000Z

    Conventional criticality-assessment methods drawn from the existing literature are often limited to evaluations of scarcity risks, or rely on price as an indicator of criticality. Such approaches, however, are ill-suited ...

  19. "Catalyzing Action Towards Sustainability of Deltaic Systems with an Integrated Modeling Framework for Risk Assessment"

    E-Print Network [OSTI]

    Foufoula-Georgiou, Efi

    -ecological systems undergoing change (Delta-SRES) 2. Develop and deliver a science-based delta sustainability framework for risk assessment and decision support (Delta-RADS) 3. Build an international repository of data

  20. Revisions to US EPA Superfund Risk and Dose Assessment Models and Guidance - 13403

    SciTech Connect (OSTI)

    Walker, Stuart A. [U.S. Environmental Protection Agency, Washington, DC. 20460 (United States)] [U.S. Environmental Protection Agency, Washington, DC. 20460 (United States)

    2013-07-01T23:59:59.000Z

    The U.S. Environmental Protection Agency (EPA) Superfund program's six Preliminary Remediation Goal (PRG) and Dose Compliance Concentration (DCC) internet based calculators for risk and dose assessment at Superfund sites are being revised to reflect better science, revisions to existing exposure scenarios and new scenarios, and changes to match up more closely with the EPA chemical regional screening level calculator. A revised version of the 1999 guidance document that provides an overview for the Superfund risk assessment process at radioactively contaminated sites, 'Radiation Risk Assessment At CERCLA Sites: Q and A', is being completed that will reflect Superfund recommended guidance and other technical documents issued over the past 13 years. EPA is also issuing a series of fact sheets in the document 'Superfund Radiation Risk Assessment: A Community Tool-kit'. This presentation would go over those changes that are expected to be finished by this spring. (authors)

  1. Modeling and control of thin film surface morphology: application to thin film solar cells

    E-Print Network [OSTI]

    Huang, Jianqiao

    2012-01-01T23:59:59.000Z

    rate profile. Chemical Engineering Science, 67:101–110,Feedback Control. Chemical Engineering Science, submitted.Monte-Carlo Model. Chemical Engineering Science, 66, 5955-

  2. Development of a Future Representative Concentration Pathway for Use in the IPCC 5th Assessment Earth System Model Simulations

    SciTech Connect (OSTI)

    None

    2010-12-29T23:59:59.000Z

    The representative concentration pathway to be delivered is a scenario of atmospheric concentrations of greenhouse gases and other radiatively important atmospheric species, along with land-use changes, derived from the Global Change Assessment Model (GCAM). The particular representative concentration pathway (RCP) that the Joint Global Change Research Institute (JGCRI) has been responsible for is a not-to-exceed pathway that stabilizes at a radiative forcing of 4.5Wm-2 in the year 2100.

  3. Statistical model based iterative reconstruction (MBIR) in clinical CT systems: Experimental assessment of noise performance

    SciTech Connect (OSTI)

    Li, Ke; Tang, Jie [Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States)] [Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States); Chen, Guang-Hong, E-mail: gchen7@wisc.edu [Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705 and Department of Radiology, University of Wisconsin-Madison, 600 Highland Avenue, Madison, Wisconsin 53792 (United States)] [Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705 and Department of Radiology, University of Wisconsin-Madison, 600 Highland Avenue, Madison, Wisconsin 53792 (United States)

    2014-04-15T23:59:59.000Z

    Purpose: To reduce radiation dose in CT imaging, the statistical model based iterative reconstruction (MBIR) method has been introduced for clinical use. Based on the principle of MBIR and its nonlinear nature, the noise performance of MBIR is expected to be different from that of the well-understood filtered backprojection (FBP) reconstruction method. The purpose of this work is to experimentally assess the unique noise characteristics of MBIR using a state-of-the-art clinical CT system. Methods: Three physical phantoms, including a water cylinder and two pediatric head phantoms, were scanned in axial scanning mode using a 64-slice CT scanner (Discovery CT750 HD, GE Healthcare, Waukesha, WI) at seven different mAs levels (5, 12.5, 25, 50, 100, 200, 300). At each mAs level, each phantom was repeatedly scanned 50 times to generate an image ensemble for noise analysis. Both the FBP method with a standard kernel and the MBIR method (Veo{sup ®}, GE Healthcare, Waukesha, WI) were used for CT image reconstruction. Three-dimensional (3D) noise power spectrum (NPS), two-dimensional (2D) NPS, and zero-dimensional NPS (noise variance) were assessed both globally and locally. Noise magnitude, noise spatial correlation, noise spatial uniformity and their dose dependence were examined for the two reconstruction methods. Results: (1) At each dose level and at each frequency, the magnitude of the NPS of MBIR was smaller than that of FBP. (2) While the shape of the NPS of FBP was dose-independent, the shape of the NPS of MBIR was strongly dose-dependent; lower dose lead to a “redder” NPS with a lower mean frequency value. (3) The noise standard deviation (?) of MBIR and dose were found to be related through a power law of ????(dose){sup ??} with the component ? ? 0.25, which violated the classical ????(dose){sup ?0.5} power law in FBP. (4) With MBIR, noise reduction was most prominent for thin image slices. (5) MBIR lead to better noise spatial uniformity when compared with FBP. (6) A composite image generated from two MBIR images acquired at two different dose levels (D1 and D2) demonstrated lower noise than that of an image acquired at a dose level of D1+D2. Conclusions: The noise characteristics of the MBIR method are significantly different from those of the FBP method. The well known tradeoff relationship between CT image noise and radiation dose has been modified by MBIR to establish a more gradual dependence of noise on dose. Additionally, some other CT noise properties that had been well understood based on the linear system theory have also been altered by MBIR. Clinical CT scan protocols that had been optimized based on the classical CT noise properties need to be carefully re-evaluated for systems equipped with MBIR in order to maximize the method's potential clinical benefits in dose reduction and/or in CT image quality improvement.

  4. Mapping surface fuels using LIDAR and multispectral data fusion for fire behavior modeling

    E-Print Network [OSTI]

    Mutlu, Muge

    2009-05-15T23:59:59.000Z

    outputs using fuel model maps, which differ in accuracy, in east Texas. Estimates of fuel models were compared with in situ data collected over 62 plots. Supervised image classification methods provided better accuracy (90.10%) with the fusion of airborne...

  5. A physical model of particulate wash-off from rough impervious surfaces

    E-Print Network [OSTI]

    Walter, M.Todd

    ; accepted 23 January 2006 Summary Current urban water quality models rely on empirical, catchment of particulate available. Current urban stormwater models such as SWMM and HSPF are still based on this original urban storm runoff pollution. There are few published explanations of physical wash- off mechanisms

  6. The potential use of Chernobyl fallout data to test and evaluate the predictions of environmental radiological assessment models

    SciTech Connect (OSTI)

    Richmond, C.R.; Hoffman, F.O.; Blaylock, B.G.; Eckerman, K.F.; Lesslie, P.A.; Miller, C.W.; Ng, Y.C.; Till, J.E.

    1988-06-01T23:59:59.000Z

    The objectives of the Model Validation Committee were to collaborate with US and foreign scientists to collect, manage, and evaluate data for identifying critical research issues and data needs to support an integrated assessment of the Chernobyl nuclear accident; test environmental transport, human dosimetric, and health effects models against measured data to determine their efficacy in guiding decisions on protective actions and in estimating exposures to populations and individuals following a nuclear accident; and apply Chernobyl data to quantifications of key processes governing the environmental transport, fate and effects of radionuclides and other trace substances. 55 refs.

  7. Further RAGE modeling of asteroid mitigation: surface and subsurface explosions in porous objects

    SciTech Connect (OSTI)

    Weaver, Robert P [Los Alamos National Laboratory; Plesko, Catherine S [Los Alamos National Laboratory; Dearholt, William R [Los Alamos National Laboratory

    2011-01-03T23:59:59.000Z

    Disruption or mitigation of a potentially hazardous object (PHO) by a high-energy subsurface burst is considered. This is just one possible method of impact-hazard mitigation. We present RAGE hydrocode models of the shock-generated disruption of PHOs by subsurface nuclear bursts using scenario-specific models from realistic RADAR shape models. We will show 2D and 3D models for the disruption by a large energy source at the center of such PHO models ({approx}100 kt-10 Mt) specifically for the shape of the asteroid 25143 Itokawa. We study the effects of non-uniform composition (rubble pile), shallow buried bursts for the optimal depth of burial and porosity.

  8. PHYSICAL REVIEW E 83, 026704 (2011) Atomistic modeling of metal surfaces under electric fields: Direct coupling of electric fields to a

    E-Print Network [OSTI]

    Nordlund, Kai

    2011-01-01T23:59:59.000Z

    at very high electric fields, as well as the general behavior of a metal surface in this conditionPHYSICAL REVIEW E 83, 026704 (2011) Atomistic modeling of metal surfaces under electric fields: Direct coupling of electric fields to a molecular dynamics algorithm F. Djurabekova,* S. Parviainen, A

  9. Coupling dry deposition to vegetation phenology in the Community Earth System Model: Implications for the simulation of surface O[subscript 3

    E-Print Network [OSTI]

    Val?Martin, M.

    Dry deposition is an important removal process controlling surface ozone. We examine the representation of this ozone loss mechanism in the Community Earth System Model. We first correct the dry deposition parameterization ...

  10. Midtemperature solar systems test facility predictions for thermal performance based on test data. Polisolar Model POL solar collector with glass reflector surface

    SciTech Connect (OSTI)

    Harrison, T.D.

    1981-05-01T23:59:59.000Z

    Thermal performance predictions based on test data are presented for the Polisolar Model POL solar collector, with glass reflector surfaces, for three output temperatures at five cities in the United States.

  11. Assessment of Dissolved Oxygen Mitigation at Hydropower Dams Using an Integrated Hydrodynamic/Water Quality/Fish Growth Model

    SciTech Connect (OSTI)

    Bevelhimer, Mark S [ORNL; Coutant, Charles C [ORNL

    2006-07-01T23:59:59.000Z

    Dissolved oxygen (DO) in rivers is a common environmental problem associated with hydropower projects. Approximately 40% of all FERC-licensed projects have requirements to monitor and/or mitigate downstream DO conditions. Most forms of mitigation for increasing DO in dam tailwaters are fairly expensive. One area of research of the Department of Energy's Hydropower Program is the development of advanced turbines that improve downstream water quality and have other environmental benefits. There is great interest in being able to predict the benefits of these modifications prior to committing to the cost of new equipment. In the case of turbine replacement or modification, there is a need for methods that allow us to accurately extrapolate the benefits derived from one or two turbines with better design to the replacement or modification of all turbines at a site. The main objective of our study was to demonstrate a modeling approach that integrates the effects of flow and water quality dynamics with fish bioenergetics to predict DO mitigation effectiveness over long river segments downstream of hydropower dams. We were particularly interested in demonstrating the incremental value of including a fish growth model as a measure of biological response. The models applied are a suite of tools (RMS4 modeling system) originally developed by the Tennessee Valley Authority for simulating hydrodynamics (ADYN model), water quality (RQUAL model), and fish growth (FISH model) as influenced by DO, temperature, and available food base. We parameterized a model for a 26-mile reach of the Caney Fork River (Tennessee) below Center Hill Dam to assess how improvements in DO at the dam discharge would affect water quality and fish growth throughout the river. We simulated different types of mitigation (i.e., at the turbine and in the reservoir forebay) and different levels of improvement. The model application successfully demonstrates how a modeling approach like this one can be used to assess whether a prescribed mitigation is likely to meet intended objectives from both a water quality and a biological resource perspective. These techniques can be used to assess the tradeoffs between hydropower operations, power generation, and environmental quality.

  12. LONG-TERM GLOBAL WATER USE PROJECTIONS USING SIX SOCIOECONOMIC SCENARIOS IN AN INTEGRATED ASSESSMENT MODELING FRAMEWORK

    SciTech Connect (OSTI)

    Hejazi, Mohamad I.; Edmonds, James A.; Clarke, Leon E.; Kyle, G. Page; Davies, Evan; Chaturvedi, Vaibhav; Wise, Marshall A.; Patel, Pralit L.; Eom, Jiyong; Calvin, Katherine V.; Moss, Richard H.; Kim, Son H.

    2014-01-19T23:59:59.000Z

    In this paper, we assess future water demands for the agricultural (irrigation and livestock), energy (electricity generation, primary energy production and processing), industrial (manufacturing and mining), and municipal sectors, by incorporating water demands into a technologically-detailed global integrated assessment model of energy, agriculture, and climate change – the Global Change Assessment Model (GCAM). Base-year water demands—both gross withdrawals and net consumptive use—are assigned to specific modeled activities in a way that maximizes consistency between bottom-up estimates of water demand intensities of specific technologies and practices, and top-down regional and sectoral estimates of water use. The energy, industrial, and municipal sectors are represented in fourteen geopolitical regions, with the agricultural sector further disaggregated into as many as eighteen agro-ecological zones (AEZs) within each region. We assess future water demands representing six socioeconomic scenarios, with no constraints imposed by future water supplies. The scenarios observe increases in global water withdrawals from 3,578 km3 year-1 in 2005 to 5,987 – 8,374 km3 year-1 in 2050, and to 4,719 – 12,290 km3 year-1 in 2095. Comparing the projected total regional water withdrawals to the historical supply of renewable freshwater, the Middle East exhibits the highest levels of water scarcity throughout the century, followed by India; water scarcity increases over time in both of these regions. In contrast, water scarcity improves in some regions with large base-year electric sector withdrawals, such as the USA and Canada, due to capital stock turnover and the almost complete phase-out of once-through flow cooling systems. The scenarios indicate that: 1) water is likely a limiting factor in climate change mitigation policies, 2) many regions can be expected to increase reliance on non-renewable groundwater, water reuse, and desalinated water, but they also highlight an important role for development and deployment of water conservation technologies and practices.

  13. Numerical modeling of elastic wave scattering by near-surface heterogeneities

    E-Print Network [OSTI]

    Al Muhaidib, Abdulaziz

    2013-01-01T23:59:59.000Z

    A perturbation method for elastic waves and numerical forward modeling are used to calculate the effects of seismic wave scattering from arbitrary shape shallow subsurface heterogeneities. Wave propagation is simulated ...

  14. Mapping surface fuels using LIDAR and multispectral data fusion for fire behavior modeling 

    E-Print Network [OSTI]

    Mutlu, Muge

    2009-05-15T23:59:59.000Z

    Fires have become intense and more frequent in the United States. Improving the accuracy of mapping fuel models is essential for fuel management decisions and explicit fire behavior prediction for real-time support of suppression tactics...

  15. Ecosystem feedbacks to climate change in California: Development, testing, and analysis using a coupled regional atmosphere and land-surface model (WRF3-CLM3.5)

    SciTech Connect (OSTI)

    Subin, Z.M.; Riley, W.J.; Kueppers, L.M.; Jin, J.; Christianson, D.S.; Torn, M.S.

    2010-11-01T23:59:59.000Z

    A regional atmosphere model [Weather Research and Forecasting model version 3 (WRF3)] and a land surface model [Community Land Model, version 3.5 (CLM3.5)] were coupled to study the interactions between the atmosphere and possible future California land-cover changes. The impact was evaluated on California's climate of changes in natural vegetation under climate change and of intentional afforestation. The ability of WRF3 to simulate California's climate was assessed by comparing simulations by WRF3-CLM3.5 and WRF3-Noah to observations from 1982 to 1991. Using WRF3-CLM3.5, the authors performed six 13-yr experiments using historical and future large-scale climate boundary conditions from the Geophysical Fluid Dynamics Laboratory Climate Model version 2.1 (GFDL CM2.1). The land-cover scenarios included historical and future natural vegetation from the Mapped Atmosphere-Plant-Soil System-Century 1 (MC1) dynamic vegetation model, in addition to a future 8-million-ha California afforestation scenario. Natural vegetation changes alone caused summer daily-mean 2-m air temperature changes of -0.7 to +1 C in regions without persistent snow cover, depending on the location and the type of vegetation change. Vegetation temperature changes were much larger than the 2-m air temperature changes because of the finescale spatial heterogeneity of the imposed vegetation change. Up to 30% of the magnitude of the summer daily-mean 2-m air temperature increase and 70% of the magnitude of the 1600 local time (LT) vegetation temperature increase projected under future climate change were attributable to the climate-driven shift in land cover. The authors projected that afforestation could cause local 0.2-1.2 C reductions in summer daily-mean 2-m air temperature and 2.0-3.7 C reductions in 1600 LT vegetation temperature for snow-free regions, primarily because of increased evapotranspiration. Because some of these temperature changes are of comparable magnitude to those projected under climate change this century, projections of climate and vegetation change in this region need to consider these climate-vegetation interactions.

  16. MODELING THE SURFACE X-RAY EMISSION AND VIEWING GEOMETRY OF PSR J0821-4300 IN PUPPIS A

    SciTech Connect (OSTI)

    Gotthelf, E. V.; Halpern, J. P. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Perna, R. [JILA and Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80309 (United States)

    2010-12-01T23:59:59.000Z

    We present a model for the unusual X-ray pulse profiles of PSR J0821-4300, the compact central object in supernova remnant Puppis A. We show that a pair of thermal, antipodal hot spots on the neutron star (NS) surface is able to fully account for the pulsar's double blackbody spectrum and energy-dependent pulse profile, including the observed 180{sup 0} phase reversal at {approx}1.2 keV. By comparing the recorded pulse modulation and phase to the model predictions, we strongly constrain the hot-spot pole ({xi}) and the line-of-sight ({psi}) angles with respect to the spin axis. For a nominal radius of R = 12 km and distance D = 2.2 kpc, we find ({xi}, {psi}) = (86{sup 0}, 6{sup 0}), with 1{sigma} error ellipse of (2{sup 0}, 1{sup 0}); this solution is degenerate in the two angles. The best-fit spectral model for this geometry requires that the temperatures of the two emission spots differ by a factor of 2 and their areas by a factor of {approx}20. Including a cosine-beamed pattern for the emitted intensity modifies the result, decreasing the angles to (84{sup 0}, 3{sup 0}); however this model is not statistically distinguishable from the isotropic emission case. We also present a new upper limit on the period derivative of P-dot < 3.5x10{sup -16} (2{sigma}), which limits the global dipole magnetic field to B{sub s} < 2.0 x 10{sup 11} G, confirming PSR J0821-4300 as an 'anti-magnetar'. We discuss the results in the context of observations and theories of nonuniform surface temperature on isolated NSs of both weak and strong magnetic field. To explain the nonuniform temperature of PSR J0821-4300 may require a crustal field that is much stronger than the external, global dipole field.

  17. A comparison of methods used in mapping of Pleistocene-bedrock unconformity: Conventional manual versus surface modeling

    SciTech Connect (OSTI)

    Weibel, C.P.; Abert, C.C.; Kempton, J.P. (Illinois State Geological Survey, Champaign, IL (United States))

    1993-03-01T23:59:59.000Z

    Surface modeling software packages allow geologists to model and map topographic and stratigraphic horizons. These map products, however, often differ from maps prepared without computerized mapping. The authors mapping of the Pleistocene-bedrock unconformity in east-central Illinois (1:100,000-scale), which includes the Mahomet paleovalley, illustrates this situation and demonstrates how both mapping methods, manual and computer, contribute to a better understanding of the paleovalley. A conventional hand-drawn map was constructed over a number of years by manually plotting and contouring bedrock elevations, primarily from water well logs, onto various county and local topographic bases. A computer-generated map of the same area was completed as part of a recent project to map the bedrock geology. It was prepared by carefully selecting data, which included geographic coordinates, unique well identification numbers, and bedrock elevations. Primary data sources were hydrocarbon exploration and storage wells. Digitizing the hand-drawn map allowed the two maps to be overlaid and compared. Several significant geomorphic features appeared on one map and not the other because of the use of different databases and inconsistent selection of data used for the hand-drawn map. The hand-drawn map appears more realistic, i.e., like a modern surface, because the mappers used their knowledge of geomorphic concepts in drawing the contours. Most of the data selection for the computer-generated map was completed prior to plotting of the map and therefore is less susceptible to bias interpretations. The computer-generated map, however, is less topographically realistic in areas where data are sparse because the extrapolation methods used to define the surface do not recognize geologic processes or bedrock lithology.

  18. A model of the near-surface seismic velocity: southern San Joaqin Valley, California

    E-Print Network [OSTI]

    Ferry, James Gerard

    1987-01-01T23:59:59.000Z

    with at Texas A k M. I have learned a great deal from all of these people about life, science and geophysics. Finally, I would like to thank Bill Phelps and the people at Tenneco in Bakersfield for providing the data for this research. TABLE OF CONTENTS... correctional trsveltimes determined with Model B (the inverse model) 44 23. The residual static corrections for the time period from ] 966-1986 . 52 CHAPTER I PROBLEMS AND OBJECTIVES Introduction A preliminary study was done for Tenneco Oil Company...

  19. ESD.864 / ESD.936 Systems Modeling and Assessment for Policy, Spring 2010

    E-Print Network [OSTI]

    Selin, Noelle

    This course explores how scientific information can be used to inform policy decision-making processes through the use of quantitative modeling techniques. It incorporates both hands-on analysis and practice using models ...

  20. Assessing the performance of thermospheric modelling with data assimilation throughout solar cycles 23 and 24

    E-Print Network [OSTI]

    Murray, Sophie A; Jackson, David R; Bruinsma, Sean L

    2015-01-01T23:59:59.000Z

    Data assimilation procedures have been developed for thermospheric models using satellite density measurements as part of the EU Framework Package 7 ATMOP Project. Two models were studied; one a general circulation model, TIEGCM, and the other a semi-empirical drag temperature model, DTM. Results of runs using data assimilation with these models were compared with independent density observations from CHAMP and GRACE satellites throughout solar cycles 23 and 24. Time periods of 60 days were examined at solar minimum and maximum, including the 2003 Hallowe'en storms. The differences between the physical and the semi-empirical models have been characterised. Results indicate that both models tend to show similar behaviour; underestimating densities at solar maximum, and overestimating them at solar minimum. DTM performed better at solar minimum, with both models less accurate at solar maximum. A mean improvement of ~4% was found using data assimilation with TIEGCM. With further improvements, the use of general ...

  1. Modeling and experimental studies of oxide covered metal surfaces: TiO{sub 2}/Ti a model system. Progress report

    SciTech Connect (OSTI)

    Smyrl, W.H.

    1991-12-31T23:59:59.000Z

    Prior work in our laboratories at the Corrosion Research Center has shown that thin, anodic TiO{sub 2} films formed by the Slow Growth Mode (SGM) on polycrystalline titanium and microcrystalline with a texture that varies from one metal grain to another. Furthermore, the underlying metal grains are mapped by the photoelectrochemical response of the oxide. The same characteristics have also been demonstrated in our laboratory for ZnO grown on Zn. The TiO{sub 2}/Ti system has been chosen for study both because of its importance in energy systems, and because it can serve as a model system for other metal-metal oxide couples. The investigations of anodic TiO{sub 2} films on Ti have shown that the properties of thin films are consistent with the rutile form of the oxide. Both experimental data and theoretical calculations show the close resemblance to results on single crystal TiO{sub 2}. Furthermore, the modeling studies reveal that the optical transitions near the bandedge arise from the bulk band structure. The photoelectrochemical properties of anodic TiO{sub 2} films have now been shown to obey the simple Gaertner-Butler model for the semiconductor-electrolyte interface, with a few modifications. The most important deviation has now been shown to be a result of multiple internal reflections in the oxide film.

  2. Modeling and experimental studies of oxide covered metal surfaces: TiO sub 2 /Ti a model system

    SciTech Connect (OSTI)

    Smyrl, W.H.

    1991-01-01T23:59:59.000Z

    Prior work in our laboratories at the Corrosion Research Center has shown that thin, anodic TiO{sub 2} films formed by the Slow Growth Mode (SGM) on polycrystalline titanium and microcrystalline with a texture that varies from one metal grain to another. Furthermore, the underlying metal grains are mapped by the photoelectrochemical response of the oxide. The same characteristics have also been demonstrated in our laboratory for ZnO grown on Zn. The TiO{sub 2}/Ti system has been chosen for study both because of its importance in energy systems, and because it can serve as a model system for other metal-metal oxide couples. The investigations of anodic TiO{sub 2} films on Ti have shown that the properties of thin films are consistent with the rutile form of the oxide. Both experimental data and theoretical calculations show the close resemblance to results on single crystal TiO{sub 2}. Furthermore, the modeling studies reveal that the optical transitions near the bandedge arise from the bulk band structure. The photoelectrochemical properties of anodic TiO{sub 2} films have now been shown to obey the simple Gaertner-Butler model for the semiconductor-electrolyte interface, with a few modifications. The most important deviation has now been shown to be a result of multiple internal reflections in the oxide film.

  3. Modelling surface ozone during the 2003 heat-wave in the UK 

    E-Print Network [OSTI]

    Vieno, Massimo; Dore, A J; Stevenson, David S; Doherty, Ruth; Heal, Mathew R; Reis, Stefan; Hallsworth, Stephen; Tarrason, L; Wind, P; Fowler, David; Simpson, David; Sutton, Mark A

    2010-01-01T23:59:59.000Z

    of ground-level ozone (O3) during the extreme August 2003 heat-wave. Meteorology is generated by the Weather Research and Forecast (WRF) model, nudged every six hours with reanalysis data. We focus on SE England, where hourly average O3 reached up to 140 ppb...

  4. DRAFT6-08Sept02 page 1 Simulation of Progressive Cutting on Surface Mesh Model

    E-Print Network [OSTI]

    Payandeh and John Dill Robotics and Computer Graphics Laboratories, School of Engineering Science Simon simulation is a promising technology for training medical students and surgery planning. An important models must be based on physical laws governing the dynamic behavior of rigid and deformable objects

  5. Evaluating CERES angular distribution models for snow using surface reflectance observations from the East Antarctic Plateau

    E-Print Network [OSTI]

    Warren, Stephen

    techniques. Data products produced by the CERES team include the observed broadband solar, window long- wave data processing algorithms, used to convert the observed upwelling radiance to an estimate of the upwelling hemispheric flux. We model top-of-atmosphere anisotropic reflectance factors using an atmospheric

  6. REGION-BASED ACTIVE SURFACE MODELLING AND ALPHA MATTING FOR UNSUPERVISED TUMOUR SEGMENTATION IN PET

    E-Print Network [OSTI]

    Wang, Jue

    hierarchical segmentation scheme consists of three steps, as shown in the system flow-chart in Fig. 2 the Poisson Gradient Vector Flow (PGVF) of Hsu et al. [2] for edge-based seg- mentation and the Markov Random segmentation model [6, 7] are used to obtain an energy function that can be minimized by convex optimization

  7. Performance Assessment of Different Control Structures for Generic Reactive Distillation Using Linear and Nonlinear Process Models

    E-Print Network [OSTI]

    Al-Arfaj, Muhammad A.

    compares the closed-loop performance of three control structures using an approximate linear model. Responses based on the linear model for various control structures show a good agreement when compared of the linear model is shown to be better in a single-end control system than in a dual-end control system

  8. Ensemble operational air quality assessments in Europe Improving modeling platforms with statistical analysis

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    with statistical analysis Anthony Ung, Laure Malherbe, Frederik Meleux, Bertrand Bessagnet, Laurence Rouil and MACCII modeling team INERIS institut, Paris, France Corresponding author: Anthony.ung@ineris.fr Abstract/QC dossiers and available on the MACC project website for each model. All models have also very significant

  9. PROBING NEAR-SURFACE ATMOSPHERIC TURBULENCE WITH LIDAR MEASUREMENTS AND HIGH-RESOLUTION HYDRODYNAMIC MODELS

    SciTech Connect (OSTI)

    J. KAO; D. COOPER; ET AL

    2000-11-01T23:59:59.000Z

    As lidar technology is able to provide fast data collection at a resolution of meters in an atmospheric volume, it is imperative to promote a modeling counterpart of the lidar capability. This paper describes an integrated capability based on data from a scanning water vapor lidar and a high-resolution hydrodynamic model (HIGRAD) equipped with a visualization routine (VIEWER) that simulates the lidar scanning. The purpose is to better understand the spatial and temporal representativeness of the lidar measurements and, in turn, to extend their utility in studying turbulence fields in the atmospheric boundary layer. Raman lidar water vapor data collected over the Pacific warm pool and the simulations with the HIGRAD code are used for identifying the underlying physics and potential aliasing effects of spatially resolved lidar measurements. This capability also helps improve the trade-off between spatial-temporal resolution and coverage of the lidar measurements.

  10. Comparison of surface meteorological data representativeness for the Weldon Spring transport and dispersion modeling analysis

    SciTech Connect (OSTI)

    Lazaro, M.

    1989-06-01T23:59:59.000Z

    The US Department of Energy is conducting the Weldon Spring Site Remedial Action Project under the Surplus Facilities Management Program (SFMP). The major goals of the SFMP are to eliminate potential hazards to the public and the environment that associated with contamination at SFMP sites and to make surplus property available for other uses to the extent possible. This report presents the results of analysis of available meteorological data from stations near the Weldon Spring site. Data that are most representative of site conditions are needed to accurately model the transport and dispersion of air pollutants associated with remedial activities. Such modeling will assist the development of mitigative measures. 17 refs., 12 figs., 6 tabs.

  11. The surface carbon and nitrogen abundances in models of ultra metal-poor stars

    E-Print Network [OSTI]

    H. Schlattl; M. Salaris; S. Cassisi; A. Weiss

    2002-05-20T23:59:59.000Z

    We investigate whether the observed high number of carbon- and nitrogen-enhanced extremely metal-poor stars could be explained by peculiar evolutionary properties during the core He flash at the tip of the red giant branch. For this purpose we compute a series of detailed stellar models expanding upon our previous work; in particular, we investigate if during the major He flash the penetration of the helium convective zone into the overlying hydrogen-rich layers can produce carbon- and nitrogen-rich abundances in agreement with current spectroscopic observations. The dependence of this phenomenon on selected model input parameters, such as initial metallicity and treatment of convection is examined in detail.

  12. Recent Approaches to Modeling Transport of Mercury in Surface Water and Groundwater - Case Study in Upper East Fork Poplar Creek, Oak Ridge, TN - 13349

    SciTech Connect (OSTI)

    Bostick, Kent; Daniel, Anamary [Professional Project Services, Inc., Bethel Valley Road, Oak Ridge, TN, 37922 (United States)] [Professional Project Services, Inc., Bethel Valley Road, Oak Ridge, TN, 37922 (United States); Tachiev, Georgio [Florida International University, Applied Research Center 10555 W. Flagler St., EC 2100 Miami Florida 33174 (United States)] [Florida International University, Applied Research Center 10555 W. Flagler St., EC 2100 Miami Florida 33174 (United States); Malek-Mohammadi, Siamak [Bradley University, 413A Jobst Hall, Preoria, IL 61625 (United States)] [Bradley University, 413A Jobst Hall, Preoria, IL 61625 (United States)

    2013-07-01T23:59:59.000Z

    In this case study, groundwater/surface water modeling was used to determine efficacy of stabilization in place with hydrologic isolation for remediation of mercury contaminated areas in the Upper East Fork Poplar Creek (UEFPC) Watershed in Oak Ridge, TN. The modeling simulates the potential for mercury in soil to contaminate groundwater above industrial use risk standards and to contribute to surface water contamination. The modeling approach is unique in that it couples watershed hydrology with the total mercury transport and provides a tool for analysis of changes in mercury load related to daily precipitation, evaporation, and runoff from storms. The model also allows for simulation of colloidal transport of total mercury in surface water. Previous models for the watershed only simulated average yearly conditions and dissolved concentrations that are not sufficient for predicting mercury flux under variable flow conditions that control colloidal transport of mercury in the watershed. The transport of mercury from groundwater to surface water from mercury sources identified from information in the Oak Ridge Environmental Information System was simulated using a watershed scale model calibrated to match observed daily creek flow, total suspended solids and mercury fluxes. Mercury sources at the former Building 81-10 area, where mercury was previously retorted, were modeled using a telescopic refined mesh with boundary conditions extracted from the watershed model. Modeling on a watershed scale indicated that only source excavation for soils/sediment in the vicinity of UEFPC had any effect on mercury flux in surface water. The simulations showed that colloidal transport contributed 85 percent of the total mercury flux leaving the UEFPC watershed under high flow conditions. Simulation of dissolved mercury transport from liquid elemental mercury and adsorbed sources in soil at former Building 81-10 indicated that dissolved concentrations are orders of magnitude below a target industrial groundwater concentration beneath the source and would not influence concentrations in surface water at Station 17. This analysis addressed only shallow concentrations in soil and the shallow groundwater flow path in soil and unconsolidated sediments to UEFPC. Other mercury sources may occur in bedrock and transport though bedrock to UEFPC may contribute to the mercury flux at Station 17. Generally mercury in the source areas adjacent to the stream and in sediment that is eroding can contribute to the flux of mercury in surface water. Because colloidally adsorbed mercury can be transported in surface water, actions that trap colloids and or hydrologically isolate surface water runoff from source areas would reduce the flux of mercury in surface water. Mercury in soil is highly adsorbed and transport in the groundwater system is very limited under porous media conditions. (authors)

  13. Dynamic modeling of physical phenomena for probabilistic risk assessments using artificial neural networks

    SciTech Connect (OSTI)

    Benjamin, A.S.; Paez, T.L.; Brown, N.N.

    1998-01-01T23:59:59.000Z

    In most probabilistic risk assessments, there is a subset of accident scenarios that involves physical challenges to the system, such as high heat rates and/or accelerations. The system`s responses to these challenges may be complicated, and their prediction may require the use of long-running computer codes. To deal with the many scenarios demanded by a risk assessment, the authors have been investigating the use of artificial neural networks (ANNs) as a fast-running estimation tool. They have developed a multivariate linear spline algorithm by extending previous ANN methods that use radial basis functions. They have applied the algorithm to problems involving fires, shocks, and vibrations. They have found that within the parameter range for which it is trained, the algorithm can simulate the nonlinear responses of complex systems with high accuracy. Running times per case are less than one second.

  14. Quantifying the Difference Between the Flux-Tube Expansion Factor at the Source Surface and at the Alfv\\'en Surface Using A Global MHD Model for the Solar Wind

    E-Print Network [OSTI]

    Cohen, Ofer

    2015-01-01T23:59:59.000Z

    The potential field approximation has been providing a fast, and computationally inexpensive estimation for the solar corona's global magnetic field geometry for several decades. In contrast, more physics-based global magnetohydrodynamic (MHD) models have been used for a similar purpose, while being much more computationally expensive. Here, we investigate the difference in the field geometry between a global MHD model and the potential field source surface model (PFSSM) by tracing individual magnetic field lines in the MHD model from the Alfven surface (AS), through the source surface (SS), all the way to the field line footpoint, and then back to the source surface in the PFSSM. We also compare the flux-tube expansion at two points at the SS and the AS along the same radial line. We study the effect of solar cycle variations, the order of the potential field harmonic expansion, and different magnetogram sources. We find that the flux-tube expansion factor is consistently smaller at the AS than at the SS for...

  15. Development of Surface Complexation Models of Cr(VI) Adsorption on Soils, Sediments and Model Mixtures of Kaolinite, Montmorillonite, ?-Alumina, Hydrous Manganese and Ferric Oxides and Goethite

    SciTech Connect (OSTI)

    Koretsky, Carla [Western Michigan University] [Western Michigan University

    2013-11-29T23:59:59.000Z

    Hexavalent chromium is a highly toxic contaminant that has been introduced into aquifers and shallow sediments and soils via many anthropogenic activities. Hexavalent chromium contamination is a problem or potential problem in the shallow subsurface at several DOE sites, including Hanford, Idaho National Laboratory, Los Alamos National Laboratory and the Oak Ridge Reservation (DOE, 2008). To accurately quantify the fate and transport of hexavalent chromium at DOE and other contaminated sites, robust geochemical models, capable of correctly predicting changes in chromium chemical form resulting from chemical reactions occurring in subsurface environments are needed. One important chemical reaction that may greatly impact the bioavailability and mobility of hexavalent chromium in the subsurface is chemical binding to the surfaces of particulates, termed adsorption or surface complexation. Quantitative thermodynamic surface complexation models have been derived that can correctly calculate hexavalent chromium adsorption on well-characterized materials over ranges in subsurface conditions, such pH and salinity. However, models have not yet been developed for hexavalent chromium adsorption on many important constituents of natural soils and sediments, such as clay minerals. Furthermore, most of the existing thermodynamic models have been developed for relatively simple, single solid systems and have rarely been tested for the complex mixtures of solids present in real sediments and soils. In this study, the adsorption of hexavalent chromium was measured as a function of pH (3-10), salinity (0.001 to 0.1 M NaNO3), and partial pressure of carbon dioxide(0-5%) on a suite of naturally-occurring solids including goethite (FeOOH), hydrous manganese oxide (MnOOH), hydrous ferric oxide (Fe(OH)3), ?-alumina (Al2O3), kaolinite (Al2Si2O5(OH)4), and montmorillonite (Na3(Al, Mg)2Si4O10(OH)2?nH2O). The results show that all of these materials can bind substantial quantities of hexavalent chromium, especially at low pH. Unexpectedly, experiments with the clay minerals kaolinite and montmorillonite suggest that hexavalent chromium may interact with these solids over much longer periods of time than expected. Furthermore, hexavalent chromium may irreversibly bind to these solids, perhaps because of oxidation-reduction reactions occurring on the surfaces of the clay minerals. More work should be done to investigate and quantify these chemical reactions. Experiments conducted with mixtures of goethite, hydrous manganese oxide, hydrous ferric oxide, ?-alumina, montmorillonite and kaolinite demonstrate that it is possible to correctly predict hexavalent chromium binding in the presence of multiple minerals using thermodynamic models derived for the simpler systems. Further, these models suggest that of the six solid considered in this study, goethite is typically the solid to which most of the hexavalent chromium will bind. Experiments completed with organic-rich and organic-poor natural sediments demonstrate that in organic-rich substrates, organic matter is likely to control uptake of the hexavalent chromium. The models derived and tested in this study for hexavalent chromium binding to ?-alumina, hydrous manganese oxide, goethite, hydrous ferric oxide and clay minerals can be used to better predict changes in hexavalent chromium bioavailability and mobility in contaminated sediments and soils.

  16. MA3T Model Application at ORNL Assesses the Future of Fuel Cell...

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

    Leveraging funding from the Fuel Cell Technologies Office, Oak Ridge National Lab (ORNL) has developed a model for simulating the market potential of fuel cell electric vehicles...

  17. Seismic Performance, Modeling, and Failure Assessment of Reinforced Concrete Shear Wall Buildings

    E-Print Network [OSTI]

    Tuna, Zeynep

    2012-01-01T23:59:59.000Z

    J.W. , (2009). Testing and Reinforced Concrete Coupling2010). "Testing and Modeling of Reinforced Concrete Couplingscale testing of four-story reinforced concrete and post-

  18. A multi-objective programming model for assessment the GHG emissions in MSW management

    SciTech Connect (OSTI)

    Mavrotas, George, E-mail: mavrotas@chemeng.ntua.gr [National Technical University of Athens, Iroon Polytechniou 9, Zografou, Athens, 15780 (Greece); Skoulaxinou, Sotiria [EPEM SA, 141 B Acharnon Str., Athens, 10446 (Greece); Gakis, Nikos [FACETS SA, Agiou Isidorou Str., Athens, 11471 (Greece); Katsouros, Vassilis [Athena Research and Innovation Center, Artemidos 6 and Epidavrou Str., Maroussi, 15125 (Greece); Georgopoulou, Elena [National Observatory of Athens, Thisio, Athens, 11810 (Greece)

    2013-09-15T23:59:59.000Z

    Highlights: • The multi-objective multi-period optimization model. • The solution approach for the generation of the Pareto front with mathematical programming. • The very detailed description of the model (decision variables, parameters, equations). • The use of IPCC 2006 guidelines for landfill emissions (first order decay model) in the mathematical programming formulation. - Abstract: In this study a multi-objective mathematical programming model is developed for taking into account GHG emissions for Municipal Solid Waste (MSW) management. Mathematical programming models are often used for structure, design and operational optimization of various systems (energy, supply chain, processes, etc.). The last twenty years they are used all the more often in Municipal Solid Waste (MSW) management in order to provide optimal solutions with the cost objective being the usual driver of the optimization. In our work we consider the GHG emissions as an additional criterion, aiming at a multi-objective approach. The Pareto front (Cost vs. GHG emissions) of the system is generated using an appropriate multi-objective method. This information is essential to the decision maker because he can explore the trade-offs in the Pareto curve and select his most preferred among the Pareto optimal solutions. In the present work a detailed multi-objective, multi-period mathematical programming model is developed in order to describe the waste management problem. Apart from the bi-objective approach, the major innovations of the model are (1) the detailed modeling considering 34 materials and 42 technologies, (2) the detailed calculation of the energy content of the various streams based on the detailed material balances, and (3) the incorporation of the IPCC guidelines for the CH{sub 4} generated in the landfills (first order decay model). The equations of the model are described in full detail. Finally, the whole approach is illustrated with a case study referring to the application of the model in a Greek region.

  19. Multi-dimensional modelling of electrostatic force distance curve over dielectric surface: Influence of tip geometry and correlation with experiment

    SciTech Connect (OSTI)

    Boularas, A., E-mail: boularas@laplace.univ-tlse.fr; Baudoin, F.; Villeneuve-Faure, C. [LAPLACE (Laboratoire Plasma et Conversion d'Energie), Université de Toulouse, UPS, INPT, 118 route de Narbonne, 31062 Toulouse cedex 9 (France); Clain, S. [Universidade do Minho, Centro de Matemática, Campus de Gualtar, 4710 - 057 Braga (Portugal); Université Paul Sabatier, Institut de Mathématiques de Toulouse, 31062 Toulouse (France); Teyssedre, G. [LAPLACE (Laboratoire Plasma et Conversion d'Energie), Université de Toulouse, UPS, INPT, 118 route de Narbonne, 31062 Toulouse cedex 9 (France); CNRS, LAPLACE, F-31071 Toulouse (France)

    2014-08-28T23:59:59.000Z

    Electric Force-Distance Curves (EFDC) is one of the ways whereby electrical charges trapped at the surface of dielectric materials can be probed. To reach a quantitative analysis of stored charge quantities, measurements using an Atomic Force Microscope (AFM) must go with an appropriate simulation of electrostatic forces at play in the method. This is the objective of this work, where simulation results for the electrostatic force between an AFM sensor and the dielectric surface are presented for different bias voltages on the tip. The aim is to analyse force-distance curves modification induced by electrostatic charges. The sensor is composed by a cantilever supporting a pyramidal tip terminated by a spherical apex. The contribution to force from cantilever is neglected here. A model of force curve has been developed using the Finite Volume Method. The scheme is based on the Polynomial Reconstruction Operator—PRO-scheme. First results of the computation of electrostatic force for different tip–sample distances (from 0 to 600?nm) and for different DC voltages applied to the tip (6 to 20?V) are shown and compared with experimental data in order to validate our approach.

  20. Development of a Hydrodynamic Model for Skagit River Estuary for Estuarine Restoration Feasibility Assessment

    SciTech Connect (OSTI)

    Yang, Zhaoqing; Liu, Hedong; Khangaonkar, Tarang P.

    2006-08-03T23:59:59.000Z

    The Skagit River is the largest river in the Puget Sound estuarine system. It discharges about 39% of total sediment and more than 20% of freshwater into Puget Sound. The Skagit River delta provides rich estuarine and freshwater habitats for salmon and many other wildlife species. Over the past 150 years, economic development in the Skagit River delta has resulted in significant losses of wildlife habitat, particularly due to construction of dikes. Diked portion of the delta is known as Fir Island where irrigation practices for agriculture land over the last century has resulted in land subsidence. This has also caused reduced efficiency of drainage network and impeded fish passages through the area. In this study, a three-dimensional tidal circulation model was developed for the Skagit River delta to assist estuarine restoration in the Fir Island area. The hydrodynamic model used in the study is the Finite Volume Coastal Ocean Model (FVCOM). The hydrodynamic model was calibrated using field data collected from the study area specifically for the model development. Wetting and drying processes in the estuarine delta are simulated in the hydrodynamic model. The calibrated model was applied to simulate different restoration alternatives and provide guidance for estuarine restoration and management. Specifically, the model was used to help select and design configurations that would improve the supply of sediment and freshwater to the mudflats and tidal marsh areas outside of diked regions and then improve the estuarine habitats for salmon migration.